GB2485879A

GB2485879A - A post driver with positioning means

Info

Publication number: GB2485879A
Application number: GB1119832.2A
Authority: GB
Inventors: John Mowatt Bryce
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-11-18
Filing date: 2011-11-17
Publication date: 2012-05-30
Anticipated expiration: 2031-11-17
Also published as: GB2485879B; IE86205B1; GB201019531D0; GB201119832D0

Abstract

A post driver 5 has a frame 20, 25 with attachment means 15a, 15b, 15c, which may be used to mount the driver to a tractor, a mast 10 supported by the frame and adapted to allow a weighted member (120, figure 10) to travel up and down. There are at least two independently operable hydraulically operated legs 50, 55. There are side shift means 125a, 125b, which may be pistons, to enable positioning of the mast to be optimised for alignment with a post to be driven. There may also be backshift means 80a, 80b. The mast is provided on an opposite side of the frame to the attachment means. A second invention discloses a post driver which has back shift means. The mast may be located at a centre of the post driver in a lateral direction.

Description

POST_DRIVER

FIELD OF flWENTION

The present invention relates to post drivers f or driving, for example, posts into the ground. The present invention also relates to a method of using said post drivers, BACKGROWW OF flWENTION Post drivers usually consist of a vertical pillar1 column or mast f or guiding a falling weight that is lifted by hydraulic power from, for example, a tractor on which the post driver is mounted. A small ram, working through a leverage system, may pull a rope over a pulley at the top of the pillar or column so as to lift the weight in order that it may then be dropped onto a post.

However, existing post drivers suffer from a number of disadvantages. For example, existing post drivers have difficulty in driving posts in hard hill country. In addition, to properly align existing post drivers, a connected tractor needs to be moved backwards and forwards to correctly posicion the post driver. Such pnvement for the tractor can lead to excessive clutch wear, it is also difficult to obtain small movements of the tractor on uneven ground.

it is known to provide a post driver comprising a frame having attachment points for mounting the frame to a vehicle such as a tractor. The mast is mounted on a side face of the frame in the vehicle width direction and a counterbalance is mounted on an opposing side face of the frame in a vehicle width direction. In this way, in use, the vehicle can be driven alongside a fence line and stopped at positions where it is desired to drive in a post, whereupon, the post can he driven in using the weight on the side mounted mast. In this way, manoeuvring and reversing of the vehicle is reduced, It is an object of at least one aspect of the present invention Lo obviate or mitigate at least one or

more problem with the prior art.

It is a further object of at least one aspect of the present invention to provide a post driver that provides improved driving power and manoeuvrability.

It is a further object of at least one aspect of the present invention to provide a more compact and/or lighter and/or less complex and/or less expensive post driver swai OP tN1NTXON According to a first aspect of the present invention there is provided a post driver comprising: a frame, the frame comprising attachment means for mounting the post driver; a mast supported by the frame and adapted to allow a weighted member to travel up and down; positioning means for enabling the position of the mast to be optimised and adapted for alignment with a post to he driven; and wherein the positioning means comprises a hackshift; and the mast is provided on an opposite side of the frame to the attachment means.

Advantageously, the positioning means may comprise a side shift.

Advantageously, the post driver may comprise at least two independently operated or operable hydraulic legs. At least two of the legs may optionally be laterally spaced apart.

The backshift may he configured to move the mast in a longitudinal direction. The sideshift may be configured to move the mast in a lateral. direction.

Preferably, the post driver may comprise tilt means for tilting the mast and/or post driver, for example, in a lateral. direction.

A combination of tilt; means for tilting the mast and/or post driver in a].ateral direction and a plurality of laterally spaced independent hydraulic legs provides particular advantages. In part cular, without the independently operable hydraulic legs, when tilting the mast, the frame may be rotated and moved, through an arc such that the post driver sits either on the left or right corner of the main frame. In addition, there may he some degree of motion or].ooseness in the support of the post driver, for example, due to deflection or flexing in the pneumatic tyres of the vehicle upon which the post driver in mounted. Additionally, there may be multiple movable joints, with ten movable joints not uncommon, between the vehicle and the post driver. Each joint may have a tolerance or inherent looseness, which may multiply up over each joint, This motion of the post driver may lead to problems when driving in a post.

The combination of independently operable hydraul i c legs with the tilt means allows each leg to be extended by the height required to support the post driver, regardless of the angle of tilt. in this way, the post driver may be operated in a stable manner, regardless of the angle of tilt or any looseness in the coupling. This extra stability may allow the post driver to he l.if ted higher and/or tilted further for example.

it will be appreciated that a longitudinal direction is a direction extending rearwardly of the vehicle and/or in a direction from an end of the post driver where the attachment means are provided to an end of the post driver where the mast is provided. The lateral direction is generally perpendicular to the longitudinal direction,

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for example in a horizontal direction, which may be a left and right in the vehicle and/or post driver.

The hackshift may be configured to move the mast toward and/or away from the attachment means. In use, S the backehift may be configured to move the mast toward and/or away from a vehicle attached to the post driver via the attachment means.

By providing the mast on the opposite side of the frame to the attachment means a vehicle or othe.r :10 apparatus upon which the post driver is mounted may be operable as the counterbalance, which may provide stable and safe operation of the post driver and may minimise the weight and number of components of tt.ie post driver and provide a more compact system.

The attachment means may comprise means for mounting the post to driver to a vehicle, such as a. tractor or the like, and/or an articulated hydraulic arm or other device or structure to which it is desired to mount the post driver, such as diggers, loaders and telehandlers, The post driver may be configured such that the vehicle, device or structure mounts to the post driver along a generally longitudinal direction of the post driver.

The mast may be located or locatable at a centre of the post driver in a lateral direction which, in use, may be a vehicle width direction. For example, the mast may be i.ocatable at the centre of the post driver in a lateral direction using the side shift4 In this way a stable transport and/or operation position may be achieved.

The mast may be located or locatable in a position on the frame opposite at least part of the attachment means.

