GB651547A - Improvements in or relating to nail-inserting machines - Google Patents

Abstract

651,547. Nailing. BRITISH UNITED SHOE MACHINERY CO., Ltd., ELLIOTT, H. E., and BARTON, G. C. May 29, 1948, No. 14546. [Class 89(iii)] In a nailing machine having means for feeding a workpiece step by step to a positively-operated driver and an abutment against which the workpiece is held by a work support during driving of a nail, means is provided for moving the workpiece first yieldingly towards the abutment and then positively further a predetermined distance and for locking the worksupport against movement away from the abutment while a nail is being driven. In a machine as decribed in Specifications 1494/93 and 4471/03, [both in Class 89], in which the work is supported in a horn carried by a post 15 and is fed by an awl, the horn is raised to prtss the work against a fixed abutment by depression of a treadle 121 which acts through a cam 111 pivoted on a bell-crank lever 107, a lever 97, a slide 33, locking plates 25 and toggle links 21, 19. The locking plates 25 interleaved with clamping plates 35 are mounted between thick end plates 39 within a housing 27, 29. One plate 39 is adjustable by a screw 43 and the other is actuated by an inverted toggle device comprising an arm 53 connected to a rod 47 on the plate 39 by a link 51. The lever 97 first rocks about its rear end 103 which is pivoted to the bellcrank lever 107, and after the work has engaged the fixed abutment rocks about its front end and a cam roll 95 therein raises a lever arm 89 and through an arm 85, a compression spring 81 on a rod 73, a lever 59 and a link 57, actuates the arm 53 so that the plates 25, 35 are locked together just prior to the highest part of the cam 111 becoming operative. The bell-crank lever 107 is controlled by a powerful spring 139 manually adjustable by bevel gears 145, 143 and a screw 141. After the locking of the plates 25, 35, the treadle trips a clutch to cause a nailing operation. To allow feeding of the work by the awl, the toggle 19, 21 is broken by a cam acting through a rod 185 adjustably connected to a bellcrank lever 177, and a link 173. The plates 25, 35 are unlocked for a short period by a cam acting through a rod 69 and a lever 67 on the lever 59, to allow the pressure on the work to be controlled by the spring 139 irrespective of the thickness thereof. The driver which, together with the awl, is mounted in a swinging head is positively operated by a crank pin. To prevent looseness due to wear of the parts, the swinging head carries a plate 189 (not shown) which co-operates with a recess 191 (not shown) in the machine frame.