Abstract: An improved flying saw of simplified and more economical construction is disclosed which operates smoothly with reduced vibration and which performs in an improved manner at higher operating speeds. The machine has a main crank arm with a rotary saw blade at one end and an adjustable counterweight at the opposite end, a stabilizing crank arm with a counterweight, and a connecting rod causing the arms to rotate in unison. Both arms telescope to permit simultaneous adjustments of arm radius while screw jacks adjust the height of the crank axis relative to the work. The work is supported on a wheel having a special sliding-block eccentric which moves the wheel in a vertical direction to deflect the work into the path of the rotary saw blade. A quick-drop support bracket permits lowering of the wheel and its eccentric away from the path of the work in an emergency situation so that flow from the mill need not be interrupted.

Abstract: A machine for the cold-sawing of steel plates in which the feed movement between the circular saw blade including its drive housing and the workpiece, in essence the steel plate, is effectuated in a horizontal direction. The saw unit, which consists of the saw blade and its drive housing is so guided in a vertical direction as to be freely movable in this direction, and is provided with means which support themselves on the workpiece in immediate proximity to the saw cut in a manner whereby the saw blade does not enter essentially deeper into the workpiece than would be necessary to divide the latter. During sawing, the saw blade should project beyond the lower surface of the workpiece by only a fraction of a millimeter.

Abstract: A cutting tool is provided with a plurality of circular cutting blades of varying predetermined thicknesses to shear sections from rings made of precious metals. Each blade is formed with a notched perimeter to provide a pair of blade cutting edges. The blades are mounted on a spindle for rotation therewith, while the spindle is rotatably mounted in a plurality of cutting blocks which are affixed to a base in an alternating arrangement with the aforesaid blades. The cutting blocks define cutting edges so that rotation of the spindle causes the blade cutting edges formed by the notched perimeter to come into a simultaneous shearing relation with the cutting edges of the two adjacent cutting blocks. Further rotation of the spindle will shear out a section of a ring interposed in the notched perimeter of the blade. The tool is further provided with removable trays to catch sheared pieces of precious metals. Rotation of the spindle is accomplished through a conventional crank handle.

Abstract: Parallelepipedic packing containers are made and filled in succession by passing a continuous web of packaging material over a forming device which converts the web into tubular form with an overlapped longitudinal seam. The tube is then filled with the intended contents, e.g., a liquid and is then divided off into individual packing containers by first pressing the tube transversely at longitudinally spaced intervals along broad zones and the opposite sides of the flattened tube are heat-sealed to each other along two narrow sealing regions close to the opposite base lines of the flattened zone while the remaining portions of the flattened zone remain non-sealed.

Abstract: The shear mechanism includes two fixed plates and a plate movable therebetween. The movable plate has a notch in one side edge which is moved out of registry with notches in the fixed plate to effect a shearing operation, the movable plate having a blade associated with its notch and one of the fixed plates having a cooperable blade associated with its notch. The fixed plates each have two appropriately located circular holes in which are received a first pair of pins, the pins extending through slots in the movable plate so that the blade on the movable plate can move sufficiently relative to the blade on the fixed plate to perform its shearing operation. Offset from the slots in the movable plate are two appropriately located circular holes in which are received a second pair of pins, the second pair of pins extending through slots in the fixed plate of sufficient size so that the shearing action can take place.

Abstract: Disclosed is a rolling cut type shear wherein a downwardly curved upper blade is moved in such a way that the midpoint thereof in the longitudinal direction passes a cycloidal path, whereby the slip of the upper blade relative to a steel plate to be cut may be prevented.

Abstract: A saw guide for use with a hand held power saw comprises in combination, a base plate having a generally planar edge, a saw blade index which is connected to a side of the base plate and which projects beyond and outwardly of the generally planar edge. The saw blade index has a generally planar first edge extending along the length thereof. The planes of the generally planar edges of the base plate and the saw blade index intersect one another at an angle of 90.degree. or less. The arrangement is such that a workpiece to be cut is placed along the generally planar first edge of the saw blade index and against the side of the base plate where the side of the base plate is held in the face-down position to sandwich the workpiece between the saw guide and a workbench surface. The angle between the planes determines the angle at which the workpiece is cut with the hand held power saw.

