Braking Unit

Abstract

To provide an inexpensive brake unit improved in operability.SOLUTION: A brake unit 1 is constituted by arranging sets of a brake bush 2 and a pair of bushes 3, 3 at both sides of a center beam 5 in a housing 4. The brake bush 2 of a cylindrical shape is formed with a slit 2a by being notched in a slit shape, and has elasticity by which an inner diameter is reduced when external force is applied to the outer diameter, and the size of the inner diameter returns to its original one when application of external force is eliminated. A torsion spring 6 is mounted on the outer diameter of the brake bush 2, and applies external force for reducing a size in a diameter direction of the brake bush 2 to the outer diameter upon being mounted. Due to that an adjustment screw 10 is displaced in a direction of approaching from a lateral face 42f of a case 42 to the other arm 6b of the torsion spring 6, the torsion spring 6 weakens external force to be given to the outer diameter of the brake bush 2 so as to insert a rod into the inner diameter of the brake bush 2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a braking unit for arresting the movement of a rod and braking the support of the rod. [Background technology]

[0002] A conventional braking unit of this type is, for example, a headrest device for a chair disclosed in Patent Document 1. In this headrest device, the headrest body is attached to the upper part of the back of the chair via a rod attached to a slide bar. When a slide bar up / down movement motor rotates forward and backward, the slide bar moves up and down, and the headrest body supported by the rod also moves up and down together with the slide bar.

[0003] Also, a conventional braking unit of this type is, for example, that in a rotating dental care chair disclosed in Patent Document 2. The head rest in this chair is composed of the head body and height and tilt adjustment fittings, which are composed of the support legs and a receiving metal fitting provided in the backrest. The support legs are composed of an upper metal fitting attached to the underside of the head body and a support vertical plate suspended downward and connected to the upper metal fitting via a tightening horizontal bolt. The head body's vertical movement is braked by tightening the fixing bolt for the support vertical plate, which corresponds to a rod, and the vertical movement of the support vertical plate is stopped. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 5-131016 [Patent Document 2] Japanese Patent Application Publication No. 10-33601 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the braking unit disclosed in the above-mentioned conventional Patent Document 1, the movement of the headrest body supported by the rod is braked by stopping the drive of the slide bar up-down movement motor. Therefore, since the braking unit is configured as an electric type, the braking unit disclosed in the above-mentioned conventional Patent Document 1 has a problem of being expensive.

[0006] In addition, in the braking unit disclosed in the above-mentioned conventional Patent Document 2, in order to change the vertical position of the head body, it is necessary to loosen the fixing bolt for the vertical support plate and then tighten the fixing bolt for the vertical support plate at the desired vertical position of the head body. For this reason, the braking unit disclosed in the above-mentioned conventional Patent Document 2 has a problem of poor operability. [Means for solving the problem]

[0007] The present invention has been made to solve such problems, a cylindrical brake bushing having elasticity such that a slot is formed by cutting out a slit from one end to the other end, and when an external force is applied to the outer diameter to reduce the radial dimension, the size of the gap in the slot becomes smaller and the inner diameter becomes smaller, and when the external force is removed, the size of the inner diameter returns to its original size; A pair of cylindrical bushings each having an inner diameter into which the outer diameters of the respective ends of the brake bushing are inserted and an inner bottom surface that abuts against the respective end surfaces of the brake bushing; a torsion coil spring that is attached to the brake bush with the inner diameter of the coil covering the outer diameter of the brake bush and applies an external force to the outer diameter of the brake bush by the spring elasticity that holds the coil; a housing having a pair of opposing side walls that sandwich a pair of bushings with the outer diameters of the respective ends of the brake bushings inserted into the inner diameters thereof, the housing having on both sides sandwiching the brake bushings a support portion that supports one arm of a torsion coil spring, and a support wall having a notch formed therein into which the other arm of the torsion coil spring is fitted and supports the other arm; an adjustment mechanism having a shaft-shaped member that is provided on a side surface of the housing on a path that the other arm supported by the support wall describes as it rotates around the axis of the torsion coil spring and that has a tip that comes into contact with the other arm and rotates the other arm around the axis of the torsion coil spring when the shaft-shaped member is displaced in a direction approaching the other arm from the side surface; The braking unit is constituted by the above.

[0008] To brake an object supported by the rod using the brake unit of this configuration, first, the shaft-shaped member of the adjustment mechanism is displaced from the side of the housing toward the other arm of the torsion coil spring, and the other arm of the torsion coil spring supported by the notch formed in the support wall is pushed by the tip of the shaft-shaped member, causing the other arm of the torsion coil spring to rotate around the axis of the torsion coil spring against the elasticity of the torsion coil spring. This rotation of the other arm weakens the external force that the torsion coil spring exerts on the outer diameter of the brake bush, and the size of the inner diameter of the brake bush is restored to its original size. In this state, the rod supporting the object to be braked is inserted into the inner diameter of the brake bush. Next, by stopping the pushing of the tip of the shaft-shaped member on the other arm of the torsion coil spring, the spring elasticity held by the torsion coil spring causes the shaft-shaped member to be pushed back from its forward / retracted position relative to the side of the housing, and the other arm of the torsion coil spring is again supported by the notch formed in the support wall. In this state, by setting the opening angle of both arms of the torsion coil spring in advance so that the external force applied by the torsion coil spring to the outer diameter of the brake bush is large enough to reduce the inner diameter of the brake bush, the outer diameter of the rod is tightened to the reduced inner diameter of the brake bush. Therefore, the movement of the rod in the axial direction of the brake bush is restricted, and the support for the rod is braked together with the rod.

