GB2089881A - Clamping device, primarily intended for attaching panels to posts - Google Patents

Abstract

The present invention relates to clamping devices for temporarily securing hoarding panels or the like to supporting posts, for example to form a fence around a building site. In one embodiment, the clamping device comprises a plate-like post clamp (4) slidably retained on an L- section post (1) by the inturned ends (4b) of the post clamp. A bolt (6) threadedly cooperates with the post clamp, and, when tightened, engages the post (1) within its angle-section to releasably clamp the post clamp in an adjusted position against sliding movement relative to the post. A plate-like panel clamp (5) is slidably mounted on the bolt (6),. and a nut (6a), when tightened, cooperates with the panel clamp (5) to releasably clamp a pair of panels (2) between the panel clamp (5) and the clamped post clamp (4). <IMAGE>

Description

SPECIFICATION Clamping device, primarily intended for attaching panels to posts The present invention relates to clamping devices, primarily but not exclusively intended to temporarily secure panels or the like to supporting posts.

Hoardings which are currently used to fence around building sites are often erected from a series of rectangular ply wood panels, for example 8 ft high by 4 ft wide, the opposied vertical side edges of which slidably engage in vertical slots in spaced apart rectangular cross-section timber posts concreted in the ground. Such hoardings, which are often scrapped when the site work has been completed, are relatively expensive to produce, and require skill in erection, particularly since the positioning of the posts must be relatively accurately controlled if the panels are to be properly slidably accepted in, and retained by, the slots in the posts.

It is an object of the present invention to provide a clamping arrangement which is capable of mitigating or effectively overcoming the above mentioned disadvantages.

From one aspect, the present invention provides a clamping device for attaching a panel or the like to a post, having spaced generally longitudinally extending side or edge zones, comprising a post clamp dimensioned to span the said longitudinally extending zones, and having opposite end portions engageable around the said longitudinally extending zones to anchor the post clamp to the post whilst permitting the post clamp to slide along the post, a releasable locking member cooperable with the post clamp, which locking member is capable of being actuated to engage the post between said zones to releasably clamp the post clamp in an adjusted position against sliding movement relative to the post, and a panel clamp which is cooperable with the locking member to releasably clamp a panel or the like relative to the clamped post clamp.

From another aspect, the invention provides a post having a plurality of clamping devices as just defined slidably mounted thereon, the post being provided with means to prevent the clamping devices from becoming unintentionally detached from the post by longitudinal sliding movement thereof.

From another aspect, the invention provides a length of panelling or the like which comprises a plurality of posts fixed to the ground in mutually spaced generally upright positions, each post carrying at least one clamping device as just defined, and panels or the like spanning adjacent posts and clamped thereto by said clamping devices.

In order that the invention may be more readily understood, reference will now be made to the accompanying drawings, in which: Figure 1 is a fragmentary isometric view of a section of hoarding embodying the present invention; Figure 2 is a fragmentary isometric view of a section of hoarding utilising a clamping device similar to that shown in Figure 1, but having a modified panel clamp; Figure 3 shows various views of the panel clamp of Figure 2; Figure 4 shows various views of the post clamp of Figure 2; Figures 5, 6 and 7 are, respectively plan, fromt and side views of the section of hoarding shown in Figure 2; and Figures 8 to 13 are views, corresponding to Figures 2 to 7, of a clamping device which enables panels to be clamped at right angles to each other to form a corner.

Figure 1 shows a metal post 1 which is fixed to the ground in any one of a number of alternative ways. For example the lower end of the post may be sunk into the ground and encased in concrete, may be pre-welded to a plate bolted to a concrete base, or may be clamped at ground level to a stub cast into a concrete post hole. The post 1 is formed from a metal angle, which, in this embodiment, is galvanised mild steel 60 x 60 x 6 mm L-section angle having a length, i.e. a height above ground level, of approximately 8 ft so as to accept rectangular hoarding sections or panels 2, such as plywood panels which are 8 ft high.

The individual panels 2 are releasably clamped to the post 1 by means of clamping devices, for example three clamping devices distributed along the length of the post, two of which are indicated at 3. Each clamping device comprises a post clamp 4 and a panel clamp 5, both formed, for example, from galvanised mild steel plate, a bolt 6 threaded into a nut 4a secured, for example welded, over a central hole in the post clamp 4 and slidably received in a central hole 5a in the panel clamp 5, and a nut 6a and associated washer Sb mounted on the outer or head end of the bolt 6.

