阅读说明：本技术 用于人力驱动车辆的活塞组件 (Piston assembly for a human powered vehicle ) 是由 小渊航平 驹田耕之 藤井伸与志 于 2021-05-18 设计创作，主要内容包括：一种用于人力驱动车辆的活塞组件。活塞组件包括主体和主密封件。主体构造为在缸膛中沿致动方向从静止位置到致动位置可移动。主密封件包括布置在主体上的主密封件本体。主密封件本体由树脂材料制成。主密封件本体具有主唇部,主唇部构造为在活塞组件布置在缸膛中的布置状态下与缸膛接触。主密封件还包括偏置部分,偏置部分构造为在布置状态下与主体的外周表面接触,以向外偏置主密封件本体的主唇部。(A piston assembly for a human powered vehicle. The piston assembly includes a main body and a main seal. The body is configured to be movable in an actuation direction from a rest position to an actuated position in the cylinder bore. The main seal includes a main seal body disposed on the main body. The main seal body is made of a resin material. The main seal body has a main lip portion configured to contact the cylinder bore in an arrangement state in which the piston assembly is arranged in the cylinder bore. The main seal further includes a biasing portion configured to contact an outer peripheral surface of the main body in the deployed state to bias the main lip of the main seal body outward.)

1. A piston assembly for a human powered vehicle, the piston assembly comprising:

a main body configured to be movable in an actuation direction from a rest position to an actuation position in a cylinder bore; and

a main seal including a main seal body disposed on the main body, the main seal body being made of a resin material and having a main lip portion configured to contact the cylinder bore in an arrangement state in which the piston assembly is arranged in the cylinder bore, the main seal further including a biasing portion configured to contact an outer peripheral surface of the main body in the arrangement state to bias the main lip portion of the main seal body outward.

2. The piston assembly of claim 1, wherein

The biasing portion is made of a rubber material.

3. A piston assembly for a human powered vehicle, the piston assembly comprising:

a main body configured to be movable in an actuation direction from a rest position to an actuation position in a cylinder bore; and

a main seal including a main seal body disposed on the main body, the main seal body being made of a resin material and having a main lip portion configured to be in contact with the cylinder bore in an arrangement state in which the piston assembly is arranged in the cylinder bore, the main seal further including a biasing portion configured to bias the main lip portion of the main seal body outward in the arrangement state, the biasing portion being made of a rubber material.

4. The piston assembly of claim 1, wherein

The biasing portion is provided as a separate member from the main seal body.

5. The piston assembly of claim 1, wherein

The main lip includes a cylindrical outer contact surface configured to contact the cylinder bore in the arranged state.

6. The piston assembly of claim 5, wherein

The main lip includes a first annular chamfer surface and a second annular chamfer surface, the cylindrical outer contact surface being disposed between the first annular chamfer surface and the second annular chamfer surface.

7. The piston assembly of claim 1, wherein

The main seal body has an annular inner surface configured to contact the biasing portion in the deployed condition.

8. The piston assembly of claim 1, wherein

The main seal body is an O-ring having a first end surface facing in a first axial direction relative to a central axis of the O-ring and a second end surface facing in a second axial direction relative to the central axis, the first axial direction being opposite the second axial direction.

9. The piston assembly of claim 1, wherein

The resin material includes one of polytetrafluoroethylene and polyethylene.

10. The piston assembly of claim 1, wherein

The resin material includes polytetrafluoroethylene filled with polyimide.

11. The piston assembly of claim 1, wherein

The main body includes a first portion having a first axial abutment surface facing the main seal and a second portion coupled to the first portion having a second axial abutment surface facing the main seal, and the main seal is axially located between the first and second axial abutment surfaces.

12. The piston assembly of claim 11, wherein

The first portion is made of a first material and

the second portion is made of a second material different from the first material.

13. The piston assembly of claim 12, wherein

The first material is a resin material, and

the second material is a metallic material.

14. The piston assembly of claim 1, further comprising

A secondary seal disposed on the main body upstream of the primary seal relative to the actuation direction.

15. The piston assembly of claim 14, wherein

The secondary seal is made of a different material than the primary seal.

Technical Field

The present disclosure relates generally to piston assemblies. More particularly, the present disclosure relates to a piston assembly for a human powered vehicle.

Background

Manually powered vehicles (e.g., bicycles) are sometimes provided with hydraulic devices. Some examples of hydraulic devices include a hydraulic operating device and a hydraulic operated device. The hydraulic operating device is operated by a user to hydraulically operate the hydraulic operated device. For example, in a hydraulic brake system, a hydraulic brake operating device is fluidly connected to the hydraulic brake device such that a user operates a brake lever of the hydraulic brake operating device to actuate the hydraulic brake device to engage a brake rotor or a rim of a wheel. One example of a hydraulic braking system is disclosed in us patent 9,874,238B 2.

Disclosure of Invention

In general, the present disclosure relates to various features of a piston assembly for a human powered vehicle, such as a bicycle. The term "human-powered vehicle" as used herein refers to a vehicle that can be driven by at least the driving force of a person, but does not include a vehicle that uses only driving force other than human power. In particular, a vehicle using only an internal combustion engine as driving force is not included in a human-powered vehicle. Human powered vehicles are generally assumed to be compact light vehicles that do not require a license to travel on public roads. There is no limit to the number of wheels on a human powered vehicle. Human powered vehicles include, for example, unicycles and vehicles having three or more wheels. The human-powered vehicles include, for example, various types of bicycles, such as mountain bicycles, road bicycles, city bicycles, cargo bicycles, and recumbent bicycles, and electric-assisted bicycles (E-bike).

