US2494603A - Firing pin - Google Patents

Description

5.. 17, 1950 R. A. WYKOFF, JR

FIRING PIN Filed Oct. 1 1946 mvN v. I I a i 1 Patented Jan. 17, 1950 v UNITED sures Granted under the act. March- 3'). 1883; as

amended; Apnili 311;; 19283 351]: Q.- GB 7557');

The invention described herein may be manu factured and used by or fort-he- Gbvernmenitfor governmentalpurposes; without the" payment to mepFaIIyrOyaItythereon:

The invention relates to firing pins for r us }in*. gun actions having reciprocating breeclr closing "boltsand a firing pinreciprocably mounted i'nr the bolt. It is particularly useful in thel3rown ingmachine gun as now used in the U S; Hriny, illustrations of which may be found the patents to Browning; 15,298,022; 1 ',628' 2}26; and others:

In these guns great difiiculty has been BEE- perienced because of the breakage of firing pin p0ints-,=- and it has been a practiceto carry a; number of spare parts including one or: more. spare firing pins; the firing pins being; quichly attached to a pin= extension which is; mounted i'n the bolt" and is itself detachable from; fireball;

These. guns are embodied in: readily: portable form toa large extent,- and incidentto field service, particularly in jungle warfare is die sirable to reduce impedimenta, because spare parts: have become lost and} failuresoi? firing? pins? have resulted inmany instances-in: putting guns; outof actionpermanently because at lack; oi? aireplacement firing pini It is therefore an; imiportant aim of this invention: to minimize. the: need for carrying spare firing pins; enabling.- the: production of a reversable' firing.- pinlwhiclr mast be readily installed in a firing. pin: extension as. proximately in: the same, way as. in. the; present? firing: pim extension; excepting: that a; slight;- en largement ofi the latter isinvolved;

Elias-heretofore been recognized as desirable tmutilizeareversible firing pin, but retainingg'the advantages of quick removal: and: re emems and maintenance of the correct. tolerances and; weights in the partsiha-ve presented a. which was; not overcome. It..-is:thereiore Bm'tant aim of thepresent invention to present tepinr which corresponds very closely tothepim in current use and: whichmay belquickly removed; and reversed or replacedby men in. the. field, principally by manual operations.

A. further aim is to present'a firing pin assemfilg which. will preserve the rugged characteristics necessary" in a gun action which is subjected tothe severe use and some abuse in the field.

It alsoan aim to minimize the number of parts required" and topreserve thesimplicity of machiningand manual assembl y and replacermerit? operations" involved the improved devicea accompanying drawings; wherein-:

Figure 1 is a longitudinat sectional View of? the bolt and a portion of the barrel extension of? a' current modelof Browning machine gun of .50ca-I; as used in the'U-i S.- Army;

179 Figure 2" a" fragmentary top View of the firing pirr extension and" a' part of thefiring pin: bordy engagedtherein; 1

Figure 3 a front end elevation of" the firing pirr extension;-

12s Figure is a sectionof the firingpin and firing' pin extension, on the line 44* ofiFi'gure 1 Figure 5'' is a; fragmentary-* top view of middle partsof'thefiring pinbody'; Figured; is an endview' of a firing pin hodt 2m in position for insertion in the firing piirexten Figure? is'a fragmentary vertical longitudinal sectional View of"the-*forward part of a firing pimextensiom modified; and a: modification of the firing? pin body? for use therewitli' Figure-8 is a similar view showing-means for holding the-rfiring-*- pin body against IOtafiOH irr theifiringspiirextension;'

Figure: 9115 a View of" the firing pinbod y from Referring more particularly to the drawings; there illustrated approximately f-ullsize; that lioit N1 of" the Browning g-un mentioned; in bat relation to the barrel M, the latter-'- being fixedih the barrel; extension I2 as heretofore,

and aifithis battery position of the parts;- abolt lock- W (:Fi'gure- 1 locks: the bolt to the barrel? extensions A sear- I is shown mounted as usual at*- rear end of the" bolt, and a coeking-1everat I5 also;- haiving the usual structureand functiom with the firing pin extension; the rearpart-oft is i entical" with the prior-device excepting:

