The present invention relates to devices used to reload casings of ammunition cartridges.
A familiar practice for those who use small firearms is to reload a casing after a bullet has been fired, for economy and good environmental practice. This practice is carried out with center-fire cartridges of the kind that are used in a pistol, rifle or other small arms weapon.
To reload a spent casing, the old primer cap is removed and replaced in the base, a new powder charge is placed within the cavity of the casing, and a new bullet is secured in the open end of the casing. However, it may happen that a new bullet will not be as securely held in the casing. This can be attributed to a slight permanent outward deformation of the open end of the casing during firing of a bullet. Thus as taught by the prior art, some remedial shaping is needed.
Manually operated devices for accomplishing such reshaping are variously referred to as, reloaders, presses and dies. Many are described in the patent literature. See for instance, see Heers U.S. Pat. No. 4,329,906, David et al. U.S. Pat. No. 4,766,798, and Bond et al. U.S. Pat. No. 7,395,746. Generally, the devices apply appropriate forces to a casing for reshaping it, and in instances enable installing a new primer cap, powder and a bullet. There are reloading devices which incorporate spring loaded internal parts, such as are shown in these U.S. patents: Alberts U.S. Pat. No. 4,188,855; Roller U.S. Pat. No. 4,984,501; and Beebe U.S. Pat. No. 5,649,465. See also Koch et al. U.S. Patent Publication No. 2004/0025677.
One recent improvement in casing construction is described in U.S. Patent Publication No. 2017/0030690 “Fire arm casing and cartridge.” The improved casing is formed of two mated pieces, compared to the traditional one piece brass casing, and the casing has significantly lighter weight and thinner but stronger walls of stainless steel. While the new casings offer a greater number of reloads prior to metal fatigue/failure than do traditional casings, there is a need to avoid damaging such casings inadvertently during the reloading process.
Furthermore, the aforementioned new casings are best made of work-hardened austenitic stainless steel, which is much harder and stiffer than the brass of traditional casings for which the prior art reloading devices have been intended. Substantially more force is required to achieve resizing and flaring, compared to reshaping traditional brass casings of the same ammunition caliber. It has also been found that substantially more force is required to disengage a new type casing from a typical prior art reforming die. For example, where it might take an estimated disengagement force of about 50 pounds to pull a small caliber brass casing off a die, for the new type casing that force may be 100 to 300 pounds for the same die.
The present invention seeks to improve the way in which the reloading process is carried out, with respect to how a casing is re-shaped and to deal with the special problems associated with new kinds of casings.
An object of the invention is to provide apparatus and method that are useful in connection with reshaping casings for cartridges from which a bullet has been fired so they can be reused. A further object is to provide such kind of apparatus and method that is particularly suited for use with casings that are made of two fastened together pieces, e.g. a base and a stainless steel sleeve. A still further object is to avoid damaging such casings by either separating the pieces, and to avoid damaging the ejector-gripping portions of any kind of casing.
In accord with the invention, one embodiment of device for use in reshaping ammunition so it can be reloaded reduces the diameter of the casing when it is pushed into the annual opening at the end of a housing, within which a spring loaded plunger shaft slides. The plunger shaft is connected to a piston which compresses a unique spring made of elastomer. The spring which is captured within the cavity of a spring housing provides the force needed for the shaft to eject the casing from the end of the housing, particularly for a new type of casings which is made of stainless steel and which presents more re-shaping difficulty than does a traditional brass casing. Preferably, the plunger shaft fits and slides within a bore of a plunger housing along almost its entire length, those allowing the shaft to be of modest diameter without a tendency to bow or buckle.
The new type casings have an exterior shape similar to that of the traditional brass casings for which they substitute. A new type casing comprises a stainless steel sleeve having a nipple which fits a hole in a disk-like base. The nipple end is flared to hold it in place. Certain embodiments of the new type casings have a wave on the bulkhead (which is at the bottom of the cavity of the casing that receives gunpowder). To avoid damage to the wave, the end of a shaft of a reshaping device has a recess or circular groove in the face of the plunger shaft which contacts the interior bottom of the casing and pushes the casing away to disengage it from the housing.
After sizing, to reduce the diameter of the casing mouth, another embodiment of the invention is used to flare the mouth of the casing so it is properly shaped to receive a new bullet. The casing is pressed onto the male end of a housing that is preferably comprises two frusto-conical sections separated by a circumscribing groove.
