Quick release joint system for assembling frames

A frame joint system including a first frame member and a second frame member. The frame members include laterally opening channels running axially thereof. The frame members are adapted to be rigidly secured together by quick release coupling. Embodiments of the frame joint system include mitered corner, end-to-face, face-to-face and end-to-end joints. The quick release coupling includes at least a first sleeve member and a gripping member. The gripping member is nested within the first sleeve member, and the first sleeve member is nested within the first frame member. The gripping member includes gripping elements that mate with a slot in a box rail element fixedly associated with the second frame member. Activating the gripping elements pulls the two frame members together into a rigid joint.

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to the field of display frame joints, particularly to quick disconnect frame joints that are useful in forming mitered corners, end-to-face joints, face-to-face joints and end-to-end joints in display frames.

BACKGROUND OF THE INVENTION

Frames, for example, display frames, generally comprise a series of generally straight frame members joined through mitered joints so as to form a closed figure such as a rectangle, or the like. The structural integrity of the frame depends on the rigidity and durability of the joints between the frame members. Previously, various expedients had been proposed for providing rigid durable corner joints. These had included, for example, one or more “L” shaped brackets at each joint mounted to both of the mating frame members and extending across the joint, and interlaced fingers engaged with one another generally along the plane of the joint. Where frames were intended to be disassembled and reassembled with some frequency, the “L” shaped brackets where generally mounted with screws or other fasteners that secured them to the respective mating frame members. When the brackets and fasteners were separated from the frames upon disassembly, it was necessary to keep track of them so they would be available the next time the frame was to be assembled. A missing bracket or screw could prevent the assembly of the frame. In those prior expedients with interlaced fingers, the interlaced fingers were sometimes retractable to release the mating frame members from engagement with one another. The interengaged fingers and “L” shaped brackets were required to carry the torsional loads that the frame was exposed to. If the fingers or brackets failed, the entire frame became useless until they were repaired. The attachment locations of the brackets and fingers on the respective frame members tended to become worn so the joints could no longer be made tight. Various previous expedients for joining frame components at locations other than at corner joints have presented similar deficiencies. By way of example, expedients for securing end-to-end, end-to-face and face-to-face joints have commonly relied on straight, “L” shaped or “T” shaped brackets with mounting screws or other fasteners.

Those in the art concerned with these matters recognized the need for improved frame joint systems.

SUMMARY OF THE INVENTION

In embodiments, a frame joint system is provided. Embodiments of the frame joint system find utility in many applications where rigid corners and other frame intersections are desired. Embodiments of the frame joint system include a quick release coupling to secure a mitered corner joint or other frame joints together. In some embodiments the quick release coupling includes first and second sleeve members and a gripping member. The frame joint system provides improvements in safety, reliability, ruggedness, ease of assembly and disassembly, rigidity, ease of manufacturing, and functionality. Embodiments provide improved functionality, particularly when the embodiments are used in temporary display systems that are frequently moved, erected, handled, and disassembled. Improvements are achieved by reducing the number and complexity of the parts, which improves reliability and reduces cost. A minimum number of operations are required to manufacture and install the components, thus reducing costs and improving quality. Simplicity of assembly and disassembly, rigidity, and durability are of great significance in certain applications such as, for example, temporary displays.

In embodiments that are particularly suited for use, among other uses, in frames in temporary displays, the frame joint system allows the quick and repeated erection, handling, and disassembly of even large display frames in the order of six feet by ten feet, or larger. The existence of rigid joints permits the handling of an assembled frame without damaging it.

The elements of a quick release coupling are generally permanently assembled to frame members so there are no loose parts to keep track of as the disassembled frame is moved from one location to another. In particular embodiments, for example, once the mitered ends of the respective frame members are brought into alignment with one another, a twist of a simple hand tool moves gripping elements in a gripping member between disengaged and engaged configurations. This locks the frame members into an assembled relationship. According to certain embodiments, similarly assembling three other joints between frame members quickly and easily secures the frame members into a substantially rigid generally rectangular frame. The assembly of the entire frame typically takes less than a minute. Disassembly is generally even quicker.

In embodiments, rigidity in the assembled joints is accomplished by using a quick release coupling in which, among other things, the area of gripping engagement is removed both spatially and angularly from the plane of the joint, and the gripping elements themselves are substantially protected from torsional forces. According to certain embodiments this spatial and angular separation from the joint plane is accomplished by the use of a quick release coupling that includes sleeve members nested in frame members, and a gripping member nested in a sleeve member. The gripping member is quickly actuatable between engaged and disengaged configurations.

