GB2495816A

GB2495816A - An arborists clamp having two jaws and a method of using the same

Info

Publication number: GB2495816A
Application number: GB1217489.2A
Authority: GB
Inventors: Adrian Baldry
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-10-18
Filing date: 2012-10-01
Publication date: 2013-04-24
Anticipated expiration: 2032-10-01
Also published as: GB201217489D0; GB2495816B; GB201117903D0

Abstract

The clamp comprises a pair of semi-circular jaws 2, 3 mounted in a handcuff-like configuration for movement about a pivot 4, the first jaw is secured to or integrally formed with a handle 5, the handle and a free end of the second jaw are formed with co-operating elements of a ratchet mechanism 8. A quick-release mechanism is operatively connected to the ratchet mechanism. In use, one of the jaws is struck against a branch, causing it to move through a fully closed position, disengaging the ratchet mechanism, to then encircle the branch and re-Âengage the ratchet mechanism, thereby to lock the clamp in place on the branch. The rotary motion of the second jaw about the pivot may be spring enhanced. The clamps are usable by arborists to lower lopped branches and the like. The invention also encompasses the method of attaching the clamp to a branch.

Description

IMPROVEMENTS IN OR RELATING TO ARBORISTS' CLAMPS

AND METHODS OF USING THEM

This invention relates to clamps usable by arborists to grip branches which are to be removed from trees and lowered safely to the ground.

The invention aims to provide, inter aha, a clamp which can be readily applied, in a single-handed operation, to a branch of a tree, and which will, either by itself or in conjunction with one or more similar clamps, securely hold and manoeuvre a branch whilst it is lowered to the ground utilising a rope, chain or the like attached to the clamp. The invention also aims to provide a method of using such a clamp to facilitate convenient and safe handling of lopped branches.

t 5 According to the invention from one aspect there is provided a clamp comprising first and second substantially semi-circular jaw members mounted in a handcuff-like configuration on a pivot for angular movement relative to one another, wherein said first jaw member is secured to, or integrally formed with, a handle member, and wherei.n the handle member and the free end of the second jaw member are formed with co-operative elements of a ratchet mechanism permitting said second jaw member to move relative to the first in a closure direction of the jaws, but restraining such movement in an opposite, opening direction; the arrangement being such that, in operation, with th.e clamp assembled with the elements of the ratchet mechanism engaged, striking the second jaw member against a branch of a tree with sufficient force causes the second jaw member to move ftiliy through the closed position of said jaws, disengaging the elements of said ratchet mechanism, to rotate about said pivot away from the branch, and re approach the branch whereupon the ratchet mechanism re-engages to automatically secure the clamp in place on the branch, the ratchet mechanism comprising the sole securing means for the clamp; wherein the clamp is adapted for connection to a rope-like or chain-like means capable of supporting the branch when severed and usable to lower the severed branch to the ground, and the clamp further comprises quick-release means operatively connected 1:0 the ratchet mechanism and adapted to free the restraint imposed by the ratchet mechanism whereby the clamp is opened, to permit its ready separation from the branch.

Preferably, the handle and the first jaw member each comprise a pair of substantially identical components juxtaposed and secured together in spaced relationship to define a central cavity into and through which the second jaw member can pass.

Further preferably, the free end of said second jaw member is formed with a linear rack portion of said ratchet mechanism arid a pawi member of said mechanism is mounted in the cavity of said handle.

In preferred embodiments of the invention, the handle and the first jaw member are formed integrally with one another.

Preferably, at least one of the jaw members has at least a portion of its inwardlyf'acing surface configured and/or treated in order to enhance its ability to grip a branch.

In preferred examples of the invention, part at least of the inwardly-facing surface of each of the jaw members is formed with serrations for this purpose. Alternatively, the inwardly-facing surfaces of one or both of the jaw members can be roughened, knurled or lined with a renewable S gripping medium, such as leather.

Preferably a quick-release facility is provided to enable a worker on the ground to free the clamp from the restraint imposed by the ratchet mechanism and thereby open the clamp to permit its ready separation from the lopped branch for re-use.

In some preferred embodiments of the invention, the handle can be formed separately from the first jaw member, and secured firmly thereto by any convenient means.

in still ftirther embodiments, the rotary motion of the second jaw member around the pivot can be spring enhanced.

