GB2385251A

GB2385251A - Digging tool

Info

Publication number: GB2385251A
Application number: GB0302575A
Authority: GB
Inventors: William Barry York
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-02-07
Filing date: 2003-02-05
Publication date: 2003-08-20
Anticipated expiration: 2023-02-05
Also published as: GB0302575D0; GB0202821D0; GB2385251B

Abstract

A digging tool 2 comprises digging means 6 pivotally attached to a shaft 4 by a ratchet. The ratchet comprising a ratchet rack 8 integral with or rigidly attached to one of the digging means 6 or the shaft 4, and an engagement member 14 mounted to an other of the shaft 4 or digging means 6 not carrying the ratchet. The engagement member 14 is biased to engage with said ratchet rack 8 such that the application of levering force to the shaft 4 in a first direction causes the digging means 6 to pivot with respect to the shaft 4. Applying a levering force in a second direction causes substantially rigid engagement of the digging means 6 and shaft 4. By this method relatively deep holes can be dug and cleared, such as post-holes.

Description

Digging Tool The present invention relates to digging tools and particularly, although not exclusively, relates to digging tools for digging post holes in the ground, and similarly for clearing choked road gullies.

A hand tool commonly used for digging deep narrow holes in the ground, particularly for digging post holes for a fence includes a device known as a"shovel-holer"or "pinch-spade"or"scissor-spade". Problems associated with using this tool include the fact that an equal and opposite horizontal force must be maintained on each of the handles to keep the earth spoil squeezed and retained in the jaws of the tool as it is lifted up out of the hole in the ground. This is tiring to the operator.

Secondly, if the earth consists of larger and smaller fragments, a larger fragment (or stone) will often be trapped between the jaws of the tool and the smaller fragments will drop back into the hole past the larger fragment instead of remaining in the jaws of the tool until released. Hence for one cycle of operation frequently only one larger fragment will be brought out of the hole. This results in many cycles of operation being almost wasted in terms of effort on the part of the operator.

It is an aim of the embodiments of this invention to address the above problems and provide a digging tool which is more efficient in use than the tool presently in common use.

According to a first aspect of the invention, there is provided a digging tool comprising digging means pivotally attached to a shaft by a ratchet, said ratchet comprising a ratchet rack integral with or rigidly attached to one of the digging means or the shaft, and an engagement member mounted to an other of the shaft or digging means not carrying the ratchet, wherein the engagement member is biased to engage with said ratchet rack such that the application of levering force to the shaft in a first direction causes the digging means to pivot with respect to the shaft, and wherein applying levering force in a second direction causes substantially rigid engagement of the digging means and shaft.

Preferably, the ratchet is located on the digging means and the engagement means, preferably a pawl, is located on the shaft to allow release of the engagement means and the return of the digging means back to the original relative position with the shaft when required.

The digging tool may be used to remove spoil from holes in a ground surface, for example, fence-post holes and for extracting dirt from choked road gullies.

The engagement means may be slidable along an axis substantially parallel to a longitudinal axis of the shaft.

Advantageously, having the engagement member slidably mounted on the shaft such that the plane of engagement/disengagement is parallel to the longitudinal plane of the shaft enables an operator to easily reach and actuate it.

Preferably, the ratchet rack comprises a plurality of teeth with spaces therebetween, each space providing an engagement member receiving position. Preferably, the ratchet rack is provided around at least a section of the circumference of a ratchet plate. Preferably, the ratchet plate extends away from the digging means towards the shaft. Preferably, the engagement member engages with the rack at a plurality of positions around the ratchet plate.

Preferably, the teeth are so arranged so that the engagement member can slide thereover in only one direction without the need to pull the engagement member to disengage the ratchet rack. Hence, preferably the ratchet is unidirectional.

Preferably, the ratchet rack is curved and preferably forms a sector of a circular ratchet rack.

Preferably, the engagement member is slidably retained within a housing which is attached to the shaft.

Preferably, the engagement member is biased by biasing means to engage with the ratchet rack. Preferably, the biasing means comprises a compression spring contained within the housing.

