TWI840761B - Hub with pawls of various lengths - Google Patents

Abstract

A hub with pawls of various lengths includes a main body, a ratchet ring, a driving member and a plurality of pawl pairs. The ratchet ring has a hole in the axial direction, the inner surface of the hole has a plurality of ratchet teeth connected continuously, and the ratchet ring is combined with the main body. One end of the driving member has a base portion, and the base portion extends into the hole of the ratchet ring. The pawl pairs are arranged on the periphery of the base portion of the driving member, each of the pawl pairs includes a first pawl and a second pawl , and the length of the first pawl is greater than the length of the second pawl. Thereby, when the first pawls are engaged in the ratchet teeth, the second pawls do not engaged in the ratchet teeth; otherwise when the second pawls are engaged in the ratchet teeth, the first pawls do not engaged in the ratchet teeth.

Description

Hub with long and short pawls

The present invention is related to the field of bicycle drive mechanism technology, and in particular to a hub with long and short pawls.

Generally, a bicycle is equipped with an axle assembly to engage a transmission system to drive the rear wheel when the bicycle is moving forward. When the pedal is not pressed in the forward direction or the bicycle slides, the transmission system disengages. When the crank is pressed again to rotate in the forward direction, the transmission system can re-engage. Since the rotation stroke of the general transmission system is long, the impact force it generates is also large, which can easily cause damage to the parts and shorten its service life. In addition, the reaction and starting are slow, so for the user, there will be a phenomenon of transmission force distortion, and the real feeling of pedaling is poor. In order to reduce the empty pedaling feeling before re-engagement and maintain part yield, it is best to provide an axle assembly that can quickly and efficiently switch between disengagement and engagement states, including sensitive and instant response when needed.

Taiwan Patent Publication No. 202005824 discloses a wheel-axle assembly for a vehicle, which may include an axle housing for a vehicle wheel, which is coupled to an axle body with an axle by a ratchet mechanism, and is configured to provide an engaged state, so that the axle body/axle rotates with the axle housing/wheel, and a disengaged state, so that the axle body/axle rotates relative to the axle housing/wheel. The ratchet mechanism may include a set of ratchets with a gear set, and a pawl set/group configured to engage/disengage with the gear teeth of a ratchet; the ratchets may be configured/installed in the axle body in an aligned state or an offset state; when the ratchets are in an offset state, the ratchet mechanism may be configured to enable the axle body/axle and the axle housing/wheel to switch between the disengaged and engaged states more sensitively. The axle assembly may include an axle housing/wheel and a free axle body/axle, which are coupled by a ratchet mechanism, wherein the ratchet mechanism includes at least one ratchet with teeth, configured to engage with a corresponding pawl set/group, so that the wheel and the axle body/axle can engage in a power transmission state.

However, the patent prior art requires the offset angle between the two ratchets to be adjusted so that the ratchets on the inner wall surfaces of the two ratchets are misaligned, thereby causing the forward rotation angle before engagement to fail to meet the minimum angle requirement.

The main purpose of the invention is to provide a hub with long and short pawls, which can provide a smaller rotation angle before engagement, thereby improving driving sensitivity.

In order to achieve the above-mentioned invention purpose, the present invention provides a hub with long and short pawls, which includes a body; a ratchet ring, which has a through hole passing through in the axial direction, and the inner surface of the through hole has a plurality of ratchets connected continuously, and the ratchet ring is combined with the body; a driving member, one end of which has a seat portion, and the seat portion extends into the through hole of the ratchet ring, and its characteristics are The invention is that: a plurality of pawl pairs are arranged on the periphery of the seat of the driving member, each of the pawl pairs includes a first pawl block and a second pawl block in parallel, and the length of the first pawl block is greater than the length of the second pawl block; by each of the first pawl blocks engaging the ratchet ring, or each of the second pawl blocks engaging the ratchet ring, the main body can be driven to rotate.