The post clamp 4 is dimensioned to span the free ends or longitudinal edges of the limbs or arms of the L section of the post 1, and the opposed end portions 4b of the post clamp 4 are bent over, for example by approximately 1350, in the direction of the nut 4a. The inturned end portions 4b serve to anchor the post clamp to the post whilst permitting the post clamp to slide along the post.

The panel clamp 5, which may have a span approximately the same as, or less than, that of the post clamp 4, also has end portions 5b which are bent over by approximately 900, or more. The panel clamp is normally retained assembled to the post clamp by the bolt 6.

To erect a length of hoarding, a number of posts 1 are fixed to the ground in an upright position as previously described, at a spacing dependent upon the width of each panel 2. For example, if the panels are 4 ft wide, the inter-post spacing will be slightly greater than 4 ft to allow for the bolts 6 to pass between adjacent vertical side edges of the panels. A number of assembled clamping devices 3, for example three clamping devices, with their bolts 6 unscrewed or retracted from the position shown in Figure 1, are slid by means of their post clamps 4 over the top of each post 1. The clamping devices are spaced apart along the post at the required levels, and are clamped at these levels by tightening the bolt 6 of each clamping device until its inner end locks into the throat or base of the angle of the post 1.With the nut 6a of each clamping device screwed back towards the bolt head to increase the spacing between the panel clamp 5 and post clamp 4, panels 2 are introduced between the panel and post clamps of the clamping devices on adjacent posts, whereafter the nut 6a of each clamping device is tightened to cause the adjacent vertical edges of adjacent panels to be clamped between the panel and post clamps, with the end portions Sb of the panel clamps engaging, and preferably biting into, the panels.

The panels may be introduced between the panel and post clamps of the clamping devices on adjacent posts in a vertically downward direction.

Preferably, however, the spacing between adjacent posts relative to the width of the panels is such that, with the panel clamps 5 rotated through 900 from the position shown in Figure 1, the panels may be moved in a generally horizontal direction past the turned panel clamps, whereafter the panel clamps are turned back to the Figure 1 position to overlie the edges of the panels.

In the basic design of clamping device shown in Figure 1, the panel and post clamps are formed from relatively heavy gauge plate, such as 60 mm mild steel. However, this may not be necessary, and Figures 2 to 7 show, in detail, one practical form of clamping device which may be made from a lighter gauge, for example 14 gauge, mild steel.

The post clamp in this embodiment although of a lighter gauge, is effectively identical in configuration to the post clamp of Figure 1.

Whilst, when the bolt 6 is tightened against the throat in the angle of the post 1, the resultant load will tend to bow the post clamp, and the tendency to bow will increase as the thickness of the post clamp is decreased, this bowing is not detrimental under normal tightening loads, since the bowing tends to inturn the end portions 4b, which tends enhance rather than detract from the anchorage of the post clamp to the post. However, since subsequent tightening of the nut 6a when the panels 2 are in place will tend to bow the panel clamp 5 towards the panels, which will not increase, and may possibly decrease, the clamping effect of the panel clamp 5 on the panels 2, the edge portions of the panel clamp 5 between the end portions Sb are bent down to form stiffening flanges 5c.

The panel clamp 5 of the clamping device shown in Figures 2 to 7 also differs from that of Figure 1 in that the end portions 5b extend generally perpendicular to the plane of the clamp, and are provided with serrations or teeth which are intended to bite into the panels 2 to enhance the clamping thereof.

Figures 8 to 13 illustrate an embodiment of clamping device which is intended to clamp panels together at right angles to each other so as to form a corner. As will be apparent, for example from Figures 10 and 1 the post clamp 4 is cranked to provide mutually perpendicular panel locating portions 4c interconnected by a web 4d to which the nut 4a is welded. As shown in Figure 11, in order to provide sufficient clearance between the web 4dand the throat of the angle of the post 1, the nut 4a is welded to the face of the web 4ddirection towards the panel clamp 5.The panel clamp 5, as viewed in Figure 11, is substantially narrower than the post clamp 4, and substantially narrower than the panel clamp of the preceding embodiments, in order to ensure that the panels 2 are clamped in a stable manner, at right angles to each other, by the clamping device.

The erection of hoardings, etc., utilising angle section posts and clamping devices as hereinbefore described possesses numerous advantages over hoardings utilising slotted posts.

