GB2115345A

GB2115345A - A pile breaker

Info

Publication number: GB2115345A
Application number: GB08204099A
Authority: GB
Inventors: Stanley Serota
Original assignee: WESTS PILING CONSTRUCT
Current assignee: WESTS PILING CONSTRUCT
Priority date: 1982-02-12
Filing date: 1982-02-12
Publication date: 1983-09-07
Also published as: GB2115345B

Abstract

The pile breaker is for cutting reinforced concrete piles (15) having reinforcing bars (16) embedded in the concrete and comprises an annular mounting (10) which is for surrounding a pile. At least one pair of pile cutters (17, 18) is supported by the mounting. The cutters (17, 18) are movable by power operated means, e.g. hydraulic rams (20) such that the cutting edges (26) meet to cut through the concrete and sever a reinforcing bar. For cutting square section piles the two cutters of each pair may be supported by two adjoining sides of the mounting for reciprocable movement in a direction inclined to respective sides, or in a direction normal to respective sides in which case each cutter has two cutting edges which cooperate with cutting edges of two adjacent cutters, or may be pivotably mounted at a corner of the mounting for scissor-like action. <IMAGE>

Description

SPECIFICATION A pile breaker This invention relates to a pile breaker for cutting reinforced concrete piles having reinforced bars embedded in the concrete.

Known devices for cutting piles split the concrete without positively cutting the reinforcing steel bars. Cutting the steel thereafter is both a clumsy operation and time consuming.

According to the present invention there is provided a pile breaker for cutting reinforced concrete piles having reinforcing bars embedded in the concrete, comprising an annular mounting for surrounding a pile and at least one pair of pile cutters supported by the mounting and movable relative to one another by power operated means also supported by the mounting such that cutting edges of the two cutters of the or each pair meet to in use cut through the concrete and sever a reinforcing bar.

Preferred and/or optional features of the invention are set forth in Claims 2-11 .

The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, wherein: Figure 1 is a sectional view of a preferred embodiment of a pile breaker according to the invention; and Figures 2 and 3 are sectional views of further embodiments of a pile breaker according to the present invention.

Referring firstly to Fig. 1, the pile breaker shown therein comprises an annular mounting 10 having four sides 11,12, 13 and 14 which define a square opening having the required dimensions for the mounting 10 to surround a pile as a close fit. A pile is indicated by the reference number 1 5 and is a reinforced concrete pile having steel reinforcing bars 1 6 embedded in the concrete adjacent the four longitudinal corner edges of the pile.

The mounting 10 houses four pairs of pile cutters. The two cutters of each pair are indicated by the reference numerals 1 7 and 1 8 and are mounted in adjoining sides of the mounting 10 adjacent a respective corner thereof. The cutters are of chisel-like shape and are operated by respective hydraulic rams 20, although, they may be operated by pneumatic cylinders or cams. Each cutter is reciprocable in a guide sleeve 21 and the cutters and sleeves have cooperating portions of matching non-circular cross-section to ensure that the cutters cannot rotate as they are reciprocated back and forth. The two cutters of each pair are reciprocable along lines 22 and 23 which intersect on a diagonal plane across the opening at a point 24.The lines 22 and 23 are preferably not common to one another but are inclined at a large acute angle to a line 25 connecting point 24 to the adjacent corner of the opening. In this case, the two cutters 1 7 and 1 8 have oblique cutting edges 26 which are parallel to each other and which meet, when the rams are operated, at the aforesaid diagonal plane. This arrangement, as compared with one in which the two cutters of each pair are reciprocable along a common line, has the advantage that the tendency for the cutters to kick outwards, away from the central axis of the pile, is reduced because a counter force will be generated which will lessen the resultant lateral forces on the cutters.

The side 1 2 of the mounting is in the form of an openable gate which is pivotably connected at one end to the side 11 and cooperable at its other end with a lock 27 fixed to the side 1 3. The side 1 2 may be opened to enable the mounting 10 to be applied laterally to a pile instead of having to thread it onto the pile. Of course, the lock could be between sides 1 3 and 1 4 with the position of the pivotable connection unchanged or one or more sides of the mounting 10 could be separable from the other sides.

The rams should be sufficiently powerful to drive the cutters 1 7 and 1 8 together so that they meet on a diagonal plane as aforesaid and sever a reinforcing bar 1 6. To do this the end load on the rams may need to be as much as 20 tons or more. As the cutters cut through the concrete pile will split or "cleave" and will be forced apart longitudinally by the thickness of the cutters (say about 1 > inches) as the cutters penetrate the pile and the cutters will then sever the reinforcing bars before damage is done to the pile by too much stretching of the bars causing the latter to break their bond with the concrete.

