JP2006124947A - Extensible strut and floodlight having extensible strut - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extensible strut for preventing rapid extension and a floodlight having the extensible strut. <P>SOLUTION: The holding part 40b of a rotating lever 40 is rotated upward to bring the contact surface 39a of an eccentric cam 39 in contact with the outer peripheral surface 21c of a first intermediate tube column 21. By this, a shaft 38 is positioned on the upper end part side of an elongated hole 37. Next, when the engagement of a shuckle 32 with a hook 33 is disengaged, the first intermediate tube column 21 and a second intermediate tube column 22 are extended in order by the energization of a gas damper 24 through a pulley 30 and a wire 31. In this case, the first intermediate tube column 21 is slightly extended since its extending speed is reduced by the rubbing thereof with the contact surface 39a of the eccentric cam 39 and, accordingly, the second intermediate tube column 22 is also slightly extended. Thus, when a light emitting part is detached from the extensible strut 3 by replacement, the first and second intermediate tube columns 21 and 22 can be prevented from being abruptly extended, and stable operation can be easily performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a telescopic strut and a projector having the telescopic strut.

  2. Description of the Related Art Conventionally, floodlights used as lighting for construction sites and the like are widely known. In general, the projector includes a light emitting unit provided with a light source such as a light bulb and a column on which the light emitting unit is mounted. Some of these projectors are equipped with telescopic struts that can be extended and retracted, and the height of the light emitting part is changed by extending and contracting the telescopic struts, and the range in which the light emitting part can be illuminated is changed. I was supposed to. And the thing provided with the urging means for extending | stretching to the expansion | extension direction in the expansion-contraction support | pillar is proposed (for example, patent document 1).

The telescopic column described in Patent Document 1 includes a base tube column and a plurality of middle tube columns whose inner diameters are sequentially reduced with respect to the base tube column, and each of the intermediate tube columns is freely slidable up and down on the base tube column. It is fitted. Each middle tube column is provided with a pulley having a wire attached thereto. One end of each wire is attached to the base tube column, and the other end is attached to the proximal end portion of the adjacent middle tube column. Then, when the lowermost middle tube column is energized and raised by the gas damper in the base tube column, each wire is sequentially pulled to extend from the base tube column. . Furthermore, the gas pressure of the gas damper is set so as to balance the weight of the light emitting part, the middle tube column, the pulley and the wire, and the stretched state of each middle tube column is maintained to ensure the height of the light emitting unit. Yes.
Japanese Patent No. 2634776

  However, in the projector of the above-mentioned Patent Document 1, when the light emitting part is detached for exchanging the light emitting part, there is a possibility that the balance with the gas pressure of the gas damper is lost and the middle tube column is rapidly expanded. It was. This can occur even when an urging means other than the gas damper is employed.

  The present invention solves the above problem, and an object of the present invention is to provide a telescopic strut that prevents rapid stretching and a projector that includes the telescopic strut.

  The telescopic strut according to claim 1 comprises a base tube column and at least one middle tube column having a successively reduced inner diameter inside the same tube column, the inner tube column having the smallest inner diameter. The load can be detachably mounted, and at least one of the inner tube columns having the largest inner diameter can be freely expanded and contracted by loosely fitting in the base tube column. In the telescopic strut urged in the extension direction, the urging force of the urging means is set to be substantially the same as the weight of the middle tube column and the load, and when the load is removed, The gist of the invention is that the base pipe column is provided with extension speed reduction means for reducing the extension speed by contacting at least the inner pipe column having the largest inner diameter.

  According to the telescopic support column of the first aspect, when the load is detached from the middle tube column, the extension rate reducing means is brought into contact with the middle tube column to reduce the extension rate of the middle tube column. Rapid extension of the tube column can be prevented.

