CA1058531A - Back-pedal brake operator for multi-speed bicycles - Google Patents
Back-pedal brake operator for multi-speed bicyclesInfo
- Publication number
- CA1058531A CA1058531A CA243,259A CA243259A CA1058531A CA 1058531 A CA1058531 A CA 1058531A CA 243259 A CA243259 A CA 243259A CA 1058531 A CA1058531 A CA 1058531A
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- Canada
- Prior art keywords
- brake
- pedal
- bicycle
- drive
- brake actuator
- Prior art date
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Abstract
S P E C I F I C A T I O N
BACK-PEDAL BRAKE OPERATOR FOR MULTI-SPEED BICYCLES
Inventor: Franklin J. Calderazzo ABSTRACT OF THE DISCLOSURE
Back-pedal. brake operator for multi-speed bicycles, such as chain-derailer bicycles or gear-shifting bicycles, which can be used to operate the brakes for either the rear wheel or the front wheel or both. The brake operating action is obtained by turning the foot pedals rearwardly a short dis-tance from any position which the pedals may occupy at the instant when the driver wishes to apply braking action, the braking operation being obtained without utilizing the sprock-et chain to apply the braking force, and the brakes are auto-matically released without any "lock-up" effect when the driver starts pedaling forward in the normal manner. Advan-tageously, the back-pedal operators shown are directly associated with the sprocket assembly as a compact self-con-tained unit integrated with the sprocket assembly and can be installed as original equipment by bicycle manufacturers or can be retrofitted by bicycle shops or owners on existing multi-speed bicycles. The bicycle is permitted to be wheeled freely rearwardly without the brakes becoming applied. The back-pedal brake operator can be adapted for adjustable automatic proportioning of the relative braking efforts to be exerted on the rear and front wheels. This invention also enables dual actuated braking systems to be installed in multi-speed bicycles for either hand or foot operation (or both) of the brakes.
BACK-PEDAL BRAKE OPERATOR FOR MULTI-SPEED BICYCLES
Inventor: Franklin J. Calderazzo ABSTRACT OF THE DISCLOSURE
Back-pedal. brake operator for multi-speed bicycles, such as chain-derailer bicycles or gear-shifting bicycles, which can be used to operate the brakes for either the rear wheel or the front wheel or both. The brake operating action is obtained by turning the foot pedals rearwardly a short dis-tance from any position which the pedals may occupy at the instant when the driver wishes to apply braking action, the braking operation being obtained without utilizing the sprock-et chain to apply the braking force, and the brakes are auto-matically released without any "lock-up" effect when the driver starts pedaling forward in the normal manner. Advan-tageously, the back-pedal operators shown are directly associated with the sprocket assembly as a compact self-con-tained unit integrated with the sprocket assembly and can be installed as original equipment by bicycle manufacturers or can be retrofitted by bicycle shops or owners on existing multi-speed bicycles. The bicycle is permitted to be wheeled freely rearwardly without the brakes becoming applied. The back-pedal brake operator can be adapted for adjustable automatic proportioning of the relative braking efforts to be exerted on the rear and front wheels. This invention also enables dual actuated braking systems to be installed in multi-speed bicycles for either hand or foot operation (or both) of the brakes.
Description
l I ~
10585;~
I B~C~GROUND OF THE INVENTION
; I ~ ~ ~ ~3 There are millions of modern multi speed bicycles in use in the United States and many more millions are being manufactured and sold each year in addition to many imported ; multi-speed bicycles. In many of these multi-speed bicyclesj : ~
the speed ratio or gear ratio between the driving (front~ ~ I
~ I sprocket which is turned by the foot pedal cranks and thel : ¦driven (rear) sprocket at the rear wheel is changed by de- :. .
I ~ Irailing the sprocket chain to shift it between sprockets o various sizes~ For example, in the so-called "ten speed!' ~
bicycles which are very popular at the present time, there ¦ ~-. are two front sprockets and five rear sprockets. The chain can be derailed and shifted by :respective hand-lever ' ¦~, ,operated derailer mechanismspositioned near the front an ~rear sprockets to provide a driving relatlonship between i tf either of the front sprockets and any one of the five rear I . ~.
sprackets, thus achieving ten different gear ratios, as may be desired by the rider for traversing various inclines or ~ :
!leveI stret~hes of roadway at various speeds, There are also I five-speed bicycles in which a single front sprocket is used with five rear sprockets. A single derailer mechanism is associated with the multiple rear sprockets for shifting the chain onto the respective rear sprockets to provide the ~! five different driving ratios. These ten speed, five speed ;
~land si.milar multi-speed bicycles are referred to herein as ¦Ithe "chain derailer'' type. ~ :
~¦ In addition, there are many multi-speed bicyclec ; ~ j !!.in which a ~ear shiftin~ mechanism is included within the hub -¦ of the rear t~heel, for examp.l.e, to provide three diferent ~ ~;, D~yn i ~ 53~ ~ ~ I
~ .~,,~
driving ratios, The rear hub gear shifting bicycles are referred to herein as the multi-speed "gear shifter" type.
Since the inven-tion and development oE such ~odern bicycles, the advantages of back-pedal braking have ¦
been recognized. Much work has been done on back-pedal brake systems and much prior art exists. Yet today in the I
marketplace in the United States, no practical system for `
back-pedal braking of the popular multi-speed "chain de-railer" type bicycle exists. Hand-operated braking systems ;
must be used~
Be~ore the advent of multi-speed bikes, the "coaster" brake was the most popular type of bicycle brake. `
The "coaster" brake mechanism was housed in the rear hub, and brake operation was ob-tained by reversing the pedals, thereby tensioning the bottom of the chain, which applied reverse torque to the rear sprocket for applying the brake. ~ -The three-speed bicycle involved a gear mechanisn located within the hub of the rear wheel as mentioned above. ~ ~-When attempts were made to include a "coaster" brake within the rear hub, together with the gear shifter mechanism, the rear hub became quite large, bulky and complex, causing 1 ~
severe disadvantages from a practical viewpoint. Thus, as `~;
a practical matter, in the marketplace in the United States, hand-operated braking systems are also used with multi-speed gear shifter type bicycles.
In these various multi-speed chain derailer and gear shifter bicycles, as now existing in the U.S, -marketplace, the brake mechanisms for the front and rear wheels are actua-ted by respective hand-operated levers posi-tioned on the he~ndle b.~r near the~ hai d~e qrips. There aro a ~`
number of serious disadvantages or safety hazards inhere~t in these hand-operated lever braking systems, as now existing in the marketplace, as follows:
1. The rider must partially release his hold on the handle grip in order to extend his fingers to reach and grasp and squeeze the brake lever. If the bicycle is negotiating a bumpy, pebbled or slippery surface, the momentary release of the handle grips can cause loss of steer-ing control.
10585;~
I B~C~GROUND OF THE INVENTION
; I ~ ~ ~ ~3 There are millions of modern multi speed bicycles in use in the United States and many more millions are being manufactured and sold each year in addition to many imported ; multi-speed bicycles. In many of these multi-speed bicyclesj : ~
the speed ratio or gear ratio between the driving (front~ ~ I
~ I sprocket which is turned by the foot pedal cranks and thel : ¦driven (rear) sprocket at the rear wheel is changed by de- :. .
I ~ Irailing the sprocket chain to shift it between sprockets o various sizes~ For example, in the so-called "ten speed!' ~
bicycles which are very popular at the present time, there ¦ ~-. are two front sprockets and five rear sprockets. The chain can be derailed and shifted by :respective hand-lever ' ¦~, ,operated derailer mechanismspositioned near the front an ~rear sprockets to provide a driving relatlonship between i tf either of the front sprockets and any one of the five rear I . ~.
sprackets, thus achieving ten different gear ratios, as may be desired by the rider for traversing various inclines or ~ :
!leveI stret~hes of roadway at various speeds, There are also I five-speed bicycles in which a single front sprocket is used with five rear sprockets. A single derailer mechanism is associated with the multiple rear sprockets for shifting the chain onto the respective rear sprockets to provide the ~! five different driving ratios. These ten speed, five speed ;
~land si.milar multi-speed bicycles are referred to herein as ¦Ithe "chain derailer'' type. ~ :
~¦ In addition, there are many multi-speed bicyclec ; ~ j !!.in which a ~ear shiftin~ mechanism is included within the hub -¦ of the rear t~heel, for examp.l.e, to provide three diferent ~ ~;, D~yn i ~ 53~ ~ ~ I
~ .~,,~
driving ratios, The rear hub gear shifting bicycles are referred to herein as the multi-speed "gear shifter" type.
Since the inven-tion and development oE such ~odern bicycles, the advantages of back-pedal braking have ¦
been recognized. Much work has been done on back-pedal brake systems and much prior art exists. Yet today in the I
marketplace in the United States, no practical system for `
back-pedal braking of the popular multi-speed "chain de-railer" type bicycle exists. Hand-operated braking systems ;
must be used~
Be~ore the advent of multi-speed bikes, the "coaster" brake was the most popular type of bicycle brake. `
The "coaster" brake mechanism was housed in the rear hub, and brake operation was ob-tained by reversing the pedals, thereby tensioning the bottom of the chain, which applied reverse torque to the rear sprocket for applying the brake. ~ -The three-speed bicycle involved a gear mechanisn located within the hub of the rear wheel as mentioned above. ~ ~-When attempts were made to include a "coaster" brake within the rear hub, together with the gear shifter mechanism, the rear hub became quite large, bulky and complex, causing 1 ~
severe disadvantages from a practical viewpoint. Thus, as `~;
a practical matter, in the marketplace in the United States, hand-operated braking systems are also used with multi-speed gear shifter type bicycles.
In these various multi-speed chain derailer and gear shifter bicycles, as now existing in the U.S, -marketplace, the brake mechanisms for the front and rear wheels are actua-ted by respective hand-operated levers posi-tioned on the he~ndle b.~r near the~ hai d~e qrips. There aro a ~`
number of serious disadvantages or safety hazards inhere~t in these hand-operated lever braking systems, as now existing in the marketplace, as follows:
1. The rider must partially release his hold on the handle grip in order to extend his fingers to reach and grasp and squeeze the brake lever. If the bicycle is negotiating a bumpy, pebbled or slippery surface, the momentary release of the handle grips can cause loss of steer-ing control.
2. A substantial hand span or finger extension - is required to reach the brake-ac~uating levers. If the rider is a young person or an adult with small hands, it is quite difficult for the rider to reach the brake lever while adequately holding onto and controlling the handle bar grip.
3. The front and rear brake mechanism are con-trolled by separate levers, which arrangemen-t presents hazards when riding down hill or at substantial speed. If ~ -the rear brake mechanism fails, or if the rider squeezes too hard on the lever for the front brake, the front wheel may suddenly stop, thereby flipping the bicycle and catapulting the rider head-first over the front wheel.
~ . On different bicycles the hand levers are located in different places and at diEferent distances (spans ~from the hand grips, depending on the orientation and place-Iment of their mounting clamps on the handle bars. When a II rider is using a borrowed or a rented bicycle in which the brake levers are locatecl differently from those on a familiar ¦ bicycle, there is an aw~ward or hazardous delay in applyin~
tho bra~es wlile the rider's finqers are nervously searching I ~ ;
lout the location of -the brake levers. Alternat~vely, the ¦Irider may avert his eyes from the path ahead in an emergency ¦
to look down to find the levers. This diversion of vision ¦
is undesirable and can be very dangerous when automotive I
traffic is near, ¦
, 5. When the hand brakes are suddenly applied l lin an emergency stop, the bicycIe may start to skid or ¦
¦lean over~ The human reflex action is often to tighten the grip, which jams the brakes and worsens the inciplent I
skid. ¦
6. When using the racing style handle bar ¦
with the underslung U-shaped hand grip, most riders cruise ¦
Iwith their hands on the straight horizontal central portions ; of the handle bar, because this central portion is higher, thereby enabling the rider to sit up straight. The brake ¦levers are often mounted down near the underslung hand grips.
¦Thus, the rider must release both hands and completely shift both hands down to new p~sitions in order to reach the brake levers. In some cases, auxiliary levers are installed so that the rider can reach this auxiliary lever with the hands remaining in the cruising position. These auxiliary levers increase the comple~ity and expense. In addition, they are not available on many modern bicycles, leading to 1 such hazards as described under paragraph No. 4 ab~ve, when ¦ the rider has become accustomed to using them on a familiar bicycle. On camping trips, some riders cannot carry all of the desired gear on their bac~i or on a carrier over the rear wheel. Some equipment then ends up strapped to the handle bar, in which case the au~iliar~ lever can become accidental-ly jammed, preventing the bra~e Erom being applied by use of the regular levcr~
105853~
1 7~ ~lso~ th-~xe are ti~nes ~hen a bi~ycle rider ma ¦¦wish to reach out to ward off an impact, and at such an in- ¦
s-tant, the rider is forced to abandon any chance of using ¦
the hand-brake lever on the respective side where the arm is being extended. It may be the rear brake which is abandoned,~
¦leaving only the front brake, which can veer the bicycle off from the rider's intended track~ -Thus, as pointed out above, there are serious disadvantages or sa~ety hazards involved with hand- ~ ¦
operated lever braking systems for multi-speed chain derailer or gear shi~ter ~icycles. These-disadvanta~es and hazards ~ ¦
are augmented in the case of children whose hands are weaker and who often ride their bicycles at top speed with exhuberanc under conditions where an adult would proceed cautiously, the ;~
children tending to rely on their ability to brake suddenly at the last instant. ! ```-The factor which does not allow the application 1 of the "coaster" brake to the "chain-derailer" type bicycles is the fâct that the chain cannot apply a reverse load (reverse torque) to the rear sprocket because of the slack which must be pxovided in the chain arran~ement and the spring _ ~;
biased take-up jockey wheel or equivalent slack take-up l ;
mechanism associated with the bottom portion of the chain.
