JP7628104B2 - Centrifugal brake - Google Patents

Description

The present invention relates to a centrifugal brake, and in particular to a centrifugal brake in which the magnitude of the braking force can be steplessly adjusted by the required operation.

Blinds are sometimes installed near indoor windows to avoid sunlight. Blinds have slats that extend horizontally. Many slats are arranged vertically, and each of the many slats is connected vertically by a lifting cord (sometimes called an operating cord). The blinds further include a winding mechanism that is arranged above the uppermost slat and a bottom rail (sometimes called a bottom pipe or weight bar) that is arranged below the lowermost slat, and one end of the lifting cord is connected to the winding mechanism and the other end to the bottom rail. In such blinds, the bottom rail is raised by operating the winding mechanism to wind up the lifting cord, and the bottom rail is held at any raised position by operating an appropriate locking mechanism provided in the winding mechanism. The bottom rail is lowered by releasing the operation of the locking mechanism. Here, since the bottom rail falls freely when the operation of the locking mechanism is released, an appropriate brake mechanism may be incorporated in the winding mechanism to reduce the speed of its descent. A well-known centrifugal brake is often used as such a brake mechanism.

The following Patent Document 1 discloses, as an example of a centrifugal brake, a centrifugal brake that includes a cylindrical housing with an inner peripheral surface that is circular in cross section and a rotor that rotates inside the housing, the axis of rotation of the rotor is the same as the central axis of the inner peripheral surface of the housing, the rotor has a support shaft that extends parallel to the rotation shaft at a position eccentric to the rotation shaft, a weight is rotatably supported on the support shaft, and when the rotor rotates, the weight rotates and the outer surface of the weight slides against the inner surface of the housing. The centrifugal force presses the outer surface of the weight against the inner surface of the housing, increasing the normal force generated between the outer surface of the weight and the inner surface of the housing, and therefore the braking force caused by friction is also increased.

Publication number 1-45353

The centrifugal brake disclosed in Patent Document 1 does not allow the magnitude of the braking force to be adjusted, and therefore, when this centrifugal brake is used as the braking mechanism for the blinds described above, the falling speed of the slats cannot be adjusted according to the user's preference. Also, if the braking force is to be changed depending on the weight of the slats, it is necessary to prepare multiple types of centrifugal brakes with different braking forces in advance, which makes inventory management of centrifugal brakes cumbersome.

In the specification and drawings of Japanese Patent Application No. 2020-187961 filed prior to this application, the present inventor proposed a centrifugal brake in which multiple weights are arranged in series in the axial direction, and an adjustment member that rotates integrally with the rotor and can advance and retreat in the axial direction relative to the rotor is combined with the rotor, and the adjustment member can selectively advance between the inner peripheral surface of the housing and the outer peripheral surface of the weight by adjusting the axial position of the adjustment member relative to the rotor (hereinafter referred to as the "preceding centrifugal brake"). According to this centrifugal brake, by adjusting the axial position of the adjustment member relative to the rotor, it is possible to change the number of weights whose outer peripheral surfaces (of the weights) are prevented from abutting against the inner peripheral surface of the adjustment member and abutting against the inner peripheral surface of the housing when the rotor rotates, thereby making it possible to adjust the magnitude of the braking force applied to the rotor in stages.

The above-mentioned pre-emptive centrifugal brakes were also not fully satisfactory, and it was found that there was a further problem in that the braking force was adjusted in stages with the pre-emptive centrifugal brakes, making fine adjustment of the braking force impossible.

The present invention was made in consideration of the above facts, and its main technical objective is to provide a new and improved centrifugal brake that allows for stepless adjustment of braking force.

After extensive research, the inventors discovered that the above-mentioned main technical objective can be achieved by connecting a pair of adjustment members that can rotate around an adjustment axis that intersects with the rotation axis so that their respective inner surfaces face each other at a distance in the adjustment axis direction, defining a cylindrical sliding inner circumferential surface against which the outer surface of the weight abuts and slides on the inner surfaces of the connected pair of adjustment members, and partitioning a number of areas with different friction coefficients adjacent to each other in the circumferential direction around the adjustment axis on the inner surface of each of the pair of adjustment members.

