Abstract: An apparatus detects an air turbulence and wind shear encountered by an air vehicle having an accelerometer sensing air vehicle vertical acceleration. The apparatus includes a pressure sensor having a pressure sensing port for sensing a pressure parameter of a local air flow which changes with changes in the local airflow turbulence, and a fast time constant pressure transducer coupled to the pressure port for generating a transducer signal representative of the parameter. Differentiating means calculates a time derivative of the transducer signal and provides a turbulence signal representative of the time derivative. Subtracter means provides the difference between the turbulence signal and a vertical acceleration signal from the accelerometer, to provide a wind shear indicating signal indicative of an increase in air turbulence.

Abstract: A vertical position and gravity map aided INS is self contained (no external signals required); covert (no signals emanated); unrestricted in operating area; able to operate in quiet or active gravity regions; and able to be configured with proven instruments.

Abstract: One side of a primary flight display has an elongated vertically disposed airspeed dial display which provides global or macro airspeed information. A rolling drum display provides a digital display of a present value of airspeed. An elongated vertically disposed altitude dial display is located on a second side of the primary flight display. The second dial display is configured to provide a predetermined amount of rotation of the pointer for a lo predetermined change in altitude. A second rolling drum display provides a digital present value of altitude. The elongated dial displays provide greatly expanded display areas and improved readout resolution.

Abstract: A thermal type flowmeter for measuring a flow rate of a fluid which is equipped with a thermo-sensitive resistor provided within a fluid passage and arranged to heat while being energized. The flowmeter includes an electric power adjusting element provided in series with the thermo-sensitive resistor for adjusting the amount of electric power to be supplied to the thermo-sensitive resistor based on a current inputted to its input terminal. It also includes a constant current source circuit connected to said input terminal of the electric power adjusting element for supplying a predetermined constant current to the input terminal of the electric power adjusting element. A control circuit outputs an adjustment signal to adjust an amount of electric power supplied to the thermo-sensitive resistor so that the thermo-sensitive resistor has a predetermined temperature.

Abstract: A flowmeter measuring chamber having a generally cylindrical outer wall, a generally cylindrical inner wall, and a piston, having a tubular wall disposed between the inner and outer walls and arranged to oscillate within the outer wall, is provided with a mechanism for controlling movement of the tubular wall. That movement is controlled so that a capillary space is maintained between the tubular wall and the inner wall and between the tubular wall and the outer wall at all positions of the piston and contact between the tubular wall and the inner and outer walls is prevented.

Abstract: A vibration gyroscope with a mass mounted for vibrational movement on a central post. Sensing capacitors are mounted adjacent the mass for sensing vibrational movement in two perpendicular axes. The mass includes a pair of elements mounted between the parallel arms of an H shaped frame and powered for equal and opposite vibrations so that no movement is imparted to the frame except that caused by forces induced by rotational movement.

Abstract: An acceleration detector includes a magnetic body movable under acceleration, and a differential transformer having primary coils and secondary coils and arranged so that an output differential is produced between the secondary coils when the movable magnetic body is displaced. The movable magnetic body extends through the primary coils and the secondary coils and has opposite ends protruding from the coils. Leaf springs are provided to support the protruding ends of the movable magnetic body. The case comprises a cylindrical body surrounding the outer periphery of the differential transformer and lids closing openings of the body at both ends thereof. Between the lids and both ends of the movable body predetermined gaps are provided through which a magnetic flux can flow. The leaf springs are secured in position between end faces of the body and the lids.

Abstract: A process and an apparatus for the ultrasonic testing of welds between plastic packaging like food trays and cover foils. The welded joint between the tray and cover foil is periodically exposed to pulses of ultrasonic radiation. The pulses pass through the weld and are picked up or received by a receiver. The amplitude of the received pulses is evaluated. The cross-section of the beam of ultrasonic radiation is so small that the radiation only passes through the weld itself. The packages and the ultrasonic tester are moved relative to each other in order to examine the whole circuit of the weld. The pulse rate is such that the weld areas covered by successive pulses overlap.

Abstract: The present invention is directed to methods and apparatus relating to an accelerometer electrical signal recorder and playback module. The recorder module may be manufactured in lightweight configuration and includes analog memory components to store data. Signal conditioning circuitry is incorporated into the module so that signals may be connected directly from the accelerometer to the recorder module. A battery pack may be included for powering both the module and the accelerometer. Timing circuitry is included to control the time duration within which data is recorded or played back so as to avoid overloading the analog memory components. Multiple accelerometer signal recordings may be taken simultaneously without analog to digital circuits, multiplexing circuitry or software to compensate for the effects of multiplexing the signals.