The angle section posts and clamping devices are relatively inexpensive to produce, simple to utilise, and enable panelling to be rapidly and readily erected and dismantled. The positioning of the clamping device merely requires the tightening of a single bolt, and the subsequent clamping of a panel merely requires the tightening of a single nut on the bolt.The clamping devices will accommodate panels of various thicknesses, and the spacing between adjacent posts in relation to the width of the panels is less critical than in the prior system since, as will be apparent, for example from Figure 5, a panel will be effectively clamped irrespective of the position of the edge of the panel in the zone between the bolt 6 and end portion 5b of the panel clamp, this latitude being effectively doubled for each panel, since each panel is secured between two posts, each associated with a set of clamping devices.

Furthermore, because of this latitude, it is possible to assemble the panels to their associated posts in a generally horizontal direction generally perpendicular to their planes, instead of having to slide them vertically downwardly into slots as in the prior system. This is achieved by spacing the posts apart by a distance greater than the width of a panel such that, when the panel clamps 5 of the clamping devices on one post, or two adjacent posts, are rotated on their bolts 6 through 900 for example from the position shown in Figure 6, the edges of the panel being assembled will clear the rotated panel clamps which are relatively narrow in a horizontal direction, whereafter the panel clamps will be rotated back to their original position to trap the panel against the post clamp preparatory to tightening the nut 6a.

As will be apparent from Figure 1 , the head of the bolt 6, and the nut 6a, are only accessible from within the site bounded by the hoarding, and the posts and clamping devices shown in Figures 1 and 2 will preferably be similarly oriented. Thus, the clamping devices cannot be tampered with by unauthorised persons outside the site.

Hoarding corners are simply formed by utilising the corner clamping devices shown in Figures 8 to 13 instead of the devices shown in Figures 1 to 7, and special corner posts are not required.

It will be understood that various modifications may be made without departing from the scope of the present invention.

For example, the shape, configuration and dimensions of the various components of the clamping devices may be changed, as may be the material from which they are made. Instead of, or in addition to, providing the panel clamp shown in Figures 2 to 7 with the stiffening flanges 5c, the panel clamp may be pressed or otherwise formed with ribs along its length between its end portions, for example two parallel ribs spaced apart by the bolt hole. The post clamp, instead of being bent up from the metal plate or sheet, could be made from two lengths of metal rod, each cranked at its opposite ends to produce end portions equivalent to the portions Sb. The two cranked rods are located in parallel spaced relation, spaced apart by, and secured, for example by welding, to opposed/flats of a nut equivalent to the nut 4a.

Although the post clamp 4 in the illustrated embodiments is provided with a captive nut 4a, the latter could be omitted, and the hole in the post clamp could be tapped to threadedly receive the bolt 6. The bolt 6 could be replaced by any other suitable threaded member, or member provided with means to cooperate with the post clamp such that rotation of the member will displace the latter axially to lock it in the throat of the angle of the post, the member also being provided with means to releasably actuate the panel clamp which will be loosely slidable on the member. If required, for example for security reasons, cap head socket screws such as Allen screws may be used in place of the hexagon headed bolts 6.

Each post may be adapted to retain the required number of clamping devices permanently assembled thereto. For example, the post may be cut to enable a pair of tabs or the like to be bent out after the required number of clamping devices have been slidingly assembled to the post. The tabs form stops to limit the extent of the sliding movement of the post clamps 4 within the required limits.

The clamping devices may be modified to fulfil a variety of additional or alternative purposes. For example, when a post is to be fixed to a short stub protruding from the ground, at least the post clamp 4 may be increased in length in the longitudinal direction of the post, and provided with two longitudinal spaced bolts 6. This post clamp is slid down over the upper end of the short stub and the lower end of the post is slid down into the upper end of the post clamp so as to butt against, or overlap, the stub. The stub, lower end of the post, and post clamp, are then clamped together by tightening the bolts 6. Similar elongate clamping devices, or pairs of clamping devices interconnected by separate or integral plates or the like may be employed to interconnect posts, post sections, beams or the like for other purposes.For example pairs of mutually inclined or cranked interconnected clamping devices may be used to clamp an inclined short post on top of the main post to receive and fix strands of barbed wire, or to support further posts serving as beams for a flat or pitched roof. Special clamping devices may also be designed to facilitate the addition of doors and gates where required.

Although the illustrated clamping devices are used to mount plywood rectangular panels, they may be employed to clamp or locate panels or members of other materials, shapes and sizes. For example, the panels may consist of wire or steel mesh carried by tubular support frames.

In this event, the end portions Sb of the panel clamp may embrace the tubular frame, and engage the mesh inwardly of the frame.