In addition, the "coaster" brake, being actuated brake ¦by the chain, could only operate the rear whee~ ~hich also is a disadvantage wherever two-wheel braking is desired as being more efficient.
THE PRIOR ART
Much prior ar-t exists in the United Sta-tes Classi~
~ication Class 192, Sub-Class 5, describin~ various mechanism ~' , Il . ..... ,~.
fi~
~05~531 fox implementing back-ped~l ac~uated brakiny. There are more than ninety paten-ts in Class 192, sub-class 5. Almost all ~- I
of these prior devices are not practical because of an in- ~ ¦
¦herent "lock-up" problem, plus an inability to wheel the ¦bicycle backwards without causing the braking mechanism to apply itself. In addition, many of these prior apparatus are not suitable for use on chain derailer bicycles. ;^
This lock-up occurs when the bicycle is brought ~to a complete stop with the brake applied. The explanation of the lock-up phenomenon is as -Eollows: Most braking systems described in the prior art consist of a mechanism actuated by back-pedaling which, in turn, causes the brakes , to be applied to the wheels. The way in which these prior ¦
¦art braking systems are intended to be released is by pedalinc in the forward direction. However, after the bicycle has ;
~een brought to a complete stop using the brakes, the brakes are now holding the rear wheel and/or front wheel stationary.
Therefore, the necessary step of pedaling forward to release . ~~
the brakes entails overpowering the friction force of the I
¦brakes whioh are still holding the wheels s-tationary.
In cases where the brakes have been applied I~
suddenly and forcefully, the friction orce of the brakes I
on the wheels is great, essentially locking up the wheels, Thus, attempting to release the brakes by pedaling ~orward would require a strong effort to overcome the locked-up braked condition. This prior art problem of the brake "lock-up"
prevents the prior art devices from being prac~ical mechanisms ~ -~
Another problem which exists in the prior art j -`~;
is that the bicycle cannot be freely wheeled backwards.
~Sinc~e the chain connects the rear wheel and the pedals, when the re~r wheels are rotated bac~wards, the pedals commcnce ;
``~
.'. ... .. ...., .-~
to rota-te backw~rds, thereb~ applying the. brakes and the. l Ibicycle stops~ This inabili~y to wheel the bike backwards l :
¦is another severe drawback of these prior art s~lstems~ l l A further problem with oth.er mechanisms ! shown !
¦in the prior art ~or back-pedal braking systems, is that they ¦
¦involve modifications to the bicycle structure itself~ Systems :~
of this type are not readily adaptable to existing bicycles~ ¦
and their usefulness âS co~nercially practical mechanisms lS ~ i, thereby limited because of the undue complications and expense of modifying the structure of the bicycle~ ¦ :
There are some ratchet-type mechanism shown in the prior art. These prior ratchet-type mechanisms ¦
have the disadvantages that they would continuously make clicking noises when pedaling forwardly, causing a continual annoyance. Also, the continuous scraping of the ratchet .
pawl prod~ces a tiring dragging force which must be overcome by the leg muscles and causes a rapid wearing of the ratchet- j ~, parts.
~U~S, Patent Mo. 765~945 - Weiler discloses a ~~;.` ~r ¦
ratchet mechanism associa~ed with the hub o:~ the rear wheel j.;
for forcing a brake-shoe against the rear wheel~ It involve complex pawls with o~set dogs which, during forward rotation !.
of the wheel, imp.inge against another spr~ng biased station- .
ary dog which is thereby lifted against the spring ~orce~
It appears to me this dog impingement would cause a conti- ;. .
nuous clicking noise and rapid wear durin~ forward travel, 1 and that the brake would become applied upon wheelin~ the bicycle backward. A].so, this ~eiler mechanism .is not usable '. -.
in chclin derailer bicycles because a reverse load is trans- r ~, ferred throuqh the chain to the rear sprocket to actuate the R i~
lll ~
1 ~513539~ ~ j l ` ~ J
brake shoe ayainst the rear wheel.
! u s. Patent No. 639,265 - Morris discloses a Icomplex ratchet mechanism for swinging a brake mem~er against ¦the tire of the rear wheel when the rider back pedals, The ratchet mechanism is very complex with plural radial springs ~
and plural transverse springs, plus a large coil spring with- ~ ¦
¦in the pedal crank bearing housing, which involves modifica-- .
tions of the bearing housing itself and precludes retrofit installation on existing multi-speed bicycles. Also, it does not appear to me that this complex Morris mechanism can be installed on a one-piece pedal crank. -;;
U.S. Patent No. ~33,6~5 - McAnulty, et al. show ~ , a ratchet mechanism associated with the pedal crank shaft in which the pawl rides continually upon the ratchet teeth when ;~
the rider pedals forward, thus producing noise, resultant wear and frictional drag. The McAnulty, e-t al.brake becomes applied when the bicycle is wheeled backward and this ratchet '`;~ ~
brake mechanism has a wheel "lock-up" problem upon full stop ~ ~ ¦
with forceful brake application, as explained above~
U S Patent No 1 483 690 - S~eddin~ describes I
~ r -a ratchet mechanism associated with the pedal crank which produces a continual clicking noise when edaling forward '~ r,' and in which the brake is mechanically applied when the bicycle is wheeled backward, unless a hand release lever is -moved to disable the pawls, in which event the brake cannot be applied by back pedaling. With a reasonably tight sprocket chain, the Spedding mechanism would exhibit a rear wheel "lock-up" problem after a full stop with forceul brake application. Tlle Speddin~ mechanlsm appears t~ be ~imitec`
'~
~ llh- I ~
05~531 1 ~
to a one-speed bicycle inasmuch as the chain is driven back- ~ ¦
~ward when back pedaling to apply -the brakes, and this back-jward chain motion is not suitable ~or multi-speed chain ~ ~ ¦
¦derailer type bicycles which have spring-biased slack take-up jockey wheels.
U.S. Patent No. 2,094,687 ~ Thompson shows a combined ratchet and over~running clutch mechanism associated with the pedal crank which requires a modified pedal crank shaft to include a sleeve bearing about its bearinsedportion.
~The braking force is appIied through over-running clutch rollers, and two sets o~ ball bearings are shown in a rela~ I ~--tively exposed races near the single front sprocket/ thus being subject to weathering and grit accumulation. The wide bulky Thompson mechanism is not suited for retrofitting on existing bicycles with conventional pedal cranks ~ U.S. Patent No. 2,186,816 ~ Bernier describes a ; complex dual ratchet and pawl mechanism associated with a wheel having the pedals on the same axle, li~e the front ~ ¦ -wheel of a tricycles The pawls are gravity operated, not positively controlled, and a continual clicking of a pawl occurs during forward pedaling. ~ l5.
. 1~
SUMMARY OF THE INVENTION
he present invention provides~a haok-pedal brake~
operator for bicycles which is advantageously conveniently and practically applicable to "chain-derailer" type bicycles ¦ -~as well as to multi-speed bicycles having ~ear mechanisms within the rear hub and also to one-speed bicycles. ~ `
The present invention is universally adaptable to current popular bicycles without modification to ~rame, pedal crank, hub or other parts.
'~he b~c~-pedal hra~e operator embodying this l3~
105853~
linvention is a compact, self-contained unit comprising a ¦Iself~contained sprocket-drive-and-brake-operator assembly.
This assembly can advan-tageously be applied as a direct replacement for the existing standard sprocke-t, and mounts 1 within the same clearance spaces, and uses the same mounting and driving means as the standard sprocket.
The back-pedal brake operator of the present invention is simple, reliable, safe and capable of operating in and withstanding the environmental conditions of mud, dirt rain, etc. which are encountered in practical, everyday bicycle usageO
The back-pedal brake operator o~ the present invention does not exhibit lock-up problems when the bicycle I ~;~
is brought to a comp~ete stop. ~ ;~
The back-pedal brake operator embodying this invention is not complex. It is easily manufacturable ~ f and practical to apply either to newly manufactured bicycles or as a retrofit assembly which can be supplied as a do-it-yourself kit to be applied to existing bicycles by their ¦owners or by bicycle shops.
A further advantage of the back-pedal brake opeator embodying the present invention is that the same ;
strong connection between the pedal crank ~rm and the driving sprocket is used to apply the br~king force.
The back-pedal brake operator of this invention can be used to brake either the rear wheel or the ~ront t~heel ~or both, thereby using the powerful leg muscles to apply ¦Ithe brakes rather than the hands. This invention overcomes .
the disadvantaqes list_d above Eor the hand-operated bra~ing ! . ,-. ~`` ~ ~
~853~L - :~
!i " ~
sys-tems currcntly ~vailable in the marketplace for multi-speed bicycles~ The rider can maintain a firm grip on the ~;
¦handle bar at all times while the brakes are being applied~
~and the handle bar is uncluttered. The braking action is ¦obtained by turning the foot pedals rearwardly a short ¦distance from any position which the pedals may occupy at ~ ;
the instant when the rider wis~es to apply braking action ~;
without utilizing the sprocket chain to apply the braking , force.
The back-pedal brake operator of ~his invention is adapted for adjustable automatic proportioning of the li~ ~
¦relative braking efforts to be exerted on the rear and front I `-s wheels to be incorporated. Thus, the ratio of the braking efforts applied respectively to the rear and front wheels ¦-can be predetermined by adjustment as may be desired over an ¦`
operating range.
This invention enables dual-actuated braking systems to be installed on multi-speed bicycles so that -the rider can apply the brakes either by foot or by hand, or by both. Various objects, aspects and advantages of the present invention will become more Eully understood ' `
from a consideration oE the following detailed desc~iption of my two presently pre~erred embodiments oE the invention.
BRIEF DESCRIPTION OF THE DRA~INGS ~, FIGURE 1 is a side elevational view oE the Eoot 1 ;~
¦pedal crank and sprocket portion o~ a multi-speed chain de-railer bicycle embodying the present invention. The pedal crank shaEt is sho~n in section which is taken generally along . .
-10~
` -~58Si3~
the line 1-1 in FIG. 2 looking toward the left. In FIG. 1, the bicycle frame and crank shaft bearlng housing are shown dash-ànd'ddtted because they are above the plane of section 1-1 as taken. In FIG. 1, the parts and components are shown in their operating positions when the rider is pedaling for-ward in the normal manner;
FIG. 2 is a front elevational view of the pedal cranks and crank shaft bearing housing and ad~acent portions of the bicycle frame with -the compact shelf-contained sprocket-drive-and-brake-operator assembly being shown in section taken along the irregular line 2-2 in FIG. l;
FIG. 3 shows a portion of the assembly of FIG. 1 with the parts and components relatively moved into their operating pos-tions when braking 0ffort is being applied by the rider;
FIG. 4 is a side-elevational view similar to FIG. 1, but showing a second embodiment of the sprocket-drive-and-brake-operator assembly of the invention. In FIG. 4, the pedal crank shaft is shown in section which is talcen generally along line 4-4 in FIG. 5. ~ few portions of FIG. 4 are b:roken away for clarity of illustration, as will be explained. In FIG.
.4, the parts and components are shown in the positions -they occupy when the braking effort is being applied;
FIG. 5 is a front-elevational view of the pedal cranks and crank shaft bearing housing and adjacent portions of the bicycle frame with the sprocket-drive-and-brake operator assembly being shown in section as taken along the irregular line 5-5 in FIG. ~;
FIG. 6 is an enlarged partial sectional view as seen taken along the line 6-6 in FIG. 4, showing the engagement of a pawl with a ratchet gear when braking effort i.s applied; and FIG. 7 shows means for equalizing the braking forces applied to rear and front wheels.
l ~
S~531 i '`~-I ~
Throughout the various Fiyures, parts and ¦ ~
components which are similar, bear the same reference numeralsl, I.s ~ ¦ ~
DETAILED DESCRIPTION ¦ ~.
l The brake ~ystem as a whole includes the compact, ¦ self-contained sprocket-drive-and-back-pedal-brake-operator assembly 10 (FIGS. 1 and 2) plus the cables or other connect- ¦
~ing means for connecting the back-pedal brake operator 10 to the brakes. The brakes may be associated with the rear wheel or the front wheel, but pre~erably the brakes are associated with both wheels. ; ¦ ~.
; The actual brake means do not compri5e a part of this invention nor do the connecting means between the i.s~.
brakes and the back pedal operator assembly 10. Any type of ~.
¦bra.ke means may be operated by the operator assembly 10 of the present invention.
The sprocket-drive-and-back-peaal~brake-operatQr assembly 10 is located on the right side of the bicycle in the positlon normally occupied by a conventionaL drive sprocket. This assembly 10 is shown mounted onto the one~ I
piece pedal crank 12 in the same manner as a standard spxocket ' That is, the assembly 10 is slipped over the left crank arm ¦
12-1 (FIG. 2~ and then over the center portion 12 (FIG, 1) f¦
the crank~ 12 until the assembly 10 stops against the mounting flange 14 (FIG. .2) near the right pedal crank 12-2. A
drive lug 16 on the right pedal crank arm 12~2 engages.a socke-t hole 18 in the assembly 10. Such a drive lug 16 is t ~ ?~
conventionally provided on the ri~ht pedal cran~ arm of a one-piece pedal crank. ~.
I . ,~;~
, .. ` !
~ ~ ~1 ~ ~1 Ii . ~1 ~ S8531 ~
I : ~
The right-hand bearing race cone 20-2 is then ¦slipped over the left crank 12~1 and then over the center portion o-f the crank and is threaded up ayainst the assembly ~ ^, 1lO, thereby retaining it. The pedal crank 12 with the ,assembly 10 attached is then installed in the bicycle in the ¦normal fashion with the central portion of the crank 12 extending through the bearing housing 22 (FIG. 2) o~ the ¦
bicycle and with the left bearing race cone 20-1 being secure I ~5 by a nut 24 or other conventional fastener. Within the bearing housing 22 of the bicycle are installed conventional anti-friction bearings associated with the left and right I bearing race cones 20-1 and 20-2 for enabling the pedal ~crank shaft 12 to be revolved freely. It is among the many advantages of this invention that no structural modifications are required to be made to the conventional bearing housing 22 nor to the bearings which are housed within it. The ,~ ~ I
pedals 26 (only one is shown) are conventional and are ~ ' ~ ¦
mounted on the outer enas of the left and right pedal crank arms 12-1 and 12-2, 1~`1 The bicycle frame may have any conventional con- , ~ ¦
figuration, for example, as shown in FIGS~ 1 and 2 there may 1 ~ ¦
be a forward frame member 28 extending forwardly and upwardly ~I
from the bearing housing 22 and an upper frame member 30 extending upwardly toward the region where the seat is located. A pair of rear rame members 32 extend rearward Erom the bearing housing 22, These rear frame members 32 ¦ straddle the rear wheel ~not shown) and extend toward opposite ends of the rear a~le.
The sproc~et-drive-and-back-pedal-brake~
opera-tor assembly 10 includes a drive plate 3~, to which is ll l 105B531 I j.z~; ~
mounted the chain sprocket (a sinyle sprocket in the case of ¦~a five-speed bicycle)or outer and inner sprockets 36 and 38, as shown. Two sprockets 36 and 38 are shown, for example, as in the case of a ten-speed chain derailer ~ype bicycle.
Large cut out openings 37 may be provided in the outer sprocket 36 to reduce its weight as is conventiona1. Also mounted to the drive plate 34 is a controlled ratchet and `~
~pàwl mechanism 40 for operating the brake or brakes, as will ¦be explained in detail below. This drive plate 34 has a center mounting hole 42 which fits snugly over the central -~
~portion of the crank 12 with the drive plate being concentric ~ ~
¦about the axis A (FIG. 1) of the pedal crank 12. The bearing ~` ;
¦ race cone 20-2 screws up tightly agains~ the inner portion ¦ of the drive plate 34 surrounding its center hole 42 for I ~ ~
¦ holding the drive plate 34 in place. 1 ~ ;
The forward and reverse torque ~forces are trans-mitted from the right pedal crank arn 12-2 through the conventional drive lug 16 located on the inside of this righk ¦pedal crank arm to the socket opening 18 which is located ¦in the driye plate 34. Thus, the drive plate 34 is rigidly ¦affixed to the pedal crank 12 and turns with this crank. ;
¦ The chain sprockets 36 and 38 are mounted to ¦the drive plate 34 in a manner which advantageously permits ¦limited relative rotation of the sproc~ets with respect to ¦the drive plate 34, about the center of the drive plate, i.e.
¦about the axis A of the pedal crank 12. The drive plate 34 i ~is sandwiched between the outer and inner sprockets 36 and ~
38. Fas-tening means 44 are provided for rigidly securing ` : '' . :~
¦the two sprockets 36 and 38 together as an assembly, so that they move together as a unit. For example, in this sprocket ¦assembly, as shown in FIG, 2, the fastening means comprise -, ¦three shoulder bolts which are riyidly secured to the two sprockets 36 and 38, by screwing into threaded holes 45 in the inner sprocket 38 with the bolt shanks snugly enyaging -~
in holes in the outer sprocket 36 which are aligned with the ,i:~
threaded holes 45. The shoulders, or sleeves, on these bolts 44, as seen in FIG. 2, provide a slight clearance between the surfaces o the drive plate 34 and the two sprockets 36 and 38 between which the drive plate is sandwiched, thereby to permit the relative limited rotational movement mentioned ~ !
above of the sprocket with respect to this drive plate. Any ~}
other ~astening means 44, such as rivets or welded studs, may be used to secure the sprocket assembly together. i~
The fastening means 44 extend through elongated ~ S~
openings 46 in the drive plate 34 near the perimeter of this drive plate. These openings 46 are elongated in a Gircum-ferential direction concentric about the center of the mount- , ing hole 42 to permit the limited relative rotation referred to above. Spring means 48 are provided to urge the sprocket assembly 36, 38 in a forward direction, i.e. in a counter- ~ -~
clockwise direction as seen in FIG. 1, relative to the drive plate 34~ The forward direct~nis the drivin~ direction for propelling the bicycle as shown by the arrow F in FIG. 1.
As shown, the spring means 48 are three similar tension 1~
springs, one end oE each tension spring 48 being hooked to ~ -the sprocket assembly 36, 38, and the other end being hooked ~ .
Ito the drive plate 34. Small holes are drilled in the drive Il . ',I ~, ~5853~ : ~
¦Iplate and inner sprocket into which the respective ends of :~
¦these tension springs are hooked~ The inner sprocket 38 ¦generally has a ring shape, as shown in FIG. 1, and the tension springs 48 are positioned within the clearance space lavailable inside of the ring configuration of the inner ; sprocket 38, :~
These spring means 48 normally urge the~ sprockets :
~ 36 and 38 in a forwardi ~counterclockwise in FIG. 1) direction :~
.~ I relative to the drive plate 34,.but the rider's legs normal.ly. :~
l urge the crank 12 and hence the drive plate 34 in a forward . .
¦ direction (counterclockwise) as the bicycle i9 being propel-led. Thus, the upper run or stretch 41 of the chain 43 ¦is in tension, ~hich, in turn, urges the sprocket as.sembly 36 138 in a clockwise direct.ion in FIG. 1 relative to the drive ¦
plate, so that the force of the spring means 48 is overcome .~ I and these springs remain stretched, as shown in FIG 1. i ~`
¦Consequently, the torque being exerted by the driver's legs I -! ¦ iS transferred from the drive plate 34 to the sprocket ¦assembly 36, 38 by the ends of the elongated openings 46 i ¦engaging the fastening means 44, as shown in FIG. 1. The torque of the sprocket assembly 36, 38 tensions the upper run 41 of the chain, thereby a~plying torque to the rear sprocket for propelling the bicycle.
Similarly, as the bicycle is wheeled b~ckward, -the rear wheel sprocket pulls on the upper run 41 of the chai:
43, thus urging the sprocket assembly 36, 38 in a clockwise direction relative to -the drive pla-te, thereby stretching the :
springs to cause the drive plate (and crank 12) to rotate cloc~wise (reverse direction) with respect to the sproc~et ¦
¦ ~ !~
~ . ~
il ~ I ,~
,' .
Il ~0~i8531 ~
¦¦assembly, thus retr~cting controlled pawls (to be explained), .
¦ so that the bicycle can be wheeled backward w.ithout the l ~
brake or brakes becoming applied, 1~.
As mentioned above, there is a controlled ~
ratchet and pawl mechanism 40 mounted to the drive plate .~
34 This mechanism 40 is not a simple ratchet hut rather ~.
it is a positively controlled ratchet mechanism. In this ~ : :~
mechanism 40, the pawls are positively driven into engagement with the abutment teeth on a gear for applying braking effort ~ ~ ?~5 when desired, These pawls are also positively drlven away . .`:;rr''~
from engayement with the abutment teeth on the gear -for re- :.. ~
leasing the brake before commencing to propel the bicycle . ~i ¦forward, and when the bicycle is wheeled backwards, i.e. .
whenever the top run 41 of the sprocket chain 43 .is under - .
active load either forward or backward.
:~ This controlled ratchet mechanism 40 includes ~ .
a ratchet gear 52: rotatable mounted on the drive plate 34. -In FIG. 1, as shown, the ratchet gear 52 is a ring gear . ~ having a large central opening 54 (FIG. 2~ which advantageous- .
ly fits around~the fixed~bearing housing 22 of the bicycle. :
Thus, the whole assembly 10 will fit onto the conventional bicycle without requiring modi~ication thereof, This ratchet gear 52 includes a raised ring portion 56 (FIG. 2) l .
Iwhich is held in concentric relationship with respec~ to the .
¦drive plate 34 by means of at least three rollers 58 which ¦engage the perimeter of this ring portion 56 in rolling contact therewith. ~.
These three rollers 58 are rotatably mounted on lugs 60 secured to the drive plate 34~ As shown, the : ~.
rollers 58 are axially retained on the lugs 60 by C-sl-aped . . .
I ~ , ~. '' ;~
. ~
~5~53~ ~ I
.' I , ~1 ¦~retainers 62, which snap into grooves in the lugs 60. A
¦~controlled pawl 66 (FIG. 2) encircles each of the lugs 60 between the rollers 58 and the drive plate 34 serving to hold these rollers spaced away from the drive plate 34 ~o accom-modate the periphery of the ratchet gear 52 in the resulting ¦¦space between these rollers and the drive plate. Thus, the ratchet gear 52 is restrained from axial movement relative ,j~"
to the drive plate 34 because the outer face (its right face) ~ '' of the ratchet gear rests against the drive plate while the ~ `
rollers 58 overlap the peripheral portion of the inner face (its left face) of this ratchet gear.
The ratchet gear 52 is prevented from rotating in the forward direction F by a proJecting stop pin element 64 (FIG. 2) which engages up against the underside o~ the rear bicycIe frame member 32. This stop pin 64 is mounted on a brake actuator arm member 65 which is attached by a plurality of machine screws 67 to the raised ring portion 56 ¦~
of the ratchet gear 52, When the ratchet gear 52 is turned in the reverse direction R, it serves to operake the brakes, as will be explained further below.
In order to turn the ratchet gear 52 in the ¦i`
reverse direction R for applying braking effort, there is provided one or more positively controlled pawls 66 pivotally mounked on the drive plate 34~ In the assembly 10, as 1 shown, the pawls 66 are pivotally mounted on the same lugs 60 t as are used to mount the rollers 58, so that these pawls ~ ~ -serve to hold the rollers spaced away from the drive plate 34 ,~
as discussed above. It is to be understood that the con-trolled pawls~ 66 could be pivotally mo~lnted upon o~ther lugs similar -to the lugs 60, in wllich case spacing ~ashers would )e provided between the rollers 5~ and the dI^.iVe plate~ How- i~
il , . ~, l ~
. I ~
1~5853~ 1 ~
ever, I prefer to uxe the lugs 6~ in this embodiment for !
the dual purpose of mounting the rollers 58 as ~ell as mount- j ~
ing the controlled pawls 66. ! ~ i In order to produce the positive enyac3ement ox Icomplete disengagement of the pawls 66 with the abutment ¦teeth of the ratchet gear 52, there is provided one or more ¦pawl-controlling cam pin elements 68 which are fixedly mountecl Ito the sprocket assembly 36~ 38, These pawl-controlling cam ¦ i;
pin elements 68 extend through elongated slots 70 in the drive plate 14 for engaging cam surfaces 72 in the controlled pawls 66. The cam surfaces 72 are inclined with respec~ to I .
a radius from the axis A of the crank 12 passing through the center of the pawl-controlling element 68~ This inclination ;
of the elongated cam surface 72 positively causes the control ~
led pawls 56 to withdraw from the ratchet gear 52 when the ~ ~t rider's legs turn the drive plate 34 ror~7ard (F) with respect to the sprocket assembly. Thus, when the rider is propellinc i~
¦ the bicycle forward, the controlled pawls 66 are completely ¦ and positively retracted by cam pins 68 away from the ratchet ¦gear. There is no frictional drag of these pawls against ~ ~
the ratchet teeth nor resultant clicking noises, )`~ ~ ;
Further, when the drive ~late 34 is rotated Irearward (R) with respect to the sprockets as the rider star~
¦to back pedal for applying the brake or brakes, the control-¦led pawls 66 are positively caused to ensage against the ¦abutment teeth of the ratchet gear 52. The elongatecl clear-ance slots 70 are concentric about the center of the drive plate 34 (concentric about axis A). The cam surfaces ; ~i~
72 comprise eloncJated openin~s in the pawls which are incline i ith respect to the c:Learance s1ots 70, as e~p`a;ned above;
Il , ,<~
i When the rider back pedals (R) for applying ~-~
brakincJ effort, the driving torque is removed from the sprockets 36~ 38, and the top run 41 of the chain becomes lunloaded. The unloaded top run 41 of the chain allows the ¦spring means 48, as shown in FIG, 3, to rotate the sprockets ^~,~
Icounterclockwise relative to the drive plate (i.e. the drive iplate turns clockwise relative to the sprockets) thereby posi- . ~
jtively engaging the controlled pawls 66 with the abutment - ;
¦teeth o~ the sprocket gear 52. As the rider contin~es to ' ~-exert torque in the back pedal ~reverse) ~irection (R) (please see FIG. 3), the now-engaged pawls 66 drive the sprocket gear 52 in the reverse direction to swing the actuator arm member 65 down as indicated b~ the braking arrow ¦
~B at the right. This brake actuator arm member 65 is con- ,, ¦nected by suitable connecting means 74 to the brake or brakes I
for the rear or front wheel or both.
