SCREEN ENCLOSURE FOR PICNIC TABLES
United States Patent 3744500
A foldable, portable, light-weight, screen enclosure for picnic tables adjustable to fit tables of various lengths and widths. The enclosure framework has corner uprights with horizontally extending arms at their lower ends slidably receivable in horizontal tubular sockets in respective attachment members releasably clamped to the table corners. Horizontal members interconnecting the upper ends of the uprights are hinged at their respective ends and midpoints, permitting the framework structure to fold into a compact bundle of parallel frame elements.
US Patent References:
Canopy construction and the like
Dusek - April 1957 - 2790452
Picnic table shelter
Ferrier - February 1966 - 3233618
Insect proof canopy for picnic tables
Luecarelli - March 1967 - 3307565
Knock-down awning device and package
Hemenway - December 1968 - 3417764
Canopy construction and the like
Dusek - April 1957 - 2790452
Picnic table shelter
Ferrier - February 1966 - 3233618
Insect proof canopy for picnic tables
Luecarelli - March 1967 - 3307565
Knock-down awning device and package
Hemenway - December 1968 - 3417764
Application Number:
05/209703
Publication Date:
07/10/1973
Filing Date:
12/20/1971
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
135/161, 135/96, 135/913, 135/912
International Classes:
E04H15/32; A45F1/00
Field of Search:
135/1R,3R,5R,7.1
Primary Examiner:
Caun, Peter M.
Claims:
What is claimed is
1. A demountable and foldable enclosure comprising:
2. An enclosure according to claim 1 wherein each of the remaining four elongate members, constituting edges of the parallelepiped in one of said planes corresponding to the top of the enclosure, is hinged at its ends to two of said parallel elongate members and at its midpoint for pivotal movement about parallel axes in said one plane, the pivotal axes of each of said remaining elongate members being substantially aligned with the corresponding axes of the elongate member parallel and opposite thereto, and orthogonal to the axes of the elongate members adjacent and perpendicular thereto.
3. An enclosure according to claim 2 wherein at least two parallel and opposite ones of said remaining elongate members each includes a telescoping slip joint permitting adjustment of the length of said two members.
4. An enclosure according to claim 3 including a wheel mounted at the end of two adjoining ones of said parallel elongate members for rotation about co-linear axes.
5. An enclosure according to claim 4 wherein said elongate members are fabricated of hollow stock of substantially square or rectangular cross-section, said remaining four of said elongate members contain longitudinal slots on their undersides, and said enclosure includes a plurality of slide members with enlarged heads slidably disposed in the slotted members, said slide members having shank and hook portions extending through said slots and secured in supporting relation to respective panels of said fabric.
6. An enclosure according to claim 5 wherein at least some of the panels of said fabric are formed of an insect-proof mesh.
7. An enclosure according to claim 6 wherein each of the four corners of the parallelepiped is formed of an end of one of said parallel elongate members and the respective ends of two of said remaining elongate members in mutually orthogonal relation pivotally joined by a hinge joint assembly comprising:
8. An enclosure according to claim 7 including means defining a third gudgeon on said parallel elongate member parallel to, and on the opposite side of the member from, one of the other gudgeons thereon and having a bore coaxially aligned with the bore of said one other gudgeon and receive said pintle member.
9. An enclosure according to claim 8 wherein said parallel gudgeons consist of flat plates secured to respective parallel faces of the elongate members with respective end portions projecting beyond the corresponding longitudinal edges of the members.
10. An enclosure according to claim 9 wherein at least some of the flat plates are L-shaped and have one leg of the L parallel to and in surface abutment with the elongate member and the other leg constituting the projecting end portion of the plate.
11. An enclosure according to claim 9 wherein at least some of the flat plates are of substantially rectilinear configuration and extend at an acute angle to the longitudinal axes of the elongate members.
1. A demountable and foldable enclosure comprising:
2. An enclosure according to claim 1 wherein each of the remaining four elongate members, constituting edges of the parallelepiped in one of said planes corresponding to the top of the enclosure, is hinged at its ends to two of said parallel elongate members and at its midpoint for pivotal movement about parallel axes in said one plane, the pivotal axes of each of said remaining elongate members being substantially aligned with the corresponding axes of the elongate member parallel and opposite thereto, and orthogonal to the axes of the elongate members adjacent and perpendicular thereto.
