DK143418B - PROCEDURE AND APPARATUS FOR DRIVING A PAEL IN EARTH - Google Patents

Description

| P (12) PUBLICATION <n> 1l + 3A18B

(19) DENMARK

DIRECTORATE OF THE PATENT AND TRADEMARKET SYSTEM

(21) Application No. 6415/71 (51) lnt.CI.3 E 02 0 7/10 (22) Submission date 29 · dec. 1971 (24) Race day 29 · dec. 1971 (41) Aim. available 50 · Jun. 1972 (44) Presented Aug. 17-Aug. 1981 (86) International Application No. - (86) International Filing Day “(85) Continuation Day” (62) Master Application No. -

(30) Priority 29 Dec. 197Ο, 102525 * US

(71) Applicant BOLT ASSOCIATES INC., Norwalk, US.

(72) Inventor Stephen Victor Chelminski, US.

(74) Clerk Th. Ostenfeld Patent bur eau å / S.

-II '-' I '' —— II i i, I 1 ^ (54) Method and apparatus for driving a pile in the ground.

The present invention relates to a method of driving a pile in the ground and, moreover, of the kind specified in the preamble of claim 1.

Formerly known diesel-powered pile-frame appliances use a fall-hauner, while steam-driven types of apparatus employ a heavy-weight falling piston which abuts an anvil surface which (Q transmits the blow to the pile. These known pile-frame appliances have a significant disadvantage which consists in the fact that from the falling mass at a stroke on an anvil surface Each stroke produces a very loud noise as metal strikes directly against metal, r_ which is highly bothersome for many people, even for persons who are relatively far from Especially q for the steam-operated type of free impact piston, this noisy stroke is an unsatisfactory method of transferring the energy to a pile for the purpose of driving it down on the severity and short duration of this impact type. the pile is also devastating when the energy level needed to drive the pile becomes too high.

This direct and short-term impact in known appliances, which is destructive to the pile as well as to the apparatus itself, is in many cases a shock-absorbing material between the end of the pile and the apparatus. Commonly used shock-absorbing materials are wooden blocks or sheets of phenolic laminates or other resins. The use of such shock-absorbing materials firstly results in an energy loss and, in addition, an increase in operating costs, since such materials are often quite expensive and must be replaced frequently.

Another disadvantage of known steam or fluid-driven pile-frame devices consists in the relatively long time allowed to lift the impact piston from its bottom position at the anvil surface and to the apex of the piston ram, where the steam or propellant fluid is allowed to expand to the atmosphere. It has been found advantageous to work with a relatively high stroke or shock frequency during the hitting of a pole. The reason for this is that the soil surrounding the pole can be kept in a more or less moving or "liquid" state when frequent blows or shocks are delivered to the pole. This reduces the frictional forces between the pile and the surrounding soil and the pile becomes easier to hit. On the other hand, when the shock is delivered at a low frequency, the surrounding soil has the opportunity to collapse or settle around the pile between each shock, which increases the frictional forces, making the pile more difficult to hit.

US Patent No. 3,417,828 discloses an example of the above-mentioned prior art which has the drawbacks mentioned.

The method according to the invention is characterized by the method of claim 1. Thus, the basic principle of the method according to the invention consists in causing the falling piston to strike and spring up from a pad of fluid under pressure. At some point, while the piston is still falling down, extra pressure fluid is injected into the pad under the piston, which further compresses this extra fluid. Gradually, the piston releases its movement energy to the now highly compressed fluid pad, which can then expand, thereby throwing the piston upwardly into the cylinder. At some point during the upward movement of the piston, the fluid under the piston is relieved so that it can turn and fall again through the cylinder. The power transfer to the pile occurs through the fluid pad at and around the time the piston is braked and thrown upward from the bottom region of the cylinder.

Hereby, a particularly advantageous pile frame technique has been provided which allows a driving impact or force impact to be delivered to a pile of substantially longer duration than the usual short-term and direct impact impact. Such a shock effect is more effective and has a greater benefit than a direct impact on an anvil surface. In addition, the impact of the shock is less damaging to the pile, and the noise is far less, as the energy transfer to the pile is done in whole or in part through the pad of compressible fluid. Furthermore, the return of the piston to the top position can be effected quickly due to the backscattering effect of the fluid cushion, and thus a high impact frequency can be worked.

A particular effect achieved with the present invention is that the impact and impact frequency are to some extent self-regulating. If a pile underneath meets softer substrate layers, the backscatter effect of the fluid cushion becomes smaller, thus automatically reducing the piston stroke length while automatically increasing the impact frequency. When the pile, on the other hand, encounters hard substrates, the piston is thrown higher up into the cylinder, thereby automatically increasing the piston stroke length while reducing the impact frequency. Thereby, each impact of the shock becomes stronger, so that the increased resistance to the pole can be overcome.

In addition, by adjusting the fluid injection specific to the invention under the descending piston, a pile may be operated in various ways. Common to these modes of operation is that the piston's moving energy is not transmitted exclusively by a direct stroke, as is the case in the prior art.

In a first mode of operation, no direct impact occurs at all, the fluid being completely enclosed, but temporarily under the piston, which thereby does not achieve significant direct contact with the cylinder bottom during the shock transfer. This embodiment is set forth in claim 2 and is further specified in claim 3.

