GB145235A - A telescopic elevator - Google Patents

Abstract

145,235. Thomas, W. May 29, 1919. Jacks; rack-and-pinion load-handling machines. -A lifting-device for use in collieries for raising timber and supporting it while props are inserted beneath comprises a pair of guides 1 in which slide columns 3 connected by a cross-head 4 and actuated by rack-and-pinion mechanism. The holder 13 for the timber is carried by a tube 14 which slides in a tube 13 loosely mounted in a bearing 15 on the cross-head 4. A collar 17 on the tube 14 rests on a flange 16 on the tube 13 which bears on the cross-head 4 when the lifting device is in the closed position. When a load is to be raised the columns 3 are extended to the position shown in Fig. 2. A strut 19 which can pass into the tube 13 is then placed under the tube 14 and the columns 3 with the tube 13 are lowered to their original position. A pin 23 is now passed through the tube 14 and the columns 3 are again extended. The parts now occupy the position shown in Fig. 3. A bar 24 is now passed through the strut 19 and supports the tube 13 when the columns 3 are again lowered. A pin 25 is then passed through the tube 13 above the cross-head 4 and on the next extension of the columns 3, the parts take up the position shown in Fig. 4. The actuating-pinion may be driven through worm gearing. In a modification described in the Provisional Specification, the tube 14 is raised by a rack and pinion.