An apparatus and method for minimizing a non-transmittable period where high-speed packet data transmission is impossible. In the apparatus, a non-transmittable period calculator receives transmission gap-related information for a UE from a radio network controller, calculates a transmission gap starting point based on the transmission gap-related information, defines a period determined by excluding the downlink transmission period from the transmission gap starting point as the non-transmittable period, and suspends transmission of the high-speed packet data to the UE for the non-transmittable period. A scheduler performs scheduling on the high-speed packet data under the control of the non-transmittable period calculator so that transmission of the high-speed packet data to the UE is suspended for the downlink transmission period.

1. Field of the Invention
The present invention relates generally to an HSDPA (High Speed Downlink Packet Access) communication system, and in particular, to an apparatus and method for minimizing a non-transmittable (or transmission impossibility) period due to execution of a compressed mode.
2. Description of the Related Art
In general, HSDPA (High Speed Downlink Packet Access) refers to a technique for transmitting data using HS-DSCH (High Speed-Downlink Shared Channel), a downlink data channel supporting high-speed downlink packet transmission, and its associated control channels in an UMTS (Universal Mobile Telecommunications System) mobile communication system, a 3rd generation asynchronous mobile communication system. The UMTS communication system supports a compressed mode, and a description of the compressed mode will be made herein below.
The "compressed mode" is a technique for providing a measurement period needed by a UE (User Equipment) to perform an inter-frequency handover (inter-FR HO), i.e., a handover between different frequencies, or an inter-RAT (Radio Access Technology) handover (inter-RAT HO), i.e., a handover between different access technologies. A typical process of performing a handover by the UE is as follows. First, the UE receives primary common pilot channel (PCPICH) signals from a plurality of possible cells, and measures strengths of the received PCPICH signals. Thereafter, the UE reports the measured strengths of the received PCPICH signals to a radio network controller (RNC). The RNC then determines, based on the strengths of the PCPICH signals reported by the UE, (1) whether the UE must perform a handover, and (2) a cell among the plurality of cells, to which the UE, if it must perform a handover, must be handed over. That is, in order to perform the handover, the UE requires a process of measuring PCPICH signals from neighbor cells.
As stated above, in order to perform a handover, the UE requires the process of measuring PCPICH signals from neighbor cells, and if, however, a frequency and a radio access technique used by a current cell to which the UE belongs are different from a frequency and a radio access technique used by the neighbor cells, the UE has difficulty performing the handover. That is, if the neighbor cells use a frequency or a radio access technique different from that of the current cell to which the UE belongs, the UE must change a frequency or a radio access technique of its transceiver in order to measure PCPICH signals from the neighbor cells. For example, when a particular UE A performs communication through UTRAN (UMTS Terrestrial Radio Access Network) with a frequency band of 2,000 MHz (hereinafter referred as "F—1") and performs inter-FR/inter-RAT HO to a GSM (Global System for Mobile communication) cell with a frequency band of 800 MHz (hereinafter referred to as "F—2"), the UE A suspends communication performed at the F—1, and then measures a signal received at the F—2, after tuning a frequency band of its transceiver to the F—2. Thereafter, the UE A must resume communication through the UTRAN by tuning its transceiver from the F—2 to the F—1. That is, as described above, the compressed mode is a technique for suspending communication between the UE and the network for a predetermined period so that the UE can switch to a frequency or a radio access technology different from that of the current cell and measure a necessary signal.
Now, a procedure for supporting the compressed mode in the UMTS communication system will be described with reference to FIG. 1.
FIG. 1 is a flow diagram illustrating a process of performing a compressed mode in a conventional UMTS communication system. In FIG. 1, ellipses represent protocol entities for transmitting and receiving messages. A message transmission/reception protocol entity between UE and RNC is an RNC (Radio Resource Control) entity, and a message transmission/reception protocol entity between Node B and RNC is NBAP (Node B Application Part) entity. Information elements (IEs) that must be included in the messages are illustrated in Table 1. For simplicity, Table 1 shows only the information related to the compressed mode. Further, Table 1 shows references that provide a full list of the corresponding IE.
TABLE 1MESSAGEIEREFERENCE101 RRC CONNECTION SETUP—3GPP TS 25.331 v4.1.0 ch 10.2.40102 RADIO LINK SETUP REQUESTTransmission Gap Pattern Sequence3GPP TS 25.433 v4.1.0 ch 9.1.36Information103 RADIO LINK SETUP RESPONSE—3GPP TS 25.433 v4.1.0 ch 9.1.37104 RRC CONNECTION SETUPDownlink DPCH info common for all3GPP TS 25.331 v4.1.0 ch 10.2.41RL105 RRC CONNECTION SETUP COMPLETE—3GPP TS 25.331 v4.1.0 ch 10.2.42106 MEASUREMENT REPORT—3GPP TS 25.331 v4.1.0 ch 10.2.19107 COMPRESSED MODE COMMANDActive Pattern Sequence Information3GPP TS 25.433 v4.1.0 ch 9.1.60108 MEASUREMENT CONTROL—3GPP TS 25.331 v4.1.0 ch 10.2.17
Now, a process of performing the compressed mode in the UMTS communication system will be described herein below with reference to FIG. 1 and Table 1.
If UE enters a particular cell, the UE acquires necessary system information (SI) through a cell selection process, and then transmits an RRC Connection Request message to RNC through Node B (Step 101). Here, the "cell selection process" is a process of adjusting synchronization with a cell using a common pilot channel (CPICH) and a primary common control channel (PCCPCH) of the cell, and then acquiring random access channel (RACH) information. The RRC Connection Request message has UE identity IE inserted therein so that the RNC can determine whether to approve RRC connection setup to the corresponding UE. The RRC connection normally is a signaling connection for transmitting necessary information to a network after the UE initially accesses the system. However, in some cases, a dedicated physical channel (DPCH) for transmitting user data is included in the RRC connection. In the following description of FIG. 1, it will be assumed that the RRC Connection Request message includes the DPCH. Upon receiving the RRC Connection Request message, RNC determines whether to approve RRC connection to the corresponding UE based on UE identity IE, and then transmits a Radio Link Setup Request message to a Node B where the UE is currently located (Step 102). The Radio Link Setup Request message includes information for making the DPCH, such as uplink/downlink scrambling codes, OVSF (Orthogonal Variable Spreading Factor) code, transmission power-related information, and compressed mode-related information. For the compressed mode-related information, there is an IE of Transmission Gap Pattern Sequence Information. This IE includes the information obtained by the mapping information (Transmission Gap Pattern Sequence information) on a length or frequency of a transmission gap and a position in a radio frame, to be used in the compressed mode, to a particular logical identifier, and a detailed description of this will be made later.
Upon receiving the Radio Link Setup Request message, the Node B forms DPCH corresponding to the DPCH information requested by the RNC, and transmits a Radio Link Setup Response message indicating successful formation of the DPCH to the RNC (Step 103). Upon receiving the Radio Link Setup Response message, the RNC transmits an RRC Connection Setup message with information related to the formed DPCH to the UE (Step 104). The RRC Connection Setup message also includes compressed mode-related information, and the compressed mode-related information is included in Transmission Gap Pattern Sequence Information within an IE of Downlink DPCH info common for all radio links. Upon receiving the RRC Connection Setup message, the UE forms DPCH according to DPCH information included in the received the RRC Connection Setup message, and after completion of forming the DPCH, transmits an RRC Connection Setup Complete message to the RNC (Step 105). When steps 101 to 105 are completed, the UE can transmit and receive user data over the formed DPCH. The UE measures strength of a CPICH signal received from a neighbor cell, while transmitting and receiving the user data. If the measured strength of the CPICH signal received from the neighbor cell is higher than a threshold, or higher than strength of a CPICH signal received from the current cell, then the UE reports this information to the RNC through a Measurement Report message (Step 106). Here, the UE transmits the Measurement Report message to the RNC at a point of time indicated by the RRC Connection Setup message transmitted from the RNC in step 104.
Upon receiving the Measurement Report message, the RNC can transmit an inter-frequency measurement request to the UE in a state as illustrated in FIG. 2. Now, a process of sending the inter-frequency measurement request from the RNC to the UE will be described with reference to FIG. 2.
FIG. 2 schematically illustrates a state in which inter-frequency measurement is required in a general UMTS communication system. Referring to FIG. 2, if UE 211 is located in a boundary region between cells using different frequency bands, i.e., if the UE 211 is located in a boundary region between a UMTS cell_A 200 and a GSM cell_B 250, the RNC (not shown) can perceive this fact through a Measurement Report message transmitted by the UE 211. In preparation for handing over the UE 211 to the GSM cell_B 250, the RNC can transmit an inter-frequency measurement command to the GSB cell_B 250. As illustrated in FIG. 2, the UMTS cell_A 200 and the GSM cell_B 250 use different frequencies, e.g., the UMTS cell_A 200 uses a frequency F—1 and the GSM cell_B 250 uses a frequency F—2, so the UE 211 currently in communication with the UMTS cell_A 200 must suspend communication with the UMTS cell_A 200 in order to measure a PCPICH signal from the GSM cell_B 250. Such a period for suspending communication for a handover to a different frequency or a different radio access technology is called "transmission gap." Further, the RNC must transmit a message so that the UE 211 and a Node B_A 201 managing the UMTS cell_A 200 can suspend and resume communication with each other at the same time.
In FIG. 2, the RNC transmits a Compressed Mode Command message to the Node B (Step 107), and a Measurement Control message to the UE (Step 108). The Compressed Mode Command message includes: (i) TGPSI (Transmission Gap Pattern Sequence Identifier) indicating one of a plurality of Transmission Gap Pattern Sequences transmitted over Transmission Gap Pattern Sequence Information of the Radio Link setup Request message; (ii) TGCFN (Transmission Gap Connection Frame Number) indicating a radio frame number from which a corresponding TGPS (Transmission Gap Pattern Sequence) starts; (iii) TGPRC (Transmission Gap Pattern Repetition Counter) indicating the number of repeating the TGPS; and (iv) TGSN (Transmission Gap Starting Slot Number) indicating a slot from which the first Transmission Gap starts. A detailed description of the information included in the Compressed Mode Command message will be made later.
Upon receiving the Compressed Mode Command message, the Node B prepares to perform a compressed mode based on the information included in the Compressed Mode Command message, and starts performing the compressed mode at the TGCFN included in the Compressed Mode Command message. Upon receiving the Measurement Control message, the UE starts performing the compressed mode at the TGCFN based on information included in an IE of DPCH compressed mode info, i.e., based on the same information as the information included in the Compressed Mode Command message. In this manner, the compressed mode is started between the UE and the Node B.