4 143418

A second mode of operation involves a first biasing thrust followed by a controlled direct stroke with a subsequent thrust. These embodiments are set forth in claim 4 and may be convenient in certain cases, the biasing thrust removing any clearance between the pile and the cylinder transmitting power. The subsequent direct blow will thus not be so detrimental to the pile that is set in motion. The closing thrust then keeps the pile moving at the same time as the piston is thrown upwards in the cylinder.

Regardless of which of these modes of operation is used, it will be appropriate for a supply of propellant fluid to be available as close as possible to the place of use, ie. immediately below the location of the fluid cushion as set forth in claim 5.

The fluid injection under the falling piston can be controlled or triggered in various ways. However, the simplest and most reliable control is obtained if the injection is induced by the plunger itself, as stated in claim 6.

In connection with the invention, it may be advantageous for the piston to be ventilated on the upper side in the top position. This will, for example, be an advantage in connection with the self-regulation of the impact mentioned above. However, in some cases, it may be convenient as stated in claim 7 for air to be trapped above the piston at its top position. In this way, the piston can, so to speak, be "thrown" back and forth at full stroke between an air cushion at the top of the cylinder and the fluid cushion at the bottom of the cylinder. Consequently, with this mode of operation which can be described as double acting, powerful shock effects of particularly high frequency can be exerted.

Claim 8 specifies an embodiment which allows for an appropriate control of the magnitude and duration of the impact, which is a consequence of the fluid injection specific to the invention under the descending piston.

A further working method which may be relevant in connection with the invention is the complete or partial pull-up of piles as claimed in claim 9. Also, the upward impact of the impact can be a compression shock without direct contact as referred to in claim 10, or a controlled operation can be included. direct impact against the cylinder head as claimed in claim 11.

143418 5

The present invention further relates to an apparatus for practicing the method. The apparatus according to the invention is otherwise of the type specified in the preamble of claim 12 and is peculiar to that of the characterizing part of the same claim.

Claims 13-21 relate to clarification of apparatus features and indications of apparatus embodiments associated with the above-described method embodiments. The apparatus embodiment specified in claim 19 causes a further noise reduction, the arrangement of outlet ports being particularly well suited for applying an effective silencer which, as mentioned in claim 20, can also be included in a lubrication system which is activated by the pressure changes for the invention. shock chamber.

In the following, the invention will be described in more detail with reference to specific embodiments and with reference to the drawing, in which fig. 1 shows a vertical side view of a pressure medium driven pile drive apparatus according to the invention on a greatly reduced scale; FIG. 2 is a section taken along line 2-2 of FIG. 1 in a downward direction and on a somewhat larger scale; FIG. Fig. 3 is a larger scale vertical axial section of the bottom of the apparatus shown at a time when a solid piston during its downward movement just comes into contact with an actuator valve actuator; 4 is a sectional view taken along line 4-4 of FIG. 3; FIG. 5 is a side elevational view of the portion of a silencer housing containing the expanded opening of the expanded pressure medium showing the silencer's internal configuration and the oil separating material; FIG. 6 is a vertical sectional view of a portion of the silencer housing taken along line 6-6 of FIG. 5, FIG. 7 is a vertical sectional view of the part of the apparatus containing oil filter and a self-acting lubricating pump for supplying lubricating oil to the movable parts of the apparatus and shown in almost natural size; FIG. 8 is a vertical sectional view of the supply of pressure medium with the supply of injection of lubricating oil into the pressure medium; FIG. 9-14 vertical axial sections corresponding to FIG. 3, but shown on a somewhat smaller scale than in FIG. 3 and showing successive operating positions of the few moving parts of the apparatus during an operating cycle for delivering a shock or compressive force to a pile to be driven, and the embodiment of FIG. 3 is located between the positions shown in FIG. 9 and 10, FIG. Figure 14 further shows the solid piston operating in a double-acting manner. 15 is a vertical axial section of the upper part of the apparatus when the piston operates in a single-acting manner; FIG. 16 is a sectional view similar to FIG. 15, but showing the single-acting mode during its transition to the double-acting mode with maximum piston travel; FIG. Fig. 17 is a side elevational view of the apparatus during its pull-up function with a pressurized medium-driven cylinder and piston at the top of the apparatus and suspended in a hoist rope to limit the maximum traction given to hoists from the shakes occurring in the apparatus during its pull-up function; 18 is a side elevation, partly in section, taken along line 18-18 of FIG. 17, FIG. 19 is a vertical sectional view of the coupling device of the apparatus with conical equipment for use in driving down wooden posts; FIG. 20 is a vertical axial section through a modified embodiment of the apparatus; and FIG. 21 is a vertical axial section through yet another embodiment of the apparatus.

In FIG. 1-4, an apparatus 20 for carrying out the invention is shown which can operate with automatic self-regulating variable stroke, variable speed and silent noise. The apparatus 20 comprises a cylinder wall 22 defining a cylinder 23 which is provided with a composite solid piston 24, as shown in FIG. 3. At the lower end of the cylinder wall 22 is placed the bottom unit 26 of the cylinder, which effectively closes the lower end of the cylinder wall 22. The bottom unit 20 is coupled to a pile 28 to be driven, and the coupling takes place via a removable coupling 30 and an adapter piece 32. which is designed to abut the upper end of the pile in question to be driven.

