Band brake device

Abstract

To provide a band brake device which can improve heat radiation efficiency and can easily and accurately perform brake gap adjustment work with a simple configuration.SOLUTION: A band brake device 10 includes a drum 12 integrally rotating with a hub 15, a housing 14 having a cylindrical bowl-shaped surrounding portion surrounding the drum 12, an arcuate belt-like band 16 arranged to surround an outer peripheral surface 12A of the drum 12, and an adjustment bolt 18 for adjusting a gap distance between the outer peripheral surface 12A of the drum 12 and the belt-like band 16. The belt-like band 16 comes into pressure contact with the outer peripheral surface 12A of the drum 12 to generate friction, and the rotation of the hub 15 is thereby braked. The band brake device further includes an almost disk-like heat radiation plate 20 provided on the drum 12 and extended in an outside radial direction of the outer peripheral surface 12A, and a cutout formed from an outer peripheral surface of the heat radiation plate 20 to a portion of the outer peripheral surface 12A of the drum 12.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a band brake device, and more particularly to a band brake device for a bicycle. [Background technology]

[0002] Conventionally, band brake devices have often been used as brakes for the rear wheels of bicycles known as light bicycles used in daily life, such as mamachari and city bicycles. A band brake device is described, for example, in Patent Document 1.

[0003] Figure 8 shows the structure of a conventional band brake device. The band brake device 100 comprises a drum 104 fixed to a hub that rotates with the rear wheel of the bicycle, a housing 108 fixed to the bicycle frame 106 and having a surrounding portion 108A that surrounds the drum 104 and has a circular space outside the outer circumferential surface 104A of the drum 104, and a band-like band 110 that is disposed in the circular space 108B within the housing 108 so as to surround the outer circumferential surface 104A of the drum 104 and has a lining fixed to the outer circumferential surface 104A side. The reference numeral 102 denotes an axle.

[0004] Then, by operating a brake lever 112 connected to a brake handle (not shown) via a brake wire (not shown) in direction A, the right side of the rotation center 114 is raised (the left side of the rotation center 114 is not joined to the right side and is fixed to the frame, so it remains stationary even if the right side of the rotation center 114 is raised), and the band 110 presses against the outer circumferential surface 104A of the drum 104. This generates friction between the band 110 and the outer circumferential surface 104A of the drum 104, braking the rotation of the hub 15 (see FIG. 6).

[0005] In this case, if the brake lever 112 is operated to press the band 110 against the outer peripheral surface 104A of the drum 104 when the gap between the band 110 and the outer peripheral surface 104A of the drum 104 is not uniform, the brake may not be applied properly due to uneven contact. Also, if there is no gap between the band 110 and the outer peripheral surface 104A of the drum 104, a brake drag phenomenon occurs in which the brake is always applied.

[0006] Therefore, when a bicycle is shipped, a worker generally performs brake clearance adjustment work by visually checking the distance between the outer peripheral surface 104A of the drum 104 and the band 110 through the side opening of the circular space, and adjusting the gap distance between the band 110 and the outer peripheral surface 104A of the drum 104 with the adjustment bolt 116 to ensure the appropriate brake clearance.

[0007] The Japan Bicycle Association has established voluntary "Bicycle Safety Standards" with the aim of providing safe, secure, and environmentally friendly bicycles for cyclists, and bicycles that pass these standards can be affixed with the BAA mark. The "Bicycle Safety Standards" also include an inspection of brake performance, examining braking force to ensure safe and smooth stopping of the bicycle in both sunny and rainy weather. From the perspective of bicycle safety standards, it is therefore important to adjust the brake clearance to eliminate uneven brake contact and brake drag. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Utility Model Application Publication No. 61-22937 Summary of the Invention [Problem to be solved by the invention]

[0009] The conventional band brake device shown in Patent Document 1 has poor heat dissipation properties, as the friction generated by pressing the outer surface of the drum with a strip-shaped band tends to build up inside the drum. This leads to unstable braking performance. For example, when braking continuously, such as when going down a long slope, the brake heats up, causing poor braking performance and possibly failing to meet bicycle safety standards. Furthermore, poor heat dissipation properties also reduce the durability of the band brake device itself.

[0010] For this reason, it is desirable to improve the heat dissipation properties of the band brake device. However, since band brake devices are used in light vehicles and the like as low-cost brake devices, it is desirable to improve heat dissipation properties easily and at low cost.

