Abstract: An apparatus for measuring the mass of a flowing medium, in particular, for measuring the aspirated air mass in internal combustion engines. The apparatus includes a flow conduit for the medium, embodied as an air intake tube and having a restricted section, into which a bypass line toward the restricted section discharges at a mouth. In the bypass line there is a temperature-dependent resistor, which ascertains the mass of air flowing via the bypass line, this mass being at a predetermined proportion to that flowing through the flow conduit of the medium, and this resistor via an electronic control unit triggers a fuel-injection valve in the flow conduit of the medium. The course of the flow cross section in the restricted section is determined by way of example by a shaped body surrounding the fuel injection valve.

Abstract: The present invention relates to a control system for a testing device for the automatic transmissions used in automobiles, and comprises a torque controlling feedback loop for controlling the torque applied to the input shaft of the transmission under test, and a speed controlling feedback loop for controlling the speed of the output shaft of the transmission under test, whereby the circumstances in an actual automobile application can be accurately and easily simulated to allow realistic testing of the automatic transmission.

Abstract: Tubular goods, such as drill pipe and production tubing, are measured while going into and coming out of a borehole. An electronic beam is directed from a transmitter and is detected by a distance measuring receiver. The beam commences at a known station relative to one end of a pipe suspended in the derrick; and is received at a second station which is indexed respective to the traveling block of the drilling rig. Another beam measures the position of the other end of the pipe respective to the traveling block. These measurements enable the length of each stand of pipe to be accurately ascertained while the pipe is held suspended within the derrick at a location above the derrick floor. Electronic circuitry, including a digital instrument, automatically computes the length, displays the length in feet and tenths on a digital readout, records the length on a print-out tape, and incorporates an accumulative memory register.

Abstract: A glide path instrument for an aircraft to display to a pilot that the aircraft is descending on a predetermined inclined glide path. The instrument includes a rectangular casing mountable in stationary position in the aircraft and carrying a freely pivotable frame which has sighting elements at opposite ends spaced different vertical distances from the plane of the frame. The frame carries a pendulum-like structure including depending legs supporting free swinging weights. The sighting elements align in a single sight plane with a runway reference point when the aircraft is at the predetermined glide angle. A lamp in the casing illuminates the sighting elements.

Abstract: Presented is a method and means for monitoring the angle of attack of an airfoil and displaying the monitored angle of attack as a visual reference to the pilot.

Abstract: An energy loss detecting apparatus for measuring the rate of flow of the vapor phase of a bi-phase fluid flow, in the presence of an unknown quantity of the liquid phase, by separating the vapor phase from the liquid phase and producing a signal representing the vapor phase flow rate. The apparatus includes a hollow separator casing provided with a tube communicating with at least one of the inlet opening and outlet opening of the casing and facing thereinto. A wall seals the interior of the tube from the interior of the casing except at reduced diameter holes in the wall, the diameter of the holes being less than the inside diameter of the tubes at the wall. Energy loss due to a faulty steam trap is measurable by interposing the vapor flow rate measuring apparatus in a steam line between a steam consuming device and the steam trap.

Abstract: A method and apparatus are proposed for measuring the mass of a pulsating medium flowing in a flow cross section, in particular for measuring the aspirated air mass of internal combustion engines. The apparatus includes a temperature-dependent measuring resistor, the temperature and/or resistance of which is regulated in accordance with the mass of flowing medium. The measurement signal representing the medium mass is influenceable in accordance with the flow direction by at least one first temperature-dependent indication resistor, whose resistance value can be ascertained by a resistance measuring circuit and can be compared with the resistance value, also ascertained by a resistance measuring circuit, of a second temperature-dependent indication resistor.

Abstract: A vane-type liquid meter in which fluid input to and output from an annular measuring space are directed parallel to the rotational axis of a rotor. The fact that a separation block within the annular space is kept in place in a self-adjusting way gives the advantage of high accuracy.

Abstract: Integrity of acetylene cylinder filler material is accurately and easily determined by monitoring acoustic emission counts as a function of load and establishing the distinctive signature of faulty filler material.

Abstract: A track inspection car supported on railroad track by flanged wheels mounted on a truck, and having means for engaging a tractor-truck at one end and wheels with highway tires at the other. The wheels are relatively vertically displaceable by selectively inflating pneumatic springs for converting the car from on-track operation to an off-track trailer-truck configuration. A pair of ultrasonic sensor probes are mounted on the wheel truck coupled to a computer in the car. The car also includes an on-track driving motor, a driver station, a computer operators station, an observer's station, and a water supply for creating a fluid acoustical coupling between the sensors and the rails.

