Patent Application
20110132123
1. Field of the Invention
The present invention relates to a speed control device for a derailleur type bicycle and, in particular, to a speed control device including an operation lever that a user can pivot in a first direction to pull a cable that controls the derailleur and a second direction to release the cable.
2. Description of the Related Art
U.S. Pat. Nos. 5,213,005, 5,361,645, 5,479,776 and 6,220,111 disclose a speed control device including one operation lever that user can use to up-shift the speed and another operation lever to down-shift the speed. However, such speed control device has the disadvantage that the operator could easily operate the wrong lever in a speed change operation.
U.S. Pat. No. 5,287,766 shows a speed control device which utilizes an operation lever for up-shifting and down-shifting the speed. The speed control device is particularly mounted on a straight handlebar type bicycles. In spite of the advantage of speed control device employing one operation lever as discussed in the proceeding, it is believed that there is a need for improvement in the field of speed control device and more specifically in the curved handlebar type bicycles.
The present invention is, therefore, intended to obviate or at least alleviate the problems encountered in the prior art.
According to the present invention, a speed control device, which is adapted to be used in connection with a derailleur type bicycle and has one operation mode for winding the cable that controls the derailleur and another operation mode for releasing the cable, includes a control assembly including a first toothed member and a second toothed member borne on a connecting shaft. The first and second toothed members are rotatable together in first and second directions. The control assembly further includes an operation mechanism which includes a user-input being pivoted in a first plane to cause the first and second toothed members rotate in the first direction for winding the cable, and in a second plane to cause the first and second toothed members rotate in the second direction for releasing the cable.
Other objects, advantages, and new features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanied drawings
Referring to the drawings, a speed control device in accordance with the present invention is adapted to be used in connection with a derailleur type bicycle. The speed control device includes a housing 1 defining a first end 101 and a second end 102 opposite to the first end 101, and one of the first 101 and second 102 ends is adapted to connect to the bicycle. The housing 1 includes an opening 11 in which a control assembly 2 and a brake assembly 3 are pivotally received. The control assembly 2 is retained in the opening 11 via a plurality of fasteners 13, and the fasteners 13 are inserted through a plurality of apertures 12 in the housing 11 and engage in a plurality of apertures 211 in a fixing member 21 of the control assembly 2. The control assembly 2 includes first engaging mechanism 20 and second engaging mechanism 30 connected to the fixing member 21.
The first engaging mechanism 20 includes a pivot 23 mounted to the fixing member 21, and the fixing member 21 includes a through hole 213 receiving an end of the pivot 23. The first engaging mechanism 20 also includes a first pawl 24 inserted by and moveably mounted between proximal 231 and distal 232 ends of the pivot 23 such that the first pawl 24 is pivotal in a plane transverse to a longitudinal length of the shaft 23, i.e. the length extending from the proximal 231 to the distal 232 ends of the pivot 23. The first pawl 24 is biased by an elastic element 25. Preferably, the elastic element 25 is a torque spring and includes a plurality of coaxially disposed coiled sections inserted by the pivot 23 and a first leg 251 extending therefrom and connecting to the first pawl 24, and a second leg 252 extending therefrom and connecting to the fixing member 21. Additionally, the coiled sections have radial distances being equal to one another.
The second engaging mechanism 30 includes a connecting shaft 31 inserting through a compartment 212 which extends through the fixing member 21 and is parallel to the through hole 213. The connecting shaft 31 is supported by a bearing 22. The bearing 22 is disposed in the compartment 212 and surrounds a first engaging peripheral section 313 of the connecting shaft 31. The engaging peripheral section 313 preferably has a circular cross-section. The connecting shaft 31 bears a first toothed member 32 and a second toothed member 33 on opposite sides of the fixing member 21, respectively. Additionally, the connecting shaft 31 includes a plurality of second engaging peripheral sections 314 on which the first 32 and second 33 toothed members are mounted. Each second engaging peripheral section 314 has a non-circular cross section. Likewise, the first toothed member 32 includes a hole 321 and the second member 33 includes a hole 331, respectively, and the holes 321 and 331, which are inserted by the connecting shaft 31, have shapes conforming to the second engaging peripheral sections 314 where the first 32 and second 33 toothed members are mounted. Therefore, the first 31 and second 32 toothed members are connected rigidly and prevented from rotation with respect to a longitudinal axis of the connecting shaft 31.
