Clamp for connecting temporary fence panels

Abstract

A clamp for coupling temporary fence panels together. The clamp comprises two pairs of clamping jaws which are arranged side by side, and openings of the clamping jaws face the same direction. The inner jaws of each pair are hinged to the frame to allow each pair to close around a post of the fence panel. Between the inner jaws is a biasing spring that biases the hinged jaws toward the closed position. The clamp also includes a locking mechanism that can selectively prevent movement of the inner jaws to maintain each pair of jaws closed to prevent unauthorized removal of the clamp.

Description

Background Art

[0001] A common form of temporary fencing includes a plurality of fencing panels that are releasably clamped together using connectors. Each panel includes upright end posts with a panel such as welded wire mesh supported therebetween. The bases of the upright end posts of adjacent panels are supported by heavy foot blocks, typically made of molded thermoplastic. The function of the connectors is to hold the panels together. Many connectors are equipped with a locking mechanism that can be operated from one side to prevent unauthorized disassembly of the connector and removal of the fencing.

[0002] Figure 1A and 1B The design of a prior art clamp 1 commonly used for joining temporary fencing panels is shown. The clamp 1 consists of two substantially identical clamping parts 2, 3 that are held together by a nut 4 and a bolt 5.

[0003] To erect the fencing, movable fencing panels 6 including upright posts 6A and mesh panels 6B are placed side by side, and adjacent panels are joined together. To join two adjacent fencing panels 6, the two clamping parts 2, 3 are manipulated to opposite sides of the fencing panel 6 and held in place while the nut 4 is rotated multiple times on the bolt 5 to tighten the clamping parts 2, 3 against the upright posts. This is a complex and time-consuming process, especially since the fencing posts 6A are usually not perfectly parallel. Thus, joining the fencing panels together typically accounts for a large proportion of the total time required to erect a temporary fence.

[0004] US2004062594, GB2414034, and GB2391560 describe prior art fencing connectors. US4550891, GB2064232, US2005260895, US8181928, and CN103075576 describe other prior art connectors. Summary of the Invention

[0005] The present invention aims to provide an improved clamp for joining temporary fencing panels that can be installed and disassembled more quickly and easily compared to the prior art.

[0006] According to a first aspect of the present invention, there is provided a clamp that, when used as a fencing connector for example, includes two pairs of clamping jaws, each pair of clamping jaws including a fixed jaw and a movable jaw; the clamp includes a frame providing the fixed jaws; each movable jaw is provided by a separate movable jaw member pivotally mounted to the frame to allow the movable jaw to rotate relative to its corresponding fixed jaw to open and close the clamping jaws.

[0007] The novel fixture design overcomes the need to arrange two separate clamping components on opposite sides of the fence, thus simplifying and reducing the time required to attach the fixture to adjacent fence posts and remove it therefrom.

[0008] The fixture generally includes means for keeping the clamping jaws closed.

[0009] The fixed jaws can be a fixed outer jaw and a movable jaw, a movable inner jaw. This arrangement allows for simplification of the means for keeping the clamping jaws closed. For example, it can allow the use of a single mechanism to keep two pairs of jaws closed.

[0010] The fixture can include a biasing means which is connected between the movable jaw members and is adapted to bias the two movable jaw members towards their respective fixed jaw members to hold both pairs of clamping jaw members in the closed position. This enables the fixture to automatically stay in place when pushed onto the post.

[0011] The fixture can be simply removed from the fence panel by laterally pulling the fixture away from the fence with a force sufficient to overcome the biasing force of the biasing means.

[0012] The biasing means itself is considered a creative concept. Thus, according to a second aspect of the present invention, there is provided a fixture which includes two pairs of clamping jaws, each pair of clamping jaws including a first movable jaw member and a second jaw member, the biasing means being connected between the first jaws and being adapted to bias the two movable jaw members towards their respective fixed jaw members to hold the two pairs of clamping jaws in the closed position. The fixture can include a frame providing the second jaws. Each movable jaw can be pivotally mounted to the frame.

[0013] According to a third aspect of the present invention, there is provided a fixture for use as a fence coupler which includes two pairs of clamping jaws and a biasing means which biases the two pairs of jaws closed. As previously mentioned, the fixture can include a frame providing the second jaws. Each movable jaw can be pivotally mounted to the frame.

