GB2235946A

GB2235946A - Tensioning device clamp

Info

Publication number: GB2235946A
Application number: GB8918453A
Authority: GB
Inventors: Michael Trevor Stanley
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-08-12
Filing date: 1989-08-12
Publication date: 1991-03-20
Also published as: GB8918453D0

Abstract

A tensioning device for tensioning material such as netting or wire strands comprises a pair of elongate members 1, 2 having formations 10, 11, 12 between which, in use, the material to be tensioned is clamped in a convoluted path, and a bolt 3, washer 4 and nut 5 by which the elongate members 1, 2 releasably are fastened together and may be moved between a clamping condition and a release condition, the elongate members 1, 2 when in the release condition permitting of at least limited slippage of the material therebetween and when in the clamping condition strongly resisting slippage of said material. <IMAGE>

Description

Title: Tensioning Device Description of Invention This invention relates to a tensioning device for use in tensioning material such as netting, lattice like structures or individual wire strands such as is suitable for providing fencing. It is particularly but not exclusively useful for tensioning material comprising either high tensile steel or mild steel.

According to a first aspect of the invention I provide a tensioning device for assisting tensioning of material such as netting, lattice-like structures or individual wire strands, the tensioning device comprising first and second co-extensive elongate members and a fastening means by which the members releasably may be fastened together, in which the elongate members each afford an abutment and the material, in use, is clamped between the elongate members such that it is convoluted in the region thereof where it abuts the abutments.

When the material is clamped a part of the material at or immediately adjacent said positions cannot readily be moved relative to the elongate members.

The fastening means may be adjusted to move the elongate members between the clamped condition and a released condition in which the material may be moved relatively freely relative to the elongate members.

The fastening means may comprise a securing member which extends through aligned transversely extending holes provided in the elongate members.

The first elongate member may afford an attachment member by which translating means to move the tensioning device releasably may be attached thereto.

When the elongate members are in the clamped condition and a substantial force is applied to the first elongate member by the translating means, the first elongate member may undergo limited movement transversely of its length relative to the second elongate member such that an abutment afforded by the first elongate member is brought closer to an abutment provided on a second elongate member and the material is thereby more securely clamped between the elongate members.

The abutments may extend longitudinally of the elongate member and the parts thereof which, in use, abut the material may be of circular or generally rounded transverse cross section so that the material, when clamped between the elongate members, is not broken.

The first elongate member preferably affords two abutments each of which extends parallel to the longitudinally extending edge of a side of the first elongate member which, in use, faces the second elongate member, the abutments defining with said side a longitudinally extending groove.

The second elongate member preferably affords one abutment which extends parallel to either longitudinally extending edge of a side of the second elongate member which, in use, faces the first elongate member, the abutment being so positioned as to be capable of at least partially extending into said longitudinally extending groove defined by the first elongate member.

When a force is applied by the translating means to move the tensioning device, the material may undergo limited slippage between the elongate members such that the tensioning device extends substantially perpendicular to a surface over which the tensioning device is moved.

One of the elongate members may provide a tongue which extends obliquely to the side thereof which faces the other elongate member at a position adjacent the transversely extending hole which is provided therein, the tongue serving to prevent the material from becoming entangled about the securing means.

Preferably one of the elongate members provides, at a bottom longitudinal end thereof, a skid plate, a portion of which protrudes beyond an anterior face of the respective elongate member and is inclined to said anterior face.

Preferably the elongate members each comprise channel section bars, the channels of which face away from each other.

Preferably the elongate members each provide, at a position adjacent the respective transversely extending apertures, an abutment plate which extends between parallel or substantially parallel limbs of a respective elongate member, the abutment plates each affording an aperture into which may be received a bolt and affording surfaces against which bearing parts of the securing member may bear.

The aperture and the transversely extending hole afforded by one of the elongate members may each be elongate to permit of relative movement of the elongate members about the securing member in a direction transverse to the length of the elongate members.

In use, the material may be clamped between the elongate members at at least two mutually spaced apart positions longitudinally of the elongate members.

According to a second aspect of the invention I provide a method of tensioning material such as netting or lattice-like structures, or individual wire strands comprising the steps of: securing a part of the material to a fixed point, clamping a further part of the material between elongate members of a tensioning device according to any one of Claims I to 17, attaching the tensioning device to a translating means which may be operated to move the tensioning device relative to the fixed point, and operating the translating means so as to move the tensioning device relative to the fixed point to tension the material.

The fixed point may be an upright post in a surface over which the tensioning device is moved.

The tensioning device according to the invention is particularly useful for tensioning "sheep netting". This kind of netting is often used to define animal enclosures because.it has the desirable property of great flexibility so that if an animal collides with the fence, generally speaking, the fence resiliently distorts and then returns to its original shape whilst not admitting the animal through the netting. This kind of netting however suffers from the disadvantage that it is relatively easily cut through by sharp surfaces.

