JP2018021644A - Contraction control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problems of prior art that there are a plurality of actions necessary for releasing a fixing device which fixes a leg part extended to an optional length from the connection part and re-fixing the fixing device so as to require much time and labor, wherein connection parts of one or a plurality of steps are provided with a plurality of tubular leg bodies different in outer diameter, and each of the connection parts is provided with the fixing device.SOLUTION: This invention relates to a contraction control device comprising: a cylindrical member that is arranged at a connection part of a small diameter tubular leg body connected within a large diameter tubular leg body in such a way that it can be loaded or unloaded and a piece is stored in a storing space arranged at a clearance between it and an outer peripheral surface of the small diameter tubular leg body; and a releasing member provided with a releasing claw for releasing the piece from a reduced diameter part. The storing space is provided with the reduced diameter part where the reduced diameter part is formed in a base end direction on a large diameter tubular leg body side, the piece is engaged with a wedge at the reduced diameter part and then the small diameter tubular leg body can be fixed.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a cylindrical large-diameter tubular leg body that is connected so as to be extendable and a stretching control device that is provided at a connecting portion of the small-diameter tubular leg body.

  A tripod equipped with a holding unit for holding a still camera, video camera, etc., is used with its legs extended to the required height when used, and shortened to make it easier to carry when not in use. The

  A tripod or the like provided with such an extendable leg portion is generally connected by inserting the leg portion into a cylindrical large-diameter tubular leg body and the distal-side opening of the large-diameter tubular leg body. The small-diameter tubular leg is configured to be extendable / contractable with respect to the large-diameter tubular leg by allowing the small-diameter tubular leg to enter and exit along the axial direction at the connected connecting portion. Further, the leg portion is provided with one or more stages of the connecting portions by a plurality of tubular legs having different outer diameters, and each connecting portion is extended from the connecting portion to an arbitrary length. A fixing device is provided for fixing the leg portion in that state.

JP 2000-227196 A

  However, in the prior art, in order to release the fixing device from the state in which the leg portion is fixed, the fixing device has a screw-type tightening structure, so that the fixing structure is fixed in the releasing direction. It was necessary to rotate the device many times to release the fixed state. And after adjusting the length of the leg part, it was necessary to rotate it again in the direction in which the fastening structure of the fixing device is fixed to be in a fixed state, so until one fixing device is opened and fixed again There were a number of operations required for this, which was time-consuming.

  In addition, when one leg has multiple stages of connecting parts, the work of releasing and fixing all the connecting parts is very time consuming, and the tripods etc. that have been purchased are left unused. It was also a cause. In addition, such problems also exist in the monopod and the leg of the music stand as well.

  Accordingly, as a means for solving the above problems, an expansion / contraction control device according to the present invention is a cylindrical large-diameter tubular leg, and is inserted into the opening on the distal end side of the large-diameter tubular leg so as to enter and exit along the axial direction. And a small diameter tubular leg that is connected to the large diameter tubular leg so as to be extendable and contractible, and an expansion / contraction control device provided at a connecting portion of the large diameter tubular leg. A cylindrical member comprising: a fixed base end portion that is fixed; and an enlarged diameter accommodation portion that is larger in diameter than the fixed base end portion and forms an accommodation space between the outer peripheral surface of the small-diameter tubular leg. A through-hole that penetrates the enlarged diameter portion of the enlarged diameter accommodating portion of the cylindrical member from the outside toward the distal end direction along the axial direction, and the cylindrical member in the accommodating space. The inner peripheral surface of the has an inclined surface that is inclined so as to reduce in diameter as it goes from the distal end side toward the proximal end side. A reduced diameter portion, a sliding portion that is accommodated in the accommodation space and that can slide smoothly in the axial direction with respect to the inner peripheral surface of the cylindrical member, and is inserted in the proximal direction with respect to the reduced diameter portion A piece having a crimping surface that can be crimped to an outer peripheral surface of the small-diameter tubular leg in a state of being wedged in the reduced-diameter portion, and a distal end surface of the cylindrical member An annular spring receiving plate that is provided, and a piece lifting spring that is installed between the inner bottom surface of the spring receiving plate and the front end surface of the piece and biases the piece in the proximal direction with a force capable of pushing up the piece. And a release member that is mounted along the outer peripheral surface of the fixed base end portion of the tubular member, is slidable in the axial direction, and is formed with a release claw that can be inserted into the through hole, The release pawl is attached to the piece that is wedged by sliding the release member in the distal direction. Characterized by comprising the frame being releasably formed from the reduced diameter portion with and strikes.

  Hereinafter, the state where the piece is wedged in the reduced diameter portion may be referred to as a fixed state of the expansion / contraction control device. On the other hand, the state in which the piece is released from the wedged state at the reduced diameter portion may be referred to as the released state of the expansion / contraction control device.

  By arranging a plurality of pieces around the small-diameter tubular leg, the fixed state of the expansion / contraction control device can be kept uniform with respect to the peripheral surface of the small-diameter tubular leg. In addition, the piece is formed in an annular shape so as to surround the peripheral surface of the small-diameter tubular leg, and has a small diameter when wedged by being a C-shaped annular shape in which a defective portion is formed in part. It may be deformed so that the crimping surface can be brought into close contact with the outer peripheral surface of the small-diameter tubular leg.

  Further, the expansion / contraction control device according to the present invention is formed with a width capable of fitting the sliding portion of the piece on the inner peripheral surface of the accommodating space of the cylindrical member, and includes a plurality of guide grooves provided with the inclined surface. Are preferably provided along the axial direction.

  A guide groove is formed, and it is possible to prevent the piece from moving in the circumferential direction by fitting the piece into the guide groove. The guide groove only needs to have a width for fitting the sliding portion of the piece. However, if the guide groove is formed to have a width capable of fitting the whole piece, the movement of the piece is more effectively suppressed in the circumferential direction. This is preferable.

  A plurality of guide grooves are preferably formed on the inner peripheral surface of the accommodation space, and more preferably three or more portions are formed at equal intervals in the circumferential direction. Three or more guide grooves are formed at equal intervals, and a piece is installed in each of them, so that three or more pieces wedged at the reduced diameter portion have the outer peripheral surface of the small-diameter tubular leg in the circumferential direction. It can be supported evenly.

  Further, the expansion / contraction control device according to the present invention engages the push-up spring formed by urging the release member in the proximal direction with respect to the tubular member, and the release member pushed up by the push-up spring. Even if it has a locking member to do.

  Here, it is desirable that the distal end of the release pawl of the release member locked by the locking member is located at a position closer to the proximal end side than the proximal end surface of the piece in a state of being wedged at the reduced diameter portion. . This is because when the release of the piece is not necessary, the push-up spring is held at a position where the release claw does not touch the piece, thereby preventing the piece that is wedged at the reduced diameter portion from being opened unexpectedly.

  Grab the release member pushed up by the push-up spring with your hand, move it in the tip direction to bring the release claw into contact with the piece, and further press the piece down in the tip direction with the release claw to reduce the diameter of the piece when necessary Can be released from the department. In addition, if the release member is returned to the proximal direction to the position before the release claw is brought into contact with the piece that has been wedged by the reduced diameter portion after the piece is released, the released element also has the base push-up spring By pushing back in the direction, the base end of the piece can be automatically returned to a position where it comes into contact with the inclined surface of the reduced diameter portion.

  Furthermore, the expansion / contraction control device according to the present invention is such that the base end portion of the release member extends to the base end side from the cylindrical member in a state where the piece is wedged by the reduced diameter portion. Even if it exists, it is preferable.

  Furthermore, in the expansion / contraction control device according to the present invention, a portion of the cylindrical member adjacent to the distal end side of the large-diameter tubular leg is between the fixed base end portion and the accommodating space. The ratchet prevention portion is formed of a concave groove portion having a central inner peripheral surface forming a gap with the outer peripheral surface of the small-diameter tubular leg, and a proximal end portion and a distal end portion are formed as described above. A proximal end side wall portion and a distal end side wall portion projecting radially inward from the recessed groove portion, and are sandwiched between the proximal end side wall portion of the rattling prevention portion and the small diameter tubular leg, A first engagement surface formed of a slanted surface whose diameter increases from the proximal end to the distal end. And the inner peripheral surface is not formed on a first contact surface composed of a surface parallel to the outer peripheral surface of the small-diameter tubular leg. A first annular wedge body, and a biasing spring that is mounted along the outer peripheral surface of the small-diameter tubular leg in the concave groove portion and biases the first annular wedge body in the proximal direction; and The inner peripheral surface of the base end side wall portion in contact with the first engagement surface of the first annular wedge body is formed as a first engaged surface including an inclined surface whose diameter increases from the base end toward the front end. Even a thing is preferable.