In this embodiment, the connecting means 74 are a pair of Bowden wire cables 74-1 and 74-2, each having an attachment shackle 76. These shackles 76 are pivotally attached to selected holes 78 extending in a row along the upper edge of the actuator arm member 65. The Elexible , sheaths 80 oE these Bowden cables 74 are ~erminated at ~ ~
anchoring bolts 82 secured by clamp means 84, adjustably ~ ~ -¦Imolmtable on the forward frame member 2S o~ the bicycle.
! One of the connecting means 74-1 extends to the ibrake mechanism for one of the wheels and the other connect~
l I ......
¦ing means 74-2 extends to the brake mechanism Eor the other wheel. The row of attachment holes 7S and the pair oE
shackles 76 provide adjus-tment means b~ which the relative brak:ing eEEort can ~e adjusted between -the ~rak~s for ~he .
. ',,:'.~'~
1058531 1 ~
rear and Eron-t wheels, as may be desired.
I Generally speakiny, the braking effort to be ¦lapplied to the front wheel should not be unduly larye as , ¦compared to the braking effort to be applied to the rear wheel, ¦Ibecause a sudden powerful braking effort could then pitch the ¦
bicycle and rider forward over the front wheel. A person~s I
leg muscles are much more powerful than the hand muscles, so -that a very powerful braking effort can be obtained using this invention~ For braking action applied to the rear wheel, there tends to be a self-limiting braking efect. This self-limiting action occurs because the deceleration of the bicycle ¦during braking tends to reduce the weight being carried by the rear wheel, thereby reducing the perpendicular force between the rear tire and the pavement, thus limiting the braking force to be exerted by the rear tire upon the pave- I j ment. I ~ ;
Advantageously, the rider or the bicycle shop can adjust the predetermined ratio of the braking efforts by the adjustment means 76 and 78, as may be desired.
-Although two sprockets 36 and 38 are shown, it will be understood that the sprocket-drive-and-back-pedal-brake-operator assembly 10 can be provided with only one sprocket whenever desired~ The missing sprocket is then I ;
replaced with a ring plate or equivalent member. Moreover, either the outer or inner sprocket 36 or 38 may be omi-tted, ¦ as desired.
l There are four operating modes: (1.) pedaling ¦forward for propelling the bicycle; (2) pedaling backward, l;i.e. applyin~ the brake or brakes; (3) wheeling the bicycle¦
l~orward as b~ coasting for~ard or as by rolling the bicycle I! ~ ``:
r 1 ~058531 ~ ~
Iforward while the rider temporarily walks ~loncJside, and ¦ ~
(~) wheeling the bicycle backward as by rolling the bicycle I ~
Ibackward while the rider temporari'33.y walks alongside. It is . .
¦lalso possible for the rider to coast backward, as a stunt, ¦while sitting on the bicycle with his ~eet, removed from the ¦Ipedals 26, so that the spring means 48 are allowed to cause .
the arive plate 34 and pedal crank 12 to r~tate in the ~¦reverse directions to follow the reverse motion of the chain .~
~143 as it pulls the sprocket in reverse rota-tion. ;~
When pedaling forward, the drive plate 34 moves I ., forward (F) relative ~o the sprockets 36, 38, so the spring l ~ll 3 means 48 are stretched and the pawl controlling cam pin' elements 68 cam the pawls 66 out of engagement, and normal .¦
f~rward pedaling operation occurs with the brake released ~ I
and with the pawls 66 retracted completel~ out of engagement ) ~.;
with the ratchet gear 52. Thus, there is no cllcking nor ratcheting noise nor ratchet drag nor resulting wear of the , teeth or pawls. ;,.
Pedaling backward removes the.tenslon of the top run 41 o the chain 43 from the sprockets 36, 38 (i.e. .
the chain load is removed) while at the same time the pedal i =.`',.
i crank commences turning the drive plate 34 rearwardly. Thus, . .
-the drive plate 14 turns rearward (clockwise) relative to the sprocket or sprockets 36, 38 assisted by the springs 148. This relative motion causes controlled pawls 66 ~o : :
Ijengage the ratchet gear 52 and rotate it and its arm 65 in ¦.the reverse (clockwise~ direction thereby applying the brakes llas shown in FIG. 3. ¦
¦l, In wheeling or coas-tlng Eorward, the over- .
',runnLn~ mecllallism in the .rear wheel hub allows the rear ~Yheel 1~' ~ ;;`;
.
~058531 to freely turn forward without revolving the chain, In wheeling bacXward, the conventional over- ¦
~running mechanism in the rear hub becomes engayed, thus pulling the top run 41 of the chain 43 rearward, i.e. to the - ¦right in the drawing. Thus, the sprocket or sprockets :
36, 38 are turned rearward (clockwise) relative to the drive plate 34, so that the pawl control pins 68 are moved in the :
.rearward direction causing the pawls 66 to be retracted away .
from the ratchet gear 52. Therefore, the brakes are not applied, and the bicycle is allowed to wheel hackwardly with-out the brakes becoming engaged. The pedal crank does revolve in the reverse direction when wheeling backward ¦
because the fastening bolts 44 engage against the rear of the , slots 46 as urged by the spring means 48, I .
Although the assen~ly 10 can advantageously be .~
applied to a conventional one-piece crank 12, it can also be , .
applled to pedal crank assemblies which are built up from ,-~
several components. The drive plate 34 is driven by a , drive lug 16 on the right pedal crank, Alternatively, the . ,~
central hole 42 in the drive plate 34 is formed with a key-way and is keyed to the central portion of the pedal crank assembly, or the drive plate is keyed to the hub of the right ~ 1~;,1 pedal crank arm by a drive lug, key, or pin, ~ :
The spring means 48 are included to assure tha-t '~
the drive plate 34 will turn rearward (clockwise) relative to the sprocket assembly 36, 38 when the rider back pedals so that the controlled pawls 66 will en~a~e the ~ear 52 to apply braking, In many cases, there is a sli~ht but suf- :
¦'ficient frictional drag in the overall chain system and ,~
I .
I
1. -?3~ ~.. ,,.. ~. ~
Il I
~58~3~L
:~
associated rear sprocket and chain guides to produce this Isame braking result when back pedaling without the use of the ¦spring means 48. Thus, these springs 48 are included as an ¦assurance but they can be omitted.
i As used herein, the term "sprocket assemblyt' is ¦intended to mean a plurality of sprockets assembled together to rotate with each other as a unit.
The term "sprocket means" is intended to be inter-preted broadly to include either one or a plurality of `
¦sprockets. ~
In the sprocket-drive-and-back-pedal operator 10A, 1 ~-shown in FIGS. 4, 5 and 6, many o the parts ana components ~;
are the same as ln the operator 10 of FIGS 1-3. Only the differences will be described.
The Bowden wire connecting means 74-1 and 74-2 are anchored to a drum actuator member 65A (FIGS. 4 and 5) by means of cylindrical end f1ttings 90 (FIG. 4) which are swaged onto the ends of the respective cables. These end fittings 90 engage in inclined slots 92 machined in the ' ~ i flanges 94 of the drum actuator mem~er 65A. As shown in FIG. 4, the inclined slots 92 are positioned so that the cables are wrapped almost a full revolution around the actuator member 65A. As shown in FIG. 4, the inclined slots 92 are positioned so that the cables are wrapped almost a full revolution around the actuator member 65A in the channel 96 between the flanges 94. By wrappin~ the cables I around the actuator nun~er 65A in this manner, the stress I on the end fittings 90 is reduced. -;
¦ This drum actuator member ~5A is rotatably ~
mountcd to the drive plate 3~ by securillg it to a ring ; ~' -21- ~
1. 1 ~1 :
i853~ i ratchet gear 52A which also is ro-tatable with respect to the drive plate. A plurality of fastening means 67, for I -example machine screws, secure the actuator member 65A and th~
ratchet gear 52A toyether as a unitary assembly.
In order to mount the sprocket ring gear and ¦ ;
actuator assembly 52A, 65A onto the drive plate 34, as seen ¦
in FIG. 5, there is bearing ring means 58A secured to the drive plate 34 by means of suitable fasteners 100, for example machine screws. The bearing means 58A has a peri-pheral flange 102 ~FIG. 5) which overlaps the inner edge of `-1:
Ithe ring ratchet gear, thus axially retaining the ratchet ¦and drum actuator assen~ly 52A, 65A with respect to the `
¦inside surface of the drive plate. l , ¦ Thus, in comparing the brake operator assemblies lOA and 10 of FIGS. 4-6 and 1-3, respectively, it is seen ..
that in the operator assembly lOA, the ratchet ring gear and lactuator assembly 52A, 65A is rotatably mounted to drive ¦plate 34 by beariny means 5~A engaging the interior perimeter ~ri-l of the ring portion of this assembly. In contradistinction, as seen in FIG. 1, the ratchet ring gear and actuator assembl 52, 65 is rotatably mounted to the drive pla-te 34 by roller bearing means 58 engaging the external perimeter of the ring portion 56 thereof. ;~
l The controlled pawls 66 (FIG. 6) are mounted ¦on lugs 60 held by C-shaped retainers 62 and the pawl con- ~ -~
~trolling cam pins 68 axe secured to the sproc~et assen~ly 36,1 ¦j38 by suitable fastening means 104 such as a machine screw.
¦IAS seen in FIG. 6, the cam pin 68 has an enlarged shoulder ¦106 for spacin~ -the controlled pawl 66 away from the outer sp~ocl~t 36.
` ~ ~
`10~853 i' Th~ stop means 6~A for preventing forward rotation ¦
I.of the ratchet gear and brake actuator assembly 52A, 65A ¦
¦lis a luy 108 secured to the inner surface of the drum 90 ¦ .
by a pair of machine screws. A resilient sleeve 110 (FIG. 4)~
of rubber or plastic surrounds this lug 108 for cushioning its contact with the rear frame member 32.
As seen ln FIG. 4, the abutment surfaces 112 of ,.: .
~the ratchet teeth are sloped slightly, so that these surfaces face directly toward the axis of the pivot mounting 60 for ~ -!
~the control pawl 66. In other words, the surface 112 is exactly perpendicular to the line from the center of this ¦surface 112 to the axis of the pivot pin 60. Thus, when the .
¦pawl- is engaged, as shown in FIG. 4, there is no resultant ~;
radial force on the pawl because the thrust is directly along.
. a line passing through the axis of the pivot 60.
The same comments about minor modifications i within the scope of my invention apply to the sprocket-driv~- .
::and-back-pedal-brake-operator assembly lOA as apply to the assembly 10 FIGS. 1-3, namely, this assembly lOA can be applied to a one-piece crank or to pedal a crank which is built up frommultiple parts. The spring means 48 are include( ~
in the assembly lOA for assurance, but such ,spring means can I ,:
¦be omitted .i there is sufficient frictional drag exerted ~.. ,~
,by the chain 43. The sprocket means 36, 38 ~hich is used :. ~with the assembly lOA may include one or more sprockets.
¦ As shown in FIG. 7, the forces exerted on the ¦brake means for the front and rear wheels may be equalized . .~
¦¦by forming the respective cables 74--1 and 74-2 as a conti , u ¦nuous cable element extending in a U-bend 114 around a . ,-pulley sheave 120 rotatably mounted on a clevis 122 ~hich is ~' ~ r~ r~ ? ~
585:~L ~
I' '~ ~
¦Iconnected by a tension link 1~4, such as mechanical link or icable to a shackle 76 which i5 pivotally mounted to the actuator 65. ¦~
Alternatively, the actuator drum member 65A .
can be replaced by an actuator arm member 65 which is similar Ito the actuator arm member 65 (FIG. 1) but it is secured by . :;~
¦fastening means 67 to the sprocket 52A. Then the shackle 76 . ~-~(FIG. 7) i_ pivotally mour~e~ t- this ac~uator arm member 65.
, ' I ~ '''`'i' . ````~'~```
~ ~ . ~
I
I .
I -~7~
I/ ' :-~; l'~''
~ . On different bicycles the hand levers are located in different places and at diEferent distances (spans ~from the hand grips, depending on the orientation and place-Iment of their mounting clamps on the handle bars. When a II rider is using a borrowed or a rented bicycle in which the brake levers are locatecl differently from those on a familiar ¦ bicycle, there is an aw~ward or hazardous delay in applyin~
tho bra~es wlile the rider's finqers are nervously searching I ~ ;
lout the location of -the brake levers. Alternat~vely, the ¦Irider may avert his eyes from the path ahead in an emergency ¦
to look down to find the levers. This diversion of vision ¦
is undesirable and can be very dangerous when automotive I
traffic is near, ¦
, 5. When the hand brakes are suddenly applied l lin an emergency stop, the bicycIe may start to skid or ¦
¦lean over~ The human reflex action is often to tighten the grip, which jams the brakes and worsens the inciplent I
skid. ¦
6. When using the racing style handle bar ¦
with the underslung U-shaped hand grip, most riders cruise ¦
Iwith their hands on the straight horizontal central portions ; of the handle bar, because this central portion is higher, thereby enabling the rider to sit up straight. The brake ¦levers are often mounted down near the underslung hand grips.
