KR100452169B1 - Tripod - Google Patents

Abstract

By improving the leg extension ratio, a tripod is provided which can be sufficiently compact when carrying and can secure an appropriate height during use.

The base body 21 which provided the fitting hole part 25 which mutually spaced and formed the opposing pair is provided. Both of the fitting holes 25 of the base body 21 were fitted so as to be rotatable and rotatable together with the rotational moving shaft portions 28 forming the pair of the first leg bodies 27. The two rotational movement shaft portions 28 were coaxially formed on the outer surface of the upper end of the first leg 27 and protruded integrally. The upper end face of the second leg body 29 inserted into the inner circumference of the first leg body 27 so that the protruding length can be adjusted can be positioned on substantially the same surface as the upper face face of the first leg body 27, Can improve the leg stretch ratio.

Description

Tripod {TRIPOD}

The present invention relates to a tripod, and more particularly to a tripod that can improve the leg expansion ratio.

As a conventional tripod, the tripod of the structure shown to FIG. 7-10 is known, for example.

This conventional tripod has, for example, a three-stage stretchable leg structure, provided with a base body (2) formed with fitting holes (1) opposed to each other, and fitted with both of the base bodies (2). The rotatable movement shaft 4 of the upper end of the first leg 3 is fitted to the fitting hole 1 so as to be rotatable. The first leg 3 of the first leg 3 is fitted. The second leg 6 is inserted into the inner circumference so that the protruding length is adjustable, and the third leg 7 is inserted into the inner circumference of the second leg 6 so that the protruding length is adjustable.

And the rotational movement axis part 4 of this 1st leg 3 is a shaft part of the bolt 9 inserted in the bolt insertion hole 8 formed in the upper end part of the 1st leg 3. It is formed at both ends.

In addition, a through hole is formed in the vicinity of the upper end of the second leg 6, and the fixing protrusion 12 of the engaging member 11 is inserted into the through hole 10, and the fixing protrusion inserted therein is inserted. This engagement member 11 is fixed to the outer periphery side of the upper end part of the said 2nd leg 6 by (12). And this fastening member 11 is located in the inner periphery of the lower end part of this 1st leg 3 in the state which the said 2nd leg 6 protruded from the said 1st leg 3 to the maximum. In engagement with the fixed engagement receiving member 15, the second leg 6 is prevented from falling out with respect to the first leg 3.

Moreover, the operation lever holding member 16 is attached to the outer periphery of the lower end part of the said 1st leg 3, The operation lever 17 is hold | maintained by this operation lever holding member 16. As shown in FIG. In addition, a brake through hole 18 is formed in the vicinity of the lower end of the first leg 3, and the brake 20 is fitted into the brake through hole 18. And the brake 20 in this fitted state is a part of the position below the lower end position of the engaging member 11 of the said 2nd leg 6 by operation of the said operating lever 17. FIG. It is press-bonded and this 2nd leg 6 is fixed with respect to the said 1st leg 3.

However, since the leg stretch ratio is small in the tripod of the conventional configuration, if the compactness at the time of carrying is pursued, an appropriate height cannot be secured at the time of use, and if the height at the time of use is pursued, it can be sufficiently compact at the time of carrying. I have a problem.

That is, in the tripod of the said conventional structure, the both ends of the shaft part of the bolt 9 which the rotational movement shaft parts 4 and 4 of the 1st leg 3 fit in the hole 8 for bolt insertion. In the minimum state of the protruding length of the second leg body 6 with respect to the first leg body 3, as shown in FIG. 9), there is a problem in that it cannot be made as compact as the size corresponding to the distance A when carrying.

Moreover, since the protrusion height dimension of the engaging member 11 of the engaging member 11 of the 2nd leg body 6 is formed comparatively large, the 3rd leg body with respect to the 2nd leg body 6 ( In the minimum state of the protruding length of 7), as shown in FIG. 9, since the upper end surface of the 3rd leg 7 contacts the fixing protrusion 12 which protruded from the inner surface of the 2nd leg 6, When carrying, there is a problem in that the size corresponding to the distance B cannot be as compact.