That is, according to the present invention, a centrifugal brake that achieves the above-mentioned main technical object is provided, which comprises a housing and a rotor that rotates inside the housing,
The rotating body has a support shaft extending parallel to the rotation shaft at a position eccentric to the rotation shaft, and a weight is rotatably supported on the support shaft,
In a centrifugal brake in which, when the rotating body rotates, the weight rotates and an outer surface of the weight abuts against and slides on an inner surface of the housing,
the housing includes a pair of adjustment members rotatable around an adjustment axis intersecting the rotation axis, inner surfaces of the pair of adjustment members are arranged opposite to each other at a distance in the adjustment axis direction, and a cylindrical sliding inner circumferential surface is defined on the inner surfaces of the pair of adjustment members against which an outer surface of the weight abuts and which can slide freely;
The present invention provides a centrifugal brake, characterized in that an inner surface of each of the pair of adjustment members is provided with a plurality of regions having different friction coefficients that are adjacently defined in a circumferential direction around the adjustment shaft.

Preferably, each of the pair of adjustment members is constructed by combining a plurality of plate-shaped adjustment pieces, and the plurality of plate-shaped adjustment pieces are formed of materials with different friction coefficients. It is preferable that the cross-sectional shape of the sliding inner peripheral surface is an arc shape and the vertical cross-sectional shape is a circle. It is preferable that the adjustment axis is perpendicular to the rotation axis. Preferably, the housing further includes a pair of movable housing pieces to which the pair of adjustment members are fixed separately and coupled to each other, and a pair of fixed housing pieces that rotatably hold the rotor and rotatably hold the pair of movable housing pieces coupled to each other. In this case, it is preferable that a rubber washer is disposed between the pair of fixed housing pieces and one of the pair of movable housing pieces. Furthermore, it is preferable that one of the pair of movable housing pieces is provided with an operating portion, and one or both of the pair of fixed housing pieces is provided with a limiting piece that limits the rotation range of the movable housing piece.

In the centrifugal brake of the present invention, the cylindrical sliding inner circumferential surface against which the outer surface of the weight abuts and slides is defined on the inner surface of a pair of adjustment members that can rotate around an adjustment axis that intersects with the rotation axis, and on the inner surface of each of the pair of adjustment members, multiple regions with different friction coefficients are defined adjacent to each other in the circumferential direction around the adjustment axis. Therefore, by rotating the pair of adjustment members around the adjustment axis, the region on the inner surface of the pair of adjustment members against which the outer surface of the weight abuts is changed, and the magnitude of the frictional resistance that the weight receives from the adjustment member can be adjusted. And since the above-mentioned regions are defined adjacent to each other in the circumferential direction around the adjustment axis, if the outer surface of the weight abuts across the multiple above-mentioned regions on the inner surface of the adjustment member, the magnitude of the frictional resistance that the weight receives from the adjustment member can be adjusted steplessly.

1 is a diagram showing the overall configuration of a centrifugal brake constructed according to the present invention. FIG. 2 is an exploded perspective view of the centrifugal brake shown in FIG. 1 , showing each component part. FIG. 2 is a diagram showing a rotor of the centrifugal brake shown in FIG. 1 alone. FIG. 2 is a front view of the inner surface of the adjustment member shown in FIG. 1 . FIG. 2 is a view showing one of a pair of housing pieces of the centrifugal brake shown in FIG. 1 alone. FIG. 2 is a view showing the other of the pair of housing pieces of the centrifugal brake shown in FIG. 1 . FIG. 2 is a view showing a stationary housing piece of the centrifugal brake shown in FIG. 1 alone; 2 is a cross-sectional view taken along line AA in FIG. 1 when the rotating body is rotating. 2 is a diagram showing a state in which an adjustment member is rotated around an adjustment shaft in the centrifugal brake shown in FIG. 1 . 2 is a diagram showing a state in which an adjustment member is rotated around an adjustment shaft in the centrifugal brake shown in FIG. 1 . 2 is a diagram showing a state in which an adjustment member is rotated around an adjustment shaft in the centrifugal brake shown in FIG. 1 .

The present invention will now be described in more detail with reference to the accompanying drawings, which show a preferred embodiment of a centrifugal brake constructed in accordance with the present invention.

Referring to Figures 1 and 2, the centrifugal brake, generally designated by the number 2, comprises a housing 4 and a rotor 6 that rotates inside the housing 4. The axis of rotation of the rotor 6 is designated by o1.

