+

WO1997018986A1 - Gear selection mechanism - Google Patents

Gear selection mechanism Download PDF

Info

Publication number
WO1997018986A1
WO1997018986A1 PCT/GB1996/002833 GB9602833W WO9718986A1 WO 1997018986 A1 WO1997018986 A1 WO 1997018986A1 GB 9602833 W GB9602833 W GB 9602833W WO 9718986 A1 WO9718986 A1 WO 9718986A1
Authority
WO
WIPO (PCT)
Prior art keywords
deraiileur
gear
gear selection
cam
cables
Prior art date
Application number
PCT/GB1996/002833
Other languages
French (fr)
Inventor
George Mcleod Stewart
Original Assignee
Borealis Engineering Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Borealis Engineering Limited filed Critical Borealis Engineering Limited
Publication of WO1997018986A1 publication Critical patent/WO1997018986A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62K—CYCLES; CYCLE FRAMES; CYCLE STEERING DEVICES; RIDER-OPERATED TERMINAL CONTROLS SPECIALLY ADAPTED FOR CYCLES; CYCLE AXLE SUSPENSIONS; CYCLE SIDE-CARS, FORECARS, OR THE LIKE
    • B62K23/00—Rider-operated controls specially adapted for cycles, i.e. means for initiating control operations, e.g. levers, grips
    • B62K23/02—Rider-operated controls specially adapted for cycles, i.e. means for initiating control operations, e.g. levers, grips hand actuated
    • B62K23/04—Twist grips
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62M—RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR SINGLE-TRACK CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES
    • B62M25/00—Actuators for gearing speed-change mechanisms specially adapted for cycles
    • B62M25/02—Actuators for gearing speed-change mechanisms specially adapted for cycles with mechanical transmitting systems, e.g. cables, levers
    • B62M25/04—Actuators for gearing speed-change mechanisms specially adapted for cycles with mechanical transmitting systems, e.g. cables, levers hand actuated
    • B62M25/045—Actuators for gearing speed-change mechanisms specially adapted for cycles with mechanical transmitting systems, e.g. cables, levers hand actuated having single actuating means operating both front and rear derailleur

