US 3666298 A
A connector for releasably joining hollow rectangular tubular members. The connector consists of a cubical body with a plurality of spigots projecting therefrom. Each spigot consists of a rigid core of polygonal cross-section enclosed within a resiliently compressible plastic casing having longitudinal ribs corresponding in number to the number of sides of the tubular member. The diameter of the spigot and casing across the ribs is less than the diameter across the diagonals of the tubular member and greater than the diameter across opposite walls of the tubular member. The locked joint is established by inserting the spigot and casing into the tubular member with the ribs aligned with the corners and, by relative rotation of the tubular member and spigot, opposed ribs are brought into an interference fit with opposed faces of the tubular member with a positive lock resulting.
Claims available in
Description (OCR text may contain errors)
[4 May 30, 1972  CONNECTOR FOR JOINING TUBULAR MEMBERS Frederick William Reilly, lslington, Ontario, Canada  Inventor:
Beautiline Limited, Downsview, Ontario, Canada 221 Filed: Jan. 28, 1971 21 Appl.No.: 110,397
 Foreign Application Priority Data Jan. 20, 1971 Canada ..l03,462
 US. Cl. ..287/54 A, 248/239, 287/126  Int. Cl ..E04g 7/00  Field of Search ..248/235, 239, 214, 215, 300-304,
248/307, 340, 287; 287/54 A, 126, 20.92 D, 20.92 Y; 211/148, 153; 312/257; 52/283, 495, 498
3,386,590 6/1968 Gretz ..287/54 A 3,532,369 10/1970 Reilly ...287/54 A 3,545,625 12/1970 MacMillan ..21 l/l48 FOREIGN PATENTS OR APPLICATIONS 656,219 8/1951 Great Britain ..248/235 Primary Examiner-Marion Parsons, J r. Attorney-George l-l. Riches  ABSTRACT A connector for releasably joining hollow rectangular tubular members. The connector consists of a cubical body with a plurality of spigots projecting therefrom. Each spigot consists of a rigid core of polygonal cross-section enclosed within a resiliently compressible plastic casing having longitudinal ribs corresponding in number to the number of sides of the tubular member. The diameter of the spigot and casing across the ribs is less than the diameter across the diagonals of the tubular member and greater than the diameter across opposite walls of the tubular member. The locked joint is established by insetting the spigot and easing into the tubular member with the ribs aligned with the comets and, by relative rotation of the tubular member and spigot, opposed ribs are brought into an interference fit with opposed faces of the tubular member with a positive lock resulting.
4 Claims, 10 Drawing Figures PATENTEU MAY 30 I972 SHEET 3 OF 3 lnvenfor Frederick W. Reilly I") Le) I 9*? m D Afforney CONNECTOR FOR JOINING TUBULAR MEMBERS This application is an improvement on applicants prior U.S. Pat. No. 3,532,369 dated Oct. 6, 1970.
One type of joint in which a vinyl insert is used has been disclosed in literature published by Apton, a division of Metalworks Limited. Essentially, the construction consists of a tapered vinyl insert which is inserted into a tube end. The connector consists of a plurality of tapered spigots, each of size to fit into the vinyl insert. The connection is made by hammering each spigot into the respective tapered insert.
Canadian Pat. No. 841,26l dated May 12, 1970, David H. Peacock inventor, comprises a three part system namely, a square tube, an insert which fits into the tube and which has thickened portions which bridge the corners of the tube and a square spigot which fits into the sleeve and locked therein by rotating the spigot so that the spigot comers jam against the thickened corners.
Applicant's U.S. Pat. No. 3,532,369 discloses a joint in which hollow tubular members are joined together by a connector having a plurality of spigots, each spigot having four diametrically opposite vinyl inserts. The vinyl inserts are separately made and individually affixed in longitudinal grooves formed on the spigot. To complete the joint, the spigot, with the inserts attached, are aligned with the tube corners and then inserted; the tube is then rotated about 45 to the locked position. While this makes a satisfactory joint, it is very time consuming when assembling and also costly to manufacture.
The connector of the present invention for connecting tubular members into a unitary frame comprises a spigot consisting of a substantially rigid core and a resiliently compressible casing surrounding the core and secured thereto so that there is no relative rotation between the core and the casing, the easing having longitudinally extending ribs corresponding in number to inner faces of the tubular member, each rib preferably having two longitudinally extending cheeks formed by a channel formed centrally in and extending longitudinally of the casing. The diameter of the spigot and easing taken across diametrically opposite ribs is less than the distance between diagonally opposite corners of the tubular member and greater than the distance between opposite walls of the tubular member by an amount sufficient to produce a press fit between the inner walls of the tubular member and said ribs with substantial deformation of the said walls, whereby when the spigot and casing are entered in a respective tubular member and rotated to bring diametrically opposite ribs into engagement with opposed inner walls, the connector and tubular member are releasably locked together.
