JPH07101077B2 - Screw type telescopic multi-stage rod mechanism - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a stand of an illuminating light, a support of a baggage elevator, etc., and expands and contracts the entire length by stacking a plurality of cylindrical rods and changing the relative position of each rod in the axial direction. The present invention relates to a telescopic multistage rod mechanism.

[0002]

2. Description of the Related Art As a conventional multi-stage rod that expands and contracts its entire length by changing the relative position of each rod of the multi-stage rod, there is a multi-stage hydraulic cylinder that sequentially expands and contracts each rod by utilizing hydraulic pressure or water pressure. This hydraulic multi-stage cylinder is a mechanism that is provided with a sequence circuit, and the hydraulic fluid is pumped into the hydraulic chamber of each rod by this sequence circuit, whereby the rods are sequentially extended or contracted. In addition, a ram type multi-stage cylinder is used as a telescopic support for the photographing lighting stand.

[0003]

However, the conventional hydraulic multi-stage cylinder has a complicated structure because a pump for pumping the hydraulic fluid, a sequence circuit including a large number of valves and a large number of flow paths are indispensable. I will end up. In addition, it is difficult to reliably prevent the leakage of the hydraulic fluid that is pumped for a long period of time, which is troublesome for maintenance and inspection, and it is difficult to eliminate the trouble that the hydraulic fluid leaks. For this reason, there is a risk of leakage of hydraulic fluid in a lighting stand for photography, etc. Further, since the structure is complicated, the hydraulic multistage cylinder has not been used. When the ram type multi-stage cylinder is used as a column, it does not descend when the load is small, or the descending speed is extremely slow. Therefore, an object of the present invention is to provide an expandable multi-stage rod mechanism that has a simple structure and is free from the risk of hydraulic fluid leakage.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been proposed to achieve the above-mentioned object, and is a cylindrical body having a rod insertion opening at one end and a male screw portion on the outer peripheral surface. A shaft that is rotatably inserted in the central portion of the outer casing, a first female screw member having a female screw portion that is screwed onto the shaft formed on the inner peripheral surface of the through hole, and a casing. A cylindrical body inserted into the first end, the first end being joined to the first female screw member in a state in which it cannot be displaced in the circumferential direction, and the other end protruding outward from the insertion opening of the casing.
A rod and a tubular body into which a shaft can be inserted inside the hollow. The hollow inside is movable in the axial direction by engaging with a rotary engaging portion provided on the shaft, but is not displaceable in the circumferential direction. A second female screw member in which a male-shaped tube having a shape-shaped receiving and engaging portion and a male screw portion formed on the outer peripheral surface and a female screw portion screwed to the male screw tube are formed on the inner peripheral surface of the through hole. And the first
It is a cylindrical body inserted inside the rod and has one end
A second rod, which is joined to the female screw member in a state in which it cannot be displaced in the circumferential direction, and has the other end protruding outward from the rod insertion opening of the casing.

[0005]

When the shaft is rotated by the operation of the motor, the first female screw member moves, whereby the first rod joined to the first female screw member moves, and the protruding length from the rod insertion opening of the casing is reduced. extend. Further, when the shaft rotates, the male screw tube rotates in the same direction as the shaft due to the engagement of the rotary engaging portion of the shaft and the receiving engaging portion of the male screw tube, so that the second female screw member moves, As a result, the second rod joined to the second female screw member moves to extend the external protruding length. Therefore, when the shaft is rotated in one direction, the entire length of the rod is extended. Further, when the shaft is rotated in the reverse direction, the moving directions of the first female screw member and the second female screw member are opposite, so that the external protruding lengths of the first rod and the second rod are shortened and the overall length is shortened.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. In the embodiment shown in FIGS. 1 to 3, the telescopic multi-stage rod mechanism is used as a column 1 of a stand for photographing illumination, in which 2 is an illuminating device and 3 is a bracket 4 of the column 1.
The legs 5 pivotally attached to the arm 5 are arms that hold the leg 3 in an open state. The leg 3 can be extended and opened as shown by the solid line in FIG. 2, or can be contracted to a state along the column 1 as shown by the chain double-dashed line. The arm 5 rotates about the shaft attachment portion on the support 1 side.

The telescopic multistage rod mechanism functioning as the support column 1 has a cylindrical casing 6, a motor 7 and a speed reducer 8 as a driving source attached to the lower end of the casing 6, and a shaft 9 inserted in the central portion of the casing 6. A first female screw member 10 that is screwed onto the shaft 9, a first rod 11 that is inserted inside the casing 6 and that expands and contracts by the movement of the first female screw member 10, a male screw tube 12 that rotates with the shaft 9, The second female screw member 13 screwed into the male screw tube 12 is inserted into the inside of the first rod 11,
The second rod 14 is configured to expand and contract due to the movement of the female screw member 13, and the tip (upper end) of the second rod 14 is formed.
Is provided with a seat 15 to which the lighting device 2 is attached.