Next, a transmission format for the compressed mode will be described with reference to FIG. 3.
FIG. 3 schematically illustrates a general transmission format for the compressed mode. Referring to FIG. 3, the compressed mode includes a plurality of different Transmission Gap patterns, which represent TGPS, and shows a certain TGPS. In each TGPS, a first Transmission Gap Pattern (TGP1) and a second Transmission Gap Pattern (TGP2) are alternately repeated by TGPRC. Different TGPSs have different TGP1 and TGP2. The TGPS is individually transmitted to the Node B and the UE over the Radio Link Setup Request message and RRC Connection Setup message described in conjunction with FIG. 1, and the information transmitted over each of the Radio Link Setup Request message and RRC Connection Setup message is as follows.
(1) TGPS include as many TGP1 and TGP2 as there are TGPRC.
(2) Each TGP includes TG1 and TG2, and the UE performs inter-frequency measurement at the TG1 and TG2.
(3) A starting point of the TG1 is calculated from the TGCFN and TGSN. That is, a starting point of the TG1 is a TGSNth time slot of the TGCFN radio frame.
(4) A starting point of the TG2 is defined as TGD (Transmission Gap Distance (TGD). That is, a starting point of the TG2 is a TGDth time slot from the starting point of the TG1.
(5) A size of the TG1 is equal to a length of TGL1 time slots.
(6) A size of the TG2 is equal to a length of TGL2 time slots.
(7) The total size of the TGP1 is equal to a length of TGPL1 radio frames.
(8) The total size of the TGP2 is equal to a length of TGPL2 radio frames.
The stated-above information (1) to (8) will be described herein below.
Each TGPS is identified by a TGPSI, and information constituting the TGPS includes information on TGP1 and information on TGP2. The information on TGP1 includes TGPL1, TG1, TG2 and TGD, and the information on TGP2 includes TGPL2, TG1, TG2 and TGD. The individual information has an independent value, and must be previously transmitted to the UE and the Node B over the RRC Connection Request message or Radio Link Setup message before the compressed mode is started. In addition to the above-stated information, the information constituting the TGPS includes TGPRS, TGCFN, and TGSN, and this information is commonly applied to TGP1 and TGP2, and individually transmitted to the UE and the Node B over the Measurement Control message and Compressed Mode Command message just before the compressed mode is started.
In addition, the radio frame is a unit indicating a transmission point in an UMTS system. Each radio frame includes 15 time slots TS#0-TS#14 and has a 10 msec length. Further, each time slot has a 0.667 msec length and includes 2,560 chips. Beginning when the DPCH is formed between the UE and the RNC, a CFN (Connection Frame Number) increases one by one. That is, if the DPCH, or a dedicated channel (DCH), between the UE and the RNC is formed in a particular radio frame, the CFN increases one by one each time one radio frame elapses, beginning at a point of time when the DPCH is formed. For the same UE, the RNC, UE and Node B maintain the same CFN. If the RNC transmits the compressed mode execution information to the Node B and UE in this way, the Node B and UE suspend transmission/reception every Transmission Gap based on the received compressed mode execution information, and the UE performs inter-frequency measurement.
Above, the compressed mode execution process has been described. Next, a description of the HSDPA will be made.
In general, the HSDPA refers to a data transmission technique using an HS-DSCH for supporting the high-speed downlink packet transmission and its associated control channels in an UMTS communication system. AMC (Adaptive Modulation and Coding), HARQ (Hybrid Automatic Retransmission Request), and FCS (Fast Cell Selection) techniques have been proposed to support the HSDPA. Herein, a structure of the UMTS communication system will be first described with reference to FIG. 4. A detailed description will be made of the AMC, HARQ, and FCS techniques.
FIG. 4 schematically illustrates a conventional CDMA communication system. Referring to FIG. 4, the UMTS communication system includes a core network (CN) 400, a plurality of radio network subsystems (RNSs) 410 and 420, and a UE 430. The RNS 410 and RNS 420 each include a RNC and a plurality of Node Bs. For example, the RNS 410 is comprised of the RNC 411 and a plurality of Node Bs 413 and 415. The RNC is classified into a Serving RNC (SRNC), a Drift RNC (DRNC), and a Controlling RNC (CRNC) according to its function. Functions of the SRNC and DRNC are defined according to their UE, and the SRNC and DRNC manage an information on the UE. A RNC managing data communication with the CN 400 is called SRNC of the UE. When data from the UE is transmitted to the corresponding SRNC through another RNC instead of the corresponding SRNC of the UE, the RNC instead of the corresponding SRNC is called DRNC of the UE. In addition, the RNC controlling the Node Bs is called CRNC of the Node Bs. In FIG. 4, if the RNC 411 manages information on the UE 430, the RNC 411 becomes the SRNC of the UE 430, and if data of the UE 430 is transmitted and received through RNC 421 due to the movement of the UE 430, then the RNC 421 becomes the DRNC. In addition, the RNC 411 controlling the Node B 413 becomes the CRNC of the Node B 413.
Next, the AMC, FCS, and HARQ techniques proposed to support the HARQ will be described with reference to FIG. 4.
AMC is a data transmission technique for adaptively determining a modulation technique and a coding technique of a data channel according to a channel condition between a specific Node B 423 and a UE 430, thus increasing the overall utilization efficiency of the Node B 423. Therefore, the AMC supports a plurality of modulation techniques and coding techniques, and modulates and codes a data channel signal by combining the modulation techniques and the coding techniques. Commonly, each combination of the modulation techniques and the coding techniques is called "MCS (Modulation and Coding Scheme)," and there are defined a plurality of MCS levels of #1 to #n according to the number of the MCSs. That is, the AMC adaptively determines an MCS level according to a channel condition of the UE 430 and the Node B 423 to which the UE 430 is currently wirelessly connected, thereby increasing the entire utilization efficiency of the Node B.
FCS is a technique for fast selecting a cell having the best channel condition among a plurality of cells, when a UE supporting the HSDPA (hereinafter referred to as "HSDPA UE") is located in a cell boundary region, or a soft handover region. Specifically, in the FCS, if HSDPA UE 430 enters a cell boundary region between Node B 423 and Node B 425, the UE 430 establishes radio links to a plurality of cells, i.e., the Node B 423 and the Node B 425. Here, a set of the cells to which the UE 430 has established the radio links is called an "active set." The UE 430 reduces overall interference by receiving HSDPA packet data only from the cell maintaining the best channel condition among the cells included in the active set. Here, a cell in the active set, which transmits HSDPA packet data due to its best channel condition, is called a "best cell," and the UE 430 periodically checks channel conditions of the cells in the active set and transmits a best cell indicator to the cells belonging to the active set in order to replace the current best cell with a new best cell having the better channel condition. The best cell indicator includes a cell ID of a cell selected as a best cell, and the cells in the active set receive the best cell indicator and detect the cell ID included in the best cell indicator. Each of the cells in the active set determines whether the received best cell indicator includes its own cell ID. As a result of the determination, if the best cell indicator includes its own cell ID, the corresponding cell transmits packet data to the UE 430 over the HS-DSCH.
A description will be made herein below of the HARQ, especially n-channel SAW HARQ (Stop and Wait Hybrid Automatic Retransmission Request). The HARQ newly proposes the following two plans in order to increase transmission efficiency of the existing ARQ (Automatic Retransmission Request). First, a retransmission request and a response are exchanged between a UE and a Node B. Second, defective data is temporarily stored, and combined with retransmitted data of the corresponding data. Further, the HSDPA has introduced the n-channel SAW HARQ in order to make up for a shortcoming of the conventional SAW ARQ. The SAW ARQ does not transmit the next packet data until it receives ACK for the previous packet data. Therefore, in some cases, the SAW ARQ must await ACK, although it can currently transmit the next packet data. However, in the n-channel SAW HARQ, the next packet data is continuously transmitted before ACK for the previous packet data is received, thereby increasing utilization efficiency of channels. That is, if n logical channels are established between a UE and a Node B, and the n logical channels can be can be identified by time and unique channel numbers, then the UE can recognize a channel over which packet data was received, and rearrange the received packets in the right reception order, or soft-combine the received packets.
Soft combing is a technique for temporarily storing defective data at a receiver and then combining the stored defective data with retransmitted data of the corresponding data, thus decreasing an error rate. The soft combing technique is divided into a Chase Combining (CC) technique and an Incremental Redundancy (IR) technique.
In the CC, a transmitter uses the same format at both initial transmission and retransmission. If m symbols were transmitted over one coded block at initial transmission, m the same symbols are transmitted even at retransmission. That is, the same coding rate is applied to the initial transmission and the retransmission. A receiver then combines the initially transmitted coded block with the retransmitted coded block, and performs a CRC (Cyclic Redundancy Check) operation on the combined coded block to determine whether an error occurs in the combined coded block.
In the IR, a transmitter uses different formats at initial transmission and retransmission. If n-bit user data was generated into m symbols through channel coding, the transmitter transmits a part of the m symbols at initial transmission, and sequentially transmits the remaining symbols at retransmission. That is, a coding rate for initial transmission is different from a coding rate for retransmission. The receiver then assembles a coded block with a high coding rate by attaching the retransmitted parts to the tail of the initially transmitted coded block, and performs error correction on the assembled coded block. In the IR, the initial transmission and each retransmission are identified by a version number. The initial transmission has a version number 1, a first retransmission has a version number 2, and a second retransmission has a version number 3. The receiver correctly combines the initially transmitted coded block with the retransmitted coded block using the version number.
The n-channel SAW HARQ introduces the following techniques in order to increase efficiency of the existing SAW ARQ. In the existing SAW ARQ, Node B does not transmit the next packet data until ACK (Acknowledgement) for the previously transmitted packet data is received. However, in the n-channel SAW HARQ, the Node B increases utilization efficiency of a radio link by continuously transmitting a plurality of data packets before receiving the ACK for the previously transmitted packet data. That is, in the n-channel SAW HARQ, n logical channels are established between UE an Node B and identified by time or channel numbers, so that the UE, upon receipt of packet data at a certain time, can determine the logical channel that transmitted the packet data. Thus, the UE can rearrange packet data in the right reception order or soft-combine the packet data.
