A connector is disclosed which allows standard hardware pieces (e.g. hinges, etc.) to be easily connected to round or other substantially non-planar surfaces or surfaces with minimal planar aspects. Currently, direct connection of standard hardware to round or other substantially non-planar surfaces is cumbersome, or not practical or possible since existing hardware is generally configured to attach only to planar surfaces. The connector comprises a first surface configured to engage the non-planar structure and second surface configured to engage the planar surface of the standard hardware piece (e.g. a hinge). The disclosed connector may be installed using the same tools used to install standard hardware, such as wrenches or screw drivers, socket drivers, etc. The connector may integrate a standard hardware piece, or it may be configured to attach to a separate standard hardware piece. Either way, the connector may be used, for example, to attach doors, side panels etc. to open shelving units that use round pipe or tubing as vertical supports. The connector expands the uses of currently limited standard hardware pieces, to allow connection to a wider range of structural surfaces.

TECHNICAL FIELD  
       [0001]     The present invention relates to connecting hardware, and more particularly, to a connector that can be used to easily allow the connection of standard hardware pieces to non-planar surfaces.  
       BACKGROUND OF THE INVENTION  
       [0002]     The invention relates to a connector that allows a user to easily connect standard hardware pieces (e.g. hinges, plates, panels, door latches, clip-on fasteners etc.) to non-planar surfaces or to surfaces having minimal planar aspects. Standard hardware pieces are generally configured to facilitate the connection of two planar surfaces (e.g. hingedly connecting a door to a doorjamb, connecting a door and a side wall, to connect the latch of a door knob to one surface, and a corresponding dash plate to a second surface). However, such standard hardware pieces are of little use in connecting substantially non-planar surfaces (e.g. hingedly connecting a door to a pipe, tube, or angle member), nor are these pieces standard pieces of use in connecting planar or substantially non-planar surfaces to surfaces having minimal planar aspects (e.g. angle or box beam members having planar dimensions so small that standard hardware is unable, either due to fastener size or to the position of the fastener holes, to engage the planar member). Need for such connections exists for users of open structures such as shelving units, room dividers, store installations etc. who would like to easily enclose such structures using standard panels, walls, sliding doors, or other types of enclosures. Because these open structures typically are constructed of small round or square tubular members, of “L” or “T” shaped extrusions or forgings having small planar surfaces, or of other complex shapes having little or no planar surfaces, standard hardware pieces are unsuitable for providing the desired connections. Another example in which standard hardware pieces alone are impractical for use is when attaching doors etc. to large concave or convex surfaces.  
         [0003]     Further, even if it were possible to modify existing hardware to attach to such structures, drilling into the structure to establish the holes necessary for the installation of screws or bolts may in some cases be problematic. Besides being cumbersome, if the structure bears heavy loads, drilling may not be advisable because it could unacceptably weaken the structure. In such cases, welding or brazing may be preferred. To address these applications, the connector may be configured to allow welding or brazing of the connector to the structure.  
         [0004]     Once the connector is affixed to the non-planar structure, the appropriate enclosure members (e.g. cabinet walls, doors) may easily be mounted to the connector's planar surface. Standard hardware pieces may also be mounted to the connector's planar surface.  
         [0005]     The connector is also aesthetically pleasing, since it may be ideally shaped to conform to the non-planar surface to which it attaches.  
         [0006]     Therefore, there is a need in the art for hardware that will enable a user to easily connect standard hardware to a wide variety of non-planar surfaces, or short planar surfaces for which standard hardware is simply to large to connect.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention provides a connector for connecting a first element to a second element, the connector comprising a first surface for connecting to the first element and having a first locking member, and a second surface for connecting to the second element and having a second locking member. The first element may be substantially planar and the second element may be substantially non-planar. The first surface may be configured to engage-the first element and the second surface may be configured to engage the second element, the first locking member configured to lock the first surface to the first element and the second locking member configured to lock the second surface to the second element. The connector second surface may have a round or oval cross-section, and the connector first surface has at least one planar aspect.  
         [0008]     The connector may further comprise at least a third surface associated with, and non-coplanar to, the first surface, wherein the third surface may be configured to engage a third planar element. The third surface may comprise at least one locking member configured to engage the third surface with the third element. The connector first surface may have a square, rectangular, or triangular cross-section. The first locking member comprises at least one recess configured to receive a fastener. The second locking member may comprise at least one clamp configured to engage the second element.  
         [0009]     The first locking member may comprise at least one recess configured to receive a fastener to connect the first surface to the first element, and the second locking member may be configured to engage the second element. The second locking member may comprise at least one clamp, and the clamp may comprise at least one threaded rod having an actuation end and a clamping end. The actuation end may comprise an actuator and the clamping end may have an associated clamping face, the first and second faces may comprise a wall therebetween, the wall having a threaded bore configured to receive the threaded rod between its actuation and clamping ends, the clamping face disposed between the first and second surfaces, wherein rotation of the at least one threaded rod in a first direction may cause the associated clamping face to extend toward the second element to engage the second element, and rotation of the at least one threaded rod in a second direction may cause the associated clamping face to retract from the second element.  
         [0010]     The second element may have a cross-section selected from the group of round or elliptical. The connector first surface may further comprises a hinge member having at least one recess for receiving a fastener, and the first locking member may comprise at least one recess configured to accept a fastener, the first locking member recess may be further configured to correspond with the recess in the hinge member, so that when the hinge member engages the connector and the hinge and locking member holes are aligned to permit insertion of a fastener therethrough, tightening the fastener fixes the hinge member to the connector.  
         [0011]     The connector first surface may further comprise a recess configured to releasably engage a tongue latch of a door so that engagement of the tongue-latch and the recess connects the connector to the door. The second surface may comprise first and second halves connected by a hinge, the first and second halves configured to assume a first unlocked position and a second locked position, wherein configuring the halves in the unlocked position allows the second element to be placed between the halves, and configuring the halves in the locked position engages the second element, coupling the second surface to the second element. Configuring the first and second halves in the locked position may substantially prevent relative movement of the first and second halves.  
         [0012]     At least one fastener may be disposed within a wall of at least one of the first and second halves, so that when the halves are configured in the locked position, the fastener may be activated to engage the second element to prevent relative movement of the connector and the second element. At least one fastener disposed may be disposed between, and operatively associated with, the first and second halves, such that tightening the fastener configures the halves to the closed locked position. A hinge may further be associated with the first surface, and the hinge may comprise a hinge face having at least one recess configured to accept a fastener for connecting the hinge face to the first element. The connector first surface may further comprise a plurality of threaded and unthreaded holes, slots or other recesses, configured to allow the installation of a variety of first element having different locking element arrangements.  
         [0013]     A second connector may be provided for connecting a third element to a fourth element, the connector comprising a third surface for connecting to the third element, and having a third locking member, a fourth surface for connecting to the fourth element, and having a fourth locking member. The third element may be substantially planar and the fourth element may be substantially non-planar, the third surface configured to engage the third element and the fourth surface configured to engage the fourth element, the third locking member configured to lock the third surface to the third element and the fourth locking member configured to lock the fourth surface to the fourth element. At least one support member my be provided having first and second ends and a drawer having at least a first side, having a guide, wherein when the connector is associated with the support member first end, the second connector may be associated with the support member second end, and wherein the support member may comprise an engaging surface configured to receive the guide. The connector, support member, second connector may comprise a unitary piece.  
         [0014]     A connector may be provided comprising at least a second connector for connecting a third element to a fourth element. The connector may comprise a third surface for connecting to the third element, and having a third locking member, a fourth surface for connecting to the fourth element, and having a fourth locking member. The third element may be substantially planar and the fourth element may be substantially non-planar, the third surface configured to engage the third element and the fourth surface configured to engage the fourth element. The third locking member may be configured to lock the third surface to the third element and the fourth locking member may be configured to lock the fourth surface to the fourth element. At least one sliding drawer assembly may be provided comprising a drawer and first and second opposing slide members; and first and second vertical non-planar support members. The first surface of the connector may be configured to engage the first opposing slide member, the second surface of said connector may be configured to engage the first support member, the third surface of the second connector may be configured to engage the second opposing slide member, and the fourth face of the second connector may be configured to engage with the second support member.  