In the use of a tripod, when the second leg 6 is fixed to the first leg 3, the second leg 6 is projected from the first leg 3 to the maximum. In the state, when the operating lever 17 is operated, the brake 20 is pressed against the position portion below the lower end position of the engaging member 11 of the second leg 6. For this reason, as shown in FIG. 10, since the distance C of the overlapping part of the 1st leg body 3 and the 2nd leg body 6 becomes long, and overlap cannot be taken more than necessary, it is suitable at the time of use. It may be difficult to secure the height.

This invention is made | formed in view of such a point, Comprising: It aims at providing the tripod which can be fully compact at the time of carrying and can secure an appropriate height at the time of use by the improvement of a leg stretch ratio.

1 is a schematic perspective view showing a tripod of an embodiment of the present invention,

2 is a front view in which a part showing a leg portion of the tripod shown in FIG. 1 is omitted;

3 is a perspective view showing an upper end portion of the first leg of the tripod shown in FIG. 1;

4 is a perspective view showing a leg portion when carrying the tripod shown in FIG. 1;

5 is a perspective view showing a leg portion when using the tripod shown in FIG. 1;

(A) and (b) are the front views which show the tripods of other embodiment of this invention, (c) the front view which shows the conventional tripod,

7 is a perspective view showing a conventional tripod,

8 is a cross-sectional view showing a leg portion of a conventional tripod;

9 is a perspective view showing a leg portion when carrying the conventional tripod shown in FIG. 7,

It is a perspective view which shows the leg part at the time of use of the conventional tripod shown in FIG.

<Explanation of symbols for the main parts of the drawings>

21: basic body 25: fitting hole

27: first leg body 28: rotational movement axis portion

29: second leg body 30: third leg body

35: operation lever holding member 36: operation lever

38: through hole 39 for brake

40: first engagement receiving member as engagement receiving member

42: through hole 44: engaging member

45: functional foundation 46: fixed protrusion

54: notch engaging member 58: notch recess

The tripod according to claim 1 has a base body having a pair of engagement holes that are spaced apart from each other and a pair of rotational movement axis portions that are rotatably fitted so as to be rotatable in both fitting holes of the base body. The first leg is coaxially located on the surface and is integrally formed to be protruded so that the protruding length can be adjusted to the inner circumference of the first leg, and the upper end portion is rotated in the minimum state of the protruding length. It is equipped with the 2nd leg body located in the substantially same surface as the upper end surface part of a said 1st leg body in the position above a part.

In the minimum state of the protruding length of the second leg relative to the first leg, the upper end face of the second leg is located on substantially the same surface as the upper end face of the first leg, so that the compactness at the time of carrying is improved. By this, leg elasticity is improved.

The tripod according to claim 2 includes a base body, a first leg body rotatably attached to the base body, and a protruding length adjustable on the inner circumference of the first leg body so that the through hole is near the upper end. A second leg having, a third leg inserted into the inner circumference of the second leg so as to be adjustable in protruding length, and an engaging member fixedly attached to the inner circumferential side of the lower end of the first leg; A working base part disposed on an outer circumferential side of the upper end of the second leg body and engaging with the engaging member in a state where the second leg body protrudes from the first leg to the maximum, and an inner surface of the working foot part; And an engaging member having a protruding height dimension that cannot be engaged with the upper end surface of the third leg and having a protruding protrusion inserted into the through hole.

And since the fixing projection of the engaging member of the 2nd leg has the protrusion height dimension which cannot be engaged with the upper surface of the 3rd leg, and is formed, the fixing of the upper surface of the 3rd leg and the engaging member is carried out. The leg extension ratio is improved by the compactness at the time of carrying, without engaging a projection part.