The present invention utilizes the different lengths of the first pawl block and the second pawl block adjacent to each pawl pair to form a staggered shape, thereby enabling the pawl pairs to re-engage the ratchet ring at a smaller rotation angle with fewer components, thereby achieving a more sensitive driving effect.

The following is a list of preferred embodiments based on the purpose, efficacy and structural configuration disclosed by the present invention, and is described in detail with accompanying drawings.

10:Hub

20: Body

22: Positioning slot

30: Thorn ring

32: Perforation

34: Positioning unit

36: Thorns

40:Driver

42: Seat

44: Storage tank

46: Elastic components

50: Pair of ratchet pawls

51: First pawl block

52: Second pawl block

441: First accommodating portion

442: Second accommodating portion

461: First elastic part

462: Second elastic part

Figure 1 is an appearance diagram of the first preferred embodiment of the present invention.

Figure 2 is a disassembled diagram of the first preferred embodiment of the present invention.

Figure 3 is a schematic diagram of the combined cross-section of the first preferred embodiment of the present invention.

Figure 4 is a schematic diagram of the appearance of the ratchet ring and the driving member combined with the ratchet pawl pair of the first preferred embodiment of the present invention.

Figure 5 is a schematic diagram of the decomposition of the pawl pair and the elastic component of the first preferred embodiment of the present invention.

Figure 6 is a schematic diagram of the first pawl block of the first preferred embodiment of the present invention when it is engaged.

Figure 7 is a schematic diagram of the state of the second pawl block of the first preferred embodiment of the present invention when it is engaged.

Figures 8a-8d are comparative schematic diagrams of the first preferred embodiment of the present invention, showing the pawls in one configuration trying to re-engage the ratchet ring after being displaced in the opposite direction at different angles.

Figure 9 is a schematic diagram of the state of the pawl pairs of the second preferred embodiment of the present invention, showing that the adjacent angles between the pawl pairs are not equal.

Please refer to Figure 1, a hub 10 is provided at the center of the rear wheel of a bicycle. The hub 10 is connected to a wheel frame of the rear wheel by a plurality of steel spokes. Secondly, a gear or a gear set (not shown) can be connected to the hub 10, and the gear or gear set is engaged with a chain. The chain drives the gear or gear set to rotate to generate a driving torque, so that the hub 10 and the rear wheel rotate by the driving torque, thereby causing the bicycle to move forward.

Please refer to Figures 2 and 3. The hub 10 provided by the first preferred embodiment of the present invention comprises a ratchet ring 30, a driving member 40, and a combination of a plurality of ratchet pairs 50 installed axially inside a body 20 to transmit the driving torque. The ratchet ring 30 is an annular member, the driving member 40 is an axial member and one end is used to extend into the axial inside of the ratchet ring 30, and the ratchet ring 30 engages a part of the ratchet pairs 50 to achieve the function of transmitting the driving torque. Figure 2 also reveals that the inner wall surface of one end of the body 20 has a positioning groove 22.

The present embodiment discloses that the ratchet ring 30 is a ring having a through hole 32 with a through structure in the axial direction. The outer peripheral surface of the ratchet ring 30 has a plurality of protruding positioning parts 34, so that when the ratchet ring 30 is aligned and placed in the main body 20, the positioning parts 34 are combined with the positioning groove 22 of the main body 20, so that the ratchet ring 30 is combined with the main body 20. The ratchet ring 30 of the present embodiment has a plurality of ratchets 36 connected continuously formed on the inner wall surface of the through hole 32.

Please refer to FIG. 4 and FIG. 5 , the pawl pairs 50 are mounted on the outer circumference of the driving member 40. In further detail, each of the pawl pairs 50 has a first pawl block 51 and a second pawl block 52 in parallel, and the length of the first pawl block 51 is greater than that of the second pawl block 52, so that when the first pawl block 51 and the second pawl block 52 are juxtaposed to form the pawl pair 50, a portion of the first pawl block 51 protrudes from the front end of the second pawl block 52. In this embodiment, one end of the driving member 40 has a generally annular seat 42, and the pawl pairs 50 have six pairs, which are mounted on the circumference of the seat 42 at equal distances (equal angles), and the adjacent angle between any two adjacent pawl pairs 50 is 60 degrees. In this way, the seat portion 42 penetrates into the through hole 32 of the ratchet ring 30, and the ratchet pair 50 can correspond to the ratchet ring 30.