For this reason conventional tensioning devices which are used for tensioning sheep netting and which grip the netting by means of surfaces which afford sharp edges can only be used with great care and there are severe restrictions upon the degree to which such netting can be tensioned, or at least the degree to which such tensioning is recommended by the manufacturers.

With the tensioning device according to the invention and the method of tensioning wire according to the invention it has been found to be possible to tension sheep netting far more than has previously been possible without significant risk of breaking the netting. By erecting sheep netting such that it is more highly tensioned the desirable flexible properties of a fence constructed from such netting are enhanced whilst at the same time the sheep netting is more economically used.

A specific embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings in which: FIGURE I is a side view of a tensioning device according to the invention.

FIGURE 2 is a view of an anterior face of the tensioning device shown in Figure 1.

FIGURE 3 is a plan view of the tensioning device shown in Figure 2.

FIGURE 4 is a section on the line A-A of Figure 2 showing a bolt extending between two elongate members of the tensioning device.

FIGURE 5 is a plan view of the underside of the tensioning device shown in Figure 2 showing a bolt extending between the elongate members and tensioned so as to bring these members close together.

Referring to the drawings a tensioning device I for use in tensioning material such as netting, or lattice-like material comprises elongate members 1, 2 between which, in use, the material to be tensioned is clamped.

The tensioning device includes a bolt 3, washer 4 and nut 5. The nut 5 and bolt 3 serve releasably to fasten together the elongate members 1, 2, and to permit of moving the elongate members 1, 2 between the clamping condition and a release condition. The clamped condition is shown in Figure 5 in which a part of the material to be tensioned is securely clamped between the elongate members 1, 2 and strongly resists movement relative thereto in a direction transverse to the length of the elongate members. The released condition is shown in Figure 3 in which the material is able to undergo at least limited slippage relative to the elongate members I, 2.

It will be understood that, if desired, the means for mutually fastening the elongate members I, 2 and the means for moving them between a clamped condition and a released condition, when mutually fastened by the fastening means, may be separate and distinct means but in the embodiment shown the bolt 3 and nut 5 serve both of these functions.

It will be understood that fastening means, other than bolts and nuts may be used if desired.

The elongate members 1, 2 each comprise elongate bars of a channel transverse cross sectional shape, the bars 31, 32 in use, being juxtaposed such that the channels face away from each other.

Each of the bars 31, 32 affords a respective transversely extending hole 6, 7 through which, in use, the bolt 3 is passed in the manner shown in Figure 4.

The hole 6 is circular and is a little bigger in diameter than the diameter of the shank of the bolt 3 such that only limited movement of the shank of the bolt 3 within the hole ó in a direction transverse to the shank is possible. The hole 7 in the bar 32 however is elongate such that the shank of the bolt 3 may be moved relative to the bar 32. This same kind of movement could be achieved by provision of an elongate hole ó in the bar 31 in addition to or alternatively to the elongate hole 7 in the bar 32.

Respective mutually facing sides 8, 9 of the bars 31, 32 each afford abutments against which, when the elongate members 1, 2 are in a clamped condition at least, the material to be tensioned abuts. The elongate member I provides on the side 8 two abutments 10, Il which extend, one adjacent each longitudinally extending edge of the side 8.

The side 9 of the bar 32 affords one abutment 12 which extends away from either longitudinally extending edge of the side 9.

Each of the abutments 10, I1, 12 extends longitudinally of the respective bars 31, 32 and is permanently fixed to the bars by means of welding, adhesive, or other appropriate means. Furthermore each of the abutments 10, II, 12 is of generally circular transverse cross sectional shape.

This is so as to facilitate limited slippage of the material 13, a portion of which is shown in Figure 3, between the elongate members I. It is also important in reducing the risk of breaking the material during tensioning, by eliminating sharp edges which might sever the material.

It will be understood that the abutments need not have a circular transverse cross section but could instead be of any shape which affords a blunt surface which is presented to the wire. When the material 13 is initially secured to the tensioning device limited slippage of the material between the abutments permits of substantially correct alignment of the material within the tensioning device prior to clamping the material more securely such that slippage is only barely possible.

When the bars 31 and 32 are juxtaposed in a coextensive manner the abutment 12 on one of the elongate members 2 extends at least partially into the groove defined by the abutments 10, 11 afforded by the other elongate member I. The degree to which the abutments 10, II, 12 thus interfit depends on how tightly the bolt and nut 3, 5 are tightened to bring together the bars 31, 32. The degree of interfitting also determines how tortuous is the path of the material 13 between the elongate members 1, 2 and thus how securely it is clamped against slippage.