3. An enclosure according to claim 2 wherein at least two parallel and opposite ones of said remaining elongate members each includes a telescoping slip joint permitting adjustment of the length of said two members.
4. An enclosure according to claim 3 including a wheel mounted at the end of two adjoining ones of said parallel elongate members for rotation about co-linear axes.
5. An enclosure according to claim 4 wherein said elongate members are fabricated of hollow stock of substantially square or rectangular cross-section, said remaining four of said elongate members contain longitudinal slots on their undersides, and said enclosure includes a plurality of slide members with enlarged heads slidably disposed in the slotted members, said slide members having shank and hook portions extending through said slots and secured in supporting relation to respective panels of said fabric.
6. An enclosure according to claim 5 wherein at least some of the panels of said fabric are formed of an insect-proof mesh.
7. An enclosure according to claim 6 wherein each of the four corners of the parallelepiped is formed of an end of one of said parallel elongate members and the respective ends of two of said remaining elongate members in mutually orthogonal relation pivotally joined by a hinge joint assembly comprising:
8. An enclosure according to claim 7 including means defining a third gudgeon on said parallel elongate member parallel to, and on the opposite side of the member from, one of the other gudgeons thereon and having a bore coaxially aligned with the bore of said one other gudgeon and receive said pintle member.
9. An enclosure according to claim 8 wherein said parallel gudgeons consist of flat plates secured to respective parallel faces of the elongate members with respective end portions projecting beyond the corresponding longitudinal edges of the members.
10. An enclosure according to claim 9 wherein at least some of the flat plates are L-shaped and have one leg of the L parallel to and in surface abutment with the elongate member and the other leg constituting the projecting end portion of the plate.
11. An enclosure according to claim 9 wherein at least some of the flat plates are of substantially rectilinear configuration and extend at an acute angle to the longitudinal axes of the elongate members.
Description:
This invention relates to demountable and foldable enclosures and more particularly to screen enclosures for picnic tables and the like.
The unwelcome presence of insects at picnics has been endured for generations and accepted as an unavoidable concomitant of outdoor dining. While to the majority of picnickers flies and even stinging insects are only a source of aggravation and unpleasantness, for many who suffer allergic reactions, the sting of a bee or a wasp can have serious, even fatal, consequences. Despite this long-existing state of affairs, and the more or less obvious solution of providing a screen enclosure for picnic use, nothing in the way of a truly practical screen covering for picnic tables has been proposed in the prior art.
Those that are known are either too cumbersome to be conveniently carried to a picnic site and/or fail to provide for adjustment to accommodate the variety of shapes and sizes of picnic tables encountered.
The objects of the present invention are to provide a screen enclosure for picnic tables which provides complete protection from flying insects, is light in weight, is easily erected and adjusted to various sizes of picnic tables, and folds into a compact bundle for easy transport even over rough terrain and woodland paths.
To the accomplishment of the foregoing and other objects, the invention contemplates an enclosure formed of four vertical and four horizontal elongated members defining four corners and the top and side faces or panels of the structure. The vertical members have horizontally extending cantelever arms which are freely slidably received in horizontal tubular portions of respective support members secured to the four corners of a picnic table. Sliding the arms into and out of the tubular support member portions enables adjustment of one horizontal dimension. Two of the horizontal members include telescoping joints to permit adjustment of the enclosure in the other horizontal direction. All of the horizontal members are hinged at their midpoints and ends to permit the enclosure to be folded into a compact bundle which can easily be carried by one person or rolled on two wheels in the manner of a golf cart. A unique hinge joint assembly is provided at each of the four corners of the enclosure which provides high rigidity in the structure when erected. Fabric, at least selected areas of which is insect screening, covers the top and four sides of the enclosure, completely enveloping a picnic table and the seats as well.
In the drawings:
FIG. 1 is a perspective elevational view of an enclosure according to the invention fully erected and installed on a picnic table;
FIG. 2 is a perspective elevational view of one of four identical support members shown installed at the corners of the picnic table in FIG. 1;
FIG. 3 is a fragmentary enlarged perspective view of one of the corner joint assemblies appearing in FIG. 1;
FIG. 4 is a plan view of the joint assembly shown in FIG. 3;
FIG. 5 is a fragmentary elevation of a portion of the structure in FIG. 1 on an enlarged scale;
FIG. 6 is a cross-sectional view taken on line 6--6 of FIG. 5; and
FIG. 7 is a perspective elevation of the enclosure of FIG. 1 demounted and folded for transport.
