Check structure and hydraulic braking system having the same

A hydraulic braking system includes a base, which has an oil chamber and a connecting hole communicating with each other, a seat, which is provided in the oil chamber and has a receiving space communicating with the oil chamber and the connecting hole, a check valve movably provided in the receiving space and the connecting hole, and an elastic member. When one end of a connecting pipe which is connected to a brake actuator is inserted into the connecting hole to engage the base, the check valve is pushed inward to inject the hydraulic fluid in the oil chamber into the connecting pipe; when the connecting pipe is detached from the base, the check valve is pushed by the elastic member, and therefore returns to the original position. Whereby, the hydraulic fluid is prevented from leaking out.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a check mechanism for liquid, and more particularly to a check structure and a hydraulic braking system having the check structure.

2. Description of Related Art

A conventional hydraulic braking structure typically includes an oil chamber filled with hydraulic fluid and a tubing, wherein the oil chamber is provided in a lever base, and one end of the tubing is connected to the lever base to communicate with the oil chamber, while another end thereof is connected to a brake actuator. By pulling a brake lever to squeeze the hydraulic fluid in the oil chamber to flow into the brake actuator along the tubing, the braking effect could be achieved. A hydraulic braking structure disclosed in the Taiwan utility model patent. No. M310861 further provides an O-ring to improve the problem of leakage at the junction of the tubing and the lever base.

Although the problem of leakage is improved by said design, the hydraulic fluid in the oil chamber would still leak out at a connecting portion between the tubing and the lever base when the tubing is detached, which would not only contaminate the surrounding, but also cause the hydraulic fluid in the oil chamber to become insufficient. Therefore, while reassembling the tubing and the lever base, the hydraulic fluid should be replenished to make sure that the hydraulic braking structure could operate smoothly. In all aspects, the conventional hydraulic braking structure still has room for improvements.

In addition, U.S. Patent No. 20160200392, titled “Hydraulic Bicycle System”, discloses a port valve provided between a hydraulic fluid chamber and a hydraulic hose connection port, and a helical compression spring provided between the port valve and a piston. By pushing the port valve to compress the helical compression spring, the position of the port valve could be changed, and therefore the hydraulic fluid chamber could communicate with the hydraulic hose connection port. Since the helical compression spring is mainly used to urge the piston to return to its original position, the elastic modulus of the spring should be high. However, a spring with high elastic modulus would increase the difficulty to move the port valve. In other words, a greater pushing force would be required to overcome the high elastic modulus while compressing the helical compression spring to move the port valve. In addition, because two ends of the helical compression spring respectively abut against the port valve and the piston, and both the port valve and the piston are movable components, it would be more difficult to move one of the objects once the other one is moved.

BRIEF SUMMARY OF THE INVENTION

In view of the above, the primary objective of the present invention is to provide a check structure and a hydraulic braking system having the check structure, which prevents liquid (such as hydraulic fluid) from leaking out.

To achieve the objective of the present invention, the present invention provides a hydraulic braking system, which includes a base, a seat, a check valve, and an elastic member. The base has an oil chamber and a connecting hole provided therein, wherein an end of the connecting hole communicates with the oil chamber, while another end thereof communicates with the outside of the base. The seat is provided in the oil chamber, wherein the seat has a receiving space communicating with the oil chamber and the connecting hole. The check valve is provided in the receiving space and the connecting hole, wherein the check valve is rod-shaped, and is movable between a first position and a second position; the check valve has a passage, which has an inlet and an outlet, wherein the outlet communicates with the connecting hole, and the inlet communicates with the receiving space when the check valve is located at the second position. On the other hand, the inlet does not communicate with the receiving space when the check valve is located at the first position. The elastic member is provided in the receiving space of the seat, wherein, in a normal condition, the elastic member urges the check valve to stay at the first position by pushing it.

The present invention further provides a hydraulic braking system, includes a base, a seat, a check valve, and an elastic member, wherein the base has an oil chamber and a connecting hole provided therein. The base further has a neck passage communicate the oil chamber and the connecting hole. The seat is provided in the oil chamber, and has a receiving space communicating with the oil chamber and the connecting hole. The check valve includes a rod passing through the neck passage, wherein at least one groove is recessed into an outer peripheral surface of the rod. The at least one groove has a first end located on an end surface of the rod and a second end located on a predetermined portion of the outer peripheral surface, wherein the first end communicates with the connecting hole. The check valve is movable between a first position and a second position. The elastic member is provided in the receiving space of the seat, wherein, in a normal condition, the elastic member urges the check valve to stay at the first position by pushing against the check valve; when the check valve is located at the first position, the second end thereof dis-communicates with the oil chamber; when the check valve is located at the second position, the second end thereof communicates with the oil chamber.

