GB529370A - Improvements relating to spring bolts, particularly for windows - Google Patents

Abstract

529,370. Bolt fastenings. MACKENZIE, A., and MACKENZIE, J. Feb. 2, 1939, No. 3572. [Class 44] In bolt fastenings using a spring-loaded bolt rotated by hand to hold the bolt in the position in which the spring is compressed, the bolt has portions of different diameters to provide a shoulder co-operating with the casing or a part carried thereby to limit movement of the bolt in the direction in which compression of the spring occurs. A collar may also be provided on the bolt in known manner to limit movement in the opposite direction. The invention is generally applicable, but is particularly described for use on window sashes. Figs. 1-3 show the bolt 1 slidable in a casing 6 let into the lower sash 2, the casing housing a spring 17 surrounding and serving to shoot the bolt, the spring being compressed on retracting the bolt by ring 15 or knob-handle. A shoulder 19 between bolt positions of different diameter limits movement of bolt in this direction. The spring abuts against one end of the casing and against a collar 18 on the bolt which limits shooting movement of the bolt. The bolt has a portion 20 with flats, slidable in a correspondingly shaped slot in a bush 10, the part 20 being withdrawn from the bush when the bolt is retracted, and engaged by rotation with the inner end of the bush to hold the bolt retracted. The bolt engages an apertured plate 4 secured to the face of the upper sash bar 5. The Specification describes alternative constructions in which parts 10, 20 are replaced by a cross-pin on the bolt cooperating with a slot in the casing, or by a pin in the casing co-operating with a slot in the bolt, and in which the bolt end, which may be tapered or bevelled, engages an aperture in an L-shaped plate mounted on the upper sash bar. Fig. 7 shows the shoulder 19 and collar 18 provided on a bolt which is retracted by the spring 17. In this form the parts 10, 20 may serve to retain the bolt in a partly shot position. When the bolt is fully shot a T-head 29 thereon passes through, and is engaged by rotation behind, an elongated aperture 3 in plate 4, the spring now serving to pull the sashes together. Modifications are described in which parts 10, 20 are omitted, and in which the rear face of the T-head 29 may be conical so as to draw the sashes together by cam action when the head is rotated into engagement behind plate 4.