In view of the state of the known technology, and according to a first aspect of the present disclosure, there is provided a piston assembly for a human powered vehicle, the piston assembly substantially comprising a main body and a main seal. The body is configured to be movable in an actuation direction from a rest position to an actuated position in the cylinder bore. The main seal includes a main seal body disposed on the main body. The main seal body is made of a resin material. The main seal body has a main lip portion configured to be in contact with the cylinder bore in an arrangement state in which the piston assembly is arranged in the cylinder bore. The primary seal further includes a biasing portion configured to contact an outer peripheral surface of the main body in the arrangement state to bias the primary lip of the primary seal body outwardly.

With the piston assembly according to the first aspect, it is possible to provide a piston assembly having improved sliding contact with the cylinder bore by using a resin material for the main seal while maintaining firm contact with the cylinder bore by using the biasing portion.

According to a second aspect of the present disclosure, the piston assembly according to the first aspect is configured such that the biasing portion is made of a rubber material.

With the piston assembly according to the second aspect, the offset portion can be manufactured inexpensively.

According to a third aspect of the present disclosure, there is provided a piston assembly for a human powered vehicle, the piston assembly substantially comprising a main body and a main seal. The body is configured to be movable in an actuation direction from a rest position to an actuated position in the cylinder bore. The main seal includes a main seal body disposed on the main body. The main seal body is made of a resin material. The main seal body has a main lip portion configured to be in contact with the cylinder bore in an arrangement state in which the piston assembly is arranged in the cylinder bore. The primary seal further includes a biasing portion configured to bias the primary lip of the primary seal body outwardly in the deployed condition. The biasing portion is made of a rubber material.

With the piston assembly according to the third aspect, it is possible to provide a piston assembly having improved sliding contact with the cylinder bore by using a resin material for the main seal while maintaining firm contact with the cylinder bore by using the biasing portion.

According to a fourth aspect of the present disclosure, the piston assembly according to any one of the first to third aspects is configured such that the biasing portion is provided as a separate member from the main seal body.

With the piston assembly according to the fourth aspect, manufacturing costs can be reduced.

According to a fifth aspect of the present disclosure, the piston assembly according to any one of the first to fourth aspects is configured such that the main lip includes a cylindrical outer contact surface configured to be in contact with the cylinder bore in the arranged state.

With the piston assembly according to the fifth aspect, it is possible to improve the sliding contact of the main lip with the cylinder bore.

According to a sixth aspect of the present disclosure, the piston assembly according to the fifth aspect is configured such that the primary lip includes a first annular chamfer surface and a second annular chamfer surface. The cylindrical outer contact surface is disposed between the first annular chamfer surface and the second annular chamfer surface.

With the piston assembly according to the sixth aspect, it is possible to smoothly slide the main lip in the cylinder bore.

According to a seventh aspect of the present disclosure, the piston assembly according to any one of the first to sixth aspects is configured such that the main seal body has an annular inner surface configured to be in contact with the biasing portion in the arrangement state.

With the piston assembly according to the seventh aspect, it is possible to effectively transmit the biasing force from the biasing portion to the main seal body.

According to an eighth aspect of the present disclosure, the piston assembly according to any one of the first to seventh aspects is configured such that the main seal body is an O-ring having a first end surface facing in a first axial direction with respect to a center axis of the O-ring and a second end surface facing in a second axial direction with respect to the center axis, the first axial direction being opposite to the second axial direction.

With the piston assembly according to the eighth aspect, axial movement of the main seal relative to the main body can be restricted.

According to a ninth aspect of the present disclosure, the piston assembly according to any one of the first to eighth aspects is configured such that the resin material includes one of polytetrafluoroethylene and polyethylene.

With the piston assembly according to the ninth aspect, the main seal can be manufactured inexpensively.

According to a tenth aspect of the present disclosure, the piston assembly according to any one of the first to eighth aspects is configured such that the resin material includes polytetrafluoroethylene filled with polyimide.

With the piston assembly according to the tenth aspect, the main seal can be manufactured inexpensively.

According to an eleventh aspect of the present disclosure, the piston assembly according to any one of the first to tenth aspects is configured such that the main body includes a first portion and a second portion coupled to the first portion. The first portion has a first axial abutment surface facing the main seal. The second portion has a second axial abutment surface facing the primary seal. The primary seal is located axially between the first and second axial abutment surfaces.

With the piston assembly according to the eleventh aspect, axial movement of the main seal relative to the main body can be further restricted.

According to a twelfth aspect of the present disclosure, the piston assembly according to the eleventh aspect is configured such that the first portion is made of a first material and the second portion is made of a second material different from the first material.

With the piston assembly according to the twelfth aspect, suitable materials may be selected to improve sliding of the body relative to the cylinder bore, while still providing a reliable piston assembly.

According to a thirteenth aspect of the present disclosure, the piston assembly according to the twelfth aspect is configured such that the first material is a resin material and the second material is a metal material.

With the piston assembly according to the thirteenth aspect, it is possible to improve sliding with respect to the cylinder bore by using a resin material for the first portion that may contact the cylinder bore while using a metal material for the second portion to fix the first portion and the second portion together.

According to a fourteenth aspect of the present disclosure, the piston assembly according to any one of the first to thirteenth aspects further comprises a secondary seal arranged on the main body upstream of the primary seal with respect to the actuation direction.

With the piston assembly according to the fourteenth aspect, it is possible to improve the seal between the main body and the cylinder bore.

According to a fifteenth aspect of the present disclosure, the piston assembly according to the fourteenth aspect is configured such that the secondary seal is made of a different material than the primary seal.

With the piston assembly according to the fifteenth aspect, the materials used for the assembly can be optimized.

Moreover, other objects, features, aspects and advantages of the disclosed piston assembly will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the piston assembly.

