JP2013145042A - Clamper and expansion and contraction mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clamper and an expansion and contraction mechanism, which can perform easily and definitely clamping and unclamping between an inner member and an outer member.SOLUTION: The clamper includes: a pair of clamp mechanisms which are inserted between an outer member and an inner member mounted to be linearly put in and out to the outer member, and are each configured to prohibit one relative movement in one direction among two directions of the inner member coming out and going into the outer member, while allowing the relative movement in the other direction, wherein their directions of prohibiting relative movements are opposite to each other; and a unclamp mechanism for invalidating the mechanism of prohibiting the relative movement of the inner member to the outer member of the pair of the clamp mechanisms and allowing the relative movement of the inner member to the outer member.

Description

  The present invention relates to a clamper and an expansion / contraction mechanism that clamp an expansion / contraction portion of an expansion / contraction mechanism such as a drip stand, a microphone stand, or a support of a camera stand so that the length can be adjusted as necessary.

The conventional expansion / contraction mechanism such as a drip stand is such that the inner member is relatively linearly inserted into the receiving hole from the linearly extending outer member insertion port, and the inner member is tightened to the outer member insertion port. A member is provided to allow length adjustment.
However, the conventional fastening member is generally a screw type, and it is necessary to rotate the fastening member one by one when adjusting the length, which is troublesome. In particular, if the tightening member is loosened, the inner member falls into the outer member by its own weight, so it is necessary to operate the tightening member with the other hand while holding the inner member with one hand. I will not be overwhelmed.
Even if the tightening member is tightened, it is unclear whether the inner member has been securely fixed.If the tightening is loose, it is necessary to retighten. It will take time to relax.
In addition, as a structure of such an extendable drip stand, it describes in patent documents 1, 2, etc., for example.

JP 2001-289208 A Utility Model Registration No. 3094782

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a clamper that can easily and reliably perform clamping and unclamping operations between the inner member and the outer member. And providing a telescopic mechanism.

In order to achieve the above object, the present invention is a clamper that is attached to an expansion / contraction mechanism including a cylindrical outer member and an inner member that is linearly assembled into the outer member.
A clamp mechanism that is disposed inside the outer member and prevents relative movement in one direction and allows relative movement in the other direction among the two directions of the inner member projecting and immersing in the outer member. When,
And an unclamp mechanism that disables the function of the clamp mechanism to prevent the inner member from moving relative to the outer member and enables the inner member to move relative to the outer member.
The clamp mechanism may be provided with a pair of clamp mechanisms whose directions to prevent relative movement are opposite to each other.
The clamp mechanism includes a wedge-shaped space forming portion that forms a wedge-shaped space whose interval gradually decreases along the axial direction between the outer member and the inner member, and the relative movement of the outer member and the inner member. And a rolling element that advances and retreats relative to the wedge-shaped space, and the relative movement of the outer member and the inner member in the direction in which the rolling element bites into the wedge-shaped space is prevented, and the rolling element is wedge-shaped. The outer member and the inner member may be allowed to move relative to each other in the direction of exiting the space.
The clamp mechanism includes a guide portion provided on the inner member, a retainer that holds a rolling element fixed to the guide member so as not to move in the axial direction, and a wedge-shaped space that is mounted on the guide portion so as to be movable in the axial direction. A tapered core having a tapered surface as a part, and a biasing member that biases the tapered surface of the tapered core toward the rolling element held by the retainer,
The rolling element is a tapered surface of the tapered core formed by a biasing force of a biasing member that forms a wedge-shaped space between the tapered surface formed on the tapered core and the inner peripheral surface of the outer member. And it can be set as the structure press-contacted to the internal peripheral surface of an outer member.
The unclamp mechanism is supported by the guide member so as to be linearly movable, and the unclamp member capable of moving the tapered core against the urging force of the spring by linear movement, and the inner exposed to the outside of the outer member. It can be set as the structure provided with the unclamp knob which can be operated linearly provided in the exposed part of a member, and the connection member which connects this unclamp knob and the said unclamp member.
The unclamp mechanism is rotatably supported by the guide member, and is exposed to the outside of the outer member, and an unclamp member capable of moving the taper core against the biasing force of the spring by rotation. A linearly operable unclamping knob provided at an exposed portion of the inner member to be moved, and a motion conversion mechanism for converting a linear motion of the unclamping knob into a rotational motion of the unclamping member. it can.
The expansion / contraction mechanism of the present invention is configured to include the clamper.
In addition, an air damper cap is attached to the insertion hole of the inner member in the outer member, and the air damper cap increases the sliding surface pressure with respect to the inner member in response to a rise in pressure inside the outer member when the inner member contracts. It can be set as the structure provided with the sliding piece.

