CA2310974C - Derailleur bicycle; retractable chain strain mechanical sensor to control an electric booster - Google Patents
Derailleur bicycle; retractable chain strain mechanical sensor to control an electric booster Download PDFInfo
- Publication number
- CA2310974C CA2310974C CA002310974A CA2310974A CA2310974C CA 2310974 C CA2310974 C CA 2310974C CA 002310974 A CA002310974 A CA 002310974A CA 2310974 A CA2310974 A CA 2310974A CA 2310974 C CA2310974 C CA 2310974C
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- Prior art keywords
- bicycle
- chain
- booster
- rider
- spring loaded
- Prior art date
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- Expired - Fee Related
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Classifications
-
- 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
- B62M6/00—Rider propulsion of wheeled vehicles with additional source of power, e.g. combustion engine or electric motor
- B62M6/40—Rider propelled cycles with auxiliary electric motor
Abstract
One of the major barriers to the daily use of a bicycle for work/home commuting purposes has always been steep climbs. An innovative chain strain sensing device that controls an interface to allow installation of a wide selection of existing cordless power tools into a derailleur bicycle power train is proposed here.
The chain tension applied by the rider is sensed by a mechanical device that has the capability of following all chain lateral positions that are imposed by the rear (or front) derailleur shifter. The tension signal is then directly sent to the power tool trigger through a control cable. The result is that the power tool motor is activated only when extra power is required by the rider. Unlike all other existing electric bike boosters having a throttle controlled manually, the main benefit of this concept is to maximize the autonomy of the motor batteries as boost is provided only when the rider pedals. The complete system is so light weight (under 12 lb) and so compact that the rider can still enjoy the regular behavior (including the gear shifting capability) and feeling of the bicycle when riding on shallow rates, flat road portions or downhill.
The chain tension applied by the rider is sensed by a mechanical device that has the capability of following all chain lateral positions that are imposed by the rear (or front) derailleur shifter. The tension signal is then directly sent to the power tool trigger through a control cable. The result is that the power tool motor is activated only when extra power is required by the rider. Unlike all other existing electric bike boosters having a throttle controlled manually, the main benefit of this concept is to maximize the autonomy of the motor batteries as boost is provided only when the rider pedals. The complete system is so light weight (under 12 lb) and so compact that the rider can still enjoy the regular behavior (including the gear shifting capability) and feeling of the bicycle when riding on shallow rates, flat road portions or downhill.
Description
Specification Summary This invention relates to a compact and lightweight electric booster controlled by an innovative chain strain sensor. The booster may allow a wide range of existing high efficiency power drills to be installed in minutes on any rigid or suspended derailleur bicycles. The unique function of the booster is to efficiently assist the rider when he (she) needs to pedal on steep climbs. For all other riding events, such as flat or shallow rate pedaling, or downhill coasting, the booster sensor may be switched "OFF" from a handlebar control to not alter the general feeling and handling of a regular bicycle.
Back ound A preliminary search on the Canadian, American and European patent database web sites has identified several bicycle booster concepts of interest. The most relevant one was found to be the Canadian patent #CA 2146284 dated April 4 1995 which refers to "Bicycle; Chain Strain Sensing Sprocket Mechanism". This device provides an automatic control of a booster by sensing of the bicycle chain tension similar to the present application. However, a more detailed examination revealed that, unlike the present application which provides full compatibility with derailleur bikes, this patented device is limited to non derailleur bicycles only as it is attached to the frame seat and chain stays without any capability to fallow the chain lateral motions that normally occur when the rider shifts gears on any derailleur bike. Besides, no manually operated sensor disconnector that allows straigl~teni~g of the chain upper string to mi~ir~i~e friction is provided for the riding events that do not require booster operation. The only ON/OFF switch that was referred to in this patent description was used to control the booster through the motor throttle, not through the chain strain sensor like the present application does.
Another finding of interest was the American patent US5758735 dated 199&06-02 that refers to a " High performance bicycle propulsion". This concept also provides a chain tension sensor of a sprocket idler type. However, unlike the present application which is entirety mechanical, the tension signal is converted into an electric signal through strain gage instrumentation and again, this sensing device is suitable to non derailleur bikes only as it is rigidly mounted on the frame.