Abstract: An automatic arpeggio musical instrument includes a pulse generator having a plurality of keys for generating periodic pulses by depression of one of the keys, each of the keys generating a voltage, a timing pulse generator connected to the pulse generator, a memory connected to the timing pulse generator for generating digital signals of a musical scale, digital-to-analog converter means connected to the memory for converting the digital signals into analog signals, a processor connected to the converter for selectively adding and subtracting the key-generated voltage to the analog signals, and for generating an output voltage therefrom, and a voltage-controlled oscillator connected to the processor for controlling the output voltage.

Abstract: A keyboard for a piano, organ, or similar instrument in which the keys are arranged in groups of three, each having a pair of flat keys with a raised key inset between. The flat keys are on a common plane in the manner of the white keys of a conventional keyboard, the raised keys being short in length and spaced between the front edge of the flat keys and the back board of the instrument. In one form of the keyboard a second set of raised keys is positioned adjacent the backboard and mechanically coupled to the basic set of raised keys, so that either raised key in a pair may be used to play a particular note for the convenience of fingering. Four groups of three keys represent the twelve tones of the chromatic scale and a related notation system identifies each tone clearly, without the need for sharp and flat symbols. The keys also have a physical relationship to the note positions in the musical notation, which simplifies playing.

Abstract: An improved mounting apparatus for high-calibre guns, for use on mobile platforms such as tanks includes a support for the gun which permits the elevation trunnions to be moved vertically from a lowered, small silhouette position to a raised position which permits optimum movement in train and elevation.

Abstract: Apparatus and method for setting and machining the surface of at least one workpiece. The apparatus includes a structural member, means for supporting the structural member for transverse and longitudinal movement, and, a cutting device and a spacing block serially mounted on the structural member. The cutting device and the spacing block are disposed on the structural member such that the machining surface of the cutting device is located in a plane outside the plane of at least one side of the spacing block by a distance sufficient to remove a predetermined thickness of material from the workpiece.

Abstract: An improved broaching machine comprises a device for accumulating at least part of the kinetic energy stored during the travel of the tool-carrier slide-block within the assembly constituted by the slide-block, the rotor of the electric motor and the transmission system as well as means for transferring the energy from the slide-block to the accumulation device and conversely.

Abstract: A dual lever control mechanism is disclosed for actuating a pair of control devices individually having first and second modes of operation, including a stationary support, a first lever arrangement pivotally mounted on the support for selectively moving both of the control devices into either their first modes of operation or their second modes of operation for effecting simultaneous coordinated movement thereof, and a second lever arrangement pivotally mounted on the support and cooperatively coupled with a portion of the first lever arrangement for selectively moving both of the control devices respectively into either their first and second modes of operation or their second and first modes of operation for effecting simultaneously opposite coordinated movement thereof.

Abstract: A fire and smoke free stairway in the event of fire in high rise buildings can be maintained by developing a velocity pressure of air through the fire doorway, from the fire stairway each time the door is opened during evacuation and without pressurizing the stairway significantly.

Abstract: The present invention relates to an adapter for converting a standard eight cup coffee brewer to the commercial type that will brew 12 cups. The stand for the eight cup coffee brewer is disconnected from the base, and an adapter is inserted between the stand and the base. The adapter raises the stand to allow additional clearance for a 12 cup coffee pot, the standard commercial size. The stand is again connected to the base with the adapter inserted therebetween. The adapter has an additional electrical outlet connected to the electrical system for the coffee brewer, which outlet may be used as an additional hot plate connection to maintain an additional pot of brewed coffee at the proper temperature.

Abstract: A donut maker for home use is disclosed which provides perfectly cooked and formed donuts having excellent taste and appearance characteristics notwithstanding the complete elimination of conventional deep fat frying of the donuts. The preferred device includes a base and openable lid section each having a pair of annular metallic concave walls disposed for cooperatively defining a pair of enclosed donut-shaped cooking chambers, along with a heating element for heating quantities of donut batter confined within the chambers; two corresponding sets of oil flow apertures are provided in the lid for allowing flow of cooking oil into the chambers during heating of the batter, in order to give the finished donut products a desirable crust and true donut flavor. In preferred donut-making procedures, cooking oil is introduced into the chamber during initial stages of cooking, whereupon the oil and cooking-generated steam are displaced from the chamber as the batter cooks and rises.

Abstract: A domestic trash compactor is provided with electromechanical means operable on a predetermined stroke of its compacting head to control a circuit, in the disclosed embodiment, a signal circuit providing a warning that the compacted trash in the receiver should be inspected.

