WO2008156343A2

WO2008156343A2 - Push pull apparatus and method for heavy load transfer

Info

Publication number: WO2008156343A2
Application number: PCT/KR2008/003541
Authority: WO
Inventors: Myeong Jun Jeong
Original assignee: Sungdong Shipbuilding & Marine Engineering Co., Ltd.
Priority date: 2007-06-21
Filing date: 2008-06-20
Publication date: 2008-12-24
Also published as: JP5213956B2; JP2010529937A; CN101678882B; BRPI0813676B1; CN101678882A; BRPI0813676A2; WO2008156343A3

Abstract

The present invention relates to a push pull apparatus for heavy load transfer, and more particularly, to a push pull apparatus and method for heavy load transfer, which generates two forces having the same magnitude, by which a bogie train with a heavy load laded thereon is pushed and pulled on a skid rail, so that the bogie train can be transferred in a pulling or pushing way. A push pull apparatus for heavy load transfer according to the present invention comprises a frame cover (2) having guide rollers (20) provided at front and rear thereof to be movable on a skid rail (110); a plurality of launching cylinders (3) having piston rods (3d) fixed at one inner side of the frame cover (2) in the same direction and operated by hydraulic pressure; and clamping devices (4) respectively coupled to the rears of the launching cylinders (3) to fix or release the launching cylinders (3) onto or from the skid rail (110). Accordingly, in a case where the bogie train should be moved in an opposite direction while a load is transferred using a bogie train, contrary to the prior art, it is possible to move the bogie train only using the push pull apparatus without any additional device such as winch, thereby being capable of ensuring convenience and efficiency in work.

Description

PUSH PULL APPARATUS AND METHOD FOR HEAVY LOAD

TRANSFER

Technical Field

[1] The present invention relates to a push pull apparatus for heavy load transfer, and more particularly, to a push pull apparatus and method for heavy load transfer, which generates two forces having the same magnitude, by which a bogie train with a heavy load laded thereon is pushed and pulled on a skid rail, so that the bogie train can be transferred in a pulling or pushing way. Background Art

[2] Generally, ship construction methods are classified into a dry dock construction method in which the ground is dug to construct a dry dock, a large ship is constructed in the dry dock, and then the dry dock is filled with water to launch the ship, an on-sea construction method in which blocks for a ship are separately constructed on the ground and then the blocks are moved to a floating dock on the sea using a crane and assembled into a ship, and an on-ground construction method in which a ship is entirely constructed on the ground and then moved to a barge on the sea for launching.

[3] The on-ground construction method has advantages in that there is no need for constructing a dock by digging the ground contrary to the dry dock construction method and a ship can be easily constructed since it is entirely done on the ground in comparison with the on-sea construction method by which a ship is constructed on the swaying sea. However, it is technically difficult to transfer a large ship with a weight of several ten hundred tons on the ground to the sea.

[4] In order to solve such a technical difficulty of the on-ground construction method, a heavy load transfer system using a bogie train as shown in FIG. 1 has recently been used. This system includes a skid rail 110 installed on the ground, a bogie train 120 having wheels mounted on a lower side thereof to move along the skid rain 110 and also having a hydraulic jack 121 for lading a heavy load by jack-up operation thereof, and a push pull apparatus 130 for transferring the bogie train 120 with a heavy load laded thereon by pushing or pulling the bogie train on the skid rail 110.

[5] In addition, the push pull apparatus 130 generally uses a push pull gripper jack, wherein the push pull gripper jack includes a clamp unit 131 for clamping or releasing a separate clamping rail protruding on the ground by hydraulic pressure, and a hydraulic cylinder 132 coupled with the clamping unit 131 and having a piston rod 132d the end of which is directly connected to the bogie train 120 or its upper structure. [6] The conventional push pull apparatus 130 configured as above transfers the bogie train 120 with a heavy load laded thereon on the skid rail 110 in such a manner that the piston rod 132d pushes and thus transfers the bogie train 120 or its upper structure on the skid rail 110 by operating the hydraulic cylinder 132 together with the clamping operation of the clamp unit 131 to the skid rail 110, the clamp unit 131 advances along the skid rail 110 by releasing the clamp unit 131 to the skid rail 110 and reversing the piston rod 132d, the bogie train 120 or its upper structure is then pushed and thus transferred by the clamping operation of the clamp unit 131 to the skid rail 110 and advancing the piston rod 132d, and then the foregoing processes are repeated.