Abstract: An apparatus for determining the time taken for sound energy to cross a body of fluid in a pipe uses a modified pipe in which flat members seal apertures in the pipe and two transducers are attached to respective fiat members, wherein the material around each aperture curves away from the centre of the pipe towards the periphery of the aperture and contacts the respective flat member along the entire periphery of the aperture.

Abstract: A method and apparatus for use in confirming hydrogen damage in a boiler tube comprises a pair of electromagnetic acoustic transducer coils which are mounted for movement toward and away from each other. An electromagnet produces pulses that generate acoustic beams across a chord and within the wall thickness of the boiler tube. For adapting to boiler tubes of different outside diameters, the transducers coils are mounted on a resilient member so that the coils can be pressed against the outer surface of coils having a variety of outside diameters. The angle of the acoustic beam between the coils must also be adjusted, however, and this is done by changing the frequency of energy applied to the coils.

Abstract: A method for measuring an adhesion strength of a resin material which is capable of accurately and readily measuring a universal adhesion strength independent of dimensions and shapes of specimen. A delamination portion is partially formed between a resin and an adherend material. Loads in two different directions are applied to an adhering interface such that opposed shear stresses are generated. As a result, a true adhering strength can be obtained from an apparent delamination propagating strength in each case.

Abstract: A Coriolis flow meter includes a measuring wheel which is driven by a motor. The measuring wheel has interior and exterior walls configured as cones with a plurality of guide blades extending between the walls. The center lines of the guide blades are at an acute angle with respect to the axis of the measuring wheel. A torque measuring device measures changes in driving torque of the motor. In one embodiment the measuring wheel is mounted on a cantilever laterally projecting out of the housing and supported at its exterior end on a load cell of the torque measuring device.

Abstract: A method for determining mass flow rate of media moving through at least one conduit under a flexural vibration comprises obtaining two alternating electrical signals respectively representing the flexural vibration of the conduit at two different sections of the conduit, and determining mass flow rate of media as a function of the ratio of a value of one of the two alternating electrical signals measured at an instant when the other of the two alternating electrical signals reaches a zero value to the amplitude of said one of the two alternating electrical signals.

Abstract: In the load cell disclosed herein, relative displacement between bridging members or end caps mounted at different points along the axis of an elastic hollow cylinder is sensed by means of a variable reluctance transducer employing a pair of magnetically permeable core elements. One of the core elements is mounted on one of the bridging members and the other core element is C-shaped and mounted on the other bridging member with the ends of the C-shape in close proximity to the first core member thereby providing magnetic gaps whose widths are aligned with the cylinder axis. Windings around the ends of the C-shaped core provide electrical connection for an inductance which is variable as a function of the widths of the gaps and thus also of the axial displacement between the bridging members.

Abstract: Load cell having a body with a ball recess therein and a ball removably disposed in the recess above a strain gauge means disposed in the body centrally below the ball recess, the load cell useful in measuring samples of geologic materials, e.g., core samples and for methods and apparatuses for measuring ultrasonic velocities in materials, particularly in the triaxial testing of low permeability rock samples.

Abstract: The invention relates to an on-line tension meter for an optic fiber. The tensile stress of a bare optic fiber is measured without contacting the optic fiber as the optic fiber is drawn in a draw machine. A loudspeaker causes a wire wave to be formed in the fiber. The fiber tension is then measured by the advancing speed of the wire wave. The speed is measured by means of two location-sensitive electro-optic indicators or cameras, the distance therebetween being known.

Abstract: A hand-manipulative apparatus is disclosed for receiving a specimen of the fuel tank contents of a fuel tank. The apparatus comprises an elongated body of substantially circular cross-section. The body is fabricated of transparent molded material and is open at its upper end. The body is of tubular character through a portion of its length for defining a fuel-receiving compartment having a central axis and communicating with the open upper end of the body. The body has spaced-apart indentations in its upper end edge for alignment and cooperation with associated actuating arms of a pet cock drain valve, if such a pet cock drain valve is utilized. The tubular portion is closed at its lower end portion. A resilient semi-rigid rod is removably attached at a first end to the lower end portion of the tubular portion.