Abstract: A trash compactor has trash compacting means attached to a chassis that is supported in the upper end of the housing for limited movement relative to its side walls and is detachable in a manner facilitating servicing of the trash compacting means. The chassis moves upwardly in response to reaction force developing on the application of compacting pressures to the trash by the compacting means and, at its upper limit of travel, it transfers the reaction forces to the side walls of the housing.

Abstract: A line printer having a plurality of printing rings having characters on the peripheries thereof and coaxially arranged adjacent to each other on a driving shaft rotated in one and the same direction during each printing cycle with springs connected between the respective printing rings and the driving shaft so that the respective printing rings can be yieldably driven by the driving shaft through the springs and a movable roller pad adapted to abut against the printing rings at the predetermined printing position so that the selected character each of the printing rings temporarily held at the printing position during the rotation of the driving shaft is simultaneously printed on a sheet of paper held between the printing rings and the roller pad.

Abstract: An endorser assembly comprising inking, ink transfer and endorser rolls resiliently mounted within a modular type supporting frame to enable removal and replacement of the entire endorser assembly from paper handling apparatus. The endorser and ink rolls are adapted to be easily removed from and replaced in the supporting frame. The endorser roll is adapted to print variable and semi-permanent graphic data on sheets processed by the document count handling device and may be selectively moved between an engaged and disengaged position without being removed from the proper handling apparatus. The data-bearing surfaces are resilient and raised relative to the endorser roll surface. A backing platen cooperative with the endorser roll is provided with grooves aligned with the data-bearing surfaces to prevent "back printing" of the processed sheets being endorsed.

Abstract: A silk screen printing process and apparatus in which a silk screen having a porous figure printing area may be divided by partitions into compartments for different types or colors of ink. The printing operation is performed by a rapid upward acceleration of the silk screen and sheet on which the printing is to be performed, thereby causing the ink to flow through the porous printing area of the screen as a result of inertia. Various types of apparatus may be used to perform the process, one consisting of a platen on which the sheet and silk screen are placed, and a hammer type element which strikes the underside of the platen to produce the upward acceleration.

Abstract: Apparatus for feeding, separating, counting and stacking documents at high speed. Documents are stacked in the infeed conveyor and are bottom fed preferably by closed loop belts and an eccentric wheel which continuously jogs the stack. Drive rollers support the closed loop belts which serve to feed the bottom-most documents beneath cooperative stripper means which assures the feeding of only one document at a time towards acceleration rollers and a cooperating platen roller for accelerating documents fed therebetween to provide a gap between succeeding documents to enable a sensor to accurately count the documents. Counted documents are driven from an outfeed location into a stacker having a floor positioned beneath the outfeed location by a distance selected to prevent incoming documents from being interleaved in their improper order and from interfering with the documents being fed into the stacker. The platen roller also serves as a backing roller for endorsing means.

Abstract: A stamp for imprinting the date, time, name of an organization or company, and so on, which comprises a subsidiary imprint body having on its surface a plurality of circumferentially arranged subsidiary imprint sections, and a disc-shaped main imprint body having on its surface a main imprint section and a marking to be directed to any one of said subsidiary imprint sections, in which said main imprint body is arranged in a central opening of said subsidiary imprint body such that the former is rotatable therein relative to the latter, whereby a desired combination of said main imprint section and one of the subsidiary imprint sections can be selectively attained by turning the main imprint body relative to the subsidiary imprint body, for example, by hand.

Abstract: The use of a laser beam to etch the surface of a printing plate made from a polymer composition on a metal or plastic base and a thin top coating of a hard hydrophilic material produces a lithographic printing plate capable of accepting ink in the etched region and accepting water in the unetched regions.

Abstract: Electroless metal coatings of increased adhesion are obtained on nitrocelose base propellant films, grains, etc., by incorporating an acrylonitrile-butadiene copolymer in the nitrocellulose propellant substrate to be electrolessly coated with the metal.

Abstract: The stage section comprises a pair of planar stage surface members hinged together for movement between a compact folded position, and an operative position. Pairs of main support legs are pivotally attached to each stage surface member so as to remain substantially vertical to support the stage in both the operative and folded positions. Castor wheel assemblies are mounted near the bottoms of the support legs, and a manually actuated mechanism is provided for controlling the retraction or extension of the wheels into ground engaging position, independently of the unfolding of the stage, so that the stage can first be unfolded, then moved precisely into the desired position before retracting the wheels to transfer the stage load to the support legs.

