GB2031484A - Device for cutting a cylindrical hole in the ground - Google Patents

Abstract

A hole cutter, 1 e.g. for forming a hole in a golf green, is provided in the form of a cylinder 5 with a cutting lower edge 5 and a coaxial upwardly extending tubular shaft provided with transversely extending handles 2, there being a graspable weight 3 loosely surrounding this shaft between the cutter 1 and the handles 2 so that the cutter can be hammered into the ground and an ejector plate 19 located across the internal space of the cylindrical cutter and connected to an ejector rod 4 located within the tubular shaft so as to progressively protrude as the cutter is hammered into the ground. The plug of earth can be removed by pressing down upon the ejector rod e.g. by a lever arrangement. <IMAGE>

Description

SPECIFICATION Cutter This invention relates to a method and associated device for cutting vertical cylindrical holes in the ground. While the invention may be useful to provide a sampling core for farmers or surveyors, or to provide a burial hole for ashes at a crematorium, its primary intended use is to cut holes in a golf green.

It is commonplace to change the position of the hole on a green frequently, both to avoid wear which would otherwise arise from keeping the holes in one place and to provide a more difficult green if the course is being used for tournament or championship purposes.

A known device for cutting the hole on a golf green consists of a cylinder with a sharpened lower edge, mounted upon an axially extending rod with transversely extending handles at the top. The cylinder edge is usually provided with three of four sawtoothed projections. To make a hole with such a device, the handles are rotated either continuously or to and fro while maintaining a downward pressure upon the cylinder. The cutting edge of the cylinders therefore bites through the turf and underlying earth, and after a depth of about 8 inches is achieved, the whole plug of soil is removed inside the cylinder. In this device the cylinder is 4- inches across, which is the standard size for the hole at golf.However, especially as stones or like difficulties are encountered in making the hole, there is a tendency for the rod to become deflected from its upright position. If this happens the upper perimeter of the hole is broadened since the tool has not maintained its vertical orientation throughout. Also, in that there is constant shear between the surface of the cylinder and the internal surface of the hole, there is a tendency for the earth in the wall of the hole to be displaced and the plug to be broken up. This displacement is especially marked towards the top of the hole, where there is more "give" in the hole wall structure anyway.Since it is specified that a hole in golf must be 41 inches diameter exactly, to contain a metal or plastics pot within the hole leaving a space of 1 inch from the surface of the ground, it will be appreciated that this shearing movement, which tends to adversely affect the upper part of the hole, taken together with any displacement from the vertical, can affect both the hole diameter and the nature of the edge of the turf unless the device is expertly used.

A more recent device sets out to overcome these problems by hammering into the turf two opposed half shells of metal defining between then the cylindrical plug of the necessary size. This suffers from the disadvantages that an extraneous tool (a mallet) must always be present and that the plug tends to break up as each half shell is separately removed from contact with it, so rendering it useless to plug the preceding hole.

The present invention sets out to overcome these disadvantages and provide a device which produces a clean accurately dimensioned hole and a firm plug which can be readily removed for plugging the previous hole.

In one aspect therefore the invention consists in a device for cutting a cylindrical hole in the ground, comprising a cylindrical cutter open and sharpened at the lower end, a coaxially upwardly extending shaft, transversely extending handles fixed to said shaft, and a graspable weight loosely surrounding said shaft and located between the cylindrical cutter and the handle; whereby when the cutter is placed in its desired location the graspable weight can be moved up and down the shaft to hammer the cutter downwards to a desired extent. After this the handles may be turned to provide shear between the cutter outer wall and the inner surface of the hole thereby to facilitate withdrawal by pulling upwards on the handles.

Preferably, the cutter is of a size and shape suitable for a hole on a golf green, that is to say 48 inches external diameter and 8 to 10 inches long. The cutting edge of the cutter is preferably tapered outwardly from the inner cutting cylindrical surface. This has the advantage that the earth previously occupying the space is now occupied by the thickness of the cylindrical cutter is consolidated back into the walls of the hole, and is not loosened by a continual shearing action, which would otherwise be the case with a rotary cutter. If anything, the movement of earth in contact with the outer surface of the cutter tends to be outward and downward to a small extent, which both consolidates the walls and provides a firm edge.

Preferably, moreover, a device is provided to facilitate removal of the plug from the cylindrical cutter. Such a device may utilize, for example, an ejector plate located across the internal space of the cutter and progressively moved farther into the cutter body as it is hammered into the ground. The ejector plate can be associated with an ejector rod, for example a vertical rod extending from the centre of the plate up through a tubular shaft, i.e. the shaft around which the weight is loosely movable. In such an instance as the cutter is hammered into the ground, the rod will protrude to a progressively greater extent from the remote end of the shaft.