The present embodiment further provides a driving means for acting on the corresponding ratchet pairs 50, so that the first ratchet blocks 51 and a part of the second ratchet blocks 52 of the ratchet pairs 50 are normally engaged with the ratchets 36 of the ratchet ring 30. The driving means can be elastic driving, magnetic driving or other equivalent means for driving the ratchets. In the present embodiment, the driving means uses elastic force to drive the ratchet pairs 50. The seat portion 42 is provided with a plurality of accommodating grooves 44 on its circumference, and the number of the accommodating grooves 44 corresponds to the number of the ratchet pairs 50. Each of the accommodating grooves 44 has a first accommodating portion 441 and a second accommodating portion 442, which are respectively located at two opposite ends of the accommodating groove 44. The pawl pairs 50 are respectively arranged in the first receiving portions 441, and the driving means include a plurality of elastic components 46 respectively arranged in the second receiving portions 442. Each of the elastic components 46 is a single element, having a first elastic portion 461 and a second elastic portion 462 elastically pressing against the first pawl block 51 and the second pawl block 52, respectively. The elastic force of the elastic components 46 acts on the first pawl block 51 and the second pawl block 52 of the corresponding pawl pairs 50, so that the pawl pairs 50 are lifted up and leaned against the ratchet ring 30 under normal conditions.

According to the above description, when the driving member 40 rotates in the direction of the bicycle moving forward, the first pawl blocks 51 and a portion of the second pawl blocks 52 of the pawl pairs 50 engage the ratchets 36 of the ratchet ring 30 to drive the ratchet ring 30, thereby causing the main body 20 to rotate, thereby achieving the purpose of moving the bicycle forward. On the contrary, if the driving member 40 rotates in the opposite direction of the forward movement of the bicycle, or if the bicycle moves forward but the driving member 40 does not rotate, the first pawl blocks 51 and the second pawl blocks 52 of the pawl pairs 50 do not form a linkable state with the ratchet ring 30. Therefore, in order to provide driving torque to the bicycle again, a maximum forward displacement or maximum forward rotation angle must be satisfied to re-engage a part of the pawl pairs 50 with the ratchet ring 30.

The present invention, which is composed of the above-mentioned component structures, provides a ratchet hub with long and short pawls. Its actual operation and application are as follows:

Please refer to Figures 6 and 7. This embodiment discloses that an inter-tooth angle θ and a ratchet distance R are formed between two adjacent ratchet teeth 36. The inter-tooth angle θ is the angle between any two adjacent ratchet teeth 36 with the center point of the ratchet ring 30 as the center. When the number of the ratchet teeth 36 is N, the inter-tooth angle θ=360/N. The ratchet distance R is the distance between the vertices of two adjacent ratchets 36; secondly, since the lengths of the first ratchet block 51 and the second ratchet block 52 of the same ratchet pair 50 are different, a ratchet distance is formed between the first ratchet block 51 and the second ratchet block 52 of the same ratchet pair 50, so that the length of the adjacent first ratchet block 51 is greater than that of the second ratchet block 52, and the ratchet distance is smaller than the ratchet distance R. Thus, a maximum forward displacement of the ratchet pair 50 and the ratchet ring 30 from a non-engaged position to a re-engagement is smaller than the ratchet distance R. As shown in FIG. 6, when the first pawl block 51 is engaged with the ratchet 36, the second pawl block 52 is not engaged; as shown in FIG. 7, when the second pawl block 52 is engaged with the ratchet 36, the first pawl block 51 is not engaged.

