US1678162A

US1678162A - Cartridge

Info

Publication number: US1678162A
Authority: US
Inventors: John D Pedersen
Original assignee: Individual
Current assignee: Individual
Priority date: 1926-05-20
Filing date: 1926-05-20
Publication date: 1928-07-24
Anticipated expiration: 1945-07-24
Also published as: BE350427A; FR652332A

Description

July 24, 1928. 1,678,162

J. D. PEDERSEN CARTRIDGE Filed May 20, 1926 Mo; D 7

I INVENTOR.

A TTORNEYS.

Patented July 24, 1928.

FIQE- 7 JOHN D. PEDERSEIL'OF SPRINGFIELD, MASSACHUSETTS.

CARTRIDGE.

Application filed May 20,

This invention relates to improvements in cartridges for fire arms and a method of rendering the same more durable and serviceable.

More particularly, the invent-ion aims to improve a cartridge in two main respects: first, to provide a weatherproof protective coat-ing for the cartridge which will enable "it to be stored without deterioration for longer periods of time than heretofore; and second, to provide a means of lubrication for the cartridge to facilitate its extraction from the chamber of the fire arm when fired As regards the feature of providing a protective coating for the cartridge, one of the principal causes for deterioration of cartridges in storage is that they are subject to what is known as season crackinglf By this it is meant that the metal case or shell of the cartridge after a time will develop a break or crack which usually starts around the thinnest part of the metal at the mouth or neck of the case and works backwardly toward the base. This season cracking is presumably due to the unrelieved strains in the metal of the case which have beenset up during the drawing and annealing of the same in its manufacture. Obviously any weakening of the thin metal composing the case by corrosion or other destructive weather effects will accelerate the occurrence of theaforesaid season cracking. I have found that if the metal case is well protected from moisture and actionof the atmosphere that the time of season cracking may be postponed and thereby the life of the cartridge in storage greatly prolonged. I have also found that such a suitable protective coating may be, furnished by certain of the hardiwaxes of commerce and further that by selecting for this purpose a wax of the 'proper characteristics certain other very desirable advantages will flow from its use as will now be mentioned.

It has long been recognized that me quick firing fire arm, the. extraction of the empty cases becomes increasingly 'diflicult as the gun becomes heated through repeated firing. This may be in large part due to the fact that during the first shot or two the chamber of the gun contains suflicient lubricant to make extraction of the case easy,'but when this lubricant is burned off or otherwise destroyed, the extraction becomes more l w t a eus attempts have been ma e 1926. Serial No. 110,559.

to lubricate cartridges as they. are introduced into the chamber of the gunin order to make the extraction of the empty cases more uniform throughout a period of continued rapid fire. Such methods necessitate the provision of lubricating devices in the. gun and demand some attention and care on the part of the gun operator. By the present invention, the means for lubrication are provided on the cartridge when manufactured, which both simplifies the solution of the problem and also requires no cooperation from the user of the gun.

I have found that a properly selected hard wax may serve both for the protective covering for the cartridge above mentioned and also when the cartridge is fired it will be melted by the heat and pressure so as to serve as a lubricant in rendering the extraction of the empty case easy and uniform.

The most suitable wax which I have found for the purposes named and which I at present prefer is ceresin, a refined product of ozokerite; but I wish to have it understood, of course, that other waxes having similar qualities may exist which might serve equally well. Someof the characteristics of ceresin which render it so desirable for the purposes in view are that it is hard and non-tacky at normal temperatures, melting somewhere between C. to 80 C. and therefore will not soften or melt under any weather condition to which it is subjected, even that of extreme tropical heat. It is chemically stable to the action of most reagents, at least such as are found in the atmosphere. When hard it forms a strongly adherent coating which will not flake oil or brush oil easily and has a smooth glassy surface which is not greasy or a collector of dust. It may be applied in a very thin transparent film, hardly perceptible vto the eye, so that the condition of the metallic case beneath it can at alltimes be inspected.

In the drawing which shows a preferred embodiment of the invention:

Fig. 1 illustrates a complete cartridge, half in section'and half in elevation.

1 indicates the metallic case or shell of the cartridge with its conically tapered shoulder'at 2, cylindrical neck 3 and mouth 4 into which the bullet 5 is secured. 6 indicates the powder charge and 7 the primer.

Preferably over substantially the entire surface of the cartridge is topped. a thin coating of hard Wax, preferably ceresin as indicated at 8. It will be understood that the drawing necessarily exaggerates the thickness of said Wax coating 8 in order to illustrate the same. In actual practice, the

coating is less than a thousandth of an inch thick. In other Words, the thickness of the coating should preferably be thin enough so as not to appreciably modify the gauging or fit of the cartridge in the chamber. It is not so essential that the coating cover the base of the cartridgs, but it is desirable that it should cover and envelop the mouth, neck and shoulder of the case and adjacent portions at which places season cracking first appears. The coating may with advantage seal the joint between the mouth of the case and the bullet to prevent the intrusion of moisture thereat.

Various methods of applying the wax coating to the ease of the cartridge may be resorted to, but the method which I at present prefer is to liquefy the war; by obtaining a solution of the same in one of its solvents and to dip the cartridges in a bath of the same. Ceresin is soluble in carbon disulphide as Well as carbon tetrachloride, but the latter solvent is preferable because its smell is less obnoxious and it is noninflammable Whereas carbon bisulphide is highly inflammable and dangerous to use on that account. Carbon tetrachloride also will very quickly evaporate from the solution.

After obtaining a suitable solution of the wax or ceresin, the cartridge may be dipped in a bath of the same, bullet end down, so as to immerse the same up to a point adjacent the base of the cartridge, thus en veloping substantially all of the cartridge except the base. This dipping causes a thin film of wax solution to adhere to the cartridge and upon Withdrawal of the latter the film Will quickly dry and harden due to the rapid evaporation of the solvent. If it is desirable to accelerate the drying and hardening of the film, an air blast may be employed.

The thickness of the hardened film which finally dries upon the cartridge will depend principally upon the percentage of Wax in the solution but, of course, this thickness may also be increased by repeated dippings and hardening operations. In the present process, I preferably dip the cartridge once for a very short time in a 7% solution of ceresin in carbon tetrachloride; that is, the ceresin forms but 7% of the liquid bath. The temperature of the bath solution is maintained preferably at approximately C.

I have described the preferred method of carrying out my invention and a preferred embodiment of the product thereof, but I Wish it to be understood that various modifications thereof and changes therein may be resorted to Without departing from the scope of the invention as hereinafter claimed.

What I claim is:

l. A cartridge comprising a case of drawn metal coated With an extremely thin film of hardened ceresin, adapted both as a protective covering for said case against a corrosion and for lubrication of said'case, said coating film being the air dried product rev sulting from an application to said case of a solution of ceresin in carbon tetrachloride. 2. A cartridge comprising a case of drawn metal coated with an extremely thin film of hardened ceresin, adapted both as a protective covering for said case against cor-' rosion and for lubrication of said case, said coating film'being the air dried product resulting from an application to said case of a solution of ceresin in carbon tetrachloride, the concentration of said solution being approximately 7% ceresin at a temperature. of said solution of approximately 50 C.

In testimony whereof I have affixed my signature.

JOHN D. PEDERSEN.