The telescopic strut according to claim 2 is the telescopic strut according to claim 1, wherein the base tube column is an outer peripheral surface of the base tube column having at least the largest inner diameter among the intermediate tube columns to be loosely fitted. The extension speed reducing means is configured to contact the intermediate tube column by moving the contact member and the contact member opposed to the intermediate tube column via the open portion. And a moving means for separating the abutting member. The abutting member is brought into contact with the middle tube column by the moving means, thereby reducing the extension speed of the middle tube column and separating the abutting member from the middle tube column. The gist is to cancel the reduction of the stretching speed by making the above.

  According to the telescopic column of the second aspect, the abutting member is brought into contact with the middle tube column by the moving means to reduce the extension speed of the middle tube column, and the abutting member is separated from the middle tube column. The reduction in the stretching speed can be canceled. Therefore, the extension speed of the middle tube column can be appropriately reduced by the moving means.

  The telescopic strut according to claim 3 is the telescopic strut according to claim 2, wherein the extension speed reducing means includes an accommodating portion for accommodating the abutting member on the outer peripheral surface side of the base tube column, The abutting member is a rotating body that is rotatably supported by a support shaft provided in the housing portion, and the housing portion guides the support shaft and makes a relative relationship between the support shaft and the outer peripheral surface. The gist is that a guide hole for changing the distance is provided.

  According to the telescopic support column according to claim 3, the rotating body approaches the outer peripheral surface of the base tube column by guiding the support shaft into the guide hole and changing the relative distance from the outer peripheral surface of the base tube column. Can be separated. That is, since the rotating body can approach or separate from the middle tube column that is loosely fitted to the base tube column, the degree of contact with the middle tube column can be adjusted. Furthermore, even if the size of the rotating body or the housing portion differs from the initial design due to manufacturing errors or the like, the rotating body can be accurately brought into contact with the middle tube column by moving the support shaft closer or away. Therefore, it is possible to reduce the influence due to manufacturing errors and the like.

  According to a fourth aspect of the present invention, there is provided a projector having a telescopic column that sets the height of the light emitting unit that emits light by the supplied driving power, and sets the illumination range of the light emitting unit. The expansion / contraction column is the expansion / contraction column according to any one of claims 1 to 3, wherein the light emitting unit is detachably mounted as a mounted object.

  According to the projector of the fourth aspect, the extension speed of the telescopic strut can be reduced by the extension speed reducing means. Therefore, when the light emitting unit is detached from the telescopic support column, the extension rate of the middle tube column is reduced by the extension rate reduction means, so that the middle tube column can be prevented from abruptly extending. As a result, the light emitting unit can be easily replaced.

  According to the telescopic column according to claims 1 to 3 and the projector according to claim 4, it is possible to prevent rapid expansion of the telescopic column by the stretching speed reducing means.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, the projector 1 of this embodiment is provided with the base 2 formed in flat form. At the center position of the upper surface 2a of the base 2, an extendable support column 3 is provided so as to be extendable. A light emitting unit 4 as a mounted object is detachably mounted on the distal end portion of the telescopic column 3. The light emitting unit 4 includes a balloon 5, and a light emitting device 6 is provided in the balloon 5. The light emitting device 6 includes an upper support plate 7a and a lower support plate 7b. The upper support plate 7a is attached to and supported by a plurality of support columns 8 erected on the lower support plate 7b and faces the lower support plate 7b. ing. The upper support plate 7 a is attached to the upper end portion of the balloon 5, and the lower support plate 7 b is attached to the lower end portion of the balloon 5. A blower 9 is disposed at the center position of the lower support plate 7b. The blower 9 is attached to the lower support plate 7b, and communicates with the atmosphere through a through hole (not shown) of the lower support plate 7b. On the other hand, a light bulb 10 as a light source is provided at a central position of the upper support plate 7a and at a position opposite to the blower 9. The blower 9 and the light bulb 10 are connected to a generator 12 as a power source via a power cord 11 and are supplied with power. The blower 9 is driven by power supply from the generator 12, sucks air from outside the light emitting portion 4 (balloon 5) through a through hole (not shown) of the lower support plate 7b, and blows the air into the balloon 5. 5 is inflated. The light bulb 10 emits light by power supply from the generator 12 and illuminates the periphery of the projector 1 through the balloon 5 in an inflated state.

