GB2500714A

GB2500714A - Hammering apparatus for hammering a stake into the ground

Info

Publication number: GB2500714A
Application number: GB1205772.5A
Authority: GB
Inventors: Gino Hoskings; Susan Knychala
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-03-30
Filing date: 2012-03-30
Publication date: 2013-10-02
Anticipated expiration: 2032-03-30
Also published as: GB201205772D0; GB2500714B

Abstract

The apparatus comprises a frame 11; an arm 18 pivotally coupled to the frame, the arm comprising a head 28 disposed at a distal end thereof. A force transfer member 13 is arranged to receive a hammering force from the head and is slidably coupled to the frame. A biasing means 16 biases the head to the member and an actuator 19 moves the arm between a loaded configuration in which the head is separated from the member against the bias of the biasing means and an unloaded configuration in which the head is arranged to abut the member. Preferably the biasing means is a spring which is arranged to compress as the apparatus becomes loaded. The actuator may comprise a cam 22 which is rotatably coupled to the drive shaft.

Description

Hammering Apparatus The present invention relates to hammering apparatus and particularly, but not exclusively, to hammering apparatus for driving posts into the ground.

When erecting fences and the like at remote locations, it is necessary to transport the necessary equipment to the locations to drive the fence posts into the ground. The posts are traditionally driven into the ground using a large hammer, such as a sledge hammer, however, it is found that unless the hammer strikes the post centrally, then the post can splinter or otherwise become damaged. It is also known to use large hydraulic driving equipment to drive the posts into the ground. However, it is often difficult to mobilise such equipment at remote locations where it is necessary to erect fences and the like.

The above described means of driving fence posts into the ground are found to be particularly disadvantageous in situations whereby the post encounters a hard object, such as a buried rock. In these situations, it is found that the use of a sledge hammer or hydraulic apparatus can damage the post. Moreover, the large recoil suffered on impact can be communicated along the handle of the hammer, to an operator and injure the operator, or to the hydraulic driving mechanism of the driving equipment, which may cause premature failure of the mechanism.

We have now devised a hammering apparatus for driving stakes, posts and the like into the ground.

In accordance with the present invention, there is provided hammering apparatus for hammering a stake into the ground, the apparatus comprising: -a frame; -an arm pivotally coupled to the frame, the arm comprising a head disposed at a distal end thereof; -a force transfer member which is arranged to receive a hammering force from the head, the member being slidably coupled to the frame; -biasing means for biasing the head to the member; and, -an actuator for reconfiguring the arm between a loaded configuration in which the head is separated from the member against the bias of the biasing means and an unloaded configuration in which the head is arranged to abut the member.

Advantageously, the apparatus provides for a more controlled impact of the stake, such as a fence post, to minimise any damage to the post, while the force transfer member is arranged to absorb any recoil of the apparatus in the event the stake strikes a hard object, such as a rock, for example.

Preferably, the head is arranged to separate from the force transfer member as the apparatus is loaded, such that the membel can slide freely with respect to the frame.

The member is preferably arranged to substantially absorb any recoil from the arm upon hammering a stake into the ground, for example.

Preferably, the arm comprises a width which varies along the length thereof. The width of the arm may reduce for example, toward the distal end thereof or alternatively, the width of the arm may reduce toward a central region thereof In this manner, the variation in width of the arm is arranged to cause the arm to flex as the apparatus reconfigures to the unloaded configuration to increase the impact of the head upon the member.

The biasing means preferably comprises a spring, such as a compression spring, which is arranged to compress as the apparatus becomes loaded, and extend as the apparatus becomes unloaded.

Preferably, the actuator comprises a drive shaft which is rotatably coupled to the frame and a handle for rotating the drive shaft. The actuator preferably further comprises a cam which is rotatably coupled to the drive shaft.

The cam is preferably arranged to cause the head to separate from the member to load the apparatus as the cam is rotated to a critical angle relative to the frame, and is further arranged to enable the head to strike the member as the cam is rotated beyond the critical angle.

The cam is preferably arranged to rotate in dependence of the rotation of the drive shaft, as the cam is rotated to the critical angle and is further arranged to rotate independently of the drive shaft, as the cain rotates beyond the critical angle.

The handle of the actuator is preferably rigidly coupled to the drive shaft. Alternatively, the handle of the actuator is preferably coupled to the drive shaft via a ratchet mechanism. It is found that the latchet mechanism provides for an increased torque in rotating the drive shaft, which is particularly suited when compressing large springs for

example.

An embodinient of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which: Figule 1 is a side view of a hammering apparatus according to an embodiment of the invention in an unloaded configuration; Figure 2 is a side view of the hammering apparatus illustrated in figure 1, in a loaded configuration; Figure 3a is a magnified view of the rear of the cam; and, Figure 3b is a magnified view of the underside of the cain.