Drawings

Referring now to the attached drawings which form a part of this original disclosure:

FIG. 1 is a top perspective view of a portion of a handlebar of a human powered vehicle equipped with a hydraulically operated device having a piston assembly (not shown in this figure) in accordance with a first embodiment;

FIG. 2 is a top plan view of a portion of the handlebar and hydraulic operating device illustrated in FIG. 1;

FIG. 3 is a partial cross-sectional view of the hydraulically operated device shown in FIGS. 1 and 2, with the piston assembly shown in full view, and with the cross-section taken along a section plane perpendicular to and passing through a cylinder axis of a cylinder bore of a base of the hydraulically operated device;

FIG. 4 is a fragmentary cross-sectional view similar to FIG. 3 of the hydraulically operated device illustrated in FIGS. 1-3, but with the operating member having been moved to an actuated position;

FIG. 5 is a first end perspective view of the piston assembly shown in FIGS. 3 and 4 according to the first embodiment;

FIG. 6 is a second end perspective view of the piston assembly shown in FIGS. 3-5;

FIG. 7 is a longitudinal cross-sectional view of the piston assembly shown in FIGS. 3-6;

FIG. 8 is a first exploded perspective view of the piston assembly shown in FIGS. 3-7;

FIG. 9 is a second exploded perspective view of the piston assembly shown in FIGS. 3-8;

FIG. 10 is a longitudinal cross-sectional view of a piston assembly for the hydraulically operated device shown in FIG. 1, in accordance with a second embodiment;

FIG. 11 is a partial longitudinal cross-sectional view of a portion of the piston assembly shown in FIG. 1, but with a first modified main seal;

FIG. 12 is a partial longitudinal cross-sectional view of a portion of the piston assembly shown in FIG. 1, but with a second variation primary seal;

FIG. 13 is a partial longitudinal cross-sectional view of a portion of the piston assembly shown in FIG. 1, but with a third variation of the primary seal as seen along section line 13-13 of FIG. 14;

FIG. 14 is a transverse cross-sectional view of the piston assembly illustrated in FIG. 13 as seen along section line 14-14 of FIG. 13;

FIG. 15 is a partial longitudinal cross-sectional view of a portion of the piston assembly shown in FIG. 1, but with a fourth variation of the main seal;

FIG. 16 is a fragmentary cross-sectional view of a portion of the hydraulically operated device illustrated in FIGS. 1-4 having a piston assembly according to a third embodiment;

FIG. 17 is a first end perspective view of the piston assembly shown in FIG. 16;

FIG. 18 is a second end perspective view of the piston assembly illustrated in FIGS. 16 and 17;

FIG. 19 is a longitudinal cross-sectional view of the piston assembly illustrated in FIGS. 16-18;

FIG. 20 is an enlarged cross-sectional view of a portion of the piston assembly shown in FIGS. 16-18;

FIG. 21 is a second end exploded perspective view of the piston assembly illustrated in FIGS. 16-20; and

fig. 22 is an exploded perspective view of the first end of the piston assembly shown in fig. 16-21.

Detailed Description

Selected embodiments will now be explained with reference to the drawings. It will be apparent to those skilled in the art of manually powered vehicles (e.g., bicycle) from this disclosure that the following description of the embodiments is provided for illustration purposes only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

Referring first to fig. 1, an operating device 10 is provided for a human powered vehicle V (only handlebar H is shown) according to a first exemplary embodiment. Here, in the illustrated embodiment, the operating device 10 is a hydraulic operating device provided for a human-powered vehicle V (e.g., a bicycle). The operating device 10 is mounted to a handlebar H of a human powered vehicle V. Here, the human-powered vehicle V is preferably a bicycle. Thus, the operating device 10 is a bicycle hydraulic brake operating device. Hereinafter, the operation device 10 is collectively referred to as a hydraulic operation device 10.

The hydraulic operating device 10 is fluidly connected to a hydraulically operated device (not shown) by a hydraulic hose 12. As shown in fig. 1 to 4, the hydraulic operating device 10 is a right-hand side hydraulic brake actuating device that is operated by the right hand of the rider from a rest position or non-operating position (fig. 1 to 3) to an operating position (fig. 4) to actuate a hydraulic operated device such as a disc brake caliper or a rim brake caliper. It will be apparent to those skilled in the art of human powered vehicles that the configuration of the hydraulically operated device 10 is applicable to left hand side hydraulic brake actuation devices operated by the left hand of the rider. Moreover, the hydraulic operating device 10 may be used with other vehicle components besides a brake caliper.

The hydraulic operating device 10 basically includes a base 14, an operating member 16 and a handlebar mounting structure 18. Here, the handlebar mounting structure 18 is coupled to the base 14. The base 14 is a rigid member, which is typically made of a metallic material. The base 14 includes a handlebar contact portion 20. The handlebar contact portion 20 is configured to contact the handlebar H in a mounted state in which the base 14 is mounted to the handlebar H by the handlebar mounting structure 18. It will be apparent from this disclosure that the handlebar mounting structure 18 is not limited to the illustrated embodiment and that other types of handlebar mounting structures may be used.

Here, the operating member 16 includes a user operating lever 22 and a torque input member 24. The user operating lever 22 is pivotally coupled to the base 14 about a pivot axis P1 by the pivot pin 26 between a rest position (see fig. 1-3) and an operating position (fig. 4). The user operating lever 22 is a rigid member, which is generally made of a metal material or a hard resin material. The torque input member 24 is also pivotally coupled to the base 14 about a pivot axis P1 by pivot pin 26.