  Next, the configuration of the above-described telescopic support 3 will be described. As shown in FIGS. 1 to 4, the telescopic support column 3 includes a base tube column 20, a first intermediate tube column 21, a second intermediate tube column 22, and a third intermediate tube column 23 made of metal such as aluminum or iron. It has.

  The base tube column 20 is formed in a cylindrical shape, and a base end portion 20a is fixed to the base 2 by welding or the like. A cylindrical first middle tube column 21 having a small inner diameter with respect to the base tube column 20 is loosely fitted in the base tube column 20 so as to be slidable up and down. The first middle tube column 21 protrudes from the distal end portion 20 b of the base tube column 20. A cylindrical second middle tube column 22 having a small inner diameter with respect to the first middle tube column 21 is loosely fitted in the first middle tube column 21 so as to be slidable up and down. The second middle tube column 22 protrudes from the tip 21 b of the first middle tube column 21. A cylindrical third middle tube column 23 having a small inner diameter with respect to the second middle tube column 22 is fitted in the distal end portion 22b in the second middle tube column 22 and fixed by welding or the like. . That is, the first middle tube column 21 has the largest inner diameter among the first to third middle tube columns 21 to 23 loosely fitted to the base tube column 20, and the third middle tube column 23 has the inner diameter. The smallest one. The third middle tube pillar 23 protrudes from the distal end portion 22 b of the second middle tube pillar 22. The third middle tube pillar 23 can be fitted into a mounting hole (not shown) provided in the lower support plate 7 b of the light emitting device 6 of the light emitting unit 4. The light emitting unit 4 is mounted on the third middle tube column 23 so that it is supported by the telescopic column 3 via the third middle tube column 23.

  On the other hand, as shown in FIG. 2, a gas damper 24 as an urging means is provided in the base tube column 20. The gas damper 24 includes a base portion 25. The base 25 is disposed on the upper surface 2 a of the base 2 on the base end 20 a side of the base column 20. A shaft portion 26 is erected on the base portion 25 along the inside of the base tube column 20 and the first and second middle tube columns 21 and 22. A cylinder 27 is fitted to the shaft portion 26 so as to be slidable up and down. While being supported by the shaft portion 26, the cylinder 27 extends upward along the base tube column 20, the first and second middle tube columns 21, 22 by the gas pressure in the cylinder 27. A pedestal 28 is fixed to the base end portion 27 a of the cylinder 27. The pedestal 28 is fixed to the proximal end portion 21 a of the first middle tube column 21. As a result, the first intermediate tube column 21 rises as the cylinder 27 extends.

  An attachment plate 29 is erected on the base 28 along the cylinder 27. A pulley 30 is attached to the upper end portion 29 a of the attachment plate 29. The pulley 30 is in contact with the upper end portion of the cylinder 27. A wire 31 is attached to the pulley 30. One end of the wire 31 is attached to the base end portion 22 a of the second middle tube pillar 22, and the other end is attached to the upper surface 2 a of the base 2. That is, when the cylinder 27 extends, the pulley 30 rises together with the pedestal 28 (first middle tube column 21). Here, the wire 31 pulls the proximal end portion 22 a of the second middle tube column 22 as the pulley 30 moves up. As a result, the second middle tube column 22 extends from the first middle tube column 21. That is, in the telescopic column 3, the first and second middle tube columns 21 and 22 are sequentially expanded from the base tube column 20 as the cylinder 27 is expanded. On the contrary, when the operator pushes the second middle tube column 22 in the direction of the base tube column 20, the first and second middle tube columns 21, 22 are contracted accordingly.