For convenience, the rotor 6 will be described first with reference to FIG. 1, FIG. 2, and FIG. 3 before the housing 4. The rotor 6 is made of an appropriate synthetic resin and has a rotating main shaft 8 with a circular cross section that extends linearly in the axial direction along the rotating axis o1 (in this paragraph and the next paragraph, unless otherwise specified, "axial direction" refers to the axial direction along the rotating axis o1, and "circumferential direction" refers to the circumferential direction based on the rotating axis o1). Disk-shaped flanges 10 are arranged on both axial ends of the rotating main shaft 8, and one of the flanges 10 is provided with a connecting portion 12 that extends linearly on the opposite side of the rotating main shaft 8 in the axial direction. The cross-sectional shape of the connecting portion 12 is a shape in which a part of the circular outer circumferential surface is cut out linearly, and the rotor 6 is connected to an external device (not shown), such as a blind winding mechanism, via the connecting portion 12. A pair of circular support plates 14 are provided at an axially intermediate portion of the rotating main shaft 8 with an axial gap therebetween. Each of the pair of support plates 14 is connected to the outer periphery by a support shaft 16 that extends parallel to the rotation axis o1. In other words, the rotor 6 has a support shaft 16 that extends parallel to the rotation axis o1 at a position eccentric to the rotation axis o1. The support shaft 16 is supported at both ends by the pair of support plates 14, so the strength of the support shaft 16 is high. In the illustrated embodiment, two support shafts 16 are provided at an angle of 180 degrees in the circumferential direction, and the cross section of the support shaft 16 has a required shape.

Continuing the explanation with reference to Figures 1 and 2, the above-mentioned support shaft 16 supports a metal weight 18 so that it can rotate. In the illustrated embodiment, two support shafts 16 are provided, and the weight 18 is supported on each of the two support shafts 16. The weight 18 has an arc shape and a required width in the axial direction. A bearing groove 20 that penetrates linearly in the axial direction is formed at one end of the outer circumferential surface of the weight 18, and the weight 18 is attached to the rotating body 6 by fitting the bearing groove 20 to the support shaft 16 of the rotating body 6. For the cross-sectional shape of the support shaft 16 and the bearing groove 20 and the method of attaching the weight 18 to the rotating body 6, please refer to Japanese Patent No. 7052122, which was filed by the present inventor prior to this application and has already been patented. A mounting groove 22 that penetrates linearly in the axial direction is formed at the circumferential middle part of the outer circumferential surface of the weight 18. A synthetic resin friction shoe 24 is attached to the mounting groove 22 in a replaceable manner.

Continuing to describe the housing 4 with reference to FIGS. 1 and 2, the housing 4 includes a pair of adjustment members 26a and 26b. In the illustrated embodiment, the housing 4 also includes a pair of movable housing pieces 28a and 28b and a pair of fixed housing pieces 30a and 30b. The pair of adjustment members 26a and 26b, the pair of movable housing pieces 28a and 28b, and the pair of fixed housing pieces 30a and 30b are all formed of an appropriate synthetic resin. The material of the pair of adjustment members 26a and 26b will be further mentioned later. Each of the pair of adjustment members 26a and 26b is rotatable around an adjustment axis o2 that intersects with the rotation axis o1, and the respective inner surfaces are arranged opposite to each other at a distance in the direction of the adjustment axis o2. In the illustrated embodiment, the adjustment axis o2 is perpendicular to the rotation axis o1, and each of the pair of adjustment members 26a and 26b has the same hemispherical shape. When the pair of adjustment members 26a and 26b are assembled, a spherical internal space is defined, and the weight 18 is placed in this internal space. As a result, the inner surface of the assembled pair of adjustment members 26a and 26b defines a sliding inner circumferential surface 32 against which the outer surface of the weight 18 abuts and slides when the weight 18 rotates, as described below (see also FIG. 9-1). In the illustrated embodiment, since each of the pair of adjustment members 26a and 26b has the same hemispherical shape, the horizontal cross-sectional shape (cross-sectional shape when cut horizontally in FIG. 9-1(b)) of the sliding inner circumferential surface 32 is an arc shape, and the vertical cross-sectional shape (cross-sectional shape when cut vertically in FIG. 9-1(b)) is a circle. Two arc-shaped notches 36 are formed on each annular edge of the pair of adjustment members 26a and 26b at an angle of 180 degrees around the adjustment axis o2.