Abstract: In a process for incinerating liquid, gaseous or pasty waste, the steps of producing a high frequency vibratory flow of a fluid in a pulverzing chamber, introducing the liquid, gaseous or pasty waste into the chamber to be pulverized in said high frequency vibratory fluid flow, providing combustion air to be drawn into said high frequency vibratory flow to be mixed with said pulverized waste and igniting the mixture of pulverized waste and combustion air. In addition the present arrangement provides a chamber in which waste material is pulverized. The chamber is equipped with first aperture means and second aperture means. Within the chamber and disposed to face said first aperture is a cavity resonator so that when high pressure fluid passes through said first aperture there results a high frequency vibratory flow of said fluid.

Abstract: Embroidering machine with a needle drive mechanism for color changeover, where each of a number of embroidering stations has a number of needles, one needle rod being working, i.e., engageable by a drive bar, all others being non-working and retained by a retaining bar, which also deflects the latch levers of these needle rods and which has a gap in the working plane for the working needle rod. In that gap is also arranged a solenoid controlled pivotable control pawl which, in its normal position, does not touch the working needle rod, and which, in its actuated position, bridges the gap of the retaining bar, thereby retaining the working needle and disengaging its latch lever from the drive bar. The needle bar, which carries all the needle rods, can then shift the needle rods into and out of the retaining bar gap.

Abstract: A thread cutting mechanism is adapted to be attached by a bracket to a portion of the body of a sewing machine. The mechanism includes a cylindrical hollow tube on the peripheral wall of which the bracket is fixed, along the length of which a guide slot or groove of a given length is formed, and within which a compression spring is inserted. The tube is slidably engaged along its inner wall with an elongated operation rod having both ends projecting outwardly from the corresponding ends of the tube so as to enter into the center of the compression spring and having a pin slidably engaged in the guide slot or groove of the tube and normally pressed against the rear end of the guide slot or groove through the action of the compression spring. The front end of the operation rod is fitted with a cutter for severing a sewing machine thread.

Abstract: A wind-propelled sailboat having a main hull and an outboard pontoon, a mast mounted upon the hull and a triangularly-shaped sail removably connected and secured at its peak to the top of the mast, the sail being controlled for propulsion of the boat by manually manipulated lines connected to each lower end of the sail, and manually controlled rudder means for steering of the boat. The sail is preferably not provided with a boom but is free for shifting either luff of the sail as a leading edge by means of the lines connected to the two lower ends of the sail. The sail-connected lines or sheets are each passed through swiveling blocks and locking cleats arranged for selectively drawing and releasably engaging the lines to draw the sail luffs taut.

Abstract: An apparatus for steering watercraft in response to changes of the wind. The craft is steered by the combination of a horizontal wind vane pivoted about an axis which is 30.degree. to the horizontal, an auxiliary rudder, an extended trim tab, and a cable control system. The extended trim tab is coupled to the auxiliary rudder. Also, the vane is coupled to the extended trim tab by the cable control system such that movement of the vane results in movement of the trim tab. Since the trim tab is coupled to the auxiliary rudder, changes in the position of the trim tab result in changes in position of the auxiliary rudder thereby steering the craft.

Abstract: Disclosed herein is a marine installation including a marine propulsion device including a transom bracket adapted to be fixed relative to a boat hull, a swivel bracket including spaced parallel apertures and mounted on the transom bracket for tilting movement about a tilt axis extending parallel to the apertures, a propulsion unit mounted from the swivel bracket for common tilting movement and for propulsion unit steering movement about a steering axis perpendicular to the tilt axis, a steering helm comprising a housing adapted to be fixed relative to the boat hull and a steering shaft mounted on the housing for rotation upon a fixed axis, a pair of flexible push-pull cables each including an outer casing having spaced first and second ends, and an inner core having a first end and a spaced second end portion extending through the respective apertures, first connections fixedly joining the outer casing first ends to the housing, second connections fixedly joining the inner core first ends to the steering sha

Abstract: Precision hover is necessary when one must position a load precisely on the deck of a ship. Manual precision hover is possible under very light wind gust conditions and a calm sea. The techniques described here are directed to those special windy days when a mission must be accomplished. The technique is to unload a containerized cargo onto a platform kept level regardless of the rolling motions of the ship. The platform is a resilient net of the proper strength to absorb the cargo's impact upon its contact with the net. During night operations under adverse weather conditions it is desirable to remove the cargo from the hoisting mechanism manually unaided. This is accomplished by an automatic sling detachment device. Usually the container will approach the net at an angle. This is desirable, enabling one or two of the devices to detach themselves first and permitting the reduction in loading upon the helicopter to be less abrupt.