[0014] The following can be applied to any aspect of the present invention described above.

[0015] The movable jaw members can each be pivotally mounted to the frame about a hinge pin or a similar mechanism.

[0016] The frame can consist of a single integral piece. Generally, the frame is made of metal, but it can also be made of other materials such as synthetic polymers.

[0017] The biasing means can include a compression spring, such as a helical compression spring. This is a simple and cost-effective way of implementing the biasing means.

[0018] Each pair of clamping jaws can provide at least one arcuate clamping surface for clamping the convex curved outer surface of the fence post.

[0019] The fixture can include a retaining mechanism that can be selectively operated to prevent the two pairs of clamping jaws from opening from the closed position. The fixing mechanism allows the fixture to be selectively locked to the fence once clamped onto the fence post to prevent its unauthorized removal.

[0020] The retaining mechanism can include a restraint member that can move laterally relative to the frame between a retaining position and a release position. In the retaining position, when the jaws are closed, the restraint member engages against two movable jaw members. In the release position, when the jaws are closed, the restraint member disengages and is spaced apart from the movable jaw elements. In practice, once the clamping jaws are closed, the user can selectively move the restraint member to the retaining position to lock the fixture and to the open position to allow the fixture to be removed from the fence.

[0021] Advantageously, the restraint member is located on the opposite side of the frame relative to each pair of clamping jaws. This prevents the retaining mechanism from being operated from the other side of the fence to the fixture. If the fixture is located inside the perimeter of the fence, this can prevent a person outside the perimeter from removing the fixture and dismantling the fence.

[0022] Each movable jaw member can include a protrusion that is arranged to project into one or more apertures of the frame, and when the jaws are closed, the restraint member engages against the protrusion. When the two pairs of clamping jaws are in the open state, the protrusion can project through one or more apertures.

[0023] A shaft can also be provided, and the restraint member is mounted on the shaft for moving along the shaft towards and away from one or more apertures between a restraint position and a release position. The restraint position is relatively close to one or more apertures, and in the restraint position, the control protrusion can project through one or more apertures to the extent of holding a pair of clamping jaws in the closed position. The release position is relatively far from one or more apertures to allow a pair of jaws to open to the open position.

[0024] The shaft can be threaded. The thread of the shaft can have a lead length L, and the protrusion is arranged to move towards or away from the restraint member by no more than a distance equal to the lead length L during the opening and closing of the two pairs of clamping jaws.

[0025] Each pair of jaws can have an opening facing the same direction, and when the fixture is moved laterally towards parallel uprights, the opening enables the clamping jaws to optionally pass through the parallel uprights of adjacent fence panels substantially simultaneously. This arrangement allows the fixture to be mounted on two parallel fence posts or removed from the fence posts by a single lateral movement of the fixture towards or away from the fence post.

[0026] Another advantage of this arrangement is that the coupler is more resistant to being pried out by prying the fence panel in a direction collinear with the fence row, such as by an intruder. This is different from the prior art clamps because the mouths of the clamps face in a direction perpendicular to the fence row.

[0027] This feature is also considered to have independent inventive advantages. Thus, according to a fourth aspect of the present invention, there is provided a clamp for use as a fence coupler, the clamp comprising two pairs of clamping jaws, each pair of jaws in the two pairs of jaws having a mouth facing in the same direction, which mouth is capable of optionally passing substantially simultaneously through the parallel uprights of adjacent fence panels when the clamp is moved laterally towards the parallel uprights.

[0028] According to another aspect of the present invention, there is provided a clamp for clamping a fence post having a circular cross-section; the clamp has two pairs of clamping jaws, each pair of clamping jaws consisting of a fixed jaw and a movable jaw, the fixed jaws being provided by a frame and each movable jaw consisting of a movable jaw element pivotally mounted to the frame; each pair of clamping jaws provides at least one arcuate clamping surface for clamping against the curved outer surface of the post; and the clamp includes a restraint mechanism that selectively holds the clamping jaws in a closed position, the restraint mechanism including a restraint member that threadedly engages a threaded shaft mounted to the frame, the thread of the shaft having a lead length L; the restraint member is arranged to be rotatable about the threaded shaft between a holding position and an open position, in the holding position, the restraint member engages against an engagement surface of the movable jaw element to hold the two pairs of clamping jaws closed, in the open position, the restraint member is spaced apart from the engagement surface; and wherein the engagement surface is arranged to move towards or away from the restraint member by no more than a distance equal to the lead length L during the opening and closing of the two pairs of clamping jaws.