Embodiments that are particularly adapted for use in temporary displays include outwardly opening artifact mounting channels that extend through the mitered frame joints. Artifact mounting channels provide locations for securing artifacts to the assembled frame, including, for example, large expanses of fabric.

In certain embodiments, the frame joint system includes a first frame member that is elongated and hollow with a first longitudinal axis and first and second generally opposed ends. The first frame member has a substantially constant first cross-sectional profile including a first frame cavity extending generally axially therein. The first frame cavity, for example, has a generally closed cross-sectional profile and opens axially. The first frame member includes at least a first artifact mounting channel extending axially and opening laterally to provide for the mounting of artifacts. The first end is beveled at approximately a predetermined angle. In certain embodiments where a rectangular frame is intended, the second end is likewise beveled approximately at a predetermined angle.

According to certain embodiments, a first sleeve member is elongated and hollow with a longitudinal axis and proximal and distal ends. The first sleeve member has a substantially constant first sleeve cross-sectional profile including a sleeve cavity extending axially therein. The sleeve cavity has a generally closed cross-sectional profile and opens axially.

The first sleeve member is axially slidably received and retained in the first frame cavity with the proximal end of the first sleeve member adjacent to the first end of the first frame member, but not intersecting the joint plane. In certain embodiments, the proximal end extends to but not through the joint plane. When received within the frame cavity of the first frame member the longitudinal axis of the first sleeve member extends generally parallel to the first longitudinal axis of the first frame member.

According to certain embodiments, a quick disconnect gripping member takes the form, for example, of a cassette member that is axially slidably received and retained in the sleeve cavity in the first sleeve member. The retention of the gripping member in the sleeve cavity is permanent in the sense that it need not be removed from the sleeve cavity when the frame joint system is disassembled.

In certain embodiments, the gripping member includes a plurality of gripping elements that project beyond the proximal end of the first sleeve member when the gripping member is received in the sleeve cavity of that first sleeve member. The gripping elements in some embodiments are formed from a specially configured leaf spring member that is actuated by sliding movement within a housing member. The sliding movement is induced, for example, by the rotation of an eccentric element against a surface of the leaf spring member. In certain embodiments the gripping elements are aligned with one another so that together they define an area of gripping engagement that generally extends at an angle to and is spaced from the joint plane. The gripping elements are adapted to being actuated between gripping and released configurations.

According to certain embodiments, as the gripping elements are moved from the disengaged to the engaged configurations they perform a compound movement in which they spread apart, engage with, and draw a mating box rail element into firm engagement with a housing in which the gripping elements are mounted, or the proximal end of the first sleeve member, or both. This compound motion is reversed when the gripping elements are moved from the gripping configuration to the released configuration. According to certain embodiments, the area of gripping engagement over which the gripping elements engage the mating box rail element generally defines a plane that includes the surfaces of the box rail element that lie on either side of the lateral axially extending opening in the box rail element.

A second frame member includes a second longitudinal axis and first and second frame ends. The second frame member has a second cross-sectional profile that in some embodiments is substantially the same as the cross-sectional profile of the first frame member. A second frame cavity extends generally axially within the second frame member. The second frame member also includes at least a second artifact mounting channel extending axially of the second frame member and opening laterally thereof. In certain embodiments adapted to create a mitered joint, the first frame end is beveled at approximately a predetermined angle. In certain embodiments where a rectangular frame is desired, the second frame end is similarly beveled at approximately a predetermined angle. For a 90 degree mitered joint the respective mating frame ends that come together at the joint plane are each beveled at approximately 45 degrees.

According to certain embodiments, a second sleeve member has a second sleeve cross-sectional profile that in some embodiments is substantially similar to the first sleeve cross-sectional profile, and a second sleeve longitudinal axis. A box rail element opens laterally of and extends axially within the second sleeve member. In certain embodiments the proximal end of the second sleeve member extends generally normal to the direction in which the lateral opening of the box rail element opens. This lateral opening of the box rail element generally parallels the longitudinal axis of the second sleeve member. The second sleeve member is axially slidably received and retained in the second frame cavity with the longitudinal axis of the second sleeve member extending either generally parallel to or perpendicular to the longitudinal axis of the second frame member. In some embodiments, the second sleeve member projects axially outwardly from a beveled frame end of the second frame member and through the joint plane. The respective beveled ends of the first and second frame members are adapted to mate with one another with the gripping elements of the gripping member that is associated with the first frame member in a gripping configuration with the second box rail element that associated with the second frame member. In certain embodiments, at least the first and second artifact mounting channels extend substantially continuously through the joint plane.

