JP2002020099A - Continuous towing jack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce size so as not to be largely restricted to the space of an installation place, allow to be installed in adjacent state even for a plurality of wire ropes required to be towed simultaneously in closed state, and eliminate an undue towing in diagonal direction. SOLUTION: Three hydraulic jacks 3, 4, and 5 are disposed linearly on a base member 2. The center hydraulic jack is used as a center hole hydraulic jack 3 and a beam material 15 is installed, in a bridged state, at the top part of the hydraulic jacks on both sides. A first chuck means 10 is installed at the top part of the center hole hydraulic jack, a second chuck means 16 is installed at the center part of the beam material, and the center hole hydraulic jack and the hydraulic jacks on both sides are driven alternately each other to tow a towed object 6 continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jack mainly used for civil engineering work, and particularly to a PC steel strand or a PC steel wire attached to (fixed to) a heavy object or an object having a large load resistance when moving it. The present invention relates to a jack that can continuously pull a towed object such as a steel rod.

[0002]

2. Description of the Related Art As a conventional jack of this type, for example, a "jack for continuously transferring heavy objects" disclosed in Japanese Patent Publication No. 4-71839 is known as a conventional example.

In the conventional jack for continuous transfer, there is an insertion hole through which a wire is inserted at the center, and four hydraulic jacks are arranged around the insertion hole. With the first and second transfer jacks, a connecting beam is attached to the rod end of each pair of hydraulic jacks, and the first and second connecting beams are crossed in the vertical position as the first and second connecting beams, respectively. The first and second connecting beams are provided with chucking means at the crossed central portions thereof to clamp the inserted wires.

In actual use, the first transfer jack portion and the second transfer jack portion are alternately operated (extended and contracted), and the chuck means clamps a wire when the jack portion is extended, The wire is opened at the time of contraction, and the wire can be alternately pulled by the extension stroke of the first and second transfer jack portions.

[0005]

However, the jack for continuous transfer according to the prior art is arranged such that the first connecting beam portion and the second connecting beam portion cross each other at a vertical position.
The use of four hydraulic jacks results in a relatively large, generally square shape, which is not only restricted by the fact that the work area is not large enough to be installed. There is a problem that handling becomes troublesome due to an increase in bulk weight.

Further, when two or more jacks are to be used at the same time in a very close juxtaposition, if the jack itself has a relatively large rectangular shape, the distance between a plurality of wires to be pulled is reduced. However, if the jacks are not wide enough, the jacks cannot be used for parallel traction with the same traction force at the same time, and there is a problem that traction must be performed in oblique directions.

[0007] Therefore, in the conventional continuous transfer jack, it is necessary to reduce the size of the jack so as not to be greatly restricted by the size of the installation place, and to use a plurality of wires which must be simultaneously pulled in close proximity. Even so,
Correspondingly, there is a problem to be solved in that it can be installed in the adjacent state so that it can be pulled in parallel by the same pulling force.

[0008]

According to a first aspect of the present invention, as a specific means for solving the problems of the prior art, three hydraulic jacks are linearly arranged and mounted on a base member, and a central portion is provided. A hydraulic jack is a center hole hydraulic jack, a beam member is attached to the tops of the hydraulic jacks on both sides in a bridged state, first chuck means is provided on the top of the center hole hydraulic jack, and a second chuck is provided at the center of the beam member. Wherein the center hole hydraulic jack and the hydraulic jacks on both sides are alternately driven to continuously pull the towed object.

According to a second aspect of the present invention, a center hole hydraulic jack is provided at a central portion of a base member having a triangular shape.
Hydraulic jacks are provided at each of the triangular corners, and triangular beam members are attached to the tops of the hydraulic jacks in a bridged state. First chuck means is provided at the top of the center hole hydraulic jack, and Second in the center of the
Wherein the center hole hydraulic jack and the other hydraulic jack are alternately driven to continuously pull the towed object.