According to the present invention, since the clamper is incorporated in the outer member, the structure can be simplified.
In addition, as the clamping mechanism is configured so that the rolling elements bite into the wedge-shaped space, the wedge action can increase the frictional force at the time of clamping. It can be clamped securely.
Furthermore, if a taper core is used as the wedge-shaped space forming portion, the rolling element can be bitten and released in the rolling direction, and clamping and unclamping operations are ensured.
In addition, if the unclamp mechanism includes a unclamping knob that moves linearly and a connecting member that connects the unclamping members that move linearly, the inner member can be inserted and removed while operating the unclamping knob with one hand. The length can be adjusted.
In addition, as an unclamping mechanism, even if a motion conversion mechanism that converts linear motion into rotational motion is provided by an unclamping knob that moves linearly, the length of the inner member can be adjusted by operating the unclamping knob with one hand. Can be adjusted. Further, even when a pair of clamp mechanisms is provided, both clamp mechanisms can be unclamped simultaneously.
Further, if an air damper cap is attached to the outer member of the telescopic mechanism, the inner member can be prevented from inadvertently dropping during unclamping.

FIG. 1 shows a telescopic pipe provided with a clamper according to Embodiment 1 of the present invention. (A) is a schematic front sectional view, (B) is a schematic side sectional view, and (C) is an enlarged view of the vicinity of a rolling element. It is sectional drawing. 2A and 2B show an expandable pipe provided with a clamper according to Embodiment 2 of the present invention, in which FIG. 2A is a schematic front sectional view, and FIG. 2B is a schematic side sectional view. 3A is a view showing the unclamped state of FIG. 2A, and FIG. 3B is a cross-sectional view in the direction orthogonal to the guide shaft of the unclamp ring portion. 4A and 4B show the configuration of the main part of an expandable pipe provided with a clamper according to Embodiment 3 of the present invention. FIG. 4A is a schematic front sectional view, FIG. 4B is a schematic side sectional view, and FIG. It is sectional drawing which shows a clamp state.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
[Embodiment 1]
FIG. 1 shows an expandable pipe provided with a clamper according to Embodiment 1 of the present invention.
That is, the expansion / contraction mechanism 100 is used for a drip stand support, and includes a hollow cylindrical base pipe 102 as an outer member, and a hollow cylinder that is assembled so that it can be linearly inserted into and removed from the hollow storage hole of the base pipe 102. And a telescopic pipe 104 as an inner member. Note that in FIG. 1B, an example of a column base is shown by a two-dot chain line.

  The clamper 1 is disposed inside the base pipe 102, and prevents relative movement in one direction out of two directions, ie, a direction in which the telescopic pipe 104 protrudes and a direction in which the base pipe 102 protrudes, and relative movement in the other direction. And a pair of clamping mechanisms 10A and 10B that are allowed, and an unclamping mechanism 20 that enables the inner type 104 to move relative to the base pipe 102 by disabling the function of preventing the relative movement of the pair of clamping mechanisms 10A and 10B. It is equipped with.

The pair of clamp mechanisms 10 </ b> A and 10 </ b> B are arranged in series adjacent to each other in directions that prevent relative movement from each other, and are assembled to an assembly guide 30 as a guide portion provided at the shaft end of the telescopic pipe 104. ing.
In the illustrated example, one clamp mechanism 10A (upper side in the figure) prevents movement of the expansion pipe 104 in the contraction direction so as to be immersed in the base pipe 102, and the other clamp mechanism 10B has the expansion pipe 104 connected to the base pipe 102. The movement in the extending direction protruding from the head is prevented. The configuration is the same except that the direction for preventing the relative movement is the reverse direction, and the same components are denoted by the same reference numerals.

