A hearing aid switch of the type shown in U.S. Pat. No. 3,475,566 issued Oct. 28, 1969, is provided with additional contact position to add an additional mode of operation without increasing the size of the switch or the structure in which it is contained. The switch has three positions: an "on" position which connects the microphone of the hearing aid unit to the amplifier, a "mid" position which connects an additional transducer in the hearing aid to the amplifier (as for instance a telephone ...

A convergence assembly for use in color television kinescopes in which the internal pole pieces are secured to the housing thereof by means of an ear or tab portion engaging a slot in the housing and by means of a substantially T-shape arrangement mechanically connected to exert a force on the pole pieces tending to keep them in proper alignment position. An interleaving sheet arrangement is further provided to shield the magnetic field associated with one pole pair from the magnetic field assoc...

A chamber filled with high-pressure SF.sub.6 surrounds the disconnect contacts of a circuit breaker when the breaker is connected to the cooperating terminals of a metal-clad switchgear housing to permit a relatively short bushing length.

A tone control circuit used in a stereo amplifier, guitar amplifier, or the like, comprising an amplifier having a first terminal and a second terminal for delivering outputs in an opposite phase relation, a plurality of circuit branches connected across the first and the second terminals for controlling tone level in the corresponding frequency ranges, and variable elements included in said plurality of circuit branches and each having a movable contact terminal connected to the ground, so that...

Venous pressures are easily and accurately measurable with a manometric device, closed at one end to substantially lessen the possibility of retrograde infection and having a sight glass affixed to a graduated ruler backing to align the zero level thereof with a patient's zero level. The reservoir of the device is comprised of a transparent plastic tube overlying a pattern imprinted along the length of the ruler, and is filled with a transparent liquid, the level of which provides the pressure i...

Compositions for electrosensitive recording material used as recording paper for facsimiles etc., comprise zinc oxide doped with trivalent or tetravalent metal elements and a binder. 7 Claims, No Drawings

A switch which is operable responsive to impact comprises a ring-shaped contact biased into bridging contact with spaced stationary contacts. The ring-shaped contact is rotatable relative to the spaced contacts to present new contacting surfaces upon rotation, and is biased toward the stationary contacts by the pressure of leaf springs pressed against the ring contact by an adjustable screw which passes through the center of the contact.

A method and apparatus is described for the handling of waste material, refuse and the like. Such waste material is normally deposited in large sized trash cans each of which are provided with an opening located near the closed bottom end thereof. A mobile unit is provided with suction generating means coupled to a flexible elongated hose of relatively large diameter. The flexible elongated hose, preferably of a corrugated type, has an outwardly directed flange spaced inwardly from its free end ...

Automatic volume control is effected in an audio amplifier comprising a multi-stage preamplifier and a direct current coupled output amplifier by processing the derived output signal to modify the preamplifier supply voltage.

The novel 1-aminoalkyl-2,6-diaryl-4,5,6,7-tetrahydroindoles of the present application are useful as analgetics and antitussives. They may be prepared by either of two routes. In the first mode of preparation, the corresponding 2,6-diaryl-4,5,6,7-tetrahydro-4-oxoindole is reacted with aminoalkylating agent. In the second mode, a 2-aroylmethyl-6-aryl- 1,3-cyclohexanedione is reacted with an appropriate diamine. In order to produce the compounds of this invention which are devoid of an oxo substit...