Abstract: A horizontal water filled vaporizer chamber is heated through the instrumentality of a horizontal combustion chamber extending through a lower portion of the vaporizer chamber. A first plenum inside the vaporizer chamber at a first end thereof receives combustion products from the chamber, and horizontal flues open to this first plenum carry these combustion products from it through the vaporizer chamber to a second plenum outside of the boiler where they are discharged up a stack. A plurality of vaporizer coils, each consisting of vertically spaced horizontal runs of pipe, extend from end to end in an upper portion of the vaporizer chamber. Each pair of adjacent pipe runs in each coil lie in a plane forming an acute angle with respect to a horizontal plane. Every vaporizer coil is connected inside the vaporizer chamber at its lower end to a liquid propane inlet header and at its upper end to a gaseous propane outlet header.

Abstract: In a refrigerator comprising a cabinet, means to refrigerate contents of a chamber within the cabinet, a door for access to such chamber, a fan to circulate air within such chamber, and a switch operable with the door to a first mode wherein the switch enables the fan when the door is closed and to a second mode wherein the switch disables the fan when the door is opened, a relay having contacts arranged to be closed after a delay of preset duration from energization of the relay and to be opened upon deenergization of the relay is connected so as to be energized in the second mode of said switch, so as to be deenergized in the first mode of the switch, and so as to enable the fan when the contacts are closed. A lamp indicates that the contacts are closed.

Abstract: A floor mounted air conditioner comprising a housing containing cylindrical condenser coils disposed about a normally vertical axis and cylindrical evaporator coils coaxially disposed above the condenser coils. A drip pan separates the condenser and evaporator coils and includes openings for discharging condensate onto the condenser coils for evaporation. A condenser fan is associated with a bottom duct adapted for installation in a mounting opening in the floor of a room, for blowing hot air through the mounting opening, and an evaporator fan is associated with a top duct for blowing cool air into the room being cooled.

Abstract: This disclosure describes a torque-balanced vibrationless rotary coupling for transmitting rotary motion without unwanted vibration into the spindle of a machine tool. A drive member drives a driven member using flexible connecting loops which are connected tangentially and at diametrically opposite connecting points through a free floating ring.

Abstract: A flexible shaft coupling for connecting a drive and a driven shaft comprises an axially stacked plurality of flexible metal discs which are connected to one another at oppositely spaced peripheral points with the directly connection between one disc and its neighboring disc on one side being displaced 90.degree. from the interconnection with the neighboring disc on its other side. The coupling is particularly suited to transmit torque yet allow movement of the driven shaft axis relative to the drive shaft axis. The invention has particular application to small precision mechanisms such as a single element typewriter wherein the single element typehead, secured to the driven shaft, must be capable of being rotated and tilted to position a desired character opposite a printing point.

Abstract: A flexible coupling for torque transmission having a plurality of helical beams extending between the coupling ends, the helical beams having beam cross-sectional dimensions selected to provide equal stresses in operation at the inner and outer diameters of the beams, irrespective of direction of rotation and being of a ratio of depth to thickness to provide for substantially simultaneous failure in the buckling and elastic modes when rotated in a direction opposite the direction of beam spiral, whereby the load capacity of the coupling is independent of the direction of coupling rotation.

Abstract: In an adjustable telescoping power take-off shaft an inner shaft extends into splined engagement with an outer shaft. An adapter sleeve encloses an axially extending part of the outer shaft and a locking assembly, including a clamp nut threaded onto the sleeve and a retainer ring located within the nut, locks the inner and outer shafts in position after the length adjustment is made.

Abstract: A detergent supplying device for supplying a detergent and a fabric conditioner into a washing basin of a washing machine. The detergent supplying device is mounted in the washing machine, and has a detergent container containing a detergent and a fabric conditioner container containing a fabric conditioner. In the preliminary washing step, the detergent supplying device delivers only water to the washing basin. In the washing step, the device delivers the detergent together with water to the washing basin. Finally, in the rinsing step, the device delivers the fabric conditioner together with the water. These three water supplying functions are performed through controls of only two water supplying solenoid valves.

Abstract: An arrow straightener for testing and straightening bent arrow shafts is provided with a pair of arrow supports, each of which has a bearing surface that is rotatable about an axis normal to a vertical plane through the longitudinal axis of an arrow positioned on the supports to maintain the bearing surface in flat contact relation to the arrow shaft, a press mechanism between the supports for applying a straightening pressure on the arrow shaft, and a deflection indicator with a feeler that extends through the press mechanism into contact with the shaft, the feeler being movable independent of the press but located at a point central to the pressure applying surface. The apparatus also includes a scale, indicator, weighted body, and spacer for testing the spine strength of wooden arrow shafts.

