The invention relates to a wad for a shotgun cartridge.
Generally, a shotgun cartridge is composed of five components, namely: a primer, gun powder, a wad, shot and a case. Modern cases are usually made of plastic and have a brass head at one end. The other end is closed by crimping the end of the plastic so that it folds down onto itself to close the case. This closure is widely referred to as a folded crimp. Located within the case are the other four components. The primer which is located in the centre of the brass head of the cartridge. Above the primer and inside the brass head is located the gun powder. Above the gun powder is a wad which is usually made of fibre or plastic and creates a seal within the cartridge so that explosive gases generated by ignition of the powder do not dissipate and the full pressure of the gases builds up below the wad to propel the wad and shot out of the cartridge with the maximum force. The wad also creates a wall between the shot and the powder so that they don't mix. The shot is made of a number of small round metal pellets. These were traditionally lead pellets but now non-lead alternatives are also used.
When the primer is hit by the firing pin of the shotgun, this creates a chemical reaction in the primer which produces heat. This heat then ignites the gun powder. Ignition of the powder creates explosive gases which in turn create the required pressure to propel the wad and shot forwards out of the cartridge case and to exit the barrel of the shotgun towards the target. Generally, due to air resistance on the wad and the relatively light weight of the wad, the wad will separate from the shot and while the shot continues to head towards the target, the wad will fall to the ground some distance from the where the gun is fired. This is typically around 20 to 40 metres from where the gun is fired.
Nowadays, most wads are plastic and are typically, in the form of a plastic cup within which the shot is held in the cartridge. Therefore, when the shotgun is fired, both the plastic wad and the shot is propelled out of the barrel of the shotgun. Although the cases of used cartridges can be collected after they are removed from the breach of the shotgun, it is difficult or impossible to collect the plastic wads as they maybe propelled out of the shotgun for around 20 to 40 metres and frequently end up falling in the undergrowth or wooded areas where they are difficult or impossible to find. Accordingly, there is an increasing concern about the environmental impact of plastic wads left lying around the countryside.
In accordance with a first aspect of the present invention, there is provided a wad for a shotgun cartridge, the wad comprising a cup-shaped member having an open end and closed end, and wherein the cup-shaped member comprises a first biodegradable fibrous material.
Preferably, the wad further comprises a separation member located inside the cup-shaped member adjacent the closed end of the cup shaped member, and the separation member comprises a second biodegradable fibrous material.
The first and second biodegradable fibrous materials may be the same or may be different.
Preferably, at least one of the first and second biodegradable fibrous materials is a natural fibrous material and more preferably is a natural organic fibrous material.
Typically, at least one of the first and second biodegradable fibrous materials is formed from at least one of a cellulose based fibrous material and a protein based fibrous material.
In one example, the cup-shaped member is formed from a cellulose based fibrous material that may be plant based or wood based.
Preferably, at least one of the cup-shaped member and the separation member are formed at least in part from a pulp material, and more preferably at least one of the cup-shaped member and the separation member are formed at least in part from card or cardboard.
Alternatively, at least one of the cup-shaped member and the separation member are formed at least in part from a felt material. For example, the felt material may be formed from one or more of wool, hair, fur and cellulose fibres.
Typically, where the at least one of the first and second biodegradable fibrous materials comprises a protein based fibrous material, the protein based fibrous material may comprise at least one of wool, hair and fur.
Preferably, the cup-shaped member may comprise a fabric material. The fabric material may be woven or knitted but is preferably, woven.
The fabric material is typically formed from a biodegradable material, which is preferably a naturally occurring material. For example, the fabric material may be formed from a plant-based fibrous material or from a protein-based fibrous material. Protein-based fibrous materials typically come from animals, such as mammals or insects. The fabric material could be formed from combinations of different plant-based fibrous materials, combinations of different protein-based materials or combinations of different plant-based and protein-based fibrous materials. Examples of plant-based fibrous materials for the fabric material include cotton, hemp, flax and jute. Examples of protein-based fibrous materials for the fabric material include wool, silk and hair.