Referring to FIG. 1, the enclosure, designated in its entirety by reference numeral 10, comprises a framework structure 12 and four attachment members 14a, 14b, 14c and 14d secured in series to the respective corners of a picnic table 16.
As best shown in FIG. 2, each attachment member 14 consists of a clamp, such as C-clamp 18, and a tubular portion 20 so oriented with respect to the clamp that it is disposed in a horizontal position when the clamp is secured to the edge of table top 22.
In the illustrated form attachment members 14 are of fabricated construction, the tubular portion 20 being a length of square-section metal tubing having a longitudinal flange 20a by means of which it is secured to clamp 18 by metal straps 22, 24. Of course, other forms of construction are possible.
Reverting to FIG. 1, framework structure 12 is made up of eight elongate members defining four corners and five contiguous faces of a rectangular parallelepiped, which faces constitute the top and side panels of the enclosure. Four of the elongate members, 26a, 26b, 26c, 26d, are disposed in mutual parallelism when the structure is erected and form the corner uprights of the framework.
The upper ends of members 26a-d are hingedly connected to the remaining elongate members, 28a, 28b, 30a and 30b to form corner joint assemblies 32a, 32b, 32c, 32d in a manner to be described presently. Adjacent their respective ends remote from corner joints 32 each of the vertical members 26 carries a cantelever support arm 34a, 34b, 34c, 34d pivotally secured at one end to the associated vertical member 26a - 26d, preferably by means of a nut and bolt assembly so that the resistance of the arm to pivotal movement can be adjusted; this adjustment is such as to maintain the arm against spontaneous pivotal movement while permitting it to be moved manually with relative ease.
When the framework is erect, arms 34a - 34d are positioned to project perpendicularly to the respective longitudinal axes of the vertical members with the arms 34a and 34d on one pair of vertical members 26a and 26d defining one side panel of the enclosure extending coaxially toward each other in the plane of that panel. Similarly the arms 34b and 34c on the remaining pair of vertical members 26b and 26c extend coaxially toward each in the plane of the side panel defined by said members.
The cross-sectional size and configuration of arms 34 enables a free-sliding fit into the tubular portions 20 of respective attachment members 14a - 14d, when the framework is erected. Consequently, the framework accommodates a wide range of table widths, i.e., for narrow tables only a small fraction of the length of arms 34 are received in tubular portions 20 and conversely for wider tables.
While support arms 34a - 34d have been described as disposed in the planes of parallel sides of the enclosure, it will be appreciated that they can be disposed in diagonal planes, i.e., planes defined by vertical members 26a and 26c and by 26b and 26d. In such an event, attachment members 14a - 14d would be installed correspondingly with the tubular portions on diagonal lines of the table top. With such an arrangement, particularly adapted to square top tables, sliding of arms 34a - 34d in and out of the tubular sockets on the attachment members, would effect simultaneous adjustment of both length and width dimensions of the structure as will be more fully understood as this description proceeds. Of course, the support arms 34 can also extend in planes intermediate the side planes and diagonal planes, if desired, and the attachment members 14 installed accordingly.
Each of the elongate members 28a, 28b, 30a, 30b is hinged at its midpoint and at its ends is hinged to respective pairs of adjoining vertical members 26a - 26d. The axes of the hinges in member 28a are parallel to each other and coaxially aligned with corresponding hinges in the opposite and parallel member 28b. In like manner, the hinge axes of member 30a are parallel and coaxially aligned with those of member 30b.
In order to provide maximum rigidity to the erected structure and maintain the horizontal members 28a,b and 30a,b in position foldable corner braces 31a to 31h, each of which preferably is a standard hardware item popularly known as a lid support. Each support extends diagonally across a respective corner angle and has its ends pivotally fastened, as by rivits, to a vertical member 26 and an adjoined horizontal member. At its midpoint, each lid support has a limited hinge joint 33 (shown in FIG. 3) which permits folding in one direction and establishes a fully extended position by means of a stop which prevents angular movement in the other direction beyond the condition in which the segments form a straight angle, i.e., 180°.
The details of a hinge joint typical of those at the midpoints of members 28a,b and 30a,b are shown in FIG. 5 for member 28a. Thus member 28a is divided into two abutting length segments along parting line 36. L-shaped plates 38a, 38b and 40a, 40b are secured in parallel pairs on opposite sides of the abutting segments of member 28a with one leg of each L-shaped plate projecting laterally beyond a longitudinal edge of member 28a to form parallel pairs of gudgeons 42 and 44 containing coaxially aligned bores receiving a gudgeon pin 46.
