Patent GB-159200-A (GB)
Title: Improvements in lifting trucks
IPC: B62B3/06
Filed: 1921-02-19
Abstract: 159,200. Brandt, E. W. Feb. 24, 1920, [Convention date]. Hand-trucks.-A rolling truck for transporting loads has its vertically movable platform lifted by two steel cables or bands which are wound upon a single drum and lift the platform at both ends. The truck frame 1, Fig. 1, is of channelled sheet metal, cross-braced, with one steel end piece 2 for supporting uprights 3 and steering wheels 4. The wheels 4 are mounted in a forked member 9, Fig. 11, working on ball-bearings 10, 11 in the member 2, the fork being held up by spring-pressed steel balls 12. The uprights 3 are split steel tubes, which are filled in by a panel and receive the projections on the steel cross-piece 16 of the platform 17, which is also of channelled sheet metal and has a board or metal floor. Two pairs 22, 26 of cross-pieces pivoted together support the platform, their inner ends being connected to the members 2, 16 and their outer ends carrying rollers 25, 29 working in the channels of the platform and frame. The lifting-mechanism is supported in a two-part casing mounted on the uprights 3 and comprises two steel bands or cables 37, Fig. 6, winding upon a drum 36, their other ends being conected to the member 16. The drum 36 is fixed to a loose . gear-wheel 41 operated by a hand-lever 46, Fig. 9, on a screwed shaft 44 through a nut carrying a pinion 42 gearing with the wheel 41. A ratchet-wheel 43 is mounted loose on the shaft 44 between the pinion 42 and a disc 45, and when the handle 46 is rotated clockwise the three members 42, 43, 45 are held together frictionally and the drum wound. A spring-controlled pawl 51 normally held out of contact with the wheel 41 by the band 37 pressing on its arm 49, locks the wheel when the platform reaches the bottom and the band slackens. A dash-pot on the frame has its piston openings closed by a valve on sudden descent of the platform, thereby checking the flow of contained oil and with it the platform. A hand-lever 92, Fig. 6, is connected to cables 93 which when operated move pawls 94, Fig. 11, into engagement with tube 95 on the steering-wheels to lock the truck. The lifting may be motor operated; thus for the mechanical drive an electric motor may be geared to the pinion 41 by speed reduction gearing, and this system may be used on electrically driven haulage trucks. If the truck has an upright at each end, the cross-pieces are dispensed with. The Specification as open to inspection under Sect. 91 (3) (a) describes also hydraulic transmission means, which may be substituted for the gearing, and consists of a double-acting pump 62, Fig. 14, (Cancelled), mounted in an aluminium casing on the frame and operated by a hand-lever 76 to press water up a pipe 63 to a press 60, the piston of which carries pulleys provided with guides and having cables 61 passing around them. The cables are connected at one end to the frame of the press and pass from pulleys 64 back round pulleys 70, 69, from which they run vertically to conical coupling-members in the corner pieces 59 of the tubular framing. Alternative arrangements of press and pulleys may be used. A valve in the pipe permits of disconnection of the pump, and a valve in the pump, operated by over-movement of the lever 76, releases the water to allow of descent of the platform. With the hydraulic drive the motor is connected to the pump lever, and in this case compressed gas may supply the motive force, and may act through a pressure multiplier. This subject-matter does not appear in the Specification as accepted.