Patent GB-568299-A (GB)
Title: Improvements in or connected with conveyors for conveying material such as coal
IPC: B65G23/00
Filed: 1943-02-05
Abstract: 568,299. Conveyers. MAVOR & COULSON, Ltd., and MAVOR, J. B. Feb. 5, 1943, No. 1943. [Class 78 (i)] A conveyer system comprises a main con. veyer and at least one tributary conveyer, means controlled or operated by the sagging of the belts of the main and tributary conveyers against spring or gravity action being provided so that if two concentrated loads, one on the main and one on a tributary conveyer approach the junction of the two conveyers, the tributary conveyer is stopped temporarily or slowed down until the load on the main conveyer has passed. The stopping means may be a pair of simultaneously operated trip devices which may, through an electrical, mechanical or fluid-pressure transmission, or a combination thereof, operate a clutch or coupling of the fluid, mechanical or magnetic type in the drive of the tributary conveyer or may stop or slow down its driving motor. Fig. 1 shows a combined electrical and fluid-pressure, clutchoperating system comprising a main conveyer A and three tributary conveyers B, C, D, all of the endless belt type, electric motors E for driving the latter conveyers, a load-operated trip device F near the discharge end of each tributary conveyer, dual load-operated trip devices H-H associated with the main conveyer at its approach to the junction with each tributary conveyer, a main electric control panel J associated with each tributary conveyer, an auxiliary electric control panel K associated with the panels J of the conveyers C, D and push-button, remote-control, stopping and starting switches M. The automatic control operates, for conveyer B, by stopping and starting its motor E and for conveyers C, D by de-clutching and re-clutching the conveyer belt from and to the respective motor E by means of a hydraulic thruster and fluid coupling of known type. Each trip device F or H comprises a frame 2, Fig. 2, mounted on a fixed pivot 3 and having a forked end 8, on the arms of which adjustable tappets 9 are mounted. Normally, the upper troughed run P of the conveyer, supported by idler rollers 1, is spaced from the frame, but when a load passes along, the belt sags and engages rollers 4, 5 on the frame which rocks clockwise against the action of a counterweight 10 so that the upper tappet 9 strikes the handle 7 of the switch box 6 and turns it to the stop position. This movement of the handle 7 does not stop the tributary conveyer unless the trip device associated with the other conveyer is operated simultaneously. In this event, in the case of conveyers C, D, the hydraulic thruster Q, Fig. 4, and fluid coupling R come into action. The thruster is a known type of servo unit comprising an electric motor, an oil pump driven by the motor, and a piston and rod 11 moved by the oil under pressure. The rod 11 operates a counterweighted lever 12 connected to a second lever 14 which operates the fluid coupling R to interrupt the drive between the motor and conveyer belt until the trip devices return to their normal positions when the fluid coupling is operated to re-establish the drive. A connection 15 from the lever 12 operates a brake on the conveyer. According to the Provisional Specification, each trip device, instead of being operated by sagging of the belt, is (1) in the form of a gate or equivalent adapted to be moved aside against spring or gravity action by the passing of a concentrated load, or (2) of photo-electric cell character actuated by the passage of a concentrated load intercepting a beam of light.