A micromechanical device having a substrate wafer has at least one first cavity and one second cavity, the cavities being hermetically separated from each other, the first cavity having a different internal atmospheric pressure than the second cavity. The cavities are capped by a thin film cap. A method is for manufacturing a micromechanical device which has a thin film cap having cavities of different internal atmospheric pressures.

Certain techniques of bonding two substrate wafers for sealing caverns for micromechanical devices are conventional. In wafer bonding, one of the two substrate wafers usually includes micromechanical structures, for example sensor structures. The other substrate wafer, the cap wafer, has recesses. The recesses in the cap wafer and the sensor structures in the sensor wafer are situated such that a hollow space, a so-called cavity, forms above each sensor structure when the wafers are joined by a wafer bonding method. The cavity is hermetically sealed against the environment and thus protects the micromechanical sensor structure against environmental effects, such as moisture and particles. To ensure this, the connecting surface between the two wafers must be arranged such that a hermetic bond connection remains around each individual chip even after the wafer has been separated into individual sensor chips.
The equipment used in the wafer bonding process provides a process pressure to be set, among other things. Since the cavities are hermetically sealed during wafer bonding, the process pressure set on the equipment is encapsulated in each individual cavity in the combined wafer at the sealing temperature. At room temperature, this pressure is reduced according to the ideal gas law. The pressure in the cavities is an important parameter for many applications. In micromechanical acceleration sensors, for example, a relatively high pressure must be encapsulated to ensure adequate damping of the sensor element. Conversely, in micromechanical yaw rate sensors, which are operated resonantly, a low internal pressure is usually selected to ensure high quality as well as a low drive voltage.
Sensor elements are becoming increasingly smaller in micromechanics. Increasing miniaturization provides for multiple sensor elements to be integrated on a single sensor chip. Certain sensor chips simultaneously detect, for example, accelerations in all 3 spatial directions. Due to the process management described above for the wafer bonding method, it is currently not possible to easily integrate different sensor elements having different internal pressures (for example, micromechanical acceleration and yaw rate sensors) on a sensor chip.
Certain publications show a micromechanical component which has multiple cavities having different internal pressures. The cavities are sealed using a wafer capping process. One cavity is opened again and subsequently resealed using an oxide layer at a different internal atmospheric pressure.

Micromechanical device which has cavities having different internal atmospheric pressures


A gripper head for use in gripping a seal and positioning the seal in an electrical terminal. The gripper head has a mounting section, a compliant section and a gripping section. The compliant section extends from the mounting section. The compliant section has compliant legs having fixed ends proximate the mounting section and free ends. The compliant legs are spaced apart by compliant section slots. The gripping section extends from the compliant section. The gripping section has gripping legs which extend from the compliant legs. The gripping legs are spaced apart by gripping section slots. As the gripper head is moved into engagement with the seal, the gripping legs and the compliant legs are resiliently deformed causing the compliant legs and the gripping legs to apply a force to the seal to retain the seal on the gripping section of the gripper head.

Gripper heads for lifting an object, for example a connector, and positioning the object in a different location, for example on a printed circuit board, are known in the industry. Many such gripper heads have mechanical or pneumatic units to control gripper jaws or arms. The gripper jaws or arms are moved into engagement with outside surfaces of the object. Force is applied to the gripper jaws or arms to secure the object between the gripper jaws or arms, allowing the gripper head to pick up and transport the object to another location. Once properly moved to the location, the gripper head moves or inserts the object as required. Once properly moved or inserted, the gripper jaws or arms are retracted from the object, allowing the object to remain in the moved or inserted position.
The known gripper heads are well suited to lift and place objects which have outside or flat surfaces which are available to be accessed by the gripper jaws or arms. However, in situations in which the outside surfaces are not available during pick up or insertion, the use of such known gripper heads is not optimal. In addition, if the object to be lifted and inserted does not have stiff walls, known gripper heads have difficulty properly inserting the object. For example, when assembling a seal into a terminal, known gripper heads may be able to pick up the seal, but cannot insert the seal into the terminal due to the configuration and composition of the seal, the configuration of the terminal, or space constraints.
It would, therefore, be beneficial to provide gripper head or mechanism which can pick up and properly insert objects, such as seals, which do not have clear access to the outside surfaces during pick up or insertion or which require additional support during insertion. It would also be beneficial to provide a gripper head or mechanism which is simple to use and does not require expensive or large mechanisms to operate the gripper head or mechanism.

Gripper head for use with terminal seals


A method of testing a radio frequency (RF) integrated circuit includes: forming, performed by the RF integrated circuit, a test loop that passes through a first transceiver circuit, a first front-end circuit, and a second transceiver circuit, based on a test control signal transmitted from a test device; adjusting, performed by the RF integrated circuit, a shift degree of at least one phase shifter in the first front-end circuit, based on the test control circuit; and receiving, performed by the RF integrated circuit, a test input signal via the first transceiver circuit from the test device, and outputting, to the test device, the test input signal that has passed through the test loop, wherein the test input signal is output as a test output signal via the second transceiver circuit.

Apparatuses and methods consistent with exemplary embodiments of the inventive concept relate to testing a radio frequency (RF) integrated circuit for determining defects occurring in a process of mass production of the RF integrated circuit.
Unlike a low-frequency band in the related art wireless communication technologies (e.g., third generation (3G) or fourth generation (4G)), signal attenuation in a millimeter-wave frequency band (or radio frequency band) has a significant impact on communication performance, and thus, there is a difficulty in realizing communication using millimeter waves (e.g., fifth generation (5G)). In order to compensate for signal attenuation, research has been conducted for an RF integrated circuit using a high transmission power and maximizing an antenna gain in a millimeter wave communication.
Meanwhile, in a characteristic evaluation environment for mass-production of the RF integrated circuit of a low frequency band according to the related art, whether the RF integrated circuit is normal or defective is tested according to a magnitude of a signal transmitting through the RF integrated circuit by using a test device (e.g., a signal generator and a signal receiver). This test method is used for testing as many RF integrated circuit products as possible within a short period of time. However, since it is difficult to test a phase shifter that is a main element of the RF integrated circuit supporting millimeter-wave communication by using the related art test device, a method of using a vector network analyzer has been suggested as a way of performing the above test. However, since the vector network analyzer is a very expensive device and is specialized for use in a design and development environment, it is difficult to use the vector network analyzer in a process of mass-production of the RF integrated circuit, and thus, research on a method of testing characteristics of the RF integrated circuit by using existing test devices for mass-production is being conducted.


This invention provides a total synthesis of Merrillactone and Merrilactone analogues for use as neurotrophic agents in the treatment of neurodegenerative diseases. The invention also provides intermediates for use in the synthesis of Merrilactone and its analogues.

Neurotrophic factors are functionally defined as molecules which promote the maintenance and growth of neurons in vitro and in vivo.1 Among such factors are the nerve growth factor (NGF) and glial cell-derived neurotrophic factor (GDNF). Intraventricular administration of NGF to rats and primates reduces cholinergic neuronal degeneration, with potential implications for the treatment of Alzheimer's disease.2a,3 GDNF may have consequences in the treatment of Parkinson's disease.2b However, optimism along these lines is tempered by concerns as to the pharmacokinetics and bioavailability of polypeptidal factors.3 It is in this connection that the discovery of non-peptidal small molecules with neurotrophic properties is potentially of great significance.4 It seems appropriate to explore non-peptidal neurotrophic agents in detail as to their biological function and their usefulness, if any, in the treatment of neurodegenerative diseases. A mastery of the total synthesis of such small-molecule natural products could be most helpful, not only in improving access to these difficultly available agents, but in providing the basis for probing their SAR profiles.
Described below is the total synthesis of the pentacyclic sesquiterpene dilactone, merrilactone A (1). This compound had previously been obtained in 0.004% yield from the methanol extract of the pericarps of Illicium merrillianum.5 Preliminary studies indicated that 1 greatly promotes neurite outgrowth in fetal rat cortical neurons at concentrations as low as 0.1–10 μmol. Further investigations to date have been hampered by the scarcity of the natural merrilactone A.

The Trustees of Columbia University in the City of New York


Disclosed is a recording sheet which comprises a substrate and an additive material selected from the group consisting of pyrrole compounds, pyrrolidine compounds, pyridine compounds, piperidine compounds, homopiperidine compounds, quinoline compounds, isoquinoline compounds, quinuclidine compounds, indole compounds, indazole compounds, and mixtures thereof.

