GB2536266A

GB2536266A - Improvements in and relating to post drivers

Info

Publication number: GB2536266A
Application number: GB1504135.3A
Authority: GB
Inventors: Mowatt Bryce John
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-03-11
Filing date: 2015-03-11
Publication date: 2016-09-14
Anticipated expiration: 2035-03-11
Also published as: IE86858B1; IE20160079A1; GB2536266B; GB201504135D0

Abstract

A post driver 5 comprises a device 60 for holding a drivable member 55 and at least one driver or ram 75 for moving the holding device between a first (operational) position and a second (storage) position. The drivable member typically comprises a rock spike, but could be an auger, post, pile or anchor. The holding device may comprise a collar or sleeve formed from at least two separable or hinged parts. The driver or ram may be powered hydraulically, pneumatically, electrically or magnetically. The holding device may comprise at least one arm pivotally mounted on a mast of the post driver and may be supported by a guide rail or track. The mast may include a weight or hammer.

Description

IMPROVEMENTS IN AND RELATING TO POST DRIVERS

FIELD OF INVENTION

The present invention relates to post drivers, for example, for driving fence posts or the like into the ground. The present invention particularly, though not exclusively, relates to an assembly that can be used to operate a drivable member such as a rock spike, a post driver comprising the assembly and a method of operating a post driver.

BACKGROUND TO INVENTION

Post drivers usually consist of a mast that is substantially vertically disposed or disposable, and which guides a falling weight or hammer. The weight is typically lifted by hydraulic power from, for example, a tractor on which the post driver is mounted. A ram, working through a lifting mechanism, may pull a rope or chain over a pulley or sprocket at the top of the mast so as to lift the weight in order that the weight may then be dropped onto a post cap or post. Examples of post drivers are disclosed in GB 2 423 549 B and GB 2 441 071 B both by the present Applicant, the content of which is incorporated herein by reference.

GB 2 423 549 B discloses a post driver that comprises a frame supported on a plurality of legs; a mast adapted to allow a weighted member to travel substantially up and down; wherein there are positioning means provided to enable the position of the mast to be optimised and adapted for alignment with a post to be driven; wherein the mast is telescopic; and the post driver comprises a plurality of pulleys allowing the post driver to be adapted to be used with different heights of post.

GB 2 441 071 B discloses a post driver comprising a frame supported on a plurality of legs; a mast adapted to allow a weighted member to travel substantially up and down; wherein there are provided positioning means to enable the position of the mast to be optimised and adapted for alignment with a post to be driven, the positioning means comprising a back shift and a side shift; and wherein the legs are independently hydraulically operable.

When driving posts into hard ground or ground that contains a high level of stones, rocks or other hard objects, it is preferable to first drive in a drivable member, for example, a metallic drivable member, such as a rock spike or a rotating auger type device, which is then removed to leave a hole. The resultant hole makes it easier to subsequently drive in a post, for example, a wooden or timber post. In addition, pre-forming a hole using the drivable member may make it easier to subsequently drive the post in to the required depth.

The rock spike can be slidably retained inside a collar. The collar is rotatably and slidably mounted to a rail on the mast. A hydraulic extractor ram is also rotatably attached to the mast and connected to the collar so as to move or slide the collar along, for example, vertically along, the rail. Both the collar and the hydraulic extractor ram are manually rotatable around the rail to move the rock spike between an out of use position adjacent to a side of the mast, out of the path of the weight or hammer, and a working position below the weight or hammer such that the post driver is operable to drive the rock spike.

Prior art post drivers suffer from various problems. For example, it may be beneficial to improve safety during post driving operations. It may also be desirable to improve efficiency and cycle time of post driving operations. Reducing the physical effort and burden required of the operator may also be beneficial.

For example, the rock spike may often be very heavy, typically weighing between 70kg and 200kg, depending on its diameter and length. As such, it may require considerable physical effort from the operator to rotate the collar and rock spike or other drivable member between the out of use and working positions, particularly when the post driver is situated on a slope or steep gradient. There may be health and safety issues with apparatus or systems that require manual operations involving the heavy rock spike, in particular, for example, due to the risk of back or other injury. Furthermore, in order to rotate the collar and rock spike between the working and out of use positions, the operator may intentionally or inadvertently stand below the weight or hammer, which may present a safety risk if the mechanism suspending the weight or hammer malfunctions Furthermore the present inventors have identified that significant operator time may be spent moving from a position where the operator operates the post driver controls, such as controls for the mechanism that operates the weight or hammer and/or mast position adjustment, and a position required to release a rock spike holder and manually move the rock spike between the out of use or storage position and an operational or working position underneath the weight or hammer.

