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WO1980002129A1 - Sprocket wheel assembly for a chain transmission in particular adapted to bicycles - Google Patents

Sprocket wheel assembly for a chain transmission in particular adapted to bicycles Download PDF

Info

Publication number
WO1980002129A1
WO1980002129A1 PCT/NL1980/000013 NL8000013W WO8002129A1 WO 1980002129 A1 WO1980002129 A1 WO 1980002129A1 NL 8000013 W NL8000013 W NL 8000013W WO 8002129 A1 WO8002129 A1 WO 8002129A1
Authority
WO
WIPO (PCT)
Prior art keywords
sprocket
wheel
spring
wheel assembly
engaging means
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/NL1980/000013
Other languages
French (fr)
Inventor
G Chappell
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
HAAGSCHE SMEDERIJ CONSTRUCTIEWERK PLAATSEN BV
HAAGSCHE SMEDERIJ CONSTRUCTIEW
Original Assignee
HAAGSCHE SMEDERIJ CONSTRUCTIEWERK PLAATSEN BV
HAAGSCHE SMEDERIJ CONSTRUCTIEW
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 HAAGSCHE SMEDERIJ CONSTRUCTIEWERK PLAATSEN BV, HAAGSCHE SMEDERIJ CONSTRUCTIEW filed Critical HAAGSCHE SMEDERIJ CONSTRUCTIEWERK PLAATSEN BV
Priority to DE19803041439 priority Critical patent/DE3041439A1/en
Publication of WO1980002129A1 publication Critical patent/WO1980002129A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B62LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62MRIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR SINGLE-TRACK CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES
    • B62M9/00Transmissions characterised by use of an endless chain, belt, or the like
    • B62M9/04Transmissions characterised by use of an endless chain, belt, or the like of changeable ratio
    • B62M9/06Transmissions characterised by use of an endless chain, belt, or the like of changeable ratio using a single chain, belt, or the like
    • B62M9/08Transmissions characterised by use of an endless chain, belt, or the like of changeable ratio using a single chain, belt, or the like involving eccentrically- mounted or elliptically-shaped driving or driven wheel; with expansible driving or driven wheel