  The urging spring may be configured to urge the first annular wedge body in the proximal direction by bringing a distal end into contact with an inner surface of the distal end side wall portion of the rattling prevention portion.

  As a result, rattling that occurs in a direction in which the shortened small-diameter tubular leg is inclined with respect to the axial direction with respect to the large-diameter tubular leg can be prevented. Even when the small-diameter tubular leg is stretched, the biasing spring urges the first annular wedge body in the proximal direction so that the first annular wedge body is brought into contact with the first engaged surface and the small-diameter tubular leg. It is possible to exert an effect of preventing rattling as well.

  Further, in the cylindrical member, a portion adjacent to the distal end side of the large-diameter tubular leg between the fixed base end portion and the accommodating space is formed in the rattling prevention portion, and the rattle The anti-sticking portion includes a concave groove portion in which a central inner peripheral surface forms a gap with the outer peripheral surface of the small-diameter tubular leg, and a proximal end portion and a distal end portion project radially inward from the concave groove portion. A proximal end side wall portion and a distal end side wall portion, sandwiched between the distal end side wall portion of the rattling prevention portion and the small-diameter tubular leg, and a part of the ring extending from the outer peripheral surface to the inner peripheral surface. It is formed in a C-shaped annular shape having a defect portion formed as a defect, an outer peripheral surface is formed on a second engagement surface that is an inclined surface that expands from the distal end toward the base end, and an inner peripheral surface is the small diameter A second annular wedge formed on a second contact surface comprising a surface parallel to the outer peripheral surface of the tubular leg, and the concave groove And a biasing spring that is mounted along the outer peripheral surface of the small-diameter tubular leg body and biases the second annular wedge body in the distal direction, and is provided with a second engagement of the second annular wedge body It is preferable that the inner peripheral surface of the distal end side wall portion in contact with the surface is formed on a second engaged surface formed of an inclined surface whose diameter increases from the distal end toward the proximal end.

  The biasing spring may be configured to bias the second annular wedge body in the distal direction by bringing a base end into contact with an inner surface of the base end side wall portion of the rattling prevention portion.

  As a result, it is possible to prevent rattling that occurs in the direction in which the elongated small-diameter tubular leg is inclined with respect to the axial direction with respect to the large-diameter tubular leg. Even when the small-diameter tubular leg is shortened, the biasing spring urges the second annular wedge body in the distal direction so that the second annular wedge body is brought into contact with the second engaged surface and the small-diameter tubular leg. While holding in between, it is possible to exert an anti-rattle effect.

  Further, it is preferable that both the first annular wedge body and the second annular wedge body are sandwiched between the rattle prevention portion and the small diameter tubular leg. In this case, the inner peripheral surfaces of the base end side wall portion and the front end side wall portion of the rattling prevention portion are formed on the first engaged surface and the second engaged surface, respectively, and the biasing spring is the first engaged surface. It is mounted between the one annular wedge body and the second annular wedge body, and is urged in a direction in which the first annular wedge body and the second annular wedge body are separated from each other in the axial direction.

  Thus, by providing both the first annular wedge body and the second annular wedge body, the small diameter tubular leg body is large in both cases where the small diameter tubular leg body is shortened or stretched. Shaking that occurs in a direction inclined with respect to the axial direction with respect to the tubular leg can be prevented.

  The spring receiving groove has a third engaged surface made of an inclined surface that expands the inner peripheral surface of the spring receiving plate from the distal end toward the proximal end, and the small diameter facing the third engaged surface. It is formed by the outer peripheral surface portion of the tubular leg body, and the spring receiving groove is formed in a C-shaped annular shape having a defective portion in which a part of the ring is lost from the outer peripheral surface to the inner peripheral surface. A thin plate shape having a third engagement surface comprising an inclined surface whose diameter increases from the base end toward the base end, and a third contact surface having an inner peripheral surface which is parallel to the outer peripheral surface of the small-diameter tubular leg. It is preferable that a front annular wedge body composed of the annular body is fitted, and the piece push-up spring is installed between a base end surface of the front end annular wedge body and a front end surface of the piece.

  As a result, the stretched small-diameter tubular leg is inclined with respect to the large-diameter tubular leg in the axial direction on the distal end side farther than the accommodating space from the connecting portion between the small-diameter tubular leg and the large-diameter tubular leg. The effect of preventing the rattling that occurs in the direction is exhibited, and the rattling of the small-diameter tubular legs can be prevented more strongly than the pair of annular wedge bodies.

  Furthermore, the present invention is preferably a tripod, a monopod, or a music stand characterized by including any one of the expansion / contraction control devices described above.

  The sliding portion of the piece may be preferably formed such that the outer surface of the piece has a low frictional resistance against the inner peripheral surface of the cylindrical member, and a part of the rotation surface of the ball bearing provided on the piece is the cylindrical shape. It is more preferable that the projection is provided from the outer surface of the piece facing the inner peripheral surface of the member, and the rotation surface is configured to be rotatable along the axial direction of the small-diameter tubular leg. By rotating a part of the ball bearing protruding from the outer surface in contact with the inner peripheral surface of the cylindrical member, the piece can be smoothly slid with respect to the inner peripheral surface of the cylindrical member. it can.

  In order to change the piece from a state where it is released from the reduced diameter portion to a fixed state inserted into the reduced diameter portion, by pressing the small diameter tubular leg toward the proximal end, a pressure bonding surface is formed on the outer peripheral surface of the small diameter tubular leg. This is realized by moving the piece in close contact with the small-diameter tubular leg in the proximal direction and inserting it into the reduced diameter portion so that the crimping surface is crimped to the outer peripheral surface of the small-diameter tubular leg. And in order for a piece to be inserted deeply in a reduced diameter part, the frictional resistance of a sliding part is so preferable that it is low. If the sliding portion is constituted by the ball bearing, the frictional resistance against the inclined surface of the sliding portion can be sufficiently lowered, so that the holding force of the crimping surface to the small-diameter tubular leg can be increased by inserting the piece deeper into the reduced diameter portion. It can be raised enough. The ball bearing may be installed inside the piece, or may be installed exposed on the side surface.

  The radial thickness that is wedged when inserted in the proximal direction with respect to the reduced diameter portion of the piece is that the maximum thickness in the radial direction from the sliding portion to the pressure-bonding surface of the piece is that of the inclined surface in the reduced diameter portion. Slightly thinner than the radial gap from the distal end to the outer peripheral surface of the small-diameter tubular leg, and in the radial direction from the base end of the inclined surface to the outer peripheral surface of the small-diameter tubular leg at the base end of the reduced diameter portion It is preferable that it is formed slightly thicker than the gap. Since the maximum thickness from the sliding part to the crimping surface of the piece is such a thickness, the piece is inclined with respect to the outer peripheral surface of the small-diameter tubular leg by being inserted in the proximal direction with respect to the reduced diameter part. This is because the small-diameter tubular leg that is sandwiched between the surfaces and can be wedged and stretched to a desired length can be held.

  Further, in a state where the piece is wedged by the reduced diameter portion, a base end portion of the release member extends to a base end side from the cylindrical member. .

  As an example, two extension control devices are attached to each connection portion on a leg having a two-stage connection portion, and the base end portion of the release member of each extension control device is a wedge with the reduced diameter portion. By being extended to the proximal end side from the tubular member in the stopped state, the release member of the expansion control device on the proximal end side is grasped, and the distal end of the leg body is pushed and shrunk in the proximal direction, After that, when the leg is shortened, the distal end surface of the spring receiving plate of the extension control device on the proximal end side is brought into contact with the proximal end surface of the release member of the extension control device on the distal end side to push down the release member. it can. If the leg is further shortened, the release claw of the release member releases the piece from the reduced diameter portion, thereby touching and operating the extension control device on the tip side, and controlling the extension on the tip side. The device can be released.

