CARGO CONTAINER
BACKGROUND
This application relates to an improved cargo container adapted for use for either air or ground transport having components which are simple to assemble and disassemble and a construction which is tolerant of flexing and deformation of the panels and frame.
The use of transparent panels is disclosed by U.S. Patent Number 4,833,771 issued May 30, 1989 to Dunwoodie. These panels are held by inner and outer corner moldings and therefore require custom fabrication of the edges of the panels to accommodate the shape of the inner and outer molds. Such processing of the panel edges necessarily introduces stress cracks which can lead to failure during use. Nuts and bolts are used to attach the inner and outer corner moldings together over the panel edges.
A shipping container capable of being assembled without tools, ie. without nuts and bolts or other like fasteners, is disclosed in U. S. Patent Number 3,517,849 issued to Presnick. Presnick uses extruded frame members with elongated slots to receive the edges of a rigid panel and corner members with legs to fit into the hollow ends of the extruded frame elements. The frame elements matingly couple to each other so that a panel enclosed by frame elements and corner members interlocks with a panel and surrounding frame element and corner members corresponding to each one of the elongated edges of the panel. The Presnick assembly is not water tight at the edges proximate the corner pieces since it is not cemented to the corner pieces. Moreover, the latter assembly is not highly deformation toleran as deformation puts a strain on the edge joints and the rigi panels themselves. Finally the panels of Presnick can not b removed without first disassembling at least in part the fram structure.
Italian patent Number 623,118 issued July 7, 1961 t
J. Langham Thompson Group Limited discloses a knockdown container assembly with corner pieces having legs dimensioned to fit into the ends of extruded frame elements and panels which are attached by screws to the extruded frame elements. The corner pieces consist of an outside rounded piece with a bolt and the inner corner piece with a bolt hole and a nut threaded onto the bolt to hold the inner and outer corner piece together.
The utilization of rigid panels with edges either glued to the frame elements or fastened thereto with screws makes the known cargo containers susceptible to fracture of the panels or failure of the edge joint on being deformed in response to an applied load. Since it is common practice to apply large loads to the inside walls during filling of a container which can cause deformation of the container and subsequent failure, such assemblies tend to have a relatively limited life when used as airline, truck or ship containers.
Accordingly, it is an object of the present invention to provide an improved cargo container. It is a further object of the invention to provide a cargo container that can be easily assembled and disassembled. It is yet a further object of the invention to provide such a container that is better able to withstand deformation than hitherto known containers. Yet another object of the invention is to provide a container which is substantially water tight.
STATEMENT OF THE INVENTION
According to the invention there is provided a cargo container which includes a plurality of elongated frame members each having an elongated channel and an elongated recess therein. A plurality of coupling members are engagable with ends of the frame members. A plurality of panels removably engage the elongated channels in the frame members with each panel having an elongated recess around a perimeter thereof. The elongated panel recess together with an elongated recess in each of the
frame members forms an elongated slot. Locking means are removably insertable into the slots to lock the frame members, panels and coupling members into a substantially rigid assembly.
Advantageously, the channels are located on the interior of the container to enhance security. Such an assembly avoids the need for using fasteners such as nuts and bolts which are time consuming and provides an easily assembled or disassembled structure.
Preferably, however, resilient means are used for removably affixing the panels to the frame members and coupling members around the perimeter of the openings. The use of a resilient means for affixing the panels to the frame and coupling members not only avoids the need for separate fasteners such as nuts and bolts but also introduces a tolerance to bending or flexing of the structure not otherwise available.
Preferably, the resilient means is a resilient elongated strip of material captured between an elongated surface portion of the frame element and an elongated surface portion of an edge of the panel.
The panel may include a flexible sheet having affixed around its edges a rigid panel frame. Use of a flexible sheet rather than a rigid sheet avoids the susceptibility of fracture of the panels due to deformation of the container and makes the structure more deformation tolerant. Moreover, no drilling of the panel edges is required so that the panel is not compromised or stressed by such treatment.
The resilient strip is preferably located on the interior of the container so that loads applied internally of the container merely tend to tighten the strip in position rather than dislodge it and so that the strip is not exposed to external uncontrolled contact. The interior location also provides for greater security against unauthorized access to the contents of
the container.