It is an object of at least one embodiment of at least one aspect of the present invention to seek to obviate or at least mitigate one or more problems in the art.

SUMMARY OF INVENTION

One or more objects of the invention are sought to be addressed by the general solution of providing a device adapted for use with a post driver comprising means for holding a drivable member and powered means for moving the means for holding between a first position and a second position.

According to a first aspect of the present invention there is provided an assembly for a post driver, the assembly comprising a device, such as a storage or retention device, for holding, storing or retaining a drivable member, and at least one driver for moving the drivable member between a first position and a second position. The assembly may be fitted to or adapted to be fitted to a post driver. The assembly may be or comprise or be comprised in a retro-fit kit or assembly.

The driver may be or comprise a powered driver. The driver may be configured to selectively move, e.g. rotate, the device for holding, storing or retaining and thereby move, e.g. rotate, the drivable member between a first position and a second position.

According to a second aspect of the present invention there is provided a post driver. The post driver may comprise an assembly according to the first aspect. The post driver may be configured to support a drivable member. The post driver may comprise at least one driver for moving, e.g. rotating, the drivable member between a first position and a second position.

The post driver may comprise a device, such as a storage or retention device, for holding, storing or retaining the drivable member.

The following features are equally applicable to the first and/or second aspects.

The device for holding, storing or retaining may comprise a collar or sleeve. The device for holding, storing or retaining may be configured to grip or hold, e.g. selectively or releasably grip or hold, the drivable member. At least part of the drivable member may be receivable, e.g. selectively or releasably receivable, within at least part of the storage or retention member, such as the collar or sleeve. The storage or retention member may comprise at least one arm. At least part of the collar or sleeve may be integral with or mounted on or to the at least one arm, e.g. to a first end of the arm.

The post driver may comprise a mast. The post driver may comprise a frame.

The mast may be mounted on and/or supported by the frame. The frame may be mounted or mountable to a supporting vehicle. The post driver may comprise a weight or hammer, which may be suspended from the mast.

At least part of the device for holding, storing or retaining, e.g. the at least one arm, such as a second end of the arm distal from or opposite the first end, may be pivotably or rotatably mounted or supported on the mast. The device for holding, storing or retaining may be directly or indirectly supported on the mast. The device for holding, storing or retaining may be rotatable in a direction or plane that is substantially perpendicular to the mast and/or in a horizontal direction.

The driver may be operable to move or reconfigure the storage or retention device between at least first and second configurations or locations, e.g. so as to move the drivable member between the first and second positions.

The driver may be configured to apply a force to the device for holding, storing or retaining. The driver may be selectively extendable and/or contractable or retractable, e.g. to move the device for holding, storing or retaining and/or the drivable member between the first and second locations, positions and/or configurations. The driver may be a powered driver, such as a hydraulically powered, pneumatically powered, electrically powered or magnetically powered driver. The driver may be or comprise an actuator. The driver may be or comprise a non-manual driver, e.g. the driver does not rely on an operator to supply part or most of the force produced or supplied by the driver. The driver may comprise a piston or ram, such as a hydraulic or pneumatic piston or ram.

The device for holding, supporting or retaining may be movable in a direction, or along an axis, parallel with the mast, e.g. by or using a second driver. The second driver may be or comprise an extractor ram, e.g. for extracting the drivable member from the ground.

The device for holding, supporting or retaining may be movably mounted to or movably supported by a guide, track, pole or rail, which may be mounted to or supported by the mast. The guide, track pole or rail may extend in parallel with the mast. The device for holding, supported or retaining may be movable, e.g. movable in parallel with the mast and/or substantially vertically or upwardly/downwardly movable, along the guide, track, pole or rail, e.g. by or using the second driver.

The device for holding, supporting or retaining may be rotatably or pivotably mounted to the guide, track, pole or rail. The device for holding, supporting or retaining may be rotatably or pivotably movable around the guide, track, pole or rail, which may be in a direction or plane that is perpendicular to the mast and/or rail or in a substantially horizontal direction, e.g. under the action of the driver.

One end of a first part, e.g. a cylinder, of the second driver may be rotatably mounted to the mast. Another end of the first part, e.g. cylinder, of the second driver may be rotatably mounted to the guide, track, pole or rail, e.g. via a supporting bracket.

The driver may be coupled between the mast and a bracket or member that is rotatably supported or mounted on the guide, track, pole or rail, which may be or comprise the supporting bracket, or the second driver. The bracket or member, the supporting bracket, the driver and/or the second driver may be coupled to the device for holding, supporting or retaining.