[0009] Therefore, according to this configuration, unlike conventional braking units, it is possible to provide a braking unit at low cost by using a simple mechanism to brake the object supported by the rod. Also, unlike conventional braking units, the support position of the object supported by the rod can be changed by a simple operation of simply displacing the shaft-shaped member of the adjustment mechanism relative to the side of the housing, without requiring operations of loosening and tightening a fixing bolt each time, which is required, thereby improving the operability of the braking unit.

[0010] The present invention is also characterized in that the housing sandwiches a pair of bushings, the inner diameter of which is inserted into the outer diameter of each end of the brake bushing, on both sides of the support portion between the pair of side walls.

[0011] According to this configuration, it is possible to brake an object supported by a pair of rods with good operability using an inexpensive braking unit.

[0012] In addition, the present invention is characterized in that the support portion is constituted by a hollow cylindrical beam having an axial length that is sandwiched between a pair of side walls.

[0013] According to this configuration, by sandwiching the beam between the pair of side walls, one arm of the torsion coil spring is supported by the beam and the strength of the housing is increased.

[0014] The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of: a long hole formed in each of a pair of side walls at a portion where the beam is sandwiched, in a direction in which one arm of the torsion coil spring rotates around an axis of the torsion coil spring; a support screw having an outer diameter and a length longer than the distance between the pair of side walls, the support screw being inserted into each of the elongated holes and the hollow cylindrical portion of the beam, the support screw having a head having an outer diameter larger than the groove width of the elongated holes at one end and a male screw at the other end; A nut having an outer diameter larger than the groove width of the elongated hole, which is screwed into a male thread formed on the other end of a support screw protruding from one of the elongated holes outside the space between the pair of side walls, thereby fixing the beam at any position between the pair of side walls in the direction in which the elongated hole is formed. The present invention is characterized by comprising:

[0015] According to this configuration, the beam sandwiched between the pair of side walls rotates one arm of the torsion coil spring around the axis of the torsion coil spring according to the position in the forming direction of the elongated hole where the nut is fastened and fixed to the other end of the support screw. Therefore, the initial value of the external force that the torsion coil spring imparts to the outer diameter of the brake bushing by its tightening force can be adjusted according to the position in the forming direction of the elongated hole where the beam is fixed between the pair of side walls by the nut.

[0016] In addition, by configuring the support part with the beam and the support screw as separate members, the beam can be easily fixed between a pair of side walls by inserting the support screw into the hollow cylindrical portion of the beam through the long hole and fastening a nut to the other end of the support screw protruding from one of the long holes, and the beam can be easily attached to the housing, improving the assembly of the brake unit. In addition, by configuring the support part with the beam and the support screw as separate members, the parts processing of the support part is facilitated.

[0017] The present invention is also characterized in that the adjustment mechanism comprises a shaft-shaped member formed by an adjustment screw, and a female threaded hole formed on the side surface and having a female thread formed on its inner diameter to screw into the adjustment screw.

[0018] According to this configuration, the adjustment screw is screwed into a female screw hole opened in the side of the housing and is attached to the side of the housing so as to be freely movable forward and backward. Therefore, the adjustment screw can be turned to adjust the forward and backward position of the tip of the adjustment screw relative to the side of the housing, and the adjustment screw can be displaced in a direction approaching the other arm of the torsion coil spring from the side of the housing. This allows the tip of the adjustment screw to push the other arm of the torsion coil spring supported by the notch formed in the support wall, and the other arm of the torsion coil spring can be rotated around the axis of the torsion coil spring against the elasticity of the torsion coil spring. Therefore, this rotation of the other arm weakens the external force applied by the torsion coil spring to the outer diameter of the brake bush, and in a state where the size of the inner diameter of the brake bush is restored to its original size, a rod supporting an object to be braked can be inserted into the inner diameter of the brake bush. Furthermore, by turning the adjustment screw in the opposite direction to return the tip of the adjustment screw to its original position relative to the side of the housing and stopping the tip of the adjustment screw from pressing against the other arm of the torsion coil spring, the other arm of the torsion coil spring is once again supported by the notch formed in the support wall and the outer diameter of the rod is tightened to the inner diameter of the reduced diameter brake bushing.

[0019] Furthermore, by turning the adjustment screw to adjust the advance / retract position of the tip of the adjustment screw relative to the side of the housing, the tip of the adjustment screw pushes the other arm of the torsion coil spring up from the notch formed in the support wall, thereby changing the rotational position of the other arm around the axis of the torsion coil spring. The changed rotational position is maintained by the screw engagement of the adjustment screw with the female screw hole. Therefore, with this configuration, by turning the adjustment screw to adjust the advance / retract position of the tip of the adjustment screw relative to the side of the housing, the initial value of the external force that the torsion coil spring applies to the outer diameter of the brake bushing can also be adjusted.

[0020] The present invention is also characterized in that the adjustment mechanism comprises an axial member formed by a pin, an insertion hole formed on the side having an inner diameter for inserting the pin, and a retaining ring that engages with the tip side of the pin to prevent the pin from slipping out of the insertion hole.

