GB1042168A - Improvements in or relating to conveyor systems - Google Patents

Abstract

1,042,168. Conveyer systems. D. A. CARGILL. and L. M. FORSTER. Oct. 23. 1963 [Jan. 14, 1963], No. 41747/63. Heading B7L. A conveyer system has pallets 18 supported by uprights 22, axles 23, 24 and wheels 25 on a track 11, 12, 13, Figs. 1, 2, 3, each pallet having a sprocket 27 engaged with a moving roller chain 14. 15, 16 through a clutch which when engaged holds the sprocket stationary whereby the pallet is driven and when released allows the sprocket to freely rotate with the pallet stationary. The clutch comprises a spring steel band 30 helically wound on an oil retaining bearing 29 of sintered metal, pressed on to the sprocket hub 28; one end of the band is preloaded by a leaf-spring 31. Fig. 1, and the other end is connected to a light spring 34 anchored to a pin 35 on an upright 22; this latter end is also clamped against a rocket arm 37 by a set-screw in the arm pivot 39, Fig. 3. A clutch control arm 41 mounted on axle 23, is biased by spring 42 to the shown position in which a small gap 45 exists between arms 37 and 41. In operation, the band 30 normally holds the sprocket 27 stationary and the pallet is moved. However should the surface 46 of arm 41 engage the rear axle of a proceding pallet or should projection 47 engage a retractable stop 49 (manually or automatically controlled), the arm 41 engages and rotates arm 37 to relieve the tension in band 30 whereby the clutch is released and the sprocket allowed to rotate freely. Further travel of arm 41 merely produces relative movement between surfaces 50, 51 of arms 41, 37 without further moving arm 37. The preload of spring 42 may be calibrated to provide a desired shockabsorbing action. However, spring 42 does provide some spring back of the pallet and this is avoided by a second embodiment, Figs. 5, 8, in which two driving sprockets 58 are mounted on a shaft 59 having track-engaging rollers 60. The clutch band is coiled on a bearing on shaft 59 and is secured at one end to an adjustable anchor 71, 78 and at the other end to a rod 72 biased by a spring 74 in pocket 75 toward a cam 76 on a control arm 77, the nut 78 of anchor 71, 78 adjusting the position of the head 73 of rod 72 relative to cam 76. Travel of arm 77 past the initial clutch releasing position produces a shock-absorbing clutch engagement of a band 82 wrapped on a bearing 83 secured to the shaft 81 of arm 77. The ends of band 82 are rigidly connected at 84 and connected by an adjustable spring 85 to the pallet frame respectively. The band 82 resists travel of arm 77 and a return spring 87 is light so that spring- back is eliminated.