The casing 6 is a metal cylinder having a substantially square cross section, and is provided with a rod insertion opening 16 having a shape and size through which the first rod 11 just penetrates at one end (upper end) and the other end (lower end). The opening is closed by attaching a reducer casing. In this embodiment, a hypoid gear is used for the speed reducer so that a large reduction ratio can be obtained with a small number of stages, but a worm wheel and a worm gear may be used. Further, the output shaft of the speed reducer may be extended with a shaft 9 to be described later and may also be used.

The shaft 9 has a male screw portion 17 formed on the outer peripheral surface excluding a portion serving as a shaft on the speed reducer side and a tip portion,
A plastic damper ring 18 is fitted to the circular small-diameter portion of the tip portion, and the core 1 is fitted to the rectangular cross-section portion at the tip of the small-diameter portion.
9 is attached to the shaft 9 in a non-rotating state.

The core 19 functions as a rotary engaging portion, and in this embodiment, it is a MC nylon ring having a substantially square outer shape, and the central opening is almost fixed to the shaft in a non-rotatable manner. It is molded into a square.
The material of the core 19 can be appropriately selected and may be made of metal.

The first female screw member 10 is a member made of MC nylon in which a female screw portion 20 to be screwed onto the shaft 9 is formed on the inner peripheral surface of the through hole. Forming a first flange 21 having a substantially square outer shape that presses the end portion of the first rod 11, and forming a concave portion 22 having a circular cross-section into which the end portion of the male screw tube 12 fits, on the tip surface. Bearing members 23 having a coefficient of friction are provided on the inner peripheral surface and the bottom surface of the portion 22.

The first rod 11 that fits at one end (lower end) of the first female screw member 10 and moves integrally with the first female screw member 10 is a metal cylinder body having a substantially square cross section. , The opening at one end (lower end) is fitted to the rectangular outer shape portion of the first female screw member 10 and joined in a state in which it cannot be displaced in the circumferential direction,
The other end is projected from the insertion opening 16 of the casing 6 to the outside. As described above, the first rod 11 is connected to the first female screw member 10
The first rod portion 11 of the first female screw member 10 is joined to the first female screw member 10 in a non-displaceable manner in the circumferential direction, and the first flange portion 21 of the first female screw member 10 is substantially square. Can only move axially with. Since the first female screw member 10 is screwed onto the shaft 9, the first female screw member 10 moves in the axial direction when the shaft 9 rotates, and this movement causes the first rod 11 to move relative to the casing 6. The length of the casing 6 protruding from the rod insertion opening 16 can be changed. A rod insertion opening member 24 having a shape and size through which the second rod 14 just penetrates is attached to the opening of the protruding end of the first rod 11.

Next, the male screw tube 12 and the second female screw member 13 for expanding and contracting the second rod 14 will be described. The male screw tube 12 is a cylindrical body into which the shaft 9 can be inserted, and the inside of the hollow tube is engaged with a core 19 provided at the tip of the shaft 9 and is movable in the axial direction. Is formed in a substantially square cross-section as a receiving and engaging portion 25 that is not displaceable in the direction, and has a male screw portion 26 formed on the outer peripheral surface thereof. A circular shake prevention plate 27 for preventing shake of the shaft 9 is fixed by a bolt, and at the other end, a circular flange 28 which is fitted into the recess 22 of the first female screw member 10 and is rotatable. Has been formed.

The second female screw member 13 is a male screw tube 1
It is a member made of MC nylon in which a female screw portion 29 that is screwed into the male screw portion 26 of the second rod is formed on the inner peripheral surface of the through hole, and the end portion of the outer shape portion formed to have a substantially square cross section has the second rod 14 A second flange portion 30 having a substantially square outer shape that presses the end portion is formed.

The second rod 14 which fits at one end (lower end) of the second female screw member 13 and moves integrally with the second female screw member 13 is a metal cylinder having a substantially square cross section. , The opening at one end (lower end) is fitted to the rectangular outer shape portion of the second female screw member 13 and joined in a state in which it cannot be displaced in the circumferential direction,
The other end is projected outside from the rectangular hole of the rod insertion opening 16 of the first rod 11, and the seat 15 is fixed to the protruding tip.

As described above, the second rod 14 is joined to the second female screw member 13 in a state in which it cannot be displaced in the circumferential direction, and the second flange portion 30 of the second female screw member 13 is substantially formed. Since it is a square, the second rod 14 can only move axially with the second female screw member 13 in the hollow portion of the first rod 11. Then, since the second female screw member 13 is screwed into the male screw tube 12, when the male screw tube 12 rotates, the second female screw member 13 moves in the axial direction, and this movement causes the second rod 14 to move. By moving relative to the first rod 11, the length of the first rod 11 protruding from the rod insertion opening 16 can be changed.