The present invention is directed to recording sheets, such as transparency materials, filled plastics, papers, and the like. More specifically, the present invention is directed to recording sheets particularly suitable for use in ink jet printing processes. One embodiment of the present invention is directed to a recording sheet which comprises a substrate and a material selected from the group consisting of pyrrole compounds, pyrrolidine compounds, pyridine compounds, piperidine compounds, homopiperidine compounds, quinoline compounds, isoquinoline compounds, quinuclidine compounds, indole compounds, indazole compounds, and mixtures thereof. Another embodiment of the present invention is directed to a recording sheet which consists essentially of a substrate, at least one material selected from the group consisting of pyrrole compounds, pyrrolidine compounds, pyridine compounds, piperidine compounds, homopiperidine compounds, quinoline compounds, isoquinoline compounds, quinuclidine compounds, indole compounds, indazole compounds, and mixtures thereof, an optional binder, an optional antistatic agent, an optional biocide, and an optional filler.
Recording sheets suitable for use in ink jet printing are known. For example, U.S. Pat. No. 4,740,420 (Akutsu et al.) discloses a recording medium for ink jet printing comprising a support material containing at least in the surface portion thereof a water soluble metal salt with the ion valence of the metal thereof being 2 to 4 and a cationic organic material. The cationic organic materials include salts of alkylamines, quaternary ammonium salts, polyamines, and basic latexes.
U.S. Pat. No. 4,576,867 (Miyamoto) discloses an ink jet recording paper with improved water resistance and sunlight fastness of the image formed on the paper wherein the recording paper has attached to its surface a cationic resin of the formula
wherein R1, R2, and R3 represent alkyl groups, m represents a number of 1 to 7, and n represents a number of 2 to 20, and Y represents an acid residue.
U.S. Pat. No. 4,446,174 (Maekawa et al.) discloses an ink jet recording method for producing a recorded image on an image receiving sheet with a jet of aqueous ink, wherein an ink jet is projected onto an image receiving sheet comprising a surface layer containing a pigment, and wherein the surface layer is capable of adsorbing a coloring component in the aqueous ink. Poly (vinyl benzyl trimethyl ammonium chloride), poly (diallyl dimethyl ammonium chloride), and poly (methacryloxyethyl-β-hydroxyethyl dimethyl ammonium chloride) are disclosed as dye absorbing adhesive materials.
U.S. Pat. No. 4,830,911 (Kojima et al.) discloses a recording sheet for ink jet printers which gives an image by the use of an aqueous ink containing a water-soluble dye, coated or impregnated with either of or a mixture of two kinds of water soluble polymers, one whose polymeric unit is alkylquaternaryammonium (meth)acrylate and the other whose polymer unit is alkylquaternaryammonium (meth)acrylamide, wherein the water soluble polymers contain not less than 50 mol percent of a monomer represented by the formula
where R represents hydrogen or methyl group, n is an interger from 1 to 3 inclusive, R1, R2, and R3 represent hydrogen or the same or different aliphatic alkyl group with 1 to 4 carbon atoms, X represents an anion such as a halogen ion, sulfate ion, alkyl sulfate ion, alkyl sulfonate ion, aryl sulfonate ion, and acetate ion, and Y represents oxygen or imino group.
U.S. Pat. No. 4,554,181 (Cousin et al.) discloses an ink jet recording sheet having a recording surface which includes a combination of a water soluble polyvalent metal salt and a cationic polymer, the polymer having cationic groups which are available in the recording surface for insolubilizing an anionic dye.
U.S. Pat. No. 4,877,680 (Sakaki et al.) discloses a recording medium comprising a substrate and a nonporous ink receiving layer. The ink receiving layer contains a water-insoluble polymer containing a cationic resin. The recording medium may be employed for recording by attaching droplets of a recording liquid thereon.
European Patent Publication 0 439 363 A1, published Jul. 31, 1991, corresponding to copending application U.S. Ser. No. 07/469,985, U.S. Pat. No. 5,302,249, the disclosure of which is totally incorporated herein by reference, discloses a paper which comprises a supporting substrate with a coating comprising (a) a desizing component selected from the group consisting of (1) hydrophilic poly(dialkylsiloxanes); (2) poly(alkylene glycol); (3) poly(propylene oxide)-poly(ethylene oxide) copolymers; (4) fatty ester modified compounds of phosphate, sorbitan, glycerol, poly(ethylene glycol), sulfosuccinic acid, sulfonic acid and alkyl amine; (5) poly(oxyalkylene) modified compounds of sorbitan esters, fatty amines, alkanol amides, castor oil, fatty acids and fatty alcohols; (6) quaternary alkosulfate compounds; (7) fatty imidazolines; and mixtures thereof, and (b) a hydrophilic binder polymer. The binder polymer may be a quaternary ammonium copolymer such as Mirapol WT, Mirapol AD-1, Mirapol AZ-1, Mirapol A-15, Mirapol-9, Merquat-100, or Merquat-550, available from Miranol Incorporated.
U.S. Pat. No. 5,223,338 (Malhotra), the disclosure of which is totally incorporated herein by reference, discloses a recording sheet which comprises a substrate and a coating consisting essentially of (1) quaternary ammonium polymers selected from the group consisting of (a) polymers of Formula I
wherein n is an integer of from 1 to about 200, R1, R2, R3, and R4 are each independently selected from the group consisting of alkyl groups, hydroxyalkyl groups, and polyoxyalkylene groups, p is an integer of from 1 to about 10, q is an integer of from 1 to about 10, X is an anion, and Y1 is selected from the group consisting of —CH2CH2OCH2CH2—, —CH2CH2OCH2CH2OCH2CH2—, —(CH2)k—, wherein k is an integer of from about 2 to about 10, and —CH2CH(OH)CH2—; (b) polymers of Formula II
wherein n is an integer of from 1 to about 200, R5, R6, R7, and R8 are each independently selected from the group consisting of alkyl groups, hydroxyalkyl groups, and polyoxyalkylene groups, m is an integer of from 0 to about 40, r is an integer of from 1 to about 10, s is an integer of from 1 to about 10, X is an anion, and Y2 is selected from the group consisting of —CH2CH2OCH2CH2—, —CH2CH2OCH2CH2OCH2CH2—, —(CH2)k—, wherein k is an integer of from about 2 to about 10, and —CH2CH(OH)CH2—; (c) copolymers of Formula III
wherein a and b are each integers wherein the sum of a+b is from about 2 to about 200, R1, R2, R3, R4, R5, R6, R7, and R8 are each independently selected from the group consisting of alkyl groups, hydroxyalkyl groups, and polyoxyalkylene groups, p is an integer of from 1 to about 10, q is an integer of from 1 to about 10, X is an anion, and Y1 and Y2 are each independently selected from the group consisting of —CH2CH2OCH2CH2—, —CH2CH2OCH2CH2OCH2CH2—, —(CH2)k—, wherein k is an integer of from about 2 to about 10, and —CH2CH(OH)CH2—; (d) mixtures of polymers of Formula I and polymers of Formula II; (e) mixtures of polymers of Formula I and copolymers of Formula III; (f) mixtures of polymers of Formula II and copolymers of Formula III; and (g) mixture of polymers of Formula I, polymers of Formula II, and copolymers of Formula III; (2) an optional binder polymer; and (3) an optional filler.
U.S. Pat. No. 5,212,008 (Malhotra et al.), the disclosure of which is totally incorporated herein by reference, discloses a recording sheet which comprises a substrate; a first coating in contact with the substrate which comprises a crosslinking agent selected from the group consisting of hexamethoxymethyl melamine, methylated melamine-formaldehyde, methylated urea-formaldehyde, cationic urea-formaldehyde, cationic polyamine-epichlorohydrin, glyoxal-urea resin, poly (aziridine), poly (acrylamide), poly (N,N-dimethyl acrylamide), acrylamide-acrylic acid copolymer, poly (2-acrylamido-2-methyl propane sulfonic acid), poly (N,N-dimethyl-3,5-dimethylene piperidinium chloride), poly (methylene-guanidine) hydrochloride, poly (ethylene imine) poly (ethylene imine) epichlorohydrin, poly (ethylene imine) ethoxylated, glutaraldehyde, and mixtures thereof; a catalyst; and a polymeric material capable of being crosslinked by the crosslinking agent and selected from the group consisting of polysaccharides having at least one hydroxy group, polysaccharides having at least one carboxy group, polysaccharides having at least one sulfate group, polysaccharides having at least one amine or amino group, polysaccharide gums, poly (alkylene oxides), vinyl polymers, and mixtures thereof; and a second coating in contact with the first coating which comprises a binder and a material selected from the group consisting of fatty imidazolines, ethosulfate quaternary compounds, dialkyl dimethyl methosulfate quaternary compounds, alkoxylated di-fatty quaternary compounds, amine oxides, amine ethoxylates, imidazoline quaternary compounds, alkyl benzyl dimethyl quaternary compounds, poly (epiamines), and mixtures thereof.
U.S. Pat. No. 4,946,741 (Aono et al.) discloses an ink recording sheet comprising a transparent support having thereon an ink recording layer comprising a mixture of an amino group deactivated gelatin derivative and a polyalkylene oxide.
U.S. Pat. No. 4,781,985 (Desjarlais) discloses an ink jet transparency which comprises a substantially transparent resinous support and a substantially clear coating thereon which includes a specific fluorosurfactant.
U.S. Pat. No. 5,073,448 (Vieira et al.) discloses a recording material for ink jet printing comprising a carrier having a surface which can be printed on or a carrier coated on one side with a material which can be printed on, wherein the carrier or the coting contains as a stabilizer at least one compound of the formula
in which R1 and R2 independently of one another are C1–C4 alkyl which is unsubstituted or substituted by one or two —OH, —COO−M+ and/or —SO3−M+ groups, C3–C5 alkenyl, C3–C5 alkynyl,
—CH2CH(OH)CH2—SO3−M+, —CO-alkyl(C1–C4) which is unsubstituted or substituted by —COORo or —CO—N(R5)(R6) or, if OR1 and OR2 are in the ortho position relative to one another, R1 and R2 together are C1–C6 alkylene, M+ being H+, a monovalent, divalent or trivalent metal cation or a group (R12′)N+(R12″)(R13′)(R14′), wherein R12′, R12″, R13 and R14 independently of one another are H, C1–C4 alkyl which is unsubstituted or substituted by 1 or 3 OH, C1–C4 alkyl interrupted by O, allyl, cyclopentyl, cyclohexyl, phenyl, benzyl or tolyl, or R1 is a group
in which p′ is a number from 2 to 6, R5 and R6 independently of one another are H or C1–C4 alkyl which is unsubstituted or substituted by an OH, COORo, —COO−M+, SO3−M+, P(O)(O−M+)2 or P(O)(ORo)2 group, R3′ and R4′ independently of one another are H, C1–C4 alkyl, OH or C1–C4 alkoxy, R3 and R4 independently of one another are H, halogen, —OR7, —COORo, —COO−M+, —OOC—R5, —CO—N(R5)(R6), —(R5)N—CO—R6, —CO—R5, —SO3−M+, —SO2N(R5)(R6), P(OR5)3, —(O)P—(O−M+)2, —(O)P—(ORo)2, C1–C8 alkyl which is unsubstituted or substituted by 1 to 7 —OR5 or —OO—C—R5 groups, by 1 or 2 —COORo, —COO−M+, or —CO—N(R5)(R6) groups or by one or two —SO3−M+, —SO2N(R5)(R6) or —(O)P—(ORo)2 or —(O)P(O−M+)2 groups, where M+, R5 and R6 are as defined above, or C5–C6 cycloalkyl or allyl, Ro being C1–C4 alkyl which is unsubstituted or substituted by an —OH group or —(CH2CH2O)r—H in which r is 1 to 12, and R7 being C1–C4 alkyl or —CO-alkyl(C1–C4) each of which is unsubstituted or substituted by 1 or 2 —OH groups or R3 and R4 independently of one another are one of the groups
in which R8 is a direct bond or methylene, R9 is H, C1–C8 alkyl, —COO−M+ or —SO3−M+, where M+, R1 and R2 are as defined above, R15 is —CO—, —(O)g—CpH2p—CO—, —OOC—CpH2p—, —COO—CpH2p—, —O—CH2CH(OH)—CH2— or
in which g is 0 or 1 and p is 1 to 6 and R24 is —OR5, —N(R5)(R6) or a group
and R16 is one of the following radicals:
in which R25 is H or C1–C4 alkyl, R17 is H, C1–C4 alkyl which is unsubstituted or substituted by an —OH group, —CH2—CH(OH)—CH2—OH, C1–C4 alkoxy, —OH, —CO-alkyl(C1–C4), —COCH═CH2, allyl, benzyl or a group
in which s is the number 2 or 3, t is a number from 0 to 2 and R21 and R22 independently of one another are H, C1–C4 alkyl or phenyl.
