GB2320879A - Hole forming apparatus - Google Patents

Abstract

A hand tool for forming circular holes in the ground comprises a cylindrical cutting head 16 divided into four cutting blades 12 each having a cutting edge 18 and a trailing edge defining a deflecting means 14 in the form of inwardly extending portions which serve to deflect material inwardly away from the cut formed by the blade as the blade is manually rotated in an anti-clockwise direction such that material inside the blades is compressed to facilitate retention thereof and subsequent removal. An elongate plunger 28 has a plate 30 attached to an end thereof which is used to remove material from within the cutting head.

Description

Hole Forming Apparatus The present invention concerns hole forming apparatus, and particularly but not exclusively to apparatus for forming holes in the ground.

There are many situations when it is desirable to form a neat and accurate hole in the ground for example when forming footings for the erection of posts, fences and the like.

Conventionally, such holes are dug using a spade or similar digging implement. However forming a clean, clearly defined and symmetrical hole using such implements is difficult, and removal of earth to form the hole is often very difficult.

It is therefore an object of the present invention to provide improved hole forming apparatus, particularly for forming holes in the ground.

According to the present invention there is provided hole forming apparatus comprising at least one cutting blade locatable in use against material to be cut and operable upon rotation thereof to cut into the material to form a substantially circular cut therein, and deflecting means operable to deflect material away from the cut formed by the blade(s) whereby to facilitate removal of material within the cut to form a hole.

Preferably the deflecting means is arranged to deflect material inwardly of the cut, whereby to desirably cause some compression of material within the cut to help hold the material together to facilitate removal thereof. The deflecting means may comprise a formation movable with the blade(s) in a rotational manner. The deflecting means may comprise a flange or similar formation which may be provided on the or at least one of the blade(s), desirably to be located rearwardly of the cutting edge(s) of the respective blade to deflect material following the cutting thereof by the blade. Preferably the deflecting flange extends from the blade in an inward direction of the cut, and may be curved to gradually extend inward.

The or each blade preferably comprises a leading cutting edge which cuts the material and preferably a lower cutting edge extending away from the leading cutting edge toward the deflecting flange. Each blade preferably comprises a curved portion the profile of which substantially determines the curvature of a hole cut by the apparatus. The cutting edge(s) are preferable provided on the said curved portion.

Preferably a plurality of blades and desirably four, are provided on a cutting head of the apparatus, the blades desirably being disposed equispaced around the cutting head to generally define a circular cutting region of the head of a diameter which determines the diameter of cuts to be made thereby, and into the interior of which material is deflected during cutting to be generally retained for removal from the hole. Preferably the cutting head comprises a further in use, upper portion which may be cylindrical and in which material cut by the blades may be diverted to be retrieved.

Preferably the blade(s) are mounted on a shaft, which shaft is rotatable to effect rotation of the blade(s). The shaft is preferably rigidly connected to the head, and may comprise handle means to facilitate manual rotation thereof.

Preferably material removal means is provided on the apparatus to remove material retained within the cutting head following formation of a hole.

The removal means may comprise means to urge the material within the cutting head down past the cutting blade(s). The removal means may comprise a plunger arrangement which may extend down, desirably within, the shaft to be selectively movable to urge material from the cutting head. The plunger arrangement may be resiliently biased away from the head to a stored, relaxed condition wherein the arrangement presents no hindrance to the cutting of holes by the blade(s).

A plate or similar formation may be provided on the end of the plunger arrangement which plate contacts the material to be removed, to mitigate penetration of the plunger arrangement into the material.

According to a further aspect of the present invention there is provided a method of forming a hole in material using the apparatus as defined in any of preceding seven paragraphs, the method comprising locating the cutting blade(s) against material to be cut, rotating the blade(s) and urging the blade(s) into the material whereby to form a generally circular cut, the deflecting means being operable to deflect material from the cut whereby to facilitate removal thereof to form a hole in the material.

Preferably the material is deflected inwardly from the cut whereby material within the cut may be compressed to facilitate removal thereof, desirably in a substantially single compressed mass.

The compressed material is preferably releasably retained within a cutting head on which the blade(s) is/are provided to facilitate removal of the material within the cut from the rest of the material to form a hole in the said rest of the material, the retained material being selectively removable from the head using material removing means are described above.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which Fig. 1 shows hole forming apparatus according to the present invention; and Fig. 2 is an end view of the apparatus of Fig. 1 in the direction of arrow II.

Referring to the drawings there is provided hole forming apparatus 10 comprising at least one cutting blade 12 locatable in use against material to be cut, such as the ground, and operable upon rotation thereof to form a substantially circular cut in the material, and deflecting means 14 operable to deflect material away from the cut formed by the blade(s) 12 whereby to facilitate removal of material within the cut to form a hole in the ground.

In more detail, four cutting blades 12 are provided on a generally cylindrical cutting head 16, and equidistantly disposed generally about the circumference of the in-use lower side of the head 16. Each blade 12 comprises a curved portion 20 of the same curvature as the cutting head 16, and on one end of which is provided a cutting edge 18. The deflecting means 14 is in the form of a flange which extends from the other end of the portion 20 to curve in an inward direction of the cutting head 16 to deflect material cut by the blade 12 as will be described.