Now, an operation of the n-channel SAW HARQ will be described in detail with reference to FIG. 4. First, it will be assumed that 4-channel SAW HARQ is used between the UE 430 and the Node B 423, and the 4 channels are assigned unique logical identifiers #1 to #4. Physical layers of the UE 430 and the Node B 423 have HARQ processors associated with the respective channels. The Node B 423 assigns a channel identifier #1 to an initially transmitted coded block (which means user data transmitted for one TTI (Transmission Time Interval)) before transmission to the UE 430. Here, the channel identifier can be assigned either specifically or suggestively. When the coded block assigned the channel identifier #1 has a transmission error, the UE 430 delivers the defective coded block to an HARQ processor #1 associated with the channel identifier #1, and transmits a NACK (Negative Acknowledgement) signal for a channel #1 to the Node B 423. Then the Node B 423 can transmit the next coded block over a channel #2, regardless of whether an ACK for the coded block on the channel #1 is received or not. If the next coded block also has an error, the Node B 423 delivers the next coded block to the corresponding HARQ processor. Upon receiving a NACK for the coded block on the channel #1 from the UE 430, the Node B 423 retransmits the corresponding coded block over the channel #1, and the UE 430 recognizes retransmission of the coded block previously transmitted over the channel #1 by analyzing the channel identifier of the retransmitted coded block, and delivers the retransmitted coded block to the HARQ processor #1. Upon receiving the retransmitted coded block, the HARQ processor #1 soft-combines the initially transmitted coded block stored therein with the retransmitted coded block. In this way, the n-channel SAW HARQ matches the channel identifiers with the HARQ processors on a one-to-one basis, thereby properly matching initially transmitted coded blocks with retransmitted coded blocks without a delay in transmitting user data until an ACK is received.
In the n-channel SAW HARQ, a channel identifier indicates whether a receiver performs soft combining received coded block and a coded block which stored in a HARQ processor or not. The channel identifier can be transmitted from a transmitter to the receiver along with the coded block, and this technique is called "asynchronous n-channel SAW HARQ."
Next, a channel structure of a communication system supporting the HSDPA (hereinafter, referred to as "HSDPA communication system") will be described.
The HSDPA communication system includes a plurality of control channels and one data channel in order to support the AMC and the HARQ, and will be described in detail herein below.
Downlink channels of the HSDPA communication system include Associated DPCH, SHCCH (Shared Control Channel), and HS-PDSCH (High Speed-Physical Downlink Shared Channel). The HS-PDSCH is a physical channel for transmitting actual user data, and is comprised of OVSF codes with a spreading factor (SF) 16 (SF=16). Further, each TTI, a transmission unit of the user data, is comprised of 3 time slots (1 TTI=3 time slots). That is, a coded block is transmitted to a particular UE for 3 time slots. As described above, a modulation technique and a channel coding technique applied to the HS-PDSCH are determined according to the channel quality between the corresponding UE and Node B. The HS-PDSCH is a common resource shared by a plurality of UEs, and can be accessed by the UEs on the basis of CDMA (Code Division Multiple Access) or TDMA (Time Division Multiple Access) technology. That is, the UEs can be assigned OVSF codes constituting the HS-PDSCH at a certain point of time (CDMA), and the UEs intermittently use the HS-PDSCH resource (TDMA). For example, UE A can be assigned 10 codes and UE B can be assigned 5 codes at time T—1, while UE C can be assigned 8 codes and UE D can be assigned 8 codes at time T—2.
The SHCCH is a channel for transmitting control information needed by UE to receive the HS-PDSCH. The control information included in the SHCCH includes code assignment information, modulation technique, TBS (Transport Block Set) size, and HARQ channel number. The TBS is a set of transport blocks (TBs) transmitted for one TTI. The TB is a basic unit in which an upper layer of a physical layer processes data. For example, if a size of TB is 300 bits, the upper layer transmits data to the physical layer by 300 bits. A plurality of SHCCHs may exist in each HSDPA system, and the SHCCHs undergo code division. At a certain point in time, the number of UEs using the HS-PDSCH is closely related to the number of SHCCHs. For example, if the HSDPA system provides the HS-PDSCH to four UEs at once, the HSDPA system must include 4 SHCCHs.
The Associated DPCH is a channel for transmitting HSDPA indicator (HI), an identifier of an SHCCH. The Associated DPCH, though it has the same structure as the existing DPCH, punctures, when necessary, a part of the user data transmitted over DPDCH (Dedicated Physical Data Channel), and then inserts the HI in the punctured space, before being transmitted to a corresponding UE. More specifically, the HI has a 2-bit structure corresponding to a logical identifier of the SHCCH, and since DPCCH (Dedicated Physical Control Channel) of the existing DPCH does not have a space for receiving the HI, the DPDCH is unavoidably subject to puncturing to insert the HI in the punctured space. Although the number of SHCCHs that can be included in each system is not restricted, the number of SHCCHs that must be monitored by each UE is limited to 4. Therefore, the 2 bits constituting the HI serve as an identifier indicating each SHCCH.
Above, the downlink channels of Associated DPCH, SHCCH, and HS-PDSCH have been described. Next, a description will be made of an uplink channel. The uplink channel includes Secondary DPCH for transmitting feedback information (FBI) that must be periodically transmitted from a UE to a Node B. The feedback information includes channel quality information based on which the Node B determines an MCS level of the corresponding UE, and ACK/NACK information indicating whether a received coded block has an error.
FIG. 5 is a flow diagram illustrating a process of setting up an HSDPA call in a conventional HSDPA communication system. Specifically, FIG. 5 illustrates a signal flow for setting up an HSDPA call among a UE, a Node B, an RNC and a CN. In FIG. 5, ellipses represent protocol entities for transmitting and receiving messages. The types of IEs that must be included in the messages are illustrated in Table 2. For simplicity, Table 2 shows only the IEs that should be newly added for the HSDPA. Further, Table 1 shows references that provide a full list of the corresponding IE.
TABLE 2MessageReference501 RRC CONNECTION REQUEST3GPP TS 25.331 v4.1.0 ch 10.2.40502 RRC CONNECTION SETUP3GPP TS 25.331 v4.1.0 ch 10.2.41503 RRC CONNECTION SETUP3GPP TS 25.331 v4.1.0 ch 10.2.42COMPLETE504 INITIAL DIRECT TRANSFER3GPP TS 25.331 v4.1.0 ch 10.2.12505 INITIAL UE MESSAGE3GPP TS 25.413 v4.1.0 ch 9.1.33506 RAB ASSIGNMENT REQUEST3GPP TS 25.413 v4.1.0 ch 9.1.3507 RADIO LINK SETUP3GPP TS 25.433 v4.1.0 ch 9.1.36REQUEST508 RADIO LINK SETUP3GPP TS 25.433 v4.1.0 ch 9.1.37RESPONSE509 RADIO BEARER SETUP3GPP TS 25.331 v4.1.0 ch 10.2.31510 RADIO BEARER SETUP3GPP TS 25.331 v4.1.0 ch 10.2.32COMPLETE511 RAB ASSIGNMENT3GPP TS 25.413 v4.1.0 ch 9.1.4RESPONSE
Now, a process of setting up an HSDPA call by the UE will be described with reference to FIG. 5 and Table 2.
If UE enters a particular cell, the UE acquires necessary system information (SI) through a cell selection process, and then transmits an RRC Connection Request message to corresponding RNC (Step 501). Here, the "cell selection process" is a process of adjusting synchronization with a corresponding cell using CPICH and PCCPCH of the cell, and then acquiring RACH information. The RRC Connection Request message has UE identity IE inserted therein so that the RNC can determine whether to approve RRC connection setup to the corresponding UE. The RRC connection normally means signaling connection for transmitting necessary information to a network after the UE initially accesses the system. However, in some cases, a dedicated physical channel (DPCH) for transmitting user data is included in the RRC connection. It will be assumed in FIG. 5 that the RRC Connection Request message includes only a signaling connection setup request.
Upon receiving the RRC Connection Request message, RNC determines whether to approve RRC connection to the corresponding UE based on UE identity IE, and then transmits an RRC Connection Setup message with IEs related to RRC connection to the UE, in order to approve the RRC connection (Step 502). The RRC Connection Setup message includes UE ID (Identifier) to be used by the UE for such common channels as RACH and FACH (Forward Access Channel). Upon receiving the RRC Connection Setup message, the UE transmits an RRC Connection Setup Complete message to the RNC along with UE radio access capability IE (Step 503). Commonly, the UE radio access capability IE includes a physical channel capability item and a turbo coding item. Herein, the UE radio access capability IE includes information indicating whether the corresponding UE supports HS-PDSCH reception. In addition, the RRC Connection Setup Complete message includes information indicating whether the UE supports inter-frequency handover. Upon receiving the RRC Connection Setup Complete message, the RNC stores the UE-related information.
After completing RRC connection setup, the UE, when necessary, transmits a message for requesting new call setup to NC (Step 504). Here, the message for requesting new call setup is transmitted along with NAS (Non-Access Stratum) message IE in an RRC Initial Direct Transfer message. The NAS message may include information needed by the CN to perform a corresponding call, i.e., include call quality-related information. Therefore, as the UE transmits an Initial Direct Transfer message to the RNC, the RNC converts the message to an RANAP (Radio Access Network Application Part) message of Initial UE message, and transmits the Initial UE message to the CN (Step 505). Upon receiving the Initial UE message, the CN determines a RAB (Radio Access Bearer) parameter based on quality-related information on NAS message IE included in the Initial UE message. The RAB parameter includes a maximum bit rate and a guaranteed bit rate of a corresponding call, and a traffic class indicating the type of the call. The traffic class includes conversational class, streaming class, interactive class, and background class. The conversational class and streaming class chiefly correspond to a multimedia service including a real-time voice call service, and the interactive class and background class chiefly correspond to a non-real-time data service. Therefore, if a call requested by the UE in the steps 504 and 505 is a data service, the CN will apply the interactive class or background class to the RAB parameter. However, if the requested call is a voice service, the CN will apply the conversational class to the RAB parameter. After determining the RAB parameter, the CN transmits a RAB Assignment Request message to the RNC (Step 506). The RNC then determines a channel to be set up to the corresponding UE, based on RAB parameter included in the RAB Assignment Request message. If the RAB parameter indicates that a call to be set up is a high-speed data service, i.e., if traffic class of the RAB parameter is the interactive class or background class having a very high maximum bit rate, the RNC can set up the call as an HSDPA call.
Upon receiving the RAB Assignment Request message, the RNC transmits a Radio Link Setup Request message to Node B, which manages the corresponding call (Step 507). The present invention newly defines an HS-DSCH info IE in the Radio Link Setup Request message, and the HS-DSCH info IE includes UE ID and other UE-related information. In addition, the Radio Link Setup Request message must include the Associated DPCH and Secondary DPCH-related information as well. The DPCH-related information may include OVSF code information, and further include activation time-related information indicating the time when the DPCHs will be activated. Upon receiving the Radio Link Setup Request message, the Node B stores the UE ID included in the Radio Link Setup Request message, and then assigns a buffer for servicing the corresponding UE. After completion of forming the DPCHs, the Node B transmits a Radio Link Setup Response message to the RNC (Step 508). Upon receiving the Radio Link Setup Response message, the RNC transmits a Radio Bearer Setup message to the UE (Step 509). The Radio Bearer Setup message includes the DPCH-related information and the information to be perceived by the UE for the HSDPA, i.e., information on the number of HARQ processors, the number of SHCCHs, and OVSF codes for the SHCCHs. Upon receiving the Radio Bearer Setup message, the UE forms the DPCHs, and then transmits a Radio Bearer Setup Complete message to the RNC, thus informing completion of preparing to receive HS-PDSCH (Step 510). The RNC then transmits an RAB Assignment Response message to the CN, informing completion of the call setup (Step 511).