On the other hand, a U-shaped shackle 32 whose base end portion is rotatably supported is provided on the outer peripheral surface 22c of the distal end portion 22b of the second middle tube column 22. The shackle 32 has first and second
When the middle tube columns 21 and 22 are in the contracted state, the first and second middle tube columns 21 and 22 are expanded and contracted by engaging with the hooks 33 provided on the outer peripheral surface 20c of the base tube column 20. Is to regulate. In the gas damper 24 of the present embodiment, the gas pressure as the urging force is such that the cylinder 27, the light emitting unit 4, the first to third middle tube pillars 21 to 23, the base 28, the attachment plate 29, the pulley 30, and the wire 31. It is set to balance the weight. Therefore, when the light emitting unit 4 is mounted on the third middle tube column 23, the height of the light emitting unit 4 can be set by expanding and contracting the first and second middle tube columns 21 and 22 by an operator. The height can be maintained (see FIG. 1).

  As shown in FIGS. 3 and 4, the outer peripheral surface 20 c of the base tube column 20 is provided with a stopper 34 as an extension speed reducing means immediately below the hook 33. The stopper 34 includes a housing 35 as a housing portion formed in the box. The housing 35 is fixed to the outer peripheral surface 20c of the base tube column 20 by welding or the like. A locking hole 36 is formed in the outer peripheral surface 20c of the base tube column 20 as a substantially square opening so as to oppose the housing space 35a of the housing 35. The locking hole 36 is configured to face the inside of the housing 35 by opening the outer peripheral surface 21 c of the first middle tube column 21 through the locking hole 36.

  On both side surfaces of the housing 35, elongated holes 37, 37 are formed as a pair of left and right guide holes, respectively. Both the long holes 37 are formed obliquely so that their upper end portions are separated from the outer peripheral surface 20c of the base tube column 20 and lower end portions thereof are close to the outer peripheral surface 20c, and are opposed to each other. A cylindrical shaft 38 is rotatably inserted into the long holes 37 and 37 as a support shaft. The shaft 38 can move up and down in an oblique direction along the long hole 37. An abutting member, an eccentric cam 39 as a rotating body, and a rotating lever 40 as a moving means are attached to a shaft 38 in the housing 35. The eccentric cam 39 is formed in a disk shape from a flexible member such as rubber, and a shaft 38 is inserted and fixed at a position eccentric from the axis. The eccentric cam 39 is supported by the housing 35 via the shaft 38 and is rotatable. The eccentric cam 39 is brought into contact with or separated from the outer peripheral surface 21c of the first middle tube column 21 through the locking hole 36 of the base tube column 20 according to its rotation. It has become. A rotating lever 40 is attached to the eccentric cam 39. The rotating lever 40 includes a fixed plate 40a and a gripping portion 40b extending from the fixed plate 40a. The fixed plate 40 a is inserted through the shaft 38 and is integrally attached to the eccentric cam 39 via the pin 41. The gripping portion 40b protrudes out of the housing 35 and can be gripped through an outlet 42 formed in the housing 35 by a notch.

  The stopper 34 configured as described above can rotate the eccentric cam 39 by the operator holding the grip portion 40b of the rotation lever 40 and rotating it up and down. As shown in FIG. 3, the eccentric cam 39 separates the contact surface 39 a from the outer peripheral surface 22 c of the second middle tube column 22 when the gripping portion 40 b of the rotation lever 40 is located at the lowermost end. It is supposed to let you. On the contrary, as shown in FIG. 4, when the gripping portion 40 b of the rotation lever 40 is located at the uppermost end, the contact surface 39 a is brought into contact with the outer peripheral surface 22 c of the second middle tube column 22. ing. Furthermore, the abutting surface 39a of the eccentric cam 39 strongly abuts on the outer peripheral surface 22c and bends as the shaft 38 is positioned on the lower end side of the elongated hole 37 and is closer to the outer peripheral surface 22c of the second intermediate tube column 22. It is supposed to be.