A shaft 22 is fixedly attached at one end to the cutting head 16 via a generally U-shaped attachment bracket 24, which may be welded or bolted to the cutting head 16. A handle 26 is provided at the other end of the shaft 22 to facilitate manual rotation of the shaft and thereby rotation of the cutting head 16 and blades 12 to effect cutting as will be described. An elongate plunger 28 extends down the centre of the hollow shaft 22 and has a plate 30 attached at its in-use lower end. A spring 32 is located about the plunger 28 to bear on the upper end of the shaft 22 to resiliently bias the plunger 28 upward in the shaft 22 to the storage position as shown in Fig. 1. A retaining formation 34 is provided on the upper end of the plunger 28 on which the spring 32 bears to urge the shafts to said position.

In use, the apparatus 10 is principally intended to form holes in the ground for example footings for posts and the like, and could also be used to form holes in which to plant trees, shrubs and other such plants.

In use, the apparatus 10 is placed in an upright condition over the site of the desired hole. The blades 12 rest on the ground, and an operator manually turns the handle 26 in an anti-clockwise direction relative to the drawings, such that the cutting edge 18 and a lower cutting edge 26 of each blade 12 cut into the ground and start to form a circular cut of the same diameter as the diameter defined by the curved potions 20 of the blades 12. As the blades 12 are rotated and urged into the ground, ground material adjacent the insides of the blade 12 contacts the deflecting flanges 14 which deflect the material inwardly from the cut formed by the blades 12. The deflecting action compresses the material inside the blades 12 to facilitate retention thereof and subsequent removal as will be explained. As the cut gets deeper, compressed material is retained in the cutting head 16.

Once the cut has been made to the desired depth, the apparatus 10 is lifted. The material within the blades 12 is compressed between the deflecting flanges 14 and therefore is held in the apparatus, the material thereabove is retained in the cutting head thereby, such that all material is removed from within the cut formed to provide a cleanly formed and symmetrical hole in the ground.

The apparatus 10 can then be carried along with the material held therein to a location at which the material is to be removed, and removal is effected by urging the plunger 28 down the shaft such that the plate 30 bears on the material within the cutting head 16, urges it passed the deflecting flanges and blades 12. Upon release of the plunger 28 it is biased back to its storage position by the spring 32.

Various modifications may be made without departing from the spirit or scope of the present invention. For example, any number of blades 12 may be provided. The deflecting means 14 may be so shaped as to deflect material inward and upward into the cutting head 16.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims (1)

1. Hole forming apparatus Application No. G.B. 9623585.8 The Claim,s The object of present invention to provide improved hole forming apparatus, particularly for forming holes in the ground according to the present invention there is provided hole forming apparatus comprising at least four cutting blade,s locatable in use against material to be cut and operable upon notation thereof to cut into the material to form a substantially circular cut therein, and deflecting mean,s operable to deflect material away from the cut formed by the blande,s whereby to facilitate removal of material within the cut to form a hole preferably the deflecting mean,s is arranged to deflect material inwardly of the cut, whereby to desirably cause some compression of material within the cut to hold the material together to facilitate removal thereof, the deflecting mean,s may comprise a formation movable with the blade,s in a rotational manner, the deflecting mean,s may comprise a flange or similar formation which may be provided on the blade,s desirably to be located rearwardly of the cutting edge,s of the respective blade to deflect material following the cutting thereof by the blade,preferably the deflecting flange extend,s from the blade in an inward direction of the cut, may be curved to gradually extend inward the or each blade preferably comprises a leading cutting edge which cut,s the material and preferably a lower cutting edge extending away from the leading cutting edge toward the deflecting flange, each blade preferably comprises a curved portion the profile of which substantially determines the curvature of a hole cut by the apparatus, the cutting edge,s are preferable provided on the said curved portion, preferably a plurality of blade,s and desirably four are provided on a cutting head of the apparatus, the blade,s desirably being disposed equispaced around the cutting head to generablly define a circular cutting region of the head of a diameter which determines the diameter of cut,s to be made thereby, and into the interior of which material is deflected during cutting to be generally retained for removal from the hole, preferably the cutting head comprises a further in use, upper portion which may be cylindrical and in which material cut by the blade,s may be divertedto be retrived preferably the blade,s are mounted on a shaft, which shuft is rotatable to effect rotation of the blade,s the shaft is preferably rigidly connected to the head, and may comprise handel mean,s to facilitate manual rotation thereof preferably material removal mean,s is provided on the apparatus to remove material retained within the cutting head following formation of a holethe removal mean,s may comprise mean, A to urge The material within the cutting head down past the cutting blad,s the removal mean,s may comprise a plunger arrangment which may extend down, desirably within, the shaft to be selectively movable to urge material from the cutting head, the plunger arrangment may be resiliently biased away from the head to a stored, reflaxed condition wherein the arrangment presents no hinderance to the cutting of hole by the blade,s a plate or similar formation may be provided on the end of the plunger arrangment which plate contact,s the material to be removed, to mitigate penetration of the plunger arrangement into the material according to a further aspect of the present invention there is provided a method of forming a hole in the material useing the apparatus as defined in any of preceding paragraphs, the method compriseing locating the cutting blade,s against material to be cut, rotation the blade,s and urging the blade,s into the material whereby to form a generally circular cut, the deflection mean,s being operable to deflect material from the cut whereby to facilitate removal thereof to form a hole in the material preferably the material is deflected inwandly from the cut whereby material within the cut may be compressed to facilitate removal thereof desirably in a substantially single compressed mass the compressed material is preferably releasably retained within a cutting head on which The blad, A is, one provided to facilitate removal of the material within the cut from the rest of the material to form a hole in the said rest of the material, the retained material being selectively removable from the head useing material removing mean,s are described above 2 A hole forming apparatus as claimed in any preceding claim which is made from all steel 3 A hole forming apparatus as herein described and illustrated in The accompanying drawing,s