TECHNICAL FIELD

This invention relates generally to joining sheet forms, but can be applied to other forms.

5 In particular, this invention describes a flex mechanism for connecting parts to attach a sheet form permanently or temporarily to at least another sheet form or another part.

In preferred embodiments, the present invention is used to attach sheets with respect to each other in variable positions. 0 BACKGROUND ART

Sheet forms are widely used, in plain sheet form and corrugated or other modified forms.

Whilst they are most commonly used as a cladding or cover, they are also used for many other purposes.

These sheets may be made of many materials, but most commonly wood, metals, composites,5 and plastics.

A big advantage of sheet forms is that they are modular in character, which can lower the cost of manufacture, transport, assembly and maintenance. Modular construction can also be quick to assemble, and by relatively unskilled persons.

However for structural, cosmetic, waterproofing, and other reasons, modular elements need to0 be attached to other parts, or connected to, or overlapped over adjacent modular parts. For example in the common corrugated iron roof multiple sheets are overlaid to adjacent sheets or flashing details, and the parts attached commonly to underlying wooden or metal rafters or roof trusses using many spaced fasteners,

Ways of currently attaching modular sheet parts include fasteners, adhesives, crimping, folding,Θ welding, and soldering.

There are times where modular sheet connection needs to be fixed and permanent, as in water tank construction, and there are times where it is advantageous to be able to disassemble later, as in emergency shelters.

The most common form of connecting modular sheet Is the use of spaced fasteners.

0 Unfortunately this means the connection is periodic as opposed to continuous. Periodic

connection has some deleterious consequences:

1. Commonly the connection of parts is the mechanically weaker area of the assembly, so that for example when a cyclone strikes the edges of corrugated sheets can lift. The sheets themselves do not tear, but the modular connection system fails.

2. Many fasteners are needed which adds significantly to the number of parts needed and the cost and time of assembly/construction.

3. Perforations created in using fasteners both weaken sheets mechanically, and offer a failure point for waterproofing.

Laminated forms are commonly used for example in laminated wooden beams, plywood, and cardboard packaging. In these cases adhesives are used but adhesives are relatively expensive and messy to use and there can be problems with implementation except in highly organised factory production, such as in the production of plywood.

The adhesive connection between adjacent sheets In laminated forms Is more distributed as opposed to localised and periodic (as in fasteners). This increases the mechanical strength significantly.

It would be advantageous if laminated or adjacent sheet form could be used where mechanical forces, as opposed to adhesives or fasteners, arrange and connect adjacent or overlying sheets securely. At the moment the only way this can be achieved is via crimping, folding, or pressing parts together. This is effective for some situations, eg factory production, but does not allow for subsequent disassembly, adjustment, and most importantly is not suitable for onslte assembly of modular sheet parts to a secure and final waterproof assembly.

If the connection between adjacent parts were easy to create, cheaper and stronger, then the application of sheet materials would be improved for many applications, Including clading, construction, tanks, roofs, siding, concreting form-work, reusable assemblies, emergence shelter, barriers, guard rails, fencing, art form, ducting, piping, floor and bridge conduction.

What is needed is a new Improved construction/assembly system which is modular in form and with the opportunity to used laminated forms, perhaps with alternate laminate layers having fiber, structural, or grain arrangements to better resist known forces, would have significant cost, weight, assembly, transport, strength, flexibility, and maintenance advantages.

Further aspects and advantages of the present invention will become apparent from the ensuing description, which is given by way of example only. DISCLOSURE OF THE INVENTION

The key principle of this mechanism invention is that there Is a space or void created in at least one area of at least a first part, and a second part Is at least partially inserted into the first part. Then via the application or re-application of a temporary or permanent force the first and second parts are changed in flex or curvature and are brought into surface contact, and/or the contact force is increase/decreased.

• If the force Is temporary, or lower in force, then on removal of the force the parts and or assembly of parts may return to the pre condition of being relatively loose to each other and be readjusted relative to each other, or disassembled entirely, for perhaps reuse, or repair,

According to one aspect of the present invention there is provided a mechanism for joining parts, where said parts may (but not necessarily) be sheet In form.

A mechanism is defined as one where a change in the curvature of adjacent surfaces causes the surfaces to be locked together permanently or temporarily.

