GB2387348A - Folding stand with hinged panels - Google Patents

Abstract

A folding stand comprises hinged panels with cut-outs in each panel (14, 15, 17, 19, 20, 21, fig 15) that allow additional materials, such as standard timber products, to be inter-linked with one or more sets of these hinged panels, in a way that enables a user to create an extended range of support structures of differing size, height, and strength. Preferably the cut-outs are proportioned so that the inserted material becomes trapped, and hence locked, between the cut-outs when the panels are opened to a certain angle, and so that the inserted material is released again when the angle is reduced by folding the panels. Preferably the hinges are strap hinges, comprising straps with knock-in fastening end blocks. The stands may be used to form a workbench for use in carpentry etc.

Description

FLAT-FOLDING STAND

This invention relates to a flat-folding stand and, more especially, this invention relates to a flat-folding multi-functional workstand.

FR1030268 and GB1267189 set out the basis of a pin-less hinge that is similar to the strap-hinge developed for this folding stand.Additional patents GB1424139, US4163303, US4619304, GB2184281, GB2189290, US4821373, US4843679, US5187897, EP0612904 also document improvements for such pinless hinge, enhancing strength and allowing it to be mounted on regular doors or display panels.The ensuing description, then, is not concerned with specifying this style of hinge per se, but concerns how it is simplified to its basics, in a way that makes the stand's panels an inseparable component of such hinge.

A key influence of this stand's conception was the idea to create a minimal form that can be extended and strengthened with the very material workmen and the like use. This solves an age old problem for those doing site-work, as it reduces what needs to be taken on a job by providing an easy way to create all sorts of support structures, many which are unique to this style of stand.

In accordance with one non-limiting embodiment of the present invention there is provided a folding stand comprising of hinged panels with cutouts in each panel that allow added materials, such as standard timber products, to be inter-linked with one or more sets of these hinged panels, in a way that enables a user to create an extended range of support structures of differing size, height and strength. The term 'cut-out' is used as a word that embodies different shapes of opening cut from a panel side, such as holes or slots that incorporate insets or recesses. Each panel also has a curved edge and staggered slots on both faces that are securing points for prefabricated straps with knock-in fastening endblocks.These straps, together with the panel's sides, form what is here termed a strap-hinge.

Since this product is more a 'modular interface' than specific stand, the description and illustrations obviously include added materials, that are not part of the design itself. This style of support structure also works best with a pair or multiple of the same stand, so invariably there is referral to a combination of two or more stands. Although building or carpentry applications are cited, since that is its obvious use, there are alternative purposes the stand could serve, anything from supporting a video projector, piano keyboard or sewing machine.

In this description, there are references to 'standard timber products'. This terminology allows for any size variation between countries. For sake of example, in the UK, a popular width of sheet material, such as ply or MDF, is 18mm or 3/4" thick. Softwood is commonly sawn in imperial sizes, like a 1" by 3" plank or 2" by 2" strut, which is planed to a smaller, smoother metric dimension. Though still referred to by the original imperial size, it is these finished timber products, commonly available, that this stand is ideally shaped for.

Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which: FIGURE 1 shows an example of two stands folded flat; then transformed to the right, one stand has been placed over the other to form a waist-height bench, that may serve as a worktop or clamping frame. This formation works best up against a wall, or when made solid by clamping the two parts together.

FIGURE 2 shows timber lengths30 linking two stands in a low 'V-V' formation, with sheet material supported on top, that has been sawn in two31.

FIGURE 3 shows two upright stands, opened 90 degrees, with an array of added timber struts and boards33 that enable a cross-cut saw34 to be supported. Such platform may be screwed together and used as a slot-in accessory.

FIGURE 4 demonstrates how an upright and side-on stand work together. One piece of timber30 is inserted through a central hole linking both stands, while another plank3l rests over the side-on stand and on the lower rim of a main cutout 17 in the upright stand. An off-cut 32 in the upper slot adds a higher ledge.

