GB2087027A - Connector for framework components - Google Patents

Abstract

A device for connecting between a multi-grooved pillar member and a multi-grooved beam member, comprises an elongated casing (10, 11, 11') and operating means (13) slidable in said casing between retracted (operative) and advanced (inoperative) positions. The operating means have hook portions (15) adapted to engage said pillar member to connect between the pillar member and beam member in said retracted position, and a wedge member (20) including an arrow-shaped leading end (21) to cause said hook portions to separate and engage said pillar member when said operating means are in the retracted position. <IMAGE>

Description

SPECIFICATION Framework components This invention relates to improvements in a locking device for connecting between a multigrooved hollow pillar member and a multi-grooved hollow beam member which have been of late increasingly used for providing a framework portion or partition of a show case or shelf.

There have been proposed and practically employed a variety of locking devices of this type, and the locking device of this type is inserted into the hollow body of a multi-grooved hollow beam member until a threaded hole in the base or rear end of the device aligns with a through hole in the beam member and a screw is screwed through the through hole into the threaded hole to cause the hook portions at the leading end of the locking device to protrude out of the leading end of the multi-grooved beam member into a multi-grooved hollow pillar member adapted to be connected to the beam member, and to expand or separate from each other to abut abainst the inner wall of a selected one of the grooves on the pillar member, or the hook portions at the leading end of the locking device which protrude out of the beam member are caused to grip the edges of the adjacent grooves in the pillar member.

However, in the conventional locking device referred to hereinabove, since the connection between the multi-grooved hollow pillar and beam members rely upon the abutment force provided by the expansion or separation of the hook portions of the locking device against the selected groove in the pillar member, or the gripping of the edges of the adjacent grooves in the pillar member by the hook portions, when the magnitude of a load applied to the beam member exceeds the abutment force, the beam member easily slides down the pillar member and thus the conventional locking device can not provide a sufficient locking force when any excessively high load is applied to the beam member.

Therefore, the present invention aims to provide a locking device for connecting between a multi-grooved hollow pillar member and a multigrooved hollow beam member which can effectively eliminate the disadvantages of the prior art locking devices of the type and which is simpler in construction.

According to the present invention, there is provided a locking device adapted to be received in the hollow body of a multi-grooved hollow beam member to connect said beam member to a multi-grooved hollow pillar member, which comprises an elongated casing of U-shaped crosssection open at the opposite ends and having a threaded hole in one of the opposite side walls of said casing, an operation means extending within said casing for movement between operative and non-operative positions along the longitudinal axis of the casing and having hook portions for engaging and disengaging from a selected one of the grooves in said pillar member, and a wedge member received in said operation means to cause said hook portions to engage and disengage from said selected groove in the grooved pillar member as said operation means moves between said operative and nonoperative positions.

The above and other objects and attendant advantages of the present invention will be more readily apparent to those skilled in the art, from a reading of the following detailed description in conjunction with the accompanying drawings which show one preferred embodiment of the present invention for illustration purpose only, but not for limiting the scope of the same in any way.

The accompanying drawings show one preferred embodiment of the locking device constructed in accordance with the principle of the present invention, in which: Fig. 1 is a perspective view of said locking device with the top plate detached from the casing; Fig. 2 is a plan view on an enlarged scale of said locking device in horizontal section showing the device in its unlocked position; Fig. 3 is similar to Fig. 2, but shows the device in its locked position; and, Fig. 4 is a perspective view of multi-grooved hollow pillar and beam members to be locked together by said locking device of the present invention.

The present invention will be now described, referring to the accompanying drawings in which one preferred embodiment of the locking device of the invention is shown for illustration purpose.

The locking device of the invention generally comprises an elongated flat bottom plate 10 and a pair of opposite side walls 11, 11' which have the same length as the bottom plate 10 and are connected at the bottom to the inner or upper surface of the bottom plate 10 at the opposite side edges of the latter by means of conventional tongue and groove connection means (not shown) to form an open-ended casing of U-shaped crosssection as seen in end elevation.Each of the side walls 11, 11' is formed on the top thereof with an upright ear 1 a which is adapted to be press-fitted in the associated one of recesses 1 2a, 1 2a formed in an elongated flat top plate 12 which has the same dimensions as the bottom plate 10 and covers the casing formed by the bottom plate 10 and side walls 11, 1 1'. The side walls 11, 11' also include aligned openings 1 b, 1 'b, respectively, the purpose of which will be described hereinafter.

