Primer pocket cleaner

A primer pocket cleaner for cartridge cases has a bundle of bristles mounted in a base with a retractable spring surrounding the bristles. The base is mounted in a motor to rotate the bundle of bristles. The spring keeps the bundle of bristles together while allowing them to vibrate as a cartridge case primer pocket is pressed against the end of the rotating bundle of bristles not mounted into the base.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to devices which clean small recesses such as primer 
pockets including the flash hole. Specifically, this invention pertains to 
primer pocket cleaners for cartridge cases. 
2. Description of Prior Art 
There are numerous devices used to clean primer pockets on cartridges. 
Several have sought to use the advantages of bristle bundles. Such bundles 
permit bristles smaller than the primer pocket to reach into the primer 
pocket to clean any residue. Such bundles quickly flare. Flaring is 
lessened if hard materials are used. However, if the level of hardness is 
equal to or greater than the hardness of the cartridge case, the bristles 
go beyond cleaning and abraid the cartridge case. 
Using bristles softer than the cartridge case avoids abrasion but results 
in quicker flaring. Shortening the length of the bristles reduces the 
flaring effect but results in very short useful life of the cleaner before 
the bristles are worn away. 
Retaining devices such as springs have been used to encase such bundles of 
bristles. These retaining devices have been anchored to the bundle of 
bristles or to the base holding the bundle. This attachment keeps the 
bristles from vibrating. This in turn significantly reduces the bristles 
ability to remain clean. The bristle bundles are rotated symetrically 
which permits skips in the cleaning and frequently fails to clean the 
flash hole. Not only does carbon build up in the flash hole but the 
bristles themselves retain carbon due to the lack of sufficient vibration. 
Accordingly, it is an object of the present invention to use bundles of 
bristles made of material softer than the cartridge primer pockets to be 
cleaned. Such bundles of bristles are retained while vibrating and are 
prevented from flaring apart. The bundle of bristles is to clean with a 
scrubbing motion which allows the flash hole to be cleaned along with the 
primer pocket. 
SUMMARY OF THE INVENTION 
In one embodiment of this invention, a bundle of bristles is mounted to a 
base. A retractable spring is placed around the bundle but not fastened to 
the bundle. The spring may slide along the bundle. The base is in turn 
rotated by a motor or other turning device. The cleaning surface of one 
end of the bristle bundle is designed flare to hold the spring from 
sliding off. 
In another embodiment, the bundle is mounted slightly off center so a 
scrubbing effect is produced when the base is rotated.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
In FIG. 1, a cylindrical base 10 has a bundle of bristles 12 mounted on the 
axis of base 10. As will be described below, there are advantages to 
mounting bundle of bristles 12 slightly off axis. Base 10 may be any 
plastic, metal or other material capable of handling high speed rotation. 
Bundle of bristles 12 can be made of copper wires, plastic fibers, or 
other materials that are softer than cartridge case primer pockets to be 
cleaned. Use of materials with a lower level of hardness avoids abrasions 
to the primer pocket which damage the primer pocket by wearing it away. A 
coil spring 14 is placed around bundle of bristles 12. Spring 14 is 
retractable and can be made of any metal. Spring 14 is not all fastened 
and may slide over bundle of bristles 12. By not being attached the 
individual bristles 13 are able to vibrate which helps them stay clean. 
Base 10 may be rotated by any turning device, such as a motor 18 as shown 
in FIG. 2. Referring back to FIG. 1, set screws 16 are one method of 
attaching base 10 to motor 18. A guard shield 17 may be made either part 
of the base as shown, or attached as a separate component. Guard shield 17 
extends around bundle of bristles 12 to catch anything thrown off as the 
bundle of bristles rotate. 
FIG. 3 is a side view of base 10 and bundle of bristles 12. One end of 
bundle of bristles 12 has a cleaning surface 20. An end on view of 
cleaning surface 20 is shown in FIG. 4. The central bristles 22 of bundle 
of bristles 12 may extend above cleaning surface 20 to fit the central 
portion of the pocket to be cleaned, known as the flash hole. As shown in 
FIG. 3 and FIG. 4 a scrubbing effect can be produced during the cleaning 
by mounting bundle of bristles 12 slightly off of the axis of cylindrical 
base 10. FIG. 3 shows an axis 24 which is the axis of symmetry for bundle 
of bristles 12. Also shown in FIG. 3 is an axis 26 which is the axis of 
rotation for base 10. When base 10 is rotated, bundle of bristles 12 does 
not rotate about axis 24, thus a scrubbing motion results. 
When a cartridge case primer pocket is pressed against cleaning surfaces 
20, spring 14 retracts allowing penetration to the base of the primer 
pocket. Individual bristles 13 will flare outward but are limited by the 
size of the primer pocket. The flare will serve to keep spring 14 from 
sliding off. Only the portion of bristles 13 exposed by the retraction of 
spring 14 are able to flare. 
FIG. 5 shows the present invention aligned for use with a cartridge case 
30. A cartridge case 30, shown in cross-section, has a primer pocket 32 
and a flash hole 34. Cartridge case 30 is pressed against bundle of 
bristles 12 such that bundle of bristles 12 is inserted into primer pocket 
32. Central bristles 22 fit into flash hole 34. Due to the off-center 
rotation of bundle of bristles 12 and central bristles 22, the bristles 
shaped into a cleaning surface scrub their way around primer pocket 32 and 
flash hole 34.