GB472518A - Sliding-clasp fastener and method of making the same - Google Patents

Abstract

472,518. Sliding - clasp fasteners. PRENTICE MANUFACTURING CO., G. E. Jan. 13, 1937, No. 1049. Convention date, Feb. 3, 1936. [Class 44] The fastener elements of a sliding-clasd fastener have affixing jaws which, prior to attachment to the stringer, are substantially parallel and separated by a recess having the same contour and dimensions as the head of the fastener. This allows the elements to be cut from a strip of suitable width without waste, as shown in Fig. 5. As shown, the parallel jaws 14, 15 are separated by an arcuate recess 17 identical in form with the head 24 in which a recess 25a is formed together with a projection 25 on the opposite face, Fig. 4. The shoulders 20, 21 are inclined at the same angles as the terminal faces 18, 19 of the jaws. The bottom of recess 17 is approximately midway along the length of the element. When applied to the stringer la, Fig. 6, the jaws 14, 15 are curved, with the faces 18, 19 bearing flat against opposite faces of the stringer. The maximum width of the element, defined by the points 26, 27, lies approximately in the central plane OP of the bead 3 on the edge of the stringer. The jaws 14, 15 being shorter than usual, give greater flexibility to the fastener. When the fasteners are interengaged, Fig. 13, channels are presented on opposite faces of the fastener, and the slider, comprising upper and lower plates 35, 36 connected by the usual wedge member, not shown, is crosssectionally shaped to conform with the fasteners. When used with bags or tobacco pouches &c. having substantially parallel walls, the elements may interengage at an angle, Fig. 20, the slider correspondingly comprising a flanged upper plate 38 and a narrower substantially flat lower plate 41. The fasteners may have covering strips of fabric &c. applied to one or both faces, the arrangement being of the kind in which the covering strips pass through the slider. In applying the strips, the fasteners are first interengaged and covering strips 30, 31, Figs. 8, 9, are secured to one or both faces of the fastening by adhesive, stitching, &c. The strips are then severed lengthwise by cutters 32, 33. The free edges 30a, 31a of the strips may be treated with a binding agent such as cellulosic cement to prevent fraying in use, but the strips may be of braided or other textile which does not readily fray. If desired, the covering strips may be left unsevered at one end of the fastening, if the stringers are not to be entirely detachable from one another. The slider depresses the edges 30a, 31a of the strips into the channels along the fastening.