The clamp mechanisms 10A and 10B are both a rolling element 12, a cylindrical retainer 14 for holding the rolling element 12, and a tapered core as a wedge-shaped space forming portion inserted between the inner periphery of the retainer 14 and the guide member. 16, the retainer 14 of one clamp mechanism 10 </ b> A is disposed on the inlet side of the base pipe 102, and the tapered core 16 is disposed on the opposite side of the base pipe 102. In addition, the retainer 14 of the other clamp mechanism 10B is disposed on the opposite side of the base pipe 102, and the tapered core 16 is disposed on the inlet side of the base pipe 102. That is, the relationship between the clamp mechanisms 10A and 10B is a relationship in which the taper cores 16 and 16 are arranged to face each other in the axial direction, and the retainers 14 are arranged on the opposite sides with respect to the taper cores 16 and 16. ing.

The assembly guide 30 to which the clamp mechanisms 10 </ b> A and 10 </ b> B are assembled has a cylindrical first fixing ring 34 fitted and fixed to the inner periphery of the insertion end of the expansion pipe 104, and one end fitted to the inner periphery of the first fixing ring 34. A cylindrical guide shaft 32 and a second fixing ring 36 fixed to the end surface of the guide shaft 32 opposite to the telescopic pipe 104.
Both the first fixing ring 34 and the second fixing ring 36 have a cylindrical shape with the same inner and outer diameters, and the length of the first fixing ring 34 fits with the expansion pipe 104 more than the second fixing ring 36. It is longer by the generation.

In the first fixing ring 34, the expansion pipe 104, the first fixing ring 34, and the guide shaft 32 are integrally screwed from the outer periphery of the expansion pipe 104 by a fixing screw 37. The ring end portion 34a is exposed from one end of the telescopic pipe 32, and one end of the retainer 14 of one clamp mechanism 10A is engaged with the ring end portion 34a. On the inner peripheral surface of the end portion of the retainer 14, an engagement step portion 14 a is provided that engages with an outer diameter side corner portion of the ring end portion 34 a.
The second fixing ring 36 has a washer shape, and is fastened and fixed by a fixing screw 38 to a screw hole 32 b that opens in the axial direction on the end surface of the guide shaft 32. One end of the retainer 14 of the clamp mechanism 10B is engaged with the ring end 36a of the second fixing ring 36. The inner peripheral surface of the end portion of the retainer 14 is also an engagement step portion 14a with which a corner portion of the outer diameter end of the ring end portion 36a is engaged.

A spacer collar 39 is interposed between the opposing surfaces of the retainers 14 and 14 of the pair of clamp mechanisms 10B and 10A. The spacer collar 39 has a thin cylindrical shape. Engagement step portions 14b and 14b with which both ends of the spacer collar 39 are engaged are provided on the outer periphery of the opposite end portions of the retainers 14 and 14. Accordingly, the retainers 14 and 14 are sandwiched in the axial direction by the first fixing ring 34 and the second fixing ring 36 while being held at a constant distance by the spacer collar 39 and are fastened and fixed by the fixing screw 38. .
The assembly guide 30 is not limited to the above-described structure. For example, the first fixing ring 34 and the guide shaft 32 may be integrated, or have various shapes and structures as necessary. It is possible.

A plurality of rolling elements 12 are provided in the circumferential direction, and the retainer 14 is provided with a holding hole 14c corresponding to the rolling element, and is movable in the radial direction through the holding hole 14c.
The tapered core 16 has a shape in which the outer peripheral surface is provided with a tapered surface portion 16a that gradually decreases in the axial direction from the large-diameter end portion 16b on one axial side, and the inner peripheral surface slides on the outer peripheral surface of the guide shaft 32. It is a cylindrical surface that fits freely.
The retainers 14 and 14 of the left and right clamp mechanisms 10A and 10B are arranged so that the small diameter ends of the tapered cores 16 and 16 face each other.
And between the opposing surface of the 1st fixing ring 34 of one clamp mechanism 10A and the large diameter end side end surface of the taper core 16, the 2nd fixing ring 36 of the other clamp mechanism 10 and the large diameter end side end surface of the taper core 16 Springs 18 and 18 are inserted in a compressed state between the surfaces facing each other to form a wedge-shaped space between the tapered surfaces 16 a and 16 a of the tapered cores 16 and 16 and the inner peripheral surface of the cylindrical base pipe 102. It is supposed to be.