The frame members may be hollow extruded aluminum with a pair of elongated rounded recesses for receiving rounded strips or O-Rings and having a channel with a sidewall slightly sloped back to form an angle with the base of the channel of slightly less than 90 degrees. The panel frames have elongated projections insertable into corresponding channels of the panel frame with a sidewall abutting and parallel to the sidewall of the frame channel. The O-Ring presses the sidewall of the panel frame against the sidewall of the frame member. Deformation of the panels so that they move outwardly causes the panel projection to simply rotate about a line on the frame member channel and at the same time to merely compress the O-Ring so that there is no prohibition to slight movement caused by frame member to panel frame material contact.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as other features and advantages thereof, will be best understood by reference to the detailed description which follows, read in conjunction with the accompanying drawings, wherein:
Figure 1 is a perspective view of the container;
Figure 2 is an end view of a frame member with a panel edge portion and panel frame in cross-section shown held in place by an O-Ring;
Figure 3 is a perspective view of an exterior surface of a frame member coupler;
Figure 4 is a perspective view of an interior surface of a frame member coupler;
Figure 5 is a perspective view of the door covering with the outer lining partially broken away and a corner of the inner lining also broken away;
Figure 6 is a cross-sectional view of the base and frame member connection thereto;
Figure 7 is a cross-sectional view of an alternative embodiment of the frame member;
Figure 8 is a cross-sectional view of an alternative embodiment of the panel;
Figure 9 is a partial cross sectional view of the embodiment of Figure 8 showing the deformation in response to loads normal to the panel; and
Figure 10 is a cross sectional view of a hollow O- Ring.
DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS
Referring to Figure 1 there is shown a cargo container 10 made up of a plurality of frame members 12 coupled to adjacent frame members 12 by couplers 14. In each open area defined by coupled frame members and couplers 14 there is attached a transparent rectangular panel 16. On one side of the container 10 there is an opening 20 and a roll-up door 22 releasably attachable to fibre attachment strips sold under the trademark Velcro* along either side of the opening 22. The entire top structure of the container 10 is removably fastenable by means of nuts and bolts to a base 24.
The cross section of a frame member 12 is shown in Figure 2 as being a hollow extruded aluminum structure. The member 12 is for use at the intersection of two panels 51 (only one of which is shown) intersecting at right angles. In.this
case arc section 26 describes a quarter circle whereas for other angles of intersection the arc section would describe a different sector of a circle. At either end of arc section 26 there is a rounded elongated recess 30 joining an end of arc section 26 to a diagonal section 28. Also at each end of arc section 26 there is an extension 32 tangent to arc section 26 terminating in a substantially orthogonal lip 36 having an inner wall 34 sloped back slightly from 90 degrees to arc section 26 by 1/32 inches in 3/8 inches distance or about 5 degrees.
Each panel 51, only a portion of which is shown in Figure 2, is a transparent flexible plastic sheet 52 glued around its perimeter to a rigid perimeter edging 40. There are other methods of affixing the sheet to the edging 40 such as, for example, ultra sonic welding. Edging 40 has enlargements 46, 48 and 50 which serve as glue channels and a pair of spaced apart lips 42 and 44 projecting substantially at right angles to the plane of panel 52. Lip 44, however, is sloped outwardly about 5 degrees to match the slope of the inner wall 34 of lip 36. The total width of lips 42 and 44 is chosen to be less than the width of extension 32 so that edging 40 can rotate slightly about a contact point 56 with lip 36 in a counter-clockwise direction as viewed in Figure 2 without contacting wall 53. Edging 40 also has a rounded elongated recess 54 so that in combination with recess 30 of frame member 12 there is provided a circular O- Ring groove subtending about 270 degrees for a resilient O-Ring 38. With O-Ring 38 in place edging 40 is held within a channel 31 formed by extension 32 and walls 53 and 34 with lip 44 abutting inner wall 34.
An outwardly directed load applied to panel 51 results in outward movement of sheet 52 and a torque applied to perimeter frame 40 about an axis coinciding with line 56. Lips 42 and 44 move toward wall 53 and compress further O-Ring 54 which resists the deformation of frame 40.
A coupler 14 for coupling together frame members 12 is
shown in Figure 3 as including an enlarged section 60 integral with three different legs 64 each having a cross-section designed to fit inside an associated frame member 12 as shown in the dotted outline of Figure 2 with a shoulder 62 between the two abutting an end of each frame member 12. As shown in Figure 4 each coupler has grooves 61, 63 and 65 which align with corresponding grooves 30 in the frame members 12. The couplers 14 are made of metal or rigid plastic such as polycarbonate. The latter material will return to its original shape after deformation. The couplers 14 need not have grooves 61, 63 and
65 but can simply be of smaller dimensions so that the 0 ring can continue around from one frame member to another.
Door opening 20 is covered by a roll-up door 22 shown in more detail in Figure 5. Door 22 is made of 2 sections 70 and 72 of flexible sheet material sewn together to enclose springs
66 along each side and the center. Springs 66 are made of stainless steel tempered to a coiled up equilibrium position so that when enclosed they tend to cause cover 22 to roll up into a coiled position. A pair of fibre attachment strips 68 fastened to the interior of door 22 align with corresponding strips 18 along the sides of opening 20 and attach to the latter to hold the door 22 in a closed position until the corresponding fibre attachment strips 18 and 68 are released from each other. A crossbar 74 located proximate a bottom end of door 22 fits into crossbar sockets 76 on either side of opening 20 on container 10 when the door is unrolled.