The male screw portion and the female screw portion are all formed in the same direction. That is, it is unified with the right-hand screw or the left-hand screw.

Next, the expansion and contraction operation of the support column 1 having the above-mentioned structure will be described. The state shown in FIG. 3 is the first rod 1
This is a state in which the first and second rods 14 are contracted to have the shortest overall length. When the shaft 7 is rotated in the forward direction by operating the motor 7 in this state, the first female screw member 10
Since the casing 6 is prevented from rotating, the female screw member 10 moves, that is, rises in accordance with the rotation of the shaft 9 by screwing the male screw portion 17 and the female screw portion 20.

When the first female screw member 10 rises in this way, the first rod 11 supported with the lower end fitted to the first female screw member 10 rises together with the first female screw member 10. The length of the casing 6 protruding from the upper end is extended, and the lower end of the male screw tube 12 rotatably fitted in the recess 22 of the first female screw member 10 is supported by the first female screw. It rises with the member 10.

The male screw tube 12 has a substantially square core 19 fitted inside a substantially square hollow. Therefore, the male screw tube 12 moves (raises) in the axial direction as the first female screw member 10 rises. It does not cause any problems. Also, the core 19 is the shaft 9
Since it rotates integrally with the male screw tube 12, the male screw tube 12 also rotates through the rotating core 19. Therefore, the male screw tube 12 rotates at the same speed as the shaft 9 while rising.

When the male screw tube 12 rotates, the second female screw member 13 is prevented from rotating by the first rod 11. Therefore, the male screw portion 26 and the female screw portion 29 are screwed to each other so that the second female screw member 13 is screwed. The member 13 relatively moves in the axial direction of the male screw tube 12 according to the rotation of the male screw tube 12.

When the second female screw member 13 moves relative to the male screw tube 12 in this manner, the lower end is moved to the second
The second rod 14 fitted and supported by the female screw member 13 moves (raises) together with the second female screw member 13. As described above, since the first rod 11 and the male screw tube 12 are moving upward, the second rod 14 moves up at a speed that is added to the moving speed of the first rod 11, and the second rod 14 becomes the first rod. The part protruding from the upper end of 11 is extended.

When the shaft 9 is rotated in this manner, the first
As the rod 11 extends, the second rod 14 also extends with respect to the first rod 11, and the overall length of the support column 1 extends. When the first rod 11 and the second rod 14 are sufficiently extended, the first female screw member 10 comes into contact with the damper 18 in front of the core 19 and stops, and the second female screw member 13 also prevents the shake preventing plate 27. It comes into contact with the front damper 31 and stops. Therefore, the pillar 1 becomes the longest in this state. It should be noted that a detector (not shown) is provided shortly before the first female screw member 10 or the second female screw member 13 reaches the top dead center, and the operation of the motor 7 is stopped by a signal from this detector. It may be configured so as to allow it.

Next, the operation for shortening the length of the column 1 will be briefly described. For example, when the motor 7 is operated and the shaft 9 is rotated in the reverse direction in the longest state described above, the rotation of the first female screw member 10 is blocked by the casing 6, so that the male screw portion and the female screw portion are screwed together. By the combination, the female screw member 10 moves, that is, descends in accordance with the reverse rotation of the shaft 9.

When the first female screw member 10 descends in this way, the first rod 11 descends together with the first female screw member 10 to reduce the length protruding from the upper end of the casing 6, and the circular shape at the lower end. The male screw tube 12 whose flange portion 28 is locked to the bearing member 23 of the first female screw member 10 also descends together with the first female screw member 10.

When the male screw tube 12 descends while receiving the reverse rotation of the shaft 9 through the core 19 and reversely rotating,
The second female screw member 13 screwed onto the male screw tube 12 moves, that is, descends, relative to the male screw tube 12. Therefore, the second rod 14 whose lower end is supported by the second female screw member 13 also descends together with the second female screw member 13.

As described above, when the shaft 9 is rotated in the reverse direction, the first rod 11 is contracted, and the second rod 14 is also contracted with respect to the first rod 11, so that the overall length of the column 1 is shortened. Then, when the first rod 11 and the second rod 14 are sufficiently contracted, the first female screw member 10 comes into contact with the damper 32 at the lower end of the casing to stop, and the second female screw member 13 is the first female screw member. It contacts the damper 33 on 10 and stops. Therefore, this state is the minimum length of the column 1. The first female screw member 10 or the second female screw member 1
A detector (not shown) may be provided shortly before the point 3 reaches the bottom dead center, and the operation of the motor 7 may be automatically stopped by a signal from this detector.

