GB427041A - Improvements to automatic feeding machinery - Google Patents

Abstract

427,041. Feeding sheets. BACKHOUSE, H. T., 12, Melina Court, St. John's Wood, London. Oct. 26, 1933, Nos. 29692 and 29693. [Class 100 (i)] In an automatic feeding device for feeding sheets one at a time from the top of a pack, there are provided in combination two combers arranged to operate at the rear edge of the top sheet and to comb towards each other to produce humps in the sheet, a pair of lifting suckers arranged to grip the sheet at the humps and to move in a direction substantially perpendicular to the plane of the pack to lift the sheet, means to move the lifting suckers away from one another above the pack and in directions approximately parallel to the rear edge of the pack, so as to stretch the rear portion of the sheet, this action preferably occurring during the lifting movement, together with forwarding suckers which grip the sheet in the region of the stretched portion and are then given a forwarding movement. The lifting suckers 11, Fig. 1, are carried by rods adjustably supported on shafts 13 rotatably mounted in bell-cranks 9, Fig. 2, and having a depending arm 15 and roller 16. The suckers receive their lifting movement from a cam 6 and at the same time are moved outwards relatively to the sheet to straighten out the latter by the rollers 16 engaging stationary cams 17. The arms 9 also carry rollers 18 which normally rest on the top of the pile 20 and limit the extent of the humps 21 produced by the rotatable combers 22. The latter are mounted in bellcranks similar to the bell-cranks 9 and operated by cams and returned by springs. The mechanism for preventing a second sheet from rising with the top sheet comprises adjustable nozzles 71 also mounted in bell-cranks operated by cams and springs ; each nozzle is in the form of a foot, intermittently supplied with compressed air, and guided by means of a cam groove so as to be moved backwards clear of the pile and then returned between the pile and the lifted sheet and lowered on to the pile. The forwarding suckers 23 are adjustably secured by tubes 24 to a shaft 26 and are oscillated thereby through a cam which engages a roller carried by linkage connected to the shaft 26, and the tubes 24 are made so long that only a small change of height of the suckers occurs during their oscillation. The tubes 24 may alternatively be attached to levers which are pivoted to oscillating arms, the levers carrying extensions sliding in contact with a fixed shaft, and the levers may be curved so that as the suckers drop towards the paper the body of the lever drops an equal amount thus ensuring that the angle of the axis of the sucker to the paper remains constant. The various mechanisms act near the rear edge of the sheets and to accommodate sheets of different widths, they are mounted on shafts extending across the machine along which they may be adjusted. A third intermediate set of lifting and/or forwarding mechanisms may be arranged between the two outside sets shown and the stretching of the sheet is then effected by the outward movement of the two outside lifting suckers. Alternatively, when two lifting suckers are used, only one may be caused to move away from the other. In addition, the forwarding suckers may be given an initial backward movement before moving forward, and the suckers may be carried on horizontal sliding rods, the movement of which is effected by cams engaging the ends of the rods. Specifications 8796 /11, [Class 100 (i)], and 399,209 are referred to.