An integrated circuit includes a terminal which is accessible externally of the integrated circuit, and circuitry (LOB) coupled to said terminal and operable to latch at said terminal a signal applied to said terminal by a source (ICT) external to said integrated circuit.

Today boundary scan design in integrated circuits (ICs) is based on an IEEE standard referred to as 1149.1. In 1149.1, flip flops and/or latches, referred to from this point forward as memories, form the boundary scan cells at the IC input, output and bi-directional pins. These boundary scan cell memories are required to be dedicated for test operation. This means that the memories cannot be used functionally by the IC when testing is not being performed. In some ICs, it is technically advantageous to be able to use the memories functionally when the IC is in normal mode, then reuse the memories for test purposes when the IC is placed in a boundary scan test mode. Reuse of memories for function and test purposes is a common practice in internal scan design of ICs. However, 1149.1 boundary scan differs from internal scan in that it requires scan access of the IC's boundary while the IC is in normal mode. Therefore the memories of the boundary scan cells must be available for scanning at all times, forcing them to be dedicated test circuits.
The reason for the aforementioned full time scan access requirement of IEEE STD 1149.1 is two-fold. First, allowing the boundary scan path to be accessed during normal IC operation provides a way to take an on-line sample of the IC's inputs and outputs during normal operation. Second, allowing the boundary scan path to be accessed during normal IC operation provides a way to preload boundary scan memories with test data prior to entering the boundary scan test mode. Of these two requirements, preloading is the most important because it allows initializing the boundary scan cells at IC output pins with safe test data prior to switching the IC into boundary scan test mode.
Sampling has not proven to be a valuable test feature, due to problems of synchronizing the sampling with normal IC operation. Due to the ineffectiveness of sampling, it may become an optional 1149.1 test feature instead of a required test feature. If sampling were made optional, it would be possible to share memories between boundary scan cells and IC functional circuitry. However, if shared memories are used in the absence of the sampling requirement, establishing safe test data in output boundary scan cells to meet the preload requirement would be difficult since sharing of the boundary scan cell memories inhibits scan access during normal IC operation.
Another requirement for 1149.1 boundary scan cells is to control output pins to a predetermined logic condition during scan operations. To achieve this, prior art output boundary scan cells utilized two memories. The first memory is used for capturing and shifting data through the cell, and the second memory is used for holding stable test data at the output pin while the first memory captures and shifts. If the sampling operation, described above, is made optional, the first memory can be shared with functional logic. However, the second memory will be required and dedicated for test to maintain stable data from the output pin while the first shared memory captures and shifts data.
A new boundary scan standard proposal currently in development, referred to as IEEE P1149.2, is based on allowing first memories (capture/shift memory) of boundary scan cells to be either shared for functional and test purposes or dedicated for test. Also, P1149.2 makes the use of second memories (output hold memory) optional. P1149.2 thus permits an output boundary cell which contains only a shared capture/shift memory. Use of such an output boundary scan cell minimizes test logic, but the IC output pin controlled by such a cell would ripple during capture and shift operations of the shared capture/shift memory. The ripple effect on output pins during capture and shift operations can cause problems during boundary test, such as corruption of the test by rippling test data at the inputs of ICs which do not themselves implement boundary scan, causing them to enter into unknown and potentially dangerous states. For example, if output ripple were to occur from the outputs of a boundary scan IC to the inputs of an non-boundary scan IC, the non-boundary scan IC could respond to the rippling inputs (on say its clock, reset and/or enable pins) to enter into an undesired state. The undesired state could damage the IC or other ICs it is connected to. Furthermore, rippling outputs prevent full control of non-boundary scan ICs during test, and therefore limit what can and cannot be tested.
Since P1149.2 allows sharing of the capture/shift memory, scanning of capture/shift memories to preload test data to optional output hold memories prior to entering boundary scan test mode is not a required feature. In P1149.2, the IC can be simply switched from functional mode into test mode, and P1149.2 assumes that the functional data stored in the shared capture/shift memories of IC output boundary cells at the time of the switch will be safe test data to initially output from the IC. This means that an IC output boundary cell which uses only a shared capture/shift memory will initially output, in test mode, the logic condition previously being output in functional mode. Since the functional outputs from an IC will be unknown at the time of the switch to test mode, unknown test data will be output.
If, for example, a short to ground exists on an output pin when the switch to test mode occurs, and a logic one is stored in the shared capture/shift memory when the switch occurs, the output buffer will attempt to drive a logic one over the ground short. If multiple outputs are shorted to themselves, to ground or to the supply voltage, and shared capture/shift memories attempt to drive out competing voltage levels when switched into test mode, the IC outputs and/or IC itself could be damaged by excessive current flow. A similar problem would exist with P1149.2 output boundary cells that use the optional output hold memory in combination with a shared capture/shift memory, since the output hold memory cannot be preloaded with safe test data. So while P1149.2 may provide a fairly safe way to enter test mode without having to scan (preload) the output cells with test data, the test mode entry method is not safe when IC output pins are subjected to being shorted to ground, supply voltage, or to other pins. Thus, neither 1149.1 or P1149.2 provides a solution to resolving voltage contention problems that can occur at IC outputs when the IC is switched from functional to test mode.
FIGS. 1 and 2 illustrate two exemplary IC functional architectures that will be used to facilitate description of the prior art and the present invention. The IC example in FIG. 1 has an input and a 2-state output and the IC example in FIG. 2 has an input and a 3-state output. During functional operation of the ICs, input data passes through an input buffer (IB) 11 and is stored in a functional input memory (FIM) 13, for example, a latch. The output of the FIM is input to the IC's functional core logic (FCL) 15. The functional core logic outputs data to be stored in a functional output memory (FOM) 17, for example, a latch, and output from the IC via an output buffer (OB) 19 in FIG. 1 or via a 3-state output buffer (3SOB) 21 in FIG. 2. Data is stored in the FIM and FOM(s) by control output 23 from the functional core logic. The only difference between the two ICs is that the FCL of FIG. 2 outputs control 25 to a FOM 27 to enable or disable the IC's 3-state output buffer. Use of FIMs and FOMs at IC inputs and outputs is beneficial in high speed IC architectures, due to the synchronizing or pipelining effect they provide for rapid IC data input and output movement. Also FIMs and FOMs can be positioned physically close to the input and output buffers, respectively, reducing input and output time delays. Because the FIM 13 is interposed between the IB 11 and the FCL 15, the IB does not directly drive the FCL. The FIM does not have the same drive capability as IB, so it is often necessary to provide between FIM and FCL a high-drive buffer (not shown) capable of providing the input drive required by FCL.
FIG. 11 is similar to FIGS. 1-2 and shows an IC which uses functional input and output memories (FIMs & FOMs) to store data and control flowing between the functional core logic (FCL) and input (I), output (O), and input/output (I/O) pins. The FIMs receive data from the input buffers and update control (UC) from the FCL to store the data. The FIMs output the stored data to the FCL. The FOMs receive data or control from the FCL and UC from the FCL to store the data or control. The FOMs output stored data or control to the output buffers. A single FOM outputs data to 2-state output buffers (2SOB) and two FOMs output data and control to 3-state output buffers (3SOB). While individual input, output, and I/O pins are shown, it should be understood that multiple input, output, and I/O pins could be used on the IC to form a bussed arrangement of input, output, and I/O pins.
It is important to note the following in FIGS. 1-2 and 11; (1) each FIM and FOM is a complete memory element requiring circuitry for receiving data, circuitry for storing data in response to UC, and circuitry for outputting stored data, (2) each FIM and FOM introduces a delay in the data path due to its required circuitry, (3) each FOM continuously drives the output buffer and the output pin with the data stored, even if the output pin is shorted to an opposing voltage data level, such as ground or supply.
FIGS. 3 and 4 illustrate the IC architectures of FIGS. 1 and 2 when test logic for 1149.1 boundary scan is implemented therein. On IC inputs, an input boundary cell (IBC) 29 is connected to the output of the input buffer (at "A"). On 2-state IC outputs (FIG. 3), an output boundary cell (OBC) 31 is inserted in series with the data path between the FOM 17 and the 2-state output buffer (at "B" & "C"). On 3-state IC outputs (FIG. 4), an OBC 31 is inserted in series with the data path between the FOM 17 and 3-state output buffer (3SOB), and another OBC 31 is inserted in series with the control path between the FOM 27 and 3-state output buffer enable input. Examples of the IBC and OBC test logic are respectively shown in FIGS. 3A and 3B. The IBC and OBC(s) are connected serially from a serial input pin of the IC to a serial output pin of the IC to allow data to be shifted through the cells. The cells receive control via control bus 33 from a test port (TP) 35 to control their operation. It is important to note with respect to FIG. 4 that a single control path OBC can control a group of data path OBCs that form a functional 3-state bus, i.e. 1149.1 does not require that each 3-state output pin of a bus have its own control cell.