Abstract: A method of using a technique of fuzzy inference for partioning a particle size distribution diagram indicative of a relationship between particle size and its frequency of a mixture of several kinds of granular substances, such as white blood corpuscles including lymph corpuscles, monocytes and granulocytes, to define particle size regions for the respective substances. More particularly, some estimation points are selected on the abscissa of the particle size distribution diagram and some characteristic parameters are calculated at each estimation point with the corresponding frequency. A fuzzy production rule for each characteristic parameter is applied to seek an estimated value of the estimation point and the estimated values for all characteristic parameters at each estimation point are combined to obtain a composite estimated value. The estimation point corresponding to the greatest one of all resultant composite estimated values is appointed to an objective partition point.

Abstract: A dry particle analyzer includes a vibrating sieve cup drizzling particles downwardly with first and second sheath air flows provided to separate the particles from boundary walls and to form the drizzling particles into a curtain for optical analysis. The particles drop vertically as a drizzle with gravitational assistance from a bulk sample to the analysis passage, after which their direction of movement is changed to horizontal and then upward for removal from the analyzer.

Abstract: This system for reversibly transforming rotary motion into self-guided rectilinear motion has the characteristic of being achieved by symmetrically coupling at least two connecting rod-crank (108A, 108B, 107A, 107B) mechanisms, which are mutually associated by the pivots (111) of their connecting rod small ends (110) and by the engagement of identical toothed wheels (112A, 112B) fixed symmetrically into the two specific cranks.

Abstract: A control cable adjusting arrangement for a gear shift locking arrangement includes a holder portion which accepts an inner cable of a control cable in one end thereof. An outer cable encasing the inner cable is retained by a bracket. The other end of the holder accepts an end of a control rod associated with a gear shift lever. Disposed around the holder is a slider portion movable between a locked and unlocked position determined between two stopper flanges formed on the outer circumference of the holder. The holder and slider are made of an elastic material such as rubber and an end of the holder which accepts the end of the control rod has a flared outer circumference.

Abstract: A bicycle front fork shock absorbing mechanism includes a lower cylindrical casing having a lower rubber ring above an inside screw hole thereof and a friction lining around the inside wall thereof, and upper cylindrical casing inserted into the lower cylindrical casing to hold a stack of upper rubber rings by a locating block, a friction ring mounted around the lower cylindrical casing in contact with the friction lining through a slide contact, a shock absorbing conical spring retained between the upper rubber rings and the lower rubber ring, and a screw rod having a head stopped above the locating block and a screw rod inserted in proper order through a hole on the locating block, the upper rubber rings, the shock absorbing conical springs, and the lower rubber ring and then threaded into the screw hole on the lower cylindrical casing.

Abstract: A lightweight self-insulating composite hand tool such as a screwdriver has a tool shank of electrically insulative material molded to and about a tip shank of a tool tip, having a working end and an integral tip shank. A mechanical interlock coupling is molded into the tip shank to resist axial tensile and compressive stress and torsional stress. A premolded replaceable elastomeric cover is slipped onto the hand tool and about the periphery of the molded tool shank. The working end of the tool tip includes a circumferential groove which receives a snap fitting bead of the replaceable elastomeric cover. The molded tool shank may be a braided composite of non-electrically conducting reinforcing filaments embedded within a settable matrix such as resin or epoxy. The tip shank is provided with an annular recess which flares rearwardly at a slight retention angle to retain the braided filaments and the settable matrix end of the composite tool shank on the tool tip shank.

Abstract: A method of trimming plastic covering a mouth opening of a blow-molded universal urinal involves rigidly holding the urinal in position opposite a trimming machine. The machine mechanically moves a knife mounted thereon in an oval pattern in one plane while simultaneously moving the knife in an alternately concave and convex pattern in a second plane orthogonal to the first plane. The knife is mounted on a platform which is movable in the second plane independently of the movement of the knife. As the platform is moved toward the urinal mouth, the knife is moved in the described pattern, thus smoothly trimming the urinal mouth.

Abstract: A boot guard for shielding the protective extensible bellows or boot of automotive brake lathes from being torn by tools used in the final surfacing operations on brake parts. The guard is formed by a partial enclosure attached to the lathe slip ring with screws, outside of the lathe boot, moving with the lathe spindle as it extends and retracts. It is guided and radially located by a guide pin extending from the body of the lathe through a guide slot in the enclosure.