Next, the operation of the stopper 34 described above will be described with reference to FIGS.
In the following description, a state in which the light emitting unit 4 is detached from the third middle tube pillar 23 of the telescopic column 3 will be described. As shown in FIG. 3, the shackle 32 of the second middle tube column 22 is engaged with a hook 33 of the base tube column 20 to restrict the extension of the first and second middle tube columns 21 and 22. The gripping portion 40b of the rotation lever 40 of the stopper 34 is located at the lowermost end in the outlet 42, and the eccentric cam 39 is not in contact with the first middle tube column 21.

  First, the gripping portion 40 b is lifted and the shaft 38 is moved to the upper end side of the long hole 37. Further, the gripping portion 40 b is rotated upward, and the contact surface 39 a of the eccentric cam 39 is brought into contact with the outer peripheral surface 21 c of the first middle tube column 21. Thus, the shaft 38 is positioned on the upper end side of the long hole 37. As shown in FIG. 4, when the engagement between the shackle 32 and the hook 33 is released, the first and second intermediate tube pillars 21 and 22 are extended by the bias of the gas damper 24 as described above. At this time, the extension speed of the first intermediate tube column 21 is reduced by friction with the contact surface 39a of the eccentric cam 39, and the second intermediate tube column 22 is extended little by little.

  Further, when the gripping portion 40b is pushed down while the contact state between the contact surface 39a of the eccentric cam 39 and the first middle tube column 21 is maintained, and the shaft 38 is positioned on the lower end side of the long hole 37, The contact surface 39a is bent more closely to the outer peripheral surface 21c of the first middle tube column 21. As a result, the first middle tube column 21 is locked, and accordingly, the second middle tube column 22 is also locked.

  When the light emitting unit 4 is mounted on the third middle tube column 23 from the state where the first and second intermediate tube columns 21 and 22 are locked in this way, the weight of the light emitting unit 4 and the gas damper 24 are set as described above. Balance with gas pressure. Therefore, even if the reduction of the extension speed of the first intermediate tube column 21 by the eccentric cam 39 of the stopper 34 is released from this state, the projector 1 can maintain its height.

As mentioned above, according to this embodiment mentioned above, there exist the following effects.
-In this embodiment, the stopper 34 was provided in the base pipe pillar 20, and the extension speed of the 1st and 2nd middle pipe pillars 21 and 22 was reduced. This can prevent the first and second middle tube pillars 21 and 22 from rapidly expanding when the light emitting unit 4 is detached from the telescopic support column 3 by replacement or the like. Therefore, even when the light emitting unit 4 is replaced from a place where the scaffold is unstable, such as on the ladder, the light emitting unit 4 can be easily replaced. Further, by extending the first and second middle tube columns 21 and 22 little by little by reducing the extension speed by the stopper 34, the light emitting unit 4 can be easily expanded and contracted even when it is detached from the expansion and contraction column 3. The height of the column 3 can be set. Thereby, work such as replacement can be performed efficiently.

  In the present embodiment, the eccentric cam 39 of the stopper 34 is a flexible member such as rubber. As a result, the eccentric cam 39 can be reliably brought into contact with the first intermediate tube column 21 by being bent, so that the extension speed of the first intermediate tube column 21 can be more reliably reduced.

  In the present embodiment, the long hole 37 is formed obliquely with respect to the base tube column 20. Accordingly, by moving the shaft 38 within the long hole 37, the relative distance between the contact surface 39a of the eccentric cam 39 and the first middle tube column 21 is changed, and the degree of contact is easily adjusted. be able to. Furthermore, even when the eccentric cam 39 or the housing 35 is slightly different from the initial design due to manufacturing errors or the like, the relative distance between the abutment surface 39a of the eccentric cam 39 and the first middle tube column 21 is set. By changing, the contact surface 39a can be contact | abutted correctly to the 1st middle pipe column 21. FIG. That is, since the long hole 37 can reduce the influence of manufacturing errors and the like, the manufacturing load of the eccentric cam 39 or the housing 35 can be reduced.