The side wall 11 also has on the outer surface a bulge 1 C provided with a threaded hole in which a hollow screw 23 having a pointed leading edge and a hexagonal threaded inner surface is to be received. One of the side walls 11' is recessed at 1 'c to provide an abutment the the purpose of which will be also described hereinafter. The bottom of the recess 1 'c is provided in the center thereof with an opening 1 'dfor the purpose to be described hereinafter.

A slidable operation means 1 3 extends longitudinally and is slidably received in the casing formed by the bottom plate 10 and side walls 11, 1 1', and comprises a pair of similar elongated upright plates 14, 14 put together back to back.

The one or leading ends of the plates 14, 14 are bent outwardly in opposite directions at right angles with respect to the rest of the plates to provide hook portions 15, 15 of which a description will be made hereinafter, and the plates are rigidly secured to each other at 1 6 adjacent to the other or rear ends thereof by means of, for example, spot welding. The plates 14, 14 include openings 17, 17 which coextend over a substantial length between the hook portions 1 5, 1 5 and the spot welding 1 6, for the purpose to be described hereinafter. The rear or right-hand edge of the opening 17 in the plate 14 which faces the side wall 11 is bevelled at 1 8 for the purpose to be described hereinafter.

A wedge member 20 having a substantially arrow-shaped leading end portion 21 as seen in plan, is received in the openings 17, 17 in the plates 14, 14 and in the openings 11 b, 1 1 'b in the side walls 11, 1 1'. The wedge member 20 includes a pair of projections 22, 22 extending outwardly in opposite directions from the opposite sides of the member, to be received in the openings 1 1 b, 1 1 'b in the side walls 1 1, 1 1'.

All the components of the locking device of the present invention as described hereinabove are formed of rigid material such as steel.

Now, a description will be made of an instance in which the locking device having the components of the above-mentioned construction and arrangement is employed for locking a multigrooved hollow pillar member 30 and a multigrooved hollow beam member 40 together (see Fig. 4, for example) which form a framework portion or partition of a show case or shelf. As shown in Fig. 4, the pillar member 30 comprises a hollow body of square cross-section having vertical grooves 31, 31 formed on its vertical two adjacent faces disposed at right angles to each other. Each vertical groove 31 is defined by the associated one face of the hollow body of the pillar member serving as the bottom of the groove and a pair of opposite and spaced side walls extending outwardly from the bottom and bent at the leading or outer edges 32 towards each other at right angles with respect to the rest of the side walls.Similarly, the beam member 40 comprises a square cross-section body having horizontal grooves 41 formed on its three adjacent horizontal faces disposed at right angles to each other. Each horizontal groove 41 is defined by the associated one face of the hollow body of the beam member serving as the bottom of the groove and a pair of opposite and spaced side walls extending outwardly from the bottom and bent at the leading or outer edges 42 towards each other at right angles with respect to the rest of the side walls.

The horizontal face of the hollow body where the intermediate groove 41 is formed includes a through hole 43 for the purpose to be described hereinafter.

In connecting the horizontal beam 40 to the pillar member 30 at a desired height along the pillar member, the leading end of the beam member 40 is maintained in abutment against a selected one of the two grooves 31 on the pillar member 30 with the intermediate groove 41 on the beam member 40 where the through hole 43 is formed facing inwardly (on the right-hand side as seen in Fig. 4) and the locking device of the invention is inserted into the hollow body of the beam member 40 at the rear end thereof (the right-hand end as seen in Fig. 4) and moved within the hollow body of the beam member until the opening 11 C in the side wall 11 aligns with the through hole 43 in the hollow body of the beam member 40.In this position of the locking device, the hook portions 1 5, 1 5 at the leading ends of the plates 14, 14 of the operation means 13 protrude out of the leading end of the beam member 40 into the adjacent groove 31.