Definitions

  • Sprocket wheel assembly for a chain transmission in particular adapted to bicycles.
  • the invention relates to a sprocket wheel assembly for a chain transmission in particular adapted to bicycles, comprising a plurality of chain engating means mounted in angulary spaced apart relation and for a radial displacement on a wheel, springmeans being provided for biasing simultaneously said chain engaging means outwardly, while at least two diametrically opposed chain engaging means are formed by a sprocket pinion mounted for rotation but means being provided for blocking said rotation in at least one rotational direction.
  • the drive ratio is automatically varied in response to changes in input torque or effort exerted on the sprocket wheel in particular by the cyclist through a pedal assembly, in that the effective diameter of the sprocket wheel assembly is determined by the radial position of the chain engaging means, which positions are changed by the radial displacements of the chain engaging means in response to the changes in the input torque, so that in increasing the torque the effective diameter of the sprocket wheel assembly is decreased and vise versa.
  • each chain engaging means is formed by a sprocket pinion while a one-way clutch is provided which locks the sprocket pinion against rotation in the direction opposite to which the torque has to be transmitted to the chain.
  • Another disadvantage of the known sprocket wheel assembly is that as each successive sprocket pinion is initially brought into contact with the chain, itr rotational position has to be adjusted relative to the sprocket pinion then already in engagement with the chain so as to take into account the pitch of the chain.
  • the object of the invention is to provide a sprocket wheel assembly of the type as mentioned hereinabove which does not show the drawback of the known assembly.
  • This is achieved in that in the sprocket wheel assembly according to the invention the two diametrically opposed sprocket pinions are co- axially connected with a toothed wheel for a joint rotation and radial displacement, each toothed wheel being in engagement with a radialy extending rack fixedly mounted to said wheel, so that in displacing radially of said two toothed wheels the sprocket pinions are rotated in opposite rotational directions and that the remaining chain engaging means are mounted for a free rotation.
  • each sprocket pinion will have the correct rotational position for engaging the chain when it is initially brought into contact with the chain, as said rotational position is determined by the position of its associated toothed wheel with respect to the rack.
  • the remaining chain engaging means are formed by rollers.
  • the changes in distances between the chain engaging means are smoothly accomodated, only four chain engaging means will suffice, so that a very simple overall construction of the sprocket wheel assembly can be provided in that the chain engaging means are slidably mounted in radial slots formed in said wheel; and a substantially disk-shaped control means is provided, which is mounted in co-axial relation with and for rotation with respect to the wheel while said control disk and said wheel are coupled to each other by means of a spring so that an angular displacement of the control disk relative to the wheel against the spring bias is permitted, while according to the invention each chain engaging means is pivotally connected to the one end of a link which at its other end is pivotally connected to said control disk.
  • the spring is mounted in a tubular member connected to said control disk, a string being provided which connects the one end of said spring with said wheel, while said tubular member may be one of the two pedal arms of a bicycle chain drive.
  • the other end of the spring may be connected with a knob or similar means mounted on the free end of said tubular member so that on rotation of said knob said spring is expanded or retracted.
  • the sprocket wheel assembly comprises a wheel disk (1) having spokes (2) and mounted for rotation on shaft (3).
  • spokes (2) slits (4) are formed in which are slidably mounted rollers (5) which are free to. rotate.
  • sprocket pinions (6) which are co-axially connected for joint rotation with toothed wheels.
  • toothed wheels are in engagement with a rack formed by the bosses (8) projecting from the spokes (2' ).
  • rollers (5) are pivotally connected to the one end of links (9) which are connected at their other ends to control disk (10) in the shape of a cross and mounted on shaft (3).
  • the sprocket pinions (6) are also connected through the pivot links (9') to control disk (10).
  • a tubular member (11) is fixedly connected with control disk (10), in which tubular member a spring (12) is mounted. At its one end spring (12) is press fitted on a block member (13) and at its other end on block member (14).
  • Block member (13) is connected with the wheel disk (1) by means of a string (15) attached at (16) to spoke (2) and passed along roller (17) mounted for free rotation inside the tubular member (11).
  • tubular member (11) On the upper end of tubular member (11) a knob (18) is rotatebly provided said knob (18) is connected with screw member (19) which is screwed in block member (14).
  • the tubular member (11) forms also one of the pedal arms of a bicycle chain drive, the pedal being indicated by reference number 20; the other pedal arm and its associated pedal are shown by 21 and 22 respectively.
  • sprocket pinions 6 and one of the rollers 5 extends the chain (23).

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Transmissions By Endless Flexible Members (AREA)
  • Gears, Cams (AREA)

Abstract

An improved sprocket wheel assembly for a chain transmission in particular adapted to bicycles, comprising a plurality of chain engaging means (5, 6) mounted in angularly spaced apart relation and for a radial displacement on a wheel (1), spring means (12) being provided for biasing simultaneously said chain engaging means outwardly, while at least two diametrically opposed chain engaging means are formed by a sprocket pinion (6) mounted for rotation but means being provided for blocking said rotation in at least one rotational direction, the improvement comprising two diametrically opposed sprocket pinions (6) coaxially connected with a toothed wheel (7) for a joint rotation, and radial displacement, each toothed wheel (7) being in engagement with a radially extending rack (8) fixedly mounted to said wheel (1), so that in displacing radially of said two toothed wheels the sprocket pinions are rotated in opposite rotational directions.