The first toothed member 32 includes a toothed section 322 formed on its outer periphery and including a plurality of teeth, in which two adjacent teeth have an interconnecting edge 3222 extending in one direction and in which each tooth has a ridge 3221 extending in another direction parallel to the one direction. The second toothed member 33 includes a toothed section 332 formed on its outer periphery and including a first plurality of teeth 3321 disposed in a plane and a second plurality of teeth 3322 disposed in another plane, which may be parallel to the plane of the first plurality of teeth 3321. Additionally, two adjacent teeth of the first plurality of teeth 3321 have an interconnecting edge 33212 extending in one direction and each tooth has a ridge 33211 extending in another direction, which has an angled relationship with respect to the direction of the interconnecting edge 33212. Furthermore, two adjacent teeth of the second plurality of teeth 3322 have an interconnecting edge 33222 extending in one direction and each tooth has a ridge 33221 extending in another direction, which is parallel to the direction of the interconnecting edge 33222. Further, the second plurality of teeth 3322 are disposed adjacent to the first pawl 24, and the first pawl 24 is engagable with the interconnecting edge 33222 between any two adjacent teeth. Particularly, when the elastic element 25 is in a “rest” position, the first pawl 24 is engaged in one of the interconnecting edges 33222 by the elastic element 25. Further, the first pawl 24 includes an engaging section 241 protruding in a plane which may cross the longitudinal length of the pivot 23 and being selectively receivable between two adjacent teeth of the second plurality of teeth 3322. Moreover, the second toothed member 33 is ensured to have a proper distance from the fixing member 21 by a spacer 315. The spacer 315 is disposed in the compartment 212 and surrounds the first engaging peripheral section 313 of the connecting shaft 31.
The connecting shaft 31 also includes a first stop 311 disposed on a proximal end thereof and a second stop 312 disposed on a distal end 317 thereof, respectively. The first stop 311 includes two opposing sides and a plurality of orifices 3111 extending from one side and toward the other side. The connecting shaft 31 further bears a first elastic member 34 which includes a proximal end 341 hooking to a resist edge 14 formed in the housing 1 and a distal end 342 engaging in one of the plurality of orifices 3111. So, if the connecting shaft 31 is rotated in a first direction such that the first elastic member 34 is tensioned, releasing the first elastic member 34 from tension would cause the connecting shaft 31 to rotate in a second direction, which is opposite to the first direction. Moreover, the connecting shaft 31 bears a spacer 316 which includes a limiting face 3161 and a tube 3162 inserted by the connecting shaft 31, and a cable-receiving member 35 which includes a hole 351 inserted by the connecting shaft 31 and being adapted to receive a shifting cable that is adapted to cause speed change upon operation of the speed control device. Additionally, the cable-receiving member 35 includes a retaining section 352 on which an end of the shifting cable is secured, and a groove 353 formed on its outer periphery and provided for preventing a length of the shifting cable which is engaged with outer periphery of the cable-receiving member 35 from dislodging therefrom.
In addition, the first stop 311 is provided for containing the first elastic member 34 in the connecting shaft 31.
The control assembly 2 further includes an operation mechanism 40 connected to the second engaging mechanism 30. The operation mechanism 40 includes a connecting member 41 being pivotal with respect to the connecting shaft 31 and in a plane which crosses the longitudinal length of the connecting shaft 31. The connecting shaft 31 bears a second elastic member 36 which includes a proximal end 361 hooking to another resist edge 14 formed in the housing 1 and a distal end 342 hooking to the connecting member 41. The connecting member 41 includes two opposing sides spaced from each other, and one of the sides includes a plurality of orifices 415 that allow the distal end 342 of the second elastic member 36 to engage in one orifice 415. So, if the connecting member 41 is rotated in a first direction such that the second elastic member 36 is tensioned, releasing the second elastic member 36 from tension would cause the connecting member 41 to rotate in a second direction, which is opposite to the first direction. Additionally, one of the sides of the connecting member 41 includes a limit section 416 which is adapted to abut the housing 1 such that the connecting member 41 is adapted to be pivoted to an extent until it is stopped by the housing 1. In the embodiment, the limit section 416 includes a first portion 4161 extending in a plane of the side and a second portion 4162 extending from the first portion and in a plane which substantially crosses the plane of the first portion 4161. With the second portion 4162, the limit section 416 would have a substantial area to abut against the housing 1.