In the above-described embodiment, the casing 6, the first rod 11 and the second rod 14 are made of square pipe material, and the first female screw member 10 and the second female screw member 13 fitted to them are substantially square. However, in the present invention, any shape may be used as long as it cannot be displaced in the circumferential direction. For example, it may have a polygonal shape such as a hexagonal cross-section, or may have a circular cross-sectional shape and may not be displaceable in the circumferential direction by the engagement of the projection and the groove.

Further, the rotary engaging portion of the shaft 9 and the receiving engaging portion of the male screw tube 12 are not limited to the above-mentioned substantially square section, but can be moved in the axial direction and cannot be displaced in the circumferential direction. Any shape may be used. For example, it may have a polygonal shape such as a hexagonal cross-section, or may have a circular cross-sectional shape or may be immovable in the circumferential direction by engaging a projection and a groove by forming a spline.

Although the multistage rod mechanism is used for the column 1 of the stand for the illumination device in the above-mentioned embodiment, the application of the multistage rod mechanism according to the present invention is not limited to this. For example, it may be used as a telescopic support of an elevator for lifting and lowering luggage.

Further, the present invention can be appropriately modified in design as long as it has the structure described in the claims.
For example, a second male screw tube is provided outside the male screw tube 12, and the second male screw tube 12 is provided with a third male screw tube.
The third screwed female screw member is inserted inside the second rod.
The number of rods can be further increased by, for example, joining the lower end of the rod to the third female screw member.

[0032]

As described above, according to the present invention, since the structure is extremely simple, the manufacturing is easy. Further, since the screw mechanism is used for the whole without utilizing hydraulic pressure such as hydraulic pressure or water pressure, there is no possibility of polluting the surroundings due to leakage of hydraulic fluid, and maintenance is almost unnecessary. Therefore,
There is almost no limit to its use, and it has high utility value as a general-purpose telescopic rod.

[Brief description of drawings]

FIG. 1 is a front view showing a state in which a rod of an illumination stand having a multi-stage rod mechanism of the present invention as a support column is extended.

FIG. 2 is a front view of the lighting stand with the rod retracted.

FIG. 3 is a front view showing a cross section of the left half when the support column is contracted.

FIG. 4A is a left side view of the first female screw member, and FIG. 4B is a front view of the first female screw member with the upper half being a cross section.

5A is a left side view of the first rod, FIG. 5B is a sectional view, and FIG. 5C is a right side view.

FIG. 6A is a side view of the core, and FIG. 6B is a sectional view of the core.

7A is a left side view of the male screw tube, FIG. 7B is a sectional view, and FIG. 7C is a right side view.

FIG. 8A is a left side view of the second female screw member, and FIG. 8B is a front view of the upper half in section.

9A is a left side view of the second rod, FIG. 9B is a sectional view, and FIG. 9C is a right side view.

[Explanation of symbols]

1 Strut composed of a screw type expandable multi-stage rod mechanism according to the present invention 2 Lighting device 6 Casing 7 Motor as drive source 9 Shaft 10 First female screw member 11 First rod 12 Male screw tube 13 Second female screw member 14 Second Rod 16 Rod insertion opening 17 Male screw part 19 Core 20 Female screw part 25 Receiving engagement 26 Male screw part 29 Female screw part

Claims (2)

[Claims] 1. A casing, which is a tubular body and has a rod insertion opening at one end, and a male screw portion on an outer peripheral surface, and a shaft rotatably inserted in a central portion of the casing. A first female screw member having a female screw portion formed on the inner peripheral surface of the through hole to be screwed into the shaft; and a cylindrical body inserted into the casing, one end of which is the first
A first rod that is joined to a female screw member in a state in which it cannot be displaced in the circumferential direction, and the other end of which protrudes from the insertion opening of the casing to the outside; and a hollow cylindrical body into which a shaft can be inserted Inside, a receiving and engaging portion having a shape that is movable in the axial direction by engaging with a rotary engaging portion provided on the shaft but is not displaceable in the circumferential direction is formed, and a male screw portion is formed on the outer peripheral surface. A male threaded tube, a second female threaded member having a female threaded portion to be screwed into the male threaded tube formed on the inner peripheral surface of the through hole, and a tubular body inserted inside the first rod, And a second rod in which the other end is joined to the second female screw member in a state in which it cannot be displaced in the circumferential direction, and the other end is projected outside from the rod insertion opening of the casing. Rod mechanism. 2. The rotary engaging portion of the shaft is formed in a polygonal shape, and the receiving and engaging portion of the male screw tube is formed in a polygonal shape that fits into the polygonal shape. Item 1. A screw-type telescopic multistage rod mechanism according to Item 1.