         [0015]     A connector may further be provided with at least a second connector for connecting a third element to a fourth element, the connector further comprising a third surface for connecting to the third element, and having a third locking member, a fourth surface for connecting to the fourth element, and having a fourth locking member. The third element may be substantially planar and the fourth element may be substantially non-planar, the third surface configured to engage the third element and the fourth surface configured to engage the fourth element, the third locking member configured to lock the third surface to the third element and the fourth locking member configured to lock the fourth surface to the fourth element. At least one shelf may be provided having first and second ends, wherein the connector may be formed integrally with the first end of the at least one shelf and the second connector may be formed integrally with the second end of the at least one shelf.  
         [0016]     The connector may be provided with a second locking member comprising a wedge member having a cone-shaped outer surface with a bottom lip and an inner surface comprising at least one projection. The connector second surface may comprises a cone-shaped inner surface configured to engage the wedge member outer surface, and the second element may comprise at least one recess configured to engage the wedge member projection, so that when the wedge member inner projection is engaged with the second element groove the wedge member is configured in a locked position with respect to the second element. Further, when the connector second surface engages the wedge member outer surface the lip maintains the position of the connector in a first direction along the second element. The lip may comprise an annular rim element configured to contact a lower surface of the connector second surface. A hinge may be associated with the first surface. The first surface may also comprise at least one recess configured to receive a fastener.  
         [0017]     A connector for connecting a hardware member to a structural member may be provided, the connector comprising a first surface for connecting to the hardware member, and having a first locking member, and a second surface for connecting to the structural member, and having a second locking member. The hardware and structural members may be substantially planar and each may have a width. The first surface may be configured to engage the hardware member and the second surface may be configured to engage the structural member, the first locking member configured to lock the first surface to the hardware member and the second locking member configured to lock the second surface to the structural member. The hardware member may have at least one surface dimension that is greater than at least one surface dimension of the structural member. The connector first surface may have a square, rectangular, or triangular cross-section. The first locking member may comprise at least one recess configured to receive a fastener, and the second locking member may comprise at least one clamp configured to engage the structural member. The first locking member may comprise at least one recess configured to receive a fastener to connect the first surface to the hardware member, and the second locking member may be configured to engage the structural member. The second locking member may comprise at least one clamp.  
         [0018]     The at least one clamp may comprise at least one threaded rod having an actuation end and a clamping end, the actuation end comprising an actuator and the clamping end having an associated clamping face, the first and second surfaces may comprise a wall therebetween, the wall having a threaded bore configured to receive the threaded rod between its actuation and clamping ends, the clamping face disposed between the first and second surfaces, wherein rotation of the at least one threaded rod in a first direction may cause the associated clamping face to extend toward the structural member to engage the structural member, and rotation of the at least one threaded rod in a second direction may cause the associated clamping face to retract from the structural member.  
         [0019]     A connecting system may be provided for attaching at least one planar member to a plurality of non-planar members. The system may comprise at least one planar member having a planar surface, the planar surface having at least first and second portions. A plurality of non-planar members may be provided, each having at least one non-planar surface. A first connector may be provided for connecting the first planar member to a first non-planar member, the first connector may comprise a first face for connecting to first portion of the planar surface, a second face for connecting to the first non-planar surface. A second connector may be provided for connecting the planar member to a second non-planar member, the second connector comprising a first face for connecting to the second portion of the planar surface and a second face for connecting to the second non-planar surface. The first connector may engage respective planar and non-planar members and the second connector may engage respective planar and non-planar members so that the at least one planar member at least partially overlaps the plurality of non-planar members.  
         [0020]     The system may comprise first and second connectors each having a hinge with at least one hinge face. The first hinge face may be configured to engage the first portion of the planar surface, and the second hinge face may be configured to engage the second portion of the planar surface.  
         [0021]     The system of connectors may further comprise third and fourth connectors and a door panel having first and second ends, the first end having a tongue-latch mechanism. The third connector may comprise a recess configured and arranged to engage the door panel tongue-latch, and the fourth connector first face may comprise a hinge member to connect to the door panel second end, so that when the door panel is in the closed configuration the tongue-latch engages the recess in the third connector and the door panel overlaps at least a portion of the non-planar members.  
         [0022]     A system of connectors may be provided for attaching a modular system of perforated members to a plurality of non-planar members comprising at least first and second planar perforated members each having first and second ends and each comprising a plurality of locking members located between said first and second ends. A first connector may be provided for connecting a first element to a second element, the first connector comprising a first surface for connecting to the first element, and having a first locking member, a second surface for connecting to the second element, and having a second locking member. The first element may be substantially planar and the second element may be substantially non-planar. The first surface may be configured to engage the first element and the second surface may be configured to engage the second element. The first locking member may be configured to lock the first surface to the first element and the second locking member may be configured to lock the second surface to the second element. At least a second connector may be provided for connecting a third element to a fourth element. The second connector may comprise a third surface for connecting to the third element, and having a third locking member. A fourth surface may be provided for connecting to the fourth element and having a fourth locking member. The third element is substantially planar and the fourth element may be substantially non-planar, the third surface may be configured to engage the third element and the fourth surface may be configured to engage the fourth element, the third locking member may be configured to lock the third surface to the third element and the fourth locking member may be configured to lock the fourth surface to the fourth element. When the first surface of the first connector is configured to engage at least one locking member of the first perforated member, the first surface of the second connector may be configured to engage at least one locking member of the second perforated member, and wherein the second surface of the first connector is further configured to engage the first non-planar member and the second fourth surface of the second connector may be further configured to engage the second non-planar member to thereby mechanically couple the first and second planar perforated members to the first and second non-planar members. The locking members may be further configured to receive at least one shelf member. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]     The features and advantages of the present invention will become more readily apparent from the following detailed description of the invention in which like elements are labeled similarly and in which:  
         [0024]      FIG. 1  is a perspective view of one embodiment of the connector attached to a round pipe, with a first outer surface section of the connector having threaded holes suitable for receiving a butt hinge and a second outer surface section having a slotted recess configured for installation of a side wall member.  
         [0025]      FIG. 2  is a perspective view of the connector of  FIG. 1 , further comprising a top cover.  
         [0026]      FIG. 3  is a perspective view of the connector of  FIG. 2 , in which a butt hinge is installed on the first outer surface section.  
         [0027]      FIG. 4  is a perspective view of the connector of  FIG. 3 , in which a door member is attached to the butt hinge, and a side panel member having a pin-ball connector is positioned for attachment to the second outer surface section slotted recess.  
         [0028]      FIG. 5  is a perspective view of the connector of  FIG. 4  showing the side panel member attached to the connector.  
         [0029]      FIG. 6  is a perspective view of the connector of  FIG. 1 , showing one of the first or second outer surface sections incorporating a rectangular recess for engaging the tongue-latch of a door assembly, the connector and door assembly configured in the open position.  
         [0030]      FIG. 7  is a perspective view of the connector and door assembly of  FIG. 6  in which the door is in the closed position.  
         [0031]      FIG. 8  is a perspective view of the connector of  FIG. 1 , showing the connector with a flat top cover configured to for attachment of a top panel member.  
         [0032]      FIG. 9  is a perspective view of the connector of  FIG. 8  with side and top panels installed.  
         [0033]      FIG. 10  is a perspective view of the connector of  FIGS. 1-9  in which the hardware has been used to construct an enclosed shelving unit having side, top and back panel members, and a door member with an operating latch.  
         [0034]      FIG. 11  is a perspective view of the connector  FIG. 1 , in which the hardware is hinged to allow direct introduction of the hardware at any desired point along the structural member.  