[0011] Furthermore, as mentioned above, when a bicycle is shipped, the brake gap must be adjusted to the appropriate level before it can be shipped, and it is necessary to improve heat dissipation after satisfying the requirement that the brake gap adjustment be performed easily and accurately.

[0012] The object of the present invention is to solve the problems of the prior art and to provide a band brake device that has a simple configuration, good heat dissipation properties, and allows for easy and accurate brake gap adjustment. [Means for solving the problem]

[0013] To achieve the above object, the present invention comprises a drum fixed to a hub that rotates with the wheel, rotating integrally with the hub and having a cylindrical outer peripheral surface; a housing fixed to the vehicle body and having a cylindrical bowl-shaped surrounding portion that has a circular space outside the outer peripheral surface of the drum and surrounds the drum; an arc-shaped band provided on the housing and arranged in the circular space to surround the outer peripheral surface of the drum; and an adjustment bolt provided on the housing that adjusts the gap distance between the outer peripheral surface of the drum and the band by pressing the outer surface of the band band toward the drum, wherein the band band presses against the outer peripheral surface of the drum to generate friction and brake the rotation of the hub, the band brake device further comprising: a substantially circular heat sink provided on the drum and extending radially outward from the outer peripheral surface; and a cutout formed from the outer periphery of the heat sink to the outer peripheral surface of the drum.

[0014] In addition, in the above-mentioned band brake device, it is preferable that the cutout portion is formed in an area corresponding to the circular space portion of the heat sink and the adjustment bolt, and that when the gap distance between the outer surface of the drum and the belt-shaped band is adjusted by the adjustment bolt, the gap distance is made visible.

[0015] Furthermore, in the above-mentioned band brake device, it is preferable that a plurality of the notches are formed, and the shape of the heat sink formed by two of the notches is a blade planar shape.

[0016] Furthermore, in the above-mentioned band brake device, it is preferable that the drum side plate of the drum is assembled to the housing side plate (14B) side of the housing, and that the heat sink has an integral cylindrical portion that is fitted into the cylindrical outer frame of the drum.

[0017] Furthermore, in the above band brake device, it is preferable that the notch and the adjustment bolt are formed in a positional relationship in which the notch is located on an extension line of the adjustment bolt in the radial direction.

[0018] It is preferable that the width of the notch in the circumferential direction is larger than the size of the adjustment bolt.

[0019] The heat sink preferably includes an annular transparent plate that covers the notch. [Effects of the Invention]

[0020] According to the present invention, a band brake device is provided which is provided with an approximately circular heat sink plate which is provided on the drum and extends radially outward from the outer peripheral surface, and which has a cutout portion formed from the outer peripheral surface of the heat sink plate to the outer peripheral surface of the drum. This makes it possible to obtain a band brake device which has a simple configuration but has good heat dissipation properties and allows for easy and accurate brake gap adjustment. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a plan view of a drum provided with a heat sink of a band brake device according to an embodiment of the present invention, viewed from the inner surface side. [Figure 2] FIG. 1 is a plan view of a drum provided with a heat sink of a band brake device according to an embodiment of the present invention, viewed from the outer surface side. [Figure 3] FIG. 1 is a side view of a drum provided with a heat sink of a band brake device according to an embodiment; [Figure 4] FIG. 1 is a plan view of a housing provided with a band-shaped band of a band brake device according to an embodiment, viewed from the inner surface side; [Figure 5] FIG. 1 is a plan view of a housing provided with a band-shaped band of a band brake device according to an embodiment, viewed from the outer surface side; [Figure 6] An assembly diagram of a drum with a heat sink according to one embodiment and a housing with a band or the like attached to a bicycle. [Figure 7] FIG. 1 is a partially enlarged plan view of a band brake device according to an embodiment. [Figure 8] An explanatory diagram illustrating the configuration of a conventional band brake device and a brake actuation method. [Figure 9]A side view of a drum provided with a heat sink of a band brake device according to another embodiment. [Figure 10] An assembly diagram of a drum with a heat sink according to another embodiment and a housing with a band or the like attached to a bicycle. [Figure 11] 1 is a plan view of a drum provided with a heat sink of a modified band brake device, viewed from the outer surface side (an example in which the cutout direction of the cutout portion 22 is the radial direction from the outer peripheral surface of the heat sink 20) DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Overall configuration of band brake device] The band brake device 10 according to the embodiment of the present invention is primarily comprised of a drum 12, a housing 14, a strip-shaped band 16, an adjustment bolt 18, a heat sink 20, and a notch 22 formed in the heat sink 20. The strip-shaped band 16 presses against the outer peripheral surface 12A of the drum 12, which rotates integrally with a hub 15 (see FIG. 6) that rotates together with, for example, a wheel (not shown), thereby generating friction and braking the rotation of the hub 15. The hub 15 rotates together with the wheel.