The IBC 29 of FIG. 3A contains an input multiplexer (Mux1) and a capture/shift memory (Mem1). Mux1 is controlled by the TP to input either serial data input (SI) or system data input (A) to Mem1. Mem1 loads data in response to TP control. The output of Mem1 is output as serial output (SO) data. The OBC 31 of FIG. 3B contains an input multiplexer (Mux1), a capture/shift memory (Mem1), an output hold memory (Mem2), and an output multiplexer (Mux2). Mux1 is controlled by the TP to input either serial data input (SI) or system data input (B) to Mem1. Mem1 loads data in response to TP control. The output of Mem1 is input to Mem2 and also output as serial output (SO) data. Mem2 loads data from Mem1 in response to TP control. Mux2 is controlled by the TP to output either data from Mem2 or system data (B) to the output buffer (C). The 1149.1 standard requires that the logic of IBCs and OBCs be dedicated for testing and not reused functionally by the IC.
The OBC differs from the IBC because 1149.1 boundary scan requires that the IC outputs be able to be controlled to a predetermined output logic condition, while data is captured into and shifted through the OBC. The reason for this requirement is to prevent connected IC inputs from receiving the data ripple effect that would occur from IC outputs during the capture and shift operations. This requirement forces the OBC to have two memories, a first memory (Mem1) for capturing and shifting data, and a second memory (Mem2) for maintaining the IC output pin at a desired logic condition (logic one, zero or tristate) while data is captured and shifted by the first memory. It is important to note that the OBC's Mux2 introduces a delay in both the data and control paths between the FOMs and 2-state/3-state output buffers, which can adversely impact IC performance.
The 1149.1 standard requires two types of test operations for boundary scan cells, a sample and preload operation (Sample/Preload) and an external test operation (Extest). The sample part of Sample/Preload allows the Mux1 and Mem1 of IBC and OBC to be controlled by the TP to capture and shift out system data while the IC is in normal operation. The preload part of Sample/Preload allows the TP to shift data into Mem1 of OBCs and update the data into Mem2 of OBCs, while the IC is in normal operation. The ability to preload Mem2 of OBCs before the IC is placed in Extest is important because it allows establishing what test data will be output from the IC when the IC enters Extest mode, i.e. when Mux2 of OBCs is switched from outputting system data (B) to outputting data from Mem2. Without the ability to preload Mem2, potentially damaging test data could be output from the IC when it is switched from normal to Extest operation.
When the IC is placed in Extest, Mux2 of OBC is controlled by the TP to output test data stored in Mem2 to the output buffer. In FIG. 3, the test data output from OB 19 when Extest is entered is either a logic one or zero. In FIG. 4, the test data output from 3SOB 21 when Extest is entered is either logic one, logic zero, or tristate. During Extest, OBCs are operated by the TP to shift in and update test data to IC outputs to tristate the output or drive logic levels onto wiring interconnects, and IBCs are operated by the TP to capture and shift out test data arriving at IC inputs from wiring interconnects. In this way, Extest is used to test wiring interconnects between IC inputs and outputs on, for example, a printed wiring board. The operation of both these 1149.1 test operations is well known by workers in boundary scan testing.
The usefulness of the sample part of the Sample/Preload operation is limited because it is difficult to synchronize the capture operation of the IBC's and OBC's Mem1 with the functional data arriving at and departing from the IC's inputs and outputs, respectively. This is because the IBC and OBC(s) are controlled by timing from the TP, and the FIM and FOM(s) are controlled by the timing from the functional core logic. As a result, the sample part of the Sample/Preload operation may become an optional boundary scan test feature in 1149.1, whereas now it is a required test feature. If the sample part of Sample/Preload is made optional, then the FIM and FOM(s) of the ICs in FIGS. 3 and 4 could serve as the Mem1 of the IBC and OBC(s), respectively, when the IC is placed in Extest mode.
FIGS. 5 and 6 illustrate boundary scan designs where the sample feature is omitted, enabling the FIM and FOM(s) to serve as functional memories during normal IC operation and boundary cell capture/shift memories (Mem1) during test operation. This reduces the boundary scan test logic overhead at input pins by one memory, overhead at 2-state output pins (FIG. 5) by one memory, and overhead at 3-state output pins (FIG. 6) by two memories. To use the FIM and FOM as functional and test memories, the control 37 to each must be switchable to allow the FIM and FOM to operate in response to control 23 from the functional core logic during normal operation, and in response to control from TP during test operation. To achieve this, a control multiplexing (CMX) circuit is shown in FIGS. 5 and 6 to allow switching of control between test and normal operations. The CMX circuit allows control from the functional core logic or control from the TP to be globally distributed to each FIM and FOM. Control to switch the CMX comes from the TP.
In FIGS. 5 and 6, it is seen that, when using shared FIMs, the IBC function is implemented with only Mux 1 required as dedicated test circuitry. In FIGS. 5 and 6, it is seen that, when using shared FOMs, the OBC function is implemented with only Mux1, Mem2 and Mux2 as dedicated test circuitry. The Mem2 and Mux2 (M&M) circuitry 41 is shown in FIG. 5A. It is important to note that Mem2 and Mux2 (M&M) must still be inserted between the shared FOM and output buffer (at "B1" and "C"). Also it is important to note that the Mux2 delay on the data and control paths is maintained in the boundary scan designs of FIGS. 5 and 6, which adversely impacts IC performance.
Although it is possible to share a functional memory with the Mem2 function, to do this would require at least one additional multiplexer and additional wire routing to enable a memory inside the FCL to be coupled to Mux2 and the shared FOM (17 or 27).
A problem with the boundary scan designs of FIGS. 5 and 6 is that there is no way to preload Mem2 by scanning data into Mem1 as previously described for the boundary scan designs of FIGS. 3 and 4. This is because the shared FOM (Mem1) is used functionally by the IC and therefore cannot be scanned by the TP to input safe test data to upload into Mem2. Thus when the IC is initially placed into Extest, Mux2 is switched to output unknown test data from Mem2 to the 2-state output buffer of FIG. 5 and 3-state output buffer of FIG. 6. This unknown test data may cause the output buffers to output conditions that might damage other circuits or output buffers when Extest is entered. So while the shared boundary scan design of FIGS. 5 and 6 does reduce the test logic overhead at IC input and output pins, it is not able to initially enter Extest with safe test conditions being output from the IC. After Extest is entered, and following the first scan operation to the IBC and OBC(s), the Mem2 at output pins is uploaded with safe test data from the shared Mem1 memory. However, the period of time between the initial entry into Extest and the updating of safe test data into Mem2 provides an opportunity for circuitry and/or buffer damage.
The boundary scan cells of FIGS. 5 and 6 are similar to those proposed in the P1149.2 boundary scan standard, in that Mem1 is shared with a functional memory (FOM). In P1149.2, the M&M circuitry in the data path of FIGS. 5 and 6 between the shared Mem1 17 and 2-state or 3-state output buffer can be optionally deleted, allowing the output of the shared Mem1 17 to be directly input to the 2-state or 3-state output buffer, as shown in FIGS. 5B and 6A. However, P1149.2, like 1149.1, requires that the M&M circuitry be placed in series between the output of the shared Mem1 27 and the 3-state control input of the 3-state output buffer 3SOB. The requirement to place the M&M circuitry in the control path allows the 3-state output to be controlled to either a 3-state or enabled condition while data is captured and shifted through the shared Mem1 27 of the control path. However, with the M&M circuitry optionally deleted from the data paths of 2-state and 3-state outputs, the data from these pins, assuming the 3-state output is enabled (which it must be to permit updating test data to the output pin during Extest), will ripple as data is captured and shifted through the shared Mem1s 17 of the data path. As mentioned previously, the rippling of data outputs during capture and shift operations can cause damage to ICs and/or limit what can and cannot be tested.
With the growing interest in sharing memories between functional and boundary scan circuits, and with the above-described problems associated with shared memories, a need has arisen for improved OBCs for 2-state and 3-state output buffers. The present invention provides a boundary scan cell including a shared capture/shift memory, and an output buffer structure which provides the ability to; (1) establish safe test data at IC outputs when the IC is switched from functional mode to boundary test mode without first having to scan safe test data in, (2) quickly resolve voltage contention problems at IC output pins due to shorts between pins, ground or supply voltage, and (3) maintain stable test data at output pins while data is captured and shifted through shared capture/shift memories, without having to use an output hold memory.
The boundary scan cell of the present invention requires very low overhead when used on 2-state and 3-state type IC output pins.
It is also desirable to: reduce circuitry overhead associated with conventional FIM and FOM structures; eliminate the need for high-drive buffers between FIMs and FCL; provide a FOM structure capable of resolving voltage contention at the output pin; reduce signal path delays associated with conventional FIM and FOM structures; and reduce signal path delays associated with conventional combinations of FIM/FOM structures and boundary scan cells. To this end, the present invention realizes the FIM function by combining the input buffer with a feedback circuit and a switch, and realizes the FOM function by combining the output buffer with a feedback circuit and a switch. The invention also realizes the FIM and FOM functions using switches and bus holder circuits. The invention also combines boundary scan structures with the aforementioned FIM and FOM functions to provide boundary scan operation without speed penalty to functional operation.