South African Patent Application 924,610 discloses a transparent recording sheet suitable for making visual transparencies which comprises a thin transparent film backing bearing on at least one major surface thereof an ink jet receptive layer comprising from 1% to 10% of at least one acid having a pKa of from 2 to 6, said acid being selected from the group consisting of aryl monocarboxylic acids, aryloxy monocarboxylic acids, alkyl carboxylic acids having alkyl groups containing at least 11 carbon atoms, dicarboxylic acids, tricarboxylic acids, and pyridinium salts, and at least one liquid-absorbent polymer comprising from 90% to 99% aprotic constituents, wherein said sheet shows reduced fading when imaged with an ink containing triarylmethane dye and at least one nucleophile over an identical composition containing no protic organic-solvent-soluble additive.
U.S. Pat. No. 5,220,346 (Carreira et al.), the disclosure of which is totally incorporated herein by reference, discloses a printing process which comprises applying in imagewise fashion to a substrate an ink composition which comprises an aqueous liquid vehicle, a colorant, and an ionic compound at least partially ionizable in the liquid vehicle, said ink composition having a conductivity of at least about 10 milliSiemens per centimeter, and subsequently exposing the substrate to microwave radiation, thereby drying the images on the substrate. A specific embodiment of the invention is directed to a thermal ink jet printing process which comprises (1) incorporating into a thermal ink jet printing apparatus an ink composition which comprises an aqueous liquid vehicle, a colorant, and an ionic compound at least partially ionizable in the liquid vehicle, said ink composition having a conductivity of at least about 10 milliSiemens per centimeter; (2) heating the ink in an imagewise pattern to cause bubbles to form therein, thereby causing droplets of the ink to be ejected in an imagewise pattern onto a substrate, thereby generating images on the substrate; and (3) exposing the substrate to microwave radiation, thereby drying the images on the substrate.
Copending application U.S. Ser. No. 08/034,917, U.S. Pat. No. 5,760,809, with the named inventors Shadi L. Malhotra, Brent S. Bryant, and Doris K. Weiss, filed Mar. 19, 1993, entitled "Recording Sheets Containing Phosphonium Compounds," the disclosure of which is totally incorporated herein by reference, discloses a recording sheet which comprises a base sheet, a phosphonium compound, an optional pigment, and an optional binder. In a preferred embodiment, the phosphonium compound is selected from the group consisting of
wherein R is an alkyl group, X is an anion, and all four R groups are the same;
wherein R is an alkyl group, wherein all three R groups are the same, wherein R is not the same as R′, X is an anion, and R′ is selected from the group consisting of alkyl groups, substituted alkyl groups, arylalkyl groups, and substituted arylalkyl groups;
wherein Ar is an aryl group or a substituted aryl group, X is an anion, and all four Ar groups are the same;
wherein Ar is an aryl group or a substituted aryl group, wherein all three Ar groups are the same, X is an anion, and R′ is selected from the group consisting of alkyl groups, substituted alkyl groups, arylalkyl groups, and substituted arylalkyl groups; and mixtures thereof.
Copending application U.S. Ser. No. 08/034,943, U.S. Pat. No. 5,314,747, with the named inventors Shadi L. Malhotra and Brent S. Bryant, filed Mar. 19, 1993, entitled "Recording Sheets Containing Cationic Sulfur Compounds," the disclosure of which is totally incorporated herein by reference, discloses a recording sheet which comprises (a) a base sheet; (b) a cationic sulfur compound selected from the group consisting of sulfonium compounds, thiazolium compounds, benzothiazolium compounds, and mixtures thereof; (c) an optional binder; and (d) an optional pigment.
Copending application U.S. Ser. No. 08/033,917, U.S. Pat. No. 5,441,795, with the named inventors Shadi L. Malhotra and Brent S. Bryant, filed Mar. 19, 1993, entitled "Recording Sheets Containing Pyridinium Compounds," the disclosure of which is totally incorporated herein by reference, discloses a recording sheet which comprises a base sheet and a material selected from the group consisting of pyridinium compounds, piperazinium compounds, and mixtures thereof.
Copending application U.S. Ser. No. 08/034,445, U.S. Pat. No. 5,320,902, with the named inventors Shadi L. Malhotra, Brent S. Bryant, and Doris K. Weiss, filed Mar. 19, 1993, entitled "Recording Sheets Containing Monoammonium Compounds," the disclosure of which is totally incorporated herein by reference, discloses a recording sheet which consists essentially of a substrate and, in contact with the substrate, a monoammonium compound of the formula:
wherein R is an alkyl group, X is selected from the group consisting of fluoride, chloride, bromide, iodide, and astatide, and R′, R″, and R″ ′ are each independently selected from the group consisting of alkyl groups, substituted alkyl groups, aryl groups, substituted aryl groups, arylalkyl groups, and substituted arylalkyl groups, wherein R, R′, R″ and R″ ′ are either the same as or different from each other; and mixtures thereof; an optional binder component; and an optional filler component.
Copending application U.S. Ser. No. 08/033,918 U.S. Pat. No. 5,457,486, with the named inventors Shadi L. Malhotra, Brent S. Bryant, and Doris K. Weiss, filed Mar. 19, 1993, entitled "Recording Sheets Containing Tetrazolium, Indolinium, and Imidazolinium Compounds," the disclosure of which is totally incorporated herein by reference, discloses a recording sheet which comprises (a) a base sheet; (b) a material selected from the group consisting of tetrazolium compounds, indolinium compounds, imidazolinium compounds, and mixtures thereof; (c) an optional pigment; and (d) an optional binder.
Copending application U.S. Ser. No. 08/196,669, U.S. Pat. No. 5,500,668, with the named inventors Shadi L. Malhotra, Kurt B. Gundlach, and Richard L. Colt, filed concurrently herewith, entitled "Recording Sheets for Printing Processes Using Microwave Drying," the disclosure of which is totally incorporated herein by reference, discloses a printing process which comprises (a) providing a recording sheet which comprises a substrate, at least one monomeric salt, an optional binder, an optional antistatic agent, an optional biocide, and an optional filler; (b) applying an aqueous recording liquid to the recording sheet in an imagewise pattern; and (c) thereafter exposing the substrate to microwave radiation, thereby drying the recording liquid on the recording sheet.
Copending application U.S. Ser. No. 08/196,922, with the named inventor Shadi L. Malhotra, filed concurrently herewith, entitled "Recording Sheets Containing Alcohols and Saccharides," the disclosure of which is totally incorporated herein by reference, discloses a recording sheet which comprises a substrate and a material selected from the group consisting of monosaccharides, oligosaccharides, and mixtures thereof. Another embodiment of the present invention is directed to a printing process which comprises (a) providing a recording sheet which comprises a substrate, a material selected from the group consisting of monomeric alcohols, monosaccharides, oligosaccharides, and mixtures thereof, an optional binder, an optional antistatic agent, an optional biocide, and an optional filler; (b) applying an aqueous recording liquid to the recording sheet in an imagewise pattern; and (c) thereafter exposing the substrate to microwave radiation, thereby drying the recording liquid on the recording sheet.
Copending application U.S. Ser. No. 08/196,679, U.S. Pat. No. 5,589,277, with the named inventor Shadi L. Malhotra, filed concurrently herewith, entitled "Recording Sheets Containing Amino Acids, Hydroxy Acids, and Polycarboxyl Compounds," the disclosure of which is totally incorporated herein by reference, discloses a recording sheet which comprises a paper substrate and a material selected from the group consisting of monomeric amino acids, monomeric hydroxy acids, monomeric polycarboxyl compounds, and mixtures thereof. Another embodiment of the present invention is directed to a recording sheet which comprises a substrate and an additive material selected from the group consisting of monomeric amino acids, monomeric hydroxy acids, and mixtures thereof.
Copending application U.S. Ser. No. 08/196,607, with the named inventor Shadi L. Malhotra, filed concurrently herewith, entitled "Recording Sheets Containing Amine Salts and Quaternary Choline Halides," the disclosure of which is totally incorporated herein by reference, discloses a recording sheet which comprises a substrate and a material selected from the group consisting of monomeric amine acid salts, monomeric quaternary choline halides, and mixtures thereof.
Copending application U.S. Ser. No. 08/196,933, with the named inventor Shadi L. Malhotra, filed concurrently herewith, entitled "Recording Sheets Containing Purine, Pyrimidine, Benzimidazole, Imidazolidine, Urazole, Pyrazole, Triazole, Renzotriazole. Tetrazole; and Pyrazine Compounds," the disclosure of which is totally incorporated herein by reference, discloses a recording sheet which comprises a substrate and a material selected from the group consisting of purine compounds, pyrimidine compounds, benzimidazole compounds, imidazolidine compounds, urazole compounds, pyrazole compounds, triazole compounds, benzotriazole compounds, tetrazole compounds, pyrazine compounds, and mixtures thereof. Also disclosed is a recording sheet which consists essentially of a substrate, at least one material selected from the group consisting of purine compounds, pyrimidine compounds, benzimidazole compounds, imidazolidine compounds, urazole compounds, pyrazole compounds, triazole compounds, benzotriazole compounds, tetrazole compounds, pyrazine compounds, and mixtures thereof, an optional binder, an optional antistatic agent, an optional biocide, and an optional filler.
Copending application U.S. Ser. No. 08/196,672, U.S. Pat. No. 6,180,238, with the named inventor Shadi L. Malhotra, filed concurrently herewith, entitled "Recording Sheets Containing Oxazole, Isooxazole, Oxazolidinone, Oxazoline Salt, Morpholine, Thiazole, Thiazolidine, Thiadiazole, and Phenothiazine Compounds," the disclosure of which is totally incorporated herein by reference, discloses a recording sheet which comprises a substrate and a material selected from the group consisting of oxazole compounds, isooxazole compounds, oxazolidinone compounds, oxazoline salt compounds, morpholine compounds, thiazole compounds, thiazolidine compounds, thiadiazole compounds, phenothiazine compounds, and mixtures thereof. Also disclosed is a recording sheet which consists essentially of a substrate, at least one material selected from the group consisting of oxazole compounds, isooxazole compounds, oxazolidinone compounds, oxazoline salt compounds, morpholine compounds, thiazole compounds, thiazolidine compounds, thiadiazole compounds, phenothiazine compounds, and mixtures thereof, an optional binder, an optional antistatic agent, an optional biocide, and an optional filler.
Copending application U.S. Ser. No. 08/196,605, U.S. Pat. No. 5,663,004, with the named inventors Shadi L. Malhotra, Brent S. Bryant, and Arthur Y. Jones, filed concurrently herewith, entitled "Recording Sheets Containing Mildew Preventing Agents," the disclosure of which is totally incorporated herein by reference, discloses a recording sheet which comprises a substrate, an image receiving coating, and a biocide.
While known compositions and processes are suitable for their intended purposes, a need remains for improved recording sheets In addition, there is a need for improved recording sheets suitable for use in ink jet printing processes. Further, a need remains for recording sheets which exhibit rapid drying times when imaged with aqueous inks Additionally, there is a need for recording sheets which enable precipitation of a dye from a liquid ink onto the sheet surface during printing processes. A need also remains for recording sheets which are particularly suitable for use in printing processes wherein the recorded substrates are imaged with liquid inks and dried by exposure to microwave radiation. Further, there is a need for recording sheets coated with a discontinuous, porous film. There is also a need for recording sheets which, subsequent to being imaged with an aqueous ink, exhibit reduced curling.