When it is desired to drive piles of different cross sections, sizes or shapes, such as pipe poles, H-shaped poles or wooden poles, the coupling 30 is removed until another adapter piece 32 which fits the particular pole is inserted. In the embodiment shown, FIG. 1 and 3, the pile 28 is tubular, but of course all the cross-sectional shapes of piles can be used to practice the invention.

In FIG. 3, there is shown a bump chamber 34 which is located within the cylinder wall 22 between the lower end of the piston 24 and the dog unit 26. An instantaneous delivery means 36 for the pressure chamber 34 under the piston 24 is arranged in the bottom unit 26. This pressure medium supply means 36 comprises a pressure medium accumulator 38 and a control valve 40 in connection with the shock chamber 34.

The solid piston 24 is moved up and down in the cylinder 23, and it hits a pad of pressure medium in the shock chamber 34. The manner in which the pressure medium is applied to the shock chamber and the many advantages obtained by the impact of the piston will be described in the following.

The solid piston 24 contains a heavy portion 42 of suitably dense and strong material. In the embodiment shown, this heavy portion 42 is e.g. of solid steel and practically cylindrical with sliding surfaces, piston rings and end caps attached to its lower and upper ends. Its lower and upper ends are identical, so only the lower end is shown in detail in FIG. 3 for simplicity. The upper end of the piston 24 is also shown in FIG. 2, 14, 15 and 16.

In particular, FIG. 3 and 7, it can be seen that a bearing sleeve 44 is disposed at both ends of the heavy portion 42 of the piston 24. This bearing sleeve 44 is annular and fits on a reduced diameter end piece 46 at the end of the heavy portion 42 and abuts an annular shoulder 48. This bearing sleeve 44 is made of a suitable bearing material suitable for sliding on the cylinder wall 22 and may e.g. be of bronze. It is retained by a toughened steel end cap 50 which is secured to the heavy portion 42 by removable fasteners, which as shown may be a plurality of machine screws 52.

To form a pressure medium-tight seal near the end of piston 24, a plurality of piston rings 54 are disposed. These piston rings 54 are arranged in an annular gasket member 56 which is held by the end cover 50 together with the bearing sleeve 44. There is a relatively large annular clearance within the gasket member 56, thus that this can be displaced radially, thereby adapting to any relative lateral movement of the piston 24 relative to the cylinder wall 22. In other words, the relatively movable or "floating" gasket member 56 provides an accurate solid support because the swimming action of the gasket member 56 prevents it being worn against the cylinder wall during the up and down movement of the piston 24. In this way, it is ensured that any lateral force occurring is caused to be absorbed by the bearing bushing 44, 8 143418 and when worn, a very small clearance between the floating packing means 56 and the cylinder wall. This ensures that the piston rings continue to provide good support so that they have a long service life.

In the described embodiment, the bottom unit 26 contains a second piston 60. This second piston 60 is adapted to be displaced up and down limited travel within a second cylinder 61, which is defined by a lower extension of the cylinder wall 22 below the level of the shock chamber 34. To hold the piston 60 in the cylinder 61, a circumferential stop shoulder 63 is provided which encloses the piston 60. An annular holding and bearing member 65 defines the lower end of the cylinder 61. The holding and bearing member 65 is secured by means of large machine screws 67 to a mounting ring 69 which is welded to the outside of the cylinder wall 22. At the lower end of the piston 60 there is a coupling flange 71 arranged to be driven by the removable coupling 30. The removable coupling coupling 30 is formed as two semi-circular clamps with associated protruding clamping flaps 73, which are secured together by means of bolts 75.

In another embodiment shown in FIG. 21, it should be noted that instead of the piston 60, the bottom unit of the cylinder may be a closed lower end piece on the wall of the cylinder 22. attached to the lower part of the cylinder wall 22 so that it forms part of the cylinder wall 22.

However, it is preferable to use a bottom unit 26 which contains a relatively slidable second piston 60 because the use of this second piston 60 allows the cylinder wall 22 to be disconnected from the pile 28. This disconnection of the cylinder wall 22 from the pile 28 reduces the size of the piston 28. masses driven downwardly when the prolonged shock is released to drive the pile 28.

As mentioned, the pressure medium supply means 36 contains both the pressure medium · accumulator 38 and the control valve 40. This supply means 36 serves to supply pressure medium through a supply port 62 in the shock chamber 34 below the downward piston 24. The supply of pressure medium is controlled by the valve 40.

The accumulator 38 is disposed within the second piston 60 of the cylinder unit 26. The accumulator 38 is defined externally by a cylinder liner 66 in a bore 64. A bottom flange 68 of a vertical valve guide 70 forms a liner at the bottom of the accumulator 38. The valve guide 70 has a bore 72 and a valve stem 74 on a valve body 76 is inserted into this bore 72. The valve body 76 has a tapered valve surface 78 which faces upwardly against a tapered valve seat 80 formed in an end cap 82 on the second piston 60. This second piston is provided with a bearing sleeve 84, piston rings 86 and an annular packer 8 having an annular clearance corresponding to the clearance provided at the corresponding portions at both ends of the piston 24.