[0023] The band brake device 10 is often used as a brake for the rear wheel of a bicycle, but it can also be used as a brake for other vehicles, such as wheelchairs and strollers, and is not limited to bicycles. However, the following explanation will be given using a bicycle (not shown) as an example of the vehicle to which the band brake device 10 is attached, and an example will be given in which the band brake device 10 of the present invention is attached to the hub 15 of the bicycle's rear wheel. Furthermore, the vehicle main body will be explained in the case of a bicycle frame 26 (see Figure 6). The hub 15 is rotatably supported on an axle 24 via a bearing (not shown).

[0024] The mechanism for pressing the band 16 against the outer peripheral surface 12A of the drum 12 uses, for example, the lever mechanism and brake wire connected to the brake handle (not shown) described in the prior art in Fig. 8. Note that this embodiment will be described using an example in which a crank member 28 is used as the lever mechanism.

[0025] Fig. 1 is a plan view of the drum 12 provided with the heat sink 20, as seen from the inner surface of the drum 12 (the side opposite the heat sink 20), Fig. 2 is a plan view as seen from the outer surface (the side of the heat sink 20), and Fig. 3 is a side view. Fig. 4 is a plan view of the housing 14 provided with the band 16, adjustment bolt 18, and crank member 28, as seen from the inner surface of the housing 14 (the side where the band 16 is disposed), and Fig. 5 is a plan view as seen from the outer surface.

[0026] Figure 6 is a diagram of the assembled band brake device 10, in which the drum 12 is fixed to the bicycle hub 15 (see Figure 6) and the housing 14 is fixed to the frame 26, and the drum 12 and housing 14 are combined so as to be attached to the bicycle.

[0027] 1, 2, and 3 and the diameter of the surrounding portion 14C of the housing 14 in Figures 4 and 5 are not drawn to be comparable. Each member of the band brake device 10 will be described in detail below.

[0028] (drum) 1 to 3, drum 12 is formed in a roughly cylindrical bowl shape, consisting of a cylindrical outer frame 12B having a cylindrical outer surface 12A and a disk-shaped drum side plate 12C. That is, cylindrical outer frame 12B of drum 12 protrudes from the front side in FIG. 1, and from the back side in FIG. 2. The width D of cylindrical outer frame 12B of drum 12, which is formed in a roughly cylindrical bowl shape, is formed to be narrow, just slightly larger than the width of band 16 (see FIG. 3).

[0029] A fixing hole 12D for fixing to a hub 15 (see FIG. 6) is formed in the center of the drum side plate 12C of the drum 12, and a female screw is formed in the fixing hole 12D. As a result, the drum 12 is fixed by screwing into a male screw member (not shown) provided on the hub 15, and rotates integrally with the hub 15. (housing)

[0030] 4 and 5, the housing 14 is composed of a surrounding portion 14C formed in a generally cylindrical bowl shape by an arc-shaped outer peripheral frame 14A and a housing side plate 14B, and a support portion 14D extending from the surrounding portion 14C in a generally U-shaped plate shape. The arc-shaped outer peripheral frame 14A of the housing 14 protrudes toward the front side in FIG. 4, and protrudes toward the back side in FIG. 5. The surrounding portion 14C is composed of the arc-shaped outer peripheral frame 14A and the circular plate-shaped portions of the housing side plate 14B, and the support portion 14D is composed of the generally U-shaped plate-shaped portions of the housing side plate 14B.

[0031] A through-hole 14E through which the axle 24 passes is formed in the center of the housing side plate 14B of the surrounding portion 14C of the housing 14. Furthermore, a fixing hole 14F is formed in the support portion 14D for fixing to a bicycle frame 26 (see FIG. 6). The frame 26 and the support portion 14D of the housing 14 are fixed together via a fixing member 30 (see FIG. 6). The frame 26 and the support portion 14D of the housing 14 are fixed together via the fixing member 30, but it is also possible to fix the housing 14 to the axle 24. In this case, the axle 24 is included as a component of the frame 26.