The inner surface of each of the pair of adjustment members 26a and 26b is divided into a plurality of regions with different friction coefficients adjacent to each other in the circumferential direction around the adjustment axis o2. In the illustrated embodiment, each of the pair of adjustment members 26a and 26b is composed of a combination of a plurality of plate-shaped adjustment pieces, and the above-mentioned regions are divided by forming the plurality of plate-shaped adjustment pieces from materials with different friction coefficients. The adjustment pieces include a main adjustment piece 38 and an auxiliary adjustment piece 40 (as will be described later, in the figures, x to z are added after the numbers for each material, but when all materials are described collectively, the above x to z are omitted). With reference to FIG. 2 and FIG. 4, the inner and outer surfaces of the main adjustment piece 38 and the auxiliary adjustment piece 40 are both isosceles triangles when viewed from the front, that is, in the axial direction along the adjustment axis o2 (in this paragraph to paragraph 0022, unless otherwise specified, "axial direction" refers to the axial direction along the adjustment axis o2, and "circumferential direction" refers to the circumferential direction based on the adjustment axis o2), and both the longitudinal and transverse cross-sectional shapes are arc shapes. Therefore, if the main adjustment piece 38 and the auxiliary adjustment piece 40 are arranged adjacent to each other in the circumferential direction, they will have a hemispherical shape. The auxiliary adjustment piece 40 is somewhat wider than the main adjustment piece 38 and somewhat shorter in vertical cross section. When the inner surface of each of the main adjustment pieces 38 and the auxiliary adjustment pieces 40 is viewed from the front, three main adjustment pieces 38 arranged adjacent to each other in the circumferential direction are arranged in pairs at an angular interval of 180 degrees in the circumferential direction, and two auxiliary adjustment pieces 40 are arranged adjacent to each other in the circumferential direction on both sides of the three main adjustment pieces 38 in the circumferential direction, and a notch 36 is defined at the circumferential portion where the auxiliary adjustment pieces 40 are arranged. Two holding protrusions 42 each having a circular cross section protruding in the axial direction are provided at intervals on the outer surface of each of the main adjustment pieces 38 and the auxiliary adjustment piece 40, and the main adjustment piece 38 and the auxiliary adjustment piece 40 are supported by the movable housing piece 28a or 28b as part of the adjustment member 26a or 26b via the holding protrusions 42. In the illustrated embodiment, the adjustment pieces (i.e., the main adjustment piece 38 and the auxiliary adjustment piece 40) are made of three types of materials x to z with different friction coefficients, and in the figure, each material is numbered with x to z. Material x is, for example, polybutylene terephthalate (PBT), and the adjustment piece formed therefrom has a relatively small friction coefficient. Material y is, for example, polyacetal (POM), and the adjustment piece formed therefrom has a relatively medium friction coefficient. Material z is, for example, a thermoplastic ester-based elastomer material, and the adjustment piece formed therefrom has a relatively large friction coefficient. As clearly shown in FIG. 4, when the inner surfaces of the adjustment members 26a and 26b are viewed from the front, the main adjustment pieces 38x to 38z are arranged so that they are located on both sides in the diametric direction (therefore, the circumferential arrangement of the three main adjustment pieces 38x to 38z arranged in pairs at an angular interval of 180 degrees in the circumferential direction is the same when viewed from one side in the circumferential direction), and the auxiliary adjustment pieces 40 are arranged to be made of the same material as the main adjustment pieces 38 adjacent to them in the circumferential direction (auxiliary adjustment pieces 40x and 40z).

Explaining with reference to FIG. 5 together with FIG. 1 and FIG. 2, the inner surface of the movable housing piece 28a is hemispherical, and its curvature corresponds to the curvature of the outer surface of the adjustment member 26a (and 26b). A plurality of bottomed retaining holes 44 into which the retaining protrusions 42 of the adjustment member 26a are inserted are formed on the inner surface of the movable housing piece 28a, corresponding to the retaining protrusions 42, and the movable housing piece 28a retains the adjustment member 26a from its outer surface (back surface). The outer surface of the movable housing piece 28a is divided into a bottom portion 46, the outer surface of which is a part of a sphere, and a peripheral wall 47 extending in the axial direction from the periphery of the bottom portion 46. The outer surface of the bottom portion 46 is parallel to the inner surface of the movable housing piece 28a. The peripheral wall 47 is generally cylindrical, but two arc-shaped notches 50 extending in the circumferential direction are formed at the free end in the axial direction at an angular interval of 180 degrees in the circumferential direction. The circumferential length of the notch 50 corresponds to the circumferential length of the notch 36 formed in the adjustment member 26a. The circumferential region of the peripheral wall 47 where the notch 50 is not formed forms the locking portion 48. Therefore, there are two locking portions 48 at an angular interval of 180 degrees in the circumferential direction. At both circumferential ends of the locking portion 48, a circumferential locking rib 52 having a rectangular cross section is provided, which protrudes radially outward from the outer peripheral surface of the peripheral wall 47 and extends linearly in the axial direction. The circumferential locking rib 52 extends from the axially open side edge 50a of the notch 50 beyond the axially closed side edge 50b to the axial middle portion of the peripheral wall 47 when viewed in the axial direction. An axial locking recess 54 extending linearly in the circumferential direction is also formed at both circumferential ends of the outer peripheral surface of the locking portion 48.

