US2301653A

US2301653A - Air pistol

Info

Publication number: US2301653A
Application number: US309947A
Authority: US
Inventors: William S Wells
Original assignee: Daisy Manufacturing Co
Current assignee: Daisy Manufacturing Co
Priority date: 1939-12-19
Filing date: 1939-12-19
Publication date: 1942-11-10
Anticipated expiration: 1959-11-10

Description

Nov. 10, 1.942. w. s. WELLS AIR PISTOL Filed Deo. 19, 1959 INVENToR. -W/LL/AM WEL/.s

' TroRNEx/s.

PL mw dNhbNl Planted Nev. 10,1942

am rrsror.

william s. wens, Pala ma, caux., minor to Daisy Manufacturing Co., a corporation of AMichigan appucauun December 1s, 193s, serai No. 309,945

' 14 Claims.

My invention relates to guns and more particularly to repeater guns powered by compressed air, and constitutes an improvement upon the subject matter oi an earlier application of mine for an Air pistol," Serial No. 261,621, iiled March 13, 1939.

It is an object of my invention to provide an improved air gun of the repeater type (l) which is capable of iiring a substantial number ofv shots at high velocity with one charge of air; (2) which eiiiciently utilizes the energy of compressed air for iiring purposes; (3) which loads and discharges in response to a single continuous movement of the trigger; (4) which may be iired in rapid succession; (5) which is fully automatic to the extent that when once conditioned, as by loading with shot and charging with air under pressure, successive discharges may be eiected by mere trigger operation; (6) in which air under pressure in a storage chamber is metered and discharged under sustained pressure to effect ring of the gun; (7) which shall avoid the use of a trigger releasable hammer to accomplish valve opening of a storage chamber in effecting discharge; (8) which shall be capable of automatic loading for a substantial number o! shots while being held at an angle below the horizontal; (9) which is of such simplitied4 construction as to facilitate assembly and disassembly and which lends itself readily to standardization.

Additional objects of my invention will be brought out in the following description of the saine taken in conjunction with the accompanying drawing wherein:

Figure 1 is a view in cross section of my invention as embodied in a fully automatic pistol.

Figure 2 is an enlarged view in section of the metering assembly of Figure 1.

Figures 3a, 3b and 3c are views in section of a 'valve constituting an important element of the metering assembly of Figure 2, depicting the manner of operation of such valve in the discharging of the gun.

My invention broadly contemplates providing a highly eiilcient metering system and control in an air gun of the type which derives its power from a compressed air storage chamber.

Such improved metering means and control involves partitioning the compressed air storage chamber with a piston adapted to be propelled to the discharge end of the chamber in response to a dierential pressure createdeto the rear of the piston following opening o! the discharge valve. The piston is thus caused to evacuate a metered amount of compressed air on the discharge side of the piston and does this under the sustained pressure of the compressed air to the rear of the piston. y

The rate of propulsion oi the piston under such conditions is a function oi the speed with which the discharge valve is opened to its full open position, which in turn determines the rate of drop in pressure of the air on the valve or discharge side of the piston and accordingly creates the differential pressure which propels the piston. A high rate of piston movement is conducive to efiicient operation of the gun as the piston then will tend to maintain the air pressure on the discharge side of the piston at a value above a practical minimum and assure a sustained high velocity of discharge against a shot located in the gun barrel.

