Patent GB-965707-A (GB)
Title: Improved extensible structure for load-moving
IPC: B66F9/08
Filed: 1961-11-16
Abstract: 965,707. Masted lift trucks. MULTI-LIFT CO. Nov. 16, 1961 [Nov. 21, 1960; July 27, 1961; Oct. 16, 1961], No. 40963/61. Heading B8H. [Also in Division F2] A load-hoisting mast comprises a number of mast sections each one including a pair of spaced parallel side members movable relative to each other at predetermined speed ratios, the corresponding side members on each side of the mast sections being grouped one within the other in nesting telescoping relationship, and endless recirculating roller chain members longitudinally mounted between the adjacent side members in each group and extending in a direction parallel to the direction of relative movement between the side members. The side members may be formed as nested channels, e.g. 20, 34, 42 (Fig. 1) one or more thereof having each side wall thereof embraced longitudinally by a roller chain such as 40 located in notches at the end of a channel so that the channel or each channel is guided on the corresponding walls of another channel or between those of two of them. There may be two spaced mutually-telescopic sections 120, 122 (Fig. 10) connected in parallel, the outer section 120 carrying the roller chains 208, 222 or three sections 10, 16, 18 (Fig. 1), the middle section 16 carrying the chains 90, 94, or four (Figs. 22 and 23) or five (Fig. 6) sections, the second and fourth (counting outwards) carrying the chains. In one form of mast (Figs. 10, 16 and 19) the extension is brought about by means of an hydraulic ram 138 acting between the lower end of the stationary section 120 and the top end of the section 122, in combination with flexible tension elements 174, 182 connecting the lower end of the section 120 at a crossmember 134 to a carriage 190 and slidable lengthwise of the section 122 and passing around sheaves 166, 168 carried by the top end of the section 122. Such a mast construction modified somewhat is also shown in Fig. 21. In another form of mast (Figs. 1, 5 and 8) the extension is brought about by means of a fluidpressure ram 32 acting between the lower end of the stationary section 10 and the top end of the section 16, in combination with flexible tension elements 83 and 87, the elements 83 connecting the lower end of the section 10 at the cross-member 28 to the lower end of the section 18 (at 86) slidable lengthwise of the section 16 and passing around sheaves 54, 56 carried by the top end of the section 16, the elements 87 connecting the top end of the section 16 to a carriage 58 at 88 (Figs. 3 and 8) slidable lengthwise of section 18 and passing around sheaves 50, 52 thereon. The carriage 58 has at each side two sets of rollers 68, 70 engaging the sides of the channels 42 and 44, respectively of the slidable sections 18, and intermediate each two rollers 68 and also 70 are two further spaced rollers engaging the base of the channels 42 and 44. There may be four mutually-telescopic sections 20<SP>1</SP>, 34<SP>1</SP>, 42<SP>1</SP> and 110, extended by means of a fluid-pressure ram 80 (Figs. 1 and 6), in this form, acting between the lower end of the section 20 and the upper end of the section 34<SP>1</SP>, in combination with tension elements between the lower end of the section 110 to a modified carriage 60<SP>1</SP> (Fig. 9) slidable within it and passing around a sheave at its top end, and further tension elements respectively passing from the lower end of each of the elements 34<SP>1</SP> and 42<SP>1</SP> around a sheave at its upper end to the lower end of the sections 20<SP>1</SP> and 341. The carriage 60<SP>1</SP> is formed with side members 112 which are guided within the channels, such as 110, of a section. A modified carriage 190b (Fig. 24) is formed with side members 200b, 202b each having its side walls embraced by two roller chains 334, 336, and 334, 346, respectively, which engage the side walls of the associated slidable section of which one channel is 280c (Fig. 25). The hydraulic ram 138 or 32 (Figs. 10 and 1) and its cylinder as well as the sheaves 166, 168 or 50, 52, 54, 56 are attached to cross-members between corresponding walls of the telescopic channels.