Each of the elongate members 28a and 28b includes a telescoping slip joint 47 by which the length of the member may be adjusted to accommodate tables of different lengths. A pin 48 on the inner member of the slip joint 47 riding in a longitudinal slot 50 in the outer member limits the extent of adjustment and prevents the members from becoming disengaged.
While slip joints are shown and necessary only in members 28a,b of the illustrated embodiment, it will be appreciated that they can be provided in members 30a and 30b as well and this would be particularly advantageous in a variant structure, discussed above, where the mounting arms 34a - 34d are disposed on diagonals of the structure.
Referring now to FIGS. 3 and 4, there is illustrated in detail the corner joint assembly 32d typical of all four such assemblies of the framework structure. With the framework erected, the respective longitudinal axes of members 30a, 28b and 26d are in mutually orthagonal relation. At the end of member 28b, an L-shaped plate 51 is secured as nut and bolt assemblies 53, or by rivits, welding or other suitable means to one side face of the member with one leg parallel to the member's long axis and the other leg 51a extending laterally beyond the longitudinal edge of the member to form one of a pair of parallel gudgeons, the other being formed by a similar plate not visible in FIG. 3 but secured to the opposite face of member 28b and visible in FIG. 4 where it is designated as 54. Spacing washers 55 are placed between plate 54 and member 28b and at other locations in the joint assembly for reasons which will be self-evident from the ensuing description. Gudgeons 51a and 54a contain coaxially aligned bores 51b and 54b.
Elongate member 30a is similarly equipped with plates 56, 58, forming gudgeons 56a, 58a, containing coaxially aligned bores 56b, 58b.
While L-shaped plates have been described, other means may be used to form gudgeons laterally off-set from the elongate members. Thus, a single gudgeon 59a is provided on the upper end of vertical member 26d by means of a rectilinear plate 59 fastened to the member at an acute angle to its long axis. Another gudgeon 60a containing a bore 60b is provided at the upper end of member 26d by means of L-shaped plate 60 in the manner of members 28b and 30a. At least one additional gudgeon 61a is provided on member 26d, parallel to gudgeon 60a by means of plate 61 having a bore 61b coaxial with 60b.
Members 28b, 30a and 26d are pivotally connected by means of a single gudgeon pin or pintle 62 containing a right angle bend. The end of the pintle on one side of the bend is journaled in the bores of gudgeons 60a, 51a, 61a and 54a and the other end in the bores of gudgeons 59a, 56a, 58a. In this manner members 28b, 30a and 26d can be folded relative to one another from the orthogonally related position shown in FIG. 3 to one in which the long axes of the three members is parallel. The corner joint assembly just described permits this movement while imparting to the corner joints great rigidity and resistance to twisting, not possible with conventional hinges of known design or practical construction.
At the lower ends of each of two of the vertical members, 26c and 26d in the illustrated embodiment, small, preferably rubber-tired ground-engaging wheels 64,66 are rotatably mounted to facilitate transport of the enclosure when folded as will be seen presently.
As shown in FIG. 1, the framework structure 12 is covered with fabric forming panels corresponding to the top and four sides of the enclosure 10. The fabric may consist entirely of a non-metallic (e.g., Fiberglas) insect screen or the top and one or two sides may be a closely woven material or solid plastic sheet to provide shade. The fabric is loosely attached to the horizontal members 28, 30 in any suitable manner. In the illustrated embodiment members 28, 30 contain longitudinal slots in their undersides as exemplified by slot 68 in the typical cross-section shown in FIG. 6. A plurality of slide members 70 such as that shown in FIG. 6 have enlarged head portions 70a slidably disposed with a respective horizontal members, a shank portion 70b extended through slot 68 and a hook portion engaging a loop 72 on the enclosure fabric. The fabric panels are split as at 74, 76 on opposite sides to facilitate entry into and egress from the enclosure. Small weights 78 are fastened at regular intervals along the bottom edge of the fabric covering to prevent lifting and blowing in the wind.
