US2366758A - Firing mechanism - Google Patents

Description

w. SUMMERBELL 2,366,758

FIRING MECHANISM Filed July 16, 1942 2 Sheets-Sheet 1 Fig.1

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Jan 9, 1945. w, SUMMERBELL 2,366,758

FIRING MECHANISM Filed July 16, 1942 2 Sheets-Sheet 2 mlli am 51.1mm 21'']: E11

@XM MW Patented Jan. 9, 1945 were UNITED STATES PATENT OFFICE 2,366,758 FIRING MECHANISM William Summerbell, Washington, D. 0. Application July 16, i942, Serial No. 451,192

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) 8 Claims.

This invention relates to a. percussive firing mechanism and more particularly to such a mechanism for a breech loading gun of the separate loading type, wherein a primer cartridge is fired through a passage in the obturator to ignite the main charge.

"It is an object of this invention to provide an improved firing mechanism of the type in which a single continuous pull of the lanyard serves to tension the firing pin spring and to release-the same to drive the firing pin to firing position.

It is a further object to provide a firing mechanism in which the firing pin spring is rendered inoperative in the later part of the firing stroke to enable the firing pin to move to firing position under its own inertia and to provide for immediate retraction of the firing pin sufficient to clear the primer cartridge.

An additional object is to provide improved means of securing a primer cartridge to the firing mechanism and to provide for automatic control of, the headspacing thereof thus improving the certainty of firing.

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 drawingsin which:

Figure l is a top plan view of the firing mechanism and a portion of thebreech block.

Figure 2 is a rear end elevational view correspondin to Figure 1.

Figure 3 is a horizontal longitudinal sectional view on the line 3-3 of Figure 2.

Figure 4 is a front elevational view of a part of the firing mechanism.

Figure 5 is a vertical longitudinal sectional View of the pull rod and tripper mechanism taken on the line 55 of Figure 3.

Figure 6 is a longitudinal sectional view of the firing pin sleeve.

Figure '7 is an end elevational view corresponding to Figure 6.

Figure 8 is a longitudinal sectional view of the spring stop collar.

Figure 9 is a partial horizontal longitudinal sectional view showing the tripper and sear'in a retracted position taken in the same plane as Figure 3.

Figure 10 is a partial longitudinal sectional view in the same plane as Figure 3 showing a modified firing pin retracting means.

Referring to the drawings by characters of reference there is shown a portion I of an obturator breech mechanism of conventional form. The member 1 comprises a chamber defining member 2 housing a primer cartridge 3 and an axial bore l leading to the powder chamber of the weapon. The member I also includes a rearwardly opening bore 5 coaxial with the member 2' and provided with internal threads 6 for the reception of the firing mechanism.

Broadly the firing mechanism comprises an ex.- ternally threaded block 1 adapted to screw into the bore 5 and means to secure thereto the primer cartridge 3 in axial alignment with the chamber in the member 2. A firing mechanism housing 8 is secured to the rear end of the block 7 and houses the firing pin 9, firing pin sprin H1, tripper ll, pull rod [2 and associated parts to be described in more detail later. A retainer I3 is provided to secure the firing mechanism within th housing and journals are provided on the housing to support the trigger arm M which is provided with means to engage the pull rod for actuation of the firing mechanism on pulling a lanyard attached to the eye I5. The housing is further provided with a radially slidable, spring restrained latch l6 adapted to engage in the teeth of a ratchet I! secured to the rear face of the member I for releasablyretaining the firing mechanism in the bore.

Referring to the drawings in more detail Figure 4 shows a front elevational View of the primer holder l8 into which the primer cartridge may be inserted from the side and secured by engagement of the extractor groove with the lip is;

From an inspection of Figure 3 it will be seen that the firing pin guide 20 has a limited capacity for axial movement in the block I and that the firing pin spring 10 through the medium of the stop collar 2| normally urges the guide 28 forwardly into a position in which the primer cartridge is firmly gripped "by engagement between the lip l9 of the primer holder and the front face of the firing pin guide 28. This engagement prevents dropping or displacement of the primer cartridge prior to insertion in the chamber and insures that the headspacing of the primer cartridge'will be maintained correct for insuring 'eflicient ignition. v

