GB2564153A

GB2564153A - A post driver

Info

Publication number: GB2564153A
Application number: GB1710829.1A
Authority: GB
Inventors: Perret Tony
Original assignee: Perrett Fencing Ltd
Current assignee: Perrett Fencing Ltd
Priority date: 2017-07-05
Filing date: 2017-07-05
Publication date: 2019-01-09
Anticipated expiration: 2037-07-05
Also published as: GB201710829D0; GB2564153B8; GB2564153A8; GB2564153B

Abstract

A post driver (10) comprising a plate (50) for transmitting a repetitive force to a post (60) to drive it into the ground, the plate comprising an array of holes (80A, 80B, 80C, 80D, sop, the post driver further comprising an array of pins (100) movable within the array of holes, the post driver being arranged such that, in use, with the underside (77) of the plate placed over one end of the post at least some pins are retracted through the respective holes relative to the underside of the plate by the presence of the end of the post, while others, not in contact with the end of the post, project through the respective holes and act to grip the sides of the post adjacent the end.

Description

The present invention relates generally to a post driver and finds particular, although not exclusive, utility in the driving of timber posts for the creation of fencing.

Powered post drivers are known which provide a reciprocal force to the upper end of a post to drive it into the ground. However, due to ground conditions, such as stones, it is difficult to maintain the post in a vertical orientation. Furthermore, even if the post can be maintained vertically in two axes the post may move away from the desired location leading to irregularly spaces posts. In fencing applications, this gives an unprofessional appearance. To counter the movement of the post during the period when it is being driven into the ground it is known to use a device for gripping the post on its sides, such as an encircling bar. However, this is held by hand and therefore the operator of a post driver has one hand less available to operate the machinery correctly. Another system uses one or more pins which penetrate the top of the post to hold it still, however, the problem with this is that it damages the top of the post which is both unsightly and leads to early rotting through water penetration.

Accordingly, it is desirable to have an improved system for maintaining posts in a desired location and orientation during the period when they are being driven into the ground.

In a first aspect, the invention provides a post driver comprising a plate for transmitting a repetitive force to a post to drive it into the ground, the plate comprising an array of holes, the post driver further comprising an array of pins movable within the array of holes, the post driver being arranged such that, in use, with the underside of the plate placed over one end of the post at least some pins are retracted through the respective holes relative to the underside of the plate by the presence of the end of the post, while others, not in contact with the end of the post, project through the respective holes and act to grip the sides of the post adjacent the end.

In this manner, no damage to the top of the post is incurred as the pins do not penetrate the top of the post since they retract upwardly through the plate away from the upper surface of the end of the post. However, there are enough pins surrounding the post that at least some will contact the sides of the post to maintain its position and orientation and prevent rotation of the post.

Although described as a ‘post driver’, it is to be understood that it could also be described as a ‘pile driver’, and the use of the word “post” herein could be replaced with the word “pile” as appropriate.

The post may have a width of at least 50mm, or at least 70mm, or at least 95mm, or at least 120mm in one dimension. The post may have an approximately square profile such as 100x100mm.

The post driver may further comprise pin retaining means to prevent the pins from falling out of the array of holes. For instance, the pin retaining means may include thickened portions on each pin, the thickened portion being wider than the width of the respective hole in which the pin movably resides. In this way, the pins may move downwardly through the holes but only as far as the thickened portion permits. Other ways of preventing the pins from falling completely out through the holes are contemplated such as the use of springs.

The post driver may further comprise biasing means for biasing at last some of the array of pins to project through the holes in the plate. For instance, springs may be used to bias them downwardly through the holes; the force provided by the springs being overcome by the post pushing up against the underside of the plate, in use. The springs may be coil springs. The springs may be the same as the springs used to prevent the pins from falling out through the holes completely.

The post driver may be mounted on a frame, and the frame may comprise a force providing means for providing a repetitive force to the plate. The post driver may further comprise a movement means for moving the plate relative to the frame. This may be used to initially position the post once the pins have engaged with the top of the post but before the post has been driven into the ground beyond an initial relatively small distance. It may also be used to reposition the top of the post relative to the point at which the post meets the ground if for some reason the post needs to be repositioned or realigned during the period when it is being driven in the ground. It may also be used to rotate the plate, and thus the post about its longitudinal axis, to provide correctly aligned posts. The movement means may be moved by hydraulics, pneumatics or by hand.

The frame may be mounted on a trailer. The trailer may be skid-mounted or include wheels. The trailer may be arranged to be towed by a tractor or other vehicle.

The frame may be mounted on a self-propelled vehicle so that it may be moved around a site without need of towing.

