JP2012201428A - Jack device for supporting leg of jib crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a jack device for a supporting leg of a jib crane which can easily confirm an extendable range and a current position.SOLUTION: The jack device 1 is attached to a tip of the supporting leg 35 of the jib crane. The jack device 1 has a base member 2, a threaded rod 3, a supporting case 4, a scaled rod 5, and a cover tube 6. The threaded rod 3 is supported by the base member 2 so as to be freely rotatable at a lower end, stands vertically, and has a rotation operating section for hanging a tool at an outer periphery of a lower portion. The supporting case 4 has a nut 12 into which the threaded rod 3 is screwed at a bottom wall, and has an observation window 13 and a connecting portion 14 of the supporting leg 35 at a sidewall. The scaled rod 5 is fixedly attached to an upper end of the threaded rod 3, and vertically extends upward. The cover tube 6 is fixedly attached in the supporting case 4, and the scaled rod 5 freely passes through a lid 17 thereof. A scale 15 which shows a degree of extension of the jack is provided at the scaled rod 5, and a scale at a position where the lid 17 passes through can be visually confirmed from the observation window 13 of the supporting case.

Description

  The present invention mainly relates to a jib crane that is used by being installed in a place where there is a difference in height on the installation surface, and is coupled to the tip of a support leg so that it can correspond to the inclination of the terrain where the support part of the jib crane is installed. The present invention relates to a jack device used.

  Conventionally, when constructing a power transmission line tower or the like in a place with uneven terrain, such as a mountainous area or a hilly area, a jib crane has been used to carry steel tower construction materials and the like. Such a jib crane has been devised so as to be installed with a minimum excavation range of the ground even on an inclined ground (see, for example, Patent Document 1). In this jib crane, a jack device is attached to the tips of a plurality of support legs arranged radially from a support base on which a turning mechanism for supporting a boom is mounted so that the mounting position can be changed in the vertical direction. It is the structure which can determine the support height of the support leg in an inclined surface by adjusting a jack expansion-contraction.

JP 7-277777 A

In the above-mentioned conventional jib crane support leg jack device, in order to prevent screw breakage due to excessive protrusion of the threaded rod and damage to the crane due to an excessive stress load on the member, it is possible to prevent the crane from falling over. Confirmation is required. Confirmation of the allowable expansion / contraction range is performed by visually confirming the relative positions of punch holes or notches marked on the screw rods. These punch holes and notches are small and difficult to see, and it is impossible to always confirm them from one direction by rotating the screw rod.
Accordingly, an object of the invention according to this application is to provide a jack device for a support leg of a jib crane that can easily check whether or not it is within an allowable expansion and contraction range.

Hereinafter, the present invention will be described with reference to the accompanying drawings, but the present invention is not limited thereto.
In order to solve the above-described problem, the jack device 1 of the invention according to this application includes a plurality of support legs 35 arranged radially from a support base 34 on which a turning mechanism 33 that supports a boom 32 is mounted. The mounting position can be changed in the vertical direction. The jack device 1 includes a base member 2, a screw rod 3, a support case 4, a scale rod 5, and a cover cylinder 6. The base member 2 is disposed on the mounting surface directly or indirectly. The screw rod 3 is rotatably supported on the base member 2 at the lower end, and rises vertically from the base member 2. The support case 4 includes a bottom wall 8 and a side wall 10 that surrounds the periphery of the bottom wall 8 and forms a receiving space 11 for the screw rod 3 inside. The support case 4 includes a nut 12 into which the screw rod 3 is screwed into the bottom wall 8. To do. The side wall 10 has an observation window 13 through which the inside can be visually observed, and a connection portion 14 for connecting the support leg 35 so that the position of the support leg 35 can be changed in the vertical direction. The scale bar 5 has a lower end fixed to the upper end of the screw rod 3 in the support case 4, extends vertically upward, and has a scale 15 in the vertical direction. An indicator member such as the cover cylinder 6 is fixed in the receiving space 11 of the support case 4, and indicates a relative position between the support case 4 and the scale bar 5 by indicating one point on the scale. The scale value indicated by the indicating member is configured to be visually confirmed from the observation window 13 on the side wall 10 of the support case 4.

  According to the apparatus of the invention relating to this application, it is possible to easily and surely confirm whether or not the jack is within the allowable expansion / contraction range and the remaining expansion allowable amount.

It is a front view of a jib crane. It is an enlarged front view of the principal part of the support leg in the jib crane of FIG. It is sectional drawing of the jack apparatus for support legs in the jib crane of FIG. FIG. 4 is a side cross-sectional view of the jack device of FIG. 3. It is a perspective view of the jack apparatus of FIG.

Embodiments of the present invention will be described with reference to the drawings.
In the jib crane 31, a plurality of support legs 35 extend radially from a support base 34 on which a turning mechanism 33 that supports the boom 32 is mounted. The jack device 1 is mounted at the tip of each support leg 35 so that the mounting position can be changed in the vertical direction according to the height of the mounting surface.

  The jack device 1 includes a base member 2, a screw rod 3, a support case 4, a scale bar 5, and a cover tube 6.

