Patent GB-741143-A (GB)
Title: Improvements in or relating to conveyor installations
Inventor: ORWIN OLAF JOHN BARCLAY
IPC: B65G47/48
Filed: 1952-12-27
Abstract: 741,143. Conveyers discharging at predetermined positions. FISHER & LUDLOW, Ltd. Dec. 21, 1953 [Dec. 27, 1952], No. 32792/52. Class 78 (1). In a conveyer for discharging goods at predetermined stations along its path, of the kind having a series of goods supporting elements each comprising a pair of interengageable members displaced relatively by a predetermined amount each time a station is passed until a predetermined total displacement has been effected upon which the goods are discharged, means is provided adapted upon said predetermined total displacement being reached to effect sudden further movement of one of the members without further relative displacement, which movement actuates goods discharge means on said goods supporting element. In one form, Figs. 1, 3 and 4, each of a series of loadcarrying platforms 13 is pivoted at 14 to a support 12 upstanding from a conveyer chain 11 which runs in a track 10 and is constructed as described in Specification 639,244. The platform is normally held in horizontal position by a pivoted stay 17 resting on a block 20 on support 12 and adapted to be displaced therefrom by projection of the end of a slidable shaft 23 through a hole 19 in the support. Shaft 23 carries a worm 24 whose teeth are of buttress form engaging a spring-pressed pawl 25 so that shaft 23 can be slidden away from stay 17 but not towards it. The end of the worm thread remote from stay 17 is ended abruptly and is followed by a plain extension 30 and an integral collar having an inclined face 31. A pivoted lever 34 acted on by a spring 36 engages the collar to urge rod 23 towards the stay so that when shaft 23 is turned to move towards the stay 17 sufficiently for pawl 27 to leave the end of the worm-thread shaft 23 is free to be moved suddenly towards the stay 17 by the spring 36 to displace the stay from block 20, allowing the platform to drop about its pivot and discharge the goods carried. Turning of shaft 23 from a set position of engagement of worm 24 with pawl 25 is effected as the support 12 moves along the track 11 by ramps 43 on the latter at each of a number of stations engaging a roller 42 carried by an extension 41 of a lever 38 which in turn carries a pawl 40 engaging a toothed wheel 37 slidable on a keyway on shaft 23. Wheel 37 is caused to move by one tooth each operation of pawl 40 by a spring-loaded detent roller 45 forcing itself between two adjacent teeth at the end of each movement. One of a hundred stations are selected by providing ten teeth on wheel 37 and ten convolutions of thread on worm 24. A knob 29 on shaft 23 is marked off in tenths of a revolution and a knob 52 associated with a parallel shaft 48 is marked off in whole revolutions. Shaft 48 has ten pins 51 arranged helically around it at tenth of a revolution circumferential spacing and one convolution pitch of worm 24 axial spacing so that upon setting of knob 52 one of the pins is brought into a position to engage the collar on worm 24 when the latter is pulled away from stay 17, after which shaft 23 can be turned back towards stay 17 for a fraction of a turn according to the setting required by knob 29. In the form shown in Fig. 6, the same control mechanism is used but the conveyer has platforms 57 pivoted to yokes 56 depending from the chain 11 and each platform is tipped by the shaft 23 moving transversely a lever 67 pivoted about a longitudinal axis 64 to a bell-crank 60 in turn pivoted at 61 to the yoke so that the lever 67 is moved into the path of one of a series of abutments (not shown) at stations along the track selected by the control mechanism, such abutment causing the bell-crank to swing about its pivot 61 and through a link 59 to tip the platform. Lever 67 is normally held in captive position by a pair of lugs 69, 70 so that it lies opposite the end of shaft 23. Lug 69 is longer than lug 70 and prevents backward pivoting of the platform. As yoke 56 is rigid with chain 10 the latter can only operate in a horizontal plane. In a further form (Fig. 8, not shown) yoke 56 is pivotally connected to a support depending from the chain and a stop is provided on the yoke to engage bell-crank 60 and thus hold the quadrilateral linkage 60, 59, 57, 56 in rigid position against backward tipping to which the platform is biased by a light spring, while allowing forward tipping to take place at a discharge point. As the suspended platform remains level on inclines it causes lever 67 to swing relatively to the support carrying the control mechanism, so that lugs 69, 70 are omitted. The discharge stations are located on level stretches of chain 10 in order that shaft 23 will be in line with lever 67.