US2980061A - Pile extractors - Google Patents

Description

A. BRANDER April 18, 1961 PILE EXTRACTORS '7 Sheets- Sheet 1 Filed July 23, 1957 April 18, 1961 A. BRANDER PILE EXTRACTORS 7 Sheets- Sheet 2 Filed July 23, 1957 April 18, 1961 A. BRANDER PILE EXTRACTORS 7 Sheets- Sheet 3 Filed July 23, 1957 April 18, 1961 BRANDER 2,980,061

FILE EXTRACTORS Filed July 25, 1957 '7 Sheets- Sheet 4 April 18, 1961 Filed July 23, 1957 A. BRANDER PILE EXTRACTORS '7 Sheets- Sheet 5 April 18, 1961 Filed July 23, 1957 A. BRANDER PILE EXTRACTORS 7 Sheets- Sheet 6 A. BRANDER April 18, 1961 PILE EXTRACTORS 7 Sheets- Sheet 7 Filed July 23, 1957 2,980,061 PIILE EXTRACTORS Arthur Brander, Ipswich, England, assignor to The British Steel Piling Company Limited, London, England, a company of Great Britain and Northern Ireland Filed July 23, 1957, Ser. No. 673,592 Claims priority, application Great Britain July 27, 1956 2 Claims. (Cl. 121-26) This invention relates to pile extractors, primarily sheet piles, of the kind comprising a fluid pressure operated single acting ram and cylinder assembly, the ram under fluid pressure applying .an impact force to a saddle forming part of the cylinder head and thus imparting an upward tractive force to a pile held by gripping jaws positioned at the foot of the cylinder and suspended from the saddle by a wire rope grommet extending at opposite sides and the length of the extractor.

Pile extractors of the kind described rely generally upon steam pressure for their operation, the entry of steam to the cylinder being controlled by valve mechanism operable directly orindirectly by the movement of the ram at a predetermined point during its stroke, the impact force applied by the ram being invariable, an exhaust port being provided in the cylinder wall and uncovered by the ram also at a predetermined point during its stroke.

According to the present application a pile extractor of the kind described is characterised in the provision of means whereby a variable impact force of the ram is obtainable irrespective of steam pressures and the stroke of the ram.

Preferably, the desired variation of impact force is obtained by the provision of a piston valve actuated by the steam pressure available in the ram cylinder and by-' passed therefrom through one of series of outlets positioned lengthwise of the cylinder and uncovered during the operative stroke of the ram.

In order that the invention may be clearly understood and readily carried into effect reference is directed to the accompanying drawings wherein:

Figure 1 shows in side elevation a sheet pile extractor according to the invention.

Figure 2 is a similar view but at right angles to Figure l. V 1

Figures 3a and 3b show on an enlarged scale and in sectional elevation valve control mechanism as fitted in a sheet pile extractor illustrated in Figures 1 and 2, Figure 3a showing the valve in the closed position and Figure 3b showing the valve in the open position.

Figure 4 shows in side elevation a modified form of sheet pile extractor according to the invention, and

Figure 5 is a similar view but at right angles to Figure 4.

\Figures 6a and 6b show on an enlarged scale valve control mechanism for use with the extractor illustrated in Figures 4 and 5, Figure 6a showing the piston valve in its leftmost position and Figure 6b showing the piston valve in its rightmost position.

Figure 7 shows in perspective a pair of gripping jaws forming part of the extractor.

Referring to the drawings which illustrate one form of sheet pile extractor constructed in accordance with the invention, the extractor comprises a cylinder 4 closed by a bottom head 5 and a top head 6 in which is seated a saddle 7, the assembly being completed by a piston United States atent I O exhaust port being provided at 15.

2,980,061 Patented Apr. 18, 1961 carrying a pair of dies 11 in a grip 11a constituting a gripping device suspended from the saddle 7 by an endless wire cable 12 suitably protected by a rubber sleeve 13 for the greater part of its length. The foregoing construction is substantially known and consists of a single acting ram the piston imparting an impact force into the saddle 7 upon admission of steam to the cylinder so that an upward pull is given to the jaws through the cable connection and the sheet pile is gradually extracted from position. The piston in its movement uncovers an exhaust port and thereafter falls, valve mechanism being actuated during its movement to control the admission and cut 011 of the fluid pressure, usually steam.