Abstract: The method resides in feeding a billet in portions into pilger rolls to be worked therein on a mandrel. The billet being positively turned about the rolling axis both in one direction and in the opposite direction in the course of deformation thereof and in the off-contact time when the billet is not engaged by the rolls.

Abstract: The present invention relates to a roll assembly comprising grooved rolls. A neck of each roll is provided with a thrust shoulder placed in a thrust hydrostatic bearing mounted in a chock secured to a housing. The bearing comprises thrust disks each arranged on both end faces of the shoulders substantially parallel thereto. The sides of the disks facing the ends of each shoulder are fitted with hydrostatic pockets communicating with a fluid source. The fluid source, designed for adjustable delivery of fluid, communicates with the hydrostatic pockets of one of the thrust disks of a roll and of the other thrust disk facing it. There is another fluid source with adjustable delivery of fluid communicating with the hydrostatic pockets of the other thrust disks. This enables, by varying the deliveries of the fluid sources, the mutual disposition of the shoulders to be adjusted relative to the thrust disks and thereby permits control over the mutual arrangement of the rolls directly in the course of rolling.

Abstract: Heat transfer elements are made by forming a plurality of tubes extending in side-by-side relation with connector means holding adjacent tubes together, cutting and outwardly projecting surface portions of the tubes to form fins, and then severing the connector means to divide the plurality of tubes into individual heat transfer elements.

Abstract: Helically corrugated tubing with corrugations of variable depth is manufactured in a twisting machine by rotating one end of a deformable tube relative to the opposite end and simultaneously applying axially directed forces to the tube to progressively develop the helical corrugations in the tube wall. The depth of the corrugations is varied by means of a tapered mandrel which is located within the tube while the corrugations are being formed. Tubing sections with variable depth corrugations define flow paths in which the effective cross sectional area varies correspondingly, and such sections are useful in various heat exchangers.

Abstract: A method and apparatus for the expansion of a hollow article out of a memory alloy, in which the hollow article, cooled below the transformation temperature, is mounted between two mandrels each having an opposing taper, and in a first phase is expanded on one face to the final dimension by one mandrel and is supported against a stop, whereupon the final shape is produced by pulling the other mandrel through the hollow article from the opposite face.

Abstract: A cyclically operable machine having a work station where a blank is deformed into a work product and in which the work product is ejected on to a conveyor oscillated between that station and another conveyor to which the work product is delivered synchronously.

Abstract: One or a number of inserts are each fitted within a housing formed in a reference part, each insert being preferably of cylindrical shape and having a predetermined defect in density. An intimate metallurgical bond is formed between the surface of the insert and the housing by depositing a layer of copper on a steel insert when the part is of steel, and by applying a heat treatment. The reference part serves to calibrate testing instruments for ultrasonic metal inspection as well as to determine the character and size of detected defects in density.

Abstract: A device and method for calibrating pulmonary function testing equipment by discharging a precise volume of compressed gas at reproducible and substantially exponentially diminishing flow rates through an orifice of a selected size into such equipment. The device includes a container defining a chamber for containing a predetermined volume of gas at a preselected pressure, a gas discharge conduit, which may serve as a conversion or expansion chamber, communicating with the container and having a flow-restricting fixed orifice of predetermined size for the discharge of gas, and a mechanism normally preventing the discharge of gas from the device but being selectively operable to release the gas through the orifice at reproducible and substantially exponentially diminishing flow rates into a spirometer for calibrating that instrument.

Abstract: A porosimeter comprises a tube of non-magnetic material connected at one end to a sample chamber capable, like the tube, of withstanding high internal pressures, means to exhaust the sample chamber and tube, means to fill the chamber and tube with mercury, means to deliver to the tube under adjustable pressure a fluid of density different from that of mercury, a float of magnetic material and of intermediate density disposed in the tube, and a differential transformer in which the float acts as a core to indicate the position of the float.

Abstract: A strain gage load cell having a primary load carrying member subjected to deformation under stress, a secondary load carrying member affixed to the primary load carrying member in bridging relationship and having a portion of reduced section substantially shorter than the primary load carrying member and a strain gage affixed to said portion of reduced section of said secondary load carrying member.