As the rolling element 12, a good roller is used as shown in an enlarged view in FIG.
The good roller has a cross-sectional shape cut along a plane passing through the central axis, and a cross-sectional shape cut along a plane passing through the central axis of the central concave surface 121 and the central concave surface 121. Has an arcuate and convex end convex surface portion 122.
The end convex surface portion 122 is in line contact with the inner peripheral surface of the base pipe 102, and the central concave surface portion 121 is in line contact with the tapered surface portion 16 a of the tapered core 16 so as to be freely rollable.
Thus, if a good roller is used as the rolling element 12, the contact area is increased and the contact area is increased, so that the friction torque is increased and the gripping force can be increased.
Of course, the rolling element is not limited to a good roller, and a ball or a spherical roller may be used, and the cross-sectional shape of the tapered surface of the base pipe and the tapered core 16 is linear. In the case of a flat surface, a cylindrical roller can be used, and various rolling elements can be used according to the structure and shape of the clamp mechanism.

The unclamp mechanism 20 engages with the taper cores 16 and 16 of the clamp mechanisms 10A and 10B, and can move the taper cores 16 and 16 against the urging force of the spring 18.18. And the telescopic pipe 1 exposed outside the base pipe 102
The unclamping knob 24 provided on the exposed portion of the unclamping rod 24 and the unclamping rod 26 that connects the unclamping knob 24 and the unclamping pin 22 are provided. The unclamping rod 26 is inserted into the telescopic pipe 104.

The unclamp knob 24 includes a slider portion 24b that is slidably inserted into the telescopic pipe 104, and a finger hook portion 24a that is fixed to the slider portion 24b by a screw 24c. The finger hook portion 24a is attached to the telescopic pipe 102. It is exposed to the outside through the provided opening window 103 and can be operated with a finger. The opening window 103 is a long hole that is longer in the axial direction than the finger hooking portion 24a, and the unclamping knob 24 can be moved in the axial direction.
The end of the unclamp rod 26 on the unclamp knob 24 side is threaded, and is screwed and fixed to the slider portion 24b of the unclamp knob 24.
The unclamp pin 22 is inserted into and fixed to a pin hole 26 a provided in the unclamp rod 26 in a direction orthogonal to the unclamp rod 26, and is connected to the taper core through a long hole 33 provided in the guide shaft 32. It protrudes between 16 opposing surfaces. The elongated hole 33 extends by a predetermined length in the axial direction so that the unclamp pin 22 can move by a predetermined amount.

An air damper cap 40 is attached to the opening end 102 a of the insertion opening of the base pipe 102.
The air damper cap 40 includes a sliding piece 43 whose sliding surface pressure with respect to the expandable pipe 104 increases as the pressure inside the base pipe 102 increases when the expandable pipe 104 contracts. When the telescopic pipe 104 is extended, the pressure inside the base pipe 102 is reduced to allow the inflow of air into the base pipe 102 so that the telescopic pipe 104 can be moved smoothly.

The sliding piece 43 of the air damper cap 40 is supported by a fitting portion that is fitted to the outer periphery of the base pipe 102. In this example, the fitting portion includes a cylindrical outer cover portion 41, a base pipe, and the like. An annular end surface cover portion 42 covering the end surface 102 is provided. The sliding piece 43 extends in an axial direction from the inner diameter end of the end surface cover portion 42 so as to gradually decrease in diameter toward the inside of the base pipe 102, and the distal end portion is the outer peripheral surface of the expansion pipe 104. Is slidably touching.
In the illustrated example, the lower end of the base pipe 102 is open, but is actually closed by a bottom lid or the like. If the expansion pipe 104 is suddenly pushed in, the pressure in the sealed base pipe 102 rises, and the pressure acting on the back surface of the sliding piece 43 of the soft air damper cap 40 is suddenly increased. The sliding piece 43 acts as a brake by increasing the frictional force with the telescopic pipe 102. Therefore, even if it becomes an unclamped state, the expansion pipe 102 does not fall into the base pipe 102 suddenly.
The increased internal pressure is appropriately released from the elongated hole 33 provided in the guide shaft 32 into the expansion pipe 104 through the sliding surface between the guide shaft and the unclamp rod 26, so that the contraction operation itself is not hindered. , Function as a damper.
On the other hand, when trying to pull out the telescopic pipe 102, the pressure acting on the back surface of the sliding piece 43 becomes a negative pressure, the sliding surface pressure of the sliding piece 43 decreases, air flows into the base pipe 102, and smoothly. Moving.