[7] Meanwhile, the hydraulic cylinder 132 is configured as a double-acting piston type hydraulic cylinder, which has a port A 132a and a port B 132b formed at front and rear sides thereof such that oil flows into or out of the cylinder therethrough, so that a piston 132c is moved from side to side by hydraulic pressure supplied through the port A 132a and the port B 132b, as shown in FIG. 2.

[8] At this time, in the piston 132c, one side surface thereof on which the piston rod

132d is not provided has a sectional area greater than the other side surface on which the piston rod 132d is provided, so that the one side surface receives greater hydraulic pressure, and therefore more large force is generated when the piston rod 132d moves forward rather than when the piston rod 132d moves backward.

[9] Thus, assuming that the force capable of moving the bogie train 120 with a heavy load laded thereon on the skid rail 110 by advancing the piston rod 132d is 100 units, the backward motion of the piston rod 132d cannot generate a force of 100 units, e.g., a half or less of 100 units, so that the bogie train 120 with a heavy load laded thereon cannot be moved.

[10] As a result, the conventional push pull apparatus 130 substantially provides only the pushing operation for pushing and thus transferring the bogie train 120, and it is substantially impossible to transfer the bogie train 120 by pulling it, so that an additional device such as a winch should be used. Thus, there is an advantage in that cum- bersomeness, inconvenience and inefficiency in work are caused.

[11] In addition, in the conventional push pull apparatus 130, while the bogie train 120 is transferred by means of the forward motion of the piston rod 132d in a state where the hydraulic cylinder 132 is fixed to the skid rail 110 by the clamp unit 131, if the clamp unit 131 advances along the skid rail 110 by the release of clamping to the skid rail 110 and the backward motion of the piston rod 132d, the pushing force is not continuously applied to the bogie train 120 but is discontinued.

[12] Thus, when the piston rod 132d is moved forward to push the bogie train 120 after the hydraulic cylinder 132 is fixed to the skid rail 110 using the clamp unit 131 again, a static frictional force that is about twice of a kinetic friction force should be overcome, so that the great force as large as in the initial stage is required. Thus, it is not easy to transfer the bogie train with a heavy load laded thereon, and the time for transferring is excessively consumed due to the stopping operation and accelerating/decelerating regions. In these reasons, the heavy load is exposed to danger for a longer time, for example should cope with the tidal range of outflowing water and inflowing water for a long time during loading-out to a floating dock or the like on the sea. In addition, the heavy load may not be completely transferred within the inflowing water period (6 hours) most suitable for loading-out, which gives many limitations in application and also causes inefficiency in transferring the heavy load.

[13] A similar technique to the foregoing is disclosed in Korean Laid-open Patent

Publication No. 10-2006-0017558. Disclosure of Invention Technical Problem

[14] The present invention is conceived to solve the aforementioned problems in the prior art. An object of the present invention is to generate two forces having the same magnitude, by which a bogie train with a heavy load laded thereon is pushed and pulled on a skid rail, so that the bogie train can be transferred in a pulling or pushing way.

[15] Another object of the present invention is to eliminate a stop region at the start and end points of reciprocation like a general push pull apparatus when the bogie train with a heavy load laded thereon is transferred by pushing or pulling it on the skid rail, whereby the force can be applied to the bogie train continuously without any interruption.

[16] A further object of the present invention is to provide a clamping device that is suitable for utilizing the skid rail for a clamping purpose without installing any separate clamping rail when a general rail is used as the skid rail. Technical Solution

[17] According to the present invention for achieving the objects, there is provided a push pull apparatus for heavy load transfer, which comprises a frame cover having guide rollers provided at front and rear thereof to be movable on a skid rail; a plurality of launching cylinders having piston rods fixed at one inner side of the frame cover in the same direction and operated by hydraulic pressure; and clamping devices respectively coupled to the rears of the launching cylinders to fix or release the launching cylinders onto or from the skid rail.

[18] Further, the launching cylinders may comprise a pair of first and second launching cylinders that make cylinder operations in opposite directions, and the clamping devices may comprise a pair of first and second clamping devices that make clamping operations oppositely to each other.