Based on the above description, the following further describes the first pawl block 51 and the second pawl block 52 adjacent to one of the pawl pairs 50 as an example, and the remaining pawl pairs 50 can be deduced in the same way:

For example, the number of the ratchet teeth 36 of the ratchet ring 30 is 60 teeth, so the inter-tooth angle θ is equal to 6 degrees; secondly, the ratchet spacing between the first ratchet block 51 and the second ratchet block 52 of the ratchet pair 50 is half of the ratchet spacing R, that is, 1/2R.

When a portion of the pawl pairs 50 are engaged with the ratchet ring 30, for example, the first pawl block 51 is engaged with the ratchet 36, the adjacent second pawl block 52 is located at the 1/2R position, between the two ratchet teeth 36, and is not engaged with the ratchet teeth 36.

When the pawl pair 50 and the ratchet ring 30 are disengaged, for example, the first pawl block 51 is displaced in the reverse direction and falls between the two adjacent ratchets 36, that is, the first pawl block 51 is displaced in the reverse direction by a distance of 0 to R, and at this time, the second pawl block 52 will also be displaced in the reverse direction by a distance of 0 to R. In other words, the position of the second pawl block 52 originally located at 1/2R can be displaced to a maximum of 3/2R.

Please refer to Figure 8a. When the first pawl block 51 is displaced 1/4R in the reverse direction and has not yet formed a meshing state, it is spaced 1/4R from the front ratchet 36. At this time, the position of the second pawl block 52 changes to 3/4R and has not yet formed a meshing state, and is spaced 3/4R from the front ratchet 36. Therefore, the pawl pair 50 is displaced 1/4R forward, so that the first pawl block 51 can be meshed with the front ratchet 36.

Please refer to Figure 8b. When the first pawl block 51 is displaced 1/2R in the reverse direction and has not yet formed a meshing state, it is spaced 1/2R from the front ratchet 36. At this time, the position of the second pawl block 52 changes to R and has not yet formed a meshing state with the rear ratchet 36, so it is spaced R from the front ratchet 36. Therefore, the pawl pair 50 rotates forward 1/2R, so that the first pawl block 51 can be meshed with the front ratchet 36.

Please refer to Figure 8c. When the first pawl block 51 is displaced 3/4R in the reverse direction and has not yet formed an engagement state, it is spaced 3/4R from the front ratchet 36 at 0 degrees. At this time, the position of the second pawl block 52 changes to 5/4R and has not yet formed an engagement state with the ratchet 36 at the rear, so it is spaced 1/4R from the ratchet 36 at the rear. Therefore, the pawl pair 50 rotates forward 1/4R to make the position of the second pawl block 52 engage with the ratchet 36 at the rear.

Please refer to Figure 8d. When the first pawl block 51 is reversely displaced by R and has not yet formed an engagement state with the ratchet 36 at the rear, it is spaced R from the front ratchet 36; at this time, the position of the second pawl block 52 changes to 3/2R and has not yet formed an engagement state, so it is spaced 1/2R from the rear ratchet 36. Therefore, the pawl pair 50 rotates forward by 1/2R, so that the second pawl block 52 can be engaged with the rear ratchet 36.

According to the above description, it can be inferred that when the pawl pairs 50 are displaced from 0 to 1/4R in the reverse direction, the pawl pairs 50 are displaced forward by a maximum of 1/4R to enable the first pawl blocks 51 to engage the ratchet teeth 36; when the pawl pairs 50 are displaced from 1/4R to 1/2R in the reverse direction, the pawl pairs 50 are displaced forward by a maximum of 1/2R to enable the first pawl blocks 51 to engage the ratchet teeth 36; when the pawl pairs 50 are displaced from 1/2R to 3/4R in the reverse direction, the pawl pairs 50 are displaced forward by a maximum of 1/4R to enable the second pawl blocks 52 to engage the ratchet teeth 36; when the pawl pairs 50 are displaced from 3/4R to R in the reverse direction, the pawl pairs 50 are rotated forward by a maximum of 1/2R to enable the second pawl blocks 52 to engage the ratchet teeth 36. Therefore, the structural form disclosed in this example can indeed make the maximum forward displacement of the ratchet pair 50 to re-engage the ratchet ring 30 equal to 1/2R, which is less than the ratchet spacing R. It should be added that, since mathematically an angle less than a certain degree can be regarded as an arc, it can also be said that the maximum forward rotation angle of the ratchet pair 50 to re-engage the ratchet ring 30 is equal to half of the inter-tooth angle θ, that is, 3 degrees, which is less than 6 degrees of the inter-tooth angle θ.