Abstract: An apparatus for the measuring of external forces by means of a preloaded roller bearing, provided with at least two strain gauges which serve to measure the forces applied to the bearings, in which apparatus the resistance variations of the strain gauge(s) are recorded individually, amplified individually and rectified individually, whereby signals which are proportional to the external forces are obtained through subtraction from the rectified signals, while due to said subtraction those parts of the individually amplified and rectified signals due to internal forces are eliminated.

Abstract: Apparatus for testing the fitness of the multiple copy sets for handwritten copies. The form set to be tested is placed on an inclined supporting plate and is clamped to the supporting plate by a slotted hold down plate. A writing instrument, which includes a spring loaded writing implement, is carried by a carriage so that the tip of the writing implement contacts the form set through the slot. The carriage is movable so as to move the tip of the writing instrument along the slot. The writing implement is supported so that the tip contacts the form set substantially without pressure in a starting position. As the carriage is shifted in the direction of increasing ascent of the supporting plate the bearing pressure of the tip of the writing implement increases as a function of the path of travel. The test line produced on the different sheets of the set is a measure of the quality of the copies.

Abstract: This disclosure deals with apparatus for and a method of testing a plurality of hydraulic and/or pneumatic systems. Each such system has a hose connected in it and the hose terminates in a valved fitting. All of the fittings are releasably attached to a subassembly which in turn is attached to center member or a manifold. When the systems are to be tested, a test fixture is attached to the center member, such attachment automatically opening the valved fittings. The test fixture also includes valved fittings identical with those connected in the systems. All of the fittings are opened by attachment of the test fixture, and the appropriate tests are then carried out. When the systems are not being tested, the test fixture is removed and a protective cover is applied to the center member in place of the fixture.

Abstract: In an ultrasonic flowmeter ultrasonic signals are transmitted alternately upstream and downstream of a fluent media whose flow velocity is to be ascertained. The repetition rate at which signals are transmitted is controlled by a voltage controlled oscillator. To increase the sensitivity of the meter, the frequency of the voltage controlled oscillator, which is related to sound speed through the fluent media, is increased.

Abstract: In a flowmeter system in which a fluid stream causes a ball to circulate in a guide track at a speed proportional to the volume flow rate of the stream, a signal is produced each time the ball passes a sensing point. The speed of the ball is continually measured, and from stored data representing the fluid volume passing through the flowmeter per signal as a function of the signal repetition rate, the volume associated with each signal is determined. The volumes thus determined during a given period are summed to give the total volume over the given period.

Abstract: A method and apparatus for determining a fluid condition adjacent an inner wall boundary of a fluid container is disclosed. A sonic pulse is applied to an outer wall boundary of the container wall and is reflected between an inner and the outer wall boundaries. The magnitude of the sonic pulse decreases each time it is reflected off of the inner wall boundary by an amount which varies as a function of the fluid condition adjacent the inner wall boundary. An electrical reflection pulse whose magnitude is representative of the instantaneous magnitude of the sonic pulse is generated each time the sonic pulse is reflected off of the outer wall boundary of the container. The electrical reflection pulses are integrated during an integration period so as to generate an integration output signal whose value varies as a function of the fluid condition within the container. The integration output signal is compared to a predetermined value to determine the fluid condition.

Abstract: A liquid level sensing electrode structure provided by flat cable which has a plurality of insulated conductors cut to various lengths with end portions exposed to provide sensing electrodes is used in a liquid level sensing system. A common electrode is provided for the system. A separate voltage inverter is provided for each sensing electrode and connects with a voltage source to provide a microprocessor compatible signal when liquid is presented to the common electrode and the sensor for the inverter. A liquid utilization apparatus having a liquid sensing system provides a flow of liquid along the electrode structure to prevent sediment buildup.

Abstract: An improved optical fiber temperature sensor includes at least one optical fiber light conductor including an optical fiber core, cladding material around the core, and a jacket surrounding the core and cladding material. The core exhibits an evanescent field which extends through the cladding material into the jacket in a first selected range of optical wavelengths. Light attenuation in the conductor below a first temperature range is less than light attenuation above the temperature range. By applying light to the conductor at a frequency with the selected optical wavelength range and detecting the light passed through the conductor, an approximate temperature within the temperature range can be sensed. A more accurate temperature can be sensed by using either two optical fiber light conductors having different optical properties or by using two light frequencies with a single conductor which responds differently to the two frequencies.