As mentioned above, in the illustrated embodiment, the hydraulic operating device 10 is a bicycle hydraulic operating device. In this case, as shown in fig. 3 and 4, the base 14 includes a cylinder bore 14a defining a cylinder axis a 1. Here, as shown in fig. 1 and 2, the hydraulic operating device 10 includes a hydraulic reservoir 28 filled with a fluid such as mineral oil. With the operating lever 22 in the rest position, the hydraulic reservoir 28 is in fluid communication with the cylinder bore 14 a. Since the hydraulic reservoir is known, the hydraulic reservoir 28 will not be discussed or illustrated in detail herein.

The hydraulic operating device 10 also includes a piston assembly 30 movably disposed in the cylinder bore 14 a. Thus, the piston assembly 30 is provided for a human powered vehicle V. The piston assembly 30 is inserted into the cylinder bore 14a from the open end 14b of the cylinder bore 14 a. The base 14 has a fluid port 14c in fluid communication with the cylinder bore 14 a. The hydraulic hose 12 is fluidly connected to the fluid port 14c (see fig. 1) by a hose connector 12a and a hollow bolt 32 of the hydraulic hose 12.

A biasing element 34 is disposed in the cylinder bore 14a and biases the piston assembly 30 to a non-actuated (rest or non-operational) position. Here, the biasing element 34 is a helical compression spring that biases the piston assembly 30 to the non-actuated position. The biasing element 34 also biases the operating member 16 to its rest position (i.e., no external force is applied to the operating member 16). Thus, when the piston assembly 30 moves in the cylinder bore 14a in response to operation of the user operated lever 22 of the operating member 16, the piston assembly 30 causes the biasing element 34 to compress.

The piston assembly 30 is operatively coupled to the operating member 16 to move the piston assembly 30 within the cylinder bore 14a in response to operation of the operating member 16. That is, as shown in fig. 4, the piston assembly 30 is coupled to the operating member 16 to be urged in response to pivotal movement of the operating member 16 from the rest position to the operating position. The piston assembly 30 moves linearly along the cylinder axis a1 within the cylinder bore 14a in response to operation of the operating member 16. Here, the hydraulic operating device 10 further includes a torque-transmitting mechanism 40, the torque-transmitting mechanism 40 operatively connecting the piston assembly 30 and the torque input member 24 of the operating member 16. Thus, by the user operating lever 22, the torque transmitting mechanism 40 pushes the piston assembly 30 within the cylinder bore 14 a.

Here, the torque transmitting mechanism 40 includes a torque transmitting member 42, a link 44, and a pair of cam guides 46 (only one shown). The torque transmitting member 42 is pivotally coupled to the base 14 about a pivot axis P2 by a pivot pin 48. The torque transmitting member 42 is a rigid member, which is generally made of a metal material or a hard resin material. When the torque input member 24 of the operating member 16 is pivoted by the user pivoting the user operating lever 22, the torque input member 24 pivots the torque transfer member 42, which in turn pushes the link 44. Since the connecting rod 44 is pushed by the torque transmitting member 42, the piston assembly 30 is pushed by the connecting rod 44 in the cylinder bore 14 a. Thus, the connecting rod 44 operatively connects the piston assembly 30 to the torque transmitting member 42.

Here, the link 44 basically includes a rod portion 44a, a yoke portion 44b, a roller portion 44c and a support pin 44 d. The rod portion 44a has one end operatively connected to the piston assembly 30 and another end fixed to the yoke portion 44 b. The yoke 44b rotatably supports the roller portion 44c via a support pin 44 d. The roller portion 44c is preferably rotatably supported on the support pin 44d by a bearing (not shown). The end of the support pin 44d is located in the cam guide 46 for controlling the movement of the link 44 relative to the base 14.

Specifically, the cam guide 46 is mounted to the base 14 on opposite sides of the link 44. Thus, the cam guide 46 supports the end of the support pin 44d of the link 44 to the base 14. The cam guide 46 is shaped to control movement of the piston assembly 30 in response to movement of the user operated lever 22 of the operating member 16. That is, each of the cam guides 46 has a profiled cam surface that controls movement of the piston assembly 30 relative to movement of the operating member 16.

Turning to fig. 5-9, the piston assembly 30 will now be discussed in more detail. The piston assembly 30 includes a main body 50 and a main seal 52. In the illustrated embodiment, the piston assembly 30 also includes a secondary seal 54. However, it will be apparent from this disclosure that the secondary seal 54 can be omitted as needed and/or desired. The primary seal 52 and the secondary seal 54 are disposed on the main body 50 such that the primary seal 52 and the secondary seal 54 slidably contact the cylinder bore 14 a. Thus, the primary seal 52 and the secondary seal 54 are in sealing contact with the cylinder bore 14a and the main body 50.

As shown in fig. 3 and 4, the main body 50 is configured to be movable in the cylinder bore 14a along an actuation direction D1 from a rest position (fig. 3) to an actuated position (fig. 4). In other words, the main body 50 of the piston assembly 30 moves in the cylinder bore 14a in the actuating direction D1 against the urging force of the biasing element 34 in response to actuation of the user operating lever 22 of the operating member 16. Once the user operating lever 22 of the operating member 16 is released, the main body 50 of the piston assembly 30 moves in the return direction D2 opposite the actuating direction D1 in the cylinder bore 14a under the urging force of the biasing element 34. Thus, the main body 50 has an upstream end portion 50a located closest to the open end 14b of the cylinder bore 14a and a downstream end portion 50b located closest to the fluid port 14c of the base 14. In other words, the term "upstream" and the term "downstream" as used herein refer to orientations relative to the actuation direction D1.

