Patent GB-700976-A (GB)
Title: Improvements in and relating to the manufacture of tin bread
Inventor: WILSON GEORGE DONALD
IPC: A21B7/00
Filed: 1949-10-25
Abstract: 700,976. Bakery plant. BAKER PERKINS, Ltd. Jan. 22, 1951 [Oct. 25, 1949], No. 27355/49. Class 28(1) In an automatic bakery plant, tins are mechanically filled with dough and then formed up into tray-load groups which groups are passed mechanically by transfer means into and through the final prover unit, oven unit and detinning machine in succession, the detinned loaves being discharged, still in groups, and passed to a bread cooler unit and empty tins being returned to the filling station to repeat the cycle. The baking tins may be used separately or strapped together in lots of three 2-lb. tins or four 1-lb. tins. "Fish scale" conveyers or slatted conveyers with "fish scale" conveyers at turning points, e.g. 10 are used. Final prover 1, oven 2 and' cooler 3 and detinning units are arranged on one floor with their charging or discharge ends or both aligned on a conveying path 4 by which the tins are transferred from one unit to another. At tin filling station A there is a divider 6, hander-up 7, first prover 8 and a moulder-panner 5. An endless conveyer 9 driven by an electric motor carries tins under the delivery of the moulder-panner 5 where each is arrested in turn by stop fingers projecting above the conveyer to receive a piece of dough. A monitoring device, e.g. 'of the photo electric cell type may be provided to prevent dough pieces from being fed from the moulder-panner if one or more tins is missing. Tins are fed into the plant until empty tins are being ejected by the detinning machine so that the whole operation takes place automatically. The moulder-panner 5 may be as described in Specification 631,995, [Group XXX], and have a trip plate, displaced by each dough piece, to operate a valve which controls the flow of air to a pneumatic cylinder whose piston is coupled to a stop-finger mechanism for arresting the tins under the delivery of the moulder-panner. The tins are then carried to the final prover by conveyer 9 and before loading are arranged in groups each of which forms a full load for one of the conveyer trays in any of the units, viz. 2-lb. loaves in five sets of three and 1-lb. loaves in five sets of four. Preferably the groups are formed by mechanism, according to Specification 647,446, [Group XXX], comprising a series of bell crank stop levers which arrest succeeding sets of tins spaced from one another in a group. The group of tins so formed is then transferred from conveyer 9 on to a fixed comb plate 27 by pusher gear 28 actuated by switch 28a, Fig. 3 (not shown), at the termination of grouping. The prover conveyer has finger trays which mesh with comb plates 27 while moving upwards 19 so that each tray lifts a group of tins off the comb plate and carries them through the prover to a discharge comb plate 29 on which the group is deposited as it meshes with the trays on a downward lap 20. A pin or lug on the prover conveyer operates switch 31a, Fig. 3 (not shown), to cause pusher gear 31 to push the group from comb plate 29 on to transfer conveyer 30 which is operated intermittently to carry the groups to the oven 2, Fig. 5, the conveyer being started by switch 30a, Fig. 3 (not shown), engaged by pusher gear 31 as it returns to rest. The tins are loaded into. the oven by pusher gear 47 which pushes the tins on to comb plate 33 from which they are picked up by a meshing swing tray of the conveyer. They are then carried along lap 43 through a steam baking chamber and back along the lower lap 44 of the oven conveyer to be unloaded by an auxiliary mechanism 49, as in Specification 696,122, [Group XXX], having platforms 50 overtaking and meshing with the trays of the oven conveyer. The groups are carried on the platforms 50 and deposited on conveyer 60 which carries them to the detinning machine 32, moving intermittently in steps of the same length as the group. The detinning machine may be as described in Specifification 652,990 or Specification 681,605 and is loaded by pusher gear 61 from conweyer 60. The loaves are ejected from their tins on to an intermittently driven transfer conveyer 70 which carries the loaves still in groups to the charging station G of cooler unit 3 where pusher gear 75 transfers the loaves to comb plate 73 from which they are lifted by meshing swing trays of the cooler conveyer from which they are discharged down a shoot or on to a loaf discharge conveyer by pusher gear 78. The empty tins are returned by a suitable intermittently driven conveyer or series of conveyers to the moulder-panner. The pusher gear is of any suitable type and pusher bars carried by endless chains such as described in Specification 647,446 suitably synchronized with the trays may be used. Puller gear comprising horizontal bar magnets mounted to be reciprocated and energized at the appropriate times may be used, e.g. for removing tins from a baking unit when it is preferred to mount the gearoutside the baking unit. The prime mover for the bakery units may also drive the detinning machine, moulder-panner and other subsidiary apparatus but preferably independent motors control each piece of apparatus. As shown, Fig. 7, a variable speed motor 120 drives the conveyers in the final prover 1, oven 2 and cooler 3 units through chain transmission and master shafting 122 at the speed appropriate to the loaves being made. A clutch 127 is provided associated with each unit and these are preferably arranged to engage in one position only so that the conveyers are engaged in step. The divider 6, hander-up 7 and first prover 8 may also be driven by the main shaft 122 through drive 128. The pusher gears, transfer conveyers and detinning unit each have a separate electric driving motor operated by the switches mentioned above. Puller gear may be used, e.g. comprising a horizontal bar electromagnet (or magnets) mounted to be reciprocated. The bakery units and machines may be arranged on several floors when some of the conveyers will run vertically. Specifications 696.123 and 700,974, [both in Group XXX], also are referred to.