¦Thus, the rider must release both hands and completely shift both hands down to new p~sitions in order to reach the brake levers. In some cases, auxiliary levers are installed so that the rider can reach this auxiliary lever with the hands remaining in the cruising position. These auxiliary levers increase the comple~ity and expense. In addition, they are not available on many modern bicycles, leading to 1 such hazards as described under paragraph No. 4 ab~ve, when ¦ the rider has become accustomed to using them on a familiar bicycle. On camping trips, some riders cannot carry all of the desired gear on their bac~i or on a carrier over the rear wheel. Some equipment then ends up strapped to the handle bar, in which case the au~iliar~ lever can become accidental-ly jammed, preventing the bra~e Erom being applied by use of the regular levcr~
105853~
1 7~ ~lso~ th-~xe are ti~nes ~hen a bi~ycle rider ma ¦¦wish to reach out to ward off an impact, and at such an in- ¦
s-tant, the rider is forced to abandon any chance of using ¦
the hand-brake lever on the respective side where the arm is being extended. It may be the rear brake which is abandoned,~
¦leaving only the front brake, which can veer the bicycle off from the rider's intended track~ -Thus, as pointed out above, there are serious disadvantages or sa~ety hazards involved with hand- ~ ¦
operated lever braking systems for multi-speed chain derailer or gear shi~ter ~icycles. These-disadvanta~es and hazards ~ ¦
are augmented in the case of children whose hands are weaker and who often ride their bicycles at top speed with exhuberanc under conditions where an adult would proceed cautiously, the ;~
children tending to rely on their ability to brake suddenly at the last instant. ! ```-The factor which does not allow the application 1 of the "coaster" brake to the "chain-derailer" type bicycles is the fâct that the chain cannot apply a reverse load (reverse torque) to the rear sprocket because of the slack which must be pxovided in the chain arran~ement and the spring _ ~;
biased take-up jockey wheel or equivalent slack take-up l ;
mechanism associated with the bottom portion of the chain.
In addition, the "coaster" brake, being actuated brake ¦by the chain, could only operate the rear whee~ ~hich also is a disadvantage wherever two-wheel braking is desired as being more efficient.
THE PRIOR ART
Much prior ar-t exists in the United Sta-tes Classi~
~ication Class 192, Sub-Class 5, describin~ various mechanism ~' , Il . ..... ,~.
fi~
~05~531 fox implementing back-ped~l ac~uated brakiny. There are more than ninety paten-ts in Class 192, sub-class 5. Almost all ~- I
of these prior devices are not practical because of an in- ~ ¦
¦herent "lock-up" problem, plus an inability to wheel the ¦bicycle backwards without causing the braking mechanism to apply itself. In addition, many of these prior apparatus are not suitable for use on chain derailer bicycles. ;^
This lock-up occurs when the bicycle is brought ~to a complete stop with the brake applied. The explanation of the lock-up phenomenon is as -Eollows: Most braking systems described in the prior art consist of a mechanism actuated by back-pedaling which, in turn, causes the brakes , to be applied to the wheels. The way in which these prior ¦
¦art braking systems are intended to be released is by pedalinc in the forward direction. However, after the bicycle has ;
~een brought to a complete stop using the brakes, the brakes are now holding the rear wheel and/or front wheel stationary.
Therefore, the necessary step of pedaling forward to release . ~~
the brakes entails overpowering the friction force of the I
¦brakes whioh are still holding the wheels s-tationary.
In cases where the brakes have been applied I~
suddenly and forcefully, the friction orce of the brakes I
on the wheels is great, essentially locking up the wheels, Thus, attempting to release the brakes by pedaling ~orward would require a strong effort to overcome the locked-up braked condition. This prior art problem of the brake "lock-up"
prevents the prior art devices from being prac~ical mechanisms ~ -~
Another problem which exists in the prior art j -`~;
is that the bicycle cannot be freely wheeled backwards.
~Sinc~e the chain connects the rear wheel and the pedals, when the re~r wheels are rotated bac~wards, the pedals commcnce ;
``~
.'. ... .. ...., .-~
to rota-te backw~rds, thereb~ applying the. brakes and the. l Ibicycle stops~ This inabili~y to wheel the bike backwards l :
¦is another severe drawback of these prior art s~lstems~ l l A further problem with oth.er mechanisms ! shown !
¦in the prior art ~or back-pedal braking systems, is that they ¦
¦involve modifications to the bicycle structure itself~ Systems :~
of this type are not readily adaptable to existing bicycles~ ¦
and their usefulness âS co~nercially practical mechanisms lS ~ i, thereby limited because of the undue complications and expense of modifying the structure of the bicycle~ ¦ :
There are some ratchet-type mechanism shown in the prior art. These prior ratchet-type mechanisms ¦
have the disadvantages that they would continuously make clicking noises when pedaling forwardly, causing a continual annoyance. Also, the continuous scraping of the ratchet .
pawl prod~ces a tiring dragging force which must be overcome by the leg muscles and causes a rapid wearing of the ratchet- j ~, parts.
~U~S, Patent Mo. 765~945 - Weiler discloses a ~~;.` ~r ¦
ratchet mechanism associa~ed with the hub o:~ the rear wheel j.;
for forcing a brake-shoe against the rear wheel~ It involve complex pawls with o~set dogs which, during forward rotation !.
of the wheel, imp.inge against another spr~ng biased station- .
ary dog which is thereby lifted against the spring ~orce~
It appears to me this dog impingement would cause a conti- ;. .
nuous clicking noise and rapid wear durin~ forward travel, 1 and that the brake would become applied upon wheelin~ the bicycle backward. A].so, this ~eiler mechanism .is not usable '. -.
in chclin derailer bicycles because a reverse load is trans- r ~, ferred throuqh the chain to the rear sprocket to actuate the R i~
lll ~
1 ~513539~ ~ j l ` ~ J
brake shoe ayainst the rear wheel.
! u s. Patent No. 639,265 - Morris discloses a Icomplex ratchet mechanism for swinging a brake mem~er against ¦the tire of the rear wheel when the rider back pedals, The ratchet mechanism is very complex with plural radial springs ~
and plural transverse springs, plus a large coil spring with- ~ ¦
¦in the pedal crank bearing housing, which involves modifica-- .
tions of the bearing housing itself and precludes retrofit installation on existing multi-speed bicycles. Also, it does not appear to me that this complex Morris mechanism can be installed on a one-piece pedal crank. -;;
U.S. Patent No. ~33,6~5 - McAnulty, et al. show ~ , a ratchet mechanism associated with the pedal crank shaft in which the pawl rides continually upon the ratchet teeth when ;~
the rider pedals forward, thus producing noise, resultant wear and frictional drag. The McAnulty, e-t al.brake becomes applied when the bicycle is wheeled backward and this ratchet '`;~ ~
brake mechanism has a wheel "lock-up" problem upon full stop ~ ~ ¦
with forceful brake application, as explained above~
U S Patent No 1 483 690 - S~eddin~ describes I
~ r -a ratchet mechanism associated with the pedal crank which produces a continual clicking noise when edaling forward '~ r,' and in which the brake is mechanically applied when the bicycle is wheeled backward, unless a hand release lever is -moved to disable the pawls, in which event the brake cannot be applied by back pedaling. With a reasonably tight sprocket chain, the Spedding mechanism would exhibit a rear wheel "lock-up" problem after a full stop with forceul brake application. Tlle Speddin~ mechanlsm appears t~ be ~imitec`
'~
~ llh- I ~
05~531 1 ~
to a one-speed bicycle inasmuch as the chain is driven back- ~ ¦
~ward when back pedaling to apply -the brakes, and this back-jward chain motion is not suitable ~or multi-speed chain ~ ~ ¦
¦derailer type bicycles which have spring-biased slack take-up jockey wheels.
U.S. Patent No. 2,094,687 ~ Thompson shows a combined ratchet and over~running clutch mechanism associated with the pedal crank which requires a modified pedal crank shaft to include a sleeve bearing about its bearinsedportion.
~The braking force is appIied through over-running clutch rollers, and two sets o~ ball bearings are shown in a rela~ I ~--tively exposed races near the single front sprocket/ thus being subject to weathering and grit accumulation. The wide bulky Thompson mechanism is not suited for retrofitting on existing bicycles with conventional pedal cranks ~ U.S. Patent No. 2,186,816 ~ Bernier describes a ; complex dual ratchet and pawl mechanism associated with a wheel having the pedals on the same axle, li~e the front ~ ¦ -wheel of a tricycles The pawls are gravity operated, not positively controlled, and a continual clicking of a pawl occurs during forward pedaling. ~ l5.
. 1~
SUMMARY OF THE INVENTION
he present invention provides~a haok-pedal brake~
operator for bicycles which is advantageously conveniently and practically applicable to "chain-derailer" type bicycles ¦ -~as well as to multi-speed bicycles having ~ear mechanisms within the rear hub and also to one-speed bicycles. ~ `
The present invention is universally adaptable to current popular bicycles without modification to ~rame, pedal crank, hub or other parts.
'~he b~c~-pedal hra~e operator embodying this l3~
105853~
linvention is a compact, self-contained unit comprising a ¦Iself~contained sprocket-drive-and-brake-operator assembly.
This assembly can advan-tageously be applied as a direct replacement for the existing standard sprocke-t, and mounts 1 within the same clearance spaces, and uses the same mounting and driving means as the standard sprocket.
The back-pedal brake operator of the present invention is simple, reliable, safe and capable of operating in and withstanding the environmental conditions of mud, dirt rain, etc. which are encountered in practical, everyday bicycle usageO
The back-pedal brake operator o~ the present invention does not exhibit lock-up problems when the bicycle I ~;~
is brought to a comp~ete stop. ~ ;~
The back-pedal brake operator embodying this invention is not complex. It is easily manufacturable ~ f and practical to apply either to newly manufactured bicycles or as a retrofit assembly which can be supplied as a do-it-yourself kit to be applied to existing bicycles by their ¦owners or by bicycle shops.
A further advantage of the back-pedal brake opeator embodying the present invention is that the same ;
strong connection between the pedal crank ~rm and the driving sprocket is used to apply the br~king force.
The back-pedal brake operator of this invention can be used to brake either the rear wheel or the ~ront t~heel ~or both, thereby using the powerful leg muscles to apply ¦Ithe brakes rather than the hands. This invention overcomes .
the disadvantaqes list_d above Eor the hand-operated bra~ing ! . ,-. ~`` ~ ~
~853~L - :~
!i " ~
sys-tems currcntly ~vailable in the marketplace for multi-speed bicycles~ The rider can maintain a firm grip on the ~;
¦handle bar at all times while the brakes are being applied~
~and the handle bar is uncluttered. The braking action is ¦obtained by turning the foot pedals rearwardly a short ¦distance from any position which the pedals may occupy at ~ ;
the instant when the rider wis~es to apply braking action ~;
without utilizing the sprocket chain to apply the braking , force.
The back-pedal brake operator of ~his invention is adapted for adjustable automatic proportioning of the li~ ~
¦relative braking efforts to be exerted on the rear and front I `-s wheels to be incorporated. Thus, the ratio of the braking efforts applied respectively to the rear and front wheels ¦-can be predetermined by adjustment as may be desired over an ¦`
operating range.
This invention enables dual-actuated braking systems to be installed on multi-speed bicycles so that -the rider can apply the brakes either by foot or by hand, or by both. Various objects, aspects and advantages of the present invention will become more Eully understood ' `
from a consideration oE the following detailed desc~iption of my two presently pre~erred embodiments oE the invention.
BRIEF DESCRIPTION OF THE DRA~INGS ~, FIGURE 1 is a side elevational view oE the Eoot 1 ;~
¦pedal crank and sprocket portion o~ a multi-speed chain de-railer bicycle embodying the present invention. The pedal crank shaEt is sho~n in section which is taken generally along . .
-10~
` -~58Si3~
the line 1-1 in FIG. 2 looking toward the left. In FIG. 1, the bicycle frame and crank shaft bearlng housing are shown dash-ànd'ddtted because they are above the plane of section 1-1 as taken. In FIG. 1, the parts and components are shown in their operating positions when the rider is pedaling for-ward in the normal manner;
FIG. 2 is a front elevational view of the pedal cranks and crank shaft bearing housing and ad~acent portions of the bicycle frame with -the compact shelf-contained sprocket-drive-and-brake-operator assembly being shown in section taken along the irregular line 2-2 in FIG. l;
FIG. 3 shows a portion of the assembly of FIG. 1 with the parts and components relatively moved into their operating pos-tions when braking 0ffort is being applied by the rider;
FIG. 4 is a side-elevational view similar to FIG. 1, but showing a second embodiment of the sprocket-drive-and-brake-operator assembly of the invention. In FIG. 4, the pedal crank shaft is shown in section which is talcen generally along line 4-4 in FIG. 5. ~ few portions of FIG. 4 are b:roken away for clarity of illustration, as will be explained. In FIG.