Referring again to fig. 5-9, the body 50 includes a first portion 56 and a second portion 58. In the illustrated embodiment, the body 50 further includes a third portion 60 coupled to the first portion 56. Where the secondary seal 54 is omitted, the third portion 60 may also be omitted. Here, the second portion 58 is removably and reattachably attached to the first portion 56. However, it will be apparent from this disclosure that first portion 56 and second portion 58 can be permanently secured together if needed and/or desired. Here, the third portion 60 is a portion separate from the first portion 56. The third portion 60 is attached to the first portion 56 at an end opposite the second portion 58. For example, the third portion 60 is press fit to the first portion 56. However, it will be apparent from this disclosure that the third portion 60 may be removably and reattachably attached to the first portion 56 in the same manner as the second portion 58 is coupled to the first portion 56.

The first portion 56 is disposed at least partially upstream of the main seal 52 relative to the actuation direction D1. The second portion 58 is coupled to the first portion 56 to be at least partially disposed downstream of the main seal 52 relative to the actuation direction D1. Thus, the primary seal 52 is at least partially disposed between the first portion 56 and the second portion 58. The third portion 60 is coupled to the first portion 56 to be at least partially disposed upstream of the secondary seal 54 relative to the actuation direction D1. Thus, the secondary seal 54 is at least partially disposed between the first portion 56 and the third portion 60. In this illustrated embodiment, the third portion 60 has a concave spherical surface portion at the upstream end 50a, and the spherical portion of the link 44 is connected to the concave spherical surface portion of the third portion 60. That is, the main body 50 is connected to the link 44 by a ball joint.

The first portion 56 has an outermost diameter equal to or slightly smaller than the inner diameter of the cylinder bore 14a such that the first portion 56 can slidably contact the cylinder bore 14 a. On the other hand, the second portion 58 has an outermost diameter smaller than that of the first portion 56, so that the second portion 58 is spaced apart from the radially inner side of the cylinder bore 14 a. Preferably, the third portion 60 has an outermost diameter equal to or slightly smaller than the inner diameter of the cylinder bore 14a such that the third portion 60 can slidably contact the cylinder bore 14 a.

In the illustrated embodiment, the first portion 56 is made of a first material. The second portion 58 is made of a second material different from the first material. Preferably, the first material of the first portion 56 is a resin material. The second material of the second portion 58 is a metallic material. The resin material of the first portion 56 has a lower coefficient of friction than the metal material of the second portion 58. In this way, the first portion 56 can easily slide on the inner surface of the cylinder bore 14 a. The third portion 60 is made of a third material different from the second material. Preferably, the third material of the third portion 60 is a resin material. More preferably, as in the embodiment shown, the third material of the third portion 60 is the same as the first material of the first portion 56. In this way, the third portion 60 can easily slide on the inner surface of the cylinder bore 14 a.

Referring to FIG. 7, the first portion 56 is configured to limit movement of the main seal 52 relative to the main body 50 in the return direction D2. In particular, the first portion 56 has a first axial abutment surface 61 facing the main seal 52. The second portion 58 is configured to limit movement of the main seal 52 relative to the main body 50 in the actuation direction D1. In particular, the second portion 58 has a second axial abutment surface 62 facing the main seal 52. As such, when the piston assembly 30 moves within the cylinder bore 14a, movement of the main seal 52 relative to the main body 50 is limited in the axial direction between the first portion 56 and the second portion 58. At least one of the first and second portions 56, 58 includes a support or connection 63 for supporting the main seal 52. Here, in the embodiment of fig. 5 to 9, the second portion 58 includes a support portion 63 that supports the main seal 52. The support 63 is disposed in an axial position between the first axial abutment surface 61 and the second axial abutment surface 62. The support 63 is integral with the second portion 58. Thus, here, the second portion 58 supports the main seal 52.

The first portion 56 is configured to limit movement of the secondary seal 54 relative to the body 50 in the actuation direction D1. In particular, the first portion 56 has a third axial abutment surface 64 facing the secondary seal 54. The third portion 60 is configured to limit movement of the secondary seal 54 relative to the main body 50 in the return direction D2. In particular, the third portion 60 has a fourth axial abutment surface 65 facing the secondary seal 54. In this way, movement of the secondary seal 54 relative to the main body 50 is restricted in the axial direction between the first portion 56 and the third portion 60 as the piston assembly 30 moves within the cylinder bore 14 a. At least one of the first portion 56 and the third portion 60 includes a support or connection portion 66 that supports the secondary seal 54. Here, in the embodiment of fig. 5 to 9, the third portion 60 includes a support portion 66 that supports the secondary seal 54. Preferably, the support 66 is integral with the third portion 60. Thus, here, the third portion 60 supports the secondary seal 54.

As described above, the second portion 58 is removably and reattachably attached to the first portion 56 to be at least partially disposed downstream of the main seal 52 relative to the actuation direction D1. In particular, the second portion 58 is inserted into the first portion 56 to be at least partially disposed downstream of the main seal 52 relative to the actuation direction D1. Here, the second portion 58 is threadedly engaged to the first portion 56. More specifically, the second portion 58 includes a self-tapping screw portion 67 configured to be threadably engaged to the first portion 56. Here, the first portion 56 includes a blind hole 68, and when the second portion 58 is connected to the first portion 56, the blind hole 68 is tapped by the self-tapping screw portion 67. Thus, the blind hole 68 becomes a threaded hole after the second portion 58 is connected to the first portion 56. Alternatively, the blind bore 68 may be pre-threaded. Also, alternatively, the second portion 58 and/or the third portion 60 may be attached to the first portion 56 in other manners (e.g., adhesively bonded, welded, etc.) after the primary seal 52 and/or the secondary seal 54 are disposed in their proper positions.