Recording sheets containing pyrrole, pyrrolidine, pyridine, piperidine, homopiperidine, quinoline, isoquinoline, quinuclidine, indole, and indazole compounds


A solid ink delivery system for use with a ink stick for use in printers is provided. The stick has an external periphery including opposed surfaces of the stick. The solid ink delivery system delivers the stick to a melting unit for melting the stick so that the ink may be transferred to media to form an image on the media. The delivery system includes a guide for guiding the stick in a prescribed path. The guide defines a loading position to permit the stick to be placed in the guide and a delivery position adjacent the melting unit. The guide at the loading position defines constraints for positioning the stick. A portion of the constraints, including a shaped insertion opening, is adapted for cooperation with the opposed surfaces of the external periphery of the stick. At least one of the constraints defining a grasping recess in the constraint for providing access to a portion of at least one of the opposed surfaces of the external periphery of the stick.

So called "solid ink" printers encompass various imaging devices, including printers and multi-function platforms and offer many advantages over many other types of high speed or high output document reproduction technologies such as laser and aqueous inkjet approaches. These often include higher document throughput (i.e., the number of documents reproduced over a unit of time), fewer mechanical components needed in the actual image transfer process, fewer consumables to replace, sharper images, as well as being more environmentally friendly (far less packaging waste).
A schematic diagram for a typical solid ink imaging device is illustrated in FIG. 1. The solid ink imaging device, hereafter simply referred to as a printer 100 has an ink loader 110 which receives and stages ink sticks which remain in solid form at room temperatures. The ink stock can be refilled by a user by simply adding more ink as needed to the ink loader 110. Separate loader channels are used for the different colors. For, example, only black ink is needed for monochrome printing, while ink colors of black, cyan, yellow and magenta are typically needed for color printing. Each color is loaded and fed in independent channels of the ink loader.
An ink melt unit 120 melts the ink by raising the temperature of the ink sufficiently above its melting point. During a melting phase of operation, the leading end of an ink stick contacts a melt plate or heated surface of the melt unit and the ink is melted in that region. The liquefied ink is supplied to a single or group of print heads 130 by gravity, pump action, or both. In accordance with the image to be reproduced, and under the control of a printer controller (not shown), a rotating print drum 140 receives ink droplets representing the image pixels to be transferred to paper or other media 170 from a sheet feeder 160. To facilitate the image transfer process, a pressure roller 150 presses the media 170 against the print drum 140, whereby the ink is transferred from the print drum to the media. The temperature of the ink can be carefully regulated so that the ink fully solidifies just after the image transfer.
While there may be advantages to the use of solid ink printers compared to other image reproduction technologies, high speed and voluminous printing sometimes creates problems not satisfactorily addressed by the prior art solid ink printing architectures. To meet the large ink volume requirement, ink loaders must have large storage capacity and be able to be replenished by loading ink at any time the loader has capacity for additional ink.
In typical prior art ink chuck or stick reservoirs, the sticks are positioned end to end in straight or linear channel or chute with a melt head on one end and a spring biased push stick on the other end. As these solid ink printers have high productivity rates, the storage of ample supplies of ink is very desirable. As the space in solid ink printers is limited, finding a location within the printer to accommodate a long straight chute for holding an ample supply of ink is a challenge. The amount of ink that can be accommodated is limited by the physical dimensions of the printer and can not be greater that the amount accommodated by a linear chute diagonally positioned in the printer.
To assure that the proper ink stick is inserted into a printer, the ink sticks may have an irregular shape which provides a key for moving the sticks by a corresponding key formed in the loading position of the printer. Since the ink sticks have this keying feature, once the ink stick has passed through the closely matched keyed opening, the ink sticks may not be retrieved easily. The planar keying surface is above the top of the ink when the ink is fully inserted. Removal of the ink stick when necessary requires the use of a tool or sharp object which must be impaled into the top surface of the ink stick. The impaling of the ink stick may create an issue when later trying to use the stick as it may crack or shed material. Further, the tool or object may not be readily available for the user and the user may not be aware of such a procedure to remove the ink stick.


A force-sensing system suitable, for example, for atomic force microscopy. This system includes a rocking beam, a base, and means for supporting the beam adjacent a surface of the base such that the beam can pivot about at least one axis parallel to the base surface. In contrast to rocking-beam systems of the prior art, the support means comprise at least one pivot element that can be held against the base surface by a magnetic field.

Force-sensing elements are widely used in scanning force microscopy. Rocking beam techniques have been applied in some of these systems. Rocking beam sensors are potentially advantageous because, in principle, they can be mechanically simple, rugged, highly sensitive, and relatively inexpensive to manufacture. In particular, these sensors offer high performance because they can be stabilized by a force-feedback servo loop. A further advantage of rocking beam sensors is that they can be used for a variety of microforce-sensing applications, including the measurement of tilt or acceleration. However, previous attempts to provide a rocking beam sensor have not been entirely satisfactory. Practitioners have found that pivoting mechanisms that offer sufficient sensitivity in the rocking direction generally tend to be fragile and too easily damaged during routine handling. At least some sensors have been found to be difficult to fabricate. The rocker elements of at least some of these sensors have proven difficult to remove and replace. (Rapid replacement is important in scanning force microscopy, for example. This is because the finely pointed probe tips, which are permanently mounted on the rocker elements, break or wear out relatively quickly.) Moreover, practitioners have encountered difficulties in stabilizing the rocker elements against undesired modes of mechanical motion.
For example, a rocking beam sensor fabricated from a thin sheet of beryllium-copper alloy is described in S. A. Joyce et al., "A new force sensor incorporating force-feedback control for interfacial force microscopy," Rev. Sci. Instrum. 62 (1991) 710-715. This sensor is a differential capacitance displacement sensor in which a common capacitor plate is suspended by torsion bars. The common capacitor plate and the torsion bars are integral with the beryllium-copper alloy sheet. Practitioners using this sensor have found that planarity of the rocker, which is essential to proper operation, is difficult to maintain because the beryllium-copper sheet tends to bend. Practitioners have also found that sensitivity is limited by stiffness of the torsion bars in the rocking direction, and that unwanted degrees of mechanical freedom make a substantial contribution to measurement noise.
An alternative rocking beam sensor is described in G. L. Miller et al., "A rocking beam electrostatic balance for the measurement of small forces," Rev. Sci. Instrum. 62 (1991) 705-709. In this sensor, which is also a differential capacitance displacement sensor, the rocker (which comprises the common capacitor plate) is a silicon beam which pivots on a carbon or tungsten fiber. The fragility of the fiber is an undesirable feature of this sensor. Damage to the fiber introduces undesired degrees of mechanical freedom, causing the signal output to be contaminated with noise. Moreover, this sensor relies on the weight of the rocker to hold it together, and therefore cannot be operated in an inverted orientation.