  Further, a projecting portion that projects in the distal direction from a position intersecting with a virtual vertical line extending from the proximal end surface of the release member on the distal end surface of the spring receiving plate at the distal end surface of the spring receiving plate. The protruding portion may be provided not to be installed in a range smaller than a circle whose diameter is the inner diameter of the release member with the central axis of the small-diameter tubular leg as a center. When the release member is locked by the locking member while being pushed up by the push-up spring, the protruding portion is wedged from the tip of the release claw in a state where the release member is locked. It is formed longer than the length to the base end of the piece in the closed state.

  As an example 2, by attaching two expansion / contraction control devices to each connection portion on a leg body having a two-stage connection portion, and providing each of the expansion / contraction control devices with the projecting portion, After grasping the release member of the expansion / contraction control device and pressing the distal end of the leg in the proximal direction to release it, when the leg is shortened, the protruding part of the expansion / contraction control device on the proximal side is expanded / contracted on the distal side The release member can be pushed down by contacting the base end surface of the release member of the control device. If the leg is further shortened, the release claw of the release member releases the piece from the reduced diameter portion, thereby touching and operating the extension control device on the tip side, and controlling the extension on the tip side. The device can be released.

  The effect of being able to be in a released state without touching the distal end side expansion / contraction control device described in Example 1 and Example 2 is to connect three or more expansion / contraction control devices to a leg having a plurality of connecting portions. Even if attached to the part, it can be demonstrated.

  The piece is preferably made of a thermoplastic resin, more preferably a polyacetal resin. Further, the large-diameter tubular leg and the small-diameter tubular leg are preferably composed of a composite material of carbon fiber and resin, and may be composed of metal. The metal is preferably aluminum or iron.

  The angle of the inclined surface of the reduced diameter portion, the first, second, and third engaging surfaces, and the first, second, and third engaged surfaces with respect to the outer peripheral surface of the small-diameter tubular leg is 45 ° or less. It is preferable. The first annular wedge body, the second annular wedge body, and the tip annular wedge body are respectively connected to the first, second, and third engaged members in order to firmly hold the wedged state in the reduced diameter portion. This is because it is easy to construct a structure for firmly holding the fitted state between the mating surface and the small-diameter tubular leg. Moreover, it is preferable that the said angle of the inclined surface of a reduced diameter part is 4 degrees-20 degrees. If the angle is less than 4 °, the wedged piece may be too firmly fixed to release the held state. Further, when the angle of the inclined surface of the reduced diameter portion is larger than 20 °, it may be difficult to secure a force for the piece wedged in the reduced diameter portion to sufficiently hold the small diameter tubular leg. There is sex.

  According to the present invention, when the small-diameter tubular leg is stretched from the large-diameter tubular leg, the small-diameter tubular leg is immediately stretched by simply grasping and pulling in the distal direction without touching and operating the expansion control device. Can do.

  Furthermore, when shortening the small-diameter tubular leg into the large-diameter tubular leg, the release member and the small-diameter tubular leg are grasped with the left and right hands and shortened simply by applying force in the direction in which the hands approach each other. Work can be done.

  By configuring the sliding portion of the piece with a ball bearing, the holding force of the crimping surface with respect to the small-diameter tubular leg can be sufficiently increased.

  Furthermore, even when one leg portion has a plurality of connecting portions, the base end portion of the release member is closer to the base end side than the tubular member when the piece is wedged by the reduced diameter portion. When the expansion / contraction control device according to the present invention is provided at each connecting portion, the distal end of the leg portion is pushed and contracted in the proximal direction by grasping the release member of the expansion / contraction control device closest to the proximal end. Accordingly, the leg can be shortened in one operation while sequentially releasing the fixed state of the extension control devices on the distal end side from the extension control device on the proximal end side.

  Similarly, a projecting portion is provided on the distal end surface of the spring receiving plate so as to project from the position intersecting with a virtual vertical line extending from the proximal end surface of the release member in the distal direction. A leg portion that grips the release member of the expansion control device on the most proximal side by providing a configuration that is not installed in a range smaller than a circle having an inner diameter of the release member centered on the central axis of the small-diameter tubular leg. By pushing and contracting the distal end in the proximal direction, the leg can be shortened in one operation while releasing the fixed state of each of the distal expansion / contraction control devices sequentially from the proximal expansion / contraction control device.

  Also, in any one of the above-described operations for shortening the leg, if the release member of the most proximal extension control device is grasped and the distal end of the leg is pushed and contracted in the proximal direction, the extension control on the proximal side is performed. Since the fixed state of each extension control device on the distal end side from the device is sequentially released, the force required for shortening work is one extension control device regardless of the number of extension control devices provided on one leg. Can be done with the force necessary to release. For this reason, even if it is a weak person, the shortening operation | work of the leg part provided with the some expansion-contraction control apparatus which concerns on this invention can be performed easily.

  By providing a pair of annular wedges and a biasing spring between the tubular member and the outer peripheral surface of the small-diameter tubular leg, the small-diameter tubular leg is inclined with respect to the axis of the large-diameter tubular leg. It is possible to prevent rattling.

  Furthermore, a tip annular wedge body is fitted into a spring receiving groove provided on the inner peripheral surface of the spring backing plate, and the piece lifting spring is interposed between the base end surface of the tip annular wedge body and the tip end surface of the piece. By being installed, the stretched small-diameter tubular leg is in the axial direction with respect to the large-diameter tubular leg at the distal end side farther than the accommodating space from the connecting portion between the small-diameter tubular leg and the large-diameter tubular leg. However, it is possible to prevent rattling of the small-diameter tubular legs more powerfully than the pair of annular wedges.

  Furthermore, the tip annular wedge body is fitted into a spring receiving groove provided on the inner peripheral surface of the spring receiving plate, so that the tip annular wedge body is always kept in close contact with the outer peripheral surface of the small-diameter tubular leg. Therefore, it is possible to prevent minute dust and dust from entering the housing space from the outside by expansion and contraction of the small-diameter tubular leg. By this effect, it is possible to prevent the dust or the like that has entered the housing space from being sandwiched between the pressure-bonding surface of the piece and the outer peripheral surface of the small-diameter tubular leg, and the force with which the pressure-bonding surface holds the small-diameter tubular leg is reduced. .

It is a front view which shows the external appearance of the expansion-contraction control apparatus 1 provided in the connection part of the large diameter tubular leg 2 and the small diameter tubular leg 3. It is a bottom view of the expansion-contraction control apparatus 1 shown in FIG. FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1 and shows a state in which a piece 18 is wedged by a reduced diameter portion 17. FIG. 4 is a cross-sectional view of the expansion / contraction control device 1 provided at the connecting portion between the large-diameter tubular leg 2 and the small-diameter tubular leg 3 on the same surface as in FIG. FIG. 3 is a perspective view of a cylindrical member 4. FIG. 4 is a cross-sectional view of the tubular member 4 along BB. 2 is a perspective view of a member composed of a fixed base end portion 5 and an inner wall portion 10. FIG. It is the bottom view which looked at the cylindrical member 4 from the front end side. It is (a) CC sectional drawing of the cylindrical member 4, and (b) DD sectional drawing. 3 is a perspective view of a piece 18. FIG. They are (a) the bottom view seen from the front end side of the piece 18, (b) front view, (c) back view, and (d) left side view. It is EE sectional drawing of the piece 18. FIG. FIG. 6 is a perspective view of the spring receiving plate 24 as viewed from the base end side. It is the top view seen from the (a) base end side of the spring receiving plate 24, (b) It is a front view. FIG. 5 is a cross-sectional view of the spring receiving plate 24 taken along line FF. FIG. 4 is a perspective view of the release member 30 as viewed from the distal end side. It is the (a) front view of the release member 30, (b) the bottom view seen from the front end side. FIG. 4 is a cross-sectional view of the release member 30 taken along the line GG. FIG. 6 is a cross-sectional view of the release member 30 taken along the line H-H. It is a perspective view of the 1st annular wedge body 41a, the 2nd annular wedge body 41b, and the tip annular wedge body 41c. It is the (a) front view and (b) bottom view of the 1st annular wedge body 41a, the 2nd annular wedge body 41b, and the tip annular wedge body 41c. It is II sectional drawing of the 1st annular wedge body 41a, the 2nd annular wedge body 41b, and the front-end | tip annular wedge body 41c. The disassembled perspective view of the expansion-contraction control apparatus 1 is shown. It is the schematic explaining the operation | work which shortens the leg part T with which the expansion-contraction control apparatus 1 was provided with one operation | movement. It is sectional drawing which cut | disconnected the expansion-contraction control apparatus 1 which concerns on 2nd embodiment provided in the connection part of the large diameter tubular leg 2 and the small diameter tubular leg 3 along the axial direction. FIG. 26 is a partially enlarged cross-sectional view showing an outline of a peripheral structure when a two-dot chain line portion of FIG. 25 is enlarged and a tip annular wedge body 41 c is provided in a spring receiving groove 127 as a second embodiment. It is sectional drawing which cut | disconnected the expansion-contraction control apparatus 1 provided with the 2nd annular wedge body 41b and the front-end | tip annular wedge body 41c along the axial direction. It is a perspective view which shows the external appearance of the tripod in which the expansion-contraction control apparatus 1 is provided.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1 and 2, the expansion / contraction control device 1 according to the present invention is inserted into the tubular large-diameter tubular leg 2 and the distal-side opening of the large-diameter tubular leg, and enters and exits along the axial direction. By doing so, it is provided at the connecting portion with the small-diameter tubular leg 3 which is connected to the large-diameter tubular leg 2 so as to be extendable and contractible.