With the aforementioned design, the hydraulic fluid in the oil chamber would not leak out during assembling, and therefore the braking process could be performed smoothly.

DETAILED DESCRIPTION OF THE INVENTION

A hydraulic braking system of an embodiment of the present invention, which has a check structure, is illustrated inFIG. 1toFIG. 5, wherein the hydraulic braking system is applied to a structure, which is a bicycle braking system as an example. However, this is not a limitation of the present invention; the hydraulic braking system could be used in other systems or devices as well. The hydraulic braking system includes a base10, a seat12, a spring14, a check valve16, an O-ring18, an elastic member20, and a connecting pipe22. An end of the connecting pipe is detachably connected to the base10, while another end thereof is connected to a brake actuator (not shown). Said seat12, said spring14, said check valve16, and said O-ring18constitute the check structure of the embodiment.

The base10is provided on a handle of a bicycle, and is pivotally connected to a brake lever24. As shown inFIG. 6andFIG. 7, an oil chamber10aand a connecting hole10bis provided in the base10, wherein an end of the connecting hole10bcommunicates with the oil chamber10a, while another end thereof communicates with the outside of the base10. When the brake lever24is pulled, the hydraulic fluid in the oil chamber10ais squeezed into the brake actuator along the connecting pipe22through a linking mechanism, whereby to provide a braking effect. However, the brake lever24and said linking mechanism are both conventional, and are not the essence of the present invention. Thus we are not going to describe them in details herein.

The seat12and the spring14are provided in the oil chamber10a, wherein the seat12includes a tubular body121and a flange122. The tubular body121is slightly cone-shaped, and has a receiving space121atherein. A closed plate121bis provided on a side of the tubular body121, while another side thereof is an open end121c. At least one bore121dis provided on the closed plate121b, wherein the at least one bore121dcommunicates with the receiving space121aand the oil chamber10a, which allows the hydraulic fluid in the oil chamber10ato enter the receiving space121athrough the at least one bore121d. In the embodiment, the at least one bore121dincludes two bores. The flange122is connected to a bottom edge of the tubular body121on the side thereof having the open end121c, wherein the flange122extends outwardly in a radial direction thereof. An end of the spring14abuts against the flange122, while another end thereof abuts against one of the components of said linking mechanism. A force exerted by the spring14would urge the seat12to abut against an inner wall of the oil chamber10a, whereby to keep the receiving space121acommunicating with the connecting hole10b. In other words, the oil chamber10acommunicates with the connecting hole10bthrough the receiving space121a.

The check valve16, the O-ring18, and the elastic member20are provided in the receiving space121aof the tubular body121of the seat12. The check valve16includes a cylinder rod161and a round blocking flange162connected to the rod161at an end thereof. An outer diameter of the blocking flange162is greater than an outer diameter of the rod161. The rod161has a radial bore161aand an axial bore161bprovided therein, which communicate with each other to form a T-shaped passage. The passage has two inlets S1and an outlet S2, wherein the inlets S1are two ends of the radial bore161a, while the outlet S2is an end of the axial bore161bcommunicating with the outside of the rod161. The O-ring18is made of an elastic material, such as rubber. However, the selection of the material for making the O-ring18is not a limitation of the present invention. The O-ring18fits around the rod161, and is located on one side of the blocking flange162. Preferably, an inner edge and an outer edge of the O-ring18respectively abut against a surface of the rod161and an inner wall of the tubular body121, whereby to provide a better sealing effect.

The rod161of the check valve16is provided in the receiving space121aand the connecting hole10b, with the end thereof with the outlet S2of the passage extending into the connecting hole10b, so that the output S2communicates with the connecting hole10b. The O-ring18abuts against an inner wall of the oil chamber10anear the connecting hole10b. In the embodiment, the rod161could be moved between a first position P1(shown inFIG. 7) and a second position P2(shown inFIG. 9). The elastic member20is a spring, wherein an end thereof abuts against the blocking flange162of the check valve16, while another end thereof abuts against an inner wall of the closed plate121bof the tubular body121. In a normal condition, the elastic member20would keep the check valve16staying at the first position P1by pushing it. Said normal condition refers to a condition when the elastic member20is not compressed. The elastic member20would be compressed and deformed by moving the check valve16from the first position P1toward the second position P2.