[0029] This arrangement allows the clamping jaws to be locked or released by a single turn of the restraint member, significantly increasing the speed at which the clamp is locked or released. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will now be described by way of example with reference to the following drawings, in which:

[0031] Figure 1A is a perspective view of a prior art temporary fence clamp;

[0032] Figure 1B is a view of the prior art temporary fence clamp of FIG. 1 connecting two fence panels;

[0033] Figure 2 is a perspective view of two temporary fence panels of a temporary fence joined together by a clamp;

[0034] Figure 3 is a first perspective view of the clamp;

[0035] Figure 4 is a second perspective view of the fixture;

[0036] Figure 5 is a plan view of the fixture;

[0037] Figure 6 is a plan view of the fixture moving parallel to the upright post of the adjacent fence panel;

[0038] Figure 7 is a plan view of the fixture mounted on the upright post and the retaining mechanism engaged to prevent disassembly of the fixture;

[0039] Figure 8 is a perspective view of the fixture mounted on the upright post; and

[0040] Figure 9 is a second perspective view of the fixture mounted on the upright post. DETAILED DESCRIPTION

[0041] REFERENCE Figure 2 shows a temporary fence 100 including a fence panel 101. Each fence panel 101 includes two upright posts 102, and a wire mesh sheet 103 is supported between the upright posts 102. The sheet 103 is typically welded to the posts 102. The fence panel 101 is supported by a foot block 104. Each foot block 104 made of molded thermoplastic defines a pair of holes that receive the bases of the adjacent upright posts 102 of the adjacent panel 101.

[0042] Adjacent panels 101 are joined together by at least one fixture 10 around their adjacent upright posts 102, and the fixture 10 is shown in more detail in Figures 3 - 9 . First, referring to Figures 3 - 5 , which shows the fixture 10 alone, the fixture 10 has a first pair of jaws 20 and a second pair of jaws 30 arranged side by side for clamping the parallel upright posts 102 of adjacent fence panels 101.

[0043] The fixture 10 includes a frame member 11, a first movable jaw member 12, a second movable jaw member 13, a helical compression spring 14, a threaded shaft 15, a washer 16, and a nut 17.

[0044] The frame member 11 consists of a single integral metal piece, for example, manufactured by one or more of molding, machining, forging, and pressing processes.

[0045] The frame member 11 includes a first arcuate portion 11A at the first end that provides the first fixed jaw 20A, a second arcuate portion 11B at the second end that provides the second fixed jaw 30A, and a connecting portion 11C between the first end and the second end that connects between the first arcuate portion 11A and the second arcuate portion 11B. An aperture 1D extends through the connecting portion 11C.

[0046] At the ends of each arcuate portion 11A, 11B, the frame member 11 bifurcates to provide fingers 11E which extend in the same plane but in a direction opposite to the bending direction of their respective arcuate portions 11A - 11B. In a variant example, the end reflecting portion may not be divided into a plurality of fingers, or may be divided into more than two fingers.

[0047] The first movable jaw member 12 is mounted to the frame member 11 adjacent the first arcuate portion 11A about a first hinge pin 18A to provide a first movable jaw 20B. The second movable jaw member 13 is mounted to the frame member 11 adjacent the second arcuate portion 11B about a second hinge pin 18B to provide a second movable jaw 30B. The pins 18A and 18B may be separate components, or each pin may be provided by a pair of trunnions which are integral with and project from the upper and lower faces (as viewed from the Figure 4 angle shown) of the respective movable jaw member.

[0048] The first and second movable jaw members 12, 13 are mounted to the frame member 11 to be located between the first and second fixed jaws 20A, 30A, i.e., the fixed jaws 20A, 30A are located outside the movable jaw members 12, 13.

[0049] The first fixed jaw 20A and the first movable jaw 20B together provide a first pair of jaws 20 for clamping to the first upright 102; the second fixed jaw 30A and the second movable jaw 30B provide a second pair of jaws 30 for clamping to the second upright 102.