  1 and 3, the X direction indicated by the arrow V is a direction indicating the distal ends of the large-diameter tubular leg 2 and the small-diameter tubular leg 3, and is hereinafter referred to as a distal direction. The Y direction indicated by the arrow V is a direction indicating the proximal end side of the large-diameter tubular leg 2 and the small-diameter tubular leg 3, and is hereinafter referred to as a proximal direction. The direction indicated by the arrow W indicates the radial direction.

  As shown in FIG. 3, the cylindrical member 4 fixes the inner peripheral surface of the fixed base end portion 5 to the distal end outer peripheral surface 6 of the large-diameter tubular leg 2 by bonding, and the large-diameter tubular leg 2. A part of the outer peripheral surface of the small-diameter tubular leg 3 is covered by extending in the distal direction from the distal end portion. FIG. 5 is a perspective view of the cylindrical member 4, and FIG. 7 is a perspective view of the fixed base end portion 5 and the inner wall portion 10. Moreover, the bottom view which looked at the cylindrical member 4 from the front-end | tip at FIG. 8 is shown.

  As shown in FIG. 3, the tubular member 4 is formed such that a portion extending from the fixed base end portion 5 in the distal direction is a thick portion 7 that is thick in the radial direction. Further, the enlarged diameter accommodating portion 8 formed continuously from the thick portion 7 in the distal direction is formed to have a diameter increased outward in the radial direction from the thick portion 7. An accommodation space 9 is formed between the outer peripheral surface and the outer peripheral surface.

  In the present embodiment, as shown in FIG. 9, the thick portion 7 is divided into two in the radial direction, and the inner wall portion 10 that continues from the fixed base end portion 5 in the distal direction, and the enlarged diameter accommodating portion 8. The outer wall portion 11 that is continuous in the proximal direction is detachably screwed. With the configuration in which the thick portion 7 is divided into two parts, the maintenance inspection work can be easily performed by disassembling other members except the fixed base end portion 5 and the inner wall portion 10 in the expansion / contraction control device 1. On the other hand, the cylindrical member 4 can be stably fixed to the large-diameter tubular leg 2 by screwing the inner wall portion 10 and the outer wall portion 11 together.

  As shown in FIGS. 3 and 6, the peripheral wall proximal end surface 36 of the enlarged diameter portion 12 formed by the enlarged diameter accommodating portion 8 having an enlarged diameter at the central portion of the cylindrical member 4 extends from the outside to the distal direction along the axial direction. A through hole 13 that penetrates to the accommodation space 9 is formed.

  A plurality of guide grooves 15 are formed along the axial direction on the inner peripheral surface 14 of the enlarged diameter accommodating portion 8 of the cylindrical member 4 constituting the accommodating space 9. The accommodation space 9 is formed with a reduced diameter portion 17 having an inclined surface 16 that is inclined so that the diameter of the guide groove 15 decreases from the distal end side toward the proximal end side. A piece 18 is fitted in each guide groove 15 and accommodated in the accommodation space 9.

  As shown in FIGS. 10 to 12, the piece 18 is formed on the proximal end surface 31, the distal end surface 28, the radial outer surface 19, the sliding portion 20 provided on the radial outer surface 19, and the radial inner surface. A crimping surface 23 is provided.

  As shown in the bottom view of FIG. 11 (a), the piece 18 is formed in a shape in which the lateral width of the outer half 18b is narrowed with respect to the inner half 18a. Since the outer half 18b is formed in a shape with a narrowed left and right width, the width of the guide groove 15 is not required to fit the inner half 18a of the piece 18, and the outer half 18b can be fitted. If it is a width | variety, the operation | movement which the piece 18 will move to the circumferential direction of the small diameter tubular leg 3 in the accommodation space can be suppressed. As a result, the thickness of the enlarged diameter accommodating portion 8 can be ensured by the amount that the width of the guide groove 15 can be narrowed. Therefore, even if the guide groove 15 is formed, deformation due to the outward stress in the radial direction from the wedged piece 18 It is possible to maintain the strength for suppressing the problem.

  Furthermore, since the inner half 18a of the piece 18 is formed wider than the outer half 18b, a large area of the crimping surface 23 formed on the inner surface of the inner half 18a can be secured. However, the area for holding the small-diameter tubular leg 3 can be increased.

  The piece 18 is provided with a sliding portion 20 that can slide smoothly in the axial direction with respect to the inner peripheral surface 14 on the radially outer surface 19. In this embodiment, the sliding portion 20 includes the piece 18. A part of the rotation surface 21 a of the ball bearing 21 provided inside the ball bearing 21 is installed so as to protrude from the outer surface 19 of the piece 18. The rotation surface 21a is rotatable along the axial direction of the small-diameter tubular leg 3. When the rotating surface 21a of the ball bearing 21 abuts on the inner peripheral surface 14 and smoothly rotates, the piece 18 slides smoothly on the inner peripheral surface 14 in a state where the piece 18 is released from the reduced diameter portion 17. Can do.

  The proximal end portion of the outer side surface 19 of the piece 18 is formed with a relief surface that is inclined from the outside to the inside so as not to hit the inclined surface 16 when the piece 18 is inserted into the reduced diameter portion 17. The crimping surface 23 is formed in a concave curved surface as shown in FIG. 11A in order to be in close contact with the outer peripheral surface 22 of the small-diameter tubular leg 3. The ball bearing 21 has a rotating shaft 21 c provided at the center of the rotating body 21 b, and the rotating shaft 21 c is supported inside the piece 18.

  Further, the piece 18 has a radial thickness from the outermost surface 21a of the ball bearing 21 to the crimping surface 23, which is the maximum radial thickness from the sliding portion 20 to the crimping surface 23, and the guide groove 15 has a radial thickness. When inserted into the reduced diameter portion 17 from the distal end direction to the proximal end direction in a state where it is fitted in, it has a thickness that can be wedged. The piece 18 is sandwiched between the outer peripheral surface 22 of the small-diameter tubular leg 3 and the inclined surface 16 by being inserted in the proximal direction with respect to the reduced diameter portion 17 in the accommodation space 9, and can be wedged. The wedge-shaped piece 18 can hold the small-diameter tubular leg 3 that is stretched to a desired length.

  The inner circumferential surface of the piece 18 in the radial direction is formed on a crimping surface 23 that can be crimped to the outer circumferential surface 22 of the small-diameter tubular leg 3 in a state where it is wedged at the reduced diameter portion 17. In the present embodiment, the piece 18 is made of polyacetal resin, which is a thermoplastic resin, and the large-diameter tubular leg 2 and the small-diameter tubular leg 3 are formed of a composite material of carbon fiber and resin. A sufficient pressure-bonding effect of the stopped piece 18 on the small-diameter tubular leg 3 can be expected.

