FASTENING DEVICE FOR SUPPORT STRUCTURES

Abstract: A fastening device (10) for use in support structures wherein the fastening of support members is accomplished by slidably inserting end connectors (22) into slotted fastening devices (10) to produce a final locking fit between the support members and the fastening device; further having a keyed screw (29) which holds the fastening device (10) and support member in an intermediate locking position to aid in the overall assembly of the support structure.

Description: The present invention relates generally to fastening or locking devices and, although it is not so restricted, it relates more particularly to fastening devices for use in lightweight support structures, such as display frames. Structures using the type of fastening devices disclosed in the present application are known generally as space frames and are constructed using lightweight, interchangeable modular elements. One example of a fastening device commonly used on this type of support structure is disclosed in U.S. Patent No. 3,356,395, issued to Dygert, et al on December 5, 1967. The Dygert patent discloses the use of an adjustable clamp to connect the horizontal and vertical members of a support frame. In Dygert, the clamp consists of a fitting through which the vertical support member is inserted. The clamp further includes a bell crank which is rotated to hold the horizontal member at the desired height along the vertical member. A similar fastening device is disclosed in U.S. Patent No. 3,362,738 issued to Dygert, et al on January 9, 1968. This second Dygert patent discloses another adjustable clamp wherein a spring biased pin is used to adjustably hold the horizontal member to the vertical member. Another type of fastening device is disclosed in U.S. Patent No. 3,888,441 issued to Rebentisch on June 10, 1975. The Rebentisch patent discloses the use of a tubular vertical support member having rectangular-shaped openings and a support bracket. The one-piece support bracket consists of an upper T-shaped extension and a lower tab-shaped extension both of which are inserted into the rectangular-shaped openings on the vertical member. A second Rebentisch patent, U.S. Patent No. 3,888,440, issued June 10, 1975, discloses a two-piece support bracket consisting of a locking clip and a separate support arm having a T-shaped extension which is inserted into the rectangular-shaped openings on the vertical member. In AU-A-444,424 there is disclosed a support structure frame adapted for ease of assembly and disassembly comprising a plurality of hollow tubular members of substantially square cross section arranged in first and second groups thereof; a plurality of locking devices, each said locking device having a first end section adapted for insertion into a first end of any of said first group of tubular members, a second end section for engagement inside a second end of any of said first group of tubular members, and an intermediate section which has a cross sectional size approximately equal to that of a tubular member of the first group and which has a slotted opening therethrough; and a plurality of end connectors adapted for insertion and affixing into either end of a tubular member of the second group, each of said end connectors having means for engaging into said slotted opening in said locking device intermediate section. According to the present invention, there is provided a support structure frame adapted for ease of assembly and disassembly comprising a plurality of hollow tubular members of substantially square cross section arranged in first and second groups thereof; a plurality of locking devices, each said locking device having a first end section adapted for insertion into a first end of any of said first group of tubular members, a second end section for engagement inside a second end of any of said first group of tubular members, and an intermediate section which has a cross-sectional size approximately equal to that of a tubular member of the first group and which has a slotted opening therethrough; and a plurality of end connectors adapted for insertion and affixing into either end of a tubular member of the second group, each of said end connectors having means for engaging into said slotted opening in said locking device intermediate section characterised in that each tubular member of the first group has at least one slot in a first end thereof, said slot having a first end access opening, and each tubular member of the first group having an access hole proximate a second end thereof, the tubular members of the second group not having an end slot, and each locking device comprising a threaded locking member for clamping a tubular member of the first group against the first end section of the locking device; the second end section of each locking device having a pair of spreadable walls adapted for engagement inside a second end of any tubular member of the first group thereof and a threaded screw engaged between said pair of spreadable walls, said screw being accessible through said tubular member second end access hole when said second end section is inserted into said tubular member second end; the slot in the said first end having a first end access opening, and the threaded