Preferably, the engagement means is substantially the same length as the shaft. Alternatively, or additionally, the engagement means may comprise disengagement means attached thereto, which may extend substantially the same length as the shaft. The disengagement means may include, for example, string, cord, wire or the like. Preferably, the disengagement means extends between a first end of the shaft where the engagement means engages the ratchet rack,

and preferably, a second end of the shaft which is held by a user.

Advantageously, the user can disengage the engagement means from the ratchet rack by pulling on the disengagement means without bending over, which is particularly advantageous for the elderly or infirm.

According to a second aspect of the invention, there is provided a method of digging holes in the ground, said method comprising placing the digging tool defined by the first aspect onto the ground and applying levering force to the said shaft such that earth is lifted out of the ground by the digging means.

All of the features described herein may be combined with any of the above aspects, in any combination.

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will be made, by way of example, to the accompanying drawings, in which :- Figure 1 shows a schematic front view of a digging tool; Figure 2 shows a schematic end view of the digging tool; Figure 3 shows a schematic partially cross-sectional side view of the digging tool in a first configuration; Figure 4 shows a schematic side view of the digging tool in a second configuration; and

Figure 5 shows a schematic side view of the digging tool in a third configuration; Referring to Figure 1, there is shown a digging tool 2 used for digging a hole in the ground, for example, a post hole. The shaft 4 is substantially round in cross-section and is held by an operator at an upper thereof. The tool 2 consists of an elongate shaft 4 with two rigid arms 22 extending from a lower end thereof. A digging attachment 6, for example, a spade, blade, scoop or fork etc is attached to the arms 22 by pivots 12, and the end of the digging attachment 6 which is not involved with digging has a ratchet plate 8 extending generally towards the shaft 4. The ratchet plate 8 has a series of ratchet teeth 10 extending from the outer circumference therefrom as shown in Figure 3 to 5.

Referring to Figure 2 there is shown an end view of the digging tool 2. The ratchet plate 8 can be clearly seen extending away from the digging attachment 6 which is pivotable about the pivot 12.

Referring to Figures 1 to 3 there is shown the digging tool 2 in use illustrating how the digging attachment 6 may be arranged into different configurations with respect to the shaft 4. A sleeve 20, which is rigidly fixed to the lower end of the shaft 4, has a pawl 14 which is slidably mounted therein together with a compression spring 16 which urges the sliding pawl 14 to engage with the teeth 10 of the ratchet plate 8. When the pawl 14 is engaged between two teeth 10, the digging attachment 6 is locked in position with respect to the shaft 4. The sliding pawl 14 may be pulled by a slidable handle 18 so that it

disengages from the teeth 10 thereby allowing the digging attachment 6 to move freely with respect to the shaft 4.

In use, the digging attachment 6 is placed on a ground surface 24 when in the configuration as shown in Figure 3, i. e. the digging attachment 6 and shaft 4 define an angle of about 1800 therebetween. The compression in the spring 16 urges the pawl 14 to engage the teeth 10 and the operator then pushes the digging attachment 6 into the ground 24. When the digging attachment 6 is sufficiently deep in the ground 24 to make a hole of adequate dimensions, the operator then levers the shaft 4 by pushing it so that end of the pawl 14 which engages with the ratchet plate 8 is able to ride over the teeth which point away therefrom. Hence, by pushing the shaft 4 away from the operator's body, the digging attachment 6 is effectively urged in a direction as shown by arrow X decreasing the angle between the shaft 4 and digging attachment 6 as shown in Figure 4.

Due to the direction in which the teeth 10 point away from the ratchet plate 8, the pawl 14 is unable to slide back over the teeth 10 in the opposite direction. The operator then pulls back on the shaft 6 which has the effect of causing the digging attachment to lift some earth 26 out with it. The operator then pushes the shaft 4 away from his body once again so that the pawl 14 can ride over the teeth 10 of the ratchet 8. Hence, by continued pushing and pulling of the shaft 4, the operator causes the angle between the digging attachment 6 and the shaft 4 to decrease as eventually shown in Figure 5.

