Patent GB-190613108-A (GB)
Title: Improvements relating to the Breech Mechanism of Ordnance.
Inventor: DAWSON ARTHUR TREVOR
Filed: 1906-06-06
Granted: 1907-06-06
Abstract: 13,108. Dawson, A. T., and Buckham, G. T. June 6. Ordnance breech mechanism.- Relates to breech mechanism of the kind described in Specification No. 5765, A.D. 1901, in which the breech-screw is withdrawn rectilinearly through the carrier ring before it is swung aside. Fig. 3 is an horizontal section of the apparatus, Fig. 4a a vertical section showing the breech-screw withdrawn, and Fig. 5 a sectional end elevation. Fig. 6 is a sectional side elevation through the axispin of the breech-screw carrier. Fig. 8 shows the mechanism for angularly displacing the breechscrew. The breech-screw B is mounted in a swinging carrier C having platforms C<1> for the support of the screw when withdrawn. A cover-plate B<1> is attached to the rear end of the breech-screw by interrupted collars band spigot b<1>, but is prevented from rotating therewith by the casing B', which encloses the rear portion B<5> of a two - part withdrawing - rack and is located between the platforms C<1>. The forward portion B<6> of the rack is formed on the breech-screw B so as to rotate therewith. A "lever-plate" D is mounted in the carrier-ring C by interrupted collars, and engages, when the breech is closed, with an interrupted collar B<2> on the breech-screw. The plate D has an arm d' with a cam-groove d<2> therein, in which a roller c' on a crank c' works, so that, when the latter is rotated, the breech-screw is angularly displaced and unlocked. A cam-groove c‹ formed in the crank c<1> controls the movements of the firing- lock frame H. The gear for rotating the crank c<1> consists of a bevel pinion e<2>, keyed to the axis pin E, the teeth e<3> of which mesh with teeth c<3> on the crank. The pinion e<2> has a specially-formed tooth e<4> and a plain portion e<5>, which, after a certain angular movement sufficient to unlock the breech screw has been performed, engage the corresponding tooth c<4> and plain portion c<5> of the crank c', and lock the latter against further movement, the pinion e<2> being however free to continue its rotation. The pinion e<2> has a second set of teeth e<6>, which, by gearing with the bevel-gear e<7>, rotate the shaft e<8>, extending transversely below the breechscrew, on which is mounted the pinion e9 of the withdrawing-gear. The pinione<9> is formed with a cam-surface e<1o>x. which at the commence-' ment of its rotation acts upon a roller e<12> carried by the cover-plate B', thereby starting the withdrawal of the breech-screw and unseating the obturator. The further rotation of the pinion e9 first engages a'tooth e<10> with the rear portion B<5> of the rack, and then engages the teeth e<11> with the part B<6> of the rack, and completes the withdrawal. The breech mechanism may be operated by hand or by power, and, to enable the change to be made from one method to the other, sliding clutch members E', E<2> are provided at the extremities of the axis-pin E and are connected by a central rod E<3>. The upper member E<1> connects the shaft E with a power-driven pinion (not shown), and the lower member E<2> connects it with the wormwheel i of the hand-gear I. The clutch is controlled by a hand-wheel E<4>, which rotates a nut E<5> on a screw-thread formed on the boss i<2> of the worm-wheel i. A catch i<3> locks the clutch in either position. The handle I<1> of the handwheel I may be slid through the boss P so as to lie beneath the breech when the power operation is resorted to.