Abstract: The present invention comprises an acoustic plug release indicator system. The acoustic plug release indicator system comprises a microphone, recording system and operator listening device.

Abstract: An electrical transducer connected to a computer-based system is temperature compensated by providing an assembly including the transducer, which assembly further includes a temperature transducer and a coding element providing a signal which is decoded by the computer to specify the zero shifts and sensitivity changes of the transducer at high and low temperature extremes.

Abstract: A pressure indicator, particularly for respirators, comprises a housing which has a pressure chamber, is connectable to a pressure source, for example a respirator gas pressure and includes a plurality of individual indicator chambers which is connected to the pressure chamber with an indicator piston member slidable in each of the chambers and biased by individual springs in a direction which brings a feeler portion of the indicator piston member within the housing. The feeler portion extends out of the housing in an indicating position which position is arrived at by pressure in the pressure chamber acting on the indicator piston to force it out of the housing. Each indicator piston member is biased by a biasing force, for example, produced by a selected spring so that it will be in a non-indicating position until a distinct pressure acts on the indicator piston member to force it in a position in which the feeler portion thereof extends out of the housing.

Abstract: An apparatus for the approximate determination of forces acting on a support frame which has a compression member disposed between two pressure plates. The compression member has a coating of a material such as enamel which separates from the member as a function of the members' deformation under compressive forces and thus is an indicator of the magnitude of such forces.

Abstract: An ultrasonic flowmeter for accurately measuring the flow rate of clean or dirty industrial process fluids passing through a pipe provided with upstream and downstream transducers. A transmission signal produced by a high-frequency generator acts to energize the transducers which are alternately excited at a relatively low switching rate whereby a beam emitted by the excited transducer is propagated through the fluid at an angle to the flow axis of the pipe and is intercepted by the other transducer to yield a received signal that is displaced in phase from the transmission signal to an extent depending on the transit time of the beam which reverses direction during each switching cycle. The received signals from the transducers are converted into a square wave that is compared to a wave derived from the transmission signal to produce a comparison output which is fed through a low-pass filter to exclude the high frequency content thereof.

Abstract: A liquid meter including a freely rotatable impeller driven by a constant speed drive. Liquid to be metered is introduced as a flow against, and accelerated by, the impeller. The energy necessary to accelerate the liquid is monitored to determine liquid flow. Preferably, the impeller is driven through a magnetic coupling which facilitates isolation of at least large portions of the drive from the liquid flow. One preferred embodiment employs a pair of spring coupled shutters with one shutter being magnetically coupled to the impeller. The displacement of the spring is dependent on liquid flow with that displacement being determined by photoelectrically monitoring the relative positions of the shutters. The power necessary to maintain the drive at constant speed may also, or alternatively, be monitored to determine liquid flow.

Abstract: A gas sampling device whose operation is activated by the blast whose gas to be sampled. This blast activates a switch which in turn starts the operation of a control box which thereafter sequentially outputs pneumatic signals at preset time intervals. These signals are received by a sampling unit assembly which functions in response thereto to receive and retain a gas sample from the blast.

Abstract: An improved pipette device for removing and transferring a plurality of liquid samples to and from a multi-well tray is disclosed. The pipette device comprises the housing having an elongated plate defining a first chamber therein. A patterned array of collector conduits are joined to the plate such that a first outwardly extending section extends into the chamber and a second outwardly extending section, in flow communication with the first, extends away from the chamber and toward the tray. A port is formed on the housing such that a vacuum can be created in the first chamber whereby a predetermined quantity of liquid is caused to flow into each of the collector conduits. The conduits are designed to contain decreasingly smaller volumes to allow precise measure of the contained volume when the conduits are filled.

Abstract: A gauge well float includes a sealed cylinder having rounded ends. A tube is disposed along the vertical axis of the cylinder and held in place by the rounded ends. A weighted cable suspended within the gauge well passes through the tube and keeps the float centered within the gauge well. It also provides a means for removing the float from the gauge well for level measurement or sampling purposes.

