US3721032A

US3721032A - Caseless cartridge firing mechanism

Info

Publication number: US3721032A
Application number: US00140856A
Authority: US
Inventors: C Lin; J Shum; D Kilbourn
Original assignee: Olin Corp
Current assignee: Olin Corp
Priority date: 1971-05-06
Filing date: 1971-05-06
Publication date: 1973-03-20
Anticipated expiration: 1990-03-20

Abstract

A caseless cartridge firing mechanism which uses a novel spring seal to seal the firing chamber. By virtue of a spring preload against the surface to be sealed, a pressure differential is built up between the sealing surfaces and creates the sealing force.

Description

Unite States atent [191 Shum, Jr. et ai. 1March 20, 1973 CASELESS CARTRIDGE FIRING [56] References Cited MECHANISM UNITED STATES PATENTS [75] Inventors: John Shum, Jr., Valley Station, Ky.;

Dean R. K l C H. 2,993,412 7/1961 Goldsmith ..89/1.80l both of Marion m 3,534,895 10/1970 Henning ..227/10 7 3,296,728 1/1967 Kuavle ..42/l R [73] Assignee; Olin Corporation, N w Hav 1,897,992 2/1933 Ailes ..42/l G Conn. Primary Examiner-Samuel W. Engle Flledi May 1971 Attorney-D0nald R. Motsko, H. Samuel Kiser and 21 Appl.No.: 140,856 wllllam w-lones 157 ABSTRACT [52] US. Cl. ..42/l R, 42/2, 89/1 B,

39/26 A caseless cartridge firing mechanism WhlCh uses a 51 Int. Cl. ..F41j 1/00 novel Spring Seal to Seal the firing chambery virtue 58 Field of Search ..42/1, 9, 2; 129/7, 1; 60/26.1; of a Spring preload against the surface to be sealed, a 227/9, 10, 11 pressure differential is built up between the sealing surfaces and creates the sealing force.

1 1 Claims, 4 Drawing Figures PATENTEDMARZO I913 SHEET 1 [IF 2 CHAO H. u/v JUHN SHUM JR. DEAN R. K/LBOURN INVENTORS BY Mi t-J4 ATTORNEY CASELESS CARTRIDGE FIRING MECHANISM This invention concerns a mechanism for firing a caseless charge of propellant in the form of a pellet or the like, wherein a preloaded spring seals the firing chamber with the sealing force being increased by a pressure differential built up between the spring and the surface to be sealed when the charge is fired.

The use of caseless propellant charges such as pellets or the like of compacted nitrocellulose has recently become the subject of renewed interest for firing firearms, power-actuated tools, and other such devices operated by high pressure combustion gases. Most of the technology for sealing the firing chambers of devices using caseless charges or pellets is still relatively new. The problems in sealing the gases generated by the caseless charge are vastly different than those encountered in sealing a cased or obturated charge such as a brass cartridge, since the cartridge casing itself provides the majority of the obturating function. The prior art relating to the sealing of caseless pellets dis closes the bolt action principle wherein a bolt mechanism cams two halves together with a separate seal to effect a gas seal. One basic disadvantage of the bolt action is that the size of the mechanism can become a problem if available space is limited. The two halves must separate to load the charge and axial movement of one of the halves relative to the other must occur. The force needed to cam the two halves together is quite large and can present a problem if done remotely. It has been found that elastomeric, labyrinth or other seals are generally required in conjunction with a boltactuated caseless charge device.

