WO2009028962A1

WO2009028962A1 - Strut post and clamp for glass panels

Info

Publication number: WO2009028962A1
Application number: PCT/NZ2008/000207
Authority: WO
Inventors: Adam Alexander Trott
Original assignee: Trott, Kay Margaret
Priority date: 2007-08-31
Filing date: 2008-08-13
Publication date: 2009-03-05
Also published as: AU2008293132A1; AU2008293132B2; NZ561106A

Abstract

A clamp for holding a panel like a frameless glass pane on a support includes a slot within which the panel is gripped. One or both sides of the slot comprise tongues fixed to the body of the clamp at one end only, usually the outer end. The clamp body includes internally placed adjustment screws each bearing across a gap to the tongue, so that each tongue can be forced against and firmly grip the panel within the slot. Adjustment of the angle or position at which the panel is held relative to the body is possible.

Description

TITLE: STRUT POST AND CLAMP FOR GLASS PANELS

FIELD This invention relates to a clamp for holding and supporting a flat panel, with particular application to clamps suitable for supporting frameless panes of glass such as along a balustrade.

BACKGROUND

Glass panels, and in particular toughened safety glass panels or sheets are often used as a fencing material for decks, balconies and around pools, where they have numerous advantages. They are preferably used in a "frameless" form in which there is no supplementary material forming a frame around the edges of the sheet; the glass itself is finished by rounding and polishing as appropriate. The glass is of course suitably toughened and the edges are rounded and polished so that the glass does not inherently present a hazard. Glass panels may also be used in staircases, tables, as projecting awnings or other substantially horizontal applications, and in architecturally designed buildings and outdoors constructions for use by the public. A variety of different systems have been devised to support panels of glass or other materials for the construction of fences and the like with such panels.

Some systems have used a frame or set of fittings on opposing edges of the panels, into which each panel is fitted and locked with capping elements, and between which the panel is securely held. Such a system however necessarily involves the use of a fairly robust support construction on opposite sides of the panel, and often this is considered to be undesirable because the intention when constructing with a glass panel is generally to provide a light, transparent construction without extra parts that may present an undesirable appearance.

Alternatively, the panel can be drilled with a number of attachment holes, and fastened to a support structure with bolts or other pins. By this means a panel can be fastened along one edge only. However, this can be relatively expensive and requires careful planning, as the holes must be drilled before the glass is toughened and no adjustment is possible subsequently. Each hole presents a point of weakness on account of the production of micro- cracks during drilling. Furthermore, the fastening system is generally exposed to view, and may present an undesirable appearance.

There may also be a risk of the, fasteners cracking or otherwise damaging the panel, if twisted or otherwise put under tension. Accordingly it is difficult or dangerous to straighten or level a panel of glass if for some reason the mountings have not been aligned or positioned correctly, and hold the pane off vertical or otherwise off square with other components of the structure.

In the relevant prior art for clamps suitable for use with frameless glass panels, almost all examples require that the panel be drilled in order to accept a transfixing fastener such as a bolt. For example see Elmer US 2002/0031397, or Chang et al, US 2008/0093520. Garret in

US2007/0107351 teaches a form of clamp in which screwing down a screw within the base of the clamp, located parallel with and beyond the plane of the panel distorts the clamp. The clamp is made with opposed, pivoted clamp halves each having a cam surface Screwing down causes the two halves of the clamp to close around the panel (see his Fig 3), holding the panel in place by friction, without drilling any holes. There is no adjustment aspect (such as tilt). Garret in US5867869 described another friction clamp (see for example Fig 13), which uses a transfixing screw perpendicular to but outside the plane of the panel that brings two parts of the clamp together around the panel, as does Hogg, US 4841697, and Sittman, US3821870.

PROBLEM TO BE SOLVED

Accordingly there is a need for an improved fastening system by which a panel - and in particular a frameless panel comprised of a brittle material - can be secured to a substrate without drilling, and in particular a fastening system which can readily allow some adjustment of the orientation of a panel.