Abstract: A pushbutton-operated waveband or station selector or tuner, comprising a front panel to which a bracket for each pushbutton is supported perpendicular thereto so as to be movable to-and-fro, said pushbutton being provided with a push piece for kick arm and a setting plate which can engage a pivoting crank, the kick arm being disposed on the rear side of said front panel parallelly thereto, so that it is pivotable with respect to right and left side plates of the apparatus. At the rear of said kick arm, there is disposed the pivoting crank (31) which is mounted at the opposite ends thereof so as to be pivotable with respect to the frame side plate, and above said pivoting crank there is movably supported a core slide which is coupled with said pivoting crank, said core slide having mounted on the rear portion thereof a plurality of cores directed toward the rear side of the apparatus, these cores each being inserted into a movable to-and-fro in a respective tuning coil disposed at the rear of the apparatus.

Abstract: Disclosed is a power drive for electric switchgear in which the driving force is elastically transmitted to an actuating member, for example, a handle. Thereby, tolerance compensation is provided to allow the drive motor to run into the end positions of the drive. A bending-type spring is disclosed as an elastic power transmitting member which is arranged transversely to the direction of motion of a slide which transmits the driving force to the switchgear. The bending-type spring can be connected to the slide. The bending-type spring can be a leaf spring, and more particularly two parallel leaf springs. In the disclosed embodiments, the two parallel leaf springs are provided as a single U-shaped leaf spring having parallel legs. The U-shaped leaf spring can either be supported at both ends thereof in the slide or the legs can be fastened in a mounting body connected to the slide.

Abstract: An improved steering wheel has a reinforcement member extending through a resin core. The reinforcement member is provided in a central connecting portion where the steering wheel is engaged with a steering shaft, a spoke portion or portions extending radially from the central portion, and at least the parts of the grip portion where the grip portion is connected with the spoke portion. The reinforcement member is made of metal of thin cross-section so that the weight thereof does not seriously interfere with formation of a light-weight steering wheel.

Abstract: A breather passage is provided to perform breathing function for both two casings, one being a first casing housing therein a power-transmission means and the other being a second casing housing therein a gear-transmission mechanism. The breather passage is defined between interfacing surfaces of a main body and a cover those providing the second casing. A gasket is interposed between the main body and the cover so as to devide the breather passage into two passages. The breather passage has one end formed with a first breather hole opened to an atmosphere and the other end formed with a second breather hole opened to an interior of said second casing. The breather passage is further formed with a branch passage at the position rearward from said second breather hole to permit liquid communication between an interior of the first casing and the atmosphere.

Abstract: The invention disclosed comprises twin clutch packs for a power shift transmission to provide two power paths through the power shift transmission and means for combining the drives in a single output drive.This invention relates to a power shift transmission and more particularly to a transmission having twin clutch packs for dividing the drive in separate power paths through the transmission and recombining in a single output drive. The transmission is a countershaft transmission having a common countershaft for the twin drives through the transmission which recombine as the drive is transmitted to the output shaft.With an increase in size and power transmitted through a power shift transmission a greater area of clutch plate surface or brake disc surface is required to transmit the increase in torque. Since the clutches are the greatest problem in transmitting increased power a doubling of the power transmitted through the transmission requires a redesign of the whole transmission.

Abstract: A vehicle drive axle including a differential carrier and a differential driven by an input shaft. A pump housing is mounted to the forward end of the carrier in circumferentially enclosing relation to a portion of the input shaft and includes rotary fluid displacement means driven internally by the input shaft.

Abstract: A vehicle driving apparatus applied to a small-sized vehicle of FF or RR type includes an input shaft connected to a drive shaft through a torque convertor, a planetary gearing including various gears and a carrier, an output gear, an intermediate transmission shaft provided at one end with a driven gear meshing with the output gear and connected at the other end to a final reduction device, and various clutches and brakes. In the apparatus, another clutch for providing an overdrive is disposed on the side opposite to the planetary gearing with respect to the output gear for disconnectably connecting the input shaft or the drive shaft to the carrier. The clutch protrudes from the transmission casing and is enclosed by a separate cover so that removal of the clutch can simply turn the four-forward speed automatic transmission into a three-forward speed automatic transmission.

Abstract: A reverser unit including a carrier having a forward double planetary pinion rotatably mounted thereon located in a forward section of an enclosing housing. The first planetary pinion of the double planetary is sized larger than a second planetary pinion of the double planetary pinion. A first sun gear coupled to a sun shaft is in constant mesh with the first planetary pinion and a second sun gear rotatably mounted on the sun shaft is in constant mesh with the second planetary pinion. A clutch drum is coupled to the second sun pinion and is generally located in the rear section of said housing. The clutch drum is coupled to a brake clutch system in the rear section of the housing for selectively braking the clutch drum to the housing. A clutch hub is coupled to the sun shaft in the rear section of the housing. A clutch system in the rear section of the housing can selectively clutch the clutch hub to the clutch drum.

