GB608853A - Improvements in or relating to the erection of sectional masts and like elongated structures and to the construction thereof - Google Patents

Abstract

608,853. Pile-drivers. HOOD, A. Dec. 18, 1944, No. 25362. [Class 68 (ii)] [Also in Groups X and XXX] A pile-driving frame is composed of two or more sections which are hinged together to fold and lie on or above each other in a horizontal position and are raised to the vertical by rotating the lowest section about its convexly curved base on the platform on which the frame is to be erected, the subsequent sections at the same time automatically being caused to rotate on their hinges so that all sections are in axial alignment when the lowest section reaches a substantially vertical position. The Figures show a two-section frame, the lower section 11 being hinged to the upper 18 at 17. The foot 12 of the lower section is formed as a quadrant 13 having two sets of teeth 14 engaging two parallel racks 16 on the platform 15 of the pile driver. A cable 20 attached at one end to a point 26 on the platform intermediate the head and foot of the lower section when horizontal, passes round and is made fast at its other end to a pulley 19 coaxial with the hinge 17 and fast with the upper section 18. The geometry of the arrangement is such that as the lower section 11 is rolled on its foot 12 to a vertical position by the cable 25 operated by a winch and power unit 24 on the platform 15, the distance between the point 26 and the pulley 19 increases, so that the pulley 19 is caused to rotate relative to the lower section 11 to bring the upper section into alignment with the lower. When erect, the frame is bolted to lugs on the platform, the upper section is bolted to the lower and the whole secured by guys. A frame of three or more sections has a pulley at each hinge, the topmost one being fast with the top section and the others being suitably geared each to the section immediately above it. The platform 15 may project forward on either side of a space 33 to embrace a pile during driving so that if the pile becomes displaced laterally it will abut a projection which will relieve the strain on the frame. If the displacement is severe the pile driver may be shifted bodily to accommodate it. The pile driver may be moved in one direction by rolling on rollers 32 and in the transverse direction by sliding along the rollers, suitable tackle being arranged so that the power unit 24 can exert a pull for this purpose.