The Node B registers, in an UE list, UEs that are setting up an HSDPA call in a cell managed by the Node B. The UE list can be updated, when the Node B receives the Radio Link Setup Request message. In addition, the Node B manages buffers for servicing the UEs, and manages channel quality information periodically reported by the UEs in association with the UEs. For the sake of convenience, the UE list and the channel quality information will be defined as a "UE context." Table 3 illustrates an example of the UE context.
TABLE 3UE IDUD ID transmitted by RNCChannel QualityChannel quality fed back by UE, or strength ofPCPICH from a corresponding cell, measured by UEBuffer StatusAmount of data stored in a buffer assigned to acorresponding UEService HistoryAmount of data serviced by a corresponding UE forthe latest reference timeEtc.Multi-code capability of UE, and modulation techniquesupported by UE
In Table 3, "reference time" of a Service History item represents a period determined by the Node B or RNC, and is used for scheduling by the Node B. This will be described in detail later. Further, in Table 3, "multi-code capacity" is information indicating the number of OVSF codes that can be simultaneously despread by a corresponding UE: For example, if the number of OVSF codes that can be simultaneously despread by a particular UE, i.e., the multi-code capacity is 8, then the Node B does not assign more than 8 OVSF codes to the corresponding UE. In Table 3, a "modulation technique" supported by UE is used by the Node B to assign an MCS level to the corresponding UE. For example, if the UE supports only QPSK (Quadrature Phase Shift Keying), the Node B assigns only an MCS level where the QPSK is included, to the corresponding UE.
Therefore, the Node B performs scheduling every TTI, using the UE context. Here, the "scheduling" by the Node B is a process of determining (i) a particular UE to which OVSF codes will be assigned for a certain TTI, and (ii) the number of the OVSF codes assigned to the UE. There are several scheduling methods. For example, the Node B can have a scheduling algorithm for calculating the number of OVSF codes to be assigned to a particular UE by receiving the Channel Quality (CQ), Buffer Status (BS), and Service History (SH).
FIG. 6 schematically illustrates a scheduling algorithm for a Node B in a conventional HSDPA communication system. Referring to FIG. 6, the Node B receives CQ, BS, and SH from each of all UEs, which are maintaining an HSDPA call at a particular point of time, and based on the received information, determines (i) UEs that will receive HS-PDSCH for TTI#n, (ii) the type and number of codes to be assigned to each of the UEs, and (iii) SHCCH for transmitting various control information, and then outputs the determined information. The scheduling algorithm has such input and output information. The input and output information of the scheduling algorithm is adaptively determined according to circumstances. For example, if the UEs that will receive HS-PDSCH are first determined in the order of the UE having a best CQ, then the Node B may assign the codes by consulting BSs from the determined UEs. Alternatively, the Node B may first transmit HS-PDSCH to UEs that have not recently received the HS-PDSCH, by consulting the SH.
FIG. 7 illustrates a structure of a Node B transceiver in a conventional HSDPA communication system. It will be assumed in FIG. 7 that the Node B supports a total of n SHCCHs, and a total of x UEs maintain an HSDPA call. If DPCH receivers 701-1 to 701-x of the Node B receive uplink Secondary DPCHs of UE#1 to UE#x, the DPCH receivers 701-1 to 701-x deliver control information included in the received Secondary DPCHs to corresponding UE context storages 702-1 to 702-x, respectively. Further, the DPCH receivers 701-1 to 701-x deliver HARQ-related information such as HARQ processor numbers and ACK/NACK information included in the received Secondary DPCHs to corresponding buffers 703-1 to 703-x, respectively. The buffers 703-1 to 703-x store user data that is received by the Node B from RNC and is to be transmitted to the corresponding UEs, and data for which the Node B has failed to receive ACK. The buffers 703-1 to 703-x provide information on an amount of the stored data to the corresponding UE context storages 702-1 to 702-x every TTI. The UE context storages 702-1 to 702-x manage the information illustrated in Table 3 in association with the UEs, and continuously update the contents stored therein based on control information included in the received Secondary DPCHs. Further, the UE context storages 702-1 to 702-x provide the updated contexts of the UE contexts to a scheduler 704 every TTI. By using a predetermined scheduling algorithm, the scheduler 704 determines (i) a particular UE to which HS-PDSCH resources, or OVSF codes are to be assigned for a particular TTI, (ii) the number of the OVSF codes to be assigned to the UE, (iii) an MCS level to be applied, and (iv) SHCCH to be used. The scheduler 704 determines the MCS level based on CQ information provided to the UE context storages 702-1 to 702-x. Further, the scheduler 704 provides information on the number of codes and the MCS level to buffers 703-1 to 703-x for the UEs assigned the HS-PDSCH resources, an HS-PDSCH transmitter 707, and SHCCH transmitters 706-0 to 706-n. In addition, the buffers 703-1 to 703-x for the UEs store an identifier of SHCCH for transmitting control information of the corresponding UEs. The buffers 703-1 to 703-x for the UEs transmit HARQ-related information such as HARQ processor number for transmission data over a corresponding SHCCH, determine an amount of transmission data based on the number of codes and the MCS level, and then provide as much data as the determined amount to the HS-PDSCH transmitter 707. The scheduler 704 provides the SHCCH identifier to DPCH transmitters 705-1 to 705-x at a time earlier than a point of time when the HS-PDSCH transmits data. The time when the scheduler 704 provides the SHCCH identifier to the DPCH transmitters 705-1 to 705-x will be described later. The DPCH transmitters 705-1 to 705-x insert the SHCCH identifier provided from the scheduler 704 in a punctured part of the corresponding DPCHs before transmission. If no SHCCH identifier was provided from the scheduler 704, the DPCH transmitters 705-1 to 705-x transmit corresponding DPCHs without the SHCCH identifier. The SHCCH transmitters 706-0 to 706-n form SHCCHs based on the information provided from the scheduler 704 and the buffers 703-1 to 703-x, and then transmit the formed SHCCHs over a radio channel. The HS-PDSCH transmitter 707 performs channel coding, modulation and spreading on the data provided from the buffers 703-1 to 703-x based on the code information and MCS level provided from the scheduler 704, and transmits the processed data over a radio channel.
FIG. 8 illustrates a timing relationship among channels in a general HSDPA communication system. Referring to FIG. 8, if HI and control information are transmitted over downlink DPCH (DL_DPCH) and SHCCH, respectively, then the UE identifies an SHCCH identifier corresponding to the UE through HI on the DL_DPCH, receives an SHCCH signal corresponding to the SHCCH identifier, and detects control information from the received SHCCH signal. After a lapse of predetermined time, the UE receives HS-PDSCH based on the control information on the SHCCH. Here, the "predetermined time" represents the time required for analyzing control information, or code information for HS-PDCH, included in the SHCCH signal, and despreading the HS-PDSCH with the analyzed code. Preferably, the predetermined time is set to a 2-time slot period. After receiving the HS-PDSCH, the UE sequentially performs despreading, demodulation, decoding, and CRC operation on a coded block received over the HS-PDSCH. As a result of the CRC operation, the UE determines whether the coded block has an error, and transmits the CRC results to Node B over an uplink DPCH (UL_DPCH).
Herein, for the convenience of explanation, the time required by the UE for performing despreading, demodulation, decoding, and CRC operation on the received coded block and transmitting the CRC result information, or ACK/NACK information, to the Node B will be referred to as "feedback delay."Since the feedback delay is the sum of a propagation delay representing the time required when a coded block transmitted by the Node B arrives at the UE, and the time required when the UE actually processes the received coded block, the feedback delay is changed according to a channel condition. However, since the Node B must previously know the time when the ACK/NACK information will arrive, the feedback delay may be determined by the HSDPA communication system and transmitted to the UE during HSDPA call setup. In this case, since the feedback delay is a value previously agreed between the UE and the Node B, both the UE and the Node B must previously recognize the feedback delay.
For the sake of convenience, it is assumed in FIG. 8 that the feedback delay has a 3-time slot period, the DL_DPCH represents Associated DPCH, and the UL_DPCH represents Secondary DPCH. As illustrated in FIG. 8, a process of transmitting a particular HS-PDSCH to a particular UE continues from the time where the Node B transmits HI until the Node B receives ACK/NACK from the corresponding UE. Herein, the time required for performing the process of transmitting a particular HS-PDSCH to a particular UE will be referred to as "HSDPA cycle." In addition, a period from a transmission starting point of the HI to a transmission ending point of the HS-PDSCH will be defined as "DL cycle," and a period from a transmission ending point of the HS-PDSCH to a transmission ending point of ACK/NACK will be defined as "UL cycle." That is, the DL cycle becomes a downlink transmission period in the HSDPA cycle, and the UL cycle becomes an uplink transmission period in the HSDPA cycle. Further, though not illustrated, scheduling for transmission of the HS-PDSCH must be ended before the transmission starting point of the HI.
FIG. 9 schematically illustrates an operation of performing a compressed mode by UE maintaining an HSDPA call. Referring to FIG. 9, the DL_DPCH and the UL_DPCH are required in order to support the HSDPA, and a connection such as a voice call service except the HSDPA call can be set up through the DL_DPCH. For the connection established over the DL_DPCH, the UE may perform either inter-frequency measurement or the compressed mode. As described above, if the compressed mode is performed, transmission gaps are generated, and during the transmission gap, since transmission/reception of HSDPA data is impossible, transmission/reception of HS, SHCCH and HS-PDSCH is also impossible. In addition, even when the HSDPA cycle overlaps with the transmission gap, the normal HSDPA call cannot be maintained. Therefore, it is necessary to prevent the HSDPA cycle from overlapping with the transmission gap. The HSDPA call is not serviceable for the transmission gap and also for a period determined by subtracting one time slot from the HSDPA cycle before the transmission gap. For example, when the HSDPA cycle has 8 time slots, if HI was transmitted before a 7th time slot preceding the transmission gap, it may not be possible to receive from the UE an ACK/NACK signal for a coded block corresponding to the HI. The period where the HSDPA call cannot be serviced due to the transmission gap in the compressed mode of the DPCH will be defined as "HSDPA non-transmittable period." Accordingly, there have been demands for a method capable of minimizing the HSDPA non-transmittable period.

