Patent GB-499917-A (GB)
Title: Improvements in and relating to elevating trucks
IPC: B62B3/06
Filed: 1938-01-11
Abstract: 499,917. Elevating-trucks. HUGHES, R. M. (Lewis-Shepard Co.) Jan. 11, 1938, No. 908. [Glass 108 (i)] In an elevating-truck comprising a main frame I having a head 3, steering-mechanism mounted on the head and having a verticallyswingable tongue 18 pivoted on its lower portion, and a load-supporting platform 21 carried by links 34 or toggles &c. and raised by movement of the tongue, the head and steering-mechanism are provided with axially-aligned apertures and the means for raising the load includes flexible lifting-mechanism uninterruptedly connected between the tongue and platform and having a portion of its length extending through the apertures along the vertical axis of the steering mechanism. As shown, the head 3 has a cylindrical extension 10 forming a, bearing for a tubular steering-post 11 having downwardly extending forks 13 on which the steering-wheel 15 and tongue are mounted. Thelifting-mechanism comprises a chain in two sections 44, 42 connected by a swivel 47 reciprocatable in the steering-post 11. The section 44 is attached to a link 45 pivoted on the tongue and is passed round a guide roller 55 carried by the forks 13. The section 42 is passed over a cam 9, rotatable on a shaft 8 rotatable in bearings in extensions 6 and 7 of the head 3, and is connected to a link 33 pivoted on a shaft 30 carried by the transverse member 25 of the platform 21. The .cam 9, which is of sector shape having a rounded lower portion 62, is integral with a sleeve 57 carrying a counter-weight 63 and connected to a collar 60 by a U-shaped member 59. The collar 60 is rotatable on a reduced portion of the end of the shaft and carries a foot pedal 61. Due to the weight 63, the cam is normally in a position where the portion 62 engages the chain, and to raise the load the chain is tensioned by rotating the cam by the pedal 61 to bring it to the position shown in Fig. 3 where the member 59 rests against an extension 65 of the portion 6. Downward movement of the tongue will then raise the load, which is locked in a raised position by pawls 31, 32, pivoted on the shaft 30 and connected by a member 66, the hooked portions 69 of which engage the top surface of the shaft 8. The pawls are guided by an extension 67 on the pawl 32, which rides on the inclined edge 68 of the portion 7. Due to movement of the chain the cam will be rotated during lifting to a position where it will rotate under the action of the weight 63 as soon as tension is released. The chain is thus slackened sufficiently to allow subsequent free movement of the tongue. To release the pawls 31 and 32 and permit descent of the load, the shaft 8 is rotatable against the action of a spring by means of a collar 70 carrying a pedal 71. A dashpot 38 is provided to cushion the descent. In a modification the shaft 8 carries a pinion and is rotatable by movement of a toothed quadrant pivoted to the portion 6. The tongue 18 may be mounted on the shaft of the steering wheel. Specification 497,178 is referred to and a construction, identical with that shown in Fig. I of that Specification is described.