The tripod of Claim 3 is a tripod of Claim 2 WHEREIN: The 3rd leg body has the notch fastening member for the fall prevention fixed to the outer periphery side of an upper end part, and this notch fastening member has a 2nd leg. The notch recess which enters the fixing projection of the engaging member of the said 2nd leg in the minimum state of the protrusion length of a 3rd leg with respect to a sieve is formed.

Then, in the minimum state of the protruding length of the third leg with respect to the second leg, the fixing projection of the engaging member of the second leg enters into the cutout recess of the notch engaging member of the third leg. The fixing projection part of the engaging member of a 2nd leg body and the upper end surface of a 3rd leg body do not mesh, and leg extension ratio improves reliably.

The tripod according to claim 4 has a base body, a first leg body attached to the base body so as to be rotatable, and having a brake through-hole near the lower end, and a protruding length adjustable on the inner circumference of the first leg body. A second leg body inserted in such a manner as to be fastened to an inner circumferential side of the lower end portion of the first leg body, and fixedly attached to an outer circumferential side of the upper end portion of the second leg body, An engaging member for engaging with the engaging member in a state where the sieve protrudes from the first leg as much as possible; an operation lever holding member fixedly attached to an outer circumferential side of the lower end of the first leg; And a control lever held by the lever holding member and inserted into the through hole for the brake, wherein the second leg protrudes from the first leg to the maximum. Fixing the second leg against the first leg, being pressed against a portion located above the lower end position of the engaging member as the outer surface of the second leg based on the operation of the operating lever. It is equipped with a brake.

The brake, which is in the state of being fitted into the brake through-hole of the first leg, is located at a portion above the lower end position of the engaging member as the outer surface of the second leg based on the operation of the operating lever. Since it press-bonds and fixes this 2nd leg body with respect to a 1st leg body, the distance of the overlapping part of a 1st leg body and a 2nd leg body at the time of use can be shortened.

EXAMPLE

EMBODIMENT OF THE INVENTION Hereinafter, the structure of one Embodiment of the tripod of this invention is demonstrated with reference to FIGS.

The tripod shown in FIGS. 1-5 is a multistage, for example, three-stage stretchable leg structure, and this tripod is provided with the base 21, and the base 21 has the lifting leg 22. As shown in FIG. This height position is inserted so that adjustment is possible, and the pedestal for a camera which is not shown in figure is attached to the upper end of the lifting leg 22 so that attachment or detachment is possible.

In addition, three pairs of bridge connecting plate portions 23 are formed in the base body 21 so as to be spaced apart from each other, and a pair of fitting hole portions 25 are formed near the distal end of the bridge connecting plate portion 23. It is.

In addition, in the fitting hole part 25 which consists of three pairs of this base body 21, the rotational movement axis part 28 which forms the pair of upper end parts of the corresponding 1st leg body 27 is rotationally moved. Each fitting so as to be possible, and the second leg 29 is inserted into the inner circumference of each first leg 27 so that the protruding length is adjustable, and the inner circumference of the respective second leg 29 The third leg 30 is inserted so that the protrusion length is adjustable.

As shown in FIGS. 2-4, the said 1st leg 27 has the 1st leg base member 31 made of thin and elongate cylindrical aluminum with a thin thickness which makes a circular or polygonal cross section. .

A cap-shaped leg rib 32 is fixedly attached to the outer circumferential side of the upper end of the first leg base member 31, and the upper rib opening 32 of the first leg base member 31 is attached to the leg rib 32. 33) is closed. From the outer circumferential wall portion of the leg rib 32, the pair of rotational moving shaft portions 28, which are paired with each other, are coaxially formed so as to coincide in the axial direction and protrude toward both sides. . The outer diameter dimension of this leg rotation movement axis | shaft part 28 is a dimension slightly smaller than the inner diameter dimension of the said leg fitting hole part 25, and this leg rotation movement axis | shaft part 28 is a leg fitting hole part ( It is inserted in the 25 so as to be rotatable.