In some preferred embodiments of the invention, part at least of the first jaw member and the handle member comprise juxtaposed components rigidly secured together and separated by spacers to define a through-chamber housing a part of the ratchet mechanism and defining an opening through which the free end of said second jaw member can move to enter said housing. In such circumstances, it is ifirther preferred that one or both edges of the opening are chamfered and/or bent outwardly at the region where the free end of the second jaw member enters the said through chamber thereby to more reliably accommodate entry of the said free end.

According to the invention from a second aspect, there is provided a method of attaching a rope-like or chain-like means to a branch in order to permit the branch to be removed safely from a tree after lopping; the method comprising the steps 0 providing a clamp device in the form of a pair of substantially semi-circular jaw members mounted on a common pivot for angular movement relative to one another, with one of said jaw members secured to, or integrally formed with, a handle member and with the handle member and the free end of the second jaw member formed with co-operative elements of a unidirectional ratchet mechanism restraining opening movement of the jaw members, once latched; attaching the clamp device to said rope-like or chain-like means; closing the clamp to engage the ratchet mechanism; striking one of the jaw members against the branch with sufficient force to cause the other jaw member to move fully through the closed position of said jaws, disengaging the ratchet mechanism, and to cause said other jaw member to rotate about said pivot away from the branch, to re-approach the branch and the struck jaw member from the opposite side, and to allow the ratchet mechanism to automatically re-engage, thereby securing the clamp in place on the branch; disposing said rope-like or chain-like means so as to provide support for the branch after lopping; lopping the branch; utihsing the rope-like or chain-like means and the tackle means to manipulate the lopped branch; and providing the clamp with a rapid release mechanism for freeing the restraint imposed by the ratchet mechanism and allowing the clamp to be opened., to permit its ready separation from the lopped branch.

S

Preferably, the method further includes the steps of: positioning tackle means in the tree to co-operate with. said rope-like or chain-like means, thereby facilitating manipulation of the branch.; and attaching the rope-like or chain-like means to the tackle means.

In order that the invention may be clearly understood and readily carried into effect, one embodiment thereof will now be described, by way of example only, with reference to the accompanying drawings, of which: Figures 1 to 3 show various views of a clamp in accordance with one embodiment of the invention; Figures 4(a), 4(b), 4(c) and 4(d) show various stages in a method of applying the clamp to a branch of a tree; and Figure 5 shows a clamp in accordance with another embodiment of the invention.

Referring now to the drawings, in all of which the same reference numbers are used for similar components, Figures 1, 2 and 3 show a clamp I, according to a first example of the invention, which comprises first and second substantially semi-circular jaw members 2 and 3 mounted in a handcuff-like conFiguration on a pivot 4. The jaw members 2 arid 3 are mounted for angular movement relative to one another about the pivot 4, and the jaw member 2 is secured to, or integrally formed with, a handle member 5.

In this example, the jaw member 2 and the handle member 5 are integrally formed, and comprised of a pair of substantially identical juxtaposed components, rigidly secured together by means such as bolts and separated by spacers to define a through-chamber 6, though it will be appreciated that such a construction is not essential. For example, the handle may alternatively comprise a cylindrical piece, formed of wood, metal or plastics and bearing a part configured to form the required housing 6 when overlain by and secured to a corresponding part of the jaw member 2.

in any event, the through chamber 6 is defined in the plane of the jaw member 3, and the jaw member 3 can move into and through the chamber 6, as will be described hereinafter.

The handle member 5 and the free end 7 of the jaw member 3 are formed with co-operative elements of a ratchet mechanism which operates whilst the free end of the jaw member 3 is in the chamber 6 and permits the jaw member 3 to move, relative to the jaw member 2, in the closure direction of the jaws, but restraining such movement in the normal opening direction. In this example, the free end of the jaw member 3 carries a linear rack member 8 which cooperates with a pawl (not shown) housed within the through-chamber 6 of the handle 5 to form the ratchet mechanism.

A feature of this construction, as will become evident from the operational procedure to be described with reference to Figure 4, is that the ratchet operates only over a limited range of the movement that can be executed by the jaw member 3 in the closure direction of the clamp 1, so that the motion of the jaw member 3 relative to the member 2 is free once that range of movement has been exceeded and the elements of the ratchet mechanism have separated. Such separation occurs automatically in this example of the invention, when the jaws have been closed together to a predetermined extent, determined by the length and position of the linear rack 8.