         [0035]      FIG. 12  is a perspective view of the connector of  FIG. 11  in its installed position.  
         [0036]      FIG. 13  is a perspective view of the connector of  FIG. 12  with two perpendicular planar outer surfaces, and a third round outer surface, with one of the planar surfaces providing for attachment of a butt hinge.  
         [0037]      FIG. 14  is a perspective view of the connector of  FIG. 13  in which the hardware is hinged to allow direct introduction of the hardware at any desired point along the structural member.  
         [0038]      FIG. 15  is a perspective view of the connector of  FIG. 14  installed on a cylindrical structural member.  
         [0039]      FIG. 16  is a perspective view of the connector of  FIG. 1 , in which the first outer surface section is of sufficient size and configured with two threaded holes to accept a full overlay hinge.  
         [0040]      FIG. 17  is a perspective view of the connector of  FIG. 16  further showing the full overlay hinge installed and connected to an associated door member.  
         [0041]      FIG. 18  is a perspective view of the connector of  FIG. 1  in which multiply-configured recesses are provided on both the first and second outer surface sections to enable easy attachment to a variety of exiting hardware pieces.  
         [0042]      FIG. 19  is a perspective view of an embodiment of the connector showing a clamping member securing the cylindrical structural member between the clamping member and two perpendicular facets of the connector, and further showing a butt hinge piece installed on an outer surface section of the hardware.  
         [0043]      FIG. 20  is a cross sectional view of the connector of  FIG. 19 .  
         [0044]      FIG. 21  is a perspective view of the connector of  FIG. 19  in which the hardware is hinged to allow direct introduction of the hardware at any desired point along the structural member, and further showing a butt hinge piece installed on an outer surface section of the connector.  
         [0045]      FIG. 22  is a cross section view of the connector of  FIG. 21 .  
         [0046]      FIG. 23  is a perspective, unassembled view of an embodiment of the connector in which the cylindrical structural member comprises an external cone section which engages a corresponding internal cone section of the connector which allows locking the two pieces together axially when the internal cone section is pushed down onto the external cone section.  
         [0047]      FIG. 24  is a cross-sectional view of the embodiment of the connector of  FIG. 23  in which the cylindrical structural member comprises an external cone section and is engaged with a corresponding internal cone section of the connector to lock the two pieces together axially.  
         [0048]      FIG. 25  is a perspective view of the connector of  FIG. 23  and  24 , further comprising an integral shelf member.  
         [0049]      FIG. 26  is a perspective view of the connector of  FIG. 2 , in which a plurality of connector pieces are used to support a drawer slide assembly.  
         [0050]      FIG. 27  is a perspective view of the connector assembly of  FIG. 26  in which the drawer is shown in an extended position.  
         [0051]      FIG. 28  is a perspective view of the connector assembly of  FIG. 27  in which a supporting element is installed between the connector pieces on each side of the drawer.  
         [0052]      FIG. 29  is a perspective view an alternate embodiment of the connector assembly of  FIG. 28  in which a supporting element is disposed between two pieces of connectors to form one hardware piece.  
         [0053]      FIG. 30  is a perspective view of a system of connector pieces used to construct an enclosed shelving unit having a double sliding front door panel configuration.  
         [0054]      FIG. 31  is a side elevation view of the system of the connector pieces of  FIG. 30 , showing the connection details for the double sliding door panel.  
         [0055]      FIG. 32  shows a perspective of a shelving unit with perforated metal flats mounted by means of the connector to the round vertical supports of the shelving unit and running parallel to them; on the perforated metal flats a drawer and a door are mounted.  
         [0056]      FIGS. 33A and 33B  are perspective and top plan views, respectively, of the connector of  FIG. 2 , without the cylindrical inner member.  
         [0057]      FIGS. 34A and 34B  are perspective and top plan views, respectively, of the connector of  FIG. 2  in which the structural member has a square cross section, and is offset from the center of the connector piece.  
         [0058]      FIGS. 35A and 35B  are perspective and top plan views, respectively, of the connector of  FIG. 2  in which the structural member is an angle member with an L-shaped cross-section, and is off set from the center of the connector piece  
         [0059]      FIGS. 36A and 36B  are perspective and top plan views, respectively, of an alternate embodiment of the connector of  FIG. 2  in which the two planar outer side surface members are connected by a third side surface, such that the external connector shape assumes a triangle when viewed from above.  
         [0060]      FIGS. 37A and 37B  are perspective and top plan views, respectively, of an alternate embodiment of the connector of  FIG. 2  in which the two planar out side surface members are connected by a rounded third side surface.  
         [0061]      FIGS. 38A and 38B  are perspective and top plan views, respectively, of an alternate embodiment of the connector of  FIG. 2  in which there is only one planar outer side surface member, and the remainder of the outer side surface of the connector is rounded, and the connector is also installed on a structural member having an elliptical cross-section.  
         [0062]      FIGS. 39A and 39B  are perspective and top plan views, respectively, of an alternative embodiment of the connector of  FIG. 1  in which there are only two planar outer side surface members, and there is no remainder outer side surface.  
         [0063]      FIG. 40  is a top plan view of two connectors of  FIGS. 39A and 39B  attached to a connecting bar.  
         [0064]      FIG. 41  is a top plan view of two connectors of  FIGS. 39A and 39B  with a connecting bar permanently attached to the connectors to form one piece.  
         [0065]      FIG. 42  is a top plan view of four connectors of  FIGS. 39A and 39B  with the connecting bars of  FIG. 41 , permanently attached to form one piece.  
         [0066]      FIG. 43  is a perspective view of a shelving unit employing the connectors of  FIGS. 39A , B through  42 .  
         [0067]      FIGS. 44A and 45B  are perspective and top plan views, respectively, of the connector of  FIG. 1  with a shelf bracket attached to it.  
         [0068]      FIG. 45  is a perspective view of the shelf bracket of  FIGS. 44A and 45B  separate.  
         [0069]      FIG. 46  is a top plan view of four connectors of  FIGS. 44A and 44B  with shelf bracket attached to it and a shelf attached to the shelf brackets.  
         [0070]      FIG. 47  is a perspective view of a shelving unit employing the connectors with the shelf brackets of  FIGS. 44A , B through  46 .  
         [0071]      FIG. 49  shows a cross-section of the wedge-type arrangement as described in  FIG. 23  and  FIG. 24  with the addition of two machine screws.  
         [0072]      FIG. 50  shows a cross-section of the same arrangement as described in  FIG. 53 .  
         [0073]      FIG. 51  shows a cross-section of the same arrangement as described in  FIG. 50  with the exception that the machine screw extends through the structural member  2 .  
         [0074]      FIG. 52  shows a cross-section of the same arrangement as described in  FIG. 51  with the exception that the machine screw is replaced with a clevis pin.  
         [0075]      FIG. 53  show a perspective view of the wedge-type arrangement as described in  FIG. 23  and  FIG. 24  with the addition of a tongue and grove arrangement that prevents the connector from rotating around the structural member.  
         [0076]      FIG. 54  shows a cross-section of the same arrangement as described in  FIG. 53 .  
         [0077]      FIG. 55  show a perspective view of locking arrangement with cylindrical insert with a bottom lip that prevents the connector from sliding down the structural member.  
         [0078]      FIG. 56  shows a cross-section of the same arrangement as described in  FIG. 55 .  
         [0079]      FIG. 57  shows the cylindrical insert of  FIG. 55  with four wedges that make for a tight fit between the connector and the cylindrical insert.  
         [0080]      FIG. 58  shows the same connector as in  FIG. 2  with four threaded holes ready to accept the receiving part of a vertically adjustable clip on fastener.  
         [0081]      FIG. 59  shows a side view of the same receiving part of the clip on fastener of  FIG. 58  attached to the connector.  
         [0082]      FIG. 60  shows a cross section of  FIG. 58  ready to engage the corresponding, horizontally adjustable insert of the clip on fastener enabling the quick attachment of a side panel to the connector.  