An alternative definition of a mechanism is defined as one where a change in the curvature of adjacent surfaces causes the surfaces to be unlocked relatively, or adjustable in position relatively.

The inventor has made a test part, A B C in Fig 1 , from a rectangular sheet form folded in half, by 180 degrees along a longitudinal axis 11, to create a U shaped form, with a space 12 created between the sides of the U so that the space between the leaves 13 of the resultant sheet Is generally a regular rectangular void with parallel sides. The space 12 can be defined by the use of a removable and reusable spacer part (not shown) so the folded part has a defined and reliable space 12.

The test part has several regions Including leaves 13 with free edges 14 where the leaves 13 are connected by a longitudinal bend 15.

The inventor has noted that if this resultant part A is flexed to a modified curved form B then the free edges 14 will fnove towards each other. If the flexure force is increased then a further modified form C will arise where the free edges 14 will move towards each other so they would eventually actually touch, which is not shown in C, but it can be seen the leaves are closer in C than B and closer in B than A.

A key inventive concept is that this change in an internal void dimension, arising from deformation, (elastic or plastic), can be used to either: 1. Lock one or more parts located relatively loosely/lightly therein the void. This can be further enhanced by utilizing non-planar form sheet material, for example, but not limited to corrugated form sheet.

2. Release a part previously "trapped" or locked irt the void.

5 It should be noted that the leaves in Fig 1c will progressively move toward each other as flexure increases in a differential way so that the leaves become closer together at the free edges 14 than at the longitudinal bend 5.

It should also be noted that the leaves in Fig 1c will progressively move toward each other as flexure increases in a differential way so that the leaves become closer together at the middle o area 16 than at the ends 17.

If the flex test part is then returned to it's original form then the void will resume its original arrangement, unless the forces applied have been extreme and have plastically deformed the part to a new shape.

Definitions:

5 1. "Plastic deformation": An applied force leads to a permanent change in form of a part.

2. "Elastic deformation": An applied force leads to a temporary change In form of a part.

An alternative form of a flex mechanism for connecting parts as in Fig 2 is one where the part is pre-curved plastically to a form B, before a flex force (usually elastic) is applied, leading to new forms A C.

0 A further alternative form of a flex mechanism for connecting parts is one where the parts are deformed or curved multiple times in the leaf form in one or more axes generally perpendicular to the longitudinal axis. An example of this is when the parts are corrugated in form. This further resists subsequent forces attempting to pull the parts apart in the direction of the second axis.

This invention may use parts that are curved or not curved before assembly, but a key character5 is that subsequent forces may change (create, decrease, or increase) the frictional force between at least a first part and at least a second part, which is at least partially-Inserted/ partially-adjacent, This subsequent force may be for example: gravity, an applied force, or a reactive force due to the elasticity of the parts.

Assembly sequences may include;

0 1 , Parts are generally formed curved prior to assembly, assembled together, and then further curved to lock the parts together.

2. Parts are generally formed curved prior to assembly, then at least one part is flexed by a temporary force so its curve reduce temporarily to facilitate assembly, and the parts are assembled together, and then the temporary force removed so the parts may be allowed to elastically curve to lock the parts together, (e.g. Fig 11)

3. Parts are generally not curved prior to assembly, assembled together, and then curved to lock the parts together, (e.g. Fig 10)

In any of the assembly scenarios above adhesive including contact adhesive or pressure sensitive adhesive may be applied to any surface.

In any of the assembly scenarios above, or any variation of this invention, an intermediary sheet, mastic, buffer, or film may be included between adjacent part surfaces.

Once assembled any other prior art connection system may be used such as rivets, pop rivets, clenching, welding, pressing, and fasteners of any kind.

A key distinction between the prior art and this invention is;

1. In the prior art the sheet material is folded into a form and pressed to closure, and the actual looking or closure arrived at solely by plastic deformation of the parts.

2. In this invention the sheet material is folded Into a form that is capable of being pressed to closure, but the actual locking or closure is, at least partially, created by elastic deformation or curving.

It should be appreciated that the invention so described here can be applied to forms that are not thought of as sheet material. The key concept is trapping and retaining a part within another by the application of a curving force.

Definition:

1. For the purpose of this Invention "curving" means flexing or twisting, regularly or irregularly, as opposed to a simple curve with one simple radius.