In a third aspect of the present invention, the first hydraulic jack and the second hydraulic jack are concentrically arranged and mounted on a base member, and the first hydraulic jack is a center hole hydraulic jack. The second hydraulic jack is a cylindrical hydraulic jack, a head member is attached to the top thereof, a first chuck means is provided at the top of the center hole hydraulic jack, and a second chuck means is provided at the center of the head member. The present invention provides a continuous towing jack characterized in that the first hydraulic jack and the second hydraulic jack are alternately driven so as to continuously tow an object to be towed.

Further, in the first and second aspects of the present invention, the base member to which the three hydraulic jacks are attached is formed in a plane rectangular shape; the center hole hydraulic jack is provided between the base member and the beam member. One-stroke expansion and contraction; Hydraulic jacks on both sides to which the beam material is attached extend and contract by one stroke outside the set length of one-stroke extension of the center-hole hydraulic jack; Center-hole hydraulic jack and beam The hydraulic jack to which the material is attached includes as an additional requirement that the length of one stroke can be set arbitrarily; that the center hole hydraulic jack is provided with a rotation preventing means.

Further, in the third aspect of the present invention, the first hydraulic jack expands and contracts by one stroke between the base member and the head member, and the second hydraulic jack includes the first hydraulic jack. The first hydraulic jack and the second hydraulic jack can be arbitrarily set to one stroke in length outside of the set length of one stroke extension of the first hydraulic jack; The second hydraulic jack includes an additional requirement that rotation preventing means is provided.

In the present invention, one of the continuous traction jacks is a center hole hydraulic jack, and a first hole is provided on the top thereof.
A beam member or a head member is attached to another hydraulic jack, and a second chuck unit is attached to a center portion of the beam member or the head member. The jack and the jack are alternately driven so that the towed object can be continuously towed, so that the configuration is simple, and even if a plurality of towed objects are arranged close to each other, they should be installed correspondingly. This makes it possible to easily and continuously pull a plurality of towed objects in a parallel state, so that the towing work can be performed efficiently.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in more detail with reference to the illustrated embodiments. 1 to 8 show a first embodiment according to the present invention. A continuous traction jack 1 made of PC stranded wire according to this embodiment has three hydraulic jacks 3, 4, and 5 attached linearly to a rectangular base member 2, and a hydraulic jack at a central portion. 3
Is a so-called center hole hydraulic jack in which a through hole 7 through which a towed object 6 such as a PC steel strand or a steel rod is inserted is provided at the center. The towed object will be described below by taking a PC steel strand as an embodiment.

The center hole hydraulic jack 3 is mainly composed of a cylinder portion 8 and a rod portion 9. The center of the rod portion 9 is aligned with the insertion hole 7 at the distal end of the rod portion 9. 10 is attached. The chuck means 10 is a commonly used hydraulic type, and can forcibly release the clamped state.

The hydraulic jacks 4 and 5 on both sides are composed of cylinder portions 11 and 12 and rod portions 13 and 14, respectively, and a beam member 15 is attached in a cross-linking state to a tip portion between the rod portions 13 and 14. A second chuck means 16 is attached to the center of the beam member 15. The second chuck means 16 is also of the same hydraulic type as described above, having the same axial center as the insertion hole 7 and capable of forcibly releasing the clamped state.

The center hole hydraulic jack 3 expands and contracts within a range (stroke) that does not collide with the beam members 15 of the hydraulic jacks 4 and 5 located on both sides. For this reason,
The position where the beam material 15 does not collide with the extended position of the center hole hydraulic jack 3 is the contraction origin position of the hydraulic jacks 4 and 5.

A center hole hydraulic jack 3
In order to control the hydraulic jacks 4 and 5 on both sides to the same output (traction speed and traction force), hydraulic pressure controlled from the same hydraulic system is supplied. Assuming that the hydraulic pressure is 1, the hydraulic pressure receiving areas of the hydraulic jacks 4, 5 to which the hydraulic pressure is branched and supplied are halved.