The bar 31 affords a tongue 14 which extends obliquely to the side 8 and is welded or attached by means of adhesive to one of the parallel sides of the channel of the bar at a position along the bar 3 1 which is adjacent the transversely extending hole 6 provided therein. The tongue 14 serves to deflect the material 13 away from the bolt 13 so that it will not become entangled around it.

Whilst in the embodiment of the tensioning device shown in the drawings each bar provides only two transversely extending holes 6, 7 with a bolt and a nut for each of them it will be understood that more than two such holes could be provided with bolts extending therebetween or, if desired, a single such holes could be provided in each bar but it will be understood that, from the point of view of clamping the bars 31 and 32 in a manner so as to minimise slippage of the material 13 between the clamped bars, at least two such holes are preferred with bolts extending therebetween and tensioned by nuts 5.

The bar 31 provides an attachment means 15 in the form of an eye which may be interfitted with a hook provided on a translating means which may be operated to move the tensioning device relative to a fixed point at which part of the material to be tensioned is attached. In this way the material may be tensioned between the tensioning device and the fixed point.

It will be understood that such an attachment means may be provided on the bar 32 instead of or as well as on the bar 31.

The translating means to move the tensioning device may be for example a winch or a motor vehicle.

At a bottom end of each of the bars, 31, 32 respective skid plates ló, 17 are provided a portion of which protrudes beyond an anterior facing edge of the respective clamping member and is inclined relative to this anterior face 18. The skid plates 16, 17 facilitate movement of the tensioning device, behind a vehicle, over rough land where the bottom end of the tensioning device is likely to strike parts of the ground as e is moved. If desired a skid plate may be provided on only one of the bars 31 or 32.

Each of the bars 31, 32 provides, at a position adjacent the respective transversely extending holes 6, 7 an abutment plate 19, 20 which extends between and is substantially flush with the extremities of parallel limbs of the respective bar 31, 32. These abutment plates 19, 20 each afford an aperture 21, 22 respectively through which may be received the bolt 3. The abutment plates 19, 20 serve as bearing surfaces against which the head of the bolt 4 and the nut 5 or a suitable washer may bear so as to force the bars 31, 32 together into a clamping condition in which the material 13 is clamped securely between the bars so that it will barely slip.

The apertures 21 in the plates 19 are circular and permit of little movement of the bolt 3 in a direction transverse to its shank. Indeed if desired the bolt 3 may be welded or fixedly secured by adhesive to the plate 19 so as to secure the bolt 3 against any movement within the aperture 21.

The apertures 22 in the plates 20 are elongate in a direction transverse to the length of the bar 32 so that the bar 32 may be moved relative to the bar 31 in a direction parallel to the direction of movement of the tensioning device when in use.

In analogy to the possible variations on the arrangement of the holes 6, 7 mentioned above, variations in the arrangement of the apertures 21, 22 can easily be envisaged by which, given an appropriate arrangement of the holes 6, 7, the aforementioned relative movement of the bars 31 could be achieved.

It will be appreciated that bars of alternative cross sectional shape could be used instead of channel shaped bars.

The tensioning device shown in the drawings is used as follows.

A part of the material which is to be tensioned, such as a length of fencing, is attached to a fixed point, such as an upright post in the ground. A further part of the material, for example an end of the fencing is secured between the elongate members 1, 2 of the tensioning device in the following manner.

The further part of the material is placed against one of the bars 3 1 or 32, the other of the bars is juxtaposed relative to the first of the bars and the two bars 31, 32 are then mutually fastened by means of bolts 3 and nuts 5.

The bolts 3 may pass through openings in the fencing depending on the height of the fencing which is to be tensioned. For example fencing of relatively small height may be inserted between the upper and lower transversely extending holes 6, 7 whereas fencing of considerable height will have to accommodate the bolts 3 or perhaps one of the bolts 3.

The bolts 3 are then tensioned making sure that the material is appropriately aligned between the mutually facing sides 8, 9 of the bars 31, 32. The bolts 3 are tensioned further until the material 13 will slip between the bars 31, 32 only under considerable tension and the tensioning device is then attached to, say, a vehicle and the vehicle operated to move the tensioning device away from the fixed point so as to tension the material.

As a force is applied by the vehicle to the tensioning device the bar 31 is moved relative to the bar 32, the hole 7 and aperture 22 permitting of such relative movement of the bars 31 and 32 about the bolts 3, and this relative movement brings the abutment 12 closer to the abutment 10 such that the material 13 is more securely clamped still than it was merely due to the clamping achieved by tensioning the bolt 3 with the nut 5. It is found in practice that the material 13 will not slip between the abutments 10, 12 except to a degree so as to ensure that the tensioning device extends substantially perpendicular to a surface over which it is moved and remains substantially perpendicularly disposed thereto. In this way an end of the material which is clamped between the bars 31, 32 also extends substantially perpendicular to the surface mentioned.This is because if the material comprises say two strands of wire which extend parallel to one another and perpendicular to the elongate members and one of the strands is slightly shorter than the other, such is the working of the device that the shorter of the two strands will be more highly tensed and will slip slightly between the elongate members so that they are and remain perpendicular to the surface.

