Patent GB-547323-A (GB)
Title: Improvements in or relating to well drilling apparatus, particularly well pipe supports, spiders or gripping devices
IPC: E21B19/10
Filed: 1940-11-15
Abstract: 547,323. Supporting, &c., pipe in wells. BYRON JACKSON CO. Nov. 15, 1940. No. 16546. Convention date, Nov. 21, 1939. [Class 85] Relates to pipe supports, spiders or gripping devices for use in wells. A body, comprising parts 1, 2, pivoted together by superposed pins 72, 76, and adapted to be held closed by a latch 4, has lower and upper eyes 5, 6, and each part 1, 2, contains a pair of serrated slips 10, 11, and 10 1 , 11 1 , which are flatbacked and are received in radial recesses bounded by walls 13, 14; each body part 1, 2, has superposed wedge surfaces 24 .. 27 separated by outwardly extending recesses 28 .. 31 and engaged, when, the slips are in gripping position, by wedge surfaces 17 .. 20 on the latter separated by inwardly extending recesses 21 .. 23 with inclined upper ends, whereby on lifting the slips slightly, substantial outward movement of the latter is allowed. The slips are lifted and moved outwardly by means of shafts 35, 35 1 , rotatably supported in bearings 37, 38 in the body parts 1, 2, and provided with flattened parts 39; bifurcated links 40, with ball and socket connections 47 to the slips, are held to the flattened parts 39 by pins 41 and elongated slots to allow the slips to move at an angle to the shafts 35; 35 1 . To hold the wedge surfaces in engagement, detachable T-headed lugs 55, 60, on the slips engage undercut recesses on the body parts when the slips are in their lower positions, but are free when the slips are raised so as to permit removal of the latter. To ensure simultaneous operation of all the slips, the shafts 35, 35 1 , have eccentric ends connected by a pitman 66, Figs. 2 and 5, in two parts connected by a pivot 69 which, when the slips are raised, is aligned with the pivot pins 72, 76, of the body to permit the latter to open. The slips are preferably lifted by means of a hand lever 87 engaging an extension 85, Fig. 5, of the shaft 35J, this extension having a projection 131 which, when the slips are lowered engages a recess 130 in the latch 4 to prevent opening of the latter; when the slips are raised and the latch is opened, a spring- pressed pin 135 moves outwardly from body part 2 and a lug 137 thereon engages a finger 138 on extension 85 to prevent lowering of the slips. The weight of the slips is partly counterbalanced by pairs of compression springs 90, 91, engaging lugs 92, 93, on the shafts 35, 35 1 . The latch 4 is of stirrup form fitting over pairs of lugs 101, 102, and 110, 111, on the body parts, and is loosely pivoted to body part 1 by pins 106, 106 1 , to permit its weight to be transferred to the lugs; a spring 115 tends to close the latch, which has an auxiliary lock comprising a finger 121 pivoted thereto and constrained by a torsion spring 122 to move into engagement with a recess 120 in the lug 110. On freeing the finger 121, a cam 124 thereon co-operates with lug 110 to force open the latch. Cover plates 140, 141, 142, enclose the shafts 35, 35 1 , and pitman 66, and have openings 143 .. 147 giving access to lubricant fittings 148.. 152. Semicircular guide plates 155, 156, are detachably secured above the body parts 1, 2, to centre the well pipe, and have bevelled inner edges and overhang the slips when the latter are in retracted position. Reference has been directed by the Comptroller to Specification 323,333, [Class 85].