  Moreover, in this Embodiment, the diameter expansion accommodating part 8 of the cylindrical member 4 is formed with aluminum. This is because, by forming the enlarged diameter accommodating portion 8 from metal, deformation caused by the radially outward stress received from the piece 18 can be suppressed. By using aluminum, the weight can be reduced as compared with other metals.

  A spring receiving plate 24 having a structure shown in FIGS. 13 to 15 is screwed to the front end surface of the cylindrical member 4 with screws 25. A spring receiving groove 27 is formed in an annular shape with respect to the axial center on the inner bottom surface 26 of the spring receiving plate 24. A piece push-up spring 29 installed between the tip end portion of the spring receiving groove 27 and the tip end surface 28 of the piece 18 urges the piece 18 in the proximal direction with a force capable of being pushed up.

  As shown in FIGS. 16 to 19, the release member 30 is formed in a cylindrical shape with a base end and a distal end released, and as shown in FIGS. 3 and 4, the diameter expansion accommodating portion of the tubular member 4. 8 is slidably mounted in the axial direction along the peripheral surface. Further, the release member 30 has a base-side half 30a formed in a single-walled cylindrical shape, and a tip-side half 30b formed in a width that can be inserted into the through hole 13 inside the cylindrical cover 35. It is formed in a double-walled cylindrical shape having release claws 32a.

  The release claw 32a is formed by forming a plurality of cuts 32b on the cylindrical wall so as to be spaced apart from each other in the circumferential direction, and a width that allows the claw portion between the cuts 32b and the cuts 32b to be inserted into the through hole 13. Formed. The release claw 32a is formed to have a length capable of coming into contact with the proximal end surface 31 of the piece 18 wedged by sliding the release member 30 in the distal direction, and the release claw 32a is in contact with the piece 18 Further, by sliding the release member 30 in the distal direction, the piece 18 can be released from the reduced diameter portion 17 when necessary by pushing the piece 18 in the distal direction with the release claw 32a.

  As shown in FIG. 18, the cover portion 35 includes a protruding portion 33 that protrudes radially outward from a boundary portion between the proximal end half portion 30 a and the distal end half portion 30 b, and extends from the protruding portion 33 to the distal end. A space 34 is formed between the release claw 32a and the release claw 32a. As shown in FIG. 3, the cover portion 35 has an inner diameter that is slightly larger than that of the enlarged diameter accommodating portion 8 of the cylindrical member 4, and the tip of the space 34 is released. Further, the peripheral wall base end face 36 of the enlarged diameter accommodating portion 8 of the tubular member 4 is in a state of entering the space 34, and the space 34 whose end side is closed by the peripheral wall base end face 36 is as shown in FIGS. A push-up spring 37 is installed. The push-up spring 37 is in contact with the peripheral wall base end surface 36 and the inner surface 38 of the overhang portion 33 and biases the release member 30 in the base end direction.

  On the other hand, on the inner peripheral surface of the base end side half 30a of the release member 30, as shown in FIG. As shown in FIGS. 3 and 4, a locking ring having an outer diameter slightly smaller than the inner diameter of the release member 30 on the enlarged diameter side of the locking step 39 is provided on the outer peripheral surface of the fixed base end portion 5 of the cylindrical member 4. 40 is attached by a gusset screw 401. The locking ring 40 functions as a locking member for the release member 30, and as shown in FIG. 3, the locking step 39 abuts on the locking ring 40, thereby causing the push-up spring 37 to move in the proximal direction. The released release member 30 is locked by the locking ring 40. The locking ring 40 may be attached to the outer peripheral surface of the large-diameter tubular leg 2.

  Since the release member 30 has such a structure, in a normal state where no force is applied from the outside, the release member 30 determines the position locked by the lock ring 40 as shown in FIG. The position K is fixed. When the user grasps the cover part 35 and slides the release member 30 in the distal direction, the release part 30 moves along the outer peripheral surface of the enlarged diameter accommodating part 8 of the cylindrical member 4 as shown in FIG. 32 a can be inserted into the accommodation space 9 from the through hole 13. When the user releases the cover 35, the release member 30 automatically returns to the home position K shown in FIG.

  Here, in a state where the release member 30 is in the fixed position K shown in FIG. 3, the release claw 32 a does not contact the piece 18 that is wedged by the reduced diameter portion 17, and the proximal end surface 31 of the piece 18. And a length that can secure a separation distance L between the tip of the release claw 32a. Further, the length L1 from the home position K until the push-up spring 37 shown in FIG. 4 is in the most contracted state is longer than the separation distance L.

  When the small-diameter tubular leg 3 is inserted into the large-diameter tubular leg 2 and shortened, the release member 30 and the small-diameter tubular leg 3 are grasped by the left and right hands, and force is applied in a direction in which the hands approach each other. When applied, the release member 30 slides in the distal direction from the fixed position K, and the distal end of the release claw 32a provided on the release member 30 presses against the proximal end surface 31 of the piece 18, as shown in FIG. The wedged state piece 18 can be released from the reduced diameter portion 17. When the small-diameter tubular leg 3 is continuously pushed in the proximal direction, the small-diameter tubular leg 3 can be inserted into the large-diameter tubular leg 2 and a shortening operation can be performed.

  When trying to complete the shortening operation, if the hand is released from the release member 30, the large-diameter tubular leg 2 is grasped by the hand holding the release member 30, and the small-diameter tubular leg 3 is pushed in the proximal direction. As shown in FIG. 3, the piece 18 together with the small diameter tubular leg 3 is again inserted into the reduced diameter portion 17 and wedged, so that the small diameter tubular leg 3 can be held in a shortened state. When the stress from the release member 30 disappears, the piece 18 is automatically pushed up to a position where the base end of the piece 18 is in contact with the inclined surface 16 of the reduced diameter portion 17 by the piece push-up spring 29 and the crimping surface 23 is a small diameter tubular. Since it is in contact with the leg 3, after releasing the release member 30, if the small-diameter tubular leg 3 is pushed in slightly, the piece 18 is inserted into the reduced diameter portion 17 and wedged.

  In the piece 18 wedged in the reduced diameter portion 17, the pressing surface 23 is pressed against the outer peripheral surface 22 of the small-diameter tubular leg 3 by the pressing force received from the inclined surface 16 inward in the radial direction. It is pushed upward from the distal direction by a piece push-up spring 29 in the proximal direction. For this reason, the piece 18 is released from the reduced diameter portion 17 and does not fall off only when the tip of the small-diameter tubular leg 3 is directed vertically downward.

  On the other hand, when the small-diameter tubular leg 3 is extended from the large-diameter tubular leg 2, if the small-diameter tubular leg 3 is grasped and pulled in the distal direction, the crimping surface 23 is brought into close contact with the outer peripheral surface 22 of the small-diameter tubular leg 3. By moving the piece 18 together with the small-diameter tubular leg 3 in the distal direction, the small-diameter tubular leg 3 can be immediately stretched by being released from the reduced diameter portion 17. In addition, while the small-diameter tubular leg 3 is being stretched, the piece 18 is moved to a position where the proximal end of the piece 18 is in contact with the inclined surface 16 of the reduced diameter portion 17 by the piece push-up spring 29 or to the inclined surface 16. Since the state where the small diameter tubular leg 3 is stretched to a desired position and then the small diameter tubular leg 3 is slightly pushed in after the small diameter tubular leg 3 is slightly pushed in can be maintained. Inserted and wedged. Since the wedged piece 18 fixes the small-diameter tubular leg 3 to the large-diameter tubular leg 2, according to the expansion / contraction control device 1, the small-diameter tubular leg 3 stretched to a desired length is immediately fixed. can do. When performing the work of stretching the small-diameter tubular leg 3 and fixing it to a desired length, the user does not need to directly touch the expansion / contraction control device 1 for operation.