Referring to figures 1 and 2 of the drawings, there is illustrated a hammering apparatus 10 accoiding to an embodiment of the invention, for driving stakes, such as fence posts (not shown) into the ground. The apparatus 10 comprises a frame having an elongate frame section 11 and a handle 12 disposed at a proximal end of the elongate frame section 11 thereof, so that a user (not shown) may suitably grip the apparatus 10. The apparatus 10 fuither comprises a foice tiansfer membel 13, which complises a substantially cylindrical body 13a, which is slidably coupled to a distal end of the frame section 11 and which in use, is arranged to slide in a substantially veitical plane relative to the elongate frame section 11. The meniber 13 further comprises a radially extending flange 13b, 13c disposed along an upper and lower peliphery of the body 13a which are arranged to limit the extent to which the body 13a can slide relative to the elongate frame section 11 The apparatus 10 further comprises a first and second frame section 14, 15 which are arranged to extend upwardly away from the elongate frame section 11, at a position disposed intermediate the handle 12 and member 13, and are arranged to support a compression spring 16 therebetween. The spring 16 is mounted upon a spring support 17 which extends between the first and second frame section 14, 15 and is arranged to support the spring 16 in a substantially parallel orientation to the elongate frame section 11.

The first frame member 14 is rigidly coupled at a proximal end thereof to the frame section 11 proximate the handle 12, and is pivotally coupled at a distal end thereof to one end of the spring support 17. The second frame section 15 is pivotally coupled at a proximal end thereof to the frame section 11, between the first frame member 14 and the member 13 and is rigidly coupled at a distal end thereof to an arm 18. The spring support 17 is further hingedly coupled at the other end thereof, to the intersection of the arm 18 and second frame section 15, such that as the second frame section 15 pivots about the elongate frame section 11, the spring 16 is arranged to compress and extend to enable a distal end of the arm 18 to rise and fall with respect to the force transfer member 13.

The apparatus 10 further comprises an actuator 19 for reconfiguring the arm 18, and thus the second frame section 15, between an unloaded configuration, in which the spring 16 is substantially uncompressed and a distal end of the arm 18 is arranged in contact with the member 13, and a loaded configuration in which the spring 16 is compressed and the distal end of the arm 18 is separated from the member 13. As the spring 16 releases the compression, the arm 18 is arranged to rapidly reconfigure to the unloaded configuration to strike the membel 13 and thus impart a hammering or driving force upon a stake, such as a fence post (not shown), to drive the stake into the ground,

for example.

The actuator 19 comprises a support frame 20 which is arranged to rotatably couple a drive shaft 21 to the frame 20 and a cam 22 which is rotatably coupled to the drive shaft 21. The drive shaft 21 is arranged to rotate in accordance with a handle 23 which may be rigidly coupled to the drive shaft 21 or which may be coupled via a ratchet mechanism (not shown), for example. Referring to figuie 3 of the drawings, the actuator 19 further comprises a drive pin 24 which is rigidly coupled to the drive shaft 21 and which is arranged to extend radially from the shaft 21 to engage the cam 22 to cause the cam 22 to rotate. In the embodiment illustrated, the cam 22 comprises a slot 25 formed thelein, which is defined between two cam walls 26, and the diive shaft 21 is arianged to extend through the cain walls 26, such that a base 27 of the slot 25 rotates around the diive shaft 21 as the cam 22 rotates.

The drive pin 24 extends within the slot 25 and is arranged to engage the base 27 of the slot 25 at one side of the drive shaft 21, to cause the cam 22 to rotate. The cam 22 comprises a longitudinal cioss-section which is substantially peal-shaped (as illustrated in figures 1 and 2 of the diawings), and is arranged to contact the second fiame section 15 over a pre-defined angular range, such that as the drive shaft 21 is rotated, the cam 22 is arranged to cause the second frame section 15 to pivot about the elongate frame section 11 to lilt the distal end of the arm 18 off the foice transfei member 13. As the rotation of the cam 22 relative to the second frame section 15 reaches a critical angle, namely as a peak 22a of the cam 22 contacts the second frame section 15, then the spring 16 becomes fully compressed and the apparatus 10 becomes configured to the fully loaded conflguiation.

Upon further rotation of the handle 23, the cam 22 is arranged to rotate further such that the peak 22a will pass beyond the second frame section 15, at which point the bias on the spring 16 will cause the cam 22 to rotate lapidly. The slot 25 formed within the cam 22 enables the rotation of the cam 22 to advance independently of the drive pin 24, which therefore prevents the drive shaft 21 and the handle 23 from similarly rotating rapidly with the cam 22. Accordingly, as the cam 22 passes beyond the critical angle, the distal end of the arm 18 is arranged to collapse violently, namely unload, onto the member 13 to cause an impacting force to be applied thereto.