locking member having clamping means which is adapted to clamp a tubular member of the first group to the first end section of the locking device. Such a structure may be used in a variety of support frames. Another advantage of the present invention is that it is particularly designed for use in modular units wherein the individual elements are readily interchangeable. Another advantage of the present invention is that once the elements are initially installed, the framework may be assembled or disassembled without the use of any tools. In its preferred form, a locking device is provided which is suitable for a variety of uses, but which is particularly adapted for use in display frames. The overall framework consists of vertical and horizontal members which are fastened together using the locking device according to the invention. The end connector is preferably fitted into the end of a horizontal member and, during assembly of the framework, is inserted into grooves formed in the locking device. The locking device is preferably attached to one end of a vertical member and is designed to slidably insert into the end of a second vertical member. The locking device further includes a keyed screw to allow the insertion of the end connector into the locking device while the elements are held in an intermediate locking position. Once the end connector has been inserted into the locking device, the keyed screw is turned 90° to allow the second vertical member to slide to the final locked position. As the second vertical member slides into the final locked position, the end connector on the horizontal member is pushed into a narrow groove on the locking device and is rigidly held in position. For purposes of this description, the terms "vertical member" and "horizontal member" are merely illustrative of relative space positions of frame members; in actual practice it is apparent that frame members can be aligned in either orientation. The locking device is preferably adaptable for use in display frames, and is readily replaceable when damaged or broken. It preferably utilizes modular elements to provide a final framework capable of assuming nearly any shape or size. The said intermediate locking position facilitates the assembly of the final structure. The support structure may preferably be assembled or disassembled without the use of screwdrivers, pliers or other tools. The invention is illustrated, merely by way of example, in the accompanying drawings, in which: Figure 1 is a perspective view of a display frame incorporating support structure frames in accordance with the present invention; Figure 2 is an exploded perspective view of a locking device forming part of the support structure frame of the present invention; Figure 3 is a side view of the locking device of Figure 2; Figure 4 is a front view of the locking device of Figure 2; Figure 5 is a top view of an end connector forming part of the support structure frame of the present invention; Figure 6 is a side view of the end connector of Figure 5; Figure 7 is a bottom view of the end connector of Figure 5; Figure 8 is a perspective view with a partial cut away view showing part of a support structure frame according to the present invention in an intermediate locking position; Figure 9 is an exploded view of a support structure frame according to the present invention illustrating the relative positioning of a locking device and end connectors; Figure 10 is a perspective cutaway view of the said support structure frame illustrating the interaction of the end connectors and the locking device; Referring to the drawings, there is shown in Figure 1, a perspective view of a display unit 21 incorporating a support structure frame according to the present invention. The display unit 21 includes a plurality of horizontal members 11 fastened to a plurality of vertical members 12 by means of a plurality of fastening or locking devices 10, each of the members 11, 12 being hollow tubular members of substantially square cross section. The locking device 10 is the basic unit from which many different structures may be assembled. In Figure 1, a group of locking devices 10 attach horizontal members 11 to vertical members 12 to form a first support frame section 13. The first support frame section 13 is then attached to a similarly constructed second support frame section 14 by lateral members 15 to create a framework which may be used as a display frame 16. It should be apparent that not every horizontal, vertical or lateral member shown in Figure 1 need be used. The vertical members 12 contain evenly spaced slots or channels 17 aligned vertically along each face of the vertical members 12 to facilitate attachment of shelves 18 or the like to the display frame 16. Vertical or hook and loop "Velcro" tape members may also have magnetic strips 19 attached to the channels 17 to allow the placement of display panels 20 on the display frame 16. Such display panels 20 would have corresponding magnetic edge surfaces to adhere to magnetic strips 19. The addition of display panels 20 to the display frame 16 creates a rigid display unit 21 which has the appearance of a custom designed display structure. It is contemplated that the horizontal, vertical and lateral members 11, 12 and 15, be