Centrifugal brake

Abstract

The invention provides a novel centrifugal brake which not only can easily change the magnitude of the brake torque acting on a rotating body (6), but also can maintain the operability of the change operation in a good state. The elastic piece (34) extends beyond the expansion section (76) toward the other side in the axial direction, and the housing (4) is provided with a protective piece (20) that extends beyond the elastic piece (34) toward the other side in the axial direction when viewed from the radial direction.

Description

Technical Field

[0001] The present invention relates to a centrifugal brake, and more particularly to a centrifugal brake capable of adjusting the magnitude of the braking torque applied to a rotating body stepwise according to a required operation. Background Art

[0002] As an example of a centrifugal brake capable of adjusting the magnitude of the braking torque applied to a rotating body stepwise according to a required operation, there is a centrifugal brake shown in Patent Document 1 below, which was applied for by the applicant of the present application before the present application and has been granted a patent. This centrifugal brake includes: a cylindrical housing having an inner peripheral surface with a circular cross section; and a rotating body that rotates relative to the housing with the central axis of the inner peripheral surface as the rotation axis. The rotating body includes a rotating plate disposed perpendicular to the rotation axis. A support shaft extending in the axial direction is provided at a position eccentric with respect to the rotation axis on one axial side surface of the rotating plate. A plurality of weights are axially supported in series on the support shaft. An elastic piece extending in the axial direction is provided at a position eccentric with respect to the rotation axis on the other axial side surface of the rotating plate. A locking projection is formed on the radially outer surface or the radially inner surface of the elastic piece. An adjustment member is combined with the rotating body. The adjustment member includes an adjustment plate disposed perpendicular to the rotation axis. The adjustment plate is disposed adjacent to the other axial side of the rotating plate. An adjustment piece extending in the axial direction is provided at the outer peripheral edge portion of one axial side surface of the adjustment plate, and the adjustment piece enters between the outer surface of the weight and the inner peripheral surface of the housing. One circumferential edge of the adjustment piece is displaced stepwise in the circumferential direction according to the respective axial positions of the plurality of weights axially supported in series. An expansion portion is provided at the central portion of the other axial side surface of the adjustment plate. A plurality of locking recesses are formed at circumferentially spaced intervals on the other axial end surface of the expansion portion according to the number of the plurality of weights axially supported in series, and the locking projections can be respectively locked in the plurality of locking recesses. And when the rotating body rotates, the plurality of weights and the adjustment member rotate integrally with the rotating body, and the plurality of weights rotate about the support shaft and their respective outer surfaces abut against the inner peripheral surface of the housing or the inner surface of the adjustment piece. At this time, according to which one of the plurality of locking recesses the locking projection is locked in, the number of weights whose outer surfaces abut against the inner peripheral surface of the housing changes. By elastically deforming the elastic piece in the radial direction with a finger to temporarily release the locking between the locking projection and the locking recess, the adjustment member can rotate relative to the rotating body, and by locking the locking projection in different locking recesses, the number of weights whose outer surfaces abut against the inner peripheral surface of the housing can be changed, that is, the magnitude of the braking torque acting on the rotating body can be changed stepwise. Prior Art Documents Patent Document

[0003] Patent Document 1: Japanese Patent Publication No. 7039761 Summary of the Invention Problems to be Solved by the Invention

[0004] In the centrifugal brake shown in the above Patent Document 1, when releasing the engagement between the engaging protrusion and the engaging recess, the elastic piece is elastically deformed by a finger. Therefore, considering the operability, it is preferable that the elastic piece protrudes beyond the expansion portion toward the other side in the axial direction. However, if the elastic piece protrudes beyond the expansion portion toward the other side in the axial direction, when the centrifugal brake moves axially along the rotation axis, there is a possibility that the elastic piece collides with the wall surface of an external device or the like and is damaged, and the elastic piece cannot be operated, that is, the engagement between the engaging protrusion and the engaging recess cannot be released. The centrifugal brake may move axially relative to the external device due to the vibration of the rotating body. When the adjusting member rotates integrally with the rotating body in a state where the extending end of the elastic piece abuts against the wall surface or the like, the elastic piece will wear, so there is a possibility that the above engagement cannot be released due to this wear. Furthermore, abnormal noise is generated while the above wear occurs, so it is not preferable.

[0005] The present invention has been completed in view of the above facts, and its main technical problem is to provide a new and improved centrifugal brake that can not only easily change the magnitude of the braking torque acting on the rotating body, but also maintain the operability of the change operation in a good state. Technical Solution for Solving the Problem

[0006] The inventor has conducted in-depth research and found that by extending the elastic piece beyond the expansion portion toward the other side in the axial direction and providing a protective piece on the housing that extends beyond the elastic piece toward the other side in the axial direction when viewed from the radial direction, the above main technical problem can be achieved.