In further accord with the invention, a device used for flaring may comprise a first portion having an interior cavity with an opening at the proximal end, and a second portion having a bore extending to a bore opening at the distal end of the device which is shaped for flaring of a casing. Thus powder may be dropped into the casing during or after the flaring of the mouth of the casing. The device may be the aforementioned combination of spring housing and plunger housing from which the spring and plunger have been removed.
In further accord with method embodiments of the invention, the foregoing devices are used in combinations. In one mode, the device which effects reshaping to reduce the exterior dimension of the casing is used in a first series of steps, followed by a second series of steps employing the device which flares (and further sizes) the casing. In another method combination, the second series of steps includes depositing gunpowder into the casing.
The foregoing and other objects, features and advantages of the present invention will become more apparent from the following description of preferred embodiments and accompanying drawings.
The disclosure of provisional patent application Ser. No. 62/363,941, filed Jul. 19, 2016, is hereby incorporated by reference.
While in general it will be accepted that any reloading apparatus should not damage the essential casing, it is important in connection with the aforementioned new design of casing to avoid forces that are of a nature and magnitude sufficient to separate the sleeve from the base. In prior art, and for the new casing, damage to the casing could be caused by the repetitive reworking (reloading), as a result of the casing being pulled from engagement with a reshaping die. An aim of the present invention is to avoid such possible damage.
As suggested in the Background, another factor attending the new casings is that the portion of the casing which is being reworked is made of work hardened stainless steel. For example, an AISI 304 stainless steel used in a casing may have a Rockwell C hardness of about 40, an ultimate tensile strength of about 150,000 pounds per square inch and a modulus of elasticity of about 28×106 pounds per square inch. Thus to achieve a given strain much more force is required than is required for cartridge brass which may have an elastic modulus of about 16×106 pounds per square inch. It follows that, compared to cartridge brass, when a stainless steel casing mouth is either compressed in sizing or expanded outwardly during flaring, there will be a higher elastic hoop stress in the casing while it is still engaged with the die, i.e., with the distal end of the plunger housing here. As a result it is much more difficult to disengage a new type casing than an old casing from a die or plunger housing distal end. Features of the present invention aim to both reduce the necessary disengagement force and apply such force in a way which avoids risk of damage.
The present invention comprises a sizing device 20 exemplified in
Embodiments of both sizing device 20 and flaring device 50 may have external shapes that suit them for being used in the types of apparatus (often generally referred to here as “presses”) which are well known in the art for reshaping and reloading casings, some of which are referred to in the Background. Devices of the present inventions may be used in alternative configurations of presses, including automated presses.
In typical use, a device 20 is mounted fixedly in a press in opposition to a platen 40 and the device and platen move toward and away from each other along the device longitudinal axis L. Neither the press which holds the body of a device 20 nor the press structure and actuators which guide and move a platen and device relative to one another, to engage the casing with the device, are shown; they are well known to artisans. For simplicity of illustration here, only the movable platen 40 is shown (mostly in phantom). The term “platen” refers to any mechanism which supports the base of a casing for engagement and disengagement with a device 20.
Some of the clearances between the different parts of the devices and workpieces (casings) shown in the cross sections of the Figures here are exaggerated for purposes of clarity of illustration. The structural parts of devices of the present invention are preferably constructed of steel with the wear-portions, optionally the whole of the housings, having a high hardness to resist wear.
The configuration and use of the sizing device 20 will now be described.
The purpose of device 20 is to reduce the diameter of the mouth, or circular open end, 73 of the casing inasmuch as the prior firing of a bullet has left it expanded. In the process carried out by device 20, the open mouth end 73 of the casing is pressed into the bore 36 of the distal end 29 of the plunger housing 24. Bore 36 has a bottom end opening that is sufficiently large to receive the end 73 of the casing in its expanded or “slightly-too-large” condition. Bore 36 has tapers inwardly with distance from the terminal end of the housing at the distal end of the device. The taper is sufficient to reduce the outside diameter of the casing to the dimension suited for the bullet to be used in reloading the casing. That portion of a device which contacts the casing to deform it may be referred to as a die.
The invention may also be used to re-shape the part of a casing which is nearer the flange 81, when that region has been bulged outwardly during the prior use. Sizing with the device 20 aims to force the casing back to near its original dimension, so it will fit into the chamber of a gun.