OBJECT

It is an object of this invention to provide an improved fastening clamp for panel materials, or at least to provide the public with a useful choice. STATEMENT OF INVENTION

A clamp for holding a frameless panel by friction and pressure; the clamp having a body and a slot within the body that, when in use, grips a peripheral part of the panel; wherein the slot has an inner end and an outer end and is sufficiently wide to encompass the panel; at least one side wall of the slot comprises a lining wall having a a length and a first inner surface adapted for contact with the panel and a second, opposite surface, the lining wall forming part of the body of the clamp yet being separated from- the body along part of the length of the lining wall, the clamp including at least one adjustable bearing member bearing against the opposite surface of the lining wall from within the body of the clamp such that inwards adjustment of the bearing member respective to the .body of the clamp will cause the adjacent lining wall to be forcibly extended into the slot, causing the clamp to grip the panel.

A clamp as previously described in this section, wherein the at least one adjustable bearing member comprises a threaded screw engaged with a thread made inside a hole penetrating said body; the member having, when in place, an end bearing across a space and against an adjacent inner wall of the slot, whereby rotation of said screw drives the end towards or away from the inner wall relative to the body of the clamp.

A clamp as previously described in this, section, wherein relative adjustment of more than one adjustable bearing member permits small alterations to the position or attitude of the clamped member.

Preferred bearing members include grub screws made of a steel or a corrosion-resistant steel.

Preferably the at least one adjustable bearing member has an axis of rotation substantially perpendicular to a plane of the panel.

A clamp as previously described in this section; wherein the slot has an inner end and an outer end and at least one of the lining walls is in the form of an elongate tongue aligned along the slot and connected to the body of the clamp by at least one root, and wherein at least one adjustable bearing member extends between the body and said tongue at a distance from said root so that, when in use, the tongue serves as' an adjustable pressure contact and pressure distribution member yet remains fixed by the root to the body of the clamp.

A clamp as previously described in this section, wherein a single root of each tongue is positioned at an outer end of the slot, like a frog's tongue. A clamp as previously described in this section, wherein a single root of each tongue is positioned at an inner end of the slot.

90 A clamp as previously described in this section, wherein each tongue is formed contiguously with said body, and each root comprises a flexion point.

In another aspect the invention provides a clamp for holding a pane of glass having a body for fastening to a substrate and paired clamping surfaces for holding said glass, wherein the orientation of the clamping surfaces is adjustable relative to said body.

95 A clamp as previously described in this section, wherein the first surfaces that line the walls of the slot are faced with a strong yet resilient surface material selected from a range of plastics materials including Nylon (T ) and polyethylene.

A strut post and clamp for holding a panel as previously described in this section, wherein the clamp includes, between a base adapted to be fastened to a substrate and the body of the 100 clamp, an extended member or strut post, thereby providing that the panel will be fixedly held in a position separated from the substrate.

A clamp as previously described in this section, wherein the body and the at least one tongue is formed contiguously from a material, selected from a range of metals including stainless steel, aluminium, and alloys thereof, the range also including plastics and wood.

105 These and other aspects of the invention may be made apparent in the following description of preferred embodiments, with reference to the accompanying drawings.

PREFERRED EMBODIMENT

The description of the invention to be provided herein is given purely by way of example 110 and is not to be taken in any way as limiting the scope or extent of the invention.

Throughout this specification unless the text requires otherwise, the word "comprise" and variations such as "comprising" or "comprises" will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. 115 DRAWINGS

Figure 1 : illustrates a preferred form of the invention in perspective view from the front as in use.

Figure 2: shows the clamp of Figure 1 from the rear.

Figure 3 - as Fig 3a to 3f: shows the clamp of Figure 1 in plan, end and side elevations.

120 In a preferred form as illustrated herein, the invention provides a clamp 10 for fastening a sheet material, such as a pane of toughened safety glass 20 which does not have a distinct frame, to a substrate such as a deck 30, to create a free-standing fence or other such structure. Of course more than one such clamp would be used for each such pane, for instance spaced apart at 700 to 1000 mm intervals. The clamp 10 is preferably comprised of

125 a single-piece metal body 11 with an orthogonal plate 12 for fastening to the substrate 30, having holes for bolts 13 or the like. The body may take a variety of shapes, but preferably has a rounded, vertically elongate lozenge-shape as shown in the drawings, so as to give a pleasing, natural appearance and avoid sharp corners or projections. Compliance with particular architectural concepts may instead require a polygonal outline, a circular outline or

130 a square one, for example.

