Height adjustment device

Abstract

To facilitate adjustment of the height of a support member.SOLUTION: There is provided a height adjustment device that is provided between a support member P and the ground and raises and lowers the lower end position of the support member P, including a first member 30 having a screw shaft A that rises above the ground and has a male threaded portion a on the outer periphery thereof, and a female threaded portion 36 that is screwed into the male threaded portion a. The first member 30 includes a pair of opening / closing pieces 31 and 32 which are rotatably supported by bases 33, 34 and 35 provided at one end and have the female threaded portion 36. The pair of opening / closing pieces 31 and 32 are rotatable between a locked state in which the male threaded portion a and the female threaded portion 36 are engaged with each other, and an open state in which the male threaded portion a and the female threaded portion 36 are separated from each other by opening the other ends of the pair of opening / closing pieces 31 and 32.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a height adjustment device used for a temporary scaffold or the like, which adjusts the height of various support members.

Background Art

[0002] A temporary scaffold generally has a plurality of support members arranged along the outer wall of a building, and a beam is used to connect between the support members, and a scaffold board is fixed along the beam. In many cases, a height adjustment device, so-called a jack device, is arranged at the lower end of the support member to adjust the lower end position of the support member. As such a height adjustment device, for example, there is one described in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-mentioned temporary scaffold or the like, there are cases where it is desired to adjust the lower end position of the support member in the vertical direction with respect to the ground at the installation location. For example, the case where the ground is inclined or the case where there are irregularities on the ground can be mentioned.

[0005] In the height adjustment device described in Patent Document 1, a receiving member that supports the lower end of the support member is screwed to a support shaft rising from a base member placed on the ground. Therefore, when adjusting the height of the support member, it is necessary to rotate the receiving member around the axis with respect to the support shaft. At this time, the amount of elevation of the receiving member is about several millimeters to several centimeters per one rotation around the axis. Therefore, when the amount of height adjustment is large, the work is complicated and it also requires time and effort.

[0006] Therefore, an object of the present invention is to facilitate the adjustment of the height of a column member used for a structure such as a temporary scaffold.

Means for Solving the Problems

[0007] In order to solve the above problems, the present invention provides a height adjustment device for raising and lowering the lower end position of a column member with respect to a screw shaft that stands on the ground and has a male screw portion on its outer periphery. The height adjustment device includes a first member having a female screw portion that engages with the male screw portion. The first member is rotatably supported by a base provided at one end and includes a pair of opening and closing pieces formed with the female screw portion. The pair of opening and closing pieces is rotatable between a locked state in which the male screw portion and the female screw portion are engaged and an open state in which the other ends of the pair of opening and closing pieces are opened and the male screw portion and the female screw portion are disengaged.

[0008] Here, a configuration can be adopted that includes a second member connected to the first member and a rotation mechanism that rotates the pair of opening and closing pieces by raising and lowering the second member with respect to the first member.

[0009] Further, the rotation mechanism can adopt a configuration having a function of maintaining the locked state.

[0010] In each of these aspects, the rotation mechanism includes an action shaft that moves up and down together with the second member, an action protrusion provided on the action shaft, and an action groove provided on the first member into which the action protrusion enters. The direction in which the action groove extends can adopt a configuration that is inclined with respect to the axial direction of the action shaft.

[0011] Further, a configuration can be adopted in which a rotation prevention protrusion provided on the action shaft enters a rotation prevention groove provided on the first member, so that the action shaft is prevented from rotating around its axis.

Effects of the Invention

[0012] The present invention can easily adjust the height of a column member used for a structure such as a temporary scaffold.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2A

Figure 2B

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 6A

Figure 6B

Figure 6C

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0014] The first embodiment of the present invention is shown in FIGS. 1 to 5B and FIG. 8. This embodiment is a height adjusting device 1 used at the lower part of a structure such as a temporary scaffold. Generally, a temporary scaffold is configured by connecting a plurality of column members P arranged along the outer wall of a building with beams and fixing a scaffold board along the beams. The height adjusting device 1 is arranged at the lower end of the column member P.

