Abstract: A photoelectric smoke detector includes a photoelectric chamber having a housing fabricated from an electrically conductive material.

Abstract: A pressure switch having a pressure responsive diaphragm with a backing plate for operating a snap-acting switch. The switch has a cantilevered contact blade spring with an adjustment screw providing a reaction support at the free end. The middle portion of the contact blade spring provides a preload bias against the diaphragm backing plate. The blade spring includes a moveable electrical contact on a tang formed in the middle region and includes an over-center spring for effecting a snap action of the moveable contact against stationary contacts. The actuation-deactuation differential is determined, independently of the pressure setting for switch actuation, by setting the position of the stationary contacts.

Abstract: A water temperature control circuit for a washing machine includes window detector and dual water valve drivers to modulate the hot and cold water valves to maintain the water temperature at a desired level. A temperature selector switch provides hot, regulated hot, warm, regulated warm, and cold temperature settings for the washing machine. During regulated temperature operation the window detector modulates one of the water valves to maintain the water temperature within a narrow temperature band. The window comparator includes two comparators that receive a common temperature input from a temperature sensing element. As such, no shunt resistor is required for one or the other comparators, thus improving accuracy. The control circuit operates open loop with respect to the hot and cold water valves that it controls, utilizing instead only the temperature input for controlling the proper water valve when enabled.

Abstract: A pressure regulating device for high pressure fuel systems includes a pressure sensing element attached directly to a pressure chamber. The pressure sensing element includes a semiconductor element that deflects in response to a deflection of a portion of the pressure caused by fuel pressure within the pressure chamber. A coil is electrically connected with the pressure sensing element and is configured to generate a magnetic field that moves a magnetic armature to control fuel pressure.

Abstract: A method and apparatus for mounting a controller (30) along with its program selector switch (36) and other electrical components (34) on appliance front panels is disclosed. A twist mount (40) removably mounts a selector switch (36) and printed circuit board (32) to a control panel (20) of an appliance. The switch (36) may be positioned off-center on the printed circuit board (32) in a manner creating a gravity-based rotational torque force on the twist mount (40), such that the printed circuit board (32) acts as a cantilever arm during mounting, and the selector switch (36) is held in the mounted position via the gravity force after mounting.

Abstract: A driver circuit for a latching type valve is provided which utilizes an electronic switch assembly to provide the dual polarity necessary to actuate the latching type valve to both its open and closed states. The driver circuitry includes a microprocessor and a slope detector circuit for monitoring the coil current used to energize the valve solenoid to determine when the valve armature has moved to its fully actuated position. The driver circuit preferably utilizes power MOSFET devices in the switch assembly configured into an H-bridge to drive the solenoid coil. Advantageously, the user of power MOSFET devices eliminates the necessity for a current sense resistor in the control circuitry, thereby decreasing power dissipation and increasing efficiency of the drive circuit, thereby prolonging the battery life used to drive the valve.

Abstract: An actuator is provided for controlling temperatures in a multiple compartment device wherein the actuator includes a housing and a linear oscillator disposed within the housing. The linear oscillator is coupled with an integral push rod, wherein the linear oscillator is adapted to reciprocably move the push rod along its longitudinal axis. In addition, the actuator includes a holder including a rigid member and a pin aperture. The sliding member has a knob on one end and first clip connector at an other end, the sliding member having a range of motion limited by the rigid member. The push rod has a second clip connector coupled to the first clip connector. A lever arm has a first end and a second end, the first end including a protruding member and the second end including a lever arm aperture and a lever arm pin. The knob is pivotably engaged with the lever arm aperture and the lever arm pin is pivotably engaged with the pin aperture. The protruding member is adapted to pivotably couple with the damper.

Abstract: An electromechanical relay drive system which prolongs relay life by ensuring operation of the relay in a manner to make and break contact between the contact electrodes at a zero crossing point of the switched waveform. Relay aging and environmental variations are dynamically compensated upon each actuation of the electromechanical relay to ensure proper timing of the energization and de-energization of the relay to ensure switching at the zero crossing point. Additionally, the drive system described compensates for variations in the actual contact operation during actuation for the positive and negative half cycle of the switched waveform. Furthermore, the system of the instant invention alternately energizes and de-energizes the electromechanical relay during the positive and negative half cycles of the switched waveform to prevent metal deposition from one contact electrode to the other.