Alternatively, the clamping devices may be used to clamp advertising hoardings, fencing, sheets, rods or rails or the like, instead of or in addition to panels, to posts, beams or the like.

Whilst the illustrated clamping devices are used with angle section posts, i.e. posts having longitudinally extending flanges or equivalent portions having an included angle of less than 1 800, the clamping devices could be designed to accommodate hollow or solid flat posts or beams, or flat flanges of posts or beams, for example a transverse flange of a T or I section post, or one side of a tubular triangular section post. For this purpose, the nut 4a, if provided, will be welded to the face of the post clamp remote from the post (i.e. as in Figure 11) to prevent the nut fouling the post.

Where greater heights are required, the posts may be of solid or hollow rectangular section to provide the necessary strength. In this case, the panel clamp may have a span equivalent to the width of one flat of the post, each end portion spanning an adjacent side flat and being inturned around the rear flat of the post, i.e. the clamp will have, in plan, the form of a rectangle with a slot in one face.

Because of the manner in which the posts are mounted, and the design of the clamping devices, the clamping devices and panels, and in certain cases the posts, are capable of being readily reclaimed and reused. If the posts, for example 11 ft posts, are sunk into the ground and directly encased in concrete, it is impractical to recover them. However, by sleeving for example the lower 3 ft of the post with a removal sheath, for example a sheath of polyvinyl chloride, the post may be withdrawn from the concrete leaving the sheath embedded in the concrete.

The free end of the bolt 6 or equivalent may be rounded, or may be pointed, tapered or otherwise profiled or formed to enhance its locking engagement with the post or equivalent.

The serrations or teeth Sd on the panel clamp may be replaced by a single lug or projection at each end of each end portion Sb.

Claims (12)

1. A clamping device for attaching a panel or the like to a post, having spaced generally longitudinally extending side or edge zones, comprising a post clamp dimensioned to span the said longitudinally extending zones, and having opposite end portions engageable around the said longitudinally extending zones to anchor the post clamp to the post whilst permitting the post clamp to slide along the post, a releasable locking member cooperable with the post clamp, which locking member is capable of being actuated to engage the post between said zones to releasably clamp the post clamp in an adjusted position against sliding movement relative to the post, and a panel clamp which is cooperable with the locking member to releasably clamp a panel or the like relative to the clamped post clamp.

2. A clamping device as claimed in claim 1, wherein said locking member is a threaded member, screw-threadedly cooperable with the post clamp, which is capable of being tightened to engage the post to releasably clamp the post clamp to the post.

3. A clamping device as claimed in claim 2 for attaching a panel or the like to an angle-section post, such as a generally L-section post, the post clamp being dimensioned to span the free ends of the limbs defining the angle-section of the post, opposite end portions of the post clamp being inturned, and engageable around said free ends of the post to retain the post clamp slidably attached to the post, the threaded member, when the post clamp is slidably attached to the post, being engageable with the included angle of the anglesection to clamp the post clamp against sliding movement relative to the post.

4. A clamping device as claimed in claim 2 or 3, wherein the threaded member comprises a bolt, the shank of which passes through an aperture in, and threadedly cooperates with, the post clamp, and slidably passes through an aperture in the panel clamp, the bolt carrying a nut which is cooperable with the panel clamp to clamp a panel or the like between the panel clamp and post clamp.

5. A clamping device as claimed in any preceding claim, wherein the post clamp and panel clamp are formed from sheet metal.

6. A clamping device as claimed in any preceding claim, wherein the panel clamp has panel-engaging surfaces provided with lugs or serrations for cooperating with the panel.

7. A clamping device as claimed in any preceding claim, wherein the span of the panel clamp is less than the span of the post clamp, and the span of the panel clamp is greater than the width of the panel clamp in a direction generally normal to its span.

8. A clamping device constructed substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings.

9. A clamping device constructed substantially as hereinbefore described with reference to Figures 2 to 7 of the accompanying drawings.

10. A clamping device constructed substantially as hereinbefore described with reference to Figures 8 to 1 3 of the accompanying drawings.

11. A post having a plurality of clamping devices as claimed in any preceding claim slidably mounted thereon, the post being provided with means to prevent the clamping devices from becoming unintentionally detached from the post by longitudinal sliding movement thereof.

12. A length of panelling or the like which comprises a plurality of posts fixed to the ground in mutually spaced generally upright positions, each post carrying at least one clamping device as claimed in any of claims 1 to 10, and panels or the like spanning adjacent posts and clamped thereto by said clamping devices.