A first end of the driver may be attached or coupled, e.g. pivotably attached or coupled, with the arm of the device for holding, supporting or retaining. A second end of the driver, which may be an end distal or opposite the first end, may be mounted to or supported by the mast and/or the guide, track, pole or rail, e.g. via a mounting bracket. The mounting bracket and/or second end of the driver may be mounted or supported by the mast and/or the guide, track, pole or rail such that it is fixed against rotation around (e.g. rotation in a direction or plane generally perpendicular to) the mast and/or the guide, track, pole or rail.

The driver may be operable to rotate the second driver, bracket or member and/or supporting bracket (e.g. the extractor ram), e.g. around the mast and/or the guide, track, pole or rail, which may thereby rotate the device for holding, storing or retaining around the mast and/or the guide, track, pole or rail.

Since one end (i.e. the second end) of the powered driver, e.g. a hydraulic or pneumatic ram or piston, may be prevented from rotating around the mast and/or the guide, track, pole or rail whilst the other end (i.e. the first end) of the powered driver may be coupled (e.g. rotatably or pivotably coupled) to the device for holding, storing or retaining the drivable member, which may be mounted for rotation relative to the mast and/or the guide, track, pole or rail, then operation of the driver, e.g. to extend or contract the driver, may act to selectively rotate the device for holding, storing or retaining (and particularly the collar or sleave and the drivable member) around the mast and/or the guide, track, pole or rail, e.g. between the first and second positions, locations or configurations.

The device for holding, supporting or retaining and/or the guide, track, pole or rail may be mounted or supported on or adjacent a side face of the mast, which may be a face perpendicular to the face of the mast upon which the weight or hammer is movable.

The first position, configuration or location may be or comprise a working position, configuration or location, e.g. in which the drivable member is positioned underneath or in a range of operation of the weight or hammer. The second position, configuration or location may be an out of use position, configuration or location, in which the drivable member is not located below the weight or hammer or outwith the range of operation of the weight or hammer, e.g. towards the frame.

The arm may be curved, L-shaped and/or define a recess, e.g. on a side of the arm facing or proximate the mast when the device for holding, storing or retaining is in the first configuration or location. In this way, undesirable contact with the mast may be prevented when the device for holding, storing or retaining is in the first configuration or location.

The driver may be controllable using a control that is remote from the driver. The post driver may comprise a control unit, which may comprise one or more controls for operating the post driver, e.g. for operating a mechanism for moving the hammer or weight and/or a mast adjustment or positioning mechanism such as a backshift and/or side shift. The control for operating the driver, e.g. for moving or rotating the device for holding, storing or retaining the drivable member, may be comprised in the control unit. In this way, the driver for moving or rotating the device for holding, storing or retaining the drivable member may be operable from the same position as other functions of the post driver such as the mechanism for moving the hammer or weight and/or a mast adjustment or positioning mechanism. This may reduce the cycle time required to drive in consecutive posts using the drivable member (e.g. the rock spike or auger) as the operator no longer needs to move away from the controls in order to manually release and locate the drivable member in an operational or working position under the weight or hammer.

The drivable member may be or comprise a ground engaging member, for example, preferably a rock spike or alternatively an auger. The drivable member may be made at least partially and preferably substantially wholly from a metallic material.

The device for holding, retaining or storing may be or comprise a guide or positioning means, such as the collar or sleeve, for guiding and/or positioning the drivable member in use. The device for holding, retaining or storing, e.g. the collar or sleeve, may be adapted to selectively release and/or retain the drivable member.

The device for holding, retaining or storing, e.g. the collar or sleeve, may be formed of at least two separable and/or hinged parts, which may allow easy insertion and/or removal of the drivable member. The at least two separable parts may be pivotably or rotatably mounted to each other. The device for holding, retaining or storing may be or comprise a clam-shell type device.

The at least two separable parts may be selectively fixable or lockable against separation and/or relative movement, rotation or pivoting, e.g. by one or more fixing or locking members, such as pins or bolts. One or more or each of the fixing or locking members may be insertable through one or more receiving portions, such as holes or apertures in two or more of the at least two separable parts. The fixing or locking members may be fixable in position through the one or more receiving portions, e.g. by engaging a corresponding bolt or bolts or a threaded portion or portions of the at least two separable parts, e.g. to retain, store or hold the drivable member in the device for holding, storing or retaining.

The fixing or locking members may be selectively releasable, e.g. to allow separation and/or relative movement, rotation or pivoting of the at least two separable parts. This may allow the drivable member to be selectively releasable from the device for holding, storing or retaining.

In this way, the drivable member may be selectively held by the device for holding, storing or retaining during use but may also be selectively releasable, e.g. in order to provide an emergency release mechanism when the drivable member is stuck in the ground, or if it is desired to switch out or store the drivable member.

The mast may be tiltable and/or telescopic.

