Patent GB-688507-A (GB)
Title: Improvements in or relating to wrapping machines
IPC: B65B11/32
Filed: 1951-02-15
Abstract: 688,507. Wrapping-machines. FOR GROVE MACHINERY CO., Ltd., and RUSSELL, A. Dec. 14, 1951 [Feb. 15, 1951], No. 3689/51. Class 94(i) In a machine in which a block of plastic material is lifted with a wrapper into a pocket of a intermittently-rotating wrapping wheel at a receiving station, whereby' the wrapper is folded into U- formation about three sides of the block, and the depending ends of the wrapper are folded against the fourth side as the wheel rotates to move the pocket to a folding station where reciprocating end tuckers form central tucks in the projecting end portions of the wrapper and two pairs of opposed rotary folders are arranged to move inwardly, after the end tuckers have completed their forward movement, to fold the ends of the wrapper over the central tucks, the end tuckers are hinged to a reciprocating carrier and are moved gradually inwards from an open to a partially-closed position during the forward stroke of the carrier, after which they are moved further inwards to a fullyclosed position in which they remain during the return stroke of the carrier until the end folders have completed their inward movement. The machine shown comprises a pocketed wrapping wheel 10, constructed as described in Specification 688,506, which is rotated intermittently about a shaft 11 to move the pockets in succession from a receiving station A to a folding station B and thence to a top pressing station C and discharge station D. A block of plastic material 19 is lifted into the pocket at station A by a member 15 and carries with it a wrapper 20 which is thereby folded into U-formation. The depending end of the wrapper at the right hand side of the block is then folded upwardly by a blade 22, and the other depending end is folded upwardly by a fixed member 23 as the pocket moves to station B. The end tuckers 35 are pivoted at 34 to a carrier 33 mounted on a tube 25 which is slidable in a fixed bracket 24 adjacent station B, the rear end of the tube being coupled by a link 27 to a bellcrank 28 pivoted on a shaft 29 and carrying a follower coacting with a cam 31. The tuckers are urged to a closed position by a compression spring 36, and extensions 37 thereof engage rollers 38 carried by bellcranks 39, each of which is pivoted on a fixed pin 40 and carries a follower 41 coacting with a cam 42 on a shaft 43. During the forward stroke of the carrier 33 the distance between the pivots 34 and the points of contact of the rollers 38 with the extensions 37 increases, so that the tuckers gradually close to the dotted line position, Fig. 2. The shafts 43 support the upper end folders 44 and carry intermeshing gears 45 which also mesh with a gear 46 engaging a rack 47, Fig. 5, which is reciprocated horizontally by a cam 52 operating through a bellcrank 49 and link 48. As soon as the tuckers have completed their forward movement, the cam 52 moves the rack to the left, thereby rotating the shafts 43 to swing the end folders 44 inwardly, and the rollers 41 ride off the high portions of the cams 42 to allow the spring 36 to close the tuckers on to the block. One of the gears 45 meshes with a gear 53, Fig. 1, which meshes with a pair of gears 54 splined to shafts 55 carrying the lower end folders 57. These shafts are coupled together by a crosshead 56 which is reciprocated by a cam 61 operating through a bellcrank 59 and link 58, the arrangement being such that the folders are initially retracted to allow the block and wrapper to move to station B and are then projected into their operative positions where they are swung inwardly by rotation of the shafts 55. The upper end folders 44 are so arranged that in their extreme positions of inward rotation their operative faces 62, Fig. 6, are not quite in contact with the block and do not foul the folders 57. The folders 44 are, however, formed with extensions 63 which press the end folds against the ends of the block as the latter is moved to station C. A pressure plate 64, Fig. 2, is attached to a rod 65 passing through the tube 25 and acted on by a spring 66, and to a further rod 67 slidable in a bracket 68 on the carrier 33 and fitted with nuts 69 which limit its outward movement. The spring 66 holds this plate in engagement with the longitudinal fold 70, Fig. 6, during the tucking and end-folding operations. Specification 565,144 also is referred to in the Provisional Specification.