  As shown in FIG. 3, the expansion / contraction control device 1 has a cylindrical member 4 between the fixed base end 5 and the accommodating space 9 and adjacent to the distal end side of the large-diameter tubular leg 2. Formed in the anti-rattle portion 50. The rattling prevention portion 50 has a concave groove portion 52 in which a central inner peripheral surface forms a gap 51 between the small diameter tubular leg 3 and the outer peripheral surface 22 of the small diameter tubular leg 3, and protrudes radially inward from the concave groove portion 52. The base end side wall part 53 and the front end side wall part 54 are provided.

  As shown in FIGS. 20 to 22, the first annular wedge body 41 a sandwiched between the proximal end side wall portion 53 of the rattling prevention portion 50 and the small-diameter tubular leg 3 has a part of the ring as the outer peripheral surface. Formed in a C-shaped annular shape having a deficient portion 411a that is deficient from the inner peripheral surface to the inner peripheral surface, and the outer peripheral surface is formed on the first engagement surface 43a that is an inclined surface that increases in diameter from the proximal end to the distal end. The inner peripheral surface is formed on the first contact surface 44a composed of a surface parallel to the outer peripheral surface of the small-diameter tubular leg. The inner peripheral surface of the proximal end side wall portion 53 in contact with the first engagement surface 43a is formed on a first engaged surface 45a that is an inclined surface that increases in diameter from the proximal end toward the distal end.

  As shown in FIGS. 20 to 22, the second annular wedge body 41 b sandwiched between the distal end side wall portion 54 of the rattling prevention portion 50 and the small-diameter tubular leg 3 has a part of the ring from the outer peripheral surface. Formed in a C-shaped annular shape having a deficient portion 411b that is deficient on the inner peripheral surface, the outer peripheral surface is formed on a second engagement surface 43b that is an inclined surface that expands from the distal end toward the base end, and An inner peripheral surface is formed on a second contact surface 44b made of a surface parallel to the outer peripheral surface of the small-diameter tubular leg. The inner peripheral surface of the distal end side wall portion 54 in contact with the second engagement surface 43b is formed as a second engaged surface 45b formed of an inclined surface that increases in diameter from the distal end toward the proximal end.

  The biasing spring 42 is mounted along the outer peripheral surface of the small-diameter tubular leg, and is accommodated in the gap 51 between the first annular wedge body 41a and the second annular wedge body 41b. The base end of the urging spring 42 is brought into contact with the first annular wedge body 41a, and the distal end is brought into contact with the second annular wedge body 41b so that the first annular wedge body 41a and the second annular wedge body 41b are pivoted relative to each other. It is biased in the direction of separating in the direction.

  The first engaging surface 43 a and the first engaged surface 45 a are formed at the same inclination angle with respect to the outer peripheral surface 22 of the small-diameter tubular leg 3. The second engagement surface 43 b and the second engaged surface 45 b are formed at the same inclination angle with respect to the outer peripheral surface 22 of the small-diameter tubular leg 3.

  When the small-diameter tubular leg 3 is inserted into the large-diameter tubular leg 2 and shortened, the outer peripheral surface 22 of the small-diameter tubular leg 3 rubs the first contact surface 44a of the first annular wedge body 41a in the proximal direction. . At the same time, the first annular wedge body 41a narrows the defect portion 411a to reduce the diameter, while the first engagement surface 43a and the first engaged surface 45a are firmly in contact with each other, and the first annular wedge body 41a The first engagement surface 43a applies a force in the direction of expanding the first engaged surface 45a radially outward. At this time, since the cylindrical member 4 is fixed to the large-diameter tubular leg 2 at the fixed base end portion 5, the first engaged surface 45a is also pushed and expanded by the force received from the first engaging surface 43a. Therefore, the first annular wedge body 41a can be brought into a state of being strongly fitted between the rattling prevention portion 50 of the tubular member 4 and the small-diameter tubular leg 3. By setting the first annular wedge body 41a to be tightly fitted between the rattling prevention portion 50 of the tubular member 4 and the small diameter tubular leg 3, the axis of the large diameter tubular leg 2 is secured. It is possible to prevent the small-diameter tubular leg 3 from rattling in the tilting direction.

  When the small-diameter tubular leg 3 is inserted into the large-diameter tubular leg 2 and shortened, the biasing spring 42 prevents the second annular wedge body 41b from being detached from the second engaged surface 45b. Applies a force to push down the second annular wedge body 41b in the distal direction.

  Further, when the small-diameter tubular leg 3 is extended from the large-diameter tubular leg 2, the outer peripheral surface 22 of the small-diameter tubular leg 3 scrubs the second contact surface 44b of the second annular wedge body 41b in the distal direction. As a result, as in the case of the first annular wedge body 41a when the small-diameter tubular leg 3 is inserted into the large-diameter tubular leg 2 and shortened, the second annular wedge body 41b narrows the defective portion 411b. While being reduced in diameter, the second engagement surface 43b of the second annular wedge body 41b is firmly in close contact with the second engaged surface 45b of the rattling prevention portion 50, and the second annular wedge body 41b is It can be set as the state tightly fitted between the rattling prevention part 50 and the small diameter tubular leg 3 of the shaped member 4. By setting the second annular wedge body 41b to be strongly fitted between the rattling prevention portion 50 of the tubular member 4 and the small diameter tubular leg 3, the small diameter tubular leg 3 is made to be a large diameter tubular leg. Even when extended from 2, rattling can be prevented in the direction in which the small-diameter tubular leg 3 is inclined with respect to the axis of the large-diameter tubular leg 2.

  When the small-diameter tubular leg 3 is extended from the large-diameter tubular leg 2, the urging spring 42 is provided with the first annular wedge so that the first annular wedge body 41a is not detached from the first engaged surface 45a. A force is applied to push up the body 41a in the proximal direction.

  Note that only one of the first annular wedge body 41a and the second annular wedge body 41b, as shown in FIGS. 25 and 27, may be installed in the rattling prevention portion 50.

  When only the first annular wedge body 41 a is installed in the rattling prevention portion 50, the biasing spring 42 is attached to the inner surface of the tip side wall portion 54 of the rattling prevention portion 50 as shown in FIG. 25. The first annular wedge body 41a is urged in the proximal direction by abutting.

  As a result, it is possible to prevent the shortened small-diameter tubular leg 3 from occurring in a direction inclined with respect to the axial direction with respect to the large-diameter tubular leg 2.

  On the other hand, when only the second annular wedge body 41 b is installed in the rattling prevention part 50, the urging spring 42 has a proximal end side wall part 53 of the rattling prevention part 50 as shown in FIG. 27. The second annular wedge body 41b is urged in the distal direction by contacting the inner surface of the second annular wedge body 41b.

  As a result, it is possible to prevent the stretched small-diameter tubular leg 3 from occurring in a direction inclined with respect to the axial direction with respect to the large-diameter tubular leg 2.

  Here, a fixing hole 47 is formed on the outer peripheral surface in the vicinity of the proximal end of the small-diameter tubular leg 3 so as to be opposed. Then, with the two semi-cylindrical curved plate members 48 facing each other, a fixing projection 49 formed on the inner surface of the curved plate member 48 is fitted into the fixing hole 47 and attached. It becomes. It is mounted along the peripheral surface of the small diameter tubular leg 3. If the small-diameter tubular leg 3 is continuously stretched, the distal end of the curved plate member 48 comes into contact with the proximal end of the first annular wedge body 41a, so that the small-diameter tubular leg 3 can be prevented from falling off.

  In the present embodiment, the expansion / contraction control device 1 has such a structure, so that when one leg portion T has a plurality of stages of connection portions as shown in FIG. When 1 is provided, the inner diameter D1 at the proximal end of the release member 30 is formed smaller than the outer diameter D2 of the spring receiving plate 24 of the expansion / contraction control device 1 provided at the adjacent position in the proximal direction. Further, in a state where the release member 30 is at the fixed position K, the base end of the release member 30 is further away from the base end of the tubular member 4 than the separation distance L between the base end face 31 of the piece 18 and the tip of the release pawl 32a. The base end portion 130 of the release member 30 extends to the base end side from the cylindrical member 4 so that the distance L2 is longer. When the locking ring 40 is attached to the outer peripheral surface of the large-diameter tubular leg 2, the distance L <b> 2 refers to the distance from the proximal end of the release member 30 to the proximal end of the locking ring 40.

  In FIG. 23, the disassembled perspective view of the expansion-contraction control apparatus 1 is shown.

  Since the expansion / contraction control device 1 has such a structure, the piece 18 is wedged by the reduced diameter portion 17 even when the single leg portion T has a plurality of connecting portions as shown in FIG. In this state, as shown in FIG. 3, the base end portion 130 of the release member 30 extends to the base end side from the fixed base end portion 5 of the tubular member 4. By providing 1, it is possible to shorten the stretched leg T in one operation.

  The shortening operation by the one operation will be described with reference to FIG. In FIG. 24, one leg portion T has a plurality of connecting portions by tubular leg bodies T1 to T4 whose diameters are gradually reduced from the base end side. The most proximal tubular leg T1 has the largest diameter, the distal tubular leg is connected to the inside of the proximal tubular leg so as to be able to enter and exit, and the most distal tubular leg T4 is the most. It is formed thin. The base end of the tubular leg T1 is provided with a connecting portion E that can be connected to a pan head such as a tripod, and the tip of the tubular leg T4 is provided with a stone protrusion S. And the expansion / contraction control apparatus 1A-1C which concerns on this invention is provided in the connection part of each tubular leg.

  (A) Among the leg portions T in which each of the expansion / contraction control devices 1A to 1C is in a fixed state, the release member 30A of the expansion / contraction control device 1A on the most proximal side is grasped, and the distal end portion of the leg portion T, for example, the stone protrusion S If it is compressed in the end direction, the expansion / contraction control device 1A can be released. Then, (b) when the release member 30A of the expansion / contraction control device 1A is grasped and the stone protrusion S of the leg T is further pressed and contracted in the proximal direction, the tubular leg T2 is accommodated in the tubular leg T1. It will be done. When the tubular leg T2 is accommodated in T1 until it cannot be seen from the outside, (c) the base end portion 130B of the release member 30B of the expansion / contraction control device 1B is formed on the distal end surface of the spring receiving plate 24A of the expansion / contraction control device 1A. Pressed. When the spring receiving plate 24A pushes down the release member 30B, the release claw of the expansion / contraction control device 1B can release the piece from the reduced diameter portion and put the expansion / contraction control device 1B into a released state.

  (D) When the release member 30A of the expansion / contraction control device 1A is gripped, if the stone protrusion S of the leg T is further pressed and contracted in the proximal direction, the tubular leg T3 is accommodated inside the tubular leg T2. Go. Furthermore, if the stone protrusion S of the leg T is continuously compressed in the proximal direction, the expansion / contraction control device 1C can be released as in the case of (e) the expansion / contraction control device 1B. (F) When the telescopic control device 1C is in the released state, the shortening operation is completed when the thinnest tubular leg T4 provided with the stone protrusion S is accommodated in the tubular leg T3.

  In this way, if the distal end of the leg portion T is continuously compressed in the proximal direction while the release member 30 of the most proximal side expansion / contraction control device 1 is gripped, all the expansion / contraction control devices provided on the leg portion T are provided. The leg T can be shortened by one operation while the fixed state of 1 is sequentially released.

  Further, in the shortening operation of the leg T by the one operation, if the release member 30 of the expansion control device 1 on the most proximal side is grasped and the distal end of the leg T is pushed and contracted in the proximal direction, the expansion and contraction on the proximal side is performed. Since the fixed state of each extension control device 1 on the distal end side from the control device 1 is sequentially released, the force required for the shortening work is independent of the number of the extension control devices 1 provided on one leg T. This can be done with the force required to release one telescopic control device 1. For this reason, even if it is a weak person, a shortening operation | work can be performed easily.

  Further, as a second embodiment, as shown in FIGS. 25 and 26, the inner peripheral surface of the spring receiving plate 124 is a third engaged surface 45c made of an inclined surface whose diameter increases from the distal end toward the proximal end. It formed so that it might become. Thereby, when the spring receiving plate 124 is attached to the tubular member 4, the spring receiving groove 127 is formed by the third engaged surface 45 c and the outer peripheral surface portion 22 a of the small-diameter tubular leg 3.

  As shown in FIGS. 20 to 22, the spring receiving groove 127 is formed in a C-shaped annular shape having a missing portion 411 c formed by missing a part of the ring from the outer peripheral surface to the inner peripheral surface, and the outer peripheral surface is the tip. A third engagement surface 43c having an inclined surface whose diameter increases from the base end toward the base end, and a third contact surface 44c having an inner peripheral surface that is parallel to the outer peripheral surface portion 22a of the small-diameter tubular leg 3. The tip-shaped annular wedge body 41c of the thin plate-shaped annular body is fitted.

  The third engaging surface 43c and the third engaged surface 45c are formed at the same inclination angle with respect to the outer peripheral surface portion 22a of the small-diameter tubular leg 3.

  A piece lifting spring 29 installed between the proximal end surface 46 of the distal annular wedge body 41c and the distal end surface 28 of the piece 18 urges the piece 18 in the proximal direction with a force capable of being pushed up.

  When the small-diameter tubular leg 3 is extended from the large-diameter tubular leg 2, the outer peripheral surface 22 of the small-diameter tubular leg 3 scrubs the third contact surface 44c of the distal annular wedge body 41c in the distal direction. As a result, the third engagement surface 43c of the tip annular wedge body 41c is spring-loaded as in the case of the annular wedge body 41a when the small diameter tubular leg body 3 is inserted into the large diameter tubular leg body 2 and shortened. The third engagement surface 45c of the receiving groove 127 can be firmly adhered, and the tip annular wedge body 41c can be brought into a state of being strongly fitted between the spring receiving plate 124 and the small-diameter tubular leg 3.

  Even when the small-diameter tubular leg 3 is extended from the large-diameter tubular leg 2 by setting the tip annular wedge body 41c to be strongly fitted between the spring receiving plate 124 and the small-diameter tubular leg 3, It is possible to prevent rattling in the direction in which the small-diameter tubular leg 3 is inclined with respect to the axis of the large-diameter tubular leg 2. In particular, when the small-diameter tubular leg 3 is extended from the large-diameter tubular leg 2, the large-diameter tubular leg from the small-diameter tubular leg 3 at the connecting portion between the small-diameter tubular leg 3 and the large-diameter tubular leg 2 is used. Since the stress acting in the direction inclined with respect to the axis with respect to the body 2 is increased, by mounting the distal end annular wedge body 41c, rattling at two points that are largely separated from the proximal end side and the distal end side of the accommodation space 9 is achieved. The prevention effect is exhibited, and rattling of the small-diameter tubular leg 3 can be effectively prevented. Further, if all of the first annular wedge body 41a, the second annular wedge body 41b, and the tip annular wedge body 41c are provided, an effect of preventing rattling at three points is exhibited, which is higher than the case of two points. It can exhibit an anti-tacking effect.

  When the small-diameter tubular leg 3 is inserted into the large-diameter tubular leg 2 and shortened, the top annular spring 29 is prevented from being detached from the third engaged surface 45c. Applies a force so as to push down the tip annular wedge body 41c in the tip direction. Thereby, even when the small-diameter tubular leg 3 is shortened, the piece push-up spring 29 holds the tip annular wedge body 41c between the third engaged surface 45c and the small-diameter tubular leg 3, and rattling. The prevention effect can be exhibited.

  If the expansion / contraction control device 1 is used, as shown in FIG. 27, even if a single leg T is a multi-stage tripod R having a plurality of connecting portions, installation and storage are much easier than before. A tripod R that is easy to use can be realized. Similarly, even if the expansion / contraction control device 1 is a monopod provided on a multi-stage leg portion having a plurality of connecting portions, the installation and storage are much easier than in the prior art. Furthermore, even if the expansion / contraction control device 1 is a music stand provided on a multi-stage leg portion having a plurality of connecting portions, installation and storage are much easier than before.

DESCRIPTION OF SYMBOLS 1 Expansion / contraction control apparatus 2 Large diameter tubular leg body 3 Small diameter tubular leg body 4 Cylindrical member 8 Expanded diameter accommodating part 9 Accommodating space 13 Through hole 15 Guide groove 16 Inclined surface 17 Reduced diameter part 18 Piece 21 Ball bearing 23 Crimp surface 24 Spring Receiving plate 27 Spring receiving groove 29 Frame lifting spring 30 Release member 32a Release claw 37 Lifting spring 39 Locking step 40 Locking ring 41a, 41b Annular wedge body 41c End annular wedge body 42 Energizing spring

Claims (13)

A cylindrical large-diameter tubular leg and a small-diameter formed by being inserted into the opening on the distal end side of the large-diameter tubular leg and extending in and out along the axial direction so that the large-diameter tubular leg can be expanded and contracted. An expansion / contraction control device provided at a connecting portion with a tubular leg,
An accommodation space is formed between the fixed base end portion fixed to the outer peripheral surface of the distal end portion of the large-diameter tubular leg and the outer peripheral surface of the small-diameter tubular leg having a diameter larger than that of the fixed base end portion. A cylindrical member provided with an enlarged diameter accommodating portion,
A through hole formed by penetrating the enlarged diameter portion of the enlarged diameter accommodating portion of the cylindrical member from the outside toward the distal end direction along the axial direction to the accommodating space;
In the housing space, the inner peripheral surface of the tubular member has a reduced diameter portion that has an inclined surface that is inclined so as to decrease in diameter from the distal end side toward the proximal end side;
A sliding portion that is housed in the housing space and that can slide smoothly in the axial direction with respect to the inner peripheral surface of the cylindrical member, and a diameter that is wedged when inserted in the proximal direction with respect to the reduced diameter portion. A piece provided with a crimping surface that can be crimped to the outer circumferential surface of the small-diameter tubular leg in the thickness in the direction and wedged in the reduced diameter portion,
An annular spring receiving plate provided on the distal end surface of the cylindrical member;
A piece push-up spring installed between the inner bottom surface of the spring receiving plate and the tip end face of the piece, and urging the piece in the proximal direction with a force capable of pushing up the piece;
A release member that is mounted along the outer peripheral surface of the fixed base end portion of the cylindrical member, is slidable in the axial direction, and is formed with a release claw that can be inserted into the through hole.
The release claw is formed so as to press against the wedged piece by sliding the release member in the distal direction and to release the piece from the reduced diameter portion. . In the sliding portion, a part of a rotating surface of a ball bearing provided on the piece is protruded from an outer surface of the piece facing an inner peripheral surface of the cylindrical member, and the rotating surface is a small-diameter tubular leg. The expansion / contraction control apparatus according to claim 1, wherein the expansion / contraction control apparatus is rotatable along an axial direction. A plurality of guide grooves provided with the inclined surfaces are provided along the axial direction, and are formed on the inner peripheral surface of the accommodation space of the cylindrical member to have a width capable of fitting the sliding portion of the piece. The expansion / contraction control apparatus according to claim 1 or 2. A push-up spring formed by urging the release member in the proximal direction with respect to the tubular member;
The expansion / contraction control device according to claim 1, further comprising: a locking member that locks the release member pushed up by the push-up spring. 5. The base member according to claim 1, wherein a base end portion of the release member extends to a base end side with respect to the cylindrical member in a state where the piece is wedged by the reduced diameter portion. The expansion / contraction control device described in 1. On the distal end surface of the spring receiving plate, a projecting portion is provided that projects in the distal direction from a position intersecting with a virtual vertical line extending from the proximal end surface of the release member,
The said projecting part is not installed in the range smaller than the circle | round | yen which makes the internal diameter of the said release member centering on the center axis | shaft of the said small diameter tubular leg body into the diameter. Telescopic control device. In the cylindrical member, a portion adjacent to the distal end side of the large-diameter tubular leg between the fixed base end portion and the accommodating space is formed in the rattling prevention portion,
The rattling prevention portion includes a concave groove portion in which a central inner peripheral surface forms a gap with the outer peripheral surface of the small-diameter tubular leg, and a proximal end portion and a distal end portion are radially inward of the concave groove portion. A proximal end side wall portion and a distal end side wall portion protruding in the direction,
A C-shaped annular shape having a deficient portion sandwiched between the proximal end side wall portion of the rattling prevention portion and the small-diameter tubular leg and having a part of the ring missing from the outer peripheral surface to the inner peripheral surface. The outer peripheral surface is formed as a first engagement surface including an inclined surface whose diameter increases from the proximal end toward the distal end, and the inner peripheral surface is formed of a surface parallel to the outer peripheral surface of the small-diameter tubular leg. A first annular wedge formed on one contact surface;
A biasing spring that is mounted along the outer peripheral surface of the small-diameter tubular leg in the concave groove and biases the first annular wedge in the proximal direction; and
The inner peripheral surface of the base end side wall portion in contact with the first engagement surface of the first annular wedge body is formed as a first engaged surface including an inclined surface whose diameter increases from the base end toward the front end. The expansion / contraction control device according to any one of claims 1 to 6. Formed in a C-shaped annular shape having a defect portion sandwiched between the tip side wall portion of the rattling prevention portion and the small-diameter tubular leg and having a part of the ring missing from the outer peripheral surface to the inner peripheral surface. And the outer peripheral surface is formed as a second engaging surface comprising an inclined surface whose diameter increases from the distal end toward the base end, and the inner peripheral surface is a second surface comprising a surface parallel to the outer peripheral surface of the small-diameter tubular leg. A second annular wedge formed on the contact surface;
The inner peripheral surface of the distal end side wall portion in contact with the second engagement surface of the second annular wedge body is formed as a second engaged surface comprising an inclined surface whose diameter increases from the distal end toward the proximal end. ,
The biasing spring is mounted between the first annular wedge body and the second annular wedge body, and in a direction in which the first annular wedge body and the second annular wedge body are separated from each other in the axial direction. The expansion / contraction control device according to claim 7, wherein the expansion / contraction control device is biased. In the cylindrical member, a portion adjacent to the distal end side of the large-diameter tubular leg between the fixed base end portion and the accommodating space is formed in the rattling prevention portion,
The rattling prevention portion includes a concave groove portion in which a central inner peripheral surface forms a gap with the outer peripheral surface of the small-diameter tubular leg, and a proximal end portion and a distal end portion are radially inward of the concave groove portion. A proximal end side wall portion and a distal end side wall portion protruding in the direction,
Formed in a C-shaped annular shape having a defect portion sandwiched between the tip side wall portion of the rattling prevention portion and the small-diameter tubular leg and having a part of the ring missing from the outer peripheral surface to the inner peripheral surface. And the outer peripheral surface is formed as a second engaging surface comprising an inclined surface whose diameter increases from the distal end toward the base end, and the inner peripheral surface is a second surface comprising a surface parallel to the outer peripheral surface of the small-diameter tubular leg. A second annular wedge formed on the contact surface;
A biasing spring that is mounted along the outer peripheral surface of the small-diameter tubular leg in the concave groove and biases the second annular wedge in the distal direction; and
The inner peripheral surface of the distal end side wall portion in contact with the second engagement surface of the second annular wedge body is formed as a second engaged surface comprising an inclined surface whose diameter increases from the distal end toward the proximal end. The expansion / contraction control apparatus according to any one of claims 1 to 6. A third engaged surface comprising an inclined surface that expands the inner peripheral surface of the spring receiving plate from the distal end toward the proximal end, and an outer peripheral surface portion of the small-diameter tubular leg facing the third engaged surface Comprising a spring receiving groove formed by
The spring receiving groove is formed in a C-shaped annular shape having a deficient portion in which a part of the ring is deficient from the outer peripheral surface to the inner peripheral surface, and the outer peripheral surface is an inclined surface whose diameter increases from the distal end to the proximal end. A tip annular wedge body comprising a thin plate-like annular body having a third engagement surface and a third contact surface having an inner circumferential surface parallel to the outer circumferential surface of the small-diameter tubular leg. Get it
The expansion / contraction control device according to any one of claims 1 to 9, wherein the piece push-up spring is installed between a proximal end surface of the distal annular wedge body and a distal end surface of the piece. A tripod comprising the expansion / contraction control device according to claim 1. A monopod comprising the expansion / contraction control device according to claim 1. A music stand comprising the expansion / contraction control device according to claim 1.

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