In addition, embodiment of invention is not limited to the said embodiment, You may change as follows.
In the above embodiment, the stopper 34 is embodied as the extension speed reduction means. However, the extension speed reduction means may be appropriately changed as long as the extension speed of the first middle tube column 21 can be reduced. Therefore, for example, a screw hole is formed through the base tube column 20, and a screw member is screwed into this screw hole so as to abut on the outer peripheral surface 21 c of the first intermediate tube column 21. May be reduced. For example, a plate-like contact member is provided in place of the eccentric cam 39, moved by the moving means, and brought into contact with the outer peripheral surface 21c of the first middle tube column 21, thereby reducing the extension speed of the first middle tube column 21. May be.

  As shown in FIG. 5, a box-shaped housing 53 having an opening 51 on the upper surface is provided as an accommodating portion on the outer peripheral surface 20 c of the base tube column 20, and a spring member is provided at the lower right corner in the housing 53. 55 is provided, and the plate member 57 is biased and supported by the spring member 55 to constitute a moving means. When the ball 59 as the contact member is pushed from the opening 51, the ball 59 is urged by the spring member 55 through the plate member 57, and the outer periphery of the first intermediate tube column 21 through the locking hole 36. You may make it contact | abut to the surface 21c and reduce the expansion | extension speed | velocity | rate of the 1st middle pipe column 21. FIG. In this case, when releasing the reduction in the extension speed, the string 61 as the moving means attached to the ball 59 is pulled up so as to be separated from the first middle tube column 21 and released. Good.

Further, as shown in FIG. 6, a rack gear 71 is provided on the outer peripheral surface 21 c of the first intermediate tube column 21, and a pinion gear 73 that meshes with the rack gear 71 is used as a housing portion provided on the outer peripheral surface 20 c of the base tube column 20. The housing 75 is rotatably mounted via a shaft 77. Then, a known transmission (not shown) is connected to the pinion gear 73 and its rotational speed is controlled, so that the rack gear 71, the pinion gear 73 and the shaft 77 constitute an extension speed reducing means, and the extension speed of the first intermediate tube column 21 is increased. May be reduced.
In the above embodiment, the first and second middle tube columns 21 and 22 are loosely fitted to the base tube column 20, but the number of middle tube columns may be changed as appropriate. Therefore, for example, only the first middle tube column 21 may be provided, or four or more middle tube columns may be provided. In the case of only the first middle tube column 21, the first middle tube column 21 corresponds to the middle tube column having the largest inner diameter and the smallest middle tube column described in claim 1.
In the above embodiment, the shaft 38 is configured to be movable through the long hole 37. However, when the housing 35 is assembled, the long hole 37 is set after setting the relative distance between the eccentric cam 39 and the first middle tube column 21. May be fixed against. At this time, the degree of contact of the eccentric cam 39 with the first middle tube column 21 may be changed as appropriate.
In the above embodiment, the urging means is specified as the gas damper 24, but may be realized as other urging means such as a coil spring.
In the above embodiment, the gas pressure of the gas damper 24 as the urging force is applied to the cylinder 27, the light emitting unit 4, the first to third middle tube pillars 21 to 23, the base 28, the attachment plate 29, the pulley 30, and the wire 31. Although it set so that it may balance with weight, it may not be restricted to this but may be set larger than the load by these weights.
In the above embodiment, the eccentric cam 39 is made of a flexible member such as rubber. However, the eccentric cam 39 is not limited to this, and may be appropriately changed as long as the extension speed of the first middle tube column 21 can be reduced. Therefore, for example, you may comprise from a metal, wood, a synthetic resin, etc.
In the above embodiment, the shaft 38 is inserted at a position eccentric from the axis of the eccentric cam 39, but the shaft 38 may be inserted through the axis of the eccentric cam 39.
-In above-mentioned embodiment, although the expansion-contraction support | pillar 3 was comprised from the metal, you may comprise from a metal, wood, a synthetic resin etc., for example.
In the above embodiment, the telescopic support column 3 is used for the projector 1, but it may be used for any column as long as the mounted object is mounted. Therefore, you may employ | adopt for the support | pillar which mounts postings, such as a signboard, so that attachment or detachment is possible.