FIGURE 5 is a magnified section of straps attached to the panels' edge and also shows a basic form of recess cut to allow closing room for the straps.

FIGURE 6 shows a temporary table and chair. The stands supporting the table-top are upside-down,with timber struts30 ledged in an inset22 beneath.

FIGURE 7 shows four profiles of how the panel edge is tooled to form a strap-hinge.

FIGURE 8 shows the plan and profile view of one extruded or moulded strap.

FIGURE 9 shows panel sides 7 with some straps inserted into slots; dotted lines indicate position of slots behind, on the back face of the panel.

FIGURE 10 shows alternative ways to fix webbing or narrow fabric straps.

FIGURE 11 show the option of plastic tacks moulded onto narrow fabric.

FIGURE 12 shows a sequence of profiles that illustrate how a strap-hinge opens and shuts both ways; this is not a literal profile representation.

FIGURE 13 shows miniaturised profiles of the cut-outs with timber, indicated by dotted lines, jamming inside these cut-outs at three angles (900, 600 and 28ù).

FIGURE 14 shows a slice-profile, with router-bits shaping the panel's edges.

FIGURE 15 shows the pattern of cut-outs over one upright panel, with another stand on its side inter-linked with timber, similar to that illustrated in Figure 4.

This stand is essentially two hinged panels, with a range of cut-outs that allow additional materials, such as standard timber products, to be inserted, inter-linked or clamped with it to form a range of support structures of various heights. One stand can also be placed over another to make a bench, without need of other materials, where the cut-outs aid numerous clamping purposes; see Figure 1.

Such simplicity, of course, is a refinement of many considerations. To begin with, imagine a piece of timber inserted through holes in two hinged panels. As the panel sides are opened, there comes a point where the timber jams and the panels can open no further; see Figure 13. Let the term jam-lock describe this act of trapping timber between panel sides. If it is done through multiple hinged panels, a double 'V-V' structure can be made.This has advantages, say, for a task of sawing a sheet of plywood 31, as both halves remain supported after the cut is made; see Figure 2. Should these panels have a range of holes, all that jam-lock with timber, this will enhance potential of inter-linking the panels.This principle provides the basis for size and position of most the cut-outs particular to this stand. The exact purpose and proportion of each is elaborated in later paragraphs.

Now consider using hinged panels positioned so that a 'V' form is seen from above. If the lower rims have rubber studs added or if the panel is tooled in a way that adds raised feet either end, there will be three main points of contact with the ground; see Figure 3. Like a stool, this instantly levels with an uneven surface. With panels opened in a 'V', you are also able to place material over the top. The advantage of this being that multiple stands can be set in various arrangements, such as a Z, l; or X formation. The choice depends on what purpose they are to serve; some configurations are more stable, some more easily linked, some best for supporting longer or wider materials. Indeed, once material placed across any one formation of stands has been clamped down, this creates a sturdy table-like structure. Not surprisingly, such potential for clamping material down is further reason for adding cut-outs in the panel sides beneath.

Combine the principles of hinged panels being jam-locked together or used as an uprightV-style trestle and you have more possibilities, particularly if the panels are proportioned higher one way, than the other. A lower 'V-V' sawing height coupling {Fig.2} can be lifted up to form a worktop height support. With careful positioning of cut-outs, one high stand can be linked with a lower stand jam-locked on its side { Fig. 4}, allowing you to create a structure of two supporting heights. Not surprisingly, then, the panels and their cut-outs are shaped to take advantage of this stand being used in an upwards, sideways, level, even upside down position; it is almost hard to say which is the right way up! For description's sake, let us define an upright stand as one positioned on its feet; eg. Figure 3.