The damper effect by the damper cap 40 is based on the premise that the pressure in the base pipe 102 increases when the expansion pipe 104 contracts, but it is natural that the inside of the base pipe 102 is not completely sealed. In the present embodiment, the elongate hole 33 of the guide shaft 32, the slide surface between the guide shaft 32 and the unclamp rod 26, and the path inside the contraction pipe 104 have been described as examples. However, the air flow path is particularly limited. It is not something.
The sliding piece 43 only needs to have a structure in which the sliding surface pressure with the contraction pipe 104 increases as the pressure increases, and is not limited to the inclined structure as described above.

Next, the operation of the clamper of the present invention will be described.
In the free state, the rolling elements 12 and 12 of any of the clamp mechanisms 10A and 10B come into contact with the tapered surfaces 16a and 16a of the retainers 16 and 16 and the inner peripheral surface of the base pipe 102 by the urging force of the springs 18 and 18. It is sandwiched.
If it tries to extend in this state, the rolling element 12 of one clamp mechanism 10A will be in the direction which bites into the wedge-shaped space of the taper surface 16a and the outer type 102, and is locked.
Also, if the contraction is attempted, the rolling element 12 of the other clamp mechanism 10B becomes a biting direction in which the gap between the tapered surface 16a and the inner peripheral surface of the base pipe 102 becomes small, and is locked and clamped in either direction. Maintained in a state.

When extending (moving upward in the figure), the unclamping knob 24 is moved downward. Then, the unclamp pin 22 moves downward through the unclamp rod 26, the taper core 16 of one clamp mechanism 10B moves downward, the lock is released, and if it is extended in this state, it is smoothly It can be stretched and stretched with one hand.
When the unclamp knob 24 is released, the unclamp pin 22 is pushed back by the spring force of the spring 18 to return to the clamped state.
When contracting (moving downward in the figure), the unclamping knob 24 is moved upward. Then, the unclamp pin 22 moves upward via the unclamp rod 26, the taper core 16 of one clamp mechanism 10A moves upward, the lock is released, and if it is contracted in this state, it is smoothly Shrink and perform a shrinking operation with one hand.
When the unclamp knob 24 is released, the unclamp pin 22 is pushed back by the spring force of the spring 18 to return to the clamped state.
In this manner, the length can be easily adjusted by taking in and out the telescopic pipe 104 while operating the unclamp knob 24 with one hand.

[Embodiment 2]
2 and 3 show a clamper according to Embodiment 2 of the present invention.
In the first embodiment, the unclamp mechanism 20 opens the pair of clamp mechanisms 10A and 10B individually. However, the unclamp mechanism 200 of the second embodiment includes a pair of clamp mechanisms 10A. 10B is different in that it is configured to unclamp simultaneously. Since the components other than the unclamp mechanism are the same, only the unclamp mechanism will be described in the following description, and the same components will be denoted by the same reference numerals and description thereof will be omitted. Note that in FIG. 2A, an example of a column base is indicated by a two-dot chain line, as in FIG.

  That is, in this embodiment, the unclamp mechanism 200 is rotatably supported by the guide shaft 32 and can move the tapered cores 16 and 16 against the urging force of the springs 18 and 18 by rotation. An unclamp ring 28 serving as a clamp member, a linearly operable unclamp knob 24 provided on an exposed portion of the telescopic pipe 104 exposed to the outside of the base pipe 102, and a unclamp ring for linear movement of the unclamp knob 24 And a motion conversion mechanism that converts the motion into 28 rotational motions.