The post driver may comprise a post cap. The post cap may be provided with a locator for locating the drivable member relative to the cap.

The frame may be supported on a plurality of legs. The mast may be adapted to allow a weighted member to travel substantially up and down. The post driver may comprise positioning means provided to enable the position of the mast to be optimised and adapted for alignment with a post to be driven. The mast may be telescopic. The post driver may comprise a plurality of pulleys allowing the post driver to be adapted to be used with different heights of post.

The positioning means may comprise a back shift and/or a side shift. The legs may be independently hydraulically operable.

The post driver may comprise a holder or retaining means for holding or retaining the drivable member, such as a rock spike holder. The holder or retaining means may be movable from the first position to the second position, and preferably vice versa. The post driver may comprise means for moving the holder or retaining means from the first position to the second position, and preferably vice versa. The first position of the holder or retaining means may be or comprise a position towards or proximate the mast. The first position of the holder or retaining means may be or comprise an exchange or a transfer position wherein the drivable member is directly transferable between the holder or retaining means and the device for holding, storing or retaining (e.g. the collar or sleeve). The exchange or transfer position may be a position in which the device for holding, storing or retaining may hold or be placed releasably around the drivable member whilst the drivable member may be optionally held by the holder or retaining means.

The second position of the holder may be located on another or an opposite side of the post driver and/or a centre of gravity of the post driver to the first position of the holder. The holder may be mounted to the frame of the post driver, for example, pivotably mounted. The first position may be closer to the mast than the second position.

The holder may comprise an arm and may comprise or be mounted or mountable to a pivot means. The arm may be mounted or mountable to the frame of the post driver, e.g. via the pivot means. The arm and/or holder may be rotatable about the pivot means such that the drivable member and/or holder may be movable between the first position and the second position. The holder may comprise a hollow tube or member that may be closed or sealed at one end, for example, a lower end. At least a portion of the hollow tube or member may form a hinged and/or releasable access section. The access section may be disposed towards the top of the holder.

According to a third aspect of the present invention there is provided a method of operating a post driver, such as a post driver according to the second aspect, the method comprising: providing a post driver adapted to drive a drivable member; and moving a drivable member between at least a first position and a second position using a driver, such as a powered driver.

The drivable member may be or comprise a rock spike, such as a metallic rock spike.

The drivable member may be held, stored, gripped or retained by a device for holding, storing or retaining the drivable member. The method may comprise moving the device into a first configuration or location using the driver to thereby move the drivable member into the first position. The method may comprise moving the device into a second configuration or location using the driver to thereby move the drivable member into the second position.

The first position may be such that the drivable member is in an operational or working position. The second position may be such that the drivable member is in a storage or not in use position.

The first position may be located on, proximate or adjacent a first side of the mast, which may be a side of the mast upon which a weight or hammer is mounted. The first position may be a position in which the drivable member is located under the weight or hammer. The second position may be located on, proximate or adjacent another side of the mast, other than the first side.

It should be understood that the individual features and/or combinations of features defined above in accordance with any aspect of the present invention or below in relation to any specific embodiment of the invention may be utilised, either separably and individually, alone or in combination with any other defined feature, in any other aspect or embodiment of the invention.

Furthermore, the present invention is intended to cover apparatus configured to perform any feature described herein in relation to a method and/or a method of using or producing, using or manufacturing any apparatus feature described herein.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the present invention will be described by way of non-limiting example only, and with reference to the accompanying figures, which are: Figure 1 a schematic side view of a prior art post driver; Figure 2 a side view of a post driver comprising a device for holding, retaining or storing a drivable member; Figure 3 an end view of the post driver of Figure 2; Figure 4 a detail view of the post driver of Figure 2 in use in a first configuration; Figure 5 a detail view of the post driver of Figure 2 in use in a second configuration; Figure 6 a detail view of the post driver of Figure 2 in use in a third configuration; Figure 7 a detail view of a locking device of the post driver of Figure 2; Figures 8a and 8b detail views of an alternative locking device for the post driver of Figure 2 in first and second configurations respectively; Figure 9 a detail view of another alternative locking device for the post driver of Figure 2; Figure 10 a plan schematic of a device for holding, retaining or storing a drivable member according to an aspect of the present invention in a first configuration; Figure 11 a plan schematic of a device for holding, retaining or storing a drivable member according to an aspect of the present invention in a second configuration; Figure 12 a rear view of a post driver with a drivable member fully driven into the ground; Figure 13 a detail view of the post driver of Figure 12 showing a device for holding, storing and retaining in a closed configuration; Figure 14 a detail view of the post driver of Figure 12 showing a device for holding, storing and retaining in an open configuration; and Figure 15 a schematic view of an alternative device for holding, storing and retaining.