Definitions

  • the invention relates to a gear selection mechanism, and in particular, a derattleur gear selection mechanism for a bicycle having front and rear derattleur mechanisms.
  • European Patent Application No 86305152.0 covers a system which operates the front and rear changers in conjunction.
  • the system uses a pre-selector & change lever.
  • a deraforementionedur gear selection mechanism for a bicycle having front and rear deraforementionedur mechanisms comprises an operating member and a gear selection device, the operating member being coupled to the gear selection device, and the gear selection device being adapted to receive two gear change cables, one gear change cable operating the front dera′′ur mechanism and the other gear change cable operating the rear derattleur mechanism, and operation of the operating member causes the gear selection device to operate the gear change cables to select a front and rear gear combination.
  • the operating member may comprise a rotable member which may be a grip mounted on handlebars of the bicycle.
  • the operating member may comprise a lever mounted on the bicycle, preferably the handlebars.
  • the gear selection device comprises a cam mechanism which is moved by the operating member to operate the cables.
  • the cam mechanism may comprise two cam tracks which are coupled to the cables to operate the cables.
  • the cables are coupled to the cam tracks by slides which are moved by movement of the cam mechanism.
  • the cam mechanism is rotated by rotation of the rotable member, and this causes linear movement of the slides which are typically non-rotable.
  • one cam track is adapted to operate the front derattleur and the other cam track is adapted to operate the rear derattleur.
  • the gear selection mechanism is adapted to prevent mismatching of front and rear gear combinations, such as a drive chain driving the largest gear at the front and the largest at the rear.
  • Figure 1 is a partial cross-sectional view through a gear selection mechanism mounted on a handlebar of a bicycle
  • Figure 2 is a schematic diagram showing possible gear combinations which may be selected by the gear selection mechanism shown in Figure 1
  • Figure 3 is a plan view of a cam mechanism in the gear selection mechanism of Figure 1
  • Figure 4 is a cross-sectional view on the line AA of Figure 1.
  • FIG. 1 shows two followers 13 (or sliders) which are each attached to a gear change cable 16 in an outer cable sheath 15.
  • the sliders 13 are mechanically programmed to move simultaneously on a double profiled cam machined into a cam barrel 14.
  • the double cam is operated by a single twist grip.
  • the proposed arrangement is shown in Figure 1.
  • the two sliders 13 are attached respectively to the handlebar ends of the front and rear derattleur mechanism gear change cables 16. These sliders 13 are engaged in cam machined into a single barrel 14 and are constrained to move axially only, by a slider track 12 (see also Figure 4).
  • the cam profile 17 operates the front derattleur mechanism, and the cam profile 18 operates the rear derattleur mechanism.
  • the track 12 is machined into a core member 28 which is fixed to the handlebar 10.
  • the sliders 13 are held to the programme profiles of the machined cams 17, 18 by the tension of return springs on the derattleur mechanisms themselves which act through the gear change cables 16.
  • the two sliders 13 (and therefore the front and rear linked derattleur mechanisms) are programmed by the machined cam profiles 17, 18 to move in conjunction in a fixed sequence.
  • the system will sequence gear changes using the front and rear derailleurs so that available gear combinations 1 to 7 are available, as shown in Figure 2.
  • Figure 2 shows a derattleur configuration of three front chain rings 19, 20, 21 and five rear wheel sprockets 22, 23, 24, 25, 26.
  • the cam profiles 17, 18 may be programmed for any front/rear combination or configuration and not only the combinations shown in Figure 2.
  • the change sequence may be modified by varying the cam profiles 17, 18. For a given cam set, the user will control over-all gearing only. The user will not be required (or enabled) to manage the front and rear chain positions independently of each other.
  • the barrel 14 incorporating the cam profiles 17, 18 is illustrated in Figure 3 for the 3 front/5 rear sprocket derattleur configuration shown in Figure 2.
  • This shows the cylindrical cam barrel 14 developed on to a flat surface, with the sliders 13 in gear position 3 shown in Figure 2 in which the chain is on the middle sized front chain ring 20 and the rear sprocket 23. If the barrel 14 is twisted to the left, relative to the sliders 13, gear 4 will be selected as the rear derabyteur moves the chain to the next highest sprocket. Twisting the cam barrel 14 to the right will change to gear 2 as the front derabyteur moves the chain to the lowest front chain ring 19.
  • Each gear position is indexed by a detente 27 machined into the cam profiles 17, 18. Alternatively indexing detentes may be machined into the slider track 12, or on the cam barrel 14 outwith the cam profiles 17, 18. This may provide some flexibility in the design of the cam profiles 17, 18.
  • cam profiles 17, 18 may be so profiled as to:-
  • Gear changing is achieved by one simple single handed action, without removing a hand from the bicycle handlebars .
  • the cyclist need not be concerned with the management of the front and rear chain positions, but only with over all gearing.
  • the gear management system is capable of tuning the front changer cage on the chain as it moves over the rear sprockets, (avoiding chain rasp on the front derattleur changer cage) and of providing an overchange facility if required.
  • the proposed system is simple and is capable of being mass produced.
  • the changer comes as a single unit for assembly on to a bicycle; subsequent set-up is simple and should be easily adapted for bicycle mass production.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Automatic Cycles, And Cycles In General (AREA)

Abstract

A derailleur gear selection mechanism for a bicycle having front and rear derailleur mechanisms. The mechanism has an operating member (11) and a gear selection device (14). The operating member (11) is coupled to the gear selection device (14) and the gear selection device is adapted to receive two gear change cables (16). One gear change cable operates the front derailleur mechanism and the other gear change cable operates the rear derailleur mechanism. Operation of the operating member (11) causes the gear selection device (14) to operate the gear change cables (16) to select a front and rear gear combination.