The connector of the present invention will now be described with reference to the accompanying drawings which illustrate a preferred embodiment of the invention. It is to be understood, however, that this is being done by way of illustration and not as a limitation. It will be apparent that alternative constructions can be devised without departing from the essential features of the invention.
In the accompany drawings FIG. 1 is an exploded view of a joint constructed in accordance with this invention with two tubular members shown connected to the connector and another member being connected thereto;
FIG. 2 is a cross-section through an assembled joint showing a spigot entered in the tubular insert in its first position;
FIG. 3 is a cross-section on the same line as FIG. 2 with the spigot and tubular member rotated relative to each other through about 45 into a locked position;
FIG. 4 shows an alternative construction, in cross-section, of the spigot and casing;
FIGS. 5, 6 and 7 illustrate cladding clips;
FIG. 8 is a fragmentary perspective view illustrating an additional feature for supporting shelves and cladding;
FIG. 9 is a plan view of the assembled comer shown in FIG. 8;
FIG. 10 is a, cross-section on the line 10-l0 of FIG. 9.
The embodiment illustrated in FIGS. 1, 2 and 3 illustrate the invention in its simplest and preferred form. In this embodiment, the connector comprises a cube shaped member 10 having a plurality of spigots -1 1, each of which is enclosed within a resilient compressible casing 12. In FIG. 1, the connector is shown with three tubular members 13, 14, 15 which are made of steel or aluminum and are substantially rigid. It is to be noted that the invention is not limited to tubular members of square cross-section.
Each spigot 1 1 projects from a face of the member I0 and at right angles thereto. Preferably, spigot 11 and member 10 are integrally formed of rigid material such as metal or hard, rigid plastic. The spigots are generally square in cross-section, smaller in cross-section than the tubular members and preferably with the comers stepped as indicated at 16 to ensure non-rotatability of the casing hereinafter mentioned.
The resilient compressible casing 12 hereinafter described is made of plastic, preferably vinyl and is chosen for durability, elasticity, memory and hardness. The casing is made to have an internal bore into which the spigot is fitted by a press fit against relative rotation as herein described. In the illustrated embodiment, the exterior of the casing is generally circular and substantially smaller in diameter than the distance between diagonally opposite comers of the tubular member into which the spigot is to be fitted. As the connector, in the present illustration, is to be used in connecting tubes having a substantially square cross-section the casing 12 is formed with four diametrically opposite ribs 17,18,19,20 thus corresponding in number to the number of the walls of the tubular member. The combined diameter across the spigot casing and ribs is greater than the distance between opposite walls of the tubular member. In actual practice, it has been found that satisfactory locking as hereinafter described, can be obtained by having the casing diameter, across the ribs, greater by approximately 0.005 inch than the distance between diametrically opposite walls which will provide an adequate press fit without undue bulging of the tube walls.
Each rib extends longitudinally on the casing and has a longitudinal channel 21 formed centrally thereof to divide each rib into a pair of compressible cheeks 23,24 in side-by-side relationship. 1
FIG. 4 illustrates an alternative construction in which the spigot 11, in cross-section, in the form of a Greek cross, having four limbs of equal length, and the casing 12 is similarly formed to fit over the core. In this construction, the casing is formed with four resiliently compressible pads 60,61,62 and 63 which cover the ends of the four limbs as shown. Each pad is divided into a pair of cheeks 23a, 24a corresponding to the cheeks 23,24 in FIGS. 1 to 3. The pads 60,61,62 and 63 correspond to ribs 17,18,19,20 in FIGS. 1 to 3.
In proceeding to assemble tubular members, the first step is to insert the spigot with its casing into its respective tubular member, e.g. the tubular member 13, with the cheeks aligned with the comers of the tubular member 13 as shown in FIG. 2. The tubular member and the spigot are then rotated about 45 relative to each other which will bring them into the position shown in FIG. 3. The cheeks are then compressed so that there are flat surfaces which engage against the flat walls of the tubular member and thus provide a positive positioning and releasably locking of the connector in its correct assembled position. The resilience of the walls of the member 13 also cooperate in the locking. Since vinyl acts like rubber, it is evident and it was established by tests carried out, that the vinyl flowed to form flat surfaces against the tube flat surfaces. Surprisingly too, locking is easier than unlocking'which is a clear gain in constructional work. Tests showed that once the cheeks have settled into place considerably more effort is needed in rotating the connector from the locked position (FIG. 3) to the unlocked position (FIG. 2).
