GB892721A - Improvements in or relating to cranes - Google Patents

Abstract

892,721. Preventing crane-loads from swing- ing. GENERAL MILLS Inc. Oct. 1, 1959 [Oct. 9, 1958], No. 33356/59. Class 78 (4). A crane unit 10, Fig. 1, movable along a track 11 which is itself movable along a further track at right-angles to the track 11 has four cable drums 19, 20, 21, 22, mounted thereon, each having one end of a cable connected thereto, the opposite ends of the cables converging towards a load-bearing member 18. The cable drums are driven by a single motor 45, Fig. 5, through shafts 46, 47, 48, 49. The drive is taken through electrically-operated clutch-brake units 57, 58, 59, 60 and irreversible speed reducers 53, 54, 55, 56. By selectively energizing the brake-clutch units from a control panel 16, Fig. 1, it is possible to raise or lower any or all of the cables. The cables must either move in the same direction or remain stationary; no provision is made for winding in whilst others are wound out. The control panel 16 also controls two electric motors which drive the crane unit along the overhead tracks. Each cable drum 19, Fig. 8, is slidably mounted on a shaft 77 by a ballspline arrangement. Each drum has a pivotally mounted tangent sheave unit 80. The load-bearing member 18, Fig. 4, comprises a cylinder 36 in which is pivoted a load-bearing member 40 to which a universal unit 41 is pivoted by a pin 42. A load hook 43 is pivotally attached to universal unit 41 by a pin 44. In a modification, an electric motor may be mounted within the cylindrical member 36 to turn the member 40 about its rotational axis. A separate drive motor may be provided for each cable drum.