GB945201A - Improvements in or relating to boring holes - Google Patents

Abstract

945,201. Boring earth; piles. R. A. LINES. Feb. 14, 1962 [Feb. 15, 1961; June 23, 1961(2)], No. 5597/62. Headings E1F and E1H. [Also in Division F2] A hole for a pile, or a hole in soft earth, is bored by inserting an auger 10 through a casing 11, positioning a blade 15 on the auger to cut a diameter at least equal to the outer diameter of the casing, boring the hole in the earth whilst maintaining the casing in the hole behind the cutter and withdrawing the auger from the casing. When the auger has reached its maximum depth an extension is fitted and boring is continued, and when the casing has been completely forced into the ground by a jack 12 an additional section of casing is fitted. When the hole is bored to the required depth, concrete 18 is poured into the casing to form a pile, the casing being removed from the hole. The casing may comprise concrete pipes which are permitted to stay in the hole with the concrete. The drive shaft 25 for the auger and the jack are carried by a tractor (Fig. 1 not shown). The jack carries an adaptor 36 which engages a male part of a bayonet joint at the top of the casing, the adaptor being released from the casing by rotating a ring 32. Each section of casing comprises inner and outer tubes 50, 51, the upper end of the inner tube carrying a male part of a bayonet joint and the lower end of the outer tube carrying a female part. The auger is a helical one with a cutting head pivoted on an offset boss 65 so that the head may be rotated to set the blade in cutting position. The blade is pivoted to the head and held by a spring latch 70 so that if the blade has not been retracted it pivots on engagement with the casing. The head has radial blades 72, and the shaft 25 has a paddle 44 for discharging spoil through windows 45 in the jack. In a modification of the auger, the head is fitted to a bucket and the major length of the helical flight is dispensed with.