[0021] According to this configuration, the pin is inserted into a through hole opened in the side of the housing, and the pin is prevented from coming out of the through hole by a retaining ring. The pin inserted into the through hole is displaced from the side of the housing toward the other arm of the torsion coil spring, and the tip of the pin is pressed against the other arm of the torsion coil spring supported by the notch formed in the support wall, so that the other arm of the torsion coil spring can be rotated around the axis of the torsion coil spring against the elasticity of the torsion coil spring. This rotation of the other arm weakens the external force applied by the torsion coil spring to the outer diameter of the brake bush, and the size of the inner diameter of the brake bush is restored, and a rod supporting an object to be braked can be inserted into the inner diameter of the brake bush. In addition, by stopping the tip of the pin from pressing the other arm of the torsion coil spring, the spring elasticity held by the torsion coil spring pushes the pin back from its forward / reverse position relative to the side of the housing. Therefore, the other arm of the torsion coil spring is again supported by the notch formed in the support wall, and the outer diameter of the rod is tightened against the inner diameter of the reduced diameter brake bush.

[0022] The present invention is also characterized in that the adjustment mechanism includes a bolt having a through hole drilled in the axial direction and having an inner diameter for inserting a pin, the through hole having an internal thread formed on its inner diameter for screwing onto the bolt, and a retaining ring that prevents the bolt from slipping out of the through hole.

[0023] According to this configuration, the bolt is screwed into the female thread formed on the inner diameter of the insertion hole and is attached to the side of the housing so as to be freely movable forward and backward. The pin is inserted into a through hole opened in the axial direction of the bolt and is guided by the through hole to move in a direction perpendicular to the side of the housing. The bolt is prevented from coming out of the through hole by a retaining ring. The pin inserted into the through hole is displaced from the tip surface of the bolt in a direction approaching the other arm of the torsion coil spring, and the tip of the pin is pressed against the other arm of the torsion coil spring supported by the notch formed in the support wall, so that the other arm of the torsion coil spring can be rotated around the axis of the torsion coil spring against the elasticity of the torsion coil spring. This rotation of the other arm weakens the external force applied by the torsion coil spring to the outer diameter of the brake bush, and a rod supporting an object to be braked can be inserted into the inner diameter of the brake bush in a state where the size of the inner diameter of the brake bush is restored to its original size. In addition, by stopping the pushing of the other arm of the torsion coil spring by the tip of the pin, the spring elasticity of the torsion coil spring pushes the pin back from its forward / reverse position relative to the tip surface of the bolt. Therefore, the other arm of the torsion coil spring is supported again by the notch formed in the support wall, and the outer diameter of the rod is tightened to the inner diameter of the reduced diameter brake bushing.

[0024] In addition, by turning the bolt to adjust the advance / retract position of the tip of the pin relative to the side of the housing, the tip of the pin pushes the other arm of the torsion coil spring up from the notch formed in the support wall, thereby changing the rotational position of the other arm around the axis of the torsion coil spring. The changed rotational position is maintained by the engagement of the bolt with the female thread formed on the inner diameter of the insertion hole. Therefore, with this configuration, by turning the bolt to adjust the advance / retract position of the tip of the pin relative to the side of the housing, the initial value of the external force that the torsion coil spring applies to the outer diameter of the brake bushing can also be adjusted.

[0025] In the present invention, the pin has a head at the end opposite to the tip side.

[0026] According to this configuration, the operation of displacing the pin inserted into the insertion hole opened in the side surface of the housing or the through hole opened in the axial direction of the bolt relative to the side surface of the housing or the tip surface of the bolt can be performed with a good feel on the head of the pin, without causing pain in the fingertips. Effect of the Invention

[0027] According to the present invention, it is possible to provide a brake unit which is inexpensive and has improved operability. [Brief description of the drawings]

[0028] [Figure 1] 1 is a diagram showing an overall configuration of a brake unit according to a first embodiment of the present invention; [Diagram 2] FIG. 2 is an exploded perspective view of the brake unit according to the first embodiment. [Diagram 3] FIG. 2 is a diagram showing a housing constituting the brake unit according to the first embodiment. [Figure 4] 4 is a diagram illustrating how a support portion formed of a center beam is attached to the housing shown in FIG. 3. FIG. [Diagram 5] 2 is a diagram showing a brake bushing, a bushing, a torsion spring, and an adjustment screw that constitute the braking unit according to the first embodiment. FIG. [Figure 6] 6A to 6C are diagrams illustrating a brake unit according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Next, an embodiment of a brake unit according to the present invention will be described, in which the same or corresponding parts in each drawing are denoted by the same reference numerals.

[0030] Fig. 1(a) is a perspective view of a brake unit 1 according to a first embodiment of the present invention, Fig. 1(b) is a plan view, Fig. 1(c) is a side view, and Fig. 2 is an exploded perspective view of the brake unit 1.

[0031] The braking unit 1 is configured by arranging a brake bush 2 and a pair of bushes 3, 3 on either side of a center beam 5 in a housing 4, and a torsion spring 6, which is a torsion coil spring, is attached to one of the brake bushes 2.

[0032] The housing 4 is composed of a cover 41 shown in Fig. 3(a) and a case 42 shown in Fig. 3(b) and (c). Fig. 3(b) is a perspective view of the case 42 seen from one direction, and Fig. 3(c) is a perspective view of the case 42 seen from another direction.

[0033] The cover 41 is fixed to one side of the case 42 by a pair of mounting screws 7, 7. The material of each of the cover 41 and the case 42 is basically metal, but may be other materials such as plastic. By attaching the cover 41 to the case 42, a pair of opposing side walls 41a, 42a is formed in the housing 4. Each of the side walls 41a, 42a has bush mounting holes 41b, 42b for mounting each bush 3 formed in two locations. In addition, between the pair of bush mounting holes 41b, 41b in the cover 41 and between the pair of bush mounting holes 42b, 42b in the case 42, elongated holes 41c, 42c for sandwiching the center beam 5 between the pair of side walls 41a, 42a are formed.