The unclamp ring 28 is interposed between the opposed end surfaces of the tapered cores 16, 16 of the pair of clamp mechanisms 10 </ b> A, 10 </ b> B, and has a support shaft 29 orthogonal to the unclamp rod 26 with respect to the guide shaft 32. It is rotatably supported as the center.
As shown in FIG. 3 (B), the unclamp ring 28 is an annular member having a circular outer periphery, a pair of parallel surfaces 28a, 28a having the same inner width as the outer diameter of the guide shaft 32, and an inner diameter guide. A support shaft 29 is provided in a shape that includes a pair of arcuate surfaces 28b, 28b having a diameter larger than the outer diameter of the shaft 32 and perpendicular to the parallel surfaces 28a, 28a. Therefore, the unclamp ring 28
Is rotated, the arc portions 28c, 28c corresponding to the arc surfaces 28b, 28b on the opposite sides with respect to the support shaft 29 are moved to the opposite sides in the central axis direction of the guide shaft 32. In addition, the corner | angular part of the end surface of the unclamp ring 28 and an outer peripheral surface is provided with the radius.

The motion conversion mechanism includes an unclamp rod 26 disposed in the telescopic pipe 104 and an unclamp pin 222 fixed to the tip of the unclamp rod 26.
As in the first embodiment, one end of the unclamping rod 26 is fixed to the slider 24 b of the unclamping knob 24 and the other end is inserted into the guide shaft 32. The unclamp pin 222 is inserted into and fixed to a pin hole 26 a provided at the tip of the unclamp rod 26 in a direction orthogonal to the unclamp rod 26, and is tapered through a long hole 33 provided in the guide shaft 32. It protrudes between the opposing surfaces of the core 16. The elongated hole 33 extends by a predetermined length in the axial direction so that the unclamp pin 222 can move by a predetermined amount. The unclamp pin 222 protrudes only to one side of the unclamp rod 26 and engages only with one arc portion 28 of the unclamp ring 28.

  One arcuate portion 28c is provided with an engagement hole 28d for engaging the unclamp pin 222, and the unclamp ring 28 is engaged with the unclamp pin 222 protruding from the elongated hole 32a of the guide shaft 32. A joint hole 28d is provided.

  In this embodiment, a spring 27 that pushes the unclamp rod 26 away from the fixing screw 38 inside the guide shaft 32 and between the tip of the unclamping rod 26 and the fixing screw 38 is in a compressed state. It is intervened. On the other hand, the axial length of the opening window 103 where the finger hooking portion 24a of the unclamping knob 24 is exposed is shorter in the upper direction than in the first embodiment, and the upper edge 103a of the opening window 103 is formed by the spring force of the spring 27. The finger-hanging portion 24a abuts and holds the unclamp ring 24 in a free state so as not to rattle.

Accordingly, when the unclamping knob 24 is moved linearly toward the lower edge of the opening window 103, the unclamping pin 22 is moved linearly via the unclamping rod 26, and the unclamping ring 28 with which the unclamping pin 22 engages. Rotates around the support shaft 29, and the arc portions 28c, 28c located on the opposite side of the support shaft 29 move in the axial direction opposite to each other, and the distance between the tapered cores 16, 16 increases. Become.
Since the corners between the end surface and the outer peripheral surface of the unclamp ring 28 are provided, the corners move smoothly with respect to the end surfaces of the tapered cores 14 and 14.
Note that the rattling-preventing spring 27 is not necessarily required. If the unclamping knob 24 can be moved upward without the spring 27, the base pipe 102 can be moved in any direction. As a result, the telescopic pipe 104 is relatively unclamped and can move in either the extending direction or the contracting direction.

[Embodiment 3]
FIG. 4 shows a main part configuration of an expandable pipe provided with a clamper according to Embodiment 3 of the present invention.
Similarly to the second embodiment, the unclamping mechanism 320 of the third embodiment also includes a pair of clamping mechanisms 10A. 10B is unclamped at the same time.
Except for the unclamping mechanism, it is basically the same as that of the first embodiment, and therefore, only the points different from the unclamping mechanism will be mainly described, and the same components as those of the first embodiment are denoted by the same reference numerals. The description is omitted.

In FIG. 4, the base pipe 102 and the telescopic pipe 104 described in the first and second embodiments are omitted, and the unclamping rod 26 includes a pull rod 326 illustrated and a unclamping knob 24 side (not illustrated). It is divided into portions and is connected via a joint 326A. The second fixing ring 36 constituting the assembly guide 30 is fixed by a retaining ring 338 at the end of the guide shaft 32.