Description

"Gear Selection Mechanism"
The invention relates to a gear selection mechanism, and in particular, a deraiileur gear selection mechanism for a bicycle having front and rear deraiileur mechanisms.
International Patent Application No PCT/US90/07163 covers the use of profiled cams actuated by twist grips for gear changing. One twist grip is used for each of the front & rear changers. These operate independently.
European Patent Application No 86305152.0 covers a system which operates the front and rear changers in conjunction. The system uses a pre-selector & change lever.
International Patent Application No PCT/FR91/00256 delineates a gear management system also using a preselector & change lever separately.
These systems have the disadvantage that no system is designed to offer a single action gear changing for a completely managed system. The systems which are available, each require two actions; gear selection followed by the actual change. This involves moving at least one hand from the handlebars .
In addition the systems thus far disclosed are relatively complex mechanically, and require two separate assemblies to be attached to the bicycle and set up.
In accordance with the present invention/ a deraiileur gear selection mechanism for a bicycle having front and rear deraiileur mechanisms comprises an operating member and a gear selection device, the operating member being coupled to the gear selection device, and the gear selection device being adapted to receive two gear change cables, one gear change cable operating the front deraiileur mechanism and the other gear change cable operating the rear deraiileur mechanism, and operation of the operating member causes the gear selection device to operate the gear change cables to select a front and rear gear combination.
Preferably, the operating member may comprise a rotable member which may be a grip mounted on handlebars of the bicycle. Alternatively, the operating member may comprise a lever mounted on the bicycle, preferably the handlebars.
Preferably, the gear selection device comprises a cam mechanism which is moved by the operating member to operate the cables. Typically, the cam mechanism may comprise two cam tracks which are coupled to the cables to operate the cables.
Preferably, the cables are coupled to the cam tracks by slides which are moved by movement of the cam mechanism.
Typically, where the operating member is a rotable member, the cam mechanism is rotated by rotation of the rotable member, and this causes linear movement of the slides which are typically non-rotable.
Preferably, one cam track is adapted to operate the front deraiileur and the other cam track is adapted to operate the rear deraiileur.
Preferably, the gear selection mechanism is adapted to prevent mismatching of front and rear gear combinations, such as a drive chain driving the largest gear at the front and the largest at the rear.
An example of a gear selection mechanism in accordance with the invention will now be described with reference to the accompanying drawings, in which:-
Figure 1 is a partial cross-sectional view through a gear selection mechanism mounted on a handlebar of a bicycle; Figure 2 is a schematic diagram showing possible gear combinations which may be selected by the gear selection mechanism shown in Figure 1; Figure 3 is a plan view of a cam mechanism in the gear selection mechanism of Figure 1; and, Figure 4 is a cross-sectional view on the line AA of Figure 1.
The essence of the invention is the simultaneous control of both front and rear deraiileur gear mechanisms on a bicycle chain drive system, from a single actuator, such as a twist grip 11 (see Figure 1) . Figure 1 shows two followers 13 (or sliders) which are each attached to a gear change cable 16 in an outer cable sheath 15. The sliders 13 are mechanically programmed to move simultaneously on a double profiled cam machined into a cam barrel 14. The double cam is operated by a single twist grip. The proposed arrangement is shown in Figure 1.
The two sliders 13 are attached respectively to the handlebar ends of the front and rear deraiileur mechanism gear change cables 16. These sliders 13 are engaged in cam machined into a single barrel 14 and are constrained to move axially only, by a slider track 12 (see also Figure 4). The cam profile 17 operates the front deraiileur mechanism, and the cam profile 18 operates the rear deraiileur mechanism. The track 12 is machined into a core member 28 which is fixed to the handlebar 10. The sliders 13 are held to the programme profiles of the machined cams 17, 18 by the tension of return springs on the deraiileur mechanisms themselves which act through the gear change cables 16.
The two sliders 13 (and therefore the front and rear linked deraiileur mechanisms) are programmed by the machined cam profiles 17, 18 to move in conjunction in a fixed sequence.
The system will sequence gear changes using the front and rear derailleurs so that available gear combinations 1 to 7 are available, as shown in Figure 2. Figure 2 shows a deraiileur configuration of three front chain rings 19, 20, 21 and five rear wheel sprockets 22, 23, 24, 25, 26. However, the cam profiles 17, 18 may be programmed for any front/rear combination or configuration and not only the combinations shown in Figure 2. The change sequence may be modified by varying the cam profiles 17, 18. For a given cam set, the user will control over-all gearing only. The user will not be required (or enabled) to manage the front and rear chain positions independently of each other.
The barrel 14 incorporating the cam profiles 17, 18 is illustrated in Figure 3 for the 3 front/5 rear sprocket deraiileur configuration shown in Figure 2. This shows the cylindrical cam barrel 14 developed on to a flat surface, with the sliders 13 in gear position 3 shown in Figure 2 in which the chain is on the middle sized front chain ring 20 and the rear sprocket 23. If the barrel 14 is twisted to the left, relative to the sliders 13, gear 4 will be selected as the rear deraiileur moves the chain to the next highest sprocket. Twisting the cam barrel 14 to the right will change to gear 2 as the front deraiileur moves the chain to the lowest front chain ring 19. Each gear position is indexed by a detente 27 machined into the cam profiles 17, 18. Alternatively indexing detentes may be machined into the slider track 12, or on the cam barrel 14 outwith the cam profiles 17, 18. This may provide some flexibility in the design of the cam profiles 17, 18.
In addition to managing the gear changes, the cam profiles 17, 18 may be so profiled as to:-
1) Centre the front deraiileur on the chain as the rear changer moves the chain over the rear sprockets. 2) Allow "overchanging" during a gear change. 3) Provide limit stops at the top and bottom gear positions . The phantom lines numbered 1 to 7 in Figure 3 correspond to the gear combinations 1 to 7 shown in Figure 2. Hence, when the sliders 13 are in the position shown in Figure 3, gear combination number 3 in Figure 2 is selected.
Gear changing is achieved by one simple single handed action, without removing a hand from the bicycle handlebars .
The cyclist need not be concerned with the management of the front and rear chain positions, but only with over all gearing.
These are major advantages (even for experienced riders) in heavy traffic, or in demanding off-road conditions. It is also a major advantage for inexperienced riders, who are, by and large, not capable of managing deraiileur systems effectively.
By eliminating cross-chain combinations of front and rear sprockets, drive efficiency can be optimised over the range of gears. In addition chain wear can be minimised.
The gear management system is capable of tuning the front changer cage on the chain as it moves over the rear sprockets, (avoiding chain rasp on the front deraiileur changer cage) and of providing an overchange facility if required.
The proposed system is simple and is capable of being mass produced. The changer comes as a single unit for assembly on to a bicycle; subsequent set-up is simple and should be easily adapted for bicycle mass production.