Abstract: Each sensor consists of a spinel substrate in the form of a beam or a diaphragm which carries a pattern of a plurality of doped silicon piezoresistive resistors. The latter are formed from layers of doped silicon, each of which layers has been epitaxially grown on a corresponding surface of the spinel substrate. The spinel minimizes the occurrence of leakage currents with respect to the resistors, while cooperating with the silicon to provide a high degree of stress transmission to the resistors. The beam form of sensor is shown as the sensor member of a differential fluid pressure to electric signal transducer, wherein the sensor is deflected and strained in accordance with the differential pressure to be sensed.

Abstract: An adjustable pitch, zero backlash, rotary-to-linear-motion converter particularly adaptable for the precision positioning of linearly movable light weight mechanisms. The spherical bearing ends of three or more dumbbell-shaped rollers, in an interference fit between a rotatable shaft and the inner surface of a cylindrical sleeve, are partially enclosed in end cages which are clamped together but which may be adjusted so that the parallel roller axes are offset from the shaft axis whereby rotation of the shaft will provide rectilinear movement to the sleeve.

Abstract: The present invention relates to a device for converting a uniform circular movement into a variable or uniform longitudinal movement. The device comprises being arranged an assembly of rods forming the generatrices of a right cylinder having a circular section. The rods may rotate with a constant angular speed. The rods are grooved with notches at equal or different distances between the notches, which grooves house a wire or cable, wound helicoidally on the cylindrical body established by the rods, so that upon the latter rods rotating, the cable generates a longitudinal movement in the direction of the axis of the rods. The movement is uniform on the stretches in which the grooves are equidistant, and is in such a form that if the distance between grooves varies in accordance with differential elements, the longitudinal movement is obtained whose velocities in relation to time would vary from zero to a maximum and again to zero.

Abstract: A moveable carriage bearing an optical element, such as a font segment track select mirror, is supported upon a flat elongated plateway by means of rollers mounted upon the carriage which is translated along the plateway so that the carriage assumes only a first or second discrete position after it comes to rest. A single spring is employed to cause first and second detent members to be maintained in firm contact with each other to cause the carriage to assume either a first discrete position or a second discrete position while simultaneously maintaining the carriage mounted rollers in firm contact with the plateway.

Abstract: An automatic transmission including: a torque converter having a pump impeller, stator vanes and turbine vanes; an overdrive gear mechanism whose input side is operably connected to the turbine vanes and transmits torque at a gear reduction ratio of 1 or less than 1; an oil pump having a pump chamber defined by an oil pump body and an oil pump cover and generating a hydraulic pressure; an underdrive gear mechanism operably coupled to the output side of the overdrive gear mechanism and transmitting torque at a gear reduction ratio of more than 1 from its input side to its output side; an overdrive case encompassing the overdrive gear mechanism in cooperation with the oil pump cover and having a hole or holes communicating the overdrive gear mechanism with the underdrive gear mechanism; and a transmission case encompassing the sides of the under drive gear mechanism in cooperation with the overdrive case.

Abstract: A long-handled adjusting tool for adjusting the internal and external dampers in a register used in an air delivery system. The tool having pointed arm-like extensions for opening dampers that are closed. The tool also having a slot along the center line, thus allowing for adjusting the internal dampers. There are also slots along the sides of the tool for positioning the external dampers to control the amount of air flow.

Abstract: A device for stripping insulation from between inner and outer conductors of coaxial cables comprising means to support a coaxial cable with the axis of an end portion rectilinear and a tubular insulation engaging bit mounted in alignment with the support means for rotary and reciprocal rectilinear movement relative to the axis of the end portion. The bit has an external helical thread and is mounted in a cable-receiving channel in the support means. A cutting blade may be mounted for movement towards the channel mouth and for rotation about the cable axis.

Abstract: A process and an apparatus for manufacturing books, blocks or calendars by cutting large sheets having printed thereon different pages into smaller sheets which must be brought into an orderly succession before the pages or sheets are bound. The usual folding of the large sheets can be omitted, in that the sheets are fed individually and successively to a conveyor means and are conveyed towards a cutting means; the individual sheets are stacked in a partially overlapping manner. The cutting of the sheets is effected whenever predetermined widths of the individual sheets have been conveyed through the cutting means.