Explaining with reference to FIG. 6 together with FIG. 1 and FIG. 2, the movable housing piece 28b includes a flat operating portion 56 arranged perpendicular to the axial direction, and a cylindrical main portion 58 extending axially from the center of one side of the operating portion 56. A plurality of irregularities 60 are repeatedly formed in the circumferential direction on the outer peripheral surface of the operating portion 56. Such irregularities 60 include protruding convex portions 62 that protrude radially outwardly more than the other convex portions. The protruding convex portions 62 are formed in pairs adjacent to each other in the circumferential direction on both sides in the diametric direction, so that there are a total of four protruding convex portions 62. The inner surface of the main portion 58 is hemispherical, and its curvature corresponds to the curvature of the outer surface of the adjustment member 26b (and 26a). A plurality of bottomed holding holes 64 through which the holding protrusions 42 of the adjustment member 26b are inserted are formed in the inner surface of the main portion 58 in correspondence with the holding protrusions 42, and the movable housing piece 28b holds the adjustment member 26b from the outer surface (rear surface). Two arc-shaped notches 66 extending in the circumferential direction are formed at the axial free end of the main part 58 at an angular interval of 180 degrees. The circumferential length of the notches 66 corresponds to the circumferential length of the notch 36 formed in the adjustment member 26b and the notch 50 formed in the movable housing piece 28a. A plate-shaped interlocking piece 68 extending linearly in the axial direction beyond the axial free end of the main part 58 is attached to the circumferential middle part of the outer circumferential surface of the two arc-shaped parts remaining between the two notches 66. Axial interlocking protrusions 70 extending linearly in the circumferential direction are formed on both circumferential ends of the inner circumferential surface of the extended end of the interlocking piece 68. In addition, an arc-shaped shoulder surface 71 is formed at the base end of the interlocking piece 68, which faces the operating part 56 in the axial direction.

1 and 2 and FIG. 7, each of the pair of fixed housing pieces 30a and 30b has the same shape, and is composed of a rectangular end plate 72 arranged perpendicular to the axial direction and a side wall 74 with a semicircular cross section that extends linearly from the end plate 72 in the axial direction, and the end face extending in the axial direction of the side wall 74 is located on the same plane as the end face of the adjacent end plate 72. The axial bottom surface of the end plate 72 defined on the inside of the side wall 74 is a part of a sphere, and its curvature corresponds to the curvature of the outer surface of the bottom part 46 of the movable housing piece 28a. The side wall 74 is connected to the end plate 72 and is divided into a base end 76 with a relatively large outer diameter and a main part 78 with an outer diameter smaller than that of the base end 76. On the inner surface of the base end 76, an arc-shaped groove 80 is formed by locally increasing the inner diameter and is continuously formed in the circumferential direction. The cross section of the groove 80 is rectangular. A circular communication hole 82 penetrating in the radial direction (i.e., the axial direction along the rotation axis o1) is formed in the circumferential center portion of the main portion 78 of the side wall 74, and a C-shaped support wall 84 protruding radially outward is formed on the outer circumferential surface of the main portion 78 along the periphery of the communication hole 82. The inner periphery of the support wall 84 is located slightly inside the periphery of the communication hole 82, and the outer circumferential surface of the support wall 84 is locally connected to the base end portion 76 at its circumferential center portion. A pair of additional portions 85 extending in the axial direction from the base end portion 76 are also formed on the outer circumferential surface of the main portion 78. The circumferential inner side surface of each of the pair of additional portions 85 is connected to the outer circumferential surface of the support wall 84, and a limiting piece 86 extending linearly in the axial direction is attached to each of the circumferential inner ends of the pair of additional portions 85. The limiting piece 86 extends in the axial direction beyond the axial free end of the main portion 78. Such limiting pieces 86 are formed on both circumferential sides of the communication hole 82. That is, a pair of limiting pieces 86 are formed. An arc-shaped shoulder surface 88 is formed on the inner peripheral surface of the main portion 78, extending circumferentially across the communication hole 82 and facing the axial bottom side of the main portion 78. An engaging claw 90 and an engaging frame 92 are formed on the outer surfaces of the end plate 72 and the side wall 74, respectively, and the pair of fixed housing pieces 30a and 30b are joined by making the inner surfaces of the side walls 74 of the pair of fixed housing pieces 30a and 30b face each other in a direction perpendicular to the axial direction (i.e., the axial direction along the rotation axis o1) and engaging the engaging claws 90 and the engaging frames 92 formed on each side wall 74 with each other. When the pair of fixed housing pieces 30a and 30b are joined, a circular cross-sectional housing space is defined inside the joined pair of fixed housing pieces 30a and 30b. The bottom surface of the housing space is a part of a sphere, and its curvature is the same as the curvature of the outer surface of the bottom 46 of the movable housing piece 28a. Additionally, the groove 80 is continuous in the circumferential direction and has a circular ring shape.