constructed of extruded aluminium tubing which may be produced as straight, angled or curved members depending on the desired configuration or size of the display frame 16. The ends of these support members further include 45° fillets 38 (see Figure 9) on their inside corners to facilitate the slidable insertion of end connectors 22 (see Figures 5-7) and locking devices 10 (see Figures 3-4) into the respective support members. The end connector 22 and locking device 10 are preferably constructed of die-cast metal to enable their manufacture to precise specifications and therefore provide a consistently tight fit within the tubular support members. The vertical members 12 may be of uniform construction, preferably formed of extruded aluminium tubing of square cross section. Each of the four elongate faces of a vertical member 12 has a plurality of spaced slots 17 adapted for holding shelf hanging brackets and the like. The ends of vertical members 12 are specially formed to accommodate insertion of locking devices 10. For example, Figure 9 shows respective end portions of vertical members 12, the end portion or slotted first end 31 particularly illustrating a slotted portion 33 and 33a which is designed to accept a keyed screw or threaded locking member 29. Also shown in Figure 9 is an end portion or second end 28 of a vertical member 12, having an access hole 27a which is aligned with threaded locking member 27 (see also Figure 2) after insertion of locking device 10 into the opening of end 28. In a preferred embodiment, both ends of each vertical member 12 may be similarly configured, wherein each end has a slot 33/33a extending inward from the end of one elongate face, and an access hole 27a positioned inwardly of an opposite elongate face. This preferred construction enables either end of vertical member 12 to accept either end of a locking device 10. Figure 2 illustrates the preferred construction of a locking device 10. Locking device 10 may be formed of two essentially mirror image halves 10a and 10b, although some differences exist as between the respective halves 10a and 10b. For example, half 10a has an extended end 24a which has affixed thereto a pedestal 23a. Pedestal 23a has a non-threaded central recess 43 which is sufficiently large to accept an end of set screw 27. Locking device half 10b has an extended end 24b which has affixed thereto a projecting pedestal 23b; however, a threaded hole 44 is tapped entirely through pedestal 23b to accept threaded set screw 27. The length of the threaded set screw 27 is precisely determined so that when the inner end of the set screw 27 contacts pedestal 23a, the opposite end of the set screw 27 is flush with the surface of extended end 24b. Similarly, locking device half 10a has a pedestal 45a affixed to its other end 25a, wherein pedestal 45a has a non-threaded recess 46 which is sized to receive and accept an end of the threaded locking member 29. Locking device half 10b has a pedestal 45b on its other end 25b, but a threaded hole 47 passes entirely through pedestal 45b, and is sized to accept the threads of keyed screw 29. A tapered pin 49 projects from an inner corner surface of locking device 10a, and a tapered recess 50 is formed into the opposite corner surface of locking device 10a. Locking device 10b has a similar recess and pin, each aligned opposite a corresponding pin and recess of locking device 10a, and sized for interference fitting therebetween. Locking device halves 10a and 10b are formed into a unified locking device 10 by compressing the respective raised pins into opposing tapered recesses 50 to thereby force an interfering and bonding fit between the respective raised tapered pin and tapered recess. After the respective halves have been compressed together, the locking device 10 becomes a unitary, single piece. Figures 3 and 4 illustrate another view of the construction of a locking device 10. Locking device 10 is comprised essentially of three sections: an extended end or second end section 24, formed of the two extended end sections 24a and 24b which constitute a pair of spreadable walls adapted for engagement inside the second end 28 of any member 12; a slidable end or first end section 25, formed of the two slidable end sections 25a and 25b; and a central or intermediate section 26 which is formed of the two central half sections 26a and 26b and which has a cross sectional size approximately equal to the cross section of a member 12. The second end section 24 of locking device 10 is inserted into a second end 28 of a vertical member 12. The set screw 27 is then tightened to expand the width of the second end section 24 to provide a tight frictional fit inside the interior surfaces of the vertical member 12. Once the second end section 24 has been inserted into a second end 28 of a vertical member 12, and set screw 27 has been fully tightened, the locking device 10 becomes affixed to the end of vertical member 12, and is normally not removed. The first end section 25 of the locking device 10 includes a threaded locking member 29, for clamping the member 12 against the slidable end 25, and an elongate sliding slot 30 opening into a narrowed slot 35. The length of the threaded locking member 29 is precisely determined so that when its inner end