Abstract: A submarine well drilling and geological exploration station includes an inner pressure hull specially configured for submerged drilling and exploration and an outer fairing hull of conventional submarine design. The pressure hull is divided by an air lock into an atmospheric pressure chamber and a superatmospheric pressure chamber. Ballast tanks are arranged so that the station may be rotated from a horizontal in-transit orientation to a vertical drilling and exploration orientation. The superatmospheric chamber permits exploration and drilling operations therein in the vertical orientation. A tandem propeller system is used to stabilize the station in position while in the vertical orientation and to propel the station from location to location while submerged in the horizontal orientation.

Abstract: A kit for permitting the direct reading from a standard speedometer having a front transparent panel and markings associated therewith in miles per hour to kilometers per hour.

Abstract: The present invention is a feed and watering device for newborn poultry having a plurality of shallow feed pans integrally formed on a circular shaped base equidistant from the center of the base and adjacent each other. A plurality of interconnected watering troughs are also formed integrally with the base between adjacent feed pans. A tank, also integrally formed with the base, is provided with a float actuated valve for maintaining the water level in each of the troughs constant.

Abstract: A stem generator with its sections arranged for the limited space available in a marine installation. The heated surfaces are exposed to both the products of combustion of original fuels and the discharge from the prime movers of marine propulsion. The water being vaporized is positively pumped up through the heated surfaces to the short length upper steam separator drum. The superheat surfaces are arranged in modular form so they may be readily replaced and can also be drained of collected liquid when maintenance is required.

Abstract: A V-type automotive diesel engine having a high pressure fuel injection pump mounted between the cylinder heads and intake manifolds and above a tappet gallery cover that is integral with the intake manifolds. The pump is supported on the cylinder block by an extension through the gallery cover and the pump drive angles downwardly through the support to a compact bevel drive gear connection with the engine camshaft. The manifold and cover member includes a water crossover connection between the cylinder heads, and the intake manifolds in the cover are interconnected by a distribution fitting that extends over the injection pump and supports an air cleaner. The arrangement provides a compact engine construction capable of being interchanged in a vehicle with gasoline engines of similar general arrangement and piston displacement.

Abstract: Variable overlap of the intake and exhaust valve opening periods for an internal combustion engine is obtained by providing a speed responsive yieldable link in the valve actuating mechanism that varies the effective valve lift with engine speed. The variation is accomplished by flow responsive valves, preferably incorporated in hydraulic tappets for actuating the valves and arranged to begin valve lift only when a predetermined lift rate of the valve actuating cam is reached. Since this rate is reached earlier as the engine speed increases, a greater portion of the cam lift curve is utilized with increased speed, thus increasing the valve lift and extending the valve opening period relative to crankshaft rotation. In this way, angular overlap of the intake and exhaust valve opening periods is varied as a function of engine speed.

Abstract: A device for retarding the timing of the spark during the initial phase of acceleration of an internal combustion engine. A bar is connected to the throttle operating linkage and to a valve. Motion of the bar operates the valve to connect carburetor suction to a spark retarding motor. A timing mechanism operates the valve to remove the suction from the retard motor after the initial phase of acceleration.

Abstract: An encoder produces for each cylinder of an internal combustion engine a plurality of crankshaft position digital code signal groups, each being a representation of a respective different crankshaft position in degrees relative to piston top dead center.

Abstract: A floating lever has an intermediate fulcrum and is pivotally connected at one end to a fuel control rod. The other end of the floating lever carries a pin. A second lever is pivotally connected at an intermediate point to a manual fuel control member and at one end to flyweights. The other end of the second lever engages with one side of the pin. An arm is pivotally carried by the second lever and is urged by a spring to engage with the opposite side of the pin. A boost compensator diaphragm assembly includes an adjustable linkage with which the pin is abuttingly engageable. The spring is adapted to yield when the flyweight rotational speed decreases and the flyweights rotate the second lever so that the pin abuts against the linkage so that the positions of the pin, floating lever and thereby the control lever in the fuel increasing direction are limited by the diaphragm assembly.