Another fording of interest was the American patent US 6,062,329 filed in April 3,1995. "Pedal Bicycle having an Auxiliary Power Means" which discloses a booster power train that uses an auxiliary chain to drive one of the existing sprockets of the bike rear hub like the present application does. However, unlike the present application which refers to a complete chain J sprocket transmission, the concept refers to transmission of a gear box type to achieve the gear ratio required by the booster.
Another findurg of interest was the European patent EP 1 097 8b3 A2 tiled in November 7, 2000 "Electric Power Assist Bicycle" which discloses a chain sprocket transmission like the present application does. However, unlike the present application which refers to chain transmission using the rear hub's largest cog, the concept refers to a chain transmission using one of the bicycle front cogs.
At this point, no patent related to the integration of a power drill for a bicycle booster was found.
Brief Description of the Drawings FIG 1 is a perspective view of the overall booster equipment.
FIG 2 is a schematic that illustrates the basic functions of the booster control and sensing unit. The front view was chosen to clarify the features that provide booster compatibility with derailleur bicycles.
FIG 3 is a side view showing some details that are more specific to the sensing and control unit.
FIG 4 is a set of side views representing the three possible modes of operation of the sensing and control unit:
View A depicts the device attitude when the control switch is set "ON" and no booster assistance is required by the rider (rider coasting or not pedaling hard).
View B depicts the device attitude when the control switch is set "ON" and maximum booster assistance is required by the rider (rider pedaling hard).
View C depicts the device attitude when the control switch is set "OFF" by the rider to deactivate the booster sensor in order to minimize chain friction (regular bicycle mode).
FIG 5 is a side view showing the power train configuration of the booster.
FIG 6 illustrates the versatility of the booster interface to accommodate various bike frames:
View A depicts the power train installation on a road bicycle.
View B depicts installation on a mountain bike with rear suspension.
FIG 7 depicts the possible configurations of the power tool trigger control system using a cam shaft located at the booster end of the chain strain sensing cable.
View A depicts the sensor cable mounted in the "pushing way".
View B depicts the sensor cable mounted in the "pulling way".
FIG 8 is an overall view of the housing of a possible interface when a power drill is to be used for a booster motor.
C7~ 02310974 2001-07-09 Red to FIG 1, the )~ooater equipm~t is campoaed of a co~rnl and chain sensing device having an idler sprocket (9) installed at the upper string paetion ofthe bicycle chain (15). The device sends the chain strain signal through a bicycle cable (8) (referred to as the sensor cable) to the trigger of an electric motor S like the powtr drill (5). The dwice is controlled by a ON /OFF switch (7) mounted on the handlebar (3) through another bicycle cable (11) (referred to as the control cable). The device also includes an idler sprocket tensioner (17) to prevent the booster chain ( 16) ~ derailing when ttte booster is in operation.
The booster chain (16) drives permanently the largest (inner) cog of the bicycle rear hub (19). The rear derailleut shifter is set to allow shifting from the 3rd gear only in order to prevent possible interference between the booster chain (16) and the bicycle chain (15). The chain (16) is mountod on a clutch unit in the booster housing (49). The function of the clutch unit is to disconnect the power drill (5) motor from the bicycle rear hub ( 19) to minimize friction when the rider pedals with the booster switched OFF, or when the rider pedals faster than the booster motor spins.
Referring to FIG Z, the control and sensing device is secured on the right hand seat stay (1) of the bicycle. The device is &ee to rotate around a pivot axis (12) allowing the idler sprocket (9) to follow any lateral motion of the bicycle chain (15) when the rider shifts gears. The idler sprocket (9) is slightly tilted to provide sufficient clearaunce with chain stay (2) when the rider shifts to the outer cog (6) (high gear) of the bicycle rear hub (19). The sensing and control device is composed of one spring loaded arm (13) whose vertical position is controlled by the "ON-OFF" switch (7) mounted on the handlebar (3) through the control cable (1I). The arm (13) is attached to the floating bracket (IO) that connects to the spring loaded arm (14). When the switch (7) is "ON", the arm (14) may plunge as the amount of strain in the bicycle chain (15) increases. The downward motion of the arm (14) is transmitted through the sensar cable (8) and causes the trigger of an electric mater, like the drill (5) shown in the figure, to be pulled to provide the rider with automatic assistance. The device that controls the motor trigger is of a cam shaft type. A spring (35) may be provided to ensure minimal cable pre-tensioning. The cam shaft device is mounted on the booster housing (49), its position may be adjusted to frt various drill models. To minimize unwanted booster powex oscillations duo to rider poor pedaling, techniq»e, or due to the absence of cages, or step~in shoes, or any other pedal device to facilitate smoother rider operation throughout the pedaling cycle, a damper (26) is provided between the floating bracket (10) sad the opposite end of arm (14).