Apparatus and method for minimizing a non-transmittable period due to a compressed mode in a mobile communication system supporting HSDPA


A recoil starter in which a side face of a rope reel is formed with a ring-like recess portion for containing a damping force storing member, a boss portion of a cam is contained at inside of the ring-like recess portion and the damping force storing member is contained between an inner peripheral face of the ring-like recess portion and an outer peripheral face of the boss portion of the cam, an inner side of the boss portion of the cam is formed with a ratchet mechanism for engaging and disengaging the cam to and from the rope reel, when the rope reel is rotated by traction of the recoil rope, the both members are disengaged from each other and when the rope reel is rotated in a direction of reeling back the recoil rope, the both members are engaged with each other.

1. Field of the Invention
The present invention relates to a recoil starter for starting an engine by rotating a rotating member connected to a crankshaft of the engine by rotating a rope reel by operating to pull a recoil rope and transmitting rotation of the rope reel to a cam by way of the cam.
2. Description of the Related Art
There is known a recoil starter for starting an engine by rotating a crankshaft of the engine by rotating a rope reel by traction of a recoil rope wound around the rope reel and transmitting rotation of a cam rotatably connected to the rope reel to a rotating member of a flywheel magnet, a drive pulley or the like attached to the crankshaft of the engine by way of a crutch mechanism of a centrifugal clutch or the like by way of the rotating member, in which a damping force storing member is interposed between the rope reel and the cam, impact by a variation in a rapid load on a side of the engine is damped by the damping force storing member such that the impact is not transmitted to a side of the rope reel, a rotational force of the rope reel is stored in the damping force storing member and the engine is facilitated to start by releasing the rotational force stored to the damping force storing member to the side of the cam.
According to the recoil starter having the damping force storing member arranged between the rope reel and the cam as described above, the rope reel rotated in an engine starting direction by traction of the recoil rope and the cam for transmitting the rotational force to the rotating member connected to the crankshaft of the engine by way of the clutch mechanism are rotatably supported respectively by a support shaft formed in a case, a ring-like recess portion is formed at a side face of the rope reel and a boss portion of the cam is contained in the ring-like recess portion, the rope reel and the cam are rotatably connected by connecting both ends of a mainspring constituting the damping force storing member contained in the ring-like recess portion to between an inner peripheral face of the ring-like recess portion of the rope reel and an outer peripheral face of the boss portion of the cam, further, a ratchet mechanism is formed at a side face of the rope reel proximate to an outer periphery thereof, the ratchet mechanism is operated by being engaged with an inner peripheral face of the case containing the rope reel and the like, when the rope reel is rotated in the engine starting direction, the ratchet mechanism is separated from an engaging member formed at an outer periphery of the cam, when the rope reel is rotated in a direction reverse to the engine starting direction by the rotational force stored to the recoil mainspring, the ratchet mechanism is engaged with the engaging member and the cam is rotated in the reverse direction integrally with the rope reel, as disclosed in JP-A-2004-197731.
According to the ratchet mechanism for interrupting rotation between the rope reel and the cam of the background art, a ratchet member is pivotably supported by a side face portion proximate to the outer periphery of the rope reel rotatably held by the reel support shaft formed in the case, when the rope reel is rotated in the case, the ratchet member is operated to pivot by engaging the ratchet member with the inner peripheral face of the case, thereby, the ratchet member is engaged with and separated from the engaging member formed at the outer periphery of the cam and therefore, it is necessary to form a peripheral wall portion in a cylindrical shape engaged with the ratchet mechanism at the inner peripheral face of the case opposed to the outer periphery of the rope reel and therefore, outer shapes of the rope reel and the case are large and part prices are made to be expensive to constitute a factor of hampering small-sized and light-weighted formation and a reduction in cost of the recoil starter.


An apparatus and a method capable of automatically adjusting an initial position of the surface of a melt without an operator are provided. In a single crystal puller using a wire as a suspender for a seed crystal for growing a single crystal of silicon or the like according to the CZ method, a reference position of the seed crystal is detected, the wire is unwound to lower the end of the wire to a position higher by a distance W-X from the reference position and then pulled upward above said reference position to correct the wire for an extension due to the weight of a single crystal attached thereto. Also, the wire is left above a melt for about ten minutes to provide a constant amount of extension to the wire due to heat of the melt These operations are automatically performed.

1. Field of the Invention
The present invention relates generally to a single crystal puller for melting a polycrystalline material and pulling a seed crystal from the melt of the polycrystalline material to produce a single crystal, and more particularly to a position adjusting apparatus for adjusting an initial vertical position of the surface of a melt when a crystal growth is started in the single crystal puller.
2. Description of the Related Art
Conventionally, a Czochralski method (hereinafter referred to as the "CZ method") is known as a method of producing a single crystal from a semiconductor polycrystalline material such as silicon. In the CZ method, a highly pure polycrystalline material is melt in a crucible or the like, and a seed crystal is brought into contact with the melt of the material and then pulled upwardly to produce a single crystal.
During the growth of a single crystal, an industrial television camera or the like, installed above the surface of the melt, is generally used to measure an apparent diameter d of a silicon single crystal on the interface between the single crystal and the melt. Then, the pulling rate is controlled to bring an actual diameter D to a predetermined value based on the apparent diameter d. In addition, adjustments of temperature and so on are performed to produce a silicon single crystal ingot substantially in a cylindrical shape.
The actual diameter D of a single crystal may be approximated by the following equation: EQU D=(.alpha.+.beta.X+.gamma.X.sup.2).times.d
where .alpha., .beta., and .gamma. and are predetermined constants, and X is expressed by L-L.sub.0, where L is the distance between the position of an industrial television camera and the surface of a melt, and L.sub.0 is a reference value for L. It should be noted that X/L is a very small number. Therefore, a change in the reference value L.sub.0 causes a deviation in the relationship between the apparent diameter d measured by the industrial television camera and the actual diameter D, so that the diameter of a single crystal cannot be maintained at a predetermined value.
As a result, if a pulled single crystal has an actual diameter larger than a predetermined value, the outer periphery of the single crystal should be ground until the diameter of the single crystal is equal to the predetermined diameter value. Since it is a recent tendency to produce single crystals of larger diameters, the outer peripheral portion lost by the grinding has become an innegligible problem in view of a manufacturing cost.
Since the reference value L.sub.0 for L is typically measured when a seed crystal is in contact with the surface of a melt at the beginning of a single crystal pulling operation, it is a critical problem to adjust the initial position of the melt surface as accurately as possible for the measurement. Thus, apparatuses for adjusting an initial position of the surface of a melt have been proposed for this purpose, and those disclosed in Japanese Patent Publication No. 5-59876 and so on are known.
Recently, it has been found, in single crystal pullers according to the CZ method which use a stranded wire as a suspender for a seed crystal in such a manner that the stranded wire is wound around a drum and unwound therefrom to raise and lower the seed crystal, that as a single crystal grows and becomes heavier, a tension is applied to the wire, which returns the wire in a direction in which the "strand" is loosened, and consequently the wire is extended. For this reason, when a single crystal is pulled upwardly, the wire is wound around a drum in an extended state, with the loosen "strand". However, when a new seed crystal is attached to the suspender after a produced single crystal ingot is removed, and the drum is rotated in the reverse direction to lower the seed crystal, no tension is applied to the wire to cause the strand to restore, whereby the wire become shorter than when it is wound around the drum. It has been found, as a result, that the wire extends approximately 10.0 millimeters per meter when a single crystal reaches a weight of 15 Kg, as can be seen from FIG. 1, thus producing a relatively large error. Therefore, when a moving distance of a single crystal is calculated from a rotating amount of the drum to determine an initial position of the surface of a melt based on this calculation, the extension and contraction of the wire will cause a large error in determining the initial position of the melt surface.
In addition, it has been found, in the above-mentioned single crystal puller according to the CZ method using a wire as a suspender for a seed crystal, that as the wire is left above a melt at a high temperature, the high temperature causes the wire to extend. It has been also found that the extension increases as the wire is left for a longer time. Specifically, as can be seen from FIG. 2, the wire extends 1.2 millimeters per three meters in ten minutes, and thereafter the wire does not extend any more even if it is left in the same situation. Thus, also in this case, when a moving distance of a single crystal is calculated from a rotating amount of the drum to determine an initial position of the surface of the melt based on this calculation, the extension and contraction of the wire will cause an error in determining the initial position of the melt surface.
Further, it has been found, in the above-mentioned single crystal puller according to the CZ method. using a wire as a suspender for a seed crystal, that when a seed crystal is stopped at a reference position, the elevating rate of the seed crystal causes an error between the reference position and the position at which the seed crystal is actually stopped. A conventional single crystal puller is typically provided with a reference position sensor such that a motor for driving a drum is automatically stopped when the reference position sensor detects the tip of a seed crystal. However, a "time delay", though very short, is present from the time the reference position sensor detects the tip of a seed crystal to the time the seed crystal is actually stopped. This time delay causes a deviation from the reference position. Specifically, it has been found that the maximum deviation of the stopping position from the reference position is 0.7 millimeters with the moving rate of a seed crystal at 250 millimeters/minute. Thus, also in this case, when a moving distance of a single crystal is calculated from a rotating amount of the drum to determine an initial position of the surface of a melt based on this calculation, the erroneous stopping position will cause an error in the initial position of the melt surface.
Further, in the above-mentioned single crystal puller according to the CZ method using a wire as a suspender for a seed crystal, after an initial position of the melt surface has been measured, a seed crystal is once raised, and a crucible is then moved in the vertical direction for correctly positioning the crucible at a defined position based on the measured initial position of the surface of the melt. The seed crystal is once raised because if the crucible only were raised without changing the position of the seed crystal, the seed crystal would be submerged in the melt. However, the crucible elevating operation also causes an error in the initial position of the melt surface.
In the conventional methods mentioned above, operations for raising and lowering a seed crystal, vertically moving a crucible, and so on are manually performed by operators. Since the operators carefully manipulate for ensuring a sufficient accuracy, a long time is required for each of the operations. In addition, variations in manipulations depending on individual operators also affect the accuracy.