Prior to demounting the enclosure, the fabric covering is folded around or reefed about the horizontal members. The framework structure is then collapsed by loosening and removing attachment members 14a -d from the table and slipping them off the support arms 34a -d; these arms are then folded up alongside the respective vertical members 26a-d. By "breaking" corner braces 31a-6, the horizontal members 28a,b and 30a,b can then be folded at their midpoints while moving the vertical members toward the central vertical axis of the enclosure so that all frame members assume parallel contiguous positions to form a compact bundle as shown in FIG. 7. A strap or other cincture device 80 binds the upper part of the bundle together and pivotal latch bars 82 of known design perform a similar function at the lower part. In FIG. 7 it will be apparent that the two vertical members 26a and b not carrying wheels 64,66 are longer than 26c and d by an amount approximately equal to the radius of the wheels to form a stand for the bundle, making it self-supporting and stable in an upright position. A handle 84 fastened to the bundle by strap 80 or in any other suitable way provides a convenient handle-hold for supporting the upper end of the bundle and pushing it when tilted back on wheels 64,66.
The demounting and folding procedure just described is reversed to erect the enclosure.
The unwelcome presence of insects at picnics has been endured for generations and accepted as an unavoidable concomitant of outdoor dining. While to the majority of picnickers flies and even stinging insects are only a source of aggravation and unpleasantness, for many who suffer allergic reactions, the sting of a bee or a wasp can have serious, even fatal, consequences. Despite this long-existing state of affairs, and the more or less obvious solution of providing a screen enclosure for picnic use, nothing in the way of a truly practical screen covering for picnic tables has been proposed in the prior art.
Those that are known are either too cumbersome to be conveniently carried to a picnic site and/or fail to provide for adjustment to accommodate the variety of shapes and sizes of picnic tables encountered.
The objects of the present invention are to provide a screen enclosure for picnic tables which provides complete protection from flying insects, is light in weight, is easily erected and adjusted to various sizes of picnic tables, and folds into a compact bundle for easy transport even over rough terrain and woodland paths.
To the accomplishment of the foregoing and other objects, the invention contemplates an enclosure formed of four vertical and four horizontal elongated members defining four corners and the top and side faces or panels of the structure. The vertical members have horizontally extending cantelever arms which are freely slidably received in horizontal tubular portions of respective support members secured to the four corners of a picnic table. Sliding the arms into and out of the tubular support member portions enables adjustment of one horizontal dimension. Two of the horizontal members include telescoping joints to permit adjustment of the enclosure in the other horizontal direction. All of the horizontal members are hinged at their midpoints and ends to permit the enclosure to be folded into a compact bundle which can easily be carried by one person or rolled on two wheels in the manner of a golf cart. A unique hinge joint assembly is provided at each of the four corners of the enclosure which provides high rigidity in the structure when erected. Fabric, at least selected areas of which is insect screening, covers the top and four sides of the enclosure, completely enveloping a picnic table and the seats as well.
In the drawings:
FIG. 1 is a perspective elevational view of an enclosure according to the invention fully erected and installed on a picnic table;
FIG. 2 is a perspective elevational view of one of four identical support members shown installed at the corners of the picnic table in FIG. 1;
FIG. 3 is a fragmentary enlarged perspective view of one of the corner joint assemblies appearing in FIG. 1;
FIG. 4 is a plan view of the joint assembly shown in FIG. 3;
FIG. 5 is a fragmentary elevation of a portion of the structure in FIG. 1 on an enlarged scale;
FIG. 6 is a cross-sectional view taken on line 6--6 of FIG. 5; and
FIG. 7 is a perspective elevation of the enclosure of FIG. 1 demounted and folded for transport.
Referring to FIG. 1, the enclosure, designated in its entirety by reference numeral 10, comprises a framework structure 12 and four attachment members 14a, 14b, 14c and 14d secured in series to the respective corners of a picnic table 16.
As best shown in FIG. 2, each attachment member 14 consists of a clamp, such as C-clamp 18, and a tubular portion 20 so oriented with respect to the clamp that it is disposed in a horizontal position when the clamp is secured to the edge of table top 22.
In the illustrated form attachment members 14 are of fabricated construction, the tubular portion 20 being a length of square-section metal tubing having a longitudinal flange 20a by means of which it is secured to clamp 18 by metal straps 22, 24. Of course, other forms of construction are possible.
Reverting to FIG. 1, framework structure 12 is made up of eight elongate members defining four corners and five contiguous faces of a rectangular parallelepiped, which faces constitute the top and side panels of the enclosure. Four of the elongate members, 26a, 26b, 26c, 26d, are disposed in mutual parallelism when the structure is erected and form the corner uprights of the framework.
The upper ends of members 26a-d are hingedly connected to the remaining elongate members, 28a, 28b, 30a and 30b to form corner joint assemblies 32a, 32b, 32c, 32d in a manner to be described presently. Adjacent their respective ends remote from corner joints 32 each of the vertical members 26 carries a cantelever support arm 34a, 34b, 34c, 34d pivotally secured at one end to the associated vertical member 26a - 26d, preferably by means of a nut and bolt assembly so that the resistance of the arm to pivotal movement can be adjusted; this adjustment is such as to maintain the arm against spontaneous pivotal movement while permitting it to be moved manually with relative ease.
When the framework is erect, arms 34a - 34d are positioned to project perpendicularly to the respective longitudinal axes of the vertical members with the arms 34a and 34d on one pair of vertical members 26a and 26d defining one side panel of the enclosure extending coaxially toward each other in the plane of that panel. Similarly the arms 34b and 34c on the remaining pair of vertical members 26b and 26c extend coaxially toward each in the plane of the side panel defined by said members.
The cross-sectional size and configuration of arms 34 enables a free-sliding fit into the tubular portions 20 of respective attachment members 14a - 14d, when the framework is erected. Consequently, the framework accommodates a wide range of table widths, i.e., for narrow tables only a small fraction of the length of arms 34 are received in tubular portions 20 and conversely for wider tables.
While support arms 34a - 34d have been described as disposed in the planes of parallel sides of the enclosure, it will be appreciated that they can be disposed in diagonal planes, i.e., planes defined by vertical members 26a and 26c and by 26b and 26d. In such an event, attachment members 14a - 14d would be installed correspondingly with the tubular portions on diagonal lines of the table top. With such an arrangement, particularly adapted to square top tables, sliding of arms 34a - 34d in and out of the tubular sockets on the attachment members, would effect simultaneous adjustment of both length and width dimensions of the structure as will be more fully understood as this description proceeds. Of course, the support arms 34 can also extend in planes intermediate the side planes and diagonal planes, if desired, and the attachment members 14 installed accordingly.
Each of the elongate members 28a, 28b, 30a, 30b is hinged at its midpoint and at its ends is hinged to respective pairs of adjoining vertical members 26a - 26d. The axes of the hinges in member 28a are parallel to each other and coaxially aligned with corresponding hinges in the opposite and parallel member 28b. In like manner, the hinge axes of member 30a are parallel and coaxially aligned with those of member 30b.
In order to provide maximum rigidity to the erected structure and maintain the horizontal members 28a,b and 30a,b in position foldable corner braces 31a to 31h, each of which preferably is a standard hardware item popularly known as a lid support. Each support extends diagonally across a respective corner angle and has its ends pivotally fastened, as by rivits, to a vertical member 26 and an adjoined horizontal member. At its midpoint, each lid support has a limited hinge joint 33 (shown in FIG. 3) which permits folding in one direction and establishes a fully extended position by means of a stop which prevents angular movement in the other direction beyond the condition in which the segments form a straight angle, i.e., 180°.
The details of a hinge joint typical of those at the midpoints of members 28a,b and 30a,b are shown in FIG. 5 for member 28a. Thus member 28a is divided into two abutting length segments along parting line 36. L-shaped plates 38a, 38b and 40a, 40b are secured in parallel pairs on opposite sides of the abutting segments of member 28a with one leg of each L-shaped plate projecting laterally beyond a longitudinal edge of member 28a to form parallel pairs of gudgeons 42 and 44 containing coaxially aligned bores receiving a gudgeon pin 46.
Each of the elongate members 28a and 28b includes a telescoping slip joint 47 by which the length of the member may be adjusted to accommodate tables of different lengths. A pin 48 on the inner member of the slip joint 47 riding in a longitudinal slot 50 in the outer member limits the extent of adjustment and prevents the members from becoming disengaged.
While slip joints are shown and necessary only in members 28a,b of the illustrated embodiment, it will be appreciated that they can be provided in members 30a and 30b as well and this would be particularly advantageous in a variant structure, discussed above, where the mounting arms 34a - 34d are disposed on diagonals of the structure.
Referring now to FIGS. 3 and 4, there is illustrated in detail the corner joint assembly 32d typical of all four such assemblies of the framework structure. With the framework erected, the respective longitudinal axes of members 30a, 28b and 26d are in mutually orthagonal relation. At the end of member 28b, an L-shaped plate 51 is secured as nut and bolt assemblies 53, or by rivits, welding or other suitable means to one side face of the member with one leg parallel to the member's long axis and the other leg 51a extending laterally beyond the longitudinal edge of the member to form one of a pair of parallel gudgeons, the other being formed by a similar plate not visible in FIG. 3 but secured to the opposite face of member 28b and visible in FIG. 4 where it is designated as 54. Spacing washers 55 are placed between plate 54 and member 28b and at other locations in the joint assembly for reasons which will be self-evident from the ensuing description. Gudgeons 51a and 54a contain coaxially aligned bores 51b and 54b.
Elongate member 30a is similarly equipped with plates 56, 58, forming gudgeons 56a, 58a, containing coaxially aligned bores 56b, 58b.
While L-shaped plates have been described, other means may be used to form gudgeons laterally off-set from the elongate members. Thus, a single gudgeon 59a is provided on the upper end of vertical member 26d by means of a rectilinear plate 59 fastened to the member at an acute angle to its long axis. Another gudgeon 60a containing a bore 60b is provided at the upper end of member 26d by means of L-shaped plate 60 in the manner of members 28b and 30a. At least one additional gudgeon 61a is provided on member 26d, parallel to gudgeon 60a by means of plate 61 having a bore 61b coaxial with 60b.
Members 28b, 30a and 26d are pivotally connected by means of a single gudgeon pin or pintle 62 containing a right angle bend. The end of the pintle on one side of the bend is journaled in the bores of gudgeons 60a, 51a, 61a and 54a and the other end in the bores of gudgeons 59a, 56a, 58a. In this manner members 28b, 30a and 26d can be folded relative to one another from the orthogonally related position shown in FIG. 3 to one in which the long axes of the three members is parallel. The corner joint assembly just described permits this movement while imparting to the corner joints great rigidity and resistance to twisting, not possible with conventional hinges of known design or practical construction.
At the lower ends of each of two of the vertical members, 26c and 26d in the illustrated embodiment, small, preferably rubber-tired ground-engaging wheels 64,66 are rotatably mounted to facilitate transport of the enclosure when folded as will be seen presently.
As shown in FIG. 1, the framework structure 12 is covered with fabric forming panels corresponding to the top and four sides of the enclosure 10. The fabric may consist entirely of a non-metallic (e.g., Fiberglas) insect screen or the top and one or two sides may be a closely woven material or solid plastic sheet to provide shade. The fabric is loosely attached to the horizontal members 28, 30 in any suitable manner. In the illustrated embodiment members 28, 30 contain longitudinal slots in their undersides as exemplified by slot 68 in the typical cross-section shown in FIG. 6. A plurality of slide members 70 such as that shown in FIG. 6 have enlarged head portions 70a slidably disposed with a respective horizontal members, a shank portion 70b extended through slot 68 and a hook portion engaging a loop 72 on the enclosure fabric. The fabric panels are split as at 74, 76 on opposite sides to facilitate entry into and egress from the enclosure. Small weights 78 are fastened at regular intervals along the bottom edge of the fabric covering to prevent lifting and blowing in the wind.
Prior to demounting the enclosure, the fabric covering is folded around or reefed about the horizontal members. The framework structure is then collapsed by loosening and removing attachment members 14a -d from the table and slipping them off the support arms 34a -d; these arms are then folded up alongside the respective vertical members 26a-d. By "breaking" corner braces 31a-6, the horizontal members 28a,b and 30a,b can then be folded at their midpoints while moving the vertical members toward the central vertical axis of the enclosure so that all frame members assume parallel contiguous positions to form a compact bundle as shown in FIG. 7. A strap or other cincture device 80 binds the upper part of the bundle together and pivotal latch bars 82 of known design perform a similar function at the lower part. In FIG. 7 it will be apparent that the two vertical members 26a and b not carrying wheels 64,66 are longer than 26c and d by an amount approximately equal to the radius of the wheels to form a stand for the bundle, making it self-supporting and stable in an upright position. A handle 84 fastened to the bundle by strap 80 or in any other suitable way provides a convenient handle-hold for supporting the upper end of the bundle and pushing it when tilted back on wheels 64,66.
The demounting and folding procedure just described is reversed to erect the enclosure.