The side shift and back shift may allow the mast to be moved respectively laterally and longitudinally without having to move the frame itself and/or a connected vehicle. Typically, the back shift and side shift are at substantially 900 to one another thereby allowing the mast to be moved over a full range of directions i.e. side to side and front to back. This has the specific advantage that the position of the mast can be altered and adjusted to obtain optimal alignment with a post. The back shift and side shift may be hydraulically operated thereby allowing easy and accurate adjustments of the position of the mast to be made. The back shift and side shift may have any suitable range of travel such as about 100 to 1,000 mm or preferably about 600 mm for the side shift and 100 mm to 1,000 mm or preferably about 300 mm for the back shift. Telescopic members may be used to obtain the movement for the side shift and/or back shift.

The frame may comprise at least a first frame section and a second frame section. The first or second frame section may be movable relative to the other of the first or second frame section.

The relative movement of the first and second sections may he under the action of backshift drive means. The hackshift drive means may comprise extendahJ.e members, which may be telescopic, such as hydraulic backshift rams. The first frame section may comprise the attachment means. The mast may be mounted or mountahi.e on the second frame section. The first and second frame sections may he configured for relative motion such that at least part of the first frame section and at least part of the second frame section are movable together and apart, which may be in a longitudinal direction of the post driver. In this way, the mast may be movable closer and further away from the attachment points to thereby provide a hackshift mechanism.

One of the first or second frame sections may comprise hollow backshift outer members and the other of the first or second frame sections may comprise backshift inner members which may be slidably located or locatable within the backshift outer members. The hackshift inner and ouEer members may be in a telescoping arrangement.

The backshi.ft inner members may be hollow. The backshift drive means may be located or locatable within the outer and/or inner backshifc members. Wear pads may he provided between the inner and outer backshift members,

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for example, between the outer top wall of the backshift inner member and the inner top wail of the back shift outer member. The wear pads may preferably he static wear pads but may instead be rotary wear pads.

The second frame section may comprise a mast support member. The mast support member may comprise a cross beam or runner, which may extend Iateral].y, The mast may comprise or be mounted or mountable on a mast carriage. The mast carriage may be slidable or movable on the support member, for example, in a lateral direction Bearings may be provided between the mast: carriage and the mast support member, The side shift may comprise a non-telescoping sideshift÷ The side shift may comprise at least one side shift driver for moving the mast in a lateral or width wise direction of the post driver, which may be a lateral direction perpendicular to a direction in which the attachment means and first frame lie.

The side shift driver(s) may be operable to move the mast laterally to at least one side of the centre of the post driver and preferably to both sides of the centre of the post driver in a lateral direction.

One or more side shift: drivers may he mounted between the mast and/or mast carriage and the second frame section. A first side shift driver may be mounted to a first portion of the second frame section. A second

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side shift driver may he mounted to a second portion of the second frame section. The first portion of the second frame may be on an opposite side of the mast to the second portion. in this way, the mast carriage may be slidable laterally along the mast support member under the action of the one or more side shift drivers.

Preferably, the at least one side shift driver may comprise at least one extendable member, which may be telescopic, such as a side shift hydraulic ram.

Two side shift drivers may be provided. At least one side shift driver may be configured for motion in a substantially opposite direction to at least one other side shift driver. The opposing side shift drivers ina.y be arranged in a piggy back configuration, which may comprise one end of the at least one side shift driver being mounted to the mast and/or mast carriage adjacent and above an end of the at least one other side shift driver. However, it will be appreciated that the opposing side shift drivers may be mounted aligned end to end. The side shift drivers may he mounted in a pull me -push you arrangement, for example, when a chamber of one opposing side shift driver is being pressurised, a chamber of the opposing side shift driver is depressurised and vice versa.

The side shift driver(s) may be single action, :i.e.

they are configured to substantially apply a force in only one direction.

However, although a pair of side shift drivers are described above2 it will be appreciated that optionally only one side shift driver may be provided, it will also be appreciated that double action (i.e. adapted to substantially apply a force in two directions, such as expanding and contracting) may be used.

Each side shift driver may comprise a hydraulic ran having at least two stages, for example, a double action ran. The hydraulic ram may be a telescoping hydraulic ram, which may have at least two telescoping stages or ranges of movement.

:1.5 A first stage of movement may comprise a first telescoping member of the ran telescopically moving relative to a second telescoping mei..her of the ram. A second stage of movement may comprise the second telescoping member telescopically moving relative to a third telescoping member of the ram, in a preferred but not essential configuration, two or more stage hydraulic rams are provided in an opposing configuration, wherein the rams are single acting rams and a first of the opposing rams is operable to respectively contract or expand the second of the opposing rams whilst the first ram is being expanded or ii contracted respectively, This configuration results in an improved side shift motion, particularly having a larger range of travel, This configuration may provide a compact side.shift mechanism having a large range of motion.

In an optional embodiment, the side shift may comprise a trunion arrangement. In an optional embodiment, the mast may comprise a screw thread member and the side shift drive means may comprise screw engagement means coupled to the second frarrie section, such as a cog or complimentary screw threaded member, for engaging and actuating the screw thread member to thereby laterally move the mast The side shift drive means may comprise a motor, such as an oil motor, for moving the screw engagement means and thereby the screw thread aeraber and mast, Typically, the mast may be uelescopic up to any suitable length such as! for example, allowing up to about ten foot posts and ground anchors to be driven in.

The telescopic mast has all the advantages of a tall fixed mast thereby offering maximum impact and yet also allowing the post driver to be moved and transported in a compacted configuration.

Preferably, the weighted member may he a hitting hammer which may have a weight of about 100 to 1,000 kilograms or preferably about 400 to 600}.ilograms The weight of the weight.ed. .member may be adapted for different situations e.g. hardness of the ground.

By providing a plurality of legs, the apparatus may have a stable configuration during use, For example, two or more supporting legs on skid plates may be used. The skid plates provide a stable footing for the post driver.

