A DEVICE FOR INSERTING A DRAINAGE WICK INTO THE GROUND

Abstract: A device for inserting into the ground a drainage wick (17) consisting of a profiled core and water permeable sleeve, said device consisting mainly of a mobile machine (1) such as a backhoe, with a mast (2), and attached to the mast a rectangular tube (3), holding a drainage wick (17), and being able to move up and down along the mast (2) in a vertical manner, wherein the tube (3) enveloping the wick (17) is inserted into the ground by a pair of hydraulic cylinders (7, 8) supported on the mast (2) and bearing a sheave carrier (9) for a flexible attachment like a cable (14, 16) fastened to said tube (3) so achieving a two times or a multiple insertion speed, in comparison with the capacity or stroke of the cylinders (7, 8) thus shortening the time needed to insert the tube (3).

Description: The invention concerns a device for inserting a drainage wick into the ground, which comprises a mobile frame 1 having a mast 2, a wick-inserting tube 3 having upper and lower ends, said drainage wick being received in the tube 3, a guide rail for guidably mounting the tube on the mast 2 for vertical motion relative thereto and a hoisting cable reeved over a sheave at the top of the mast and connected to the top of the tube. In order to insert water or to de-water soil it is customary to insert a drainage wick vertically in the soil, to for example a depth of 10 m. Such a drainage wick inserted by means of a tube, such tube being driven into the ground. When such tube is extracted from the ground, the drainage wick remains in the soil, the soil pressurizes against the wick, and water may travel through the permeable sleeve of the wick along the wick either up or down, depending on the function. As disclosed in NL-A-7707303, and described in the preamble of claim 1, it is common practice to drive the aforementioned tube into the ground by means of pile driving leads. Such leads of themselves are relatively heavy, and the driving activity is relatively slow. As drainage wicks are inserted at a frequency of 2 to 3 meters, for example on a dike pad, relatively much time is needed in order to introduce the number of wicks required. This invention has for its object to resolve this problem by providing means to inserting wicks into the ground at a much faster rate. The device according to the invention is distinguished by piston/cylinder means connected to a block 9 adjacent the upper end thereof and a length of a driving cable dead-ended at the bottom of the frame reeved over a pulley in said block and a pulley at the bottom of the frame and being connected at its opposite end to the top of the tube. This cylinder may be hydraulic or pneumatic with the advantage that such cylinder will apply a continuous driving force to the tube with the result that the drainage wick will be inserted into the ground at a much faster rate. Moreover the device can be built lighter and may be used by attaching it to a standard hydraulic backhoe, having the backhoe bucket removed, and the linkages and hydraulic arm attached to the mast with the installation tube. Such a setup will be far more mobile than the traditional pile driving leads, and may be moved on and around the job site much more easily than traditional equipment. It is known in the art to provide a hydraulic ram alongside a vertical mast for pressing stakes into the ground, as disclosed GB-A-2028902. The known device is not provided with a cable means for multiplying the insertion speed. The invention furthermore provides for two cylinders placed in series (one after the other). Hereby it will be possible to keep the shaft diameter of the cylinder relatively small, so that small hydraulic capacity is needed whilst providing for large displacement. Because of the slenderness of the hydraulic cylinders, it is preferred to provide for a guide path for each of the cylinders attached to the mast. The invention is further described in the detailed description of an embodiment as depicted and explained below. In the drawings is: Fig. 1 a schematic side view of the various parts of the equipment according to the invention showing the cable connections, and tube travel, Fig. 2 a perspective view of the device according to a first embodiment, Fig. 3 & 4, each a perspective view of a part of the device in figure 2 according to the cross sections III-III, IV-IV in figure 2 respectively. The equipment as depicted in the drawings consists principally of a mobile machine 1, carrying a mast 2, wherein a tube 3 may be moved up and down in a vertical sense. It should be noted that the mobile equipment 1 can be any type of equipment, such as a hydraulic backhoe or excavator, in figure 1 only the arm of which is schematically shown. This arm is attached to the mast 2 with connector 4 which is journalled around pin 5 attached to the arm. A hydraulic cylinder 6 of the device is able to bring the connector piece and thereby the mast 2 about pin 5 in a vertical position. The mast 2 is furthermore provided with a pair of hydraulic cylinders 7 and 8 connected in series, with one end of the bottom cylinder 8 supported on the mast 2 whilst the cylinder rod of the upper cylinder 7 supports the sheave housing for block 9. At both ends of the mast there is a housing 10 and 11, in each of which a pair of sheaves 12 