[0034] FIG. 4(a) is a perspective view of the support screw 8 used to hold the center beam 5 between a pair of side walls 41a, 42a, and FIG. 4(b) is a perspective view of the center beam 5. The center beam 5 has a hollow cylindrical shape with an axial length that is held between the pair of side walls 41a, 42a via washers 5c, 5c. The support screw 8 can be inserted into the hollow cylindrical portion 5a as shown in FIG. 4(c). The diameter dimension of the outer diameter 5b of the center beam 5 is set to be larger than the groove width of the long holes 41c, 42c. The center beam 5 and the support screw 8 are basically made of metal, but may be made of other materials such as plastic. The support screw 8 has an outer diameter that is inserted into each of the long holes 41c, 42c and the hollow cylindrical portion of the center beam 5, and a length that is longer than the distance between the pair of side walls 41a, 42a. In addition, a head 8a with an outer shape larger than the groove width of the long holes 41c, 42c is formed at one end, and a male screw (not shown) is formed at the other end 8b. The head 8a is provided with a cross hole or the like into which a tool can be inserted. The other end 8b of the support screw 8 protrudes from one of the elongated holes 42c outside the space between the pair of side walls 41a, 42a, and as shown in the perspective view of Fig. 4(d), a nut 9 is screwed onto the male thread formed on the other end 8b of the support screw 8, thereby fixing the center beam 5 between the pair of side walls 41a, 42a. The nut 9 has an outer shape larger than the groove width of the elongated holes 41c, 42c.

[0035] The case 42 also has a pair of opposing support walls 42e with cutouts 42d formed therein. As shown in FIG. 1, the torsion spring 6 has one arm 6a supported by the center beam 5 and the other arm 6b fitted into the cutout 42d of the support wall 42e for support. A through hole 42g forming a female screw hole is formed in a side surface 42f of the case 42. A female screw is formed in the inner diameter of the through hole 42g, into which the adjustment screw 10 constituting the adjustment mechanism is screwed.

[0036] The long holes 41c, 42c are formed at positions facing each other between the pair of side walls 41a, 42a. The long holes 41c, 42c are formed in the pair of side walls 41a, 42a at the positions where the center beam 5 is sandwiched, in a direction in which one arm 6a of the torsion spring 6 rotates around the axis of the torsion spring 6, that is, in the short side direction of each side wall 41a, 42a. The nut 9 is screwed into a male thread formed on the other end 8b of the support screw 8 protruding from one of the long holes 42c, thereby fixing the center beam 5 at an arbitrary position between the pair of side walls 41a, 42a in the formation direction of the long holes 41c, 42c. The center beam 5, the washers 5c, 5c, the support screw 8, and the nut 9 constitute a support part that supports one arm 6a of the torsion spring 6. The housing 4 holds a pair of bushings 3, 3, with the outer diameter 2b of each end of the brake bushing 2 inserted into the inner diameter 3a, on both sides of the support portion between a pair of side walls 41a, 42a. The center beam 5 is not necessarily provided, and when the center beam 5 is not provided, one arm 6a of the torsion spring 6 is supported by a support screw 8. When the support portion itself is not provided, the one arm 6a of the torsion spring 6 is directly supported by a side surface 42f of the case 42.

[0037] Figure 5(a) is a perspective view of the brake bush 2, Figure 5(b) is a perspective view of the bush 3 seen from one direction, Figure 5(c) is a perspective view of the bush 3 seen from another direction, Figure 5(d) is a perspective view of the torsion spring 6, and Figure 5(e) is a side view of the adjustment screw 10 that constitutes the adjustment mechanism.

[0038] The brake bush 2 has a cylindrical shape with a slit-like notch extending from one end to the other end to form a slot 2a. When an external force is applied to the outer diameter 2b of the brake bush 2, which reduces the radial dimension, the size of the gap in the slot 2a decreases and the inner diameter 2c decreases, and when the external force is removed, the inner diameter 2c returns to its original size. The material of the brake bush 2 is basically plastic, but it may be other materials such as metal having the above elasticity.

[0039] The bush 3 has a cylindrical shape with an inner diameter 3a into which the outer diameter 2b of each end of the brake bush 2 is inserted, and an inner bottom surface 3b that abuts against each end surface 2d, 2d of the brake bush 2. The inner bottom surface 3b prevents the brake bush 2 inserted into the inner diameter 3a from penetrating the inner diameter 3a of the bush 3 and coming out of the bush 3. In addition, a reduced diameter portion 3c having a smaller outer diameter is formed on the outer periphery of one end of the bush 3, and side surfaces 3d rise from the reduced diameter portion 3c at predetermined intervals in the circumferential direction, and recesses 3e are formed between each side surface 3d. In addition, a bearing portion 3f having a predetermined length in the axial direction of the bush 3 is formed inside the reduced diameter portion 3c. A rod that supports an object to be braked by the brake unit 1 is inserted into this bearing portion 3f. The rod moves stably as its outer periphery slides on the inner periphery of this bearing portion 3f, and its linear motion is guided with precision. By forming the reduced diameter portion 3c, the side surface 3d, and the recess 3e in the bush 3, the thickness between the reduced diameter portion 3c and the bearing portion 3f is made uniform, the length for the bearing portion 3f to support the rod is ensured, and deformation caused by the resin being pulled during the resin molding process is prevented, thereby improving the dimensional accuracy of the cylindrical shape of the bearing portion 3f. The material of the bush 3 is basically plastic, but it may be other materials such as metal.

[0040] 1, two pairs of bushes 3, 3, each having an outer diameter 2b of each end of a brake bush 2 inserted into an inner diameter 3a, are sandwiched between a pair of opposing side walls 41a, 42a of a housing 4. At this time, the reduced diameter portion 3c of each bush 3 is inserted into a bush mounting hole 41b, 41b of a cover 41 and a bush mounting hole 42b, 42b of a case 42, and a side surface 3d of each bush 3 is abutted against a side surface of each side wall 41a, 42a. In addition, when the outer diameter 2b of each end of the brake bush 2 is inserted into the inner diameter 3a of the bush 3, the inner diameter 3a of the bush 3 functions as a guide for linear motion.

[0041] The torsion spring 6 is formed with arms 6a, 6b extending from both sides of a coil body 6c, and is attached to the brake bush 2 with the coil inner diameter 6d covering the outer diameter 2b of the brake bush 2. This attachment position is set to the outer diameter 2b of the brake bush 2 at a position that is exposed when the outer diameter 2b of each end of the brake bush 2 is inserted into the inner diameter 3a of the bush 3 and each end face 2d, 2d of the brake bush 2 abuts against each inner bottom face 3b, 3b of the pair of bushes 3, 3. When the torsion spring 6 is attached to the outer diameter 2b of the brake bush 2, the spring elasticity it retains constantly applies an external force to the outer diameter 2b of the brake bush 2 that reduces the radial dimension of the brake bush 2.

[0042] The adjustment mechanism according to this embodiment includes a shaft-shaped member formed by the adjustment screw 10 shown in FIG. 5(e) and the insertion hole 42g. A truss screw or a pan head screw is used as the adjustment screw 10, but a hexagonal bolt, a flat head screw, or the like can also be used. The adjustment screw 10 is screwed into the insertion hole 42g and attached to the side surface 42f of the case 42 so as to be freely movable forward and backward. The attachment position is on a path drawn by the other arm 6b supported by the support wall 42e as it rotates around the axis of the torsion spring 6. When the adjustment screw 10 is rotated and displaced in a direction approaching the other arm 6b from the side surface 42f, the tip of the adjustment screw 10 comes into contact with the other arm 6b as shown in FIG. 1(c), causing the other arm 6b to rotate around the axis of the torsion spring 6.

[0043] To brake an object supported by a rod using the brake unit 1 of this embodiment, first, the adjusting screw 10 is displaced in a direction approaching the other arm 6b of the torsion spring 6 from the side surface 42f of the case 42, and the other arm 6b of the torsion spring 6 supported by the notch 42d formed in the support wall 42e is pushed by the tip of the adjusting screw 10, causing the other arm 6b to rotate around the axis of the torsion spring 6 against the elasticity of the torsion spring 6. This rotation of the other arm 6b weakens the external force that the torsion spring 6 applies to the outer diameter 2b of the brake bush 2, and the size of the inner diameter 2c of the brake bush 2 is returned to its original state. In this state, a rod supporting the object to be braked is inserted into the inner diameter 2c of the brake bush 2. Next, by stopping pressing the other arm 6b of the torsion spring 6 with the tip of the adjustment screw 10, the spring elasticity held by the torsion spring 6 pushes the adjustment screw 10 back from its forward / backward position relative to the side surface 42f of the case 42, and the other arm 6b of the torsion spring 6 is again supported by the notch 42d formed in the support wall 42e.

[0044] In this state, the fixing position in the direction in which the long holes 41c, 42c of the center beam 5 are formed is adjusted so that the external force applied by the torsion spring 6 to the outer diameter 2b of the brake bush 2 is large enough to reduce the inner diameter 2c of the brake bush 2, and the opening angle of both arms 6a, 6b of the torsion spring 6 is set in advance, whereby the outer diameter of the rod is tightened to the reduced inner diameter 2c of the brake bush 2. Therefore, by fixing the braking unit 1 to the structure, the movement of the rod in the axial direction of the brake bush 2 is restricted, and the rod support is braked together with the rod. The opening angle of both arms 6a, 6b of the torsion spring 6 can also be set in advance by adjusting the height to which the tip of the adjustment screw 10 pushes the other arm 6b of the torsion spring 6 from the notch 42d. In this case, the initial position of the other arm 6b of the torsion spring 6 becomes a position where the tip of the adjustment screw 10 pushes up the other arm 6b of the torsion spring 6 from the notch 42d, instead of the position where it is supported by the notch 42d. Note that it is assumed that the opening angle of both arms 6a, 6b varies depending on the processing state of the torsion spring 6.

[0045] Therefore, according to the brake unit 1 of this embodiment, it is possible to brake the object supported by the rod with a simple mechanism without using an electric motor as in the conventional brake unit, and it is possible to provide the brake unit 1 at a low cost. In addition, the support position of the object supported by the rod can be changed by a simple operation of displacing the adjustment screw 10 relative to the side surface 42f of the case 42, without requiring an operation of loosening and tightening the fixing bolt each time as in the conventional brake unit, and the operability of the brake unit 1 is improved. Note that the support position of the object supported by the rod can also be changed by applying a force to the brake unit 1 that exceeds the force with which the torsion spring 6 tightens the outer diameter 2b of the brake bush 2 without operating the adjustment screw 10.

[0046] In this embodiment, the housing 4 holds a pair of bushes 3, 3, each of which has an outer diameter 2b of each end of the brake bush 2 inserted into an inner diameter 3a, on both sides of the center beam 5 between the pair of side walls 41a, 42a, making it possible to brake an object supported by a pair of rods with good operability using the inexpensive braking unit 1. Note that, although the present embodiment describes a case in which the torsion spring 6 is attached to only one of the brake bushes 2, by similarly attaching the torsion spring 6 to both brake bushes 2, the object supported by the pair of rods can be braked by the braking unit 1 more firmly and in a balanced manner.

[0047] In this embodiment, the support portion that supports one arm 6a of the torsion spring 6 is configured by a hollow cylindrical center beam 5 having an axial length that is sandwiched between a pair of side walls 41a, 42a. Therefore, by sandwiching the hollow cylindrical center beam 5 between the pair of side walls 41a, 42a, one arm 6a of the torsion spring 6 is supported by the center beam 5 in a stable state, and the strength of the housing 4 is increased.

[0048] Furthermore, in this embodiment, the center beam 5 sandwiched between the pair of side walls 41a, 42a rotates one arm 6a of the torsion spring 6 around the axis of the torsion spring 6 depending on the position in the forming direction of the elongated holes 41c, 42c where the nuts 9 are fastened to the other ends 8b of the support screws 8 to fix the center beam 5. Therefore, the initial value of the external force that the torsion spring 6 imparts to the outer periphery 2b of the brake bushing 2 by its tightening force can be adjusted depending on the position in the forming direction of the elongated holes 41c, 42c where the center beam 5 is fixed between the pair of side walls 41a, 42a by the nuts 9.

[0049] In addition, in this embodiment, by configuring the support part by separately forming the center beam 5 and the support screw 8, the center beam 5 can be easily fixed between the pair of side walls 41a, 42a by inserting the support screw 8 into the hollow part of the center beam 5 through the long holes 41c, 42c and fastening the nut 9 to the other end 8b of the support screw 8 protruding from one of the long holes 42c. This makes it easy to assemble the center beam 5 into the housing 4, improving the assembly of the brake unit 1. Furthermore, by configuring the support part by separately forming the center beam 5 and the support screw 8, the parts processing of the support part becomes easier.

[0050] In this embodiment, the adjustment screw 10 constituting the adjustment mechanism is screwed into an insertion hole 42g formed in a side surface 42f of the case 42 and is attached to the side surface 42f of the case 42 so as to be freely movable forward and backward. Therefore, the adjustment screw 10 can be turned to adjust the forward and backward position of the tip of the adjustment screw 10 relative to the side surface 42f of the case 42, and the adjustment screw 10 can be displaced in a direction approaching the other arm 6b of the torsion spring 6 from the side surface 42f of the case 42. This allows the tip of the adjustment screw 10 to push the other arm 6b of the torsion spring 6 supported by the notch 42d formed in the support wall 42e, and the other arm 6b of the torsion spring 6 can be rotated around the axis of the torsion spring 6 against the elasticity of the torsion spring 6. Therefore, this rotation of the other arm 6b weakens the external force that the torsion spring 6 applies to the outer diameter 2b of the brake bush 2, and in a state in which the size of the inner diameter 2c of the brake bush 2 is returned to its original size, a rod supporting an object to be braked can be inserted into the inner diameter 2c of the brake bush 2. Furthermore, by turning the adjusting screw 10 in the opposite direction to return the advance / retract position of the tip of the adjusting screw 10 relative to the side surface 42f of the case 42 to its original position, and stopping the tip of the adjusting screw 10 from pressing the other arm 6b of the torsion spring 6, the other arm 6b of the torsion spring 6 is again supported by the notch 42d formed in the support wall 42e, and the outer diameter of the rod is tightened to the reduced inner diameter 2c of the brake bush 2.

[0051] Also, by turning the adjustment screw 10 to adjust the advance / retract position of the tip of the adjustment screw 10 relative to the side surface 42f of the case 42, the tip of the adjustment screw 10 pushes the other arm 6b of the torsion spring 6 up from the notch 42d formed in the support wall 42e, thereby changing the rotational position of the other arm 6b around the axis of the torsion spring 6. The changed rotational position is maintained by the screw engagement of the adjustment screw 10 with the insertion hole 42g. Therefore, in addition to adjusting the fixed position of the center beam 5, the initial value of the external force that the torsion spring 6 applies to the outer periphery 2b of the brake bush 2 can also be adjusted by turning the adjustment screw 10 to adjust the advance / retract position of the tip of the adjustment screw 10 relative to the side surface 42f of the case 42.

[0052] Fig. 6(a) is a plan view of a brake unit 1' according to a second embodiment of the present invention, and Fig. 6(b) is a side view. Fig. 6(c) is a side view of a pin 11 constituting an adjustment mechanism in the brake unit 1' according to the second embodiment, Fig. 6(d) is a perspective view of a hexagonal bolt 12 constituting the adjustment mechanism, and Fig. 6(e) is a side view of the state in which the pin 11 and a retaining ring 13 are assembled to the hexagonal bolt 12. In Fig. 6, parts that are the same as or correspond to those in Fig. 1 are given the same reference numerals and their explanation will be omitted.