         [0083]      FIG. 61  shows a perspective view of the same connector bar as in  FIG. 29  with two horizontally adjustable inserts of clip on fasteners.  
         [0084]      FIG. 62  show the side view of  FIG. 61  ready to engage a side panel by means of the corresponding, receiving parts of a clip on fastener. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0085]     The connector disclosed herein is discussed with reference to preferred embodiments adapted to connect standard hardware pieces to non-planar surfaces, such as the cylindrical structural members associated with standard open-style shelving units. It should be understood, however, that the invention finds applicability for use in any circumstance in which it is desired to connect planar and substantially non-planar surfaces.  
         [0086]     The connector simplifies the attachment of standard hardware (e.g. locks, hinges, catches, spring catches, strikes, clip connectors, modular tracks, etc.) or other surfaces having planar attributes (e.g. panel members, door members drawers etc.), to surfaces for which such standard hardware is ill suited to connect. Such ill-suited surfaces may comprise pipes or tubes having cylindrical attributes, or they may comprise structural box members or angle members which have planar attributes too small to practically allow connection of standard hardware (e.g. small panels, cladding panels, sidings, doors, sliding doors, covers, rooves, etc.).  
         [0087]     In this description, the term “standard hardware” shall mean hardware that is designed generically to connect two or more planar surfaces, either rigidly or hingedly. Non-limiting examples of “standard hardware” are plate hinges, brackets, plate reinforcing members and the like.  
         [0088]     In general, the connector is configured to at least partially enclose a segment of the substantially non-planar member to whom it is attached. The connector may comprise a first (outside) surface configured to allow easy attachment to standard hardware pieces or panel or door members using typical fastening devices (e.g. screws, bolts, rivets), and a second (inside) surface configured to engage a planar member. The connector may have a unitary inner surface that conforms to the shape of the non-planar member and may simply be slipped over the end of the non-planar member, or it may have a hinged “clam-shell” configuration which closes around the non-planar member (useful where one or both ends of the non-planar member is inaccessible, or where the configuration of the member is such that sliding the connector along the member to the desired location is not possible).  
         [0089]     Referring more particularly to the drawings,  FIG. 1  shows a perspective view of the adjustable connector  1  installed on a vertical cylindrical member  2 . As shown in  FIG. 1 , the connector  1  may comprise a generally box-shaped exterior surface  4 , with flat (planar) outer and inner surfaces  5 ,  6 , with open top and bottom sections  7 ,  8 , and a generally cylindrical inner member  3  having outer and inner surfaces  9 ,  10  and open top and bottom sections  11 ,  12 . Inner member  3  is configured and sized to conform to the outer surface  15  of the cylindrical member  2 , while maintaining sufficient clearance between the two members so that the cylindrical member may slide freely within the inner member  3  to allow positional adjustment of the connector  1  along the cylindrical member  2 . Wall “w” lays between the inner member  3  and the exterior surface  4 .  
         [0090]     The flat outer and inner surfaces  5 ,  6  each may comprise one or more recesses  13  configured to accept screws, bolts, clips, pins, push-locks, magnetic connectors or any other suitable fasteners, to allow easy connection of standard hardware pieces (e.g. hinges), or flat panels, doors or other similar structural members. For the purposes of this patent the term “recess” shall mean any geometric or volumetric female element (e.g. hole, slot, cavity, threaded hole, key hole, catch, etc.) configured to receive a male fastener element (e.g. rod, threaded rod, screw, machine screw, set screw, strike, pin-and-ball fastener, etc.) Such recesses may have smooth, threaded, ridged or any other surfaces configuration that facilitates connection to and/or retention of a corresponding male fastener element. Likewise, the male fastener elements may have any surface configuration that facilitates connection to a corresponding recess. The connector of  FIG. 1  is configured with three pre-drilled threaded holes  14  to allow connection of a standard butt hinge  16  (shown installed in  FIG. 3 ). The cylindrical inner surface member  3  is configured and sized to conform to the outer surface  15  of the cylindrical member  2 , while maintaining a minimum clearance (not shown) between the two surfaces to allow the connector to slide freely along the cylindrical member  2  to allow adjustments in connector position.  
         [0091]     A pair of setscrews  16 ,  18  may be disposed in correspondingly threaded through-holes  17 ,  19  in wall “w.” A user may rotate the setscrews  16 ,  18  in a first direction to thereby engage the setscrews  16 ,  18  with the outer surface  15  of the cylindrical member  2 . This engagement fixes the connector  1  and the cylindrical member  2  axially and rotationally. Conversely, rotation of the setscrews  16 ,  18  in a second direction decouples the setscrews  16 ,  18  from the cylindrical member outer surface  15 , thereby decoupling the connector  1  from the cylindrical member  2  to allow the connector to be repositioned or removed.  
         [0092]     The connector's inner member  3  and exterior surface  4  may be formed from individual box and cylinder elements of similar or different lengths that are joined using known techniques such as welding, brazing, epoxy, or any other suitable attachment method to yield the unitary piece of  FIG. 1 . Alternately, the inner member  3  and exterior surface  4  may be formed (e.g. cast, forged, extruded) as a single piece.  
         [0093]     The connector  1  may be fabricated of any suitable material known in the art (e.g. metal, plastic, wood), and where the connector  1  is formed from individual box  4  and cylinder  3  members, each member may be fabricated from a different material as appropriate for the intended application.  
         [0094]      FIG. 2  is an alternate embodiment of the connector of  FIG. 1 , in which the top and bottom sections  7 ,  8  are enclosed. In this embodiment, the connector  1  may comprise a generally cylindrical inner surface member  3  as in the embodiment of  FIG. 1 , with the addition of at least a top cap  20  having a cylindrical cutout  21  to accept the cylindrical member  2 . A bottom cap (not shown) may also be used. Such caps may add structural stability to the connector and may also be more aesthetically pleasing. The connector may incorporate only a top cap, only a bottom cap, or both a top and bottom cap as desired by the user.  
         [0095]     Alternatively, the connector  1  of  FIG. 2  may comprise an box-shaped, exterior surface  4  having top and bottom caps  20 ,  22 , but without a cylindrical inner member  3 . In this embodiment, the cylindrical cut-outs of the top and bottom caps  21 ,  23  are configured and sized to conform to the outer surface  15  of the cylindrical member  2 , while maintaining sufficient clearance between the two surfaces so that the connector may slide freely within the top and bottom caps to allow positional adjustment of the connector  1  along the cylindrical member  2 .  
         [0096]      FIG. 3  shows the connector of  FIG. 2 , engaged with cylindrical member  2 , in which a standard hardware piece  24  (a “butt hinge”) having first and second hinge faces  25 ,  26 , is attached with screws  27  to one side  28  of the connector's flat outer surface  5 . The first hinge face  25  is attached to the flat side  28  of connector  1 , while the second hinge face  26  incorporates screw holes  29  configured to accept fasteners (not shown) for attachment to an additional planar surface  
         [0097]      FIG. 4  shows connector  1  of  FIG. 3 , in which a panel member  32  is bolted to the second hinge face  26  of butt hinge  24  using nut and bolt combinations  31 . Also shown is a second panel  32 , incorporating pin-and-ball fastener  33 , being fit-up to slot  13  in the flat side  34  of the flat outer surface  5  of connector  1 .  
         [0098]      FIG. 5  shows the connector  1  of  FIG. 4 , in which the second panel  32  is installed on second flat side  34  of connector  1 , with a pin-and-ball fastener  33  fully engaged in recess  13 . The enlarged ball end of fastener  33  is retained by the reduced width recess  13 , thereby preventing the second panel  32  from separating from the connector  1 .  