The first and second chuck means 10, 1
6 has substantially the same configuration and is generally used, so one of them (second chuck means 16)
Referring to FIG. 3, the collet 17 divided into three in the longitudinal direction is urged by a suitable spring 18 in a direction in which the collet 17 is always closed, thereby acting in a direction in which the hydraulic jacks 4 and 5 extend. Then, in combination with the bias of the spring 18, the PC stranded wire 6 inserted is tightened (clamped) and pulled.

On the side facing the spring 18, a clamp removing member 19 for pushing back the collet 17 against the pressing force of the spring 18 is provided.
The clamp removing member 19 is slid in the length direction by the hydraulic mechanism 20, and the cylindrical end 19a is in contact with the tip of the collet 17, so that even if the collet 17 is in a strong clamping state, By applying the hydraulic pressure, the clamp removing member 19 slides, and the collet 17 is forcibly pushed back to release the clamped state.

Further, by pulling and tensioning the PC steel stranded wire 6, the PC steel stranded wire 6 itself has an untwisting action, and the untwisting action becomes a rotational force to cause the first twist of the jack.
And the second chuck means 10 and 16. Then, the second chuck means 16 includes two rod portions 13, 1
The first chuck means 10 is attached to the beam 15 supported by the center 4 so as to be able to oppose the rotation of the untwisting action.
, The rotation of the untwisting action is directly transmitted to the rod portion 9, the shaft rotates while the rod portion 9 is supported by the cylinder portion 8, and the function as a jack is damaged.

Therefore, in the center hole hydraulic jack 3, a pair of rotation preventing means 21 is provided in a symmetrical direction so that the rod portion 9 does not rotate with respect to the cylinder portion 8 (see FIG. 2).

An example of the rotation preventing means 21 will now be described. As shown in FIG. 4, a fixing member 22 attached to the distal end of the rod portion 9 in a projecting state, and a fixing member 22 attached to the fixing member 22 in a hanging state. The guide bar 23 has a U-shaped cross section and a guide key 24 slidably engaged with the recess 23 a of the guide bar 23 and attached to the outer surface of the cylinder portion 8.

The guide bar 23 has at least the rod 9
The guide key 24 has a rectangular rectangular shape or a cubic shape as a whole, and has a length on the top outer surface of the cylinder portion 8. Mounted vertically along the direction. The guide bar 23 and the guide key 24
The rod portion 9 is prevented from rotating and expands and contracts vertically in the state in which is engaged.

Another example of the rotation preventing means 21 is shown in FIG. The rotation preventing means 21 attaches a flange member 70 to the rod 9, and attaches a slide bar 71 to each of the symmetrical positions of the flange member 70,
1 is extended upward, and a wire cover 72 is attached to the extended upper end. The wire cover 72 is positioned above the chuck means 10 in a bridged state, and a hole 73 of a predetermined size is provided in the center. ing. The hole 73 is a hole through which a wire such as a PC steel stranded wire 6, which is a towed object, is inserted.
When the steel stranded wire is unlocked, a bouncing phenomenon occurs in the wire, and various inconveniences caused by the bouncing are prevented.

The lower end of the slide bar 71 is formed to be longer than the maximum extension length of the rod portion 9, and a guide member 74 having a U-shaped cross section to which the slide bar 71 is slidably guided is formed by a cylinder portion. 8 is attached to the outer surface. In this case, one guide member 74 is sufficient if it has a predetermined length, but a plurality of guide members 74 are attached at predetermined intervals in order to reduce the overall weight and reduce material waste. When the slide bar 71 and the guide member 74 are engaged with each other,
Is prevented from rotating and expands and contracts vertically. It is to be noted that this kind of rotation preventing means 21 is not limited to these constituent members, and an appropriate design change is possible.
In short, it is only necessary that the rod portion 9 can be supported so as not to rotate.

[0027] The continuous traction jack 1 constructed as described above.
6A to 6C and FIG.
A description will be given based on (A) to (C). The base member 2 of the continuous towing jack 1 is set on a predetermined reaction plate 25, and the PC steel strand 6 to be towed is inserted into the insertion hole 7 and the first and second chuck means 10, 16. It has been inserted. Although not shown, there is an operation panel having a plurality of switches, buttons, and a display unit for operating and driving the continuous towing jack 1.