Independently hydraulically operable legs allow the apparatus to operate on uneven ground and/or stabilise the post driver, as described above. The legs may be mounted on the first frame section.

The legs may be operable using one or more hydraulic rams, which may be driven from a hydraulic pressure feed and/or controller via hydraulic pipes A safety valve may be provided between the hydraulic pressure feed and the hydraulic rams, wherein the safety valve may be adapted to shut/close in the event that the hydraulic ram, feed or pipes are depressurised, such as being suddenly or rapidly depresurised, eg due to a leak or burst. In this way, the pressurised line on the other end of the safety valve from the leak remains at least partially pressurised, which may prevent the hydraulic legs from unexpectedly retracting.

Preferably, the safety valve is located on the hydraulic pressure feed further towards the hydraulic ran than towards a pressure source. The safety valve may preferably by incorporated with, located on, adjacent to or proximate to the hydraulic ram. In this way, a proportion of the hydraulic system in which leaks or bursts could occur and where the safety valve could still protect the pressure supplied to hydraulic ram would be maximised, At least one arid preferably each of the hydraulic rams of the post driver may be provided with a safety valve, which may be a safety valve as described above.

For example, safety valves could be provided in, on, adjacent to or proximate to a hydraulic tilt ram, a hydraulic ram for extending/contracting the mast and/or hythaul. Ic rams for operating the back and! or side shifts, The attachment means may comprise means for allowing arcuate motion of the post driver in a plane substantially perpendicular to a ground surface and/or a substantially vertical plane.

The attachment means may provide a plurality of attachment points between the post driver and the vehicle.

Typically, the post driver may comprise a plurality of attachment means, for example, first, second and third attachment means for directly or indirectly attaching the post driver to first, second, and third attachment portions of the vehicle respectively.

The first and/or second attachment portions may be located near a bottom portion of a rear chassis of the vehicle.

The third attachment portion may be located near a rear chassis portion of the vehicle in an elevated position relative to the first and/or second attachment portion.

Typically, the first and/or second attachment means may be attachable to the respective first and second attachment portions of the vehicle via respective first and second support arms extending from and/or secured to a bottom portion of the rear chassis of the vehicle, and typically also respective first and second attachment members for attaching the respective first and second Is support arms to the respective first and second attachment means of the post driver.

Typically, the third (or upper) attachment means may be attachable to the third (or upper) attachment portion of the tractor via a top or third extendable attachment member between the third attachment portion of the tractor and the third attachment means of the post driver. By such provision, the post driver may be pivoted relative to an imaginary axis extending between the first and second attachment members, Le.. in a vertical plane and/or a plane perpendicular to the ground, in use, by operation of the third extendable attachment member.

The top or third extendable attachment member may comprise, eg. * a hydraulic ram, or a mechanically extendable member.

Typically, the third extendable attachment member may be secured to the third attachment portion of the tractor and/or the third attachment means of the post driver by fixing means such as a knuckl.e link, perforated plates and pins or the like. The fixing means may comprise a plurality of fixing points, for example, a plurality of holes in a perforated plate, which may provide a range of fixing angles.

Optionally, the first and/or second attachment members may comprise movable or pivotable attachment members, which may comprise a ball Joint> In one embodiment, the third (or upper) extendable attachment member may he pivotahle relative to the third attachment portion of the tractor and/or to the third attachment means of the post driver, Typically, the third extendable attachment member may be secured to the third attachment portion of the tractor and/or to the third attachment means of the post driver by at least one

pivotable member.

In another embodiment, the attachment of the third extendable attachment member to the third attachment portion of the tractor and/or to the third attachment means of the post driver may comprise e.g. a bracket provided with eg. guiding grooves to allow for such arcuate motion, In another embodiment, the attachment of the third extendable attachment member io the third attachment portion of the tractor and/or to the third attachment means of the post driver may exhibit a degree of looseness sufficient to allow for arcuate motion.

Preferably, the at least one third pivotable member may comprise a ball provided within a receiving portion of the third extendable member, which may he at or near an end nearest the third attachment portion of the tractor and/or the third attachment means of the post driver.

Conveniently? the receiving portion may be arranged to allow for rotational and/or pivotal motion of the ball, and may be arranged to prevent disconnection of the ball from the third extendable member.

The third telescopic member may comprise a two stage hydraulic link. By providing a two stage third hydraulic member, additional z.:ravel may be provided, which may he used to get the travel required to get the mast vertical on sloping ground. Furthermore, with at least one of the independent hydraulic legs extended so that the post driver is raised, some of the extension of the third telescopic member may be used to accommodate the extension of the legs. By using a two stage hydraulic l±nk, extra travel is provided, which may be used to align the mast, even when the some of the extension is taken up by accommodating the hydraulic leg extension.

According to a second aspect of the present invention is a post driver comprising: a frame, the frame comprising attachment means for mounting the post driver; a a mast supported by the frame and adapted to allow a weighted member to travel up and down; and positioning means for enabling the position of the mast to be optimised and adapted for alignment with a post to be driven; and the mast is located or locatable centrally of the post driver in a lateral direction.

By making the mast located or locatable centrally in a lateral direction (eg. a direction perpendicular to the direction in which a vehicle mounts to the post driver), the mast may be more stably configured.

The mast may be movable lateral..ly to both sides of the centre of the post' driver in a lateral direction.

According to a third aspect of the present invention there is provided a post driver comprising: a frame, the frame comprising attachment means for mounting the post driver and a mast support member; a mast adapted to allow a weighted member to travel up and down; and wherein, the mast is mounted on or integral with a mast carriage and the mast carriage is movably mounted on the mast support member.

The mast carriage may be slidably mounted on the mast support member.

The mast suoport member may extend in a lateral direction. The mast support member may comprise a beam, :to which may comprise a hollow beam such as a box section beam.

The mast carriage may comprise bearings and/or wheels and/or rollers. The mast carriage may he movable by one or more extendable members, which may comprise a hydraulic piston, and preferably comprises two opposing pistons.

