Patent GB-1334258-A (GB)
Title: Clamp assemblies
IPC: F16B7/06
Filed: 1971-02-02
Abstract: 1334258 Clamps GRAY TOOL CO 2 Feb 1971 3716/71 Heading E2B [Also in Division F2] A clamp assembly comprises a circular, segmental clamp 36 and a peripheral wall 82 surrounding the clamp which is adapted to clamp together the flanges 24, 26 of a pair of conduit parts 12, 14, the clamp comprising a plurality of interconnected segments 38 and incorporating between two such segments an expansion and contraction device 64 actuable in a first sense to move said two segments towards one another for contracting the clamp against the flanges and actuable in an opposite sense to move said two segments away from one another for expanding the clamp to free the flanges, the peripheral wall encircling the clamp and being arranged to be engaged by and to radially confine the segments upon expansion of the clamp, a plurality of cams carried by one of said conduit parts and disposed axially adjacent said clamp at a plurality of angularly spaced locations and cam followers on the clamp at a corresponding plurality of angularly spaced locations. The cams and the cam followers are interengaged and cooperate together so that they act: upon initial contraction of the clamp from an expanded condition, to move the clamp segments in a first group furthest from said expansion and contraction device generally radially inwardly and the clamp segments in two second groups nearest said expansion and contraction device on angularly opposite sides thereof angularly towards said expansion and contraction device and the clamp segments in two third groups respectively angularly intermediate said first group and second groups radially inwardly at a lesser rate than the segments of said first group and angularly towards said expansion and contraction device at a lesser rate than the segments of said second groups; upon further contraction of said clamp to a contracted condition, to move the clamp segments in said third groups radially inwardly to the same radial extent as the segments of said first group; upon initial expansion of said clamp from a contracted condition, to force said clamp segments in said third groups radially outwardly into engagement with said generally peripheral wall; and upon further expansion of said clamp to an expanded condition. to move said clamp segments in said third groups angularly of said clamp in guided sliding contact with said peripheral wall, to move the clamp segments in said second groups radially outwardly into engagement with said peripheral wall and angularly away from said expansion and contraction device, and to move the clamp segments in said first group generally radially outwardly, whereby in contracting, the clamp segments are progressively brought into contact with the flanges beginning with the segments furthest from the expansion and contraction device and whereby in expanding, the clamp segments are progressively removed from contact with the flanges beginning with the segments nearest the expansion and contraction device. As shown, arcuate segments 38 are connected by hinge pins 62 and links 66, the clamp being contracted or expanded by a rotatable screw 84 engaged in trunnions 92, 94, the stub axles 96 of which when the clamp is contracted are lodged in a slot in a locking plate 106 hinged at 108. The cam slots 100a, 100b and 100c are provided in an annular support plate 78 secured to the conduit 14 and carrying the wall 82, the segment connecting pins 62a, 62b and 62c being extended into the slots to act as cam followers; slots are also provided for engagement therein of the stub axles 96. Each segment is provided with a groove to engage the correspondingly shaped flanges of the conduits. In modifications, (a) the support plate 78 is carried on a sleeve 43, Fig. 5, slidable axially on the conduit 14, (b) the clamp assembly, Fig. 9b, is inverted and carried by the conduit 14, the clamp being supported on springs 154 provided at each pin projection 62a, 62b, 62c so that the clamp is urged upwardly and (c) the support plate 78, Fig. 13, seats on a radial flange on the conduit 14.