V foraaslight increasein diameter: 1

The:- foregoing named parts of the structure 45% are well understood and their functionsremain unchanged, in consequence ofwhiehthey 'wiil not be described in greater detail pin assembly-in the present instancev comprises atubular firing pin extension lawman 505 isi practically: identical; in ihrm to the pIiOFIE- pfacedi element" with theexeeption oi the formai oi: thesfonwardi end: thereof; extensiom engaged in a longitudinal main bore l l the halt-g, somewhat; larger in diameterthan the bore fisr the: prior fi'ring pin ext'ensiong the result" ing that the increased weight in my improved device is compensated for by removal of material in the bolt as far as mass in the bolt is concerned. The firing pin extension has at the rear the usual vertical longitudinal diametrical slot 18 receiving therein a slidable sear stop pin I9 by which the pin extension is held against roa tation in the bolt. This pin also serves as a seat for the firing pin spring 26, which is somewhat larger in diameter than the prior spring, the firing pin extension being correctly bored to permit free action of this spring therein. The larger 4 the collar 25. A semicircular retaining flange 39 is thus formed in the firing pin extension forwardly of channel 35.

A leaf spring 31 is set in a longitudinal slot 38 formed through the wall of the pin extension, the spring being shaped so as to press downwardly and engage upon the flat .28 of collar 25 when properly positioned in the firing pin extension as will be obvious from inspection of Figure 1. The forward extremity of the spring 31 is bent radially outwardly to permit one of the collars 25 to cam lit ioutwardly when the firing pin is pressed longispring has an interior diameter which is adapted J to receive freely therein a rearwardly directed firing pin of the same diameter as the prior firing pin, as will be described. Contrary to prior practice, instead of a single seat pin heretofore set across the forward end of the firing pin extentudinally into the pin extension with the part 26 uppermost.

. By the formation of the parts as described, it will be seen that assembly of the pin 22 with extension l6 may be effected by sliding movement .of pin 22 into the forward end of the firing pin sion as a seat for the forward end of the spring,

two pins 2| are set across the firing pin exten-- sion a distance short of its forward end, the pins being spaced apart a distance-slightl more than the diameter of the principal shank portion of the conventional firing pin. The firings-pin extension in this instance is also slightly longer.

than the prior displaced element.

A firing pin body 22 is shown (Figures 1, 4, 5 and 6), having identical end portions 29 joined by a somewhat thickened middle shank 23 centrally of which a circular stop flange 24 is formed integrally thereon corresponding to a similar flange heretofore used on the conventional firing. pin and of a diameter slightly less than the diameter of the main bore [1. The forward end of the extension l6 and the two main faces of the flange 24 are planiform and normal to the axis of the bore l1. Spaced from the flange 24 there are integrally formed on the middle shank 23 collars 25 each comprising a semicircular part 26 of relatively large diameter and a second semicircular part 21 of less diameter than part 26. Flats 28 are formed on parts 21, as clearly shown at Figures 5 and 6. End portions 29 which may be circular in cross section or substantially rectangular as has been a more recent practice extend from collars 25. Each end portion 29 has at its outer part a reduced cylindrical shank 3|) and cylindrical firing pin point 3| of conventional size and form for engagement through the pressure plate 32 at the forward end of the bolt. Points 38 project beyond plate 32 when the firing pin assembly is at the forward limit of its movementin the bolt. The bolt has a reduced forward bore 33 adapted to receive the firing pin proper slidably therein, this bore being enlarged around the part 30 of the firing pin and reduced adjacent the faceof the bolt to fit snugly around the firing pin point 3i as heretofore, Limitation of movement of the firing pin is effected as heretofore byextending bore l1 forwardly so that when the firing pin assembly is engaged in the bore and the sear depressed, the forward collar 25 will engage the forward end of the bore and limit the forward motion of the pin with its point projected into the T-slot 34 of the bolt.

Av circular channel 35 is cut in the interior of pin extension [6 a distance rearwardly from its forward end l6 a distance equal to the spacing between the flange 24 and one of the collars-25. Forwardly of this channel, the upper half of the pinextension I6 is cut away to an equal radius to form a semicircular entrance channel 36 flush with the bottom of the channel 35, the radius of the channels 35 and 36 is slightly reater than the radius of the semicircular lower part 26 of extension, the spring 31 being cammed outwardly by portion 26, Figure 6. When the rearward collar 25 has entered sufficiently to align with the channel 35, the firing pin body is then "rotated 180 so as to bring the semicircularpart 26 into the channel part 35 behind flange 39 so that flat 28 is engaged by spring 31. Accidental rotation of the firing pin 22 from proper locked position relatively to extension I6 and its escape from the firing pin extension are thereby prevented.