2. The curving force may be generally in one plane, but may be more complex than this, and even be helical in form.

This invention describes a connection system between adjacent parts which is easy to create, cheaper and stronger, and therefore the application of sheet materials can be improved for many applications, including clading, construction, tanks, roofs, siding, concreting form-work, reusable assemblies, emergence shelter, barriers, guard rails, fencing, art form, ducting, piping, and bridge contruction.

A key advantage of this invention is the connection forces are distributed instead of focal, and therefore lower forces can be used over large areas. This means less stress Is on any particular area. Thinner sheets may be used, and therfore both weight and cost saved. Further (partial or fully) overlapping areas of sheet forms can create "laminated" beams (or "laminated" sheets) for strength. For additional strength or to assist assembly the invention can be attached to conventional beams or parts, which may be linear or curved in form,

Further the new construction system which this patent discloses is modular in form and with the opportunity to used laminated forms, perhaps with alternate laminate layers having fiber, structural, or grain arrangements to better resist known forces, would have significant cost, weight, assembly, transport, strength, flexibility, and maintenance advantages.

With many prior art connection and building systems the weak area of the final assembly is the connection. The Invention described herein considerably strengthens the connection so that the connection can be actually be both the structural strength of the assembly as well as the conventional cladding.

Further aspects of the present Invention will become apparent from the following description, which is given by way of example only and with reference to the accompanying drawings:

BRIEF DESCRIPTION OF DRAWINGS

NOTE: For clarity, and printing accuracy, the spaces in the drawings herein are shown as relatively oversize. However in most situations the parts would fit together quite closely immediately after assembly, perhaps even lightly touching, and the subsequent curving or de- curving force would lock or release the parts.

Fla 1a is a flex test part, with a pair of, initially, Identical leaves, each with a length, and a thickness (and a width, not shown in this view), that are connected at each leaf end, (by any means), where the flex is increasing progressively from A to B to C.

(Note: The end connections of the leaves are not shown (for clarity), and the leaves are actually continuously touching, as opposed to the space shown for visualization clarity between 5 and 6.)

When a flex occurs, such as when a flex force F is applied at each end, and a resisting force exists (as in RF in Fig 1b), the upper leaf would become thinner in Its central area and/or the lower leaf would thicken in its central area. The top sheet would be in relative tension, and the lower sheet 6 In relative compression. Close up views 1 and 2 show that the butt ends 5 6 remain parallel as flex force F is applied.

Fig 1b Is an alternative flex test part, with a pair of leaves that are NOT connected at each end, where the flex Is increasing progressively from D to E to F. (Note: The leaves are actually continuously touching.) When a flex force F is applied at each end, and a resisting force exists RF, the upper leaf 7 would lengthen and/or the lower leaf 8 would shorten in length. Close up views 3 and 4 show that the butt ends 7 8 are no longer parallel as flex force F is applied. Notes:

1. Parts depicted in Figs 1a/b are not to scale, and the visual effects are exaggerated for clarity.

2. The thinning/thickening effect in Fig 1a, and the lengthening/shortening effect in Fig 1b arise because of simple geometry, where the radius of the upper leaf must be greater than that of the lower leaf when a downward force F is applied to create a flex.

Fig 1c is the flex test part previously described, where the flex is increasing progressively from A to B to C, and as the flex force increases and the radii of curve decreases so the void decreases and the parts would bind to an inserted sheet progressively more.

Fig 2 is an alternative flex test part, where the as-formed starting part is pre-curved already as depicted by B.

A and C are variations from B after a force Is applied.

Part C is part B flexed to increase its curve and narrow the void 21, particularly in the central area 22. Part A is part B de-flexed to decrease its curve, flatten it and widen the void 23, particularly in the central area 24.

Fig 3 depicts some flat forms of the invention: In A two sheet forms (truncated at 31) each with a U bend at one end are fitted together. In B and C there are end termination folds 32 33 respectively, which will aid resistance to a pull-apart force as indicated by the arrows 34. In D there is an S connector 35 which plain end sheets 36 are fitted Into. For all the assemblies when a force is applied to deform flex or curve the parts they will bind together via interference surface forces. The geometry change will inherently resist pulling the parts apart in most directions.

Fig 3b is a view of Fig 3 but some parts are deleted. The S connector 35 can be seen clearly in D.