Moreover, the cylindrical operation lever holding member 35 which opened the upper and lower surfaces is attached to the outer periphery of the lower end part of this 1st leg base member 31, and this operation lever holding member 35 is a cam type operation lever. 36 is maintained to be rotatable. A brake housing portion 37 is formed in this operation lever holding member 35.

In addition, a brake through hole 38 is formed at a position opposite to the brake accommodating portion 37 in the vicinity of the lower end of the first leg base member 31, and the brake 39 is provided in the brake through hole 38. ) Is embedded. The outer surface portion of the brake 39 in the fitted state is located in the brake accommodation portion 37, and when the outer surface portion in the brake accommodation portion 37 is pressed by the operation lever 36, the brake 39 ) Is pressed at a predetermined position on the outer surface of the second leg (29).

Further, a first engagement member 40 as a thin cylindrical cylindrical engagement member is fixedly attached to the inner circumferential side of the first leg base member 31. Moreover, this 1st engagement member 40 prevents friction, rattling, etc. of the 1st leg base member 31 and the 2nd leg foundation member 41, and has It is to be able to smoothly adjust the protruding length of the second leg (29).

The second leg body 29 is a thin and long cylindrical aluminum second leg base member 41 having a diameter smaller than that of the first leg base member 31 in a thin thickness having a circular or polygonal cross section. In the vicinity of the upper end of the second leg base member 41, for example, two through holes 42 are formed at positions facing each other.

In addition, for example, two engagement preventing members 44 for preventing the removal of the second leg base member 41 are fixedly attached to positions facing each other. The leg engaging member 44 has a rectangular plate-shaped functional foundation 45 having a thin thickness curved corresponding to the outer surface shape of the second leg foundation member 41. A rectangular parallelepiped fixing protrusion 46 is protruded toward the inner side in the center of the inner surface.

Then, the fixing protrusion 46 of the leg engaging member 44 is inserted into the corresponding through hole 42, and the working base portion 45 is formed by the inserted fixing protrusion 46. It is fixed to the outer periphery side of the upper end part of the 2nd leg base member 41, respectively. As shown in FIG. 5, the functional foundation 45 of the leg engaging member 44 is in a state where the second leg 29 protrudes from the first leg 27 to the maximum. The lower edge of the functional base 45 is engaged in contact with the upper edge of the first engagement receiving member 40 so that the second leg 29 falls out with respect to the first leg 27. Is prevented.

In addition, on the inner circumferential side of the lower end portion of the second leg base member 41, like the first leg base member 31, a second engagement member as a non-illustrated engagement member having a thin cylindrical shape is formed. Is fixedly attached. Moreover, this 2nd engagement member prevents friction, rattling, etc. of the 2nd leg foundation member 41 and the 3rd leg foundation member 51, and is the 3rd leg with respect to the 2nd leg 29. The protruding length of the sieve 30 is to be adjusted smoothly.

In addition, a cylindrical operating lever holding member 48 having an upper and a lower surface fixed thereto is attached to the outer circumferential side of the lower end portion of the second leg base member 41, as shown in the first leg base member 31. A cam-type operating lever (not shown) is held so as to be rotatable by this operating lever holding member 48, and a brake housing portion (not shown) is formed in the operating lever holding member. In addition, near the lower end of the second leg base member 41, a brake through hole (not shown) is formed at a position facing the brake accommodating portion, similar to the first leg base member 31, When a brake (not shown) is fitted into the brake through hole, the outer surface portion of the brake in the inserted state is located in the brake accommodation portion, and the outer surface portion of the brake accommodation portion is pressed by the operation lever. The inner surface portion of the brake is crimped to a predetermined position on the outer surface of the third leg body 30.

The third leg body 30 is a thin and long cylindrical aluminum third leg foundation member 51 having a diameter smaller than that of the second leg foundation member 41 at a thin thickness having a circular or polygonal cross section. In the vicinity of the upper end of the third leg base member 51, for example, two through holes 52 are formed at positions facing each other.

