TECHNICAL FIELD

The invention is in the field of play structures and the connectors used therein.

5 BACKGROUND ART

Play structures and connectors used to assemble such structures are known in the art, as discussed below. However, in contrast to embodiments of the present invention, the prior art play structures and connectors suffer from various drawbacks, including difficulties with maintaining a consistent and 10 stable fit between the connectors and other pieces of the structure. As a result, the prior art play structures tend to fall apart, which is inconvenient and frustrating for the user.

U S. Patent Nos. 4352255 and 5318470, to Warehime and Denny respectively, disclose modular construction sets with tubes that are assembled 15 together using various connectors. However, the connectors in these patents lack the physical structure of the inventive connector, including the flexing arms that lock into the tube. While the Warehime patent does show a slot in the tube, the slot does not engage with any element on the connector. Instead, it merely helps the tube end expand as the connector is inserted— /. e., it helps 20 to maintain a good friction fit between the tube and the connector.

U S. Patent Nos. 8708765 and 9283491, both to Pope-Gusev, disclose various tube connectors. However, in U.S. Patent No. 8708765, the connectors are garden-variety, friction fit connectors that differ significantly from embodiments of the invention. In U.S. Patent No. 9283491, the connectors are 25 more complex, but still lack flexing arms which lock into apertures in the tube as in embodiments of the invention.

U S. Patent No. 5049105 to Glickman (hereinafter "the Glickman 105 patent") discloses a hub connector for tubes in a toy construction set. In this connector, the male member flexes as it goes into the tube, and then locks against the internal structure of the tube. The connector of the Glickman 105 patent has key differences versus embodiments of the invention: first the flexing in the Glickman 105 patent occurs at the leading edge of the male member, and the two sides of the male member are fixed toward the hub/center part of the connector. This is the exact opposite of the inventive connector's flexing structure, wherein the leading edge of the flexing tabs are fixed and the flexing ends of the tabs are toward the hub/center part of the connector. In other words, in embodiments of the invention, the tabs flex at the trailing edge and not the leading edge, as the tube is inserted over the male member. Moreover, in the 105 patent, the flexing elements do not lock into holes or apertures in the tube, as in embodiments of the invention. Further, the structure around the circular opening in the Glickman 105 patent is very different from the structure in the inventive connector.

U.S. Patent Nos. 5199919 and 5350331, also to Glickman, disclose construction toy systems wherein tubes of various lengths are used with connectors to build a structure. The connector in these systems has flexing arms with protrusions that lock into a circular groove on the tube, but its flexing arms lock onto the outside of the tube and not the inside, as in embodiments of the invention. In addition, as with the Glickman 105 patent discussed above, the flexing in these systems occurs at the leading edge of the connector, and the two sides of the connector are fixed toward the hub/center part— which is the exact opposite of the inventive connector's flexing structure.

U.S. Patent No. 3648404 to Ogsbury discloses a connector used in a toy building set. This connector has a radial, ball-shaped male member that is slotted, so the sides of the ball can flex toward each other when the male member is inserted into the tube. However, the radial member merely has a friction fit with the tube, and does not lock into holes or apertures in the tube as in embodiments of the invention. And again, the flexing in Ogsbury occurs at the leading edge of the connector, and the two sides of the connector are fixed toward the hub/center part— which is the exact opposite of the inventive connector's flexing orientation.

U.S. Patent No. 4078328 to Rayment discloses a connector similar to that in the Ogsbury patent discussed above, except that the base of the ball- shaped male member has a shoulder which engages the inside of the tube to restrict pivotal movement of the tube. Also, the end of the tube can have a slot therein, and the slot in the tube engages the base of the ball-shaped male member to lock the tube into a perpendicular orientation with the connector rather than a straight-on orientation. However, neither the shoulder engagement nor the slot engagement involves a flexing arm that locks into the tube, as in embodiments of the invention.

