Abstract: A pair of opposed valve members defines a radial flow path therebetween which extends from the outer radial peripheries of each valve member to an axial bore formed in one of the valve members. The other valve member is mounted on a stem having an upper end which is urged upwardly by a spring disposed around the stem. A substantially cylindrical element is threadably engaged in the upper end of a valve body in which the valve members are received and the stem is urged thereagainst. In another embodiment, the stem is fixedly connected to the cylindrical element. Rotational movement of the cylindrical element axially moves the stem thereby controlling flow through the valve.

Abstract: The disclosed valve may be configured for use as a pressure relief valve, pressure regulator valve or pressure reducing valve. A pair of opposed valve members defines a radial flow path therebetween which extends from the outer radial peripheries of each valve member to an axial bore formed in one of the valve members. The other valve member comprises a substantially pressure balanced piston, the axial movements of which control flow through the valve. A pilot valve for relieving pressure above the piston has its inlet positioned within a cavity formed on the upper surface of the piston. In a second disclosed valve, a pair of opposed valve members defines a radial flow path therebetween which extends from the outer radial peripheries of each valve member to an axial bore formed in one of the valve members. The other valve member is mounted on a stem having an upper end which is urged upwardly by a spring disposed around the stem.

Abstract: An in-system programmable logic device is disclosed which may be configured or reconfigured while installed in a user's system. The disclosed device employs non-volatile memory cells such as floating gate transistors as the programmable elements, and hence the device retains a particular programmed logic configuration virtually indefinitely during a powered-down state. The device is operable in a normal state and in several utility states for reconfiguring the device. The device state is controlled by an internal state machine which executes several state equations whose variables are the logic levels driving two dedicated pins and the present device state. One device pin receives serial input data which loads a shift register latch. The contents of the latch are employed to select a particular row of the cells to be programmed and the logic level to which the selected cells are to be programmed.

Abstract: A dopant-opaque layer of polysilicon is deposited on gate oxide on the upper substrate surface to serve as a pattern definer during fabrication of the device. It provides control over successive P and N doping steps used to create the necessary operative junctions within a silicon substrate and the conductive structures formed atop the substrate. A trench is formed in the upper silicon surface and a source conductive layer is deposited to electrically contact the source region as a gate conductive layer is deposited atop the gate oxide layer. The trench sidewall is profile tailored using a novel O.sub.2 --SF.sub.6 plasma etch technique. An oxide sidewall spacer is formed on the sides of the pattern definer and gate oxide structures, before depositing the conductive material. A planarizing layer is applied and used as a mask for selectively removing any conductive material deposited atop the oxide spacer.

Abstract: The disclosed valve may be configured for use as a pressure relief valve, pressure regulator valve or pressure reducing valve. A pair of opposed valve members defines a radial flow path therebetween which extends from the outer radial peripheries of each valve member to an axial bore formed in one of the valve members. The other valve member comprises a substantially pressure balanced piston, the axial movements of which control flow through the valve. A pilot valve for relieving pressure above the piston has its inlet positioned within a cavity formed on the upper surface of the piston.

Abstract: A hydraulically-driven, self-propelled, in-line sewer tap cutter includes roller bearings mounted to the skids and extending beyond the outer edge of the skids to maintain the frame spaced apart from the sewer pipe and facilitate rolling locomotion of the cutter through the pipe. The roller bearings are positioned so as to align the frame with respect to the bit so that, in use, adequate bit clearance is maintained to cut off taps close to the sidewall of the pipe without jaming the bit at offsets. The specially sized bit includes an integral support shelf formed on the exterior of a generally cylindrical barrel to support cutting teeth mounted extending radially outside the barrel to improve bit life and prevent jamming the bit.

Abstract: Methods and apparatus are disclosed for reflecting a laser beam so that it traverses a path on a display surface defining a visible display pattern responsive to an audio frequency input signal. The input signal is provided to a speaker, and the laser beam reflects off a front surface mirror, mounted onto the speaker so that the mirror vibrates responsive to the input signal.

Abstract: A method and apparatus for determining exhaust backpressure in which a bore is created in the wall of a manifold, pipe, muffler, of the like which is in fluid communication with an exhaust port of an internal combustion engine. A pressure-indicating device of the type having an elongate probe is inserted through the bore in unsealed and unthreaded relation therewith. After reading the backpressure indicated by the device, the probe is withdrawn and a plug is frictionally engaged with the bore thereby sealing against exhaust leakage.