In certain embodiments, the frame joint extends at approximately 45 degrees to the longitudinal axes of the mated frame members. According to further embodiments, the gripping member is axially slidably received and releasably retained in the sleeve cavity. According to some embodiments, the first and second sleeve members are substantially shorter than the first and second frame members in which they are mounted. In general, the respective sleeve members need only be of sufficient axial length so that when retained in the respective frame cavities and releasably engaged in a joint system, they are substantially prevented from lateral or rotational movement in the respective frame members in which they are nested.

Embodiments comprise a frame joint system that includes a rigid quick disconnect joint. The frame joint system includes first and second frame members. The first and second frame members are elongated, they have major axes, and in mitered corner embodiments they include beveled ends. The beveled ends of the respective frame members are adapted to being abutted against one another generally along a joint plane to define an approximately right angled mitered joint. The first frame member includes therein a socket portion adjacent to the beveled end of the first frame member. Certain embodiments of the frame joint system also include a sleeve member with a laterally opening axially extending box rail element. The sleeve member is mounted generally within the second frame member so that it projects generally axially beyond the beveled end of the second frame member. The sleeve member is adapted to project generally laterally into the socket portion in the first frame member. A gripping member is mounted generally within the first frame member. The gripping member includes a plurality of gripping elements that are located within the socket portion and separated spatially and angularly from the joint plane. The gripping elements are adapted to engage the laterally opening axially extending box rail element when the sleeve member is projected into the socket portion. The gripping elements are adapted to being actuated between a gripping configuration and a released configuration with respect to the box rail element.

Embodiments of the frame, sleeve, and gripping members may be constructed of various materials, including, aluminum alloys, engineering plastics, stainless steel, or the like. The materials will be selected by those skilled in the art of quick disconnect frame structures depending on such factors as the intended operating environment (corrosive, abrasive, impact, or the like), anticipated assembly conditions, and the like, as specific applications may dictate.

If a teaching of a reference or application herein incorporated by reference contradicts or is inconsistent with a teaching that is expressly set forth in the present application, the express teaching in the present application shall control.

The detailed description of embodiments of the frame joint system is intended to serve merely as examples, and is in no way intended to limit the scope of the appended claims to these described embodiments. Accordingly, modifications to the embodiments described are possible, and it should be clearly understood that the invention may be practiced in many different ways than the embodiments specifically described below, and still remain within the scope of the claims.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and may herein be described in detail. The drawings may not be to scale. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications.

DETAILED DESCRIPTION OF THE INVENTION

The following description of the best mode presently known generally relates to a system in which one quick release frame joint system holds two mating frame members in a strong, safe, rugged, and easily assembled and disassembled structural relationship.

With particular reference to the accompany drawings; in the embodiment of a frame joint system8illustrated inFIG. 1, a first frame member is indicated at10and a second frame member is indicated at12(see, for example,FIGS. 1-3, and4). First beveled end14of first frame member10is beveled at approximately 45 degrees, and beveled first frame end16of second frame member12is likewise beveled at approximately 45 degrees. When these beveled ends are brought together, a 90 degree mitered joint is formed along joint plane106. In the assembled configuration, first toe element11of first frame member10is in registry with second toe element13of second frame member12so that the laterally opening channels in the respective frame members are in registry with one another, as illustrated, for example, by the registry of first channel18with second channel20. The laterally opening channels are thus continuous through the mitered joint. Web36provides rigidity to first frame member10, and also confines first sleeve member22, when it is nested within first frame member10, against lateral or angular motion relative to the frame member.