The cup-shaped member preferably comprises the fabric material and at least one other material. The other material may be, for example, a material formed from a pulp, such as card. The fabric material may be incorporated into the cup-shaped member, such as, by being laminated onto the at least one other material. For example, the fabric material may be incorporated into the cup-shaped member by being laminated onto the at least one other material such that it forms an outer layer of the cup-shaped member on the outside or inside of the cup-shaped member or laminated between layers of the at least one other material so that it is within a side wall of the cup-shaped member.
Alternatively, the fabric material may be incorporated into the cup-shaped member by being entrapped or embedded within the at least one other material. This may be during a manufacturing process, for example, during a molding process.
In a further alternative, the cup-shaped member may comprise a number of layers of fabric material and a number of layers of at least one other material with at least one of the layers of the at least one other material having a fabric material entrapped or embedded within it.
The fabric material may be incorporated into only a section of the cup-shaped member or may extend throughout the cup-shaped member. Preferably, the fabric material extends completely around a side wall of the cup-shaped member. Preferably, the fabric material extends along the full length of the cup-shaped member.
An advantage of the cup-shaped member comprising a fabric material is that the fabric material assists in improving the structural strength of the cup-shaped member. This reduces the risk of the cup-shaped member disintegrating when a shotgun cartridge including the wad is fired from a gun.
The separation member may be formed from a compressed fibrous material. The compressed fibrous material may be a compressed protein based fibrous material, such as wool, hair or fur. In one example, the fibrous material could be in the form of a felt, such as a felt formed from one or more of wool, hair, fur and cellulose fibre. Alternatively, the compressed fibrous material may be a compressed cellulose based fibrous material, such as cotton or flax or a compressed pulp material.
Preferably, the cup-shaped member comprises a tubular member having a closed end forming the base and an open end.
Preferably, the tubular member is crimped at one end to form the closed end. More preferably, the crimped closed end comprises a folded crimp. The folded crimp may be a six star folded crimp or an eight star folded crimp.
Typically, the tubular member has substantially cylindrical side-walls extending between the closed end and the open end.
In one example, a side wall of the cup-shaped member may have at least one slit extending from adjacent the open end to at least part way along the side wall towards the closed end.
Preferably, the at least one slit is open at the open end. In one example, opposite sides of the at least one slit are spaced apart from each other so that the slit forms a slot.
Typically, the end of the at least one slit closest to the closed end is spaced from the closed end.
Preferably, the cup-shaped member comprises a friction reducing outer surface. More preferably, the friction reducing outer surface comprises a coating. The coating may comprise a resin material. Preferably, the coating may be biodegradable. The coating may be water soluble.
Typically, the separation member is adapted to separate the closed end of the cup-shaped member from a projectile located adjacent the open end of the cup-shaped member, in use.
In one example, the separation member may be in the form of a plug or disc that is typically solid. Preferably, the separation member is substantially cylindrical and more preferably a solid cylinder.
Preferably, the separation member extends across substantially all of the internal cross-sectional area of the cup-shaped member adjacent the closed end of the cup-shaped member. The separation member may be a friction fit in the cup-shaped member.
An advantage of the separation member is that it helps to provide additional structural strength or support to the cup-shaped member, particularly at the closed end of the cup-shaped member. The separation member also acts as a barrier between the closed end and the projectile located in the cup-shaped member above the separation member. The separation member can also provide some shock absorption between gun powder in the cartridge and the projectile.
In accordance with a second aspect of the present invention, there is provided a shotgun cartridge comprising an outer casing, the casing containing a primer located in a base of the casing, an explosive powder adjacent the base of the casing and the primer, a wad comprising a cup-shaped member located on the opposite side of the powder from the base and a projectile located within the cup-shaped member; and wherein the cup-shaped member comprises a first biodegradable fibrous material.
Preferably, the wad further comprises a separation member located within the cup-shaped member which may comprise a second biodegradable fibrous material. More preferably, the separation member is located between a closed end of the cup-shaped member and the projectile.
Preferably, the cup-shaped member comprises a tubular member having a crimped closure at one end. More preferably, the crimped closure is a folded crimped closure.
The wad may further comprise a barrier member located between the explosive powder and the cup-shaped member. The barrier member may be in the form of a disc.