DETAILED DESCRIPTION OF DRAWINGS

Figure 1 shows a post driver 1 according to the prior art.

Figures 2 and 3 show an assembly 2 comprising a post driver 5 and a device 90, the assembly 2 being mounted to a rear or back of a tractor 10. Post drivers 1 and 5 each comprise a longitudinal frame 15 having a mast 20 at one end and a counterweight 25 at the other. The mast 20 is mounted on the frame 15 by hydraulically operated sliders such that it is movable on two horizontal axes. The mast 20 is provided with a weight or hammer 30 suspended from a rope 35, which is guided over a pulley or pulleys 40 at the top of the mast 20. A ram 45 is mounted on the frame 15, and is arranged to pull the rope 35 through the pulley 40 so as to lift the weight 30 in order that the weight 30 can be released to drop onto a post cap 50. In alternative devices, other arrangements can used, such as a swinging arm arrangement that is pivotably attached to the mast or frame, as would be apparent to a person skilled in the art. The post cap 50 is slidably mounted on the mast 20 such that the post cap 50 can be lowered to abut the top of a post (not shown), rock spike 55, piling or other drivable member.

The cap 50 of post driver 5 is provided on an underside thereof with locating means or spike 80, which in this embodiment is in the form of a locating spike, and the top of the rock spike 55 is provided with a recess 85 such that when the cap 50 abuts the rock spike 55, the locating spike 80 on the cap 50 cooperates with the recess 85 on the top of the rock spike 55 in order to locate the rock spike 55 relative to the cap 50.

In use, the rock spike 55 is slidably mounted in a collar 60. A flange 65 extends radial outwardly from the top of the rock spike 55. The flange 65 is arranged to engage the collar 60 such that the rock spike 55 is suspendable from the collar 60. Alternatively, a plastic cap can be provided that engages with the top of the rock spike 55 or a recess on the rock spike 55 that minimises vibrations from the impact of the weight. The collar 60 is rotatably mounted to a rail 70 (shown in Figures 3 to 7) on or adjacent the mast 20. The rail 70 extends at least partially along a height or length of the mast 20. This partial length rail 70 minimises weight relative to a rail running the full height of the mast 20. A hydraulic ram 75 is also rotatably attached to the mast 20 and connected to the collar 60 so as to move the collar 60 generally vertically along the rail 70. Both the collar 60 and the hydraulic ram 75 are rotatable between respective first and second positions to move the rock spike 55 between a respective first position, adjacent and to a side of the mast 20 and a respective second position below the weight 30 and cap 50. In the first position, the rock spike 55 is held clear of the area below the weight 30 such that the weight 30 can be used to drive, for example, posts. In the second position, the post driver 5 is operable to drive the rock spike 55, i.e. the rock spike 55 is positioned below the weight 30. As such, it will be appreciated that the first position represents a not in use or storage position whilst the second position represents a working position.

With the collar 60 and spike 55 in their second position, the hydraulic ram 75 is operable to slidably lower the collar 60 on the rock spike 55 such that the collar 60 is in a position close to, or adjacent, the ground. The weight 30 can then be dropped such that it strikes the striking cap 50, which in turns transfers the force to the rock spike 55 to drive it into the ground. This process may be repeated as many times as necessary in order to drive the rock spike 55 into the ground.

After the rock spike 55 is driven into the ground, the striking cap 50 can then be attached to the weight 30, e.g. by a linkage such as a chain, and both the cap 50 and weight 30 lifted to a position towards the top of the mast 20. The hydraulic ram can then be used to raise the collar 60, which acts against the flange 65 on the rock spike 55 in order to raise both the rock spike 55 and the collar 65, leaving a hole, e.g. "pilot" hole, in the ground. The collar 65, rock spike 55 and ram 75 can then be rotated back into the first position adjacent and to the side of the mast 20.

The mast 20 is provided with a locking device 77, such as a spring-loaded pin or latch for securing the collar 65 and hydraulic ram 75 in the first position, so that the post driver 5 can be securely transported when moving between post positions. The rail 70 and collar 65 are also provided with means for locking the collar 65 in a raised position, such as a hole and pin arrangement, which prevents the collar 65 falling when stored due to creep of the hydraulic ram 75 over time. A post (not shown) may then be placed in or above the hole (not shown) and driven into the ground in a conventional fashion.

When the operator wishes to use the rock spike 55, initially stored in the first (not in use) position, the operator raises the weight or hammer 30 and the post cap 50 as described above and operates the locking device 77 in order to release the collar 60 and hydraulic ram 75 so as to be rotatable around the rail 70, as shown in Figure 4. The operator then manually swings the rock spike 55, collar 60 and hydraulic ram 75 around the rail 70 to the second (working) position, as shown in Figure 5. The operator then holds the rock spike 55 in position whilst the post cap 50 and weight or hammer 30 are lowered such that the spike 80 on the post cap 50 locates in the recess 85 in the top of the rock spike 55, as shown in Figure 6. The process of driving the rock spike 55 into the ground using the weight or hammer 30 as described above can then begin.

