Abstract: A modular alarm system includes a plurality of sensing devices, each of which is adapted to sense the presence or absence of a particular condition, specifically a fire or over heat condition (hereinafter referred to merely as a fire condition), and the presence or absence of a fault including a short circuit or open circuit. The system also includes a detector module for producing an equal plurality of identical logic output signals indicative of and in response to the presence of the particular condition being monitored at the various sensing devices and a single, identical logic output signal indicative of and in response to the presence of a fault at any of the sensing devices.

Abstract: A water level recorder for use with pressure-sensitive chart paper and having a framework with a lead screw rotatably mounted in the framework. A pulley is secured to the lead screw. The pulley is driven by a tape which is positioned by a float that is adapted to rest upon the surface of the water. A lead screw nut is mounted on the lead screw for movement longitudinally of the lead screw as the lead screw is rotated. A marking member for marking the chart paper is carried by the lead screw nut. A drum is secured to the lead screw for rotation with the lead screw. A helix for marking the chart paper is formed on the drum. Chart paper drive means is provided for advancing the chart paper over the helix and the marking member.

Abstract: A new microprocessor controlled digital multimeter offers significant advantages to the user. Automatic calibration and correction routines ensure long term stability and simplify maintenance; self diagnostics greatly help troubleshooting and even warn of impending failures; software implementation of logic design simplifies hardware, improves reliability and adds capabilities such as fast auto ranging and software I/O control; the ability to process data permits averaging, linearization and normalization of input measurements, minimum/maximum storage and limit detection.

Abstract: Linear accelerometer mechanism having a mounting flange with an opening therein. A body is to be carried by the mounting flange and also has an opening therein. A float, a pendulous elongated member having one end secured to the float and a cylindrical torque coil secured to the other end of the pendulous member are disposed in the opening of the body. Means is provided for pivotally mounting the float, the pendulous member and the torque coil in the body to permit pivotal movement about a pivot axis. A planar conducting element is carried by the pendulous member. Pickoff means is carried by the body adjacent to the planar conducting element. First and second covers are disposed on opposite sides of the flange and close the body and are secured to the flange to aid in providing liquid-tight seals between the covers and the flange.

Abstract: A cylindrical bearing housing has an axial bore therethrough and external threads. A land is formed around the circumference of the bore having a width less than the axial length of the bore. A bearing member has a bearing surface on one end accessible through one end of the bore and has shoulders on each end of the bearing member. The bearing member is fabricated to pass through the bore and to have a length such that the shoulders are spaced apart a distance greater than the width of the land. An elastic filler material is disposed between the bearing member and the walls of the bore while the bearing member is suspended centrally therein, thereby retaining the bearing member axially in the bore. The bearing housing is configured for mounting and axial adjustment in a base member. A rotating member having a pair of pivots, one each on opposite sides thereof is provided having an axis of rotation passing through the pivots.

Abstract: A coupling that permits a connection to be made to a fluid system with a minimum of included air, even though the coupled device is not pre-filled. The coupling is particularly advantageously employed as part of a sampler used to take fluid samples for analysis as to air content. It includes a valve housing, a valve seat slidable within the housing and a valve closure member slidable within the seat. A lost motion mechanism allows joint movement of the seat and closure member prior to disengagement of the seat from the closure member. The fluid passage by which fluid is withdrawn from the system extends through the closure member.

Abstract: A thin plate-like rotor is mounted on a hub which in turn is attached to the shaft of a motor which drives the rotor at a predetermined rotational speed about a spin axes. A framework is provided for mounting the motor. The rotor has a damping face and an opposite signal face. A damping plate is mounted on the hub in close spaced relation with the damping face. A spring member is disposed between the hub and the rotor so that the rotor is free to move in restrained rotational fashion about one diameter of the rotor. Surrounding air is pumped through the space between the damping face and the damping plate to provide damping of the motion of the rotor about the one diameter. Pickoffs are mounted in the framework in close spaced relation to the signal face of the rotor. The pickoffs provide output indicative of the spacing between the signal face and the pickoffs which corresponds to angular velocity inputs about the separate axes disposed orthogonally with the spin axes.

