Abstract: A bindery caliper is provided in the form of a non-contacting capacitive change measuring device capable of determining the page count of a multi-page stack with high sensitivity. The capacitance of a pair of plates between which the stack of pages is disposed sets the frequency of an oscillator which is sampled for a predetermined time period. The sampled pulses are counted and compared to a standard within tolerances, and the comparison determines whether the page count is satisfactory. Means for updating the standard value on the basis of accumulated measurements is also provided.

Abstract: A tape end warning apparatus comprises an alarm switch which is closed in response to the detection of a terminal end of a running tape being reached during a record or playback operation of a tape recorder, and an oscillator circuit which is activated by the closure of the switch. The oscillator circuit produces an alarm signal which is fed to an amplifier inherently contained in a tape recorder so as to give off an audible alarm through a loudspeaker which is connected with the amplifier.

Abstract: A volume controlled tape and alarm for a tape recorder is disclosed. The tape end alarm is coupled between a microphone and an audio amplifier and includes an automatic gain control circuit for maintaining a constant recording level, an oscillator for generating an audio frequency signal, and a variable volume control resistor for coupling the output of the oscillator circuit to the automatic gain control circuit. The volume of the audio alarm signal can be adjusted by adjusting the position of an externally adjustable knob connected to the variable resistor.

Abstract: A tri-level output sensor senses faulty window construction in a web of continuous business forms of stationery, for controlling visual and audible indicators, including a display of the relative position of the faulty sensed window construction, within a continually fanfolding end stack. Pulsing circuitry drives tri-level-to-digital processing circuitry, conjointly providing referencing information to process the sensor output and timing information to sample the processing circuitry, and drives a pair of counters for fanfold position indication and consecutive-fault-occurrence determination, dependent on the processing output.

Abstract: A proximity caliper for sensing the correct thickness of printed signatures is mounted on an apparatus for feeding printed sheets. A metal gripper which retains a signature against a rotatable drum traverses the caliper as the drum transfers the signature from one point to another. The proximity of the metal gripper with respect to the caliper is a function of signature thickness. Hence, the signature having too many or too few pages is detected. The proximity caliper includes at least two proximity sensors which do not come in contact with the metal gripper. The position of the sensors is adjustable with respect to the rotatable drum to accommodate signatures having a wide range of different thicknesses. The sensors are also adjustable with respect to each other to control the sensing tolerance. Signatures of the correct thickness are transferred by the drum and normal operation of the feeding apparatus proceeds. Signatures which are detected as having an incorrect number of pages may be removed.

Abstract: A release device is provided which disables a tape end detection in a tape recorder which is provided with an apparatus for indicating a tape end, such as an end alarm unit or auto "shut-off" unit (which returns a sliding plate carrying a head assembly, thereby producing an audible indication). The release device comprises means including an externally operable member to disable a tape end detection. Said means may be automatically reset in response to a movement of a record/playback actuating member or in response to the loading or removal of a tape cassette. In addition, the release device includes a release inhibit means which prevents the release means from operating when the record/playback member is not in its operative position or when a tape cassette is not loaded.