The pile breaker may be held in the pile frame leaders of a pile driving rig and slid up and down freely so that, after a cutting operation, the rig may be moved and the off-cut driven immediately.

In small pile breakers the pairs of co-operating cutters may have to be located on different planes in order to accommodate them in the mounting.

Fig. 2 shows another pile breaker comprising an annular mounting 10' having sides 11 ',12', 1 3' and 14' defining a square opening. Only one cutter 28 is provided in each side of the mounting. Each cutter 28 is driven by a ram 29 located centrally in the respective side of the mounting and has a cutting edge made up of a central portion 30 which lies normal to the direction of movement of the cutter and edge portions 31 and 32 each inclined at 45 to the central portion 30.

In operation the two edge portions of each blade will meet edge portions of each of two adjacent cutters on respective diagonal planes across the opening to sever two reinforcing bars. This latter pile breaker may be more successful than the pile breaker of Fig. 1 with prestressed concrete piles because the cutters may cut through the prestressing strands.

Cutters with longer edge portions 31 and 32 may be employed so as to be effective in cutting through inwardly disposed prestressing strands and indeed cutters with edge portions 31 and 32 of maximum length, i.e.

where the cutters are of arrow head shape and the central portion 30 is non existent, may be utilized and in this case it will be understood that all four cutters will meet or substantially meet at the longitudinal axis of the pile.

Fig. 3 shows yet another pile breaker having a pair of cutters 33, 34 mounted at each corner of the mounting 10" (only one pair being shown) and pivotable about a common axis indicated by reference numeral 35. A ram, shown schematically at 36, is connected between the outer ends of arms 37 and 38 integral with the cutters and can be operated to pivot the cutters 33 and 34 towards each other so that their cutting edges 39 and 40 meet on a diagonal plane across the opening defined by the mounting, to sever a reinforcing bar 16".

In the embodiments shown in Fig. 1 and 3 it is not essential to provide four pairs of cutters. Indeed, for example, only two pairs may be provided, in which case it will be necessary to remove the pile breaker, turn it round and replace it in order to sever the reinforcing bars at all four corners of a pile.

It is to be understood that the breaker can be modified to cut piles of other than square section, such as of rectangular, regular polygonal or circular section.

Claims

1. A pile breaker for cutting reinforced concrete piles having reinforcing bars embedded in the concrete, comprising an annular mounting for surrounding a pile and at least one pair of pile cutters supported by the mounting and movable relative to one another by power operated means also supported by the mounting such that cutting edges of the two cutters of the or each pair meet to in use cut through the concrete and sever a reinforcing bar.

2. The pile breaker of claim 1, wherein the mounting defines an opening of rectangular or regular polygonal shape and is for surrounding a pile of corresponding section with reinforcing bars adjacent the angles thereof and wherein the two cutters of the or each pair are supported by two adjoining sides respectively of the mounting.

3. The pile breaker of claim 2, wherein the two cutters of the or each pair are reciprocable along lines which intersect on a plane bisecting the angle between the respective adjoining sides.

4. The pile breaker of claim 3, wherein the mounting defines a square opening and wherein the two cutters of the or each pair are reciprocable along lines which are at an acute angle to a line extending from the point of intersection to the angle between the respective adjoining sides and wherein the cutters have oblique cutting edges.

5. The pile breaker of any one of claims 2-4, wherein the number of pairs of cutters corresponds to the number of angles of the opening defined by the mounting.

6. The pile breaker of claim 1, wherein each cutter has at least two cutting edges which cooperate with the cutting edges of two adjacent cutters.

7. The pile breaker of claim 1, wherein the two cutters of the or each pair are pivotally supported by the mounting.

8. The pile breaker of any one of the preceding claims, wherein the power operated means is an hydraulic ram or rams.

9. The pile breaker of any one of the preceding claims, wherein the mounting includes means whereby it can be opened so as to enable it to be applied laterally to a pile.

10. The pile breaker of claim 8, wherein the mounting is in two parts pivotable relative to one another and is provided with associated releasable fastening means for fastening the parts together.

11. The pile breaker of claim 9, wherein the mounting is in two separable parts.

1 2. A pile breaker for cutting reinforced concrete piles, substantially as hereinbefore described with reference to any one of the embodiments shown in the accompanying drawings.