The housing 4 and the rotating body 6 described above are combined as follows. To explain this mainly with reference to FIG. 2, first, a pair of movable housing pieces 28a and 28b are arranged on both sides of the weight 18 attached to the rotating body 6, on both sides of the adjustment axis o2 that intersects with the rotation axis o1 (orthogonal in the illustrated embodiment). Each of the pair of movable housing pieces 28a and 28b is arranged in a state in which the inner surface of the adjustment member 26a held by the movable housing piece 28a and the inner surface of the adjustment member 26b held by the movable housing piece 28b face each other on the adjustment axis o2.

Next, the notch 50 of the movable housing piece 28a and the notch 36 of the adjustment member 26a, as well as the notch 66 of the movable housing piece 28b and the notch 36 of the adjustment member 26b are aligned with the main rotation shaft 8 of the rotor 6, and the pair of movable housing pieces 28a and 28b are brought close to each other on the adjustment axis o2, and the weight 18 is embraced by the inner surfaces of the pair of adjustment members 26a and 26b. When the pair of movable housing pieces 28a and 28b are combined in this manner, as shown in Figures 9-1 to 9-3, the notches 36, 50 and 66 define a pair of arc-shaped windows 94 through which the main rotation shaft 8 of the rotor 6 passes. Furthermore, when the pair of movable housing pieces 28a and 28b are brought close to each other as described above, the locked piece 68 of the movable housing piece 28b enters between the two circumferential locking ribs 52 adjacent in the circumferential direction formed on the movable housing piece 28a, and the axial locking protrusion 70 formed on the inner surface of the locked piece 68 rides up onto the outer surface of the locking portion 48 of the peripheral wall 47 and then fits into the axial locking recess 54. This restricts the circumferential and axial movement of the movable housing piece 28b relative to the movable housing piece 28a, and the pair of movable housing pieces 28a and 28b are joined together.

Then, the pair of movable housing pieces 28a and 28b, which are joined together while containing the rotating body 6, are brought closer to each other from both sides of the rotation axis o1, so that the connection portion 12 of the rotating body 6 is connected to the communication hole 82 of the fixed housing piece 30b, and the two flanges 10 are supported by the support walls 84 formed on each of the pair of fixed housing pieces 30a and 30b in a direction approaching each other from both axial sides of the rotation axis o1. Thus, the rotating body 6 is supported by the pair of fixed housing pieces 30a and 30b to be rotatable around the rotation axis o1. Further, the outer surface of the bottom portion 46 of the movable housing piece 28a faces the axial bottom surface defined on the inner side of the side wall 74 of each end plate 72 of the pair of fixed housing pieces 30a and 30b, and the pair of movable housing pieces 28a and 28b are supported by the pair of fixed housing pieces 30a and 30b so as to be rotatable about the adjustment axis o2. In the illustrated embodiment, a rubber washer 96 is disposed between the pair of fixed housing pieces 30a and 30b and the movable housing piece 28a. The rubber washer 96 has an annular shape and is disposed in the groove 80. The shoulder surface 71 of the interlocking piece 68 of the movable housing piece 28b is engaged with the shoulder surface 88 of the pair of fixed housing pieces 30a and 30b, which allows the pair of movable housing pieces 28a and 28b to rotate around the adjustment axis o2 relative to the pair of fixed housing pieces 30a and 30b, but prevents them from moving in the direction of the adjustment axis o2 relative to the pair of fixed housing pieces 30a and 30b and falling off.

As can be understood by comparing the A-A cross-sectional view in FIG. 1 with FIG. 8, when the rotor 6 rotates in the centrifugal brake 2, the weight 18 supported on the support shaft 16 of the rotor 6 rotates, and the outer surface of the weight 18, in the illustrated embodiment, the friction shoe 24, comes into contact with and slides against the inner surface (sliding inner circumferential surface 32) of the housing 4. This sliding acts on the rotor 6 with a braking force.