         [0099]      FIGS. 6 and 7  show the connector  1  of  FIG. 2 , engaged with cylindrical member  2 , in which the connector  1  incorporates a rectangular recess  35  in flat outer side  34 . This recess  35  may be positioned and configured to accept a corresponding tongue portion  36  of a door-latch mechanism  37  which includes a door knob  38  for engaging/disengaging the tongue  36  and recess  35 . The door-latch mechanism itself may be attached to a door  39 . Alternately, the connector  1  of this embodiment may comprise a second recess (not shown), configured to receive the bolt portion of a dead-bolt locking mechanism, to provide affirmative locking capabilities for the door  39 .  
         [0100]      FIG. 8  shows the connector  1  of  FIG. 1 , further incorporating a solid top cap member  40 , which covers the otherwise open end section  7  of connector  1 . The inclusion of a top cap  40  requires the connector  1  to be installed on one end of the cylindrical member  2 , rather than at an adjustable point along the length of the cylindrical member  2 . The cap member  40  of this embodiment may be used either as an axial support for a planar member attached to one of the flat side surfaces  7 ,  8  or as aesthetic finish to cover the end of the cylindrical member  2 . The cap member  40  may have a planar surface to which standard hardware pieces or panels may be attached. As such, cap member  40  may be provided with a threaded hole  41  suitable for accepting a fastener to allow a panel or other planar member to be attached to the top of the cylindrical member  2 . Also shown is a recess  42  on the flat outer surface  28 .  
         [0101]      FIG. 9  shows the connector of  FIG. 8 , in which side panel members  43  are attached using pin-and-ball fasteners  33  disposed in respective recess  13 ,  42  of the connector  1  as described above in relation to  FIG. 5 . In addition, top panel member  44  may be attached to cap  40  using a machine screw  45 , which is disposed in threaded hole  41 , which in this embodiment is threaded. This arrangement allows easy installation of top, side and/or back panels using the connector I and standard fasteners and panel members.  
         [0102]      FIG. 10  shows a system of connectors  1 , used to enclose a standard open shelving unit  50  with side  51 , top  52  and door  53  panels, door hinge connections  54 , and a door knob assembly  55 ,  56 . The arrangement of  FIG. 10  is achieved by installing successive levels of shelving  57  and connectors  1  (i.e. from the ground up).  
         [0103]      FIG. 11  shows a connector  1  comprising two clamp halves  58 ,  59  joined by a hinge element  60  having a hinge axis  61 . The connector clamp halves  58 ,  59  are rotatable about the hinge axis  61 , so that they may be clamped about the cylindrical structural member  2  at any point on the member. This embodiment is particularly advantageous for instances in which the shelving unit  50  ( FIG. 10 ) has already been constructed, and where it is not possible to place the connector  1  of  FIGS. 1-10  over the end of the structural members  2  and to slide it along the member to reach the desired fixation position.  
         [0104]     The clamp halves  58 ,  59  may each comprise a flange section  62 ,  63  which extend beyond the box shaped outer surface  64  of the clamp halves  58 ,  59 .  62  and  63  mates with each other when the opposing clamp halves  58 ,  59  close around the structural pipe  2 . To close the flange sections  62 ,  63  may comprise one or more holes  65  suitable for the introduction of fasteners  67 , which may be used to maintain the clamp halves  58 ,  59  locked together about the structural member  2 , as shown in  FIG. 12 .  
         [0105]     The connector  1  may be configured so that the clamping force imparted when the clamp halves  58 ,  59  are locked together maintains the connector  1  and the structural member  2  rotatably and axially fixed together. Alternately, such fixation may be achieved by the use of one or more set screws  69  disposed in the wall “w” of the connector  1 , which, when activated, are configured to engage the outer surface  15  of the structural member  2 .  
         [0106]     The connector halves  58 ,  59  each may comprise planar outer faces  64  and clamping faces  67 ,  68  that comprise at least a portion of a cylinder. The clamping face  67 ,  68  of each half  58 ,  59  is sized and configured to engage at least a portion of the outer surface  15  of the cylindrical member  2 . The planar outer faces  64  are configured with the appropriate recesses to enable easy attachment of side or door panels using standard fasteners such as screws, bolts, pins, etc.  
         [0107]      FIG. 12  shows the connector  1  of  FIG. 11  where clamp halves  58 ,  59  are engaging the cylindrical structural member  2 , and are locked using machine screws  65  inserted in holes  66 .  
         [0108]      FIG. 13  shows connector  70 , comprising all of the described characteristics of connector  1 , with the exception that exterior member  4  has two-planar surfaces  71 ,  72  oriented perpendicularly with respect to each other, and a round surface  73  connecting them. Integral butt hinge  74  having a hinge axis  75  substantially parallel to the longitudinal axis of cylindrical structural member  2 , is provided on planar surface  71 . The round surface  73  provides additional clearance on its respective side, which may be preferable when the connector  70  is used in a shelving unit, as it provides for more space on the shelf. It also may be more aesthetically pleasing compared to the box configurations of  FIGS. 1-12 .  
         [0109]      FIG. 14  shows the connector  70  of  FIG. 13  with the clamp halves  58 ,  59  positioned open and ready for installation about cylindrical structural member  2 .  
         [0110]      FIG. 15  shows the connector  70  of  FIGS. 13 and 14  installed about cylindrical structural member  2 , and showing flange elements  62 ,  63  fastened by machine screws  65 .  
         [0111]      FIG. 16  shows the connector  76 , comprising all of the described characteristics of connector  1  of  FIG. 1 , with the added feature of an enlarged first outer side surface  76 ,  77  configured with appropriately located and threaded holes  78  suitable for attaching the a full overlay hinge  79 .  
         [0112]      FIG. 17  shows the connector  76  of  FIG. 16  attached to a full overlay hinge  79 , which itself is attached to a door panel  80 . The overlay hinge  79  is attached to the connector  1  using machine screws  81  that engage threaded holes  78 . The overlay hinge  79  is likewise connected to the door panel  80  using machine screws  82 .  
         [0113]      FIG. 18  shows the connector  76  of  FIG. 16 , incorporating on at least its first and second outer side surfaces  77 ,  46  variously configured and sized recesses  13 ,  43  and threaded holes  14 ,  78  suitable for accepting a variety standard fasteners for attaching a side panel, a full overlay hinge, a butt hinge, or a door-latch mechanism. Threaded holes  17 ,  19  are suitable for accepting setscrews  16 ,  18  for use in fixing the connector  76  to the cylindrical member  2 . This “universal” embodiment illustrates the potential for using various sizes and configurations of recesses in one connector  76  to allow the attachment of any of various standard hardware pieces or panels to cylindrical member  2 .  
         [0114]      FIGS. 19 and 20  show an alternative embodiment of the connector  85  mounted on a cylindrical structural member  2 . The connector  85  of this embodiment has a longitudinal axis “A” that is substantially parallel to the cylindrical member longitudinal axis. The connector  85  of this embodiment comprises first and second substantially planar members  86 ,  87 , each having substantially planar inner and outer side surfaces  88 ,  89 ,  90 ,  91 . The first and second planar members  86 ,  87  are joined so that their respective outer and inner surfaces  88 ,  89 ;  90 ,  91  are generally oriented perpendicular with respect to each other. It will be appreciated that first and second planar members  86 ,  87  may also be oriented so that their joinder creates an angle of greater or less than 90 degrees, as appropriate for any particular application. The connector  85  further comprises at least a third substantially planar member  92  having substantially planar inner and outer side surfaces  93 ,  94  with wall “w 1 ” disposed therebetween. The third planar member's  92  inner and outer side surfaces  93 ,  94  join the respective inner and outer side surfaces  88 ,  89 ;  90 ,  91  of the first and second members  86 ,  87  so that the external shape of the connector  85  appears generally triangular when viewed along the connector's longitudinal axis “A.” The third planar member  92  may further comprise at least one threaded hole  94  through wall “w 1 ,” the hole  94  located substantially in the center of the third planar member  92 , and configured to engage a threaded rod  95  having a first actuation end  96 , a second clamping end  97  and a longitudinal axis “X.” The hole  94  in wall “w 1 ” is located such that the threaded rod's  95  longitudinal axis “X” may intersect a line created by the joinder of the first and second planar members  86 ,  87 .  