Low overhead memory designs for IC terminals


An electrical connector includes a base and an elastic terminal. The base has a recess. The elastic terminal is connected to the base and extends to the recess. The elastic terminal has a fixed end and a free end, the fixed end is connected to the base, and the free end is located at the recess and is curved. When the contact moves towards the recess, the contact is capable of pushing the contact protrusion to bend towards the bottom of the recess so that the free end leans against the bottom of the recess. The electrical connector may further include a contact protrusion connected to the elastic terminal. When the contact moves towards the recess, the contact is capable of pushing the contact protrusion to make the elastic terminal bend towards the bottom portion of the recess so that the free end leans against the bottom of the recess.

1. Field of the Invention
The invention generally relates to an electrical connector, and more particularly, to an electrical connector suitable for contacting contacts (such as flat contacts or the bump contacts).
2. Description of Related Art
Usually, an electrical connector is used for electrical connection between two electronic apparatuses for transmitting signals or supplying power. In the technical field of semiconductor chip packaging, a so-called land grid array (LGA) is a type of high-density contacts used in a circuit carrier, where a plurality of flat contact arrays are arranged on the bottom-surface of the circuit carrier, and the flat contacts can be electrically connected to each other via the internal circuit in the circuit carrier and the integrated circuit (IC) chip mounted on the top surface of the circuit carrier.
In order to mount an LGA-type circuit carrier to a circuit board, in the prior art, a plurality of upward-bent elastic terminals are disposed on a base so as to respectively contact a plurality of flat pads of the circuit carrier in downward moving to realize the electrical connection between the circuit carrier and the electrical connectors. To ensure the contact between the elastic terminals and the flat contacts, the elastic terminal must have a shape required by producing a certain elastic force and the end of the elastic terminal must have an arc shape for contacting the flat pad, and thus, the elastic terminal must be bent upwards by using a machining process.


The present invention aims to reduce exposure at a helical scan in an X-ray CT apparatus using an X-ray area detector typified by a multi-row X-ray detector or a flat panel. When the angle of an X-ray cone beam spread in a z direction is assumed to be Acone, a scanning gantry is tilted by Acone/2 to start X-ray irradiation/data acquisition of the helical scan, after which the X-ray irradiation/data acquisition is completed at the number of revolutions corresponding to “integral number n+0.5”.