Abstract: A novel two part punch stripper (10) for use with punches (12) carried by a punch press (16). The novel two part urethane punch stripper of this invention includes generally cylindrical concentric tubular upper and lower parts (50 and 52). The lower part (52) is formed of a urethane of a conventional hardness for a punch stripper, the hardness being in the range of 80A to 100A (Shore). The tubular upper part (50) is formed of a urethane substantially harder than the lower part of the stripper, for example, in the range of 75D (Shore). The combined length of the upper and lower parts is greater than the length of the portion of the punch which extends below the punch retainer assembly (14) so that a proper preload can be achieved. The upper part and lower parts are bonded to each other by a suitable adhesive. Alternatively, they may be bonded to each other by sequentially casting in a common mold.

Abstract: A high speed web cutter has a rotating roller with an extended bar mounted perpendicular to its surface and angled to be aligned askew with respect to the roller's axis. During the rotation of the roller, the bar interferingly contacts a plate having an angled edge that is mounted on a relatively stiff cantilever spring. The bar edge and the plate edge are not mounted parallel with each other nor are either of them parallel with the plane of the web. As the roller rotates, the extended bar deflects the cantilever spring, allowing the edges to intersect in a cutting intersection that travels axially with roller rotation, thereby severing a web member passing between the roller and the plate edge.

Abstract: A perforator has a perforator disk rotatably seated in a U-shaped bearing bracket. The bearing bracket is movable into and out of the path of movement of a piece to be perforated by a piston-cylinder unit which is actuated from either side of the piston. The piston-cylinder unit is housed in a fastening element which can be connected to a machine frame. The bearing bracket has guide bolts which extend into the fastening element to secure the bearing bracket against rotation in respect to the fastening element. The fastening element comprises a cylinder having a blind bore extending from the side of the fastening element facing the U-shaped bearing bracket in which a piston having seal rings is sealingly guided in a displaceable manner.

Abstract: An improved, multi-store dispenser is described which uses a solenoid and ring combination to eject individual stores after an electrical pulse is sent from the transporting aircraft. As each store is loaded into the dispenser, the loading action forces a spring into a compressed mode and a latch is closed to prevent expulsion. An electric pulse trips a solenoid, which in turn causes the latch to release, thereby allowing the store to be ejected.

Abstract: In the field of infrared or electromagnetic decoys for protecting light aircraft or helicopters, pyrotechnic cartridges and ammunition comprising racks receiving the cartridges are described. Thus it is possible for the same volume of ammunition to have a larger number of shots and to carry out the loading of the ammunition simply and quickly. The cartridge (1) consists of a sole (2) fixed to a case (3), in which are accommodated a plurality of assemblies (11) comprising pyrotechnical ejection charges (6), pyromechanical assemblies (7), ignition charges (8), effective charges (9) and the caps (10). The case (3) is provided with a plurality of receptacles and comprises at its base a blocking device (4). The assemblies (11) are independent and are arranged in parallel in the various receptacles of the case (3); the sole (2) is common to the various receptacles of the case (3) and is provided with electrical fuses.

Abstract: A method for confinement of a gun propellant during the initial stage of ignition provides the ignition by electrical, pyrotechnic, or laser irradiation means. A liquid and or a solid propellant is placed in a substantially closed chamber. A portion of the propellant in a conduit of the chamber exits from the chamber and is cooled in the exit conduit by a thermoelectric or cryogenic means to a sufficiently low temperature for producing a viscous, glassy, or substantially solidified condition to enhance the propellant containment. An ignition stimulus is then applied. A closure means in the exit conduit selectively varies the amount of flow whereby a relatively high temperature and pressure are reached from the chemical energy release of the propellant. Venting of the formed combustive products is provided through the exit conduit whereby sufficient thermal energy is generated to sustain combustion and to ignite the next stage.

Abstract: RF energy radiated by impacting munition rounds is used to provide an indication to a gunner where the rounds from his gun are striking, or to control a gun servo (158) to automatically correct the aiming of the gun. The RF energy from the rounds is received by several antennas (32, 34, 36) in a known geometry and the angle of arrival computed from the differences in the times of arrival at each antenna. The impact locations can be displayed in the existing gun sight, or in a head up display for the gunner. The angle of arrival information can further be used to control a gun aiming servo (158) to correct the aim of the gun to improve accuracy.