Fig 4 depicts some corrugated forms of the invention: In C two sheet forms each with a generally U bend at one end 41 are fitted together. In A and B the U bends include a circle end detail 42 to aid assembly. If the diameter of the circle end is big enough, and/or the corrugation shallow enough, and/or the material flexible enough, the parts can be pre-assembled together side-ways as well as length ways. To further aid sideways assembly a flare termination 43 is shown in B. In B there is a rod 45 inserted to strengthen the final assembly. The void where the rod is located 46 In A can also form a void to act a conduit passage for electrical cable, or plumbing pipe.

For all the assemblies when a force is applied to deform flex or curve the parts they will bind together via interference surface forces. The geometry change will inherently resist pulling the parts apart In most directions, Fig 4b is a view of Fig 4 but some parts are deleted for clarity.

Fig 5 depicts an S connector 51 in A, and in B and C there are modified S connectors 56 57 which respectively connect sheets 52 to 53 and sheets 54 to 55 but also separate and define a void 58 which may be useful as an air gap for insulation (heat or sound), or indeed a place to put insulation product, electrical cable, services etc.

Note: The paired S connectors 56 57 can be joined as one as shown but could equally be connected to another element such as a beam, post or other element. It would be

advantageous if this element were able to flex.

Fig 5b is a view of Fig 5 with the sheet form parts deleted for clarity, so that just the S connector 51 and the modified S connectors 56 57 are shown here.

Fig 6 shows the flexibility of the invention: A depicts a modified S connector 61 that may act as a joiner, spacer or vibration dampener, B shows a hybrid form where the sheet is corrugated but the termination is flat in form. C shows an assembly where stiffening or attachment elements 62 are inserted before or after flexing the assembly and creating the lock forces.

Fig 6b/6c are alternate views of Fig 6 with the sheet form parts deleted for clarity.

Fig 7 depicts a number of forms for connecting standard corrugated sheets at the end of the sheet. These can be used as flex mechanism for connecting parts If the sheets are flexed in one direction. Alternately they can be merely joiners where the sheets are not under flex and therefore just convenient ways of connecting adjacent or overlying corrugated sheets. A is a U connector capable of accommodating more than one sheet,

B and C are S connectors capable of "joining" two or more conventional corrugated sheets end to end. D and E show that the S form of a sheet, or connector, may have the termination U bends in a "contra" arrangement as in D or an "ortho" (same side) arrangement as In E.

Fig 8 depicts a flat form S connector in A, a corrugated S connector in B, Corrugated U connectors are shown in C and D, with the U at differing edges in C and D, relative to the wave of the corrugation of each sheet. E represents an S connector with an orientation of the bend suitable for connecting the ends of corrugated sheets currently available. F depicts the ends of two sheets each with a U detail. This detail allows corrugated sheets to be connected together side ways.

(Not shown here: A termination detail such as 32 33 in Fig 3 could be used here to make for an initial "click-fit")

Notes:

1. Any flex mechanism for connecting parts details in this specification could be as part of a connector item (used to connect sheets or parts), or an integral end or edge detail on a sheet or part. 2. While the letters "U" and "S" are used in this specification to label forms of detail they are not restrictive to those exact shapes. There are many forms that can be used that are not necessarily to be seen as U or S. Generally a U detail may be seen as having one void, where as an S connector as having two or more voids, commonly at 180 degrees to each other In orientation.

Fig 9 shows multiple corrugated single sheet parts A B that have end U details that give the capability of being relatively lopsely fitted together alternately as in C and then locked together by flexural deformation of the sheets (not shown here).

Fig 9b shows a pair only of the six multiple corrugated single sheet parts in Fig 9. The end U details are upward in A, and downward in B, and when fitted together there may be a gap between the respective end U details as shown in C.

Notes:

(1 ) If the gap specifically is smaller only a lesser flex will be able to be achieved.

(2) The width of the gap between elements, or absence of gap, together with the overlap extent and corrugation or geometry of parts, and the character of the material such as strength, surface finish and elasticity will all be parameters that can be calculated and deliberately designed and varied to suit a specific design or situation.