The front view explaining the structure of the projector of this embodiment. Sectional drawing explaining the structure of the expansion-contraction support | pillar of the projector. Sectional drawing explaining the effect | action of the expansion-contraction support | pillar of the projector. Sectional drawing explaining the effect | action of the expansion-contraction support | pillar of the projector. Sectional drawing explaining the example of a change of an expansion-contraction support | pillar. Sectional drawing explaining the example of a change of an expansion-contraction support | pillar.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Light projector, 3 ... Telescopic support | pillar, 4 ... Light-emitting part as a mounting thing, 20 ... Base pipe pillar, 20c ... Outer peripheral surface of a base pipe pillar 21, 22, 23 ... 1st-1st as a middle pipe pillar 3. Middle pipe column, 24 ... Gas damper as urging means, 34 ... Stopper as extension speed reducing means, 35 ... Housing as housing part, 36 ... Locking hole as opening part, 37 ... Elongate hole as guide hole , 38... Shaft as support shaft, 39... Eccentric cam as contact member and rotating body, 40... Rotating lever as moving means, 53... Housing as accommodating portion, 55. 57 ... Plate member constituting moving means, 59 ... Ball as abutting member, 61 ... String constituting moving means, 71 ... Rack gear constituting extension speed reducing means, 73 ... Pinion gear constituting extension speed reducing means, 75. Housing formed, 77 ... shaft constituting the extension rate reducing means.

Claims (4)

A base tube column, and at least one middle tube column having an inner diameter successively reduced in the inside of the same tube column, and a mounted object is detachably mounted on the inner tube column having the smallest inner diameter, In the telescopic strut in which at least the largest inner diameter of the inner tube pillars can be vertically expanded and contracted by loosely fitting the inner tube pillars in the base tube columns, and the intermediate tube columns are urged in the extension direction by the urging means. ,
While setting the urging force of the urging means to be substantially the same as the weight of the middle tube column and the load,
An expansion / contraction column, wherein the base column is provided with an extension rate reduction means for reducing an extension rate by contacting at least the inner tube column having the largest inner diameter when the mounted object is detached. The telescopic strut according to claim 1,
The base tube column includes an open portion that opens at least an inner tube column having a maximum inner diameter among the intermediate tube columns to be loosely fitted on the outer peripheral surface of the base tube column,
The extension speed reducing means includes an abutting member facing the middle pipe column via the opening portion,
Moving means for moving the abutting member to abut or separate from the middle tube column;
The abutment member is brought into contact with the middle tube column by the moving means to reduce the extension speed of the middle tube column, and the extension speed is reduced by separating the contact member from the middle tube column. Telescopic strut characterized by releasing the. The telescopic strut according to claim 2,
The extension speed reducing means includes an accommodating portion for accommodating the contact member on the outer peripheral surface side of the base tube column,
The contact member is a rotating body that is rotatably supported by a support shaft provided in the housing portion,
The said accommodating part was equipped with the guide hole which guides the said support shaft and changes the relative distance of the support shaft and the said outer peripheral surface, The expansion-contraction support | pillar characterized by the above-mentioned. In the floodlight equipped with a telescopic support column, which is set by expanding and contracting the height of the light emitting unit that emits light by the supplied driving power, and setting the illumination range of the light emitting unit,
The said expansion-contraction support | pillar is an expansion-contraction support | pillar as described in any one of Claims 1-3, Comprising: The said light emission part is detachably mounted as a mounting thing, The projector characterized by the above-mentioned.

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