The potential of combining these key features was not the starting point for devising such a stand. It began by thinking of the quickest way to recreate an earlier version of a timber 'clamping-frame'. Instead ofjointing wood together, it was considered easier to tool and duplicate a pattern of holes in sheet material. This awakened the potential simplicity of manufacturing such product (most evident in later paragraphs of production methods), and instilled the wish to make everything about the design suit minimal labour in production.

Once the thought of a folding 'clamping frame' arose, other ideas flooded to mind, however, it was soon realised the hinge would be a critical component. A conventional pin-hinge is not really suited to having forces applied in all directions, as this pulls the fixings out, especially when screwed into a thin panel side. Multiplying the number of fixings, as with a piano hinge, is one way to compensate for this, but dealing with many fixings is labour intensive. Bolting a hinge through each side is similarly problematic, as the panels should really have no protruding parts. Even fixing by glue is of concern, as many hinges have a limited opening span, where a hard twist will make it prone to rip loose.

Narrowing down the options, and thinking what might work with a quick knock-in fitting, lead to developing what can be termed a strap-hinge. With this, a number of prefabricated straps with end-blocks are knocked into staggered slots, cut either side of each panel's edge. It is that simple a 3600 span, frictionless and arguably strongest hinge for such an application; see Figures 7 to 12.

Of course, there are a points of note, regarding how this hinge is integrated with the stand's design.The panel's side is curvedi, to form the 'rolling edge' of such hinge. Should both panel sides be rounded off, this has the added benefit of reducing any splitting or chipping of edges, when the stand is used sideways; eg. Figure 2. Another essential detail is to displace the position of slots 3, into which strap end-blocks are knocked{Fig.9}, and position these far enough away from the edge to insure these mounting points do not break away.With this, a slight recess 2 can be cut from the panel side, to allow closing room for the straps. In a basic form this recess may be a strip cut down one or both faces adjacent to the curved edge {Fig.5}, or a precise strap width section cut beside each slot3.

Ideally, the strap would be a finger length strip 4 with opposite blocks 5 at right angles fixed either end; see Figure 8. These could have ribbed detail or claw-like spines 6 that clip in or 'dig' into the slot or securing point. Should the strap be wide, it reduces the number of pieces that make up the overall hinge; it gives the block 5 more frictional grip inside a slot; while it also allows a thinner strip 4 to be used, for extra width adds strength to each strap.

Such strap could be manufactured in several ways. They can be massproduced by injection moulding. Extruded plastic, of profile shown in Figure 8, could be cut into suitable strap sized pieces. Short lengths of narrow fabric or webbing may also be secured to serve the same purpose; see Figure 10. A simple option is to wedge short webbing lengths into the slots with a wide tack 8. If the webbing is stapled or welded onto such tack, it can be knocked in the other way round 9. This adds a better mechanical locking feature, since tension on the strap rotates the tack and thereby traps the webbing tighter inside its slot. A further option is to injection mould plastic tacks 10 onto a run of webbing, and later cut this up into finished straps with knock-in end-blocks 11; see Figure 11.

All these strap options have pros and cons, the deciding factor having much to do with manufacturing or marketing preferences. Whatever option is taken, all these approaches require similar tooling of the stand-the panel sides 7 are an integral part of how this minimal form of strap- hinge can be made to work.

Now consider more detail of how the panels are shaped, working down from the top; see Figure 15. An upright stand is best waist height, so as to support things at a comfortable standing height. The top rim 12 is not curved, as it is better flat, to resist rocking movement when items are clamped on top of a stand in an upright position; eg. Figure 3. A slight bevel is however added, to prevent splintering or * chipping of the edges, and this bevel 16 is added to all the cut-outs. If routered, the bit 35 that shapes this bevel is curved {Fig.14}, as timber jam-locks in cut-outs at different angles {Fig. 13}, and because the depth of plunge increases this bevel size, allowing fine tuning to the exact angle timber jam-locks in each cut-out.