First, when the origin return button is pressed on the operation panel, as shown in FIG. 6A, the rod 9 of the center hole hydraulic jack 3 detects the origin at the reduced end (shrinked position). , Move in the shrinking direction. The detection of the origin at the reduced end is performed by, for example, an appropriate limit switch 26.
And the like. At the time of this movement, the second chuck means 16 receives a reaction force, but the clamping action works, so that the PC steel strand 6 does not move.

Subsequently, the hydraulic jacks 4 and 5 are moved to the positions shown in FIG.
As shown in (B), the movement is performed until the origin of the reduction end (reduction position) is detected. In this case, the hydraulic jacks 4, 5
When is located at the origin of the set reduction end, the stop state is maintained, and when it is at a position further reduced than the origin of the reduction end, the expansion operation is performed. At this time, the hydraulic pressure is automatically applied to the second chuck means 16 and the collet 17 moves with the clamp state removed. Further, when it is located at a position extended from the origin of the reduced end, a contracting operation is performed. At the time of this contraction operation, the first chuck means 10 receives a reaction force, but has a clamping action.
Never move. The origin of the reduced end is also detected by, for example, an appropriate limit switch 27.

In this state, the origin positions of the reduced ends of both hydraulic jacks are detected, and the hydraulic jacks 4, 5 are driven as shown in FIG. The pre-tension of the PC strand is performed.
In this case, when a single continuous traction jack 1 is used, the tension due to the pretension does not cause much problem. For example, when a plurality of continuous traction jacks 1 are used side by side, each jack is used. Must be adjusted so that the tension pressure at is approximately constant. Then, when the tension pressure becomes substantially constant, the hydraulic jacks 4, 5 are returned to the origin positions at the reduced end, and the origin return is completed. Note that the extension origin position is also limited to the limit switches 28, 2
9 and so on.

After the preliminary tension is completed, for example, by turning on the towing operation button on the operation panel,
As shown in FIG. 7 (A), the center hole hydraulic jack 3 extends to the extension origin in a state where the first chuck means 10 clamps the PC steel strand 6, and so-called one-stroke traction is completed. In this traction, the PC steel strand 6 is connected to the second chuck means 1 on the hydraulic jacks 4 and 5 side.
The collet 17 passes through for one stroke so as to be expanded.

Immediately before the one-stroke towing by the center-hole hydraulic jack 3 is completed, the hydraulic jacks 4, 5 extend, whereby the second chuck means 16 clamps the PC steel strand 6 and continuously pulls. I do.

While the hydraulic jacks 4 and 5 continue to extend, as shown in FIG. 7 (B), the center hole hydraulic jack 3 moves the first chuck means 10 to the unclamped state. The center hole hydraulic jack 3 is driven again immediately before the hydraulic jacks 4 and 5 reach the extension origin and the one-stroke towing is completed, being forcibly released by the member and quickly returning to the home position of the reduced end. Then, the PC steel strand 6 is clamped by the first chuck means 10 to perform the extension operation, and the PC steel strand 6 is continuously pulled.

Then, as shown in FIG. 7 (C), during the one-stroke retraction by the center hole hydraulic jack 3 again, the hydraulic jacks 4, 5 quickly return to the home position at the reduced end, and the same as described above. Immediately before the end of one-stroke towing, the hydraulic jacks 4 and 5 extend to make the PC steel strand 6
The traction of the PC steel strand 6 can be efficiently and continuously performed without interruption by repeating these operations.

As shown in FIG. 8, a plurality of continuous traction jacks 1 according to the first embodiment can be used in an adjacent state. In this case, when a plurality of PC steel strands to be simultaneously towed are arranged in a very close state, the continuous towing jack 1 is rectangular, so that it is arranged in an adjacent state correspondingly. You can do it.