Plunger 30 of device 20 has a piston end 32 that slides resiliently within the bore 25 of spring housing 22. Preferably, there is a close fit between the periphery of the piston and the interior wall of the bore 25, but a lesser fit may be employed in view of the sliding engagement of the shaft with the plunger housing. Plunger 30 moves lengthwise (vertically in the Figures) along central axis L of the device when force is applied to the terminal end of plunger shaft 31, which projects from the bottom end of the device 20 when the device is in its rest configuration. Preferably, as shown, the shaft is supported along its length by means of its good sliding fit within the whole length of bore 36, excluding the end where there is an annular space, thus allowing the shaft to be of modest diameter without bending or buckling under the high spring force. The cavity of spring housing 22 is closed by threaded plug 23 at the proximal end of the device, so the elastomer body which is spring 28 is captured. The spring and piston are removable from the device by removing plug 23. Other closures than a plug threaded into a bore hole may be used, sufficient to provide support for the spring and keep the spring in place within the cavity. Alternatively, when the housings 22, 24 are separate interconnected pieces the closure of the cavity at the proximal end of the housing 22 may be an integral wall.
During use, the platen bearing a casing 70 moves toward the distal end of the housing (i.e., it rises upwardly in the Figure). When shaft 31 is contacted by the casing, piston 32 of plunger 30 is caused to move slidably within the bore 25 of the spring housing, to compress the spring 28, as indicated by the phantom 32P of the piston end of the plunger in
Preferably spring 28 is made of an elastomer such as polyurethane having a Shore A Durometer Number of 85-100, more preferably Shore A 95. Other compressible resilient substances may be used in substitution of the preferred material. In an exemplary device 20 which is useful with a 9 mm cartridge casing and which has the just-mentioned more preferred spring material. Spring 28 may be about 0.5 inch in diameter and about 1.6 inch in length; and it can exert a force of about 300 pounds when the piston compresses the spring about 0.3 inch. The spring rate (ratio of force to displacement) is about 1,000 pounds per inch. Having such a high spring force for such a short stroke in a compact 0.5 inch diameter size is peculiarly characteristic of the particular-material elastomer spring material described above. Preferably the spring rate is between 800 and 1,500 pounds per inch in embodiments of the invention. That the spring is wholly contacted by the piston and that the spring substantially fills the spring housing cavity contribute to the effectiveness of the invention.
The dimension of the bore 36 at the distal end of the plunger housing is chosen to be that which (taking into account any spring back of the metal of the casing), will restore by compression and permanent deformation the diameter of the mouth end of the casing. In a typical resizing of a 9 mm casing, the outside diameter of the open end of the casing might be reduced by about 0.002 to 0.005 inches along about 0.4 to 0.6 inches of axial length from the mouth end opening. The die region of the bore near the opening, which defines the annular space, is subject to wear from shaping many casings, and therefore a carbide bearing insert (or die) may be incorporated in the distal end of device 20.
Shaft 31 preferably has a terminal end (which may be stepped) that has a loose fit within the bore of a casing, sufficient to center the casing on the shaft while allowing the casing to fall from engagement with the shaft when the platen is removed. For example, there may be about 0.010 inch radial clearance.
Preferably the terminal end of shaft 31 comprises a pin 34 which projects axially from the terminal end of the shaft. As can be envisioned from
When the platen is moved away from the device 20, the stored energy in the spring provides a force which pushes the plunger piston downwardly, so the shaft 31 moves downwardly in the Figure. That causes the casing to be thrust out of the bore of the plunger housing. Since the end of the plunger has by design a loose fit within the cavity of the casing, the casing can then fall downwardly away from the plunger, onto or around the platen, ultimately to a bin or other receiving means for further processing. Advantageously, the invention enables engagement with a casing which is not gripped to the platen.
After sizing by means of device 20, the next step typically includes flaring of the outer extremity of the casing mouth to facilitate insertion of a bullet. Flaring may be carried out by device 50, the construction and use of which will now be described.
An embodiment of device 50 preferably has spring housing, spring and plunger construction that is like that described for device 20, for the same advantageous reasons as have been described. In particular, flaring device 50 comprises a spring housing 52, plunger housing 54, spring 58, and plunger 60. Plunger 60 comprises piston 62 which slides within bore 55 and shaft 61 which slides within the bore 82. The functions of the components are essentially similar to what is described in connection with device 20, except for the distal end of plunger housing 54. That distal end comprises nose 80 that is shaped for being forced within the mouth 73 of the casing 70 to flare it outwardly. As mentioned, the distal end that deforms the casing may be referred to as the die.