There is a requirement to allow application of a significant clamping force to the panel, so that it cannot move within the clamp, while distributing the clamping force so that it does not focally cause the panel to break. Force applied by the or each adjustable bearing member is distributed over a larger area by the tongue, at a distance from said root so that, when in use,

135 the tongue serves as an adjustable pressure contact and pressure distribution member yet remains fixed by the root to the body of the clamp.

As shown particularly in Figure 3 c and 3e, the two side walls of the slot 14 comprise moveable tongues 16, each separated from the body 11 by a recursive slot 17 extending horizontally into the body 11 from the base of the slot 14 and back upwardly substantially

140 parallel to the slot 14, so that the tongues 16 are connected to the body 11 at a root only at the top end 18. This resembles the anatomy of a frog's tongue. Flexion of the tongues 16 at the top end 18 where they attach to the body 11 allows the free lower end of each of the tongues 16 to flex inwardly or outwardly. To hold a pane of glass 20, the body 11 is provided with a vertical slot 14 with a specified

145 width in relation to the thickness of a pane of glass. The walls of the slot are preferably faced with strips of a strong yet resilient material 15 such as polyethylene, or other resilient plastics materials with a good weathering capability that will deform under pressure so that the force applied by the clamp will be spread over the area of the jaws. Rubber (often synthetic), or natural materials such as leather might be used, as is well-known to those

150 skilled in the art. The width of the slot including two layers of the lining should be slightly greater than the thickness of a pane of glass, by perhaps 1 mm.

At least one, and preferably two threaded holes 19A extend usually perpendicularly to the slot through the body 11 of the clamp behind each tongue 16. An adjustment screw 19 having an external matching thread is rotationally mounted inside each' threaded hole. For

155 convenience each adjustment screw may be a machine grub screw, M3, M4 or M5 size that is 5 to 10 mm in length having a recessed hexagonal aperture at the available end. By turning a hexagonal key within the aperture the screw may be advanced or retracted within the threaded hole so as to bear tighter or less tightly against the tongue and thereby force the tongue into the slot and against the glass or other panel. By turning any screw 19, the inside

160 surface of the tongue 16 on that side can be driven inward or released outward by pressure from the tip of the screw. When the pane of glass 20 is mounted in the slot 14, the adjustment screws 19 can be tightened to press the tongues 16 inwardly against the pane, and thereby clamp the pane between the resilient facings 15. The facings 15 provide a wide area of resilient contact with the pane of glass 20, by which it can be held firmly but without risk

165 of damage. A second grub screw in the same hole and tightened against the back of the first may help to secure it in place, or one of the commercial screw fixing materials such as "Loctite"® may be used. Resultant stress in an installed sheet of glass might be assessed by looking through the pane with a pair of sheets of "Polaroid", one on each side of the pane of glass and one rotated to maximum extinction. Stressed areas will instantly become visible as

170 concentric light and dark rings, as is well known to those skilled in the art.. This technique serves to indicate under or over-tightened clamps, or mis-aligned clamps.

Two opposing screw assemblies (19, 19A (Fig 3 c)) are provided so that small errors in alignment of a row of brackets can be compensated by relative screw movement before final tightening. One would not want to impose distortions and stress on an originally flat pane. 175 Furthermore, the angle of the side walls of the slot 14 can be adjusted relative to the body 11 of the clamp 10. If an inconsistency in the substrate 30 or an inaccuracy in the placement or fastening of the clamp 10 means that the slot 14 is not exactly vertical, the angle can be altered by releasing one screw 19 and further tightening the other. By this means the pane of glass 20 can be held at the correct angle without being put under excessive tension, even if 180 the body 11 is not mounted at exactly the correct angle on the substrate 30.

Preferably the screws once adjusted are sealed in place with a waterproofing compound such as a wax. Many environments would expose the brackets to sea spray, pool water or rain water and opportunities for any corrosion should be minimised.