In short, by arranging three or three hydraulic jacks 3, 4, and 5 in a straight line in order to achieve a structure capable of continuous towing, the entire jack can be formed in a rectangular shape. Because of its rectangular shape, it is easier to use. Note that, in the illustrated embodiment, the second chuck means 16 is the beam material 1.
Although the example attached to the inside of the beam member 5 has been described, the present invention is not limited to this, and the attachment to the outside of the beam member 15 is naturally included.

FIGS. 9 to 12 show a continuous towing jack 31 according to the second embodiment. The continuous traction jack 31 has a substantially triangular prism shape as a whole, and is formed by attaching four hydraulic jacks 33, 34, 35, and 36 to a substantially triangular base member 32. The hydraulic jack 33 is a so-called center hole hydraulic jack in which an insertion hole 37 through which a towed object such as a PC stranded wire is inserted is provided at the center.

This center hole hydraulic jack 33 is
In substantially the same manner as in the first embodiment, a cylinder portion 38 and a rod portion 39 are provided. Chuck means 40 are attached. The first chuck means 40 is of a hydraulic type generally used as in the first embodiment.

Hydraulic jacks 34, 35 and 36 disposed at the respective corners of the triangular shape each have a cylinder portion and a rod portion, and beam members 45 having a substantially triangular shape are provided at the tips of the three rod portions. Are attached in a bridge state, and a second chuck means 46 is attached to the center of the beam member 45. The second chuck means 46 also has the same axis as the insertion hole 37 and is of the same hydraulic type as described above.

Also in this embodiment, the center hole hydraulic jack 33 is composed of three hydraulic jacks 34, 35, 3
6 is extended or contracted in a range (stroke) where it does not collide with the beam material 45 of the center hole. It becomes.

The center hole hydraulic jack 33
And the three hydraulic jacks 34, 35, and 36 are controlled by the same hydraulic system to supply the same output (traction speed and traction force). Assuming that the pressure receiving area of the hydraulic pressure is 1, the hydraulic jack 34 to which the hydraulic pressure is branched and supplied,
The hydraulic pressure receiving area at 35 and 36 may be reduced to 1/3.

The operation of the continuous traction jack 31 according to the second embodiment is substantially the same as that of the continuous traction jack 1 according to the first embodiment, and the description thereof will not be repeated. .

The continuous towing jack 31 according to the second embodiment has a substantially triangular shape as a whole, so that the installation state at the work place is stable and the center hole hydraulic jack 33 is excluded. In addition, the three hydraulic jacks 34, 35, and 36 support the beam member 45, so that the horizontality can be easily obtained and the outputs can be made uniform.

Further, in the continuous traction jack 31 according to the second embodiment, as shown in FIGS. 11 and 12, a plurality of jacks can be used in an adjacent state. In other words, when a plurality of PC steel strands to be simultaneously towed are arranged close to each other, the continuous towing jack 31 is turned in the same direction or in a different direction, and the PC steel strands or the like are turned. Can be installed adjacent to each other in accordance with the positional relationship of the towed object.

Next, a third embodiment shown in FIGS. 13 to 15 will be described. The continuous traction jack 51 according to this embodiment has a substantially columnar shape as a whole, and a first hydraulic jack 53 is attached to the center of a disc-shaped base member 52. And a cylindrical second hydraulic jack 54 is attached concentrically so as to surround the periphery of the second hydraulic jack 54, and has a so-called jack-in-jack configuration. The first hydraulic jack 53 has an insertion hole 5 through which a towed object such as a PC stranded wire is inserted at the center.
7 is provided, and is of the same type as the center hole hydraulic jack described in the first and second embodiments.

That is, the first hydraulic jack 53 comprises a cylinder portion 58 and a rod portion 59 in substantially the same manner as in the first and second embodiments. The first chuck means 60 is attached to the distal end portion so that the insertion hole 57 is aligned with the axis. This first
The chuck means 60 is of a hydraulic type commonly used as in the first and second embodiments.