During operation of device 50, the upward movement F of platen 140 causes casing 70 to contact the distal end of plunger shaft 61; that thrusts the shaft upwardly within its housing. That in turn causes plunger piston 62 to move along bore 55 of the spring housing and compress spring 58, as indicated by the arrow G and phantom 62P in
In one embodiment, the outside surface of the distal end of plunger housing 54 is slightly conical in shape, transitioning from a first diameter nose 80 which preferably is shaped to effect resizing of the bore of the casing, to a larger diameter portion that effects flaring, as detailed further below. After the casing 70 is pushed sufficiently onto the housing of device 50 to permanently deform the casing, the platen is separated from the housing. Then, the stored energy in the spring pushes the plunger downwardly, causing the plunger shaft to push the casing off of the distal end of the plunger housing. Since the fit of the plunger shaft within the bore of the casing is loose, when the casing is removed from engagement with the housing, the casing can fall downwardly onto or around the platen and ultimately to a bin or other receiving means for further processing, i.e., for installation of a new primer, gunpowder, and a bullet using other devices. Because the exterior of the distal end of the plunger housing, or die portion, is subject to wear, that portion of the housing, or the whole of the two integral housings, can be made of hardened steel.
The distal end of the plunger housing of the flaring device 50 may have a rounded end and straight (cylindrical) circumscribing shape that extends to a taper portion which causes the flaring, as in prior art devices. Preferably, the distal end of the housing is shaped in a better way, which lessens the force needed to get the casing off the housing, after flaring.
In an exemplary nose suitable for a 9 mm casing, a groove will be about 0.005 inch deep and have a width D2 of about 0.06 inch. The groove edge will be a distance D3 of about 0.08 inch from the tip of the nose. In a casing which has been flared, the flared portion will extend about 0.020 to 0.030 inches lengthwise from the mouth edge (compared to an overall casing length of about 0.75 inches). To achieve that flare and resizing of the casing bore, the operative die portion of a preferred housing 154 will enter to a depth of about 0.2 to 0.3 inches.
The first section 84 starts the flaring process, and ensures the casing will be centered. And when the plunger housing is fully inserted in the casing, the first section 84 expands the dimension of the casing bore that is adjacent the flare region and nearer to the bottom of the casing, as needed to get the right fit for a bullet. Thus when the housing is fully inserted there is elastic hoop force in the casing at both sections 84, 86. And that creates frictional force that must be overcome by the force of spring powered shaft 61, in order to eject the casing from the housing when the platen is moved away from the housing.
With reference to the above dimensions for an exemplary situation, when a housing is fully engaged with a casing, and ready for withdrawal, the presence of the groove will reduce by about 30 percent that portion of the length of the nose which is in hoop-stretching engagement with the housing. The force needed to separate a casing from the housing is substantially reduced by presence of a groove.
The foregoing plunger housings 154, 254 are useful in connection with a plunger having a shaft that is spring loaded, as shown in
In alternative embodiments of tool 90 there may be a constant external diameter and or a constant diameter bore 92. Tool 90 has a nose 280 like a preferred nose 180 of housing 154. In the use of tool 90, the casing 70 (shown with a primer cap in place) is clamped to a platen 140 shown in phantom. After the platen or tool is moved so that the nose enters the casing mouth and causes flaring, the platen moves away from tool 90, to pull the casing from the nose. In
The invention, with explicit and implicit variations and advantages, has been described and illustrated with respect to several embodiments. Those embodiments should be considered illustrative and not restrictive. Any use of words such as “preferred” and variations suggest a feature or combination which is desirable but which is not necessarily mandatory. Thus embodiments lacking any such preferred feature or combination may be within the scope of the claims which follow. Persons skilled in the art may make various changes in form and detail of the invention embodiments which are described, without departing from the spirit and scope of the claimed invention.
This application claims benefit of provisional patent application Ser. No. 62/363,941, filed Jul. 19, 2016.
Number | Name | Date | Kind |
---|---|---|---|
3242790 | Bachhuber | Mar 1966 | A |
3693497 | Jacobitz | Sep 1972 | A |
4188855 | Alberts | Feb 1980 | A |
4329906 | Heers | May 1982 | A |
4766798 | David | Aug 1988 | A |
4984501 | Roller | Jan 1991 | A |
5221806 | Chaney | Jun 1993 | A |
5649465 | Beebe | Jul 1997 | A |
7395746 | Bond | Jul 2008 | B2 |
20040025677 | Koch | Feb 2004 | A1 |
20170030690 | Viggiano | Feb 2017 | A1 |
Number | Date | Country | |
---|---|---|---|
62363941 | Jul 2016 | US |