Abstract: A device for feeding a ribbon of sausage support loops into a clip attachment apparatus is attached to the clip attachment apparatus and includes a body member with a guide track for directing the ribbon of loops from a storage reel to the clip apparatus. A reciprocating piston operated drive pin engages the ribbon to incrementally drive the ribbon forward into position for attachment of a single loop to a sausage casing. A knife separates the single loop from the ribbon upon attachment of the loop to the sausage casing by the clip apparatus. Subsequently, the drive pin is disengaged from the ribbon and is reversibly driven into position for re-engagement and further advancement of the ribbon. The movement of the drive pin and knife is controlled by a cam track in the body member.

Abstract: There is disclosed a punch change mechanism for a double pressure pin press or the like having a reciprocating press carriage and a punch holder plate swingably mounted thereon. The punch holder plate is driven by plate cams rotated by the main drive for the press through a gear train. The gear train includes a driven elongated first spur gear mounted on fixed structure against axial movement with respect thereto, and a second spur gear rotatably mounted on the carriage for reciprocation therewith parallel with the axis of the first spur gear and in constant mesh therewith, the second spur gear being fixedly connected to a shaft journalled on the carriage and having the cam plates fixedly mounted thereon.

Abstract: In a modular, expandable organ system comprising a plurality of large scale integrated circuit (LSI) chips an LSI chip is provided which produces frequencies corresponding to notes played on an organ keyboard. Outputs of different duty cycles of rectangular waves are provided for best simulating desired sounds. Other outputs are provided in which the notes are in octave groups facilitating filtering thereof. Each group of outputs has different attack and decay characteristics respectively under the control of the organist so that similar or different types of attack and decay may be provided on different outputs.The present LSI chip provides three generators on one chip. The chips are capable of being interconnected such that any multiple of three generators may be provided.

Abstract: There is disclosed a trumpet incorporating rotary potentiometers which are controlled by means of circular wheels coupled to the shaft of the potentiometers. By rotating the wheel, the musician can vary the resistance of the potentiometer to thereby control the modulation and pitch characteristics of a synthesizer. The pitch of the trumpet is transduced by means of a pickup located in the mouthpiece of the instrument. The signal produced by the pickup is coupled to a pitch follower circuit whose output is coupled to the external input of a synthesizer module to hence use the actual pitch of the trumpet to vary the characteristics of the synthesizer. A transposition switch is located on the rear valve assembly and operates to control the transposition mode of the pitch follower. A glide switch is positioned beneath the transposition switch and is employed to control the portamento input of the synthesizer module.

Abstract: A keying arrangement for electronic organs in which a tone signal consisting of a square wave having, for example, a fifty percent duty cycle is connected to the input of the keyer circuit, and the output thereof, upon the depression of a playing key, consists of a pulse train with the amplitude rising at a controlled rate and the pulse width or duty cycle decreasing at a controlled rate but lagging the increase in amplitude so as to closely duplicate the playing of a muted brass instrument in the attack fashion. A muted brass tremulant affect is achieved by applying a cyclically time variant signal to modulate the pulse amplitude and pulse duty cycle, again with the change in duty cycle lagging the change in amplitude. The circuitry for accomplishing this comprises a diode keyer wherein a pair of resistor-capacitor circuits having different time constants control the keyer to effect variations in pulse amplitude and duty cycle over respective intervals of time.

Abstract: An electronic musical instrument includes a tone signal generator whose operation is controlled by active electronic signal processing. The instrument includes both tone effect control means to provide an alternating current control signal to the tone signal generator and manually operable tone frequency control means having selectively variable resistance and selectively variable capacitance characteristics, with one of these characteristics being variable among logarithmically spaced increments and the other characteristic being variable among linearly spaced increments.

Abstract: In the construction of a damper assembly of pianos, the conventionally used long-sized damper wire is replaced by a pair of separate short-sized lever components operationally related to each other via an additional intermediate damper lever for stabilized action of the assembly even without provision of the conventionally used guide rail. A shorter length damper wire joins the upper lever component to the damper head.

Abstract: A device for affecting deflection control of an elongated stringed musical instrument neck or shaft is provided to compensate for undesired neck deflections. The device includes a substantially rigid sleeve which is carried within and extends along the neck. At least one core element is removably positioned within the sleeve. A control element is adjustably secured to the sleeve and cooperates with the core element or elements to exert deflection control forces on the sleeve. The sleeve in turn, imparts such deflection control forces to the elongated neck or shaft in which it is carried.