The present invention relates to an X-ray CT (Computed Tomography) apparatus and an X-ray CT imaging method, and more specifically to an X-ray CT apparatus and an X-ray CT imaging method both having no needless X-ray irradiation and capable of reducing an exposure range of a subject at a helical scan (including a variable pitch helical scan or a variable speed helical scan).
There has heretofore been known an X-ray CT apparatus wherein when a helical scan is performed, a collimator located on the front side as viewed in a linearly-moved direction of the helical scan restricts the position of an end surface of an X-ray cone beam on the front side as viewed in the linearly-moved direction at the start of X-ray irradiation in order to prevent exposure of the front side as viewed in the linearly-moved direction rather than a linearly-moved range in which one desires to collect projection data, and the collimator located on the rear side as viewed in the linearly-moved direction restricts the position of an end surface of the X-ray cone beam on the rear side as viewed in the linearly-moved direction at the completion of the X-ray irradiation in order to prevent exposure of the rear side as viewed in the linearly-moved direction rather than the linearly-moved range in which one desires to collect the projection data (refer to, for example, a patent document 1).
[Patent Document 1] Japanese Patent Publication Laid-Open No. 2002-320609
In the conventional X-ray CT apparatus, an X-ray spread to the front side as viewed in the linearly-moved direction rather than the linearly-moved range in which one desires to collect the projection data, is shielded or blocked by the collimator, and an X-ray spread to the rear side as viewed in the linearly-moved direction rather than the linearly-moved range in which one desires to collect the projection data, is shielded by the collimator, thus reducing an exposure range of a subject at the helical scan.
However, a problem arises in that the X-ray at each shielded portion results in needless X-ray irradiation. It is also difficult to perform the collimator control with satisfactory accuracy by real-time control. There is a possibility that an error in X-ray irradiation will occur due to a control error. Hence problems associated with image quality and needless exposure have arisen.

X-ray CT apparatus and X-ray CT imaging method

GE Medical Systems Global Technology Company, LLC


A stroke adjusting device for removing eccentric instability in an mechanical rotary system. The stroke adjusting device includes an adjustable rotation balancing weight adjustable about an eccentric bushing positioned on an eccentric shaft. The adjustable rotation balancing weight includes a weight portion adaptable to counteract the instability of the mechanical rotation system, thus minimizing vibration. A hydraulic system enables simple adjustment of the stroke adjusting device.

