GB726734A - Improvements in sash-windows - Google Patents

Abstract

726,734. Window fastenings. HEDERUS, N. F. R. May 11, 1953, No. 13119/53. Class 44. [Also in Group X] In a sash window having guide grooves 10, Fig. 1, in the vertical sides 3 of the fixed window frame, the sash 5 being such that its external contour lies wholly within the internal contour of the window frame so that the sash is completely detachable without removing any parts of the window frame, the sash carries on each side a vertical latch rod 11 having extensions 12 so that on rotating the rod the extensions may engage the guide groove to clamp the sash in the closed position or engage the groove to allow the sash to slide with respect to the frame or be disengaged from the groove to allow the sash to be removed from the fixed frame. Each rod 11 which is housed in a longitudinal track 16, Fig. 9, along the edge of the sash is operated by a lever 13 which is pivotally mounted on the rod 11 by means of an angularly positioned portion. The lever 13 is guided by the edges of a recess 18, Fig. 5, in a fitting 19 secured to the sash and when in the position shewn in Fig. 5, the rod 11 is so rotated that its extensions 12 lock the sash in the closed position, the sash being pressed against its stopping 20. On moving the lever 13 to the horizontal portion of the recess 18, shewn in dotted lines, the extension 12 press the sash away from stopping 20 and engage grooves 10 to allow sliding movement Further movement of the lever 13 is prevented by a sliding plate 22. On moving the plate 2: upwardly by its knob 23, the lever 13 may be moved to the end of the horizontal portion o recess 18 thus releasing extensions 12 from the grooves 10 and allowing removal of the sash Since the lever 13 is pivoted on the rod 11 by i portion making an angle of about 10 degrees with a plane perpendicular to the latch rod, the movement of lever 13 vertically downwards to the locking position causes an increase of the pressure exerted by the sash towards the window frame. In a modification this effect is enhanced by giving to the left hand edge of recess 18 a wedge-like obliquity. The sash is balanced by cords 27 having their lower ends hooked to the sash and their upper ends wound round the larger area of frusto-conical pulleys 26 rotatably mounted in the top member 1 of the window frame the extreme upper ends of the cords being secured to the pulleys, and cords 28 are secured to the smaller ends of the pulleys, wound around the smaller ends, and have their opposite ends secured to springs 30. In a modification the cords 27, 28 associated with each pulley 26 are formed from a single cord being secured to the pulley where it passes from the pulley part of larger area to that of smaller area.