Source: {"pile_set_name": "USPTO Backgrounds"}

1. Field of the Invention.
The present invention relates to shotgun shell loading and reloading, and particularly to a method and apparatus for slitting cylindrical shotgun shell wads.
2. Description of the Prior Art.
In recent times, the interest in low volume devices for recharging and reloading shotgun shells has greatly increased. Numerous shell reloaders are available to hand loaders, such as the Versamec 700 Shotgun Shell Reloader manufactured by the Mayville Engineering Company, Inc. of Mayville, Wis. With such devices, a used shotgun shell casing can be refitted with a new shot charge and shot load for reuse.
Historically, the shot or "buckshot" found in shotgun shells has consisted essentially of lead pellets. However, because of environmental concerns related to lead poisoning of wildlife, the use of lead shot has become somewhat restricted, causing hunters and sportsmen to substitute steel shot in place of lead. Steel shot is much harder than lead and can cause scratching of the interior surfaces of a shotgun barrel when fired. To counteract this problem, cylindrically shaped "wards" have been designed for insertion within the casing of the shotgun shell for holding the shot prior to firing. Typically, a wad is formed of a lightweight plastic material which can contain the shot while in the barrel but does not scratch the barrel as it passes through. When a shell containing a wad is fired, the wad and shot travel together along the barrel of the shotgun thus keeping the shot from contacting the barrel. After the wad and shot exit the shotgun, the wad falls harmlessly to the ground while the shot continues on to the desired target.
Examples of such wads or wad columns for shotgun shells are shown and discussed in U.S. Pat. No. 3,788,224, granted to Merritt on Jan. 29, 1974, U.S. Pat. No. 4,103,621, granted to Fackler on Aug. 1, 1978, and brochures distributed by Ballistic Products, Inc. of Wayzata, Minn. entitled "10 Gauge Magnum Ballistic Pattern Drivers" and "100 10 Gauge Magnum Ballistic Pattern Drivers". Not only do such shotgun wads protect the interior of the shotgun barrel from scratching, but they also provide a means for sealing the charged powder gases behind the shot load in the shell and a means for producing a uniform and long-range pattern for the shot upon firing.
The pattern produced by a certain shot load depends, to a certain extent, on the form of the wad. The cylindrical walls of the wad must be slit to allow the wad to separate cleanly from the shot upon exiting the barrel of the shotgun. If not slit, the wad and shot can become a dangerous plastic encased "slug" emerging from the shotgun barrel which could seriously injure a fellow hunter or damage property. To prevent this, and to obtain a uniform pattern, the slits must be equally spaced radially about the wad so that the "petals" formed by the slits in the cylindrical wad are identical in size and shape. Thus, as the wad containing shot leaves the shotgun barrel, the air catches the edges of the petals causing them to fold out so that the wad drops away and the shot goes on to its target. Uniform spacing of the slits allows the shot to separate from the wad clearly and limits wad interference with the trajectory and pattern of the shot.
Wads incorporated into shotgun shells produced in high volume facilities are slit by expensive high volume cutting machines. The reloading or recharging of shotgun shells is usually a low volume process, usually done by hand. Wads are often supplied to handloaders in an unslit form so that they may be slit as desired. A sharp knife or scissors is used to slit the wads and the slitting is done by eye, so that uniformity and clean straight slits are not always attained. In addition, the use of a sharp knife in such a manner presents certain safety problems.
Although not specifically related to the slitting of wads for shotgun shells, devices for slitting or slotting the ends of cylindrical members are shown in several U.S. patents. U.S. Pat. No. 3,715,941, granted to Andrews et al on Feb. 2, 1973 shows an arrangement for making a plurality of slits through the whole length of a tube of insulating material. U.S. Pat. No. 3,153,360, granted to Coulon on Oct. 20, 1964 shows an arrangement which goes into a power press and is used to press a punch element with cutting edges in the end of the tube to form a slot. U.S. Pat. No. 3,069,951, granted to Bares on Dec. 25, 1962 discloses a cutting tool used to produce two slits in the end of a central tube for partitioning the walls of multiple tube hoses. U.S. Pat. No. 3,059,515, granted to Lindsey on Oct. 23, 1962 shows a device for cutting grooves which do not go all the way through the wall of a tube or workpiece for the purpose of providing a means to remove shavings generated during the machining of the workpiece. While the devices of these patents are directed to the slitting or grooving of various workpieces, none of them are directed in function to the unique constraints and problems involved in slitting shotgun shell wads.