1. Field of the Invention
The present invention relates to a slide stroke adjusting device equipped to minimize the vibration in the rotation system of a press machine.
2. Description of the Related Art
A conventional device for adjusting the stroke of a slide for a press machine is disclosed in Japanese laid-open Utility Model Publication 7-26099.
Referring now to FIGS. 4A and 4B, showing a large end of a connecting rod 11 of a press machine (not shown). A small end of connecting rod 11 is connected with a slide of the press machine (not shown).
A liner 11A is affixed on the inside of the large end part of connecting rod 11. An eccentric bushing 2 is slidably and rotatably connected through liner 11A to connecting rod 11. An eccentric part 1A, of an eccentric shaft 1, connects and joins by an interference fit to eccentric bushing 2. A groove 5 is provided on one side of eccentric bushing 2. Groove 5 receives a fixing rod 6 movable in parallel with the axial direction of eccentric shaft 1. In other words, groove 5 and fixing rod 6 act as a fixing means to fix eccentric bushing 2 relative to connecting rod 11.
An internal gear and a hub 3 are positioned on eccentric bushing 2 opposite groove 5. Internal gear is affixed to eccentric bushing 2. Hub 3 is movable in an axial direction about eccentric shaft 1. A teeth space 7A, is formed on the outer perimeter surface of hub 3. Teeth space 7A meshes with inner teeth (not shown) of internal gear 7. Further, a collar 9 formed on eccentric shaft 1. Collar 9 acts to restrict the movement o hub 3 away from internal gear 7 and eccentric bushing 2.
A coupling body 10 is movable in the axial direction of eccentric shaft 1, away from hub 3. Coupling body 10 contacts and pushes the side surface of hub 3, to mesh the teeth (not shown) formed on the outer perimeter surface of hub 3, with the inner teeth (not show n) of internal gear 7.
An oil passage 4, through eccentric shaft 1 helps release the interference fit of eccentric part 1A with eccentric bushing 2. Pressurized oil, provided through oil passage 4 to an opening (not shown), contacts the inner surface of eccentric bushing 2. A packing 2A and a packing 2B are formed about the outer perimeter surface of eccentric part 1A where eccentric part 1A joins eccentric bushing 2. Under some conventional constructions, packing 2A and packing 2B are omitted.
A packing 3A and 3B are positioned on the inner perimeter surfaces of hub 3 where hub 3 contacts the outer perimeters of eccentric part 1A and eccentric shaft 1. An oil passage 8, is formed through eccentric shaft 1 to a surface of eccentric part 1A opposite hub 3. Oil passage 8 allows the passage of pressurized oil to urge hub 3 outward away from eccentric part 1A.
During stroke adjustment operations, fixing rod 6 is placed in groove 5, to fix the rotation of eccentric bushing 2. Pressurized oil next passes through oil passage 8. Hub 3 moves outward from eccentric part 1A toward collar 9. As a result, hub 3 no longer meshes with internal gear 7. Pressurized oil then passes through oil passage 4. Eccentric bushing 2 is partially elastically deformed. As a result, the interference fit of eccentric part 1A is released, and eccentric shaft 1 rotates to adjust the amount of eccentricity relative to eccentric bushing 2.
Referring to FIG. 4B, the top-dead center position places an eccentricity P, of eccentric part 1A with respect to eccentric shaft 1, in the position shown. The top-dead center position further places an eccentricity Q, of eccentric bushing 2 with respect to eccentric part 1A, in the position shown. Thus, a maximum stroke length is 2xc3x97(P+Q). Further, a minimum stroke length is 2xc3x97(Qxe2x88x92P).
After stroke adjustment, pressurized oil in oil passage 4 and oil passage 8 is released. The shape of eccentric bushing 2 is elastically reformed. The interference fit with eccentric part 1A re-engages. Coupling body 10 presses against hub 3 and meshes the outer perimeter teeth of hub 3 to the inner teeth of internal gear 7. Fixing rod 6 is withdrawn from groove 5, and coupling body 10 is withdrawn from hub 3 and placed on standby in a non-interfering area.
Using the described stroke adjustment process, the stroke of connecting rod 11 is adjusted. The stroke adjustment conforms to the pitch of the inner teeth of internal gear 7. Contact provided by meshing internal gear 7 with hub 3, transfers torque from eccentric part 1A to eccentric bushing 2. Torque is then transferred from eccentric bushing 2 to connecting rod 11.
Negative results arise when using the above type of conventional stroke adjustment. Under rapid stroke rate, or an increasing stroke rate, the multiple eccentric members rotate rapidly. Thus, internal centrifugal and centripetal forces result in vibration, heat, wear, shorter equipment life span, and increased maintenance costs and operation down-time.
It is an object of the invention to provide a stroke adjustment device for a press machine.
It is another object of the invention to provide a stroke adjustment device that minimizes the unbalance and vibration resulting from the rotation of conventional stroke adjusting devices.
It is another object of the invention to provide a stroke adjustment device that is adaptable to vary stroke adjustment positions.
It is another object of the present invention to provide a stroke adjustment device that both minimizes vibration from a press machine and adjusts simultaneously to stroke adjustments of the press machine.
It is another object of the present invention to provide a stroke adjustment device that is adaptable to a range of rotary systems requiring stroke adjustment and vibratory dampening.
Briefly stated, the present invention relates to a stroke adjusting device for removing instability in a mechanical rotation system. The stroke adjusting device includes an adjustable rotation balancing weight attached to an eccentric bushing positioned about an eccentric shaft. The adjustable rotation balancing weight contains a weight portion adaptable to counteract the instability of the eccentric mechanical rotation system thus minimizing vibration. A hydraulic system enables simple adjustment of the stroke adjusting device.
According to an embodiment of the present invention, there is provided a stroke adjusting rotation balancing device, comprising: an eccentric shaft portion, the eccentric shaft portion receiving a vibration from an external mechanical system, a rotation balancing eccentric bushing affixed about a first part of the eccentric shaft portion, a rotation balancing weight adjustably joined to the eccentric bushing, means for fixing the rotation balancing weight relative to the eccentric bushing, and means for adjusting the rotation balancing weight relative to the eccentric bushing and the eccentric shaft whereby the rotation balancing weight counteracts and dampens the vibration from the external mechanical system.
According to an embodiment of the present invention, there is provided a stroke adjusting and rotation balancing device, wherein: the means for adjusting includes a hydraulic circuit, and the hydraulic circuit supplying a hydraulic pressure to the eccentric bushing and the rotation balancing weight thereby allowing adjustment of the rotation balancing weight relative to the eccentric bushing to dampen the vibration.
According to an embodiment of the present invention, there is provided a stroke adjusting and rotation balancing device, wherein: the means for fixing includes a groove, the groove formed in the rotating balancing weight, the means for fixing further includes a fixing rod, the fixing rod extending from a fixed external position, and the fixing rod formed to fit into the groove, whereby the rotation balancing weight is prevented from rotation relative to the eccentric bushing thereby allowing adjustment of the rotation balancing weight relative to the eccentric bushing to dampen the vibration.
According to an embodiment of the present invention, there is provided a rotation balancing device for a press machine, comprising: a connecting rod having a large end, an eccentric bushing slidably and rotatably provided inside the large end, an eccentric shaft having a first and second side, an eccentric part formed on a first side of the eccentric shaft, the eccentric part adjustably fittable inside the eccentric bushing, the eccentric shaft receiving vibration during operation of the press machine, a rotation balancing eccentric bushing, the rotation balancing eccentric bushing affixed to a second side of the eccentric shaft, a rotation balancing weight, the rotation balancing weight adjustably joined to the rotation balancing eccentric bushing and formed to minimize vibration during operation of the press machine, means for fixing the rotation balancing weight during adjustment, and means for adjusting the rotation balancing weight relative to the rotation balancing eccentric bushing and the eccentric bushing relative to the eccentric part thereby minimizing vibration during operation of the press machine.
According to an embodiment of the present invention, there is provided a rotation balancing device for a press machine, wherein: the means for fixing includes a fixing rod affixed to an external member, the means for fixing includes a groove formed in the rotation balancing weight, and the fixing rod engagable with the groove during adjustment of the rotation balancing device thereby preventing rotation of the rotation balancing weight relative to the external member.
According to an embodiment of the present invention, there is provided a rotation balancing device for a press machine, wherein: the means for adjusting includes a first and a second hydraulic circuit, the first hydraulic circuit providing adjustment of the eccentric part relative to the eccentric bushing, the second hydraulic circuit providing adjustment of the rotation balancing eccentric bushing relative to the rotation balancing weight, and the first and second hydraulic circuits being supplied simultaneously whereby adjustment of the eccentric part and the rotation balancing eccentric bushing occur simultaneously.
According to an embodiment of the present invention there is provided a stroke adjusting device in a rotary system including a connecting rod, an eccentric bushing slidably and rotatably provided inside a first end of the connecting rod, and an eccentric shaft in which an eccentric part is joined to the eccentric bushing by an adjustable fit, the stroke adjusting device comprising: a rotation balancing eccentric bushing affixed to the eccentric shaft, a rotation balancing weight fitted to the rotation balancing eccentric bushing, the rotation balancing weight adjustable relative to the rotation balancing eccentric bushing, means for fixing the rotation balancing weight during adjustment, and a hydraulic circuit enabling the adjustment of the rotation balancing weight relative to the rotation balancing eccentric bushing whereby vibration is minimized in the rotary system.
According to an embodiment of the present invention there is provided a stroke adjusting device, wherein: the hydraulic circuit enables simultaneous adjustment of the eccentric part relative to the eccentric bushing and the rotation balancing weight relative to the rotation balancing eccentric bushing.
According to an embodiment of the present invention there is provided a stroke adjusting device, wherein: the means for fixing includes a groove portion formed on the rotation balancing weight, and a fixing rod member affixed to an external member and insertable into the groove portion to restrain rotation of the rotation balancing weight relative the eccentric shaft.
Furthermore, when conducting the operation of stroke adjustment, the interference fit of the eccentric part and the eccentric bushing is released. In the present embodiment, in addition to the interference fit of the eccentric part and the eccentric bushing, the interference fit of the rotation balancing eccentric bushing and the rotation balancing weight is release-able and adjustable. Thus, when the eccentric shaft is rotated in order to adjust the stroke, together with the rotation of the eccentric part, the rotation balancing eccentric bushing is also rotated, and the eccentricity of the rotation balancing weight changes and vibration is damped.
As a result, the eccentricity of the rotation balancing weight can be changed according to the change in eccentricity of the eccentric bushing. Therefore, regardless of the various stroke amounts, the vibration or unbalance in the rotation system may always be minimized.
In the invention according to the present embodiment, the oil pressure circuit that releases the interference fit of the eccentric bushing and the eccentric part and the oil pressure circuit that releases the interference fit of the rotation balancing eccentric bushing and the rotation balancing weight operate in common. As a result, adjustment is simplified and the time consumed in the adjustment procedure is minimized thereby minimizing costs.
The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.

Stroke adjusting device for press machine


A storage device including an information structure produced by a method comprising: determining unique cluster names during a time interval; creating, in a storage device, one or more relationship tables, wherein for each unique cluster name, creating one or more relationship tables includes, creating one or more pairings that each includes an individual object identifier member of a cluster corresponding to the unique cluster name and includes a produced association score for the individual object identifier member, and wherein for each unique cluster name, creating one or more relationship tables includes creating a relationship between a unique key name that matches the unique cluster name and each of the one or more pairings created for the unique cluster name; and repeating the acts of determining and updating at selectable time intervals.

The Internet provides a communication network over which persons can exchange information using a wide variety of different devices. For example, a user may own a smartphone, a mobile tablet, a laptop computer. And a family of users can own a connected TV. As users work, socialize, research, and buy products across different Internet connectable devices, companies will continue to shift focus to reaching users and families more effectively across their multiple devices. Although a person may own and use different devices to communicate over the Internet, the relationship among different devices and users of the different devices is not readily apparent to outsiders such as companies seeking to understand and reach the person across his or her multiple devices.
A person may use different devices with different device identifiers, through network connection points associated with different network addresses, to communicate over the Internet. A person may communicate anonymously over the Internet without disclosing a personal identifier. A user may have multiple different email accounts and may participate in use of social media under different pseudonyms. Thus, there is no readily available solution to identify users using different devices accessing the Internet.
Similarly, a family online activity involves many different personal devices and shared devices, with a wide range of access points, different email accounts, and social media handles. There is no readily available solution to identify and analyze user-user, users-family relationship using different devices accessing the Internet.