Abstract: A novel mechanism for moving a gun bolt toward and away from a firing chamber of a barrel assembly having movement relative to a receiver in a cartridge-firing weapon, having a camming channel formed in the receiver of the weapon, uses a rack member having an end coupled to the gun bolt and moving substantially linearly with the gun bolt toward and away from the chamber. A gear train has a housing affixed to the moving barrel assembly; an input member moves in the camming channel responsive to barrel assembly movement, to cause an output member to move the rack member and attached gun bolt toward and away from the chamber with substantially-linear displacement, velocity and acceleration greater than the associated displacement, velocity and acceleration of the moving barrel assembly with respect to the weapon receiver.

Abstract: A method to manufacture an articulated piston head wherein the two portions composing the head, i.e. the top portion and the pin boss portion, are formed separately from blanks of forged or cast chromium-molybdenum steel or a low alloy steel, subjected to preliminary machining operations, joined together by friction welding and then machined to final dimensions.

Abstract: A combination smoker and cooker comprising adjustably spaced grills so as to make easier access to the grills and to replenish cooking fuel. The cooker comprises a grill support bar for supporting multiple grills including a water pan steamer assembly, at adjustable vertically spaced intervals in a housing. The grill support bar comprises pairs of vertically spaced slots cut into oppositely facing sides thereof and is held in the housing by a socket which is sized and shaped to firmly receive a bottom end of the support bar and secure the support bar in place in the cooker.

Abstract: An appliance for cooking a sausage on a stick embedded in a batter. One or a plurality of cylinders are provided for receiving a cooked sausage skewered on a stick which is then filled with a pancake batter. The cylinders are then submerged in a hot oil for a few minutes to cook the batter to produce a breakfast on a stick. The appliance can be in the form of a plurality of cylinders on a plate or can be individual cylinders. The appliance is provided with hooks or a clip to mount it in a deep fat frying basket for submersion in hot oil, In another embodiment the appliance can be free-standing by surrounding each cylinder with a heating coil.

Abstract: An apparatus for producing an edible sandwich having a cavity with uniform thickness of bread surrounding the cavity. Edible filler material is injected into the cavity that has a self-sealing entrance. The apparatus forms the sandwich by first making a keyhole shape slit in the bread casing. Then an expandable mandrel is inserted into the slit and expanded by filling it with air. As the mandrel expands, it compresses the bread in the casing to form a cavity having walls of substantially uniform thickness throughout. An edible filling is then inserted into this cavity via the slit previously formed.

Abstract: The invention relates to the field of fruit and vegetable juice and puree extractors in general. More precisely, it relates to a rotary-type extractor having at least two refinement stages arranged vertically and coaxially and being activated by a single, common motorization.

Abstract: A device to permit the individual striping and indication by means of color coding wires is provided, such that a guide tube receives a wire therethrough, with a guide housing mounted to the guide tube and the guide housing having a first end arranged in surrounding relationship relative to an opening in the guide tube to permit a felt tip marker tip portion to project through the opening and permit striping of a wire directed through the guide tube.

Abstract: To prepare a screen printing stencil, a pattern of resist, having a complementary design to the final screen printing stencil, is applied to a conductive mandrel. A patterned layer is electroformed onto the exposed surface of the mandrel such that the layer corresponds to the exposed orifices of the pattern of resist. The resulting screen printing stencil has raised edges surrounding orifices. The raised edges are placed against a surface of a substrate to be printed in use of the stencil. The screen printing stencil can be used for printing substrates in the electronic substrate fabrication and electronic assembly industries.

Abstract: A device (14) for delivering signatures (S) in a printing press (10) having a fly (18) having a plurality of open pockets (26) to receive the signatures (S), a device (20) for rotating the fly (18), a device (36) for stripping the signatures (S) from the fly (18) in an exit portion (34) of the fly (18), and a device (32 and 30) for driving the stripping device (36) at a speed relative to the speed of the fly (18) in a manner reducing their relative velocity less than the relative velocity between the fly (18) and a stationary condition of the stripping device (36).

Abstract: A device for delivering signatures (S) for a printing press (10) having a delivery device (50) having a plurality of sets (60a and 60b) of flies (58a, 58b, 58c, and 58d), with the flies (58a-d) each having a plurality of open pockets (26) disposed around the flies (58a-d), a device (62a and 62b) for stripping signatures (S) from the pockets (26) disposed between a pair of adjacent flies (58a and b, and 58c and d) in each set (60a and b) of the flies (58a-d), a device (76, 78, and 80) for adjusting the sets (60a and b) of flies (58a-d) and stripping devices (62a and b) in unison laterally across the delivery device (50), and a device (64 and 84) for modifying the lateral distance between adjacent sets (60a and b) of the flies (58a-d) and respective stripping devices (62a and b).