Abstract: An epicyclic transmission with steplessly-variable speed control includes a set of three planet wheels (46) which are in the form of tapered rollers of dual conicity and are supported for rotation by a planet carrier (34) driven by a drive shaft (28). The tapered planet wheels have a larger frusto-conical portion (48) in rolling contact with a governing annulus (58) which is locked for rotation and is displaceable axially, and a smaller frusto-conical portion (50) associated with a driven annulus (92) which rotates a driven shaft (102). The tapered planet wheels also have two axially-spaced bearing surfaces (52,54) in rolling contact with two corresponding bearing surfaces (136,138) of a freely-rotatable sun wheel in the form of a sleeve (122) coaxial with the drive shaft (FIG. 1).

Abstract: A planetary gearing system comprising a planet carrier and planet gear wheels and planet friction wheels supported on planet wheel shafts on said planet carrier, said planet gear wheels cooperating with a gear ring encircling them and a sun gear wheel, said planet friction wheel cooperating with a friction ring circumscribing them and with a sun friction wheel, a housing enclosing the planet gearing system, said friction ring or ring gear being radially movable relative to said housing and means for mounting said gear ring and/or friction ring 20 in said housing by means providing an adjustable friction force so that they rotate in the housing when subjected to a torque exceeding a torque determined by said friction force.

Abstract: An adjustable intermittent incremental advance system is provided having a rotatable shaft for driving a work take-off in a start-stop rotary incremental advance. A clutch disk and brake disk alternately permit or stop rotary motion of the shaft to provide the intermittent advance. A flywheel is attached to the rotary shaft and acts through a crank arm driven by a motor to provide rotary power to the shaft for predetermined incremental movement. First and second sensors provide timed application of the clutch and brake disks to provide accurate incremental advance and prevent accumulated error in length of advance during prescribed periods of operation of the system.

Abstract: A master controller can be set by the driver in any of a range of forward drive positions D1 to D6 to pre-set upper and lower limits to the engine speed in any of a range of forward ratios such that any increase or reduction in vehicle speed which would cause the engine speed to exceed the upper limit or to fall below the lower limit of the setting chosen will result in an automatic shift to the next higher or to the next lower ratio respectively. Thus gear shifts occur at lower engine speeds in setting D1 than in setting D6. An additional setting B automatically brings about a shift to whatever ratio raises the engine speed nearest to the maximum safe limit to provide the maximum engine braking effect.

Abstract: A torque transmitting system for transmitting torque from a drive shaft of an engine to an output shaft without transmitting torque variation comprises a friction clutch unit interposed between these shafts, a fluid pressure-operated actuating unit for engaging and disengaging the friction clutch unit, operating condition detectors detecting the operation condition of the engine, and a rotation speed difference detector for detecting the rotation speed difference between the drive shaft and the output shaft. In the system, means are provided for setting the rotation speed difference between the shafts on the basis of the output signals from the operating condition detectors and for controlling the pressure of actuating fluid supplied to the fluid pressure-operated actuating unit so that the detected rotation speed difference approaches the pre-set rotation speed difference, whereby the torque can be transmitted from the drive shaft to the output shaft without any substantial variation.

Abstract: A control valve system for an automatic power transmission mechanism having planetary gearing defining plural torque delivery paths comprising fluid pressure servo operated brakes and clutches and a vehicle speed sensitive servo release shuttle valve which cooperates with the timing valve circuit to establish a first timed relationship between the application and release of the servos during a ratio change from the high ratio to an intermediate underdrive ratio at a relatively high speed and for establishing a different timing relationship between those circuit elements during a corresponding ratio change at a lower vehicle speed, the rate of application of the underdrive ratio servo during a ratio change from the lowest ratio to an intermediate underdrive ratio being calibrated independently of the calibration required for a ratio change from the high speed ratio to the same intermediate underdrive ratio.

Abstract: A reversible ratchet socket wrench assembly having a handle portion with a base containing the gear mechanism and a cylindrical sidewall at the upper edge of the base. The cylindrical sidewall and the base define a recess for storing sockets and a cover on the upper edge of the cylindrical sidewall closes the recess. A stub extends downwardly from the gear mechanism and an elongated drive shaft for a socket is attached to the stub. A bore extends from the bottom of the recess through the gear mechanism and the stub to connect with a bore formed in the upper end of the drive shaft which forms an elongated storage bore in the wrench assembly for storing a power bar.