Abstract: An electronic variable orifice tube suitable for use as an expansion valve in a refrigeration system providing two flow rates in response to electronic control signals comprises a bodytube, a restrictor mounted within the bodytube and defining a first flowpath. A plunger is translatably positioned within the bodytube in proximity to the restrictor and defines a second and a third flowpath. A valve actuator is functionally coupled to the plunger to translate the plunger within the bodytube to transition between the two flow rates. A high flowpath is formed through the bodytube by the first, second, and third flowpaths, and a low flowpath is formed through the bodytube by the first and the second flowpaths to the exclusion of the third flowpath. A solenoid may be used as the valve actuator and a spring may be employed to return the plunger to its quiescent state when the solenoid is not energized.

Abstract: A pipe coupling (10) for coupling and sealing adjacent ends of two pipe sections (12, 14) of the same or different outer diameters. The pipe coupling (10) includes an annular sleeve (24), a pair of annular gaskets (22) and a pair of follower flanges (20) that surround the adjacent ends of the pipe sections (12, 14). The gaskets (22) have inclined front walls (42) that are angled generally complementary to clamping surfaces (28) formed at opposite ends of the sleeve (24). The gaskets further include inclined back walls (52). As the follower flanges (20) are urged toward the opposite ends of the sleeve (24), the inclined back walls (52) of the gaskets (22) cooperate with skirts (32) formed on the follower flanges (22) to cause the gaskets (22) to readily toe-in toward the outer walls of the pipe sections (12, 14) at relatively low torque and cause sealing engagement with pipe ends sections (12, 14).

Abstract: A motor start circuit for A-C electric motors. A microprocessor-based circuit is used to detect the phase shift that occurs in the motor current as the motor goes from the initial locked-rotor state to the running state. This circuit applies current to a motor `start` winding when the motor is first switched on, but turns off the start winding when the motor achieves sufficient running speed, as indicated by the shift in phase of the current in the motor's `run` winding. For bi-directional motors with two start windings, the microprocessor can apply current to either start winding.

Abstract: A plastic pipe adaptor (10) includes a length of pipe (12) having a plastic pipe wall (14) with a substantially rigid pipe stiffener (32) disposed inside the pipe and a substantially rigid collar (34) disposed about the pipe exteriorly of the pipe wall (14), the collar having a recess (40) therein. The stiffener (32) and collar (34) are positioned such that a portion (50) of the plastic pipe wall is disposed between the stiffener (32) and the collar recess (40) and at least a portion (52) of the pipe stiffener is deflected outwardly against the pipe wall portion (50) by an amount sufficient to wedge the pipe wall portion (50) into engagement with the collar recess (40). The result is a firm grip to the pipe which allows the collar to serve as an attachment to another member such as a mechanical joint (30). A method of making the adaptor (10) is also described.

Abstract: In a dangerous condition sensing alarm system which includes a plurality of interconnected dangerous condition sensing units, such as smoke detectors, of the general type in which each unit responds to an apparently sensed dangerous condition by issuing an audible alarm and also by transmitting, from an input/output terminal, a signal to the other units (received as an external alarm signal at corresponding input/output terminals of the other units) so that an alarm condition sensed by any one of the units results in alarms being sounded by all the units, a unit initiating an alarm (which may be false) is marked by an alarm origination circuit. The alarm origination circuit includes a visual indicator (such as an LED) and a latch device (such as an SCR) connected in-circuit such that, when the SCR is turned "on", the LED is activated and remains lit until the SCR is turned "off".

Abstract: An integral gas burner manifold and pressure regulator with an inlet fitting received through one wall of the manifold and threadedly engaging in the manifold a regulator body received through a second oppositely disposed wall of the manifold. The body has a valve seat and downstream ports for supplying the interior of the manifold. Portions of the body extending exteriorly of the manifold, retain and seal a housing shell having a pressure responsive diaphragm exposed to the pressure of the ports. A poppet is disposed on the valve seat and is connected to the diaphragm by a rod; and, the poppet is moved by the rod in response to changes in pressure acting on the diaphragm. The diaphragm is preloaded by an adjustable spring.

