Wads For Cartridges

Abstract

A one piece plastic wad for a shotgun cartridge forming a cover for the powder charge, having conical leaves forming a shot pouch, the leaves being axially separated with their edges inclined to the radius of the wad.

Description

The invention is for an improved wad for cartridges particularly shotgun cartridges. The invention is concerned with an overwad for use with a cartridge in which there is a cylindrical case having at one end priming means. A powder charge is inserted into the cylindrical cartridge case and the wad of the kind for which the present invention is concerned is then inserted into the cartridge case over the powder charge and is provided with a shot pouch. The shot is inserted into the pouch and the open end of the cylindrical cartridge case is then crimped over or otherwise closed.

The requirements of an overwad of the kind with which the present invention is concerned are firstly that it must provide a cover for the powder charge and an effective seal with the interior walls of the barrel of the shotgun in order to prevent the escape of gas and thus to utilise the gas expansion when the powder charge is ignited to obtain the maximum propulsive force. Also the wad of the kind with which the present invention is concerned retains the shot in the pouch until the wad has left the muzzle of the barrel whereupon the wad is retarded in its forward flight due to contact with the air enabling the shot to continue in its forward flight and leave the pouch. While the shot is travelling up the barrel it is preferable that it is retained in the pouch so that the shot shall not be damaged and thus will emerge in a compact form and undistorted from hitting the interior walls of the barrel as occurs when a cartridge containing shot not retained in a pouch is fired. It is known that irregular pattern of shot is the result of the round shot being deformed in one way or another from hitting the interior walls of the barrel.

The present invention provides a one piece wad for a shotgun cartridge of the kind referred to formed of a synthetic plastics material and having a cylindrical portion with a closed recess at one end for forming a cover for a powder charge and to seal said charge against the walls of a cartridge case, a shot pouch portion formed by at least two leaves which are formed as part of the surfaces of a cone, said leaves being secured to the cylindrical portion or an extension thereof at one end and tapering outwardly towards the opposite end of the wad, said leaves being separated from each other in the axial direction, the edges of adjacent leaves at the separation being inclined to the radius of the wad and adapted so that the leaves may overlie each other to form a cylindrical outer surface for the shot charge portion while in the cartridge case and in the barrel of a shotgun.

According to the present invention there is desirably a resilient or less rigid formation between the shot pouch portion and the powder charge portion which cushions or absorbs some of the recoil of the explosion when the powder charge is exploded by the priming means. Desirably there are four leaves adapted to form part of the surface of a cone having four separation points enabling the four leaves to overlie each other when inserted into the cartridge case.

The resilient or less rigid formation between the shot pouch and the powder charge portion may consist of an area of outer structure so that when explosion takes place this area of outer structure is able to collapse and provide cushioning. The collapse may either be in the longitudinal direction or alternatively the said area may be provided with weakened lines on one side thereof so as to encourage a rotational force during the collapsing action.

In order that the present invention may be more readily understood reference is now made to the drawings in which:

FIG. 1 is a side view of a wad according to the present invention,

FIG. 2 is a cross sectional view of FIG. 1,

FIG. 3 is a perspective view of a wad according to the present invention and

FIG. 4 is a plan view,

FIG. 5 is a perspective view of a wad according to one embodiment of the present invention,

FIG. 6 is a side view thereof,

FIG. 7 is a plan view thereof,

FIG. 8 is a cross sectional view thereof and

FIG. 9 is a cross sectional view on the line 9--9 of FIG. 8.