Preferred materials (listed here without limitation) are the stainless steel alloys 304 and 316;

185 alternatively the aluminium alloy 6061 T6. The preferred thickness for initial applications is stated to be 16 mm; again without limitation. Hence it is possible to make the brackets from sheet material, using a water cutter (as is known in the relevant arts) or possibly a laser cutter; driven from a CNC console. Outer edges or corners may be chamfered or rounded. Then the brackets are drilled and threaded, and finally surface-finished such as by polishing

190 or painting or anodizing as appropriate. (The inventor has found the laser cutter prone to wander and prefers the water cutter, but this may reflect the condition of particular machinery). Other methods of manufacture may be used, as found appropriate. For example; the brackets could first be cast or stamped to outline shape and then finished using a suitable metal cutting device, and drilled and finished as above.

195 VARIATIONS

The specific form of the clamp may vary considerably within the scope of the invention.

In particular, the fastening plate 12 may take any of a wide range of forms to suit attachment in different ways, as needed, onto or against different substrates. The usual substrate would for example be a length of square-section steel or another metal, but may be wood, and the

200 strut post serves to hold the panel slightly apart from the substrate. The example shown is a vertical plate for mounting on the- vertical facing of a deck or the like, but it could equally comprise a horizontal plate for mounting onto a horizontal surface, or a member adapted for bolting onto ties set in cement, one adapted for bolting to a rod or pipe, or a clamp or other type of fastener. The version of plate 12 as shown in Fig 3d and 3e is bolted into the body of

205 the bracket with cap screws, for example, into holes 20. It might alternatively be welded into place, or comprise part of a casting. While the rounded lozenge-shaped body as shown in the drawings is currently preferred as an aesthetically-pleasing form unlikely to cause injury or damage to things knocking against it in normal use, it will be appreciated that the same structural characteristics could be 210 achieved with an angular body such as a generally triangular or rectangular form, and that such forms might be preferred for example in applications where the clamp will be hidden from view in use.

While it is preferred for the tongues 16 to be attached to the body at the top end as shown, a similar function could be achieved with tongues attached at the bottom end only, with the 215 adjustment screw or screws being positioned near the top end. In this case the slots 17 would comprise simple vertical slots parallel to the main slot 14. Such a construction might however hold the glass panel less securely, in that the top end of the -tongues could flex sideways relate to the body allowing the pane to pivot. Accordingly the arrangement described above is preferred at present.

220 Similarly, the tongues 16 could be pivotally mounted on the body with a hinge at one end, or even partway along its length, and the adjustment screw 19 used to pivot the tongue about the hinge-point. This is considered less preferable at present because the mechanism would necessarily be somewhat more complex, and also because the tongue would not resiliently press against the adjustment screw 19, introducing a potential degree of slack. One 225 advantage of the present invention is that there is little opportunity for corrosion to take place, in the absence of a hinge. Tongues could be fixed to the body at both ends, while tightening a screw against the middle of the tongue will cause it to bulge out into the gap, where it may be used to press against the panel.

The absence of an actual pivot or hinge means that the clamping surfaces which are the

230 inside surfaces of the tongue or tongues, always form an integral part of the body of the clamp since they are contiguous at 18. Therefore this type of clamp holds the panel more securely than if separate parts were to be used. The amount of flexion that is expected to occur during adjustment at the root of each tongue is small, since the unadjusted gap 14 inside the clamp is preferably made just slightly (perhaps 1 mm) greater than the thickness of 235 the panel to be clamped (taking account of the facings 15). The inner, opposing walls of the two tongues (or one tongue in relation to a facing, passive inner surface) tend to remain parallel to each other, although that condition is amenable to adjustment of the respective screws 19. Note that, when in use, the tongue serves as an adjustable pressure contact member yet remains fixed by the root to the body of the clamp.

240 It will be appreciated that the principle of the clamp as herein described may be applied to other kinds of panel holder and is not limited to the. "strut post" type. For example the clamps could be used in hinges for glass shower doors or could be used to support lighting fixtures above a fence made of glass panels.