Abstract: Text (indicia, words, symbols, etc.) of documents is highlighted in such a way that it will reproduce when electronically copied (e.g. photocopied or telecopied). This is accomplished by applying a tone to only that area of the document to be highlighted and so that the tone remains in place during copying. The tone is sufficiently dark so as to highlight the text, but light enough so that the text is readable. The tone may be a dot or line screened tone having about 30-65 lines per inch with a density of about 10-22%. The tone may be applied on adhesive tape and just placed over the document portions to be highlighted. The tape may be dispensed from a dispenser. Alternatively, the tone may be on a transfer sheet, and is transferred to the document merely by the act of rubbing on the transfer sheet. The tone may also be applied to the document utilizing a print wheel in a casing, that is moved over the document. After the document is electronically copied (e.g.

Abstract: A self-inking hand stamper with an inking pad tilted from the horizontal. In moving from its retracted, inking position to its forward, stamping position, and back again, the die plate pivots around two pivot points to move through an arc of substantially less than 180.degree., resulting in a smaller stamper interior. The first pivot point is provided by a single pivot pin mounted on each side wall of the stamper, and slidably journaled in a single curved cam slot in the respective die plate support leg. The second pivot point is provided by the die plate axle, which is secured to the downwardly extending legs of the actuator yoke and is slidably journaled in a straight, vertical guide slot in the stamper frame.

Abstract: Clamping and tensioning device for an inwardly bent trailing edge of a flexible printing plate disposed in an axial gap at the circumference of a plate cylinder adjustable in axial spacing and cooperating with a blanket cylinder, the printing plate being fixable at a leading edge thereof on the plate cylinder and being tensionable in circumferential direction on the plate cylinder, includes two clamping bars displaceably supported in the axial gap and forming therebetween a clamping slot for receiving therein an inwardly bent trailing edge of the printing plate, the two clamping bars extending axially in the gap within the cross-sectional contour of the plate cylinder and being loadable by reversible opposing clamping forces as well as by reversible tensioning forces in common in tensioning direction of the printing plate, and being respectively braced against the plate cylinder, the two clamping bars being formed with radially outer edges, the clamping and tensioning device being radially displaceably dispos

Abstract: A directional ordnance for a missile. The missile contains circuitry to determine the direction of a target relative to the missile and to selectively detonate directing charges to force the blast from the warhead towards the target. The circuitry for determining the direction of the target includes two transmit antennas, each transmitting a different pseudo noise sequence, and two receive antennas; each coupled to a receiver which can determine the level of each pseudo noise sequence at each receive antenna. The relative strengths of the different pseudo noise sequences tell the direction of the target relative to the transmit and receive antennas.

Abstract: A device for generating a shockwave for initiating detonation of a main explosive charge and a method for producing same are provided. A device according to the instant invention is capable of producing a more planar wave front than is possible according to the prior art. Also, the wave front generated by such a generator flattens out in less time than in the prior art, and therefore the weight and axial length of a warhead equipped with a generator according to the instant invention may be substantially reduced without a corresponding reduction of the detonator's explosive yield.

Abstract: A simulator which is chemically equivalent to an explosive, but is not detonable. The simulator has particular use in the training of explosives detecting dogs and calibrating sensitive analytical instruments. The explosive simulants may be fabricated by different techniques, a first involves the use of standard slurry coatings to produce a material with a very high binder to explosive ratio without masking the explosive vapor, and the second involves coating inert beads with thin layers of explosive molecules.

Abstract: A cartridge 10 for low-mass, frangible projectiles 60 comprises a cartridge ase 12 having a primer 14 at its base and a sabot 30 or piston 30 at its mouth. The piston 30 can be provided with longitudinal orifices 44, diagonal orifices, 44a, grooves 64 or any combination of orifices and grooves. The projectile 60 is inserted into a cylindrical recess 46 in the front portion of the sabot 30. The orifices 44 are in communication with this recess 46 to permit propellant gas to bleed through and accelerate the projectile 60 upon ignition. The case 12 and the sabot 30 can be provided respectively with a crimp 24 and a stepped portion 48 in order to limit travel of the sabot 30 out of the case.