Description

Sprocket wheel assembly for a chain transmission in particular adapted to bicycles.
The invention relates to a sprocket wheel assembly for a chain transmission in particular adapted to bicycles, comprising a plurality of chain engating means mounted in angulary spaced apart relation and for a radial displacement on a wheel, springmeans being provided for biasing simultaneously said chain engaging means outwardly, while at least two diametrically opposed chain engaging means are formed by a sprocket pinion mounted for rotation but means being provided for blocking said rotation in at least one rotational direction.
Such sprocket wheel assembly is known from US Patent Specification 3.995.508.
In such sprocket wheel assembly the drive ratio is automatically varied in response to changes in input torque or effort exerted on the sprocket wheel in particular by the cyclist through a pedal assembly, in that the effective diameter of the sprocket wheel assembly is determined by the radial position of the chain engaging means, which positions are changed by the radial displacements of the chain engaging means in response to the changes in the input torque, so that in increasing the torque the effective diameter of the sprocket wheel assembly is decreased and vise versa. In the known sprocket wheel assembly each chain engaging means is formed by a sprocket pinion while a one-way clutch is provided which locks the sprocket pinion against rotation in the direction opposite to which the torque has to be transmitted to the chain.
By means of the one-way clutch, rotation in the other direction is permitted to the sprocket pinions in order to accomodate changes in the distances between the sprocket pinions at chain engaging locations along the chain which distances vary with changes in the effective wheel diameter.
However these changes in said distances between the sprocket pinions or the changes in chain length between the sprocket pinions at chain engaging locations cannot be accomodated smoothly when these distances or chain lengths increase in displacing outwardly of the sprocket pinions or increasing of the effective diameter of the wheel assembly. This is a serious drawback of this known sprocket wheel assembly.
Another disadvantage of the known sprocket wheel assembly is that as each successive sprocket pinion is initially brought into contact with the chain, itr rotational position has to be adjusted relative to the sprocket pinion then already in engagement with the chain so as to take into account the pitch of the chain.
The object of the invention is to provide a sprocket wheel assembly of the type as mentioned hereinabove which does not show the drawback of the known assembly. This is achieved in that in the sprocket wheel assembly according to the invention the two diametrically opposed sprocket pinions are co- axially connected with a toothed wheel for a joint rotation and radial displacement, each toothed wheel being in engagement with a radialy extending rack fixedly mounted to said wheel, so that in displacing radially of said two toothed wheels the sprocket pinions are rotated in opposite rotational directions and that the remaining chain engaging means are mounted for a free rotation.
By the invention the changes in the distances between the chain engaging means are smoothly accomodated by the fact that in radially contracting or expanding of the sprocket pinions the toothed wheels associated therewith are simultaneously rotated in the correct rotational direction and with the appropriate rotational speed by their movements along the respective racks. Moreover each sprocket pinion will have the correct rotational position for engaging the chain when it is initially brought into contact with the chain, as said rotational position is determined by the position of its associated toothed wheel with respect to the rack.
Preferably the remaining chain engaging means are formed by rollers. As in the sprocket wheel assembly according to the invention the changes in distances between the chain engaging means are smoothly accomodated, only four chain engaging means will suffice, so that a very simple overall construction of the sprocket wheel assembly can be provided in that the chain engaging means are slidably mounted in radial slots formed in said wheel; and a substantially disk-shaped control means is provided, which is mounted in co-axial relation with and for rotation with respect to the wheel while said control disk and said wheel are coupled to each other by means of a spring so that an angular displacement of the control disk relative to the wheel against the spring bias is permitted, while according to the invention each chain engaging means is pivotally connected to the one end of a link which at its other end is pivotally connected to said control disk.
Advantageously the spring is mounted in a tubular member connected to said control disk, a string being provided which connects the one end of said spring with said wheel, while said tubular member may be one of the two pedal arms of a bicycle chain drive. When it is desired to have the tension in the spring adjustable the other end of the spring may be connected with a knob or similar means mounted on the free end of said tubular member so that on rotation of said knob said spring is expanded or retracted.
The invention will now be explained in more detail while referring to the drawing in which a sprocket wheel assembly is shown in front elevation, a portion being shown in section.
As shown in the drawing the sprocket wheel assembly comprises a wheel disk (1) having spokes (2) and mounted for rotation on shaft (3). In two oppositely extending spokes (2) slits (4) are formed in which are slidably mounted rollers (5) which are free to. rotate. In the other two oppositely extending spokes (2) slits (5) are formed in which are slidably mounted sprocket pinions (6) which are co-axially connected for joint rotation with toothed wheels. (7), which toothed wheels are in engagement with a rack formed by the bosses (8) projecting from the spokes (2' ).
The rollers (5) are pivotally connected to the one end of links (9) which are connected at their other ends to control disk (10) in the shape of a cross and mounted on shaft (3). The sprocket pinions (6) are also connected through the pivot links (9') to control disk (10). A tubular member (11) is fixedly connected with control disk (10), in which tubular member a spring (12) is mounted. At its one end spring (12) is press fitted on a block member (13) and at its other end on block member (14). Block member (13) is connected with the wheel disk (1) by means of a string (15) attached at (16) to spoke (2) and passed along roller (17) mounted for free rotation inside the tubular member (11). On the upper end of tubular member (11) a knob (18) is rotatebly provided said knob (18) is connected with screw member (19) which is screwed in block member (14). As shown the tubular member (11) forms also one of the pedal arms of a bicycle chain drive, the pedal being indicated by reference number 20; the other pedal arm and its associated pedal are shown by 21 and 22 respectively. Around sprocket pinions 6 and one of the rollers 5 extends the chain (23).