U.S. Patent No. 3469339 to Thomas discloses interconnecting tubes, and the connectors have flexing arms that lock into apertures in the tubes. However, the flexing here occurs at the leading edge of the connector, and the two sides of the connector are fixed at the trailing edge. This is the exact opposite of the inventive connector's flexing structure, wherein the leading edge of the flexing tabs are fixed and the flexing ends of the tabs are at the trailing edge. Moreover, the structure around the circular opening in Thomas is different from the structure in the inventive connector.

U.S. Patent No. 7419325 to Rantrua discloses a tube assembling device. The flexing arms in Rantrua do not lock into apertures in the tubes as in the inventive connector. As with the other patents discussed above, the flexing orientation here is also different than in the inventive connector, and other aspects of the physical structure differ as well. BEST MODE OF THE INVENTION

A best mode of the invention is a tube connector for a play structure, and a play structure system that uses such tube connectors to connect a plurality of tubes together, as shown in FIGS. 1-9, discussed further below. The tube connector has a center portion and at least one projecting member extending from the center portion. To construct a play structure, tubes are fitted over the projecting members in the tube connectors. Flexing tabs on the projecting members, which are fixed at the end of the projecting member and extend back toward the center portion, lock into openings in the tubes to secure the tubes to the projecting members and connect the tubes together into a play structure. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a tube connector in embodiments of the invention.

FIG. 2 is a top view of the tube connector shown in FIG. 1.

FIG. 3 is a perspective view of a tube of embodiments of the invention.

FIG. 4 is a top view of the tube in position for placement over the projecting member.

FIG.5 is a top view of the tube fully pushed over the projecting member, before the tube openings are engaged with the flexing tab buttons.

FIG. 6 is a top view of the tube fully locked in place on the projecting member, where the tube openings are engaged with the flexing tab buttons.

FIG. 7 is a top view of the tube in position for "straight-on" placement over the projecting member, wherein the tube openings are pre-aligned with the flexing tab buttons.

FIG.8 is a perspective view of the tube connector shown in FIG. 1, with a tube inserted through the center opening in the tube connector. FIG.9 is a perspective view of the tube connector shown in FIG. 1, with a tube inserted into the center opening of the tube connector and the tube openings engaged with the tube connector center buttons.

FIG. 10 is a perspective view of a second tube connector in an 5 embodiment of the invention.

FIG. 11 is a top view of a second tube connector in an embodiment of the invention.

FIG. 12 is a perspective view of a third tube connector in an embodiment of the invention.

10 FIG. 13 is a top view of a third tube connector in an embodiment of the invention.

FIG. 14 is a perspective view of a fourth tube connector in an embodiment of the invention.

FIG. 15 is a top view of a fourth tube connector in an embodiment of 15 the invention.

FIG. 16 is a perspective view of a fifth tube connector in an embodiment of the invention.

FIG. 17 is a top view of a fifth tube connector in an embodiment of the invention.

20 FIG. 18 is a perspective view of a sixth tube connector in an embodiment of the invention.

FIG. 19 is a top view of a sixth tube connector in an embodiment of the invention.

FIG. 20 is a perspective view of a seventh tube connector in an 25 embodiment of the invention.

FIG. 21 is a top view of a seventh tube connector in an embodiment of the invention FIG. 22 is a perspective view of an eighth tube connector in an embodiment of the invention.

FIG. 23 is a top view of an eighth tube connector in an embodiment of the invention.

5 FIG. 24 is a perspective view of a ninth tube connector in an embodiment of the invention.

FIG.25 is a top view of a ninth tube connector in an embodiment of the invention.

FIG. 26 is a perspective view of a tenth tube connector in an 10 embodiment of the invention.

FIG.27 is a top view of a tenth tube connector in an embodiment of the invention.

FIG. 28 is a perspective view of an eleventh tube connector in an embodiment of the invention.