According to a fourth aspect of the present invention there is provided a post driver comprising a frame, the frame comprising attachment means for mounting the post driver; a mast supported by the frame and adapted to allow a weighted member to travel up and down.; and positioning means for enabling the position of the mast to he optimised and adapted for alignment with a post to be driven, The positioning means may comprise side shift means, which may be configured to move the mast in a lateral direction of the post driver.

The post. driver may comprise at least t.wo S independently operable hydraulically operated legs.

The post driver may comprise tilt means for tilting the mast and/or post driver1 for example, in a lateral direction.

The mast may be provided on an opposite. side of the frame to the attachment means.

The positioning means may comprise back shift means, which may be configured to move the mast in a forwards/backwards or longitudinal direction of the post driver or towards and away from the attachment means.

The frame may comprise a firsL frame section, which may comprise or be provided with at least one and preferably all of the attachment means, The mast: may be movable or slidable relative to the first frame section.

The frame may comprise a second frame section or mast support for supporting the mast:. The second frame section or mast support may be movably or slidably mounted to the first frame section.

The side shift may comprise the relative movement or sliding of the first and second frame sections.

One of the first or second frame sections may comprise at least one hollow member for receiving at

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least one corresponding slidable member of the other of the second or first frame sections. Relative movement of the first and second frame sections may he hydraulically operable, for example, using one or more hydraulic rams mounted between the first and second frame sections.

The post driver may comprise two or more legs. At least one leg may be adjustable. At least one leg may be hydraulically adjustable. The legs may be independently adjustabi.e, At least one leg may be fixed, At least one leg may be slidably receivable within a hollow member of the frame, which may be an. upright member.

The attachment means may comprise at least two and preferably three attachment means. The attachment means may be adapted to pivotably couple to a vehicle, hydraulicly operated arm or other supporting apparatus.

The attachment means may comprise or be configured to receive a ball of a ball joint or may comprise at least part of a ball joint.

The post driver may comprise at least one and preferably at least two tilt mechanisms, which may he configured to tilt the post driver through a vertical tilt plane. At least one and preferably each tilt mechanism may he configured to rotate the post driver and/or mast in a lateral direction, which may be perpendicular to the direction in which the post driver couples to the vehicle, arm or other supporting apparatus.

At least one of the tilt mechanisms may comprise a movable or sliaable tilt member, which may be mounted on the frame so as to be relatively movable or slidabie therewith. The slidable member may comprise or be provided with at least one oi. the attachment means for coupling the post driver to a vehicle, arm or other support apparatus.

The movable or slidable tilt member may be hydraulically mocrable or slidable relative to the frame.

The movable or slidable tilt member may be movably or slidably mounted to a member of the frame, such as an upright member. The movable or slidable member may be movable or slidable in a vertical direction of the frame.

The post driver may comprise a hydraulic tilt ram, which may be provided between the slidable member and the frame, for example, in parallel with the slide direction of the slidable member, which may be substantially vertical, in use The hydraulic tilt ram may he configured to slide the slidable member relative to the frame.

The post driver may comprise at least one further attachment means, whIch may be comprised in or mounted to the frame, for example, on another upright member of the frame. The further attachment means may be spaced laterally from the attachment means of the tilt member.

The further attachmenc means may comprise a pivoting or pivotable attachment means, such as a ball joint.

In this way, since one attachment means is provided on the tilt member so as to be movable or slidable relative to the frame, utilst another attachment means is fixed relative to the frame, operation of the hydraulic tilt ram moves the frame relative to the slidable member so as to tilt, pivot or rotate the post driver around the pivotable joint of the attachment means that is fixed relative to the frame. Since the attachment means that i.e fixed relative to the frame (and preferably also the attachment means provided on the tilt member) is coupled to the vehicle via a pivotable joint, such as a ball joint, the post driver is free to rotate around the fixed attachment means.

With. the attachment means of the slidable member being laterally spaced from the attachment means of the frame, the tilting of the frame (and thereby the mast) is in a lateral plane.

The tilt mechanism may be a primary tilt mechanism.

The independently adjustable legs may comprise or form a secondary tilt mechanism and/or a machine stabiliser including height contrrol, The secondary tilt mechanism may comprise extending at least one leg and/or retracting at least one other leg in order to tilt the post driver.

The mast may be provided with a support leg at the bottom of the mast. The support leg may be extendable

and retractable.

The post driver of the fourth aspect may comprise one or more features described in relation to any of the first to third aspects. The post driver of any of the first to third aspects may also comprise one or more features described in relation to the fourth aspect.

According to a fifth aspect of the invention is apparatus comprising a vehicle provided with or having mounted on it a post driver according to any of the first to fourth aspects of the invention.

According to a sixth aspect of the present invention there is provided a method of using the post driver according to any of the first to fourth aspects of the vehicle of the fifth aspect in driving a post into the ground.

Features described in relation to any of the above aspects of invention! may also be optionally applicable to any other of the above aspects of invention. Method features analogous to any described apparatus features or vice versa are also incorporated herein. 7 Li

RXEF DESCRIPTION OF DRAWINGS

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which; Figure 1 is a front or vehicle mounting end view of a. post driver according to an embodiment of the present invention; Figure 2 is a rear or mast end view of the post driver shown in Figure 1; Figure 3 is a side view of the post driver shown in Figures 1 and 2; Figure 4 is a top view of the post driver shown in Figures 1 to 3; Figure 5 is a perspective view of a frame for use in the post driver of Figures 1 to 4; Figure 6 is a perspective view of the frame shown in Figure 5; Figure 7 is a side view of the frame shown in Figures 5 and 6; Figure 8 is a side view of the post driver of Figures 1 to 4 mounted to a vehicle; Figure 9 is a side view of the post driver of Figures 1 to 4 in a hackshif ted configuration and mounted to a vehicle; Figure 10 is a portion of a mast for use with the post driver of Figures 1 to 4; Figure 11 is a rear view of the post driver of Figures 1 to 4 mounted to a vehicle; Figure 12 is a rear view of the post driver of Figures 1 to 4 in a first sideshifted configuration and znounced on a vehicle; Figure 13 is a rear view of the post driver of Figures 1 to 4 in a second sideshif ted configuration and mounted on a vehicle; Figure 2L& is a rear view of the post driver of Figures 1 to 4 in a configuration wherein at least one of the independently operable hydraulic legs has been extended; Figure 15 is a side detail view of a part of a post driver according to an embodiment of the present invention; Figure 16 is a detail view from the rear and side of a part of the post driver of Figure 15; and Figure 17 is a rear view of the post driver of Figures 15 and 16 is use.