.4, the parts and components are shown in the positions -they occupy when the braking effort is being applied;
FIG. 5 is a front-elevational view of the pedal cranks and crank shaft bearing housing and adjacent portions of the bicycle frame with the sprocket-drive-and-brake operator assembly being shown in section as taken along the irregular line 5-5 in FIG. ~;
FIG. 6 is an enlarged partial sectional view as seen taken along the line 6-6 in FIG. 4, showing the engagement of a pawl with a ratchet gear when braking effort i.s applied; and FIG. 7 shows means for equalizing the braking forces applied to rear and front wheels.
l ~
S~531 i '`~-I ~
Throughout the various Fiyures, parts and ¦ ~
components which are similar, bear the same reference numeralsl, I.s ~ ¦ ~
DETAILED DESCRIPTION ¦ ~.
l The brake ~ystem as a whole includes the compact, ¦ self-contained sprocket-drive-and-back-pedal-brake-operator assembly 10 (FIGS. 1 and 2) plus the cables or other connect- ¦
~ing means for connecting the back-pedal brake operator 10 to the brakes. The brakes may be associated with the rear wheel or the front wheel, but pre~erably the brakes are associated with both wheels. ; ¦ ~.
; The actual brake means do not compri5e a part of this invention nor do the connecting means between the i.s~.
brakes and the back pedal operator assembly 10. Any type of ~.
¦bra.ke means may be operated by the operator assembly 10 of the present invention.
The sprocket-drive-and-back-peaal~brake-operatQr assembly 10 is located on the right side of the bicycle in the positlon normally occupied by a conventionaL drive sprocket. This assembly 10 is shown mounted onto the one~ I
piece pedal crank 12 in the same manner as a standard spxocket ' That is, the assembly 10 is slipped over the left crank arm ¦
12-1 (FIG. 2~ and then over the center portion 12 (FIG, 1) f¦
the crank~ 12 until the assembly 10 stops against the mounting flange 14 (FIG. .2) near the right pedal crank 12-2. A
drive lug 16 on the right pedal crank arm 12~2 engages.a socke-t hole 18 in the assembly 10. Such a drive lug 16 is t ~ ?~
conventionally provided on the ri~ht pedal cran~ arm of a one-piece pedal crank. ~.
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The right-hand bearing race cone 20-2 is then ¦slipped over the left crank 12~1 and then over the center portion o-f the crank and is threaded up ayainst the assembly ~ ^, 1lO, thereby retaining it. The pedal crank 12 with the ,assembly 10 attached is then installed in the bicycle in the ¦normal fashion with the central portion of the crank 12 extending through the bearing housing 22 (FIG. 2) o~ the ¦
bicycle and with the left bearing race cone 20-1 being secure I ~5 by a nut 24 or other conventional fastener. Within the bearing housing 22 of the bicycle are installed conventional anti-friction bearings associated with the left and right I bearing race cones 20-1 and 20-2 for enabling the pedal ~crank shaft 12 to be revolved freely. It is among the many advantages of this invention that no structural modifications are required to be made to the conventional bearing housing 22 nor to the bearings which are housed within it. The ,~ ~ I
pedals 26 (only one is shown) are conventional and are ~ ' ~ ¦
mounted on the outer enas of the left and right pedal crank arms 12-1 and 12-2, 1~`1 The bicycle frame may have any conventional con- , ~ ¦
figuration, for example, as shown in FIGS~ 1 and 2 there may 1 ~ ¦
be a forward frame member 28 extending forwardly and upwardly ~I
from the bearing housing 22 and an upper frame member 30 extending upwardly toward the region where the seat is located. A pair of rear rame members 32 extend rearward Erom the bearing housing 22, These rear frame members 32 ¦ straddle the rear wheel ~not shown) and extend toward opposite ends of the rear a~le.
The sproc~et-drive-and-back-pedal-brake~
opera-tor assembly 10 includes a drive plate 3~, to which is ll l 105B531 I j.z~; ~
mounted the chain sprocket (a sinyle sprocket in the case of ¦~a five-speed bicycle)or outer and inner sprockets 36 and 38, as shown. Two sprockets 36 and 38 are shown, for example, as in the case of a ten-speed chain derailer ~ype bicycle.
Large cut out openings 37 may be provided in the outer sprocket 36 to reduce its weight as is conventiona1. Also mounted to the drive plate 34 is a controlled ratchet and `~
~pàwl mechanism 40 for operating the brake or brakes, as will ¦be explained in detail below. This drive plate 34 has a center mounting hole 42 which fits snugly over the central -~
~portion of the crank 12 with the drive plate being concentric ~ ~
¦about the axis A (FIG. 1) of the pedal crank 12. The bearing ~` ;
¦ race cone 20-2 screws up tightly agains~ the inner portion ¦ of the drive plate 34 surrounding its center hole 42 for I ~ ~
¦ holding the drive plate 34 in place. 1 ~ ;
The forward and reverse torque ~forces are trans-mitted from the right pedal crank arn 12-2 through the conventional drive lug 16 located on the inside of this righk ¦pedal crank arm to the socket opening 18 which is located ¦in the driye plate 34. Thus, the drive plate 34 is rigidly ¦affixed to the pedal crank 12 and turns with this crank. ;
¦ The chain sprockets 36 and 38 are mounted to ¦the drive plate 34 in a manner which advantageously permits ¦limited relative rotation of the sproc~ets with respect to ¦the drive plate 34, about the center of the drive plate, i.e.
¦about the axis A of the pedal crank 12. The drive plate 34 i ~is sandwiched between the outer and inner sprockets 36 and ~
38. Fas-tening means 44 are provided for rigidly securing ` : '' . :~
¦the two sprockets 36 and 38 together as an assembly, so that they move together as a unit. For example, in this sprocket ¦assembly, as shown in FIG, 2, the fastening means comprise -, ¦three shoulder bolts which are riyidly secured to the two sprockets 36 and 38, by screwing into threaded holes 45 in the inner sprocket 38 with the bolt shanks snugly enyaging -~
in holes in the outer sprocket 36 which are aligned with the ,i:~
threaded holes 45. The shoulders, or sleeves, on these bolts 44, as seen in FIG. 2, provide a slight clearance between the surfaces o the drive plate 34 and the two sprockets 36 and 38 between which the drive plate is sandwiched, thereby to permit the relative limited rotational movement mentioned ~ !
above of the sprocket with respect to this drive plate. Any ~}
other ~astening means 44, such as rivets or welded studs, may be used to secure the sprocket assembly together. i~
The fastening means 44 extend through elongated ~ S~
openings 46 in the drive plate 34 near the perimeter of this drive plate. These openings 46 are elongated in a Gircum-ferential direction concentric about the center of the mount- , ing hole 42 to permit the limited relative rotation referred to above. Spring means 48 are provided to urge the sprocket assembly 36, 38 in a forward direction, i.e. in a counter- ~ -~
clockwise direction as seen in FIG. 1, relative to the drive plate 34~ The forward direct~nis the drivin~ direction for propelling the bicycle as shown by the arrow F in FIG. 1.
As shown, the spring means 48 are three similar tension 1~
springs, one end oE each tension spring 48 being hooked to ~ -the sprocket assembly 36, 38, and the other end being hooked ~ .
Ito the drive plate 34. Small holes are drilled in the drive Il . ',I ~, ~5853~ : ~
¦Iplate and inner sprocket into which the respective ends of :~
¦these tension springs are hooked~ The inner sprocket 38 ¦generally has a ring shape, as shown in FIG. 1, and the tension springs 48 are positioned within the clearance space lavailable inside of the ring configuration of the inner ; sprocket 38, :~
These spring means 48 normally urge the~ sprockets :
~ 36 and 38 in a forwardi ~counterclockwise in FIG. 1) direction :~
.~ I relative to the drive plate 34,.but the rider's legs normal.ly. :~
l urge the crank 12 and hence the drive plate 34 in a forward . .
¦ direction (counterclockwise) as the bicycle i9 being propel-led. Thus, the upper run or stretch 41 of the chain 43 ¦is in tension, ~hich, in turn, urges the sprocket as.sembly 36 138 in a clockwise direct.ion in FIG. 1 relative to the drive ¦
plate, so that the force of the spring means 48 is overcome .~ I and these springs remain stretched, as shown in FIG 1. i ~`
¦Consequently, the torque being exerted by the driver's legs I -! ¦ iS transferred from the drive plate 34 to the sprocket ¦assembly 36, 38 by the ends of the elongated openings 46 i ¦engaging the fastening means 44, as shown in FIG. 1. The torque of the sprocket assembly 36, 38 tensions the upper run 41 of the chain, thereby a~plying torque to the rear sprocket for propelling the bicycle.
Similarly, as the bicycle is wheeled b~ckward, -the rear wheel sprocket pulls on the upper run 41 of the chai:
43, thus urging the sprocket assembly 36, 38 in a clockwise direction relative to -the drive pla-te, thereby stretching the :
springs to cause the drive plate (and crank 12) to rotate cloc~wise (reverse direction) with respect to the sproc~et ¦
¦ ~ !~
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¦¦assembly, thus retr~cting controlled pawls (to be explained), .
¦ so that the bicycle can be wheeled backward w.ithout the l ~
brake or brakes becoming applied, 1~.
As mentioned above, there is a controlled ~
ratchet and pawl mechanism 40 mounted to the drive plate .~
34 This mechanism 40 is not a simple ratchet hut rather ~.
it is a positively controlled ratchet mechanism. In this ~ : :~
mechanism 40, the pawls are positively driven into engagement with the abutment teeth on a gear for applying braking effort ~ ~ ?~5 when desired, These pawls are also positively drlven away . .`:;rr''~
from engayement with the abutment teeth on the gear -for re- :.. ~
leasing the brake before commencing to propel the bicycle . ~i ¦forward, and when the bicycle is wheeled backwards, i.e. .
whenever the top run 41 of the sprocket chain 43 .is under - .
active load either forward or backward.
:~ This controlled ratchet mechanism 40 includes ~ .
a ratchet gear 52: rotatable mounted on the drive plate 34. -In FIG. 1, as shown, the ratchet gear 52 is a ring gear . ~ having a large central opening 54 (FIG. 2~ which advantageous- .
ly fits around~the fixed~bearing housing 22 of the bicycle. :
Thus, the whole assembly 10 will fit onto the conventional bicycle without requiring modi~ication thereof, This ratchet gear 52 includes a raised ring portion 56 (FIG. 2) l .
Iwhich is held in concentric relationship with respec~ to the .
¦drive plate 34 by means of at least three rollers 58 which ¦engage the perimeter of this ring portion 56 in rolling contact therewith. ~.
These three rollers 58 are rotatably mounted on lugs 60 secured to the drive plate 34~ As shown, the : ~.
rollers 58 are axially retained on the lugs 60 by C-sl-aped . . .
I ~ , ~. '' ;~
. ~
~5~53~ ~ I
.' I , ~1 ¦~retainers 62, which snap into grooves in the lugs 60. A
¦~controlled pawl 66 (FIG. 2) encircles each of the lugs 60 between the rollers 58 and the drive plate 34 serving to hold these rollers spaced away from the drive plate 34 ~o accom-modate the periphery of the ratchet gear 52 in the resulting ¦¦space between these rollers and the drive plate. Thus, the ratchet gear 52 is restrained from axial movement relative ,j~"
to the drive plate 34 because the outer face (its right face) ~ '' of the ratchet gear rests against the drive plate while the ~ `
rollers 58 overlap the peripheral portion of the inner face (its left face) of this ratchet gear.
The ratchet gear 52 is prevented from rotating in the forward direction F by a proJecting stop pin element 64 (FIG. 2) which engages up against the underside o~ the rear bicycIe frame member 32. This stop pin 64 is mounted on a brake actuator arm member 65 which is attached by a plurality of machine screws 67 to the raised ring portion 56 ¦~
of the ratchet gear 52, When the ratchet gear 52 is turned in the reverse direction R, it serves to operake the brakes, as will be explained further below.