In the embodiment of a frame joint system8illustrated inFIG. 1, the respective frame members are secured together by way of a quick release coupling comprised of first and second sleeve members22and24, and a gripping member56(see, for example,FIGS. 1-3, and4). Gripping member56is nested within first sleeve member22, and first sleeve member22is nested within first frame member10. Second sleeve member24is nested within second frame member12. In an assembled configuration, one end of second sleeve member24(e.g., a generally triangular boss portion of the second sleeve member as shown, for example, inFIG. 1) projects through joint plane106and into socket portion50of first frame cavity69so that box rail element26is presented for gripping engagement with gripping elements40,42, and44in an approximately right angle gripping configuration. As illustrated inFIG. 1, the box rail element26may extend substantially parallel to the second artifact mounting channel20. More specifically, in embodiments in which the first frame end16is beveled at a 45 degree angle, the box rail element26may extend at approximately a 45 degree angle with respect to the beveled first frame end16. Also as illustrated, the box rail element26may extend in non-parallel fashion with respect to the beveled end16of the second frame member12. As illustrated inFIG. 1, the socket portion50of the first frame cavity69may extend from the first sleeve member22through the beveled first end14. Socket portion50receives the second sleeve member24in close fitting sliding engagement so that the sleeve member prevents the mated frame members from rotating out of the joint plane. This removes the gripping elements both angularly and spatially from the joint plane106. It also brings the external side walls of second sleeve member24into close sliding engagement with the internal side walls of first frame cavity69. First frame cavity69has about the same internal dimensions as second frame cavity64, and second sleeve member24has about the same external dimensions as first sleeve member22. Torsional rigidity is thus imparted to the mitered joint that is formed between the respective frame members, and the gripping elements are protected from experiencing substantial, and potentially destructive torsional forces.

According to certain embodiments, the frame and sleeve members are elongated and hollow with substantially constant cross-sectional configurations throughout their lengths. In further embodiments, the cross-sectional configurations and the sizes of the mating frame members are substantially the same. Likewise, in additional embodiments, the cross-sectional and the sizes of the sleeve members are substantially the same. The frame and sleeve members are conveniently formed, for example, by extrusion through a die with the desired cross-section. For the sake of clarity and convenience, only the mating ends of two frame members, two sleeve members, and one quick release coupling are illustrated inFIGS. 1 through 9. As will be understood by those skilled in the art, multiple members and couplings are generally required to assemble a desired frame with multiple joints.

Gripping member56is slidably axially received and retained in sleeve cavity66in first sleeve member22(see, for example,FIG. 2). In the embodiment of a frame joint system8illustrated inFIG. 1, first sleeve member22is slidably axially received in and retained in first frame cavity69of frame member10. Gripping member56includes a plurality of gripping elements40,42, and44. These gripping elements project axially outward of the end of first sleeve member22, but within first frame cavity69.

In the embodiment selected for illustration inFIGS. 1-9, second sleeve member24is slidably axially received and retained in second frame cavity64, which is in second frame member12. An end of second sleeve member24projects outwardly beyond frame cavity64. Second sleeve member24includes a box rail element26. The end of second sleeve member24projects from the beveled end of second frame member12with slot62in box rail element26positioned to releasably engage with gripping elements40,42, and44. The beveled first and first frame ends14and16of frame members10and12, respectively, are mated together to form a mitered corner by moving frame member12as indicated at54until the beveled ends meet with toe elements11and13together. Gripping elements40,42, and44are then moved to grip box rail element26. Box rail element26includes a box rail cavity28. Wall30of box rail element26is spaced far enough from slot62to permit the gripping elements to be fully inserted into box rail cavity28. In the gripping configuration the gripping elements bear against the inside surfaces of box rail element26adjacent to and on either side of slot62, and clamp box rail element26against the end of housing member57and/or the end of sleeve member24.

In the embodiments chosen for illustration purposes, a prior art gripping member is illustrated. Any gripping member may be used that functions to firmly and reliably hold one sleeve member against the other at a location that is spatially and angularly spaced from joint plane106, and is quickly actuatable between released and gripping configurations. Gripping member56comprises a housing member57, a leaf spring member76that is specially configured, and an eccentric member46(see, for example,FIGS. 4-7). Leaf spring member76is mounted for axial movement within housing member57. Eccentric member46is rotatably mounted in housing member57, as indicated at90. Rotation of eccentric member46in housing member57causes leaf spring member76to move axially as indicated at78. Housing member57includes cam blocks92,96, and100(see, for example,FIG. 7) with cam surfaces94,98, and102, respectively, that camingly engage spring finger elements89,86, and88. The spring finger elements are part of leaf spring member76. As leaf spring member76moves axially of housing member57under the urging of eccentric member46, the spring finger elements move relative to the respective cam surfaces with which they are camingly engaged. The spring finger elements terminate in gripping elements44,40, and42, respectively. The gripping elements project beyond the housing member, and are adapted to grippingly engage a box rail element such as box rail element26(see, for example,FIGS. 1-3,8, and9). The actuating rotation of eccentric member46is effected, for example, by the rotation of a wrench (not shown) engaged in socket80. For tensioning purposes part of spring finger element89is divided into three leaves82,83, and84.