After the cutter is removed from the hole, the plug can be ejected by any means which exerts downward force upon the shaft. We have found however that a percussive means is not preferable since it tends to loosen and break up the plug and render it unsuitable to fili a previous hole. We therefore prefer a lever action. In one possible arrangement a lever having a recess near its pivoted end is mounted with the free end of the rod in the recess and the pivoted end of the lever pivotally attached to an arm terminating in a pivotally attached oversized collar capable of sliding on the shaft. By this arrangement, the collar takes up its equilibrium position on the shaft but bites into the shaft and provides frictional resistance to movement of the lever pivot as soon as any pressure is exerted on the lever.Thus, the only possible movement is to push the rod down the shaft and eject to some extent the plug of earth. If the lever is then lifted again, the collar slips to a new equilibrium position and the action can be repeated until the plug is carefully ejected as a single unit for suitable filling of a previous hole.

In the possible arrangement, however, there exists the disadvantage that the lever mechanism for removing the plug of earth is a separate mechanism from the cutter assembly itself. That is to say, when the plug of earth is in place in the withdrawn cutter, the lever mechanism is dropped over one end and operated to eject the earth.

A preferred embodiment therefore sets out to provide a unified mechanism in which the ejection means are compactly associated with the cutter assembly.

In this preferred embodiment one of said handles has a selective pivotable mode, and is linkable to said ejector rod, so as to move said ejector rod downwards when it is moved around its pivot towards it transverse position.

Preferably, this preferred embodiment is defined as possessing a lever-action removal means to push the said rod in relation to the tubular shaft and thereby remove the plug, the lever action removal means comprising an outermost shaft affixed to the free end of the rod so as to surround, and move in relation to, the said tubular shaft at its upper end; an oversized collar surrounding said outermost shaft and capable of sliding thereon or of locking by friction thereon, the said collar being itself pivoted to one end of a link arm; pivot means at the other end of said link arm attached to one of said handles; and pivot means on said handle between said shaft and the link-to-handle pivot; whereby when the oversized collar is pulled up the outermost shaft the connected link draws one handle upwardly at an angle formed at the handle-toshank pivot and restoring of the handle to a lower position drags the link, oversized collar, and outermost shaft downwards so as to eject the plug of earth, at least in part, prior to any necessary further manual raising of the oversized collar in relation to the outermost shaft.

It will be clear from the above that the preferred embodiment envisages a pivoted handle, i.e. with a handleto-shaft pivot. This has the advantage that for storage or dispatch this pivoted handle can be folded back parallel to the shaft. It will therefore be advantageous to provide dismantling (or even pivoting) means on the other handle of a similar nature.

Such a pivot, or pivots, can be if necessary covered with an immobilising collar during preliminary (positioning) and terminal (shearing) use of the cutter so that rotary motion of the shaft can still be readily imparted without the pivot detrimentally affecting such motion.

Also the outermost shaft, on which the collar grips, is permanently attached to the ejector roll. Thus, all the working parts are permanently and compactly attached.

In practice, it is usually necessary to position the oversized collar on the outermost shaft two or three times in use. It will be found convenient to have a finger hook upon the periphery of the collar e.g. at a point remote from its pivot with the link, to assist in such repositioning.

While the invention primarily extends to the device and its preferred features as described above, a method of forming a hole in the ground such as a hole on a golf green is also a feature of the invention, and comprises firstly locating the cutting edge of a cylindrical cutter upon the ground, thereafter hammering the cutter into the ground by a vertically constrained reciprocating hammer means, and finally loosening the cutter and its associated plug by angular displacement of the cylindrical cutter so as to facilitate withdrawal. Preferably, the method of the invention is initiated by a brief turning movement to locate the cutting edge of the cylindrical cutter firmly in the ground i.e. in the top portion of the hole prior to starting the hammering movement.

The invention will be further described with reference to the accompanying drawings in which: Figure 1 is a broken away perspective view of a device for forming holes, shown during use, and Figure 2 shows an associated mechanism for removing the plug of earth from the device of Fig. 1 and Figure 3 shows an alternative embodiment in partial cross-section.

Fig. 1 shows a cylindrical cutter and associated coaxial tubular shaft assembly 1, transversely extending handles 2, a graspable weight 3 slidable on tubular shaft, and an ejector assembly 4 with the rod located within the tubular shaft.

Cutter and shaft assembly 1 consists of a cutter 5 open arounds its lower cutting edge 6 and chamfered at an angle of about 10 at location 7 around the cutting edge. The upper end of the cutter is turned inwards and carries a cruciform reinforcement 8 and a heavy collar 9 all welded securely to one another and to the cutter. Around the upper rim of the cutter there is an indicator line 10. The shaft is secured to the cutter by the welded members 8 and 9, and extends vertically so that the distance between the cutting edge and the remote end 11 of the shaft is about 48 inches.