The connecting pipe22is not connected to the base10yet in the condition shown inFIG. 6andFIG. 7. At this time, the check valve16is pushed by the elastic member20and therefore stay at the first position P1, and the inlets S1of the passage do not communicate with the receiving space121a. In this way, the hydraulic fluid in the oil chamber10awould not leak out along the passage. In addition, the blocking flange162of the check valve16would push the O-ring18to abut against the inner wall of the oil chamber10a, whereby to further prevent the hydraulic fluid from leaking out.

A pushing portion22ais provided at one end of the connecting pipe22. When one end of the connecting pipe22enters the connecting hole10bof the base10, as in the condition shown inFIG. 8andFIG. 9, the pushing portion22aof the connecting pipe22abuts against an end of the check valve16which extends into the connecting hole10b, wherein the check valve16would be continuously pushed toward the receiving space121a, and the elastic member20would be compressed and deformed consequently. When the check valve16arrives at the second position P2, the inlets S1of the passage would communicate with the receiving space121a. In the meantime, the hydraulic fluid in the oil chamber10acould be injected into the connecting pipe22through the receiving space121aand the passage.

A hydraulic braking system of another embodiment of the present invention having a check structure is illustrated inFIG. 10andFIG. 11, wherein the hydraulic braking system also includes the seat12, the spring14, the O-ring18, the elastic member20, and the connecting pipe22described in the previous embodiment. In addition, the hydraulic braking system of the current embodiment further includes a base80and a check valve90which are different from those of the previous embodiment. As describe above, one of the ends of the connecting pipe22is detachably connected to the base80, while the other end thereof is connected to a brake actuator (not shown). In the current embodiment, said seat12, said spring14, said check valve90, said O-ring18, and said elastic member20constitute the check structure.

In the current embodiment, the base10is also provided on a frame or a handle of a bicycle, and is pivotally connected to the brake lever24. As shown inFIG. 12andFIG. 13, an oil chamber80a, a connecting hole80b, and a neck passage80care provided in the base80, wherein an end of the connecting hole80bcommunicates with the outside of the base80, while another end thereof communicates with the oil chamber80athrough the neck passage80c. Similarly, when the brake lever24is pulled, the hydraulic fluid in the oil chamber80awould be squeezed into the brake actuator along the neck passage80cand the connecting pipe22through a linking mechanism, whereby to provide a braking effect. However, the brake lever24and said linking mechanism are not the essence of the present invention. Thus we are not going to describe them in details herein.

The seat12and the spring14are provided in the oil chamber80a, wherein the structure of the seat12has described above. The at least one bore121dprovided on the closed plate121bcommunicates with the receiving space121aand the oil chamber80a, which allows the hydraulic fluid to enter the receiving space121athrough the at least one bore121d. In the current embodiment, the at least one bore121dalso includes two bores. The flange122is connected to the tubular body121on the side thereof which has the open end121c, wherein the flange122extends outwardly in a radial direction thereof. One of the ends of the spring14abuts against the flange122, while the other end thereof abuts against one of the components of said linking mechanism or an inner wall of the base80. A force exerted by the spring14would urge the seat12to abut against the inner wall of the oil chamber80a. On the other hand, the receiving space121acommunicates with the neck passage80c. In the current embodiment, an end of the spring14is adapted to move the piston of the linking mechanism, and the tubular body121and the flange122are integrally made.

As mentioned in the previous embodiment, the check valve90, the O-ring18, and the elastic member20are provided in the receiving space121aof the tubular body121of the seat12. The check valve90includes a cylinder rod901and a round blocking flange902connected to the rod901at a body thereof, wherein the rod901and the round blocking flange902are integrally made, and an outer diameter of the blocking flange902is greater than an outer diameter of the rod901. Two ends of the rod901are respectively an end surface901A and an end surface901B. The rod901is provided passing through the neck passage80cin a movable manner, and a plurality of grooves901aare recessed into an outer peripheral surface of the rod901in an axial direction thereof. Each of the grooves901ahas a first end T1located on the end901A of the rod901, and a second end T2formed on the outer peripheral surface of the rod901, wherein the second end T2is located between the end surface901A and the end surface901B. The end of the rod901which has the end surface901A enters the connecting hole80bto communicate the first ends T1of the grooves901aand the connecting hole80b, while the other end of the rod901which has the end surface901B is located in the oil chamber80a. The blocking flange902is located between the seconds end T2of the grooves901aand the end surface901B of the rod901.

