Patent GB-683566-A (GB)
Title: Improvements in and relating to window sash balances for hinging sashes
IPC: E06B3/50
Filed: 1950-07-27
Abstract: 683,566. Windows. MATTHEWS, E., and UNIQUE BALANCE CO., Ltd. July 13, 1951 [July 27, 1950], No. 18776/50. Class 20(iii) A slidable window sash 4 balanced by a spiral or helical spring 31b which is wound or unwound by the action of an elongated spiral member 31 when the sash is lowered or raised, and adapted to be swung on hinges 9 when required, is detached from the balancing spring by means of a device comprising a shaped part or lock fitting attached to the lower end of the spring balance and formed to be engaged with and disengaged from the sash at the side opposite the hinges when the sash is swung, and means brought into operation by this relative sliding movement for securing the lock fitting against vertical movement prior to its disengagement from the sash and for releasing it after re-engagement with the sash. The window shown includes upper and lower sliding sashes 2, 3 and 4, 5 guided by frame members 6, 7, and supported by spring balances housed in grooves 8. Sashes 4, 5 may be swung inwardly for cleaning on hinges 9, each comprising a leaf 10 secured to the frame, and' a leaf 11 formed with slots 14 which are engaged by screws at 15 on the side rails 16 of the sash. When not in use leaves 11 are folded, but for operation the sash is raised slightly, leaves 11 opened, and the sash lowered so that the screws 15 engage slots 14. At the side opposite to the hinges a part of the sash retaining head 19 can be swung outwardly to permit the swinging of' the sash. A hollow dove-tail section metal fitting 23 with an outwardly extending striker pin 24 is secured in a recess 21 at the free side of the sash, the ends 25 of the fitting being bent inwardly and being relatively inclined, see Fig. 6. The metal lock fitting has a hollow body 26 with a detachable cover plate 27, the body being chamfered and inclined so as to slide into the fitting 23. The lock fitting is secured to the end of the spiral element 31 by means of a bifurcated headed pin 32 which passes through a hole in a lug 29 of the fitting and receives the end of element 31 to which it is secured by a cross-pin 33. The element 31 can be adjustably rotated by the pin 32 which is held by a ratchet against rotation by the spring. A sliding bolt 34 in the body 26, which can be projected to engage in a recess 35 in the frame, has a recess 37 which is engaged by a projection 38 on a lever 39 pivoted on a pin 40 in the body 26. The lever 39 has a slot 41 with unequal sides which is engaged by the striker pin 24, the plate 27 being slotted at 42 to admit the pin. Angle section retaining members 43, 44 secured to the frame member 7 receive the lock fitting when the latter is in position to be disengaged from the sash. When the sash is swung the fitting 23 slides off the lock fitting and the striker pin 24 actuates lever 39 to project the bolt 34 through an aperture in the retaining member 43 into the recess 35, and the striker pin can be separated from the lever 39 over the short side of the slot 41. In this position the lock fitting and the element 31 are secured against vertical movement, and the lock fittting is prevented from rotating by the retaining members 43, 44. On the return motion the pin 24 striking the long side of slot 41 actuates the lever 39 to retract the bolt 34. Specifications 384,534, and 465,925. are referred to.