Force-sensing system, including a magnetically mounted rocking element


Information representing content of a plurality of elements which are included in a structured document defined as a layer structure is obtained, and one of the elements included in the structured document is selected in accordance with the content of the elements included in the structured document. Then, the selected element is output separately from the other elements.

In recent years, people can access servers through the Internet and obtain various information from displayed web pages. The web pages are represented by structured documents described by a structured language (markup language) such as an HTML (Hyper Text Markup Language) or an XHTML (Extensible Hyper Text Markup Language). Then, the structured documents are analyzed by software referred to as a browser and the browser performs display in accordance with analysis results whereby the web pages can be displayed.
Furthermore, when such a web page is to be printed, a certain region of a web page selected by a user may be printed. For example, Japanese Patent No. 03588337 discloses a technique of copying an element included in a structured document such as text or an image corresponding to a portion of a web page selected in response to a selection of a certain rectangle portion included in the web page performed by a user using a pointing device such as a mouse so that a new structured document is generated. Furthermore, Japanese Patent No. 03588337 discloses a method for displaying only text or an image selected by the user in accordance with the newly-generated structured document.

Outputting selective elements of a structured document

Abstract: Note that the elements included in the structured document are selectable in the plurality of layers and an element selected from any one of the layers is output separately from the other elements.

Abstract: By this, an appropriate element can be selected and output from among the plurality of elements included in the structured document.


A curb box locking device has a core unit with a head at its upper end and a foot at its lower end. A sleeve surrounds and is shiftable axially in relation to the core unit. Claw members are carried on the core unit for pivotal movement through side openings in the sleeve. The locking device is externally configured and dimensioned to be lowered into the curb box to a position at which the foot of the core unit is at rest on a valve or the like at the bottom of the curb box. The sleeve is engageable with the claw members during upward displacement of the sleeve relative to the core unit to pivotally urge the claw members radially outwardly into extended positions engaging the interior of the curb box to thereby resist upward removal of the locking device. The locking device is upwardly removable from the curb box by employing a tool specially designed to pull upwardly on the core unit.

1. Field of the Invention
This invention relates generally to locking devices, and is concerned in particular with an improved lock for preventing unauthorized access to a utility valve or the like located at the bottom of a curb box.
2. Description of the Prior Art
As shown for example by U.S. Pat. No. 135,822 (Laforge); U.S. Pat. No. 1,229,429 (Farley) and U.S. Pat. No. 5,234,029 (Thomas et al.), curb box locks are conventionally located at ground level. Locks of this type are easily accessible and thus prone to being picked, broken or otherwise compromised by those seeking unauthorized access to valves located at the bottom of the curb boxes.
The objective of the present invention is to provide an improved lock which can be dropped into the curb box, and which is not readily removable from the curb box without employing a tool specially designed for that purpose.


A transfer device for moving a personal storage container from a storage position at the rear of a wheelchair to a deployed position at a side of the wheelchair. The device includes a bracket adapted to be mounted to the backrest frame and a swivel mechanism with a first hinge leaf rotationally mounted to the bracket for rotation about a first axis and a second hinge leaf rotationally mounted to the first hinge leaf about a second axis spaced apart from the first axis. The second hinge leaf has a portion adapted to mount the personal storage container. The portion adapted to mount the personal storage container moves along an arc contained within a plane between the storage and the deployed positions, and the first and second axes are normal to the plane. A personal storage container assembly is also provided.

Several patents exist showing various personal storage devices or backpacks which are movable between a first position behind a wheelchair to a second position sideways of the wheelchair whereby the storage device is more readily accessible to the wheelchair user. Such patents include, for example, U.S. Pat. No. 4,919,443 Kehler 1990; U.S. Pat. No. 5,180,181 Letechopia 1993; and U.S. Pat. No. 8,496,260 Jutkiewicz et al. 2013. However existing storage devices may be relatively expensive and/or complex.

Personal storage accessory for wheelchairs


Techniques described herein provide a computing device configured to provide an indication that the computing device has recognized a voice-initiated action. In one example, a method is provided for outputting, by a computing device and for display, a speech recognition graphical user interface (GUI) having at least one element in a first visual format. The method further includes receiving, by the computing device, audio data and determining, by the computing device, a voice-initiated action based on the audio data. The method also includes outputting, while receiving additional audio data and prior to executing a voice-initiated action based on the audio data, and for display, an updated speech recognition GUI in which the at least one element is displayed in a second visual format, different from the first visual format, to indicate that the voice-initiated action has been identified.

Some computing devices (e.g., mobile phones, tablet computers, personal digital assistants, etc.) may be voice-activated. Voice-activated computing devices can be controlled by means of audio data, such as a human voice. Such computing devices provide functionality to detect speech, determine an action indicated by the detected speech, and execute the indicated the action. For example, a computing device may receive audio input corresponding to a voice command, such as "search," "navigate," "play," "pause," "call," or the like. In such instances, the computing device may analyze the audio input using speech-recognition techniques to determine a command and then execute an action associated with the command (e.g., provide a search option, execute a map application, begin playing a media file, stop playing a media file, place a phone call, etc.). In this way, a voice-activated computing device may provide users with the ability to operate some features of the computing device without use of the user's hands.

Visual confirmation for a recognized voice-initiated action


An electric submersible pump (ESP) seal section assembly. The assembly comprises a seal section filled with dielectric oil; a coupling body partially inserted into the seal section, and a coupling body, wherein the coupling body is substantially cylindrical and has a first outside diameter at an upper end of the coupling body, has a second outside diameter smaller than the first diameter below the first outside diameter, has a circumferential tapered shoulder between the portion of the coupling body having the first diameter and the portion of the coupling body having the second diameter; a service-less flange coupled to the seal section, wherein the service-less flange defines a circumferential opening having a circumferential tapered shoulder on an upper edge that contacts the circumferential tapered shoulder of the coupling body.

Electric submersible pumps (ESPs) are installed in wellbores to lift production fluids up within a wellbore to a surface location. ESPs commonly comprise assemblies of collaborating components including a centrifugal pump, upstream of the centrifugal pump an optional gas separator, upstream of the optional gas separator a fluid inlet, upstream of the fluid inlet a seal unit, upstream of the seal unit an electric motor, and upstream of the electric motor an optional sensor package. An electric cable extends from the surface down the wellbore to the electric motor and supplies power from a surface located electrical power source (e.g., a variable speed drive) to the electric motor. The electric motor turns a drive shaft that is coupled via other drive shafts within the ESP assembly to provide power the optional gas separator and to the centrifugal pump. For example, a drive shaft in the seal section is mechanically coupled to the drive shaft in the electric motor; the drive shaft in the seal section is mechanically coupled to a drive shaft in the optional gas separator, and the drive shaft in the optional gas separator is mechanically coupled to a drive shaft in the centrifugal pump. When the drive shaft of the electric motor turns (e.g., when electric power is provided via the electric cable to the electric motor), the drive shaft in the seal section is turned; when the drive shaft in the seal section is turned, the drive shaft in the optional gas separator turns, providing motive force to components within the optional gas separator; when the drive shaft in the optional gas separator turns, the drive shaft in the centrifugal pump turns, providing motive force to the centrifugal pump stages of the centrifugal pump. When the ESP assembly is disposed and operated downhole in the wellbore, an interior of the seal section is in fluid communication with an interior of the electric motor, and the seal section provides dielectric oil to the electric motor as well as pressure equalization between an outside of the ESP assembly and the interior of the electric motor.

Electrical submersible pump (ESP) seal section service-less flange


An internal retaining ring for placement in a bore of an outer component of a rotating assembly comprises a semi-annular body having an outer circumferential surface with a curvature defined about a first center of curvature and radially outward protruding anti-rotation tabs operable for engagement with a corresponding anti-rotation feature of the outer component. An inner circumferential surface of the semi-annular body has radially inward protruding tabs circumferentially spaced apart around the inner circumferential surface. The radially inward protruding tabs have radially inner surfaces concentric with the outer circumferential surface, and recessed portions between the radially inward protruding tabs and having curvatures defined about a second center of curvature, the second center of curvature different from the first center of curvature.

Retaining rings are fasteners that may be used in gas turbine engines that are installed onto shafts or other rotating assemblies. Internal retaining rings are installed within the bore of a component whereas external retaining rings are installed on an outer surface of a component, typically within a groove. Internal retaining rings may be used to axially retain a component within the bore, for instance a sealing ring.
Internal retaining rings typically rely on internal spring-back forces to prevent their rotation once installed within a bore of a rotating part, for instance to prevent scoring. Such spring-back forces may render the installation of the retaining ring difficult, for instance due to the required stiffness to attain such spring-back forces. In addition, such spring-back forces would produce undesirable excessive radial loads on the retained components, which may lead to unacceptable stress concentrations that could reduce the component's lifespan. In other cases, an internal retaining ring must be installed between two components, for instance between two concentric shafts, where spacing is limited.