In accordance with the present invention the bottom head 5 houses the valve mechanism for controlling the fluid pressure, i.e. steam through an inlet 14, the usual The inlet of steam is controlled by a piston valve 16 arranged to open and close a port 17 admitting steam from an annular channel 18 to the underside of the piston 8. The piston valve is operated by the steam presssure prevailing in the cylinder through a by-pass 19 to the underside of the piston valve 16 causing it to raise to close off the port 17 when the piston in its upward movement has uncovered one of a series of ports 20 in the Wall of the cylinder 4 and communicating with the by-pass 19 common to all.

[It will be appreciated that by this means the impact force of the piston 8 can be controlled as the steam pressure is operative until such time as one of the ports 20 is uncovered by the upward movement of the piston to by-pass steam at the same pressure tothe base of the piston valve 16, the piston valve having a differential cross section larger at the base than at the top to be effective against the steam pressure prevailing in the annular channel 18 and against the upward stroke of the piston valve 16, The ports 20 are each closed by a removable plug 21 which is available for removal by withdrawal and return of a closure 22. The impact force of the piston is increased if the uppermost plug 21 is removed and the remaining two left in place, similarly the impact force is decreased if the lowermost plug is removed and the remaining two left in place. I Removal of the intermediate plug will also provide for'regulating the impact force. It will be appreciated thattwo or more plugs 21 maybe provided and positioned lengthwise of the cylinder.

T he construction of the sheet pile extractor shown in Figures 4 and 5 is substantially of the same construction of the extractor as illustrated in Figures 1 and 2 with the main exception that a horizontally operating valve control is employed as shown in Figure 6 in place of the vertically operating valveshown in Figure 3.

As in the previous construction, the extractor comprises a cylinder 4, bottom head 5, top head 6, saddle 7 and piston 8 (see Figure 6). The top and bottom heads are connected by bolts 9 and 10 respectively the assembly having suspended therefrom the usual dies 11 through the intermediary of a grip 11a suspended from the saddle 7 by a wire rope grommet 12 that is to say an endless wire cable which serves as a pulling link upon functioning of the extractor. The cylinder 4 and associated parts are suspended from a crane for example by means of an eye bolt 30 connected to the head 6 by means of cables 31.

The valve for controlling the operation of the extractor is illustrated in Figure 6 and in this arrangement is horizontally disposed in the bottom head 5 which also constitutes an oil chamber 32 to which oil is introduced through a filler 33. The valve proper 34 is slidably disposed in a valve sleeve 35 suitably fixed within the bottom edge and held in place by a nut 36. The valve 34 is oscillatable from one extreme position as indicated at the upper half thereof to the other extreme position as indicated in the bottom half of the figure, the reciprocation taking place between nylon buifers 37. 14 is the usual steam inlet from which the steam passes to the cylinder 4 through the valve to exhaust through an exhaust port not shown but indicated as 15 in Figure 3. The piston valve 34 upon reciprocation opens and closes a port 38 through which steam is admitted to an annular chamber 29 and thence through a port 40 to the cylinder 4, to raise the piston 8. The valve 34 is of differential cross section providing a greater pressure face as at 34a than at 34b consequently when steam admission to the cylinder takes place when the piston valve 34 is in the position indicated in the lower half thereof the piston 8 will rise until one of the ports 20 is uncovered placing the bye-pass 19 in communication with the piston valve sleeve 35 through a port 41 resulting in the pressure of steam at the greater pressure face 34a of the piston valve being effective to force the valve to the position shown at the upper half of the piston and thus shut off the steam pressure to the cylinder 8. Upon the fall of the piston 8 after covering the port 20 previously uncovered the pressure in the cylinder 4- will rise to counteract the pressure at the face 34a and as pressure increases against the pressure face 34b the piston valve 34 will move to the position at the lower half thereof as shown in the drawing and permit steam to again enter through port 38. The operation of the valve is identical to that shown in Figure 3 The provision of the nylon buffers 37 at each end of the travel of the piston valve 34 reduces chatter and the noise of the valve operation.

