GB2040221A

GB2040221A - A pruning saw for trimming standing trees

Info

Publication number: GB2040221A
Application number: GB8002378A
Authority: GB
Original assignee: Fiskars Oyj Abp
Current assignee: Fiskars Oyj Abp
Priority date: 1979-01-24
Filing date: 1980-01-24
Publication date: 1980-08-28
Also published as: BR8000424A; JPS55108219A; FR2447139A1; IN152120B; FR2447139B1; DE3002379A1; GB2040221B

Abstract

A handle has a first member (1) and a second, telescopic extension member (3). A saw blade (2) is affixed to the top of the member (1) and provided with saw teeth. A feed device (5) is connected by a pivot (6) to the top of the telescopic extension member (3) in the opposite side of the saw blade to where the saw teeth are provided. The feed means has a hook-shaped part (7) terminating at a location on the same side of the saw blade (2) as the saw teeth. In use, a branch (13) to be sawn is engaged by the hook-shaped part (7) at a location above the pivot (6) and the branch (13) is urged into contact with the saw teeth by the exertion of a downward force on the handle. The downward force determines the cutting force exerted on the branch (13). <IMAGE>

Description

SPECIFICATION Pruning saw The present invention relates to a pruning saw for trimming standing trees, the saw comprising a saw blade, a handle with a telescopic extension and a feed means.

Pruning saws with feed means known in the art are positively fed, that is, the feed is linked with the length of the sawing or pulling motion. Such saws have the drawback that the force requirements increase in proportion to the thickness and/or hardness of the branch, ultimately becoming insurmountable.

An object of the present invention is to provide a pruning saw of which the feed is automatically controlled in accordance with the object that is being sawed, so that under all circumstances the force requirements of the pulling sawing motion will be reasonable.

According to the invention there is provided a pruning saw for trimming standing trees, comprising a handle having a first member and a second, telescopic extension member; a saw blade affixed to the top of the said first member and provided with saw teeth; and a feed means pivotally connected to the top of the telescopic extension member in the opposite side of the saw blade to where the saw teeth are provided, the feed means further comprising a hook-shaped part terminating art a location on the same side of the saw blade as the saw teeth; whereby, in use, a branch is to be sawn is engaged by the hook-shaped part at a location above the said pivotal connection and the branch is urged into contact with the saw teeth by the exertion of a downward force on the handle, which downward force determines the cutting force exerted on the branch.

It has been found in experiments that have been carried out, that pruning performed with the saw according to the invention is less exerting physically, faster, and more accurate than with known pruning saws.

The sawing phase proper starts when the handle is pulled downwardly. If the branch is not cut off with the first stroke, the saw with handle is automatically pushed back up, if the telescopic extension is fitted with a return spring.

Owing to the design of the feed means, the force required for the pulling sawing motion is always reasonable and substantially independent of the thickness our a degree of hardness of the branch.

Using the saw according to the invention there is no risk of damage being inflicted on the trunk because the feed means keeps the blade accurately at the work object. The risk of a falling branch tearing the bark of the tree is likewise non-existent because the severing pull takes place rapidly.

In the accompanying drawings, which show one embodiment of the invention; Figure 1 shows the saw in the base position and Figures 2 and 3, in the operating position. The saw is shown in side elevation in Figures 1 and 2, and in front elevation in Figure 3.

The saw comprises a handle 1 which consists of a square cross-section tube carrying on its upper part a straight saw blade 2. The saw blade is affixed to the outer surface of the tube parallel thereto. The handle tube 1 has a telescopic extension 3 consists of another square cross-section tube fitted to slide in the handle tube 1. At its top end the extension 3 has a backwardly pointing lug 4, to which a feed means 5 is pivotally attached by a pivot pin 6. The feed means extends past the side of the saw blade 2 without being in frictional contact therewith and terminates at a location forward of the saw blade. The front portion of the feed means is in the form of a hook-shaped part 7. In the embodiment shown, the feed means is of sheet metal, which forms a supporting sleeve running around the back of the saw, the supporting sleeve being a slide fit on either side of the saw back.A stop 8 controls the backward pivoting motion of the feed means. The travel of the telescopic extension is limited by the back of the feed means hitting a transverse pin 9 on the saw blade. The telescopic extension is connected to the handle tube by means of an enclosed helical spring 10 attached at its upper end to the telescopic extension by a pin 11 and at its lower end to the handle tube buy a pin 12.

The saw operates as follows. The hook 7 of the feed means is lifted to rest upon a branch 13, and is so positioned that the side with the saw blade faces against the trunk. When the handle 1 is pulled downwardly (Figures 2 and 3) the handle lengthens, as a result of the telescopic extension, and the feed means 5 is forced backwards as a result of the location of its pivot 6. If the branch is not cut off before the back of the feed means hits against the transverse pin 4 on the saw blade, the helical spring 10 will return the handle with saw blade to its base position, and the saw is ready for the next stroke.