[0050] The first movable jaw member 12 is rotatable about its hinge pin 18A relative to the frame member 11 to permit the first movable jaw 20B to travel towards and away from the first fixed jaw 20A. Similarly, the second movable jaw member 13 is rotatable about its hinge pin 18B relative to the frame member 11 to permit the second movable jaw 30B to travel towards and away from the second fixed jaw 30A. When the jaws open and close, the first and second movable jaw members 12, 13 rotate about parallel axes of rotation but in opposite directions to each other.

[0051] A compression spring 14 is connected between the first and second movable jaw members 12, 13. In the rest state, the compression spring 14 exerts a biasing force which holds the movable jaws 20B, 30B apart and towards their respective fixed jaw counterparts 20A, 30A such that both pairs of jaws 20, 30 are in a closed state.

[0052] In the closed state, the free ends of the fixed and movable jaws of each pair of jaws 20, 30 are spaced apart to provide openings 20C, 30C facing in the same direction. Due to the reflected fingers 11E, each opening has a tapered shape, wider at its mouth than the diameter of the post 102, but narrowing to a spacing less than the diameter of the post 102.

[0053] Each movable jaw member 12, 13 includes a tip 12A, 13A, as Figure 5 and Figure 6 shown by the dashed lines in, which tip extends into different orifices 1D. Each tip 13A is arranged to project through one orifice 1D when the movable jaw members 12, 13 rotate against the biasing force of the spring 14 to open the pairs of jaws 20, 30.

[0054] On the opposite side of the frame member 11 from where the movable jaw members 12, 13 extend, a threaded shaft 15 is mounted to the connecting portion 11C between the orifices 11D. The thread of the threaded shaft 15 has a pitch length P. Since in this example the shaft 15 has a single thread, the pitch length P also corresponds to the lead length L of the thread. A washer 16 and a nut 17 are retained on the shaft 15. The nut 17 is rotatable on the shaft 15 between a locked position and an open position towards and away from the connecting portion 11C, in the locked position the nut 17 being relatively close to the connecting portion 11C and in the open position the nut 17 being relatively remote from the connecting portion 11C. The outer diameter of the washer 16 is sufficient to at least partially extend across the two orifices 11D. The degree of freedom of the washer 16 to move laterally away from the orifices 11D is determined by the position of the nut 17. In the locked position, the washer 16 is held against the connecting portion 11C by the nut 17 to prevent the tips 12A, 13B from passing through the orifices 12D, thereby keeping the jaws 20, 30 closed.

[0055] In the open position, the nut 17 is spaced far enough from the frame member 11 to allow the tips 12A, 13A to project through the orifices 11D. The movable jaw members 12, 13 are arranged such that when the jaws are opened wide enough to allow the post to pass through their respective openings 20C, 30C, the tips 12A, 13B travel a distance not exceeding the lead length L of the thread towards the nut 17.

[0056] This arrangement means that only one full rotation of the nut 17 on the shaft 15 is required to switch between the open state and the locked state, in the open state in which the fixture 10 can be attached to or removed from the fence and in the locked state in which the fixture 10 is locked to the fence post 102.

[0057] Refer to Figure 6, with the nut 17 in the open position, in order to hold the clamp 10 on the parallel upright 102, the orientation of the clamp 10 is such that the openings 20C, 30C of the two pairs of jaws 20, 30 face directly towards the respective uprights 102; the clamp 10 is moved transversely, i.e. in a direction perpendicular to the spindle axis of the upright 102, to engage the upright 102 at a point between the upper and lower ends of the upright 102 such that the upright 102 is located within the openings 20C, 30C. As the clamp 10 is pressed against the upright 102, each movable jaw 20B, 30B is pushed away from its respective fixed jaw 20A, 30A against the biasing force of the compression spring 14, thereby widening the openings 20C, 30C to allow the upright 102 to enter the receiving areas 20D, 30D of the respective jaws 20, 30. As the movable jaws 20B, 30B open, the points 12A, 13B rotate to project through the apertures 11D.

[0058] Once the uprights 102 are located within the receiving areas 20D, 30D, they no longer resist the biasing force of the compression spring 14. Accordingly, the movable jaws 20B, 30B move towards their fixed jaw counterparts 20A, 30A to clamp the uprights 102 with sufficient force to hold the clamp 10 in place against the upright 102.