In order to turn the ratchet gear 52 in the ¦i`
reverse direction R for applying braking effort, there is provided one or more positively controlled pawls 66 pivotally mounked on the drive plate 34~ In the assembly 10, as 1 shown, the pawls 66 are pivotally mounted on the same lugs 60 t as are used to mount the rollers 58, so that these pawls ~ ~ -serve to hold the rollers spaced away from the drive plate 34 ,~
as discussed above. It is to be understood that the con-trolled pawls~ 66 could be pivotally mo~lnted upon o~ther lugs similar -to the lugs 60, in wllich case spacing ~ashers would )e provided between the rollers 5~ and the dI^.iVe plate~ How- i~
il , . ~, l ~
. I ~
1~5853~ 1 ~
ever, I prefer to uxe the lugs 6~ in this embodiment for !
the dual purpose of mounting the rollers 58 as ~ell as mount- j ~
ing the controlled pawls 66. ! ~ i In order to produce the positive enyac3ement ox Icomplete disengagement of the pawls 66 with the abutment ¦teeth of the ratchet gear 52, there is provided one or more ¦pawl-controlling cam pin elements 68 which are fixedly mountecl Ito the sprocket assembly 36~ 38, These pawl-controlling cam ¦ i;
pin elements 68 extend through elongated slots 70 in the drive plate 14 for engaging cam surfaces 72 in the controlled pawls 66. The cam surfaces 72 are inclined with respec~ to I .
a radius from the axis A of the crank 12 passing through the center of the pawl-controlling element 68~ This inclination ;
of the elongated cam surface 72 positively causes the control ~
led pawls 56 to withdraw from the ratchet gear 52 when the ~ ~t rider's legs turn the drive plate 34 ror~7ard (F) with respect to the sprocket assembly. Thus, when the rider is propellinc i~
¦ the bicycle forward, the controlled pawls 66 are completely ¦ and positively retracted by cam pins 68 away from the ratchet ¦gear. There is no frictional drag of these pawls against ~ ~
the ratchet teeth nor resultant clicking noises, )`~ ~ ;
Further, when the drive ~late 34 is rotated Irearward (R) with respect to the sprockets as the rider star~
¦to back pedal for applying the brake or brakes, the control-¦led pawls 66 are positively caused to ensage against the ¦abutment teeth of the ratchet gear 52. The elongatecl clear-ance slots 70 are concentric about the center of the drive plate 34 (concentric about axis A). The cam surfaces ; ~i~
72 comprise eloncJated openin~s in the pawls which are incline i ith respect to the c:Learance s1ots 70, as e~p`a;ned above;
Il , ,<~
i When the rider back pedals (R) for applying ~-~
brakincJ effort, the driving torque is removed from the sprockets 36~ 38, and the top run 41 of the chain becomes lunloaded. The unloaded top run 41 of the chain allows the ¦spring means 48, as shown in FIG, 3, to rotate the sprockets ^~,~
Icounterclockwise relative to the drive plate (i.e. the drive iplate turns clockwise relative to the sprockets) thereby posi- . ~
jtively engaging the controlled pawls 66 with the abutment - ;
¦teeth o~ the sprocket gear 52. As the rider contin~es to ' ~-exert torque in the back pedal ~reverse) ~irection (R) (please see FIG. 3), the now-engaged pawls 66 drive the sprocket gear 52 in the reverse direction to swing the actuator arm member 65 down as indicated b~ the braking arrow ¦
~B at the right. This brake actuator arm member 65 is con- ,, ¦nected by suitable connecting means 74 to the brake or brakes I
for the rear or front wheel or both.
In this embodiment, the connecting means 74 are a pair of Bowden wire cables 74-1 and 74-2, each having an attachment shackle 76. These shackles 76 are pivotally attached to selected holes 78 extending in a row along the upper edge of the actuator arm member 65. The Elexible , sheaths 80 oE these Bowden cables 74 are ~erminated at ~ ~
anchoring bolts 82 secured by clamp means 84, adjustably ~ ~ -¦Imolmtable on the forward frame member 2S o~ the bicycle.
! One of the connecting means 74-1 extends to the ibrake mechanism for one of the wheels and the other connect~
l I ......
¦ing means 74-2 extends to the brake mechanism Eor the other wheel. The row of attachment holes 7S and the pair oE
shackles 76 provide adjus-tment means b~ which the relative brak:ing eEEort can ~e adjusted between -the ~rak~s for ~he .
. ',,:'.~'~
1058531 1 ~
rear and Eron-t wheels, as may be desired.
I Generally speakiny, the braking effort to be ¦lapplied to the front wheel should not be unduly larye as , ¦compared to the braking effort to be applied to the rear wheel, ¦Ibecause a sudden powerful braking effort could then pitch the ¦
bicycle and rider forward over the front wheel. A person~s I
leg muscles are much more powerful than the hand muscles, so -that a very powerful braking effort can be obtained using this invention~ For braking action applied to the rear wheel, there tends to be a self-limiting braking efect. This self-limiting action occurs because the deceleration of the bicycle ¦during braking tends to reduce the weight being carried by the rear wheel, thereby reducing the perpendicular force between the rear tire and the pavement, thus limiting the braking force to be exerted by the rear tire upon the pave- I j ment. I ~ ;
Advantageously, the rider or the bicycle shop can adjust the predetermined ratio of the braking efforts by the adjustment means 76 and 78, as may be desired.
-Although two sprockets 36 and 38 are shown, it will be understood that the sprocket-drive-and-back-pedal-brake-operator assembly 10 can be provided with only one sprocket whenever desired~ The missing sprocket is then I ;
replaced with a ring plate or equivalent member. Moreover, either the outer or inner sprocket 36 or 38 may be omi-tted, ¦ as desired.
l There are four operating modes: (1.) pedaling ¦forward for propelling the bicycle; (2) pedaling backward, l;i.e. applyin~ the brake or brakes; (3) wheeling the bicycle¦
l~orward as b~ coasting for~ard or as by rolling the bicycle I! ~ ``:
r 1 ~058531 ~ ~
Iforward while the rider temporarily walks ~loncJside, and ¦ ~
(~) wheeling the bicycle backward as by rolling the bicycle I ~
Ibackward while the rider temporari'33.y walks alongside. It is . .
¦lalso possible for the rider to coast backward, as a stunt, ¦while sitting on the bicycle with his ~eet, removed from the ¦Ipedals 26, so that the spring means 48 are allowed to cause .
the arive plate 34 and pedal crank 12 to r~tate in the ~¦reverse directions to follow the reverse motion of the chain .~
~143 as it pulls the sprocket in reverse rota-tion. ;~
When pedaling forward, the drive plate 34 moves I ., forward (F) relative ~o the sprockets 36, 38, so the spring l ~ll 3 means 48 are stretched and the pawl controlling cam pin' elements 68 cam the pawls 66 out of engagement, and normal .¦
f~rward pedaling operation occurs with the brake released ~ I
and with the pawls 66 retracted completel~ out of engagement ) ~.;
with the ratchet gear 52. Thus, there is no cllcking nor ratcheting noise nor ratchet drag nor resulting wear of the , teeth or pawls. ;,.
Pedaling backward removes the.tenslon of the top run 41 o the chain 43 from the sprockets 36, 38 (i.e. .
the chain load is removed) while at the same time the pedal i =.`',.
i crank commences turning the drive plate 34 rearwardly. Thus, . .
-the drive plate 14 turns rearward (clockwise) relative to the sprocket or sprockets 36, 38 assisted by the springs 148. This relative motion causes controlled pawls 66 ~o : :
Ijengage the ratchet gear 52 and rotate it and its arm 65 in ¦.the reverse (clockwise~ direction thereby applying the brakes llas shown in FIG. 3. ¦
¦l, In wheeling or coas-tlng Eorward, the over- .
',runnLn~ mecllallism in the .rear wheel hub allows the rear ~Yheel 1~' ~ ;;`;
.
~058531 to freely turn forward without revolving the chain, In wheeling bacXward, the conventional over- ¦
~running mechanism in the rear hub becomes engayed, thus pulling the top run 41 of the chain 43 rearward, i.e. to the - ¦right in the drawing. Thus, the sprocket or sprockets :
36, 38 are turned rearward (clockwise) relative to the drive plate 34, so that the pawl control pins 68 are moved in the :
.rearward direction causing the pawls 66 to be retracted away .
from the ratchet gear 52. Therefore, the brakes are not applied, and the bicycle is allowed to wheel hackwardly with-out the brakes becoming engaged. The pedal crank does revolve in the reverse direction when wheeling backward ¦
because the fastening bolts 44 engage against the rear of the , slots 46 as urged by the spring means 48, I .
Although the assen~ly 10 can advantageously be .~
applied to a conventional one-piece crank 12, it can also be , .
applled to pedal crank assemblies which are built up from ,-~
several components. The drive plate 34 is driven by a , drive lug 16 on the right pedal crank, Alternatively, the . ,~
central hole 42 in the drive plate 34 is formed with a key-way and is keyed to the central portion of the pedal crank assembly, or the drive plate is keyed to the hub of the right ~ 1~;,1 pedal crank arm by a drive lug, key, or pin, ~ :
The spring means 48 are included to assure tha-t '~
the drive plate 34 will turn rearward (clockwise) relative to the sprocket assembly 36, 38 when the rider back pedals so that the controlled pawls 66 will en~a~e the ~ear 52 to apply braking, In many cases, there is a sli~ht but suf- :
¦'ficient frictional drag in the overall chain system and ,~
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~58~3~L
:~
associated rear sprocket and chain guides to produce this Isame braking result when back pedaling without the use of the ¦spring means 48. Thus, these springs 48 are included as an ¦assurance but they can be omitted.
i As used herein, the term "sprocket assemblyt' is ¦intended to mean a plurality of sprockets assembled together to rotate with each other as a unit.
The term "sprocket means" is intended to be inter-preted broadly to include either one or a plurality of `
¦sprockets. ~
In the sprocket-drive-and-back-pedal operator 10A, 1 ~-shown in FIGS. 4, 5 and 6, many o the parts ana components ~;
are the same as ln the operator 10 of FIGS 1-3. Only the differences will be described.
The Bowden wire connecting means 74-1 and 74-2 are anchored to a drum actuator member 65A (FIGS. 4 and 5) by means of cylindrical end f1ttings 90 (FIG. 4) which are swaged onto the ends of the respective cables. These end fittings 90 engage in inclined slots 92 machined in the ' ~ i flanges 94 of the drum actuator mem~er 65A. As shown in FIG. 4, the inclined slots 92 are positioned so that the cables are wrapped almost a full revolution around the actuator member 65A. As shown in FIG. 4, the inclined slots 92 are positioned so that the cables are wrapped almost a full revolution around the actuator member 65A in the channel 96 between the flanges 94. By wrappin~ the cables I around the actuator nun~er 65A in this manner, the stress I on the end fittings 90 is reduced. -;
¦ This drum actuator member ~5A is rotatably ~
mountcd to the drive plate 3~ by securillg it to a ring ; ~' -21- ~
1. 1 ~1 :
i853~ i ratchet gear 52A which also is ro-tatable with respect to the drive plate. A plurality of fastening means 67, for I -example machine screws, secure the actuator member 65A and th~
ratchet gear 52A toyether as a unitary assembly.
In order to mount the sprocket ring gear and ¦ ;
actuator assembly 52A, 65A onto the drive plate 34, as seen ¦
in FIG. 5, there is bearing ring means 58A secured to the drive plate 34 by means of suitable fasteners 100, for example machine screws. The bearing means 58A has a peri-pheral flange 102 ~FIG. 5) which overlaps the inner edge of `-1:
Ithe ring ratchet gear, thus axially retaining the ratchet ¦and drum actuator assen~ly 52A, 65A with respect to the `
¦inside surface of the drive plate. l , ¦ Thus, in comparing the brake operator assemblies lOA and 10 of FIGS. 4-6 and 1-3, respectively, it is seen ..
that in the operator assembly lOA, the ratchet ring gear and lactuator assembly 52A, 65A is rotatably mounted to drive ¦plate 34 by beariny means 5~A engaging the interior perimeter ~ri-l of the ring portion of this assembly. In contradistinction, as seen in FIG. 1, the ratchet ring gear and actuator assembl 52, 65 is rotatably mounted to the drive pla-te 34 by roller bearing means 58 engaging the external perimeter of the ring portion 56 thereof. ;~
l The controlled pawls 66 (FIG. 6) are mounted ¦on lugs 60 held by C-shaped retainers 62 and the pawl con- ~ -~
~trolling cam pins 68 axe secured to the sproc~et assen~ly 36,1 ¦j38 by suitable fastening means 104 such as a machine screw.
¦IAS seen in FIG. 6, the cam pin 68 has an enlarged shoulder ¦106 for spacin~ -the controlled pawl 66 away from the outer sp~ocl~t 36.
` ~ ~
`10~853 i' Th~ stop means 6~A for preventing forward rotation ¦
I.of the ratchet gear and brake actuator assembly 52A, 65A ¦
¦lis a luy 108 secured to the inner surface of the drum 90 ¦ .
by a pair of machine screws. A resilient sleeve 110 (FIG. 4)~
of rubber or plastic surrounds this lug 108 for cushioning its contact with the rear frame member 32.
As seen ln FIG. 4, the abutment surfaces 112 of ,.: .
~the ratchet teeth are sloped slightly, so that these surfaces face directly toward the axis of the pivot mounting 60 for ~ -!
~the control pawl 66. In other words, the surface 112 is exactly perpendicular to the line from the center of this ¦surface 112 to the axis of the pivot pin 60. Thus, when the .
¦pawl- is engaged, as shown in FIG. 4, there is no resultant ~;
radial force on the pawl because the thrust is directly along.
. a line passing through the axis of the pivot 60.
The same comments about minor modifications i within the scope of my invention apply to the sprocket-driv~- .
::and-back-pedal-brake-operator assembly lOA as apply to the assembly 10 FIGS. 1-3, namely, this assembly lOA can be applied to a one-piece crank or to pedal a crank which is built up frommultiple parts. The spring means 48 are include( ~
in the assembly lOA for assurance, but such ,spring means can I ,:
¦be omitted .i there is sufficient frictional drag exerted ~.. ,~
,by the chain 43. The sprocket means 36, 38 ~hich is used :. ~with the assembly lOA may include one or more sprockets.
¦ As shown in FIG. 7, the forces exerted on the ¦brake means for the front and rear wheels may be equalized . .~
¦¦by forming the respective cables 74--1 and 74-2 as a conti , u ¦nuous cable element extending in a U-bend 114 around a . ,-pulley sheave 120 rotatably mounted on a clevis 122 ~hich is ~' ~ r~ r~ ? ~
585:~L ~
I' '~ ~
¦Iconnected by a tension link 1~4, such as mechanical link or icable to a shackle 76 which i5 pivotally mounted to the actuator 65. ¦~
Alternatively, the actuator drum member 65A .
can be replaced by an actuator arm member 65 which is similar Ito the actuator arm member 65 (FIG. 1) but it is secured by . :;~
¦fastening means 67 to the sprocket 52A. Then the shackle 76 . ~-~(FIG. 7) i_ pivotally mour~e~ t- this ac~uator arm member 65.