Claims

Claims
1. A deraiileur gear selection mechanism for a bicycle having front and rear deraiileur mechanisms comprising an operating member and a gear selection device, the operating member being coupled to the gear selection device, and the gear selection device being adapted to receive two gear change cables, one gear change cable operating the front deraiileur mechanism and the other gear change cable operating the rear deraiileur mechanism, and operation of the operating member causes the gear selection device to operate the gear change cables to select a front and rear gear combination.
2. A deraiileur gear selection mechanism according to claim 1, wherein the operating member comprises a rotatable member.
3. A deraiileur gear selection mechanism according to claim 2, wherein the rotatable member comprises a grip mounted on a handlebar of the bicycle.
4. A deraiileur gear selection mechanism according to any of the preceding claims, wherein the gear selection device comprises a cam mechanism which is moved by the operating member to operate the cables.
5. A deraiileur gear selection mechanism according to claim 4, wherein the cam mechanism comprises two cam tracks which are coupled to the cables to operate the cables.
6. A deraiileur gear selection mechanism according to claim 5, wherein the cam tracks are coupled to the cables by slides which are moved by movement of the cam mechanism .
7. A deraiileur gear selection mechanism according to claim 6, whereby operation of the operating member causes a rotational movement of the cam mechanism which is translated by the cam tracks into linear movement of the slides.
8. A deraiileur gear selection mechanism according to any of claims 5 to 7, wherein one of the canii tracks operates the cable which operates the front deraiileur mechanism and the other cam track operates the cable which operates the rear deraiileur mechanism.
9. A deraiileur gear selection mechanism substantially as hereinbefore described, with reference to the accompanying drawings.
PCT/GB1996/002833 1995-11-17 1996-11-18 Gear selection mechanism WO1997018986A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9523587.5 1995-11-17
GBGB9523587.5A GB9523587D0 (en) 1995-11-17 1995-11-17 Bicycle derailleur gear management system

Publications (1)

Publication Number Publication Date
WO1997018986A1 true WO1997018986A1 (en) 1997-05-29

Family

ID=10784076

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1996/002833 WO1997018986A1 (en) 1995-11-17 1996-11-18 Gear selection mechanism

Country Status (2)

Country Link
GB (1) GB9523587D0 (en)
WO (1) WO1997018986A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004089736A1 (en) * 2003-04-10 2004-10-21 Ross Mitchell Gear shifting mecanism
WO2008071177A1 (en) * 2006-12-15 2008-06-19 Paul Rumpf Automatic gear-shifter for bicycle rear dérailleur gears
DE102011102788A1 (en) * 2011-05-28 2012-11-29 Joachim Trommlitz Operating device for gearbox of bicycle, has hub circuit in rear wheel hub, and chain circuit in rear wheel axle, where hub circuit and chain circuit are controlled from handlebar grip having two carriages with sliding blocks
DE102011102670A1 (en) * 2011-05-28 2012-11-29 Joachim Trommlitz Bicycle has chain assembly and gear box assembly that includes five gears which are evenly graded in such a way that only one assembly is actuated at a time