I The firing pin 9 is threadably secured to the firing pin sleeve' 22, shown'in detail in Figures 6 and '7, and the front face of the head 23 of the firing pin is engaged by the rear face of the inner flange 24 of the retracting collar 25. A stop collar 2i is slidable on the firing pin and has legs 26 projectin 'through the-cut out portions 21 of the sleeve 22. The firing pin spring I is engaged between the rear face of the spring stop collar 2! and the front face of the outer flange 28 of the retracting collar 25. A retainer it has a portion 29 of reduced diameter extending forwardly into the housing and is provided on the forward end thereof with a pair of opposed locking ears 30. In assembly the retainer is inserted into the end of the housing, the cars 30 passing through cut away openings 3|, pressed forwardly againstthe resistance of the firing pin spring, and given a quarter turn to bring the cars 30 into alignment with the partially cut out seats 32 in th housing in which it is. held by the firing pin spring. Disassembly is effected by a reversal of the above procedure. The'firing pin retracting device functions generally in the same manner as that shown in my prior Patent No. 2,245,621. Briefly the sleeve 22 is moved rearwardly by the engagement of a tripper H with the flange 33 surrounding the rear end of the sleeve. As the sleeve is moved rearwardly it carries with it the stop collar 2! and tensions the spring l0. Upon release ofthe sleeve from the tripper the firing pin, sleeve, and stop collar are impelled forwardly by the spring until the legs 26 of the spring stop collar contact the rear face of the firing pin guide 20. The sleeve and firing pin continue due to their own inertia and the firing pin forceably engages the primer. However, as the head 23 of the firing pin engages the inner flange 24' of the retracting collar, the collar will be carried forward by the firing pin during its latter phase of motion and will serve to place tension on the firing pin spring tending to withdraw the pin from the primer and return it to the normal, retracted position in which it is shown in Figure 3, and in which it offers no obstruction to insertion or removal of the primer cartridges.

The tripper II, as has been mentioned above, engages the flange 33 in tensioning the spring. The tripper is pivotably mounted in the bifurcated end of the pull rod H! which i slidable axially in the bore 34 and carries on its exposed end the button 35 engaging the tripper pin 36 on the trigger arm [4. A bushing 31 is slidable on the pull rod and is provided on its upper side with a'slot 38 of sufficient width to allow the finger 39 of the tripper H to swing therethrough. A pull rod spring 40 is confined on the pull rod between the bushing 31 and the end of the firing mechanism housing serving to yieldingly maintain the pull rod within the housing and to hold the bushing 31 as far to the right in Figure 3 as it may go. It will be noted that the foot 4| of the tripper II is of greater width than the finger 39, see Figure 5, providing shoulders 42 which engage the front face of the bushing and will retract the bushing slightly as shown in Figure 9 when the tripperis rocked in either direction. Thus the action of the spring against the bushing constantly urges the finger of the tripper into flange engaging position. The forward end of the bore 34 has a portion 43 of enlarged diameter and when the pull rod is drawn to the rear by the tripper the foot 4! of the tripper engages the shoulder 44 at the transition zone between the two diameters of boreand forces the finger 39v out of engagement with the flange 33 on the firing pin sleeve at the time when the firing pin spring is fully tensioned.

It will be seen from the foregoing that a Single operation of the trigger results in carrying the firing pin to the rear and tensioning the firing pin spring in which position the finger is released by the camming action of the shoulder upon the tripper foot and the firing pin is driven forwardly to initiate the primer. Upon completion of the forward stroke the firing spring will have been retensioned to an extent sufficient to withdraw the firing pin to a safe retracted position.

Figure 10 shOWS a modified form of the invention in which a separate spring is utilized to effect retraction of the firing pin. In this modification a firing pin 45 is threadably supported in the firing pin sleeve 22a but does not necessarily extend rearwardly therewithin. Slidable on the firing pin and retained thereon by a nut 46 is a bushing 41 which is normally maintained in an extended position by a spring 48 engaged between the flange on the bushing and the front face of the sleeve 22a. A rearwardly facing shoulder 49 is provided in coaxial relation to the passage through the firing pin guide 20a and serves to engage the bushing when the firing pin is driven forward under its own momentum in the last phase of its firing stroke after the stop collar 26a has contacted the guide 20a. When the momentum has been absorbed by impact with the primer the compressed retracting spring 48 will extend itself and retract the firing pin. In other respects the modified form functions as described above.