, ' I ~ '''`'i' . ````~'~```
~ ~ . ~
I
I .
I -~7~
I/ ' :-~; l'~''
Claims (10)
1. A back-pedal brake operator for use on a multi-speed bicycle of the chain derailer type or gear shifter type having at least one brake mechanism associated with a wheel and having a pair of pedal crank arms attached to a crank shaft rotatably mounted in a bearing housing on the bicycle frame for propelling the bicycle when said crank shaft is rotated in the forward direction, said back-pedal brake operator being adapted to be conveniently retrofitted on existing multispeed bicycles of said types as well as to be installed on new multi-speed bicycles of said types being manufactured without structural modification of the bicycle frame or pedal crank bearing housing and bearings, and said back-pedal brake operator permitting the bicycle to be wheel-ed backwards without applying braking effort to said brake mechanism, said back-pedal brake operator comprising:
a drive member rigidly affixed to the pedal crank shaft to turn with the crank shaft;
sprocket means associated with said pedal crank shaft and being mounted for limited relative rotational motion between said sprocket means and said drive member, said sproc-ket means being adapted to be engaged with a drive chain for driving the bicycle;
brake actuator means mounted for free rotational motion about the axis of the pedal crank shaft, said brake actuator means being connectible to said braking mechanism for applying braking effort thereto;
controlled unidirectional drive means operatively inter-posed between said drive member and said brake actuator means and responsive to limited relative motion of said sprocket means with respect to said drive member in one direction pro-duced by chain loading for permitting free Claim 1 - cont'd rotation of said drive member with respect to said brake actuator means whereby the brake actuator means does not apply braking effort during chain loading produced by for-ward pedaling or when the bycycle is wheeled backwards, and said controlled unidirectional drive means being responsive to limit the relative motion of said sprocket means with respect to said drive member in the other direction produced by unloading of said chain for interconnecting said drive member and said brake actuator means for applying braking effort when the bicycle rider back pedals.
a drive member rigidly affixed to the pedal crank shaft to turn with the crank shaft;
sprocket means associated with said pedal crank shaft and being mounted for limited relative rotational motion between said sprocket means and said drive member, said sproc-ket means being adapted to be engaged with a drive chain for driving the bicycle;
brake actuator means mounted for free rotational motion about the axis of the pedal crank shaft, said brake actuator means being connectible to said braking mechanism for applying braking effort thereto;
controlled unidirectional drive means operatively inter-posed between said drive member and said brake actuator means and responsive to limited relative motion of said sprocket means with respect to said drive member in one direction pro-duced by chain loading for permitting free Claim 1 - cont'd rotation of said drive member with respect to said brake actuator means whereby the brake actuator means does not apply braking effort during chain loading produced by for-ward pedaling or when the bycycle is wheeled backwards, and said controlled unidirectional drive means being responsive to limit the relative motion of said sprocket means with respect to said drive member in the other direction produced by unloading of said chain for interconnecting said drive member and said brake actuator means for applying braking effort when the bicycle rider back pedals.
2. A back-pedal brake operator as claimed in Claim 1, in which said controlled unidirectional drive means comprises:
first and second engageable elements one of said engageable elements being carried by said brake actuator means for rotation therewith, the other of said engageable elements being carried by said drive member for rotation therewith, a first of said engageable elements being movable between either of two positions in one of whcih positions said first engageable element is engaged with the second for preventing any relative rotation between said brake actuator means and said drive member and in the other of which positions said first engageable element is retracted from the second engageable element for permitting said drive member to rotate in the forward direction relative -to said brake actuator means, and control means responsive to said limited relative rotation for producing said engagement and retraction of said one engageable element.
first and second engageable elements one of said engageable elements being carried by said brake actuator means for rotation therewith, the other of said engageable elements being carried by said drive member for rotation therewith, a first of said engageable elements being movable between either of two positions in one of whcih positions said first engageable element is engaged with the second for preventing any relative rotation between said brake actuator means and said drive member and in the other of which positions said first engageable element is retracted from the second engageable element for permitting said drive member to rotate in the forward direction relative -to said brake actuator means, and control means responsive to said limited relative rotation for producing said engagement and retraction of said one engageable element.
3. A back-pedal brake operator as claimed in Claim 1, in which said controlled unidirectional drive means comprises:
a ratchet gear included in said brake actuator means, a controlled pawl pivotally mounted upon the drive member, and control means responsive to said limited relative rotation between the sprocket means and drive member for moving said pawl into engagement with said ratchet gear and for retracting said pawl away from said ratchet gear.
a ratchet gear included in said brake actuator means, a controlled pawl pivotally mounted upon the drive member, and control means responsive to said limited relative rotation between the sprocket means and drive member for moving said pawl into engagement with said ratchet gear and for retracting said pawl away from said ratchet gear.
4. A back-pedal brake operator as claimed in Claim 1, in which said controlled unidirectional drive means comprises:
a ratchet gear included in said brake actuator means, a controlled pawl pivotally mounted upon the sprocket means, and control means responsive to said limited relative rotation between said sprocket means and drive member for moving said pawl into engagement with said ratchet gear and for retracting said pawl away from said ratchet gear.
a ratchet gear included in said brake actuator means, a controlled pawl pivotally mounted upon the sprocket means, and control means responsive to said limited relative rotation between said sprocket means and drive member for moving said pawl into engagement with said ratchet gear and for retracting said pawl away from said ratchet gear.
5. A back-pedal brake operator as claimed in Claim 1, in which:
said brake actuator means includes a ring member having a sufficiently large diameter to encircle said bearing housing and being rotatably mounted upon said drive member in position to encircle said housing, and a brake actuator member attached to said ring member, said brake actuator member being connectible to said brake mechanism.
said brake actuator means includes a ring member having a sufficiently large diameter to encircle said bearing housing and being rotatably mounted upon said drive member in position to encircle said housing, and a brake actuator member attached to said ring member, said brake actuator member being connectible to said brake mechanism.
6. A back-pedal brake operator as claimed in Claim 1, for use on a bicycle which has brake mechanisms associated with the front and rear wheels, and in which said brake mechanisms are cable actuated, said brake operator including a single cable extending to both of said brake mechanisms, guide means forming said cable into a U-bend, and said brake actuator means being connected to said guide means for pulling upon said U-bend in said cable for equalizing the braking pull exerted by said cable upon both the braking mechanisms for the front and rear wheels.
7. A back-pedal brake operator for use on a multi-speed bicycle of the chain derailer type or gear shifter type having at least one brake means associated with at least one wheel and having a pair of pedal crank arms attached to a crank shaft rotatably mounted in a bearing housing on the bicycle frame fox propelling the bicycle when said crank shaft is rotated in the forward direction, said back-pedal brake operator comprising:
Claim 7 - cont'd .
a drive plate adapted for mounting on the crank shaft between the bearing housing and one of the pedal crank arms for rotation with the crank shaft;
a brake actuator assembly connectible to said brake means for applying braking effort thereto;
bearing means rotatably mounting said brake actuator assembly upon said drive plate;
means preventing said brake actuator assembly from turning in the forward direction as the rider pedals forward;
sprocket means mounted upon the drive plate for limited rotational movement relative to said drive plate, said sprocket means being adapted for engagement with a drive chain;
controlled unidirectional drive means including first and second engageable elements;
one of said engageable elements being carried by said brake actuator assembly for motion therewith;
the other of said engageable elements being carried by said drive plate for motion therewith;
one of said engageable elements being movable between either of two positions in one of which positions said one engageable element is engaged with the other engage-able element for preventing any relative rotation between said brake actuator assembly and said drive plate and in the other of which positions said one engageable element is retracted from the other engageable element for permitting said drive plate to rotate in the forward direction; and control means for controlling the engagement and retraction of said one engageable element, said control
7. A back-pedal brake operator for use on a multi-speed bicycle of the chain derailer type or gear shifter type having at least one brake means associated with at least one wheel and having a pair of pedal crank arms attached to a crank shaft rotatably mounted in a bearing housing on the bicycle frame fox propelling the bicycle when said crank shaft is rotated in the forward direction, said back-pedal brake operator comprising:
Claim 7 - cont'd .
a drive plate adapted for mounting on the crank shaft between the bearing housing and one of the pedal crank arms for rotation with the crank shaft;
a brake actuator assembly connectible to said brake means for applying braking effort thereto;
bearing means rotatably mounting said brake actuator assembly upon said drive plate;
means preventing said brake actuator assembly from turning in the forward direction as the rider pedals forward;
sprocket means mounted upon the drive plate for limited rotational movement relative to said drive plate, said sprocket means being adapted for engagement with a drive chain;
controlled unidirectional drive means including first and second engageable elements;
one of said engageable elements being carried by said brake actuator assembly for motion therewith;
the other of said engageable elements being carried by said drive plate for motion therewith;
one of said engageable elements being movable between either of two positions in one of which positions said one engageable element is engaged with the other engage-able element for preventing any relative rotation between said brake actuator assembly and said drive plate and in the other of which positions said one engageable element is retracted from the other engageable element for permitting said drive plate to rotate in the forward direction; and control means for controlling the engagement and retraction of said one engageable element, said control
Claim 7 - cont'd means being actuated by the limited relative rotational motion between said drive plate and said sprocket means for retracting said one engageable element when the chain is under load and engaging said one engageable element with the other engageable element when the rider back pedals for moving said brake actuator to apply braking effort, whereby said back-pedal brake operator can be conveniently retrofitted on existing multi-speed bicylce as well as being installed on new bicycles being manufactured without structural modification of the bicycle frame or pedal crank bearing housing and bearings.
8. A back-pedal brake operator as claimed in Claim 7, in which:
said bearing means is a bearing ring of suf-ficiently large diameter to encircle said bearing housing, said bearing ring being attached to said drive plate in a position to encircle said bearing housing, said one engageable element included in said brake actuator assembly being a ratchet ring gear encircling said bearing ring, and said other engageable element is a controlled pawl pivotally mounted upon said drive plate, and said control means retracts said pawl away from said ratchet ring gear in response to said limited rotation-al motion in a first direction when said chain is under load and moves said pawl into engagement with said ratchet ring gear in response to said limited rotational motion in a second direction when said chain is unloaded as the rider back-pedals said crank shaft for applying braking effort to said brake means.
said bearing means is a bearing ring of suf-ficiently large diameter to encircle said bearing housing, said bearing ring being attached to said drive plate in a position to encircle said bearing housing, said one engageable element included in said brake actuator assembly being a ratchet ring gear encircling said bearing ring, and said other engageable element is a controlled pawl pivotally mounted upon said drive plate, and said control means retracts said pawl away from said ratchet ring gear in response to said limited rotation-al motion in a first direction when said chain is under load and moves said pawl into engagement with said ratchet ring gear in response to said limited rotational motion in a second direction when said chain is unloaded as the rider back-pedals said crank shaft for applying braking effort to said brake means.
9. A back-pedal brake operator as claimed in Claim 7, in which:
said brake actuator assembly includes a ring member, and said bearing means include a plurality of rollers each rotatably mounted upon said drive plate by pivots spaced about the axis of said pedal crank shaft, said plurality of rollers engaging the periphery of said ring member in rolling engagement therewith..
said brake actuator assembly includes a ring member, and said bearing means include a plurality of rollers each rotatably mounted upon said drive plate by pivots spaced about the axis of said pedal crank shaft, said plurality of rollers engaging the periphery of said ring member in rolling engagement therewith..
10. A back-pedal brake operator as claimed in Claim 7, in which:
said sprocket means includes a plurality of sprockets in spaced parallel relationship concentric about the axis of said pedal crank shaft, said drive plate is sandwiched between a pair of said sprockets, a plurality of fastening means extending between said pair of sprockets, said drive plate having a plurality of circum-ferentially elongated openings therein and said fastening means extending through respective ones of said elongated openings for mounting said sprockets upon said drive plate while providing for limited rotational movement relative to said drive plate.
said sprocket means includes a plurality of sprockets in spaced parallel relationship concentric about the axis of said pedal crank shaft, said drive plate is sandwiched between a pair of said sprockets, a plurality of fastening means extending between said pair of sprockets, said drive plate having a plurality of circum-ferentially elongated openings therein and said fastening means extending through respective ones of said elongated openings for mounting said sprockets upon said drive plate while providing for limited rotational movement relative to said drive plate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA243,259A CA1058531A (en) | 1976-01-09 | 1976-01-09 | Back-pedal brake operator for multi-speed bicycles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA243,259A CA1058531A (en) | 1976-01-09 | 1976-01-09 | Back-pedal brake operator for multi-speed bicycles |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1058531A true CA1058531A (en) | 1979-07-17 |
Family
ID=4104942
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA243,259A Expired CA1058531A (en) | 1976-01-09 | 1976-01-09 | Back-pedal brake operator for multi-speed bicycles |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1058531A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112762110A (en) * | 2021-02-02 | 2021-05-07 | 北京理工大学 | Radial clamp tooth type brake |
-
1976
- 1976-01-09 CA CA243,259A patent/CA1058531A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112762110A (en) * | 2021-02-02 | 2021-05-07 | 北京理工大学 | Radial clamp tooth type brake |
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