Abstract: A current source is formed utilizing a reference voltage which is impressed on an impedance connected to the input of an operational amplifier. A buffer amplifier is coupled between the output and the input of the operational amplifier to prevent interaction between a high impedance signal source and a low impedance load. A constant output current appears at the output of the buffer amplifier, connected to a first electronic switch. A second electronic switch is connected to the other side of the load. A pair of signals having unstable amplitude are connected to control the first and second electronic switches. When the second electronic switch is either continuously on or alternatively on and off with the first electronic switch, the constant current is directed through the load when the first electronic switch is actuated to the off or open position, and is directed by bypass the load, when the first electronic switch is actuated to the on or closed condition.

Abstract: A servo system has a moving member supported for movement therein and a pickoff device for sensing the position of the moving member relative to a reference position. The pickoff provides a position output which is connected to an attenuator at the input of a high gain amplifier having a feedback loop for attaining gain stability. The feedback loop contains circuit components which provide stability in the servo system. An amplifier output attenuator reduces the feedback loop signal levels. Amplifier output is coupled to motive means for driving the moving member toward the reference position. A timing circuit produces a timed output which dissipates over a predetermined period of time. The timed output operates to enable a field effect transistor which causes the input divider to attentuate the position output to the high gain amplifier.

Abstract: The servo system has a fluid damped moving mass, a pickoff providing a signal indicative of the position of the moving mass, and a torquer disposed to move the mass. A single operational amplifier has a pair of inputs and an output. One input is connected to the pickoff signal and the other is connected to a reference signal. A feedback path extends between the operational amplifier input and output, and includes a temperature sensitive combination in series with a feedback resistor. A basic gain control resistance is connected between the node located intermediate of the temperature sensitive combination and feedback resistor and the reference signal. Basic gain and gain change over a temperature range are independent of interaction therebetween as each is set, and a selected servo system operational characteristic is maintained substantially constant over the temperature range.

Abstract: A two axis rate gyro for sensing angular velocity about two input axes includes a rotating disc which is bearing mounted in a framework. A motor is provided for driving the disc rotationally in the bearing mounts. Pickoffs are mounted in the framework which are spaced from the faces of the rotor and oriented along axes which are orthogonal to the two angular velocity input axes. Circuitry is provided for receiving the outputs from each of the orthogonally oriented pickoffs, including circuit means for removing noise in the outputs due to variation caused therein by spacing variation between the rotor faces and the pickoffs resulting from departure of the rotor faces from a flat condition.

Abstract: Linear accelerometer mechanism having a housing and a pendulous member. Means is provided for pivotally mounting the pendulous member in the housing. A torque coil is carried by the pendulous member and first and second magnets are mounted in the torque coil for establishing a magnetic field in the vicinity of the torque coil. A conducting planar element is carried by the pendulous member and pick-off means is mounted within the housing in the vicinity of the pendulous member.

Abstract: Valve apparatus is disclosed for discharging pressurized fire extinguisher fluid from a container. A valve housing includes a valve body and manifold between which a diaphragm which is removably mounted to facilitate field replacement. The diaphragm comprises a semi-spherical shell which is mounted across a passage in the housing with a concave side of the shell facing the pressurized fluid. The shell is fabricated of a metal which is pre-stressed so that the diaphragm ruptures above a predetermined fluid pressure for relieving over-pressure from the container. A dual seal is formed about the rim of the diaphragm by means of an O-ring and an annular knife edge which are disposed within a recess of the manifold body. The valve body and manifold are secured together in metal-to-metal contact at their interface to prevent leaking. A squib cartridge is mounted in the housing to rupture the diaphragm and permit the fluid to discharge through the passage.

Abstract: A linear accelerometer is contained within a combination framework and case having a magnetic circuit including an annular gap with a magnetic flux density therethrough. An insulated bearing mount is fixed within the framework carrying a pair of opposed axially adjustable bearings defining a pivot axis. The bearings are supported in a resilient mass. A moving member carries a pair of pivots which seat in the bearings allowing motion of the moving member about the pivot axis. The moving member carries a torque coil disposed in the annular gap. Pick-off coils are mounted on the framework closely spaced from opposing planar conducting surfaces on the moving member. A pair of flexible leads extend between the framework and the moving member, providing electrical power to the torque coil. The flexible leads are disposed proximate to the pivot axis and at substantially 180.degree. separation thereabout to reduce static and dynamic torques on the moving member.