In addition, for example, two notch engaging members 54 for preventing the removal of the third leg base member 51 are fixedly attached to positions facing each other. This leg notch engaging member 54 has a square plate-shaped functional base part 55 with a thin thickness curved corresponding to the outer surface shape of the 3rd leg base member 51, This functional base part 55 In the center of the inner surface of the rectangular parallelepiped fixing projections 56 are formed to protrude inward.

Then, the fixing protrusion 56 of the leg notch engaging member 54 is inserted into the corresponding through hole 52, and the working foundation portion 55 is inserted by the inserted fixing protrusion 56. It is fixed to the outer periphery of the upper end of the said 3rd leg base member 51, respectively. The functional foundation portion 55 of the leg notch engaging member 54 has the third foundation 30 protruding from the second leg 29 as much as possible. A bottom edge is engaged with the top edge of the second engagement receiving member, and the third leg 30 is prevented from falling out with respect to the second leg 29.

In addition, a cutout recess 58 is formed at an upper end of the working base portion 55 of the leg cutout engaging member 54 in the center of the width direction, and the cutout recess 58 has the second leg. The fixing projection 46 of the engaging member 44 of the second leg 29 enters the minimum length of the protruding length of the third leg 30 relative to the sieve 29. That is, the fixing protrusion 46 of the engaging member 44 fixed to the upper end of the second leg base member 41 of the second leg body 29 has a projected height dimension of the third leg body 30. The third leg base member 51 of) has a dimension that cannot be engaged with the upper surface.

Moreover, the rubber cap 60 which becomes a ground spike is fixedly attached to the outer periphery of the lower end part of this 3rd leg base member 51, and is attached.

Next, the operation of the above embodiment will be described.

First, when carrying a tripod, after adjusting the protruding length of the 2nd leg 29 with respect to the 1st leg 27 to a minimum state, the 2nd leg 29 is moved by the brake 39. FIG. While fixing to the first leg 27 and adjusting the protruding length of the third leg 30 with respect to the second leg 29 to a minimum state, the third leg ( 30) is fixed to the second leg 29.

And in the state which the protruding length of each of these 2nd leg 29 and the 3rd leg 30 was minimized, as shown in FIG. 2, the 1st-3rd leg base members 31,41, The upper end face of each 51) is in contact with the leg ribs 32 and is located on substantially the same face, and the total length of the tripod is the minimum dimension.

Moreover, in the state which each protruding length of these 2nd leg body 29 and the 3rd leg body 30 was minimum, as shown in FIG. 4, the leg notch engaging member of the 3rd leg body 30 is shown. The fixing projection 46 of the engaging member 44 of the second leg 29 enters into the notched recess 58 of 54, and these engaging members 44 and the notched engaging member 54 are located. Is catching up.

And when using a tripod, for example, when extending a tripod and making the whole length into the maximum dimension, the 1st leg base member 31 derives the 2nd leg base member 41, and the 1st After adjusting the protruding length of the second leg 29 to the leg 27 to the maximum state, the second leg 29 is fixed to the first leg 27 with the brake 39. .

In addition, by drawing the third leg base member 51 from the second leg base member 41, the protruding length of the third leg body 30 with respect to the second leg body 29 is adjusted to the maximum state. Then, the third leg 30 is fixed to the second leg 29 by the brake.