15 FIG. 29 is a top view of an eleventh tube connector in an embodiment of the invention.

FIG. 30 is a perspective view of a twelfth tube connector in an embodiment of the invention.

FIG. 31 is a top view of a twelfth tube connector in an embodiment of 20 the invention.

FIG. 32 is a perspective view of a thirteenth tube connector in an embodiment of the invention.

FIG. 33 is a top view of a thirteenth tube connector in an embodiment of the invention.

25 FIG. 34 is a perspective view of a fourteenth tube connector in an embodiment of the invention.

FIG. 35 is a top view of a fourteenth tube connector in an embodiment of the invention. FIG. 36 is a perspective view of a fifteenth tube connector in an embodiment of the invention.

FIG.37 is a top view of a fifteenth tube connector in an embodiment of the invention.

FIG. 38 is a perspective view of a play structure assembled using various tube connectors and tubes of embodiments of the invention.

DETAILED DISCLOSURE

In contrast to the prior art discussed above, embodiments of the invention provide a consistent and stable fit between the connectors and tubes forming the play structure, allowing the user to create stable play structures that will maintain their integrity, while the play structures may also be disassembled easily.

The following provides a list of the reference characters used in the

15 drawings:

10. Tube connector

11. Center portion

12. Projecting member

13. Center opening

20 14. Center flexing member

15. Center button

16. Knurl

17. Tip

18. Bevel

25 19. Flexing tab

20. Tab button

21. Tab stop

22. Abutment 5

10

15

20 . ay s ruc ure

As seen in FIG. 1, a particular tube connector 10 of an embodiment of the invention comprises a center portion 11 and one projecting member 12 which is attached to center portion 11. A center opening 13, suitably sized to 25 admit a tube, extends through center portion 11. Said another way, in embodiments of the invention, the center opening and the outer part of the tube may be suitably sized such that the tube slides into the center opening in a free and easy manner, but the tube may also fit snugly in the center opening without excessive clearance.

Two center flexing members 14 may be located opposite each other on the periphery of center opening 13. Center flexing members 14 may serve to maintain tension on an inserted tube, and prevent inadvertent movement of the tube after it has been inserted into center opening 13. A center button 15, having a beveled circular shape, may be located on each center flexing member 14 and extends inward into center opening 13. Center button 15 may engage with an opening on an inserted tube, to further secure the tube within center opening 13.

Center portion 11 may have a knurled outer circumference— that is, knurls 16 or indentations may be present at regularly-spaced intervals on the outer circumference. The knurls 16 or indentations, which may be semicircular or arcuate in nature, allow a user to more easily grip center portion 11 when adding tubes to tube connector 10, or when assembling tubes and tube connectors together into a play structure.

Projecting member 12 may be attached to and project outward from center portion 11. In this embodiment of a tube connector, projecting member 12 lies in the same plane as center portion 11, and is not angled up or down versus the center portion. Projecting member 12 may have a circular tip 17 located at its non-center portion-proximate end. The circumference of tip 17 may be substantially the same as the inner circumference of a tube which fits over projecting member 12, thus providing a snug fit for projecting member 12 inside the tube.

Said another way, in embodiments of the invention, the projecting member and the inner part of the tube may be suitably sized such that the tube slides over the projecting member in a free and easy manner, but the tube and projecting member may also fit together snugly without excessive clearance. Tip 17 also may have a bevel 18 on its leading edge, in order to facilitate the placing of a tube over the end of projecting member 12 The end of projecting member 12 close to center portion 11 may be generally cylindrical, apart from two cut-outs at the top and bottom, and may have substantially the same circumference as the inner part of the tube.

