A conventional phonograph arm consists essentially of a balanced rod on one end of which is mounted a phono pick-up device (cartridge) and at the other end a counterweight. A pivot system located near the counterweight is so arranged that the cartridge can move vertically and laterally. Such arms suffer from the fact that when the turntable is suddenly tilted or vibrated the cartridge frequently leaves the surface of the record. The present disclosure describes the use of a two-element arm where...

An array of sonic transducers, useful for medical ultrasonic imaging, has individual sections thereof separately coupled for forming separate beams of sonic energy which converge, respectively, to separate foci along a common axis of the beams. The ratio of the diameter of the radiating aperture of the array relative to a wavelength of the sonic energy is chosen to provide a moderate degree of focusing so that the depth of field at one focus blends with the depth of field of the next focus. Ther...

A programmable logic circuit is formed by at least one gate. The gate is formed by four logic circuits, one being a first exclusive NOR circuit having a first input, a second input and an output. A second exclusive NOR circuit having a first input, a second input and output is provided, the first input of the second exclusive NOR circuit being coupled to the first input of said first exclusive NOR circuit. An AND circuit having a first input, a second input and an output is also provided. The fi...

Apparatus for use with a rate feedback controlled servo monitor system maintains close static monitor tolerances under dynamic conditions by using the rate feedback to compensate for the velocity lag error component of the monitor tolerance.

A dynamically variable keyboard terminal system having a keyboard display unit using an input panel with a plurality of touch-sensitive locations thereon and a keyboard display unit in alignment therewith. The system includes means for generating and storing information concerning symbols which make up one or more working symbol sets, such symbol information being author definable in accordance with a predetermined terminal definition language. The symbol information can include a symbol configu...

A trim press for severing articles differentially pressure formed in a thermoplastic sheet comprising a pair of dynamically balanced trim die members mounted for movement toward and away from each other between spaced apart positions and closed positions engaging opposite sides of the sheet to sever the article from the sheet. One of the trim die members includes an opening therethrough for receiving the article as it is being trimmed and for passing the article therethrough after it is trimmed ...

A method is provided for dynamically timing an apparatus which includes cyclically generating reference and timing pulses. The method also includes counting the number of reference pulse per generating cycle; measuring a first timing fraction between a leading edge of the first timing pulse and a leading edge of the preceding reference pulse; measuring a second timing fraction between a leading edge of the second timing pulse and a leading edge of the preceding reference pulse; counting the numb...

A rotating power transmission member engaged with a segmented power transmission means is balanced to counteract vibratory torques and forces by three tuned pendulum balance weights spaced 120.degree. apart. A specific application is to a crawler vehicle with tuned pendulums in the track drive, bogey and idler wheel assemblies to balance and counteract vibratory forces and torques transmitted to the wheels by the track. The balance weights are built into each wheel assembly and are tuned to the ...

In free-rotor flexure suspended gyroscopes it is common to mount the inertia wheel-gimbal at one end of the drive shaft and to mount the motor drive assembly at the other end of the shaft. This arrangement usually produces an offset between the mass center of the inertia wheel-gimbal assembly and the rotation axis of the shaft. The offset, in turn, creates a dynamic torque unbalance which causes a "wobbling" or vibration about the gyroscope mounting plane. In order to cancel this dynamic unbalan...

Dynamic membranes are obtained by coating on a porous polymeric substrate containing functional groups a chemically reactive hydrophilic polymer from a dilute aqueous solution under pressure and crosslinking said polymer present on the porous substrate as thin layer with low molecular polyfunctional compounds. The new membranes show good solvent and compaction resistance and resistance to separation of the individual layers. They can be used in ultrafiltration and reverse osmosis processes.