[0032] The arc-shaped outer peripheral frame 14A that forms the surrounding portion 14C of the housing 14 is larger in diameter than the cylindrical outer peripheral frame 12B of the drum 12. When the drum 12 and housing 14 are attached to the bicycle and assembled, the housing 14 surrounds the drum 12, forming a circular space 14G outside the outer peripheral surface 12A of the drum 12. In this case, the drum 12, which is approximately cylindrical and bowl-shaped, and the surrounding portion 14C of the housing 14, which is also approximately cylindrical and bowl-shaped, are aligned facing each other. A crank member 28 is attached to the support portion 14D of the housing 14. The crank member 28 is supported so as to be swingable relative to the support portion 14D via a swing shaft 32 provided at a fulcrum portion 28A, which serves as the swing center.

[0033] (Welt band) 4, the band 16 is disposed in an arc shape on the inner surface of the arc-shaped outer peripheral frame 14A of the housing 14. When the drum 12 and the housing 14 are attached to the bicycle and assembled, the band 16 is disposed in an arc shape so as to surround the outer peripheral surface 12A of the drum 12.

[0034] One end of the belt-like band 16 is fixed to one end of the arc-shaped outer peripheral frame 14A with a fixing pin 34, and the other end of the belt-like band 16 is connected to a connecting pin 36 provided at the application point 28B of the crank member 28. In addition, a connecting bolt 38 is provided at the application point 28C of the crank member 28 to connect one end of a brake wire (not shown).

[0035] The belt-shaped band 16 is composed of a belt-shaped metal plate 16A made of a leaf spring material and a belt-shaped friction member 16B (for example, a belt-shaped rubber plate) attached to the inner surface of the belt-shaped metal plate 16A (the side facing the outer peripheral surface 12A of the drum 12). The belt-shaped band 16 is curved in an arc along the inner surface of the arc-shaped outer peripheral frame 14A of the housing 14, and thus a biasing force acts outward (in the direction away from the outer peripheral surface 12A of the drum 12).

[0036] When the bicycle is not braked, a gap is formed between the band 16 and the outer peripheral surface 12A of the drum 12. This prevents the band 16 from interfering with the rotation of the drum 12, which rotates together with the hub 15 (see FIG. 6). When the bicycle is braked and the force point 28C of the crank member 28 is pulled in the X direction in FIG. 4 with a brake wire (not shown), the crank member 28 swings around the swing shaft 32 (fulcrum 28A), and the application point 28B of the crank member 28 swings in the direction of arrow Y in FIG. 4.

[0037] As a result, the band 16 is pulled in a direction that reduces the curvature of the band 16, causing the band-like friction member 16B of the band 16 to press against the outer circumferential surface 12A of the drum 12. As a result, friction occurs between the band 16 and the rotating drum 12, and the bicycle is braked.

[0038] (Adjustment bolt) 4 and 5, a plurality of adjustment bolts 18 are provided on the arc-shaped outer peripheral frame 14A of the housing 14. This embodiment will be described using an example in which two adjustment bolts 18 are provided. The two adjustment bolts 18 are supported in a state in which they are threaded into female screw holes formed at a predetermined interval near the center of the arc of the arc-shaped outer peripheral frame 14A.

[0039] The two adjustment bolts 18 are turned to adjust the amount of projection and retraction of the adjustment bolts 18 from the arc-shaped outer peripheral frame 14A toward the drum 12, so that the tips of the adjustment bolts 18 come into contact with and press against the outer surface of the belt-like band 16. The adjustment bolts 18 are also threadedly engaged with the arc-shaped outer peripheral frame 14A so that their tips face the central axis of the axle 24.

[0040] It is preferable that the installation positions and predetermined spacing of the two adjustment bolts 18 on the arc-shaped outer frame 14A of the housing 14 be such that when the two adjustment bolts 18 press against the outside of the band 16, the gap distance of the entire band 16 relative to the outer surface 12A of the drum 12 is approximately uniform.

[0041] This allows the gap distance between the strip-shaped friction member 16B of the strip-shaped band 16 and the outer peripheral surface 12A of the drum 12 to be adjusted evenly by pressing two points on the outer surface of the strip-shaped band 16 toward the drum 12 with two adjustment bolts 18.

[0042] (heat sink) As shown in Figures 1 to 3, the heat sink 20 is formed in an approximately circular plate shape extending radially outward from the outer peripheral surface 12A of the drum 12, and has a central hole 20B formed in the center that has the same diameter as the fixing hole 12D through which the drum 12 is fixed to the hub 15.