(3) Bespoke design can even deliver laminated forms capable of deformation under load to a limit (relatively), or deforming in a particular character. This bespoke design can act to define the maximum flexural deformation as a result of an applied force. This principle and careful selection of laminated details and overlap can be used to create a leaf-spring type arrangement, and could be used for example to create relatively inexpensive beams for bridges.

(4) Alternate sheets can be formed curved in opposite directions and then straightened just enough to allow assembly and then allowed to lock by the natural attempt to resume the as formed curved shape.

Fig 10 shows the progressively curved formation of a shelter or building from the multiple single sheet parts depicted in A and B in Figs 9 & 9b, and shown preassembled in flat from in C in Figs 9 & 9b, which Is effectively a new building system.

The depiction shown here is at its absolute simplest without any other parts or fasteners, and may for example be used to create a stock or emergency shelter, bam, or open carport using just one new form of corrugated sheet as per this invention.

Note:

(1) The overlap of the sheets creates multiple layers effectively creating spaced arched beams.

(2) Cross braces may be used for example 62 in Fig 6, Such cross braces may be solid, sheet-form, corrugated, box or any form, and may be generally perpendicular or diagonal in arrangement relative to the sheets they brace,

(3) End sheets may have integral attached or inserted lugs (not shown) that are able to be bent, or are pre bent, at an angle, often 90 degrees, to allow fixture of end walls,

Assembly Notes:

(1 ) (Shown here) The sheets are previously slid together and the assembly of sheets is draped over a generally horizontal form and the ends allowed to drape down towards the ground before being pulled or pushed together to create the final curved form then created, perhaps by using gravity, a winch, motorised machinery, human or animal power.

(2) (Not shown here) Alternatively the sheets are slid together and then one end is secured to the ground (could be as simple as buried In a narrow trench), and the curved form then created.

(3) (Not shown here) Alternatively a first sheet is curved and secured, and then an adjacent sheet is curved and clipped to the first, and then the process is continued until the building form is complete.

Fig 11 shows the use of a flex mechanism for connecting parts to form spiral tubes.

A B and C represent the formation sequence of a flex mechanism for connecting parts A is a spiral form (probably rolled) with a space 14 between. At either edges of the spiral form are complementary U details 113 119 which are capable of fitting together, (Details other than U details may be used including a spiral ridge fitting into a spiral groove).

B shows that the open spiral form of A may be progressively increased 15 16 117 in diameter, and the U details 113 119 fitted together. If the increase In diameter is within the elastic limit of the material then the spiral form will subsequently "try" to reduce in diameter to that originally present in A. The result is that a spiral flex mechanism for connecting parts will be formed, and a mechanically sound spiral rib with the parts in close frictional contact/connection and is capable of sealing, and/or may have a film or sheet inserted in assembly.

C and D are final forms of corrugated and flat form spiral tubes respectively, trimmed to a normal end form. 110 and 111 show close ups connections of the pipes of C and D respectively.

Fig 12 shows an application of the flex mechanism for connecting parts invention to plain sheets to form a simple arched farm bridge. (1) Sheets forms 121 in A and 122 and 123 in B are laid out in C in a manner that they overlap by 50% (in this example).

(2) Then all the sheets may, at least at one end, be connected mechanically, perhaps by bolts, not shown,

(3) Finally the partially connected overlapping sheets may be curved to create either side of the stream, probably to a concrete mass.

Note: If corrugated sheets are used and joined at the ends then subsequent flexure will create a significant frictional engagement of the sheets, the sheets will be in compression and tension alternately, but there will be a strong side ways resistance to forces via the 3D aspect of the arched corrugated form.

A further example of the use of this layered compression-tension variation of a flex mechanism for connecting parts is that an Improved simple roof could be formed, (not shown), by the following general process:

(1) Multiple new or prior art corrugated roofing sheets are laid out in at least two layers, overlapping by at least one half corrugation, (or up to half the sheet width),

(2) The sheets are connected together at least one end, but preferably both ends, forming a sheet assembly,

(3) One end of the sheet assembly is attached to the top of a first wall at an incline up from horizontal,

(4) If the free end of the sheet assembly is now pulled down to and attached to the top of a second distant wall, then a curved distributed load wide laminate sheet beam structure is formed.

This can be used to create a curved corrugated roof that needs no rafters or other support. For a large span many (possibly corrugated) elements can bo used in a matrix of sheets that overlap at the ends as well as the sides as described above.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope therein