Handle 2 consists of separate clamping members 1 2 and 1 3 located in a recess in the wall of the tubular shaft, and tightened in the recess by bolts 1 4. Transversely extending rods 15 terminate in grips 16.

The regraspable weight 3 can be of any convenient size and shape, but will be preferably about 5 pounds in weight and possess smooth end flanges 1 7 to locate the fingers of the user towards the centre of the weight and ensure they do not slip under the weight when it is being used to hammer the cylindrical cutter.

Within the tubular shaft there is an elongate rod 1 8 terminating at its bottom end in an ejector plate 1 9 and having fixed stop member 20 towards its top end so that the rod cannot fall out of the shaft when the device is raised.

In use, the device is placed vertically upon the grass of a golf green and turned either continuously or with a to-or-fro motion until the first portion of the cutting edge is embedded in the earth, typically by about half an inch or so. At this stage, the handles are relinquished and the turning motion is discontinued, and one hand is used to grasp the weight 3 and to move it up and down the tubular shaft to give a succession of hammer blows upon the strength of the assembly 8 and 9 at the the top of the cylindrical cutter.

If desired, the other hand can steady the shaft in its vertical position for the initial stages of this hammering. Eventually the hammering motion will force the cylindrical cutter so far into the ground that the indicator line 10 is located at the ground surface. (Alternatively, the progressive protrusion of rod 1 8 from the end of the tubular shaft can be used as a measure of the depth of the cut). When the cylindrical cutter has reached this desired position, a small rotary movement imparted by grasping the gripping handles 1 6 and turning slightly, will be enough to loosen the cutter and allow it to be pulled from the hole.

Because there is a contact repeated hammering motion, rather than a constant turning motion, it will be found that the sides of the hole are well consolidated and that the material otherwise occupying the thickness of the cutter cylinder has been pressed back into the hole wall. Moreover, the upper peripmeter of the hole will be of the desired size and will be compacted by this same action, being subjected to only a minimum of shear during its formation.

The plug of earth within the cutter at this stage is, of course, used to plug the preceding hole. This could be removed by hammering the end of the rod 1 8 back until the stop 20 contacts the end of the tubular shaft. Such a hammering actidn, however, may break up the free surface of the bottom of the plug. It is therefore preferred to utilize a device as shown in Fig. 2.

Fig. 2 shows the same reference numerals as before the upper of the tubular shaft and the protruding ejector rod at the end of its travel. Over these is located an articulated device consisting of an elongate lever 21 with a recess 22 for receiving the end of rod 1 8 and a pivot 23 at the end. The remote end of the lever is provided with convenient grip 24.

Pivoted at 23 is a link member 24 which comprises a further pivot 25 at its lower end.

Pivoted in turn to this is an arm 26 connected firmly to an oversized collar 27 capable of sliding loosely upon the tubular shaft. In use, the articulated assembly is arranged as shown. Downward pressure upon the grip moves the ejector rod downwards by a small amount and thus causes the plug to protrude by the same amount from the cutter. When the handle 21 has reached the bottom of its stroke, the grip 24 is raised at which stage the oversized collar, being loosely pivoted at 25 will slide down the shaft until it reaches a new equilibrium position. A second downward stroke of the handle will then cause a further amount of the plug to protrude.This procedure is continued until the whole of the plut is ejected, at which stage the oversized collar 27 will have more or less reached the position of the clamping bars 1 2 and 1 3 of the transverse handles. We have found that a suitable sharp edged high tensile steel collar will have an adequate grip even upon a smooth tubular shaft, and that circumferential ribs on the shaft, while exerting no adverse affect, are not strictly necessary.

Alternatively, an embodiment as shown in Fig. 3 can be utilized.

In Fig. 3 a tubular shaft 301 carries at its lower end a cylindrical cutter 302 with cutting edge 302a and is surrounded by a hammering weight 303 which when desired can be grasped and used to strike the top of the cutter. These features are shown in Fig. 1 and need not be described herein in more detail, except to explain the environment of the present invention.

Within the cutter is an ejector plate 304 and ejector rod 305 extending the whole length of the shaft. Attached to the remote end of ejector rod 305 by a spacing member 306, welds 307, and bolted connection 307a is an outermost tubular shaft 308 located to slide up and down at the top of the tubular shaft 301.

At an intermediate location on tubular shaft 301 are provided transversely protruding handles one of which, 309a in the embodiments shown, is bolted at 310 to a suitable fixing bracket or sleeve 311, and the other of which 309b in the embodiments shown, is pivoted at 312 this pivot being associated with a suitable immobilising collar 313 which can if desired be slid over the pivot to immobilise the handle 309b in a transverse position. The said other handle 309b is also pivoted at 314 to a link member 313 which in turn is pivoted at its further end 316 to one side of an oversized collar 31 7 fitting loosely over the outermost shaft 308. The oversized collar 317 is provided with a finger hook 320 as shown whose function is described in more detail below.

