Patent GB-825572-A (GB)
Title: Improvements relating to screw-driving machines
Inventor: PATTISON WALTER TREHEARN
IPC: B25B23/02
Filed: 1956-10-20
Abstract: 825,572. Screw-driving machines. RUSSELL AUTO-FEED SCREWDRIVERS Ltd. Oct. 17, 1957 [Oct. 20, 1956], No. 32002/56. Class 83 (3). A screw-driving machine in which screws (not shown), from a hopper are fed, through a guide 14, to a nozzle receiving the rotatable and axially-movable screw-driving spindle (not shown), comprises a shoot-plate 10 having a slot 20 to guide the shanks of the screws while the heads are supported by the margins of the shoot-plate bordering on the guide-slot, and a gating-device including arresting and parting- fingers 23, 24, 27 for feeding the screws singly, the parting-finger 23, 27 having a cam-face 30 for feeding a parted screw along the guideslot by engaging its shank at positions adjacent the undersurface of its head and further down the shank, the spaced-engagement positions, assisted by the arresting-finger 24, preventing angular deflection of the screws. As illustrated, the parting-finger is in two parts, the upper element 23 being formed integrally with the body 22 of the escapement and with the arresting-finger 24, and the lower element, spaced from the upper by packing 37, being attached to the upper by screws 35, 36. The escapement may be reciprocated in a guide on the wing-tube 14 or, as illustrated, oscillated about a bolt 25 by a lever 40, 45 which is rocked about a pivot 38 in a bracket 39 depending from a plate 16 attached, as by welding, to the wing-tube. Operation of the lever 40, 45 is effected by moving downwardly the screwdriving spindle, hopper and associated parts, including the lever, the lower end of which contacts a stop on the structure embodying the nozzle, which engages the work. The end 40 of the lever oscillates the escapement in the parting direction by pressing against an operating member 41 on the bolt 25 and connected to the escapement, as by a spring 44 or a friction coupling which permits relative movement between the escapement and member 41 in the event of a screw obstructing the parting- finger. The upper element 23 of the parting- finger operates between the plates 10, 16, and thelower element 27 in a slot 29, 31, in one or both wings 15 of the wing-tube, which may have a baffle located between the wings and movable or removable to afford access to its guidepassage. The arresting finger 24 overlaps the side or rearward end of an enlargement 21 at the end of the slot 20 to permit the screws to fall into the passage of the wing-tube, the screws moving into the enlargement while receiving support under their heads, first from the forward surface 32 of the arresting finger 24, then the corner 33, and lastly the end surface 34 as the finger withdraws through an opening 46 in the wing-tube. Alternatively, the arresting finger 24 may be disposed below the level of the finger element 23. The size of the passage (not shown), above the shoot-plate 10, for the heads of the screws, may be adjustable, as in Specification 825,571. The screwdriving spindle is driven, through a torquelimiting clutch, by an input-spindle encircled by the hopper. Screws from the wing- tube 14 pass through a deflection tube into a delivery tube and thence to the nozzle, the upper end of the deflection tube having a universal joint to accommodate screw-feeding movements of the hopper. Specification 825,574 also is referred to.