Apparatus for adjusting initial position of melt surface


Novel sodium-independent small neutral amino acid transporters which transport L- and D-amino acids. A protein comprising the amino acid sequence represented by SEQ ID NO:1 or 4 or an amino acid derived therefrom by deletion, substitution or addition of one or more amino acids and being capable of sodium-independently transporting L- and D-small neutral amino acids and analogs thereof; a gene encoding the above protein; a method of screening substances inhibiting or promoting the function of the above protein; an antibody against the above protein; and a method of regulating cell function by using the above antibody, function inhibitors, function promoters, etc.

Cells are required that amino acids are to be always incorporated thereinto as nutrition and such a function is carried by an amino acid transporter which is a membrane protein existing in cell membrane. The amino acid transporter is aligned in a specific site in each tissue in multicellular living things and plays an important role in expression of specific functions in each tissue.
A transport system asc is an amino acid transport system which transports small neutral amino acids mostly alanine, serine and cysteine and, originally, it was found in erythrocyte membrane and mentioned in many literatures. After that, its existence was confirmed in cultured cells as well (Christensen, Physiol. Rev., volume 70, page 43, 1990). The transport system asc is a transporter which is sodium-independent or, in other words, it does not need sodium ion for its function. Its transport substrate selectivity and transport characteristic have been known to have some differences depending upon cells and animal species.
The transport system asc shows a high affinity to a transport substrate such as alanine, serine or cysteine and, as a transport system similar thereto, there is a transport system C where small neutral amino acid such as alanine, serine or cysteine is a transport substrate as well but affinity to a transport substrate is low (Young et al., Biochem. J., volume 154, page 43, 1976; Young et al., Biochem. J., volume 162, page 33, 1977). The transport system C is believed to be a subsystem for the transport system asc. Sheep where the transport system C is genetically deficient was found, reduction in glutathione content in its erythrocytes was shown and the importance of incorporation of cysteine mediated by cell membrane in the production of glutathione was proved (Young, et al., Nature, volume 254, page 156, 1975).
However, in the conventional methods, it is difficult to analyze the details of transport of amino acid and analogs thereof mediated by the amino acid transport system asc and the functional role in vivo and there has been a demand to isolate gene of neutral amino acid transporter carrying a function of the amino acid transport system asc so as to make the detailed function analysis possible.
As to a small neutral amino acid transporter, there were cloned ASCT1 and ASCT2 (Kanai, Curr. Opin. Cell Biol., volume 9, page 565, 1997). However, they are sodium-dependent transporters and are entirely different from a sodium-independent amino acid transport system asc. In the meanwhile, glycine transporter and proline transporter were cloned (Amara and Kuhar, Annu. Rev. Neurosci., volume 16, page 73, 1993) but both of them transport only glycine and proline in a sodium-dependent manner and are different from the transport system asc.
cDNA of rBAT and 4F2hc which are type II membrane glycoproteins having only one transmembrane structure which is considered to be an activating factor of an amino acid transporter were cloned although they are not transporters per se and it was known that, when they were expressed in oocytes of xenopus, incorporation of basic amino acid together with neutral amino acid was activated (Palacin, J. Exp. Biol., volume 196, page 123, 1994).
With regard to a transporter which selectively transports neutral amino acid, there were cloned neutral amino acid transporter LAT1 (Kanai et al., J. Biol. Chem., volume 273, pages 23629–23632, 1998) and LAT2 (Segawa et al., J. Biol. Chem., volume 274, pages 19745–19751, 1999) corresponding to a transport system L. It was further shown that LAT1 and LAT2 functioned only when they coexist together with a cofactor 4F2hc. Both are not dependent on Na+ but LAT1 shows an exchange transport activity for transporting the large neutral amino acids such as leucine, isoleucine, valine, phenylalanine, tyrosine, tryptophane, methionine and histidine and LAT2 has a wide substrate selectivity transporting the small neutral amino acids such as glycine, alanine, serine, cysteine and threonine in addition to large neutral amino acids. However, even they are different from the amino acid transport system asc in terms of substrate selectivity.
With regard to proteins analogous to the neutral amino acid transporters LAT1 and LAT2, there were cloned the above-mentioned y+LAT1 and y+LAT2 having a function of a transport system y+L transporting the neutral amino acids and basic amino acids (Torrents et al., J. Biol. Chem., volume 273, pages 32437–32445, 1998). It was also shown that both y+LAT1 and y+LAT2 functioned only when coexisted together with the cofactor 4F2hc. y+LAT1 and y+LAT2 mainly transport glutamine, leucine and isoleucine as neutral amino acids and are different from the amino acid transport system asc in terms of the substrate selectivity.
With regard to a transporter demanding the cofactor 4F2hc for the expression of the function, there was cloned xCT which is a protein analogous to the neutral amino acid transporters LAT1 and LAT2 (Sato et al., J. Biol. Chem., 274: 11455–11458, 1999). The xCT transports cystine and glutamic acid and is different from the amino acid transport system asc in terms of the substrate selectivity.
With regard to a transporter demanding other cofactor rBAT having a structure analogous to 4F2hc for expressing the function, there was cloned BAT1 which is a protein analogous to the neutral amino acid transporters LAT1 and LAT2 (Chairoungdua et al., J. Biol. Chem., 274: 28845–28848, 1999). BAT1 transports cystine, neutral amino acids and basic amino acids and is different from the amino acid transport system asc in terms of substrate selectivity.
As such, molecular substances of the transporters which function upon linking to 4F2hc and rBAT were made clear and it was clarified that there was a group of transporters which achieve a transporting function when a molecular complex is formed with the type II glycoprotein.

Sodium-independent small neutral amino acid transporter transporting L- and D-amino acids

Japan Science and Technology Corporation


A method and system for presentation of risks comprising using standardized two colored risk rating symbols in a graphical user interface of a client representing risks, wherein main colors representing risk level/rating is used as fill colors of the standardized two colored risk rating symbols. The method and system is further be arranged for detecting if a risk is close to another risk level/rating and displaying the standardized two colored risk rating symbol of a risk with a borderline color in another color than the main color, and if there is no close other risk level/rating displaying the standardized two colored risk rating symbol of a risk with a borderline color in the same color as main fill color or without borderline color.

The disclosure is related to a method and system for presentation of risks.
Risk exists in every business activity, and risk management has become an integral part of modern business management.
Risk is the potential of gaining or losing something of value and can be categorized as a threat or an opportunity.
Risk with potential negative impact is categorized as a threat, which can prevent value creation or erode existing value.
Risk with potential positive outcome is categorized as an opportunity, which can positively affect the achievement of objectives, supporting value creation or preservation.
The amount of risk is usually categorized into a small number of levels organized into risk matrices as neither the probability nor severity can typically be estimated with accuracy and precision. Risk matrices—also known as risk assessment matrices—are matrices that are used during risk assessment to define the various levels of risk as the product of the harm probability categories and harm severity categories.
Enterprise risk management (ERM) systems typically use the terms 'risks' if the potential outcome is a threat and opportunity if the potential outcome is positive.
U.S. Pat. No. 8,214,235 B2 teaches a method of enterprise risk management including defining a hierarchical organizational model to represent an enterprise where each subordinate level including one or more entities has a reporting relationship to one of the entities in the preceding level.
U.S. Pat. No. 7,603,367 B1 describes a computer-implemented method for displaying information related to items categorized into a plurality of nodes logically arranged into a hierarchy.
US 20050060647 A1 describes an invention that relates to automated presentation of data and, in particular, to the automatic selection of suitable presentation methods for hierarchical data.
US 20140375667 A1 describes a computer-implemented method of generating a visualization of a plurality of catastrophic risk metrics associated in an image having a plurality of portions, each corresponding to one of the catastrophic risk metrics associated with the risk agent.
US 20110219324 A1 describes a graphical hierarchical data wheel for displaying hierarchical nodes where the wheel further includes one or more concentric rings comprising a plurality of segments.
U.S. Pat. No. 6,219,053 B1 describes an icon display and method which reflect the perspective of correlation between icons which have hierarchical relationships.
U.S. Pat. No. 8,423,445 B2 relates to method and system for three-dimensional presentation of financial data using geometric figures and connections in different colors.
A drawback of the mentioned prior art is that they are not able to provide a solution which can be adapted to the end user, and especially by that they do not provide a solution where a hierarchy can be split into several independent hierarchies based on filters set by the end user.
A further drawback of prior art is that the they are not able to visualize risk and its risk rating in a simple manner, and especially by that they do not provide standardized two colored risk rating symbols generated from risk matrices to enable presentation of risks in a graphical user interface for enterprise-wide risk management.