[0007] That is, according to the present invention, there is provided a centrifugal brake as a centrifugal brake for achieving the above main technical problem, the centrifugal brake comprising: a cylindrical housing having an inner peripheral surface with a circular cross-section; and a rotating body that rotates relative to the housing with the central axis of the inner peripheral surface as the rotation axis, The rotating body includes a rotating plate disposed perpendicular to the rotation axis, a support shaft extending toward one side in the axial direction is provided at a position eccentric with respect to the rotation axis on one side surface in the axial direction of the rotating plate, a plurality of weights are axially supported in series on the support shaft, an elastic piece extending toward the other side in the axial direction is provided at a position eccentric with respect to the rotation axis on the other side surface in the axial direction of the rotating plate, and an engaging protrusion is formed on the radially outer side surface or the inner side surface of the elastic piece, An adjusting member is combined with the rotating body, The adjustment member includes an adjustment plate disposed perpendicular to the rotation axis. The adjustment plate is disposed adjacent to the other axial side of the rotation plate. An adjustment piece extending toward the axial side is provided at the outer peripheral edge of the axial side surface of the adjustment plate. The adjustment piece enters between the outer surface of the counterweight and the inner peripheral surface of the housing. The circumferential one side edge of the adjustment piece is periodically displaced circumferentially according to the axial positions of the plurality of counterweights arranged in series in the axial direction. An expansion portion is provided at the central portion of the other axial side surface of the adjustment plate. At the end surface on the other axial side of the expansion portion, a plurality of locking recesses are formed at circumferential intervals according to the number of the plurality of counterweights arranged in series in the axial direction. The locking protrusion can be respectively locked in the plurality of locking recesses. When the rotating body rotates, the plurality of counterweights and the adjustment member rotate integrally with the rotating body, and the plurality of counterweights rotate about the support shaft and their outer surfaces abut against the inner peripheral surface of the housing or the inner surface of the adjustment piece. According to which one of the plurality of locking recesses the locking protrusion is locked to, the number of the counterweights whose outer surfaces abut against the inner peripheral surface of the housing changes. The elastic piece extends toward the other axial side beyond the expansion portion. A protective piece extending toward the other axial side beyond the elastic piece when viewed radially is provided on the housing.

[0008] Preferably, a plurality of the protective pieces are provided at equal angular intervals in the circumferential direction. Preferably, a pair of the locking protrusions and the plurality of locking recesses are respectively provided on both sides in the diameter direction. Preferably, the expansion portion is cylindrical, and the elastic piece passes through the inside of the expansion portion. Advantages of the Invention

[0009] In the centrifugal brake of the present invention, the elastic piece extends toward the other axial side beyond the expansion portion, so that the elastic piece can be easily operated with a finger. Since the locking protrusion is formed on the elastic piece, the operation of temporarily releasing the locking between the locking protrusion and the locking recess and rotating the adjustment member relative to the rotating body has good operability. Further, in the centrifugal brake of the present invention, when viewed radially, the protective piece extending toward the other axial side beyond the elastic piece is provided on the housing. Therefore, even if the centrifugal brake moves axially along the rotation axis, only the protective piece collides with the wall surface of an external device or the like, and the elastic piece does not collide with the wall surface of an external device or the like and is damaged. Since the elastic piece does not abut against the wall surface of an external device or the like, the elastic piece does not wear and does not generate abnormal noise when the adjustment member rotates integrally with the rotating body. Therefore, according to the centrifugal brake of the present invention, not only can the magnitude of the braking torque acting on the rotating body be easily changed, but also the operability of maintaining the change operation can be maintained in a good state. Description of the Drawings

[0010] Figure 1 FIG. is a view showing the overall structure of a preferred embodiment of a centrifugal brake constructed according to the present invention. Figure 2 FIG. is a perspective view showing the centrifugal brake shown in Figure 1 FIG. disassembled into each structural component. Figure 3 FIG. is a view showing the housing of the centrifugal brake shown in Figure 1 FIG. shown as a single unit. Figure 4 FIG. is a view showing the rotating body of the centrifugal brake shown in Figure 1 FIG. shown as a single unit. Figure 5 FIG. is a view showing the counterweight of the centrifugal brake shown in Figure 1 FIG. shown as a single unit. Figure 6 FIG. is a view for explaining the process of mounting the counterweight shown in Figure 5 FIG. on the support shaft of the rotating body. Figure 7 FIG. is a view showing the adjusting member of the centrifugal brake shown in Figure 1 FIG. shown as a single unit. Figure 8 FIG. is a developed view schematically showing the positional relationship between the adjusting piece and the counterweight in the centrifugal brake shown in Figure 1 FIG. Figure 9 FIG. is a view showing the overall structure of the speed increaser of the centrifugal brake shown in Figure 1 FIG. Figure 10A FIG. is a view for explaining the operation of the centrifugal brake shown in Figure 1 FIG. Figure 10B FIG. is a view for explaining the operation of the centrifugal brake shown in Figure 1 FIG. Figure 10C FIG. is a view for explaining the operation of the centrifugal brake shown in Figure 1 FIG. Figure 11 FIG. is a view magnifying the other end portion on the axial side in the A - A cross-sectional view shown in Figure 1 FIG. Detailed Description of the Preferred Embodiment

[0011] Hereinafter, with reference to the drawings showing preferred embodiments of the centrifugal brake constructed according to the present invention, a more detailed description will be given. It should be noted that in the following description, "one axial side" and "the other axial side" are, unless otherwise specified, Figure 1Based on the state shown in the A - A cross - section, in this figure, the "axial one side" refers to the left side, and the "axial other side" refers to the right side. Also, in the following description, as long as not specifically specified, the "circumferential one side" and the "circumferential other side", the "circumferential one side" refers to the clockwise side when observed from the right side of the A - A cross - sectional view of Figure 1 and the "circumferential other side" refers to the counter - clockwise side. In other words, when observed from the axial one side, the "circumferential one side" becomes the counter - clockwise side, and the "circumferential other side" becomes the clockwise side.