[0059] Once in place, the nut 17 is rotated (one full turn is sufficient) on the shaft 15 towards the connecting portion 11C to the Figure 7 locking position as shown to prevent the pairs of jaws 20, 30 from opening.

[0060] To remove the clamp 10, the nut 17 is rotated (again, one full turn is sufficient) on the shaft 15 to the open position and then the clamp 10 is pulled transversely away from the upright with sufficient force to overcome the biasing force of the compression spring 14 to push the movable jaws 20B, 30B together to release the upright.

[0061] Most commercially available fences of the above type, such as those provided by Haras(RTM), are of standardised dimensions. The diameter of the uprights of the fence panels is approximately 38 mm. The feet are usually standardised to support the uprights of adjacent panels and the spacing between the centres of the uprights is approximately 90 mm. To provide compatibility with these standards, the pairs of jaws can have imaginary centres spaced approximately 90 mm apart and when the clamp is closed, the imaginary diameter of the arcuate gripping surface provided by the jaws does not exceed approximately 38 mm.

[0062] It should be understood that the pairs of jaws 20, 30 do not need to cross over their respective uprights 102 simultaneously. Alternatively, one of the pairs of jaws can first clamp onto one upright 102 and then the clamp 10 is rotated about that upright to engage the free pair of jaws on an adjacent upright 102.

[0063] The above-mentioned fixture is considered particularly popular because it is simple and thus relatively inexpensive to manufacture. However, it should be understood that variations in the design are possible. Non-limiting examples of variations are described below.

[0064] A helical compression spring is a simple and convenient device that can provide substantially equal "pushing" biasing forces to two movable jaws simultaneously. However, it is not necessarily preferred, and other forms of biasing devices can also be contemplated, such as one or more leaf springs or gas springs. Instead of using a single biasing device, each movable jaw can be equipped with a separate biasing device.

[0065] The movable jaw member can be coupled to the frame member 11 by means other than a hinge, so as to provide, for example, linear motion instead of rotational motion. However, such an arrangement is not advantageous because it increases the complexity of the design.

[0066] Although for manufacturing cost considerations, the frame member 11 can be not a single integral piece.

[0067] The openings 20C, 30C of the jaws 20, 30 can be inclined and not parallel, while still allowing the fixture 10 to be held on or removed from the fence panel. For example, the openings can face in directions that are 90 degrees apart. In this case, it is necessary to first clamp a pair of jaws onto a post and then rotate the fixture around the post so that the other pair of jaws abuts another post. However, such an arrangement is less desirable because the post position needs to be moved slightly in order to be able to install the fixture. This is possible at the top of the fence panel but less likely at the bottom because the panel posts are held by foot blocks.

[0068] A single larger orifice can replace and provide the function of the separate orifices 11D.

[0069] The functions of the washer 16 and the nut 17 can be combined by using a flange nut or the like.

[0070] Advantageously, the shaft 15 is welded to the connecting portion 11C. Alternatively, the shaft can be provided by a bolt extending through the connecting portion 11C and held in place by a nut located between the spring 14 and the connecting portion 11C. In this case, the head of the bolt can replace and provide the function of the nut 17.

[0071] The forking of the free end of the frame member 11 is optional. The tapered characteristic of the opening is also optional.

[0072] In one variant, the pointed tip can be arranged to project slightly through the aperture 11D when the movable jaws 20C, 30B are closed, and when the movable jaw members 12, 13 rotate against the biasing force of the spring 14 to open the pairs of jaws 20, 30, the pointed tip can move to project further through the aperture. This arrangement allows the nut 17 to be tightened, for example with a wrench, against the pointed tip, pushing the movable jaws against the post, thereby applying an additional clamping force on the fence post that exceeds the biasing force provided by the biasing device. This may help to prevent the fixture 10 from rotating relative to the fence panel post 102 after being locked in place. In this variant, the movable element can be arranged such that the pointed tip does not move a distance greater than or equal to the lead length L towards or away from the nut when in the open position.

[0073] It is known that struts are used to provide additional support for a fence row where there is no sharp change in the direction of the fence row. In use, the upper end of the strut can be passed through the threaded rod before reinstalling and tightening the nut and washer.

