Patent GB-1128475-A (GB)
Title: A separable seam assembly and associated seam opening and closing device
IPC: A44B19/26
Filed: 1966-01-06
Abstract: 1,128,475. Sliding clasp fasteners. W. A. PLUMMER. 6 Jan., 1966, No. 662/66. Heading E2S. A separable seam assembly includes a pair of interengaging supple resilient extruded plastics tapes 11, 12 and an associated seam opening and closing device 13 slidably mounted on said tapes for opening and closing the seam according to the direction of its sliding movement, said tapes having mounting webs 20 and respectively interengaging parts of substantially T and U shape in cross section, the stem 22 of the substantially T-shaped part entering between the legs 23 of the substantially U-shaped part, the head 21 of the substantially T-shaped part having portions 28 partly embracing the free extremities of the legs of the substantially U shaped part the embracing portions of the substantially U shaped part and the extremities of the legs being formed with inclined interengaging surfaces the stem of the substantially T-shaped part and the interior surface of the substantially U-shaped part being likewise formed with inclined interengaging surfaces, the inclined surfaces forming a fluid seal and the inclination of all the surfaces being such that under load conditions tending to open the seam, the interengaging surfaces tend to move more firmly in inter-engaging relationship the seam opening and closing device being contoured internally to open and close the legs of the substantially U-shaped part and move the embracing parts of the substantially T- shaped part into and out of their seam closing position. As shown the legs of the substantially U-shaped part are bowed inwardly towards one another to engage the adjacent surfaces of said T stem to form a supplemental fluid seal between the contacting surfaces. The opening and closing device 13 is formed along its opposite longitudinal sides with slots for the mounting webs 20, the device adjacent the substantially T and U shaped parts having tangs 54 for engaging said parts to move them into interengagement when the device is moved in one direction the device including means 56, 60 for disengaging the portions 28 of the substantial T-shaped part from outwardly directed projections 32 of the extremities of the legs of the substantially U-shaped art when the device is moved in the opposite direction and opening the legs of the substantially U- shaped part to disengage inwardly directed portions 30 of the legs from outwardly directed projections 25 of the stem of the substantially T-shaped part and thereafter separating the tapes, the projections 32 and 25 and the portion 28, 30 provide the inclined interengaging surfaces. As shown the body of the device 13 consists of three main parts, a pair of generally rectangular and similar outer casing halves 40, the interior surfaces of which are mirror images of one another, and a spacer member 41 which holds the casing halves 40 sufficiently apart to provide the slots for the web 20 and which also provides the means 56 and 60, the means 56 being a flange which has a narrow knife-like edge at one end and bulges to a considerably thicker size at its other end which is close to the tangs 54; the flange opens the legs of the substantially U shaped part as the device is moved in the opening direction The means 60 are a pair of ramp members which lie on opposite sides of a key-hole slot 53 which receives the stem of the substantially T-shaped part; the ramp members force the projections 28 to open away from one another and become disengaged from the projections 32 of the substantially U-shaped part as the device 13 is moved in the opening direction. The opening and closing movement of the substantially T and U shaped parts is assisted. by the interior contour of the casing halves. A handle is attached to the upper casing half to aid the opening and closing movement of the device 13.