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Y0lFi i:~'~ 3,~ iFVCP,°f Referring to FIG 3, the sensing and control device is secured through its fixed bracket (2S) along the right hand seat stay ( 1 ) by means of clamps like the pair of U-bolts (4).
The device is articulated around a pivot point (12) in order to follow all possible lateral motions of the chain ( 1 S) when the rider shifts gears. Fixed bracket (2S) may have means to ensure that the axis of (12) is set approximately parallel to chain stay (2) regardless of the angle between seat stay ( I ) and chain stay (2). As the rider pedals harder, the chain tension (T) increases, causing an increase of chain angle (a) which in turn, applies a downward force (F) to the idler sprocket (9) and causes the arm (14) to plunge. Downward motion of arm (14) transmits a trigger signal (S) through sensor cable (8). Cable (8) is shown in the Figure connected in the ""pushing way"' (through pivots (21) and (22)) relative to parallelogram arm (14). However, sensor cable (8) may be connected in the ' "pulling way" " instead, through pivots (23) and (24) to produce a similar trigger signal. When chain tension (19) decreases, a recall spring (18) brings the arm (14) back to its original up position. The parallelogram arm ( 14) is rigidly attached to the 1 S floating bracket (10). This floating bracket is able to move up or down, driven by the "ON / OFF" switch signal {C) through control cable (11), and to swing around pivot (12) depending on chain (1S) lateral position. A spring loaded chain tensioner sprocket (17) is provided to prevent possible derailing of the booster drive chain (16) off the rear hub {19) largest cog it is installed on. A damper (26) is mounted between the floating bracket (10) and parallelogram (14) through lever (27) to filter-out chain tension spikes due to pedaling irregularities that may affect smooth operation of the booster motor.
Damper (26) may be of a design similar to miniature oleo shock absorbers commonly used in radio-controlled cars.
Referring to FIG 4, View A shows the position of parallelograms (13), (14) when the 2S booster is switched " "ON" but no assistance is required by the rider at this point. Chain tension (T) is insufficient to overcome the recall effect of spring (18).
View B shows the plunging of parallelogram arm (14) when the rider pedals harder and therefore requires booster assistance. The magnitude of chain tension (T) is now sufficient to overcome the recall effect of spring ( I 8), and arm ( 14) is driven downward to send signal (S) to booster trigger.
View C shows the device switched ' "OFF" by the rider through signal (C) which causes both the arm {13) and the floating bracket (10) to plunge. Once floating bracket (10) reaches its low position, chain tension (T) has no more effect on signal (S) to be sent to booster. The booster sensor is now deactivated. As chain upper string (1S) is back into a 3S straight configuration (~ = 1800), it is no longer able to drive vertically the idler sprocket (9) and lower arm ( 14), and the chain friction caused by the idler sprocket (9) is now eliminated.
Referring to FIG S, the power train lay-out is shown when the largest cog of the existing rear hub (19) of the bicycle is used. A one-way clutch (48) is installed inside the booster housing (49) to avoid unwanted friction caused by the booster motor when the rider pedals faster than the motor spins. A primary chain (53) connects the motor shaft (45) to the clutch (48). A secondary chain (16) connects the clutch (48) to the largest cog of bicycle rear hub ( 19). For best efficiency on steep climb, a gear ratio of about 5:1 needs to be achieved when 300 Watts to Watts power drills having a maximum speed of 1,500 rpm are used. A sprocket chain tensioner (17) (which is attached to the fixed bracket of the contml and sensing device (25) that was described in FIG 3) is spring loaded by (55) and has an artn length (x) that may be adjusted depending on the geometry of the existing bicycle frame.
Referring to FIG 6, View A shows the configuration when the boosts is installed on a road bicycle type flame that rxhibita a typical high seat stay to chain stay angle (~ 1). The arm length of the chain temsioner needs to be reduced to (xl) to allow proper installation of the control and sensing device along the bicycle seat stay. The lockable pivot of the booster frame is set in low position (-h) relative to the seat post clamp (41).