Claims

Claims
1. A sprocket wheel assembly for a chain transmission in particular adapted to bicycles, comprising a plurality of chain engaging means mounted in angulary spaced apart relation and for a radial displacement on a wheel, spring means being provided for biasing simultaneously said chain engaging means outwardly, while at least two diametrically opposed chain engaging means are formed by a sprocket pinion mounted for rotation but means being provided for blocking said rotation in at least one rotational direction, c h a r a c t e r i z e d in that said two diametrically opposed sprocket pinions are co-axially connected with a toothed wheel for a joint rotation, and radial displacement, each toothed wheel being in engagement with a radially extending rack fixedly mounted to said wheel, so that in displacing radially of said two toothed wheels the sprocket pinions are rotated in opposite rotational directions.
2. Sprocket wheel assembly according to claim 1, c h a r a c t e r i z e d in that the diameter of each toothed wheel is smaller than the diameter of the associated sprocket pinion.
3. Sprocket wheel assembly according to claims 1 or 2, c h a r a c t e r i z e d in that the remaining chain engaging means are formed by rollers.
4. Sprocket wheel assembly according to claims 1-3, in which the chain engaging means are sildably mounted in radial slots formed in said wheel, and a substantially disk-shaped control means is provided which is mounted in co-axial relation with and for rotation with respect to the wheel while said control disk and said wheel are coupled to each other by means of a spring so that an angular displacement of the control disk relative to the wheel against the spring bias is permitted, c h a r a c t e r i z e d in that each chain engaging means is pivotally connected to the one end of a link which at its other end is pivotally connected to said control disk.
5. Sprocket wheel assembly according to claim 4, c h a r a c t e r iz e d in that said spring is mounted in a tubular member connected to said control disk, a string being provided which connect the one end of said spring with said wheel.
6. Sprocket wheel assembly according to claim 5, c h a r a c t e r i z e d in that said tubular member is one of the two pedel arms of a bicycle chain drive.
7. Sprocket wheel assembly according to claims 5 or 6 in which the tension of the spring is adjustable c h a r a c t e r i z e d in that the other end of the spring is connected with a knob or similar means mounted on the free end of said tubular member so that on rotation of said knob said spring is expanded or retracted.
PCT/NL1980/000013 1979-04-10 1980-04-10 Sprocket wheel assembly for a chain transmission in particular adapted to bicycles Ceased WO1980002129A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE19803041439 DE3041439A1 (en) 1979-04-10 1980-04-10 SPROCKET WHEEL ASSEMBLY FOR A CHAIN TRANSMISSION IN PARTICULAR ADAPTED TO BICYCLES

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NL7902814A NL7902814A (en) 1979-04-10 1979-04-10 CHAINWHEEL ASSEMBLY FOR A CHAIN TRANSMISSION, IN PARTICULAR FOR A BICYCLE.
NL7902814 1979-04-10

Publications (1)

Publication Number Publication Date
WO1980002129A1 true WO1980002129A1 (en) 1980-10-16

Family

ID=19832958

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/NL1980/000013 Ceased WO1980002129A1 (en) 1979-04-10 1980-04-10 Sprocket wheel assembly for a chain transmission in particular adapted to bicycles

Country Status (2)

