Abstract: A combined specific ion and reference electrode structure having an air gap, gas permeable membrane and in which the active, conducting solution has a surface tension and boiling point which are great enough that with equal ambient pressures on both sides of the membrane the active solution will neither leak nor evaporate rapidly through the membrane at the temperature range over which the electrode structure is operated, namely -40.degree. C to 60.degree. C. In the preferred embodiment, the active solution solvent as well as the reference solution solvent are selected from among the class consisting of ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, tetraethyleneglycol, hexylene glycol, propylene carbonate, dimethyl sulfoxide and dimethyl formamide.

Abstract: Braking apparatus for a web transport system to move a web between rotary members wherein at least one motor is provided for moving the rotary members to drive the web. One of the rotary members is coupled to and drives a first mechanism; and another movable member is coupled to and drives a second mechanism which mechanisms exert retarding forces on the respective rotary members such that when the driving force from the motor is removed and the rotary members are no longer driven, the retarding forces exerted thereon act to brake the rotary members.In an embodiment wherein the shoeless braking apparatus is used in a tape recording and/or playback device, one motor drives a take-up reel rotary member. In addition, a second motor may be provided to selectively drive the take-up reel rotary member in a "fast-forward" direction and to selectively drive the supply reel rotary member in a "rewind" direction.

Abstract: Magnetic recording/playback apparatus for playing back pre-recorded messages and for recording replies to such messages, finding particular application as an unattended telephone message recording device. Successive ones of the pre-recorded messages are separated by detectable indicia. A playback transducer is provided to reproduce the pre-recorded messages and a recording transducer is provided to record the replies to such pre-recorded messages. A detector coupled to the playback transducer detects the indicia and a sensor in communication with the recording transducer senses when a reply to a pre-recorded message has terminated. Switching devices are provided to switch the apparatus from a playback mode to a recording mode when the indicia are detected and for switching the apparatus from the recording mode to the playback mode when the end of a reply is sensed.

Abstract: A cassette changer apparatus for use in a multiple cassette record and/or playback system. An input magazine stores a stack of cassettes, preferably in a vertical stack, each cassette housing magnetic tape therein. An output magazine is spaced from the input magazine and stores a stack of cassettes; and a record/playback station is disposed intermediate the input and output magazines. A fresh cassette is conveyed by an endless conveyor from the input magazine to the record/playback station, and thence to the output magazine whereat an elevator loads the cassette into the stack in the output magazine. A record/playback deck is pivotally driven at the record/playback station from a first position that is spaced from a cassette conveyed to the station to a second position that is in operative relation with respect to such a cassette so that a record and/or playback operation can be performed.

Abstract: A catalytic combustion-type, gas sensing, resistive element and the method of making it by forming an electrical conductor, whose electrical resistance varies with temperature, into a helical coil, coating the coil with a refractory material whose coating matures at a temperature in the range of 1200.degree. C to 1400.degree. C, and heating the coated coil at that temperature range until the coating matures and shrinks into a dense, gas-tight sheath about the helical coil. The coating on the helical coil is integral between adjacent loops and there is a hollow space along the longitudinal axis of the coil. The exterior of the sheath coating may then be further coated with a catalyst, catalytic wash coating, or in some embodiments the hollow space is filled with a porous catalytic material such as platinum and the ends of the hollow space are capped with a porous refractory ceramic material.

Abstract: Apparatus for selectively imparting rotary motion to two spaced apart rotary members which may be used in a web or tape transport mechanism to bi-directionally transport a web or tape. In a preferred embodiment, this apparatus is used as a tape transport in a magnetic recording and/or playback machine. A drive roll in the tape transport mechanism selectively contacts one of the rotary members. The drive roll is coupled to a bi-directional drive motor and includes an extending shaft segment. A string member, tensioned at each end, has an intermediate portion thereof deployed about the extending shaft segment of the drive roll. Upon rotation of the drive motor in one direction, the drive roll and shaft segment rotate and the frictional forces between the string member and the shaft segment cause the shaft segment to traverse the string in a corresponding direction so as to bring the drive roll into contact with one of the rotary members.

Abstract: Head support apparatus for a recording and/or playback apparatus including a pivotable support member upon which the head is mounted. The support member is pivotally coupled to a pivot rod and pivots in a plane substantially normal to the movement of tape past the record and/or playback head with the pivotal movement of the support member controlled to selectively place the head in contact with the tape. In one embodiment, the tape is stored in a housing which is supported within the recording/playback apparatus, the tape and tape housing being loaded and unloaded with the assistance of a tray. A second support member adjacent the first-mentioned support member is pivotally coupled to the same pivot rod. A spring is coupled between the tray and the second support member to bias the tray toward a receiving position for receiving a tape housing and to bias the second support member toward the tray.

Abstract: Shaft position sensing apparatus includes a group of generally parallel vanes extending generally longitudinally of the shaft axis, means for mounting the vanes in that relationship and attaching them to the shaft for rotation with the shaft, a light source providing a beam of light directed transversely of the shaft axis against the vanes, and a light sensor aligned with the light beam and positioned on the opposite side of the shaft axis from the light source for receiving varying amounts of light dependent upon the angular position of the shaft.

