Improvements relating to fastening devices

Abstract

 A fastener is for holding a first panel (P1) (Figure 2) against lifting or hinging relative to a second panel (P2). The illustration shows the fastener in the disengaged position. Spring 30 is used to urge latch member 21 to the illustrated position or to a position in which it underlies the panel P2 when the actuator 17 is generally coplanar with the panels P1 and P2. The fastener includes a lock having a lug 44 which can be turned into engagement with a slot in the sides of the housing 11 upon which the latch and actuator are pivoted, when the latch is in the engaged position.

Description

[0001] This invention relates to fasteners of the kind described in prior Patent GB 1153635 and which comprise a generally U-shaped housing in which is pivoted an actuator plate and, on a separate axis, a latch. The two parts (latch and actuator) are connected together by a link which is pivoted at each end to the respective parts on third and fourth axes. The parts may be coupled together by a torsion spring which has the effect of urging the parts into either of two positions, in a first of which (the latched position) the actuator plate and latch are generally parallel and the latch projects from the housing whereas the actuator may form a cover for the housing, and in the other or disengaged position, both parts are turned through substantially 90^o. By arranging for the link to go over-centres with respect to the pivotal axes of the latch and actuator, the fastener can be arranged so that it cannot be moved from the latched to the released position by pressure applied to the latch itself, but only by pressure applied to the actuator.

[0002] The object of the present invention is to provide an improved version having key actuated locking.

[0003] According to the invention a fastener of the kind comprising a latch part pivoted for movement about a first axis between two angularly related positions, an actuator part pivoted for movement about a second axis between two angularly related positions, and a link connecting the latch and actuator and pivoted thereto on third and fourth axes, in which the third and fourth axes move across a straight line intersecting the first and second axes in movement of the latch and actuator from the latched position to the unlatched position, said parts being pivoted on pins extending across a U-shaped housing, is characterised in that a key actuated lock member is journalled in said actuator and projects into said housing at least in the latched position of the fastener, said lock member including a radially extending locking lug which is arranged to engage in a slot in a side wall of said housing when key turned to immobilise the actuator and prevent its pivoting action from the latched position.

[0004] One presently preferred embodiment of the invention is now more particularly described with reference to the accompanying drawings wherein:-

Figure 1 is a part sectional elevation showing the fastener in the released or unlatched position;

Figure 2 is a sectional view taken at right angles to Figure 1 showing the fastener in the same unlatched position;

Figure 3 is a view similar to Figure 1 but with the latch in the engaged or latched position;

Figure 4 is a view similar to Figure 2 and again with a latch in the engaged or latched position; and Figure 5 is a section taken on the line V-V Figure 4.

[0005] Referring to the drawings, the latch comprises a generally U section housing 11 having out-turned flanges 12 which may be (by way of illustration) secured on the margin of an aperture in a panel P1 by means of screws and nuts as shown. The housing is completed by a closure plate 11a which is provided with a cutout slot of the same shape and size as the actuator member 17 so that when that member is in the closed position of Figure 4 for example it substantially fills that slot.

[0006] The actuator member further comprises bracket 13 which is fixed to the plate 17 for example by rivets 13a or possibly by welding, and the bracket is apertured for pin 14 which extends across the part 11 and hinges the actuator part.

[0007] Latch 21 is similarly hinged on pin 22 also extending across the housing 11 and the latch may be of inverted (as seen in Figure 3) U-shape in cross section with the bridge 23 connecting the side members forming the actual latch abutment surface for engagement for example with a panel P2.

[0008] The bracket 13 and the latch 21 are connected together by a link 25, in this instance in the form of a screw member having a slot at one end for rotation of the screw to enable the effective length to be adjusted. The screw is connected to pin 26 at the bracket 13 end and pin 27 at the latch 21 end and the parts 26, 27 are parallel to the pins 14,22. A torsion spring 30 has one tail hooked around the screw 25 and the other around the pin 22, and between its ends has a loop 32 encircling the pin 27.

[0009] As thus far described the fastener is generally similar to that in Figures 5-8 of the said prior patent GB 1153635 and operates in a similar manner. From the latched position of Figure 4, finger pressure in the area P3 will swing the actuator plate 17 from the Figure 4 position to the Figure 1 position, and finger pressure in the area P4, Figure 2, will swing the actuator plate from that position back to the Figure 4 position. In other words the latch can be opened and closed by pressure applied to either end of the plate 17, as appropriate. It will also be noticed that pressure applied to the end 22a of the latch itself in the same direction as the arrows P3 P4 is ineffective to swing the latch from the Figure 4 position to the Figure 2 position i.e. disengage the latch.

[0010] The invention provides a lock comprising a barrel 40 which may be angularly and axially fast with the plates 17 for example by means of a clip 42. Insertion of the appropriate key in the vicinity of the point P4 Figure 2 will enable locking lug 44 to be angularly turned by the key.

[0011] As best seen in Figures 3,4 and 5 the barrel is located wholly between the side walls of the housing 11 and the lug can be turned by the key so as to project at 46 Figures 3 and 5 through an appropriately shaped and positioned slot in one side wall of the housing 11. In that position, the fastener is locked.

[0012] It will be observed that any attempt to force the fastener to an open condition when locked by applying pressure at the point P3 will place the locking lug 44 in shear and by making that lug of appropriate material the lock can be made particularly strong. It is preferred to have the plate 17 a close fit in the slot so as to minimise the possibility of a crowbar being inserted to apply extra pressure to it.

[0013] The panel P1 may be, for example, hinged so that it can be moved to a position parallel with panel P2, or may be moved bodily into that position and secured by a plurality of these fasteners.

[0014] The face plate 11a is optional, and its presence or absence may depend on the thickness of the material P1, P2 and whether it is particularly required to make the arrangement flush or proud of the surrounding surface. It will also be appreciated that the slot in the material does not require to be cut with precision.

Claims

1. A fastener of the kind comprising a latch part (21) pivoted for movement about a first axis (22) between two angularly related positions, an actuator part (17) pivoted for movement about a second axis (16) between two angularly related positions, and a link (25) connecting the latch and actuator and pivoted thereto on third and fourth axes (26,27), in which the third and fourth axes move across a straight line (B-B) intersecting the first and second axes in movement of the latch and actuator from the latched position (Fig.4) to the unlatched position (Fig.2), said parts being pivoted on pins extending across a U-shaped housing (11), and characterised in that a key actuated lock member (40) is journalled in said actuator and projects into said housing at least in the latched position of the fastener, said lock member including a radially extending locking lug (44) which is arranged to engage in a slot in a side wall of said housing when key turned to immobilise the actuator and prevent it pivoting from the latched position.

2. A fastener as claimed in Claim 1 wherein the housing (11) is U-shaped with out-turned flanges (12) arranged to be secured to a part mounting the latch.

3. A fastener as claimed in Claim 1 wherein the lock member comprises a lock barrel secured to a face of the actuator part (17) so as to be contained between the side walls of the housing (11) when the fastener is in the engaged position.

Drawing