Internal retaining ring for a rotating assembly in a gas turbine engine


A power ring device that includes: a ring conductor; a plurality of controllers, each controller being connected to the ring conductor and includes a first control unit; a plurality of paired pick ups, wherein each pair connects either an electrical consumer device or an electrical power supply to the ring conductor and to one of the plurality of controllers, wherein a first pair of pick ups of a first controller is connected to a first power supply; and a plurality of current sensor signal lines connecting each control unit to form a data connection; wherein each controller has a right and left side, a right sided and left sided switch elements; and a right sided and left sided current sensors connected so that a first current value measured by the left sided current sensor of the first controller is transmitted as data to the first control unit of a second controller.

It is known that to supply devices with electrical energy, as individual components and consumers of electrical power in a vehicle such as a military vehicle, a so-called "power ring" is frequently employed. A power ring is a ring conductor that transports output energy and that connects each electrically consuming device with a power generator, which is different from star-shaped electrical connections that can be employed to connect each electricity consuming device (also referred to as an "electrical consumer") with a generator.
A short circuit in the ring conductor of the conventional power ring has the disadvantage that all electrical consumers connected to the power ring are no longer supplied with electrical power. Consequently, a repair shop is then sought so that the error causing the short circuit in the power ring can be addressed and fixed.
Military vehicles, however, have special requirements and it is an undesirable shortcoming that the internal electrical current supply for all connected devices should fail due to a simple short circuit. Furthermore, repair shops are not always readily available in places where military vehicles may travel. To address this problem, known embodiments of the prior art provide, for example, division of the power ring into individual segments by employing a power-ring controller. Thus, energy consuming devices supplied by the power ring with electrical power are connected to different segments of the power ring. When a short circuit occurs in one segment, only those devices that are connected to this one malfunctioning segment are impaired and fail, while those devices connected to the other isolated segments of the power ring are not affected by the short circuit and continue to be supplied with electrical energy and remain functioning.
In DE 199 16 452 C2 to Joehnke et al., a device is disclosed for a power ring employing a ring conductor in a military vehicle, in order to supply electricity to various devices. This prior art power ring device includes several controllers functioning as oversight and switch devices that are connected along, and to, the ring conductor. The prior art power ring device disclosed by Joehnke et al. also includes additional component devices for the oversight and control of the ring conductor, wherein security is adjusted by means of a number of controlled switches so that ring conductor segments to the left or right of a pick-up controller can be closed or shut off.
After a failure caused by a short circuit in the ring conductor, for example, the power ring is subsequently completely shut off. In other words, a short in any segment of the ring conductor causes the entire power ring to cease conducting power. Subsequently, by means of successive switching, the failing conductor segment is identified and decoupled from the power ring. However, this technique of isolating the failed conductor segment, by systematically testing each segment while the ring conductor is unable to conduct electricity has disadvantages. In particular, it is a disadvantage that the power ring, in a case of electrical failure (i.e., short circuit), must be subsequently shut off completely, thereby interrupting the energy supply to all of the connected electrically consuming devices. In addition, the power ring device disclosed by Joehnke et al. cannot readily locate failures that are sporadic failures. The Joehnke et al. power ring can only localize an electrical failure that persists for a given period of time.


An exemplary safety circuit includes a plurality of contacts that are configured to establish a conductive path across the contacts when the contacts are in electrically conductive contact with each other. The contacts selectively interrupt the conductive path across them when the contacts are separated. A controller selectively introduces a voltage pulse across the contacts at a voltage level that is effective to overcome an electrical resistance of any contamination on at least one of the contacts. The controller introduces the voltage pulse at least when the contacts are expected to be in contact to establish the conductive path.

Safety circuits are used in a variety of applications. A safety circuit typically provides a control over a supply of power to a load, for example. One use of safety circuits is within elevator systems. A daisy chain arrangement of safety switches along a hoistway provides an ability to control whether the elevator machine is powered to cause movement of an elevator car. The switches of the safety circuit along the daisy chain are associated with an elevator door component such as a hoistway door lock. Whenever the door component is not in a properly closed position, the safety switch remains open and interrupts a conductive path along the safety chain. Under these conditions, power is not provided to the elevator machine so that the elevator car cannot move. The safety chain therefore provides an ability to prevent elevator car movement in the event that a hoistway door is not closed or properly locked.
Known safety chains in elevator systems operate based on 110 volt AC power. While such systems have proved reliable and useful over the years, there is a desire to reduce power consumption in elevator systems. One opportunity to reduce power consumption would be to introduce a lower power safety chain circuit. This cannot be done, however, without introducing new design challenges and complexities.


A pull-down circuit in a sense amplifier, such a sense amplifier in a memory integrated circuit, includes a pull-down transistor having a drain coupled to a common node, a gate, and a source coupled to ground. An inverter provides a gate control signal to the gate of the pull-down transistor. A choke transistor has a drain coupled to a power terminal of the inverter, a gate, and source coupled to the power supply voltage. A regressive drive bias circuit is coupled to the gate of the choke transistor and provides a relatively low voltage to the gate of the choke transistor at relatively low power supply voltages resulting in a relatively large gate-to-source voltage on the choke transistor and provides a relatively high voltage to the gate of the choke transistor at relatively high power supply voltages resulting in a relatively small gate-to-source voltage on the choke transistor.

In the electronics industry, integrated circuit device manufacturers design and produce commodity parts that are capable of operating in a variety of electronic systems that have different electronic specifications. For example, dynamic random access memory (DRAM) devices are designed for use in electronic systems with a wide range of power supply voltage. To keep pace with changes in system specifications, device manufacturers face the difficult task of designing new parts that operate over a wider range of conditions.
A DRAM is comprised of an array of individual memory cells. Typically, each memory cell comprises a capacitor capable of holding a charge and an access transistor for accessing the capacitor charge. The charge is representative of a data bit and can be either a high voltage or a low voltage. Data can be either stored in the memory cells during a write mode, or data may be retrieved from the memory cells during a read mode. The data is transmitted on signal lines, referred to as digit lines, which are coupled to input/output lines through transistors used as switching devices. For each bit of data stored, its true logic state is available on an I/O line and its complementary logic state is available on an I/O complement line. Thus, each memory cell has two digit lines, digit and digit complement.
Typically, the memory cells are arranged in an array and each cell has an address identifying its location in the array. The array comprises a configuration of intersecting rows and columns, and a memory cell is associated with each intersection. In order to read from or write to a cell, the particular cell must be selected, or addressed. The address for the selected cell is represented by input signals to a row decoder and to a column decoder. The row decoder activates a word line in response to the row address. The selected word line activates the access transistors for each of the memory cells in communication with the selected word line. The column decoder selects a digit line pair in response to the column address. For a read operation the selected word line activates the access transistors for a given row address, and data is latched to the digit line pairs.
Conventional DRAMs use memory cells fabricated as capacitors in an integrated circuit to store data where a logical "1" is stored as a charge on the capacitor and the capacitor is discharged for a logical "0". The pairs of digit lines are typically fabricated as metal lines on the integrated circuit and connected to the memory cells for transmitting data stored in the memory cells. Sense amplifiers are utilized to sense small differentials on the digit lines and drive the digit lines to full power supply rails for either reading or writing the memory cells.
Typically, a sense amplifier includes a pair of n-channel transistors having a cross-coupled gate and drain configuration. Due to the positive feedback of this configuration, the sense amplifier senses slight changes in the voltages on the digit and digit complement lines and produces full logic values on the digit lines based on the slight voltage differential. The source of each transistor is coupled to a pull-down circuit, which, in operation drives the source of the transistors to ground thus allowing the sense amplifier to amplify the small changes in voltage on the digit and digit complement lines.
Conventionally, the pull-down circuit of an n-channel sense amplifier comprises an n-channel MOS transistor. Unfortunately, conventional pull-down circuits do not function properly over the wider range of power supply voltages demanded by newer systems. At low supply voltages, the current in a typical pull-down circuit is not sufficient to allow the sense amplifier to settle quick enough to produce an accurate reading at the digit lines. Further, at high power supply voltages, the pull-down circuit draws too much current and drives the common source and the drains of both transistors to ground before the digit lines can reach the proper voltages.
Therefore, since current generation DRAMs rely on the analog sense amplifiers to correctly sense a small amount of stored charge in a memory cell and then amplify this charge to full digit-line voltages, the sense amplifiers are difficult to operate across a large voltage range for the power supply voltages. To aid in the operation of the sense amplifier, a current impulse that discharges a sense amplifier's common node must be carefully controlled with the pull-down circuit. If the current pulse is too small, the sense amplifier is not able to properly sense all digits in the given time period. If the current pulse is too large, the sense amplifier is essentially too strong and can corrupt data due to excessive noise and coupling mechanisms.
Therefore, for the reasons stated above, and for other reasons presented in greater detail in the Description of the Preferred Embodiments section of the present specification, there is a need in the art for a memory-integrated circuit having sense amplifier circuitry which functions properly over a wide range of power supply voltages.


A helicopter stall warning method includes receiving an airspeed of the helicopter, determining a stall airspeed based on multiple factors associated with the helicopter, the multiple factors comprising ambient temperature near the helicopter, the helicopter's altitude, and the helicopter's gross weight, determining a stall warning threshold derived from the stall airspeed, and providing a tactile warning through a collective helicopter control when the helicopter's airspeed meets or exceeds the stall warning threshold.

