US2436826A - Primer - Google Patents

Description

March 2, 1 948. ap. REZGZAD ET AL PRIMER Filed Sept. is, 1942 I F L I FIL W 4 63 mm -m w,

d um i 3 .RM D. T w 3. mi. m ODOOQJ ooooe 000000 0 6 Q Q 0 ll v a o 9 o o e o o o 0 0/ 0 o e o w o blil .IQIOJOOQ o o w o 0 0000 000 lwlwivhrlmlli Patented Mar. 2, i948 PRIMER Eugene D. Regad and Andrew T. Anderson,

. Dover, N. J.

Application September 15, 1942, Serial No. 458,443

4 Claims. (01. 102-865) (Granted under the act of March 3,1883, as

amended April 30,

The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to us of any rovalty thereon.

This invention relates to primer tubes particularly to those designed for insertion in the propellant charge for ammunition.

Previously metallic primers have been used containing flash holes for directing the ignition into the charge. In order to retain the primer charge an inner sleeve was provided to cover the holes, the sleeve beint. destructible on ignition of the primer, and the holes were further sealed off against external foreign matter and sealed to the tube by patches of asphaltum. The tubes have for the most part been constructed of co per or other materials now considered strategic and subiect to conservation measures.

It is an object of this invention to provide a primer tube so constructed as to function in a manner prescribed to conventional primers as described above a d yet be capable of fabrication from non-stra egic materials and omit the extra means for closing the tube.

This and other objects are accomplished by providing a tube which is in itself capable of retaining the chargeand kee ing out moisture but is weakened along lines which will y eld to permit passage of the pr mer flash accord ng to the desired nattern of ignition of the propellent.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

Fig. 1 is a view in elevation of a primer tube in one embodiment of the invention.

Fi 2 is a bottom plan v ew thereof.

Fig. 3 is a view similar to Fig. 1 showing a modifled tube.

F g. 4 is a sectional view taken on the line 4-4 of Fi 3.

Fig. 5 is a view in elevation of the blank before roll ng into the tube form of Fig, 3, and

Fig. 6 is a sectional view similar to that of Fig. 4 showing a modification.

Referring to the drawings by characters of reference there is shown a tube i of plastic containing a powder charge 9. The tube is preferably non-inflammable so that the flash direction may be controlled and it may be fabricated of molded Bakelite or any other of the well-known plastics, such as formaldehyde urea, cotton-filled or wood flower phenolics, cellulose derivatives, particularly acetates, vinyl compounds, methacrylates,

casein products or lignin.

The tube as shown is molded in one piece and has a chamber with thickened walls 2 at one end 5 for receiving the percussion member. This receiver may also be a separate member metallic or otherwise designed to flt over or be received by the primer tube as shown at H] in the case illustrated in Fig. 3. The molding operation may be performed by any appropriate method as employed in the plastics art. At certain selected portions of thetube the wall thickness is diminished to furnish weakened regions. As shown these regions are small circles 3 of a size commonly employed as flash holes. They are not flash holes in the present instance, however, until the weakened wall portions 4 have been ruptured by firing of the primer composition.

As shown in Fig. 6 the weakened portions may 20 be formed in another manner by a punching operation in which the punching is stopped short of complete separation of the slug 5. Since this type need not be molded the tube can be made of any material, including metal.

For the tube of Fig. 3 the blank of Fig. 5 is used. A rectangular blank 6 has a portion 7 unperforated. This portion is sufiicient when rolled on a mandrel to form a complete circumference representing the inside wall of the primer tube. 30 Thereafter is laid down the perforations 8 and these will have, as a closed bottom, the layer contributed by the portion 1. The desired number of rows of holes (four in the device shown) will be laid down on a single layer and thereafter the holes are so spaced as to coincide with those already laid down by the wrapping. The ends of the tube are sealed within and without the tube by any desirable method, for instance by the use of a solvent in the case of plastic sheet such as cellulose acetate.

We claim: a

1. A laminated primer tube consisting of an elongated hollow cylinder having as sidewalls a single continuous sheet of flexible material spirally wound upon itself in layers, said sidewalls having areas of lesser thickness than the remaining portions whereby the areas having the lesser thickness will be ruptured by the primer blast to permit passage of the primer flash.

2. A primer tube having as sidewalls a single continuous sheet of flexible material having a portion of its length imperforate and the remainder of its length perforated with a plurality of openings predeterminedly spaced with each other, 55 the said sheet being spirally wound upon itself into a hollow cylinder with the openings of each layer registering with corresponding openings of the remaining layers to form passages for primer blast and with imperforate portions over-lapping said passages and adapted to be ruptured by the primerblashand means forclo'singone end of said cylinder.

3. A primer tube consisting of a single continuous sheet of flexible material spirally wouhd upon itself into layers or laminations, a plurality of said layers being perforated with aligned openings and the remainder of said layers being imperforate and across the aligned openings to form closures therefor, said imperforate portions being adapted to be ruptured by the'priiner blast permitting passage of the primer flash.

4. A primer tube with cylindrical side wall, s'aid wall comprising contiguous layers of a "single sheet of flexible material in successive convolu tions whereby to afford a cross-section of spiral form for the tube, 'a pluralityofpartial perforations in the said wall, said perforationseach com"- prisirig a series of radiallyali'gned perforations in all except at least oneor said layers, said at-leas't one layer being imperforate in the radial line of said aligned perforations whereby to normally block said aligned perforations but yield upon explosion of the primer.

5 EUGENE D. REGAD.

ANDREW T. ANDERSON.

REFERENCES CITED The following references are of record in the 10 file of this patent:

UNITED STATES PATENTS Number Name Date 399,881 Graydon Mar. 19, 1889 15 612,494 Hathway Oct. 18, 1898 19013169 Piccard Mar. 14, 1933 2,327,902 Johnson Aug. 24, 1943 FOREIGN PATENTS 20 Number Country Date 17,443 QratBritaih Dec. 13, 1913 273,792 qermai y "May 6, 1914 382,247 Great Britain 'Oct. 20, 1932

Images