Abstract: A circuit for providing an oscillatory driving signal from the point in time when power is supplied to a predetermined point in time thereafter. A force balance transducer having a pick-off device with a stationary member and a moving member mechanically mounted for movement relative to the stationary member is disposed to sense a predetermined physical quantity and to produce an output relative thereto. A force producing device is coupled to the moving member for receiving the output and for driving the moving member to a predetermined neutral position. The transducer is actuated by a source of electrical power and contains a gating circuit, an astable multi-vibrator and a coupling circuit. The gating circuit is actuated by initial application of the electrical power to the transducer and actuates the astable multivibrator for a predetermined period of time.

Abstract: A high frequency pickoff is disclosed having two spaced inductors electrically connected in series and a capacitor connected in parallel with the inductors, thereby forming a parallel resonant circuit. A conducting member is mounted for motion in the space between the two inductors. A pair of transistors are mounted in push/pull configuration to alternately connect first one end and then the other of the resonant circuit to a source of electrical energy. The source disclosed is a current source for matching the high impedance of the parallel resonant circuit. When the electrical energy is switched at substantially the resonant frequency of the parallel circuit, differential motion of the conducting member relative to the inductors provides differential amplitude output at the frequency of resonance of electrically opposed ends of the resonant circuit.

Abstract: Valve apparatus is disclosed for discharging pressurized fire extinguisher fluid from a container. The valve includes a diaphragm which is removably mounted within a two-part housing to facilitate field replacement. The diaphragm is formed with a semi-spherical shell which is mounted across a passage in the housing with a concave side of the shell facing the pressurized fluid. The shell is fabricated of a metal which is pre-stressed so that the diaphragm ruptures above a predetermined fluid pressure for relieving over-pressure from the container. An annular rim of the diaphragm includes a ductile metal ring which is compressed between the housing parts into fluid sealing relationship with an annular knife edge seal. A squib cartridge is mounted in the housing to rupture the diaphragm and permit the fluid to discharge through the passage. A screen is mounted in the passage to screen out fragments of the ruptured diaphragm from the flow stream.

Abstract: A structural body is monitored in angular position about at least one axis by utilizing a tilt sensor responsive to tilt about the one axis and a sensor responsive to angular acceleration of the body about the one axis. The tilt sensor also responds to the tangential component of angular acceleration and the angular acceleration sensor output contains a component which results from linear acceleration sensitivity along a cross axis of the angular acceleration sensor. The cross axis of the angular accelerameter is aligned with the sensitive axis of the tilt sensor and a portion of the tilt sensor output related to the ratio of the two sensor scale factors is injected into the angular acceleration sensor output to cancel the cross axis sensitivity. A portion of the angular acceleration sensor output related to the distance between the one axis and the mounting position of the tilt sensor is injected into the tilt sensor output to cancel the tangential component of angular acceleration.

Abstract: Kinematic mounting of an optical mirror cube in an athermal system is obtained wherein the optical mirror cube has a mounting post extending from a support surface thereon. The mirror cube also has an optical surface and a registration surface. A mounting pedestal extends from a structural surface upon which the mirror cube is fastened. The mounting pedestal has a mounting bore formed therein passing through a pedestal support surface for contacting the mirror cube support surface. The bore is formed to loosely receive the mounting post and a pedestal registration surface is provided for matching the mirror cube registration surface. The pedestal has a pair of lateral bores therethrough formed to intersect the mounting bore at substantially right angles. The mounting post has a pair of lateral bores therethrough with axes aligned with the lateral pedestal bores.

Abstract: A command signal is provided through a buffer amplifier to an exponential signal generator which provides an exponential signal envelope at the output thereof. The exponential signal envelope is coupled to an inverting unity gain amplifier for providing an inverse exponential signal envelope. The exponential and inverse exponential signal envelopes are coupled to an astable element which provides an output frequency having an amplitude related to the exponential signal envelopes. Means are included in the exponential signal generator for providing a predetermined decay time for the exponential signal envelopes. Means are included in the astable element for providing a predetermined frequency at the output of the astable element. Means are also included in the astable element for providing a common assymptote for the exponential and inverse exponential signal envelopes.