contacts pedestal 45a, the outer end of the threaded locking member 29 extends outwardly from the surface of the first end section 25 with the shoulder section of keying means 32 of the threaded locking member 29 in the slot 33 or 33a of a vertical member 12. The slot 33 on the vertical member 12 is slightly larger than the longest dimension of the keying means 32, and the slot 33a is slightly larger than the narrow dimension of the keying means 32. By turning the threaded locking member 29 to the position shown in Figure 4, first end section 25 fits only partially into an end 31 of a vertical member 12, becoming stopped at narrowed slot 33a, (see Figure 8). Therefore, by turning the threaded locking member 29 to a horizontal orientation, as shown in Figures 3 and 4, the first end 31 of the vertical member 12 is held in an intermediate locking position by the keying means 32 on the threaded locking member 29 which contacts the narrower top slot 33a adjacent slot 33 (illustrated in Figure 8). By rotating the threaded locking member 29 to a vertical orientation (see Figure 9) the shoulder section 32 is turned so as to pass through the narrow slot 33a on vertical member 12. To facilitate the insertion of the end sections 24 and 25, of the locking device 10 into the vertical members 12, chamfers, 53 and 54, are located longitudinally along the corners and ends of the respective end sections 24 and 25. The longitudinal chamfers 53 are preferably deepest along the medial surface of the inner edge and gradually decrease in depth distally outwardly along the edges of each end section 24 and 25. The intermediate section 26 of the locking device 10 has an outside dimension larger than the outer dimension of either the second end section 24 or the first end section 25 to enable the first and second ends 31 and 28 of the vertical members 12 to contact fillets 38 between the corners of the intermediate section 26 and the edges of each end section 24, 25 when the display frame 16 is assembled. The intermediate section 26 further includes a locking slot or slotted opening 35 which is narrower than the slotted opening 30 on the first end section 25. The use of the narrower slotted openings 35 provides a tight fit between the male connector 34 on an end connector 22 and the intermediate section 26 on the locking device 10. Figures 5-7 illustrate the preferred construction of an end connector 22. As in the second end section 24 of the locking device 10, the end connector 22 includes an adjustable set screw 27 to adjust the width dimension between the sides 48 and 49 of the end connector 22. Set screw 27 is threaded through one of the pedestals on side 48 or side 49, and the pedestal on the other side has a non-threaded recess to accept the end of set screw 27. The length of the set screw 27 is precisely determined so that when the inner end of the set screw 27 contacts the non-threaded pedestal, the outer end of the set screw is flush with or just below the outer surface of the end connector 22. As with the extended ends 24 and the slidable ends 25 of the locking device 10, longitudinal chamfers 53 are located along the edges of the end connector 22 and end chamfers 54 are located on the distal end of each end connector 22. The end connector 22 slidably inserts into the end of a horizontal member 11. Once the end connector 22 is inserted into the end of a horizontal member 11, the set screw 27 is turned, through an aligned opening in the horizontal member, to expand the width dimension of the sides 48 and 49 of end connector 22 and to provide a tight frictional fit at contact points within the end of the horizontal member 11. The end connector 22 further includes an outwardly projecting male connector or neck 34 and a guide section or enlarged head 36 extending beyond the end of the horizontal member 11. The guide section 36 extends perpendicularly from the end of the male connector 34 and guides the male connector 34 into tapered engagement with the slotted opening 35. The contact occurs by reason of a tapered interference between the wedged surfaces 51 and 52, against locking device 10, which compensates for all dimensional tolerances between the components. Figures 9 and 10 illustrate the orientation and connection of the end connectors 22 to the locking device 10 for assembly of a display frame 16. Additionally, in the preferred embodiment, an elastic cord 37 is used to maintain the proper end-to-end relationship of the vertical members 12 while the structure is assembled and disassembled. The elastic cord 37 facilitates reassembly of the framework because the vertical members 12 are flexibly coupled. The elastic cord 37 also helps to pull the first and second ends 31 and 28, of the vertical members 12 into close contact with the locking device 10. Assembly of a structure similar to the display unit 21 in Figure 1 may be accomplished rapidly and without the need for numerous specially adapted connectors. During the original assembly of the display frame 16, the end connectors 22 are inserted into the ends of all of the horizontal members 11 and lateral support members 14. Next, the set screws 27 are turned to expand the ends of the end connectors 22 to contact fillets 38 located on the inner corners of the horizontal and lateral