A helicopter can stall if its airspeed is too high. This is referred to as a retreating blade stall. In forward flight, a helicopter's retreating blade (the blade moving in the opposite direction as the aircraft) has a lower airspeed than its advancing blade. A retreating blade stall occurs when the retreating blade exceeds its critical angle of attack. As the helicopter's airspeed increases, the retreating blade's airspeed decreases and angle of attack increases. A stall occurs when the helicopter's airspeed exceeds an upper limit corresponding to the retreating blade's critical angle of attack.
The upper limit of helicopter airspeed is influenced by a number of factors. Some of these factors are outside of a pilot's control. For example, a change in ambient temperature near the aircraft can change the airspeed upper limit. In some cases, a pilot may maintain the same flight path and speed, but a stall may occur because of such external factors. Such a stall can be disorienting for a pilot, not just because of the loss of control of the helicopter, but also because the stall occurs without a warning to the pilot.
Stall warnings are available for fixed-wing aircraft, but not for helicopters. Fixed wing pilots and helicopter pilots can calculate a stall speed, but fixed wing pilots have an advantage because their calculations (and memory of their calculations) are supplemented by active warning systems in the aircraft. This may explain why helicopters' safety record is inferior to fixed wing aircraft's record.


The present disclosure relates to identifying potential fracture treatment locations in a rock formation for oil and/or gas production based on production potential. One example method includes receiving internal imaging data of a core sample of a rock formation; generating a digital core sample model of the structure of the core sample based on the internal imaging data; analyzing the core sample model to determine the density distribution of a deposit in the core sample; and determining a production potential value from the density distribution of the deposit.

This specification relates to identifying potential fracture treatment locations in a rock formation for oil and/or gas production based on production potential.
Deposits that correlate to oil and/or gas production potential may be deposited in various locations throughout a rock formation. The deposits may be of varying sizes and may occur at different frequencies in different parts of the formation. Producing oil and/or gas from the formation may involve choosing a "sweet spot" in the formation to produce from in an attempt to maximize the production and, thus, maximize profits.
Like reference symbols in the various drawings indicate like elements.

Identifying potential fracture treatment locations in a formation based on production potential


A method of controlling the endfill of elongated tobacco articles, whereby at least one collimated beam of electromagnetic radiation is directed on to a series of photosensors aligned in a direction parallel to a longitudinal axis of an article, and is partially intercepted by one end of the article; the signal emitted by each photosensor struck by the nonintercepted portion of the beam is rejected by means of a threshold measurement; and the signal emitted by each photosensor struck by the portion of the beam intercepted by and penetrating the article is compared with a range of limit values characteristic of the endfill.

The present invention relates to a method of controlling the endfill of tobacco articles.
More specifically, the present invention relates to a method of controlling the endfill of cigarettes, to which the following description refers purely by way of example.
The endfill of cigarettes is normally controlled, as the cigarettes are conveyed side by side, by sensors for determining the presence of tobacco in a given end portion of each cigarette. The sensors may be capacitive, optical, inductive, etc., and are located along a path of the cigarettes, close to one end of the cigarettes. As the ends of the cigarettes are not normally aligned perfectly and are therefore variously positioned with respect to the sensors, the sensor readings are affected by the distance between the sensors and the ends being controlled.
One known solution to the problem is to correct the axial position of the cigarettes via mechanical means, such as inclined surfaces, for pushing the cigarettes into line as they are fed forward. The impact or sliding movement imposed on the cigarettes by such mechanical means, however, may result in damage to the cigarettes.
Another known solution is to determine the position of the ends of the cigarettes by means of a first optical sensor, as a succession of side by side cigarettes is fed along a given path; subject one end of each cigarette frontally to a beam of electromagnetic radiation parallel to the axis of the cigarette; and, finally, determine, by means of a second sensor, the radiation reflected by the surface of said end to generate a corresponding signal characteristic of the endfill of each cigarette.
The reading of the second sensor is corrected, taking into account the distance between the end of each cigarette and the second sensor, by means of a mathematical algorithm based on a physical model or test data; and a reject signal is generated in the event the characteristic signal is below a given threshold value.
The above front control method, however, fails to determine any cavities beneath an apparently satisfactory end surface, and involves mathematically correlating heterogeneous quantities such as the distance between the sensor and the ends of the cigarettes, and the quantity of light reflected.

Method of controlling the endfill of tobacco articles


A digital PLL circuit capable of stabilizing a phase comparison operation to largely reduce a jitter of an output signal, including a peak detection circuit for detecting a peak of an input signal level, a two-points sampling circuit for sampling two data points determined at a predetermined time interval in the peak to output two sample values, an inclination calculation circuit for calculating an inclination value from the two sample values, and a discrimination circuit for discriminating whether the inclination value is zero or either a positive or negative value to output a control signal for a VCO depending on the discrimination result.

The present invention relates to a digital PLL circuit for use in a digital synthesizer or the like. Description of the Related Arts
In a conventional digital PLL (phase-locked loop) circuit, a phase comparison is carried out at a zero cross point.
In FIG. 1 there is shown a conventional digital PLL circuit. The digital PLL circuit is comprised of a sampling circuit 7 for sampling input signals I, a discrimination circuit 8 for comparing an output value of the sampling circuit 7 with a predetermined threshold value T to generate a control signal C, a loop filter 9 for smoothing the control signal C output from the discriminating circuit 8 to output a smoothed control signal CS, a VCO (voltage-controlled oscillator) 6 controlled by the smoothed control signal CS output from the loop filter 9, a zero cross detection circuit 10 for detecting the zero cross point of the input signal I to output an enable signal E, and a reference signal generating circuit 5 set by the enable signal E to generate a timing signal TK to the sampling circuit 7 in synchronism with an output signal O of the VCO 6.
Next, the operation of the conventional digital PLL circuit will now be described in connection with FIG. 2.
FIG. 2 is a timing chart showing an operation of the conventional digital PLL circuit shown in FIG. 1. First, an input signal I of a sine wave signal given an A/D (analog-digital) conversion is input from an input terminal TI, and the input signal I is applied to the sampling circuit 7 and the zero cross detection circuit 10.
Next, the zero cross detection circuit 10 detects the zero cross point of the input signal I and outputs an enable signal E rising at a timing of the detection of the first zero cross signal Z1 to the reference signal generating circuit 5. This enable signal E, for example, can be generated by an RS (reset-set) flip-flop using the zero cross signal as a set signal.
Then, the reference signal generating circuit 5 inputs the output signal O of the VCO 6 at a timing of the setting of the enable signal E and outputs the timing signal TK whose frequency is synchronized with the output signal O.
In the sampling circuit 7, this timing signal TK is input as a sampling timing signal to carry out the sampling of the input signal I to output sample values S (S1 to S4).
Next, in the discrimination circuit 8, each sample value S is compared with a predetermined threshold value T to output a control signal C for the VCO 6. In this case, the threshold value T is either a positive threshold value TP or a negative threshold value TN with respect to the central value TO. For instance, as shown in FIG. 2, when the sample value S4 sampled by the positive threshold value TP is large, it is discriminated that the phase of the output signal O of the VCO 6 is lagged compared with the input signal I, and a control signal C for raising the frequency is output to the VCO 6. On the contrary, when the sample value 3 sampled by the negative threshold value TN is small, it is discriminated that the phase of the output signal O of the VCO 6 is led compared with the input signal I, and a control signal C for dropping the frequency is output to the VCO 6. Further, in case of the sample value S2 positioned between the positive threshold value TP and the negative threshold value TN, it is discriminated that the phase of the output signal O of the VCO 6 is equal to the input signal I, and a control signal C for maintaining the frequency is output to the VCO 6. Alternatively, in case of a VCO for holding the frequency when no control signal is input, the output of the control signal C is stopped. As described above, the discrimination circuit 8 controls the VCO 6 so that the sample value S obtained by sampling the input signal I in the sampling circuit 7 may be within a range between the positive threshold value TP and the negative threshold value TN.
Next, the output of the discrimination circuit 8 is smoothed in the loop filter 9 to output a smoothed control signal CS to the VCO 6. The VCO 6 is controlled by the smoothed control signal CS to output an output signal O having a predetermined frequency range as an output signal of the digital PLL circuit to an output terminal TO.
In the above-described conventional digital PLL circuit, when the value of the A/D-converted input signal is largely varied near the zero cross and the input signal is accompanied with an amplitude variation in particular, since the value near the zero cross is further increased, the variation of the output signal of the discrimination circuit becomes large and, even when the smoothing in the loop filter is carried out, a jitter of the output signal of the digital PLL circuit is still large.


An apparatus for covering a plurality of permanent magnets on a rotor with a cylindrical sleeve has a movable jig, a holder jig having a plurality of insertion grooves for inserting therein the permanent magnets disposed in grooves of the rotor, the holder jig and the movable jig being pressable partly into an insertion end of the cylindrical sleeve, a plurality of resilient members disposed in the insertion grooves for pressing the permanent magnets against the outer circumferential surface of the rotor, and a presser device for inserting the movable jig, together with the rotor and the permanent magnets into the cylindrical sleeve under the guidance of the holder jig. The permanent magnets on the rotor are reliably and efficiently covered with the cylindrical sleeve without the need for an adhesive to secure the permanent magnets to the rotor.

