Patent GB-973627-A (GB)
Title: Apparatus and process for providing bails on cans
IPC: B21F45/00
Filed: 1963-06-18
Abstract: 973,627. Attaching bails to cans; shearing; angular bending. R. A. HEISLER. June 18, 1963 [Sept. 12, 1962], No. 24186/63. Headings B3A, B3E and B3W. Apparatus for providing eared cans with bails comprises a bail applying mechanism in the form of a pair of bending dies having wire engaging portions in a single plane, means to feed wire into position in said plane between said bending dies, means to move at least one bending die toward the other in said plane to shape said wire into a bail, a pair of oppositely disposed die means providing guideways to conduct the ends of the bail into the ears of the can and means to move the ends of the bail into, through and out of said guideways which are curved to curve the ends of the bail to seat them in the ears of the can. Eared cans 80 are fed to a gate feeding mechanism driven by a cam 89 fitted to a shaft 82 of a pair of differentially driven chain conveyers 83, 84 which convey the cans to the bailing unit. The mechanism comprises pairs of front and rear pivoted arms 94, 96 interconnected by a tension spring 97 and is operated by the cam 89 and crank 91 which rocks the arms to and fro to arrest a can against fingers 98 of the arms 94, lower the arms 94 to release the can whilst raising the rear arms 96 to arrest the following cans which are subsequently intermittently released by the fingers 98 on to the continuously moving conveyer and between rim and ear guide bars 101, 103. Due to the speed difference of the conveyers, the cans are rotated until one ear abuts against the bar 103 whilst the opposite ear trips a bar 110 to open a valve 114 which controls the bailing unit. Cans having one or no ears will pass through the unit without actuating the trip. The crank driven bail making and inserting unit comprises a conventional wire straightener unit 118, a pair of adjustable grooved feed rolls 123, 124, the roll 124 being spring biased towards the driven roll 124 which frictionally engage the wire 119 and feed it through a die block 135 and a groove 138 in a main plate 72 to a stop 140 at which point the wire feed is stopped by moving the roller 124 back against the spring by cam actuation of its mounting bracket. A pair of transfer arms 143 and a cutter arm 132 mounted on a shaft 143a attached to a connecting bar 142 are camactuated to effect simultaneous shearing of the wire against a bushing 134a of the die block 135 and the transfer of the cut wire from the grooves 138 forward of the plate 72 against a central wire block 144 attached to the front face thereof. The stop 140 may be replaced by a second cutter arm and die block mounted and constructed in a similar manner to the members 132, 135. Forward movement of the wire is also limited by a pair of spring-loaded retractable fingers 145. Subsequently a spring- loaded convex lower die shoe 147 slidably mounted on a back plate 149a is raised until its uppermost part engages the wire against the block 144 at which point a crank operated upper die shoe 150 having carbide or hardened steel contact blocks 151 and a forming groove 153 is lowered to bend the wire about the shoe 147 and form vertically extending legs 121. Continued movement of the shoe depresses shoe 147 and the ends of the galvanized soft steel wire enter the taper sided or round sided curling grooves formed in the face of curling dies 152, pivotally mounted on the plate 72 and spring- loaded into the retracted position, positioned adjacent the ears of the can to deflect the wire into the holes thereof. When a can passes the end of the guide bar 103 the differential speeds of the conveyers orientate it into its final position whence it is arrested by its ears against stop arms 190 pivotally mounted on shafts 195 and spring loaded into the closed position. The arms also serve to close the wire slots, Fig. 44, in the faces of the curling dies 152 and are opened to release the bailed cans by a cam and crank means 202, 198. A conventional pawl type single revolution clutch unit as used on punch presses is modified to incorporate a hold system to cover the time taken by the can to travel from the tripping point to the bail inserting point. A spring-biased pawl 211 slidable within keyways 212, 212a in crank-shaft 116 and a trip cam 213 engages the stepped face of a continuously rotating hub and sprocket assembly 208, 207 to impart rotation to the shaft 161. The lower end of an arm 215 pivoted at 216 is coupled via a link to a rocker arm 221 which is also coupled to the valve piston 224 controlled by the trip valve 114, upward movement of which causes an arm 237a of the rocker to engage a detent 237 formed on one end of a spring biased arm 235b, also pivoted at 216, to hold the upper end of the arm 215 out of engagement with the pawl 211 and allow continuous driving engagement with the hub 208. The trip cam 213 actuates the end of the arm 235a in each revolution to raise the detent arm and release the rocker 221 which allows the spring biased valve to re-set. With a continuous flow of cans this resetting is cancelled by the re-activation, by the moving cans, of the valves 114, 224. To release the bailed can the lower die 147 is moved further down by a cam 149c engaging a cam arm 256 attached thereto whilst the upper die 150 moves upwardly and the stop arms 190 retract to allow the can to be carried away on the conveyer chains. In an embodiment a pair of chain conveyers 260, travelling at the same speed, may be arranged between and in a plane slightly lower than the chains 83, 84 on which smaller cans, e.g. 4, 2 and 1 pint sizes, which may be earless, are fed to the bailing unit. In a modification a unit for bailing single cans is similarly constructed and operated using pneumatic drive means in lieu of a crank-shaft. The stop arms are also pneumatically controlled. Single pieces of pre-cut bailing wire are supplied via a shoot 300 which is pivotally mounted on brackets attached to a main plate 281. In the position shown in Fig. 57 a single wire drops on to the lower die shoe 290 and as the upper dieplate 286 moves down the lower end of the shoot is deflected outwardly into a shoot cover 304 which prevents loss of wires therefrom. Contactors 309a depending from the die 286 engage the ends of the wire as it is lowered and bend it about the die 290 prior to the insertion of ends thereof into the curling dies, the wire receiving grooved faces of which are covered by the faces of the contactors. To release a bailed can the upper die and stop arms are retracted, and a spring-biased pivoted finger 312 pushes the bail forward prior to lifting the can clear. A spring biased pivoted lock arm 320 which holds the lower die 290 down via the back slide plate 293 is retracted by a pneumatic cylinder assembly 334 via linkage 338, 328 to allow the die 290 to reset.