Abstract: A tool turret has a housing and a revolving tool head which can be locked relative to the housing by means of gear teeth including annular toothed rings with axially extending teeth which can be interlocked in different rotational positions. A device having a cam drive controls the selective looking and unlocking of the gear teeth, the cam drive being arranged coaxial to the shaft. A Geneva wheel is provided to drive the head unlocked by the gear teeth. The cam drive has an annular groove in which rides a cam follower which is mounted on a axially movable, annular locking element which carries one set of teeth. The set of teeth can be removed axially to concurrently engage rings of teeth on the head and the fixed housing, locking the head.

Abstract: An automatically-controlled system for ripcutting a cant into a plurality of boards includes the conveyor for advancing the cant transversely along a substantially straight path. Optical scanning stations along the path determine the shape of the usable board area which is fed to a control system. The control system, in turn, directs a mechanism which orients the cant on a sawing table. The cant is held in a fixed position on this table while a plurality of overhead saws make a series of parallel cuts on the board. The wane edges fall away and the resulting cut boards are transferred to an outfeed conveyor.

Abstract: A bucking station for small logs is disclosed, in which a log is scanned to determine its size and shape, the resulting data are analyzed by a computer which determines the optimum locations for cuts, and the proposed cut locations are displayed on the log optically for the operator's inspection. If the operator overrides any of the proposed cuts, the computer recalculates any cuts not specified by the operator. When all cuts have been approved, the log is kicked to a cutting bed, where the cuts are made by means of two independently controllable traveling saws. The cutting bed is preferably defined by three sets of parallel plates. The first set comprises stationary plates having V-shaped upper edges which define a V-shaped trough in which the log is initially received. The second and third sets of plates are vertically movable and, when raised, together define a second V-shaped trough located above the first trough.

Abstract: A key cutting device (20), for replacement keys, having a key blank support member (30), a lever-actuated shearing punch (25) for the key blank, and a depth-gauging stop (33) for the support member (30); the shearing punch (25) is formed to provide an optional two-step (44, 46) cut on the key with a control stop (49) for limiting the stroke of the punch to one step or two steps, as desired, for creating different cuts on the key blank; a locking device (63) automatically moves into locking position with respect to the yieldably-actuated support member (30) to prevent its displacement when the operating lever (37) is manipulated for the key cutting operation.

Abstract: This invention relates with the method for manufacturing frames from aluminum profile rails, which undergo a series of cuts and perforations, done with a mechanism formed by two sections, an upper section which is made up of an upper plate to which a determined number of perforating bolts and knives are attached perpendicularly and a lower plate to which a determined number of blocks with different designs on their faces are affixed, resulting, as a consequence, a number of cavities into some of which aluminum profile rails will be inserted for cutting and perforation; and in others the perforating bolts and knives will penetrate making the cuts on the profile rails possible. Both sections are mounted on a support which by way of removable legs (preferable a tripod) can be positioned for operation.

Abstract: A keyboard operated electronic musical instrument is disclosed which has a number of tone generators that are assigned to actuated keyswitches. Logic is provided for generating a note range signal for each preselected group of contiguous keyswitches in which the note range signal is selected for an actuated keyswitch. Musical effects such as vibrato and tone changes are selectively actuated in response to the note range signal. A mixture tone generator is described which uses a single set of harmonic coefficients which are translated and shifted in response to the note range signal.

Abstract: Apparatus for detecting note selection on a guitar fretboard including a differential amplifier for detecting voltage drops across successive fret pairs, a multiplexer for connecting successive fret pairs to the differential amplifier, counters for maintaining an indication of the string and fret position under examination, and a shorting string placed across the frets for insuring reliable circuit operation.

Abstract: A musical instrument includes a keyboard having a number of keys which produce input signals corresponding to different musical chord progressions which may be selected by a user. The instrument also includes a synthesizer for producing certain ones of a number of different chords in four voices in response to control signals, and control circuitry including a storage device for storing a number of algorithms which determine the control signals wherein the synthesizer produces the selected musical progression. Each successive chord of the selected progression is computed in accordance with one of the algorithms stored in the storage device.