In order to activate the valve 40 by means of the plunger 24, an upwardly extending control means in the form of an actuator 91. is formed in the form of an actuator 91. The actuator 91 is provided with a pressure medium blocking means 93 in the form of a thickening, i.e.. a larger diameter cylindrical piece. This thickening 93, when the valve body is directed downwardly, fits snugly into the port 62 for blocking the pressure medium in the shock chamber 34.

As the valve body 76 is pushed away from its valve seat 80, pressure medium from the accumulator 38 can flow through a plurality of channels 90 as seen in FIG. 4, thereby flowing past the circumference of the valve body 76 and thereby flowing through the port 62 of the shock chamber 34. The ducts 90 are formed as grooves between projections 92 in the interior of the cylindrical liner 66.

The print medium is supplied from a suitable source e.g. from a container not shown on a compressed air compressor, also not shown. The compressed air may conveniently be at a pressure of e.g. between 5.6 and 210 ato.

When the valve body 76 is depressed, an annular groove cooperates therein, as shown in FIG. 3, with the upper end of the valve guide 70 seen in FIG. 12, to form an elastic deceleration means, the pressure medium being confined to the groove 95. This confined amount of pressure medium produces an elastic resilient deceleration for the depressed valve body, thereby preventing it from crashing against the valve guide 70.

The pressure medium is supplied to the apparatus 20 through a flexible pressure hose 94 and through a connection fitting 96. This fitting 96 opens into a supply duct 98 which is connected to the bore 72 in the valve guide 70. The pressure medium from the bore 72 flows through a calibrated opening 100 into the accumulator 38. When the valve stem 74 is in its upper position, as shown in FIG. 3, the pressure medium can also flow through a larger aperture 102 into the accumulator 38. The two apertures 100 and 102 are connected in parallel and the lower calibrated aperture 100 is always open, while the upper uncalibrated aperture 102 is shut off when the valve body 76 together with its valve spindle 74 is pressed down by the plunger 24.

After the plunger 24 is thrown upwardly from the pad of pressure medium as shown in FIG. 13, the expanded pressure medium 104 is released from the cylinder 23 through a plurality of outlet ports 106 in the cylinder wall 22. The outlet ports 106 are connected to an annular silencer 108 which is delimited by a removable silencer housing 109 which contains a pair of mutually cylindrical walls 110 and 112 are spaced apart. The silencer housing walls 110 and 112 are fixedly interconnected via a bottom ring plate 114 which is removably secured to a mounting ring 116 by a plurality of bolts 118. The mounting ring 116 is secured to the outside of the cylinder wall 22 by welding.

In FIG. 5 and 6, the upper end of the removable muffler 109. The annular muffler chamber 108 is connected via a number of ports 120 to a certain amount of oil-air separation material 122 at the top of an annular muffler chamber 123 for separating lubricating oil drops from the expanded pressure medium 104. after this has passed through the ports 120. The oil separation material 122 may be coarse stainless steel wool. A removable cover 124, secured by screws 126, allows the oil separating material 122 to be removed and replaced.

As the expanded pressure medium 104 flows down through the material 122 and then through the holes 127 in a support ring 129, as shown in FIG. 6, the pressure medium 104 flows into an inverted U-shaped pressure medium outlet prefabricated surface 12. The interior of the baffle surface 128 is connected to an exhaust port 130 through which the expanded pressure medium can flow into the atmosphere. The purpose of the bead surface 128 is to prevent the separated small oil droplets from being blown out to the atmosphere.

As shown in FIG. 5, the separated small oil droplets 132 fall from the separating material 122 into the chamber 123 and, as shown in FIG. 3, this oil is collected in an annular lubricating oil container 134 at the bottom of the chamber 123. This provides an oil container for the self-replenishing lubrication system, which will be explained in greater detail later.

The muffler housing 109 can be removed thereby providing access to the ports 106, if desired by unscrewing the bolts 118 as shown in FIG. 3 and 7. As shown in FIG. 6, the upper part of the silencer housing 109 has an O-ring gasket 136 for sealing the silencer core 108. Thus, the gasket 136 can be pushed up along the outer side of the cylinder wall 22 to remove the silencer housing 109. From FIG. 1, it can be seen that if a mounting ring 138 for the guide of the apparatus and a silencer and air filter 140 located at the top of the apparatus is removed, the entire silencer housing 109 can be removed if desired.

The self-supplementing lubrication system is seen in greater detail in FIG. 7 and 8. The oil level in the container 134 can be seen through an oil level tube 135 of a transparent impact-resistant plastic tube. Oil from the container 134 can flow down through an oil supply line 142 to an inlet duct 144 sealed by a gasket 145 and connected to an inlet chamber 146 for an oil filter 150. A cylindrical filter cartridge 148 of filter material such as felt separates the inlet chamber 146 exit chamber 152 through which a bolt 154 is guided to retain an end cap 156. The filter cartridge 148 can be removed and replaced by unscrewing the bolt 154 and removal of the end cover 156 with its associated oil pipes 158 and 159.

