GB750793A - Fork lift or industrial trucks - Google Patents

Abstract

750,793. Lift trucks. ELECTRO-HYDRAULICS, Ltd. Feb. 16,1954 [Nov. 21, 1952; Feb. 16, 1953; June 25, 1953], Nos..29527/ 52, 4309/53 and 17699/53. Class 78(3). A fork lift truck in which the forks are mounted on a carrier in front of the truck carriage, comprises means for traversing the forks across the truck and positive guide means for ensuring that the carrier is prevented from tipping with respect to the truck carriage or its normally provided support, the positive guide means comprising either a double rack-and-pinion device, or a nut and lead screw device, or a link system or an endless chain mechanism. A fork lift truck as shown in Fig. 1, is fitted with a carriage 2 movable on uprights 3, and a carrier 5 with forks 6 has an upright extension 5a mounting a torsion rod with end pinions traversable over a pair of guide racks 7 on members 4 secured to the carriage. The forks are traversed by a screw 18, Fig. 1, engaging a nut 19 on the member 5a and driven by a motor having a pinion engaging a pinion 21 on the screw. The forks may be traversed by an hydraulic cylinder 11, Fig. 11, the piston 14 of which is fixed to the carriage 2 and the cylinder 11 has a sprocket at each end round each of which passes a chain anchored to the carriage 2 and upright 5a. The carrier is guided by upper and lower rollers 23 engaging in grooves in the members 4. Rollers 26 on a bogie connected to the upright 5a also engage the top of the lower member 4. The forks are removably mounted to slide in a groove 27 on the carrier 5 so that they can be supported to project from either side. The piston 14 is mounted in an end bearing, the piston being fixed and the cylinder movable. Alternatively, the piston may be movable and secured to a member connecting the members 4 and 5a. The carrier may be traversed by an endless chain secured to the member 5a and passing over sprockets at the ends of the members 4. The forks may be mounted to pivot as well as traverse. A motor 38, Fig. 14, is mounted on an extension of member 5a and a bevel-wheel 4 driven thereby engages a pinion on an upright rod mounted in bearings in the member 5a and carrying the carrier 5, operating the motor 38 pivots the forks. The motor may be dispensed with and the traversing mechanism used to pivot the forks. Operating a handle rotates a bevel gear into engagement with the upper pinion on the torsion rod used for traversing. The shaft of the bevel gear has a worm engaging a pinion on the upright rod mounted in bearings in the member 5a and thereby rotates the forks.