To overcome these disadvantages, the mechanism of this invention utilizes a spring-type seal which is mounted on a rotor containing the firing chamber. The rotor and spring seal are mounted for rotational movement in a housing having a bore for this purpose. The spring seal is in the form of a curved spring blade having an outer diameter which is larger than the diameter of the housing bore in which it is disposed. The spring blade includes a gap which permits the blade to be compressed for insertion into the housing bore so that once inserted into the housing bore, the spring blade will flex outwardly into snug engagement with the wall of the housing bore. The rotor is disposed inside of the housing bore and inside of the spring, and the rotor has an opening in its side wall which communicates with the firing chamber. A pair of pins are secured to the rotor and extend outwardly therefrom into the spring gap, the pins serving to align the spring gap with the rotor opening, and also serving to cause the spring to rotate conjointly with the rotor. The housing also includes a pellet feed inlet, and a combustion gas outlet which intersect the housing bore and extend radially outwardly therefrom. The inlet and outlet are angularly spaced apart from each other in such a manner that the rotor opening and spring gap can both be moved into selective alignment with either the inlet or the outlet. An operating handle is provided for rotating the rotor between the inlet and outlet, so that when the rotor opening and spring gap are aligned with the inlet, a caseless pellet can be fed into the firing chamber. The rotor is then rotated so that the rotor opening and spring gap are aligned with the outlet and the pellet is then fired to produce high pressure combustion gases which pass through the outlet. The device can be used with any apparatus which uses high pressure gases to do work, as for example, with a firearm, a power-actuated tool, or the like.

It is, therefore, an object of this invention to provide a caseless pellet firing mechanism which operates without longitudinal movement occurring between the chamber sealing members.

It is a further object of this invention to provide a caseless pellet firing device of the character described wherein a spring member is provided to seal the firing chamber.

It is still another object of this invention to provide a caseless pellet firing device of the character described wherein rotary movement is used to load and position a pellet for firing.

These and other objects and advantages of this invention will be readily apparent from the following detailed description and accompanying drawings, in which:

FIG. 1 is an exploded perspective view of a preferred embodiment of the mechanism of this invention;

FIG. 2 is a side perspective view of the mechanism of FIG. 1 shown as assembled;

FIG. 3 is a side sectional view of the device taken along line A-A of FIG. 2; and

FIG. 4 is a sectional view of the device taken along line B-B of FIG. 3.

Referring now to FIG. 1, the device includes a housing 2 having a first bore 4 which intersects a second bore 6 (see FIG. 4) at substantially right angles. The second bore 6 is an outlet for high pressure combustion gases formed when the pellet is fired, and is threaded as at 8 for connection to a related device which uses the combustion gases to do work. For example, the housing 2 may be connected to a barrel for firing a projectile, or a fastener, as in a firearm or power-actuated tool, or may be connected to a cylinder for driving a piston or the like. A port 10 is formed through the wall of the housing 2, the port 10 intersecting the bore 4 to form a passage through which pellets may be loaded into the device. The outer end of the bore 4 is enlarged and threaded as at 12 for a purpose more clearly set forth hereinafter. A hollow rotor 14 having a first enlarged portion 16 and a second reduced portion 18 separated by a shoulder 20 is rotatably mounted in the bore 4. The diameter of the shoulder 20 is substantially the same as the diameter of the bore 4 with the diameter of the enlarged portion 16 being somewhat smaller than the diameter of the bore 4. A pellet feed opening or slot 22 is cut through the wall of the enlarged portion and communicates with the interior of the rotor 14. A seal in the form of a spring member 24 is positioned around the exterior of the enlarged portion 16 of the rotor. The spring member 24 is in the form of an annular sheet of spring material, preferably spring steel, with an outside diameter which is slightly greater than the diameter of the bore 4, and with an inside diameter which is slightly greater than the outside diameter of the enlarged portion 16 of the rotor. The longitudinally extending end surfaces 26 and 28 of the spring 24 are spaced apart to form a longitudinal gap 30 in the spring 24 which permits the latter to be compressed to reduce the outside and inside diameters thereof and put the spring in a state of stress. In order to mount the spring 24 on the rotor 14, the spring 24 is slipped over the enlarged portion 16 of the rotor 14 and then compressed to reduce the springs outside diameter. The rotor 14 and compressed spring 24 are then inserted into the bore 4 where the spring 24 tries to assume its original dimensions. Thus the spring 24 is biased into snug engagement with the wall of the bore 4. A pair of pins 32 and 34 are mounted on the enlarged portion 16 of the rotor 14 and extend outwardly therefrom to engage the end surfaces 26 and 28 on the spring 24. The pins 32 and 34 keep the gap 30 and the slot 22 aligned and cause the spring 24 to rotate conjointly with the rotor 14. A plug 36 is fitted into the bottom of the bore 4 to close off the inner end of the interior of the rotor 14.