Thereafter, the hollow screw 23 is inserted through the aligned through hole 43 and the threaded hole in the bulge 11 c and then driven by a suitable driver (not shown) in the tightening direction. As the screw 23 is driven in that direction, the pointed leading edge of the screw 23 moves down along the bevelled face 1 8 at the rear edge of the opening 1 7 formed in one of the plates 14 of the operation means 1 3, until the pointed leading edge of the screw is received in the opening 11 'din the recess 11 'c to cause the operation means 13 to retract gradually within the casing.As the operation means 1 3 retracts, the arrow-shaped leading end portion 21 of the wedge member 20 is forced to advance into the clearance between the plates 14, 14 to separate the plates from each other whereby the hook portions 1 5, 1 5 at the leading ends of the plates 14, 14 tend to abut against the bent leading edges 32, 32 of the particular groove 31.The abutment force of the hook portions 1 5, 1 5 applied against the bent edges 32, 32 of the groove 31 increases to a predetermined maximum value when the screw has been fully driven into the threaded hole 11 c in the side wail 11 of the casing and the abutment of the hook portions 15, 1 5 against the leading edge 32 and the tightened screw 23 firmly hold the pillar member 30 and beam member 40 in their assembled condition with the hook portions 1 5, 1 5 abutting against the leading edges 32, 32 of the groove side walls.When it is desired that the pillar and beam members 30, 40 are disconnected from each other, the hollow screw 23 is loosened to allow the operation means 1 3 to advance within the casing and as a result, the plates 14, 14 of the operation means 1 3 resiliently return to their normal or original contacting positidn in which the hook portions 1 5, 1 5 at their leading ends disengage from the side wall leading edges 32,32.

As clear from the foregoing description on the preferred embodiment of the present invention, according to the present invention, as the screw 23 is driven into the threaded hole 11 c in the side wall 11 , the operation means 13 retracts within the casing, the wedge member 20 tends to gradually separate the hook portions 1 5, 1 5 from each other to cause the hook portions to firmly abut against the side wall leading edges 23 of the groove 21 whereby the pillar member 30 and beam member 40 are firmly connected together.

Thus, different from the conventional locking device of this type in which the connection between the pillar and beam members solely relys upon the abutment of the expanded hook portion against the pillar member groove side walls, according to the present invention, both the fastened screw and expanded hook portions firmly hold the pillar and beam members in their connected condition and thus, the present invention will contribute to the art greatly.

While the present invention has been particularly shown and described with reference to the preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

Claims (6)

1. A locking device adapted to be received in the hollow body of a multi-grooved hollow beam member to connect said beam member to a multigrooved hollow pillar member, comprising an elongated casing of U-shaped cross-section open at the opposite ends and having a threaded hole in one of the opposite side walls of said casing, an operation means extending within said casing for movement between operative and nonoperative positions along the longitudinal axis of the casing and having hook portions for engaging and disengaging from a selected one of the grooves in said grooved pillar member and a wedge member received in said operation means to cause said hook portions to engage and disengage from said selected groove in the grooved pillar member as said operation means moves between said operative and nonoperative positions.

2. The locking device as set forth in Claim 1, in which said operation means comprises a pair of elongated plates put together back to back and having said hook portions at the leading ends and secured together at the rear ends, said plates having through openings between said leading and rear ends, and said wedge member is received in said through openings in the plates and has an arrow-shaped leading end adapted to separate said hook portions from each other to cause the hook portions to engage said selected groove in the grooved pillar member as said operation means moves to said operative position.

3. The locking device as set forth in Claim 2, in which the rear edge of said opening in one of the plates is bevelled and a screw having a pointed leading edge is received in a threaded hole so that said pointed leading edge of the screw is guided along said bevelled edge as the screw is driven into the threaded hole.

4. The locking device as set forth in any preceding Claim, in which the opposite side walls of said casing have aligned through holes and said wedge member has a pair of projections extending from the opposite sides of the member in the opposite directions and received in said through holes in the opposite side walls.

5. A locking device for connecting a grooved beam member to a grooved pillar member, substantially as hereinbefore described with reference to the accompanying drawings.

6. The features as herein described, or their equivalents, in any novel selection.