[19] Furthermore, the clamping device may include a push plate brought into close contact with a upper portion of a head of the skid rail by a hydraulic device; and jaws provided at both sides of a lower portion of the head of the skid rail and brought into close contact with the lower portion of the head of the skid rail by the operation of the hydraulic device.

[20] In addition, there is provided a push pull method for heavy load transfer, which comprises a hydraulic pressure supplying step of supplying hydraulic pressures to a pair of hydraulic cylinders in opposite directions, the hydraulic cylinders having piston rods fixed in the same direction at one inner side in a frame cover; a clamp fixing step of, when the piston rod of one of the hydraulic cylinders moves forward, fixing the hydraulic cylinder to a skid rail by a clamping device coupled to the hydraulic cylinder; a clamp releasing step of, when the piston rod of the other one of the hydraulic cylinders moves backward, releasing the hydraulic cylinder fixed by the clamping device coupled to the hydraulic cylinder; and a load transferring step of transferring a bogie trains with a heavy load laded thereon by continuously pushing or pulling the bogie train on a rail by repeatedly executing the hydraulic pressure supplying step, the clamp fixing step and the clamp releasing step.

[21] According to another aspect of the present invention, there is provided a push pull apparatus for heavy load transfer, which comprises a frame cover arranged to roll or slide along a skid rail; a hydraulic cylinder positioned inside of the frame cover in parallel with the skid rail and having a piston rod with an end fixed to an inside of the frame cover; and a clamping device configured to fix the hydraulic cylinder to the skid rail or release the fixing.

[22] According to a further aspect of the present invention, there is provided a push pull method for heavy load transfer, which comprises arranging a frame cover to roll or slide along a skid rail; positioning a hydraulic cylinder inside of the frame cover in parallel with the skid rail, the hydraulic cylinder having an end fixed to an inside of the frame cover; and moving forward the piston rod when the hydraulic cylinder is fixed to the skid rail, and moving backward the piston rod when the fixing of the hydraulic cylinder is released.

Advantageous Effects

[23] According to the present invention so constructed, two forces having the same magnitude, by which a bogie train with a heavy load laded thereon is pushed and pulled on a skid rail, are generated, whereby the bogie train can be transferred in a pulling or pushing way. Therefore, in a case where the bogie train should be moved in an opposite direction while lading a heavy load, contrary to the prior art, it is possible to move the bogie train only using the push pull apparatus without any additional device such as winch, thereby being capable of ensuring convenience and efficiency in work. [24] In addition, when the bogie train with a heavy load laded thereon is transferred on the skid rail by pushing or pulling the bogie train, the force can be continuously exerted on the bogie train. Thus, there is an advantageous effect in that the heavy load can be more easily and rapidly transferred. [25] Also, according to the present invention, a push plate at an upper side of a skid rail head and a jaw at a lower side thereof make the clamping operation to the skid rail by strong adhering force, whereby it is possible to ensure the accurate and secure clamping. Moreover, a general rail can be used as it is without affixing any additional structure to the skid rail, so that there is an advantage in that better convenience is ensured.

Brief Description of the Drawings [26] Fig. 1 is a schematic view showing an example of a general heavy load transfer system.

[27] Fig. 2 is an exemplary view of the configuration of a hydraulic cylinder of Fig. 1.

[28] Figs. 3 and 4 show the overall configuration of an apparatus of the present invention, wherein Fig. 3 is a front view, and Fig. 4 is a plane view. [29] Figs. 5 to 7 are exemplary views of a first embodiment of the apparatus of the present invention. [30] Figs. 8 to 10 are exemplary views of a second embodiment of the apparatus of the present invention. [31] Figs. 11 to 13 are exemplary views of a third embodiment of the apparatus of the present invention.

[32] Figs. 14 to 17 are sectional views showing an installation state of a skid rail of Fig. 1.

[33] Fig. 18 is a sectional view showing a clamping device of the apparatus of the present invention. [34] Fig. 19 is a sectional view showing a guide roller of the apparatus of the present invention. [35] Fig. 20 is a sectional view showing a fixed roller of the apparatus of the present invention.

[36] [Explanation of Reference Numerals for Major Portions Shown in Drawings]

[37] 1: Hydraulic pressure generator 2: Frame cover

[38] 3: Launching cylinder 4: Clamping device

[39] 11 : Frame 12: Guide roller

[40] 13: Engine 14: Generator [41] 15: Motor 16: Hydraulic pump

[42] 20: Guide roller

[43] 31, 32: First and second launching cylinders

[44] 41, 42: First and second clamping device

[45] 43: Hydraulic device 44: Push plate

[46] 45: Jaw

Best Mode for Carrying Out the Invention

[47] Hereinafter, embodiments of an apparatus of the present invention will be described in detail with reference to the accompanying drawings.

[48] Figs. 3 and 4 show the overall configuration of an apparatus of the present invention, wherein Fig. 3 is a front view, and Fig. 4 is a plane view.

[49] As shown in the figures, the push pull apparatus of the present invention is configured to operate by hydraulic pressure supplied from a hydraulic pressure generator 1, and has a frame cover 2 provided at its outside. The frame cover 2 has guide rollers 20 provided at front and rear sides thereof so as to be movable along a skid rail 110.

[50] The hydraulic pressure generator 1 has guide rollers 12 at front and rear sides of a frame 11 so as to be also movable along the skid rail 110. The frame 11 has an engine 13, a generator 14, a motor 15 and a hydraulic pump 16 mounted therein, so that the hydraulic pressure is configured to generate hydraulic pressure using power produced by its own. The hydraulic pressure generator 1 can move on the skid rail 110 along which the frame cover 2 moves, or move along another skid rail 110 adjacent to the aforementioned skid rail 110.

[51] Also, the frame cover 2 is provided therein with a plurality of launching cylinders 3 and clamping devices 4 for fixing or releasing the launching cylinders 3 to or from the skid rail 110 by clamping operation. The clamping device 4 is coupled to the rear of the launching cylinder 3 to move together therewith.

[52] In addition, a controller 5 is provided to generally control the hydraulic pressure generator 1, the launching cylinders 3 and the clamping devices 4. The controller 5 is also configured to be movable along the skid rail 110. The controller 5 is provided therein with a hydraulic pressure control unit and a display for displaying data detected by various meters and sensors provided at the push pull-related devices such as the hydraulic pressure generator 1, the launching cylinders 3 and the clamping devices 4.

[53] Also, the controller 5 is configured to allow an operator to control the system while he or she rides on the controller 5 which is connected to the hydraulic pressure generator 1 and pulled along the skid rail 110 or an operator, or to allow an operator to control the system using a control panel provided at a side of the hydraulic pressure generator 1 while walking. Here, unexplained reference numeral 21 designates a fixed roller for preventing the frame cover from being lifted.

[54] Figs. 5 to 7 are exemplary views of a first embodiment of the apparatus of the present invention.

[55] As shown in the figures, piston rods 3d of the plurality of launching cylinders 3 are fixed in parallel with each other at an inner side of the frame cover 2, and the clamping devices 4 are coupled to the launching cylinders 3, respectively.

[56] In addition, a bogie train with a heavy load laded thereon is connected to the rear of the frame cover 2, and hereinafter, will be referred to as "load".

[57] In the present invention configured as above, if hydraulic pressure is supplied through a port B 3d of the launching cylinder 3 in a state where the launching cylinder 3 is fixed to the skid rail 110 by the clamping operation of the clamping device 4 as shown in Fig. 5, the supplied hydraulic pressure causes a piston 3c and the piston rod 3d to advance, thereby pushing and thus transferring the frame cover 2.

[58] Then, if hydraulic pressure is supplied through a port A 3a of the launching cylinder

3 after the launching cylinder 3 fixed to the skid rail 110 is unfixed therefrom by releasing the clamping device 4, the launching cylinder 3 and the clamping device 4 move forward in an advancing direction of the frame cover 2 by the piston 3c and the piston rod 3d that are fixed to the frame cover 2.

[59] Thereafter, the launching cylinder 3 is fixed to the skid rail 110 by the clamping operation of the clamping device 4, and hydraulic pressure is supplied into the cylinder through the port B 3d of the launching cylinder 3, so that while the piston 3c and the piston rod 3d push and thus transfer the frame cover 2 repeatedly, a load 100 connected to the rear of the frame cover 2 is pulled and thus transferred.

[60] Meanwhile, as shown in Fig. 7, in a case where the load 100 having been connected to the rear side of the frame cover 2 is connected to the front side of the frame cover 2, the frame cover 2 pushes and thus transfers the load 100.

[61] Figs. 8 to 10 are exemplary views of a second embodiment of the apparatus of the present invention.

[62] Here, this embodiment has an essential feature in that when a load 100 is transferred by pushing or pulling, the force is continuously exerted on the load 100 without interruption.

[63] To this end, the aforementioned launching cylinder is configured to be divided into a first launching cylinder 31 and a second launching cylinder 32 to which hydraulic pressure is respectively supplied in opposite directions. Also, the clamping device is configured to be divided into a first clamping device 41 and a second clamping device 42 whose the clamping operations to a skid rail 110 are executed oppositely.

[64] In addition, piston rods 3 Id and 32d of the first and second launching cylinders 31 and 32 are fixed to one side of a frame cover 2 in parallel with each other as in the first embodiment of the present invention. The first launching cylinder 31 has a port IA 31a and a port IB 31b communicating with the inside thereof, and the second launching cylinder 32 has a port 2A 32a and a port 2B 32b communicating with the inside thereof.

[65] In the present invention configured as above, the push pull method comprising a hydraulic pressure supplying step - a clamp fixing step - a clamp releasing step - a load transferring step is performed by successively operating these steps, which will be described below in more detail with reference to the accompanying drawings.

[66] [Hydraulic Pressure Supplying Step]

[67] In this step, hydraulic pressure is respectively supplied into the port IB 31b of the first launching cylinder 31 and the port 2A 32a of the second launching cylinder 32, which have the piston rods 3 Id and 32d fixed to one inner side of the frame cover 2 in parallel with each other in the same direction. The supplied hydraulic pressure generates the force which causes the pistons 31c and 32c and the piston rods 3 Id and 32d of the first and second launching cylinders 31 and 32 to move in opposite directions, i.e., the piston 31c and the piston rod 3 Id of the first launching cylinder 31 to move forward while the piston 32c and the piston rod 32d of the second launching cylinder 32 to move backward.

[68] [Clamp Fixing Step]

[69] In this step, the force of the piston 31c and the piston rod 3 Id of the first launching cylinder 31, which move forward by the supplied hydraulic pressure, is applied to the frame cover 2. In order for the force of the piston 31c and the piston rod 3 Id to be applied to the frame cover 2, the first launching cylinder 31 should be fixed to the skid rail 110.

[70] Thus, when the piston 31c and the piston rod 3 Id of the first launching cylinder 31 move forward by the supplied hydraulic pressure, the first clamping device 41 makes the clamping operation for gripping and fixing the skid rail 110.

[71] At this time, the second clamping device 42, which is positioned at the rear of the second launching cylinder 32 and operated in the opposite direction to the first launching cylinder 31, does not make the clamping operation to the skid rail 110.

[72] [Clamp Releasing Step]

[73] In this step, the clamping operation of the first clamping device 41 to the skid rail

110 is released, whereby the first launching cylinder 31 may move forward together with the first clamping device 41 along the skid rail 110.

[74] That is, if hydraulic pressure is supplied through the port IA 3 Ia, the force by which the piston 31c and the piston rod 3 Id of the first launching cylinder 31 intend to move backward is generated. At this time, since the piston 31c and the piston rod 3 Id are fixed to the frame cover 2, such backward motion is not directly made, but the first launching cylinder 31 moves forward due to its reaction force. Also, the first clamping device 41 moves together with the first launching cylinder 31.

[75] At this time, the piston 32c and the piston rod 32d of the second launching cylinder

32 move forward by the supplied hydraulic pressure, and the second clamping device 42 makes the clamping operation to the skid rail 110 as in the clamp fixing step, whereby the force of the piston 32c and the piston rod 32d of the second launching cylinder 32, which move forward, may be applied to the frame cover 2.

[76] [Load Transferring Step]

[77] In this step, the force of the cylinders continuously applied to the load 100 to pull and thus transfer the load 100 by repeatedly execute of the hydraulic pressure supplying step, the clamp fixing step and the clamp releasing step through which the piston rod 3 Id of the first launching cylinder 31 pushes the frame cover 2, the second launching cylinder 32 and the second clamping device 42 move forward along the skid rail 110, the piston rod 32d of the second launching cylinder 32 pushes the frame cover 2, and the first launching cylinder 31 and the first clamping device 41 move forward along the skid rail 110.

[78] At this time, if the load 100 is connected to the front of the frame cover 2 as shown in

Fig. 10, the frame cover 2 pushes and thus transfers the load. Also, in either case where the load 100 is connected to the front or rear side of the frame cover 2, hydraulic pressure is supplied to one side surface of a piston, on which a piston rod is not provided, to push the frame cover 2 with the same force, so that it is possible to transfer the load 100 by pushing or pulling.

[79] Figs. 11 to 13 are exemplary views of a third embodiment of the present invention.

[80] As explained above, the first and second embodiments of the present invention are configured so that a pair of launching cylinders and a pair of clamping devices are provided in one frame cover and operated oppositely at the same time, whereby the force can be continuously exerted on the bogie train without interruption. In the meantime, the third embodiment of the present invention has a feature in that a plurality of launching cylinders and clamping devices included in one frame cover 2 make the same operation, and a plurality of launching cylinders and clamping devices included in the other frame cover 2 make the operation opposite to the launching cylinders and clamping devices included in the one frame cover 2.

[81] More specifically, as shown in Fig. 11, a first frame cover 2a is provided therein with a plurality of first launching cylinders 31 and first clamping devices 41, and a second frame cover 2b is provided therein with a plurality of second launching cylinders 32 and second clamping devices 42. If a piston 31c and a piston rod 3 Id of the first launching cylinder 31 move forward by supplied hydraulic pressure, a piston 32c and a piston rod 32d of the second launching cylinder 32 receive hydraulic pressure in a backward direction, so that the second launching cylinder 32 and the second clamping device 42 move forward at the same time along the skid rail 110.

[82] In addition, when the piston 31c and the piston rod 3 Id of the first launching cylinder

31 receive hydraulic pressure in a backward direction and thus the first launching cylinder 31 and the first clamping device 41 move forward, the piston 32c and the piston rod 32d of the second launching cylinder 32 move forward by the supplied hydraulic pressure, thereby giving continuous power to the load 100. Thus, this embodiment makes it possible to pull and thus transfer the load 100 using greater force than the first and second embodiments of the present invention.

[83] In addition, as shown in Fig. 13, in a case where the load 100 is positioned at the front side of the first and second frame covers 2a and 2b, the load 100 is pushed and thus transferred.

[84] Figs. 14 to 17 are exemplary views showing a skid rail of Fig. 1.

[85] Generally, vehicles such as forklift trucks are used frequently in a shipyard for constructing ships. Thus, the skid rail 100 installed on the ground is formed inside of a rail installation groove 113 or with a low height as shown in Figs. 14 and 15. In other case, a steel plate 110b is spread on the ground without installing a skid rail so that wheels 122 of the bogie train may run on the steel plate as shown in Fig. 16.

[86] Thus, it is difficult to execute the clamping operation of the clamping device to the skid rail, so that it is required to provide a plurality of separate clamping rails installed along the skid rail to protrude over the ground such that the operation to the skid rail can be easily executed.

[87] Fig. 17 shows a skid rail 110a having a shape of a general railroad. In case of using this skid rail 110a, since there is no need of affixing an additional clamping rail to the skid rail 110 as mentioned above, what is needed is to dig the rail installation groove 113 deeply in the ground and then install the skid rail 110 with the same height as the ground.

[88] The clamping device 4 of the present invention has a structure suitable for clamping a common skid rail 110 having a shape of a railroad, which will be explained below in detail with reference to the accompanying drawings.

[89] Fig. 18 is a sectional view showing a clamping device of the present invention.

[90] As shown in the figure, the clamping device 4 of the present invention includes a push plate 44 contacting with an upper side of a skid rail head 111, and a jaw 45 contacting with a lower side of the skid rail head 111. The push plate 44 and the jaw 45 are brought into strongly close contact with the upper and lower sides of the skid rail head 111 by the operation of a hydraulic device 43, thereby executing the clamping operation to the skid rail 110. [91] This operation will be described in more detail. If hydraulic pressure is supplied into the hydraulic device 43 through an upper port 43c, a piston 43a moves downward such that a rod 43b strongly presses an upper side of the push plate 44 downward, and the jaw 45 at the lower side thereof moves upward due to the reaction force to press the lower side of the skid rail head 111 upward. Thus, the push plate 44 and the jaw 45 are brought into strongly close contact with the upper and lower sides of the skid rail head 111, thereby executing the clamping operation to the skid rail 110.