         [0115]     The threaded rod's  95  first actuation ends  96  may have an actuator  98  to allow the rod  95  to be rotated by hand, or by using an appropriate driving tool. The threaded rod second clamping end  97  may have a clamp  99  attached that is configured to engage the outer surface  15  of the cylindrical structural member  2 . Rotation of the rod actuation end  96  in a first direction causes the rod threads to engage the threads of the hole  94 ; thereby advancing the rod  95  and its associated clamping end  97  through the hole toward the line joining the first and second members  86 ,  87 . Rotation of the actuation end  96  in a second direction causes the rod  95  and its associated clamping end  97  to move away from the line joining first and second members  86 ,  87 .  
         [0116]     When the connector  85  of this embodiment is slipped over the end of the cylindrical structural member  2  and positioned along the structural member  2  at a desired location, the rod actuation end  96  may then be rotated so that the clamp  99  engages the structural member  2  outer surface  15 , thereby nesting the structural member between the inner surfaces  88 ,  89  of the first and second planar members  86 ,  87 , and fixing the connector  85  to the cylindrical structural member  2  both axially and rotationally.  
         [0117]     The clamp  99  may comprise a flat surface  100 , or its surface may be curved to more closely conform to the cylindrical surface  15  of the structural member  2 .  
         [0118]     The connector  85  of this embodiment may incorporate an additional fourth side member  101  positioned between the first and third side members  86 ,  92 , and a fifth side member  102  positioned between the second and third side members  87 ,  92 . These additional members may reduce the overall size of the connector  85 , while still providing sufficient internal clearance to accommodate the largest anticipated size cylindrical structural member  2 . Use of the additional side members also may provide a more aesthetically pleasing external appearance to the connector  85 . It should be appreciated that the above described side members may comprise surfaces that are not substantially planar, as long as they provide the requisite clamping engagement of the cylindrical structural member  2 , while providing at least one planar outer surface to which a standard hardware piece may be attached.  
         [0119]     The planar members of this embodiment may be configured to incorporate a variety of connecting recesses to enable easy installation of existing hardware pieces, and they may also be configured to include one or more butt hinges  103  as may be appropriate.  
         [0120]     In an alternative embodiment illustrated in  FIG. 20 , the third planar surface  92  may comprise a shouldered region  104  having a recess  105  into which a corresponding shoulder  106  of the clamp  99  may fit, in order to allow maximum retraction of the clamp within the connector  85 , which may reduce the connector's overall size. Threaded hole  94  in wall “w 1 ” may reside in an extension portion  107  to provide a larger threaded interaction surface with threaded rod  95  within recess  105 .  
         [0121]      FIGS. 21 and 22  show the connector of  FIGS. 19 and 20  in which the connection between the first and fourth planar members  86 ,  101  comprises a hinge  108  having a hinge axis “Y” generally parallel to a longitudinal axis of the cylindrical support member  2 , and the connection between the second and fifth planar members comprises a screwed connection  109 . In this embodiment the first and second planar members  86 ,  87  form a first half  110  of connector  111 , and the third, fourth and fifth planar members  92 ,  101 ,  102 , form a second half  112  of the connector  111 . The first and second halves  110 ,  112  are rotatable with respect to each other about the hinge axis “Y.” This embodiment differs from the embodiments of  FIGS. 19 and 20 , in which the connector  85  must be slipped over one end of the structural member  2  and then slid along the member  2  to the desired point of fixation. The connector  111  of  FIGS. 21 and 22  may be applied directly to the desired point of fixation by opening the halves  110 ,  112  about the hinge axis “Y.” slipping the halves over the structural member  2 , and closing the hinge. This configuration is particularly useful in instances where it is not possible to slide the connector along the structural member, such as where a shelving unit has already been constructed, and where it would be impractical to take the system apart.  
         [0122]     The connector halves  110 ,  112  may be fixed using a screwed connection  109 , or other suitable fastening arrangement. In all other respects the connector  111  of  FIGS. 21 and 22  is same to the connector  85  of  FIGS. 19 and 20 .  
         [0123]      FIG. 23  and  FIG. 24  show an embodiment of the connector  113 , which contains all the described characteristics of connector  1  of  FIG. 1 , but which attaches to the cylindrical structural member  2  using a complementary wedge arrangement.  FIG. 23  shows the connector  113  disengaged from the structural member  2  and  FIG. 24  shows a cross-sectional view of the same arrangement with the connector  113  engaged with the structural member. Wedge member  114  has seam  121 , which divides the wedge member in half and allows the wedge member  114  to be fit onto the outer surface of the structural member  2  between upper portion  115  and lower portion  116 . The wedge member  114  may be fixed to the structural member  2  by one or more tabs  117  that may fit into a corresponding annular groove  118  formed in the structural member  2 .  
         [0124]     Connector  113  may comprise a box-shaped outer surface  119  having one or more substantially planar exterior connecting surfaces, and a wedge-shaped inner surface  120  configured to correspond to wedge member  114 , so that when the connector  113  is slid over the end of the structural member  2 , the corresponding wedges  120 ,  114  engage to fix the connector  104  and structural member  2  axially.  
         [0125]     Wedge member  114  may further comprise a lip  122  at the bottom of the wedge member  114  to allow for precise vertical positioning of the connector  113  along the structural member  2 . For attaching side panels to doors, particularly where such panels or doors are prefabricated, multiple connectors  113  are used to support each panel/door, and thus these connectors  113  should be fixed in the same vertical position along multiple structural members  2  to obtain a level positioning of the panel or door. The lip  122  at the bottom of wedge  114  allows the connector  113  to be placed at a consistent distance from groove  118  so that all corresponding connectors  113  holding a similar elements (side panel, door, etc.) may be placed at the same relative height. Existing wedge-type arrangements have no such lip  122  or other stop element, and thus it can be very difficult to ensure that all corresponding connectors are placed at the same height (since up to a quarter inch difference in vertical positioning may result from simply pressing the cone member harder into the wedge member). Such differences may be of little importance when assembling a shelf unit by itself; however, precise positioning is important where side panels or doors are to be mounted to the structural member. The lip  122  allows precise pre-placement of the connector with respect to the groove  118 , regardless of the amount of force placed on the cone element, and thus guarantees proper alignment of the door or side panel on the structural member  2 . Other types of stop element such as knobs, screws, metal posts or other suitable stop element inserted into the wedge member  114  may be used to perform the same function as lip  122  without changing the spirit of the invention.  
         [0126]     Although not illustrated, and as with the previously disclosed embodiments, it is clear that connector  113  may incorporate a hinge element to allow the connector to be installed at any location along the structural member that contains a corresponding wedge member  101 .  
         [0127]      FIG. 25  shows the connector of  FIG. 23  further comprising an integral shelf member  123 . The connector  124  of this embodiment comprises a corner element of shelf member  123 , and also has a first outer side surface  125  to which a butt hinge  126  is attached using machine screws  127  or other suitable fastening device. Connector  122  may also comprise a second outer side surface  128  having a recess  129  suitable for the installation of a side panel member (not shown) using, in this particular illustration, a pin-and-ball fastener. Connector  122  may be fixed to cylindrical structural member  2  using the wedge arrangement described above for connector  113  of  FIG. 23  and  FIG. 24 , or it may be configured to engage the cylindrical structural member in any of the manners described above in relation to the connectors of  FIGS. 1-22 . Although the shelf member  123  of this embodiment is illustrated as attaching to only a single connector  124 , it will be appreciated that a plurality of connectors may be integrated into the shelf member  123  as appropriate to the particular application.  
         [0128]      FIG. 26  shows a system of two connector pairs  130 , attached to respective cylindrical structural members  2 , wherein each connector  130  is attached to an opposite end of a drawer guide  131 , where drawer guide  131  guides the opening and closing of drawer  132 .  