As mentioned above, the third portion 60 is attached to the first portion 56 so as to be at least partially disposed upstream of the secondary seal 54 with respect to the actuation direction D1. In particular, the third portion 60 is inserted into the first portion 56 so as to be arranged at least partially upstream of the secondary seal 54 with respect to the actuation direction D1. Here, the third portion 60 is press-fitted to the first portion 56. More specifically, the third portion 60 includes a press 70, the press 70 configured to be press-fit into a blind bore 71 of the first portion 56. Here, the blind hole 71 has a plurality of longitudinal ribs which are plastically deformed so that an interference fit occurs.

The main seal 52 includes a main seal body 80 disposed on the main body 50. The main seal body 80 is made of a first sealing material. Here, the main seal body 80 is made of a resin material. Therefore, the first sealing material includes a resin material. Preferably, the first sealing material (resin material) includes one of polytetrafluoroethylene and polyethylene. More preferably, the first sealing material comprises polytetrafluoroethylene filled with polyimide.

The main seal body 80 is an O-ring having a uniform cross-sectional profile. The main seal body 80 includes a main lip 80a, and the main lip 80a is configured to be in contact with the cylinder bore 14a in an arrangement state in which the piston assembly 30 is arranged in the cylinder bore 14 a. The main seal body 80 also includes a central opening 80b, the central opening 80b configured to closely contact the support portion 63 of the second portion 58. The main seal 52 also includes a biasing portion 82, the biasing portion 82 configured to bias the main lip 80a of the main seal body 80 outwardly in the deployed state. Here, the biasing portion 82 is a coil spring. However, it will be apparent from this disclosure that the biasing portion 82 is not limited to a coil spring. For example, the biasing portion 82 may be an annular elastomeric O-ring, or an annular cantilevered or V-shaped spring having a V-shaped cross-section, or any other suitable member that may be used to apply a radial biasing force to the main lip 80a of the main seal body 80. Thus, preferably, the main seal 52 is a spring-loaded seal when the biasing portion 82 is included.

The secondary seal 54 is disposed on the main body 50 upstream of the primary seal 52 relative to the actuation direction D1. That is, the secondary seal 54 includes a secondary seal body 54a disposed on the main body 50 upstream of the primary seal 52 relative to the actuation direction D1. The secondary seal body 54a is an O-ring having a uniform cross-sectional profile. The secondary seal body 54a is made of a second sealing material that is more elastic than the first sealing material. The secondary seal body 54a includes a secondary lip 54b, and the secondary lip 54b is configured to contact the cylinder bore 14a in an arrangement state in which the piston assembly 30 is arranged in the cylinder bore 14 a. Preferably, the second sealing material of the secondary seal body 54a includes a rubber material.

Referring now to fig. 10, a piston assembly 130 according to a second embodiment will now be explained. Basically, the piston assembly 130 is used in the hydraulic operating device 10 in place of the piston assembly 30. In view of the similarity between the first and second embodiments, the parts of the second embodiment that are identical to the parts of the first embodiment will be given the same reference numerals as the parts of the first embodiment. Moreover, the descriptions of the parts of the second embodiment that are identical to the parts of the first embodiment may be omitted for the sake of brevity.

The piston assembly 130 includes a main body 150, the first embodiment primary seal 52 and the first embodiment secondary seal 54. The body 150 includes a first portion 156, a second portion 158 and the third portion 60 of the first embodiment. As described above, the secondary seal 54 and the third portion 60 may be omitted as needed and/or desired. Here, the third portion 60 is coupled to the first portion 156 and supports the secondary seal 54 in the same manner as in the piston assembly 30 in the first embodiment. However, in the second embodiment, the main seal 52 is supported on the first portion 156, and the connection between the first portion 156 and the second portion 158 has been changed.

Here, in the second embodiment, the first portion 156 includes a support portion or a connection portion 163 for supporting the main seal 52. The support 163 is integral with the first portion 156. Further, here, in the second embodiment, the second portion 158 is screw-engaged to the support portion or the connection portion 163 of the first portion 156. More specifically, the second portion 158 includes a self-tapping screw portion 167 configured to be threadably engaged to the first portion 156. Here, the first portion 156 includes a blind hole 168, and when the second portion 158 is coupled to the first portion 156, the blind hole 168 is tapped by the self-tapping screw portion 167. Thus, the blind bore 168 becomes a threaded bore after the second portion 158 is coupled to the first portion 156. Alternatively, blind bore 168 may be pre-threaded. Also, alternatively, the second portion 158 and/or the third portion 60 may be attached to the first portion 156 in other manners (e.g., adhesively bonded, welded, etc.) after the primary seal 52 and/or the secondary seal 54 are disposed in their proper positions.

Referring now to FIG. 11, a first variation main seal 252 is disposed between the first portion 56 of the body 50 and the second portion 58 of the body 50. The first variation main seal 252 includes the main seal body 80 and the biasing portion 282 as described above. Here, the biasing portion 282 is an annular cantilever spring having a V-shaped or U-shaped cross section. The biasing portion 282 may be made of a suitable metallic material, a resin material, or an elastomeric material.

Referring now to FIG. 12, a second variation main seal 352 is disposed between the first portion 56 of the main body 50 and the second portion 58 of the main body 50. The second modified main seal 352 includes the main seal body 80 and the biasing portion 382 as described above. Here, the biasing portion 382 is an annular elastomeric spring that fills the annular space inside the main seal body 80. However, the offset portion 382 may be an O-ring having a circular cross-section. The biasing portion 382 is shown as being removable, but may be embedded or bonded to the main seal body 80.