and 13 are mounted. The system comprises a flexible element 14, fastened to the top of the mast 2, and led around the upper sheave of block 9, around the sheave system 12, and finally secured to the tube 3. A similar flexible element 16 is secured to the bottom of the mast 2, led around the bottom block of sheave 9, furthermore around the bottom sheave system 13 and also secured to tube 3. From a supply roller drainage wick 17 is led upwards via the mast 2 and subsequently inserted into tube 3, so that the bottom end of the wick protrudes from the lower end of the tube 3. By folding around or attaching an anchor plate, the wick 17 will be carried into the ground in the direction of arrow P1, until tube 3 is entirely inserted into the ground. By means of extraction of tube 3 the folded over end of the wick 17 shall remain in the ground and will allow the tube 3 to move upwards freely. As soon as tube 3 is entirely extracted the wick 17 may be cut off from the bottom of the tube 3 and subsequently the whole process may be repeated. The insertion of tube 3 is made possible by applying power to cylinder 7 and 8 either simultaneously or consecutively. The supply of power to cylinders 7 and 8 is provided by the main hydraulics of the hydraulic machine 1 and shall provide for the action of cylinder 7 and 8 to cause the equipment to produce the cycle starting from a position as shown in figure 1. Thus cylinder 7 shall move upwards relative to cylinder 8 and block 9 will move relative to cylinder 7 and 8. As the block 9 moves upwards, the right-hand part of flexible element 16 will move at twice the rate of block 9 while inserting tube 3. In order to extract tube 3 from the ground, cylinders 7 and 8 must be activated inversely, so that flexible element 14 will extract tube 3 twice as fast upwards as the movement of block 9. Finally it must be noted in order to achieve sufficient counter pressure to inserting the tube 3, a counter weight 18 may be attached to mast 2. Actual construction details are shown in figures 2 and 3. From these figures it is clear that the mast consists of a hollow square tube, which is provided with an opening 19 at the bottom with a guide roll 20, which provides for the smooth carriage of the wick 17. This roll of wick 17 may spin freely on carrier 21 which is suitably attached to the mast opposite said hydraulic implement 1. The mast is fitted at the adjacent side with a guide rail 22 (see figure 3) whereby a guide block 23 can move up and down. This guide block is attached to the bottom end of the upper cylinder 7 as well via a connector piece 24, pivotably connected to the cylinder rod 8' of the bottom cylinder. Similarly block 9 could be inserted into the guide rail 22. The guide rail 22 therefore provides for an optimum power distribution for both cylinders 7 and 8, so that slender and relatively small cylinder diameters may be used. This speeds up the operation of the equipment substantially because only a relatively small amount of hydraulic fluid, like oil, is needed. The mast 2 is fitted on the opposite side with a similar guide rail 25, along which the tube 3 may be moved up and down. To this end tube 3 has been fitted with a T-rail 26, which fits into the guide rail 25 comprising two L-profiles. From the above it will become obvious that the equipment may be embodied relatively light, and is capable of being moved and set up at a very faste rate. It has been proven that the cycle time to inserting drainage wick may be reduced to within 1/3 of the usual insertion time. This invention is not restricted to the above described embodiment. For example the block 9 does not to be provided for but the cable may be attached directly to cylinder head of 7, whereby the multiple insertion speed is obviously eliminated, but the slender hydraulic cylinders may be maintained. Alternatively it is also possible to attach multiple sheaves therefore providing for a four or more multiple insertion speed.

Claims: A device for inserting a drainage wick (17) into the ground, which comprises a mobile frame (1) having a mast (2), a wick-inserting tube (3) having upper and lower ends, said drainage wick (17) being received in the tube (3), a guide rail (22) for guidably mounting the tube on the mast (2) for vertical motion relative thereto and a hoisting cable (14) reeved over a sheave at the top of the mast and connected to the top of the tube characterized by piston/cylinder (7,8) means connected to a block (9) adjacent the upper end thereof and a length of a driving cable (16) dead-ended at the bottom of the frame and reeved over a pulley in said block and a pulley at the bottom of the frame and being connected at its opposite end to the top of the tube (3). A device according to claim 1, characterized in that said hoisting cable is furthermore dead-ended at one end to the top of the frame and reeved over a pulley in said block. A device according to claim 1 or 2, characterized in that said piston/cylinder means comprises two cilinders connected in series to each other. A device as per any one of the prior claims, characterized in that the mast is provided with a guide rail for the first or second cylinder rod and/or sheave block.

Inventors: CORTLEVER, NICO GERHARD
Applicants: GEOTECHNICS HOLLAND B.V.
Application year: 1986
Main classification: E02D3
IPC codes: E02D3