View B shows the opposite configuration when the booster has to be installed on a mountain bike type frame equipped with roar suspensions. These frames exhibit a typical shallow seat stay to chain stay angle (,(32) as illustrated. The arm length of the chain tensioner needs to be increased to (x2) to allow proper installation of the cornrol and sensing device along the bicycle seat stay. The booster body is mounted on tire bicycle frame through attachment points (56) that are usually provided by standard M5.80 threaded holes in the vicinity of the left hand and right baud dmp-outs for fenders or rack installation. The boostex houai~g is c~nected in the back to legs (40) through pivots (57), and in the front to the existing seat tube quiok release through pivots (41 ). The purpose of lockable pivot (47) and link (58) is to provide means to adjust the height (+h) of the booster housing depending on bicycle rear hub ( 19) largest cog diameter and frame geometry. For a bicycle with rear suspension, pivots (41), (56), and (57) are equipped with lose fit bushings to allow the whole booster interface to follow the up and down motion of rear suspension.
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\le°~Ih~ ,,,, Referring to FIG'1 Views A and B , the chain strain sealing device drives a cam shaft (32) in rotation through cable (8). Rotation of cam shaft (32) causes the trigger of the booster motor to be pulled by the pressure of a low friction roller (30) (like a ball bearing) mounted on the cam shaft (32). The function of the roller (30) is to eliminate contact friction between the cans shaft (32) and trigger (33). A rotational spring (34) or a linear spring (35) or a combination of both is provided to ensure proper residual cable tension. The pre-load of the recall spring, or spring combination (34), (35) needs to be significantly lower than the pre-load of spring ( 18) shown in FIG (3) for a proper operation of the chain strain sensing device.
View A shows the cam shaft cable mounted in the "puahit~ way", when a decrease (-S) of the cable tension generates an increase (P) of booster assistance.
View B shows the cam shaft cable mounted in the "pulling way", when a cable tension increase (+S) generates a increase (P) of power assistance.
Referring to P'iG 8, The housing for a booster using a power drill is composed of a light weight frame secured to the rear of the bicycle through legs (40) that connect to two standard M5.80 dueaded holes that are usually provided on the left hand and right hand bicycle drop-outs. The front of the housing is attached to the existing seat post quick release through lugs (41) that are equipped with loose- fit bushings (42) for install~ion on bicycles having roar suspension. The power drill handle is secured between the foam pads (43). The drill chuck is tightened around the hexagonal shaft (44) that drives the booster power train through cog (45).
Some openings (46) aro provided for proper cooling of the power drills that may have air intakes located in the front part of their body. Pivot (4'~ are lockable in order to secure the booster frame in position once the chain of the booster power train is adjusted properly. The right hand side of the frame receives the booster clutch (48) through axis shown. The top of the booster frame may be coverod with a light weight fairing (not shown) of a streamline design for the sake of aerodynsrnics and cosmetics.
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Back ound A preliminary search on the Canadian, American and European patent database web sites has identified several bicycle booster concepts of interest. The most relevant one was found to be the Canadian patent #CA 2146284 dated April 4 1995 which refers to "Bicycle; Chain Strain Sensing Sprocket Mechanism". This device provides an automatic control of a booster by sensing of the bicycle chain tension similar to the present application. However, a more detailed examination revealed that, unlike the present application which provides full compatibility with derailleur bikes, this patented device is limited to non derailleur bicycles only as it is attached to the frame seat and chain stays without any capability to fallow the chain lateral motions that normally occur when the rider shifts gears on any derailleur bike. Besides, no manually operated sensor disconnector that allows straigl~teni~g of the chain upper string to mi~ir~i~e friction is provided for the riding events that do not require booster operation. The only ON/OFF switch that was referred to in this patent description was used to control the booster through the motor throttle, not through the chain strain sensor like the present application does.
Another finding of interest was the American patent US5758735 dated 199&06-02 that refers to a " High performance bicycle propulsion". This concept also provides a chain tension sensor of a sprocket idler type. However, unlike the present application which is entirety mechanical, the tension signal is converted into an electric signal through strain gage instrumentation and again, this sensing device is suitable to non derailleur bikes only as it is rigidly mounted on the frame.
Another fording of interest was the American patent US 6,062,329 filed in April 3,1995. "Pedal Bicycle having an Auxiliary Power Means" which discloses a booster power train that uses an auxiliary chain to drive one of the existing sprockets of the bike rear hub like the present application does. However, unlike the present application which refers to a complete chain J sprocket transmission, the concept refers to transmission of a gear box type to achieve the gear ratio required by the booster.