To increase the force of the impact, the distal end of the arm 18 comprises a weighted head 28 and the width of the arm 18 is airariged to vary along the length thereof In this respect, the width of the arm 18 may decrease in a direction which is toward the distal end thereof, or alternatively, the width of the arm 18 may decrease toward a central region thereof In either case, the tapered width profile of the arm 18 is arranged to enable the arm 18 to flex upon rapidly reconfiguring from the loaded configuration to the unloaded configuration, to further increase the speed of the head 28 at the moment of impact with the member 13.

The apparatus 10 further comprises a vibration absorption block 29 disposed between the apparatus handle 12 and the elongate frame section 11, so that in the event that the apparatus 10 develops a recoil as the arm 18 strikes the member 13, any residual vibration which passes beyond the member 13 becomes dampened by the block 29, to minimise any injury to an operator of the apparatus, for example.

In use, the stake (not shown) to be driven into the ground is supported in the desired orientation and the member 13 of the apparatus 10 is placed upon an upper surface of the stake. The handle 23 is then rotated to cause the drive shaft 21 and thus the pin 24 to rotate to drive the cam 22 into abutment with the second frame section 15. The handle 23 is then further rotated to lift the head 28 of the arm 18 off the member 13, so that the distal end of the elongate frame section 11 can fall with respect to the member 13. Upon further rotating the handle 23, the cam 22 is arranged to pass beyond the critical angle, such that the bias on the spring 16 causes the spring 16 to extend rapidly thereby causing the head 28 of the arm 18 to strike the member 13 in a downward direction to drive the stake (not shown) into the ground. This process may be repeated several times until the stake (not shown) has been driven to a sufficient depth.

In the event that the stake (not shown) or post strikes a hard object (not shown), then the impact of the arm 18 on the member 13 will cause the distal end of the elongate frame section 11 to move upwardly of the member 13 and thus counteract the recoil of the arm 18. From the foregoing therefore, it is evident that the apparatus 10 provides for a simple yet effective means of hammering a stake into the ground.

Claims

Claims 1. Hammering apparatus for hammering a stake into the ground, the apparatus comprising: -a frame; -an arm pivotally coupled to the frame, the arm comprising a head disposed at a distal end thereof; -a force transfer member which is arranged to receive a hammering force from the head, the member being slidably coupled to the frame; -biasing means for biasing the head to the member; and, -an actuator for reconfiguring the arm between a loaded configuration in which the head is separated from the member against the bias of the biasing means and an unloaded configuration in which the head is arranged to abut the member.
2. Apparatus according to claim 1, wherein the distal end of the arm is arranged to separate from the force transfer member as the apparatus is loaded, such that the member can slide freely with respect to the frame.
3. Apparatus according to claim 1 or 2, wherein the member is arranged to substantially absorb any recoil from the arm upon striking the member.
4. Apparatus according to any preceding claim, wherein the arm comprises a width which varies along the length thereof.
5. Apparatus according to claim 4, wherein the width of the arm reduces in a direction which is toward the distal end of the arm.
6. Apparatus according to claim 4, wherein the width of the arm reduces in a direction which is toward a central region thereof.
7. Apparatus according to any preceding claim, wherein the biasing means comprises a spring which is arranged to compress as the apparatus becomes loaded, and extend as the apparatus becomes unloaded.
8. Apparatus according to any preceding claim, wherein the actuator comprises a drive shaft which is rotatably coupled to the frame and a handle for rotating the drive shaft.
9. Apparatus according to claim 8, wherein the actuator further comprises a cam which is rotatably coupled to the drive shaft.
10. Apparatus according to claim 9, wherein the cam is arranged to cause the head to separate from the member to load the apparatus as the cam is rotated to a critical angle relative to the arm, and is further arranged to enable the head to strike the rnerriber as the cam is rotated beyond the critical angle.
11. Apparatus according to claim 10, wherein the cain is arranged to rotate in dependence of the rotation of the drive shaft as the cam is rotated to the critical angle and is arranged to rotate independently of the drive shaft as the cam rotates beyond the critical angle.
12. Apparatus according to any of claims 8 to 11, wherein the handle is rigidly coupled to the drive shaft.
13. Apparatus according to any of claims 8 to 12, wherein the handle is coupled to the drive shaft via a ratchet mechanism.
14. Apparatus substantially as herein described and with reference to the accompanying drawings.