It will be understood that, if desired, the tensioning device could be permanently secured to a vehicle and the material to be tensioned could be clamped to the tensioning device with the tensioning device fixed to the vehicle in this way.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, or a class or group of substances or compositions, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

I. A tensioning device for assisting tensioning of material such as netting, lattice-like structures, or individual wire strands, the tensioning device comprising first and second co-extensive elongate members and a fastening means by which the members releasably may be fastened together, in which the elongate members each afford an abutment and the material, in use, is clamped between the elongate members such that it is convoluted in the region thereof where it abuts the abutments.
2. A tensioning device according to Claim I in which a part of the material at or immediately adjacent the position thereon at which it is clamped cannot readily be moved relative to the elongate members.
3. A tensioning device according to Claim I or Claim 2 in which the fastening means can be adjusted to move the elongate members between the clamped condition and a released condition in which the material may be moved relatively freely relative to the elongate members.
4. A device according to any one of the preceding claims in which the fastening means comprises a securing member which extends through aligned transversely extending holes provided in the elongate members.
5. A tensioning device according to any one of the preceding claims in which the first elongate member affords an attachment member by which translating means to move the tensioning device releasably may be attached thereto.
6. A tensioning device according to any one of the preceding claims in which, when the elongate members are in the clamped condition and a substantial force is applied to the first elongate member by the translating means, the first elongate member undergoes limited movement transversely of its length relative to the second elongate member such that an abutment afforded by the first elongate member is brought closer to an abutment provided on a second elongate member and the material is thereby more securely clamped between the elongate members.
7. A tensioning device according to any one of the preceding claims in which the abutments extend longitudinally of the elongate member and the parts thereof which, in use, abut the material are of circular or generally rounded transverse cross section so that the material, when clamped between the elongate members, is not broken.
8. A tensioning device according to any one of the preceding claims in which the first elongate member affords two abutments each of which extends parallel to the longitudinally extending edge of a side of the first elongate member which, in use, faces the second elongate member, the abutments defining with said side a longitudinally extending groove.
9. A tensioning device according to Claim 8 in which the second elongate member affords one abutment which extends parallel to either longitudinally extending edge of a side of the second elongate member which, in use, faces the first elongate member, the abutment being so positioned as to be capable of at least partially extending into said longitudinally extending groove defined by the first elongate member.
10. A tensioning device according to any one of Claims 6 to 9 in which, when a force is applied by the translating meons to move the tensioning device, the material may undergo limited slippage between the elongate members such that the tensioning device extends substantially perpendicular to a surface over which the tensioning device is moved.
II. A tensioning device according to any one of Claims 4 to 10 in which one of the elongate members provides a tongue which extends obliquely to the side thereof which faces the other elongate member at a position adjacent the transversely extending hole which is provided therein, the tongue serving to prevent the material from becoming entangled about the securing member.
12. A tensioning device according to any one of the preceding claims in which one of the elongate members provides, at a bottom longitudinal end thereof, a skid plate, a portion of which protrudes beyond an anterior face of the respective elongate member and is inclined to said anterior face.
13. A tensioning device according to any one of Claims 5 to 12 in which the elongate members each comprise channel section bars, the channels of which face away from each other.
14. A tensioning device according Claim 13 when appendant to Claim 4 in which the elongate members each provide, at a position adjacent the respective transversely extending apertures, an abutment plate which extends between parallel or substantially parallel limbs of a respective elongate member, the abutment plates each affording an aperture into which may be received the securing member and affording surfaces against which bearing parts of the securing member may bear.
15. A tensioning device according to Claim 14 in which the aperture and the transversely extending hole afforded by one of the elongate members are each elongate to permit of relative movement of the elongate members about the securing member means in a direction transverse to the length of the elongate members.
16. A tensioning device according to any one of the preceding claims in which, in use, the material is clamped between to the elongate members at at least two mutually spaced apart positions longitudinally of the elongate members.
17. A tensioning means substantially as described hereinbefore and with reference to the accompanying drawings.
18. A method of tensioning material such as netting, or lottice-like structures, or individual wire strands comprising the steps of: securing a part of the material to a fixed point, clamping a further part of the material between elongate members of a tensioning device according to any one of Claims I to 17, attaching the tensioning device to a translating means which may be operated to move the tensioning device relative to the fixed point, and operating the translating means so as to move the tensioning device relative to the fixed point to tension the material.
19. A method according to Claim 19 in which the fixed point is an upright post in a surface over which the tensioning device is moved.
20. A method substantially as described hereinbefore and with reference to the accompanying drawings.
21. Any novel feature or combination of features disclosed herein.