1
Andres R Lucero, Neil J Netley, Richard C Raven, Chester C Egan Jr: Electronic gaming apparatus. Bally Manufacturing Corporation, Fitch Even Tobin Flannery & Welsh, December 9, 1980: US04238127 (194 worldwide citation)

In amusement and game apparatus of the type having a set of symbol-bearing reels and mechanism for spinning the reels after depositing the proper coins, an electronic control for selecting the stopping positions for the reels, for detection of the reel position, for calculating the payout to the pla ...


2
William F Ehrsam, Robert C Elander, Stephen M Matyas, Carl H W Meyer, John L Smith, Walter L Tuchman: Cryptographic file security for single domain networks. International Business Machines Corporation, Edwin Lester, December 9, 1980: US04238854 (190 worldwide citation)

A file security system for data files associated with a host data processing system. The host system includes a data security device which contains a secure host master key and is capable of performing a variety of cryptographic operations. At initialization time, the host system generates a series ...


3
Gerhard Gunter Gassmann: Method of and system for transmitting two different messages on a carrier wave over a single transmission channel of predetermined bandwidth. International Standard Electric Corporation, John T O Halloran, Peter C Van Der Sluys, December 9, 1980: US04238849 (188 worldwide citation)

In a radio broadcoast channel, an additional message is superimposed on the normal message so as to be inaudible to the listener. To accomplish this, the additional message, consisting of digital signals, is modulated on a subcarrier lying in the ear-physiological masking range of the normal message ...


4
Zafer Termanini: Dynamic intramedullary compression nailing. Towmotor Corporation, Kenyon & Kenyon Reilly Carr & Chapin, December 9, 1980: US04237875 (186 worldwide citation)

A dynamic compression nail for intramedullary compression nailing in treating the fractures of long bones includes a proximal part having at its distal end a central cylindrical recess open on the distal end and a central bore through the remaining portion of the part; a distal part having a tip por ...


5
William F Ehrsam, Robert C Elander, Stephen M Matyas, Carl H W Meyer, Robert L Powers, Paul N Prentice, John L Smith, Walter L Tuchman: Cryptographic communication security for single domain networks. International Business Machines Corporation, Edwin Lester, December 9, 1980: US04238853 (152 worldwide citation)

A communication security system for data transmissions between remote terminals and a host system. The remote terminals and the host system include data security devices capable of performing a variety of cryptographic operations. At initialization time, a host master key is written into the host da ...


6
Donald I Gonser: Electrosurgical device. Valleylab, Gerald J Ferguson Jr, Joseph J Baker, December 9, 1980: US04237887 (141 worldwide citation)

A radio-frequency electrosurgical device which includes an active electrode, a passive electrode, and means for generating a radio-frequency potential. The generating means induces the radio-frequency potential on a primary winding of an isolation transformer. The secondary winding of the isolation ...


7
Joseph H Schulman, Douglas G Ritchie: Implantable calibration means and calibration method for an implantable body transducer. Pacesetter Systems, Freilich Hornbaker Wasserman Rosen & Fernandez, December 9, 1980: US04237900 (134 worldwide citation)

An implantable body transducer having a self-contained calibration means. An exemplary embodiment comprises an implantable body pressure measuring transducer utilizing an L-C oscillator having a resonant circuit comprising a fixed L and a variable C, the variable C having a fixed capacitive electrod ...


8
William H DeLuca, Fred Hornstra Jr, George H Gelb, Baruch Berman, Larry W Moede: System and method for charging electrochemical cells in series. The United States of America represented by the United States Department of Energy, James E Denny, Frank H Jackson, Hugh W Glenn, December 9, 1980: US04238721 (121 worldwide citation)

A battery charging system capable of equalizing the charge of each individual cell at a selected full charge voltage includes means for regulating charger current to first increase current at a constant rate until a bulk charging level is achieved or until any cell reaches a safe reference voltage. ...


9
Steven Kunreuther: Automatic attaching apparatus. Kunreuther & Beringhause, James & Franklin, December 9, 1980: US04237779 (114 worldwide citation)

The apparatus is designed for automatic attachment of a header, a tag or the like to a softgoods article by means of a plastic fastener. A commercial fastener attacher of the non-automatic, hand-held variety is fixedly mounted on a support and has a stationary hollow needle through which the fastene ...


10
John F Schenck: Field effect transistor for detection of biological reactions. General Electric Company, Marvin Snyder, James C Davis, December 9, 1980: US04238757 (106 worldwide citation)

A field effect transistor including conventional source and drain electrodes employs, in the gate region, a layer of antibody specific to a particular antigen. An electrolyte solution such as 0.155 Normal sodium chloride atop the antibody layer provides a predetermined drain current versus drain vol ...