In the Figures a powder charge cover portion 1 is provided with a closed recess 6 to overlie the powder charge when the wad is inserted into a cartridge case. The wad according to the present invention is made as a one piece moulding of synthetic plastics material. A cylindrical portion 2 extends between the powder charge portion 1 and four leaves 4 each formed as part of the surface of a cone and separated from each other by separation lines 5. The interior of the wad defined by the four leaves 4 forms a shot charge pouch 7. Apertures 3 are formed in the otherwise solid body 2 of the wad to provide areas of weakness between the shot charge pouch 7 and the powder charge 6 to enable a cushioning or resilient effect to occur between the pouch 7 and the charge 6, thus reducing the effect of recoil when the powder charge is ignited. The separation lines 5 are defined by edges 4a and 4b of the opposite edges of the leaves 4. The edges 4a and 4b are adapted to overlie each other as illustrated in FIG. 4 and are formed with a chamfer or surface inclined to the radius of the cylindrical form of the wad to ensure that as the outer end of the wad is formed from conical to cylindrical the edges readily meet with each other and overlie each other. A wad according to the present invention when emerging from a barrel of a shotgun will enable the wad to be retarded quickly by the leaves opening out to adopt their conical form thus enabling the shot in the pouch 7 to continue undisturbed in its forward flight. As the wad at the muzzle hits the resistance of the air the leaves will be bent back and the wad fall to the ground comparatively soon after emerging from the barrel.

By virtue of the leaves overlapping each other as illustrated in FIG. 4 it is apparent that the shot cannot come into contact with the interior walls of the barrel. It will also be appreciated that the internal barrel diameter of a shotgun can vary with a range of 0.40 inches for a 12 bore gun according to present United Kingdom laws. It will be appreciated that different laws apply in other countries but the diameter of a shotgun barrel can vary with a range of a permissible upper and lower limit. Accordingly with the present invention the wad having overlapping leaves is able to conform to these variations and still maintain both an adequate seal and form a wholly closed pouch for the shot. Thus the shot on emerging from the pouch 7 at the muzzle is undamaged as a result of the explosion of the charge or its passage up the barrel. The charge located in the recess portion 7 forces the sides of the wad 1 outwardly thus increasing the effective seal between the interior walls of the barrel, shotgun and the said recess portion 6 when explosion occurs.

It is thought that a wad according to the present invention may be moulded as one piece of synthetic plastics material and the separation lines 5 formed thereafter.

Referring now to FIGS. 5 to 9 a powder charge portion 1 has four webs 9 forming a cross extending upwardly thereon and being surmounted by the leaves 4 which are separated by the lines 5. The webs 9 are provided with a radially extending line 10 of weakened form as seen more particularly in FIGS. 5-9 so that when the wad is in use and the explosion of the powder charge occurs there is a tendency for the webs 9 to collapse and for the base of the shot pouch to approach the powder charge cover portion 1 by the webs rotating as well as collapsing in the longitudinal direction.

The leaves 4 desirably taper from the outer edge 4a to increase in thickness to their root 4b. Adjustment of the taper gives control to the speed of opening of the leaves after leaving the barrel and hence effect the tightness of the shot pattern.

Claims

What we claim is:

1. A one piece wad formed of synthetic plastic, adapted for insertion within a substantially cylindrical cartridge case, comprising:

a. a cylindrical portion with a closed recess at one end for forming a cover for a powder charge and to seal said charge against the walls of the cartridge case;

b. a shot pouch portion formed by at least two leaves, each leaf having the form of a portion of the surface of a truncated cone, the leaves being secured to said cylindrical portion;

c. said leaves being separated from each other in the axial direction, the side edges of adjacent leaves being inclined in a plane normal to the wad axis at complementary angles to the radii of the wad at said edges; and

d. said adjacent leaves having said adjacent edges overlapping when said wad is inserted into said substantially cylindrical cartridge and forming a first circumference around the upper edge of said leaves conforming to the inner diameter of said cartridge, and said leaves having a second expanded circumference around said upper edge of said leaves when not constrained by said cartridge.

2. A wad as described in claim 1 having an area of reduced strength between the shot pouch portion and the cylindrical powder charge portion.

3. A wad as described in claim 2 wherein said area of reduced strength consists of material having parts removed therefrom to form structurally weakened areas.

4. The wad as described in claim 2 wherein the said area of reduced strength consists of webs having radially directed weakened lines to encourage rotational as well as longitudinal collapse of said portion.

5. The wad as described in claim 4 in which the leaves taper in the longitudinal direction, the thickest part being at the root and the thinnest part at the outermost edge.

6. A wad as described in claim 1 formed by an injection molding process of synthetic plastic material.

7. The wad as described in claim 1 wherein said cartridge case has a diameter within a fixed range, and said wad is adapted to fit varying sized cartridges within said range.