A rope 9 is aftached by any convenient means, in this example a karabiner 10, to the handle 5 and usually, in deployment, the rope is guided over tackle such as a pulley previously located higher up the tree than the branch to be lopped and is manipulated by a worker on the ground to safely lower the branch once it has been lopped. It will be understood that chains, cables or tile like could be used instead of or in addition to the rope 9 if desired or if necessary.

Figures 4(a), 4(h), 4(c) and 4(d) show various sequential stages in the attachment of the clamp 1 to a branch of a tree.

In order to attach the clamp to the branch, an arborist scales the tree and, with the clamp I in a normally closed position arid with the free end 7 of the latch 3 located in the through-chamber 6 of the handle 5 to engage the ratchet mechanism, as shown in Figure 4(a), strikes the centre of the outwardly-facing surface 3o of the second jaw member 3 against a branch of the tree with sufficient force to cause the jaw member 3 to move through the filly closed position. disengaging the ratchet mechanism, to leave the handle 5 and to rotate about the pivot 4 and away from the branch, as shown in Figures 4(b) and 4(c). The jaw member 3 then re-approaches the branch from the opposite side, to encircle it within the clamp 1. Having encircled the branch, the jaw member 3 continues its motion until its inwardly-facing surface 3i contacts the surface of the branch, an opposite surface of which is already in contact with the S inwardly-facing surface 21 of the jaw member 2. By this time, the free end 7 of the jaw member 3 has entered the through-chamber 6 in the handle 5, automatically re-engaging the ratchet mechanism, thereby to lock the clamp I in place on the branch as shown in Figure 4(d).

Depending upon the size and weight of the branch, more than one clamp may be needed to assure its safe and convenient handling. In any event, the branch, once lopped can be readily manipulated by ground workers using the rope 9 (and possibly other ropes too, if more than one clamp is required) with the branch held securely and safely by the clamp or clamps.

Once on the ground, the clamp I can be readily released from the branch by actuating a quick-release lever 11 of known kind which disengages the ratchet mechanism and permits the clamp to be opened in the normal way by separation of the jaw members 2 and 3 about the pivot 4.

In this example of the invention, the inwardly-facing surfaces 2i, 3i of the jaw members 2 and 3 are serrated in order to enhance their ability to grip branches. In other examples of the invention, however, different treatments may be applied to part at least of one or both of the surfaces 21, 31. In such other examples, the inwardly-facing surfaces of the jaw members can be roughened, knurled or lined with a renewable gripping medium, such as leather.

Mindftd of its intended usage, it is preferred that the clamp I is made of high tensile steel and clamps can be made in any size required. Usually an arborist will carry a range of differently sized clamps. The construction of the clamp, and the weight of its component parts, is normally sufficient to ensure that the intended motion of the jaw member 3 needed for attachment of the clamp to a branch is readily achieved under the impetus crated by striking the jaw member 3 against the branch.

If necessary, however, clamps with spring-assisted movement can be used.

Rather than fonning it integrally with the jaw member 2, the handle 5 can, if desired, be formed separately from the jaw member, and secured firmly thereto by any convenient means.

A major benefit of the invention is that an arborist can apply the clamp to a branch using only one hand. Clearly, the handle 5 is held in the hand when striking the jaw member 3 against the branch and ihereafter the clamp I is secured to the branch. The capability of single-handed usage is beneficial from a safety point of view as veli as from the standpoint of convenience The invention further provides a time and labour-saving device which avoids wastage of time on tying and untying ropes. n -

in order to ensure that the free end 7 of the jaw member 3 freely enters the chamber 6 even after the clamp I has. suffered some wear or damage through use, one or both of the edges of the handle member 5 may, if desired, be chamfered and/or bent outwardly at the opening, marked in Figure 3 as 12a, and 12b, where th.e free end 7 of the jaw member 3 enters the chamber 6, in order to more reliably arid more readily accommodate the said free end 7 and if necessary to guide it into the chamber 6. This S expedient reduces the degree of criticality in. the alignment of the jaw member 3 with the chamber 6 and allows for misalignment that could occur through usage-induced wear and/or production tolerances.

In view of the forces applied thereto in operation of the clamp 1., reinforcing or self-lubricating materials may be utilised at the pivot 4.

In some examples of the invention, as shown in Figure 5, the hanñle member 5 is provided with a hinge member 13 which eases stress on the clamp when it is under load.