Two flexing tabs 19 may be located on opposing sides of projecting member 12. Flexing tabs 19 may be fixed at their non-center portion-proximate ends and free to flex inward and outward i.e., toward and away from the main body of projecting member 12— at their center portion-proximate ends. In other words, the flexing tabs in embodiments of the invention may be fixed at their leading edge and flex in and out at their trailing edge, when a tube is placed over the projecting member. This configuration allows for the flexing tabs to flex outward against the tube at a location significantly back from the non-center portion-proximate end of the projecting member, after the tube is placed over the projecting member. Said another way, in embodiments of the invention, this configuration provides more consistent support for the tube along the length of the projecting member and better holds the tube in place.

A tab button 20, having a beveled circular shape, may be located on the flexing end of flexing tab 19. As further discussed with regard to FIGS. 4-7, tab button 20 may fit into a corresponding circular through-opening on a tube placed over projecting member 12. Tab stop 21 may be located on the main body of projecting member 12, and may serve to limit the inward movement of flexing tab 19 toward the main body of projecting member 12. Abutments 22 may be located on opposite sides of the center portion-proximate end of projecting member 12, and these abutments may provide stable resting surfaces for the tube end when the tube is fully in position over projecting member 12.

As further shown in FIGS. 4-7, an embodiment of a tube fully in position over projecting member 12 is well supported at the non-center portion- proximate end of the projecting member by tip 17 pressing against the inner part of the tube; is also well supported between the center portion-proximate and non-center portion-proximate ends of projecting member 12 by the flexing tabs 19 pressing against the inner part of the tube; and is also well supported by the cylindrical nature of the projecting member at its center portion- proximate end.

Tube connector 10 is further shown in FIG.2, in a top view. The ability of flexing tabs 19 to move toward and away from the main body of projecting member 12 is indicated by the arrows shown between the flexing tabs and the main body of the projecting member. The ability of center flexing members 14 to move toward and away from center opening 13 is indicated by the arrows shown in that area. A center tab 23 may be attached to center flexing member 14 on the side that is opposite center button 15. A void or open space 24 may surround center tab 23, and this open space between the back wall of center flexing member 14 and the main body of center portion 11 allows center flexing member 14 to move toward and away from center opening 13 when a tube is inserted or removed from the center opening. Put another way, in embodiments of the invention, center flexing member 14 is attached only at its ends to the main body of center portion 11, and this allows center flexing member 14 to flex back and forth.

FIG. 3 illustrates tube 25 of embodiments of the invention, which connects in various ways to the various tube connectors described herein in order to form play structures. Tube 25 may be substantially round and hollow, and as indicated in FIG.3, may come in any suitable length from short to long. Four substantially circular tube openings 26 may be located around the circumference of each end of tube 25. Tube openings 26 may be spaced 90 degrees from each other around the circumference of tube 25, such that there are openings through the wall of tube 25 at the top, bottom, and sides thereof. Tube openings 26 may correspond with center buttons 15 or tab buttons 20, depending on whether tube 25 is inserted into center opening 13 or placed over projecting member 12, as further discussed below with regard to FIGS. 4-9.

FIG. 4 shows tube 25 in position for placement over projecting member 12. In this example, tube 25 is first positioned lengthwise with its hollow end next to tip 17 of projecting member 12, and then tube 25 is pushed inward over projecting member 12 towards center portion 11, as indicated by the directional arrow. It should be noted that in this figure, tube openings 26 in tube 25 are not yet aligned with tab buttons 20 of projecting member 12. Thus, when tube 25 is pushed over projecting member 12, flexing tabs 19 are pushed inward toward tab stops 21 and are held there by the inner wall of tube 25.

FIG. 5 shows an example with tube 25 fully pushed over projecting member 12, with the end of tube 25 butting up against abutments 22. Tab buttons 20 on flexing tabs 19 do not yet extend through tube openings 26, because tube openings 26 and tab buttons 20 are not yet aligned with each other. To align tube openings with tab buttons 20, tube 25 is twisted or rotated about projecting member 12 as indicated by the directional arrow, until tube openings 26 are brought in line with tab buttons 20. When the tube openings are aligned over the tab buttons, flexing tabs 19 move outward from the main body of projecting member 12, and tab buttons 20 extend through tube openings 26 and thereby lock tube 25 in place on projecting member 12. The fully locked in position of tube 25 on projecting member 12 is shown in FIG. 6.

