Patent GB-755427-A (GB)
Title: Improvements in and relating to foundation pile, cylinder and like driving and withdrawal
Inventor: AUGER HAROLD
IPC: E21B3/025
Filed: 1954-01-25
Abstract: 755,427. Driving and withdrawing piles. BRAITHWAITE & CO., ENGINEERS, Ltd. Jan. 20, 1955 [Jan. 25, 1954; May 21, 1954]. Nos. 2139/54 and 14959/54. Class 68(2) [Also in Group XXIX] A pile is turned about its own longitudinal axis by a tangentially applied force, the means being so arranged that, if necessary, a component of the force may be exerted axially of the pile to produce longitudinal movements of the pile. As shown in plan in Fig. 1, the pile P is engaged by releasable clutch parts 12. 13. 14 which turn it, the whole equipment being carried by a triangular frame consisting of side members 1 and stiffeners 2, the frame being anchored to the ground by jacks 4. The turning of the pile is effected by six double-acting hydraulic cylinders 10 pivoted at 10a to the side members 1, the rods 10b being connected at 8 to horizontal rockers 5 on pivots 6, each rocker 5 being thus connected to two cylinders 10. The rockers are kept in synchronism by connecting links 9. Rods 15, 16 connect the rockers to the clutch parts 12, 13, 14 which are oscillated around the pile axis as the rockers are operated by the cylinders 10. As the pile sinks or rises, the plane of the clutch parts 12-14 alters relatively to the plane of the rockers 5, so that it is necessary to make the rods 15, 16 telescopically adjustable, which also allows the rods which are, at the moment, thrusting on the clutch to shorten whilst the other rods are lengthening. The minimum effective length of each rod is that which allows it, as in Fig. 10, to become substantially co-planar with the clutch a roller-ended stop 17 preventing the clutch from dropping below this position, by bearing on a track 17b. The stop includes a spring which is compressed as the pile sinks, and which returns or lifts the clutch on the pile when the clutch is released for repositioning. When a pile is being withdrawn, Fig. 12. it is necessary to increase the minimum lengths of the rod's 15. 16, by inserting sleeves 15b, and springs 15c, 16c are provided for cushioning the fall of the clutch on the pile when it is released for re-positioning. The clutch parts 12, 13, 14 are pivoted together and the parts 13, 14 are connected by a toggle lever system 18 operated by a double-acting hydraulic cylinder 19 pivoted to the part 14. clutch engagement and disengagement being thereby effected. Pressure liquid is supplied to. the cylinders 10 and the cylinder 19 in appropriate sequence, the control being either manual or by an automatic system (see Group XXIX) operated by the swinging of one of the rockers 5. If the apparatus is used for turning a screw pile, the pile is turned unidirectionally and one rod 15, 16 in each pair may be omitted. The clutch, moreover, may be arranged to maintain itself closed until positively opened, or may be of a type not requiring positive opening, or may be self-energized, i.e., is engaged or disengaged by -the driving torque as it is applied and released. The equipment may be operated unidirectionally and intermittently without return stroke.