The cylindrical second hydraulic jack 54 has a cylinder portion 55, a rod portion 56, and an inner cylinder 67,
A head member 6 having a circular shape at the tip of the rod portion 56
5 is attached in a cover state, and the head member 65
The second chuck means 66 is attached to the center of the second chuck. The second chuck means 66 is also disposed so that the insertion hole 57 and the axis are aligned. Each of these chuck means has substantially the same configuration as that of the hydraulic configuration described in the first embodiment. .

Also, since the first and second hydraulic jacks 53, 54 in this embodiment each have a columnar or cylindrical shape, for example, the first and second hydraulic jacks 53, 54 pull and twist a PC steel strand.
Due to the tension, the untwisting action of the PC steel strand itself is transmitted to the respective rod portions 55 and 59 as a rotational force, and the rod portions 55 and 59 rotate, which may lead to damage to the function as a jack. Therefore, each of the hydraulic jacks 53 and 54 is provided with a rotation preventing unit having substantially the same configuration as the rotation preventing unit 21 having the configuration shown in FIG. 4 described in the first embodiment.

Also in the third embodiment, the first hydraulic jack 53 does not collide with the head member 65 attached to the cylindrical hydraulic jack 54 (stroke).
In a position where the first hydraulic jack 53 is extended, a position where the head member 65 does not collide is
This is the position of the reduction origin of the cylindrical second hydraulic jack 54.

Also, in order to control the first hydraulic jack 53 and the second hydraulic jack 54 to the same output (traction speed and traction force), controlled hydraulic pressure is supplied from the same hydraulic system. The hydraulic pressure receiving area of the first hydraulic jack 53 and the hydraulic pressure receiving area of the second hydraulic jack 54 to which the hydraulic pressure is branched and supplied may be the same.

The operation of the continuous traction jack 51 according to the third embodiment is substantially the same as the operation of the continuous traction jacks 1 and 31 according to the first and second embodiments. It is omitted because it is duplicated.

The feature of the continuous traction jack 51 in the third embodiment is that, since the whole has a substantially cylindrical shape, the installation area can be remarkably reduced, and a so-called jack-in-jack structure is provided. Therefore, the number of components is reduced, the weight is reduced as a whole, and the handling and transportation are facilitated.

Further, in the continuous towing jack 51 according to the third embodiment, as shown in FIG.
A plurality can be used in an adjacent state. In other words, when a plurality of towed objects, such as PC strands, to be towed at the same time are arranged close to each other, the continuous towing jack 51 is caused to correspond to the positional relationship between the towed objects in the adjacent state. , So that each towed object can be towed in a parallel state at the same time.

In any case, in the present invention, the continuous towing jacks 1, 31, and 51 do not increase the overall shape by using the center-hole hydraulic jacks 3, 33, and 53. It can be formed in a rectangular, triangular or circular shape, so that the installation area at the working place is not so much restricted. In each of the embodiments, the beam members 15, 4, and
Although the configuration attached to the inside of the head member 5 or the head member 65 is shown, the configuration is not limited to this and, for example, the configuration attached to the outside is naturally included.

[0055]

As described above, the continuous towing jack according to the first aspect of the present invention has three hydraulic jacks arranged and mounted linearly on the base member, and the center hydraulic jack is mounted at the center. A hole hydraulic jack, a beam material is attached to the top of the hydraulic jacks on both sides in a bridge state, a first chuck means is provided at the top of the center hole hydraulic jack, and a second chuck means is provided at the center of the beam material. The configuration is such that the center hole hydraulic jack and the hydraulic jacks on both sides are alternately driven so that the towed object can be continuously towed.In particular, by arranging three hydraulic jacks in a straight line. Since the base member can be formed in a rectangular shape and one beam member is provided, the overall width is narrow and the configuration is compact, and the installation location at the work site is small. About the it can be installed without being so,
In addition, even when a plurality of PC stranded wires related to simultaneous towing are in a state of being close to each other, a plurality of continuous towing jacks can be arranged in an adjacent state corresponding to the state, so that a plurality of towed objects can be easily parallelized. It has an excellent effect of towing.