FIG. 7 shows tube 25 in position for "straight-on" placement over projecting member 12. In this embodiment, tube openings 26 at the sides of tube 25 are pre-aligned with tab buttons 20 which are also at the sides of projecting member 12. Thus, when tube 25 is pushed straight onto projecting member 12 as indicated by the directional arrow, tab buttons 20 will extend into tube openings 26 and lock the tube onto the projecting member without any twisting required. When the tube is fully seated on the projecting member in this situation, the tube and tube connector are as shown in FIG. 6.

Removal of tube 25 from projection member 12 is basically the opposite of installation. With sufficient force, tube 25 can be pulled straight off projecting member 12, as the beveled nature of tab buttons 20 allow tube openings 26 to ride back over them. During the removal process, each flexing tab 19 may be forced inward towards tab stop 21, such that tube 25 may then be easily pulled off projecting member 12.

Alternatively, tube 25 may first be twisted or rotated about projecting member 12 until tube openings 26 are no longer aligned with tab buttons 20. Flexing tabs 19 will be forced inward towards tab stops 21 , thus allowing tube 25 to be easily pulled off projecting member 12.

FIG.8 illustrates an embodiment of tube 25 inserted into center opening 13. In this embodiment, tube openings 26 are not engaged with center buttons 15. Instead, center flexing members 14 located on opposite sides of center opening 13, and center buttons 15 on the center flexing members, move back as tube 25 is inserted and then press against the outer wall of tube 25 to hold the tube in place in the center opening. Thereafter, a reasonable amount of force can move tube connector 10 along the length of tube 25, but the tube connector will not move inadvertently in relation to the tube.

FIG. 9 also depicts an embodiment with tube 25 inserted into center opening 13. In this embodiment, tube openings 26 on opposite sides of tube 25 are engaged with center buttons 15 on opposite sides of center opening 13. Similar to when tube 25 is pushed onto a projecting member, in order to engage the tube openings with the center buttons, tube 25 may be pushed into center opening 13 with the tube openings and center buttons not pre-aligned. In this case, a simple twist or rotation of tube 25 in center opening 13 (or, said another way, a twist or rotation of tube connector 10 about tube 25) may be used to align the tube openings with the center buttons. Once center buttons 15 are aligned over tube openings 26, center flexing members 14 flex back toward the tube and the center buttons extend into the tube openings, thus locking the tube in place in the tube connector.

Removal of tube 25 from center opening 13 is basically the opposite of installation. With sufficient force, tube 25 can be pulled straight out of center opening 13, as the beveled nature of center buttons 15 allow tube openings 26 to ride back over them. During the removal process, center flexing members 14 may be forced slightly outward, and tube 25 may then be easily pulled out of center opening 13.

Alternatively, tube 25 may first be twisted or rotated inside center opening 13 until tube openings 26 are no longer aligned with center buttons 15. Center flexing members 14 may be forced outward, thus allowing tube 25 to be easily pulled out of center opening 13.

FIGS. 10-35 illustrate other tube connectors in embodiments of the invention. These other tube connectors have multiple projecting members attached to a center portion at various angles to each other. In some of these tube connectors, the projecting members lie in the same plane as each other and in the same plane as the center portion. In other tube connectors, the projecting members lie in different planes from each other (i.e., a projecting member may be tilted up from the plane of another connector); and/or the projecting members may lie in a different plane from the center portion (i.e., a projecting member may be tilted up from the plane of the center portion).

These other tube connectors allow tubes to be connected together at various angles and in many different configurations to form a play structure. Other than having multiple projecting members at various angles and in various planes, the structures of these other tube connectors (i.e., the components of the projecting members and the components of the center portion) may be the same as the structure of tube connector 10. Operationally, the manner in which a tube is connected to and disconnected from the projecting members, and the manner in which a tube is connected to and disconnected from the center portion, may be the same as described with respect to tube connector 10.