members, 12 and 14. Similarly, the second end sections 24 of the locking devices 10 are inserted into the second ends 28 of each vertical member 12 until the second end 28 contacts the fillets 38 on the intermediate section 26. The set screws 27 are then turned to expand each second end section 24 until further fillets 38 on the inner corners of the vertical members 12 are contacted. Once these expandable ends are inserted into their respective support members, they remain attached to the support members and need not be removed unless they become damaged or broken. In practice, the foregoing procedure may be conducted as a factory pre-assembly activity, for it need be accomplished only once, and is not related to the normal steps of assembly and disassembly of the portable framework. A further pre-assembly step which may be accomplished at this time is the attachment of elastic cords to an appropriate arrangement of vertical members 12. This step is accomplished after it has been determined what the vertical height of the display frame 16 is to be in final form. The cord attachment step is illustrated in Figure 10, wherein the elastic cord 37 has respective ends formed into a fixed loop, one loop end being fitted about set screw 27 in a second end 28 of the vertical member 12. The elastic cord 37 is then fed through the interior of one or more further vertical members 12, as determined by the ultimate height of display frame 16, and the other end of the elastic cord 37 is looped about a further set screw 27 in the distal vertical member 12. In this manner, any reasonable number of vertical members 12 may be coupled in a resilient end-to-end relationship, in much the nature of assembly of supporting struts for camping tents. This permits the requisite number of vertical members 12 to be loosely held together and oriented, and facilitates the ultimate assembly and disassembly of a display frame 16. The resiliency of elastic cord 37 also facilitates the snap-locking action which is achieved in cooperation with keyed screws 29 and their associated locking grooves 33 and 33a. Next, the first and second ends 31 and 28, of the vertical members 12 are aligned so that when the threaded locking member 29 of the fastening device 10 is turned to a horizontal position the threaded locking member 29 is aligned with the groove 33 on the first end 31 in an intermediate locking position. The first end 31 of the vertical member 12 is fitted over the first end section 25 until the intermediate locking position is reached. Elastic cord 37 assists in holding the aligned vertical members in this intermediate locking position. When the vertical members 12 are aligned in the intermediate locking position, the end connectors 22 are inserted into the sliding slot 30, and moved into the slotted openings 35. Once the guide section or enlarged head 36 of the end connector 22 is inserted beyond the sides of the slotted opening 35, the threaded locking member 29 is turned to allow the first and second ends 31 and 28, of the vertical members 12 to slide, with the assistance of elastic cord 37, into their final locked position adjacent the fillets 38 on the intermediate center section 26 of the locking device 10. When the vertical members 12 reach their final locked position, the horizontal member 11 and the end connector 22 are in confronting relation with the slotted opening 35 to provide a rigid structural joint wherein the guide section 36 of the end connector 22 prevents any movement of the end connector 22 within the slotted opening 35. This locking procedure is repeated at each joint until a display frame 16 of the desired shape and size is constructed. The threaded locking members 29 may then be tightened to complete the locking procedure. Once the display frame 16 is assembled, panels 20 and shelves 18 may be attached to the vertical members 12. Although the panels 20 are preferably constructed of flexible materials, conventional materials such as plywood or particle board may be used. The panels 20 may be attached to the vertical members 12 by using strip magnets 19 or hook and loop tape, on the back of the panels 20 and on the vertical members 12. These magnets 19 are aligned vertically along both sides of the slots 17 to provide a nearly invisible seam between the panels 20. The use of flexible materials for the panels 20 allows the placement of panels 20 around each end of the display frame 16. Finally, shelves 18 may be added to the display unit 21 by inserting support braces 42 into the slots 17 to provide a surface for placement of the shelf 18. The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention. For example, it is apparent that the present invention may be configured to form an infinite variety of display frame assemblies, beyond the particular embodiments illustrated herein. Vertical, horizontal and lateral members may be curved, angled or formed into unequal lengths to construct practically any type of frame assembly. Complex wall and beam structures may also be formed using the basic teachings of the present invention. Of course, it is also apparent that the basic teachings of the present invention may be utilized for purposes other than portable exhibit frames, including enclosures of all types and configurations.

