DEVICE FOR BREAKING OFF PILES

Abstract: The invention relates to a device for breaking off piles, said device being provided with a frame built up of a plurality of links (1), whereby the links (1) are interconnected in a closed loop by means of hinge pins (5) and ears forming part of the links (1), said loop forming a passage for accommodating a pile (6) to be broken off. At least some of the links (1) each support a setting cylinder (4)¸ by means of which a cutter (3) can be moved to and fro, such that a part of the pile (6) located inside the passage can be broken by the cutters (4). The links (1) in a direction provided with co-­ operating stops (7) limiting the pivoting of the links (1) in a direction in which the free ends of the cutters (4) supported by the links (1) in question move towards each other, all this such that the cutters (4) cannot touch each other in the position in which they are completely moved out.

Description: The invention relates to a device for breaking off piles, said device being provided with a frame built up of a plurality of links, which are interconnected at both their ends, to form a closed loop, by means of hinge pins and ears forming part of the links, said loop forming a passage for accommodating a pile to be broken off, whilst at least some of the links each support a setting cylinder, by means of which a cutter can be moved to and fro, such that a part of the pile located inside the passage can be broken by the cutters. Such a device is e.g. known from NL-A-8,400,404 or DE-A-3,541,786 (Figures 6, 7). In itself such a device is quite satisfactory. It has become apparent, however, that in case of inexpert use there is a risk that in some cases the cutters may touch each other when moving towards the centre of the closed loop, which, also in view of the great forces with which the cutters are moved, may lead to considerable damage to the device. The object of the invention is to obtain a device of the above kind, wherein the above risk can be simply avoided. According to the invention this objective can be accomplished in that the links are provided with co-operating stops for limiting the pivoting of the links in a direction in which the free ends of the cutters supported by the links in question move towards each other, all this such that the cutters cannot touch each other in the position in which they are completely moved out. By using the construction according to the invention serious damage to the device can be avoided in a simple manner. It is noted that from US-A-4,044,774 there is known a device for breaking off concrete, whereby the tools are mounted on curved supporting parts. During operation said supporting parts form an essentially rigid annular means, which is pivotal forwards and backwards about its central axis in order to allow the tools to act on a concrete covering of a pipe. The construction and operation of said known device is entirely different from the construction and operation of the device according to the invention, therefore. The invention will be explained in more detail hereinafter, with reference to the accompanying Figure, which diagrammatically shows a plan view of a device according to the invention. The device shown in Figure 1 is built up, in a manner similar to the manner which is described in the above-mentioned Dutch Patent Application No. 8,400,404, of a plurality of links 1, which are each provided with a block 2 in which a cutter 3 is movably guided in its longitudinal direction. On one side of the block 2 there is mounted a hydraulic setting cylinder 4, by means of which the cutter 3 can be moved to and from in its longitudinal direction. For this purpose a pressurized fluid can be supplied to the setting cylinder 4 in question by means of pipes (not shown). As is further illustrated in Figure 1 a number of such links 1 are interconnected by means of hinge pins 5, in order to form a closed loop-shaped unit. The device thus built up of a number of links can e.g. be suspended from a crane or the like by means not shown, and be moved by means of said crane over the upper end of a concrete pile 6 which has been driven into the ground. By then pressing the cutter into the concrete of the pile by means of the setting cylinders 4, as is illustrated for one of the cutters by means of dotted lines in the Figure, the concrete of the pile can be broken in order to expose the reinforcement present in the pile. As is furthermore illustrated in the Figure the links are provided with stops 7 on both sides of the blocks 2. Said stops 7 are formed and arranged such that when two adjacent links 1 pivot about the hinge pin 5 interconnecting said links in a direction in which the ends of the cutters 3 move towards each other, said stops will touch each other at a certain moment and thus prevent further pivoting in that direction. The construction is thereby such that when the stops of two adjacent links abutt against each other and the cutters 3 supported by the links in question are moved out of the blocks 2 as far as possible by means of their setting cylinders 4, it is still not possible for the cutters to come into contact with each other. This is done in order to prevent that the cutters will exert undesired forces on each other. It will be apparent that the location and the design of the stops 7 will also depend on the length of the stroke of the cutters 3 or the lengths of the cutters 3 that can be used in the device.

Claims: Device for breaking off piles, said device being provided with a frame built up of a plurality of links (1), which are interconnected at both their ends, to form a closed loop, by means of hinge pins (5) and ears forming part of the links, said loop forming a passage for accommodating a pile to be broken off, whilst at least some of the links (1) each support a setting cylinder (4), by means of which a cutter (3) can be moved to and fro, such that a part of the pile located inside the passage can be broken by the cutters (3), characterized in that the links (1) are provided with co-operating stops (7) for limiting the pivoting of the links in a direction in which the free ends of the cutters (3) supported by the links (1) in question move towards each other, all this such that the cutters (3) cannot touch each other in the position in which they are completely moved out. Device according to claim 1, characterized in that the cutters (3) are guided in a block (2) forming part of the link, and that said stops (7) are provided on both sides of a relevant block.

Inventors: VAN DER TOORN, AART
Applicants: KENT-AIR EUROPA B.V.
Application year: 1990
Main classification: E02D9
IPC codes: E04G23, E02D5, E02D9