Country Link
NL (1) NL7902814A (en)
WO (1) WO1980002129A1 (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1983002925A1 (en) * 1982-02-18 1983-09-01 Chappell, Gilmore, H. Automatic transmission
EP0112112A1 (en) * 1982-12-14 1984-06-27 Michel Deal Variable ratio transmission
WO1984002690A1 (en) * 1983-01-10 1984-07-19 Shiber Samuel Incrementally variable transmission
EP0116731A1 (en) * 1983-02-09 1984-08-29 FULLERTON, Robert L. Automatic transmission having a continuously variable drive ratio
GB2355771A (en) * 1999-10-28 2001-05-02 Richard John Kilduff A bicycle with infinitely variable transmission
WO2002047965A2 (en) 2000-12-12 2002-06-20 Graeme Stafford Murray Drive transmission apparatus
CN100402369C (en) * 2003-02-26 2008-07-16 余蜀翔 Automatic continuously variable speed chain disc device
DE102014002779A1 (en) * 2014-02-24 2015-08-27 Alexander Degtjarew The chain transmission for the vehicle with the smooth change of the transmission ratio, which depends on the load.
DE102014003749A1 (en) * 2014-03-12 2015-09-17 Alexander Degtjarew Chain transmission for the vehicle with the changed transmission ratio that depends on the load
RU2603292C2 (en) * 2014-03-09 2016-11-27 Александр Васильевич Дегтярев Vehicle chain transmission with variable gear ratio depending on load
DE102016008839B3 (en) * 2016-07-19 2018-01-25 André Röhl Stepless mechanical gear device with torque-dependent change of the transmission ratio for positive power transmission.
DE102018008221B3 (en) * 2018-10-17 2020-02-06 André Röhl Automatic mechanical transmission device with variable transmission range for positive power transmission

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR961243A (en) * 1950-05-09
US3850044A (en) * 1973-05-10 1974-11-26 D Hagen Bicycle transmission
US3956944A (en) * 1975-01-02 1976-05-18 Tompkins Leo L Torque operated, variable diameter belt sheave or chain sprocket
US3969948A (en) * 1975-08-25 1976-07-20 Pipenhagen Jr Charles A Automatic bicycle transmission
US3994180A (en) * 1975-04-11 1976-11-30 Leonard Stanley Ackerman Expansible sprocket device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR961243A (en) * 1950-05-09
US3850044A (en) * 1973-05-10 1974-11-26 D Hagen Bicycle transmission
US3956944A (en) * 1975-01-02 1976-05-18 Tompkins Leo L Torque operated, variable diameter belt sheave or chain sprocket
US3994180A (en) * 1975-04-11 1976-11-30 Leonard Stanley Ackerman Expansible sprocket device
US3969948A (en) * 1975-08-25 1976-07-20 Pipenhagen Jr Charles A Automatic bicycle transmission

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1983002925A1 (en) * 1982-02-18 1983-09-01 Chappell, Gilmore, H. Automatic transmission
EP0112112A1 (en) * 1982-12-14 1984-06-27 Michel Deal Variable ratio transmission
WO1984002690A1 (en) * 1983-01-10 1984-07-19 Shiber Samuel Incrementally variable transmission
EP0116731A1 (en) * 1983-02-09 1984-08-29 FULLERTON, Robert L. Automatic transmission having a continuously variable drive ratio
GB2355771B (en) * 1999-10-28 2003-09-03 Richard John Kilduff Infinitely variable transmission for human powered vehicles
GB2355771A (en) * 1999-10-28 2001-05-02 Richard John Kilduff A bicycle with infinitely variable transmission
WO2002047965A2 (en) 2000-12-12 2002-06-20 Graeme Stafford Murray Drive transmission apparatus
CN100402369C (en) * 2003-02-26 2008-07-16 余蜀翔 Automatic continuously variable speed chain disc device
DE102014002779A1 (en) * 2014-02-24 2015-08-27 Alexander Degtjarew The chain transmission for the vehicle with the smooth change of the transmission ratio, which depends on the load.
RU2603292C2 (en) * 2014-03-09 2016-11-27 Александр Васильевич Дегтярев Vehicle chain transmission with variable gear ratio depending on load
DE102014003749A1 (en) * 2014-03-12 2015-09-17 Alexander Degtjarew Chain transmission for the vehicle with the changed transmission ratio that depends on the load
DE102016008839B3 (en) * 2016-07-19 2018-01-25 André Röhl Stepless mechanical gear device with torque-dependent change of the transmission ratio for positive power transmission.
WO2018014895A1 (en) 2016-07-19 2018-01-25 Röhl André Franz Continuously variable mechanical transmission system with torque-dependent change of the transmission ratio for positive engagement power transmission
DE102018008221B3 (en) * 2018-10-17 2020-02-06 André Röhl Automatic mechanical transmission device with variable transmission range for positive power transmission

Also Published As

Publication number Publication date
NL7902814A (en) 1980-10-14

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