         [0129]      FIG. 27  shows the drawer-connecting system of  FIG. 26 , with drawer  132  in the open position, and showing the drawer guide  131  attached to the drawer using screws  133  and the drawer  132  attached to the drawer guide  131  using screws  134 .  
         [0130]      FIG. 28  shows the drawer-connecting system of  FIG. 27 , in which the connectors  130  of each connector pair are themselves connected by an extension member  135 . This extension member  135  provides a large planar surface to which drawer guide  131  may be attached. Extension member  135  also provides additional stability to the connectors  130 , preventing them from rotating around their respective structural members  2 .  
         [0131]      FIG. 29  shows the drawer-connecting system of  FIG. 27 , in which two connectors are comprised within a unitary connecting piece  136 . On such unitary connecting piece  136  may be installed on either side of the drawer  132 . Unitary connecting piece  136  may comprise two or more connectors consisting of any one or more of the embodiments illustrated in  FIGS. 1-24  above. The unitary connecting piece  136  may be formed by welding an appropriately sized structural box member to one or more individual connectors, or the unitary connecting piece  136  may be formed from a single box.  
         [0132]      FIG. 30 . shows a system of connector pieces used to construct an enclosed shelving unit  140  having a pair of sliding doors  141 . In this embodiment eight connectors  142  are used to construct and enclose the shelving unit  140  with side and top panels  143 ,  144 . Four of the eight connectors  1  are also used to support the sliding doors  141 , using standard top and bottom tracks  145 ,  146  that may be screwed into pre-existing holes  121  in the connector pieces  142 . In this embodiment, the shelves and cylindrical structural members  2  are fixed to each other using the connector  1 . Thereafter the top panel  144  is installed on connectors  142  having top cap members  142  as described in reference to  FIG. 8 .  
         [0133]      FIG. 31  shows a side view of the enclosed shelving unit  140 , showing the relative placement of top and bottom tracks  145 ,  146 , sliding doors  141 , and the attachment scheme for attaching the top and bottom tracks  145 ,  146  to the connectors  1 .  
         [0134]      FIG. 32  shows a system of connector pieces that allow modular assembly of doors, drawers, shelves etc. to a shelving unit  150 . Perforated metal flats  151  are mounted by means of the connectors  152  to the round vertical supports  2  and running parallel to them. On the perforated metal flats  151  a drawer  153  with two drawer guides  154  may be mounted. Alternatively, a door  155  may be connected to the perforated metal flats  151  by means of a full overlay hinge  156 . Modular shelving units having evenly spaced holes are usually only found in wooden furniture where the holes are drilled into the sidewalls of cabinets. The connector allows for the mounting of the perforated metal flats  151  which in turn allow for the attachment of all standard hardware used for such modular systems.  
         [0135]      FIGS. 33A and 33B  show a simplified embodiment of the connector  1  of  FIG. 2  in which the inner cylindrical member  3  is eliminated, and instead the inner surface of the external box member  4  is sized to slideably accept the outer surface of the cylindrical structural member  2 .  
         [0136]      FIGS. 34A and 34B  show an alternative embodiment of the connector  1  of  FIG. 2  in which the inner surface  160  of external member  161  is sized to slideably accept at least a portion of the outer surface  162  of structural box member  163 .  
         [0137]      FIGS. 35 and 35 B show an additional alterative embodiment of the connector of  FIG. 2 , where the structural support member comprises an angle or “L-shaped” beam  164 , and the connector inner surface  165  is configured and sized to engage and retain the beam  164 . Connectors with this configuration may be used to connect standard hardware to flat-sided members having planar dimensions too small to receive the attachment mechanisms of standard hardware such as for example standard butt or full overlay hinges. In this case the connector supplies an enlarged planar surface, which allows for the installation of the above standard hardware to such flat-sided members with small, planar dimensions.  
         [0138]      FIGS. 36A and 36B  show an alternative embodiment of the connector of  FIG. 2 , in which the first and second outer side surface members  166 ,  167  are joined by a third outer side surface member  168  which is substantially planar. The first and second outer side surface members  166 ,  167  may be oriented substantially perpendicular with respect to each other, so that the first, second and third side members join to form an external shape of the connector  1  which is generally triangular when viewed along the axis of the cylindrical structural member  2 .  
         [0139]      FIGS. 37A and 37B  show a further alternative embodiment of the connector of  FIG. 36A  and  FIG. 36B , in which the third side member  169  is curved.  
         [0140]      FIGS. 38A and 38B  show an alternative embodiment of the connector of  FIG. 37 , comprising only one substantially planar outer side surface member  170 . The outer side surface member  170  has first and second ends  1781 ,  172  that are joined by a rounded outer side surface member  173 , which also surrounds an elliptical structural member  174 .  
         [0141]      FIGS. 39A and 39B  show an alternative embodiment of the connector of  FIG. 1 , in which the box-shaped exterior surface  4  of  FIG. 1  is replaced by an L-shaped exterior surface  175 . The design of this embodiment may provide a connector that is lighter and less expensive, while still providing an appropriate attachment surface to connect to various standard hardware pieces.  FIG. 40  shows a connecting bar  176  attached to two opposing connectors  175  using machine screws  177 , although any appropriate fastening mechanism known in the art may be used to effectuate this attachment. In an alternative embodiment, illustrated in  FIG. 41 , the two connectors and the connecting bar of  FIG. 40  may be formed as an integral and unitary connecting bar  178 . A further alternative embodiment, shown in  FIG. 42 , comprises four connectors  175  and four connecting bars which are formed into a single unitary, connecting piece  179 . This unitary connecting piece  179  may be configured to receive a standard butt hinge  9  ( FIG. 43 ), or other attachment mechanisms, such as a keyhole attachment  7 , to allow for the attachment of doors or panels to the connecting piece  179 . The connecting piece  179  may alternatively be provided with a shelf surface, shown in  FIG. 43  as a series of parallel rods  181 .  
         [0142]      FIG. 44  and  FIG. 46  show a perspective and plan view, respectively, of the connector  1  of  FIG. 1  with a shelf bracket  190  attached by means of two machine screws  191  that pass through the holes  192  as seen in  FIG. 45 . The shelf bracket  190  has three holes  193  which allow for the attachment of a shelf  194  (shown hatched) by means of screws  195  as shown in  FIG. 47 .  FIG. 48  reveals a shelving unit  196 , which employs the shelf brackets  190  and the shelves  194 . The advantage of being able to use a shelf bracket  190  in conjunction with the connector  1  is that it allows the attachment of shelves of all dimensions to the cylindrical member  2 . The connector  1  in conjunction with the shelf bracket  190  therefore allows for more dimensional flexibility for the shelving unit  195 .  
         [0143]      FIG. 49  through  FIG. 54  show several variations to keep the connector  1  from rotating around the cylindrical member  2  and to fix the height of the connector  1  more precisely along the cylindrical member  2 . One improvement already described in the text accompanying  FIG. 23  and  FIG. 24  is the lip  122  at the bottom of wedge  114  that allows the connector to be placed at a consistent distance from groove  118  so that all corresponding connectors holding a similar member (side panel, door, etc.) may be placed at the same relative height. The additional improvements described in  FIG. 49  through  FIG. 54  are specific to this invention as well. They are several variations to keep the connector  1  from rotating around the cylindrical member  2 .  
         [0144]      FIG. 49  through  FIG. 52  show variations that keep the connector  113  from rotating around or sliding up and down the cylindrical member  2 . These variations are illustrated in connection with the complementary wedge arrangement that is described in  FIG. 23  through  25 .  FIG. 49  shows a cross-sectional view of the same arrangement with the connector  113  engaged with the structural member  2  as in  FIG. 24  with the addition of two machine screws  200  and  201 , which keep the connector  113  from rotating around the structural member  2 .  