Preferably the barrier member extends across substantially all of the internal cross-sectional area of the casing to minimise contact between the powder and the cup-shaped member. Therefore, the barrier member acts to substantially isolate the powder from the cup-shaped member.
In one example, the cup-shaped member comprises at least one slit extending from adjacent an open end of the cup-shaped member at least part way along the side wall towards the closed end.
The shotgun cartridge of the second aspect may comprise a wad having any of the features of the first aspect of the invention.
Typically, the projectile is metal shot, such as lead shot. However, other projectiles could be used.
Examples of a wad for a shotgun cartridge in accordance with the invention will now be described with reference to the accompanying drawings, in which:
The biodegradable material may be composed of natural (as opposed to synthetic or man-made) materials, such as natural fibres. For example, the biodegradable material may comprise at least one of a cellulose based fibrous material and a protein based fibrous material. Examples of cellulose based fibrous materials include cotton, flax and cardboard. Examples of protein based fibrous materials include wool, hair, fur and silk. Cellulose based fibrous materials may be formed from a pulp, such as a wood-based or a plant-based pulp. The biodegradable fibrous material may be a compressed fibrous material, such as compressed cellulose based fibres (such as cotton fibres, flax fibres, wood-based pulp or plant based pulp) and/or compressed protein based fibres (such as wool, fur or hair). In one example, the biodegradable fibrous material could be formed from a felt material.
The cup section 4 is in the form of a cylindrical tube 5 having an open end 6 and a closed end 7. The closed end 7 is typically closed by crimping the end of the cylinder 5 to form a folded crimp 8 at the closed end 7 of the tube 5. In the example shown, the folded crimp 8 is a six star folded crimp. However, any suitable or desirable folded crimp could be used, such as an eight star folded crimp.
An advantage of using a folded crimp to form the closed end 7 is that a folded crimp adds structural strength to the closed end of the cup section 4.
The outside surface of the cup section 4 has a friction reducing surface. The friction reducing surface maybe an inherent part of the material from which the cup section 4 is formed or maybe a coating applied to the external surface of the cup section 4. For example, the coating may comprise a varnish, which may comprise a resin, and the varnish cures to form the coating on the external surface of the cup section 4. The coating may be water soluble.
The cup section 4 is configured so that the external diameter of the cylindrical tube is the same as or slightly less than the internal diameter of the plastic sleeve 2. This enables the cup section 4 to fit inside the sleeve 2, as shown in
The cup section 4 is then inserted into the open end 13 of the plastic sleeve 2 of the case 1 and the separation member 9 inserted into the open end 6 of the cup section 4.
The cup section 4 is pressed down into the case 1 so that it rests on the gun powder 11, as shown in
Shot 12 is then inserted into the cup section 4 above the separation member 9 and open end 13 of the case 1 is then closed by crimping the open end of the plastic sleeve 2 over the open end 6 of the cup section 4 and across the top of the shot 12 to form a folded crimp closure 15.
In use the shotgun cartridge 20 is used in the same way as a conventional shotgun cartridge. When the shotgun is fired, the firing pin of the shotgun strikes the primer 10 which causes ignition of the gun powder 11. Ignition of the gun powder 11 generates explosive gases that compress between the base 14 and the closed end 7 of the cup section 4. These gases create the required pressure to propel the wad (comprising the cup section 4 and the separation member 9) together with the shot 12 out of the cartridge 20 by pushing the cup section 4 through the folded crimp 15 and out of the barrel of the gun towards the target.
An advantage of the separation member 9 is that it helps to provide additional structural strength or support to the cup section 4, particularly at the closed end 7 of the cup section 4. The separation member 9 also acts as a barrier between the closed end 7 and the projectile 12 located in the cup section 4 above the separation member 9. The separation member 9 can also provide some shock absorption between the explosive gases generated by the powder 11 in the cartridge 20 and the projectile 12.
After exiting the barrel of the gun, the shot 12 continues to fly towards the target but air resistance on the wad and the relatively light weight of the wad (which consists of the cup section 4 and the separation member 9) results in the wad separating from the shot and falling to the ground some distance from the gun.
An advantage of the wad of the invention is that as the cup section 4 and the separation member 9 are formed from natural materials that are biodegradable, they naturally breakdown into the ground over time to have a reduced environmental impact compared to conventional plastic wads.