Abstract: A two cylinder, two cycle engine for an outboard motor includes an alternator driven, capacitor discharge ignition system. The alternator includes an annular permanent magnet secured within a flywheel skirt and includes a pair of circumferential opposite poles with diametrical spaced neutral areas. The magnet is a flexible ferrite strip with a butt joint at one of the neutral areas. A stator assembly is mounted within the annular rotor and includes a semicircular core with a charging coil at each end. Each movement of the magnetic gap means past the coils generates a pulse. A trigger coil within a housing is mounted in coplanar relation between the charging coils, with a pole aligned with and spaced from the stator core. The housing is rotatably mounted and includes an integral cam for positioning a throttle lever.

Abstract: An ignition system comprises first and second series supply circuits including an ignition coil having a primary winding and a set of breaker contacts serially connected to said primary winding of said ignition coil, said first and second sets of breaker contacts having different opening times. A thyristor is connected in at least one of the two circuits. A firing signal is applied to the thyristor in accordance with the mode of operation of an associated engine, to enable the conduction of said thyristor in a first ignition mode being effected by said first and second sets of breaker contacts and in a second ignition mode being effected by either one of said first and second sets of breaker contacts.

Abstract: An internal combustion engine has a cylinder and a piston with rectangular cross sections. A guideway slot extends across one face of the piston, and engages an off-center pin affixed to the crankshaft for translating linear movement of the piston to rotational movement of the crankshaft. The cylinder may be formed of four side wall plates mounted to define the side walls of the cylinder, and plate means covering the ends of the side wall plates to define a combustion chamber and a crankcase. The crankshaft may be hollow, to define a fuel inlet passageway.

Abstract: An automobile engine driven fuel pump operates to cause alternate fuel pumping and fuel vacuum cycles in a fuel pumping chamber and concurrent alternate air vacuum and air pumping cycles respectively in an air pumping chamber and also to maintain a normally closed fuel control valve open in the fuel supply conduit to the pump during the fuel vacuum and air pumping cycles completely independently of the fuel pumping cycles. If the engine stalls, as for example in the event of a collision or automobile roll-over, the pump will stop and the control valve will close to prevent fuel leakage from the supply conduit. Pressure in the supply conduit also urges the control valve to its closed position.

Abstract: A device for slowing an internal combustion engine in the event of oil pressure failure at an engine speed above idle, includes an SCR with the gate thereof connected through a resistor to the field winding of the engine generator. The SCR is connected between an oil pressure sensing switch typically provided for the engine, and the ignition distributor points. Should the oil pressure switch close, indicating low oil pressure, and the engine is turning at sufficient speed so that the generator field provides enough voltage to the SCR gate, the SCR will fire and short the ignition.

Abstract: A compound bow with a pair of limbs having a pair of improved eccentric pulleys rotatably affixed adjacent free ends thereof and adapted to receive a bowstring and a tension cable on center line of said bow, said compound bow optionally having roller cable adjustment deflectors for use with said improved eccentric pulleys to deflect the tension cables away from a sight window in the compound bow.

Abstract: A generally inverted U-shaped member is provided and includes a pair of side-by-side legs interconnected at one pair of corresponding ends by an integral bight portion. The member is constructed of stiff, but resilient material whereby the free end portions of the legs may be spread, at least slightly, apart and therafter allowed to return to their original predetermined spaced relationship. One of the legs includes structure for attachment of that leg to a selected side of the mid-portion of a bow with the other leg spaced outwardly from that side of the bow. The free end portion of the other leg includes an outwardly projecting arrow rest element extending away from the leg attached to the bow and adjustable spacing structure is interconnected between the legs of the U-shaped member for adjustably increasing the spacing between the free end portions of the legs in excess of the predetermined spaced relationship thereof.

Abstract: A blow gun and projectile combination for use in connection with targets which provide safety, enjoyment, and fun without being hazardous. The blow guns are accurate with the projectiles used, and the projectiles are extremely lightweight and do not have sufficient mass to cause injury if fired so that they strike a person. In addition, the blow gun includes mouthpiece indentations. These indentations cooperate with a disc located on the forward end of each projectile to prevent the projectiles from being inhaled through the mouthpiece by a user of the blow gun.