FIGS. 10 and 11 show an embodiment of a second tube connector 27, wherein two projecting members 12 are attached to a center portion 11 at substantially 180 degrees to each other. In this particular embodiment of a tube connector, projecting members 12 lie in the same plane as center portion 11, and are not angled up or down versus the center portion.

FIGS. 12 and 13 show an embodiment of a third tube connector 28, wherein two projecting members 12 are attached to a center portion 11 at substantially 90 degrees to each other. In this particular embodiment of a tube connector, projecting members 12 lie in the same plane as center portion 11, and are not angled up or down versus the center portion.

FIGS. 14 and 15 show an embodiment of a fourth tube connector 29, wherein four projecting members 12 are attached to a center portion 1 1 at substantially 90 degrees to each other. In this particular embodiment of a tube connector, projecting members 12 lie in the same plane as center portion 11, and are not angled up or down versus the center portion.

FIGS. 16 and 17 show an embodiment of a fifth tube connector 30, wherein three projecting members 12 are attached to a center portion 11 at substantially 90 degrees to each other. In other word, three "sides" of the center portion have projecting members attached, and one "side" has no projecting member. In this particular embodiment of a tube connector, projecting members 12 lie in the same plane as center portion 11, and are not angled up or down versus the center portion. FIGS. 18 and 19 show an embodiment of a sixth tube connector 31, wherein two projecting members 12 are attached to a center portion 11 at substantially 90 degrees to each other. Another projecting member 12 is located between the two projecting members, substantially 45 degrees from each of them. In this embodiment, the two projecting members 12 lie in the same plane as center portion 11, and the other projecting 10 member 12 is tilted up from the plane of center portion 11 at substantially a 45 degree angle.

FIGS. 20 and 21 show an embodiment of a seventh tube connector 32, wherein four projecting members 12 are attached to a center portion 11 at substantially 90 degrees from 15 each other. In this embodiment, each of the projecting members 12 is tilted up from the plane of center portion 11 at substantially a 45 degree angle.

FIGS. 22 and 23 show an embodiment of an eighth tube connector 33, wherein two projecting members 12 are attached to a center portion 11 at substantially 90 degrees to each other. Another projecting member 12 is located not between the two projecting members, but instead is substantially 45 degrees from one of them. In this embodiment, all the projecting members 12 lie in the same plane as center portion 11.

FIGS. 24 and 25 show an embodiment of a ninth tube connector 34, wherein two projecting members 12 are attached to a center portion 11 at substantially 60 degrees to each other. In this embodiment, the projecting members 12 lie in the same plane as center portion 11.

FIGS. 26 and 27 show an embodiment of a tenth tube connector 35, wherein four projecting members 12 are attached around a center portion 11 at substantially 90 degrees from each other. In this embodiment, each of the projecting members 12 is tilted up from the plane of center portion 11 at substantially a 75 degree angle. FIGS.28 and 29 show an embodiment of an eleventh tube connector 36, wherein two projecting members 12 are attached to a center portion 11 at substantially 90 degrees to each other. Another projecting member 12 is located between the two projecting members, substantially 45 degrees from each of them. In this embodiment, the two projecting members 12 lie in the same plane as center portion 11, and the other projecting member 12 is tilted up from the plane of center portion 11 at substantially a 75 degree angle.

FIGS. 30 and 31 show an embodiment of a twelfth tube connector 37, wherein two projecting members 12 are attached to a center portion 11 at substantially 45 degrees from each other. In this embodiment, one projecting member 12 lies in the same plane as center portion 11, and the other projecting member 12 is tilted up from the plane of center portion 11 at substantially a 75 degree angle.

FIGS.32 and 33 show an embodiment of a thirteenth tube connector 38, wherein two projecting members 12 are attached to a center portion 11 at substantially 45 degrees from each other. In this embodiment, one projecting member 12 lies in the same plane as center portion 11, and the other projecting member 12 is tilted up from the plane of center portion 11 at substantially a 75 degree angle. This tube connector is similar to embodiments of twelfth tube connector 37, except that the tilted-up projecting member is on the other side of the non-tilted-up projecting member. Said another way, when the non-tilted- up projecting member is at "zero degrees" as seen in FIGS. 31 and 33, the tilted-up projecting member is 45 degrees to the right in thirteenth tube connector 38, rather than 45 degrees to the left as in embodiments of twelfth tube connector 37.

FIGS. 34 and 35 show an embodiment of a fourteenth tube connector 39, wherein two projecting members 12 are attached to a center portion 11 at substantially 45 degrees to 20 each other. In this embodiment, projecting members 12 lie in the same plane as center portion 11.

FIGS. 36 and 37 show an embodiment of a fifteenth tube connector 40, wherein two projecting members 12 are attached to a straight center portion 41 at substantially 180 degrees to each other. Fifteenth tube connector 40 may be used to attach two tubes together end-to-end, such that the attached tubes lie in the same plane. Except for having a straight center portion rather than a center portion through which a tube can be inserted, the projecting member components of fifteenth tube connector 40 are substantially the same as the projecting member components of tube connector 10 and the other tube connectors discussed above. Operationally, the manner in which a tube is connected to and disconnected from the projecting member is the same as described with respect to tube connector 10 and the other tube connectors.

FIG. 38 illustrates an embodiment of the play structure system of the invention, wherein multiple tubes are connected together using multiple tube connectors, to form a play fort. In this embodiment, Tubes 25 of various lengths form the frame of a play structure 42. For simplicity, tube openings 26 are not shown in this figure— but it can be appreciated that the tube openings may be the same as those already shown in FIGS. 3, 6, et al. The tubes in this particular embodiment of a play structure are connected together using third tube connectors 28 and eighth tube connectors 33, as discussed below:

Third tube connectors 28 are used at the bottom corners of play structure 42. One tube 25 is inserted into center opening 13, and a tube 25 fits over each of the two projecting members 12 that are spaced substantially 90 degrees apart. It should be noted that the orientation of third tube connector 28 may be different than the orientation shown in Fig. 37— e.g.., any one of the three tubes which meet at the bottom corner may be inserted into the center opening of the tube connector, with the other two tubes fitting over the two projecting members that are spaced substantially 90 degrees apart.

An eighth tube connector 33 is used at each top comer of play structure 42. One tube 25 is inserted into center opening 13; a tube 25 fits over each of the two projecting members 12 that are spaced substantially 90 degrees apart; and a tube 25 also fits over the projecting member 12 that is spaced substantially 45 degrees apart from one of the other two projecting members 12.

Still referring to the embodiment of FIG. 38, a third tube connector 28 is used at each end of the roof peak of play structure 42. One tube 25 is inserted into center opening 13, and a tube 25 fits over each of the two projecting members 12 that are spaced substantially 90 degrees apart. And as with the connectors at the bottom corner, the orientation of third tube connector 28 at the roof peak may be different than the orientation shown— e.g., any one of the three tubes which meet at the roof peak may be inserted into the center opening of the tube connector, with the other two tubes fitting over the two projecting members that are spaced substantially 90 degrees apart.

It should be understood that various different tube connectors of embodiments of the invention and tubes of various lengths can be used to build any number of different play structures. In addition, solid or flexible panels or other coverings can be attached to the tubes and tube connectors in embodiments of the invention, in order to entirely or partially cover the frame of play structure 42.

While the above description contains many specific examples, these examples shall not be construed as limitations on the scope of the claimed invention, but rather as examples of embodiments thereof. Many other variations are possible without departing from the spirit of the invention. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims.