GB2095731A

GB2095731A - Apparatus for driving and extracting sheet piles and other members

Info

Publication number: GB2095731A
Application number: GB8205411A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-03-28
Filing date: 1982-02-24
Publication date: 1982-10-06
Also published as: DE3112396A1; FR2502663A1; JPS57174537A

Abstract

Apparatus for driving and extracting sheet piles by vibration, or driving the piles by striking if an obstruction is met comprises a vibration driving mechanism 1 with out of balance rotary vibrating weights 2 and a pile gripping device 16. A striker 3 is fixed to the mechanism 1 and an anvil is fixed to the device 16. The striker 3 and the anvil are biassed apart by a spring, but an internal releasable locking device enables them to be locked against each other. When the striker and anvil are locked against each other, the apparatus acts as a vibration driver or extractor, but when they are released and separated, the mechanism 1 causes the striker 3 to move up and dawn and strike the anvil for percussive driving. Since the vibration mechanism is situated above the striker and the anvil, substantially the whole vibration energy is available for moving the striker 3 up and down during percussive driving. <IMAGE>

Description

SPECIFICATION Apparatus for driving and extracting sheet piles and other members This invention relates to an apparatus for driving and extracting sheet piles, trench sheeting, pipes or other members, the apparatus comprising a vibration driving and extracting mechanism, and a striking driving mechanism having means for making it operative or inoperative and including a striker and an anvil.

One example of such apparatus is disclosed in German OLS No. 22 55 129. The vibration mechanism in this apparatus is directly connected to a clamping device which grips the pile or other member being driven. The upper surface of the vibration mechanism is formed as an anvil and above this a striker, which is suspended by means of a spring from a guide rod extending upwardly from the vibration mechanism, reciprocates. So long as the driving speed of the pile produced by the vibration mechanism lies above a predetermined value, the vibration amplitude of the striker is too small for it to strike the anvil. If the driving speed of the pile falls below the predetermined value, then the striker starts to strike the anvil. In this way the vibration driver develops the action of a striking driver and the ground layer which is impeding the progress of the vibration driving is penetrated.

In order to achieve the greatest possible impact effect during striking driving, it will be evident that the most undamped excitation energy of the vibration mechanism that is possible should act upon the striker.

In the apparatus disclosed in the above German specification, however, this is not the case, since the vibration mechanism is clamped by the clamping device directly on to the pile or other member being driven and because of this the greater part of the vibration energy is always fed into the pile, even if only a small advance is achieved because the resistance of a ground layer makes it unsuitable for vibration driving. The striking energy exerted by the striker upon the anvil can therefore never be very high in this apparatus and therefore it is not very effective in operation as a striking driver.

The object of the present invention therefore is to provide an apparatus as initially described which, with simple construction, permits operation as desired as a vibration driver or extractor or as a striking driver and in which substantially all the vibration energy generated by the vibration mechanism is transmitted to the striker and then through the anvil to the pile or other member being driven.

To this end, according to this invention, in apparatus as initially described the striker and the anvil are disposed between the vibration driving and extracting mechanism and a clamping device for gripping the member being driven, and the striker and anvil having a locking device by which they can be locked together for vibratory driving or be separated for striking driving.

With this arrangement, the apparatus acts, so long as the striker is locked against the anvil, as a vibration driver or extractor so that a pile or other member can be driven into the ground at high speed and with low noise production. As soon as the pile is held up by a ground layer which is too resistant for vibration driving, the locking device is released, so that the vibration mechanism, at each impulse directed away from the clamping device, lifts together with the striker away from the anvil and, at each impulse oriented towards the pile, the striker with the vibration mechanism behind it strikes with great energy against the anvil. After the locking device has been released, the vibration driver thus acts as a striking driver.Since the vibration mechanism with the striker is guided freely relative to the anvil and the clamping device, no energy is removed from the vibration part of the apparatus during the upward impulse, whereas during the downward impulse substantially the entire kinetic energy is transmitted as striking energy via the anvil and the clamping device to the pile.

Preferably, the locking device is hydraulically operated by means of a piston-cylinder unit, so that the locking and unlocking can be controlled remotely as required at all times. The apparatus may have an aperture extending transversely to the driving direction through the anvil, a crosshead passing through the aperture and mounted on the striker which fits over the anvil, and a wedge disposed between the cross head and a transverse surface of the aperture, for the purpose of locking.

In this embodiment, the striker is pressed by means of the wedge against the anvil when the locking device is locked, and the free stroke of the striker relative to the anvil can be influenced by the distance of displacement of the wedge.

Preferably with this arrangement there is a spring biassing the wedge into a position in which it clamps the striker to the anvil and the pistoncylinder unit is arranged to displace the wedge against the action of the spring.

In order to keep the noise produced by the apparatus as low as possible even when operating as a striking driver, an acoustically damping facing may be situated between the striker and the anvil.

Furthermore, elastomeric vibration elements may be fixed between side cheeks of the anvil and lateral guide surfaces of the striker, so that the striker and the anvil constitute an oscillation system. The piston-cylinder unit which presses the striker and the anvil together may be disposed between the vibration mechanism and the clamping device. If the piston-cylinder unit is fixed at one end to the vibration mechanism or the clamping device and at the other end is guided with limited displacement on the clamping device or the vibration mechanism respectively, then it can serve simultaneously as a guide connection between the vibration mechanism and the clamping device, and no special guide elements, such as for example elastomeric oscillation elements, are necessary.

To enable the striker to be pressed against the anvil, the piston rod of the piston-cylinder unit may have, on the side of the piston rod guide remote from the cylinder, a stop, which when the piston-cylinder unit is pressurized is drawn against an abutment surface of the clamping device and thus presses the clamping device with the anvil against the striker. In this form of embodiment also an oscillation system is obtained if a spring is incorporated between the vibration mechanism and the clamping device and biasses them apart.

A compression spring disposed concentrically around the piston-cylinder unit advantageously serves this purpose.

If there is only one piston-cylinder unit between the vibration mechanism and the clamping device, this must of necessity be oriented in the longitudinal central plane of the apparatus. If at least two piston-cylinder units are used, then these may be disposed symmetrically about the longitudinal central plane laterally beyond the striker and the anvil. This provides advantages in regard to accessibility and simplicity of construction.

Two examples of apparatus in accordance with the invention are illustrated in the accompanying drawings in which: Figure 1 is a diagrammatic side elevation of one example; Figure 2 is a section along the line Il-Il in Figure 3 of the striking mechanism of the first example; Figure 3 is a section along the line Ill-Ill in Figure 2; Figure 4 is a section along the line lV-IV in Figure 2; and Figure 5 is a diagrammatic side elevation of a second example.

The example illustrated in Figure 1 comprises a vibration mechanism 1 , the vibration energy of which is generated by two oppositely rotating unbalanced weights 2. Under the vibration mechanism 1, a striking mechanism 3 is fixed, and this in turn is bolted to a clamping device 1 6. The striking mechanism 3 has a striker 4, which is rigidly fixed to the vibration mechanism 1 and which co-operates with an anvil 5, which is rigidly fixed to the clamping device 1 6.

The anvil 5 has a transverse aperture 6, the upper transverse face 7 of which is inclined. The striker 4 fits over the anvil 5 in the manner of a hat and has lateral cheeks 10, on which a crosshead 9, which passes through the aperture 6, is fixed. In the aperture 6, a wedge 8, which is arranged to co-operate with the upper, inclined surface 7 and with the crosshead 9, is disposed. The wedge is biassed by a compression spring 1 3 thrusting against one lateral cheek 10 in a direction such that the anvil 5 is pressed against the striker 4. In this position, the apparatus operates as a vibration pile driver or extractor since there is no clearance between the striker 4 and the anvil 5 and the vibration energy generated by the vibration mechanism 1 is transmitted directly via the clamping device 1 6 to a pile being driven or extracted.The wedge 8 can be displaced in opposition to the action of the compression spring 13 by means of a piston-cylinder unit 11 and its piston rod 12.

If, during driving, the pile strikes a ground stratum which offers considerable resistance to vibration driving, then by pressurizing the piston cylinder unit 11 the wedge 8 can be displaced and the locking mechanism acting between the striker 4 and the anvil 5 can be released. The vibration mechanism 1 then starts, together with the striker 4, to vibrate relative to the anvil 5 and the clamping device 16, with elastomeric vibration elements 1 5 fixed to the cheek plates 10 and the lateral guide surfaces 26 of the anvil 5 serving as guides. At each downward vibration, the striker 4 strikes upon the acoustically damping facing 14 of the anvil 5 and thus drives the pile by high-energy blows through the obstructing ground layer.As soon as the obstructing layer has been penetrated, the piston-cylinder unit 11 can again be depressurized the compression spring 13 then displaces the wedge 8 back into the locking position, and the device again operates as a vibration pile driver.

A connection which is as rigid as possible but rapidly releasable between the clamping device 16 and the pile is assured by a clamping jaw 17, which is displaceable by means of a piston cylinder unit 18. The clamping jaw 17 in the clamping device 1 6 enables the apparatus to be used also for extracting piles.

In the example illustrated in Figure 5, only the striking mechanism 3 is of different construction from the first example. A striker 1 9 which is rigidly fixed to the vibration mechanism 1, is situated adjacent an anvil 20, which is rigidly fixed to the clamping device 16. An acoustically damping facing 14 is located on the striker 1 9. On each side of the striker 1 9 and the anvil 20, symmetrically about the longitudinal central plane of the apparatus, is a piston-cylinder unit 21 comprising a piston rod 22. The cylinders of the piston-cylinder units 21 are rigidly fixed to the vibration mechanism 1 , whereas the piston rods 22 are displaceably guided with limited movement in guide bores 24 in the clamping device 16.On the ends of the piston rods 22, stops 23 are disposed on the side of the guide bores 24 remote from the cylinders of the piston-cylinder units 21.

Compression springs 25 extend concentrically around the piston-cylinder units 21.

In the position illustrated in Figure 5, the piston rods 22 are extended from the piston-cylinder units 21, so that the clamping device 1 6 together with the anvil 20 are elastically suspended from the springs 25 and there is a predetermined gap between the striker 1 9 and the anvil 20. This is the position in which the apparatus acts as a striking pile driver.

If the clamping device 1 6 is clamped on to a pile, which is not shown, then the vibration mechanism 1 together with the striker 1 9 oscillates up and down on account of the revolving unbalanced weights 2 and the striker 1 9 strikes the anvil 20 at each downward stroke. Thus the vibration energy of the vibration mechanism 1 is transmitted at every downward stroke in an undamped manner on to the pile. If the device is to be operated as a vibration pile driver, it is only necessary to pressurize the piston-cylinder units 21, so that the piston rods 22 are retracted, causing the anvil 20 to be pressed by the stops 23 against the striker 1 9.

Claims

1. Apparatus for driving and extracting sheet piles, trench sheeting, pipes or other members, the apparatus comprising a vibration driving and extracting mechanism, and a striking driving mechanism, having means for making it operative or inoperative and including a striker and an anvil, wherein the striker and the anvil are disposed between the vibration driving and extracting mechanism and a clamping device for gripping the member being driven, and the striker and anvil having a locking device by which they can be locked together for vibratory driving or be separated for striking driving.

2. Apparatus according to Claim 1, in which the locking device is hydraulically operated by a piston-cylinder unit.

3. Apparatus according to Claim 1 or Claim 2, in which an aperture extends through the anvil transversely to the direction of driving and a crosshead passes through the aperture and Is mounted on the striker, the striker fitting over the anvil and a wedge being disposed between the crosshead and a transverse surface of the aperture for locking the striker to the anvil.

4. Apparatus according to Claim 3 when dependent on Claim 2, in which a spring biasses the wedge into a position in which it clamps the striker to the anvil, and the piston-cylinder unit is arranged to displace the wedge against the action of the spring.

5. Apparatus according to Claim 4, in which there is an acoustically damping facing disposed between the striker and the anvil.

6. Apparatus according to any one of Claims 1 to 5, in which elastomeric vibration members are disposed between side cheeks of the anvil and lateral guide surface of the striker.

7. Apparatus according to Claim 2, in which the piston-cylinder unit acts between the vibration driving and extracting mechanism and the clamping device and presses the striker and the anvil against each other when actuated to lock the striker and anvil together.

8. Apparatus according to Claim 7, in which the piston-cylinder unit is fixed at one end to the vibration mechanism or to the clamping device and has its other end guided with limited displacement on the clamping device or the vibration mechanism respectively.

9. Apparatus according to Claim 8, in which the cylinder of the piston-cylinder unit is fixed to the vibration mechanism and a piston rod of the unit is displaceably guided in the clamping device, a stop being situated on the piston rod on the side of a piston rod guide in the clamping device remote from the cylinder.

10. Apparatus according to Claim 9, in which a spring is disposed concentrically around the piston-cylinder unit and biasses the anvil away from the striker.

11. Apparatus according to Claim 1, substantially as described with reference to Figures 1 to 4, or Figure 5 of the accompanying drawings.

New claims or amendments to claims filed on Superseded claims 1.

New or amended claims:

1. Apparatus for driving and extracting sheet piles, trench sheeting, pipes, or other members, the apparatus comprising a vibration driving and extracting mechanism, and a striking driving mechanism which has locking means for making it operative or inoperative and includes a striker and an anvil, wherein the striker and the anvil are disposed between the vibration driving and extracting mechanism and a clamping device for gripping the member being driven, and wherein the locking means acts between the striker and anvil whereby the striker and the anvil can be locked against each other for vibratory driving or be separated from each other for striking driving.