TAtLED ESCRXPTION OF DWINGZ Figures 1 to 4 show a mountable post driver 5 having a mast 10 mounted on a side of the post driver 5 opposite to a side of the cost driver 5 that comprises means for mounting the post driver iSa, 15b, lSc. The post driver comprises a first frame section 20 and a second frame section 25, which are shown in detail in Figures 5 to 7., Throughout the Figures, the mast may be shown in a generalised or partial form and it will be appreciated that the mast optionally comprises features such as at least one of a hammer, telescoping mast sections, one or more pulleys, guide rails, hitting cap and the like that are known in the art, for example.

The first frame section 20 is formed from hollow steel box section members and comprises upper 30 and lower 35 cross beams extending between left 40 and right upright sections. Each of the left 40 and right 45 upright sections contain respective left 50 and right 55 legs, which are slida.bly received within the left 40 and right 45 upright sections,, The left 50 and right 55 legs are independently hydraulically operable and may be adjusted to any required level, for example to compensate for the ground being sloping or to tilt the post driver.

Each leg is provided with a skid 60a, 6Db in order to prevent the leg 50, 55 becoming bogged down in infirm ground.

The upper cross beam 30 of the first frame section is provided with an upper attachment portion 15c at the centre of the upper cross beam 30 in a lateral direction. The lower cross beam 35 is provided with left iSa and right 15b lower attachment portions, the left iSa and right 15b lower attachment portions being respectively laterally displaced relative to the upper attachment portion 15c, such that the upper attachment portion 15c lies above and between the left ISa and right i5h lower attachment portions in a triangular arrangement. The upper lSc, lower left ISa arid lower right iSh attachment portions each comprise a pair of plates mounted in parallel to each other, the plates being welded to the appropriate upper or lower cross beam and extending therefrom in a direction away from the ID second frame section. Each plate comprises one or more holes for receiving a pin in order to mount the post driver.5. Provision of more than one hale allows a variety of mounting options.

The first frame section 20 is provided with two IS parallel hollow box section tubular hackshift outer members 65a, 65b rigidly mounted or formed between the upper 30 and lower 35 cross beams of the first frame section 20. The backshift outer members 65a, 65b, for example. welded to or integral with an upper surface 70 of the lower cross beam 35 and to a lower surface 75 of the upper cross beam.30. The hackshift outer members 65a, 65b extend in a direction perpendicularly to both the cross members 30, 35 and the upright members 40? 45 of the first frame section 20.

Backshift inner members 80a1 ROb are slidably mounted within respective backahift outer members 65a, 65k. An end of each backshift inner member BOa, 8Db that is positioned furthest from the end of the post driver 5 that comprises the means for mounting iSa, 15k, lSc is attached to the second frame section 25, for example by being welded to upper 85a and lower 85k cross members of the second frame section 25.

The second frame section 25 is formed from tubular steel box section members and comprises at least upper 85a and lower BSb cross beams disposed between left 95a and right 95k upright members, Hydraulic backshift rams YOa, 90k are provided to act between each of the respective inner BOa, 8Db and outer 65a, 65k backshift members. In this way, the second frame section 25 is movable towards and away from the first frame section 20 by the relative sliding motion of the inner BOa, BOb and outer GSa, 65k backsh±ft members under the action of the hydraulic backshift rams 90a, 90h, as shoi in Figures 8 and 9, in this case, in a direction that is perpendicular to both the cross members 30, 35, 85a, 85b and the upright members 40., 45, 95a, 95k of the first 20 and second 25 frame sections.

One or more, and in this case two, balancing legs iOOa, 100k are provided extending from the second frame section 25 and extend in a longitudinal direction perpendicular to both the upright 95a, 95b and cross members BSa, 85k and in a direction away from the first frame section 20. The end of the balancing legs are provided with downwardly extending feet 105a, lUSh such that the post driver 5 may be sat On the ground restina on the left and right independent hydraulic legs 60a, 6Db of the first frame section 20 in a fully retracted configuration and the feet lOSa, 105b of the balancing legs of the second frame portion 25. This configuration with balancing legs iDOa, IDOb extending in a direction away from the first section 20 increases the stability of the post driver 5 when resting on the ground,.

A mast carriage 110 is movably or slidably mounted on the top cross beam SSa of the second section 25. A mast 115 is mounted on or integral with the mast carriage, such that the mast is provided on an opposite side of the second frame section to the first frame section. ie. on a side of the post driver opposite to the attachment portions. The mast 115 comprises a hitting hammer 120 (shown in Figure 10) that is slidable up and down the mast 11.5 in use to drive in a post, support or the like. The mast 115 may take the form of any suitable mast: configuration known in the art, for example, the double pulley telescoping mast described in GB2441071B, which is hereby incorporated by reference, a portion of which is shown in Figure 10.

The mast carriage 110 comprises a vertically extending piston attachment rod 120. A pair of opposing 3 U sideshift pistons 125a, 125b are provided between the second frame section 25 and the mast carriage 110 for moving the mast carriage 110 on the top cross beam. The first opposing sideshift piston 125a is provided between the left upright member 95b of the second frame section and the piston attachment rod 120 of the mast carriage and the second opposing sideshift piston 125b is provided between the right upright member of the second frame section and the piston attachment rod of the mast.