Abstract: A drum snare control mechanism comprises a frame on which a snare is supported and one or more pairs of snare-engaging members are supported on stems slidable within the frame and movable by cams to bring the pairs of snare-engaging members selectively into and out of contact with a length of the snare, or different lengths of the snare, to vary the tone. The mechanism frame serves to isolate the drum frame from the tension within the snares.

Abstract: A musical education game for teaching children to associate each letter name with a staff position and key position includes in exemplary form a keyboard operated array of hammers, each of which on the upstroke will lift or jiggle a corresponding note-related removable figurine or token and on the downstroke will sound a corresponding tone, if the token is positioned in proper location in a staff display by a student. A corresponding tone also sounds when the token is dropped into correct location, driving the corresponding hammer down. If the token is incorrectly located, it does not sound a note when dropped into place and when the hammer is actuated remains unmoved; in any case on the downstroke the hammer strikes a note corresponding to the respective key position but not identifiably aligned with it visually. Overlays for the keyboard include indicia grouping the notes in register, and additional structural provisions can aid the student in associating token position with staff position.

Abstract: An automatic visual music teaching device for displaying the structure of coded chords. The device comprises a plurality of actuable switches for selecting a desired coded chord. Signals associated with the actuated switches are temporarily stored and are indicative of the desired coded chord to be visually displayed. A further switch is activated to transfer the stored signals indicative of the desired coded chord to a decoding circuit. The decoded circuit feeds a memory system to select in a matrix the composite parts of the desired coded chord in accordance with a coded data signal sent to it by the decoder whereby the composite parts of the desired coded chord are visually indicated on a visual display element.

Abstract: A blind fastener has a nut with a threaded bore, a core bolt having external threads for receipt by the nut, and a sleeve for expansion by the head of the core bolt and a shoulder of the nut to form a blind side folded bulb against the backside sheet of a joint. A thin-walled, tapered section of the sleeve fits over a relieved section of the nut and bears against the shoulder of the nut. The taper is such that the thin wall increases in thickness away from the shoulder. An axially adjacent thick-walled section of the sleeve bears on the core bolt head and resists sleeve tuck-out over the core bolt head, concentrically aligns the sleeve on the core bolt, and assures that the thin-walled section of the sleeve is the section that bulbs. During setting, the sleeve expands by compression exerted on it by the core bolt head and the shoulder. The thin wall section folds against the backside sheet with an ever-increasing area as tightening continues.

Abstract: A shock suppressing device adapted to be attached to the aft end of a shoulder-fired rocket launcher. The device comprises a cylindrical housing defining a substantially enclosed expansion chamber having a diameter and cross-sectional area greater than that of the exhaust end of the launch tube. A plurality of annular baffles extend radially inwardly from the cylindrical housing and define aligned through openings through which a plug from a rocket being launched can be emitted rearwardly from the launch tube. The initial shock which follows the expulsion of the plug from the rocket is spread outwardly into the expansion chamber to engage the baffles therein. The baffles suppress the shock by absorbing a substantial portion of the energy of the shock wave, and also partially reflecting the shock wave in an upstream direction toward the launch tube. In the preferred form, the housing is made of several members which telescope together for storage, and are pulled out to an expanded position for use.

Abstract: A firearm and in particular a pistol is described in which there is provided a novel self-retracting trigger-actuated safety mechanism for preventing involuntary firing of the firearm, a trigger-actuated magazine-latching mechanism for latching and releasing a magazine, a trigger-actuated firing and trigger release mechanism and a slide assembly safety mechanism for preventing firing of the firearm if the slide assembly is not in its firing position. In the self-retracting trigger-actuated safety mechanism there is provided a safety trigger member and a ball point pen point extending and retracting type mechanism including a safety mechanism linkage member which is selectively positioned in and withdrawn from the path of travel of a sear in the firing mechanism with successive actuations of the safety trigger member.

Abstract: A brake booster includes a housing with an inner wall defining a pair of pressure chambers. A passage in the inner wall communicates the pressure chambers with each other and an input member is slidably disposed in one of the pressure chambers and an output member is slidably disposed in the other pressure chamber. A resilient member extends between the inner wall and the input member and substantially defines a variable orifice to control fluid communication between an inlet and a return. The return is disposed within the inner wall and the resilient member comprises a coil spring which permits fluid communication between the coils. When the input member is moved the coil spring is contracted to decrease the spacing between the coils, thereby restricting fluid communication between the inlet and the return. Consequently, increased fluid pressure within the other chamber urges the output member to move thereby actuating braking.