[0012] Refer to Figure 1 for illustration. The centrifugal brake represented by the number 2 as a whole includes a cylindrical housing 4 and a rotating body 6.

[0013] While referring to Figure 1 and referring to Figure 2 as well as Figure 3 for illustration, the housing 4 is a cylindrical shape formed of a relatively hard synthetic resin, penetrating axially, and having an inner peripheral surface 8 with a circular cross - section. At the axial one - side end of the inner peripheral surface 8, a ring - shaped support wall 10 that protrudes radially inward and extends continuously in the circumferential direction is formed. At the axial one - side end of the outer peripheral surface of the housing 4, the base end of an extension piece 12 that extends linearly toward the axial one side beyond the circular axial one - side edge is connected. One extension piece 12 is provided on each of the two sides in the diameter direction. An axial locking projection 14 is formed on the inner surface of the extension end of the extension piece 12. At the axial one - side end of the outer peripheral surface of the housing 4, a pair of ear portions 16 that protrude radially outward are also formed on the two sides in the diameter direction, and a positioning pin 18 with a circular cross - section that protrudes toward the axial one side is erected on each of the pair of ear portions 16. The axial locking projection 14 and the positioning pin 18 are arranged at an angular interval of 90 degrees alternately in the circumferential direction. Also, a protection piece 20 that extends toward the axial other side is provided on the axial other - side end surface of the housing 4. In the illustrated embodiment, 4 protection pieces 20 are arranged at equal angular intervals in the circumferential direction. The outer surface and the inner surface of each protection piece 20 are continuous with the inner peripheral surface 8 and the outer peripheral surface of the housing 4, and the extension end of the protection piece 20 is in an arc shape. In the centrifugal brake configured according to the present invention, the protection piece 20 extends toward the axial other side beyond the elastic piece 34 described later.

[0014] The rotating body 6 is disposed inside the housing 4 and can rotate about the central axis of the inner peripheral surface 8 of the housing 4. This rotation axis is represented by the lowercase letter o in English. While referring to Figure 1 and referring to Figure 2 as well as Figure 4A description will be given. The rotating body 6 is made of synthetic resin and has a cylindrical rotating main shaft 22 that extends linearly along the rotation axis o and penetrates in the axial direction. The cross-section of the rotating main shaft 22 is circular except for the end portion on one axial side, and a sun gear 24 is formed at the end portion on one axial side. A rotating-side support wall 26 is disposed adjacent to the other axial side of the sun gear 24. Further, a rotating plate 28 is formed at the other axial end of the rotating main shaft 22, and a rotating auxiliary plate 30 is formed at the other axial side of the rotating-side support wall 26. Both the rotating plate 28 and the rotating auxiliary plate 30 are circular, are arranged perpendicular to the rotation axis o, and have a common central axis with the rotation axis o. Therefore, the centers of the rotating plate 28 and the rotating auxiliary plate 30 also penetrate in the axial direction. The outer diameter of the rotating plate 28 is slightly smaller than the outer diameter of the rotating auxiliary plate 30. A support shaft 32 extending toward one axial side is provided at a position eccentric with respect to the rotation axis o on one axial side surface of the rotating plate 28. In the illustrated embodiment, one support shaft 32 is provided on each of the two sides in the diameter direction at the outer peripheral edge portion of the rotating plate 28. The end portion on one axial side of the support shaft 32 is connected to the other axial side surface of the rotating auxiliary plate 30. Therefore, the support shaft 32 is supported at both ends by the rotating plate 28 and the rotating auxiliary plate 30. The support shaft 32 has a required cross-sectional shape as described later. Further, an elastic piece 34 extending in the axial direction is provided at a position eccentric with respect to the rotation axis o on the other axial side surface of the rotating plate 28. In the centrifugal brake configured according to the present invention, the elastic piece 34 extends toward the other axial side beyond an expansion portion 76 described later. In the illustrated embodiment, a cylindrical rotating-other-side support wall 36 is formed at the central portion of the other axial side surface of the rotating plate 28, and the inner surface of the base end portion of the elastic piece 34 is connected to the outer peripheral surface of the rotating-other-side support wall 36. One elastic piece 34 is provided on each of the two sides in the diameter direction, and the circumferential positions of the elastic pieces 34 are offset by 90 degrees from the support shaft 32. A locking protrusion 38 is formed on the radially outer side surface of the elastic piece 34.