Referring now to fig. 13 and 14, a third variation main seal 452 is disposed between the first portion 56 of the main body 50 and the second portion 58 of the main body 50. The third variation main seal 452 includes the main seal body 80 and the biasing portion 482 as described above. Here, the biasing portion 482 is an annular elastomeric spring having a plurality of recesses. These recesses may be through holes and/or have other shapes. In the illustrated embodiment, the offset portion 482 fills an annular space inside the main seal body 80. However, the offset portion 482 may be an O-ring having a circular cross-section. The offset portion 482 is shown as being removable, but may be embedded or bonded to the main seal body 80.

Referring now to FIG. 15, a fourth variation primary seal 552 is disposed between the first portion 56 of the body 50 and the second portion 58 of the body 50. The fourth variation main seal 552 includes the main seal body 80 and the biasing portion 582 as described above. Here, the biasing portion 582 is a ring-shaped cantilever spring having a V-shaped or U-shaped cross section and having two resin layers. However, the biasing section 582 can have more than two layers as needed and/or desired. As shown, the layers of the biasing portion 582 can have different hardnesses as needed and/or desired. The biasing portion 582 is shown as being removable, but may be embedded or glued to the main seal body 80. The resin of the biasing portion 582 may be harder or softer than the main seal body 80 as needed and/or desired.

Referring now to fig. 16 to 22, a piston assembly 630 according to a third embodiment will be explained. The piston assembly 630 provides for a human powered vehicle V. In particular, as shown in FIG. 16, a piston assembly 630 is used in place of the piston assembly 30 in the hydraulically operated device 10 discussed above. In view of the similarity between the first and third embodiments, the descriptions of the parts of the third embodiment that are identical to the parts of the first embodiment may be omitted for the sake of brevity.

As shown in fig. 16-19, the piston assembly 630 includes a body 650 and a main seal 652. In the third embodiment, similar to the first embodiment, the piston assembly 630 further includes a secondary seal 654 disposed on the body 650 upstream of the primary seal 652 with respect to the actuation direction D1. However, it will be apparent from this disclosure that the secondary seal 654 may be omitted as needed and/or desired. Here, the secondary seal 654 is made of a different material than the primary seal 652.

As shown in fig. 16, a main seal 652 and a sub seal 654 are provided on the main body 650 to slidably contact the cylinder bores 14a in a state where the piston assembly 630 is mounted in the hydraulic operating device 10. Accordingly, the primary seal 652 and the secondary seal 654 are in sealing contact with the cylinder bore 14a and the main body 650 in a state in which the piston assembly 630 is mounted in the hydraulic operating device 10. Similar to the first embodiment, the main body 650 is configured to be movable in the cylinder bore 14a in an actuation direction D1 from a rest position (e.g., fig. 3) to an actuated position (e.g., fig. 4).

Further, as shown in fig. 19-22, the body 650 includes a connecting first portion 656 and a second portion 658 coupled to the first portion 656. However, it will be apparent from this disclosure that first portion 656 and second portion 658 can be permanently secured together if needed and/or desired. Alternatively, the first portion 656 may be split into two portions similar to the first embodiment. Here, the second portion 658 is removably and reattachably attached to the first portion 656. The first portion 656 is made of a first material. The second portion 658 is made of a second material different from the first material. In the third embodiment, the first material is a resin material, and the second material is a metal material. The resin material of the first portion 656 has a lower coefficient of friction than the metal material of the second portion 658. In this way, the first portion 656 can easily slide on the inner surface of the cylinder bore 14 a.

Referring to fig. 19, the first portion 656 is configured to limit movement of the main seal 652 in a return direction D2 relative to the body 650. In particular, the first portion 656 has a first axial abutment surface 661 facing the main seal 652. The second portion 658 is configured to limit movement of the main seal 652 relative to the body 650 in the drive direction D1. In particular, the second portion 658 has a second axial abutment surface 662 that faces the primary seal 652. Thus, the primary seal 652 is axially located between the first and second axial abutment surfaces 661, 662. As such, movement of the main seal 652 relative to the main body 650 is limited in the axial direction between the first portion 656 and the second portion 658 as the piston assembly 630 moves within the cylinder bore 14 a.

At least one of the first and second portions 656, 658 includes a support or connection 663 for supporting the main seal 652. Here, in the third embodiment, the second portion 658 includes a support portion 663 that supports the main seal 652. The support portion 663 is disposed in an axial position between the first axial abutment surface 661 and the second axial abutment surface 662. The support 663 is integral with the second portion 658. Thus, here, the second portion 658 supports the primary seal 652.

The first portion 656 is also configured to limit movement of the secondary seal 654 relative to the main body 650 in a drive direction D1 and a return direction D2. In particular, the first portion 656 has a third axial abutment surface 664 and a fourth axial abutment surface 665. The third axial abutment surface 664 faces the secondary seal 654 to limit movement of the secondary seal 654 relative to the body 650 in the drive direction D1. The fourth axial abutment surface 665 faces the secondary seal 654 to limit movement of the secondary seal 654 relative to the body 650 in the return direction D2. As such, movement of the secondary seal 654 relative to the body 650 is limited in the axial direction as the piston assembly 630 moves within the cylinder bore 14 a. Here, the first portion 656 includes a support 666 that supports the secondary seal 654. The support 666 is located between the third axial abutment surface 664 and the fourth axial abutment surface 665.

