GB656738A - Improvements in or relating to pipe tongs for making and breaking well pipe joints - Google Patents

Abstract

656,738. Screwing-up and unscrewing wellpipe sections. GRABLE, D. B., and JACKSON, J. M. May 11, 1948, No. 12902. [Class 83 (iii)] Pipe tongs for making and breaking well pipe joints comprise upper and lower body sections having aligned recesses to receive a pipe, lateral openings in the sections through which the pipe may enter upon movement transversely of the pipe, each of said sections including a lever extending outwardly from the pipe, interlocking elements on the sections for supporting one from the other while permitting relative oscillation thereof about the pipe axis, pipe gripping means carried by each section and fluid-pressure actuated means carried by the tongs and operable between the levers to effect said relative oscillation. The upper section 11 carries pipe-gripping elements comprising fixed-jaw inserts 28, Fig. 2, and a movable jaw 40 connected to the rod 46 of a piston and cylinder device 45. The lower section 12 has a similarly operated movable jaw 55 but one of the opposite gripping elements 30 is backed by springs 33 and stands proud of fixed-jaw inserts 31. The outer ends of the two sections are connected to the piston and cylinder respectively, of an air-operated power means for producing relative movement between the sections. A swivel joint for this movement is made, after the sections have been passed transversely over a pipe joint J, Fig. 1, by a split ring 35, Fig. 2. A spinner mechanism 22 is slidably carried on the upper section and includes a depending bracket 50 connected through a compression spring 48 with the piston 46 of the upper gripping cylinder. The wheel 62 of the spinner is driven by gearing from a fluid motor or turbine 65. Spring-pressed rollers 88 support the pipe 16 opposite the spinner wheel. A control box 73, Fig. 1, enables air at low-pressure to be supplied, firstly, to the gripping cylinders which brings the spinner roller and light gripping means into operation to take up the screwed joint J to a snug condition. Secondly, highpressure fluid is next introduced to operate the main gripping elements and the cylinder 56 is put under pressure to produce relative rotation of the upper and lower sections to complete the tightening of the joint.