         [0145]      FIG. 50  shows how the machine screws  200  and  201  intersect with the connector's  113  box-shaped outer surface  119 , the wedge-shaped inner surface  120 , the corresponding plastic wedge member  114  and the structural member  2 . The machine screw  200  is a standard shoulder screw with a short, flat head  202 , which is inlayed in the outer surface  119  and whose thread  204  clears the inner surface  120  and the wedge member  114  by a distance  203 , and only engages in a threaded opening in the structural member  2 . The gap  203  is prevents the thread  204  from accidentally engaging the inner surface  120  and the wedge member  114 . This arrangement is easy to engage because it only touches in the above-described two places pulling the connector  113  tightly to the structural member  2 . The machine screw  201  has a long head  205  which when the screw is tightened pushes against the wedge member  114  and whose thread  207  engages with the structural member  2 . In this arrangement the fastening of the connector  113  takes place by pushing the wedge-member against the structural member  2 . Again there is a gap  206  between the wedge member  114  and the thread  207 .  
         [0146]      FIG. 51 a  long shoulder screw  210 , which engages the opposite side of the structural member  2  by means of a nut  213  and thread  212  arrangement. An opening  214  that fits the nut  213  has been cut into the outer surface  119 , the inner surface  120  and the wedge member  114  allowing the nut to push against the structural member  2 . And the head  211  pushes against the outer surface  120 . This arrangement is structurally stronger than the arrangements described in the text accompanying  FIG. 50 . It also has a gap  215 , which helps in the easier insertion of the screw  210 .  
         [0147]      FIG. 52  shows a clevis style pin  216  whereby the nut and bolt configuration of  FIG. 51  is replaced by a mechanism that when the pin  216  is pushed in or pulled out hard a steel ball  217  retracts. With this arrangement the connector  113  is very quickly attached to and disengaged from the structural member  2 .  
         [0148]      FIG. 53  shows a perspective view and  FIG. 54 a  cross-sectional view of an additional tongue and groove arrangement keeps the connector  113  from rotating around the structural member  2  when the wedge-type arrangement is engaged. For this, one groove  220  has been cut into the structural member's  2  surface along its vertical axes, which fits a tongue  221  located on the inside of the wedge member  114  along its vertical axes. Another groove  222  is located on the inside of the inner surface  120  along its vertical axes as well, which fits a tongue  223  located on the outside of the wedge member  114  along its vertical axes. When the connector  113  is pushed down onto the wedge-member  114  with the two tongues and grooves aligned the Connector will be prevented from rotating around the structural member  2 .  
         [0149]      FIG. 55  and  FIG. 56  show an embodiment of the connector, which attaches to the cylindrical structural member  2  using a cylindrical insert  230 .  FIG. 55  shows the connector  1  disengaged from the structural member  2  and  FIG. 56  shows a cross-sectional view of the same arrangement with the connector  1  engaged with the structural member  2 . The cylindrical insert  230 , made from plastic or any other suitable materials, has a seam  121  as in  FIG. 23 , which divides the insert  230  in half and allows the insert  230  to be fit onto the outer surface of the structural member  2  between upper portion  115  and lower portion  116 . The insert  250  may be fixed to the structural member  2  by one or more tabs ( in this  FIG. 56  two tabs)  117  that may fit into a corresponding annular groove  118  formed in the structural member  2 .  
         [0150]     Connector  1  may comprise a box-shaped outer surface  7  as in  FIG. 1  having one or more substantially planar exterior connecting surfaces, and a cylindrical inner surface  11  as in  FIG. 1  with the difference to  FIG. 1  that it is configured first to correspond to the cylindrical insert  230 , which then is configured to engage the structural member  2 , so that when the connector  1  is slid over the end of the structural member  2 , the cylindrical surfaces  11 ,  230  engage to fix the connector  1  and structural member  2  axially.  
         [0151]     The cylindrical insert  230  further comprises a lip  122  as in  FIG. 23  at the bottom of the insert  230  to allow for precise vertical positioning of the connector  1  along the structural member  2  and stopping the connector  1  from sliding through the insert  230 . For attaching side panels to doors, particularly where such panels or doors are prefabricated, multiple connectors  1  are used to support each panel/door, and thus these connectors  1  should be fixed in the same vertical position along multiple structural members  2  to obtain a level positioning of the panel or door. The lip  122  at the bottom of insert  230  allows the connector to be placed at a consistent distance from groove  118  so that all corresponding connectors holding a similar member (side panel, door, etc.) may be placed at the same relative height. There are no cylindrical arrangements with such a lip or other stop element, and this arrangement makes it easy to ensure that all corresponding connectors are placed at the same height. The lip  122  allows precise placement of the connector with respect to the groove  118 , regardless of the amount of force placed on the connector  1 , and thus guarantees proper alignment of the door or side panel on the structural member. This precise placement of the connector relative to the structural member  2  was not achievable in previous wedge type fastening arrangements with inserts because one couldn't control how far down the shelf goes on the wedge. Other types of stop element such as knobs, screws, metal posts or other suitable stop element inserted into the insert  230  may be used to perform the same function as lip  122  without changing the spirit of the invention.  
         [0152]     Although not illustrated, and as with the previously disclosed embodiments, it is clear that connector  1  may incorporate a hinge element or any other standard hardware as discussed in the previous drawings.  
         [0153]      FIG. 57  shows the cylindrical insert  230  with long small wedges  231  on its outer surface  232  that when the inner surface  11  of the connector  1  is pushed over them will crease under that pressure and will make the fit between the insert  230  and the inner surface  11  of the connector  1  and ultimately between the structural member  2  and the connector  1  very tight.  
         [0154]      FIG. 58  through  FIG. 62  show two variations of using clip on fasteners to attach a side panel.  FIG. 58  shows the same connector  1  as in  FIG. 2  with four threaded holes  242  ready to accept the receiving part  240  of a vertically adjustable clip on fastener. The receiving part  240  has four slots  241  through which it can be fastened to the connector  1 . The slots  241  allow for the vertical adjustment of the receiving part  240  of a clip on fastener as shown in  FIG. 59 . The receiving part  240  is flexible to be able to engage the corresponding, horizontally adjustable insert  243  of the clip on fastener enabling the quick attachment of a side panel  244  to the connector  1 . The vertical and horizontal adjustability of the receiving part  240  and the insert  243  of the clip on fastener allow for the fine tuned adjustment of the side panel's  244  connection to a shelving unit. This is of advantage if the shelf unit is slightly askew or if the vertical adjustment of shelves to the structural members  2  is slightly of register. The vertical and horizontal adjustability of any standard hardware in combination with the connector  1  renders the connector  1  even more versatile.  
         [0155]      FIG. 61  shows a perspective view of the same unitary connecting piece  136  as in  FIG. 29  with two horizontally adjustable receiving parts  250  of two clip-on fasteners. The receiving parts  250  have four slots  251  each through which they can be fastened to the unitary connecting piece  136 . The slots  251  allow for the horizontal adjustment of the receiving parts  240  of clip on fastener as shown in  FIG. 61 .  FIG. 62  show the side view of  FIG. 61  with the receiving parts  250  ready to engage a side panel  253  by means of a corresponding, insert  252  of a clip on fastener. The side panel  253  in this arrangement when attached to the connector  1  will be flush with the connector  1 , and vertically and horizontally adjustable with the aforementioned advantages of such an arrangement to a shelving unit.  
         [0156]     The arrangements of clip-on fasteners in conjunction with connecting pieces  136  as described in  FIG. 58  through  62  have an additional advantage. The clip-on fasteners' receiving ends  240  and  250  function like a funnel to receive the inserting parts  243  and  252  therefore, with the assistance of the connecting piece  136 , making the attachment of side panels to for example a shelving unit comprising structural members  2  easier.  
         [0157]     As is apparent, the connector of this invention can be modified in a number of ways other than as described in the foregoing and still be within the scope of the appended claims.