GB2370963A - Digging tools - Google Patents

Abstract

The invention relates to digging tools such as spades, forks and the like. Repeated use of such tools on hard ground can cause repetitive strain injury. The tool has a construction comprising as part of a shaft 2 and a handle 3 a sector therebetween to allow a limited linear movement of the handgrip towards the end of the shaft 2 to which the handle 3 is attached, and hence towards a head at the opposite end of the shaft 2, said sector being able to resist arcuate flexing as between the handgrip 4 and the shaft 2 and hence between the handgrip 4 and the head (1, figure 1) at the opposite end of the shaft 2. The linear movement is permitted due to the use of a compressible block 9 between handle 3 and shaft 2.

Description

DIGGING TOOLS This invention relates to digging tools such as shovels, spades, forks and the like.

Whilst digging tools can be used extensively in the DIY and gardening sectors, It IS recognised that professionals or trades persons using such tools as part of their normal work employ them for considerably longer periods. It is equally true that such users inevitably encounter a wide range of ground conditions and frequently are obliged to work with hard, or compacted, rocky ground that makes digging particularly difficult, and requires the digging tool to be driven into the ground with considerable force.

Such extensive repeated use of digging tools can be the cause of so-called"repetitive strain injury", resulting from the shock applied particularly to the hands and arms of the user.

The object of the present invention IS to provide digging tools particularly of the type referred to, that can help in reducing the possibility of repetitive strain injury arising.

According to the present invention, a digging tool comprises as part of a shaft and a handle, a sector therebetween to allow a limited linear movement of the handgrip towards the end of the shaft to which the handle is attached, and hence towards a head at the opposite end of the shaft, said sector being able to resist arcuate flexing as between the handgrip and the shaft and hence between the handgrip and the head at the opposite end of the shaft. Preferably, the said sector has a means of maintaining itself in an extended condition when the digging tool is not being used.

To assist in circumstances where the digging tool must be used in a horizontal condition in close proximity to the ground, it is desirable for the hand grip of the handle to be offset from the plane of the handle, to hold the hand/knuckles of the user clear of the ground. An offset handgrip also assists in picking-up the tool when lying on the ground. The offset handgrip may be achieved by providing an angled connecting section between the handgrip and that part of the handle connected to the shaft, or providing a connecting section of stepped configuration.

Thus, when use of a digging tool necessitates it being thrust at the ground with noticeable force, the said sector can be compressed and acts as a cushion at the point of first contact of the tool head with the ground, to reduce considerably, the shock on impact being transmitted through the handgrip and to the hand and arm of the user. Because the degree of permitted linear

movement is limited, and preferably relatively small, compression of the said sector does not detract in any major way from the force applied by the user driving the head Into the ground The said sector is desirably provided at the connection of a handle to a shaft, and resilient means may be located In a socket on the handle Into which is fitted the end of the shaft Alternatively, resilient blocks can be insert into the part of the handle connected to the shaft, to permit a controlled and limited compression as the tool head impacts on to the ground, but without any ability of the handgrip to pivot about the connection to the shaft The cushioning effect provided by the invention, albeit relatively small, has a significant effect on reducing impact forces being applied to the hand and arm of the user, with a resultant significant lessening of the possibility of repetitive strain injury arising by the use of the digging tool over prolonged periods Two embodiments of the invention will now be described by way of example only with reference to the accompany drawings in which' Figure 1 is a front elevation of a digging tool in accordance with the invention ; Figure 2 is a side elevation of the digging tool of Figure 1; Figure 3 shows to an enlarge scale a sectional elevation of one embodiment of handle and connection to the shaft, in accordance with the invention; Figure 4 shows to an enlarged scale an elevation of a second embodiment of handle and connection to the shaft in accordance with the invention; and Figure 5 is a side elevation of Figure 4.

In Figures 1 and 2, a digging tool in the form of a spade has a head 1, a shaft 2, a handle 3 and a handgrip 4. The handle 3 has a socket 5 into which the shaft fits.

As is shown more particularly by Figure 2 the handle 3 is set at an angle to the axis of shaft, and is inclined to the same side of the tool as the operative face 6 of the head 1, such that if the digging tool is to be used in a horizontal condition or laid on the ground, the hand grip 4 is held away from the ground, for the convenience of the operative who can grasp the hand grip 4 without catching the hand or knuckles of the hand on the ground.