[0043] With the fixing holes 12D of the drum 12 aligned with the center hole 20B of the heat sink 20, the heat sink 20 is fixed to the drum side plate 12C of the drum 12 with screws 40. It is preferable to use aluminum or other relatively inexpensive metals with good thermal conductivity as the heat sink 20.

[0044] In this embodiment, the drum 12 and the heat sink 20 are formed as separate members, and the heat sink 20 is fixed to the drum 12 by screws 40, but the drum 12 and the heat sink 20 may also be molded integrally.

[0045] A plurality of holes 20C are formed in the inner peripheral surface of the heat sink 20 between the outer peripheral surface 12A of the drum 12 and the fixing holes 12D. The holes 20C are not necessary, but are convenient to use as holes for hooking a tool when attaching or detaching the drum 12 to or from the hub 15.

[0046] (Notched part) As shown in Figures 1 and 2, a notch 22 is formed from the outer peripheral surface of the heat sink 20 to a portion close to the outer peripheral surface 12A of the drum 12. The notch 22 is formed in an area that corresponds to the circular space 14G of the housing 14 when the drum 12 and the housing 14 are assembled. The notch 22 serves as a viewing window when adjusting the gap between the outer peripheral surface 12A of the drum 12 and the band 16 using the adjustment bolt 18. In other words, the gap can be confirmed through the notch 22. The inner peripheral side of the notch 22 is not limited to a round shape, but may also be a square shape, and is preferably formed concentrically with the outer peripheral surface 12A of the drum 12.

[0047] 1 and 2, the direction of the notches 22 is (almost) tangential to the fixing hole 12D from the outer peripheral surface of the heat sink 20, and it is preferable from the standpoint of heat dissipation that the shape of the heat sink 20 formed by the two notches 22 be the blade shape of an axial fan. (In FIG. 3, the heat sink 20 is flat, so the shape of the heat sink 20 formed by the two notches 22 is a flat blade shape.) Note that FIG. 11 is a plan view of the drum 12 provided with the heat sink 20 of a modified band brake device 10, as seen from the outer surface, and the cutout direction of the notches 22 does not necessarily have to be formed in the approximately tangential direction; it may be radial from the outer peripheral surface of the heat sink 20, as shown in FIG. 11 for FIG. 2.

[0048] The number of each of the notches 22 and the adjustment bolts 18 may be one, but it is preferable to form the same number of them in multiples. In Fig. 6, nine notches 22 and two adjustment bolts 18 are formed, and the shape of the heat sink 20 formed by the two notches 22 is made similar to the blade shape of an axial flow fan.

[0049] The notches 22 and the adjustment bolts 18 are preferably formed in a positional relationship such that the notches 22 are positioned on radial extension lines M of the adjustment bolts 18. This allows the brake clearance adjustment work to be performed while observing how each adjustment bolt 18 presses the belt-shaped band 16 toward the drum 12.

[0050] In other words, the gap distance between the outer peripheral surface 12A of the drum 12 and the band 16 can be visually observed through each notch 22. This not only improves the efficiency of the brake gap adjustment work, but also enables the work to be performed accurately. Note that, although it is preferable to form the same number of notches 22 and adjustment bolts 18, they are not limited to the same number and may be different numbers.

[0051] It is more preferable that the circumferential spacing of the notches 22 be approximately the same as an integer multiple of the spacing between the adjustment bolts 18, and that the centers of the notches 22 be located on the extension line M of the two adjustment bolts 18. In other words, when the drum 12 with the heat sink 20 attached is fixed to the hub 15 of a bicycle (not shown), and the housing 14 with the belt-like band 16, adjustment bolts 18, and crank member 28 attached is attached to the frame 26 of the bicycle (not shown) to complete the band brake device 10, the centers of the two notches 22 are located on the extension line M of the two adjustment bolts 18. However, the respective center positions do not need to be exactly aligned as long as the circumferential width of the notches 22 is made sufficiently larger than the size of the adjustment bolts 18.

[0052] As shown in FIG. 6, it is preferable that the cutout portion 22 formed in the heat sink 20 is formed so that its inner circumferential side coincides with the outer circumferential surface 12A of the drum 12 and that the cutout portion 22 is positioned in the widthwise center at an appropriate adjustment position where the gap distance is appropriately adjusted using the adjustment bolt 18.