Abstract: Apparatus for indicating the location of particular information, such as instructions, represented by predetermined signals previously recorded on a record medium. An array of light emitting sources is selectively energized to indicate the position of the particular information relative to the length of the record medium while the array is scanned in synchronism with the scanning of the record medium to detect the presence of such predetermined signals. Indexing means sequentially conditions each of the light emitting sources to be energized during scanning; and a temporary storage circuit stores a representation of a detected predetermined signal, until a light emitting source is conditioned.

Abstract: Indexing apparatus for indicating the amount of information recorded on or transcribed from a record medium. A non-linear index scale having, for example, time markings thereon, is moved into view concurrently with the rewind movement of the record medium to a beginning location in preparation of a reproducing, or transcribing operation. The length of index scale viewable by an operator represents the amount of recorded information to be transcribed; and as transcription proceeds, the scale remains stationary and is scanned by an indicator. For an information recording operation, the index scale is moved fully into view and is scanned by the indicator.

Abstract: A central dictation system including a plurality of remote dictate stations, a plurality of record/reproduce stations and a plurality of transcribing stations operatively connected to respective ones of the record/reproduce stations. Any one of the remote dictate stations is capable of communicating with any one of the record/reproduce stations so as to execute a dictate and/or playback operation. When a record/reproduce station is communicating with a dictate station, the remaining dictate stations are prevented from gaining access to that communicating record/reproduce station. A transcribing operation can be performed substantially independent of the dictate and/or playback operation. Code recording apparatus is provided to automatically record a predetermined code signal at the conclusion of each dictated message. This recorded code signal prevents the recorded message from being reviewed or erased by the subsequent use of a remote dictate station.

Abstract: A telephone call-diverter system for interconnecting an incoming telephone line to an outgoing telephone line so that an incoming telephone call can be transferred to a predetermined remote telephone station. A DC conducting channel is established between the call-diverter system and the incoming telephone line subsequent to the detection of the incoming telephone call, the transmission of dialing signals from the call-diverter system over the outgoing telephone line and a remote station answer condition provided on the outgoing telephone line. In one embodiment, a voice frequency transmission channel is provided in the incoming telephone line connection so that voice frequency communication between the incoming and outgoing telephone lines is provided independent of the completion of the DC connection. Hence, voice frequency signals can be communicated even before the DC connection is established.

Abstract: Indexing apparatus for use with dictating and transcribing systems, such as a tape recorder or the like, which provides a cumulative indication of the amount of tape awaiting an operation such as transcription of dictated material. The indexing apparatus is coupled to an apparatus such as a dictating and transcribing apparatus and indicates the quantity of tape upon which dictation has been made. As a transcriptionist transcribes dictation from the tape, the indexing apparatus reflects the quantity of tape transcribed so that at all times the indexing apparatus indicates the amount of tape ready to be transcribed to provide an indication of the load level of material waiting to be transcribed. Thus, as transcription is accomplished without further dictation the indicating apparatus will revert to a zero indication.

Abstract: A central dictation system including a plurality of remote dictate stations and a plurality of record/reproduce stations. Any one of the remote dictate stations is capable of communicating with any one of the record/reproduce stations so as to execute a dictation operation. When a record/reproduce station is communicating with a dictate station, the remaining dictate stations are prevented from gaining access to that communicating record/reproduce station. Various operating functions at the record/reproduce station are controlled from the remote dictate station by the transmission of constant currents having predetermined magnitudes representing the particular functions to be performed. The constant currents received at the record/reproduce station are decoded into predetermined control signals whereby functions such as dictate, rewind, stop, playback, fast forward and transfer can be attained.

Abstract: A power supply apparatus having minimal power dissipation for supplying a substantially constant voltage regardless of the variation of an input voltage. A transformer having primary and secondary windings is provided to receive an input voltage and to produce an output voltage from which the substantially constant voltage is derived. The turns ratio of the transformer is varied in response to variations in the amplitude of the input voltage which exceed a predetermined range such that the turns ratio is reduced when the input voltage is increased and the turns ratio is increased when the input voltage is reduced. In one embodiment of this invention, when the supplied substantially constant voltage exhibits variations of greater than predetermined magnitude, an audio signal processing circuit which is powered by the substantially constant voltage is substantially disabled.

Abstract: A central dictation system including a plurality of remote dictate stations, a plurality of record/reproduce stations and a plurality of transcribing stations operatively connected to respective ones of the record/reproduce stations. Any one of the remote dictate stations is capable of communicating with any one of the record/reproduce stations so as to execute a dictate and/or playback operation. A transcribing operation is capable of being performed substantially independent of the dictate and/or playback operation and, therefore, may be performed simultaneously therewith. Apparatus is provided for each record/reproduce station to provide an indication of the cumulative amount of record medium upon which dictated information has been recorded which is awaiting transcription. This indication is affected in a first direction when dictation proceeds and is affected in a opposite direction when the dictated information is transcribed.

Abstract: A catalytic combustion-type, gas sensing, resistive element and the method of making it by forming an electrical conductor, whose electrical resistance varies with temperature, into a helical coil, coating the coil with a refractory material whose coating matures at a temperature in the range of 1200.degree.C to 1400.degree.C, and heating the coated coil at that temperature range until the coating matures and shrinks into a dense, gas-tight sheath about the helical coil. The coating on the helical coil is integral between adjacent loops and there is a hollow space along the longitudinal axis of the coil. The exterior of the sheath coating may then be further coated with a catalyst, catalytic wash coating, or in some embodiments the hollow space is filled with a porous catalytic material such as platinum and the ends of the hollow space are capped with a porous refractory ceramic material.