Patent GB-470257-A (GB)
Title: Improvements in or relating to apparatus for the manufacture of folding-box blanks
IPC: B31B17/00
Filed: 1936-02-07
Abstract: 470,257. Attaching spiked strips in the manufacture of boxes. KRUSE, H. H. J. Feb. 7, 1936, Nos. 3839 and 5930. [Class 89 (iii)] In the manufacture of folding box blanks, comprising a plurality of panels held together by two metal strips, each with an upstanding flange along one edge and a row of teeth along the other, a set of panels for one blank are brought into register with a pair of toothed strips and forced by a press into preliminary engagement with the strip teeth, all the teeth to be driven into at least one panel edge being driven simultaneously, and the partly assembled blank is fed between loaded rollers, the tread of which is interrupted to receive the teeth so that the teeth are pressed fully home into the panels, whereupon the projecting points of the teeth are finally clenched. The machine includes a bed plate 30, Figs. 1, 2 and 4, on which is a longitudinal member 31 and a parallel transversely slidable member 31a connected by screws 32 engaging holes in member 31a and journalled in member 31 and an upright 33. Each member 31, 31a has a horizontal flange 34 to support the upper run of an endless roller chain 35 carried on sprockets 36, 37 and serving as conveyer for the toothed strips. Sprocket 36 is keyed to shaft 38 driven by gearing including a clutch Cl, Fig. 6, comprising a drum 40, Fig. 19, on shaft 38 and driven from a continuously running motor. The inner surface of the drum has a number of keyways 41, and the clutch driven member 44 has a semicircular member 46 which when the clutch is disengaged fits in a keyway 47 in member 44. Member 46 carries a radial lever 48, Fig. 6, which when the clutch is disengaged is held by a strut 54 from moving under the action of a spring away from a projection 49 on flange 44<1>. When a solenoid 57 is energized strut 54 is lifted from the path of lever 48 and member 46 is moved into keyway 41 to engage the clutch. A pinion 51 integral with member 44 drives through gear 52 a cam 53 which holds the strut 54 out of the path of lever 48 until after 8 revolutions, during which time the conveyer chains make one complete circuit, projection 541 on strut 54 moves into cam notch 53<1>, engages lever 48 and disengages the clutch. Each chain has two continuous series of bearing blocks 60, 60<1> separated by spring clips 61, spaced at equal intervals and level in a transverse direction on the two .chains. Each movement of the chains stops with a clip 61 at the entry end of the upper runs of the chains. A clip 61 automatically grips the leading end of a strip 5 as it is fed by continuously running friction rollers 203 into the clip and releases it when the chain has carried forward the strips to blank forming position when a lever on the spring clip is tripped by a member set between flanges 34. Press beams 70, 70a movable in guides 71 are disposed above and parallel to members 31, 31a and are operated in unison by connecting rods 72 actuated by cranks 73 keyed to rocking shafts 74, 75, coupled together by a coupling rod 76 and cranks 77. The shaft 74 is driven through a clutch C4 similar to clutch C1 from an electric motor. The box panels P are stacked in rows of hoppers alongside member 31 and having a common floor 101 with two slots 103, and a common front wall 102 raised from the floor to leave a gap 104 slightly greater than the thickness of one box panel. The four hoppers are formed by end walls 105, 105<1> and division walls 106, a shallow gap 107 being left between the bottom of the walls and the floor 101. Pawls 128 pivoted to the hopper walls engage behind the lowest panels of each stack. A feed plate 100 is moved to-and-fro across the hopper floors by chains 108 connected to the plate by lugs 109 in the slots 103. The chains are actuated by sprockets 110 on an oscillating shaft 111 driven from a sprocket 113 actuated from a crank 117 driven through the medium of a clutch C3, similar to clutch C1, from a continuously running motor 123. A vertically movable table 130, 130a guided by bolts 132 passing through slots 133 in frame members 31, 31a supports in its raised position the panels being fed from the hoppers. The table is actuated from coupled rocking shafts 136, 137, shaft 137 carrying a friction brake 140, 141 and shaft 136 being driven from an eccentric operated through a clutch C2 from a motor. This motor also drives through suitable gearing two pairs of rolling-in rollers 182, 183 and two pairs of clenching rollers 180, 181, the upper rollers of each pair being spring-loaded to bear against the lower ones. The upper rollers 183 have circumferential grooves 183<1> to enable the strip teeth to be driven fully home without risk of crumpling. Each press beam 70, 70a has a movable stop in the form of a bolt 190, Fig. 14, slidable in a vertical slot 191. The bottom of the bolt is parallel with the upper surface of the conveyer blocks 60 and aligns with the flange 51 of the box binding strip as it is drawn under the beam by the spring clips 61. The strips are located transversely by members 192, 193. The bottom of each bolt is bevelled at 194. The top has a lug 195 to prevent the bolt dropping through the beam. The foot of each bolt has an abutment 202 to be engaged by the under surface of the beam. A lever 196 is pivoted to each beam, its upper end having a notch 198 engaging under the influence of spring 200 under lug 195 to hold the bolt raised in the beam. When a pair of toothed strips are fed into the machine and carried by rollers 203 into spring clips 61, arms 214, Fig. 20, are raised and contacts 213 closed. Current flows in circuit I, since contacts 222 are arranged to be closed at the beginning of an operation when the press beams are in their raised position, and solenoid 57 is energized to engage clutch C1 to set the conveyer chain in motion and carry the strips forward, arms 214 dropping behind them to re-open contacts 213. After 4 revolutions of conveyer drive shaft 38 and one-half of a circuit of the chain cam 53 disengages clutch C1 and spring clips 61 opened by tripping pins release the strips just before they abut against the bevelled edges 194 of stop bolts 190. Return of strut 54 to position shown in Fig. 20 closes contacts 212 just before cam 210 opens contacts 211 and current flows momentarily in circuit II energizing solenoid 156 to engage clutch C2 and raise the panel supporting table, brake 140, 141 holding it in raised position. Rotation of table drive shaft 157 causes cam 215 momentarily to close contacts 216 and complete circuit III energizing solenoid 124 and engaging panel feed clutch C3 for one revolution of shaft 118, so that the panel feed plate moves across the floor of the hoppers feeding the bottom panel of each stack and returns slipping under the stacks, backward movement of which is prevented by pawls. Shortly before shaft 118 comes to rest, cam 217 momentarily closes contacts 218 and current flows in circuit IV energizing solenoid 92 to engage beam drive clutch C4. Press beams then descend in unison, the bolts not descending until the beams engage abutments 202 since their bevelled faces rest on the ends of the strips. When the bolts descend they position the strips by their bevelled faces in an exact longitudinal position. The beams then force the teeth into the panels, their thrust being taken by the frame members through the bearing blocks and chains, and the table 130, 130a being forced downwards (brake 140, 141 slipping). As the beam rises again, stop bolts 190 supported by levers 196 are raised above the strips 5. As a new pair of strips is fed into the machine, the partly assembled blank is fed outwardly between rollers 182, 183 and 180, 181, engaging as it leaves lower arm 199 of levers 196 to allow the stop bolts 190 to fall again. Specification 449,094 is referred to. According to the first Provisional Specification, the strip conveyers may control contacts which close the press beam control circuit only when the strips are accurately positioned. The panels may be fed beneath the beams before the strips. The strip conveyers may be driven through friction clutches adapted to slip when the load exceeds a certain value and the chains may be arrested at predetermined points by electromagnetically operated stops. The bearing blocks may slide directly on the machine frame to transfer the press load directly through the blocks to the frame.