[0015] A plurality of weights 40 are axially supported in series on the support shaft 32 of the rotating body 6 described above. In the illustrated embodiment, three weights 40 are respectively axially supported on each of the two support shafts 32. In the following description, when referring to each of the three weights 40 axially arranged in series, they are referred to as a to c from the one axial side toward the other axial side. While referring to Figure 1 while referring to Figure 2 and Figure 5When continuing the description, in the illustrated embodiment, the counterweight 40 is composed of a main portion 44 made of metal and a sliding piece 46 made of a relatively soft synthetic resin. The main portion 44 has an arc shape that extends in a circumferential direction over an angle range slightly smaller than 180 degrees in a plan view and has a required axial width. An axial hole 48 for inserting the support shaft 32 of the rotating body 6 is formed at the circumferentially other end of the main portion 44. The axial hole 48 extends linearly in the axial direction and penetrates in the axial direction, and has a cross-sectional shape to be described later. At a required portion of the outer surface of the main portion 44 on the circumferentially other side of the axial hole 48, a mounting groove 50 for detachably mounting the sliding piece 46 is formed. The mounting groove 50 also extends linearly in the axial direction and penetrates in the axial direction. At the axially one end of the outer surface of the main portion 44, a stepped portion 52 having an arc shape formed by slightly reducing the outer diameter is provided. The sliding piece 46 has a base portion 46a that fits into the mounting groove 50, and an exposed portion 46b that, when the base portion 46a fits into the mounting groove 50, as shown in the C-C cross section of Figure 1 , has an outer surface located more outside than the outer surface of the main portion 44, and the axial width of the sliding piece 46 corresponds to the axial width of the mounting groove 50. Figure 1 As shown in the C-C cross section and the like, the outer surface is located more outside than the outer surface of the main portion 44, and the axial width of the sliding piece 46 corresponds to the axial width of the mounting groove 50.

[0016] The rotating body 6 and the counterweight 40 will be further described. Referring to Figure 4 the enlarged view of the X portion of Figure 4 for description, the cross-sectional shape of the support shaft 32 of the rotating body 6 has an arc-shaped outer peripheral portion 32b that forms a part of the periphery of a reference circle 32a indicated by a single-dot chain line, and a cutout portion 32c obtained by cutting off a part of the periphery of the reference circle 32a. A pair of the arc-shaped outer peripheral portion 32b and the cutout portion 32c are provided on both sides in the diameter direction of the reference circle 32a, and the arc-shaped outer peripheral portion 32b and the cutout portion 32c are alternately arranged in the circumferential direction. The pair of cutout portions 32c are respectively flat surfaces that are parallel to each other and, in the B-B cross-sectional view of Figure 4 , face in the clockwise direction and are slightly inclined radially inward. Figure 4 In the B-B cross-sectional view, it faces in the clockwise direction and is slightly inclined radially inward.

[0017] Referring to Figure 5 the left (a) figure of Figure 5 for description, the cross-sectional shape of the axial hole 48 formed in the main portion 44 of the counterweight 40 has an arc-shaped inner peripheral portion 48b that forms a part of the periphery of a reference circle 48a (indicated by a single-dot chain line) having the same size as the reference circle 32a, and a pair of introduction portions 48c that extend from both ends of the arc-shaped inner peripheral portion 48b to the outer surface of the main portion 44. In the illustrated embodiment, the pair of introduction portions 48c respectively extend from both ends of the arc-shaped inner peripheral portion 48b toward the outer surface of the main portion 44 while being separated from each other, and the width D of the groove defined by the pair of introduction portions 48c gradually increases toward the outer surface of the main portion 44. The minimum value of the width D is set to be the same as or slightly larger than the minimum diameter d passing through the center 32d of the reference circle 32a in the support shaft 32.

[0018] In the centrifugal brake 2 of the illustrated embodiment, the support shaft 32 of the rotating body 6 and the counterweight 40 have the structures as described above, so that the counterweight 40 can be mounted on the support shaft 32 as follows. First, as shown in Figure 6 (a) thereof, with the cutout portion 32c of the support shaft 32 facing the introduction portion 48c of the shaft hole 48, the support shaft 32 is inserted into the shaft hole 48 from the outer surface of the main portion 44. As shown in Figure 6 (b) thereof, the arc-shaped outer peripheral portion 32b of the support shaft 32 is brought into surface contact with the arc-shaped inner peripheral portion 48b of the shaft hole 48. Next, as shown in Figure 6 (c) thereof, with the support shaft 32 as the axis, the counterweight 40 is rotated in the direction in which its inner surface faces the rotation axis o, that is, in the clockwise direction in this figure. The arc-shaped outer peripheral portion 32b of the support shaft 32 and the arc-shaped inner peripheral portion 48b of the shaft hole 48 are both parts of the circumferences of the reference circles 32a and 48a of the same size, so that the counterweight 40 can rotate about the support shaft 32. In this way, the counterweight 40 is mounted on the support shaft 32. Figure 6 The rotation angle of the counterweight 40 relative to the support shaft 32 in the state shown in (b) of Figure 1 is larger than the rotation angle at which the outer surface of the counterweight 40 comes into contact with the inner peripheral surface 8 of the housing 4, which will be mentioned later. The "rotation angle" here is based on the state in which the rotating body 6 is not rotating, that is, the state shown in Figure 1 . The counterweight 40 is mounted on the support shaft 32 at a rotation angle larger than the rotation angle at which the outer surface of the counterweight 40 comes into contact with the inner peripheral surface 8 of the housing 4.