Another findurg of interest was the European patent EP 1 097 8b3 A2 tiled in November 7, 2000 "Electric Power Assist Bicycle" which discloses a chain sprocket transmission like the present application does. However, unlike the present application which refers to chain transmission using the rear hub's largest cog, the concept refers to a chain transmission using one of the bicycle front cogs.
At this point, no patent related to the integration of a power drill for a bicycle booster was found.
Brief Description of the Drawings FIG 1 is a perspective view of the overall booster equipment.
FIG 2 is a schematic that illustrates the basic functions of the booster control and sensing unit. The front view was chosen to clarify the features that provide booster compatibility with derailleur bicycles.
FIG 3 is a side view showing some details that are more specific to the sensing and control unit.
FIG 4 is a set of side views representing the three possible modes of operation of the sensing and control unit:
View A depicts the device attitude when the control switch is set "ON" and no booster assistance is required by the rider (rider coasting or not pedaling hard).
View B depicts the device attitude when the control switch is set "ON" and maximum booster assistance is required by the rider (rider pedaling hard).
View C depicts the device attitude when the control switch is set "OFF" by the rider to deactivate the booster sensor in order to minimize chain friction (regular bicycle mode).
FIG 5 is a side view showing the power train configuration of the booster.
FIG 6 illustrates the versatility of the booster interface to accommodate various bike frames:
View A depicts the power train installation on a road bicycle.
View B depicts installation on a mountain bike with rear suspension.
FIG 7 depicts the possible configurations of the power tool trigger control system using a cam shaft located at the booster end of the chain strain sensing cable.
View A depicts the sensor cable mounted in the "pushing way".
View B depicts the sensor cable mounted in the "pulling way".
FIG 8 is an overall view of the housing of a possible interface when a power drill is to be used for a booster motor.
C7~ 02310974 2001-07-09 Red to FIG 1, the )~ooater equipm~t is campoaed of a co~rnl and chain sensing device having an idler sprocket (9) installed at the upper string paetion ofthe bicycle chain (15). The device sends the chain strain signal through a bicycle cable (8) (referred to as the sensor cable) to the trigger of an electric motor S like the powtr drill (5). The dwice is controlled by a ON /OFF switch (7) mounted on the handlebar (3) through another bicycle cable (11) (referred to as the control cable). The device also includes an idler sprocket tensioner (17) to prevent the booster chain ( 16) ~ derailing when ttte booster is in operation.
The booster chain (16) drives permanently the largest (inner) cog of the bicycle rear hub (19). The rear derailleut shifter is set to allow shifting from the 3rd gear only in order to prevent possible interference between the booster chain (16) and the bicycle chain (15). The chain (16) is mountod on a clutch unit in the booster housing (49). The function of the clutch unit is to disconnect the power drill (5) motor from the bicycle rear hub ( 19) to minimize friction when the rider pedals with the booster switched OFF, or when the rider pedals faster than the booster motor spins.
Referring to FIG Z, the control and sensing device is secured on the right hand seat stay (1) of the bicycle. The device is &ee to rotate around a pivot axis (12) allowing the idler sprocket (9) to follow any lateral motion of the bicycle chain (15) when the rider shifts gears. The idler sprocket (9) is slightly tilted to provide sufficient clearaunce with chain stay (2) when the rider shifts to the outer cog (6) (high gear) of the bicycle rear hub (19). The sensing and control device is composed of one spring loaded arm (13) whose vertical position is controlled by the "ON-OFF" switch (7) mounted on the handlebar (3) through the control cable (1I). The arm (13) is attached to the floating bracket (IO) that connects to the spring loaded arm (14). When the switch (7) is "ON", the arm (14) may plunge as the amount of strain in the bicycle chain (15) increases. The downward motion of the arm (14) is transmitted through the sensar cable (8) and causes the trigger of an electric mater, like the drill (5) shown in the figure, to be pulled to provide the rider with automatic assistance. The device that controls the motor trigger is of a cam shaft type. A spring (35) may be provided to ensure minimal cable pre-tensioning. The cam shaft device is mounted on the booster housing (49), its position may be adjusted to frt various drill models. To minimize unwanted booster powex oscillations duo to rider poor pedaling, techniq»e, or due to the absence of cages, or step~in shoes, or any other pedal device to facilitate smoother rider operation throughout the pedaling cycle, a damper (26) is provided between the floating bracket (10) sad the opposite end of arm (14).