A sleeve 38 is threaded into the counterbore l2 and thus secured to the housing 2. The sidewall of the sleeve 38 includes a transverse slot 40 and a pair of Iongitudinally extending similar slots 42 (one of which is shown), the latter being spaced preferably 180 apart on the sleeve. The slots 42 are formed with a transverse extension 44 which defines a shoulder 46. A camming surface 48 is positioned opposite the extension 44. An operating handle 50 having a threaded end portion 52 extends through the slot 40 and is screwed into a threaded port 54 formed on an annular collar 56 which is mounted on the reduced portion 18 of the rotor 14. The threaded end 52 of the handle 50 extends through the collar 56 and is screwed tightly against a flat 58 formed on the reduced portion 18 of the rotor 14, thus the collar 56 and rotor 14 are locked together. The collar 56 is positioned within the sleeve 38 and includes a pair of notches 60 each of which is bounded on one side by an

inclined camming surface

62 and 64, and on the other side by a surface 66 which is contained in a plane parallel to the axis of the collar. It is noted that longitudinally extending projections 68 and 70 are formed at one end of the

camming surfaces

62 and 64, and laterally extending projections 72 are formed at the corresponding end of the surface 66.

A firing pin 74 is mounted in the interior of the rotor 14, it being noted that the interior of the rotor 14 includes an enlarged bore 76 defining a firing chamber, and a reduced bore 78 in which the firing pin 74 is slidably mounted (see FIG. 3). The firing pin 74 is threaded as at 80 and a disc 82 having a threaded aperture 84 is screwed on to the firing pin. The disc 82 includes a pair of projecting ears 86 which are positioned in the slots 42 and which extend through the collar notches 60.

A cap 88 is screwed into the sleeve 38 to close one end thereof and a compressible spring member 90 is positioned within the cap 88 and in contact with the disc 82 to bias the firing pin 74 toward the firing chamber 76.

Referring now to FIGS. 2-4, it will be noted that the spring 24 is stressed against the wall of the bore 4 so that when the pellet feed slot 22 and spring gap 30 are aligned with the outlet port 6, the spring 24 seals the loading port from the firing chamber 76. Also when the slot 22, the gap 30, and the outlet port 6 are aligned, the firing pin 74 is disposed in its fired position under the influence of the spring 90.

The device operates in the following manner. As mentioned above, FIGS. 2 and 3 show the fired condition of the device wherein the firing chamber 76 is empty. In this condition the operating handle 50 is positioned at the intersection of the slots 40 and one of the slots 42, and the disc ears 86 are positioned at the ends of the slots 42 nearest the housing 2. In order to load the device and cock the firing pin, the handle 50 is moved through the slot 40 to the position 50 shown in phantom in FIG. 2. This causes the collar 56 and the rotor 14 to rotate within the sleeve 38. The pins 32 and 34 cause the spring 24 to rotate conjointly with the rotor 14. When the handle is in the position 50, the rotor slot 22 and spring gap 30 are disposed in alignment with the pellet loading port 10 so that a propellant pellet can be inserted into the firing chamber 76 through the port 10. As the collar 56 rotates, the cam surfaces 62 and 64 move against the disc ears 86 and force the latter to slide through the slots 42 toward the camming surfaces 48. Thus the disc 82 and attached firing pin 74 move away from the firing chamber 76 and compress the spring 90. The cars 86 move against the camming surfaces 48 and with the aid of the projections 68 and 70, are cammed over and onto the shoulders 46 when the handle reaches the position 50'. In this manner the firing pin 74 is cocked at the same time that the device is loaded. To fire the device, the handle 50 is moved from the position 50' back to the position shown in FIG. 3 to rotate the rotor slot 22 and the spring gap 30 back into alignment with the outlet bore 6 and to seal the loading port 10. The return of the handle 50 to the position shown in FIG. 3 causes the collar 56 to rotate back until the projections 72 thereon engage the disc ears 86 and push the latter off of the shoulders 46. The spring is then free to drive the disc 82 and firing pin 74 toward the firing chamber 76 where the firing pin 74 strikes the chambered pellet (not shown) causing the latter to burn. Thus reciprocal movement of the handle 50 serves to permit loading of a pellet, cocks the firing pin, and fires the device. It is noted that, while a firing pin mechanism has been disclosed as the preferred mode for firing a pellet, any other firing mechanism such as a hammer or electrical igniter may be used in conjunction with the spring seal of this invention without departing from the spirit of the invention.