The locking device 77 can be, for example, a spring loaded pin 90 that is selectively insertable into and out of a corresponding recess 95 in a rotatable bracket 100 using a pivoting handle 105, as shown in Figure 7. The pivoting handle 105 is mounted to the mast 20. The rotatable bracket 100 is rotatably mounted to the rail 70 so as to rotatably support a cylinder portion of the hydraulic ram 75 on the rail.

When the pin 90 is located in the recess 95 when the collar 60 is in the first position, the bracket 100 and thereby the hydraulic ram 75 and the collar 60 are prevented from rotating. When the handle 105 is pivoted so as to move the pin 90 out of the recess 95, the bracket 100 and thereby the hydraulic ram 75 and the collar 60 are free to be rotated around the rail 70, e.g. into the second position.

An alternative locking device 77a is shown in Figures 8a and 8b. In this case, the locking device 77a comprises a latch 110 fixed to the bracket 100, wherein the latch 110 is inserted through a corresponding slot 115 coupled with the mast 20 so as to engage the slot 115 and prevent rotation of the bracket 100 and thereby the collar 60 when in the first position. Retracting the hydraulic ram 75 raises the bracket 100 and thereby the latch 110, disengaging it from the slot 115 so that the collar 60 and hydraulic ram 75 can be manually rotated around the rail 70 into the second position. In order to re-store the collar 60, the collar 60 is swung back round into the first position, with the hydraulic ram 75 can suitably adjusted such that the latch 110 can be inserted into the slot, then the hydraulic arm 75 is slightly extended so that the latch 110 engages with the slot 115 to lock the collar in the first position again.

Another alternative locking device is shown in Figure 9, which simply comprises a pivoting handle 120 mounted to the mast, the handle being biased into position using a spring 125 and configured with a hook end to selectively latch a corresponding portion of the bracket 100 when in the first position, depending on whether the handle 105 is pivoted or not.

In a preferred variation shown in Figures 10 and 11, instead of being manually movable between the first and second positions, the collar 60 is operated using a collar operating ram 150. The collar 60 is provided on one end of a curved arm 155, the other end of the arm 155 being slidably and rotatably mounted to the rail 70. One end of the collar operating ram 150 is mounted via a protruding bracket 157 to the mast 20 whilst the other end of the collar operating ram 150 is mounted to the bracket 100 that rotatably supports the cylinder of the hydraulic rock spike extraction arm 75 on the rail. In this way, when the collar operating ram 150 is contracted, as shown in Figure 10, the collar 60 is rotated around the rail 70 to the first position, adjacent a side face of the mast 20, and away from the range of operation of the weight or hammer 30. When the collar operating ram 150 is extended, as shown in Figure 11, the collar 60 is rotated around the rail 70 to the second position, adjacent a face of the mast 20 upon which the weight or hammer 30 slides so as to be locatable under the weight or hammer 30.

This arrangement of using the hydraulic ram 150 to move the collar can improve safety, as the ram 150 can be operated remotely, minimising the likelihood of the operator inadvertently straying under the hammer. It can also reduce the exertion required by the operator. Furthermore, since the hydraulic ram 150 can be operated remotely, e.g. from a control unit used to control other functions of the post driver 5 such as the ram 45 for operating the weight or hammer 30 and/or a side shift and/or back shift, the cycle times involved in driving in a post when the rock spike 55 is used can be reduced, as the operator no longer needs to manually swing the rock spike 55 into the operational position under the weight or hammer 30.

The collar 60 is formed of (in this case two) sections 155a, 155b, joined by a hinge and selectively locked together with at least one pin or bolt 160, as shown in Figures 12 to 14. Thus, the pin or bolt 160 is removable from the collar 65 such that the two hemi-tubular sections 155a, 155b of the collar 65 can be swung apart in order to release the rock spike 55 from the collar 65, e.g. in a clam-shell arrangement.

When the rock spike 55 is fully inserted into the ground, as shown in Figures 12 and 13, the rock spike may become stuck. In this case, the collar arrangement described above having hinged sections 155a, 155b can be operable as an emergency release mechanism. In this case, the pin or bolt 160 can simply be removed and the sections 155a, 155b hinged or moved apart so that the rock spike can be removed from the collar 60 by passing between the sections 155a, 155b, as shown in Figure 14. This allows the rock spike 55 to be released from the driver, so that the rock spike 55 can be removed by other means such as by using a tractor or digger unit.

A collar 60a that is a variation of the collar 60 is shown in Figure 15. In this case, the collar 60a is similar to collar 60 shown in Figures 12 to 14 apart from a pin 160a is provided horizontally between the hinged sections 155a, 155b, rather than vertically, as is the case in the collar 60.

Whilst specific embodiments of the present invention has been described above, it will be appreciated that this has been given by way of non-limiting example only, and that departures from the described embodiment will fall within the scope of the invention.

For example, although the cap 50 is described as having a locator spike 80, other locating means known to a person skilled in the art, such as a rod, recess, raised projection or other device for engaging with or locating the rock spike 55 relative to the cap 50 may be used. Whilst the rock spike 55 is described as having a corresponding recess 85, other corresponding locating means such as a slot or projection for interacting with the locating means on the cap 50 may be used.

Furthermore, whilst the rock spike 55 and holder 95 are shown and described as being tubular sections having a circular cross section, it will be appreciated that other forms may be used, such as box sections or oval sections. Whilst the arrangement described above are advantageously described for use with a rock spike 55, it will be appreciated that they may be used with other drivable members, such as posts, piles, augers, anchors and the like. Drivable members include any accessory, object or device for use with the post driver, such as rotating augers, and not necessarily just objects that are struck by the weight 30. Furthermore, whilst the collar 60 is described as being formed from two hinged sections, it will be appreciated that more sections or releasable rather than hinged sections may be used and/or other means for selectively retaining/releasing the rock spike 55 may be used. In addition, whilst the described post driver 5 uses a collar 60 to guide the rock spike 55 during driving, it will be appreciated that other guides such as grooved wheels, eyelets, engaging arms and the like may also be used. In addition, the post driver may comprise a rock spike holder 95 having an arm pivotably mounted on the frame of the post driver, wherein the rock spike 55 may be directly transferable between the collar 60 and the rock spike holder 95 in at least one respective position of the rock spike holder 95 and collar 60, as described in GB 2461777, the full contents of which are hereby incorporated by reference.

Claims

CLAIMS1. A post driver comprising a device, such as a storage or retention device, for holding, storing or retaining a drivable member, and at least one driver or ram for moving the storage or retention device and/or drivable member between a first position and a second position.
2. The post driver according to claim 1, wherein the device for holding, retaining or storing is formed of at least two separable and/or hinged parts.
3. The post driver of claim 2, wherein the at least two separable parts are selectively fixable or lockable against separation and/or relative movement, rotation L.0 or pivoting by one or more fixing or locking members.

40)
4. The post driver of any preceding claim, wherein the device for holding, storing or 0 15 retaining comprises a collar or sleeve.
5. The post driver of claim 2 or any claim dependent thereon, wherein the device for holding, retaining or storing is or comprises a clam-shell type device.
6. The post driver of any preceding claim, wherein the driver is a powered driver or ram.
7. The post driver of claim 6, wherein the driver comprises a hydraulically powered, pneumatically powered, electrically powered or magnetically powered driver or a pneumatic or hydraulically powered ram or piston.
8. The post driver of any preceding claim, wherein the at least one driver or ram is configured to rotate the drivable member between the first position and the second position.
9. The post driver of any preceding claim, wherein the driver or ram is controllable using a control that is remote from the driver or ram.
10. The post driver of any preceding claim, wherein the post driver comprises a control unit for operating the post driver to perform a post driving action, wherein the control for operating the driver or ram is comprised in the control unit.
11. The post driver of any preceding claim, wherein the drivable member is or comprises a ground engaging member. a)
12. The post driver of any preceding claim, wherein at least part of the drivable member is configured to be receivable within at least part of the storage or retention Cn device.
13. The post driver of any preceding claim, wherein the device for holding, supporting or retaining is movable using a second driver or ram in a direction parallel with the axis of rotation of the first driver and/or a longitudinal direction of a mast of the post driver.
14. The post driver of any preceding claim, wherein the post driver comprises a mast supported by a frame and a weight or hammer is suspended from the mast, wherein the storage or retention member comprises at least one arm, at least part of the collar or sleeve is integral with or mounted on or to a first end of the arm and a second end of the arm distal from or opposite the first end is pivotably or rotatably mounted or supported on the mast.
15. The post driver of any preceding claim, wherein the driver or ram is selectively extendable and/or contractable or retractable to move the device for holding, storing or retaining between the first and second positions.
16. The post driver of claim 14 or any claim dependent thereon, wherein the device for holding, supporting or retaining is movably supported by a guide, track, pole or rail that extends in parallel with the mast and the device for holding, supported or retaining is movable in parallel with the mast and/or substantially vertically or upwardly/downwardly movable, along the guide, track, pole or rail by a second driver or ram. a)
17. The post driver of claim 16, wherein the device for holding, supporting or retaining is rotatably or pivotably mounted to the guide, track, pole or rail so as to be Cn rotatably or pivotably movable around the guide, track, pole or rail under the action of the driver or ram.
18. The post driver of claim 17, wherein a first end of the driver or ram is pivotably attached or coupled with the arm of the device for holding, supporting or retaining and a second end of the driver or ram is mounted to or supported by the mast and/or the guide, track, pole or rail such that it is fixed against rotation around the mast and/or the guide, track, pole or rail.
19. A method of operating the post driver of any preceding claim, the method comprising: providing a post driver adapted to drive a drivable member; and moving a drivable member between at least a first position and a second position using a driver or ram, such as a powered driver or ram.
20. An assembly for a post driver, the assembly comprising a device, such as a storage or retention device, for holding, storing or retaining a drivable member, and at least one driver or ram for moving the drivable member between a first position and a second position. (3) OOAmendment to Claims have been filed as followsCLAIMS1. A post driver comprising a device for releasably holding a drivable member, wherein the drivable member is an accessory for use with the post driver, and at least one powered driver for moving the device between a first operational position and a second storage position, wherein the post driver comprises a mast supported by a frame and a hammer suspended from the mast, wherein the device for releasably holding is movably supported by a rail that extends in parallel with the mast, and the device for releasably holding is movable along the rail by a second driver.2. The post driver according to claim 1, wherein the device for releasably holding comprises a collar formed of at least two separable or hinged parts.N 15 3. The post driver of claim 2, wherein the at least two separable or hinged parts C\I are selectively lockable against relative movement by one or more locking members.4. The post driver of any preceding claim, wherein the device for releasably holding is a retention device.5. The post driver of any preceding claim, wherein the device for releasably holding is or comprises a clam-shell type device.6. The post driver of any preceding claim, wherein the at least one powered driver is selected from a hydraulically powered, pneumatically powered, electrically powered or magnetically powered driver or a pneumatic or hydraulically powered ram or piston.7. The post driver of any preceding claim, wherein the at least one powered driver is configured to rotate the drivable member between the first operational position and the second storage position and/or the at least one powered driver is controllable using a control that is remote from the driver.8. The post driver of claim 7, wherein the post driver comprises a control unit for operating the post driver to perform a post driving action, wherein the control for operating the at least one powered driver is comprised in the control unit.9. The post driver of any preceding claim, wherein the drivable member is or comprises a ground engaging member.10. The post driver of any preceding claim, wherein at least part of the drivable member is configured to be receivable within at least part of the device for releasably C\I holding.11. The post driver of any preceding claim, wherein the device for releasably holding is movable using the second driver in a direction parallel with a longitudinal direction of a mast of the post driver.12. The post driver of claim 2 or any claim dependent thereon, wherein the device for releasably holding comprises at least one arm, at least part of the collar is integral with or mounted on a first end of the arm and a second end of the arm distal from the first end is pivotably supported on the rail.13. The post driver of any preceding claim, wherein the at least one powered driver is selectively extendable and retractable to move the device for releasably holding between the first operational and second storage positions.14. The post driver of claim 12, wherein a first end of the at least one powered driver is pivotably coupled with the arm of the device for releasably holding and a second end of the at least one powered driver is supported by the mast such that the at least one powered driver is fixed against rotation around the mast.15. The post driver of any preceding claim, wherein the drivable member is positioned underneath hammer in the first operational position, and the drivable member is not located below the hammer in the second storage position.16. A method of operating the post driver of any preceding claim adapted to drive a drivable member, wherein the drivable member is an accessory for use with the post driver, the method comprising: C\I providing the post driver; moving the device for releasably holding the drivable member of the post driver between at least a first operational position and a second storage position using a powered driver; and removing the drivable member from the device for releasably holding; or placing the device for releasably holding into a configuration in which the device for releasably holding holds the drivable member.17. An assembly for a post driver, the assembly comprising a device for releasably holding a drivable member, wherein the drivable member is an accessory for use with the post driver, and at least one powered driver for moving the device for releasably holding between a first operational position and a second storage position, wherein the assembly comprises a mast supported by a frame and a hammer suspended from the mast, wherein the device for releasably holding is movably supported by a rail that extends in parallel with the mast, and the device for releasably holding is movable along the rail by a second driver.18. A post driver as hereinbefore described with reference to Figures 10 to 15.19. A method of operating the post driver as hereinbefore described with reference to Figures 10 to 15.20. An assembly for a post driver as hereinbefore described with reference to Figures 10 to 15. N C\I