To assist in the reduction of the possibility of repetitive strain injury arising from the

repeated driving of the digging tool In the ground, a cushioning means is provided on or In the socket 5. Thus, as IS illustrated In Figure 3, the socket 5 of the handle 3 IS secured by a rivet 7 to a sliding spigot 8, the spigot extending as a sliding fit through a hole In a compressible block 9, to a head 10 positioned below the block The head 10 lies in a shouldered recess 11 in the top 12 of a sleeve 13, over which the socket 5 fits, and the sleeve 13 is secured by a rivet 14 to the shaft 2 As the head 6 of the tool IS driven Into the ground, the Internal face of the socket compresses the block 9 against the top of the sleeve 13 causing the head 10 on the spigot 8 to ride down the recess 11, until it contacts the top of the shaft 2 This limited degree of permitted movement of the handgnp 3 towards the head 6 is to the considerable benefit to the user, and at the point where the head 10 meets the top of the shaft 2, a rigidity is achieved that allows a required force to be applied through the shaft 2 to the head 6 to enable ground penetration.

When force is removed from the handgrip, the compressible block relaxes to assume its original condition, and the head 10 of the spigot 8 brought to the top of the recess 11 in readiness for the next usage of the digging tool.

In Figures 3 and 4, an alternative handle 3 with a socket 5 is provided, but where again, it is inclined to the axis of the shaft 2 to hold the handgrip 4 clear of the ground, for the convenience of the user as is described above in relation to Figures 1 and 2.

Here, the shaft 2 is permanently secured within a hollow socket 5 to provide a rigid connection between the handle 3 and the shaft 2. To allow a movement of the handgrip 4 towards the head of the tool, resilient and compressible inserts 15 are provided in pairs, the inserts of each pair being positioned in diametrically opposed slots through the wall of the socket above the top 16 of the shaft. As the head of the tool is applied with force to the ground, the handgrip 4 is permitted to move towards the head to a limited degree, by compression of the inserts 15 thereby cushioning the hand and arm of the user. Once the limit of compressibility of the inserts is reached, the connection of the handle to the shaft goes solid, to allow the head to be driven into the ground with maximum force. When force is removed from the handgrip, the inserts relax to return the handgnp 4 to Its position of rest.

With the construction of both Figure 3 and Figures 4 and 5, the sliding engagement of the socket on the sleeve, and the strategic positioning of the compressible inserts, is such that a flexing of the handle out of its plane and in relation to the axis of the shaft is prevented

Claims (9)

1. CLAIMS 1 A digging tool comprising as part of a shaft and a handle, a sector therebetween to allow a limited linear movement of the handgrip towards the end of the shaft to which the handle IS attached, and hence towards a head at the opposite end of the shaft, said sector being able to resist arcuate flexing as between the handgrip and the shaft and hence between the handgrip and the head at the opposite end of the shaft.
2. 2. A digging tool as In Claim 1, wherein the said sector has a means of maintaining itself in an extended condition when the digging tool is not being used.
3. 3. A digging tool as in Claim 1 or Claim 2, wherein to assist in circumstances where the digging tool must be used in a horizontal condition In close proximity to the ground, the hand grip of the handle is offset from the plane of the handle, to hold the hand/knuckles of the user clear of the ground.
4. 4. A digging tool as in Claim 3, wherein the offset handgrip IS achieved by providing an angled connecting section between the handgrip and that part of the handle connected to the shaft, or providing a connecting section of stepped configuration.
5. 5. A digging tool as in any of Claims 1 to 4 wherein the handle has a socket in sliding engagement with a sleeve fitted to the end of the shaft, with a compressible block interposed between the end of the sleeve and the inner end of the socket.
6. 6. A digging tool as in Claim 5, wherein the socket is attached to a spigot extending through the compressible block and into the sleeve, the spigot having a head located in a shouldered recess in the top of the sleeve.
7. 7. A digging tool as in any of Claims 1 to 4, wherein the handle has a hollow socket attached directly to the end of the shaft, there being resilient inserts set in slots in the socket wall.
8. 8. A digging tool as in Claim 7, wherein the resilient inserts are in pairs, each pair being positioned diametrically opposite to each other.
9. 9. A digging tool substantially as hereinbefore described with reference to the accompanying drawings.