Probabilistically generated identity database system and method


An emergency signaling or diagnostic device (10), particularly with an ECG signaling device (11, 11xe2x80x2) embedded within a wallet (35) for signaling a health condition of an owner of the device. The wallet (35) may have embedded therein functions (40) of a cellular telephone and may include a vocalizing unit (16) for producing an acoustic signal representative of the owner""s ECG.

This invention relates to portable electronic instruments for personal use and, in particular, to so-called Personal Emergency Response Systems.
It is known that certain people are particularly vulnerable to attack or seizure such as, for example, the elderly and infirm. To this end, it is also known to provide such people with panic alarm devices so that at the onset of an attack, in whatever form that might be, or even in the event of imminent risk thereof, the panic alarm device may be manually operated so as call for help in time of need and inform a central monitoring unit. Upon receipt of a panic signal, the central monitoring unit may then take appropriate action. Panic alarm devices are, therefore, an important component in the arsenal of those who are vulnerable, thereby providing them with greater security and self-confidence.
Typically, such panic alarms include a manually operated r.f. transmitter energized by a miniature hearing-aid type battery and which, when operated, sends an encoded signal characteristic of the user. By such means, a remote monitoring unit, upon receiving the encoded signal, knows from where the signal emanated. Most simply, the coding can be by way of modulating an r.f. signal with data representative of the user""s personal code so that the received signal is indicative of the sender. A problem associated with such devices is their accessibility. It clearly defeats the whole object of the device if, at a moment of panic, the device is not readily accessible for actuation and precious time must be wasted in locating it. To this end, such devices are commonly worn as a pendant around the owner""s neck, which is liable to be both obtrusive and cumbersome.
It has also been proposed to provide such panic alarms in a wrist-mounted casing including a conventional watch movement, so that the device can double as both a conventional watch and a panic alarm. By such means, the same device serves two functions, thereby increasing its convenience and rendering the panic alarm function completely unobtrusive. In such a device, communication with the remote monitoring unit is effected via the telephone line and, to this end, there must be provided a base unit connected to the telephone line for effecting wireless communication with the portable device. This is acceptable when the patient is house-bound but is obviously unsuitable for those patients who are generally free to live normal lives but must nevertheless have ready access to the remote monitoring unit in case of emergency.
Upon effecting communication with the monitoring unit, a patient is frequently required to undertake an interactive dialog with medical personnel at the monitoring unit so as to enable the medical personnel to diagnose the patient""s medical symptoms. Since many of those who are particularly at risk suffer from heart-disease, an ECG is usually one of the first tests which should be carried out. To this end, much effort has been directed to the provision of portable instruments for allowing a patient to carry out an ECG on himself. At their most rudimentary, such instruments comprises a pair of electrodes which are held against a patient""s body, usually near his chest to detect an electrical voltage indicative of the electrical activity of the heart. The resulting current waveform response permits partial determination of the patient""s cardiac health. A more detailed determination may be realized by using more than two electrodes and portable devices are known having, for example, twelve electrodes mounted on a common carrier and amenable to placement on a patient""s chest area by the patient with minimum effort.
It will be appreciated that no less important than the technical suitability of such ECG transmitters, is that they must be instantly accessible in a moment of crisis. In the first instance, the required accessibility can only be realized by a portable device. However, experience indicates that this in itself is often not enough. Most people find it difficult to function and to preserve their mental health if they live in constant fear of their mortality. Particularly, those who have a history of heart disease or other serious illness can do without constant remainders that they might need to perform an instant ECG in the street or elsewhere remote from hospital or home. As a result, there are many who consign the thought to their sub-conscious and it is then but a small step to relegating it to their unconscious altogether.
Such a likelihood would be reduced if the ECG transmitter were not only portable but were so disguised as to be indistinguishable from an everyday item which, in any case, the patient would carry on his or her person. However, the prior art does not seem even to have addressed the problem associated with the almost wanton forgetfulness by the infirm, let alone propose a solution thereto.
This problem is solved in accordance with a broad aspect of the invention by means of an emergency signaling or diagnostic device integrally embedded within a wallet for signaling a health condition of an owner of the device.
According to a preferred embodiment, the emergency signaling or diagnostic device is an ECG transmitter having at least two electrodes sewn or otherwise fixed to a surface of the wallet and having controls accessible from inside the wallet. Such a wallet is provided with pockets for accommodating therein cash, credit cards and so on in known manner so that the patient who carries it is psychologically immune from the uncomfortable thought that anything medical is associated therewith.
In order to allow the patient to relay the ECG signal to a remote monitoring unit, a vocalizing unit may be provided for converting the ECG signal to a representative acoustic signal which can be sent over the telephone to the monitoring unit. Alternatively, the ECG signal may be modulated on to an r.f. carrier signal for direct transmission with the monitoring unit, thus not requiring that the patient be in ready access with a telephone.

Emergency signaling or diagnostic device


An optical characteristic measuring apparatus provided with an integrating sphere measures an optical characteristic of a sample based on an intensity of light from the sample. The apparatus includes the first illuminating system which diffusely illuminates the sample by projecting light to a specified region of the inner surface of the integrating sphere, the second illuminating system which projects light on the sample in such an angle that the light is specularly reflected by the sample to the light measuring system, a storage unit which stores weighting factors in connection with inclusion and exclusion of specular component in the reflection light from the sample, and a calculator which calculates an optical characteristic of the sample based on the measurement data and the weighting factors. The first and second illuminating systems are controlled to operate in a specified sequence.