Abstract: A programmable music synthesizer has a keyboard which also generates an expression signal representing the pressure on the keyboard and utilizes the change in an infrared path length for producing this expression signal.

Abstract: A solenoid driving apparatus for actuating keys of a player piano is provided in which respective key striking strength data can be applied to respective solenoids of keys, so that musical tones can be reproduced correctly and in which the key striking strength data at the time of musical performance can be compensated for high fidelity reproduction. The solenoid driving apparatus includes a plurality of keys and solenoids provided on each key. When a key is depressed, a first key striking strength data corresponding to key striking strength and a data designating the depressed key are generated. The first key striking strength data is then converted into a second key striking strength data so as to make the latter data in linear proportion to an operating or response speed of the solenoid. In accordance with the second key striking strength data, a solenoid driving data is generated, and is applied to the solenoid corresponding to the key designated by the designating data.

Abstract: A method of forming a non-tunable head for a drum, banjo, tambourine, or similar musical instrument is described. A highly oriented crystalline polymeric film is immersed into a liquid solvent bath containing a halogenated methane compound until the film swells to become sufficiently soft so that it can be draped. The film is then removed from the solvent bath and preferably mechanically wiped to remove solvent remaining on its surface. The film is securely attached to an annular member before it dries, and is then dried by allowing the solvent to evaporate. As the film dries, it shrinks to substantially its original dimensions to provide a constant tension in the head. The heads formed by this method have sufficient tension to provide an effective musical tone without the utilization of clamping or stretching means which must be periodically readjusted to maintain a desired tension in the head.

Abstract: A rotary valve for selectively inserting and removing a slide loop from the sound path of a musical instrument is disclosed. The valve includes a rotor having an outer surface portion that is substantially conical and also includes a casing with a substantially conical inner surface portion that receives the outer surface portion of the rotor. Two sound passages entending through the rotor are no more than slightly curved. These passages align axially with the instrument's lead pipe, main bore, and slide loop ends so that a minimum of undesired harmonics are added to the tone of the instrument due to presence of the valve in the sound path.

Abstract: A plurality of vertical, elongated tubes are suspended longitudinally between a horizontal upper cross-piece and a horizontal lower cross-piece of a frame. Flanking the elongated tube on each side thereof is a striker element which is also suspended between the upper cross-piece and the lower cross-piece, the suspended, elongated tube and the two suspended striker elements on either side representing a single tube assembly. Interposed between adjacent tube assemblies are longitudinal frame pieces. Pivoting the upper cross-piece about a stationary point on the lower cross-piece results in the striker elements reciprocating laterally. When moving in one direction, a striker element contacts the elongated tube; in the opposite direction, the striker element contacts a longitudinal frame piece. Resilient pads are located on the longitudinal frame pieces where the striker elements make contact, thereby decreasing the sound of a striker element as it strikes a longitudinal frame piece.

Abstract: A training bass drum has a length significantly larger than those of conventional training bass drum so that it generates musical tones with sufficient noise control but attains ample bass range effect. The resultant elongated internal space is advantageously utilized for encasing other sorts of percussive musical instruments such as snare drums and tomtoms.

Abstract: A marine firing or weapon system is disclosed for fighting rapidly moving targets in zenith and possesses an azimuth or lateral alignment axis which is inclined through about 35.degree.. The ammunition infeed is accomplished from four stationary drum magazines rotatable about vertical axes. The drum magazines are located below the weapon. Since the belted ammunition, owing to the inclined azimuth alignment or aiming axis is infed along a bent, central, column which is vertical or upright at its lower region, there is required lengthwise compensation of the belted ammunition during azimuth alignment or aiming of the weapon. The weapon barrels are cooled. Because of the inclined azimuth alignment axis the minimum elevation is limited by an adjustable stop or impact member. The drum magazines possess compartments each of which contain a respective loop of the cartridge belt.

Abstract: The automatic fire arm is provided with a bolt and hammer which reciprocate along the axis of the barrel. A first spring normally biases the bolt against the breech end of the barrel and a second spring normally biases the hammer against a firing pin which is slidably mounted within the bolt. A moveable retaining lever is pivotally mounted below the chamber in which the bolt and hammer are located. An upwardly extending projection is provided on each end of the lever which is extendable into the chamber through axially spaced apertures. A trigger mounted pin normally holds the lever with the rearmost projection extending into the chamber so that upon retraction of the bolt and hammer the hammer will be held in cocked position by the rearmost projection when the bolt returns to engage the breech end of the barrel.