If desired, a bevel 26' may be formed as clearly shown at Figure 6, to facilitate passage of thecollar past the tongue of the spring 31.

The firing pin assembly comprising body 22 and extension I6, may then be introduced into the bolt in conventional manner and the sear stop pin cocking lever and other parts replaced as heretofore.

It is apparent that either end of the firing pin body may be extended forwardly from the firing pin extension without changing the function of; the pin and that a quick manual removal and manual replacement of the firing pin body in the firing pin extension is made possible with a minimum of effort.

.In Figure '7 there is illustrated a modification: of the invention in which the forward part of thefiring pin extension I6 is a simple tubular part;

with a flush planiform forward end, its bore being slightly enlarged and interiorly threaded. The

firing pin body in this case has identical end portions as before, but in place of each collar 25, an;

exteriorly threaded concentric boss 40 is integrally formed at the base of each firing pin proper 29. Between and joining the bosses 40, the flange 24' is formed, corresponding to the flange 24, and

the length of the firing pin body from the flange.

24 to the extremity of each point portion should be approximately the same as the distance.be.-

tween flange 24 and point 3| in the first described.

The main bore 11' in the bolt in this in-- device. stance is somewhat shorter than the bore I1, and

is counterbored forwardly as at 4| to accommo-' date with clearance the forwardly located boss 40 of the device, and the shoulder 42 thus provided should engage the flange 24 when the firing pin has its point in firing position as in Figure 1.

within the bore in extension [6' when'body 22 is unscrewed from the extension and thus prevent the possibility of its loss.

In Figures 8 and 9 the construction is the same as in Figure 7, but the flange 24a corresponding to the flange 24 is peripherally notched as at 42' so that the firing pin may be readily rotated by a tool engaged in one or more of the notches, and on the end of the firing pin extension spring pressed means is provided, arranged to engage in one or more of the notches as the firing pin is screwed into place, and so yieldingl hold the firing pin against rotation in the firing pin extension. In the present instance the spring device comprises a simple bullet latch 43, although other equivalent devices suitable for the purpose may be substituted as discretion may dictate.

While I have disclosed the invention with particularity in its best form known to me, it will nevertheless be understood that this is purely exemplary and that changes in construction, substitution of materials and equivalents, mechanical or otherwise, may be made without departing from the spirit of the invention set forth in the appended claims.

I claim:

1. An elongated firing pin terminating at one end in a firing pin point, said =pin having, remote from said point, a radial flange comprising two coplanar semi-circular portions of difierent radii.

2. An elongated firing pin of uniform cross-section tapering to a point at one end, said pin having first and second axially spaced flanges remote from said point, said first flange comprising two coplanar semi-circular portions of different radii, said second flange being circular and of a radius greater than said first two radii.

3. A firing pin as recited in claim 2, said first flange having its semi-circular portion of smaller radius bounded by a chord at right angles to the center radius of said portion.

4. In a firing pin assembly, a tubular firing pin extension having an internal peripheral channel spaced a predetermined distance from one end thereof, the flange thus formed between said channel and said one end being removed throughout of arc, a firing pin tapering to a point at one end and having a first radial flange remote from said one end, said flange comprising two semi-circular portions of difierent radii, one said portion having a radius equal to the internal radius of said extension, the other said portion having a radius equal to that of said channel, whereby said extension and pin may be united by axiall inserting said pin into the channeled end of said extension, followed by a 180 relative rotation of said pin and extension from a first to a second position.

5. An assembly as recited in claim 4, said firing pin having a point at each end, said radial flange being midway between said ends, whereby when said pin and extension are assembled, one half of said pin is housed within said assembly.

6. An assembly as recited in claim 4, said pin having a second radial flange spaced axially from said first flange and constructed and arranged to abut the adjacent end of said extension when said pin and extension are assembled.

7. An assembly as recited in claim 4, said semicircular flange portion of smaller radius being truncated along a chord thereof and spring means carried by said extension and adapted to engage said truncated portion to yieldingly maintain said pin in said second position of rotational adjustment relatively to said extension.

ROY A. WYKOFF, JR.

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

UNITED STATES PATENTS Number Name Date 1,284,478 Shepard Nov. 12, 1918 1,313,912 Reising Aug. 26, 1919 1,696,537 Kewish Dec. 25, 1928 1,993,887 Kewish Mar. 12, 1935 2,069,887 Laudensack Feb. 9, 1937

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