In the state shown in Figure 1, one of a pair of protruding convex portions 62 formed on the operating portion 56 of the movable housing piece 28b, which is located on the clockwise side (in the upper right image of Figure 1; the same applies below), abuts against one of a pair of limiting pieces 86 formed on each side wall 74 of the fixed housing pieces 30a and 30b, which is located on the counterclockwise side, thereby preventing the movable housing piece 28b and the movable housing piece 28a integral with it from rotating clockwise around the adjustment axis o2 relative to the pair of fixed housing pieces 30a and 30b. Fig. 9-1 shows the same state as shown in Fig. 1, Fig. 9-1(a) shows the same view as the upper right view of Fig. 1, Fig. 9-1(b) shows the rotor 6 in the B-B cross section of Fig. 1 with a two-dot chain line, the weight 18 is omitted, and the sliding inner peripheral surface 32 is shown in light ink, and Fig. 9-1(c) shows a perspective view with the fixed housing piece 30b omitted (the same applies to Figs. 9-2 and 9-3 (a) to (c) mentioned later). As shown in Fig. 9-1(c), the rotating main shaft 8 of the rotating body 6 is located at one circumferential end of the window 94. The rotating main shaft 8 is not in contact with the pair of movable housing pieces 28a and 28b. When the rotor 6 rotates in the state shown in FIG. 9-1, the sliding inner surface 32 on which the outer surface of the weight 18 slides against the inner surfaces of the pair of adjustment members 26a and 26b is dominated by the inner surface of the main adjustment piece 38x, which has a relatively small coefficient of friction, as can be seen by referring to FIG. 9-1(b), so the frictional force, or in other words, the resistance that the outer surface of the weight 18 receives from the sliding inner surface 32 is small.

Figure 9-2 shows a state in which the operating portion 56 of the movable housing piece 28b has been rotated somewhat counterclockwise from the state shown in Figure 9-1. In this state, as shown in Figure 9-2(c), the main rotation shaft 8 of the rotating body 6 is located in the circumferential center of the window 94. Then, when the rotating body 6 rotates in the state shown in Figure 9-2, as can be understood by referring to Figure 9-2(b), the inner surface of the main adjustment piece 38y, which has a relatively medium friction coefficient, dominates the sliding inner surface 32, so the frictional force, or in other words, the resistance, that the outer surface of the weight 18 receives from the sliding inner surface 32 is medium.

Figure 9-3 shows a state in which the operating portion 56 of the movable housing piece 28b is further rotated counterclockwise from the state shown in Figure 9-2. In the state shown in Figure 9-3, the other of the pair of protruding protrusions 62 formed on the operating portion 56 of the movable housing piece 28b located on the counterclockwise side abuts the other of the pair of limiting pieces 86 formed on each side wall 74 of the fixed housing pieces 30a and 30b located on the clockwise side, and the movable housing piece 28b and the movable housing piece 28a integrated therewith are prevented from further rotating counterclockwise around the adjustment axis o2 relative to the pair of fixed housing pieces 30a and 30b. At this time, as shown in Figure 9-3 (c), the rotating main shaft 8 of the rotating body 6 is located at the other circumferential end of the window 94, and the rotating main shaft 8 is not in contact with the pair of movable housing pieces 28a and 28b. When the rotor 6 rotates in the state shown in FIG. 9-3, as can be seen by referring to FIG. 9-3(b), the inner surface of the main adjustment piece 38z, which has a relatively large coefficient of friction, dominates the sliding inner surface 32, and the frictional force, or in other words, the resistance, that the outer surface of the weight 18 receives from the sliding inner surface 32 is large.

Therefore, in the centrifugal brake of the present invention, the cylindrical sliding inner peripheral surface 32 against which the outer surface of the weight 18 abuts and slides is defined by the inner surface of a pair of adjustment members 26a and 26b that can rotate around an adjustment axis o2 that intersects with the rotation axis o1, and a plurality of regions with different friction coefficients are defined adjacent to each other in the circumferential direction around the adjustment axis o2 on the inner surface of each of the pair of adjustment members 26a and 26b. Therefore, by rotating the pair of adjustment members 26a and 26b around the adjustment axis o2, the region of the inner surface of the pair of adjustment members 26a and 26b against which the outer surface of the weight 18 abuts is changed, and the magnitude of the frictional resistance that the weight 18 receives from the adjustment members 26a and 26b can be adjusted. Since the above-mentioned regions are divided into a plurality of regions adjacent to each other in the circumferential direction around the adjustment axis o2, the magnitude of the frictional resistance that the weight 18 receives from the adjustment members 26a and 26b can be adjusted steplessly if the outer surface of the weight 18 abuts across the plurality of regions on the inner surface of the adjustment members 26a and 26b. In the illustrated embodiment, a rubber washer 96 is disposed between the pair of fixed housing pieces 30a and 30b and the movable housing piece 28a, so that a certain degree of holding force acts on the pair of movable housing pieces 28a and 28b against the pair of fixed housing pieces 30a and 30b, and when the outer surface of the weight 18 slides along the sliding inner circumferential surface 32, the pair of adjustment members 26a and 26b are prevented from unintentionally rotating around the adjustment axis o2 as much as possible.