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4055093A (en) * 1976-06-18 1977-10-25 Amf Incorporated 10-Speed bicycles
US4201095A (en) * 1975-08-25 1980-05-06 Jack Myles Semi-automatic gearshift for dual derailleur bicycle
EP0647558A1 (en) * 1993-10-06 1995-04-12 Shimano Inc. Shifting apparatus for operating front and rear derailleurs with a single manual lever
EP0727348A1 (en) * 1995-02-15 1996-08-21 Franck Savard Method for synchronised management of a bicycle gear change and associated device
WO1996032316A1 (en) * 1995-04-11 1996-10-17 Garcia Prada Jose Manuel Integrated device for the switching of developments in bicycles

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4201095A (en) * 1975-08-25 1980-05-06 Jack Myles Semi-automatic gearshift for dual derailleur bicycle
US4055093A (en) * 1976-06-18 1977-10-25 Amf Incorporated 10-Speed bicycles
EP0647558A1 (en) * 1993-10-06 1995-04-12 Shimano Inc. Shifting apparatus for operating front and rear derailleurs with a single manual lever
EP0727348A1 (en) * 1995-02-15 1996-08-21 Franck Savard Method for synchronised management of a bicycle gear change and associated device
WO1996032316A1 (en) * 1995-04-11 1996-10-17 Garcia Prada Jose Manuel Integrated device for the switching of developments in bicycles

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004089736A1 (en) * 2003-04-10 2004-10-21 Ross Mitchell Gear shifting mecanism
US7204169B2 (en) 2003-04-10 2007-04-17 Ross Mitchell Gear shifting mechanism
CN100443366C (en) * 2003-04-10 2008-12-17 罗斯·米切尔 Speed change mechanism
WO2008071177A1 (en) * 2006-12-15 2008-06-19 Paul Rumpf Automatic gear-shifter for bicycle rear dérailleur gears
DE102011102788A1 (en) * 2011-05-28 2012-11-29 Joachim Trommlitz Operating device for gearbox of bicycle, has hub circuit in rear wheel hub, and chain circuit in rear wheel axle, where hub circuit and chain circuit are controlled from handlebar grip having two carriages with sliding blocks
DE102011102670A1 (en) * 2011-05-28 2012-11-29 Joachim Trommlitz Bicycle has chain assembly and gear box assembly that includes five gears which are evenly graded in such a way that only one assembly is actuated at a time

Also Published As

Publication number Publication date
GB9523587D0 (en) 1996-01-17

Similar Documents

Publication Publication Date Title
US4900291A (en) Bicycle gear shifting method and apparatus
EP1613527B1 (en) Gear shifting mecanism
US4938733A (en) Bicycle gear shifting method and apparatus
US5970816A (en) Method for selecting gears for a cycle with adequate chain alignment and associated selection device
EP1911667B1 (en) Bicycle shifting control apparatus
CN100387484C (en) Bicycle shift operating device for bicycle transmission
US3919891A (en) Electrical gear changer for chain driven vehicle
DE602006000756T2 (en) Bicycle gear change device
US20060058134A1 (en) Gearshift control apparatus for a bicycle and a bicycle equipped with such apparatus
CA1116498A (en) Single lever 10 speed bicycle shifter
JPH05338581A (en) Gear shifting device for cycle having chain and pinion transmission
CN102464086A (en) Position control mechanism
EP1134157B1 (en) Force transfer unit with gear position indicator
WO1996027092A1 (en) Multi-speed transmission
DE69824816T2 (en) Bike circuit
WO1984002562A1 (en) Automatic variable speed transmission
US4740190A (en) Variable ratio bicycle chain drive
US20090124440A1 (en) Gear changing mechanism for chain drive
WO1997018986A1 (en) Gear selection mechanism
US5865062A (en) Method and device for speed control of a bicycle
EP0794114A2 (en) Shifting apparatus
EP0394355B1 (en) Gear shifting apparatus for bicycles
DE4005102A1 (en) Bicycle change-speed selector lever - actuates both front and rear changeover devices using CAM mechanism
DE19609723A1 (en) Single-lever gearchange control for bicycle
CN109305284B (en) Actuating device for actuating a front derailleur of a bicycle

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CN GB JP US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载