And in the state which made the protruding length of each of these 2nd leg 29 and the 3rd leg 30 maximum, as shown in FIG. 5, it is located in the vicinity of the lower end of the 1st leg 27. FIG. The brake 39 is provided such that the upper half of the brake 39 is positioned between the two engaging members 44 and is positioned above the lower end position of the engaging member 44 of the second leg 29. It is crimped | bonded to the predetermined position of the outer surface of the 2nd leg body 29, this crimping state is hold | maintained as the operation lever 36, and the 2nd leg body 29 is being fixed with respect to the 1st leg body 27. As shown in FIG. In addition, although not shown, the brake located in the vicinity of the lower end of the 2nd leg body 29 is located between the both notch engaging members 54, and the upper half is cut off of the 3rd leg body 30, and is not shown. It is crimped | bonded to the predetermined position of the outer surface of this 3rd leg 30 so that it may include the part located higher than the lower end position of the fitting member 54, and this crimped state is hold | maintained as an operation lever, and the 3rd leg 30 ) Is fixed to the second leg 29.

As a result, the distance W of the overlapping part of the 1st leg body 28 and the 2nd leg body 29, and the 2nd leg body 29 in the state which made the full length of the tripod into the largest dimension, The distance W of the overlapping part with the three legged bodies 30 becomes a short distance compared with each conventional distance C. As shown in FIG.

Therefore, according to the said embodiment, the leg extension ratio of a tripod can be improved, As a result, it can be compact enough at the time of carrying, and can ensure an appropriate height at the time of use.

That is, the rotational movement axis portion 28, which is paired on the outer surface of the upper end of the first leg 27, is coaxially formed to integrally protrude and at the same time, the engaging member of the second leg 29 Since the fixing projection 46 of 44 has a protruding height dimension that cannot be engaged with the upper surface of the third leg 30, the first to third leg foundations are formed with the tripod as the minimum dimension. Since the upper end surfaces of the members 31, 41, and 51 are positioned on substantially the same surface in contact with the leg ribs 32, the leg stretching ratio is improved, which can be sufficiently compact when carrying and suitable for use. The height can be secured.

In addition, approximately the upper half of the brake 39 positioned at the lower end positions of the first leg 27 and the second leg 29 is the second based on the operation of the corresponding operation lever 36. As an outer surface of each of the leg body 29 and the third leg body 30, the fitting member 44 and the notch engaging member 54 are pressed to portions located above the lower end positions of the respective fitting members, respectively, Since the leg 29 and the third leg 30 are fixed, the distance W between the overlapping portions of the first leg 27 and the second leg 29 in a state where the tripod is at the maximum dimension. And the distance W of the overlapping portions of the second leg 29 and the third leg 30 can be made smaller than in the related art, and as a result, the leg stretching ratio is improved and can be sufficiently compact when carrying. It is also possible to ensure an appropriate height during use.

Moreover, in the said embodiment, although the tripod demonstrated the structure of the three-stage stretchable leg structure provided with the 1st leg 27, the 2nd leg 29, and the 3rd leg 30, It can also be applied to the configuration of a two-stage bridge structure or a four-stage or more stretchable bridge structure.

That is, the tripod shown in FIGS. 6 (a) and 6 (b) is a configuration applied to, for example, a four-stage stretchable leg structure, and is formed on the inner circumference of the third leg 30 in the tripod shown in FIG. 4 is inserted to allow the bridge member (30 _a) to adjust the protruding length, the fourth bridge member (30 _a) that constitute the legs of the least significant stage in place of the third leg member (30).

When the tripod with the smallest dimension L0 shown in Fig. 6A is extended to the maximum, the total length of the tripod becomes the maximum dimension Ll as shown in Fig. 6B. On the other hand, in the tripod of the conventional structure, even if the thing of the same minimum dimension L0 is extended to the maximum at the time of use, it becomes only the maximum dimension L2 as shown to FIG. 6 (c). As described above, the tripod of the present embodiment has a significantly larger leg extension ratio L1 / L0 than the conventional tripod. Further, Fig. 6 (c) a conventional tripod, can be 7 to the fourth bridge member (7 _a) the projection length adjustment side inner circumference of the third leg unit 7 in the conventional tripod shown in Fig. 10 shown in The fourth leg 7 _a is configured to be the lowermost leg in place of the third leg 7.