The effect of this is that the digging attachment 6 digs into the ground 24 and, as the operator pulls the tool 2 out of the ground 24, the digging attachment 6 lifts the earth 26 out leaving a hole. The operator can then easily lift the tool and the digging attachment 6 carrying the earth 26 to another position as desired. Once the earth 26 has been dumped elsewhere, the operator can pull on the release handle 18 which causes the pawl 14 to disengage from the ratchet plate 8. The release handle 18 may extend the length of the shaft 4 thus alleviating the need for the operator to bend down to pull thereon. The release handle 18 can have a length of string or the like (not shown) attached thereto, which extends the length of the shaft 4 thereby facilitating the disengagement of the pawl without the operator having to bend and reach down to the release handle 18. The operator can then manually push the digging attachment 6 back to its original position as shown in Figure 3 should it not return under gravity, ready for digging again.

Advantages of the digging tool 2 reside in the very effective manner in which holes can be dug in the ground 24. The ratchet plate 8 allows the operators to easily adjust the angle between the digging attachment 6 and the shaft 4 without the need to bend over. Hence, earth 26 is effectively dug and pulled up out of the ground 24 without the need to bend over. The provision of the ratchet plate 8 on one of the digging attachment 6 or the shaft 4, and the pawl 14 on the other, provides a simple mechanism with advantages for inexpensive manufacture.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to

this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment (s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMS 1. A digging tool comprising digging means pivotally attached to a shaft by a ratchet, said ratchet comprising a ratchet rack integral with or rigidly attached to one of the digging means or the shaft, and an engagement member mounted to an other of the shaft or digging means not carrying the ratchet, wherein the engagement member is biased to engage with said ratchet rack such that the application of levering force to the shaft in a first direction causes the digging means to pivot with respect to the shaft, and wherein applying levering force in a second direction causes substantially rigid engagement of the digging means and shaft.
2. A digging tool as claimed in claim 1, wherein the ratchet is located on the digging means.
3. A digging tool as claimed in either claim 1 or claim 2, wherein the engagement means is located on the shaft to allow release of the engagement means and the return of the digging means back to the original relative position with the shaft when required.
4. A digging tool as claimed in any preceding claim, wherein the engagement means is slidable along an axis substantially parallel to a longitudinal axis of the shaft.
5. A digging tool as claimed in any preceding claim, wherein the ratchet rack comprises a plurality of teeth with spaces therebetween.

<Desc/Clms Page number 10>
6. A digging tool as claimed in claim 5, wherein each space provides an engagement member receiving position.
7. A digging tool as claimed in any preceding claim, wherein the ratchet rack is provided around at least a section of the circumference of a ratchet plate.
8. A digging tool as claimed in claim 7, wherein the ratchet plate extends away from the digging means towards the shaft.
9. A digging tool as claimed in either claim 7 or claim 8, wherein the engagement member engages with the rack at a plurality of positions around the ratchet plate.
10. A digging tool as claimed in any of claims 5 to 9, wherein the teeth are so arranged so that the engagement member can slide thereover in only one direction without the need to pull the engagement member to disengage the ratchet rack.
11. A digging tool as claimed in any preceding claim, wherein the ratchet is unidirectional.
12. A digging tool as claimed in any preceding claim, wherein the ratchet rack is curved.
13. A digging tool as claimed in any preceding claim, wherein the ratchet rack forms a sector of a circular ratchet rack.

<Desc/Clms Page number 11>
14. A digging tool as claimed in any preceding claim, wherein the engagement member is slidably retained within a housing which is attached to the shaft.
15. A digging tool as claimed in any preceding claim, wherein the engagement member is biased by biasing means to engage with the ratchet rack.
16. A digging tool as claimed in claim 15, wherein the biasing means comprises a compression spring contained within the housing.
17. A digging tool as claimed in any preceding claim, wherein the engagement member is substantially the same length as the shaft.
18. A digging tool as claimed in any of claims 1 to 16, wherein the engagement member has disengagement means attached thereto which extends substantially the same length as the shaft.
19. A digging tool as claimed in claim 18, wherein the disengagement means extends between a first end of the shaft where the engagement member engages the ratchet rack and a second end of the shaft which is held by a user.
20. A method of digging holes in the ground, said method comprising placing the digging tool according to any preceding claim onto the ground and applying levering force to the said shaft such that earth is lifted out of the ground by the digging means.

<Desc/Clms Page number 12>
21. A digging tool substantially as hereinbefore described with reference to, and as illustrated by, the drawings.
22. A method of digging substantially as hereinbefore described with reference to, and as illustrated by, the drawings.