As the spring finger elements move axially over the cam surfaces they are deflected laterally against the tension in the leaf spring member so the gripping elements move between gripping and released configurations relative to the box rail element. As the spring finger elements are moved to the gripping configuration, the gripping elements are moved laterally outwardly and drawn axially closer to the housing member so that a box rail element with which they are engaged is drawn tightly against the housing member. Reversing this action moves the gripping elements axially outwardly of the housing member and allows the tension in the leaf spring member to move the gripping elements laterally inwardly to release the engaged box rail element. The gripping elements may thus be adapted to being actuated with respect to the housing member.

The quick release coupling is retained in first sleeve member22through at least the engagement of eccentric member46in sleeve port49. Sleeve port49is in the side of first sleeve member22(see, for example,FIGS. 1 and 4). In the fully assembled configuration, sleeve port49is in registry with port48in first frame member10. Port48allows access to eccentric member46. The rotation of eccentric member46actuates the gripping elements between gripping and released configurations. Eccentric member46projects into sleeve port49under the urging of leaf spring member76. Depressing eccentric member46out of engagement with sleeve port49, against the tension in leaf spring member76, as indicated at104(FIG. 6), releases gripping member56to slide axially of sleeve cavity66. Boss38and boss39project outwardly from opposed sides of housing member57. Boss38defines shoulder70. In the embodiment selected for illustration inFIGS. 1-9, for example, bosses38and39enter the slot62in box rail element26on either side of the gripping elements where they serve to prevent the gripping member56from twisting out of alignment with slot62. This serves to rigidify the frame joint.

The several frame members, sleeve members and couplings are nested together in snug sliding fits to minimize any play that would impair rigidity. The sleeve members are generally secured to the respective frame members by bolts, rivets, adhesives, welds, or the like to provide a substantially rigid connection. See, for example, rivets32,34, and52inFIG. 1, and rivets33inFIGS. 12-26. These rivets engage rivet holes in the respective frame and sleeve members. Rivet hole51(FIG. 4) is typical. The snug fit between gripping member56and the sleeve cavity in which it is mounted minimizes any relative movement between the two. Also, when the gripping elements are drawn into full engagement with the mating box rail element, the tension between the two is such that there is very little play between them. The mating edges of the frame members are drawn into tight engagement by the tension between the gripping elements and the box rail element. This secures the frame members against rotational movement relative to one another.

In the embodiment selected for illustration inFIGS. 1-9, and with particular reference toFIGS. 8 and 9, there is illustrated a set of gripping elements in the gripping (FIG. 9) and released (FIG. 8) configurations relative to a box rail element26. Gripping element40includes a beveled end74that bears flat against the surface of box rail element26in the gripping configuration ofFIG. 9. InFIG. 9the position occupied by gripping element40in the released configuration is indicated in phantom at72. The axial movement of leaf spring member76responsive to the rotation of eccentric member46draws the gripping elements down and laterally outwardly against the adjacent surface of box rail element26. This pulls box rail element26tightly against the adjacent surface of housing member57. The gripping elements provide tension to draw the mating frame surfaces tightly together so that frictional engagement between them prevents relative movement. The mating frame surfaces surround the gripping elements. The gripping elements do not need to provide torsional stability because they are spatially and angularly separated from the joint line itself. The gripping elements40,42, and44, in the released configuration (see, for example,FIGS. 6 and 8) extend generally parallel to locking plane110. When moving to the gripping configuration (see, for example,FIGS. 7 and 9) the gripping elements deflect outwardly at an angle to locking plane110as they are simultaneously drawn into engagement with a mating box rail element.