In the continuous traction jack according to the second aspect of the present invention, a center hole hydraulic jack is provided at the center of a triangular base member, and hydraulic jacks are provided at each of the triangular corners. At the same time, a triangular beam member is attached in a bridged state to the tops thereof, a first chuck is provided at the top of the center hole hydraulic jack, and a second chuck is provided at the center of the beam. The center hole hydraulic jack and the other hydraulic jacks are alternately driven so that the PC steel stranded wire can be continuously pulled, so that the overall shape has a triangular prism shape. This provides an excellent effect that the balance is improved and the drive balance of another hydraulic jack with respect to the center hole hydraulic jack is also improved.

Further, in the continuous traction jack according to the third aspect of the present invention, the first hydraulic jack and the second hydraulic jack are concentrically arranged on the base member and mounted.
The hydraulic jack is a center hole hydraulic jack, the second hydraulic jack is a cylindrical hydraulic jack, a head member is mounted on the top thereof, and a first chuck means is provided on the top of the center hole hydraulic jack. By providing a second chuck means at the center, the first hydraulic jack and the second hydraulic jack are alternately driven so that the towed object can be continuously towed,
By reducing the number of parts, the overall size can be further reduced, and the weight can be reduced.Even if a plurality of towed objects are arranged in close proximity, it can be used for each towed object. It can be installed in an appropriate state, and not only can a plurality of towed objects be towed in parallel without difficulty, but also it has an excellent effect that handling and transportation work such as installation at a construction site become easy.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing a continuous traction jack according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the continuous traction jack with a part removed.

FIG. 3 is a schematic side view showing a part of the continuous traction jack in cross section.

FIG. 4 is a perspective view of a main part showing an example of a rotation preventing means of the continuous towing jack.

FIG. 5 is a perspective view of a main part showing an example of a rotation preventing means of the continuous towing jack.

FIGS. 6 (A) to 6 (C) are schematic views schematically illustrating an operation state of performing pre-tensioning of the continuous towing jack.

FIGS. 7A to 7C are schematic diagrams schematically illustrating an operation state in which the continuous towing jack performs continuous towing.

FIG. 8 is an explanatory diagram showing an arrangement state when the continuous towing jack is used.

FIG. 9 is a plan view showing a continuous traction jack according to a second embodiment of the present invention, with a part thereof removed.

FIG. 10 is a schematic side view of the continuous traction jack.

FIG. 11 is an explanatory diagram showing an example of an arrangement state when the continuous towing jack is used.

FIG. 12 is an explanatory diagram showing an arrangement state of another example when the continuous towing jack is used.

FIG. 13 is a schematic side view of a continuous towing jack according to a third embodiment of the present invention, with a part thereof removed.

FIG. 14 is a plan view showing a part of the continuous towing jack removed.

FIG. 15 is an explanatory diagram showing an example of an arrangement state when the continuous towing jack is used.

[Explanation of symbols]

1, 31, 51 Continuous towing jack 2, 32, 52 Base member 3, 33, Center hole hydraulic jack 4, 5, 34, 35, 36 Hydraulic jack 6 Towed object (PC steel strand or steel rod) 7, 37 , 57 Insertion hole 8, 11, 12, 38, 55, 58 Cylinder part 9, 13, 14, 39, 56, 59 Rod part 10, 40, 60 First chuck means 16, 46, 66 Second chuck means 15, 45 Beam material 17 Collet 18 Spring 19 Clamp removing member 19a Cylindrical end 20 Hydraulic mechanism 21 Anti-rotation means 22 Fixing member 23 Guide bar 23a Depression 24 Guide key 25 Reaction force plate 26, 27, 28, 29 Limit switch 53 First hydraulic jack (center hole hydraulic jack) 54 Second hydraulic jack (cylindrical hydraulic jack) G) 65 head member 67 inner cylinder 70 flange member 71 slide bar 72 wire cover plate 73 hole 74 guide member.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mitsuo Chichiiwa 2-3-5 Misaki-cho, Chiyoda-ku, Tokyo Inside Tekkaken Construction Co., Ltd. (72) Inventor Yasuhiro Ito 2-53-3 Misaki-cho, Chiyoda-ku, Tokyo No. 72 (3) Inventor Yasuo Yamamura 2-53-3 Misaki-cho, Chiyoda-ku, Tokyo In-house (72) Inventor Tadao Suzuki 2-53 Misaki-cho, Chiyoda-ku, Tokyo (72) Inventor Takao Goda 5-13-4 Tachibana, Sumida-ku, Tokyo Suzuki Industry Co., Ltd. (72) Inventor Takeshi Ken 5-13-4, Tachibana, Sumida-ku, Tokyo Suzuki Industrial Co., Ltd.