The force providing means may be a reciprocating hammer and/or a vibratory hammer. The hammer may strike the plate indirectly via another surface connected to, but above, the plate, the force being transmitted to the plate. Alternatively, the plate may be relatively thick such that even with the pins fully retracted inside it they do not project through an upper surface of the plate. In this case, the hammer may strike the upper surface of the plate.

The ends of the pins which project through the holes may be rounded. Other shapes are contemplated such as square-cut and bullet-shape.

The array of pins may have at least two different size pins. The size may be the length and/or the thickness (diameter). For instance, the central area of the array of pins may have thinner and/or shorter pins as compared to the pins arranged around the perimeter of the array which may be thicker and/or longer. This is to provide a longer life for the pins which press against the sides of the posts in use.

The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference figures quoted below refer to the attached drawings.

Figure 1 is a general view of a post driver mounted on a self-propelled vehicle;

Figure 2 is a cross-section through a plate;

Figure 3 is a perspective view of the underside of the plate with no post in place; and

Figure 4 is a perspective view of the underside of the plate with a post in place.

The present invention will be described with respect to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. Each drawing may not include all of the features of the invention and therefore should not necessarily be considered to be an embodiment of the invention. In the drawings, the size of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other sequences than described or illustrated herein.

Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other orientations than described or illustrated herein.

It is to be noticed that the term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

Reference throughout this specification to “an embodiment” or “an aspect” means that a particular feature, structure or characteristic described in connection with the embodiment or aspect is included in at least one embodiment or aspect of the present invention. Thus, appearances of the phrases “in one embodiment”, “in an embodiment”, or “in an aspect” in various places throughout this specification are not necessarily all referring to the same embodiment or aspect, but may refer to different embodiments or aspects. Furthermore, the particular features, structures or characteristics of any embodiment or aspect of the invention may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments or aspects.

Similarly, it should be appreciated that in the description various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Moreover, the description of any individual drawing or aspect should not necessarily be considered to be an embodiment of the invention. Rather, as the following claims reflect, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

Furthermore, while some embodiments described herein include some features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form yet further embodiments, as will be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

In the discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

The use of the term “at least one” may mean only one in certain circumstances.

The principles of the invention will now be described by a detailed description of at least one drawing relating to exemplary features of the invention. It is clear that other arrangements can be configured according to the knowledge of persons skilled in the art without departing from the underlying concept or technical teaching of the invention, the invention being limited only by the terms of the appended claims.

In Figure 1, a post driver 10 is shown mounted on a self-propelled vehicle 15. Not all of the vehicle 15, or the various components typically provided on such a vehicle, are shown. The vehicle comprises tracks 15, enabling it to run on rough terrain.

The post driver 10 includes a mast 30 on which a hammer 20 may slidably be moved up and down via a pulley and rope 40. Typically, the hammer is pulled up and let go such that gravity pulls it down. The reciprocating motion applied repeated blows of force to a post 60 to drive it into the ground.

In the present case, a plate 50 is also arranged on the mast. This plate may slide up and down the mast. It may be releasably attached to the hammer so that it may be moved upwardly to be placed on top of a post ready for driving it into the ground. Once in place it may be released from the hammer and the hammer 20 raised and dropped repetitively to deliver force to the post via the plate. The plate may also slide down the mast as the post is driven into the ground so that it remains in contact with the top of the post as it is driven into the ground.

The vertical orientation of the mast 35 may be adjusted via a hydraulic ram 35 so that the post 60 may be driven into the ground at the desired orientation. This orientation may not always be vertical as other angles to the horizontal other than 90 degrees may be desirable.

Not all of the various components typically required with a post driver are shown to improve the clarity.

The plate 50 will now be further described with reference to Figure 2. The plate 50 comprises a relatively thick block having a substantially planar upper surface 75 and a substantially planar lower surface 77 substantially parallel to the upper surface 75. Within the plate 50 an array of holes or passages 80A, 80B, 80C, 80D, 80E is arranged. Each hole, comprises an upper portion, or shaft 85, having a substantially uniform diameter and a lower portion, or mouth 90, in which the diameter is reduced as compared to the diameter of the upper portion 85. In reality, there will be many more pins than shown, only four are shown to demonstrate the principle.

Within each hole 80A, 80B, 80C, 80D, 80E a pin 100 is arranged. Each pin has a substantially uniform diameter lower portion, or shank 110, and an upper portion, or head 120, which has a diameter greater than the lower portion 110 and which is also greater than the reduced diameter lower portion 90 of the hole. In this way, a pin cannot fall out of the hole it is in because the head 120 will not pass through the mouth 90.