Method and system for presentation of risks


A backup ring for a face seal in a roller cone bit is configured to resist wear from drilling fluids present adjacent exposed faces of the backup ring. Portions are removed from an exposed end face in a variety of shapes while the hardness of the material is increased. The removal of material offsets an increase in force that would be transmitted through the backup ring on face seal assembly due to flexing. A spring can optionally be included in the removed material location. Another way is to increase the edge density of all or part of the exposed edges while leaving the interior portions unaffected by using electron beam radiation to increase the crosslink density or by other techniques that allow a unitary structure with a more durable edge region.

Components of a rolling cone bit mechanical face seal system utilized to seal the bearing typically include (A) two hard material components typically metal having surfaces engaged and sliding with relation to each other, (B) an elastomeric static seal ring with the primary function of providing an energizing force to one of the hard material components such that the surfaces of the hard material components are engaged at some designed contact pressure, (C) a second static sealing elastomer component sometimes referred to as a backup ring residing outside of a first elastomer component and engaged with one of the hard material components. This second elastomer component having the primary function of stopping ingress of the drilling environment into the annular space between one of the hard material seal components and the base area of the bearing pin which forms a gland for the elastomer energizer. This second static sealing elastomer component sometimes referred to as a backup ring often is the first component in the mechanical face sealing system to fail. Failure is typically in the form of tearing and wear generally initiating in the area of the outside diameter of the backup ring and on the surface engaged with one of the hard material seal components.
A backup ring (BUR) in a mechanical face seal assembly serves one or more of the following purposes: contribute to the face load; protect the energizer or energizing mechanism; provide resisting torque to prevent stationary seal from rotating; and fill the gland area to reduce the effect of mud packing. In the prior art, a low Shore A hardness elastomeric compound was used to meet the design requirements. Field experience shows that this material can degrade and often suffers tear and loses its function.
The basic assembly of a roller cone bearing seal assembly using a backup ring 55 is described in U.S. Pat. Nos. 6,142,249 and 7,168,147 which is presented below for context for the improvements to the backup ring contemplated by the present invention.
The numeral 11 in FIG. 1 of the drawing designates an earth-boring bit having a threaded upper portion 13 for connection to a drill string member (not shown). A fluid passage 15 directs drilling fluid to a nozzle (not shown) that impinges drilling fluid or mud against the borehole bottom to flush cuttings to the surface of the earth.
A pressure-compensating lubrication system 17 is contained within each section of the body, there usually being three, which are welded together to form the composite body. The lubrication system is preferably similar to that shown in U.S. Pat. No. 4,727,942, to Galle.
In each section of the body, a lubricant passage 19 extends from each compensator 17 downwardly into intersection with another lubricant passage 21 in which a ball plug 23 is secured to the body by a plug weld 25. Lubricant passages 27 carry lubricant to a cylindrical journal bearing surface defined between a cylindrical insert 29 (interference fit in cutter 33) and a corresponding cylindrical surface on bearing shaft 30, which is cantilevered downwardly and inwardly from an outer and lower region of the body of the bit, commonly known as the shirttail. Ball plug 23 retains a series of ball bearings 31 that rotatably secure cutter 33 to bearing shaft 30. Dispersed in the cutter are a plurality of rows of earth-disintegrating cutting elements or teeth 35 that may be constructed of a sintered tungsten carbide secured by interference fit into mating holes in cutter 33. A seal assembly 37, including a secondary seal is disposed adjacent the base of bearing shaft 30 and seals lubricant within the bearing and debris out of the bearing.
FIGS. 2 and 3 are enlarged section views of the bearing and seal assembly of the earth-boring bit. A pair of axial surfaces 39, 41 formed in cutter 33 and last-machined surface 43 of the shirttail portion of the bit body cooperate with a pair of radial surfaces 45, 47 to define a bearing seal gland generally at the base of bearing shaft 30. A seal assembly 37 is disposed in the seal gland and includes a rigid seal ring 49 and an o-ring energizer 51, which urges a seal face 53 on ring 49 into sealing engagement with a corresponding seal face 41 on an insert 29 in cutter 33. This rigid face seal is formed in accordance with U.S. Pat. No. 4,753,304, to Kelly.
Seal assembly 37 may be regarded as a primary seal because it is designed to seal the journal bearing against entry of foreign material or debris and to accommodate pressure fluctuations in the lubricant. Seal 37 is also a dynamic seal because it seals the moving or dynamic interface between each cutter and its bearing shaft and the relative rotational movement between them.
In addition to dynamic seal 37, a secondary or backup seal ring 55 is disposed in the seal gland opposite between seal assembly 37 and last-machined surface 43 to seal the seal gland and seal assembly 37 against entry of debris, particularly drilling mud particles, from the exterior of bit 11. To accommodate seal ring 55 and seal 37, axial surface 39 is in a groove machined into last-machined surface 43 to a depth approximately one-third to one-half the nominal axial thickness of ring 55. Axial surface 39 may be flush with last-machined surface 47.
FIG. 4 is an enlarged cross-section view of ring 55. Preferably, secondary seal ring 55 is a continuous ring formed of nitrile elastomer material of about 40-45 durometer (Shore A) and a modulus of about 200-400 psi/in/in. Preferably, no adhesive is used to secure ring 55 in the seal gland. Alternatively, secondary seal ring 55 may be attached or secured by adhesive to axial seal gland surface 39 (or last-machined surface 43) and to rigid seal ring 49 to enhance its sealing ability. Because secondary seal ring 55 remains stationary with last-machined surface 47 and does not seal relative rotary motion, it is a static seal, as opposed to seal 37, which is a dynamic seal.
For an 8½ inch bit, secondary seal ring 55 has an outer diameter D of approximately 2.480 inch and a radial width W is of about 0.211 inch. Outer diameter D is selected to be about 0.040 to 0.060 inch larger than the outer diameter of rigid ring 49. The inner surface or diameter and end 57 of secondary seal ring 55 are configured to be similar to and respectively conform to radial surface 45 and axial surface 39 of the seal gland. A radius R1 of about 0.085 inch and a tip radius R2 of about 0.015 inch are provided at the inner end of secondary seal ring 55.
Ring 55 also includes two raised ribs 57 which are approximately 0.025 inch to 0.030 inch wide and 0.010 inch to 0.014 inch high. The purpose of the ribs is to form high-stress areas to deter the entry of fluid and/or debris into the seal gland when secondary seal ring 55 is forced into contact with surface 39.
Ring 55 has an axial thickness t of about 0.095 inch (in the uncompressed or relaxed state), which is greater than the gap formed between axial surface 39 and the end of seal ring 49. The intent is to provide sufficient "squeeze" on secondary seal ring 55 between axial surface 39 and seal ring 49. In the preferred embodiment, this squeeze is approximately 20% to 25% of the uncompressed or relaxed radial thickness t of ring 55 using nominal values and with the cutter forced outward on the bearing shaft. A radius R3 of about 0.125 inch is provided to permit deformation of energizer ring 51 and to closely conform to it. The remaining width w of ring 55 is about 0.104 inch.
In the assembled configuration, the area in the seal gland bounded by surfaces 39 and 45, including rings 49, 51, and 55, is intended to be assembled so as to minimize or exclude air. Upon assembly, a continuous ring of heavy mineral oil is applied to at least axial surface 39, then secondary seal ring 55 is placed in the seal gland and energizer 51 and seal ring 49 are installed. This assembly process helps to insure that void areas are minimized and/or eliminated in the aforementioned area of the seal gland. In a later improvement shown in U.S. Pat. No. 7,413,037 the mineral oil was not needed as the shape of the backup ring was changed to have protrusions to fill the gaps that formerly were filled with the heavy mineral oil.
The problem with this design in the past is the tearing or breaking off of segments from the outer end of the backup ring 55 on the exposed face opposite surface 47 due to grit in the mud permeating toward this exposed surface that ultimately lead to seal failure of seal 37. The present invention addresses this issue in a variety of options. In one sense the material of the backup ring of the present invention is made harder but at the same time maintaining flexibility to address conflicting requirements for durability from well fluids and the need for application of a desired contact force between relatively moving surfaces 53 and 41 and a needed sealing force into the backup ring 55 into surface 39. Some of the ways this accomplished is material removal between opposed ends at the exposed edge where the removed portion is in the shape of a U or a V alone or in conjunction with support in the removed location that acts akin to a spring. Another option is to strengthen all or parts of the exposed edge with electron beam radiation to increase crosslink density at the extremities while leaving interior segments unaffected for control of the sealing force on the backup ring 55 and the contact pressure against relatively rotating surfaces 53 and 41.
These and other features of the present invention will be more readily apparent to those skilled in the art from a review of the detailed description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is to be found in the appended claims.