Referring now to FIGS. 5 to 9, there is illustrated, a device for use with the spigot by means of which cladding and shelving may be supported.
FIG. 5 illustrates one form of the device which comprises a pair of legs 31,32 joined together at the top by a cross-bar 33. Projecting outwardly from the leg 32, is a shelf supporting projection 34. The distance between the top edge of the projection 34 and the top edge of the bar 33 is equal to the thickness of the shelf which is to be supported thereby. This is used as the top clip for supporting a table top having shelves and vertical walls or cladding as will be clearly seen in FIG. which will be described in detail later.
Referring now to FIG. 6, the clip is of particular usefulness as the support for the bottom shelf and also the cladding; the clip comprises spaced apart legs 36,36 with a cross member 37 spaced intermediate the ends to provide recesses which receive the edges of the cladding and also to straddle the spigot as shown in FIG. 9 and which will be described later. The bottom portion of the leg 36 is provided with a shelf supporting projection 38.
Referring now to FIG. 7, the clip shown is for use in intermediate shelving and also for securing the cladding in place. The clip comprises spaced apart legs 39,40 joined together by a cross-bar 41 which is spaced relative to the ends of the legs so that a slot will be formed for the edges of the cladding and also to span the core 11 of the connector. A shelf supporting projection 40a is also provided.
FIGS. 8, 9 and 10 show the cladding clip in use in association with a skeletal frame formed of tubular members connected together by the connector of the present invention. The skeletal frame is fragmentarily illustrated and consists of a pair of horizontal tubular frame members 42,43 and upright tubular frame members 44,45 joined together, for the purpose of illustration only, by the connector hereinbefore described. The clips are set in position on the spigots so that the tube end can be jammed tightly against the clip during the step of connecting the tube to the connector. In FIG. 8, the connector illustrated in FIG. 5 is shown in relation to the horizontal tubular member 42 and the clip of FIG. 6 is shown in relation to tubular member 43. This is to illustrate the manner in which the cladding 46 and a shelf 47 are supported.
FIG. 10 illustrates a structure comprising a top shelf 48, bottom shelf 49, the intermediate shelf 47, upper cladding 46 and lower cladding 52. In FIG. 10, the upper shelf 48 and the upper edge of the cladding 46 are supported and retained in position by a clip similar to the one shown and described in FIG. 5. The intermediate shelf 47, the bottom edge of the cladding 46 and the upper edge of the cladding 52 are supported and retained in position by a clip similar to theone illustrated and described with reference to FIG. 7. The bottom shelf 49 and the bottom edge of the cladding 52 are supported by and retained in position by a clip similar to that shown in FIG. 6.
What I claim is:
l. A connector for connecting tubular members having an internal square cross-section comprising in combination:
a. a solid body having a plurality of spigots, adapted to be inserted in the tubular members, each spigot projecting outwardly from a different face of said body, the number of spigots corresponding to the number of tubular members to be joined together by one connector,
b. a one piece resilient compressible casing completely circumferentially enclosing each spigot and secured thereto to rotate therewith, said casing having longitudinally extending, diametrically opposite compressible ribs corresponding in number to the number of internal flat walls of the tubular member,
the diameter taken across diametrically opposite ribs being less than the length of the diagonals across the comers of the tube and greater than the distance between diametrically opposite walls of the tubular members by an amount to provide a press fit between the ribs and the inner walls of the tubular member whereby when a spigot with its compressible casing is entered in its respective tubular member and rotated to bring each rib into engagement with its respective wall, the spigot and the tubular member are releasably locked together.
2. A connector according to claim 1 in which each rib is divided into a pair of side-by-side longitudinally extending flat surfaced cheeks forming a stop locating the spigot in its fully locked position.
3. A connector according to claim 1 in which each spigot is formed as a solid square with steps in each longitudinal corner in which an opposing portion of the casing engages.
4. A connector according to claim I in which the spigot has a cross-section in the shape of a Greek cross having four arms substantially shorter than the distance between opposing faces of the tubular member and the envelope is of tubular shape and the said ribs are constituted by four thickened portions to form said compressible ribs along the entire length of the envelope and of a thickness slightly greater than the distance between free ends of the arms and the contiguous and the opposing face of the tubular member, and uniformly circumferentially spaced at intervals, each of said thickened portions having a recess on the inner wall, said recess receiving the free end of a cross arm to thereby restrain relative rotating movement between the envelope and the spigot.