As shown in FIG. 9 , the hub with long and short pawls provided by the second preferred embodiment of the present invention has a structure similar to that of the first preferred embodiment, but the present invention relatively offsets the angle between the pawl pair 50 and the two pawl pairs 50 adjacent to each other. That is, generally speaking, the pawl pairs 50 are adjacent to each other at equal distances (equal angles), and the angle between any two pawl pairs 50 should be 60 degrees; however, the present invention specifically deflects the entire pawl pair 50 and the entire two pawl pairs 50 adjacent to each other by an offset angle φ, so that the adjacent angle between any one pawl pair 50 and the two pawl pairs 50 adjacent to each other are different. For example, as shown in the figure, the offset angle φ is 1/4 θ, then one of the adjacent angles between any ratchet pair 50 and the two adjacent ratchet pairs 50 in front and behind is 60+1/4 θ, and the other is 60-1/4 θ.

According to the above description, in this embodiment, the tooth angle θ between two adjacent ratchets 36 can be defined; secondly, the length between the parallel first pawl block 51 and the second pawl block 52 is half of the ratchet spacing R; secondly, the offset angle φ is 1/4 θ, then one of the adjacent angles between any one of the pawl pairs 50 and the two adjacent pawl pairs 50 is 60+1/4 θ, and the other is 60-1/4 θ. Thus, the maximum forward rotation angle of a part of the pawl pairs 50 and the ratchet ring 30 from the non-engaged position to the re-engagement is 1/4 θ.

When part of the first pawl block 51 is engaged with the ratchet teeth 36, the other pawl blocks 51 and 52 are not engaged; when part of the second pawl block 52 is engaged with the ratchet teeth 36, the other pawl blocks 51 and 52 are not engaged.

For example, the number of the ratchet teeth 36 of the ratchet ring 30 is 60 teeth, so the inter-tooth angle θ is equal to 6 degrees; secondly, the length of the parallel first pawl block 51 greater than the second pawl block 52 is half of the ratchet distance R; secondly, the offset angle φ between the pawl pairs 50 is equal to 1.5 degrees, then one of the adjacent angles between each pawl pair 50 and the two adjacent pawl pairs 50 in front and back is 58.5 degrees, and the other is 61.5 degrees. Therefore, the maximum forward rotation angle of a part of the pawl pairs 50 and the ratchet ring 30 from the unengaged position to reengagement is 1.5 degrees, which is less than the inter-tooth angle of 6 degrees.

For example, the number of the ratchet teeth 36 of the ratchet ring 30 is 45, so the inter-tooth angle θ is equal to 8 degrees; secondly, the length of the parallel first pawl block 51 greater than the second pawl block 52 is half of the ratchet distance R; secondly, the offset angle φ between the pawl pairs 50 is equal to 2 degrees. Therefore, the maximum forward rotation angle of a part of the pawl pairs 50 and the ratchet ring 30 from the unengaged position to re-engagement is 2 degrees, which is less than 8 degrees of the inter-tooth angle. From the above example, it can be seen that no matter how much the inter-tooth angle is, its maximum forward rotation angle is less than the inter-tooth angle. Therefore, the present invention can effectively reduce the re-engagement rotation angle.

In summary, the hub with long and short pawls disclosed in the present invention utilizes the different lengths of the first pawl block 51 and the second pawl block 52 adjacent to each pawl pair 50 to form a staggered shape, and the adjacent angles between any pawl pair 50 and the two adjacent pawl pairs 50 are not equal, thereby enabling the pawl pairs 50 to re-engage the ratchet ring 30 at a smaller rotation angle with fewer components, thereby achieving a more sensitive driving effect.