The opposing sideshift pistons 125a, 125b are arranged in a piggy-back configuration, i. e. one of the opposing sideshift pistons 125b is positioned to he higher than the other opposing piston 125a such that the end of the upper opposing piston l25h that is connected to the piston attachment rod 120 sits immediately above an end of the other opposing piston 125a, 125b. in this embodiment, two single action pistons are used, i.e. each piston is operable to apply force in only one direction, although it will be appreciated that one or more than one double action pistons (i.e. operable to apply a force in two opposing directions) may be used instead. The opposing pistons are telescoping rams having two stages, Le. the rams comprise a first inner telescoping member slidahly arranged within an. outer telescoping member and a second inner telescoping member slidably arranged within the first inner telescoping member Thereby, a ran having two distinct movement stages is provided As shown in Figures 11 to 13, the first opposing piston 125a is operable to push the mast 115 away from S the left upright member 95a and toward the right upright member 95b, i.e. in a left to right when viewed from the front of the post driver 5 or widthwise or lateral direction (as shown in Figure 13), whilst the second upright piston 125b is operable to push the mast 115 away from the right upright member 95b towards the left upright member 95a, Le. right to left when viewed from the front of the post driver or widthwise or lateral direction (as shown in Figure 12).

In this way, the opposing sideshift pistons 125a, l2Sb may be utilised in a "pull me push you" fashion? wherein, when one side shift piston 125a, 125b is pressurised with hydraulic fluid, it acts to move the mast carriage 110 and hydraulic fluid is evacuated from the other opposing sideshift piston 125b, 125a, to move the mast carriage 110 and thereby the mast 115 about a position in the centre of the top cross beam 85a of the second frame section 25 towards the right or left side of the cross beam BSa by appropriate activation of a selected opposing hydraulic sideshift piston 125a, 125b.

In. this way, a controlled and smooth lateral movement of the mast 115 i.s achieved, Furthermore, a wide range of lateral. notion is provided, the range of motion extending to both sides of the centre of the post driver 5 in a widthwIse or lateral direction. In addition, the use of two opposing pistons 125a, l25b in this manner provides a S compact and reliable means for lateral movement. Since the lateral or sideways range of)tion of the mast is at the widthwise centre of the post driver 5, greater balance and stability may be achieved.

By providing the mast 115 on a side of the post driver 5 opposing the vehicle attachment means ISa, lSb, l.Sc, in use, a lighter and more compact but stable post driver can be provided, since the vehicle to which the post driver is attached may act as a counter balance! which may eliminate or reduce the need for a dedicated counterbalance, The post driver 5 may be attached to a vehicle or other apparatus by any means known in the art1 for example; by a. conventional 3 point linkage, comprising two i.ower attachment points and an tipper attachment point. The post driver nay be attached via attachment means that allow a degree of pivotable motion, such as ball. joints. The two lower attachment points may be on the end of respective first and second support arms IGUa, 16Db.

The post driver may he attached to an upper attachment point:iSOc of the vehicle or apparatus via a top shift extending member lSSc, such as a telescoping hydraulic ran. The distal end of the top shift extending member 155c is attached to the vehicle near a rear chassis portion of the vehicle and in an elevated position ISOc relative to the first and second support arms lGOa, 160b. In this way, the top shift extending member 155c is operable to pivot the post driver 5 relative to an imaginary axis extending between the ends of the lower right and lower left support arms to which the post driver is mounted, which may comprise pivoting in a generally vertical plane and/or a plane substantially perpendicular to a ground surface 170.

In this embodiment, the top shift extending member l55c is secured to the third attachment portion l5Oc of 15. the tractor and to the upper attachment portion of the post driver 15c by means of a bracket and pin or knuckle Advantageously, the top shift extending member:1.SOc may he a two stage hydraulic ram having a first inner telescoping member slidahly arranged within an outer telescoping member and a. second inner telescoping member sli.dahly arranged within the first inner telescoping member. Thereby, a twoS-stage top shift extending member 150c is provided. In this way, enough travel may be provided in the top shift in order to accommodate vertical alignment of the mast by arcuately rotating the post driver in a vertical plane and also have sufficient travel to also accommodate operation of the hydraulic legs, for example, as shown in Figure 14.

As detailed above, movement of the second frame 25 section relative to the first frame section 20 by sliding of the inner backshift slide members BOa, BOb of the second frame section 25 in the outer backshift members GSa, GSh of the first frame section 20 under the action of the backshift hydraulic rams 90a, 90b, the mast is positionable in a forward/backward direction, as shown in Figure 8 and 9 By mounting the mast 115 On the mast carriage 110, the mast is slidable under the action of the opposing side shift pistons 125a, l2Sb in a lateral (left/right) direction and to both sides of the centre of the post driver in a lateral direction, as shown in Figures II to 13. Furthermore, extension and/or retraction of the top extension means lSSc allows the post driver S to be pivoted in a vertical arc around the lower ball joints l35a, :i.35b.

Operation of the independently hydraulically operated legs allows raising, lowering and side to side tilting of the post driver, as shown in Figure 14. In this way, further axes of motion. are provided, which may be especially suitable for aligning the post driver on slopes.

Therefore1 a compact and stable post driver 5 that has a wide range of mast position adjustment options is provided. This is particularly beneficial on a front or rear facing post driver, as additional vehicle manoeuvring may be require to back" the vehicle/post driver up to the post relative to a post driver having a side facing mast The wide range of alignment options provided by the provision of hackshift, sideshift, arcuate motion and/or independent hydraulic operation of the legs allows the mast to be positioned and aligned quickly and simply whilst minimising movement of the vehicle.

In an alternative embodiment, the mast slide member 110' may comprise at least one screw member 175 and the post driver 5 is provided with a motor 180, such as an oil motor for turning a cog 185 or screw for engaging with and actuating the screw member 175 to thereby move the mast slide 110". In a further alternative embodiment, a t:runion may be used to actuate the mast slide.

