GB532318A - Improvements in or relating to sliding clasp fasteners - Google Patents

Abstract

532,318. Sliding-clasp fasteners. TULLIO, A. DI., and LIGHTENING FASTENERS, Ltd. July 17, 1939, No. 20768. [Class 44] A locking device for the slider of a sliding- clasp fastener in which the locking member engages the legs of the fastener members by movement substantially parallel to the plane of the fastener is housed within the upper member of the slides and comprises (shown separted) a slider body with upper and lower flanged members 7, 6, Fig. 3, defining the usual guide channels, a cover 4, Fig. 4, secured over member 7 by adhesive, with positioning projection 14 engaged in apertures 15, a pull-tab 5, Fig. 5, and a spring locking member, Fig. 6. The slider body, cover, and tab are of moulded non-metallic material such as a cellulose acetate composition. The locking member is of spring steel or other resilient metal. The tab has a metal pivot pin the ends 24 of which are held in recesses 21 by projections 22. Normally the tab rests against the part 20 of the cover. Member 7 has a V-form groove 8 in which the spring locking member is housed. This member has a segmental portion 9 of slightly greater diameter than the distance between the substantially parallel limbs 9a which are of different lengths and end in prongs 13. These prongs depend through apertures 10 and normally engage between the outer ends of the fastener members by resilient action. When the tab is turned down, the pivot end lies within the part 9 of the spring, but when the tab is raised, this end engages betweeen the shoulders 9b, separates limbs 9a by cam action, and releases the slider. A recess 16a provides clearance for the end of the tab, which has a transverse wire the flush ends 23 of which take the wear. Groove 8 is of sufficient width to allow the requisite movements of limbs 9a. Alternatively, the limbs 9a separate by spring action and the tab is bifurcated to embrace the limbs and positively move them to locking position when the tab is turned down. A single locking member may be used. In a further modification the pull tab is in two parts which normally lie flat at opposite sides of the slider and are pivoted on an axis longitudinal of the slider, each part having means for releasing the locking member when the two are raised to operate the slider.