Claims: 1. A support structure frame adapted for ease of assembly and disassembly comprising a plurality of hollow tubular members (11, 12) of substantially square cross section arranged in first and second groups thereof; a plurality of locking devices (10), each said locking device (10) having a first end section (25) adapted for insertion into a first end (31) of any of said first group (12) of tubular members (11, 12), a second end section (24) for engagement inside a second end (28) of any of said first group (12) of tubular members (11, 12), and an intermediate section (26) which has a cross-sectional size approximately equal to that of a tubular member (12) of the first group and which has a slotted opening (35) therethrough; and a plurality of end connectors (22) adapted for insertion and affixing into either end of a tubular member (11) of the second group, each of said end connectors (22) having means (34, 36) for engaging into said slotted opening (35) in said locking device intermediate section (26) characterised in that each tubular member (12) of the first group has at least one slot (33, 33a) in a first end (31) thereof, said slot (33, 33a) having a first end access opening (33), and each tubular member (12) of the first group having an access hole (27a) proximate a second end (28) thereof, the tubular members (11) of the second group not having an end slot, and each locking device (10) comprising a threaded locking member (29) for clamping a tubular member (12) of the first group against the first end section (25) of the locking device (10); the second end section (24) of each locking device (10) having a pair of spreadable walls (24a, 24b) adapted for engagement inside a second end (28) of any tubular member (12) of the first group thereof and a threaded screw (27) engaged between said pair of spreadable walls (24a, 24b), said screw (27) being accessible through said tubular member second end access hole (27a) when said second end section (24) is inserted into said tubular member second end (28); the slot (33, 33a) in the said first end (31) having a first end access opening (33), and the threaded locking member (29) having clamping means (32) which is adapted to clamp a tubular member (12) of the first group to the first end section (25) of the locking device (10). 2. A support structure frame as claimed in claim 1 characterised in that the said first end (31) has a relatively wide first end access opening (33) leading to a relatively narrow inner access opening (33a), the threaded locking member (29) having a keying means (32) which is adapted to pass through the relatively wide first end access opening (33) in all angular dispositions of the threaded locking member (29) and which is adapted to pass through the relatively narrow inner access opening (33a) when the threaded locking member (29) is in a predetermined angular disposition. 3. A support structure frame as claimed in claim 1 or 2 characterised in that each of said locking devices (10) further comprises a slotted opening (30) in an end section (25) bridging into the slotted opening (35) in the intermediate section (26), the end section slotted opening (30) being of larger dimension than said intermediate section slotted opening (35). 4. A support structure frame as claimed in claim 3 characterised in that each of said end connectors (22) further comprises an enlarged head (36) projecting from a narrower neck (34), said head (36) having a dimension sized to fit through said locking device end section slotted opening (30) but not through said locking device intermediate section slotted opening (35). 5. A support structure frame as claimed in any preceding claim characterised in that there are resilient means (37) for attaching at least two of said tubular members (12) of said first group in relative end-to-end alignment. 6. A support structure frame as claimed in claim 4 characterised in that said head (36) further comprises wedge-shaped surfaces for contacting said intermediate locking section (26). 7. A fastener and lock for use in securing frame structural members of support structures, comprising a) a locking device (10) having an intermediate section (26) and first and second end sections (25, 24), said second end section (24) being attachable to a structural member (12), said first end section (25) being slidably attachable to another structural member (12) and including an adjustment means (29) for releasably holding the locking device (10) and the other structural member (12) in an intermediate locked position; the said intermediate section (26) having a receiving slot (35); and b) an end connector (22) being attachable to one end of a third structural member (11) said end connector (22) projecting beyond the end of the said other structural member and being adapted to be received into said receiving slot (35) in said locking device to produce locking engagement between the end connector and locking device in one direction of movement, the receiving slot (35) extending from the intermediate section (26) of the locking device into the first end section (25) of the locking device and having a larger width dimension in the first end section (25) than the width dimension in the intermediate section of the locking device. 8. Apparatus as claimed in claim 7 characterised by comprising means for magnetically attaching panels to the structural members.

Inventors: BEAULIEU, BRYAN J.
Applicants: BEAULIEU, BRYAN J.
Application year: 1987
Main classification: F16B12
IPC codes: F16B12