As part of my improved metering assembly, I embody therein a special valve which has the ability to snap open to its full open position practically instantly, and such opening of the valve can be made to occur in direct response to an increasingpressure upon the trigger of the gun, whereby it is possible to eliminate the hammer and associated elements customarily employed in air guns which derive theirenergy from a storage chamber. -This improved valve is of elastic material capable of substantial stretching and is so designed as to be stretched under tension against the pressure within the air chamber until a limit of stretch has been reached and the valve snaps to its full open position from its' seating 4position on the valve seat. Such instantaneous opening of the valve to its full open position will bring about a high rate of discharge of the air' on the discharge side of the piston and cause practically instantaneous movement of the piston in the direction of the valve toV maintain the velocity of discharge above va practical minimum value. The construction of my improved metering means permits the piston to travel to the discharge end of the storage chamber whereby complete evacuation of the air on the discharge side of the piston will be eiected, all of such air being discharged at such high velocity behind a shot and within such a short period of time that practically complete cylindrical wall of the main storage chamber 5 of the gun in the breech block, and is connected with the main storage chamber by an air passage 9 through the "contacting walls of the two tubes 3 andl 1. This latter tube 1 constitutes an auxiliary air storage chamber and supports a gun barrel Il axially thereof by means of perforated partition walls |3 and a supporting plug I5 inthe muzzle end of the auxiliary chamber. This supporting plug effects sealing of the auxiliary chamber at that end. The barrel at the breech end of the gun extends through the breech block. The breech block and the associated halves of the storage chambers and gun barrel are enclosed in a casing |1, which at the top cooperates with a rib on the auxiliary chamber to form a magazine 2|.

. 'I'his magazine connects with the interior of the gun barrel by a well 23 in the breech lock directed at an acute angle to the gun barrel. This permits the well to be of substantial length, sufflcient to hold a plurality of shot when full, thus enabling automatic loading and repeated ring with the gun pointed in a direction below the horizontal and without the necessity of raising the muzzle of the gun after each shot to effect loading.

Through the breech end of the barrel, there extends a breech pin 25 adapted for limited movement within the barrel between a point permitting a shot to be delivered to the barrel from the well and a point determining the ring position of such shot. Such movement is limited by providing the breech pinwith a flattened intermediate section and inserting a fixed stop 21 in the breech block which extends into the barrel between the shoulders thus formed on the breech pin. The breech pin is magnetized to position and hold shot of magnetic material and is normally biased to its loading position lby a spring 29 positioned under compression between the rear end portion of the breech block surrounding the gun barrel and a head or flange 3i provided at the exterior or protruding extremity of the pin.

'I'he main storage chamber is closed at its forward end by a check valve 33 and at the breech end by my improved metering assembly 35, and is charged with air under pressure by a pump 91 located at the muzzle end of the gun and comprising a pump casing 39 which may or may not constitute an integral extension of the main storage chamber tube 3, and a piston 4| having a piston rod 43 extending beyond the muzzle end of the pump, through a piston rod bearing 45. To the exposed end of the piston rod is applied a suitable handle or grip 41 for facilitating operation ofthe pump.

'I'he improved metering assembly comprises a cylindrical block 49 having a circumferential rib 5| abutting against a shoulder formed by an internal circumferential rib 53 within the storage chamber tube 3 and maintained in pressure engagement therewith by a gland nut 55 threaded into the breech end of the tube against the rib 5|. Arr air tight seal is assured by interposing a soft rubber sealing gasket 51 about the cylindrical block to each side of the circumferential rib 5| prior to assembling the metering assembly within the storage chamber tube.

The cylindrical block has integrally formed therewith an open ended cylinder 59 extending from the interior end wall 8| of the block into the storage chamber and constituting a part thereof, said cylinder having wall openings 63 therethrough adjacent the open end thereof.

A discharge air duct extends through the block, starting at the interior end 6| of the block, and constituting an axial portion 65 and a radial prtion 61 extending through the circumferentialiiiib 5| in the 'direction of the gun barrel, and in alinement with a continuation of the discharge duct through the breech block to the immediate rear of the firing position of a shot in the gun barrel. This axial portion of the discharge air duct is of sulliciently larger diameter than the radial portion, to substantially equal the radial portion in cross-sectional area when allowance is made for the cross-sectional area taken upby the valve stem 69 of a discharge valve 1|, which stem extends axially through the block 49 and beyond, to receive a seating spring 12 for urging the valve to its seating position.

The region of the block 49 surrounding the entrance to the discharge duct, is counter-sunk to provide a seat 13 for such discharge valve, the counter-sink being preferably of such depth as to submerge the valve within the 1clock 49, when in its normal seated position under the action of the spring 12,

This valve comprises a disc 15 of soft rubber which is clamped between two collars 11 and 19 adjacent an end of the valve stem. This disc is of greater diameter than the elements between `which it is clamped, to permit free flexing of the rim portion of the valve disc and when properly seated will also engage the cylindrical wall surface of the counter-sink in addition to contact with the valve seat. In its assembled position on the stem, the disc is slightly cupped to a degree, such that the peripheral edge of the disc will make contact with the valve seat in advance of the clamping element 11, which clamping element in turn is of a diameter suilcient to enable it to span the axial portion 65 of the discharge duct when the valve is in its seating position and thereby preclude any possibility of the valve being pulled through it seat into the axial portion of the discharge duct.

A piston 9i is located in the cylinder 59 and is adapted for movement therein. This piston faces the valve discharge end of the storage chamber and is provided with a piston rod 83 extending through a disc 85 threaded within the open end of the cylinder to constitute any end wall thereof. The piston is normally urged toward this end of its cylinder by a spring 91 surrounding the piston rod underv compression between this end disc 85 and a nut 89 attached to the end of the piston rod. The exact position of the piston is determined by the adjustment of a stop 9| on the piston rod within the cylinder.

The piston itself comprises a loosely fitting di'sc 93 having an integral shank 95 to which the piston rod 83 is attached. A leather cup 91 adapted to contact the interior wall of the cylinder is mounted on the shank and is clamped in such position against the disc 93 by a washer 99 and a nut |0| threaded to the shank portion of the piston. The piston is provided with an air duct |03 extending through the shank thereof and terminating in a needle valve seat |05 at the center of the working face of the piston, which seat is adapted to receive a needle valve |01 formed at the valve end of the piston stem 69 and extending into the storage chamber.'

lThe breech pin 2B and the discharge valve 1| are sequentially operated directly in response to movement of a trigger by means ot a compound lever assembly acting against the breech pin and valve stem, such assembly being maintained in direct pressure transfer relationship with 'the trigger, and comprising a breech pin lever III and a discharge valve lever H3. The breech pin lever at one end engages the breech pin head Il and at its other end is in contact with the trigger through a pressure transfer rod Ill. This breech pin lever is pivoted at an intermediate point to one end of the valve lever. The valve lever in turn is pivoted at an intermediate point to the gun casing, with its other end bearing against the valve stem 89. It will be apparent that movement'of the trigger in the direction to provide operation of the gun will ilrst bring about movement of the breech pin lever to eiect positioning of a shot in firing posi- 'tion within the barrel, at the termination of which the engaging end of the breech pin lever is blocked against further travel. Continued movement of the trigger will thereupon bring the valve lever into action, causing opening of the valve to release air from the storage chamber and ef fect ring of the shot from its firing position in the barrel.

To better understand the features of my improved metering assembly it will be necessary to refer to Figures 2, 3a, 3b and 3c, as the successful operation thereof depends in large measure upon exacting relationships caused to exist among the elements in the design thereof. The mode of operation of the discharge valve 1I will ilrst be, described and then its relationship and cooperation with the rest of the metering assembly will be brought out in detail.

The Valve as previously described comprises a disc of stretchable material such as rubber, and is capable of being stretched against the air pressure within the storage chamber in response to trigger actuation of the valve stem 69. Inasmuch as this pressure is considerably higher than that existing on the discharge side of the valve, the valve will grip its seat until it has stretched to a degree Where the valve can no longer stretch in response to added movement of the valve stem, and separation of the valve from its seat will occur. excessive tension, due to such stretching, it will snap to its full open position from its seat practically instantaneously, and such sudden removal of the load from the trigger has the added effect of projecting the entire valve further into the I trigger. Upon such opening of the valve in the manner described, the air on the discharge side of the piston, which air is at the same pressure as the rest oi the air throughout the storage chamber, will have full valve opening access to the discharge duct, and such air will accordingly begin discharging through the air duct against the shot positioned in the gun barrel at an exceedingly high initial velocity. In so discharging, however, the tendency for the pressure of the air on the discharge side of the piston to drop suddenly to an insignificant value, which would be the case, were the discharge chamber of xed volume, is effectively overcome, for the piston in my improved construction, by being suddenly thrust forward to theend of the storage chamber s under the prevailing differential air pressure ex- Since the valve at this instant is under isting against its rear surface, tends to maintain of the piston rod spring 81.

thus sustain the velocity of the air against the shot, above a minimum practical value throughout the entire discharge period. And inasmuch as my' improved metering assembly construction provides unobstructed movement of the piston to the extreme end of the storage chamber, all of the air on the discharge side oi' the piston will be utilized in this eillcient manner, and the proportion of the air in the storage chamber. to be employed for the firing of each shot, may be regulated by adjustment of the stop 8l on the piston rod 83. By manipulating such adjustment one may obtain a setting which will give the highest velocity with maximum eillciency in the utilization of the energy of the air under discharge.

During the latter portion of the forward thrust of the piston, the piston and the needle valve are in engagement and the piston air passage is effectively sealed against discharge of air from the rear side of the piston to the discharge side. In this manner the pressure of air in the storage chamber to the rear of the piston is substantially preserved during the discharge thrust of the piston, and the valve in the meantime is simultaneously and automatically being thrustback by the piston with suilicient force to overcome any nger pressure upon the trigger, whereby the trigger will be forciblyl restored to its normal position in spite of any such pressure being applied against The metering assembly is preferably so designed that the peripheral edge of the discharge valve contacts the valve seat as the piston butts up against the discharge end of the storage chamber. This contact by the peripheral edge of the valve disc, however, does not necessarily represent the complete restoration of the valve to its seating position, ior due to inertia of the valve and the restoring effect of the valve spring l2, the valve is capable of an additional slight movement in the direction of seating, suillcient to withdraw the needle valve from its seating position in the piston.` Since the discharge valve is located in a counter-sink, withdrawal of the needle valve immediately exposes the discharge side ofthe piston to a rush of air under pressure from the rear of the piston to rapidly bring about an equalization of pressure to a degree permitting the piston to fly back under the restoring action Complete equalization of pressure follows practically instantaneously. Such increase in pressure on the discharge side of the piston assists the valve'spring l2 in laiecting complete seatingof the discharge valve.

The inclusion in the metering assembly of the needle valve to seal the air passage through the 'piston during the discharge thrust of the piston, permits substantial leeway with respect to the size of such passage, and it accordingly can be made of such diameter, as to cause restoration of the piston to its normal position in the cylinder in time to accommodate the most rapid ring movement of which the trigger finger is capable. Under the conditions noted above, only a predetermined metered amount of air is permitted to discharge, and the remainder is preserved to be metered out in like manner for subsequent operations of the gun.

Such preservation of the air in the storage chamber will be realized even in spite of any determined attempt to hold the discharge valve off its seat against the thrust of the piston, for the needlev valve will serve to maintain the piston air passage sealed as long as such holding is attempted.

The elimination of the needle valve feature from the improved metering assembly of my invention, will not preclude satisfactory operation of my metering assembly. The absence of such valve will merely necessitate a reduction in the cross sectional area oi the piston air passage to a degree where the passage may be termed a leak passage, in order to avoid a possible Waste of stored' energy during each discharge. Aliough this will necessarily slow up the return ci the piston as compared with the rate of return possible through the use of a larger passage and a needle valve seal therefor, such return can v still be fast enough to permit high speed operation of the gun.

It will be apparent that the objects of my invention are capable of being fulfilled by the embodiment described above and illustrated in the accompanying drawing. My invention however, is not limited to the specic details of construction disclosed by me, as it is apparent that various changes might be made Without departing from the principles involved. I accordingly do not desire to be limited in my protection to the details of construction disclosed by me except as may be necessitated by the prior art and the appended claims.

I claim: A

l. An air gun comprising a gun barrel, a compressed air storage chamber, an air duct leading from one end of said storage chamber to said gun barrel, a valve normally closing said duct to the flow of air between said storage chamber-'and said gun barrel, and piston means in said storage chamber normally spaced from the duct end of said storage chamber for the metering of van exact volume of air during closure of said duct and movable in the direction of the entrance to said duct to the end of said storage chamber in response to a differential pressure created by an opening of said valve.v

'2. An air gun comprising a gun barrel, a compressed air storage chamber, an air duct leading from said storage chamber to said gun barrel, a valve normally closing said duct to the flow of air between said storage chamber and said gun barrel, said storage chamber including a cylinder extending from the duct end thereof and having an air passage interconnecting said cylinder at its distal end with the rest of said stor.

age chamber, and a piston in said cylinder normally spaced for metering an exact volume of air and movable in the direction of the entrance to said duct in response to a differential pressure created by an opening of said Valve.

3. An air gun comprising a gun barrel, a compressed air storage chamber, an air duct leading from said storage chamber to said gun barrel, a Valve normally closing said duct to the ow of air between said storage chamber and said gun barrel, said storage chamber including a cylinder extending Irom the duct end thereof and having an air passage interconnecting said cylinder at its distal end with the'rest of said storage chamber,

`a piston in said cylinder having an air ductl therethrough, said piston being movable in the direction of the entrance to said first mentioned air duet in response to a diierential pressure Ycreated by an opening of said valve, and means for normally positioning said piston in spaced relationship to the duct end of said storage chamber during closure of said first mentioned air duct by said valve for metering an exact volume of air to be discharged through said duct.

4. An air gun comprising a gun barrel, a compressed air storage chamber, an air duct leading from one end of said storage chamber to said gun barrel, said end of said storage chamber being counter-sunk to provide a valve seat surrounding said duct, a trigger operable valve normally seated 1n said counter-sink to close said duct to the flow of air between said storage chamber and said gun barrel, said valve having a needle valve extending into said chamber beyond the end surface thereof, piston means in said storage chamber including a piston normally spaced from said duct end and movable to said end in response to a differential pressure created by an opening of said valve, said piston having an air passage therethrough terminating in a needle valve seat adapted to be engaged by said needle valve during such movement oi said piston in response to the opening of said trigger operable valve for closing said piston air passage during such needle valve engagement, and means for opening said needle valve upon completion of such movement of said piston to the end of said storage chamber.

5. An air gun comprising a gun barrel, a compressed alr storage chamber, an air duct leading from said storage chamber to said gun barrel, a valve seated at the storage chamber end of said duct for normally closing said duct to the ilow of air between said storage chamber and said gun barrel, said valve being of stretchable material, means for stretching said valve against the pressure of air in said storage chamber until said valve snaps from its seating position, and piston means in said storage chamber including a piston movable to the duct end of said storage chamber in response to a differential pressure created by such snapping of said valve to its open position.

6. An air gun comprising a gun barrel, a compressed air storage chamber, an air duct leading `from one end of said storage chamber to said gun barrel, a valve supported in said air duct in spaced relationship to said storage chamber for normally closing said duct to the flow of air between said storage chamber and said gun barrel, and metering means for discharging through said ductV a predetermined portion of the air in said storage chamber and under pressure in response to opening of said valve, comprising a piston in said storage chamber, means normally positioning said piston in spaced relationship to the duct end of said storage chamber, said piston being movable to substantially the duct end of the storage chamber in response to a differential pressure created by such opening of said valve.

7. An air gun comprising a gun barrel, a compressed air storage chamber, an air duct leading from one end of said storage chamber to said gun barrel, a valve supported in said air duct in spaced relationship to said storage chamber for normally closing said duct to the flow o1' air between said storage chamber and said gun bar-- rel, and metering means for discharging through said duct a. predetermined portion of the air in of and having air communication with the rest of said storage chamber, a piston normally positioned between the duct end of said storage chamber and the point o! air communication terial seated on said valve seat to close said duct to the flow of air between said storage chamber and said gun barrel, metering means for discharging into said duct a predetermined portion.

of the air in said storage chamber and at maintained pressure in response to opening `of said valve, a trigger, and means interconnecting said' trigger and said valve for stretching said valve against the existing pressure within said storage chamber to the point when the stretching of said valve will give way to separation thereof from its valve seat.

9. An air gun comprising a gun barrel,- a'compressed air storage chamber, a breech vblock having an air duct therein leading from one end of said storage chamber to said gunbarrel, a valve of stretchable material in said air duct having an associated valve stem extending through said breech block and protruding therebeyond, said valve being stretchable against the pressure of air in said stor-age chamber by pressure applied to said valve stem until snapping of said valve from its seat occurs, metering means for discharging a predetermined portion of the air in said storage chamber and under maintained pressure in response to such opening of said valve, a trigger, and means linking said trigger to said valve stem in direct pressure transmitting relationshipA for applying to said stem the necessary pressure to unseat said stretchable valve. y

10. Air gun comprising a compressed air storage chamber, a discharge air duct leading from said storage chamber, valve means including a valve seat and a valve seating thereon for closing said air duct to the discharge of air from said compressed air storage chamber, one of said valve means components being of stretchable material permitting stretching of the same against the pressure of air in said storage cham- 'ber, a trigger, means responsive to Pressure against said trigger for stretching said valve means component against the pressure in said storage chamber to the point where snap separation of said valve means components occurs, and means in said storage chamber acting against said valve means to eifect instant closing of the same following such separation.

11. An air gun comprising a gun barrel, a compressed air storage chamber, an air -duct leading from onel end of said storage chamber to said gun barrel, said end of said storage chamber being counter-sunk to provide a valve seat surrounding said duct, a trigger operable valve seated in said counter-sink, for normally closing said duct to the flow of air between said maintained pressure in response to opening of said valve, comprising a piston in said storage chamber normally positioned in spaced relationship to the duct end of said storage chamber and movable to substantially said end of the storage chamber in response to a differential pressure created by an opening of said valve, said piston having an air duct therethrough adapted to receive said needle valve during such movement of the piston toward the duct end of said storage chamber.

12. An air gun comprising a gun barrel. a compressed air storage chamber, an air duct leading from one end ofl said storage chamber to said gun barrel, a valve in said air duct adjacent the duct end of said vstorage chamber for normally closing said duct to the flow of air between said storage chamber and said gun barrel, and metering means for discharging a predetermined portion of the air in said storage chamber and at maintained pressure in response to opening of said valve, comprising a cylinder forming a part of said storage chamber and extending from the duct end thereof and having an air passage interconnecting the' interior of said cylinder with the rest of the storage chamber, a piston in said cylinder having an operating range between said air passage and the duct end ofthe storage chamber, a piston rod extending through the end wall of said cylinder and terminating in a head, a coil spring about the protruding end of said piston rod between said piston rod head and said cylinder end wall urging said piston toward the aforesaid cylinder end wall and away from the duct end of said storage chamber, and stop means adjustable along said piston rod within said cylinder to determine a desired normal position of'said piston.

13. An air gun comprising a compressed air chamber, an air duct leading therefrom, valve means normally closing said air duct tothe storage ,chamber and said gun barrel, said valve having a needle valve component extending therefrom into said storage chamber, and meter' discharge of air from said air chamber, said valve means comprising a valve seat component in the wall of said air chamber surrounding the entrance to said air duct, and a cupped valve of elastic material having its peripheral edge in contact with said valve seat component. and means 'for stretching said valve against the pressure in said air chamber to a point where snap separation of said valve from its seat occurs to effect a sudden full opening of said valve means and permit a discharge through said air duct from said al1- chamber.

14. An air gun comprising a compressed air chamber, an air vduct leading therefrom, valve means normally closing said air duct to the discharge of air fromcsaid air chamber. said valve means comprising a valve seat component in the wall of said'air chamber surrounding the entrance to said air duct, and a cupped valve of elastic material having the peripheral edge in contact with said valve seat component. and triggerr operated means for stretching said valve against the pressure in said air chamber toa point where snap separation of said valve from its seat occurs to effect a sudden full opening of said valve means and permit a discharge through said air duct from said air chamber.

warum s. wams.