A variety of different adjustment mechanisms could be. used, possibly including a wedge to

245 be driven between the body and the tongue by action of the mechanism. A tapered screw might be used; perhaps coming from the outer end or directly into the slot, rather than from a side as shown. A single adjustment mechanism could be provided on one tongue only, with the other simply flexing to stay in alignment, but some alteration or care would be required in. this case to ensure secure clamping of the panel. Use of two adjustment mechanisms

250 bearing against the concealed side of each tongue seems to be the best and simplest method known, given the present choice of materials.

Materials other than metals could be used for the clamp and/or the resilient facings of the slot, to suit different styles or uses. The material of the clamp would however need to be sufficiently strong and/or resilient to allow the tongues to be adjusted without breaking. 255 Some transparent plastics may be strong enough despite exposure to daylight over time possibly leading to loss of plasticity and development of cracks. They would provide a pleasing appearance. It is likely that they will be thicker than 16 mm, although that is a function of the properties of the materials. Engineer acceptability in terms of building regulations and safety would be required for any proposed material.

260 Finally, it will be understood that the scope of this invention as described by way of example and/or illustrated herein is not limited to the specified embodiments. Where in the foregoing description, reference has been made to specific components or integers of the invention having known equivalents, then such equivalents are included as if individually set forth. Those of skill will appreciate that various modifications, additions, known equivalents,

265 and substitutions are possible without departing from the scope and spirit of the invention as set forth in the following claims.

Claims

WE CLAIM

1. A clamp for holding a frameless brittle panel by friction and pressure; the clamp having a body and a slot within the body that, .when in use, grips a peripheral part of

270 the panel; characterized in that the slot has an inner end and an outer end and is sufficiently wide to encompass the panel; at least one side wall of the slot comprises a lining wall having a a length and a first inner surface adapted for contact with the panel and a second, opposite surface, the lining wall forming part of the body of the clamp yet being separated from the body along part of the length of the lining wall,

275 the clamp including at least one adjustable bearing member bearing against the opposite surface of the lining wall from within the body of the clamp such that inwards adjustment of the bearing member respective to the body of the clamp will cause the adjacent lining wall to be forcibly extended into the slot, causing the clamp to grip the panel.

280 2. A clamp as claimed in claim 1; characterized in that at least one of the lining walls is in the form of an elongate tongue aligned along the slot and connected to the body by at least one root, and wherein pressure applied by the bearing member is transmitted across the tongue, deforming the tongue and causing the tongue to grip the panel while the tongue remains fixed by the root to the body of the clamp.

285 3. A clamp as claimed in claim 2, characterized in that the first inner surfaces that line the walls of the slot are faced with a resilient surface material selected from a range of plastics materials including Nylon (T ) and polyethylene.

4. A clamp as claimed in claim 2, characterized in that a single root of each tongue is positioned at an outer end of the slot, like a frog's tongue.

290 5. A clamp as claimed in claim 2, characterized in that a single root of each tongue is positioned at an inner end of the slot.

6. A clamp as claimed in claim 4 or in claim 5, characterized in that each tongue is formed contiguously with said body, and each root comprises a flexion point.

7. A strut post and clamp for holding a panel as claimed in claim 1, characterized in 295 that the clamp includes an extended member or strut post between a base adapted to be fastened to a substrate and the body of the clamp, the strut post comprising to hold the clamped panel in a position separated from the substrate.

8. A clamp as claimed in claim 6, characterized in that the body and the at least one tongue is formed contiguously from a material, selected from a range of metals

300 including stainless steel, aluminium, and alloys thereof, the range of materials also including plastics and wood.

9. A clamp as claimed in claim 1, characterized in that the at least one adjustable bearing member comprises a threaded screw engaged with a thread made inside a hole penetrating said body; the member having, when in place, an end bearing across

305 a space and against an adjacent inner wall of the slot, whereby rotation of said screw drives the end towards or away from the inner wall relative to the body of the clamp.

10. A clamp as claimed in claim 9, characterized in that relative adjustment of more than one adjustable bearing member permits alterations to the position or attitude of the clamped member.

310