Further, here, in the third embodiment, as shown in fig. 19, the second portion 658 is threadedly engaged to the first portion 656. More specifically, the second portion 658 includes a self-tapping screw portion 667 configured to be threadedly engaged to the first portion 656. Here, the first portion 656 comprises a blind hole 668, which blind hole 668 is tapped by the self-tapping screw portion 667 when the second portion 658 is connected to the first portion 656. Thus, after the second portion 658 is connected to the first portion 656, the blind hole 668 becomes a threaded hole. The first portion 656 is provided with a first tool engagement structure 672 (e.g., a non-circular hole) and the body 650 is provided with a second tool engagement structure 674 (e.g., a pair of parallel planar surfaces) for assisting a user in coupling the first portion 656 to the second portion 658. Alternatively, blind hole 668 can be pre-threaded. Further, optionally, the second portion 658 may be attached to the first portion 656 in other manners (e.g., adhesively bonded, welded, etc.) after the main seal 652 is disposed in its proper position.

The main seal 652 includes a main seal body 680 disposed on the main body 650. The main seal 652 also includes a biasing portion 682. The main seal body 680 is an O-ring having a uniform cross-sectional profile. The main seal body 680 has a main lip 684 configured to contact the cylinder bore 14a in an arrangement state where the piston assembly 630 is arranged in the cylinder bore 14 a. In addition, the main seal body 680 has an annular inner surface 686 that is configured to contact the biasing portion 682 in the deployed state. As shown in fig. 20, the annular inner surface 686 is configured to surround the offset portion 682 such that the offset portion 682 is disposed between the annular inner surface 686 and the support portion 663 of the second portion 658. As shown in fig. 22, the annular inner surface 686 defines a central opening 687 of the main seal body 680.

The biasing portion 682 is configured to contact the outer peripheral surface of the main body 650 to bias the main lip portion 684 of the main seal body 680 outward in the deployed state. In other words, the biasing portion 682 is configured to bias the main lip 684 of the main seal body 680 outward in the deployed condition. Here, the biasing portion 682 is provided as a separate member from the main seal body 680. Thus, the biasing portion 682 may be made of a different material and/or material having different properties than the main seal body 680. In the third embodiment, the biasing portion 682 is made of a rubber material. On the other hand, the main seal body 680 is made of a resin material. In other words, the biasing portion 682 is made of a more resilient material than the main seal body 680. In addition, the main seal body 680 is harder than the biasing portion 682. For example, the resin material of the main seal body 680 includes one of polytetrafluoroethylene and polyethylene. Alternatively, for example, the resin material of the main seal body 680 includes polytetrafluoroethylene filled with polyimide.

Referring to fig. 20, in the third embodiment, the main lip 684 includes a cylindrical outer contact surface 684a configured to contact the cylinder bore 14a in the arranged state. Here, the primary lip 684 includes a first annular chamfered surface 684b and a second annular chamfered surface 684 c. The cylindrical outer contact surface 684a is disposed between the first annular chamfered surface 684b and the second annular chamfered surface 684 c.

In the third embodiment, the main seal body 680 is an O-ring having a first end surface 690 and a second end surface 692. The first end surface 690 faces in the first axial direction X1 with respect to the center axis of the O-ring. The second end surface 692 faces the second axial direction X2 with respect to the central axis. The first axial direction X1 is opposite to the second axial direction X2.

In understanding the scope of the present invention, the term "comprising" and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words of similar import, e.g., the terms "comprising," "having," and their derivatives. Furthermore, the terms "part," "section," "portion," "member" or "element" when used in the singular can have the dual meaning of a single part or a plurality of parts unless otherwise specified.

As used herein, the following directional terms "frame-facing side," "non-frame-facing side," "forward," "rearward," "front," "rear," "up," "down," "above," "below," "up," "down," "top," "bottom," "side," "vertical," "horizontal," "vertical," and "lateral" as well as any other similar directional terms refer to those directions of a human-powered vehicle (e.g., a bicycle) in an upright riding position and equipped with a piston assembly. Accordingly, these directional terms used to describe the piston assembly should be understood with respect to a human powered vehicle (e.g., a bicycle) in an upright riding position on a horizontal surface and equipped with the piston assembly. The terms "left" and "right" are used to indicate "right" when referring to the right side when viewed from behind a human powered vehicle (e.g., a bicycle), and "left" when referring to the left side when viewed from behind a human powered vehicle (e.g., a bicycle).

The phrase "at least one" as used in this disclosure refers to "one or more" of the desired selections. As an example, the phrase "at least one" as used in this disclosure means "only one selection" or "both selections" if the number of selections is two. As another example, the phrase "at least one" as used in this disclosure means "only one selection" or "any combination of equal or more than two selections" if the number of selections thereof is equal to or more than three.

Also, it will be understood that, although the terms "first" and "second" may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, for example, a first element discussed above could be termed a second element, and vice-versa, without departing from the teachings of the present invention.

The term "attached" or "attaching" as used herein encompasses: an arrangement in which an element is directly fixed to another element by directly adhering the element to the other element; an arrangement for indirectly securing an element to another element by adhering the element to an intermediate member which in turn is adhered to the other member; and arrangements in which one element is integral with another element, i.e. one element is essentially part of another element. This definition also applies to words having similar meanings such as "combine," "connect," "couple," "mount," "adhere," "secure," and derivatives thereof. Finally, terms of degree such as "substantially", "about" and "approximately" as used herein mean a deviation of the modified term such that the end result is not significantly changed.

While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. For example, unless otherwise specifically stated, the size, shape, location or orientation of the various components may be changed as needed and/or desired, so long as the changes do not substantially affect their intended function. Unless otherwise specifically stated, components shown directly connected or contacting each other may have intermediate structures disposed between them so long as the changes do not substantially affect their intended function. Unless specifically stated otherwise, the functions of one element may be performed by two, and vice versa. The structure and function of one embodiment may be adopted in another embodiment. Not all advantages may be required to be present in a particular embodiment at the same time. Each feature which is different from the prior art, alone or in combination with other features, also should be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts embodied by such features. Accordingly, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.