As this firing mechanism is intended to be capable of functioning with equal facility for guns, howitzers, or mortars the trigger arm has been designed to permit operation either by pulling the lanyard to one side or in a generally rearward direction. Firing mechanisms which require a rearward pull are highly inconvenient at the high angles of elevation employed with howitzers and mortars. It will be appreciated that the firing mechanism shown will allow the gun crews to take advantage of any cover which may be available without interfering with efficient operation of the firing mechanism.

I claim:

1. In a firing mechanism, a pull rod having a bifurcated end, a tripper pivoted in said end, a spring encircling said pull rod and opposing rearward movement thereof, and a bushing surrounding the pull rod engaged by the spring to bias said tripper to a predetermined angular position with respect to said pull rod.

2. In a firing mechanism, a pull rod, a bifurcated end on said pull rod, a tripper comprising a finger pivoted in the bifurcated end of said pull rod and having a foot of greater width than said finger forming a continuation thereof beyond the pivotal point of said finger, a bushing slidable on said pull rod and having a slot to allow said finger to oscillate therethrough, means on said bushing engaging the foot on said tripper, and spring means engaging said bushing tending to move the same toward said tripper.

3. In a firing mechanism, a pull rod, an enlarged bifurcated end providing arms on said pull rod, a pivot pin spanning the arms of said pull rod, a tripper comprising a finger received be tween the arms of said pull rod and oscillatable about said pivot, a bushing slidable on the said pull rod and continuing over the bifurcated end, and having a slot therein through which said fin- 'ger is oscillatable, a. foot on said tripper of greater width than said finger and engageable with the end of said bushing when said tripper is oscillated, and a spring encircling said pull rod tend- 4. In a firing mechanism, a breech block, a stationary primer holder in the block and having a side opening for insertion of a primer cartridge and a lip for engagement with the groove in the primer cartridge, a firing pin guide slidably mounted in said holder, a firing pin, a firing pin sleeve, a stop collar surrounding the firing pin within the sleeve and having extensions extending through said sleeve into engagement with the rear face of the firing pin guide to hold said guide in engagement with the primer cartridge, a spring surrounding the firing pin and normally urging said stop collar and pin forwardly, means for moving said firing pin rearward against the pressure of said spring, and means for releasing said pin at an appropriate point in its rearward movement.

5. In a firing mechanism, a breech block, a stationary primer holder in said block and having a side opening for insertion of a primer cartridge and a lip for engagement with the groove in the primer cartridge, a firing pin guide slidably mounted in said holder, a firing pin, a firing pin sleeve having a sear-engaging portion on its periphery adjacent its rear end, a stop collarwithin the sleeve and surrounding the firing in and having forward extensions extending through the firing pin sleeve into engagement with the face of the firing pin guide to hold said guide in engagement with the primer cartridge, a spring surrounding the firing pin and urging the collar against the guide, a pull rod, and means for urging it-normally forward, a sear pivoted in said pull rod and normally engaging the sear-engag-' ing portion of said sleeve, and means for disengaging the sear from said sleeve portion at a predetermined point in the rearward movement of the pull rod.

6. In a firing mechanism, a pull rod, a tripper pivoted to one end of said rod, a spring encircling said pull rod and opposing rearward movement thereof, and a bushing surrounding a portion of said pull rod engaged by the spring to bias said tripper to a predetermined angular position with respect to said pull rod.

7. In a firing mechanism, a pull rod, a tripper comprising a finger and foot portions pivoted to one end of said pull rod, a bushing slidable on said pull rod and having a slot to allow said finger to oscillate therethrough, means on said tripper engaging one end ofsaid bushing, and spring means engaging the other end of said bushing tending to move the same toward said tripper.

8. In a firing mechanism, a pull rod, a tripper comprising a finger pivoted to one end of said pull rod and having a foot of greater width than .said finger forming a continuation thereof beyond the pivotal point of said finger, a bushing slidable on said pull rod and having a slot to allow said finger to oscillate therethrough, means on said bushing engaging the foot on said tripper and spring means engaging said bushing tending to move the'same toward said tripper.

WILLIAM SUMMERBELL.

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