The filtered oil is delivered from the outlet chamber 152 through a channel 157 in the end cap 156 and through the oil pipes 158 and 159 which carries the oil to an oil pump 160. The oil tube 158 feeds the oil through a check valve 162 to a low pressure pump chamber 164 which holds a pump piston 166. This piston 166 pumps low-pressure oil through a non-return valve 168 and through an oil pipe 170 extending up to an oil hole 172, as shown in FIG. 1, for dispensing lubricating oil above the piston 24 for lubricating it and the cylinder wall 22.

The second oil pipe 159 directs the oil through a check valve 174 to a high pressure pump chamber 176 which holds a smaller diameter piston 178. This plunger 178 pumps oil under high pressure through a counter-valve! 179 to an oil pipe 180 which, as shown in FIG. 8 leads down to a swivel drain pipe 182 on the pressure fitting connection fitting 96. The swivel drain pipe 182 has a channel 183 and an annular chamber 184 for feeding oil radially inward through a pair of oil holes in the bore 97 of the connector fitting 96.

Thereby, the lubricating oil is mixed with the flowing pressure medium, thereby delivering oil through the supply channel 98 for lubricating the pressure medium supply means 36, which contains the valve 40. This oil which is introduced through the supply channel 98 also serves to lubricate the shock chamber 34, piston 60 and the cylinder wall 22 which surrounds the piston 60.

It should be noted here that in FIG. 7, pistons 166 and 178 are interconnected to form a double piston. A spring 186 in the low pressure pump chamber 164 both presses pistons 166 and 178 to the left. In other words, the spring 186 pushes the pistons 166 and 178 in their suction stroke direction. The high pressure occurring in the shock chamber 34 is used to drive the pistons 166 and 178 to the right, i.e. in their direction of pressure. A small port 188 in the cylinder wall 22 is connected via a drilled passage 189 in a footplate 190 to a channel 192 which leads into the pump activation chamber 194.

12 143418

The foot plate 190 serves to support both the oil filter 150 and the oil pump 160. This foot plate 190 can be removed from the outside of the cylinder wall 22. As shown in FIG. 3, this foot plate is removably fastened with machine screws 196, which however can only be seen in FIG. Third

When a pile is to be driven as shown in FIG. 1 and 2, the apparatus is controlled by a pair of spaced parallel vertical guide rails 200 and 201, which are the so-called guide guides. The use of guide steering is well known in pole driving, and their use is not new. These guides are engaged with lower and upper guides 204 and 206 which grip the respective guides and are lubricated so that they can easily slide up and down the guides. The lower pair of guide 204 is secured by a clamping ring 208 (Fig. 2) which encloses the muffler housing 109. This lower clamping ring 208 is formed in two semicircular portions with protruding associated fixing flaps 209 which are mutually secured by bolts 210. top pair guide 206 is similarly secured by clamping ring 138 which encloses cylinder wall 22. The upper mounting ring 138 is formed in two semicircular portions with protruding cooperating patches 213 which are mutually secured by bolts 214.

To allow atmospheric air to flow into and out of the upper portion of the cylinder 23 above the piston 24, a number of vent ports 216, as seen in FIG. 15, and which is connected to an annular housing 140 with silencer and air filter. This housing delimits inner and outer annular silencer chambers 218 and 220. In FIG. 15 shows how the atmospheric air 222 flows out of the cylinder 23 because the piston 24 moves upward. It will be understood, of course, that as soon as piston 24 begins to move down again, atmospheric air will be sucked back into cylinder 23. To avoid dirt and dust, an air filter element 224 is provided in chamber 220 next to air vent openings 226.

In order to obtain different means for driving piles at the apparatus 20, different types of top units 230 in FIG. 15 and 230A in FIG. 1. The tops are removably attached to the upper end of the cylinder wall 22 by removable fasteners 232, which as shown may be machine screws.

The deepest peak unit 230A shown in FIG. 1, extends downwardly so as to block the air vent openings 216, thereby providing a double-acting pile propulsion method, which will be explained in detail later.

The FIG. 15 shows a single-acting pile drive method.

When the piston 24 makes particularly large upward travel in the cylinder 23, as shown in FIG. 16, the single-action pile casting method is automatically switched to a double-acting method.

When the apparatus 20 of FIG. 1 or 20A in FIG. 20 or 20B in FIG. 21, it can be carried by a cable 236 (Fig. 1) from a suitable crane, not shown, and which is attached to a suitable carrier 234, such as e.g. a connecting means attached to the upper end of the apparatus, e.g. to the top unit 230 or 230A.

When the apparatus is used for raising piles, as shown in Fig. 17 and 18, the carrier cable 236 can conveniently be attached to connecting means 238 which are attached to a pressure medium driven carrier cylinder 240 with a piston 242 and with a cylinder space 244 under the piston. The piston rod serves as a carrier 234 attached to the upper end of the apparatus.

A pressure medium such as e.g. compressed air or another type of gas under pressure is supplied from a pressure medium source 246, e.g. may be the pressure vessel of a compressed air compressor. This pressure medium is delivered through a reduction valve 248 to the cylinder chamber 244.