An alternative or additional embodiment of the invention is illustrated in Figures 15 to 17. These figures show a post driver 1000 having a primary tilt mechanism 1005 and a secondary tilt mechanism 1010 that also acts as a machine stabiliser and height control mechanism.

The nost driver 1000 shown in Figures 15 to 17 comprises a frame 1015 for supporting a mast 1020, a hammer 1025 slidably mounted on the mast 1020 and driving means (not shown) for slidably actuating the hammer 1025 up and down the mast 1020.

The post driver 1000 is mountable to a vehicle 1030 or other support structure via a three point linkage having an upper attachment means 1035a and two lower attachment means 1035b, lO3Sc. The lower attachment means 1O35b 1035c are configured to be pivotable and form, for exanple ball joints, as described above.

A first lower attachment means comprises 1035c a ball 104Cc attached by a spindle lO4Sc that passes through apertures in each of two parallel fixing plates 1050c. The spindle.1045c is secured in position with a fixing pin. The parallel fixing plates:Losoc of the first lower attachment means l035c are fixedly mounted on a first upright section 1055 of the frame 1015.

A second lower attachment means l035b comprises a ball 104Db attached via a spindle 1045b to two apertured parallel plates 105Db1 as in the first lower attachment means 1035c. The apertured parallel plates 105Db are fixed to a movable slide 1050 such that the second lower attachment means 1035b is laterally spaced from the first lower attachment means 1035c.

The balls lO40b l04Oc of the first and second lower attachment means l035b, 1035c may be received or receivable wi chin correspondingly shaped receiving portions l065b, :i.065c coupled with the vehicle 1030 or other support structure so as to be pivotable therein.

The movable slide 1060 comprises a hollow box section mounted so as so be slidably movable up and down a second upright section 1070 of the frame 1015, such as an outer box of a hydraulic leg. The slide 1060 is movable under the action of a hydraulic tilt ram 1075 that extends substantially vertically between the slide 1060 and a fixing point on the second upright section 1070 of the frame 1015.

In this way1 by extending or contracting the hydraulic tilt ram 1075, the second upright section 1070 of the frame 1015 is slidable relative to the slide 1060 comprising the second lower attachment means l035b. As the position of the first lower attachment means l035c is fixed relative to the frame 101.5, extending or retracting the hydraulic tilt ram 1075 causes the frame 1.015 to rotate in a lateral direction through a vertically extending plane around the first attachment means lO3Sc, via pivoting of the ball joints of the first attachment means 1035c.

The above tilt mechanism forms the primary tilt mechanism 1005 for the post driver 1000.

The secondary tilt mechanism 1010 is provided through use of independently adjustable and laterally spaced hydraulic legs 1080a, IDSOb. As described above in relation to the first embodiment, each of the first and second upright sections 1055, 1070 contain respective left. and right legs 108Da, 108Db; which are slidably received within the first and second upright sections 1055, 1070. The first and second legs 1080a, 108Db are independently hydraulically operable and may be adjusted to any required level, for example to compensate for the ground being sloping or to tilt the post driver.

In. this way, extension of one of the legs 1080a, 108Db and/or retraction of another of the legs 1080a, 108Db may be used to tilt the post driver 1000 laterally through a generally vertical and. laterally extending plane In this way an alternative tilt mechanism may be provided or the primary 1005 and secondary 1010 tilt mechanisms may be used in combination in order to provide a far greater range of tilt that that provided by either mechanism 1005, 1010 alone. Furthermore, the independently operable legs lO8Oa, 108Db may be used as a machine stabiliser in order to securely support the post driver 1000 on uneven ground. The legs 1080a, 108Db also provide height control for raising or lowering the post driver 1000, for example, to accommodate long posts.

An. alternative side shift mechanism is disclosed below in relation to this embodiment. However, it will be appreciated that the side shift mechanism of any other embodiment described herein may also he used. in the alternative side shift mechanism, the frame 1015 comprises first: 1085 and second frame sections 1090, wherein the attachment means 1035a, 1035b, 1035c are provided on the first frame section 1085 and the mast is supported on the second frame section 1090. A pair of laterally extending slidable sections 1095a, 1095b of the second frame 1090 are laterally slidable into and out of corresponding laterally extending hollow box section members llOOa, 110Db of the first frame section 1085 under the action of hydraulic rams (not shown). In this embodiment, the mast 1020 is located in a position offset to one side of the centre of the post driver 1000 In a lateral direction.

Whilst specific examples of possible implementations are described in detail above, it will be appreciated that variations to the above examples within the scope of the claims are contemplated.

For ezample, whilst an opposing piston arrangement 125a, 125b for moving the mast in a lateral (side shift) direction comprising two single action pistons is described, It will be appreciated that one or more double action pistons may be used instead.

Furthermore, whilst a dual pulley telescoping mast such as that described in GB 2441071 is detailed above, it will be appreciated that other mast arrangements known in the art may be used, Whilst examples of post drivers are described where the mast is offset to one side and the side shift is provided by two frame sections telescoping into and out of each other and post drivers where the side shift is achieved by providing the mast:. on a carriage that is movably mounted on a frame section are also described, it will he appreciated that features described in relation to one of the above examples may also be equally applicable to any other example of a post driver described herein.

Furthermore, whilst the use and positioning of safety valves has been described in relation to the hydraulic rams used to operate the legs of the post driver, it wi I. be appreciated chat equivalent safety valves may be provided in, adjacent or proximate at least one and preferably each of the other hydraulic rams of the post driver, such as the hydraulic tilt ram(s) mast extension ram(s) and/or side shift and/or backshift rams.

Therefore, the above detailed description is made by

way of example only.