SECT E.J1~ 8 CORr~ECTtOf~l S>=.E C~V'7T~FIC~TE
COHf~~~,':~i ~'v~~ rIRTICLE $
Y0lFi i:~'~ 3,~ iFVCP,°f Referring to FIG 3, the sensing and control device is secured through its fixed bracket (2S) along the right hand seat stay ( 1 ) by means of clamps like the pair of U-bolts (4).
The device is articulated around a pivot point (12) in order to follow all possible lateral motions of the chain ( 1 S) when the rider shifts gears. Fixed bracket (2S) may have means to ensure that the axis of (12) is set approximately parallel to chain stay (2) regardless of the angle between seat stay ( I ) and chain stay (2). As the rider pedals harder, the chain tension (T) increases, causing an increase of chain angle (a) which in turn, applies a downward force (F) to the idler sprocket (9) and causes the arm (14) to plunge. Downward motion of arm (14) transmits a trigger signal (S) through sensor cable (8). Cable (8) is shown in the Figure connected in the ""pushing way"' (through pivots (21) and (22)) relative to parallelogram arm (14). However, sensor cable (8) may be connected in the ' "pulling way" " instead, through pivots (23) and (24) to produce a similar trigger signal. When chain tension (19) decreases, a recall spring (18) brings the arm (14) back to its original up position. The parallelogram arm ( 14) is rigidly attached to the 1 S floating bracket (10). This floating bracket is able to move up or down, driven by the "ON / OFF" switch signal {C) through control cable (11), and to swing around pivot (12) depending on chain (1S) lateral position. A spring loaded chain tensioner sprocket (17) is provided to prevent possible derailing of the booster drive chain (16) off the rear hub {19) largest cog it is installed on. A damper (26) is mounted between the floating bracket (10) and parallelogram (14) through lever (27) to filter-out chain tension spikes due to pedaling irregularities that may affect smooth operation of the booster motor.
Damper (26) may be of a design similar to miniature oleo shock absorbers commonly used in radio-controlled cars.
Referring to FIG 4, View A shows the position of parallelograms (13), (14) when the 2S booster is switched " "ON" but no assistance is required by the rider at this point. Chain tension (T) is insufficient to overcome the recall effect of spring (18).
View B shows the plunging of parallelogram arm (14) when the rider pedals harder and therefore requires booster assistance. The magnitude of chain tension (T) is now sufficient to overcome the recall effect of spring ( I 8), and arm ( 14) is driven downward to send signal (S) to booster trigger.
View C shows the device switched ' "OFF" by the rider through signal (C) which causes both the arm {13) and the floating bracket (10) to plunge. Once floating bracket (10) reaches its low position, chain tension (T) has no more effect on signal (S) to be sent to booster. The booster sensor is now deactivated. As chain upper string (1S) is back into a 3S straight configuration (~ = 1800), it is no longer able to drive vertically the idler sprocket (9) and lower arm ( 14), and the chain friction caused by the idler sprocket (9) is now eliminated.
Referring to FIG S, the power train lay-out is shown when the largest cog of the existing rear hub (19) of the bicycle is used. A one-way clutch (48) is installed inside the booster housing (49) to avoid unwanted friction caused by the booster motor when the rider pedals faster than the motor spins. A primary chain (53) connects the motor shaft (45) to the clutch (48). A secondary chain (16) connects the clutch (48) to the largest cog of bicycle rear hub ( 19). For best efficiency on steep climb, a gear ratio of about 5:1 needs to be achieved when 300 Watts to Watts power drills having a maximum speed of 1,500 rpm are used. A sprocket chain tensioner (17) (which is attached to the fixed bracket of the contml and sensing device (25) that was described in FIG 3) is spring loaded by (55) and has an artn length (x) that may be adjusted depending on the geometry of the existing bicycle frame.
Referring to FIG 6, View A shows the configuration when the boosts is installed on a road bicycle type flame that rxhibita a typical high seat stay to chain stay angle (~ 1). The arm length of the chain temsioner needs to be reduced to (xl) to allow proper installation of the control and sensing device along the bicycle seat stay. The lockable pivot of the booster frame is set in low position (-h) relative to the seat post clamp (41).