The reduction valve 248 is set by the operating personnel so that the total force developed by the pressure medium in the cylinder space 244 and acting on the drive area of the piston 242 is somewhat less than the safety limit of the crane pulling the cable 236.

When the apparatus operates according to the pile pulling method, as shown in FIG. 17 and 18, a strong upward pull is exerted in the cable 236, while the apparatus releases upward thrust to pull the pile 28. Thus, by regulating the pressure of the reduction valve 248, the carrier cylinder 240, piston 242 and cylinder space 244 serve as overload protection for the crane or lifting unit. , which is used. The carrier cylinder 240 also serves as a mechanical shock absorber because the pressure medium in the form of air or a gas type in the cylinder space 244 is compressible and acts as an elastic resilient carrier. In this way, the cable 236 and the crane or other lifting member are spared to be subject to wear and damage which could otherwise occur as a result of the upward impact of the pile support apparatus.

In the pile pulling method, the plunger 24 migrates as shown in FIG. 16, near the top unit 230, so that the trapped compressed air illustrated by double arrows at the upper end of the cylinder 23 below the top unit 230 exerts an upward compressive force on the pile support apparatus during each stroke of the piston 24. If desired, the upper end cover 50 of the piston 24 may be arranged to abut against the top unit 230, thereby exerting an upwardly impactful shock to U3A18 14 to shake the pile 28 with. This upward impact is achieved by a top unit which is designed to extend down to the level of the vent ports 216.

The upward pull of cable 236 in FIG. 17 of the apparatus brings the circumferential shoulder 63 of FIG. 18 in the second piston 60 to abut the retainer and bearing member 65. The overflow coupling 250 is a loose coupling which is connected to the coupling 30 to the bottom unit 60 of the cylinder. This loose overhang coupling 250 allows downward movement of the bottom unit 60 of the cylinder without dispensing any downward force on the pile 28. However, the upward force which arises at the outermost end of each upward stroke of the piston 24 is transmitted by the coupling 250 to the pile 28 which is under tension.

The pile 28 of FIG. 17 and 18 are, for example, shown as a pile with an H-shaped cross section, but other pile cross sections can of course also be drawn up by the method according to the invention.

The loose coupling 250 is shown with a cylinder having a chest 254 at its lower end. A pull-up bar 256 is attached to the pile 28 to be pulled up. A head 252 on this rod abuts the chest 254 for delivering upward compressive forces to the pile for its retraction.

FIG. 19 shows the apparatus 20 of FIG. 1 or 20A in FIG. 20 or 20B in FIG. 21 used for driving a wooden pile 28. A tapered guide 258 is shown for centering the apparatus 20, 20A or 20B on top of the wooden pile 28, The tapered guide 258 is secured by means of a fastening means to a fastening groove 260 which is also shown. in FIG. 3, in the pole fitting piece 32.

In FIG. 20 is shown another apparatus 20A for carrying out the method according to the invention. The only difference from the apparatus 20 is that the valve actuator 91A contains no blocking means in the form of a thickening as shown at 93 in FIG. Third

When the plunger 24 of FIG. 20 is thus moved downwardly, it is decelerated by the pressure medium in the shock chamber and then pressurizes the pressure medium back into the pressure medium accumulator 38. A shock is thereby allowed at reduced speed between the piston 24 and the second piston 60. is discharged through the open valve 40 from the accumulator 38.

The FIG. The apparatus shown in Fig. 20 is therefore well suited for exercising the fourth mode of application of the apparatus, namely for biasing plus shock plus prolonged compressive force. The biasing occurs while the pad of pressure medium supplied to the shock chamber through the valve 40, as well as any remaining pressure medium in the shock chamber, decelerates the piston 24. This bias removes any clearance between the second piston 60 and the pile 28. When the piston 24 abuts it. second piston 60 having a shock like impact as shown in FIG. 20, the resulting shock begins the downward movement of the pile, as shown by the double arrows near the coupling 30 of FIG. 20. After the shock, a prolonged compressive force is delivered to the moving pile, thereby keeping it moving downward for high utilization of the impact energy. This prolonged shock is delivered to the pile during the re-acceleration of the piston 24 in an upward direction.

Furthermore, it is possible to increase or decrease the impact-like impact occurring in the apparatus 20A in FIG. 20. This can be done by making the actuator 91A longer to reduce the impact shock and by shortening the actuator to increase the impact impact. This extension or shortening can be done by removing the valve body 76 and replacing it with another having longer or shorter actuator 91A, as desired.

When a longer actuator 91A is used, the valve 40 is opened to release pressure medium below the downward piston 24 as it is further from the bottom unit 00 of the cylinder. The pressure medium thereby provides longer time to actuate and thereby decelerate piston 24 at a slower rate. before the percussive shock occurs, making this shock weaker, and vice versa.

If a sufficiently long actuator 91A is used, no percussive shock will occur, provided that the pressure medium accumulator 38 is sufficiently large and to sufficiently fill the shock chamber with pressure medium at an appropriate pressure to decelerate piston 24 for the time available.