This invention relates to an apparatus for measuring an optical characteristic of a sample using an integrating sphere, which is adopted in a spectral colorimeter.
In spectral calorimeters or optical characteristic measuring apparatus using an integrating sphere, there are cases of requiring both a spectral reflection coefficient including specular components from a sample (hereinafter, SCI spectral reflection coefficient) and a spectral reflection coefficient excluding specular components (hereinafter, SCE spectral reflection coefficient). For example, for computer color matching (CCM), the SCI data which are unlikely to be influenced by a surface state are often used. For color estimation, etc., the SCE data having a high correlation with visual sense are often used.
In a conventional d/8 optical system which diffusely illuminates a sample by an integrating sphere and receives a reflected light by a light receiving device disposed at 8.degree. with respect to a normal line to a sample surface, a trap aperture is formed at the position of a wall of the integrating sphere that corresponds to -8.degree. with respect to the normal line to the sample surface. This trap aperture is opened and closed to switch specular reflection light incident upon the light receiving device on and off.
FIG. 4 shows a conventional optical characteristic measuring apparatus. On an inner surface la of an integrating sphere 1 is applied with BaSO.sub.4 or the like material having a high diffusion coefficient and a high reflection coefficient. A beam of light from a light source 11 is introduced into the integrating sphere 1 through an aperture 16, undergoes a multiple reflection at the inner surface of the integrating sphere 1, and diffusely illuminates a sample 3 disposed at a sample aperture 2.
The light reflected by the sample 3 is introduced through an aperture 31 to a sample spectral device 30 via a receiving optical system 32. At the same time, a part of the light diffusely illuminating the sample 3 is taken by a light guide 41 and introduced to a monitoring spectral device 40. The reflection coefficient of the sample 3 is calculated based on the outputs of the sample spectral device 30 and the monitoring spectral device 40.
An optical axis 32a of the receiving optical system 32 is slanted by 8.degree. with respect to a normal line 2a of the surface of the sample 3 as shown in FIG. 4. On the other hand, a trap aperture 4a is formed at the position of a wall of the integrating sphere 1 which corresponds to a direction symmetrical to the optical axis 32a of the receiving optical system 32 with respect to the normal line 2a, i.e., along a direction at -8.degree. with respect to the normal line 2a. The trap aperture 4a is selectively closeable by a closing member 4' having a reflective inner surface. In the state that the surface of the sample 3 is smooth, the inner surface of the closing member 4' acts as a light source of the specular reflection light of the sample 3 to be incident upon the receiving optical system 32.
Accordingly, when the closing member 4' is removed as shown in FIG. 4, the SCE spectral reflection coefficient can be measured. On the other hand, when the closing member 4' is placed in the trap aperture 4a, the SCI spectral reflection coefficient can be measured.
However, the conventional apparatus requires a lot of time and labor for the measurement since it makes it necessary to open and close the closing member 4' each time the sample 3 is replaced. In addition, since the conventional apparatus requires such mechanical operation, the reliability of measurement result is inevitably reduced.

Optical characteristic measuring apparatus


The present invention is directed to a method for determining whether a woman has, or is likely to develop, ovarian cancer based upon assays of the alpha subunit of haptoglobin.

The identification of novel cancer biomarkers opens the possibility for early detection, better monitoring of tumor progression, and even targeted therapy. Such markers are especially needed for ovarian cancer, which is often at an advanced stage at the time of diagnosis, leaving patients with poor prospects for survival (Mill, et al., J. Nat'l Cancer Inst. 93:1437–39 (2001); Daly, et al., Cancer Cell 1:111–2 (2002)).
Classical approaches to cancer biomarker identification involved immunizing animals with tumor cells and then screening for antibodies that recognize a cell-specific antigen (Bast, et al., N. Engl. J. Med. 309:883–73 (1983)). Recently, tumor mRNA has been compared with normal tissue mRNA in an attempt to identify up-regulated genes in cancer tissue using cDNA micro-arrays (Mok, et al, J. Nat'l Cancer Inst. 93:1458–64.3 (2001); Kim, et al., J. Am. Med. Assoc. 289:1671–804–5 (2002)). A limitation of the traditional approach is its high cost and labor intensity, while a limitation of the cDNA micro-array approach is that transcriptional activity in the tumor does not necessarily reflect the proteins observed peripherally.
Since protein-protein interactions and post-translational modifications (e.g. phosphorylation, glycosylation, and enzymatic cleavage) may alter the protein patterns found in a patient's circulation, proteomic high throughput approaches that allow for the identification of circulating biomarkers could accelerate oncology research. In this regard, there has been considerable interest in analyzing surface enhanced laser desorption/ionizaton mass spectrometry (SELDI-MS) spectra for markers useful for disease detection (Petricoin, et al., Lancet 359:572–77 (2002); Vlahou, et al., Am. J. Pathol. 1;158:1491–02 (2001)). If these approaches lead to a biomarker that can be used to detect ovarian cancer in its early stages, e.g., a test analogous to the Pap smear used for uterine cancer, survival rates could undoubtedly be substantially improved.

Detection of ovarian cancer based upon alpha-haptoglobin levels


A two-step method is described for making transparent aerogels which have a density of less than 0.003 g/cm.sup.3 to those with a density of more than 0.8 g/cm.sup.3, by a sol/gel process and supercritical extraction. Condensed metal oxide intermediate made with purified reagents can be diluted to produce stable aerogels with a density of less than 0.02 g/cm.sup.3. High temperature, direct supercritical extraction of the liquid phase of the gel produces hydrophobic aerogels which are stable at atmospheric moisture conditions. Monolithic, homogeneous silica aerogels with a density of less than 0.02 to higher than 0.8 g/cm.sup.3, with high thermal insulation capacity, improved mechanical strength and good optical transparency, are described.