The oil chamber 32 (Figures 3 and 5) is vented to the cylinder through a small passage 32a not shown in Figure 5 whereby the oil in minute portions together with steam forming an emulsion is drawn into the cylinder upon each upward stroke of the piston and thus serving an eflective means of lubrication of the cylinder 4 and the piston 8.

Figure 7 shows in greater detail the jaws of the extractor comprising a pair of dies 11 proper of wedge form supported in a grip 11a consisting of a pair of plates 11]; held together by bolts 42 the plates also forming a hold for the one looped end of the Wire rope grommet '12 which forms a pulling link with the saddle 7 over which the other looped end of the grommet extends. The dies 11 are connected at each side of the grip 11a by hair-pin springs 43 which hold the jaws 11 outwards against ramp faces 110 formed on a gapped part 11d of the grip 11a thus when an upward force is exerted on the grip 11a by an upward pull applied to the grommet 12 upon the piston 8 striking the saddle 7 as an anvil the grip of the jaws 11 is increased and a sheet pile firmly held therebetween. The backs of the dies 11 are recessed to provide of locating the dies on the sliding surfaces 110 of the grip 11a.

Release of the dies from the steel pile is achieved through allowing the weight of the extractor body to impact on the grip 11a thereby forcing the grip downwards in relation to the dies which are gripping the pile. The flexibility of the wire rope sling permits this to be done. The force is transmitted through the fork-shaped pieces 44- (Fig. 7) which embrace the grip. The impact may be no more than a tap or the dies may release merely by the Weight of the extractor resting on the grip.

It will be appreciated that although the invention has been described more specifically in relation to the extraction of sheet piles the invention is applicable to extractors for piles of all kinds, the dies and grip for instance being suitably modified. For example the extractor can be equally well used for pulling a steel bearing pile.

What I claim and desire to secure by Letters Patent is:

1. A pile extractor comprising a cylinder, a top head and a bottom head on the cylinder, a saddle seated in the top head, means connecting the top and bot-tom heads to the cylinder, a pile gripping means'suspended from the saddle and disposed below the bottom head, a piston within the cylinder having a constant length of stroke, the cylinder having an open exhaust port adjacent the top head to exhaust the pressure operating on the piston at the end of its stroke, a valve chamber in the bottom head, the cylinder wall having a plurality of manually controlled ports intermediate the top and bottom heads and also a by-pass therein connecting the manually controlled ports with the valve chamber, an inlet port in the cylinder from the valve chamber, a pressure fluid means connected to the bottom head and passage means connecting the valve chamber with the pressure fluid means, valve means in the valve chamber comprising a ported valve sleeve and a valve member reciprocable therein, the valve member having means providing on its opposite sides a larger surface area and a smaller surface area, the former being positioned in the valve sleeve adjacent the bypass port and the latter positioned adjacent the inlet port thus forminga differential pressure operated valve member, the manually controlled ports being openable by selection to allow by-passing of the pressure fluid from the cylinder thus relieving the pressure upon the piston to vary the amount of impact upon the saddle, the pressure fluid so by-passed acting on the larger surface area of the valve member to cause the valve member to move to close otf the inlet of pressure fluid into the cylinder, the lowermost manually controlled port when opened allowing less amount of impact and the uppermost manually controlled port when opened allowing the highest amount of impact, the valve member being operated to open the inlet port to the cylinder by the pressure produced on the smaller surface area by the return of the piston to the nonworking end of its stroke.

2. A pile extractor as claimed in claim 1, in which the gripping device is suspended from the saddle by an endless wire cable grommet which forms a pulling link with the saddle over which a looped end of the grommet extends.

References Cited in the file of this patent UNITED STATES PATENTS 947,861 Soley Feb. 1, 1910 1,736,104 Warrington Nov. 19, 1929 2,068,045 Wohlmeyer Jan. 19, 1937 FOREIGN PATENTS 345,837 Great Britain Apr. 2, 1931

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