This method, in which there is bias as well as percussive shock and prolonged compressive force, can be used advantageously for driving very difficult to drive piles. The magnitude of the impact-like impact can be adjusted in the aforementioned manner to begin the downward movement of the pile. The apparatus then produces a strong prolonged shock to push the moving pile further downward for better utilization of the impact energy. The size of the impact shock can be adjusted so that it is just sufficient to start the downward movement of the pile, which start becomes easier, precisely because the pile has been subjected to a bias immediately before. This avoids the very powerful impact-like shocks that occur in the known pile drive apparatus. The subsequent prolonged shock becomes very effective because it is delivered to a pile already set in downward motion.

In FIG. 21, another embodiment of the apparatus 20B for practicing the method according to the invention is shown. The only difference from the apparatus 20 is that the cylinder bottom unit 60A of the apparatus 20B is attached to the lower end of the cylinder wall 22. This bottom unit is fixed to the cylinder wall. By means of a large number of powerful machine screws 262. This attachment is advantageous because it reduces the number of moving parts of the apparatus to two, namely the piston 24 and the valve body 76.

When the moving parts are only counted to a number of two, it is because the lubrication system 150,160 is not counted because the lubrication system is shown as an advantageous equipment for said embodiments of the apparatus. Of course, other known lubrication systems could also be used.

Apparatus 20 or 20A, which has three moving parts, 24, 60 and 76, is sometimes preferred because the movement of the base unit 60 reduces the effective mass to be driven by disengaging the mass resulting from the cylinder wall 22 and the thus fixed for the dogs parts from the pile to be demolished, thereby making the demolition work correspondingly easier. However, during certain pile drive operations, a smaller number of moving parts is advantageous when this is more important than reducing the effective mass being driven.

When the apparatus 20, 20A or 20B is arranged to drive a pile, the up and down movement of the piston 24 is thus started.

Prior to the start, the plunger 24 rests on the base unit 60 or 60A, depending on the apparatus in question. The valve actuator 91 or 91A is depressed so that the valve body 76 is displaced from its seat. There is a clearance around the thickening 93 so that pressure medium can flow from the accumulator 38 into the bump chamber 34. There is a large clearance around the actuator 91A so that the pressure medium can flow from the chamber 38 into the chamber 34.

The operator operating the apparatus 20.2QA or 20B starts the apparatus operation by suddenly opening a shut-off valve not shown to start supplying pressure medium through the tube 94. Pressure medium is then supplied to the accumulator 38 through the calibrated lower opening 100 in the valve guide 70 of FIG. 3. At this point, the larger upper opening 102 is blocked by the depressed valve spindle 74.

In the apparatus 20 or 20B, the pressure medium flows into the shock chamber through the clearance around the thickening 93. The piston 24 is raised by the flowing pressure medium 17 143A18, and the pressure medium in the bore 72 affects the valve stem 74 for displacing the valve body 76 in an upward direction together with the piston 24. When the thickening 93 exits the inlet port 62 of the pressure medium, the pressure medium collected in the accumulator 38 flows rapidly into the thrust chamber 34 to deliver an instantaneous push upward on the piston 24. The valve body 76 then rises and abuts its seat 80 to close the valve 40. The opening 102 is because the valve stem 74 is moved upward. The pressure medium now flows rapidly through both apertures 100 and 102 so that the pressure in the accumulator 38 is raised to practically the supply pressure.

In the embodiment of FIG. 20, the operator starts the piston 24 in the same way as with the apparatus 20 and 20B, namely by suddenly opening the supply of pressure medium through the hose 94. The opening 100 allows the pressure medium to flow into the accumulator 38 and it flows up through the open valve. 40. This pressure medium flow through the open valve 40 momentarily pushes the plunger 24 upwards.

The instantaneous upward push on the piston 24 of the apparatus 20, 20A or 20B causes it to rise as shown in FIG. 13 to a position in the cylinder 23, in which the exit ports 106 are closed. The expanded pressure medium in the shock chamber 34 is then discharged through the outlet ports 106 so that the plunger 24 can fall down again as shown in FIG. 9. When the piston 24 hits the actuator 91, as shown in FIG. 10, the valve 40 is momentarily opened for delivery of pressure medium from the accumulator 38 into the shock chamber 34. This second inflow of pressure medium is greater than the first because the pressure in the accumulator 38 has reached a value closer to the pressure of the supply pressure. The piston 24 is therefore accelerated more strongly and increases as shown in FIG. 13 up to an upper position further upstream of the exit gates 106 than before.

The expanded pressure medium is relayed and the plunger drops again, as shown in FIG. 9. The piston drops faster than the first time, and it opens the valve as shown in FIG. 10, this time the valve is opened more and longer than the first time because the piston drops faster. Accordingly, an even greater amount of pressure medium flows into the piston, which is thrown up even higher than the second time, etc.