  In the third embodiment, the unclamp mechanism 320 includes a rotor plate 328 that is rotatably supported by the guide shaft 32 via the support shaft 329, and an end portion on the opposite side of the support shaft 329 of the rotor plate 328. And a pair of sliders 330A and 330B that linearly move to the opposite sides along the guide shaft 32 by the rotation of the rotor plate 328. The pair of sliders 330 </ b> A and 330 </ b> B is moved along the guide shaft 32 in the direction of contact and separation through the rotor plate 328.

The pair of sliders 330A and 330B and the rotor plate 328 are interposed between the opposing end surfaces of the tapered cores 16 and 16 of the pair of clamp mechanisms 10A and 10B, and the sliders 330A and 330B are centered on the rotor plate 328. Are arranged on opposite sides in the axial direction of the guide shaft 32.
One slider 330A of the pair of sliders 330A and 330B is located on the first fixing ring 36 side and is connected to the pull rod 326 by an unclamp pin 322.

The sliders 330A and 330B have the same configuration, and include a ring portion 331 fitted to the guide shaft 32 and a semi-cylindrical portion 332 protruding in the axial direction from the ring portion 331. The ring portions 331 and 331 of the sliders 330A and 330B The tapered cores 16, 16 are in contact with the small-diameter end surfaces of the tapered cores 16 and 16 so that the longitudinally split surfaces of the semi-cylindrical portions 332, 332 are slidably in contact with each other. The semi-cylindrical portions 332 and 332 are provided with holes 333 and 333 into which the end of the rotor plate 328 opposite to the support shaft 329 is inserted.
The ring portion 331 of the slider 330A on the first fixed ring side, which is the open end side of the telescopic pipe, is fixed to the pull rod 326 by an unclamp pin 322.

In the third embodiment, the motion conversion mechanism includes a pull rod 326 connected to the main body side of the unclamp rod 26, an unclamp pin 322 fixed to the tip of the pull rod 326, a slider 330A, and a rotor plate 328. The rotational movement of the rotor plate 328 is further converted into a linear movement of the other slider 330B.
One end of the pull rod 326 is connected to the joint 326 </ b> A, and the other end is inserted into the guide shaft 32. The unclamp pin 322 is orthogonal to the pull rod 326 in the pin hole 26 a provided at the tip of the pull rod 326. It is inserted and fixed in the direction, and is fixed to the ring portion 332 of one slider 330 </ b> A through a long hole 33 provided in the guide shaft 32. The long hole 33 extends by a predetermined length in the axial direction so that the unclamp pin 322 can move by a predetermined amount.

Normally, the sliders 330A and 330B are pushed to the center by the spring force of the springs 18 and 18 that bias the tapered cores 16 and 16 into the roller 12, and the rotor plate 328 is orthogonal to the guide shaft 32. And the tips of the semi-cylindrical portions 332 and 332 of the sliders 330A and 330B are in positions where they contact the ring portions 331 and 331 of the sliders 330A and 330B on the opposite side.
In this state, when one slider 330A is pulled via the unclamp pin 322 against the spring force of the springs 18 and 18 via the pull rod 326, the rotor plate 328 engaged with the slider 330A is supported by the support shaft 329. The slider 330B located on the opposite side moves in the axial direction to the opposite side, and the distance between the tapered cores 16 and 16 is increased.
As described above, the sliders 330A and 330 between the rotor plate 328 and the taper cores 16 and 16 are provided.
By using B, a force can be applied evenly to the taper cores 16 and 16 in the circumferential direction, and unclamping can be performed smoothly.

  In each of the above embodiments, the expansion / contraction mechanism has been described by taking the drip stand support as an example. However, the expansion / contraction mechanism is not limited to the drip stand but can be applied to a microphone stand, a camera stand, a cane, etc. Widely applicable. Of course, the present invention is not limited to the case of expanding and contracting in the vertical direction, but can be applied to the case of expanding and contracting in the horizontal direction. Moreover, as an expansion / contraction mechanism, the base member as the outer member is fixed and the inner member expands / contracts. However, the expansion / contraction of the outer member and the inner member is relative, and the inner member is fixed and the outer member is fixed. A movable configuration may be used.