To install the pins in the holes the plate 50 may be split into two portions 72, 73 which bolt together; but so that unbolted and separated, the tops of the holes are accessible to drop in the pins 100. Such a bolt 84 is shown in Figure 3. The splitting of the plate also allows for damaged pins to be replaced.

In Figure 2 a post 60 is shown pressed up against the underside 77 of the plate 50. The three holes 80B, 80C, 80D immediately above the post have had their pins pushed fully inside by contact with the post. Therefore, the lower ends of the pins do not penetrate the top of the post 60 and thus cause no damage. However, the two outer holes 80A, 80E have not had their pins pushed inside by the post because the post is not immediately below them. Rather, they project downwardly through the lower surface 77 of the plate 50. A portion of each shank of each pin contacts with the side of the post 60. This contact prevents the top of the post from moving around during the period it is being driven into the ground.

Figure 2 also shows a coil spring 88 in the hole 80E on the far left-hand side. The spring in shown in two parts but it may comprise a single continuous coil spring. This spring urges the pin downwardly and outwardly of the hole. However, if the post was positioned underneath it, the biasing force of the spring would be overcome and the pin would be pushed/retracted inside the hole. All, or only some, or none of the holes may include biasing means.

A typical array of pins projecting through the underside 77 of the plate 50 is shown in Figure 3. At least one hundred holes with pins are depicted although fewer or more are contemplated. Each pin has a diameter of approximately 10mm, although pins in the range of 5 to 20mm or greater are possible.

The holes are arranged approximately 10mm apart, although other distances are contemplated such as 5 to 25mm. The array has a substantially grid-like pattern, but other patterns are contemplated such as concentric circles. The array may be regular or irregular in nature.

In Figure 4 the underside of the plate is shown with a post 60 in situ. The top of the post is pushed up against the underside of the plate so that the pins 100 in the area immediately above the top of the post have been fully pushed inside the plate.

However, the remaining pins 100 are still projecting downwardly. It may be seen that at least 4 pins are spaces along each side. The array of pins ensures that even though some pins may not actually contact with the side of the post at least some will do so to prevent it from turning or moving while it is being driven into the ground.

Claims

1. A post driver comprising a plate for transmitting a repetitive force to a post to drive it into the ground, the plate comprising an array of holes, the post driver further comprising an array of pins movable within the array of holes, the post driver being arranged such that, in use, with the underside of the plate placed over one end of the post at least some pins are retracted through the respective holes relative to the underside of the plate by the presence of the end of the post, while others, not in contact with the end of the post, project through the respective holes and act to grip the sides of the post adjacent the end.

2. The post driver of claim 1, further comprising pin retaining means to prevent the pins from falling out of the array of holes.

3. The post driver of claim 2, wherein the pin retaining means includes thickened portions on each pin, the thickened portion being wider than the width of the respective hole in which the pin movably resides.

4. The post driver of any preceding claim, further comprising biasing means for biasing at last some of the array of pins to project through the holes in the plate.

5. The post driver of any preceding claim, being mounted on a frame, the frame comprising a force providing means for providing a repetitive force to the plate.

6. The post driver of claim 5, further comprising a movement means for moving the plate relative to the frame.

7. The post driver of either one of claims 5 and 6, wherein the frame is mounted on a trailer.

8. The post driver of either one of claims 5 and 6, wherein the frame is mounted on a self-propelled vehicle.

9. The post driver of any of claims 5 to 8, wherein the force providing means is a reciprocating hammer and/or a vibratory hammer.

10. The post driver of any preceding claim, wherein the ends of the pins which project through the holes are rounded.

5

11. The post driver of any preceding claim, wherein the array of pins has at least two different size pins.

06 02 18

5 11. The post driver of any preceding claim, wherein the array of pins has at least two different size pins.

06 02 18

Amendments to the claims have been filed as follows:

1. A post driver comprising a plate for transmitting a repetitive force to a post to drive it into the ground, the plate comprising an array of holes, the post driver

5 further comprising an array of pins movable within the array of holes, the post driver being arranged such that, in use, with the underside of the plate placed over one end of the post at least some pins are retracted through the respective holes relative to the underside of the plate by the presence of the end of the post, while others, not in contact with the end of the post, project through the 10 respective holes and act to grip the sides of the post adjacent the end.

15 3. The post driver of claim 2, wherein the pin retaining means includes thickened portions on each pin, the thickened portion being wider than the width of the respective hole in which the pin movably resides.

4. The post driver of any preceding claim, further comprising biasing means for

20 biasing at last some of the array of pins to project through the holes in the plate.

25 6. The post driver of claim 5, further comprising a movement means for moving the plate relative to the frame.

9. The post driver of any of claims 5 to 8, wherein the force providing means is a

35 reciprocating and/or a vibratory hammer.