Patent GB-538418-A (GB)
Title: Improvements in or relating to conveyor systems
IPC: B65G35/06
Filed: 1940-02-15
Abstract: 538,418. Conveyers. KING, Ltd., G. W., and KING, D. M. Feb. 15, 1940, No. 2935. [Class 78 (i)] A conveyer system applicable as a cooling conveyer for a carburizing plant comprises two conveyers 10, 11 arranged one above the other and driven in opposite directions, lift devices 13, 14 to convey load-carrying trays 12 from the upper to the lower conveyer and vice versa to form a circuit, means for feeding loads to the trays on the conveyer 10 at one end and for removing loads from the trays at one or more pre-selected points, and a set of rollers 21 at the loading end or at each end of the conveyer 10, each set of rollers forming an extension of the conveyers to facilitate movement of the trays between the conveyer and the lift devices. As shown, the lower conveyer 11 comprises a pair of chains, belts &c. so spaced as to allow both lift devices to pass between them and is extended beyond the conveyer 10 at each end. The lift devices 13, 14 each comprise a platform having a depending rack 16 movable between guides and actuated by a pinion 17 driven by a reversible electric motor 18. Rollers 19 are mounted on the platforms 13, 14 and groups of powerdriven rollers 20, 21 are arranged at the ends of the conveyer 10. At the right-hand end of the conveyer 10, each tray is transferred by the rollers 20 to the platform 13 and actuates switches to stop the drive to the rollers 19 and to switch on the motor 18, lowering the platform to the conveyer 11. The motor may be automatically reversed to return the platform 13 to the upper position. On reaching the lefthand end of the conveyer 11, the tray passes on to the platform 14, which is actuated to raise it to the upper level, where it is unloaded by an electrically operated arm and reloaded by means of a pusher bar 25 transferring the load over driven rollers 27. A switch actuated by the bar 25 causes the platform 14 to be lifted to bring the rollers 19 to the level of the rollers 21 and the rollers 19 are energized to transfer the tray to the conveyer 10. A switch operated by the tray on leaving the platform 14 reverses the motor 18 to return the platform to the lower position. In a modification, the conveyers are of approximately the same length and the drive of the platform rollers 19 is reversible to assist in driving the trays on and off the platforms. To prevent the trays from passing off the discharge ends of the conveyers before the platforms 13, 14 are in position to receive them, stop devices each comprise a weighted arm 30, Fig. 3, pivoted at 31 and connected by a slot 40 and pin 39 to a link 38 actuated by a pivoted arm 34. A notch 36 in the arm 34 is engaged by a projection 41 of the platform 13 to withdraw the end 32 of the stop arm from the path of a tray 12. The platform 14 may alternatively have depending arms 45 obstructing trays on the conveyer 11 until the platform is in its lower position. The rollers 19, 20, 21 may be frictionally connected to their driving shafts in order to slip when the trays are arrested, the bore of each roller being enlarged and packed with grease. The trays may be unloaded by a pusher arm at the right-hand end of the conveyer 11 returning empty trays and the cycle of operations being similar to that described in Specification 486,087.