1. Field of the Invention
The present invention relates to a method of and an apparatus for covering permanent magnets of a motor rotor with a cylindrical sleeve.
2. Description of the Related Art
Electric motors generally comprise a stator core having as many windings as the number of phases and a rotor rotatably disposed in the stator core and having a plurality of permanent magnets disposed on its outer circumferential surface. The rotor has a shaft and a yoke with the permanent magnets positioned at angularly spaced intervals on the outer circumferential surface of the yoke. The permanent magnets are covered with a cylindrical sleeve made of fiber-reinforced synthetic resin and held against the outer circumferential surface of the yoke.
In order to keep the permanent magnets firmly against the outer circumferential surface of the yoke, it is necessary that the cylindrical sleeve be securely held in intimate contact with the permanent magnets. To meet such a requirement, the diameter of the cylindrical member is considerably smaller than the diameter of the rotor. Therefore, it is a tedious and time-consuming task to install the cylindrical member on the yoke to cover the permanent magnets.
Japanese laid-open patent publication No. 55-111645 discloses an automatic magnet inserting device which comprises means for transferring an array of unmagnetized magnets to a magnetizing position, means for magnetizing the transferred magnets to a predetermined magnetized state in the magnetizing position, means for converting the shape of the magnetized magnets to a cylindrical shape, and means for pushing the cylindrical assembly of the magnets in an axial direction thereof and simultaneously inserting the magnets into a rotor case.
According to the disclosed automatic magnet inserting device, the magnets are simultaneously inserted into the rotor case with a jig and secured in position by an adhesive. To hold the magnets intimately against the outer circumferential surface of the yoke, the yoke has to be pressed into the magnets that have been fixedly positioned in the rotor case. Such a process of pressing the yoke into the magnets is cumbersome. The cost of rotors manufactured by the automatic magnet inserting device cannot be reduced because of the use of the adhesive for securing the magnets.
According to Japanese laid-open patent publication No. 7-336966, there is known a process of covering permanent magnets with a cylindrical member by forcibly spreading the cylindrical member radially outwardly under a fluid pressure, inserting a rotor and the permanent magnets into the cylindrical member, and then discharging the fluid.
The disclosed process will be described below with reference to FIGS. 33A and 33B of the accompanying drawings. As shown in FIG. 33A, a rotor 2 and permanent magnets 3 are supported by a holder jig 4 and a movable jig 5. A cylindrical sleeve 6 is disposed in a casing 7 and has an end spread and gripped by an O-ring 8 mounted in the casing 7, the holder jig 4, and the movable jig 5.
A fluid is introduced into the casing 7 to spread the cylindrical sleeve 6 radially outwardly under a fluid pressure. Then, the rotor 2 and the permanent magnets 3 are inserted together with the movable jig 5 into the cylindrical sleeve 6.
When the movable jig 5 is inserted into the cylindrical sleeve 6, the cylindrical sleeve 6 is contracted radially inwardly between the movable jig 5 and the holder jig 4, and pulled to a straight shape between teeth 4a of the holder jig 4, as show in FIG. 33B. The permanent magnets 3 inserted together with the movable jig 5 into the cylindrical sleeve 6 are held in sliding contact with the straight portions of the cylindrical sleeve 6. Therefore, surfaces of the permanent magnets 3 and the cylindrical sleeve 6 are liable to be damaged due to the frictional engagement therebetween.
Cylindrical members often have mechanical strength variations. A cylindrical member which tends to stretch under a given pressure is unable to impose tightening forces that are required to prevent permanent magnets from being displaced off the rotor. On the other hand, a cylindrical member which is less likely to stretch under a given pressure exerts resistance to the insertion of permanent magnets into the cylindrical member. Even if the permanent magnets can be covered with the cylindrical member, the cylindrical member will be cracked by centrifugal forces developed when the rotor rotates upon energization of the motor.

Apparatus for covering permanent magnets on motor rotor with cylindrical sleeve


A ramjet for supersonic and/or hypersonic aircraft, designed to operate over a wide range of speeds, includes an inlet for a combustion supporting gas; a fuel injection device; and a ramjet body. The ramjet body has a combustion chamber in which the combustion supporting gas is mixed with a fuel to be burned and an exhaust nozzle to channel gases leaving the combustion chamber and which has, at least in a transition area between the combustion chamber and the exhaust nozzle, a variable geometry enabling its longitudinal section to be progressively modified. The ramjet body has at least one controllable opening adapted to establish communication between the combustion chamber and the exterior to enable the introduction of an exterior air stream into the transition area.

1. Field of the Invention
The present invention concerns a ramjet for supersonic and/or hypersonic aircraft designed to operate over a wide range of speeds, for example Mach numbers between 1-2 and 15-20.
2. Description of the Prior Art
French patent application 95 08417 describes a ramjet able to operate over a range of speeds in this order whilst retaining maximum efficiency. To this end, it comprises:
a combustion supporting gas inlet; PA1 a fuel injection device; and PA1 a ramjet body which comprises a combustion chamber in which the combustion supporting gas is mixed with a fuel to be burned and an exhaust nozzle to channel the gases leaving the combustion chamber and which has, at least in a transition area between the combustion chamber and the exhaust nozzle, a variable geometry progressively varying from a convergent then divergent longitudinal section for speeds corresponding to a low Mach number to an approximately constant and then divergent longitudinal section for speeds corresponding to a high Mach number.
A variable geometry of the longitudinal section of the body is obtained, in the embodiment described in the above patent application, by having one of the lateral walls of the body in the form of plates hinged together about axes transverse to the longitudinal direction of the ramjet at least in the transition area (nozzle throat). Accordingly, depending on the selected airspeed, the geometry of the longitudinal section of the body can be varied, in particular in the transition area, by moving the plates progressively into the appropriate position, which enables optimal flight conditions to be conserved for the indicated range of speeds, in particular a maximal thrust value independent of external conditions (fuel consumption, aerodynamic pressure, profile of the flow of combustion supporting gas in the corresponding inlet). In other words, this amounts to "eliminating" the nozzle throat (convergent-divergent geometry) that exists at "low" speeds so as finally to obtain (at a Mach number equal to or greater than around 7) a constant section of the combustion chamber followed by the divergent section of the exhaust nozzle.
Although technically operational, this embodiment of the variable geometry of the body can give rise to problems with correct operation at the hinges of the plates, from the point of view of reliability under extreme conditions, in particular of temperature. Air blower means may then be provided to eliminate these drawbacks. What is more, the set of hinged plates and the blower means, if used, help to increase the mass of the ramjet, which is undesirable.
An object of the present invention is to propose a ramjet in which the design of the variable geometry of the body eliminates the problems referred to hereinabove.

Aerospatiale Societe Nationale Industrielle


A facsimile apparatus equipped with multiple recording sheet feeding devices is provided with a memory for storing information designating the size of a recording sheet to be used for recording a received image. There is a control device for selecting a sheet feeding device from among the multiple sheet feeding devices for recording the received image in accordance with the information stored in the memory and based on the length and width of the received image. The received image is recorded on a sheet of such size as desired and prescribed by a user by a printing mechanism.

1. Field of the Invention
The present invention relates to a facsimile apparatus equipped with multiple recording sheet feeding devices and more particularly to the manner of designating the size of a recording sheet to be used to record a received image and selecting an appropriate sheet feeding device from among the multiple sheet feeding devices.
2. Discussion of the Background
In general, a facsimile apparatus is so made to transmit A4 size documents (a size corresponding to a letter size in the US) which is the most widely used size. However, there exists a need to transmit documents of other sizes such as A5, B5, B4 and A3 sizes, and some facsimile apparatuses are capable of transmitting and recording such sizes in addition to the A4 size. Further, some apparatuses are provided with a device for feeding a rolled sheet having an A4 width so that an image of continuous length can be recorded. In such an apparatus having multiple recording sheet feeding devices, however, there exists a problem in that it is difficult to determine which one of such multiple recording sheet feeding devices is the most appropriate one to be used for recording a received image.

Facsimile apparatus which selects the size of a recording sheet to be used for recording a received image


A system and method for preventing unauthorized use of a remotely operated system, by using a sophisticated bi-directional verification schemes. The bi-directional verification schemes are based on random challenge and response between a mobile station and a cellular network. The cellular network discriminates between "pirate" mobile stations and mobile stations authorized to use the cellular network. The security afforded by bi-directional verification is applied to a system and method for use in conjunction with remotely operated systems, including one or more pieces of application equipment or a home automation system.

Many systems in homes and in automobiles are operated remotely using low-power radio transmitters, some of which comply with FCC Part 15 rules. Examples of remotely operated systems include garage door openers and intruder alarm disable switches. Although these systems, like modern cordless telephones, employ some basic security encoding of their transmitted signals, they have some pitfalls. For example, the basic security coding on remotely operated systems may be easily duplicated.
Typically, remotely operated systems include a transmitter and a receiver, each having the same security code programmed onto it. The security code is identical on each transmission between the transmitter and receiver, is transmitted at a low rate, and has a very limited number of separate code combinations possible (typically up to 2.sup.15). This basic security code is easily duplicated by intercepting a transmission from the transmitter, or by "tumbling" the security code in a duplicate transmitter.
In addition to the problem of transmitter duplication, there is typically no verification of the transmitter by the receiver. Thus, if a duplicate or pirate transmitter is created in one of the aforementioned ways, there is no way for the receiver to distinguish the duplicate transmitter from a legitimate transmitter by interrogation, because the radio link operates in one direction only.
Some improved transmitters have been designed to attempt to overcome these defects by using a "rolling code" which changes each time the transmitter is successfully used. However, these improved transmitters are still vulnerable to duplication because there is no bi-directional verification of the transmitter. This situation is similar to that which currently exists in cellular systems, where duplication of a mobile station's identification number (MIN) and its electronic serial number (ESN) in a "pirate" mobile station allows calls to be made on the pirate mobile station which are then charged to the account of a legitimate user.

Secure equipment automation using a personal base station