Background of the Invention
In the construction of many items, wherein tubular members are interconnected, especially in furniture construction, it is desirable to provide a connector construction which holds the parts together securely and provides a pleasing appearance. Typical connectors are shown in U.S. Pat. No. 3,850,534, issued Nov. 26, 1974 to Robert W. O'Halloran, entitled "Chair Connector"; U.S. Pat. No. 4,261,667, to Evander M. Ervin, Ervin E. Dargan and Richard Ferguson, issued Apr. 14, 1981, entitled, "Cove Joints, Furniture Therefrom, And Furniture Manufacturing Method"; and U.S. Pat. No. 4,262,230, to Robert D. Vandermiden, issued Apr. 28, 1981, entitled, "Joint For Outdoor Furniture". All of the connector constructions disclosed in the aforementioned patents are not particularly well adapted for use with furniture which is manufactured from extruded plastic tubing. In the utilization of extruded plastic tubing, it is desirable not only to provide a connector construction which may be easily concealed, but one in which the construction may be assembled when certain of the parts are made of a long continuous piece of tubing. It is therefore desirable to provide a connector construction wherein there is a minimum of exposed parts or openings and which exposed parts or openings may be selectively placed in positions which are not readily noticeable.
Summary of the Invention
The present invention relates to an improved construction for coupling one tubular member to another tubular member which tubular member constitutes a part of an article of furniture. A first tubular member has an aperture contained therein. A first screw fastener member is mounted in the aperture of the tubular member. Said first screw fastener member has an enlarged portion exteriorly of the tubular member preventing the screw fastener member from passing through the aperture into the interior of the tubular member. The screw fastener member has a second enlarged portion in the interior of the tubular member. The first and second enlarged portions of the screw fastener member frictionally engage the portion of the tubular member surrounding the aperture to prevent rotation of the screw fastener member relative to the tubular member. A second tubular member has a portion positioned adjacent to the aperture in the first tubular member. A second screw fastener member is rotatably mounted in the second tubular member and is held in the second tubular member. The second screw fastener member threadedly engages the first mentioned screw fastener member connecting the second tubular member to the first tubular member.
Description of the Drawings
FIG. 1 is a fragmentary perspective view of a chair frame made of a plurality tubular members, wherein the instant connector construction for connecting one tubular member to another tubular member is utilized;
FIG. 2 is an enlarged fragmentary perspective view of the chair frame shown in FIG. 1 with portions broken away and others exploded showing two connector constructions each connecting one tubular member to another tubular member and both embodying the instant invention;
FIG. 3 is an enlarged cross sectional view taken on line 3--3 of FIG. 1 showing one tubular member connected to another tubular member;
FIG. 4 is a cross sectional view taken on line 4--4 of FIG. 3;
FIG. 5 is an enlarged cross sectional view showing a screw fastener member positioned in an aperture in a tubular member; and
FIG. 6 shows the screw fastener member of FIG. 5 deformed to have an enlarged portion in the interior of the tubular member to lock the screw fastener member in the tubular member.
Description of the Preferred Embodiment
Referring now to the drawings and especially to FIG. 1, a chair frame generally indicated by numeral 10 is shown therein. Frame 10 utilizes a plurality of connector constructions for connecting tubular members which connector constructions embody the herein disclosed invention.
The chair frame is made up of a plurality of extruded flexible weather-resistant polyvinyl chloride tubular members. Chair frame 10 generally includes a pair of mirror image sides 12 and 14 which are connected to each other by tubular cross members 16, 18, 20, 22, and 24.
The sides 12 and 14 having substantially identical parts will have like and mirror image parts identified by the same name and same number. Each side includes a rear upright 26 which has its lower end formed integral with a horizontal floor rail 28. A front upright 30 is formed integral with the other end of each horizontal rail 28. An arm portion 32 is formed integral with the upper end of each upright 30.
Each back upright includes an upper back portion 34 with a main back portion 36 formed integral with the lower end of the upper back portion. A back leg portion 38 is formed integral with the lower end of the main back portion. The lower end of back leg portion 38 is formed integral with horizontal rail 28.
Each arm portion 32 includes a seat bar 40 which has one end formed integral with the upper end of front upright 30. A back bar 42 has its lower end formed integral with the upper end of front upright 30. Back bar 42 is substantially parallel to main back portion 36. An arm rest 44 has one end formed integral with the upper end of back bar 48. A curved connector 46 has one end formed integral with arm rest 44. A lock bar 48 has one end formed integral with other end of connector 46. The lock bar is parallel to seat bar 40.
Referring now to FIG. 3, a construction for connecting tubular member 16 to tubular member 30 is shown therein. The subject construction is generally indicated by numeral 50. As may be seen in FIGS. 2, 3, and 4, each of the tubular members includes a pair of parallel faces 52 and 54. The parallel faces are connected at their edges by semicircular connectors 56 and 58. Tubular cross members 16, 18, 20, 22, and 24 have the same cross section described above. The main portions of sides 12 and 14 also have the same cross section; however, the cross section changes in the sides at positions where the respective tubular members are bent.
Looking now to FIG. 3, upright 30 has a pair of parallel faces 60 and 62 which are joined by semicircular connector 64. The semicircular connector contains a circular aperture 66 in its center which aperture has its axis parallel to faces 60 and 62. The axis of aperture 66 is equidistantly spaced from the interior surfaces of faces 60 and 62.
Looking now to FIG. 5, a screw fastener member 68 having an internal thread 70 is positioned in aperture 66. Screw fastener member 68 includes a head 72 which is an enlarged portion positioned generally exteriorly of the interior of the tubular member. The fastener member includes a cylindrical sleeve 74. By inserting a threaded member into the internally threaded portion 70 and pulling the member toward head 72. Sleeve 74 is expanded to form an enlarged portion 76, as shown in FIG. 6. The enlarged portion is embedded into the plastic of the tubular member so that head 72 and enlarged portion 76 frictionally engage the tubular member at the material surrounding aperture 66 to prevent the screw fastener member from rotating in the aperture.
As may be seen in FIG. 3, cross member 16 has an end 80 conforming to the exterior shape of the semicircular connector 64. Face 52 and face 62 are in the same plane as are faces 54 and 60 to give a smooth interconnection between the cross member and the upright.
A retainer block 82 is adhesively secured in the interior of cross member 16 adjacent to end 80. The exposed surface of block 82 also conforms to the exterior surface of semicircular connector 64. The block includes a fastener aperture 84 which has its axis aligned with the axis of aperture 66.
A screw fastener member 86 is mounted in aperture 84 of the block. Screw fastener member 86 includes an externally threaded portion 88 which threadedly engages the interiorly threaded portion 70. Screw fastener member 86 also includes a conventional head 90, which engages block 82. An elongated drive aperture 92 is formed in face 54 adjacent to the end of the retainer block to allow the screw fastener member 86 to be inserted therein and to allow a tool to be inserted into the interior of cross member 16 for the purpose of tightening or loosening screw fastener member 86.
A molded plastic cap 93 is removably mounted in drive aperture 92. The cap includes a substantially flat cover plate 94 with stops 96 formed integral with the cover plate at opposite ends of the cover plate for positioning the cover plate relative to the aperture. A pair of hooks 98 is formed integral with the cover plate and engages the interior of the tubular cross member for holding the cover plate in position.
The same construction for connecting the other end of cross members 16 to side 12 is utilized therein. Each of the other cross members 18, 20, 22, and 24 has its respective ends connected to sides 12 and 14 by the same construction.
Looking now to FIG. 2, a construction used to secure the lock bar to the seat bar is shown therein. Seat bar 40 has a pair of parallel faces 100 and 102. The lock bar has an identical pair of parallel faces 104 and 106. Face 102 includes an aperture 108 which has a screw fastener member 110 mounted therein. Screw fastener member 110 is identical in construction to screw fastener member 68 and is secured in position in the same manner. A fastener aperture 112 is formed in face 104 and is aligned with aperture 108. A drive aperture 114 is formed in face 106. Drive aperture 114 is aligned with fastener aperture 112 and with screw fastener member 110. A screw fastener member 116 is threadedly mounted in screw fastener member 110. Screw fastener member 116 includes a head 118 which engages the interior surface face 104. Drive aperture 114 allows screw fastener member 116 to be inserted into position and allows for ingress and egress of a tool for driving screw fastener member 116. A molded plastic cap 120 is removably mounted in drive aperture 114. The cap includes a cover 122 with a plurality of legs 124 formed integral therewith for holding the cover in position.
A pair of identical connectors described above secures the lock bar to the seat bar and another pair of identical connectors secures the back bar to the respective back upright.
From the foregoing description, it may be seen how the instant construction for connecting tubular members may be easily utilized, simply by drilling holes in appropriate locations and inserting a screw fastener member which is locked into the tubular member. For an end connection, a retainer is added and an elongated drive aperture is made in the tubular member. For a flat connection, it is only necessary to drill two holes through the other tubular member. The cap may be readily and conveniently inserted into the aperture to provide a substantially flush construction which gives a pleasing appearance and does not protude excessively. Thus, garments or other materials do not catch on the chair frame. Furthermore, it may be appreciated that the construction of the connection may be selected for a position which is least obstrusive both from a visual and a functional standpoint.
Although a specific embodiment of the herein disclosed invention has been shown in the accompanying drawings and described in detail above, it is readily apparent that those skilled in the art may make various modifications and changes without departing from the spirt and scope of the present invention. It is to be expressly understood that the instant invention is limited only by the appended claims.