Tests of the firing mechanism have produced approximately 1,800 lbs. of sealing force with 12,000 psi chamber pressure using primed impact ignition caseless pellets of compacted nitrocellulose. It is readily apparent that the invention offers the metal to metal sealing advantages of a cased round for firing caseless ammunition. The device is of compact, simple construction and operates without the need of complex labyrinth seals or nondurable elastomeric seals. Furthermore, the firing mechanism can be used with any number of related structures which utilize high pressure combustion gases to do work, such as firearms, power-actuated tools, or the like.

We claim:

1. A firing mechanism for caseless ammunition, said mechanism comprising:

a. a housing having a first bore and a loading port communicating with said first bore;

'b. rotor means mounted in said first bore, said rotor means being hollow to define a firing chamber and having an opening communicating with said firing chamber, said rotor means being rotatable between a first position wherein said opening is aligned with said loading port, and a second position wherein said opening is angularly offset from said loading port;

c. sheet-like spring means mounted on said rotor means for conjoin movement therewith, said spring means being in stressed engagement with a wall of said first bore and operative to seal said firing chamber from said loading port when said rotor is in said second position;

d. a firing pin slidably mounted in said rotor and movable between a cocked position and a fired position;

/ eecoil spring means operative to bias said firing pin toward said fired position;

f. camming means mounted on said rotor and conjointly rotatable therewith, said camming means being operable to move said firing pin to said cocked position when said rotor is moved to its first position; and

g. means operable to retain said firing pin in its cocked position.

2. A firing mechanism for caseless ammunition, said mechanism comprising:

a. a housing having a first bore and a loading port communicating with said first bore; rotor means mounted in said first bore, said rotor means providing a firing chamber, said rotor means being rotatable between a first position wherein said firing chamber is open to said loading port, and a second position wherein said firing chamber is angularly offset from said loading port; c. fiat spring means having an arcuate crosssection and mounted on said rotor for conjoint movement therewith, said spring means being in stressed engagement with a wall of said first bore and operative to seal said firing chamber from said loading port when said rotor is in said second position;

. sleeve means secured to said housing and coaxial with said first bore, said sleeve means having a first circumferential slot, and at least one longitudinal slot;

e. a firing pin slidably mounted in said rotor and movable between a cocked position and a fired position;

f. disc means secured to said firing pin, said disc means having at least on lateral extension slidably disposed in said longitudinal sleeve slot;

g. collar means secured to said rotor means and rotatable conjointly therewith, said collar means having at least one camming surface engageable with said disc lateral extension and operable when said collar means is rotated in a predetermined direction, to slide said lateral extension through said longitudinal slot to cock said firing pin; and

h. spring means operable to bias said firing pin toward its fired position.

3. The mechanism of claim 2, further comprising shoulder means formed on said longitudinal slot and operative to engage said lateral extension to detain said firing pin in said cocked position.

4. The mechanism of claim 3, further comprising means formed on said collar operative to dislodge said lateral extension from engagement with said shoulder means to fire the mechanism.

5. The mechanism of claim 2, further comprising an operating handle secured to said collar means and extending outwardly through said circumferential slot.

6. A firing mechanism for caseless ammunition, said mechanism comprising:

a. a housing having a bore and a loading port communicating with said bore;

b. rotor means mounted in said bore, said rotor means being hollow to define a firing chamber and having an opening communicating with said firing chamber, said rotor means being rotatable between a first position wherein said opening is aligned with said loading port and a second position wherein said opening is angularly offset from said loading port;

c. springy seal means operative to seal said firing chamber from said loading port when said rotor is in said second position;

e. spring means operative to bias said firing pin toward said fired position; and

f. camming means mounted on said rotor and conjointly rotatable therewith, said camming means being operable to move said firing pin to said cocked position when said rotor is moved to said first position.

7. The mechanism of claim 6, further comprising means operative to retain said firing pin in said cocked position.

8. A firing device for caseless ammunition, said device comprising:

a. a housing having a bore formed therein and a loading port communicating with said bore;

b. means mounted in said housing providing a firing chamber accessable through said loading port whereby a round of caseless ammunition can be inserted into said firing chamber through said loading port;

c. a sheet-like annular metal member with substantial inherent resiliency mounted in said bore between said port and said firing chamber, said member being in an internally stressed condition so as to be biased into snug engagement with the wall of said bore, and said member being movable from a first position exposing said firing chamber to said port to a second position covering said port; and

d. means operative to ignite a round of caseless ammunition disposed in said firing chamber.

9. The device of claim 8 wherein said annular metal member is an interrupted sleeve of spring steel having an outside diameter which, when the sleeve is in an unstressed condition, is somewhat larger than the diameter of said bore.

10. A firing mechanism for caseless ammunition, said mechanism comprising:

a. a housing having a first bore, a second bore communicating with said first bore, and a loading port communicating with said first bore;

b. a rotor mounted in said first bore, said rotor having a hollow interior defining a firing chamber, and an opening in said rotor communicating with said firing chamber, said rotor being rotatable between a first position wherein said opening is aligned with said loading port, and a second position wherein said opening is aligned with said second bore;

. a sheet-like annular metal member with substantial means operative to ignite a round of'caseless ammunition in said firing chamber.

11. In a firing mechanism for caseless ammunition, the mechanism including a housing, a firing chamber disposed in the housing, a loading port communicating with the firing chamber, and means operative to ignite a round of caseless ammunition in the firing chamber, the improvement comprising: a movably mounted sheet-like annular inherantly resilient metal member interposed between said firing chamber and said loading port, said member being in an internally stressed condition so as to be biased into snug engagement with the periphery of said loading port to seal the firing chamber from the loading port; and means for moving said member into and out of said biased snug engagementwith the periphery of said loading port.

Claims

1. A firing mechanism for caseless ammunition, said mechanism comprising: a. a housing having a first bore and a loading port communicating with said first bore; b. rotor means mounted in said first bore, said rotor means being hollow to define a firing chamber and having an opening communicating with said firing chamber, said rotor means being rotatable between a first position wherein said opening is aligned with said loading port, and a second position wherein said opening is angularly offset from said loading port; c. sheet-like spring means mounted on said rotor means for conjoin movement therewith, said spring means being in stressed engagement with a wall of said first bore and operative to seal said firing chamber from said loading port when said rotor is in said second position; d. a firing pin slidably mounted in said rotor and movable between a cocked position and a fired position; e. coil spring means operative to bias said firing pin toward said fired position; f. camming means mounted on said rotor and conjointly rotatable therewith, said camming means being operable to move said firing pin to said cocked position when said rotor is moved to its first position; and g. means operable to retain said firing pin in its cocked position.

2. A firing mechanism for caseless ammunition, said mechanism comprising: a. a housing having a first bore and a loading port communicating with said first bore; b. rotor means mounted in said first bore, said rotor means providing a firing chamber, said rotor means being rotatable between a first position wherein said firing chamber is open to said loading port, and a second position wherein said firing chamber is angularly offset from said loading port; c. flat spring means having an arcuate crosssection and mounted on said rotor for conjoint movement therewith, said spring means being in stressed engagement with a wall of said first bore and operative to seal said firing chamber from said loading port when said rotor is in said second position; d. sleeve means secured to said housing and coaxial with said first bore, said sleeve means having a first circumferential slot, and at least one longitudinal slot; e. a firing pin slidably mounted in said rotor and movable between a cocked position and a fired position; f. disc means secured to said firing pin, said disc means having at least on lateral extension slidably disposed in said longitudinal sleeve slot; g. collar means secured to said rotor means and rotatable conjointly therewith, said collar means having at least one camming surface engageable with said disc lateral extension and operable when said collar means is rotated in a predetermined direction, to slide said lateral extension through said longitudinal slot to cock said firing pin; and h. spring means operable to bias said firing pin toward its fired position.

6. A firing mechanism for caseless ammunition, said mechanism comprising: a. a housing having a bore and a loading port communicating with said bore; b. rotor means mounted in said bore, said rotor means being hollow to define a firing chamber and having an opening communicating with said firing chamber, said rotor means being rotatable between a first position wherein said opening is aligned with said loading port and a second position wherein said opening is angularly offset from said loading port; c. springy seal means operative to seal said firing chamber from said loading port when said rotor is in said second position; d. a firing pin slidably mounted in said rotor and movable between a cocked position and a fired position; e. spring means operative to bias said firing pin toward said fired position; and f. camming means mounted on said rotor and conjointly rotatable therewith, said camming means being operable to move said firing pin to said cocked position when said rotor is moved to said first position.

8. A firing device for caseless ammunition, said device comprising: a. a housing having a bore formed therein and a loading port communicating with said bore; b. means mounted in said housing providing a firing chamber accessable through said loading port whereby a round of caseless ammunition can be inserted into said firing chamber through said loading port; c. a sheet-like annular metal member with substantial inherent resiliency mounted in said bore between said port and said firing chamber, said member being in an internally stressed condition so as to be biased into snug engagement with the wall of said bore, and said member being movable from a first position exposing said firing chamber to said port to a second position covering said port; and d. means operative to ignite a round of caseless ammunition disposed in said firing chamber.

10. A firing mechanism for caseless ammunition, said mechanism comprising: a. a housing having a first bore, a second bore communicating with said first bore, and a loAding port communicating with said first bore; b. a rotor mounted in said first bore, said rotor having a hollow interior defining a firing chamber, and an opening in said rotor communicating with said firing chamber, said rotor being rotatable between a first position wherein said opening is aligned with said loading port, and a second position wherein said opening is aligned with said second bore; c. a sheet-like annular metal member with substantial inherant resiliency sandwiched between said rotor and the adjacent wall of said first bore, said member being in an internally stressed condition so as to be biased into snug engagement with the wall of said first bore, said member being conjointly movable with said rotor, and said member including a gap aligned with said rotor opening, said member being operative, by virtue of its snug engagement with said wall of said first bore, to seal said loading port from said firing chamber when said rotor is in said second position; and d. means operative to ignite a round of caseless ammunition in said firing chamber.

11. In a firing mechanism for caseless ammunition, the mechanism including a housing, a firing chamber disposed in the housing, a loading port communicating with the firing chamber, and means operative to ignite a round of caseless ammunition in the firing chamber, the improvement comprising: a movably mounted sheet-like annular inherantly resilient metal member interposed between said firing chamber and said loading port, said member being in an internally stressed condition so as to be biased into snug engagement with the periphery of said loading port to seal the firing chamber from the loading port; and means for moving said member into and out of said biased snug engagement with the periphery of said loading port.