Claims (14)

[Claims] Claims: 1. Three hydraulic jacks are linearly arranged on a base member and mounted, a central hydraulic jack is a center hole hydraulic jack, and a beam member is mounted on top of the hydraulic jacks on both sides in a bridge state. A first chuck means is provided at the top of the center hole hydraulic jack, a second chuck means is provided at the center of the beam material, and the center hole hydraulic jack and the hydraulic jacks on both sides are alternately driven to be pulled. A continuous towing jack characterized by being able to tow things continuously. 2. The continuous traction jack according to claim 1, wherein the base member to which the three hydraulic jacks are attached has a flat rectangular shape. 3. The continuous traction jack according to claim 1, wherein the center hole hydraulic jack expands and contracts by one stroke between the base member and the beam member. 4. The continuous traction jack according to claim 1, wherein the hydraulic jacks on both sides to which the beam member is attached extend and contract by one stroke outside a set length of one stroke extension of the center hole hydraulic jack. 5. The continuous traction jack according to claim 1, wherein the center hole hydraulic jack and the hydraulic jack to which the beam member is attached can each set a length of one stroke arbitrarily. 6. The continuous traction jack according to claim 1, wherein the center hole hydraulic jack is provided with a rotation preventing means. 7. A center hole hydraulic jack is provided at the center of the base member having a triangular shape, and hydraulic jacks are provided at each of the triangular corners. A first chuck means is provided at the top of the center hole hydraulic jack, a second chuck means is provided at the center of the beam material, and the center hole hydraulic jack and another hydraulic jack are alternately provided. A continuous towing jack characterized in that it can be driven to continuously pull the towed object. 8. A center hole hydraulic jack expands and contracts by one stroke between a base member and a beam member, and the other hydraulic jack is one of center hole hydraulic jacks.
8. The continuous traction jack according to claim 7, wherein the expansion and contraction of one stroke is performed outside the set length of the stroke extension. 9. The continuous traction jack according to claim 7, wherein each of the center hole hydraulic jack and the hydraulic jack to which the beam member is attached can have any length of one stroke. 10. The continuous towing jack according to claim 7, wherein the center hole hydraulic jack is provided with a rotation preventing means. 11. A first hydraulic jack and a second hydraulic jack are arranged and mounted concentrically on a base member, the first hydraulic jack is a center hole hydraulic jack, and the second hydraulic jack is a cylinder. A head member mounted on the top of the hydraulic jack, a first chuck means provided on the top of the center hole hydraulic jack, a second chuck means provided on a center portion of the head member, the first hydraulic jack And a second hydraulic jack alternately driven to continuously pull the towed object. 12. The first hydraulic jack expands and contracts by one stroke between the base member and the head member, and the second hydraulic jack extends outside the set length of one stroke extension of the first hydraulic jack. 10. The continuous traction jack according to claim 9, wherein the expansion and contraction is performed by one stroke. 13. The continuous traction jack according to claim 11, wherein each of the first hydraulic jack and the second hydraulic jack can have any length of one stroke. 14. The continuous traction jack according to claim 11, wherein the first hydraulic jack and the second hydraulic jack are provided with rotation preventing means.