[0053] Furthermore, the circumferential width of the notch portions 22 need only be the minimum length that allows the two notches 22 to be used to check whether there is any bias in the arc shape of the strip-shaped band 16 that is arranged in an arc shape to surround the outer peripheral surface 12A of the drum 12.

[0054] 7, it is preferable to attach an annular transparent plate 42 to cover the notch 22 of the heat sink 20 to prevent water such as rainwater from entering through the notch 22 between the drum 12 and the band 16. The transparent plate 42 preferably has a marking line P on its inner periphery to indicate that the adjustment position is correct. Any transparent material may be used for the transparent plate 42, but a plastic one is preferable because it is inexpensive.

[0055] Furthermore, it is preferable that the transparent plate 42 functions as a convex lens. This allows the band 16 inside the cutout 22 to be enlarged by the magnifying function of the transparent plate 42, making it possible to perform brake clearance adjustment work more easily and accurately.

[0056] [Operation of the band brake device] Next, the operation of the band brake device 10 of the embodiment configured as described above will be explained using Figure 6. Note that in Figure 6, the band 16 is not shown because showing it with a dashed line would make the drawing too crowded.

[0057] The band brake device 10 applies a brake to the drum 12, which rotates integrally with the hub 15, by pressing the outer peripheral surface 12A of the drum 12 with the strip-shaped band 16, but frictional heat is generated due to friction between the strip-shaped band 16 and the drum 12. In this case, frictional heat is most likely to accumulate on the outer peripheral surface 12A of the drum 12, which is the braking surface.

[0058] Therefore, in the band brake device 10 configured as described above, the substantially circular heat sink 20 is provided extending radially outward from the outer peripheral surface 12A of the drum 12, which makes it easier for frictional heat to be efficiently dissipated to the outside via the heat sink 20. This improves the heat dissipation properties of frictional heat generated in the drum 12, resulting in a band brake device 10 with excellent heat dissipation properties despite its simple configuration.

[0059] However, simply extending the heat sink 20 radially outward from the outer circumferential surface 12A of the drum 12 would result in the circular space 14G of the housing 14, i.e., the circular space 14G in which the band 16 is disposed, being shielded by the heat sink 20. This would make the band 16 invisible, and therefore, for example, when shipping a bicycle, an operator who adjusts the gap between the band 16 and the outer circumferential surface 12A of the drum 12 using the adjustment bolt 18 would not be able to easily and accurately adjust the brake gap.

[0060] The band brake device 10 of the embodiment described above does not simply provide a heat sink 20 on the drum 12, but rather forms a cutout portion 22 in the circular space 14G of the housing 14, i.e., the circular space 14G in which the band 16 is arranged, for adjusting the gap distance between the band 16 and the outer peripheral surface 12A of the drum 12, making it possible to perform brake gap adjustment work easily and accurately.

[0061] Another embodiment will be described with reference to Figures 9 and 10. Figure 9 is a side view of the drum 12 provided with a heat sink 20 of a band brake device 10 according to another embodiment, and Figure 10 is an assembly diagram of the drum 12 provided with a heat sink according to another embodiment and a housing 14 provided with a belt-like band 16 and the like, mounted on a bicycle.

[0062] 3 and 6 are that the drum 12 is turned over and the drum side plate 12C is assembled to the housing side plate 14B side of the housing 14, and the heat sink 20 has an integral cylindrical portion 20D that is fitted into the cylindrical outer frame 12B of the drum 12. The rest is the same. Therefore, the screws 40 that secure the heat sink 20 to the drum side plate 12C of the drum 12 may not be necessary.

[0063] The band brake device 10 applies a brake to the drum 12 by pressing the outer peripheral surface 12A of the drum 12 with the strip-shaped band 16, and frictional heat accumulates most on the outer peripheral surface 12A of the drum 12, which is the braking surface. In contrast, the cylindrical portion 20D of the heat sink 20 directly contacts the outer peripheral surface 12A, where frictional heat accumulates most, as shown in Figure 9, so that the frictional heat is efficiently transferred to the heat sink 20. Therefore, the ability to dissipate frictional heat generated in the drum 12 can be significantly improved. [Explanation of symbols]