The first aerogels, made in the the 1930's by S. S. Kistler (Nature 127: 741 (1931)) and disclosed in U.S. Pat. No. 2,249,767 were translucent pieces of porous silica glass which were prepared by formation of silica `hydrogels` that were initially exchanged with alcohol, then dried with little shrinkage. When alcohol was supercritically extracted from the wet gel under pressure and at high temperature, the aerogel produced had a density of about 0.05 g/cm.sup.3, or a porosity as high as 98 percent. However, Kistler's process was time consuming and laborious and subsequent advances in the art, have reduced the processing time and increased the quality of the aerogels produced.
The high porosity silica aerogels first made were scientific curiosities and were not used in practical applications. Recently, in the 1970's, the high porosity aerogels were used as part of detectors for charged particles in high-energy physics experiments. The aerogels have a thermal conductivity which is about 100 times less than conventional, non-porous silica glass. The high transparency of silica aerogels, combined with their excellent insulating properties, suggest that aerogels could serve as superinsulating window materials. Other practical applications for silica aerogels include use as insulation in refrigerators, boilers, or as passive solar collectors.
Sound transmission through aerogels is slower than through air and their acoustic impedance is intermediate between that of most sound transducers and air. This suggests that aerogels could be used to improve the efficiency of such transducers in applications such as micro-speakers and distance ranging. The unique properties of aerogels make them useful for a variety of applications which require transparency, low thermal conductivity and strength with very low weight.
An improvement over Kistler's method was described by Teichner et al., in U.S. Pat. No. 3,672,833, where a silicon alkoxide such as tetraethoxysilane (TEOS) or tetramethoxysilane (TMOS), in an aliphatic alcohol solvent, was hydrolysed by one to five times the stoichiometric quantity of water, in a single mixing step. This single-step sol-gel process involves the hydrolysis reaction of silicon alkoxide compounds with water in either an acid, neutral, or basic medium, followed by the condensation reactions in which the hydrolysis products polymerize to form a gel. In this method, the wet gel already contains alcohol solvent as a result of the reactions, and therefore does not require the slow process of exchanging solvents before drying by supercritical extraction, as does Kistler's method. Also, the alcohol can be directly removed from the wet gel at high temperatures and pressures required for its supercritical extraction. These are the conditions necessary to re-esterify the aerogel surfaces which makes the material hydrophobic in character and stable toward variations when exposed to atmospheric moisture (E. C. Broge, U.S. Pat. No. 2,680,696). The silica aerogels made by this process have improved properties of transparency and strength, over those produced from Kistler's method. However, the silica aerogels produced by the method of the instant invention can be made in a much extended range of densities and have substantially improved physical properties.
In a commercial process, exemplified by that which is described by S. Henning and L. Svensson (Phys. Scripta 23: 698 (1982) and U.S. Pat. No. 4,402,927 by von Dardel et al.)), tetramethoxysilane (TMOS) was reacted with water in the presence of basic catalyst (NH.sub.4 OH), in a single mixing step, according to the following reactions: ##STR1## The condensation reaction immediately follows the hydrolysis in the same reaction vessel.
The microstructure of the aerogel made by this process is composed of spherical primary particles linked together to form chains which are themselves linked to form a continuous matrix of silica, surrounded by the reaction solvent, alcohol. The reaction rates of the hydrolysis and condensation steps strongly depend on the pH through the influence of the catalyst and these rates ultimately determine the microstructure of the gel (R. K. Iler, The Chemistry of Silica (Wiley Interscience, New York, 1979) and D. W. Schaefer, Science 243:1023 (1989)). Conventional silica aerogel glasses have distinguishable microstructures which are characteristic of the particular reaction process used for their formation.
Conventional silica aerogels, made by the "single-step" hydrolysis/condensation reactions given above in equations [1] and [2], have a bulk density in the range of 0.05 to 0.27 g/cm.sup.3. Stoichiometric and miscibility considerations limit monolithic aerogels attainable to a maximum density of near 0.3 g/cm.sup.3. Lower densities are achieved by dilution of the initial reactants with additional alcohol. However, the higher the dilution, the longer the time that is required for gelation to occur. Also, at some maximum dilution level, the reverse equilibrium reactions [Eq.1] will inhibit gelation, thereby setting the ultimate density limit for low density aerogels.
Aerogels are generally transparent, however, when aerogels are prepared by conventional "single-step" method, there is a loss in the clarity of those aerogels which have a density less than 0.04 g/cm.sup.3. It is believed that the loss of transparency in the low density aerogels is produced by light scattering from pores in the aerogel which have diameters greater than 100 nm.
Tewari et al., in U.S. Pat. No. 4,610,863, "Process for Forming Transparent Aerogel Insulating Arrays", described an improved process for making silica aerogels wherein alcohol that was generated in a "single-step" hydrolysis/condensation reaction of silicon alkoxide to form an "alcogel", was removed by substitution with liquid CO.sub.2 and subsequent supercritical drying of the alcogel to remove the CO.sub.2 Tewari suggested that substitution of CO.sub.2 for the alcohol solvent would allow removal of solvent at less severe conditions of temperature and pressure.
The "single-step" process described by Tewari et al., produced aerogels containing 5% silica, which would have a density of about 0.11 g/cm.sup.3. The chemistry of the "single-step" method, which Tewari et al., used to make the alcogel, limits the highest attainable density of an aerogel to be about 0.3 g/cm.sup.3 and it limits the lowest attainable density of an aerogel to about 0.02 g/cm.sup.3. These density limitations exist even with their described method of substitution and extraction of solvent Supercritical extraction of CO.sub.2 solvent following exchange with alcohol as described by Tewari et al., however, produces an aerogel with hydrophilic surfaces. Hygroscopic attraction of moisture to the surfaces of the aerogel leads to instability and eventually to collapse of the aerogel structure, if it is exposed to atmospheric moisture.
It is known in the art that the microstructure, and therefore, the properties of the dried aerogel are determined by its precursor chemistry. It is also known that the precursor chemistry is controllable through the use of catalysts to adjust the pH of the reacting solutions, through the amount of water used in the reactions, and by the reaction sequence. For example, single-step base catalysed hydrolysis/condensation of silicon alkoxide leads to a colloidal particle gel, whereas, single-step acid catalysed hydrolysis/condensation leads to polymeric gels. The importance of the reaction sequence was demonstrated by Brinker et al., (J. Non-Cryst. Sol. 48:47 (1982)) wherein a two-step process was described for making silica gels from which high density "xerogels" resulted after evaporative drying. The first step of the Brinker process involved the acid catalysed hydrolysis of silicon alkoxide using a sub-stoichiometric amount of water required to fully hydrolyse the silicon alkoxide. This first step produces a partially hydrolysed, partially condensed silica in alcohol solution, in which the presence of the alcohol limits continued condensation by affecting the reverse equilibrium reactions. The sol from this step could be characterized as consisting of clusters of polymeric silica chains. The second step involved the base catalysed completion of the hydrolysis/condensation reaction where the condensation continues until gelation occurs. The microstructure of the final gel made from this two-step process was more highly crosslinked and generally stronger than that of a single-step process gel.
Schaefer et al., (Physics and Chemistry of Porous Media II. J. R. Banavar, J. Koplik and K. W. Winkler, Eds. AIP New York (1987) pp. 63-80) described a modified two-step process in which the alcohol that is generated by the reactions of the first step was removed from the reaction by distillation, leaving a partially condensed silica intermediate. The intermediate was dissolved with another alcohol, before completing the hydrolysis/condensation with base catalyst. The alcohol in the product gel was then supercritically extracted, producing aerogel. The microstructure of the aerogel resulting from this two-step process was polymeric as in the single-step hydrolysis/condensation reactions. Neither of these references recognized the adverse effects of the alcohol solvent on the hydrolysis/condensation reactions which are due to the re-esterification of the hydrolysed species in the presence of excess alcohol. The presence of alcohol in the reactions affect both the rates and the degree of polymerization of the condensing gel, and thus affect its morphology. The presence of the alcohol also limits the gelation process to preclude the formation of very low density aerogels (i.e. densities less than 0.02 g/cm.sup.3).

Method for producing metal oxide aerogels having densities less than 0.02 g/cc


A waterproof container is provided including a housing formed of an elastomeric material defining an interior space with an open top having a planar top peripheral edge. An interior lining of the housing is constructed from a foam material. The lining is situated within the interior space of the housing for protecting the contents thereof. Further provided is a cover having a planar rectangular configuration with a top face, a bottom face, and a periphery formed therebetween. The bottom face of the cover has a cut out with a rectangular cross-section formed adjacent the entire periphery. The cut out has a width equal to a thickness of the faces of the housing. The cover further has a planar bottom lining constructed from a foam material situated on the bottom face of the cover. Next provided is a gasket having a planar rectangular configuration and a width equal to the thickness of the faces of the housing. A coupling mechanism is included for selectively securing the cover to the housing. During use, the cover is situated over the open top of the housing with the top peripheral edge of the housing situated within the cut out of the cover with the gasket positioned therebetween. The coupling mechanism functions to maintain the cover fixed to the housing to preclude water from entering the interior space of the housing.

1. Field of the Invention
The present invention relates to storage chests and more particularly pertains to a new protective storage housing for storing and protecting valuables during hurricanes, tornadoes, and other acts of god.
2. Description of the Prior Art
The use of storage chests is known in the prior art. More specifically, storage chests heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art storage chests include U.S. Pat. No. 4,838,418; U.S. Pat. No. 3,865,323; U.S. Pat. Des. 343,715; U.S. Pat. Des. 345,862; U.S. Pat. No. 4,091,852; and U.S. Pat. No. 4,082,200.
In these respects, the protective storage housing according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of storing and protecting valuables during hurricanes, tornadoes, and other acts of god.