GB1024375A - A conveyor including an overload prevention device - Google Patents

Abstract

1,024,375. Ratchet gearing; variable-ratio gearing; linkwork. C. R. DYSON, and J. D. DYSON. March 12, 1964 [March 27, 1963], No. 12125/63. Headings F2D, F2K and F2Q. In a conveyer drive, an overload prevention device comprises a continuously rotating driving crank 10 which is connected to pawl-andratchet mechanism 16, 18, 20 by a rod 14 consisting of two parts 14a, 14b movable axially of each other and biased by means of one or more springs 24 into the condition of fixed length but being capable of yielding when the conveyer is overloaded or becomes jammed. The end 14b of the rod 14 is connected to a pawl carrier 16 rotatably mounted about the centre of a circular ratchet 20 with which a pawl 18 on the carrier 16 co-operates. A modified form of the link 14 comprises telesoopic parts 14a, 14b, Fig. 2 (not shown), connected by a compression spring 24b and two or more tension springs 24a. In another modification, a resilient connection between a rod 40, Fig. 3 (not shown), and a pawl carrier 32 comprises a triangular plate 38 pivotally mounted on the axis of rotation 34 of a ratchet-wheel 36, compression springs 48 being located between seats 44, 46 on the plate 38 and carrier 32 respectively. In a further modification, a pawl carrier 62, Fig. 4 (not shown), of inverted Y-form is pivotally mounted on the axis of rotation 64 of a ratchet.wheel 66. A lever 68, also pivotally mounted on the axis 64, is arranged to be oscillated through a fixed angle 70 by the driving means, and is connected to a rod 72 which passes through apertures in the limbs of the carrier 62. Helical springs 76, 78 surround the rod 72 and extend between the limbs and the oscillatory lever 68 and between the limbs and fixed stops 74. Speed variation may be effected by angular displacement of a stroke limiting member 80 by means of a handle 82, a scale 84 being provided.