[0053] A brake unit 1' according to the second embodiment differs from the brake device 1 according to the first embodiment only in that the configuration of the adjustment mechanism differs from that of the adjustment mechanism according to the first embodiment.

[0054] The adjustment mechanism in the brake unit 1' includes a shaft-shaped member formed by the pin 11, a hexagonal bolt 12 in which a through hole 12a having an inner diameter for inserting the pin 11 is formed in the axial direction, an insertion hole 42g formed in a side surface 42f of the case 42, and a retaining ring 13 that prevents the hexagonal bolt 12 from coming out of the through hole 12a. A female thread that screws into the hexagonal bolt 12 is formed on the inner diameter of the insertion hole 42g. The retaining ring 13 is fitted into a groove 11a formed in the tip of the pin 11 and is engaged with the tip side of the pin 11. The pin 11 has a head 11b at the end opposite to the tip side.

[0055] In the brake unit 1' according to the second embodiment, the hexagonal bolt 12 is screwed into a female thread formed on the inner diameter of the insertion hole 42g, and is attached to the side surface 42f of the case 42 so as to be freely movable forward and backward. The pin 11 is inserted into a through hole 12a opened in the axial direction of the hexagonal bolt 12 so as to be relatively movable, and is guided by the through hole 12a to move in a direction perpendicular to the side surface 42f of the case 42. The pin 11 is prevented from coming out of the through hole 12a of the hexagonal bolt 12 by a retaining ring 13. By displacing the pin 11 inserted into the through hole 12a in a direction approaching the other arm 6b of the torsion spring 6 from the tip surface of the hexagonal bolt 12 and pressing the other arm 6a of the torsion spring 6 supported by the notch 42d formed in the support wall 42e with the tip of the pin 11 as shown in Figure 6 (b), the other arm 6b of the torsion spring 6 can be rotated around the axis of the torsion spring 6 against the elasticity of the torsion spring 6.

[0056] This rotation of the other arm 6b weakens the external force that the torsion spring 6 applies to the outer diameter 2b of the brake bush 2, and in this state where the size of the inner diameter 2c of the brake bush 2 is returned to its original size, a rod supporting an object to be braked can be inserted into the inner diameter 2c of the brake bush 2. Also, by stopping the tip of the pin 11 from pressing the other arm 6b of the torsion spring 6, the spring elasticity held by the torsion spring 6 pushes the pin 11 back from its advanced / retracted position relative to the tip surface of the hexagonal bolt 12. Therefore, the other arm 6b of the torsion spring 6 is supported again by the notch 42d formed in the support wall 42e, and the outer diameter of the rod is tightened to the reduced inner diameter 2c of the brake bush 2.

[0057] Also, by turning the hexagonal bolt 12 to adjust the advance / retract position of the tip of the pin 11 relative to the side surface 42f of the case 42, the tip of the pin 11 pushes the other arm 6b of the torsion spring 6 up from the notch 42d formed in the support wall 42e, thereby changing the rotational position of the other arm 6b around the axis of the torsion spring 6. The changed rotational position is maintained by the engagement of the hexagonal bolt 12 with the female thread formed on the inner diameter of the insertion hole 42g. Therefore, in addition to adjusting the fixed position of the center beam 5, the initial value of the external force applied by the torsion spring 6 to the outer diameter 2b of the brake bush 2 can also be adjusted by turning the hexagonal bolt 12 to adjust the advance / retract position of the tip of the pin 11 relative to the side surface 42f of the case 42.

[0058] Therefore, the brake unit 1' according to the second embodiment also provides the same operational effects as the brake unit 1 according to the first embodiment, making it possible to provide a brake unit 1' that is inexpensive and has improved operability.

[0059] In this embodiment, the pin 11 has a head 11b at the end opposite to the tip side. This head 11b is not necessarily required, but according to this embodiment, the operation of displacing the pin 11 inserted through the through hole 12a opened in the axial direction of the hexagonal bolt 12 relative to the tip surface of the hexagonal bolt 12 can be performed with a good tactile sensation on the head 11b of the pin 11 without causing pain to the fingertips.

[0060] In the second embodiment described above, the hexagonal bolt 12 may not be provided, and the insertion hole 42g may have an inner diameter for inserting the pin 11 therethrough, without forming a female thread on the inner diameter. In this case, the retaining ring 13 prevents the pin 11 from coming out of the insertion hole 42g.

[0061] According to the configuration of the modified example of the second embodiment, the pin 11 is inserted into an insertion hole 42g formed in a side surface 42f of the case 42, and is prevented from coming out of the insertion hole 42g by a retaining ring 13. The pin 11 inserted into the insertion hole 42g is displaced in a direction approaching the other arm 6b of the torsion spring 6 from the side surface 42f of the case 42, and the other arm 6b of the torsion spring 6 supported by a notch 42d formed in the support wall 42e is pushed by the tip of the pin 11, whereby the other arm 6b of the torsion spring 6 can be rotated about the axis of the torsion spring 6 against the elasticity of the torsion spring 6.

[0062] This rotation of the other arm 6b weakens the external force that the torsion spring 6 applies to the outer diameter 2b of the brake bush 2, and in this state where the size of the inner diameter 2c of the brake bush 2 is returned to its original size, a rod supporting an object to be braked can be inserted into the inner diameter 2c of the brake bush 2. Also, by stopping the tip of the pin 11 from pushing the other arm 6b of the torsion spring 6, the pin 11 is pushed back from its advanced / retracted position relative to the side surface 42f of the case 42 by the spring elasticity held by the torsion spring 6. Therefore, the other arm 6b of the torsion spring 6 is supported again by the notch 42d formed in the support wall 42e, and the outer diameter of the rod is tightened to the reduced inner diameter 2c of the brake bush 2.