According to the invention as set forth in claim 1, the protruding length of the second leg with respect to the first leg is formed because the rotational movement axis portions paired on the outer surface of the upper end of the first leg are coaxially formed. In the minimum state of, the upper end face portion of the second leg member is located on substantially the same surface as the upper face portion of the first leg member, so that the leg elasticity ratio is improved, and it is sufficiently compact when carrying, and the appropriate height is used during use. It can be secured.

According to the invention as set forth in claim 2, since the fixing projection of the engaging member of the second leg is projected to have a projected height dimension that cannot be engaged with the upper surface of the third leg, the engaging member of the second leg The fixing projections of and the upper end face of the third leg body do not engage, and the leg stretch ratio is improved, and it can be sufficiently compact when carrying, and an appropriate height can be ensured during use.

According to the invention as set forth in claim 3, the fastening member of the second leg member is fastened to the cutout recess of the notch engaging member of the third leg in a minimum state of the protruding length of the third leg body with respect to the second leg body. Since the projection portion enters, the fixing projection portion of the engaging member of the second leg body and the upper end surface of the third leg body do not engage, and the leg extension ratio can be reliably improved.

According to the invention of claim 4, the brake in a state of being fitted into the brake through-hole of the first leg is lower than the lower end position of the engaging member as the outer surface of the second leg based on the operation of the operating lever. Since the second leg is fixed to the first leg, the distance between the overlapping portions of the first leg and the second leg can be shortened at the time of use. The stretching ratio is improved, it can be sufficiently compact when carrying, and an appropriate height can be ensured during use.

Claims (4)

A basic body having fitting holes that are spaced apart from each other to form an opposing pair A first leg body having a pair of rotational moving shaft portions fitted to both fitting holes of the base body so as to be rotatable and coaxially formed on the outer surface of the upper end portion and protruding integrally; The protrusion length is inserted into the inner circumference of the first leg, and the upper end face is positioned approximately on the same plane as the upper end face of the first leg at a position above the rotational movement axis in the minimum state of the protruding length. A tripod characterized by including a second leg to be. With primitives, A first leg body rotatably attached to the base body, A second leg body inserted into the inner circumference of the first leg so that the protrusion length is adjustable, and having a through hole near the upper end; A third leg inserted into the inner circumference of the second leg so that the protruding length is adjustable; An engaging member fixedly attached to an inner circumferential side of the lower end of the first leg, A working base part disposed on an outer circumferential side of the upper end of the second leg body and engaging with the engaging member in a state where the second leg body protrudes from the first leg to the maximum, and an inner surface of the working foot part; And an engaging member having a projecting height dimension that cannot be engaged with an upper end surface of the third leg and having a fixing projection which is formed to be inserted into the through hole. 3. The third leg body according to claim 2, wherein the third leg has a notch engaging member for preventing release, which is fixedly attached to the outer circumferential side of the upper end portion, The notch engaging member is provided with a notch recess in which the fixing projection of the engagement member of the said 2nd leg enters in the minimum state of the protrusion length of a 3rd leg with respect to a 2nd leg. With primitives, A first leg body attached to the base body so as to be rotatable and having a brake through hole in the vicinity of the lower end thereof; A second leg inserted into the inner circumference of the first leg so that the protruding length is adjustable; An engaging member fixedly attached to an inner circumferential side of the lower end of the first leg, A fastening member fixedly attached to an outer circumferential side of the upper end of the second leg, and engaging with the engaging member while the second leg protrudes from the first leg to the maximum; An operation lever holding member fixedly attached to an outer circumferential side of the lower end of the first leg, An operation lever held by the operation lever holding member, It is arranged in the state inserted in the said through hole for brakes, and it hangs as an outer surface of the said 2nd leg based on operation of the said operation lever in the state which the said 2nd leg protruded to the maximum from the said 1st leg. And a brake for fixing the second leg pressed against the portion located above the lower end position of the fitting member with respect to the first leg.