The use of an extension handle enables pruning to be readily carried out even at a great height.

1. A pruning saw for trimming standing trees, comprising a handle having a first member and a second telescopic extension member; a saw blade affixed to the top of the said first member and provided with saw teeth, and a feed means pivotally connected to the top of the telescopic extension member on the opposite side of the saw blade to where the saw teeth are provided, the feed means further comprising a hook-shaped part terminating at a location on the same side of the saw blade as the saw teeth; whereby, in use a branch to be sawn is engaged by the hook-shaped part at a location above the said pivotal connection and the branch is urged into contact with the saw teeth by the exertion of a downward force on the handle, which downward force determines the cutting force exerted on the branch.

2. A pruning saw according to claim 1, wherein the first and second handle means are connected together by means of a return spring.

3. A pruning saw according to claim 1 or 2, wherein the feed means at the same time constitutes

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Pruning saw The present invention relates to a pruning saw for trimming standing trees, the saw comprising a saw blade, a handle with a telescopic extension and a feed means. Pruning saws with feed means known in the art are positively fed, that is, the feed is linked with the length of the sawing or pulling motion. Such saws have the drawback that the force requirements increase in proportion to the thickness and/or hardness of the branch, ultimately becoming insurmountable. An object of the present invention is to provide a pruning saw of which the feed is automatically controlled in accordance with the object that is being sawed, so that under all circumstances the force requirements of the pulling sawing motion will be reasonable. According to the invention there is provided a pruning saw for trimming standing trees, comprising a handle having a first member and a second, telescopic extension member; a saw blade affixed to the top of the said first member and provided with saw teeth; and a feed means pivotally connected to the top of the telescopic extension member in the opposite side of the saw blade to where the saw teeth are provided, the feed means further comprising a hook-shaped part terminating art a location on the same side of the saw blade as the saw teeth; whereby, in use, a branch is to be sawn is engaged by the hook-shaped part at a location above the said pivotal connection and the branch is urged into contact with the saw teeth by the exertion of a downward force on the handle, which downward force determines the cutting force exerted on the branch. It has been found in experiments that have been carried out, that pruning performed with the saw according to the invention is less exerting physically, faster, and more accurate than with known pruning saws. The sawing phase proper starts when the handle is pulled downwardly. If the branch is not cut off with the first stroke, the saw with handle is automatically pushed back up, if the telescopic extension is fitted with a return spring. Owing to the design of the feed means, the force required for the pulling sawing motion is always reasonable and substantially independent of the thickness our a degree of hardness of the branch. Using the saw according to the invention there is no risk of damage being inflicted on the trunk because the feed means keeps the blade accurately at the work object. The risk of a falling branch tearing the bark of the tree is likewise non-existent because the severing pull takes place rapidly. In the accompanying drawings, which show one embodiment of the invention; Figure 1 shows the saw in the base position and Figures 2 and 3, in the operating position. The saw is shown in side elevation in Figures 1 and 2, and in front elevation in Figure 3. The saw comprises a handle 1 which consists of a square cross-section tube carrying on its upper part a straight saw blade 2. The saw blade is affixed to the outer surface of the tube parallel thereto. The handle tube 1 has a telescopic extension 3 consists of another square cross-section tube fitted to slide in the handle tube 1. At its top end the extension 3 has a backwardly pointing lug 4, to which a feed means 5 is pivotally attached by a pivot pin 6. The feed means extends past the side of the saw blade 2 without being in frictional contact therewith and terminates at a location forward of the saw blade. The front portion of the feed means is in the form of a hook-shaped part 7. In the embodiment shown, the feed means is of sheet metal, which forms a supporting sleeve running around the back of the saw, the supporting sleeve being a slide fit on either side of the saw back.A stop 8 controls the backward pivoting motion of the feed means. The travel of the telescopic extension is limited by the back of the feed means hitting a transverse pin 9 on the saw blade. The telescopic extension is connected to the handle tube by means of an enclosed helical spring 10 attached at its upper end to the telescopic extension by a pin 11 and at its lower end to the handle tube buy a pin 12. The saw operates as follows. The hook 7 of the feed means is lifted to rest upon a branch 13, and is so positioned that the side with the saw blade faces against the trunk. When the handle 1 is pulled downwardly (Figures 2 and 3) the handle lengthens, as a result of the telescopic extension, and the feed means 5 is forced backwards as a result of the location of its pivot 6. If the branch is not cut off before the back of the feed means hits against the transverse pin 4 on the saw blade, the helical spring 10 will return the handle with saw blade to its base position, and the saw is ready for the next stroke. The use of an extension handle enables pruning to be readily carried out even at a great height. CLAIMS

3. A pruning saw according to claim 1 or 2, wherein the feed means at the same time constitutes a sleeve which runs behind the back of the saw blade and supports the saw blade on both sides thereof with a slide fit.

4. A pruning saw substantially as herein described with reference to the accompanying drawings.