[0063] Also, in this modified example, head 11b is not necessarily required, but since pin 11 has head 11b at the end opposite to the tip side, the operation of displacing pin 11 inserted through insertion hole 42g opened in side surface 42f of case 42 relative to side surface 42f of case 42 can be performed with a pleasant tactile sensation on head 11b of pin 11 without causing pain to the fingertips.

[0064] Therefore, this modification of the second embodiment also provides the same advantageous effects as the second embodiment. [Industrial Applicability]

[0065] The braking units 1, 1' according to each embodiment and variant example can be used to brake headrests supported by a rod on dental treatment chairs, headrests supported by a rod on haircutting chairs used in barber shops, and lifting platforms supported by a rod on lifting devices that raise and lower any object. [Explanation of symbols]

[0066] 1,1'...braking unit, 2...brake bush, 2a...slot, 2b...outer diameter, 2c...inner diameter, 2d...end face, 3...bush, 3a...inner diameter, 3b...inner bottom face, 3c...reduced diameter portion, 3d...side face, 3e...recess, 3f...bearing portion, 4...housing, 41...cover, 42...case, 41a, 42a...side wall, 41b, 42b...bush mounting hole, 41c, 42c...long hole, 42d...notch, 42e...support wall, 42f...side face, 42g...insertion hole, 5...center beam, 5a...hollow cylindrical portion, 5b...outer diameter, 5c...washer, 6...torsion spring (torsion coil spring), 6a...one arm, 6b...other arm, 6c...coil body, 6d...coil inner diameter, 7...mounting screw, 8...support screw, 8a...head, 8b...other end, 9...nut, 10...adjusting screw, 11...pin, 11a...groove, 11b...head, 12...hexagonal bolt, 12a...through hole, 13...retaining ring

Claims

1. a cylindrical brake bushing having elasticity in which a slot is formed by cutting out a slit from one end to the other end, and when an external force is applied to the outer diameter to reduce the radial dimension, the size of the gap in the slot becomes smaller and the inner diameter becomes smaller, and when the application of the external force is removed, the size of the inner diameter returns to its original size; a pair of cylindrical bushings each having an inner diameter into which the outer diameters of the respective ends of the brake bushings are inserted and an inner bottom surface that abuts against the respective end surfaces of the brake bushings; a torsion coil spring attached to the brake bush such that an inner diameter of the coil covers an outer diameter of the brake bush and applies the external force to the outer diameter of the brake bush by the spring elasticity of the torsion coil spring; a housing having a pair of opposing side walls that sandwich the pair of bushings with the outer diameters of the respective ends of the brake bushings inserted into the inner diameters thereof, the housing having on both sides sandwiching the brake bushings a support portion that supports one arm of the torsion coil spring, and a support wall that has a notch formed therein into which the other arm of the torsion coil spring is fitted and supports the other arm; an adjustment mechanism having a shaft-shaped member that is provided on a side surface of the housing on a path that the other arm supported by the support wall describes as it rotates around the axis of the torsion coil spring and that, when displaced from the side surface in a direction approaching the other arm, has a tip that comes into contact with the other arm and rotates the other arm around the axis of the torsion coil spring; A braking unit comprising:

2. The braking unit according to claim 1, characterized in that the housing sandwiches a pair of the bushings on both sides of the support portion between the pair of side walls, with the outer diameters of each end of the brake bushings inserted into the inner diameter.

3. 3. The brake unit according to claim 1, wherein the support portion is constituted by a hollow cylindrical beam having an axial length and sandwiched between the pair of side walls.

4. a long hole formed in each of the pair of side walls at a portion where the beam is sandwiched, in a direction in which one of the arms of the torsion coil spring rotates around an axis of the torsion coil spring; a support screw having an outer diameter inserted into each of the elongated holes and the hollow cylindrical portion of the beam and a length longer than the distance between the pair of side walls, the support screw having a head portion at one end with an outer diameter larger than the groove width of the elongated holes and a male screw at the other end; a nut having an outer diameter larger than the groove width of the elongated hole, which is screwed onto the male thread formed on the other end of the support screw protruding from one of the elongated holes to the outside between the pair of side walls, thereby fixing the beam at an arbitrary position between the pair of side walls in the direction in which the elongated hole is formed; 4. A brake unit according to claim 3, comprising:

5. The brake unit according to any one of claims 1 to 4, characterized in that the adjustment mechanism comprises the axial member formed by an adjustment screw, and a female threaded hole formed on the inner diameter and drilled in the side surface, the female threaded hole being adapted to screw into the adjustment screw.

6. A brake unit as described in any one of claims 1 to 4, characterized in that the adjustment mechanism comprises the axial member formed by a pin, an insertion hole formed on the side surface having an inner diameter for inserting the pin, and a retaining ring that engages with the tip side of the pin to prevent the pin from falling out of the insertion hole.

7. The brake unit described in claim 6, characterized in that the adjustment mechanism includes a bolt having a through hole drilled in the axial direction with an inner diameter through which the pin is inserted, the insertion hole having an internal thread formed on its inner diameter to screw into the bolt, and the retaining ring prevents the bolt from coming out of the through hole.

8. 8. The brake unit according to claim 6, wherein the pin has a head at an end opposite to the tip side.

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