In the embodiment selected for illustration inFIGS. 1-9, the respective mating beveled ends of first frame member10and second frame member12, when in the assembled configuration, form a generally right angle mitered joint along joint plane106(see, for example,FIGS. 1 and 4). Joint plane106(see, for example,FIG. 4) extends at an angle to first longitudinal axis108of first frame member10, first sleeve member22, and gripping member56. When the gripping elements40,42, and44are engaged with box rail element26(see, for example,FIGS. 1,3, and9) the end of second sleeve member24projects beyond the beveled end of second frame member12to define a generally triangular prismatic boss portion, and through joint plane106so that box rail element26extends substantially normal to first longitudinal axis108. The gripping engagement between the gripping elements and the box rail element with which it mates occurs at a location that is axially spaced inwardly from the first beveled end14of first frame member10, and within the frame cavity in first frame member10.

With particular reference toFIGS. 1-3, several elongated laterally opening channels are illustrated at18,20,68,58, and60. In a typical application, these serve as mounting locations for various artifacts such as, for example, sheets of material upon which text and/or images are displayed. In such applications it is desired by the users that the channels be uninterrupted and continuous as they change directions at joints in the frames. Embodiments provide this desired feature, because the joints are secured together by coupling members that are internal to the assembled structure. Embodiments are sufficiently rigid that, for example, canvas can be stretched and the edges held in place in the channels without distorting the frames. The frames are robust enough to withstand hard usage in displays. Frames can be assembled and disassembled very quickly and easily. Frame members are brought together by hand as indicated inFIGS. 1,16and22. Approximately a half turn of eccentric member46engages and tightens the gripping elements to the box rail element, and the joint is complete. Disassembly is accomplished by an approximate half turn of eccentric member46. Because the gripping member is not subjected to rotational loads it has a very long useful life (hundreds of assembly and disassembly cycles).

With particular reference toFIGS. 10 and 11, there is illustrated frame members in which both ends of the frame members are beveled at approximately 45 degrees. These frame members are suitable, for example, for use in forming rectangular frames. If a rectangular frame is not desired, then the opposed ends of the frame members may be configured differently from that shown inFIG. 10or11.

Frame member112includes a first beveled end116and a second beveled end118. Frame member114includes a first beveled end120and a second beveled end122. Beveled ends116and120are adapted to being mated to form a mitered generally right angle joint. Likewise, beveled ends118and122are similarly so adapted. Box rail element124is mounted to frame member112so that it projects outwardly from first beveled end116through what would be the joint plane formed when frame members112and114are mated to one another. Box rail element124includes an axially extending slot130, which is defined by axially extending rail elements126and128. Adjacent second end118a socket portion132of frame member112opens laterally of the frame member. Gripping fingers138extend from a housing136into socket portion132. When a box rail element, such as124on a different frame member, is inserted into socket portion132, gripping fingers138are adapted to be actuated between gripping and released configurations with rails of the box rail element. The region in which the engagement occurs is generally separated both spatially and angularly from the joint plane between the mated frame members. In the embodiment chosen for illustration, the locations of this engagement between the gripping elements and the opposed rails of the box element generally define a plane that extends at an angle to the joint plane.

Frame member114includes a first beveled end120and a second beveled end122. Socket portion140of frame member114opens laterally of the frame member similarly to socket portion132. Gripping elements142project from area144of frame member114. Gripping elements142function to grippingly engage the rails of a box rail element similarly to gripping elements138. Adjacent to second end122, box rail element150projects out of frame member114through where a joint plane would form when frame member114is mated to another frame member with an end constructed similarly to, for example, first end120. Box rail element150includes a closed ended slot146. Opposed rails are defined by the opposed sides of slot146.

Laterally opening channels are provided on both frame members112and114. These laterally opening channels serve to provide artifact attachment locations at various locations on a frame constructed from these frame members. When, for example, the respective first ends116and120are mated to form a mitered joint, gripping elements142enter slot130as box rail element124enters socket portion50. Upon actuation, gripping elements142grippingly engage opposed rails126and128to draw box rail element124firmly against area144. Area144may include other structure (not shown in thisFIG. 11). Similarly, the engagement of second end122with a mating frame member, and the actuation of a quick disconnect coupling causes the two frame members to be drawn into firm engagement with one another. When so engaged the laterally opening channels extend continuously around the resulting frame. For example, The engagement of ends116and120permits laterally opening channels152-154,160-162, and156-158to continue through the joint uninterrupted. Where the artifacts to be mounted to the assembled frame have continuous edges or rims that are to be engaged with the frame, the continuous nature of the laterally opening channels is important to achieving the intended result. Similarly, the joinder of ends118and122permits laterally opening channels164-166and168-170, for example, to continue uninterrupted around the frame.