The upper slot 13 is cut a standard 2" timber width down from top rim 12 and is just wide enough for popular sheet materials. There are several motives for this slot.With a piece of board inserted32, there is an extended ridge near the top of each panel, for clamping material down above; see Figure 4.This is useful, as many clamps are limited to a short span. If this board extends through multiple upright stands, it will also add stability by resisting rocking movement, without the need for any clamps. Such insert may further serve as a base for small models of pillar drill or cross-cut saw 34 { Fig.3}, many which have base plinths tooled to standard timber widths. Slot-in fixtures made to support such tools, with special guides or jigs attached, could become specialist accessories of this stand.

A central inset 14 below the upper slot 13 is tooled so that 2" by 2" timber will jam-lock the hinged panels open at 90 degrees {Fig.13}, and just fits below any sheet material slotted-in above. One reason for this is to allow a support 33 to be inserted beneath a tool base slotted-in above, particularly those suspended through two or more stands; see Figure 3. Another motive is to allow a single timber strut to stabilise upright stands opened at 90 degrees. A third consideration is providing a generous sized opening for clamps near the top rim of each panel.

Each side of the upper main cut-out 17, there are two indents 15. These are mainly intended for when the stand is on its side. Standard 2" timber 30 will jamlock a stand open at 60 degrees in this position. Used in combination with a second strut through a lower indent 21, multiple stands can be linked in a 'V V' formation, which makes for a sturdy knee level support structure; see Figure 2.

The upper main cut-out 17 serves three main purposes. It provides a big enough opening for clamps to be easily inserted when attaching things to the face of a stand or when using longer clamps on something above. It is sufficiently wide for many sizes of material to be loosely inserted Fig. 4, 6}, so as to provide a platform for hand-sawing or allow a lower shelf to be added. This cut-out's bottom rim is also positioned so that it is level with another stand placed on its side, should 2" timber be jamlocked through central holes 19; see Figure 4. This adds potential for combining two working heights and is a determining feature for the width of panel relative to the height of an upright stand.

The central holes 19 are tooled so 2" timber jam-locks the panels at an angle of 28 degrees.This allows a single insert to link stands in a tighter 'I' formation, for supporting short material. For sake of strength and balancing weight this takes a central position, and is set closer to each side, than mid-panel.

An obvious motive, for two further central slots 18, is to give the stand a handle, which is why they are set close to each side. It is tooled so that various widths of standard 1" plank will jam-lock the stand open at 60 degrees, and this is compatible with both the upper 15 and lower 21 insets, that jam-lock at the same angle with 2" timber; see Figure 13. Overall, this enhances opportunity to link multiple stands with a combination of different sizes of timber insert.

Beneath these holes there is an inverted version 20 of the upper main cutout 17. This works in a similar way to the one above and is cut in exactly the same position, should the stand be turned upside down. Inserting flat material through here, or timber in either of the lower insets 21, can provide a step or bar which a user can stand on or add weights, further stabilising an upright stand.

On the base rim there is a centralised inset22 that jam-locks with timber at 90 degrees. Like the cut-out 14 beneath the upper slot 13 this serves to add 'cross-bar' support, yet for materials placed over an upside-down stand; see Figure 6. This inset 22 is cut sufficiently deep so that 2" timber, laid in it, will lie level with the the stand's feet 24. Note the curved corners of this inset. This is intentional, as when you ledge a cross-bar support in such inset and widen the panel's opened position, this cross-bar will 'ride up' the curved or diagonal sides of each corner. If the ledged cross-bar, then, does not lie exactly flush with the stand's feet, you can make it rise up to a point where it does. The wide recess 23 across the base, serves to give both feet clearance from the ground, and is tooled so 1" cross-bar supports also will lie level with the the stand's feet.These feet 24 may have rubber or nylon soles 25, for grip and extra durability.