[0019] Referring again to Figure 1 for illustration, an adjustment member 56 is incorporated in the rotating body 6. In Figure 1 , Figure 8 , Figures 10A to 10C , for easy understanding, the adjustment member 56 is shown in light ink. While referring to Figure 1 , refer also to Figure 2 and Figure 7When explaining, the adjustment member 56 is made of synthetic resin and includes an adjustment plate 58 arranged perpendicular to the rotation axis o. The adjustment plate 58 is circular, its central axis is common with the rotation axis o, and it is arranged adjacent to the other axial side of the rotary plate 28. A circular through-hole 60 is formed in the center of the adjustment plate 58. The rotation other-side support wall 36 of the rotating body 6 is fitted in the through-hole 60 to prevent the so-called core wobbling between the adjustment member 56 and the rotating body 6. On the inner peripheral surface of the adjustment plate 58, a recess 62 with a locally increased inner diameter is provided on each of the two sides in the diameter direction. On the outer peripheral edge portion of the one axial side surface of the adjustment plate 58, an adjustment piece 64 extending toward the one axial side beyond the rotary plate 28 is provided. The adjustment piece 64 is a thin plate with an arc-shaped cross section and enters between the outer surface of the counterweight 40 and the inner peripheral surface 8 of the housing 4. The extending end of the adjustment piece 64, that is, the one axial side end, is axially located between the counterweight 40a and the counterweight 40b. In the illustrated embodiment, one adjustment piece 64 is provided on each of the two sides in the diameter direction, and the extending ends of the two adjustment pieces 64, that is, the one axial side ends, are connected to a common auxiliary ring 66. Here, the one circumferential side edge 68 of the adjustment piece 64 is periodically displaced circumferentially according to the axial positions of the plurality of counterweights 40 arranged in series along the axial direction. Regarding this, refer to Figure 8 for explanation. Figure 8 is a schematic diagram showing the unfolded outer surfaces of the counterweights 40a to 40c arranged in series along the axial direction in the state shown, the left side of this figure is the one axial side, the right side is the other axial side, the upper side is the one circumferential side, and the lower side is the other circumferential side. As Figure 1 shown, both the one axial side half portion 68a and the other axial side half portion 68b of the one circumferential side edge 68 extend linearly along the axial direction, but the one axial side half portion 68a is displaced more toward the other circumferential side than the other axial side half portion 68b. Thus, an intermediate portion 68c perpendicular to the axial direction is defined between the one axial side half portion 68a and the other axial side half portion 68b of the one circumferential side edge 68. The intermediate portion 68c is integrated with the one axial side edge of the counterweight 40c. The whole of the other circumferential side edge 70 extends linearly along the axial direction. Thus, the adjustment piece 64 is divided into a first portion 72 located on the one axial side and extending shorter from the other circumferential side edge 70 toward the one circumferential side, and a second portion 74 located on the other axial side and extending longer from the other circumferential side edge 70 toward the one circumferential side. Figure 8 shown, both the one axial side half portion 68a and the other axial side half portion 68b of the one circumferential side edge 68 extend linearly along the axial direction, but the one axial side half portion 68a is displaced more toward the other circumferential side than the other axial side half portion 68b. Thus, an intermediate portion 68c perpendicular to the axial direction is defined between the one axial side half portion 68a and the other axial side half portion 68b of the one circumferential side edge 68. The intermediate portion 68c is integrated with the one axial side edge of the counterweight 40c. The whole of the other circumferential side edge 70 extends linearly along the axial direction. Thus, the adjustment piece 64 is divided into a first portion 72 located on the one axial side and extending shorter from the other circumferential side edge 70 toward the one circumferential side, and a second portion 74 located on the other axial side and extending longer from the other circumferential side edge 70 toward the one circumferential side.

[0020] Refer to Figure 7Continuing the description, an expansion portion 76 is provided at the central portion on the other axial side of the adjustment plate 58. On the other axial end face of the expansion portion 76, a plurality of locking recesses 78 are formed at circumferential intervals corresponding to the number of a plurality of weights 40 arranged in series along the axial direction. The locking projections 38 can be respectively locked in the plurality of locking recesses 78. By locking the locking projections 38 in the locking recesses 78, the adjusting member 56 rotates integrally with the rotating body 6. In the illustrated embodiment, the expansion portion 76 is in a cylindrical shape that expands from the other axial side surface of the adjustment plate 58 around the outer peripheral edge of the through hole 60 and the recess 62, and the elastic piece 34 passes through the inside of the expansion portion 76. The circumferential region where the plurality of locking recesses 78 are formed is integrated with the circumferential region where the recess 62 is formed, and the elastic piece 34 passes through the recess 62, whereby the rotation of the adjusting member 56 relative to the rotating body 6 is restricted by the circumferential width of the recess 62. In the illustrated embodiment, three weights 40 are arranged in series along the axial direction, so three locking recesses 78 are also formed at circumferential intervals. The locking recesses 78 may be formed in at least the same number as the number of a plurality of weights 40 arranged in series along the axial direction. When referring to each of the three locking recesses 78, they are referred to as a to c in the circumferential direction from one side to the other. In addition, since one elastic piece 34 and one locking projection 38 are provided on each of the two sides in the diameter direction, one locking recess 78a to 78c is also formed on each of the two sides in the diameter direction. A gripping portion 80 is attached to the outer peripheral surface of the expansion portion 76.