[0064] 10...Band brake device, 12...Drum, 12A...Outer surface, 12B...Cylindrical outer frame, 12C...Drum side plate, 12D...Fixing hole, 14...Housing, 14A...Circular outer frame, 14B...Housing side plate, 14C...Surrounding portion, 14D...Support portion, 14E...Through hole, 14F...Fixing hole, 14G...Circular space portion, 15...Hub, 16...Strip band, 16A...Strip metal plate, 16B...Strip friction member, 18...Adjustment bolt, 20...Heat sink, 20B...Center hole, 20C...Hole, 20D...Cylindrical portion, 22...Notch portion, 2 4...Axle, 26...Frame, 28...Crank member, 28A...Fulcrum portion, 28B...Application point portion, 28C...Force point portion, 30...Fixed member, 32...Oscillating shaft, 34...Fixed pin, 36...Connecting pin, 38...Connecting bolt, 40...Screw, 42...Transparent plate, 100...Band brake device, 102...Axle, 104...Drum, 104A...Outer periphery, 106...Frame, 108...Housing, 108A...Surrounding portion, 108B...Circular space portion, 110...Strip-shaped band, 112...Brake lever, 114...Pivot center, 116...Adjusting bolt

Claims

1. a housing fixed to a vehicle body and having a cylindrical bowl-shaped surrounding portion with a circular space outside the outer peripheral surface of the drum surrounding the drum; an arc-shaped band provided on the housing and disposed in the circular space so as to surround the outer peripheral surface of the drum; and an adjustment bolt provided on the housing for adjusting a gap distance between the outer peripheral surface of the drum and the band by pressing the outer surface of the band toward the drum, wherein the band presses against the outer peripheral surface of the drum to generate friction and brake the rotation of the hub, a substantially circular heat sink provided on the drum and extending radially outward from the outer circumferential surface; A band brake device having a notch formed from the outer periphery of the heat sink to a portion of the outer peripheral surface of the drum, the notch being formed in an area corresponding to the circular space portion of the heat sink and the adjustment bolt, so that the gap distance between the outer peripheral surface of the drum and the band-shaped band can be visually observed when adjusting the gap distance using the adjustment bolt.

2. a housing fixed to a vehicle body and having a cylindrical bowl-shaped surrounding portion with a circular space outside the outer peripheral surface of the drum surrounding the drum; an arc-shaped band provided on the housing and disposed in the circular space so as to surround the outer peripheral surface of the drum; and an adjustment bolt provided on the housing for adjusting a gap distance between the outer peripheral surface of the drum and the band by pressing the outer surface of the band toward the drum, wherein the band presses against the outer peripheral surface of the drum to generate friction and brake the rotation of the hub, a substantially circular heat sink provided on the drum and extending radially outward from the outer circumferential surface; a band brake device having a notch formed from the outer periphery of the heat sink to the outer peripheral surface of the drum, wherein the drum side plate of the drum is assembled to the housing side plate side of the housing, and the heat sink has a cylindrical portion integrally formed therewith and fitted into the cylindrical outer peripheral frame of the drum.

3. a housing fixed to a vehicle body and having a cylindrical bowl-shaped surrounding portion with a circular space outside the outer peripheral surface of the drum surrounding the drum; an arc-shaped band provided on the housing and disposed in the circular space so as to surround the outer peripheral surface of the drum; and an adjustment bolt provided on the housing for adjusting a gap distance between the outer peripheral surface of the drum and the band by pressing the outer surface of the band toward the drum, wherein the band presses against the outer peripheral surface of the drum to generate friction and brake the rotation of the hub, a substantially circular heat sink provided on the drum and extending radially outward from the outer circumferential surface; A band brake device having a notch formed from the outer periphery of the heat sink to the outer periphery of the drum, wherein the notch and the adjustment bolt are formed in a positional relationship such that the notch is located on a radial extension of the adjustment bolt.

4. a housing fixed to a vehicle body and having a cylindrical bowl-shaped surrounding portion with a circular space outside the outer peripheral surface of the drum surrounding the drum; an arc-shaped band provided on the housing and disposed in the circular space so as to surround the outer peripheral surface of the drum; and an adjustment bolt provided on the housing for adjusting a gap distance between the outer peripheral surface of the drum and the band by pressing the outer surface of the band toward the drum, wherein the band presses against the outer peripheral surface of the drum to generate friction and brake the rotation of the hub, a substantially circular heat sink provided on the drum and extending radially outward from the outer circumferential surface; a notch formed from the outer periphery of the heat sink to the outer periphery of the drum, The band brake device has a heat sink provided with a transparent annular plate that covers the notch.

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