The above embodiments are only for illustrative purposes to illustrate the technology and its effects of the present invention, and are not intended to limit the present invention. Anyone skilled in the art can modify and change the above embodiments without violating the technical principles and spirit of the present invention. Therefore, the scope of protection of the present invention shall be as described below in the scope of the patent application.

10:Hub

20: Body

22: Positioning slot

30: Thorn ring

32: Perforation

34: Positioning unit

36: Thorns

40:Driver

50: Pair of ratchet pawls

Claims (7)

A hub with long and short pawls, comprising a main body; a ratchet ring having a through hole in the axial direction, the inner surface of the through hole having a plurality of ratchets connected in series, and the ratchet ring is combined with the main body; a driving member having a seat at one end, and the seat extends into the through hole of the ratchet ring, wherein the hub has a plurality of pawl pairs arranged on the periphery of the seat of the driving member, each of the pawl pairs comprising a first pawl block and a second pawl block in parallel, and the length of the first pawl block is greater than that of the second pawl block. The length of the two pawl blocks; the main body can be driven to rotate by each of the first pawl blocks engaging the ratchet ring, or each of the second pawl blocks engaging the ratchet ring; wherein, there is a ratchet distance between any two adjacent ratchets of the ratchet ring; there is a ratchet distance between the first pawl block and the second pawl block of the same pawl pair; wherein the ratchet distance is smaller than the ratchet distance, so that the maximum forward displacement of the pawl pairs and the ratchet ring from the unengaged position to the reengagement is smaller than the ratchet distance. A hub with long and short pawls as described in claim 1, wherein the periphery of the seat has a plurality of accommodating grooves at equal intervals, and the accommodating groove has a first accommodating portion for arranging the first pawl block and the second pawl block of the pawl pair side by side; wherein the length of the first pawl block is greater than that of the second pawl block by half of the ratchet tooth spacing, so that the maximum forward displacement of the pawl pairs and the ratchet ring from a non-engaged position to re-engagement is half of the ratchet tooth spacing. The hub with long and short pawls as described in claim 1, wherein there is an inter-tooth angle between any two adjacent pawls of the pawl ring, the number of the pawls is N, so that the inter-tooth angle θ=360/N; and the length of the first pawl block of each pawl pair is greater than the length of the second pawl block, which is half of the distance between the pawls; and the number of the pawl pairs is six, and the angles between any pawl pair and the two adjacent pawl pairs in front and back are 60+1/4 θ, 60-1/4 θ; wherein part of the first pawl block is correspondingly engaged with the ratchets, or part of the second pawl block is correspondingly engaged with the ratchets, so that the driving member can drive the ratchet ring and the body; furthermore, the maximum forward rotation angle of the pawls and the ratchet ring from the unengaged position to the reengagement is 1/4 θ. For a hub with long and short pawls as described in claim 3, where the number of the pawls of the pawl ring is 60, the angle between the teeth is equal to 6 degrees; and the length of the first pawl block of each pawl pair is greater than the second pawl block by half of the distance between the pawls; and the angle between each pawl pair and the two adjacent pawl pairs in front and back is one 58.5 degrees and the other 61.5 degrees; whereby the maximum forward rotation angle of the pawl pairs and the pawls of the pawl ring from the unengaged position to the reengagement is 1.5 degrees. The hub with long and short pawls as described in claim 1 further includes a driving means for corresponding to the first pawl block and the second pawl block, so that the first pawl block and the second pawl block are driven in coordination to respectively lift up the ratchets leaning against the ratchet ring. As described in claim 5, the hub with long and short pawls, wherein the driving means includes an elastic component mounted on the periphery of the seat of the driving member, each of the elastic components having a first elastic portion and a second elastic portion, corresponding to the first pawl block and the second pawl block respectively, and elastically pushing against the corresponding first pawl block and the second pawl block. The hub with long and short pawls as described in claim 6, wherein the periphery of the seat has a plurality of receiving grooves, each of which has a second receiving portion, so that the elastic component is received in the second receiving portion.

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