[0021] As Figure 1 shown, a speed increaser 82 composed of a planetary gear mechanism is also connected to the rotating body 6. While referring to Figure 1 and referring to Figure 2 and Figure 9 for description, the speed increaser 82 includes a sun gear 24 formed on the rotating body 6, a planetary gear 84 meshing with the sun gear 24, a planet carrier 86 that axially supports the planetary gear 84 so that it can rotate and can also rotate about the rotation axis o, and a fixed ring gear 88 meshing with the planetary gear 84. In the illustrated embodiment, three planetary gears 84 are axially supported by the planet carrier 86. The planet carrier 86 has a circular planet carrier plate 90 arranged perpendicular to the rotation axis o, and a regular hexagonal connection hole 92 penetrating axially is formed in the center of the planet carrier plate 90. By inserting, for example, the rotation transmission shaft s of the winding mechanism of the shielding member into the connection hole 92 (in Figures 10A to 10C(indicated by a double-dashed line), whereby the rotation is transmitted to the planet carrier 86. On the other axial side of the planet carrier plate 90, there are provided: three planet carrier shafts 94, which extend linearly toward the other axial side and respectively axially support the three planet gears 84; and three connecting columns 96, which are respectively disposed between two circumferentially adjacent planet carrier shafts 94 and extend linearly toward the other axial side. The outer diameters of the extending ends of the three planet carrier shafts 94 are reduced in diameter. The planet carrier 86 is combined with a planet carrier auxiliary plate 98 which is disposed on the opposite side of the planet carrier plate 90 in the axial direction with the planet gears 84 interposed therebetween. The planet carrier auxiliary plate 98 is in the shape of a ring, and the rotating body 6 is inserted therethrough inside. The outer peripheral edge portion of the other axial side is supported from the other axial side by a support wall 10 formed on the inner peripheral surface 8 of the housing 4. Circular holes 100 for inserting the extending portions of the planet carrier shafts 94 and arc-shaped holes 102 for inserting the extending portions of the connecting columns 96 are respectively formed in the planet carrier auxiliary plate 98. In a state where the planet carrier auxiliary plate 98 and the planet carrier plate 90 sandwich the planet gears 84 from both axial sides, the planet carrier auxiliary plate 98 rotates integrally with the planet carrier 86.

[0022] The fixed ring gear 88 is formed on the inner peripheral surface of the protective member 104. The protective member 104 is disposed in series on one axial side of the housing 4 and fixed thereto. The protective member 104 has a substantially square protective end plate 106. A circular recess 108 is formed at the center of the other axial side of the protective end plate 106, and the planet carrier plate 90 of the planet carrier 86 is fitted into the recess 108 in a state capable of rotating about the rotation axis o. A circular through-hole 110 penetrating in the axial direction is formed at the center of the protective end plate 106, and the above-mentioned rotation transmission shaft s passes through the through-hole 110 and is inserted into the connection hole 92 of the planet carrier plate 90. A protective cylinder wall 112 extending axially toward the other axial side around the outer peripheral edge of the recess 108 is provided on the other axial side of the protective end plate 106, and the fixed ring gear 88 is formed on the inner peripheral surface of the protective cylinder wall 112. When observing the protective cylinder wall 112 from the other axial side, that is Figure 9 in the left figure of (a) of, one pair of corner portions located on both sides in the diameter direction are integrated with the corner portions of the protective end plate 106. Positioning holes 114 for inserting the positioning pins 18 formed on the housing 4 are respectively formed at the pair of corner portions integrated with the corner portions of the protective end plate 106. On the other hand, the other pair of corner portions located on both sides in the diameter direction are displaced more radially inward than the corner portions of the protective end plate 106, and their outer surfaces are formed in an arc shape. Axial engaged protrusions 116 capable of engaging with the axial engaging protrusions 14 formed on the housing 4 are respectively formed on the pair of outer surfaces formed in an arc shape. Therefore, the protective member 104 is fixed to the housing 4 through the cooperation of the positioning pins 18 and the positioning holes 114 and the cooperation of the axial engaging protrusions 14 and the axial engaged protrusions 116.

[0023] In the illustrated embodiment, the sun gear 24 has 18 teeth, the planet gear 84 meshing therewith has 12 teeth, and the fixed ring gear 88 meshing therewith has 42 teeth. The planet carrier 86 is equivalent to the input member, and the sun gear 24 is equivalent to the output member. Therefore, according to the following mathematical formula, the rotation speed of the planet carrier 86 is increased to 10 / 3 times and transmitted to the sun gear 24. It should be noted that it goes without saying that the speed increase ratio can be arbitrarily adjusted by changing the number of teeth of each gear. [Equation 1] n r +(Z s / Z r )n s -(1+Z s / Z r )n c =0 Wherein, Z s : The number of teeth of the sun gear, Z r : The number of teeth of the ring gear, n s : The rotational speed of the sun gear, n r : The rotational speed of the ring gear, n c : The rotational speed of the planet carrier.

[0024] Next, while referring to Figure 1 and referring to Figures 10A to 10C at the same time, the operation of the centrifugal brake 2 configured according to the present invention will be described. In Figure 1 the state shown, the locking protrusion 38 of the elastic piece 34 formed on the rotating body 6 is locked with the locking concave portion 78c of the expansion portion 76 formed on the adjusting member 56, and the rotating body 6 does not rotate.