Claims

1. A fixture, characterized in that, Comprising two pairs of clamping jaws for clamping the posts of corresponding fence panels, each pair of clamping jaws including a fixed outer jaw and a movable inner jaw; the fixture includes a frame providing the fixed jaws; each movable inner jaw is provided by a separate movable jaw member pivotally mounted to the frame to allow the movable inner jaw to rotate relative to its corresponding fixed outer jaw to open and close the clamping jaws; and the fixture includes means for keeping each pair of clamping jaws closed.

2. The fixture according to claim 1, wherein Including a retaining mechanism which can be selectively operated to prevent the two pairs of clamping jaws from opening from the closed position.

3. The fixture according to claim 2, wherein, Wherein, The retaining mechanism includes a restraint member which can move laterally relative to the frame between a retaining position and a release position. In the retaining position, when the jaws are closed, the restraint member engages against two movable jaw members; in the release position, when the jaws are closed, the restraint member disengages and is spaced apart from the movable jaw members.

4. The fixture according to claim 3, characterized in that Wherein, Each movable jaw member includes a protrusion arranged to project into one or more apertures of the frame, and when the jaws are closed, the restraint member engages against the protrusion.

5. The fixture according to claim 4, wherein Wherein, The retaining mechanism includes a threaded shaft, and the restraint member is threadedly mounted on the threaded shaft; the restraint member can move along the shaft between the retaining position and the open position towards and away from the one or more apertures, the retaining position being relatively close to the one or more apertures to control the degree to which the protrusion projects through the one or more apertures to hold the pair of clamping jaws in the closed position; the open position being relatively far from the one or more apertures to allow the pair of jaws to open to the open position.

6. The jig according to any one of the preceding claims, characterized in that, Further including a biasing means connected between the movable jaw members and adapted to bias the two movable jaw members towards their corresponding fixed jaw members to hold the two pairs of clamping jaws in the closed position.

7. The jig according to claim 6, wherein Wherein the biasing means includes a compression spring.

8. The jig according to any one of the preceding claims, characterized in that, Wherein the frame member consists of a single integral piece at least partially defining the fixed jaws.

9. The fixture according to any one of the preceding claims, used as a fence coupler.

10. A clamp used as a fence connector, characterized in that, The fixture includes two pairs of clamping jaws and a biasing means which biases the two pairs of jaws closed.

11. The fixture according to claim 10, wherein Wherein, Each pair of jaws in the two pairs of jaws has an opening facing the same direction so as to allow the two pairs of jaws to pass through the parallel posts when the fixture moves laterally towards the parallel posts of an adjacent fence panel.

12. A fixture used as a fence connector, characterized in that, The fixture includes two pairs of clamping jaws, each pair of jaws having an opening facing the same direction so as to allow the clamping jaws to pass through the parallel posts when the fixture moves laterally towards the parallel posts of an adjacent fence panel.

13. A fixture for clamping a column with a circular cross-section; characterized in that, The fixture has two pairs of clamping jaws, each pair of clamping jaws consisting of a fixed jaw and a movable jaw, the fixed jaws being provided by the frame and each movable jaw consisting of a movable jaw element pivotally mounted to the frame; each pair of clamping jaws provides at least one arcuate clamping surface for clamping the curved outer surface of the column; and the fixture includes a restraint mechanism that selectively holds the clamping jaws in a closed position, the restraint mechanism including a restraint member threadedly engaged to a threaded shaft mounted to the frame, the thread of the shaft having a lead length L; the restraint member is arranged to be rotatable about the threaded shaft between a holding position and an open position, in the holding position, the restraint member engages against a mating surface of the movable jaw element to hold the two pairs of clamping jaws closed; in the open position, the restraint member is spaced from the mating surface; and wherein the mating surface is arranged to move towards or away from the restraint member by no more than a distance equal to the lead length L during opening and closing of the two pairs of clamping jaws.

14. A fence, characterized in that, Comprising a plurality of movable fence panels arranged in a row, each fence panel including an upright member, the upright members of adjacent fence panels being held together by a fixture according to any one of claims 1-13.

15. A method for assembling a fence, characterized in that, Comprising arranging a plurality of movable fence panels in a row and coupling adjacent uprights of adjacent fence panels together using a fixture according to any one of claims 1-13.

16. A set of parts, characterized in that, Comprising at least two fence panels and at least one fixture according to any one of claims 1-13.

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