After between three and six cycles, the piston 24 has reached its full stroke for driving the pole. As shown in FIG. 9, 10, 11, 12, 13 and 14, when the plunger has reached its full stroke, the plunger falls so far down in each cycle that the thickening 93 is brought down to shut off gate 62, as shown in FIG. 11th

Claims (16)

During the pull-up of the pile, the cable 236 of FIG. 17 until the apparatus 20 rests on the pile, after which pressure medium is connected via the hose 94 to start the up and down movement of the piston 24. As soon as this up and down movement has reached its full stroke, an upward pull is provided to the cable 236 to start the pull-up. In all of the mentioned embodiments of the apparatus according to the invention, the up and down movement of the piston 24 is stopped by blocking the pressure medium supply through the hose 94. The apparatus 20A or 20B can also be used to pull piles in the same way as the apparatus 20. The operating personnel of the apparatus can increase the duration of each operation. of the prolonged thrusts and reduce the maximum compressive force occurring during each thrust by increasing the degree of confinement of the pressure medium by the locking means or thickening 93; 3, and vice versa. By increasing the height of the thickening 93, the gate 62 is blocked when the piston 24 is at a greater predetermined distance from the base unit 26, thereby increasing the degree of confinement of the pressure medium, and vice versa. The apparatus may, as an option, have interchangeable thicknesses 9-3 of different height, removably fixed with fasteners, such as screws, to actuator 91. A method of driving a pile into the ground by periodically introducing a pressurized fluid under a piston into the interior of a cylinder for moving the piston in the upward direction of the cylinder, by bringing the piston into the cylinder and by transferring the kinetic energy of the piston mass to driving the pile, CHARACTERIZED by the plunger (24, 42) being caused to strike and spring back from a fluid pad, the extra fluid being injected under pressure into the pad under the plunger as it moves downward (Fig. 10), and AT expanded fluid is released from the underside of the piston as it moves upwards (Fig. 13). Method according to claim 1, characterized in that the injected fluid below the downward piston is temporarily confined (C and C 'in Figs. 11 and 12), 3. A method according to claim 1 or 2, characterized in that the fluid is trapped below the downward piston at a first level (106), said injection of extra fluid occurring as the piston has moved down to a second and lower level (FIG. 10), and 143-418 19 AT the temporary confinement of injected fluid under the downward piston occurs when it has moved down to a third level (Fig. 11) lower than said second level. 4. A method according to claim 1, characterized in that the bouncing piston (24) is caused to collide with a means (20, Fig. 20) to produce a direct stroke plus a downward pressure shock via the fluid pad. Method according to one or more of claims 1-4, characterized in that the fluid is temporarily stored in an area (38) located near but below the position of the fluid pad. 6. A method according to claims 1-5, characterized in that the injection of pressurized fluid into the fluid pad is triggered by the downward plunger (24). Process according to one or more of claims 1-6, characterized in that atmospheric air is captured over the upward piston (Figs. 1 or 14 or 16). Method according to claim 2, characterized in that the amount of the injected and below the descending piston (24). in the "blocked fluid" during each of the plunger's springs is increased in such a way that the duration of each driving thrust acting on the pile is increased while the peak value of the force occurring during the driving thrust is reduced, and vice versa. A method according to claim 1, characterized in that sufficient fluid is injected under the piston to cause the upward piston to exert an upward thrust against an upper head (230) of the cylinder to produce an upward thrust transmitted to the pile. drawing up this one. Method according to claim 9, characterized in that atmospheric air is trapped between the upward piston and the upper head (230 or 230Λ). 11. A method according to claim 9, characterized in that the upward piston is caused to strike directly on the top head of the cylinder (230). Apparatus for carrying out the method according to one or more of claims 1-11 for driving a pile in the ground by periodically supplying a fluid under pressure under a piston in the interior of a cylinder for moving the piston in direction upwardly in the cylinder, by bringing down the piston into the cylinder and by transferring the energy of the piston mass to drive the pile, which apparatus includes a cylinder wall (22) defining the cylinder, a massive piston block (24) movable upwards and downwardly in the cylinder, and a bottom structure (26 or 6ΌΑ) associated with the cylinder wall and arranged below the piston block, and which apparatus is characterized by the fact that the piston block and the cylinder bottom structure define an intermediate bump chamber (34) and the AT device further comprises a fluid storage chamber (38) pressurized and arranged to communicate with the shock chamber, a valve (40) for controlling communication between the storage chamber and the shock chamber, means (91 or 91A) for opening this valve for injecting fluid under pressure from the storage chamber into the bump chamber as the piston block (24) moves downwardly in the cylinder (23), and means for releasing expanded fluid from the bump chamber as the piston block moves turn upwards in the cylinder. 13. Apparatus according to claim 12, characterized in that said means (91 or 91Λ) for opening venti Umi (40) is arranged for activating the downward piston block (Fig. 10 or Fig. 20). Apparatus as claimed in claim 12 or 13, characterized by means (93) for confining fluid under pressure in the plunger chamber (34) under the downwardly extending piston block in such a manner as to produce a fluid smoothed or mitigated impact (C and C '). ) of the piston block, thereby providing a downward thrust of the cylinder bottom structure during each of the piston block's bumps and springs from the trapped fluid pad. Apparatus according to claim 12, characterized in that the cylinder bottom structure (26) contains a second piston (60) which is movable upwards and downwards relative to the cylinder wall and which is adapted to be coupled to the pile. Apparatus according to claim 15, characterized in that the second piston contains said pressurized fluid storage chamber (38) and said fluid (40) for releasing fluid from. the storage chamber and into the bump chamber (34) as the piston block (24) moves downward and approaches the second piston (60), and the AT valve (40) includes an activator (91 or 91A) extending upwardly and is arranged to be affected by the downward piston block to