[0025] In Figure 10AThe state in which the rotating body 6 rotates when the locking projection 38 is locked to the locking recess 78c is shown. As described above, the rotation of the rotation transmission shaft s (indicated by a double-dashed line) is increased in speed by the speed increaser 82 and transmitted to the rotating body 6. The rotation transmission shaft s preferably rotates in such a direction that the other side in the circumferential direction, that is, the side where the shaft hole 48 is formed in the counterweight 40, becomes the upstream side in the rotation direction. When the rotating body 6 rotates, the counterweight 40 and the adjustment member 56 rotate integrally with the rotating body 6, and the counterweight 40 rotates about the support shaft 32 by centrifugal force, and the outer surfaces thereof come into contact with the inner peripheral surface 8 of the housing 4 or the inner surface of the adjustment piece 64 of the adjustment member 56. At this time, the outer surface of the counterweight 40a, more specifically, the outer surface of the sliding piece 46 comes into contact with the inner peripheral surface 8 of the housing 4 (C-C cross-sectional view), but in the counterweight 40b, the outer surface of the main portion 44 comes into contact with the inner surface of the first portion 72 of the adjustment piece 64 of the adjustment member 56 (D-D cross-sectional view) and does not come into contact with the inner peripheral surface 8 of the housing 4, and in the counterweight 40c, the outer surface of the main portion 44 comes into contact with the inner surface of the second portion 74 of the adjustment piece 64 of the adjustment member 56 (E-E cross-sectional view) and does not come into contact with the inner peripheral surface 8 of the housing 4. Therefore, in the Figure 10A state shown, only the outer surface of the sliding piece 46 of the counterweight 40a is pressed against the inner peripheral surface 8 of the housing 4 by the above-mentioned centrifugal force and slides relative to the inner peripheral surface 8, and a braking force (braking torque) generated by the friction caused by the above-mentioned sliding acts on the rotating body 6. In the illustrated embodiment, the housing 4 is made of a relatively hard synthetic resin, and the sliding piece 46 of the counterweight 40 is made of a relatively soft synthetic resin. Therefore, only the replaceable sliding piece 46 is unevenly worn to prevent the inner peripheral surface of the housing 4 from being worn.

[0026] In the centrifugal brake of the present invention, the adjusting piece 64 of the adjusting member 56 that rotates integrally with the rotating body 6 enters between the outer surface of the counterweight 40 and the inner peripheral surface 8 of the housing 4. The circumferential side edge 68 of the adjusting piece 64 is displaced stepwise in the circumferential direction according to the positions of the plurality of counterweights 40 arranged in series in the axial direction. Therefore, by changing the circumferential position of the adjusting member 56 relative to the rotating body 6, the number of counterweights 40 whose outer surfaces abut against the inner peripheral surface 8 of the housing 4 can be changed. The more the number of counterweights 40 whose outer surfaces abut against the inner peripheral surface 8 of the housing 4, the greater the braking torque acting on the rotating body 6. Therefore, the braking torque applied to the rotating body 6 changes stepwise. To change the circumferential position of the adjusting member 56 relative to the rotating body 6, after temporarily releasing the engagement between the engaging protrusion 38 and the engaging recess 78 by elastically deforming the engaging protrusion 38 or the elastic piece 34 radially inward with a finger, the adjusting member 56 is rotated relative to the rotating body 6 about the rotation axis o. At this time, the user can easily rotate the adjusting member 56 relative to the rotating body 6 by operating the engaging protrusion 38 or the elastic piece 34 with the finger of one hand and placing the finger of the other hand on the gripping portion 80. In the centrifugal brake configured according to the present invention, the elastic piece 34 extends beyond the swelling portion 76, so that the elastic piece 34 can be easily operated with a finger.

[0027] In order to make the magnitude of the braking torque acting on the rotating body 6 when the rotating body 6 rotates larger than Figure 10A the state shown, the adjusting member 56 is rotated relative to the rotating body 6 to the other side in the circumferential direction. In Figure 10B is shown the state where the rotating body 6 rotates when the engaging protrusion 38 is engaged with the engaging recess 78b. As can be understood by comparing and referring to Figure 10B and Figure 10A as understood, in Figure 10B the state shown, in addition to the counterweight 40a, the outer surfaces (the outer surfaces of the respective sliding pieces 46) of the counterweight 40b also abut against the inner peripheral surface 8 of the housing 4 and slide relative to the inner peripheral surface 8 of the housing 4. Therefore, the braking torque applied to the rotating body 6 increases. The outer surface of the counterweight 40c continues to abut against the inner surface of the second portion 74 of the adjusting piece 64 of the adjusting member 56 and does not abut against the inner peripheral surface 8 of the housing 4. In Figure 10C is shown the state where the adjusting member 56 is further rotated relative to the rotating body 6 to the other side in the circumferential direction and the rotating body 6 rotates when the engaging protrusion 38 is engaged with the engaging recess 78a. As can be understood by comparing and referring to Figure 10C and Figure 10B as understood, in Figure 10C the state shown, in addition to the counterweights 40a and 40b, the outer surfaces (the outer surfaces of the respective sliding pieces 46) of the counterweight 40c also abut against the inner peripheral surface 8 of the housing 4 and slide relative to the inner peripheral surface 8 of the housing 4. Therefore, the braking torque applied to the rotating body 6 further increases.