[0015] The height adjustment device 1 adjusts the lower end position of the support member P with respect to the ground. By adjusting the lower end position of the support member P, even when there are inclinations or irregularities in the ground at the location where the structure is installed, the gap between the structure and the ground can be eliminated, and its installation state can be stabilized. The height adjustment device 1 assumes a vertical screw shaft A rising from the ground as its installation target. As shown in FIG. 8, the screw shaft A is integrally fixed to a plate-shaped base portion B placed on the ground by welding or the like. A male screw portion a is formed on the outer periphery of the screw shaft A.

[0016] The height adjustment device 1 includes a first member 30 having a female screw portion 36 that engages with the male screw portion a, and a second member 40 that is connected to the first member 30 and supports the lower end of the support member P.

[0017] The first member 30 is composed of an annular member that surrounds the screw shaft A. In this embodiment, the first member 30 is composed of a pair of arc-shaped opening and closing pieces 31 and 32. As shown in FIG. 1, the pair of opening and closing pieces 31 and 32 are rotatably supported by base portions 33, 34, and 35 provided at one end (hereinafter referred to as one end) along the circumferential direction. By rotating around the base portions 33, 34, and 35, the other end (hereinafter referred to as the other end) of the pair of opening and closing pieces 31 and 32, which is on the opposite side of one end across the axis of the first member 30, can be opened and closed. However, in this embodiment, the pair of opening and closing pieces 31 and 32 are arc-shaped members from one end to the other end, but the cross-sectional shape of the pair of opening and closing pieces 31 and 32 is not limited as long as they are members that surround the screw shaft A. Hereinafter, one of the pair of opening and closing pieces 31 and 32 is referred to as the first opening and closing piece 31, and the other is referred to as the second opening and closing piece 32.

[0018] The base 34 of the first opening / closing piece 31 is provided so as to protrude laterally at about the middle in the vertical direction of the first opening / closing piece 31. Also, the bases 33, 35 of the second opening / closing piece 32 are provided so as to protrude laterally with a space therebetween in the vertical direction. For this reason, the base 34 of the first opening / closing piece 31 can enter between the bases 33, 35 of the second opening / closing piece 32. By inserting the later-described operating shaft 41 through the holes 33a, 34a, 35a provided in the bases 33, 34, 35, the first opening / closing piece 31 and the second opening / closing piece 32 are rotatably supported. Note that the reference numeral 2 in the figure is a handle portion by which an operator manually holds the height adjusting device 1.

[0019] An internal thread portion 36 is formed on the inner periphery of the first member 30. The internal thread portion 36 is formed along the inner peripheral surfaces of the pair of opening / closing pieces 31, 32. As the first opening / closing piece 31 and the second opening / closing piece 32 open and close, when the other ends of the first opening / closing piece 31 and the second opening / closing piece 32 are closed, a locking state is achieved in which the external thread portion a of the screw shaft A and the internal thread portion 36 mesh with each other, and when the other ends of the first opening / closing piece 31 and the second opening / closing piece 32 are opened, an open state is achieved in which the external thread portion a and the internal thread portion 36 are disengaged. In the locking state, by rotating the first member 30 around the axis of the screw shaft A, the first member 30 moves up and down along the axial direction of the screw shaft A while the external thread portion a and the internal thread portion 36 mesh with each other.

[0020] The rotation (opening / closing) of the first opening / closing piece 31 and the second opening / closing piece 32 is performed by a rotation mechanism 50. The rotation mechanism 50 functions by raising and lowering an operating shaft 41, which functions as a rotation center of the first opening / closing piece 31 and the second opening / closing piece 32, together with a second member 40 with respect to a first member 30. In the embodiment, the operating shaft 41 is press-fitted and fixed in a hole 42a provided in a base 42 of the second member 40. However, the operating shaft 41 and the second member 40 may be integrally molded as one member.