  The base member 2 is horizontally disposed on the installation surface directly or indirectly through the joint leg 36.

  The screw rod 3 is supported on the base member 2 so as to be rotatable about the axis at the lower end, and rises vertically from the base member 2. The screw rod 3 has a rotation operation portion 7 for hanging a rotation operation tool on the outer periphery of the lower portion.

  The support case 4 has a substantially rectangular parallelepiped box shape, has a bottom wall 8, a top wall 9, and a side wall 10 surrounding the both walls 8, 9, and forms a space 11 for receiving the screw rod 3 inside. A nut 12 for screwing the screw rod 3 is provided at the center of the bottom wall 8. The side wall 10 includes an observation window 13 through which the inside can be visually observed, and a connection portion 14 that connects the support leg 35 so that the position of the support leg 35 can be changed in the vertical direction through the pin.

  The scale bar 5 is a rod-like body, and the lower end is fixed to the upper end of the screw rod 3 in the support case 4 and extends vertically upward. A scale 15 is attached to the scale bar 5. In the illustrated embodiment, the scale 15 displays the jack expansion / contraction allowable range (permissible relative displacement width between the screw rod 3 and the support case 4) by dividing the color into five in the vertical direction. That is, for example, the color is divided into five sections by “black” at the center, “green” adjacent to the top and bottom, and “red” adjacent to the top and bottom, and “black” is “intermediate” and “green”. Means “safety part” and “red” means “caution part”.

  The lower end of the cover cylinder 16 is fixed to the bottom wall 8 of the support case so as to receive the screw rod 3 screwed into the support case 4, and extends vertically in the receiving space 11. The cover cylinder 16 includes a lid 17 at the upper end. The lid 17 has an insertion hole 16 at the center for allowing the scale bar 5 to freely pass therethrough. Therefore, the length protruding from the lid 17 of the screw rod 3 changes with the relative displacement of the screw rod 3 and the support case 4 in the vertical direction. Then, the lid 17 indicates one point on the scale bar 5. By reading the scale value indicated by the lid, the degree of expansion / contraction of the jack device can be confirmed. In this case, the cover cylinder 16 serves as a scale indicating member. The specific configuration of the indication member is not limited to the form of the cover cylinder 16. Any structure that is fixed in the receiving space 11 of the support case 4 and indicates the relative position between the support case 4 and the scale bar 3 by indicating one point of the scale bar 5 is sufficient.

  By visually confirming the scale value indicated by the lid 17 of the cover cylinder 6 in the scale bar 5 from the observation window 13 of the support case 4, whether the jack device 1 is within the expansion / contraction allowable range or the remaining expansion / contraction allowable amount is determined. You can easily check how much you have. For this reason, it is difficult to make a confirmation error, and it is possible to prevent the crane from being installed in a state where it deviates from the expansion / contraction adjustment range of the screw rod 3. Can be prevented.

DESCRIPTION OF SYMBOLS 1 Jack apparatus 2 Base member 3 Screw rod 4 Support case 5 Scale bar 6 Cover cylinder (indicating member)
7 Rotating operation part 8 Bottom wall 9 Top wall 10 Side wall 11 Space 12 Nut 13 Observation window 14 Connection part 15 Scale 16 Insertion hole 17 Lid 31 Jib crane 32 Boom 33 Turning mechanism 34 Support base 35 Support leg 36 Joint leg

Claims (2)

A jack device that is mounted on the distal ends of a plurality of support legs that are arranged radially from a support base that carries a turning mechanism that supports a boom, so that the mounting position can be changed vertically.
A base member that is directly or indirectly placed on the mounting surface;
A screw rod that is rotatably supported on the base member at the lower end and rises vertically from the base member;
It has a bottom wall and a side wall that surrounds the periphery of the bottom wall and forms a receiving space for the screw rod, and has a nut for screwing the screw rod into the bottom wall. A support case having an observation window that can be connected and a connecting portion to which the support leg is connected to be vertically changeable;
The lower end is fixed to the upper end of the screw rod in the support case, and the scale rod has a vertical scale extending vertically upward,
An indicator member fixed in the receiving space of the support case, and indicating a relative position between the support case and the scale bar by indicating one point of the scale bar;
A jack device for a support leg of a jib crane, characterized in that the scale value indicated by the indicating member can be visually confirmed from an observation window on a side wall of the support case. The screw rod has a rotation operation part on the lower outer periphery,
The support case has a bottom wall, a top wall, and a side wall that surrounds both walls and forms a receiving space for the screw rod on the inside, and a nut for screwing the screw rod into the bottom wall. Provided with an observation window through which the inside can be visually observed on the side wall and a connecting portion to which the support leg is connected so that its position can be changed in the vertical direction.
The indicating member indicating the relative position of the support case and the scale bar is fixed in the receiving space of the support case so as to receive the screw bar screwed into the support case, and the scale bar can be freely moved. 2. The jib crane according to claim 1, wherein the jib crane includes a cover cylinder having a lid to be penetrated at an upper end, and the lid indicates a relative position between the support case and the scale bar by indicating one point of the scale bar. Jack device for support legs.

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