In the cup section 30, the slots 31 extend from the open end 6 of the cup 30 to approximately adjacent the upper end of the plug section 9 in the cup 30. That is, the end of the plug section 9 that is opposite the closed end 7 of the cup section 30. However, slots of difference length could be used as desired and it is possible that the slots 31 may not necessarily extend all the way to the open end 6. The slots 31 extend substantially parallel to the longitudinal axis of the cylindrical tube 5.
An advantage of the cup section 30 and the slots 31 is that the slots 31 permit the side walls of the cup section 30 to compress if necessary, to facilitate easier exit of the cup section 30, containing the separation member 9 and the shot 12 from the case 1 and the barrel of the gun, and particularly through the choke at the end of the barrel.
The barrier member 41 is approximately disc shaped and extends across the internal diameter of the plastic sleeve 2. Hence the barrier member 41 separates the powder 11 from the cup section 4 and helps to minimise or prevent contact between the powder 11 and the cup section 4.
The advantage of the barrier member 41 is that it helps to minimise the impact of the explosive gases, created by ignition of the powder 11, on the closed end 7 of the cup section 4 by providing a barrier which helps to protect the closed end 7. Typically, the barrier member 41 is also manufactured from a biodegradable material and that is preferably a naturally occurring material. This may be the same or a similar material to the material from which the separation member 9 is manufactured.
For example, the barrier member 41 could be formed from any suitable biodegradable material, and preferably a biodegradable fibrous material. The biodegradable material may be composed of natural (as opposed to synthetic or man-made) materials, such as natural fibres. For example, the biodegradable material may comprise at least one of a cellulose based fibrous material and a protein based fibrous material. Examples of cellulose based fibrous materials include cotton, flax and cardboard. Examples of protein based fibrous materials include wool, hair, fur and silk. Cellulose based fibrous materials may be formed from a pulp, such as a wood-based or a plant-based pulp. The biodegradable fibrous material may be a compressed fibrous material, such as compressed cellulose based fibres (such as cotton fibres, flax fibres, wood-based pulp or plant based pulp) and/or compressed protein based fibres (such as wool, fur or hair). In one example, the biodegradable fibrous material could be formed from a felt material.
In use, the barrier member 41 is propelled out of the case 1 and the barrel of the gun together with the wad (comprising the cup section 4 and the separation member 9) and the shot 5, in a similar manner to how the wad and shot is propelled out of the shotgun cartridges 20, 35.
It is also possible that the cup section 50 could be modified to include more than three layers. For example, it could comprise five layers having three layers of wood pulp material and two layers of fabric material arranged so that each fabric material layer is are located between two layers of wood pulp material. It is also possible that a layer of wood pulp material could be sandwiched between two fabric material layers.
The cup section 55 could be modified to include more than two layers. For example, it could comprise four layers having two layers of wood pulp material and two layers of fabric material arranged so that layers of fabric material alternate with the layers of wood pulp material, so that the innermost layer is a wood pulp material layer.
The cup section 60 could be modified to include more than two layers. For example, it could comprise four layers having two layers of wood pulp material and two layers of fabric material arranged so that layers of fabric material alternate with the layers of wood pulp material with the outermost layer being a wood pulp material layer.
Any of the cup sections 50, 55, 60, 65 or any of the alternative or modified cup sections described above could also incorporate slots similar to the slots 31 in the cup section 30.
An advantage of the wad used in the shotgun cartridges 20, 35, 40 is that it is composed of biodegradable material, such as natural fibres, thereby reducing the impact of the wad 4, 9, 30, 41 on the environment compared to conventional plastic wads.
Number | Date | Country | Kind |
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1912778.6 | Sep 2019 | GB | national |
2007625.3 | May 2020 | GB | national |
This application is a 371 of PCT/GB2020/052099 filed Sep. 2, 2020 which claims priority to GB application No. 2007625.3 filed May 21, 2020 and GB application No. 1912778.6 filed Sep. 5, 2019.
Filing Document | Filing Date | Country | Kind |
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PCT/GB2020/052099 | 9/2/2020 | WO |