[92] In addition, if hydraulic pressure is supplied into the hydraulic device 43 through a lower port 43d, the piston 43a moves upward and thus the rod 43b releases the press to the push plate 44, and the jaw 45 moves downward due to the reaction force and is thus separated from the skid rail head 111, thereby releasing the clamping operation to the skid rail 110.

[93] Fig. 19 is a sectional view showing a guide roller of the apparatus of the present invention, and Fig. 20 is a sectional view showing a fixed roller of the apparatus of the present invention.

[94] As shown in Fig. 19, guide rollers 12 and 20 of the hydraulic pressure generator 1 and the frame cover 2 have a common railroad shape and are configured to in contact with and roll on the skid rail 110a fixed to the ground by means of fixtures 112.

[95] Also, as shown in Fig. 20, a fixed roller 21 is provided at the lower side of the skid rail head 111 such that a front end of the frame cover is not lifted up when the frame cover 2 pushes the load.

Claims

[1] A push pull apparatus for heavy load transfer, comprising: a frame cover (2) having guide rollers (20) provided at front and rear thereof to be movable on a skid rail (110); a plurality of launching cylinders (3) having piston rods (3d) fixed at one inner side of the frame cover (2) in the same direction and operated by hydraulic pressure supplied from a hydraulic pressure generator (1); and clamping devices (4) respectively coupled to the rears of the launching cylinders

(3) to fix or release the launching cylinders (3) onto or from the skid rail (110).

[2] The push pull apparatus as claimed in claim 1, wherein the launching cylinders

(3) comprise first and second launching cylinders (31)(32) that make cylinder operations in opposite directions, and the clamping devices (4) comprise first and second clamping devices (41)(42) that make clamping operations oppositely to each other.

[3] The push pull apparatus as claimed in claim 2, wherein the first launching cylinder (31) and the first clamping device (41) are provided inside of a first frame cover (2a), and the second launching cylinder (32) and the second clamping device (42) are provided inside of a second frame cover (2b).

[4] The push pull apparatus as claimed in any one of claims 1 to 3, wherein the clamping device (4) includes a push plate (44) brought into close contact with an upper portion of a head (111) of the skid rail (110) by a hydraulic device (43); and jaws (45) provided at both sides of a lower portion of the head (111) of the skid rail (110) and brought into close contact with the lower portion of the head (111) of the skid rail (110) by the operation of the hydraulic device (43).

[5] A push pull method for heavy load transfer, wherein a hydraulic cylinder and a clamping device mounted in a frame cover, which is movable along a skid rail and connected to a load, transfer the frame cover by pushing or pulling it through the clamping operation to the skid rail and forward motion of a piston rod fixed to the frame cover.

[6] A push pull method for heavy load transfer, comprising: a hydraulic pressure supplying step of supplying hydraulic pressures to a pair of hydraulic cylinders in opposite directions, the hydraulic cylinders having piston rods fixed in the same direction at one inner side in a frame cover; a clamp fixing step of, when the piston rod of one of the hydraulic cylinders moves forward, fixing the hydraulic cylinder to a skid rail by a clamping device coupled to the hydraulic cylinder; a clamp releasing step of, when the piston rod of the other one of the hydraulic cylinders moves backward, releasing the hydraulic cylinder fixed by the clamping device coupled to the hydraulic cylinder; and a load transferring step of transferring a bogie trains with a heavy load laded thereon by continuously pushing or pulling the bogie train on a rail by repeatedly executing the hydraulic pressure supplying step, the clamp fixing step and the clamp releasing step.

[7] A push pull apparatus for heavy load transfer, comprising: a frame cover arranged to roll or slide along a skid rail; a hydraulic cylinder positioned inside of the frame cover in parallel with the skid rail and having a piston rod with an end fixed to an inside of the frame cover; and a clamping device configured to fix the hydraulic cylinder to the skid rail or release the fixing.

[8] A push pull method for heavy load transfer, comprising: arranging a frame cover to roll or slide along a skid rail; positioning a hydraulic cylinder inside of the frame cover in parallel with the skid rail, the hydraulic cylinder having an end fixed to an inside of the frame cover; and moving forward the piston rod when the hydraulic cylinder is fixed to the skid rail, and moving backward the piston rod when the fixing of the hydraulic cylinder is released.