Claims

<claim-text>Ciaims 1. A clamp comprising first and second substantially semi-circular jaw members mounted in a handcuff-like configuration on a pivot for angular movement relative to one another, wherein said first jaw member is secured to, or integrally formed with, a handle member, and wherein.the handle member and the free end of the second jaw member are fbrmed with co-operative elements of a ratchet mechanism permitting said second jaw member to move relative to the first in a closure direction to of the jaws, hut restraining such movement in an opposite, opening direction; the arrangement being such that, in operation, with the clamp assembled with the elements of the ratchet mechanism engaged, striking the second jaw member against a branch of a tree with sufficient force causes the second jaw member to move fully through the closed position of said jaws, disengaging the elements of said ratchet mechanism, to rotate about said pivot away from the branch, and re-approach the branch whereupon the ratchet mechanism re-engages to automatically secure the clamp in place on the branch, the ratchet mechanism comprising the sole securing means for the clamp; wherein the clamp is adapted for connection to a rope-like or chainjike means capable of supporting the branch when severed and usable to lower the severed branch to the ground. and the clamp further comprises quickrelease means operatively connected to the ratchet mechanism and adapted to free the restraint imposed by the ratchet mechanism whereby th.e clamp is opened, to permit its ready separation from the branch.</claim-text> <claim-text>2. A clamp according to c].airn I, wherein the handle and the first jaw member each comprise a pair of substantially identical components juxtaposed and secured together in spaced relationship to define a central cavity into and through which the second jaw member can pass.</claim-text> <claim-text>3. A clamp according to claim 2, wherein the free end of said second jaw member is formed with a linear rack portion of said ratchet mechanism and a pawl member of said mechanism is mounted in the cavity of said handle.</claim-text> <claim-text>4. A cap according to any preceding claim, wherein the handle and the first jaw member are formed integrally with one another.</claim-text> <claim-text>5. A clamp according to any preceding claim, wherein at least one of the jaw members has a portion of its inwardly-facing surface configured and1or treated in order to enhance its ability to grip a branch.</claim-text> <claim-text>6. A clamp according to claim 5. wherein part at least of the inwardly-facing surfaces of both of the jaw members are serrated.</claim-text> <claim-text>7. A clamp according to any preceding claim, wherein the rotary motion of the second jaw member around the pivot is spring-enhanced.</claim-text> <claim-text>8. A clamp according to any preceding claim, wherein part at least of the first jaw member and the handle member comprise juxtaposed components rigidly secured together and separated by spacers to define a through-chamber housing a part of the ratchet mechanism and defining an opening through which the free end of said second jaw member can move to enter said housing.</claim-text> <claim-text>9. A clamp according to claim 8, wherein one or both edges of the opening are chamfered and/or bent outwardly at the region where the free end of the second jaw member enters the said through chamber thereby to more reliably accommodate entry of the said free end.II. An arborist's clamp substantially as herein described with reference to the accompanying drawings.12. A method of attaching a rope-like or chain-like means to a branch in order to permit the branch to be removed safely from a tree afler lopping; the method comprising the steps of: providing a clamp device in the form of a pair of substantially semi-circular jaw members mounted on a common pivot for angular movement relative to one another, with one of said jaw members secured to, or integrally formed with, a handle member and with the handle member and the free end of the second jaw member formed with co-operative elements of a unidirectional ratchet mechanism restraining opening movement of the jaw members, o.nce latched; attaching the clamp device to said rope-like or chain-like means; closing the clamp to engage the ratchet mechanism; striking one of the jaw members against the branch with sufficient force to cause the other jaw member to move filly through the closed position of said jaws, disengaging the ratchet mechanism, and to cause said other jaw member to rotate about said pivot away from the branch, to re-approach the branch and the struck jaw member from the opposite side, and to allow the ratchet mechanism to automatically re-engage, thereby securing the clamp in place on the branch; disposing said rope-like or chain-like means so as to provide support for the branch after lopping; lopping the branch; u.tilising the rope-like or chain-like nreans and the tackle means to manipulate the lopped branch; and providing the clamp with a rapid release mechanism for freeing the restraint imposed by the ratchet mechanism and allowing the clamp to be opened, to pennit its ready separation from the lopped branch.13. A method according to claim 9 thrther including the steps of positioning tackle means in the tree to co-operate with said rope-like or chain-like means, thereby facilitating manipulation of the branch; and attaching the rope-like or chain-like means to the tackle means.</claim-text>