Further, the connecting member 41 defines a gap between the opposing sides and in which the first toothed member 32 is adapted to be received, and includes a hole 411 extending through the sides and inserted by the connecting shaft 31. Additionally, the gap may receive a bushing 413 and a spacer 414. The operation mechanism 40 further includes a catching member 43 which is moveably connected to the connecting member 41 by a pivot 42, and the pivot 42 extends through an aperture 412 which extends through the sides of the connecting member 41 and a first side of the catching member 43. Thus, the catching member 43 is pivotal in a plane which crosses a longitudinal length of the axle 42. Additionally, the catching member 43 is biased by an elastic element 432. The elastic element 432 is a torque spring and includes a first leg 4321 abutting against the catching member 43 and a second leg 4322 abutting against the spacer 414. Particularly, when the elastic element 432 is in a “rest” position, the elastic element 432 keeps the catching member 43 away from the first toothed member 32. Moreover, the catching member 43 includes a catching section 431 which is formed on its first side and is selectively engagable with the toothed section 322 of the first toothed member 32.
The operation mechanism 40 further includes a second pawl 44 which is moveably connected to the connecting member 41 by an axle 443, and an operation lever 45 which is moveably connected to the connecting member 41 through the catching member 43. The axle 443 extends through two second sides of the catching member 43 which extends from the first side and are disposed oppositely, and a hole 445 of the second pawl 44 which extends in its longitudinal length. The operation lever 45 includes two lugs 451 formed on an end thereof and are spaced from each other oppositely. The second pawl 44 and the operation lever 45 are pivotal in a plane which crosses a longitudinal length of the axle 443. In addition, the second pawl 44 includes a first engaging section 441 and a second engaging section 442 which protrude radially outwardly from an outer periphery thereof, and the first 441 and second 442 engaging sections extend in two different directions. Moreover, the second pawl 44 and the operation lever 45 are biased by elastic elements 444 and 453, respectively. The elastic element 444 is disposed between the operation lever 45 and the second pawl 44, and the elastic element 453 is disposed between the operation lever 45 and the catching member 43. Preferably, the elastic elements 444 and 453 are torque springs, and the elastic element 444 includes a first leg 4441 abutted against the first engaging section 441 of the second pawl 44 and a second leg 4442 abutted against a stop wall 452 of the operation lever 45 which extends between the lugs 451, and the elastic element 453 includes a first leg 4531 abutted against the catching member 43 and a second leg 4532 abutted against the stop wall 452 of the operation lever 45.
Additionally, the first engaging section 441 of the second pawl 44 is adapted to selectively engage with the first plurality of teeth 3321 of the toothed section 332 formed on the second toothed member 33.
Further, the first pawl 24 includes a protrusion which includes a first surface 242 being selectively depressible by the second engaging section 442 of the second pawl 44 to cause the engaging section 241 of the first pawl 24 disengage from the second plurality of teeth 3322 of the second toothed member 33.
The speed control device has two operation modes. In one operation mode, i.e. the cable-winding operation as shown in
In another operation mode, i.e. the cable-releasing operation, as shown in
When the operation lever 45 is released to return to the initial position where the operation lever 45 is positioned before commencing this cable-releasing operation, the second pawl 44 is pivoted in another direction, and the second engaging section 442 of the second pawl 44 is disengaged from the first surface 242 of the protrusion of the first pawl 24, and as the second engaging section 442 of the second pawl 44 is disengaged from the first surface 242 of the protrusion of the first pawl 24 the first engaging section 441 of the second pawl 44 is disengaged from the first plurality of teeth 3321 of the toothed section 332 formed on the second toothed member 33 the second toothed member 33, and the first pawl 24 is engaged with the second plurality of teeth 3322 of the toothed section 332 formed on the second toothed member 33 afterwards.
In addition, it is an aspect of the present invention that the operation lever 45 will not cause a speed change despite it is depressed by the brake assembly 3, as shown in
Further, it is another aspect of the present invention that the axle 443 is pivoted from a first position through an angle to a second position despite that the second pawl 44 is restrained by the shift lock 52. Accordingly, the axle 443 has two opposing straight sides, and the hole 445 of the second pawl 45 has a cross section in a shape of a “8”, and the axle 443 has upper right and lower left sections (as shown in
While the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of invention, and the scope of invention is only limited by the scope of the accompanying claims.