The O-ring18fits around the rod901. Once these components are assembled, an inner edge of the O-ring18abuts against the blocking flange902, and an outer edge of the O-ring18abuts against the inner wall of the tubular body121as well, whereby to provide a better sealing effect. In the current embodiment, the elastic member20is also a spring, wherein one of the ends thereof abuts against the blocking flange902of the check valve90, while the other end thereof abuts against the inner wall of the closed plate121bof the tubular body121. In this way, as recited in the previous embodiment, the elastic member20could provide a force to move the check valve90toward a predetermined direction in a normal condition, wherein said normal condition refers to a condition when the elastic member20is not compressed.

The connecting pipe22is not connected to the base80yet in the condition shown inFIG. 12andFIG. 13. At this time, the check valve90is pushed by the uncompressed elastic member20. Whereby, the O-ring18would about against the inner wall of the oil chamber80anear the neck passage80c. Meanwhile, the check valve90is located at the first position P1defined above. As explained in the previous embodiment, at this time, the second ends T2of the grooves901aof the check valve90do not communicate with the receiving space121a, so that the hydraulic fluid in the oil chamber80awould not leak out along the grooves901a. In addition, the O-ring18would be compressed by the force exerted by the elastic member20, which could further prevent the hydraulic fluid from leaking out as well.

One of the ends of the connecting pipe22enters the connecting hole80bof the base80in the condition shown inFIG. 14andFIG. 15, wherein the pushing portion22aof the connecting pipe22abuts against the end surface901A of the rod901of the check valve90. When the connecting pipe22is engaged with the connecting hole80bof the base80, the check valve90would be pushed toward the receiving space121, and the elastic member20would be compressed and deformed consequently. At this time, the check valve90is located at the second position P2defined above. Meanwhile, as recited in the previous embodiment, the second ends T2of the grooves901aof the check valve90communicate with the receiving space121a, so that the hydraulic fluid in the oil chamber80acould be injected into the connecting pipe22through the receiving space121aand the grooves901a.

Because the grooves901aof the check valve90of the current embodiment are designed to simply recess into the outer peripheral surface of the rod901, the process of making the grooves901acould be simplified and accelerated. In addition, the extending direction of the grooves901ais not necessary to be the axial direction of the rod901, other directions would be acceptable as long as each of the grooves901acould satisfy the condition that the first end T1is located on the end surface901A of the rod901, and the second end S2is located between the end surface901A and the end surface901B. That means, the grooves901acould be helical in other embodiments.

It is worth mentioning that, the check structure of each of the aforementioned embodiments is constituted of said seat12, said spring14, said check valve90, said O-ring18, and said elastic member20, and could be modularized. Therefore, the check structure could be easily installed or replaced. Also, said modular check structure could be pre-installed in a housing before being engaged with the base, which could be then installed at a disk, a caliper, or the middle section of the oil chamber.

Furthermore, since the spring14is used to urge the linking mechanism to return to its original location, a spring with high elastic modulus could be selected to ensure that the linking mechanism precisely goes back to the right position. On the other hand, since the elastic member is used to keep the check valve16biasing in a predetermined direction, and is provided in the receiving space121aof the seat12, a spring with low elastic modulus could be selected. By using two springs with different elastic modulus, the problem and the inconvenience caused by the conventional design that provides just one single spring between the check valve and the linking mechanism could be eased.

In conclusion, in the aforementioned embodiments, when the connecting pipe22is not connected to the base10,80, the hydraulic fluid in the oil chamber10a,80awould not leak out. When the connecting pipe22is connected to the base10,80, the hydraulic fluid in the oil chamber10a,80acould be injected into the connecting pipe22. Furthermore, when the connecting pipe22is detached from the base10,80again, the check valve16,90would be urged by the force exerted by the elastic member20to return to the first position P1in no time, whereby to prevent the hydraulic fluid from leaking out. Therefore, the hydraulic fluid in the oil chamber10a,80acould be ensured not to leak out while connecting and disconnecting the connecting pipe22.