Moving on to manufacturing such a stand, there are several approaches. If made entirely of plastic, a half section of each panel could be injection moulded in an 'open and shut' mould, and these half sections stuck back to back so as to form a single panel. Hidden inside, there would be a web of ridges that give structural rigidity and allow each section to be mostly hollow. It is likely these ridges will have 'male and female' detail that effectively allow the two half panel sections to clip together. Separately moulded hinge straps could then be clipped into place, to form a version of the described strap-hinge.With more complex moulds, one half panel section could have a set of hinge strips (with end- block fastener) moulded in position, while the other half section just receiving slots. Here, once both panel halves where joined together, each set of hinge strips would simply clip into the receiving slots of the other panel, forming a finished stand.

Blow moulding is another option. The entire panel would be blown inside a two part mould, that closes in a way that seams the inside of each cutout. Once set, the remaining plastic across each cut-out would be punched out by a separate tool. For extra rigidity, the cavity inside each panel could be filled with expanding foam as the moulding is blown or added later through small incisions. Again, prefabricated hinge straps could clip into moulded slots. Should the slot detail be inconsistent or hard to mould, synthetic webbing could be welded to the plastic panel, using moulded detail on each panel as a fixing point guide.

Organic sheet materials, such as MDF, could also be used, where the panels are tooled entirely by computer-guided router or CNC machine. With more modest facilities, any carpenter could also produce a reasonable number of the panels by hand. A template of one panel would simply be clamped over new material and a hand-held router set to the task of duplicating the same slots and holes. This may require several changes of router bit, for bevelling and rounding off rims and edges. Depending on the finish required, each panel might be dipped in a sealant or spray painted. The final task would be to knock hinge straps into slots, that where added during either CNC machining or manual tooling process.

Claims (11)

1 A folding stand comprising of hinged panels with cut-outs in each panel that allow additional materials, such as standard timber products, to be inter-linked with one or more sets of these hinged panels, in a way that enables a user to create an extended range of support structures of differing size, height and strength.

2 A stand of claim 1 wherein the said panel cut-outs are insets, slots or holes proportioned so that inserted material will become trapped between these cut-outs should the panels be opened to a certain intended angle, and release this inserted material once this opened angle is reduced back towards the folded state.

3 A stand of claim 1 or claim 2 that serves as a V-style trestle, where the said panels can be opened in a 'V over surface ground, in a form that's self-supporting and allows material to be placed over it's top rims or through cut-outs in the panels.

4 A stand of any preceding claim wherein the said panels have their side tooled as an integral part of a strap-hinge, the panel's edge being curved and has, either side of this curved edge, a slight recess aligned with a number of staggered slots, that are securing points for prefabricated straps with knock-in fastening end-blocks.

A stand of claim 4 wherein the said strap-hinge is alternatively made up of straps welded to the panel side or moulded as an intrinsic part of each panel.

6 A stand of any preceding claim wherein the said cut-outs are shaped and positioned to aid clamping purposes from all aspects; this includes consideration of a cut-out having sufficient opening for a clamp head to purchase on, a cut-out being wide enough to allow clamps to be partially inserted for clamping to the face of the panel, and there being sufficient selection of cut-outs, particularly towards the sides and edges of a panel, to allow for the short range of many clamps.

7 A stand of any preceding claim wherein the said panels have an inset cut from the base edge that is sufficiently deep for permitting standard timber, laid in this inset, to lie level with the stand's feet; this inset may have curved or diagonal detail.

8 A stand of any preceding claim wherein the said panels have both sides rounded off and a flattened top edge, plus a centralised recess across the base edge that leaves material either side to function as feet.

9 A stand of claim 3 where supporting sides have a large opening wide enough for work material to be loosely inserted and ledged on the lower rim of such opening, that for sawing purposes is best positioned just above knee-height.

A stand of any preceding claim wherein the said panels have a long slot running perpendicular to the side the panel is hinged from, proportioned to tightly fit any inserted accessory or strip of popular sheet or board material.

11 A folding stand as herein described and illustrated in the accompanying drawings.