View B shows the opposite configuration when the booster has to be installed on a mountain bike type frame equipped with roar suspensions. These frames exhibit a typical shallow seat stay to chain stay angle (,(32) as illustrated. The arm length of the chain tensioner needs to be increased to (x2) to allow proper installation of the cornrol and sensing device along the bicycle seat stay. The booster body is mounted on tire bicycle frame through attachment points (56) that are usually provided by standard M5.80 threaded holes in the vicinity of the left hand and right baud dmp-outs for fenders or rack installation. The boostex houai~g is c~nected in the back to legs (40) through pivots (57), and in the front to the existing seat tube quiok release through pivots (41 ). The purpose of lockable pivot (47) and link (58) is to provide means to adjust the height (+h) of the booster housing depending on bicycle rear hub ( 19) largest cog diameter and frame geometry. For a bicycle with rear suspension, pivots (41), (56), and (57) are equipped with lose fit bushings to allow the whole booster interface to follow the up and down motion of rear suspension.
BECl bC~P~ 8 C~RRECTtOM
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CUHF;;.-=: ';'~!.~ i',F?T~';.LE B
\le°~Ih~ ,,,, Referring to FIG'1 Views A and B , the chain strain sealing device drives a cam shaft (32) in rotation through cable (8). Rotation of cam shaft (32) causes the trigger of the booster motor to be pulled by the pressure of a low friction roller (30) (like a ball bearing) mounted on the cam shaft (32). The function of the roller (30) is to eliminate contact friction between the cans shaft (32) and trigger (33). A rotational spring (34) or a linear spring (35) or a combination of both is provided to ensure proper residual cable tension. The pre-load of the recall spring, or spring combination (34), (35) needs to be significantly lower than the pre-load of spring ( 18) shown in FIG (3) for a proper operation of the chain strain sensing device.
View A shows the cam shaft cable mounted in the "puahit~ way", when a decrease (-S) of the cable tension generates an increase (P) of booster assistance.
View B shows the cam shaft cable mounted in the "pulling way", when a cable tension increase (+S) generates a increase (P) of power assistance.
Referring to P'iG 8, The housing for a booster using a power drill is composed of a light weight frame secured to the rear of the bicycle through legs (40) that connect to two standard M5.80 dueaded holes that are usually provided on the left hand and right hand bicycle drop-outs. The front of the housing is attached to the existing seat post quick release through lugs (41) that are equipped with loose- fit bushings (42) for install~ion on bicycles having roar suspension. The power drill handle is secured between the foam pads (43). The drill chuck is tightened around the hexagonal shaft (44) that drives the booster power train through cog (45).
Some openings (46) aro provided for proper cooling of the power drills that may have air intakes located in the front part of their body. Pivot (4'~ are lockable in order to secure the booster frame in position once the chain of the booster power train is adjusted properly. The right hand side of the frame receives the booster clutch (48) through axis shown. The top of the booster frame may be coverod with a light weight fairing (not shown) of a streamline design for the sake of aerodynsrnics and cosmetics.
SECT t~l 8 CORFIEC110N
$~ a (~EnT~~iC:ATE
~:uHi~~ ,~ ~ f'';', - ~,I~TICLE B
s~CJI~ s tit i52'iFdC~l~,
Claims (7)
1. A mechanical chain strain sensing device for purpose of bicycle electric booster control at low speed on steep climbs comprising:
an idler sprocket driven by the middle portion of the upper string of the original bicycle chain;
a spring loaded arm carrying the idler sprocket whose motion is driven by the tension of the original chain and serves to control the throttle of an electric booster through a bicycle cable;
a floating bracket carrying the spring loaded arm and the idler sprocket and connected to a damper to dampen the arm's vertical motion in the event of abrupt chain tension variations;
another spring loaded arm carrying the floating bracket, whose vertical motion is controlled by an ON/OFF switch through a bicycle cable;
a fixed bracket rigidly clamped to the middle portion of the bicycle right hand seat stay, and carrying the assembly of the two arms, floating bracket and idler sprocket through a lateral articulation to accommodate lateral motion of the bicycle chain due to derailleur shifting, and where means are provided to set angularly that articulation depending on bicycle chain stay to seat stay angle.
an idler sprocket driven by the middle portion of the upper string of the original bicycle chain;
a spring loaded arm carrying the idler sprocket whose motion is driven by the tension of the original chain and serves to control the throttle of an electric booster through a bicycle cable;
a floating bracket carrying the spring loaded arm and the idler sprocket and connected to a damper to dampen the arm's vertical motion in the event of abrupt chain tension variations;
another spring loaded arm carrying the floating bracket, whose vertical motion is controlled by an ON/OFF switch through a bicycle cable;
a fixed bracket rigidly clamped to the middle portion of the bicycle right hand seat stay, and carrying the assembly of the two arms, floating bracket and idler sprocket through a lateral articulation to accommodate lateral motion of the bicycle chain due to derailleur shifting, and where means are provided to set angularly that articulation depending on bicycle chain stay to seat stay angle.