[0028] In the centrifugal brake configured according to the present invention, the elastic piece 34 extends beyond the expansion portion 76, so that the elastic piece 34 can be easily operated with a finger. Since the locking projection 38 is formed on the elastic piece 34, the operability of the operation of temporarily releasing the locking between the locking projection 38 and the locking recesses 78a to 78c and rotating the adjusting member 56 relative to the rotating body 6 is good. Furthermore, in the centrifugal brake of the present invention, as Figure 11 shown, when viewed radially, the protective piece 20 extending axially to the other side beyond the elastic piece 34 is provided on the housing 4 (the straight line shown by the single-dot chain line in Figure 11 represents the position of the axially other end of the protective piece 20), so that even if the centrifugal brake moves axially along the rotation axis o, only the protective piece 20 collides with the wall surface of an external device or the like, and the elastic piece 34 does not collide with the wall surface of an external device or the like and break. Since the elastic piece 34 does not contact the wall surface of an external device or the like, the elastic piece 34 does not wear and does not generate abnormal noise when the adjusting member 56 rotates integrally with the rotating body 6. Therefore, according to the centrifugal brake of the present invention, not only can the magnitude of the braking torque acting on the rotating body 6 be easily changed, but also the operability of the changing operation can be maintained in a good state. Even if the protective piece 20 is formed in a ring shape, the above-described effects are achieved. However, if the protective piece 20 is formed in a ring shape, the operability of rotating the adjusting member 56 relative to the rotating body 6 is deteriorated. Therefore, it is preferable that a plurality of protective pieces 20 are provided at intervals in the circumferential direction, and it is more preferable that a plurality of protective pieces 20 are provided at equal angular intervals in the circumferential direction.

[0029] As described above, the centrifugal brake configured according to the present invention has been described in detail with reference to the drawings. However, the present invention is not limited to the above-described embodiments, and appropriate modifications and changes can be made without departing from the scope of the present invention. For example, in the illustrated embodiment, the three weights 40 are arranged in series in the axial direction, but the number of the weights 40 can be arbitrary. Further, in the illustrated embodiment, the elastic piece 34 extends axially to the other side inside the cylindrical expansion portion 76, but the elastic piece 34 may be located outside the expansion portion 76. When the elastic piece is located outside the expansion portion, the locking projection is formed on the radially inner surface of the elastic piece, and the user can release the locking between the locking projection and the locking recess by elastically deforming the locking projection or the elastic piece radially outward. Reference Signs

[0030] 2: Centrifugal brake 4: Housing 6: Rotating body 8: Inner circumferential surface of housing 20: Protective piece 28: Rotating plate 32: Support shaft 34: Elastic piece 38: Latching projection 40 (40a to 40c): Counterweight 56: Adjusting member 58: Adjusting plate 64: Adjusting piece 68: Circumferential side edge of the adjusting piece 76: Expansion part 78a to 78c: Latching recesses.

Claims

1. A centrifugal brake comprising: a cylindrical housing having an inner peripheral surface with a circular cross section; and a rotating body that rotates relative to the housing with a central axis of the inner peripheral surface as a rotation axis, The rotating body comprises a rotating plate arranged perpendicularly to the rotating shaft, a supporting shaft extending to one axial side is provided at a position eccentric to the rotating shaft on one axial side surface of the rotating plate, a plurality of counterweights are axially supported in series on the supporting shaft, an elastic piece extending to the other axial side is provided at a position eccentric to the rotating shaft on the other axial side surface of the rotating plate, and a locking protrusion is formed on a radially outer side surface or an inner side surface of the elastic piece, The rotating body is combined with an adjustment member, The adjustment member includes an adjustment plate arranged perpendicular to the rotating shaft, the adjustment plate being arranged adjacent to the other axial side of the rotating plate, an adjustment piece extending axially to one side is provided at the outer peripheral edge portion of one axial side surface of the adjustment plate, the adjustment piece enters between the outer surface of the counterweight and the inner circumferential surface of the shell, one circumferential side edge of the adjustment piece is displaced circumferentially in stages according to the axial positions of the plurality of counterweights arranged in series in the axial direction, an expansion portion is provided at the central portion of the other axial side surface of the adjustment plate, and a plurality of locking recesses are formed at intervals in the circumferential direction on the end surface of the other axial side of the expansion portion according to the number of the plurality of counterweights arranged in series in the axial direction, the locking protrusions being able to be respectively locked in the plurality of locking recesses, When the rotating body rotates, the plurality of counterweights and the adjustment member rotate integrally with the rotating body, and the plurality of counterweights rotate about the support shaft and the outer surface of each counterweight abuts against the inner peripheral surface of the housing or the inner surface of the adjustment sheet. The number of the weights whose outer surface contacts the inner peripheral surface of the housing changes depending on which of the plurality of locking recesses the locking protrusion is locked with. The elastic sheet extends beyond the expansion portion to the other side in the axial direction. The housing is provided with a protection sheet which extends to the other side in the axial direction beyond the elastic sheet when viewed in the radial direction.

2. The centrifugal brake according to claim 1, wherein: A plurality of protection sheets are arranged at equal angular intervals along the circumferential direction.

3. The centrifugal brake according to claim 1, wherein: The locking protrusion and the locking recesses are provided in pairs on both sides in the diameter direction.

4. The centrifugal brake according to claim 1, wherein: The expansion portion is cylindrical, and the elastic sheet passes through the inner side of the expansion portion.

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