Enhanced backup ring features for metal face seal in roller cone drill bits


A golf putting training apparatus for improving a golf stroke along a line of intended travel of a golf ball. The golf training apparatus includes a pair of upright supports and an eye alignment tool for aligning a user's eyes above the apparatus and in a vertical plane that includes the golf ball and the line of intended travel. The eye alignment tool is supported by and connected between the supports and above the golf ball and includes a substantially linear top edge and pair of generally parallel planar sides depending from the top edge toward a bottom edge. With the golf putting training apparatus further including a longitudinally elongated tool arranged under the lower bottom edge of said eye alignment tool and extending along the line of intended travel of said golf ball. A method of training a golfer to use a putter used by the golfer during a golf putting stroke is also disclosed.

Golf is a popular game but one that is technically demanding. Learning correct techniques to be used on a golf course can lead to significant improvements in a golfer's performance and, thus, lead to lower scores. To become a better golfer, a golfer must master consistency in all aspects of their various swings.
The putting stroke is only one of several types of golf swings, yet it accounts for nearly half of all swings made during regulation play. Despite its rather innocent-looking appearance, and as any good golfer knows, the ability to accurately and consistently putt a golf ball is a very difficult skill to develop, acquire and maintain.
During putting, a golfer typically imagines a target line between the position of the ball on the green or putting surface and the golf cup or "hole." The target line imagined by the golfer is that path for the ball which, if followed, results in the ball landing in the cup. To properly envision the target line, it is helpful for a golfer to vertically align their line of sight with a vertical plane which is perpendicular to the putting green or surface and passes through the centerline of the ball. If the golfer's line of sight is not aligned in this manner, it is less likely the golfer will correctly envision the target line, and more likely the golfer will envision a line that does not lead the ball to the cup thereby adding frustration to the game and the golfer. Even if the remainder of the golfer's putting stroke is perfect, the ball is likely to follow the improperly envisioned line, rather than the target line and not land in the cup.
Even if the golfer does properly envisions the target line, the ball can still miss the cup if the club face or striking surface of the putter does not travel along a target line during the golfer's putting stroke. Additionally, and even if the golfer does properly envision the target line and swings the club face of the putter in line with the target line during the putting stoke, the ball can nevertheless still miss the cup if the striking surface or club face of the putter is not square to the ball when the club face contacts the ball. In order to develop an accurate and consistent putting stroke, the golfer will find it helpful to combine each of the elements of properly aligning the golfer's line of sight over the target line, swing the putter club face in line with the target line, and squaring the club face of the putter when the club face contacts the ball.
In view of the foregoing, there is continuing need and desire for a golf putting training apparatus in which a correct putting swing can be taught along with a method for training a user to swing a golf putter.

This patent is subject to a terminal disclaimer.

Golf putting training apparatus and method of training a golfer to use a putter


Disclosed is a material testing system that includes an output shaft configured to be moved by operation of a motor, the output shaft coupleable to a test specimen such that movement of the output shaft imparts a mechanical force on the test specimen. The material testing system includes a haptic feedback system configured to provide an operator of the material testing system haptic feedback related to a position or state of the output shaft relative to the test specimen during setup. Methods of testing using haptic feedback are also disclosed.

Material testing systems typically include one or more shafts or other load applying actuators that extends to a clamp or holding device within which a test specimen may be placed or otherwise received prior to testing. When setting up such a material testing machine, a process may require an operator to follow several steps, each requiring a different position of the actuator(s). An operator typically adjusts the position of the actuator(s) either via an instrument control panel, or by manipulating an actuator, or output shaft thereof, by hand. When manipulating the actuator by hand, an operator is required to split their attention between a gauge or GUI display of the position and/or load on the actuator(s) and the clamp or holding device. This splitting attention can lead to longer set up times, errors in set up, and in some cases unintentional damage to the system and/or test specimen.
Thus, material testing system that provides user aid in set up and configuration would be well received in the art.

Haptic feedback for configuring materials testing systems


A test tube rack for supporting, storing and carrying a plurality of test tubes in a laboratory environment comprising a tray, a central support panel and/or lower support panel and a cover. The tray and cover are identical and interchangeable, and tapered for storage in nested stacks. Wells in the tray bottom are in alignment with corresponding openings in the central support panel and corresponding holes in the lower support panel and with domes in the cover, and serve to locate and retain test tubes within the test tube rack. The cover snap-attaches to the tray with at least one molded-in tab on the tray or cover which is received and frictionally retained by a corresponding well on the opposite element, thereby locating and securing the cover to the tray, and also locating and securing the central support panel between the tray and the cover. A dual-purpose support panel has manually removable perforated edges allowing it to serve either as a central support panel or, with the perforated edges removed, as a lower support panel. The test tube rack is preferably made of transparent injection-molded or thermoformed plastic.

In a laboratory environment, particularly in laboratories working with biologically active materials, it is important to have a secure means of supporting an array of test tubes, often in a predetermined order, and of transporting and storing them between uses. Among the desirable features in such a product are: transparency, so that the test tubes and their contents are readily visible; nestability, so that the parts of the test tube rack may be compactly nested when not in use; stackability, so that assembled test tube racks may be stacked one on top of the other for storage; and disposability, so that a rack containing a group of used test tubes may be disposed of as a unit, thereby avoiding the need to remove the tubes individually and the need to clean and sterilize the test tube rack for re-use.
To accomplish at least some of the above purposes, a number of devices are disclosed by the prior art, including the following.
Delair U.S. Pat. No. 3,184,071 (May 18, 1965) discloses an injection-molded plastic case for various kinds of containers, including glass containers, in which the principal embodiment has both a central perforated rack and a similarly perforated cover to give two levels of support to hold the containers in an upright position.
Mander, et al. U.S. Pat. No. 3,643,812 (Feb. 22, 1972) shows a storage rack intended specifically for test tubes. It incorporates a base unit and a cooperating cover unit, both made of vacuum-formed thermoplastic such as polypropylene, in which the base unit is a one-piece deep-drawn bucket shape having at its bottom a plurality of evenly spaced tetrahedron-shaped wells, each adapted to receive and support an individual test tube. A drain opening is provided at the bottom of each well to permit condensate to escape.
Korum U.S. Pat. No. 4,284,603 (Aug. 18, 1981) discloses a three-piece test tube rack, open at the sides, in which the component parts may be stored separately and then snapped together for use. The top component has clear-through openings allowing the test tubes to be inserted; the middle component has corresponding clear-through openings for center support; and the base component has semi-closed wells instead of clear-through openings to prevent the test tubes from falling out while still allowing drainage. The base and cover are therefore of necessity not identical, although the specification suggests that the base and cover can be produced using the same mold (col. 3, lines 1-3). Clearly a separate supply of both tops and bases would have to be kept on hand in order to use the device at all, which is a problem solved by the present invention.
Mehra U.S. Pat. No. 4,588,095 (May 13, 1986) shows a complex one-piece injection molded test tube rack having perforated wells at the bottom, and grids for the middle and top supports. The claimed invention resides in the device as a single integral piece, distinguishing it from multi-component units which allow compact nested storage prior to assembly for use, as with the present invention.


A microphone support and enclosing windscreen has microphone supports curving about 270 degrees about an axis with upper and lower fingers to grip the microphone above and below the longitudinal axis of the microphone. The microphone supports move along an upper rail of a connector. First and second cage portions have longitudinal ribs connected to circular rings forming a windscreen support, with base rings on each cage portion connected to a bracket to encircle the microphone and its supports during use. One of the cage portions moves along the connector and rotates to allow access to the microphone.

Various structures have been provided to support microphones in ways that reduce the sensitivity of the microphone to vibrations and motion. But these prior art devices make it difficult to fasten the microphones to the support and inadequately reduce vibration which can distort microphone signals and cause other undesirable audio distortions and noises. There is thus a need for an improved microphone mount that allows easy and fast insertion and removal of the microphone and that deadens or reduces the sound transmission through the microphone support resulting from movement of the microphone or any windscreen enclosing the microphone.
Microphones come in different sizes and lengths. Unfortunately, may existing microphone supports have fixed dimensions so that a microphone is supported at one location and thus rotates or swings with movement of the support, causing distortion of the audio signal from the microphone and inadequate support of the microphone. Supports that grip the microphone body at more than one location are difficult to use, take time to insert the microphone into the supports and are often bulky—resulting in large windscreens to enclose the microphone and supports. There is thus a need for a microphone support and enclosure that more readily accommodates different microphones and that provides a stable support for microphones of various size and length.
Microphones used in sound recording studios are often so sensitive such that air from ventilation vents, wind and even mild breezes can cause noises that are picked up by the microphones or that distort recorded audio signals. Enclosing the microphones in casings reduces wind noise and distortion, but reduces microphone sensitivity. Further, the microphones are often used on long booms and the enclosures are heavy and difficult to maneuver or to fasten in position during sound recordings. There is thus a need for a lightweight windscreen that reduces wind noise and is easy to position and fasten in place.
Microphone windscreens are often glued together or held together by elastic bands. Over time the glued joints loosen and the rubber bands deteriorate so the windscreens become loose and creak when moved slightly as by wind blowing against the windscreens. The resulting noises are picked up by microphones enclosed in the windscreen or held in the supports, and that degrades the sound performance of the microphone. There is thus a need for a windscreen and support that reduces or avoids these problems.
Microphones may be placed in protective structures to protect the microphone and to shield the microphone from wind-generated noise. But such protective structures are often heavy and costly, and may even block or distort the acoustic signals the microphone is to detect. There is thus a need for an improved microphone enclosure that is lightweight yet strong and that is easy to manufacture.
Microphone supports and windscreens are often subjected to harsh use, varying from being dropped, hit with things, hit by animals, or having some or all of the windscreen crushed by various objects, animals or accidents. It is expensive to replace a windscreen or support each time it is damaged. There is thus a need for an improved microphone support and windscreen that allows fast repair and/or partial replacement of portions of the support or windscreen.
In addition to the above deficiencies, existing microphone enclosures are cumbersome to apply to the microphones and make it difficult to switch or adjust microphones placed within such disclosures. It is difficult to fit microphones into the supports and to then place the supports inside a windscreen. Thus, changing microphones becomes difficult and time consuming. There is thus a need for a microphone enclosure that allows easy access to microphones placed within the enclosures.

Microphone mounting method and apparatus