Claims

CLAflW 2.. A post driver comprising: a frame, the frame comprising attachment means for mounting the post driver; a mast supported by the frame and adapted to allow a weighted member to travel up and down; at least two independently operable hydraulically operated legs; and.positioning means f or enabling the position of the mast to he optimised and adapted for alignment with a post to he driven.; wherein the positioning means comprises a side shift and a backshift; and the mast is provided on an opposite side of the frame to the attachment means.
2+. The post driver of claim 1, wherein the post driver comprises tilt means for tilting the mast and/or post driver in a lateral direction.
3+ The post driver according to claim I or claim 2, wherein the backshift is configured to move the mast toward and/or away from the attachment means.
4, The post driver according to any preceding claims, where the mast is located or locatable at a centre of the post driver in a lateral direction.
5, The post driver according to any of the preceding claims, wherein the frame comprises at least a first frame section and a second frame section, wherein the first or second frame section are movable relative to the other of the first or second frame section under the action of backshift drive means.
6. The post driver according to claim 5, wherein the first frame section comprises the attachment means and the mast is mounted or mountable on the second frame section and the first and second frame sections are configured for relative motion such that the mast and attachment means are moveable toward and away from each other.
7.. The post driver according to claim S or claim 6, wherein one of the first or second frame sections comprise hollow backshift outer members and the other of the first or second frame sections comprise hollow hackshift inner members that are slidably located or locatable within the hackshift outer members and the backshift drive means are located or locatable within the outer and/or inner backshift members,
8. The post driver of claim 7, wherein wear pads are provided between the inner and outer hackshift members.
9. The post driver according to any of claims S to 8, S wherein the second frame section comprises a laterally extending mast support member, and the mast comprises or is mounted or mountable on a mast carriage, the mast carriage being slidable or movable on the support member 10, The post: driver according to any preceding claim, wherein the side shift comprises a non-telescoping side-shift.1.1. The post driver according to any preceding claim, wherein the side shift comprises at least one side shift driver for moving the mast in a lateral or width wise direction of the post driver.12. The post driver according to claim 11, wherein the side shift driver (a) is/are operable to move the mast laterally to both sides of the centre of the post driver in a lateral direction.13. The post driver according to claim 11 or claim 12, comprising at least first and second Opposing side shift drivers.14 The post driver of claim 13, wherein the first side shift driver is mounted to a first portion of the second frame section arid a. second side shift driver is mounted to a second portion of the. second frame section, wherein the first portion of the second frame section may be on an opposite side of the mast to the second portion.15. The post driver according to claim 13 or claim 14 wherein the first and second side shift drivers are arranged in a piggy back configuration, where one end of the first side shift driver is mounted to the mast and/or mast carriage adjacent above an end of the second side shift driver.16. The post driver according to any of claims 13 to 15, wherein the side shift driver(s) are single action.17. The post driver according to claim 11 or 12, comprising a single double action side shift driver.18. The post driver according to any of claims 11 to 17, wherein each side shift driver comprises a hydraulic ran having at least two stages and/or a double action ram.19. The post driver according to any preceding claim, wherein the hydraulically operable leg are operable using one or more hydraulic rams driven from a hydraulic pressure feed and/or controller via hydraulic pipes and a safety valve is provided between the hydraulic pressure feed and/or controller and the hydraulic rams1 wherein the safety valve is adapted to shut/close in the event that the feed, controller or pipes are depressurised.20. The post driver according to claim 19, wherein, the safety valve is located further towards the hydraulic ram than towards the hydraulic pressure feed and/or controller.21.. The post driver according to claim 20., wherein the safety valve is incorporated with3 located, on, adjacent to or proximate to the hydraulic ram.22. The post driver according to any preceding claim, wherein the attachment means comprise movable or pivotable attachment members 23. A post driver comprising: a frame, the frame comprising attachment means for mounting the post driver; a mast supported by the frame and adapted to allow a weighted member to travel up and down; at least two independently operable hydraulically operated legs; and positioning means for enabling the position of the mast to he optimised and adapted for alignment with a post to be driven; wherein the positioning means comprises a side shift configured S to move the mast in a lateral direction; and the mast is provided on an opposite side of the frame to the attachment means.24, A post driver according to claim 23, wherein the frame comprises a first frame section, which may comprise or be provided with at least one and preferably all of the attachment means and the mast is movable or slidabie relative to the first frame section.25. The post driver according to claim 24, wherein the frame comprises a second frame section for supporting the mast and the second frame section is movably or slidably mounted to the first frame section and the side shift comprises the relative lateral movement or sliding of the first and second frame sections.26, The post driver according to any preceding claim, wherein at least one of the attachment means is adapted. to pivotably couple to supporting apparatus.27, The post according to any preceding claim, comprising at least one tilt mechanism configured to rotate the post driver and/or mast in a lateral direction.28. The post driver according to claim 27, comprising at least two tilt mechanisms configured to tilt the post driver through a vertical tilt plane..29. The post driver according to claim 27 or 28, wherein one or more tilt mechanisms comprises a movable or slidable tilt member, which may be mounted on the frame so as to be relatively movable or slidable therewith and the slidable member may be fixed relative to at least one attachment means for coupling the post driver to the support apparatus 30. The post driver according to claim 29, wherein the movable or slidable tilt member is movably or slidably mounted to an upright member of the frame.31. The post driver according to claim 29 or claim 30, wherein the post driver comprises at least one further attachment means comprised in or mounted to the frame and spaced laterally from the attachment means of the tilt member.32. The post driver according to claim 31, wherein the further attachment means comprises a pivoting or pivota.ble attachment means.33. The post driver according to any of claims 28 to 32, wherein one or more tilt mechanisms comprises extending at least one leg and/or retracting at least one other leg in order to tilt the post driver.34.. A post driver comprising: a frame, the frame comprising attachment means for mounting the post driver; a mast supported by the frame and adapted to allow a weighted member to travel up and down; positioning means for enabling the position of the mast to be optimised and adapted for alignment with a post to be driven; and wherein the positioning means comprises a backahift; and the mast is provided on an opposite side of the frame to the attachment means.35. Apparatus comprising a vehicle provided with or having mounted on it a post driver according to any of the preceding claims.36%. A method of using the post driver according to any of claims I to 33 in driving a post into the ground.37. A post driver substantially as shown in the drawings and/or described herein with respect to the drawings.