FIGS. 12-18illustrate components and configurations relating to a further embodiment of a frame joint system8. Such a further embodiment is shown in mated configuration generally at8inFIGS. 16 and 17, and in cross-section inFIG. 18. As with other embodiments, first frame member10and second frame member12are mated together by way of a quick release coupling. However, in the embodiment depicted inFIGS. 16-18, first sleeve member22is mounted in first frame member10such that first sleeve longitudinal axis107is substantially perpendicular to first longitudinal axis108(seeFIGS. 12-15for more detail). First sleeve member22is generally secured to first frame member10by bolts, rivets (see, for example, rivets33), adhesives, welds or the like to provide a substantially rigid connection. As illustrated, for example, inFIGS. 16-18, this arrangement allows first frame member10and second frame member12to be mated in a substantially face-to-face relationship, as distinguished from, for example, a mitered corner or a more end-to-end relationship enabled by other embodiments. Gripping elements40,42, and44(see, for similar construction,FIGS. 8 and 9) engage a box rail channel running axially in second frame member12.

In addition to improving ease of frame construction, the embodiment illustrated inFIGS. 16-18presents both structural and manufacturing advantages. With first sleeve member22acting as a structural interface between gripping member56and first frame member10, loads applied to gripping member56are more broadly distributed to first frame member10, particularly bending and torsional loads. This improvement in load distribution can help prevent the failure of thin-walled load bearing components within which a gripping member is mounted, such as first frame member10. Further, turning now toFIGS. 12 and 13, with first sleeve member22as a structural interface between gripping member56and first sleeve member10, the tolerances required to machine an opening in first frame member10sufficient to rigidly retain gripping member56in the proper gripping position are substantially reduced. Instead, the ultimate position of gripping member56can be fine-tuned by adjusting the relationship between first sleeve member22and first frame member10, for example, just prior to securing first sleeve member22to first frame member10. If this relationship needs to be corrected, rivets33, for example, can be inexpensively removed and first sleeve member22re-drilled or recycled, rather than having to repair or recycle the much larger first frame member10as a result of an imprecise machining operation.

FIGS. 20-26illustrate components and configurations relating to an additional embodiment of a frame joint system8. Such an additional embodiment is shown in mated configuration generally at8inFIGS. 23 and 24, and in cross-sections inFIGS. 25 and 26. As with other embodiments, first frame member10and second frame member12are mated together by way of a quick release coupling. However, in the embodiment depicted inFIGS. 23 and 24, first sleeve member22is mounted in first frame member10such that first sleeve longitudinal axis107is substantially parallel to first longitudinal axis108(seeFIG. 20for the relationship between the axes), and second sleeve member24is mounted in second frame member12such that second sleeve longitudinal axis111is substantially perpendicular to second longitudinal axis109(seeFIG. 21). Sleeve members22and24are generally secured to their respective frame members10and12by bolts, rivets (see, for example, rivets33), adhesives, welds or the like to provide a substantially rigid connection. As illustrated, for example, inFIGS. 22-24and26, this arrangement allows first frame member10and second frame member12to be mated in an end-to-end relationship, as distinguished from, for example, a mitered corner or a more face-to-face relationship enabled by other embodiments. Gripping elements40,42, and44(see, for similar construction,FIGS. 8 and 9) engage a box rail channel running axially in second sleeve member24.

For purposes of ease of illustration, the frame members have been depicted as straight with one gripping member per joint. As will be understood by those skilled in the art, arcuate frame members can be employed. The frame members can be arcuately formed so that they are within plane110, or they can curve out of plane110in a direction that is normal to this plane or at any other angle or combination of angles, as may be desired. In certain embodiments, the joints form 90 degree corner angles. According to certain embodiments, particularly where large frames are involved, more than one gripping member can be used at each joint. The gripping members can be located on the same side of the joint, or there can be one or more gripping members on each side of the joint.

The foregoing detailed description of the invention is intended to be illustrative and not intended to limit the scope of the invention. Changes and modifications are possible with respect to the foregoing description, and it is understood that the invention may be practiced otherwise than that specifically described herein and still be within the scope of the claims.