Abstract: A method of stiffening a flexible pipe using inserts or stiffeners. To account for non-uniformities and toe in of the flexible pipe, the method involves inserting a pipe stiffener into an end of the pipe and expanding the pipe stiffener within the end to a desired diameter. The stiffener is expanded using an expander, and may be sized to any desired diameter. The pipe stiffener may be expanded within the pipe until its outside diameter approximates the inside diameter of the pipe. Alternatively, the pipe stiffener may be expanded within the pipe by an expander until its inside diameter approximates the inside diameter of the pipe before the pipe stiffener is expanded within the pipe. Finally, the stiffener may be expanded within the pipe until the outside diameter of the pipe approximates the outside diameter of other pipes to be joined thereto.

Abstract: A battery operable dangerous condition warning device adapted to issue an alarm when a sensed dangerous condition exceeds a predetermined status incorporates a monitoring device circuit including: a processor, a dangerous condition sensor, a horn, a battery condition monitoring procedure cooperating with the processor to periodically check the integrity of the battery for detecting a first battery integrity condition in which battery failure can be expected after a relatively long period and a second battery integrity condition in which battery failure is imminent. The circuit further implements an audio low battery warning generator adapted to drive the horn to issue a distinctive audio warning (e.g.

Abstract: In order to facilitate determination of which of a plurality of dangerous condition warning devices is issuing an audio failing battery signal, the device incorporates a circuit including: a processor, an audio annunciator such as a horn, at least one visual indicator such as an LED and a processor controlled, periodically invoked battery condition determining procedure to check the output voltage of the battery under load. If a low battery condition is detected, the horn is driven to issue an audio warning (e.g., a pulse of about 10 milliseconds duration every minute) and the LED is driven to issue a distinctive series brief flashes (e.g., five flashes of about 10 milliseconds each spaced about 500 milliseconds apart), the first flash being issued in coordination with the issuance of each brief audio warning.

Abstract: In a processor controlled, battery operated dangerous condition warning device employing a DC-to-DC converter, the converter selectively operates at two voltage outputs. A first output voltage is used when a sensor is polled and when audio visual devices, such as LEDs and a horn, are driven; i.e., when higher power is momentarily required; at all other times, a second, lower voltage output, sufficient for ongoing operation of the processor as it keeps time and processes information, is issued by the converter. In a presently preferred embodiment, when the processor determines that the higher voltage is momentarily required, it sends a first signal to a transistor switch to change the voltage at a reference input to the converter which responds by issuing the higher voltage. When the higher voltage is no longer needed, the processor sends a second signal to change the state of the transistor switch such that the converter reverts to the lower output voltage, thus decreasing the load on the battery.

Abstract: In a dangerous condition sensing alarm system which includes a plurality of interconnected dangerous condition sensing units, such as smoke detectors, of the general type in which each unit responds to an apparently sensed dangerous condition by issuing an audible alarm and also by transmitting, from an input/output terminal, a signal to the other units (received as an external alarm signal at corresponding input/output terminals of the other units) so that an alarm condition sensed by any one of the units results in alarms being sounded by all the units, a unit initiating an alarm (which may be false) is marked by an alarm origination circuit. The alarm origination circuit includes a visual indicator (such as an LED) and a latch device (such as an SCR) connected in-circuit such that, when the SCR is turned "on", the LED is activated and remains lit until the SCR is turned "off".

Abstract: A dangerous condition warning device for issuing an alarm when a dangerous condition is sensed incorporates a circuit including a replaceable dangerous condition sensor, a processor coupled to the sensor for periodically determining the ambient concentration of a potentially dangerous substance (e.g., CO) and a horn to issue alarm signals if indicated, the processor also periodically checking the integrity of the sensor, and the device incorporates sensor placement apparatus for facilitating removing and correctly replacing a sensor of suspect integrity. The sensor has an outer periphery and a reduced dimension portion employed as first and second electrodes. The sensor placement apparatus includes a sensor receptacle; a first contact member positioned to contact the reduced dimension portion of the sensor when the sensor is correctly emplaced and to electrically connect to the outer periphery of the sensor when the sensor is incorrectly emplaced.