Patent GB-190712631-A (GB)
Title: Improvements in the Firing Mechanism of Automatic Guns.
Inventor: DAWSON ARTHUR TREVOR
Filed: 1907-05-31
Granted: 1908-05-28
Abstract: 12,631. Dawson, A. T., and Buckham, G. T. May 31. Machine guns.-Relates to the firing-mechanism of automatic guns, particularly those of riflecalibre pattern .provided either with a rifle butt for firing from the shoulder or with a handle block for firing from a tripod &c. mounting. The mechanism is of the type which can be arranged for firing automatically, for firing single shots, or in a safety position. Fig. 1 shows the arrangement for a gun provided with a rifle butt and a pull trigger. The trigger lever H<1> is pivoted at h and acts upon the sliding trigger-plate H. The trigger L is pivoted on a transverse pin l forming part of an indicator M<1>, and is slotted to receive the tripping-piece M, which is provided with two arms m<1>, m<3> and is adapted to move with the indicator M<1>. The trigger-pawl N is pivoted to the lever H<1> at h<2>, and has a nose-piece n<3>, a hook n<2> to engage a lug l<2> on the trigger, and a finger n<4> which is engaged by a safety trigger 0 pivoted to the trigger L. In operation, the indicator is set in the position x for firing single shots. The arm m<1> of the tripping-piece M is thus brought behind the nose piece n<3> and, on the trigger being pulled, the parts 0, L are first brought into line, the lever H' is then drawn backwards, and the hook n<2> is released from the lug l<2> by the arm m<1> engaging the nose-piece n<3>. When the triggers are released, the hook n<2> re-engages the lug l<2>, but, if this reengagement is not completely effected, at the next pull of the trigger the arm o<2> of the safety-trigger 0 will engage the finger n' and bring the parts n<2>, l<2> into complete engagement. For automatic firing, the indicator is turned to the position y. The arm m<2> then engages the pawl N and holds the hook n<2> and lug l<2> in engagement, so that the lever H<1> and plate H cannot return to their original position until the trigger is released. For safety, the indicator is moved to the position z. The arm m<1> then engages the base of the nosepiece n<3> and prevents movement of the lever H<1>. Fig. 2 shows the arrangement for a gun provided with a handle block P and a hinged push-trigger Q. The lever H<1> is pivoted at h<3>, and the pawl N is pivoted thereto at n<6> and comprises an arm n<4> engaging the trigger and an arm n<5> which cooperates with the tripping-piece M. The usual safety-catch R is provided. The positions x, y, z are respectively for firing single shots, firing automatically, and safety as before. In the position x, the piece M engages the arm n<5> and raises the arm n<4> to a position opposite an opening q in the trigger, so that the trigger must return before a second shot is fired. In the position y, the piece M is clear of the arm n<5>, and in the position z the piece M lies against the arm n<5>. Fig. 3 shows a modified arrangement in which the lever H<1> is acted upon by a push trigger S, the plate H being arranged at the bottom of the casing. The pawl N has an arm n<8> engaging a flange h<x> on the plate H, and an arm n<7> co-operating with the tripping- piece M which moves in a plane perpendicular to that of the lever H<1>.