In each of the above embodiments, a pair of clamping mechanisms are arranged in opposite directions. However, when clamping only in one direction, only one direction clamping mechanism may be used.
In addition, the clamp mechanism can freely move the taper core as the wedge-shaped space forming portion so as to form a wedge-shaped space between the base pipe and the extendable pipe whose interval is gradually narrowed along the axial direction. However, it is good also as a structure which fixes a taper core and moves the retainer of a rolling element, and may provide a taper ring part in the base pipe side. In short, the structure includes a rolling element that moves forward and backward relative to the wedge-shaped space with the relative movement of the outer member and the inner member, and the outer member and the inner member in a direction in which the rolling element bites into the wedge-shaped space. It is only necessary that the relative movement of the outer member and the inner member is permitted in a direction in which the relative movement is prevented and the rolling element comes out of the wedge-shaped space.

DESCRIPTION OF SYMBOLS 1 Clamper 10A, 10B Clamp mechanism 12 Rolling body 121 Central concave surface part 122 End convex surface part 14 Retainer 16 Tapered core 16a Tapered surface part 18 Spring (biasing member)
20 Unclamp mechanism 22 Unclamp pin 24 Unclamp knob 26 Unclamp rod 30 Assembly guide (guide part)
32 Guide shaft 34 First fixing ring 34a Ring end 36 Second fixing ring 39 Spacer collar 100 Telescopic mechanism 102 Base pipe (outer member)
104 Telescopic pipe (inner member)

Claims (8)

A clamper attached to an expansion / contraction mechanism comprising a cylindrical outer member and an inner member that is assembled so as to be linearly retractable into and out of the outer member,
A clamp mechanism that is disposed inside the outer member and prevents relative movement in one direction and allows relative movement in the other direction among the two directions of the inner member projecting and immersing in the outer member. When,
A clamper comprising: an unclamping mechanism that disables the function of the clamp mechanism to prevent relative movement of the inner member with respect to the outer member and enables relative movement of the inner member with respect to the outer member.   The clamper according to claim 1, wherein the clamp mechanism is provided with a pair of clamp mechanisms whose directions to prevent relative movement are opposite to each other.   The clamp mechanism includes a wedge-shaped space forming portion that forms a wedge-shaped space in which the interval gradually decreases along the axial direction between the outer member and the inner member, and the relative movement of the outer member and the inner member. A structure including a rolling element that advances and retreats relative to the wedge-shaped space, wherein relative movement of the outer member and the inner member in a direction in which the rolling element bites into the wedge-shaped space is prevented, and the rolling element is wedge-shaped space The clamper according to claim 1, wherein the outer member and the inner member are allowed to move relative to each other in a direction of coming out of the clamper. The clamp mechanism includes a guide portion provided on the inner member, a retainer that holds a rolling element fixed to the guide member so as not to move in the axial direction, and a wedge-shaped space that is mounted on the guide portion so as to be movable in the axial direction. A tapered core having a tapered surface as a part, and a biasing member that biases the tapered surface of the tapered core toward the rolling element held by the retainer,
The rolling element is a tapered surface of the tapered core formed by a biasing force of a biasing member that forms a wedge-shaped space between the tapered surface formed on the tapered core and the inner peripheral surface of the outer member. The clamper according to claim 2, wherein the clamper is pressed against the inner peripheral surface of the outer member. The unclamp mechanism is supported by the guide member so as to be linearly movable, and the unclamp member capable of moving the tapered core against the urging force of the spring by linear movement; and
A linearly operable unclamp knob provided on an exposed portion of the inner member exposed to the outside of the outer member; and a connecting member that connects the unclamp knob and the unclamp member. The clamper according to claim 4.   The unclamp mechanism is rotatably supported by the guide member, and is exposed to the outside of the outer member and the unclamp member that can move the taper core against the urging force of the spring by rotation. A linearly operable unclamping knob provided on an exposed portion of the inner member, and a motion conversion mechanism that converts linear motion of the unclamping knob into rotational motion of the unclamping member. The clamper according to claim 4.   An expansion / contraction mechanism comprising the clamper according to any one of claims 1 to 6. An air damper cap is attached to the insertion hole of the inner member in the outer member,
The expansion / contraction mechanism according to claim 7, wherein the air damper cap includes a sliding piece whose sliding surface pressure increases with respect to the inner member in accordance with an increase in pressure inside the outer member when the inner member contracts.

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