The device as shown operates as follows.

With the handles 309 a and 309bimmobil- ised transversely and the link and collar lying loosely where it will, the cutter is turned for a quarter-turn or so, with pressure, so as to locate the cutting edge 302daccurately in the ground. Then, holding the shaft 301 above the handles 309aand 309bto preserve verticality, the hammering process is started by sliding weight 303 sharply down on cutter 302, this being repeated until the cutter is driven into the ground to a indicated level.

The handles 309aand 309bare still immobilised transversely. They are given another quarter-turn or so, to shear the cutter against its outside earth surface and the plug is them pulled upwards by pulling on the handles.

After this immobilising collar 313 is slid back to the position shown in Fig. 1, and handle 309b is raised as shown. This in turn enables the user to pull collar 317 upwards at an angle as shown, using finger grip 320.

Handle 309b is then pressed down. A strong lever action is obtained and transmitted by link 31 5 to the collar which at the angle shown binds on the outermost shaft 308 and so pulls it downward. This pulls rod 305 downward and thus, via the ejector plate 305, ejects the plug of earth without subjecting it to percussive breakdown. Repeated repositioning of collar 317, and relevering with handle 309b are usually necessary, due to the geometry of the device. The end result is a smooth accurately dimensioned plug of earth which accurately plugs a preceding such hole e.g.

on a golf green.

Claims (13)

1. A device for cutting a cylindrical hole in the ground, comprising a cylindrical cutter open and sharpened at the lower end, a coaxially upwardly extending shaft, transversely extending handles fitted to said shaft, and a graspable weight loosely surrounding said shaft and located between the cylindrical cutter and the handle; whereby when the cutter is placed in its desired location the graspable weight can be moved up and down the shaft to hammer the cutter downwards to a desired extent.

2. A device as claimed in claim 1, in which the cylindrical cutter is 4i inches external diameter and less than 10 inches long, whereby it is suitable for cutting a hole on a golf green.

3. A device as claimed in claim 1 or 2, in which the cutting edge of the cutter is tapered outwardly from the inner cylindrical surface.

4. A device as claimed in claim 1, 2 or 3, further provided with means to facilitate removal of the plug of earth within the cutter.

5. A device as claimed in claim 4, wherein means to facilitate removable of the plug comprises an ejector plate located across the internal space of the cutter, whereby it is progressively moved farther into the cylindrical cutter body as this is hammered into the ground.

6. A device as claimed in claim 5, in which the ejector plate is attached to a coaxial rod extending from the centre of the plate up through the shaft of the cutter, which is tubular in form.

7. A device as claimed in claim 6, further comprising a lever-action removal means to push the said rod downwards and remove the plug.

8. A device as claimed in claim 7, in which the said lever-action removal means comprises a lever having a recess near its pivoted end, said lever being mounted with the free end of the rod in the recess and with the pivoted end of the lever pivotally attached to an arm itself, terminating in a further pivotally attached oversized collar located around, and capable of sliding on the shaft.

9. A device as claimed in claim 7 in which one of said handles has a selective pivotable mode, and is linkable to said ejector rod, so as to move said ejector rod downwards when it is removed around its pivot towards its transverse position.

10. A device as claimed in claim 9 possessing a lever action removal means to push the said rod in relation to the tubular shaft and thereby removed the plug, the lever action removal means comprising an outermost shaft affixed to the free end of the rod so as to surround, and move in relation to, the said tubular shaft at its upper end; an oversized collar surrounding said outermost shaft and capable of sliding thereon or of locking by friction thereon, the said collar being itself pivoted to one end of a link arm; pivot means at the other end of said link arm attached to one of said handles; and pivot means on said handle between said shaft and the link-tohandle pivot; whereby when the oversized collar is pulled up the outermost shaft the connected link draws one handle upwards at an angle formed at the handle-to-shaft pivot and restoring of the handle to a lower position drags the link, oversized collar, and outermost shaft downwards so as to eject the plug of earth, at least in part, prior to any necessary further manual raising of the oversized collar in relation to the outermost shaft.

11. A device as claimed in claim 1 and substantially as herein described with reference to the accompanying drawing.

1 2. A method of forming a hole in the ground such as a hole on a golf green comprising firstly locating the cutting edge of a cylindrical cutter upon the ground, thereafter hammering the cutter into the ground by a vertically constrained reciprocating hammer means, and finally loosening the cutter and its associated plug by angular displacement of the cylindrical cutter so as to facilitate withdrawal.

13. A method as claimed in claim 10 initiated by a first turning movement to locate the cutting edge of the cylindrical cutter firmly in the ground.