As shown in Figure 6, the bottom extruded frame members 12 are bolted to a base 24 to complete the structure of the container 10. The entire container 10 with the exception of the base 24 and door suspension attachment is assembled without fasteners such as nuts and bolts. Assembly of the container proceeds from the base and progresses upwardly. The bottom layer of frame members are coupled together with couplers 14 and then upwardly directed frame members are slid onto corresponding legs 64. Once all of the frame members are assembled the bottom layer
is bolted onto base 24. Following bolting of the bottom layer to base 24, the transparent panels 51 are set in place from the interior of the container 10 and then the resilient O-Rings are inserted into O-Ring grooves 30 and corresponding ones of 61, 63 and 65 on couplers 14. The top of the door is fastened to the top of the container 10 to complete the assembly. The entire structure can be rapidly disassembled for shipment and then reassembled once it reaches its destination.
An alternative variant of the frame members and couplers is shown in cross section in Figure 7. In this case the O-Ring 80 is trapezoidal as is the groove formed by walls 82 and 83 of frame member 81 and surfaces 85 and 87 of perimeter frame 88. Other similar variants are obviously possible.
Yet another variant of the frame members is shown in Figure 8, in which an alternative perimeter edging 90 is employed. Edging 90 includes a rounded recess 96 for abutting O-Ring 38, and a projecting head 93 formed by an inner and an outer lip 92 and 94, respectively, rounded recess 96 and a connecting arm 95. Lips 92 and 94 are insertable into a channel 91 formed by inner wall 53, extension wall 32 and lip wall 43 of lip 36. An angled wall portion 98 connects the projecting head 93 to a panel receiving portion 100 having a slot 102 which receives the panel 52. Again the flexible panels 52 are positioned to be substantially flush with the outer surface of the frame members 26 thereby avoiding or largely minimizing water capture by the panel areas when used in positions such as for the roof of a structure. Both the sheet or panels 52 and semi-rigid edging 90 are polycarbonate. Such similarity of materials enhances the glue bond between the two. Other materials such as aluminum could also be used.
The presence of angled wall portion 98 provides significant unexpected advantages in terms of resistance to panel loads. Examining the mode of transmission of loads arising in the panel 52 into the frame member 26, in turn:
(i) Loads in the plane of the panel 52 towards frame member 26 result in compression of ,,0" ring 38 initially, followed by flexing of the angled wall portion 98 about fulcrum point 36. As the panel 52 is also flexible it will deform before the angled portion 98 becomes parallel with outer lip 94.
(ii) Loads in the plane of the panel 52 away from frame member 26 are transmitted linearly from the panel 52 into the frame member 26 without creating a torque about contact point 56 because of the rigidity of the edging 90. There is a tightening of the contact between the outer lip 94 and the lip wall 34. As the tension loads increase flexing of the angled wall portion 98 occurs as it tends towards alignment with the plane of the panel 52. A torque then develops about contact point 56 and ultimately the projecting head 93 first compresses and then dislodges the resilient O-Ring 38. The panel with its edging then comes away from the frame member.
(iii) Loads normal to the plane of panel 52 from the right to the left as shown in Figure 9 result in clockwise rotation of the projecting head 93 about the fulcrum point 36. This compresses the O-Ring 38. Before the rotation is such that the projecting head 93 squeezes past O-ring 38, and the panel is dislodged, the outer lip 94 and the angled wall portion 98 jam (at points 110 and 116) at each end of lip 36. Higher loads then cause no further rotation of projection head 38 but a deformation of the panel edging at fulcrum point 114, and ultimate failure at this point. The effect of this is that even though high loads in two directions can be sustained without component failure the O-Ring is not dislodged. When the load is relaxed the projecting head 93 is forced back into its original position by
the O-Ring.
(iv) Loads normal to the plane of the panel 52 from the left to the right in Figure 9 cause portion 98 to rotate counterclockwise. Such rotation causes the projecting head 93 to rotate so as to further lock resilient O- Ring 38 more firmly in place. Ultimate failure is at point 112.
The perimeter edging 90 can, therefore, sustain significantly greater ultimate loads than the unit described in Figure 2, especially in the directions (ii) and (iii) above, and, at the same time, allow for more flexibility in the structure when subjected to load from any of the four directions. These loadings may also occur through thermal expansion and contraction in addition to mechanical impacts.
Clearly various other container shapes than that of Figure 1 are possible to conform to the vehicle into which the container is loaded.
Obviously, metal panels can be substituted for the flexible plastic ones although with some loss of deformation tolerance.
The resilient O-Ring 38 can be replaced by a rigid or semi-rigid bar or tube inserted into the ends of each extruded frame member with one of the two couplers removed. Although reduced tolerance to deformation is achieved the assembly is still simple to assemble and disassemble when used in this way.
Alternatively, O-ring 38 may be hollow as shown in Figure 10 in order to decrease its resistance to deformation.
Accordingly, while this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various
modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments as fall within the true scope of the invention.