[0021] The working shaft 41 is provided with a working protrusion 51 that protrudes laterally. The working protrusion 51 fits into a working groove 52 formed in the hole 33a of the first member 30. Further, in this embodiment, the working shaft 41 is provided with an anti-rotation protrusion 53 that is different from the working protrusion 51. The anti-rotation protrusion 53 fits into an anti-rotation groove 54 formed in the hole 34a of the first member 30. The working protrusion 51 and the anti-rotation protrusion 53 are provided at different orientations along the axial rotation direction of the working shaft 41.

[0022] The working groove 52 into which the working protrusion 51 fits is provided in a direction inclined with respect to the axial direction of the working shaft 41 (see FIGS. 3, 5A, and 5B). Also, the anti-rotation groove 54 into which the anti-rotation protrusion 53 fits is provided parallel to the axial direction of the working shaft 41 (see FIG. 4). Since the anti-rotation protrusion 53 fits into the anti-rotation groove 54 of the first member 30, even if the working shaft 41 moves up and down with respect to the first member 30, the second opening / closing piece 32 and the working shaft 41 do not rotate relative to each other about the axis. Also, since the working protrusion 51 fits into the working groove 52 of the first member 30, when the working shaft 41 moves up and down with respect to the first member 30, the first opening / closing piece 33 rotates relative to the working shaft 41 about the axis. For this reason, due to the up and down movement of the working shaft 41 with respect to the first member 30, the other ends of the first opening / closing piece 31 and the second opening / closing piece 32 open and close.

[0023] In this embodiment, the anti-rotation groove 54 is parallel to the axial direction of the working shaft 41, and the working groove 52 is in a direction inclined with respect to the axial direction of the working shaft 41. However, as long as the other ends of the first opening / closing piece 31 and the second opening / closing piece 32 open and close due to the up and down movement of the working shaft 41 with respect to the first member 30, the extending directions of the working groove 52 and the anti-rotation groove 54 can be changed. For example, both the direction of the working groove 52 and the direction of the anti-rotation groove 54 may be in a direction inclined with respect to the axial direction of the working shaft 41. In this case, both the protrusions 51, 53 and the grooves 52, 54 contribute to the opening and closing of the first opening / closing piece 31 and the second opening / closing piece 32.

[0024] In addition, the rotation mechanism 50 also has a function of maintaining the locked state of the height adjustment device 1 with respect to the screw shaft A. That is, in the embodiment, as long as the working shaft 41 is not pulled upward with respect to the first member 30, the first opening / closing piece 31 and the second opening / closing piece 32 are maintained in the locked state and do not shift to the open state against the intention of the operator. At this time, if an appropriate friction is generated between the working protrusion 51 and the working groove 52, the working shaft 41 will not come out of the first member 30 unless an external force of a certain degree is applied to the working shaft 41. Therefore, the maintenance of the locked state is more reliable.

[0025] Here, as shown in FIG. 3, if the inclination angle (obtuse angle) β of the working groove 52 (lower working groove 52b) with respect to the horizontal direction at the position where the working protrusion 51 is in the locked state is made smaller than the inclination angle (obtuse angle) α of the working groove 52 (upper working groove 52a) with respect to the horizontal direction at the position where the working protrusion 51 is in the open state, the locked state of the first opening / closing piece 31 and the second opening / closing piece 32 becomes more stable. That is, it is desirable that the direction of the lower working groove 52b corresponding to the locked state is closer to the vertical direction, that is, the axial direction of the working shaft 41, than the direction of the upper working groove 52a corresponding to the open state. This is the same when setting an inclination in the anti-rotation groove 54.

[0026] As described above, when the other ends of the first opening / closing piece 31 and the second opening / closing piece 32 are in a closed state (the locked state of the first member 30), by rotating the first member 30 around the axis of the screw shaft A, while the male screw portion a and the female screw portion 36 are engaged, the first member 30 moves up and down along the axial direction of the screw shaft A with respect to the screw shaft A. However, when the height for moving the first member 30 up and down (hereinafter referred to as the adjustment height) is large, the number of times of rotating the first member 30 with respect to the screw shaft A becomes very large. For this reason, the operator has to rotate the first member 30 many times, which takes time and effort for the work. However, according to this invention, by changing the first member 30 from the locked state to the open state, the first member 30 is once detached from the screw shaft A, and by setting the first member 30 in the locked state at an arbitrary axial position of the screw shaft A, the position of the first member 30 can be immediately adjusted. Thereby, it is possible to facilitate the work and shorten the working time. Incidentally, the subsequent fine adjustment of the height can be achieved by rotating the first member 30 around the axis of the screw shaft A in the same manner as in the prior art.

