Abstract: A charge-discharge switching circuit for use in a cordless telephone which automatically connects and disconnects the receiver and transmitter circuits from a rechargeable storage battery in the handset in response to the base unit charger signal so that the transmitter and receiver circuits are disconnected from the storage battery when it is being charged by the charger in the base unit of the cordless telephone.

Abstract: A telephone ringer system is disclosed which uses an oscillator circuit to drive a piezoelectric transducer to produce the ring signal.

Abstract: A ringer circuit for a telephone is disclosed which is equipped with a transformer, having its primary winding connected to the telephone line through hook-switches. The secondary winding of the transformer is connected to a rectifying circuit so that it may convert the high voltage and low current of the ringer signal received into a secondary ringer signal having high current and low voltage. This secondary ringer signal is rectified and fed to an oscillator which drives a sound generator to provide a call signal.

Abstract: An inverting circuit of the series resonant type and including a pair of SCR's operated at variable off-times for controlling the charging of a battery. A control circuit is provided for gating the SCR's at appropriate times in response to sensed circuit current, and battery voltage. Instantaneous resonant circuit current is monitored to derive timing information for firing the SCR's and for anticipating commutation failures.

Abstract: A disc formed of a resilient plastic exhibiting a low creep characteristic and having a pressure vent is used to close the mouth of a tubular cell envelope of a primary cell. An elongated terminal is inserted through the disc and into the cell interior. The pressure vent is in the disc at a location between the terminal and the edge of the disc. The vent comprises a recess having a frangible diaphragm with at least one groove. At a predetermined pressure the diaphragm breaks at the groove, releasing pressure.

Abstract: A polarity indicating system using a light emitting diode is mounted on the clip for a battery charger to provide an indication that the battery charger is properly connected to the battery being charged. In the preferred embodiment, the LED is connected to a test probe mounted in one of the handles of the negative clip and connected in series between the test probe and the positive cable. An alternate embodiment uses the polarity indicating system on battery booster cables.

Abstract: A process for preparing a polymeric material grafted throughout its bulk is provided. A polymer having finely divided particles is blended with silica and maintained in a fluidized bed. The polymer is activated by passing ozone uniformly through the blend to initiate incipient labile sites in the molecular structure of the polymer. The polymer is then reacted with an ethylenically unsaturated ionogenic monomer to graft polymerize the monomer onto the polymer. The grafted polymer may then be converted to a salt form by reacting with alkaline compounds. The resultant powders can be fused into any desired shape by conventional polymer plastic processes.

Abstract: A material useful as a separator in batteries and a process for making the material is provided. This material is a polyolefin having grafted to it side chains derived from an ethylenically unsaturated ionogenic monomer and cross-linked with sulfur.

Abstract: A process for improving leakage resistant in a galvanic cell is provided. This is done by making an improved grommet and metal cover. The process comprises swelling a grommet which has been placed tightly around the periphery of a metal cover until the grommet is loose upon the metal cover, forcing a sealant solution between the swollen grommet and metal cover and then shrinking the grommet to substantially its original size to trap the sealant compound between the grommet and metal cover.

Abstract: A pacemaker pulse generator for providing impulses to stimulate living tissue by means of an electrode at the distal end of a conductive catheter. The catheter is coupled to the pacemaker by means of a connector having engaging surfaces formed by a number of helically-extending, tensioned metal strands.

Abstract: A unique alloy comprising lead with small additions of zinc and tin is used to make grids for lead acid cells. The alloy as produced is softer than is desirable. It is hardened by mechanical working. When properly worked, it has a strength and stiffness approaching that of other low alloy lead materials currently in use as storage battery grids.

Abstract: A vent system for an electric storage battery having a flame arresting capability to minimize the possibility of battery explosion from ignition of explosive gases flowing from the vent plug. The vent system includes a vent plug design having an internal restricted passage and a flange extending around the top of the vent plug which cooperates with the upper surface of the battery cover to create an explosion chamber, so that in the event the explosive gases being vented are ignited, the resulting controlled explosion extinguishes the flame. One embodiment is provided wherein the top surface of the plug is flush with the top of the battery cover. A modified vent well is required for this embodiment, whereby the vent well in the battery cover has a recessed shoulder to receive the flange portion of the vent plug. A second embodiment is also provided wherein the vent plug can be used on conventional battery cover designs, but is not flush with the top of the battery cover.

Abstract: A vent system for an electric storage battery having a flame arresting capability to minimize the possibility of battery explosion from ignition of explosive gases flowing from the vent plug. The vent system includes a vent plug design having an internal restricted passage and a flange extending around the top of the vent plug which cooperates with the upper surface of the battery cover to create an explosion chamber, so that in the event the explosive gases being vented are ignited, the resulting controlled explosion extinguishes the flame. One embodiment is provided wherein the top surface of the plug is flush with the top of the battery cover. A modified vent well is required for this embodiment, whereby the vent well in the battery cover has a recessed shoulder to receive the flange portion of the vent plug. A second embodiment is also provided wherein the vent plug can be used on conventional battery cover designs, but is not flush with the top of the battery cover.

Abstract: A system for providing a signal suitable for transmission by telephone equipment to indicate the duration of pulses produced by a heart pacer. The system includes a pickup for detecting pacer pulses and a switched circuit responsive to pulse duration for applying charge to a first capacitor. During the inter-pulse period a second or reference capacitor is charged to a level corresponding to that of the first capacitor though a timed switching circuit, after which another timed switching circuit discharges the first capacitor to prepare it for receiving a subsequent charge. The potential accumulated upon the second capacitor is then used to operate an output stage pulse generator which controls the duration of an audio-frequency tone burst.

Abstract: A system for rapidly substituting one source of AC power for another. A solid-state gated electronic valve is coupled in circuit with a principal power source or "line" and the current through the valve is monitored. Line voltage is also monitored and a timing signal produced to keep the system in synchronism with the principal power source. When the source voltage decreases or changes abruptly, or if its phase drifts unacceptably, the difference detected between the source and a reference effects the termination of valve gating signals, and allows the application of synchronous enabling signals to a standby power source. If the solid-state valve is non-conducting the standby source starts immediately in synchronism with the previously-supplied load voltage. If current is flowing in the valve, however, a commutating signal is produced which overrides the synchronous standby enabling signal to energize the standby power source with the proper polarity to extinguish current through the valve.