GB596577A - Improvements in or relating to weight indicating lifting jacks - Google Patents

Abstract

596,577. Weighing-apparatus. GRIME, E. P. Sept. 18, 1944, No. 17796. Convention date, Sept. 11, 1943. [Class 143] [Also in Group XXX] A weight indicating lifting jack includes a cap cylinder supported on a plunger within a cylindrical casing, a cap plunger adapted to extend above the cap cylinder casing, a fluid pressure system with a flexible connection maintaining connection to the cap cylinder in any position the cylinder may assume, a weight indicator, and a cylinder connected with the fluid pressure system so that it is subjected to the same pressure as that in the cap cylinder and having a plunger thrusting against the weight indicator. The cap cylinder 20, Fig. 1, is movable in a bore 19 formed in a block 12 which is pivotally mounted on a pin 13 extending transversely between a pair of plates 7. These plates are pivotally mounted on a rod 8 which is supported by plates 9 upstanding from the side bars 3 of the base 1. The plates 7 are connected to the plunger 6 of a cylinder 4 which is rotatably mounted on a rod 5 extending between the bars 3. A link 15 connects one of the plates 9 to an arm 14 projecting from the block 12 and ensures that the block remains vertical during the movement of the plates 7 between the vertical and the horizontal positions. An aperture 16 in the lower part of the block receives the upper end of the plunger 11 of a cylinder 10 which is secured to a platform welded to the plates 7. A twin elbow connection 25, Fig. 21, in communication with the space between the parts 20, 21, is connected by a hose 28 to a pump 29 and by a hose 33 to a weight indicating device 34. The hose 33 supplies fluid to the space above the plunger 40, Fig 4, of a miniature cylinder 39 disposed adjacent to the actuating arm 38 of a pivoted scale beam 36. A flat finger 41 attached to the plunger projects through a slot 42 in the cylinder and engages a notch 43 in the arm 38. When the plates 7 are in the horizontal position, !the plunger 11 is within the cylinder 10 and is not in contact with the block 12. If fluid is pumped from the reservoir 18 into the cylinder 4 by actuating the pump 17, the plates 7 will be turned into the vertical position. During this movement the load 22 rests on the plunger 21 which is at the bottom of the cylinder 20, Fig. 3. When the plates are vertical, fluid under pressure is admitted at 23 to the cylinder 10 to raise the plunger 11 into engagement with the cylinder 20. The pump 29 is then actuated to supply fluid under pressure to the space 24 whereupon the load is indicated by the device 34. The cylinder 20 is interchangeable with jacks having cylinders of larger or smaller diameter than the cylinder 10.