Patent GB-1478021-A (GB)
Title: Releasable fastenings
IPC: F16B1/00
Filed: 1975-02-04
Abstract: 1478021 Releasable fastening FERRANTI LTD 4 Feb 1975 [7 Feb 1974] 05773/74 Heading E2A  A releasable fastening 10 comprises two members 11, 18 relatively movable in order to be fastened together, one of the members (e.g. 11) having latching means 15 actuated by the other member (18) during relative movement leading to fastening of the members 11, 18, separation of the two members, when fastened, being prevented by the latching means 15, which however are operable by hand or mechanical means for allowing release of members 11, 18; the arrangement is such that when the two members 11, 18 are fastened they themselves restrict relative movement in all directions orthogonal to that of the relative movement leading to fastening. In the embodiment of Figure 1 the member 11 may be fixed to a baseboard by the lower edges of sidewalls 12. Each sidewall 12 is formed with notches 13 for latches 15, a spring 16 biasing the latches 15 towards the inner ends of the notches 13. The movable member 18 which may be fastened to the object to be secured to the baseboard is of channel form and has slots 19 in the ends of the sidewalls; the sidewalls between the slots 19 and the lower edges 20 present sloping edges 21 which act against the latches 15 to move them along notches 13 against the bias of spring 16 as the movable member 18 is slid over member 11. A bar 17 prevents the middle portion of the spring 16 from being displaced with the latches 15 so that they are carried over the ends of the sloping edges 21 into slots 19 to fasten the members 11, 18 together. A protrusion 23 on the member 11 also engages in a recess 22 in member 18 to restrict movement of the members 11, 18, and the surface 24 of the member 18 abuts the upper surface 25 of the member 11. Figure 3 (not shown) illustrates an alternative form of movable member made from sheet material and having stepped shoulders (46) to locate the latches (15). In the embodiment of Figure 2 (not shown) the uppermost edges (54) of the notches (53) in the fixed member (51) slope upwards at an angle of about 10‹. In the embodiment of Figure 4 the fixed member 71 is of channel form, and the movable member 78 of channel form will fit inside the member 71.  In the embodiment of Figure 5 (not shown) two springs (96) located one on the outside of each sidewall of the fixed member (91), instead of a single spring inside, bias the latches (95) together. The movable member (98) is in the form of an elongate e.g. rectangular bar with sloping ends. In the embodiment of Figure 6 the fixed member 131 is of channel form with slots 133 having latches 135 extending therethrough which latches 135 are biassed to the ends of the slots by a leaf spring 136. The movable member 138 is formed with slots 139 to engage latches 135. The ends of the slots 133 curve or slope. In a modification, a latch may be provided at only one end of a fixed member, the movable member being hooked around a fixed bar at the other end and pivoted into position. A sloping edge may be provided on only one of the members. A key and keyway (or spline and groove) may replace the protrusion and recess (e.g. 23, 22 of Figure 1). The ends of the latch may be enlarged and the latch may be T-shaped to prevent the latch being displaced sideways during operation. The sidewalls of the fixed member may have flanges for securing to the base board.