The centrifugal brake constructed according to the present invention has been described above in detail with reference to the attached drawings, but the present invention is not limited to the above-mentioned embodiment, and appropriate modifications and changes are possible within the scope of the present invention. For example, in the illustrated embodiment, each of the pair of adjustment members 26a and 26b is constructed by combining multiple plate-shaped adjustment pieces (main adjustment piece 38 and auxiliary adjustment piece 40), and these multiple plate-shaped adjustment pieces are formed of materials with different friction coefficients, but each of the pair of adjustment members may be constructed of a single plate-shaped adjustment piece and the inner surface may be polished or a paint of a material with a different friction coefficient may be applied to the inner surface of the single plate-shaped adjustment piece to partition multiple areas with different friction coefficients. If each of the pair of adjustment members is constructed of a single adjustment piece and can be connected to each other by itself, the pair of movable housing pieces can be omitted. Also, if the communication hole 82 is open in the direction of the adjustment axis o2, instead of combining a pair of fixed housing pieces, a single fixed housing in the form of a combination of a pair of fixed housing pieces can be used. In the illustrated embodiment, each of the pair of adjustment members 26a and 26b is hemispherical, but it may be hemispherical (a shape obtained by cutting a rugby ball in the short direction at the center in the longitudinal direction). When each of the pair of adjustment members 26a and 26b is hemispherical, the cross-sectional shape of the sliding inner circumferential surface is arc-shaped, and the vertical cross-sectional shape is elliptical. Furthermore, the number and arrangement of the support shaft and the weights supported by it can be changed as appropriate.

2: Centrifugal brake 4: Housing 6: Rotating body 16: Support shaft 18: Weight 26a and 26b: Adjustment member 32: Sliding inner circumferential surface 38x, 38y, 38z: Main adjustment piece (area)
o1: Rotation axis o2: Adjustment axis

Claims (7)

The rotor includes a housing and a rotor that rotates inside the housing.
The rotating body has a support shaft extending parallel to the rotation shaft at a position eccentric to the rotation shaft, and a weight is rotatably supported on the support shaft,
In a centrifugal brake in which, when the rotating body rotates, the weight rotates and an outer surface of the weight abuts against and slides on an inner surface of the housing,
the housing includes a pair of adjustment members rotatable around an adjustment axis intersecting the rotation axis, inner surfaces of the pair of adjustment members are arranged opposite to each other at a distance in the adjustment axis direction, and a cylindrical sliding inner circumferential surface is defined on the inner surfaces of the pair of adjustment members against which an outer surface of the weight abuts and which can slide freely;
A centrifugal brake, characterized in that an inner surface of each of the pair of adjustment members is defined with a plurality of regions having different friction coefficients adjacent to each other in a circumferential direction around the adjustment shaft. The centrifugal brake according to claim 1, wherein each of the pair of adjustment members is formed by combining a plurality of plate-shaped adjustment pieces, and the plurality of plate-shaped adjustment pieces are each formed of a material having a different coefficient of friction. The centrifugal brake according to claim 1 or 2, wherein the cross-sectional shape of the sliding inner circumferential surface is an arc shape and the longitudinal cross-sectional shape is a circle. The centrifugal brake according to claim 1 or 2, wherein the adjustment axis is perpendicular to the rotation axis. The centrifugal brake according to claim 1 or 2, wherein the housing further includes a pair of movable housing pieces to which the pair of adjustment members are fixed and connected to each other, and a pair of fixed housing pieces that rotatably hold the rotor and rotatably hold the pair of movable housing pieces that are connected to each other. The centrifugal brake of claim 5, wherein a rubber washer is disposed between the pair of fixed housing pieces and one of the pair of movable housing pieces. The centrifugal brake according to claim 5, wherein one of the pair of movable housing pieces is provided with an operating portion, and one or both of the pair of fixed housing pieces is provided with a limiting piece that limits the rotation range of the movable housing piece.

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