[0027] By the way, the function as a receiving member for supporting the lower end of the support member P is borne by the second member 40. The second member 40 is connected above the first member 30 such that the support member P and the load from above are transmitted to the screw shaft A through the first member 30. The second member 40 includes an annular receiving portion 3 on the inner diameter side of the peripheral wall portion 4 that is circular in plan view, on which the lower end of the support member P is placed. When the lower end of the support member P is placed on this receiving portion 3, the support member P is held by the peripheral wall portion 4 so that the support member P does not come off from the second member 40 and drop off.

[0028] As described above, the second member 40 has both the function of rotating the first opening / closing piece 31 and the second opening / closing piece 32 in the rotation mechanism 50 and the function of maintaining the locked state between the first opening / closing piece 31 and the second opening / closing piece 32, and further can exhibit the function of supporting the support member P. Thereby, the number of parts can be reduced and the simplification of the structure is also realized.

[0029] The second embodiment of the present invention is shown in FIGS. 6, 7, and 9. In this embodiment, a handle portion 2 for manually grasping the height adjustment device 1 is provided on the first member 30. Since the other configurations are common to the first embodiment, the description thereof is omitted.

[0030] In each of the above embodiments, the usage form of the height adjustment device of the present invention has been described by taking a temporary scaffold used at a construction site or the like as an example. However, the structures to which the height adjustment device of the present invention can be applied are not limited to temporary scaffolds. For example, it can also be applied to other uses such as temporary stages, temporary bridges, and prefabricated racks (shelves). Further, in each of the above embodiments, the material of each member is metal, but the material of the member may be other materials such as resin as long as it has a predetermined strength and durability.

Explanation of Reference Numerals

[0031] 1 Height adjustment device 2 Handle portion 3 Receiving portion 4 Peripheral wall portion 30 First member 31, 32 Opening / closing pieces 40 Second member 50 Rotating mechanism 51 Acting protrusion 52 Acting groove 53 Anti-rotation protrusion 54 Anti-rotation groove P Support member

Claims

1. In a height adjustment device for raising and lowering the lower end position of a support member (P) with respect to a screw shaft (A) that rises on the ground and has a male screw portion (a) on its outer periphery, a first member (30) having a female screw portion (36) screwed onto the male screw portion (a) is provided, the first member (30) is rotatably supported by a base portion (33, 34, 35) provided at one end and includes a pair of opening and closing pieces (31, 32) in which the female screw portion (36) is formed, the pair of opening and closing pieces (31, 32) are rotatable between a locked state in which the male screw portion (a) and the female screw portion (36) are engaged and an open state in which the other ends of the pair of opening and closing pieces (31, 32) are opened and the male screw portion (a) and the female screw portion (36) are disengaged, a second member (40) connected to the first member (30), and a rotation mechanism (50) for rotating the pair of opening and closing pieces (31, 32) by raising and lowering the second member (40) with respect to the first member (30) are provided, the rotation mechanism (50) includes an action shaft (41) that moves up and down together with the second member (40), an action protrusion (51) provided on the action shaft (41), and an action groove (52) provided on the first member (30) into which the action protrusion (51) fits, a height adjustment device in which the direction in which the action groove (52) extends is inclined with respect to the axial direction of the action shaft (41).

2. The height adjustment device according to claim 1, wherein the rotation mechanism (50) has a function of maintaining the locked state.

3. The height adjustment device according to claim 1 or 2, wherein the rotation prevention protrusion (53) provided on the action shaft (41) fits into the rotation prevention groove (54) provided on the first member (30), thereby preventing the action shaft (41) from rotating around its axis.

Images