2. A device as defined in claim 1 where these two spring loaded arms have permuted their locations, in other words, the spring loaded arm and damper that serve to send and dampen the chain strain signal to the booster are now installed between the fixed bracket and the floating bracket and, the other spring loaded arm that is controlled by the ON/OFF switch is now mounted between the floating bracket and the idler sprocket.
3. A device as defined in claim 1 or 2 where the fixed bracket is equipped with a spring loaded chain tensioner having an adjustable arm length, for boosters attached to the lower portion of the bicycle seat post or to the seat tube clamp and to the rear drop-outs, and where these boosters use a chain power train that drives the existing largest cog of the bicycle rear hub through a one-way clutch.
4. A device as defined in claim 3 used to control the trigger of a cordless drill type booster using a camshaft mechanism, where the drill is installed to an interface attached to the lower portion of the bicycle seat post or to the seat tube clamp and to the rear drop-outs.
5. A device as defined in claim 3 used to control the trigger of a 110V or 220V cord drill using a camshaft mechanism and where the drill is installed to an interface attached to the lower portion of the bicycle seat post or to the seat tube clamp and to the rear drop-outs, and where the cord drill is powered by a low voltage DC battery pack through a light weight power inverter.
6. A device as defined in claim 3 that mechanically controls the throttle of an electric motor through an adequate electronic variator, and where the motor/variator system is fully integrated to the booster.
7. A device as defined in claim 1 or 2 that mechanically controls the throttle of an electric motor fully integrated in the front ar rear hub of the bicycle through an adequate electronic variator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002310974A CA2310974C (en) | 2000-06-21 | 2000-06-21 | Derailleur bicycle; retractable chain strain mechanical sensor to control an electric booster |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002310974A CA2310974C (en) | 2000-06-21 | 2000-06-21 | Derailleur bicycle; retractable chain strain mechanical sensor to control an electric booster |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2310974A1 CA2310974A1 (en) | 2001-08-05 |
| CA2310974C true CA2310974C (en) | 2002-02-05 |
Family
ID=4166408
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002310974A Expired - Fee Related CA2310974C (en) | 2000-06-21 | 2000-06-21 | Derailleur bicycle; retractable chain strain mechanical sensor to control an electric booster |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2310974C (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2058638A2 (en) | 2007-11-08 | 2009-05-13 | Johann DI Müller | Measuring transducer for circulating pulling devices |
| US20110272203A1 (en) * | 2010-05-10 | 2011-11-10 | Makita Corporation | Electric wheeled apparatus powered by battery packs |
| US8851215B2 (en) | 2009-09-10 | 2014-10-07 | Makita Corporation | Electric wheeled apparatus |
| US11850969B1 (en) | 2022-08-23 | 2023-12-26 | Intercontinental Mobility Company | Portable motorized vehicles |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW201637927A (en) * | 2015-04-30 | 2016-11-01 | 佳承精工股份有限公司 | Bicycle status sensing device |
| CN109927843A (en) * | 2017-12-18 | 2019-06-25 | 辛永升 | A kind of bicycle rope drive mechanism |
-
2000
- 2000-06-21 CA CA002310974A patent/CA2310974C/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2058638A2 (en) | 2007-11-08 | 2009-05-13 | Johann DI Müller | Measuring transducer for circulating pulling devices |
| US8851215B2 (en) | 2009-09-10 | 2014-10-07 | Makita Corporation | Electric wheeled apparatus |
| US9282695B2 (en) | 2009-09-10 | 2016-03-15 | Makita Corporation | Electric power mower |
| US20110272203A1 (en) * | 2010-05-10 | 2011-11-10 | Makita Corporation | Electric wheeled apparatus powered by battery packs |
| US8490732B2 (en) * | 2010-05-10 | 2013-07-23 | Makita Corporation | Electric wheeled apparatus powered by battery packs |
| US11850969B1 (en) | 2022-08-23 | 2023-12-26 | Intercontinental Mobility Company | Portable motorized vehicles |
Also Published As
| Publication number | Publication date |
|---|---|
| CA2310974A1 (en) | 2001-08-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |