CA2309063C

CA2309063C - Automatic transmission systems for humanly powered vehicles

Info

Publication number: CA2309063C
Application number: CA002309063A
Authority: CA
Inventors: Frederic Francis Grant
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-11-10
Filing date: 1997-11-10
Publication date: 2007-01-16
Anticipated expiration: 2017-11-10
Also published as: WO1999024735A1; JP2001522973A; AU5433198A; CA2309063A1; EP1030983A1; CN1276045A; CN1151944C; EP1030983A4; WO1999024735A8

Abstract

A shiftable bicycle transmission (30) is automatically shifted by automatically sensing output power torque of the transmission (30), automatically converting sensed output power torque to transmission shifting motion, and automatically shifting the shiftable transmission (30) with that transmission shifting motion. A shiftable bicycle (10) driving power transmission has a transmission shifting element (47, 49), a bicycle output power torque sensor (51), and an output power torque-to-transmission shifting motion converter (1, 2, 3) having an output power torque input coupled to that output power torque sensor (51) and having a transmission shifting motion output. Such transmission shifting element (47, 49) is coupled to the transmission shifting motion output of that converter.

Description

. WO 99/24735 PCT/US97/20492 3 Technical Field of Invention 4 The technical f field of the invention relates to bicycles and other humanly powered vehicles and, more specifically, to 6 automatic and hybrid transmission systems for humanly powered 7 vehicles, herein generically referred to as "bicycles".
g Background 9 Forty years ago the automatic transmission for automobiles was for many people what the electric automobile engine starter 11 had been for an earlier generation. Yet, even though bicycles 12 and the like have been around for as long as the automobile, 13 velocipedists all over the world still do not have automatic 14 transmissions that would actually benefit them on their humanly powered vehicles.
16 Various proposals for automatic bicycle transmissions have 17 not been widely successful. One recent proposal adds three 1g weights, 120 degrees apart. to the rear wheel. These weights add 19 increased air resistance and more than a kilogram of mass to the bicycle. Also, these weights respond to rear Wheel speed by 21 centrifugal or centripetal action, shifting a derailleur 22 transmission automatically. In practice, shifting a transmission 23 or derailleurs in response to speed has its disadvantages.
24 Consider for instance approaching an upgrade with a bicycle. In such a case, the cyclist would pedal harder; his or her reaction 26 being to maintain the speed. This, of course, would delay the 27 necessary shifting of the transmission until the hard pedaling 28 cyclist can no longer maintain the speed. By thus losing speed, 29 the cyclist in effect has to work harder in taking the hill, eves after the transmission has shifted. Conversely. going downhill 31 and onto a level surface may be hard on the brakes, since that 32 transmission will not shift back until the speed has gone down.
33 Velocipedists thus continue to shift their bicycles manually 34 in response to the load on their legs and feet. This has led to a continual increase in the number of gears or transmission shift 36 positions with which bicycle transmissions are manufactured, 1 especially for mountainous driving. A high number of 2 transmission shift positions, in turn, is requiring increasing 3 sophistication of bicycle riders as to how and when to shift, and 4 has been discouraging many people from acquiring one of the more advanced racing bicycles or "mountain bikes".

6 The problem may be gauged from a commercial eight-speed 7 version is which the speed change or change in drive ratio is 22%
g from the first to the second gear, 15 % from the second to the 9 third gear. 18% from the third to the fourth gear, 21% from the fourth to the f i f th gear, 2 0 % from the f i f th to the s ixth gear, 1l 17% from the sixth to the seventh gear, and 22% from the seventh 12 to the eighth gear. That the problem has assumed grotesque 13 proportions may be seen from the example of a modern eighteen-14 speed derailleur-type bicycle having front sprocket control cam followers and rear sprocket control cam followers providing 16 together the following plethora of drive ratio changes : 22 % from 17 the first to the seconds 11% from the second to the third; 3%
18 from the third to the f ourth; 18 % f rom the f our th to the f i f th;
i9 nothing from the fifth to the sixth, due to the combined action of the front sprocket and rear sprocket shiftss 4 % each between 21 the sixth and the seventh, the tenth and the eleventh, and the 22 fifteenth and the sixteenth; 9% between the seventh and the 23 eight; 2% between the eight and the ninth; 5% between the ninth 24 and the tenth; 7% between the eleventh and the twelfth, the twelfth and the thirteenth, the fourteenth and the fifteenth, and 26 the seventeenth and the eighteenth; with only 6% between the 27 thirteenth and the fourteenth; and 13 % between the sixteenth and 28 the seventeenth.
2g This averages out as a ratio change of 0.07166 per shift of that 18-speed transmission, with actual values being very 31 unequally distributed among the eighteen shift positions. In 32 consequence, more sophistication, concentration and judgment are 33 required for operating the transmission, that what is needed to 34 conduct the;bicycle itself.
Rnown hub type of bicycle transmissions work With one or two 36 planetary gear systems, but are not automatic.
37 Further problems arise from the fact that recurring torque 1 variations are inherent in many humanly powered drives, such as 2 in bicycles where twice-around drops in torque occur from the 3 fact that the angularly moved pedals in turn have to go through 4 tops and bottoms of their circular motions. This. in turn, has beset efforts to develop an automatic bicycle transmission with 6 problems of erratic shifting due mainly 'to the above mentioned 7 cyclically recurring power torque variations.
g In consequence, a newer approach thus uses a microprocessor 9 for shifting gears which, however, harks back to the power assisted manual type of transmission of the old Hudson 1l automobile, circa 1938. A new approach obviously is needed, eves 12 in the case of electromechanical solutions.
13 The prior-art inability to evolve a widely acceptable 14 automatic bicycle transmission is regrettable also from environmental and socio-economic points of view, since bicycles 16 cost much less and take much less space than automobiles, put 17 less of a load on the road, do not pollute the atmosphere like 18 automobiles, are much less expensive to operate, and subject the 19 rider to continual salubrious exercise unavailable in any automobile.
21 Sua~marv of the Invention 22 The primary object of the invention is to provide improved 23 automatic bicycle transmission systems.
24 The invention resides in a method of shifting a shiftable bicycle transmission, comprising, in combination, automatically 26 sensing output power torque of the transmission, automatically 27 converting sensed output power torque to transmission shifting 28 motion, and automatically shifting the shif table transmission 29 with that transmission shifting motion.
The invention resides also in a shiftable bicycle driving 31 power transmission having a transmission shifting element, 32 comprising, ,in combination, a bicycle output power torque sensor, 33 and an output power torque-to-transmission shifting motion 34 converter having an output power torque input coupled to that output power torque sensor and having a transmission shifting 1 motion output, such transmission shifting element being coupled 2 to the transmission shifting motion output of the converter.
3 Brief Description of the Drawings 4 The subject invention and its various aspects and objects will become more readily apparent from the following detailed 6 description of preferred embodiments thereof, illustrated by way 7 of example in the accompanying drawings which also constitute a 8 written description of the invention, wherein like ref erence 9 numerals designate like or equivalent parts, and in which:
Fig. 1 is a side view of a relevant portion of a.bicycle 11 representative of bicycles, tricycles and other humanly powered 12 vehicles within the scope of the invention and including an 13 outline of an automatic transmission according to an embodiment 14 of the invention;
Fig 2. is a diagrammatic view of an automatic transmission 16 according to an embodiment of the invention;
17 Fig. 3 is a longitudinal section through an automatic 18 transmission according to an embodiment of the invention;
19 Fig. 4 is a graph illustrating a step-action shifting function according to an embodiment of the invention;
21 Fig. 5 is an elevation of a shifting mechanism detail seen 22 in Fig. 3 by viewing cam 80 and associated parts in an axial 23 direction from right to left; .
24 Fig. 6 is a diagrammatic view of a detail of Fig. 5 shown in a dynamic manner according to an embodiment of the invention;
26 Fig. 7 is a graph illustrating hysteresis in gear shif tiag 27 according to an embodiment of the invention;.
28 Fig. 8 and 9 are elevations of a ratchet shown respectively 29 in an activated condition and in a disabled condition, such as sees in Fig. 3 at 48 in an axial direction;
31 Fig. 10 is a view of a one-way clutch according to an 32 embodiment of the invention, as seen in Fig. 3 at 101 in an axial 33 direction from right to left;
34 Fig. 11 is an elevation of auxiliary planetary gearing WO 99/24?35 PCT/US97/20492 1 according to an embodiment of the invention, as seen in Fig. 3 at 110 in an axial direction from right to left;
gig. 12 is a longitudinal section of a shift position arrester according to an embodiment of the invention as a 5 modification of Fig. 3s g gig. 13 is a longitudinal section and block diagram of an ? electromechanical transmission according to a further embodiment g of the invention, and g Fig. 14 is a diagrammatic view of a derailleur type of automatic transmission according to a further embodiment of the 11 invention.

1 Modes of Carrying Out TheInvention 2 gig. 1 is a side view of a relevant potion of a bicycle 10, 3 representative of bicycles, tricycles and other humanly powered 4 vehicles within the scope of the invention.
gig. 1 shows part of the vehicle frame 12 including the so-b called seat tube 13 on which the seat post (not shown), Which 7 carries the seat or saddle (not shown), is adjustably mounted by 8 the seat lug (not shown). The seat tube 13 is fortified by the 9 seat stays 14 on which the rear wheel axle 15 and thereby the rear wheel is mounted with the aid of the chain stays 16 and 17 11 and a pair of wheel mounts 18.
12 Also visible in Fig. 1 is the crank axle 20 rotating in the 13 familiar bearing where the seat tube 13, downtube 19 and chain 14 stays 16 and 17 meet, one of the two pedals 21 and the two crank arms 22 which drive the so-called chain ring 23 and thereby the 16 drive chain 24 which in turn rotates the chain sprocket 25 for propulsion of bicycle 10.
1g Also seen in Fig. 1 is part of a caliper brake 26 acting on 19 the rim 27 of the rear wheel 28 and being representative of a manually actuable braking system for the bicycle or other humanly 21 powered vehicle.
22 Other more or less significant parts not shown in Fig. 1 23 include the familiar top tube in a men's bicycle or the 24 equivalent cross-bar structure in.a ladies' bicycle that extends between the seat tube 13 and the front head tube (not shown).
26 That cross-bar or top tube is joined by the downtube 19 in 27 mounting the front head tube in which the handlebar stem (not 28 shown) is mounted for steering of the bicycle by angular movement 29 of the front wheel (not shown) which is mounted between a pair of fork blades of the so-called fork that extends from the lower 31 end of the handlebar stem.
32 Fig. 1 diagrammatically indicates an automatic transmission 33 according to an embodiment of the invention at 30 With reference 34 to the remaining drawings and to the following description.
Within the scope of the invention. the bicycle may have a 1 front-wheel drive, instead of the rear-wheel drive shown in Fig.
2 1, or both rear wheels may be driven in the case of a tricycle, 3 for instance.
4 In the embodiment of Fig. 1, the crank arms 22 carry pedals 21 at their ends whereby the vehicle is humanly powered through 6 a rider's body, including legs and feet. In this respect, 7 bicycles and other vehicles with manually powered cranks are also 8 known and are within the scope of the invention in terms of 9 utility of the disclosed automatic transmission system.
Manually actuated multi-speed transmissions that may be 11 automated pursuant to the subject invention are apparent from the 12 following patents:
13 US Patent 832,442, by J. Archer, issued 2 October 1906, for 14 Variable Speed Gear;
US Patent 2,301,852, by W. Brown, issued 10 November 1942, 16 for Epicyclic Variable Speed Gearing;
17 US Patent 3,021,728, by Keizo Shimano, issued 20 February 18 1962, for Three Stage Speed Change Mechanism for a Bicycle; and 19 Swiss Patent 258,751, by Hans Schneeberger, issued 15 December 1948, for a three-speed transmission for bicycles.
21 This prior-art literature contains some of the sun gear, 22 planet gear and related terminology used also in the present 23 disclosure and in the description of the accompanying drawings.
24 Basically, the subject invention automatically senses output power torque of a shiftable bicycle transmission. The subject 26 invention thus avoids the disadvantages of the speed-sensitive 27 bicycle transmission mentioned above by way of background. The 28 subject invention thus truly assists the cyclist in automatically 29 shifting the bicycle's transmission whenever the torque necessary for smooth operation in any uphill, downhill or level operation 31 of the bicycle so requires.
32 The invention automatically converts sensed output power 33 torque to transmission shifting motion, and automatically shifts 34 the shiftable transmission by automatically applying such transmission shifting motion to the transmission shifting element 36 of that shiftable bicycle transmission without waiting for a 1 speed change and without subjecting the cyclist to overexertion.
2 Fig. 2 diagrammatically shows an embodiment of the invention 3 that applies these principles. Figs. 3 and 13 by way of example 4 shoal a couple of related embodiments of the invention.
In particular, 30 is an automatic transmission having two 6 planetary systems 31 and 32, each having a sun gear 33 or 34 on 7 or around the rear wheel axle 15 shown in Figs. 1 and 3 and 8 symbolically also in Fig. 2. Sun gear 33 is keyed to shaft 15, 9 such as shown at 39 in Figs. 3 and 13. Planetary systems 31 and 32 also have planet gears 35.or 36 around the corresponding sun 11 gear 33 or 34 and meshing therewith. Each of these planetary 12 systems also has a ring gear 37 or 38 internally meshing with the 13 corresponding planet gears 35 or 36. The ring gear 38.of the 14 second or sensor planetary system 32 carries the wheel hub 40 to Which the spokes 41 of the rear wheel 28 are attached, such as 16 via spoke spider anchors 42. Of course, within the scope of the 17 invention, the part 40 may symbolize other kinds of driven wheel 1g systems of humanly powered vehicles.
1g The automatic transmission 30 in Fig. 2 includes a first ratchet 43 that connects the humanly powered sprocket 25 at the 21 input of the transmission 30 to the internal ring gear 37 of the 22 first planetary system 31, except when it is free-wheeling, such 23 as mentioned below. That transmission 30 also includes a second 24 ratchet 44 that interconnects the planet gears 35 and 36 of the two planetary systems 31 and 32, except when it is free-wheeling, 26 such as also mentioned below. Transmission 30 further includes 27 a third ratchet 46 that can be disabled by the gear shift 28 mechanism, as indicated in the first set 47 of block positions 29 l, 2, 3 shown in Fig. 2, assuming a three-speed transmission by way of example. The transmission 30 moreover includes a forth 31 ratchet 48 that also can be disabled by the gear shift mechanism, 32 as indicated in the second set 49 of block positions l, 2, 3 33 shown in Fig. 2. If enabled, the third ratchet 46 connects the 34 sprocket 25.to the planetary gears 35 of the first planetary system 31. Alternatively or additionally, the fourth ratchet 48, 36 if enabled, either connects the sprocket 25 via the first ratchet 37 43 or connects the ring gear 37 to the planet gears 36 of the 1 second planetary system 32, for the various shift positions.
2 In the embodiment of Figs. 2 and 3, the first and second 3 ratchets 43 and 44 are mechanically interconnected through the 4 internal ring gear 37 of the first planetary system 31. That is a practical mechanical arrangement in some embodiments, but that 6 ring gear could, for instance, be internal of a common structure 7 of both the first and fourth ratchets 43 and 48. In other words, 8 both the first and fourth ratchets 43 and 48 could be 9 interconnected directly as long as they are also connected to the ring gear 37, such as for transmission of human power through the 11 first planetary system 31 in certain shift positions. Also 12 within the scope of the invention, a similar arrangement is 13 possible for the second and third ratchets 44 and 46, which could 14 be interconnected directly as long as they are also connected to planet gears 35 of the first planetary system 31.
16 As far as gear shitting is concerned, blocks 1 of the first 17 and second set of blocks 47 and 49 are shown in solid outline, 1g indicating that both second and forth ratchets 46 and 48 are 19 disabled in the first shift position (1) of the automatic transmission. Accordingly, the humanly powered sprocket input 21 25 drives the wheel hub 40 through the ratchet 43, ring and 22 planet gears 37 and 35 of the first planetary system 31, and 23 through the ratchet 44 and the planetary gear 36 and ring gear 24 38 of the second planetary system 32. This shift position (1) thus may serve to provide low-speed operation with high torque 26 for the bicycle or other humanly-powered vehicle.
27 Block position 2 is still solid in the first set of blocks 28 47 fox the third ratchet 46, whilst block 2 is dotted in the 29 second set of blocks 49 for the fourth ratchet 48, indicating that the third ratchet 46 is still disabled, while the forth 31 ratchet 48 is not disabled, but is active or enabled in the 32 second shift position (2) of the automatic transmission.
33 Accordingly, the humanly powered sprocket input 25 drives the 34 wheel hub 4C) through the first ratchet 43, enabled fourth ratchet 48 directly or via ring gear 37 of the first planetary system 31, 36 and through the planetary gears 36 and ring gear 38 of the second 37 planetary system 32; the ratchet 44 being free-wheeling at this 1 point. This shift position (2) thus may serve to provide what 2 may be called a straight or direct drive, such as for a mid-i speed, mid-torque kind of operation of the bicycle or other 4 humanly powered vehicle.
5 Conversely, the blocks 3 of the first and second set of 6 blocks 47 and 49 are shown in dotted outline, indicating that 7 both second and forth ratchets 46 and 48 are not disabled, but g are enabled or active in the third shift position (3) of the 9 automatic transmission. Accordingly, the humanly powered 10 sprocket input 25 drives the wheel hub 40 through the ratchet 46, 11 planetary gear 35 and ring gear 37 of the first planetary system 12 31, and through the ratchet 48, planetary gear 36 and ring gear 13 38 of the second planetary system 32; the ratchets 4~. and 44 14 being free-wheeling at this point. This shift position (3) thus may serve to provide a high-speed, low-torque kind of operation 16 for the bicycle or other humanly powered vehicle.
17 While both planetary gear systems 31 and 32 participate in 1g the power transmission from the driven sprocket input 25 to the 19 wheel 28 or wheel hub 40 output, depending on shift position, the second planetary system 32 may be considered part of the torque 21 sensor system according to a preferred embodiment of the 22 invention, since the primary role of such second planetary system 23 in the gear shifting function of the automatic transmission 30 24 is to sense output torque of that transmission for automatic shifting.
26 Accordingly, the second planetary system 32 is connected to 27 a torque sensor 51 shown in block diagram form in conjunction 2g with the remainder of Fig. 2, but being representative of or 29 including any apparatus that automatically senses output power torque, such as indicated by the arrow 52, and that automatically 31 converts sensed output power torque to transmission shifting 32 motion in steps corresponding to shift positions, such as steps 33 1, 2, 3, of one or more transmission shifting elements, such as 34 indicated at 47 and 49 is Fig. 2.
As further indicated by dotted lines 54 and 56, the 36 shiftable transmission 30 is automatically shifted by 37 automatically shifting the transmission shifting element with the 1 converted transmission shifting motion in steps, such as 1, 2, 2 3. in the case of a three-speed transmission.
3 In this respect, while separate sets of shifting blocks 47 4 and 49 have been shown is Fig. 2 for the ratchets 46 and 48, respectively, there may in fact be one shifting element for the 6 entire transmission. as is generally the case in manually 7 actuated transmissions, such as those disclosed in the above 8 mentioned incorporated patents.
g In terms of Fig. 3, for example, the transmission 30 may have an input rotor 60 that may mount the sprocket 25 for 11 application of human power to the transmission and hence to the 12 driven wheel 28. This rotor is coupled to pawls 59 which with 13 bias springs 61 are part of the first ratchet 43. The.secoad 14 ratchet 44, in turn, has pawls 62 spring biased at 63. Such ratchets may be of a conventional type that permit one-way 16 operation for power transmission in one direction, and that are 17 free wheeling in the opposite direction or sense of rotation.
1g Accordingly, the humanly driven input rotor 60 drives the 19 bicycle 10 through first and second ratchets 43 and 44, via ring gear 37 and planetary gears 35 of the first planetary system 31 21 and through planetary gears 36 and ring gear 38 of the second 22 planetary system 32. This represents the above mentioned shift 23 position (1) for low-speed operation with high torque.
24 The torque sensor 51 in the embodiment of Fig. 3 operates through the sun gear 34 of the second planetary system 32 in 26 automatically sensing output power torque of transmission 30.
27 Such transmission has an end cover 66 keyed to the shaf t 15, such 28 as at 67, in order to be stationary relative to the hub 40 and 29 other moveable parts. The heart of the torque sensor in the embodiment of Fig. 3 is a torque measuring spring 68 that is 31 anchored to end cover 66 by as annular spring housing structure 32 69. In principle. that spring may be a type of clock spring 33 having one or more turns or may in fact be a spring system 34 composed of ,several spiral or other types of springs . The spring or spring system used at 68 can be adapted to the kind of load 36 or system employed or can even be personalized to the owner and 37 user of the particular bicycle, for optimum gear shifting _ PCT/US97/20492 1 comfort .
2 The inner end of spring 68 is connected to an annulus 70 3 connected by coupling 52 to the sun gear 34 of the second planetary system. Both that annulus and that sun gear are angularly moveable relative to shaft 15. Accordingly, torque 6 generated by the bicycle rider not only drives the bicycle wheel 7 28 through ring gear 38, but also tensions the spring 68 through 8 sun gear 34 of the second planetary system 32 thereby sensing 9 output power torque and storing energy for transmission shifting.
The invention automatically converts sensed output power 11 torque to transmission shifting motion and automatically shifts 12 the shiftable transmission 30 by automatically applying that 13 transmission shifting motion to a transmission shifting element.
14 By way of example, the shaft 15 may at least partially be hollow cylindrical, and the transmission shifting element may be or 16 include a push rod 72 in that hollow shaft.
17 The push rod includes and is actuated by a push bar 73 1g riding on the face of a cam 74, which, for example, may be of an 19 axially acting type. A development of an essential portion of cam 74 on a plane is seen in Fig. 4, and a frontal view of that 21 cam 74 is seen in Fig. 5, indicating alternative flat and sloped 22 sections 75, 76, 77, 78 and 79 of increasing or decreasing height 23 is axial direction, depending on the sense of rotation imparted 24 by the sun gear 34 of the second planetary system 32. A like set of sections 75 to 79 preferably is provided on cam 74 26 diametrically opposite the first-mentioned set 75 to 79, such as 27 shown in Fig. 5.
2g The annulus 70 angularly moves cam 74 as measured output 29 power torque tensions and conversely relaxes spring 68. Cam slopes 76 and 78 act on the push bar 73 and thereby on push rod 31 72 to shift gears among several positions, such as those 32 indicated as (1), (2), and (3) in conjunction with Fig. 2, for 33 instance.
34 Ia practice, an automatic shifting mechanism may overreact, with torque exerted by the bicycle rider and shifting of gears 36 is effect "hunting" each other, manifesting itself in an annoying 37 continual up and down shifting of the automatic transmission.

1 Within the scope of the invention, some form of damping could be 2 employed to alleviate the problem. However, embodiments of the 3 invention prefer provision of some hysteresis to avoid "hunting"
4 within the automatic transmission. In practice, such hysteresis may be realized by a built-in reluctance of the automatic 6 transmission to shift gears.
7 By way of example, a shift control hub or cam 80 may be used 8 for that purpose, such as shown in Figs. 3 aad 5. Such cam may 9 cooperate with rollers 81 pivoted on pivot arms 82 or other cam followers riding for iastance on the periphery of cam 80. Such 11 pivot arms may. for instance, be supported by hinge pins 83 12 anchored in the ring structure 69 shown in Fig. 3 as a spring 13 housing and support. A tension spring 85 may act on the roller 14 support a~ns 82 in order to tension rollers 81 into contact with cam 80.
16 The cam 80 may be of a radially acting type wherein pairs 17 of cam protrusions or bumps 87 and 88 cooperate with rollers 81 18 to realize the desired reluctance or hysteresis of the shifting 19 mechanism to engage in senseless "hunting". As seen in Fig. 6, for instance, a single cam follower 81 with a single pair of cam 21 bumps 87 and 88 could be used within the scope of the invention.
22 However, Fig. 6 can also be viewed as an enlargement of a 23 peripheral region of cam 80, which includes a like diametrically 24 opposed symmetrical peripheral region.
Fig. 6 shows phantoms of a roller or cam follower 81 as a 26 peripheral region of the cam 80 moves relative thereto. In the 27 illustrated embodiment, it is the cam that moves angularly, while 2g the cam follower staads still peripherally and only moves 29 radially in respoase to bumps 87 and 88. Fig. 6 is of a polar coordinate nature, whilst its related Fig. 4 is of a Cartesian 31 character, wherein radial extent of cam 80 and height of cam 74 32 and are symbolized as h in terms of angular movement or 33 development d.
34 In Figs. 4 aad 5, zero degrees, 0°, are positioned in a mid range that, for instance, may correspond to a shift position (2) , 36 such as mentioned in conjunction with Fig. 2. Bumps 87 and 88 37 of cam 80 effectively reign in that mid position by preventing 1 the automatic transmission from dwelling between shif t positions 2 and from shifting prematurely. In particular, bumps 87 and 88 3 effectively prevent the pusher bar 73 from dwelling on either cam 4 slope 76 or cam slope 78. Bumps 87 and 88 of cam 80 cooperate in releasably retaining pusher bar 73 within the plus and minus 6 7° raage of the secoad flat 77 of cam 74 representing, for 7 example, shift position (2).
g By way of further example, the above mentioned shift 9 position (1) may correspond to the flat 75 of cam 74 and an angular range between 30° and 23° counterclockwise of the mid 1l range represented by flat 77. The transmission shifting 12 mechanism has to overcame bump 87 before it can shif t either way 13 between shift positions (1) and (2). w 14 Conversely, the above mentioned shif t position (3) may correspond to the flat 79 of cam 74 and an angular range between 16 30° and 23° clockwise of the mid range represented by flat 77.
17 The transmission shifting mechanism has to overcome bump 88 1g before it can shift from position (2) forward to position (3), i9 or from such position (3) back to position (2).
In this respect, the preferred embodiment of the invention 21 introduces the desired hysteresis, as may, for instance be seen 22 from the graph of Fig. 7 representing the wheel 28 to pedal 22 23 ratio R as a function of torque T of wheel 28 and also as a 24 function of torque S of sensor spring 68. As may be seen from Fig. 7 there is a hysteresis 190 between mid and high gears (2) 26 and (3) , and another hysteresis 19.1 between low and mid gears (1) 27 and (2) . Tension spring 85 and other parameters of the system may 2g be dimensioned for realization of optimum hystereses for various 29 given purposes.
Preferred embodiments of the invention thus provide stable 31 and accurate shifting of gears for superior comfort and 32 utilization of the human power of the bicycle rider.
33 Free-wheeling ratchets of the type of the first and second 34 ratchets 43;and 44 are well known. Mechanisms for alternatively enabling and disabling ratchets are also known and may be 36 employed in automatic transmission 30 with the shifting element 37 72 (push rod) etc. actuating such mechanisms.

~VVO 99/24735 PCTNS97/20492 1 In this respect, the humanly powered rotor 60 drives both 2 the first ratchet 43 and the shiftable third ratchet 46. In Fig.
3 3, these ratchets axe both internal ratchets wherein pawls 59 and 4 64 are internal to the array of ratchet teeth of these ratchets.
5 Plaaet gears 35 of the first planetary system 31 drive the 6 second ratchet 44, Which in Fig. 3 is an external ratchet wherein pawls 62 are external to an array of ratchet teeth of that g ratchet. This in effect accommodates the fourth ratchet 48 in 9 its design around the second ratchet 44.
10 In Fig. 3 the fourth ratchet 48 is an internal ratchet 11 wherein the array of ratchet teeth drive the pawls 164 as 12 indicated by arrows in Figs. 8 and 9, but under the control of 13 a ratchet shifter or pawl disabler 91. As seen in Fig. 3, pawls 14 164 are arranged in a slot of an output rotor 116 that may be a 15 spider for planet gears 36 of the second or torque sensing planet 16 system 32.
1~ Fig. 8 and 9 by way of example show partial cross-sections 18 of the fourth ratchet 48 which are also illustrative of possible 19 executions of the first, second and third ratchets shown in Fig.
3, except that the first and second ratchets 43 and 44 would not 21 have a ratchet shifter or disabler 90, 91, the configurations of 22 the first and second ratchets 43 and 44 would be mirror images 23 of the fourth ratchet, with the pawls driving the ratchet, and 24 the third ratchet 46 is an external ratchet as mentioned above.
The pawl bias springs are only shown as torque 165 in Figs.
26 8 and 9. The heart of each shiftable ratchet is a ratchet 27 shifter 90 for third ratchet 46 and a ratchet shifter 91 for 28 fourth ratchet 48. Such elements disable the ratchet 46 or 48 29 in their axial position such as shown in Fig. 9 for the ratchet 48, by depressing the active ends of pawls 164 away from the 31 correspoading ratchet teeth 93. Third and fourth ratchets 46 and 32 48 are thus disabled from transmitting any power in their 33 condition illustrated in Fig. 3.
34 Conversely, the ratchet shifters 90 and 91 in their axial position, such as illustrated for ratchet 48 in Fig. 8, enable 36 the ratchet 46 or 48 by sufficiently clearing ends of pawls 64 37 or 164 to permit rotation of these pawls by their spring bias 65, 1 165 until active ends of these pawls 64 or 164 are positioned for 2 engagement with the ratchet teeth 93 in one sense of rotation of 3 the ratchet 46 or 48.
4 Such shifting may. for instance, be effected with the above mentioned cam 74 and a corresponding bias spring 95 acting 6 conversely on pusher bar 73 which, in turn, shifts the central 7 shifting rod 72 and thereby a pusher bar 96 for the ratchet g shifter 90 and pusher bar 97 for the ratchet shifter 91. Passive 9 and active conditions of ratchets 46 and 48 are indicated by solid and phantom illustrations thereof in Fig. 3 . Reference may 11 in this respect be had to Fig. 2, to shifting blocks 47 and 49 12 and to the operational description thereof. Within the scope of 13 the invention, ratchet shifters 90 and 91 may be of di-fferent 14 width or thicknesses for different shifting effects, such as indicated by shifting blocks 47 and 49 in Fig. 2, for instance.
16 Within the scope of the invention, different configurations 17 or types of pawls may be used in the requisite ratchets, or 18 sprag-type or other forms of one-way clutches may be employed for 19 what is herein referred to as "ratchets."
According to an embodiment of the invention, input power 21 torque applied to the transmission is equalized by coupling each 22 foot of a bicycle rider to a pedal of the bicycle. To this end, 23 foot-to-pedal couplings from each foot of a bicycle rider to each 24 bicycle pedal may be associated with the automatic transmission.
One example of such foot-to-pedal couplings is seen at 99 and may 26 be representative of the familiar toe clips and toe straps of 27 racing bikes and other upscale bicycles or other pedal couplings 28 attached to riders' shoes. Such foot-to-pedal couplings aid 29 skilled, attentive riders to exert power not only on the downward angular motion of the pedal, but also during other phases, 31 including upward motion and angular motion through tops and 32 bottoms of the pedalling cycles. In conjunction with automatic 33 transmissions pursuant to the invention, this in practice helps 34 to prevent erratic shifting of the automatic transmission.
Additionally or more typically alternatively, a preferred 36 embodiment of the invention adds an internal anti-erratic 37 shifting feature to its automatic transmission Which retards 1 upshifts as compared to corresponding downshifts. By way of 2 example, a one-way type of clutch, such as shown in Fig. 10, may 3 be employed in or with the torque sensor 51 to retard 4 transmission upshifts relative to downshifts.
Such a one-way clutch 100 may, for instance, act on the sun 6 gear 34 of the second or sensing planetary- system 32 . The clutch may ride on a cylindrical extension of that sun gear and may g itself constitute or be included in an auxiliary sun gear 101 9 rotating on that cylindrical extension, such as seen in Figs. 3, 10 and 11.
11 The one-way clutch 100 may include unidirectionally biased 12 clutch elements or rollers 102. In the embodiment of Fig. 10, 13 the clutch has tapered cavities 103 having internal surfaces 14 parallel to axes of the gears and being open at the axial extension of sun gear 34. Rollers 102 are located in these 16 cavities and are biased against that extension by springs 104 17 causing rollers 102, extension of sun gear 34 and auxiliary sun 1g gear 101 to bind during relative movement indicated by arrow 106.
1g Conversely, biased rollers 102 are able to disengage from that bind during relative angular motion 107. Unidirectional clutch 21 100 thus is able to retard upshifts that would occur prematurely 22 during fluctuations of the pedalling power or erratically as a 23 reaction to spring-mass oscillations of the drive structure.
24 Clutch 100 or its sun gear 101 may be part of further planetary gearing 110, such as shown in Figs. 3 and 11. Since 26 the second sun gear 112 covers the first sun gear 101 in Fig. 11, 27 reference need to be had to Fig. 10 for a showing of the clutch 2g 100 in such first sun gear 101.
2g Either an even or an odd number of planet gears may be used in any planetary system herein disclosed. For example, Figs. 3 31 and 13 show sun gear systems 31, 32 and 110 that have an even 32 number of planet gears. On the other hand, Fig. 11 shows as odd 33 number of planet gears with the understanding that an even number 34 of planet gars may alternatively be employed.
In addition to its first sun gear 101, gearing 110 may 36 include the second sun gear 112 which may be keyed to shaft 15 37 to be relatively stationary. Such second sun gear 112 preferably 1 is of larger diameter than the first sun gear 101. The 2 preferably smaller sun gear 101 has planet gears 113, and the 3 preferably larger sun gear 112 has further planet gears 114, each 4 being preferably of smaller diameter than each of the planet gears 113.
6 Planet gears 113 and 114 are interconnected to rotate in 7 synchronism and are journalled between planet gears 36 and a 8 spider 116 of such planet gears 36 of the second or torque 9 sensing planetary system 32. Such spider may serve as an output rotor of the second and fourth ratchets 44 and 48 and may be 11 present, even if the auxiliary gearing 110 is not used in any 12 different embodiment of the invention.
13 In particular, planet gears 114 have pivots 119 connected 14 to spider 116 and planet gears 36 of second planetary system 32 to revolve in synchronism therewith about their stationary sun 16 gear 112. Planet gears 113 are connected to these planet gears 17 114 to rotate in synchronism therewith and to angularly move 1g their sun gear 101 slowly in a direction 107 that is opposite to 19 the direction of rotation 106 of spider 116.
In the illustrated embodiment, the pitchline velocity of sun 21 gear 101 is proportional and opposite in direction to the veloci-22 ty at 106 multiplied by the difference of radii of planet gears 23 113 and 114 divided by the radius of planet gear 113. According 24 to a preferred embodiment of the invention, gear ratios within auxiliary gearing 110 are selected to assure that during each mi-26 nimum torque quarter turn of each pedal 21, the clutch 100 in sun 27 gears 101 restrains the sun gear 34 and hence the angular move-2g meat of cam 80 through coupling 52 so that the automatic trans-29 mission cannot upshift as a result of such minimum torque phase.
The embodiment of the invention shown in Figs. 3. 10 and 11 31 retards upshif is without affecting dowashif ts.
32 In particular, as the cyclist applies torque through the 33 automatic transmission, the second sun gear 34 torques the sensor 34 spring 68 via coupling 52 which thereby stores energy, reaching a point at Which cams 74 and 80 downshift the transmission via 36 shifting bar 73 and element 72. Two such downshifts are 37 illustrated in succession in Fig. 7 by downwardly pointing 1 arrows. Auxiliary planetary gearing 110 and its clutch 100 have 2 no effect on such downshifting, inasmuch as the extension of the 3 sensing sun gear 34 then is angularly moving clockwise as seen 4 in Fig. 10 relative to the auxiliary sun gear 101 so that clutch rollers 102 would move out of any locking position at surfaces 6 103 against the bias of springs 104.
7 Sensing spring 68 stores energy imposed thereto by sensed g output torque. If the torque applied by the cyclist decreases, 9 such energy previously stored in sensing spring 68 tends to angularly move the sensing sun gear 34 counterclockwise as seen 11 in Fig. 10. In the absence of clutch 100 this would effect 12 upshifting of the transmission via cams 74 and 80 whenever torque 13 applied by the cyclist decreases.
14 However, the auxiliary planet system 110 is turning its sun gear 101 in the direction of arrow 107 as long as the bicycle is 16 going forward. Due to the action of clutch 100 neither the 17 sensing sun gear 34, nor its coupling 52 can go faster 18 counterclockwise than the auxiliary sun gear 101. In 19 consequence, upshifting via cams 74 and 80 is retarded until the energy stored in or by sensing spring 68 balances with the sensed 21 output torque, whereupon upshifting occurs, such as indicated in 22 succession by upwardly pointing arrows in Fig. 7 for two shifting 23 operations.
24 The currently discussed embodiment of the invention meters the stored energy of sensing spring 68 in the automatic 26 conversion of sensed output torque to transmission shifting 27 motion to the effect that spring-mass oscillations occurring in 28 the system are dampened, if not precluded, and that inevitable 29 fluctuations is bicycle operation, such as from driving torque diminutioas during pedaling through peaks of the pedal rotations, 31 cannot eventuate erratic shifting or dithering of the automatic ' 32 transmission.
33 By way of example. stored energy in sensing spring 68 is 34 metered to ;retard upshif is in the shifting of the shif table transmissions 30 and 230. In this respect, clutch 100 and 36 auxiliary planetary gearing 110 may be employed to meter the rate 37 at which sensing spring 68 releases its energy, such as disclosed 1 above with the aid of Figs. 3, 10 and 11. In apparatus terms, 2 the bicycle output power torque sensor 51 may include a sensed 3 output torque energy storing device 68 and the output power 4 torque-to-transmission shifting motion converter 70, 74, 80 5 includes a stored energy metering device 101, 110. Such stored 6 energy metering device may be a unidirectional upshift retarding 7 device. such as in the form of or including one-way clutch 100.
g According to a further embodiment of the invention, the 9 automatic transmission may be arrested at a given shift position.
10 What may be termed a "manual shift arrester" 123 may be made to 11 act on part of the automatic transmission, such as on an element 12 of its torque sensor 51.
13 In this respect, Fig. 12 shows an auxiliary annulus 124 14 acting on the sensor annulus 70 via corresponding coupling 15 elements, such as pins 125 and corresponding cavities 126. The 16 number of cavities may correspond to the number of shifting 17 positions or flats 75, 77, 79 shown in Figs. 4 to 6.
1g Such coupling elements may be manually actuated. By way of 19 example, the kind of cable pull 53 used, for instance, in prior-20 art manual transmissions may be used to retain the auxiliary 21 annulus 124 disengaged from the sensing system annulus 70 against 22 the bias of springs 128. The auxiliary annulus 124 may be 23 released, such as by release of the cable pull 53, whereupon the 24 bias of springs 128 will cause pins 125 to engage cavities 126 so that the sensing sun gear 34 is no longer able to rotate the 26 annulus 70 relative to stationary cover 66. The cable pull 53 27 is again actuated to pull the shift arresting elements 125 away 28 from the sensing annulus 70, when resumption of the automatic 29 shif tiag function of transmission 30 is again desired.
Within the scope of the invention, torque may be sensed 31 electrically and/or the automatic transmission may be operated 32 electromechanically. By way of example, Fig. 13 shows such an 33 electrified version. The mechanical portion of such 34 electromechanical transmission 130 may. for example, include the sprocket-driven input rotor 60, first planetary system 31 and 36 ratchets 43, 44, 46, 48 coupled respectively to planet and ring 37 gears 35 sad 37, ratchet shifters 90 and 91, an output rotor 216 *rB

. WO 99/24735 PCT/US97I20492 ' 21 1 similar to the above mentioned output rotor 116, but more 2 directly coupled to the bicycle wheel hub 40, and other 3 mechanical parts such as shown jointly in Figs. 3 and 13.
4 The electromechanical transmission 130 also includes an electrical part which, for more rapid understanding, carries 6 reference numerals that are elevated by "100" relative to similar 7 if not equivalent mechanical parts in embodiments shown in Figs.
g 2 to 6. 10 and 11, for instance. Of course, this by way of 9 example, and not by way of limitation.
Torque pickup in Fig. 13 may include electric gages, such 11 as strain gages 134, picking up torque from shaft 15 which is 12 torqued by sun gear 33 against its restraints at opposite ends 13 of that shaft. Such strain gages preferably are mounted on 14 opposite sides of shaft 15 at 45 degrees to the shaft axis.
Bending moments of the shaft will thus be canceled and torsional 16 forces imposed by the sun gear 33 of the humanly powered 17 planetary system 31 can thus be made additive in an electronic 1g torque sensor 151 that may include a strain gage reference i9 amplifier which in a manner known per se from strain gage technology converts strain gage signals into a switching signal 21 indicative of sensed human power torque.
22 Such electric torque signal 171 may be equivalent to the 23 torque delivered by the annulus 70 shown in Fig. 3. In analogy 24 to the cammed arrangement 80 illustrated in Figs. 3 and 4 to 6, the circuitry of Fig. 13 may include electronic circuitry 180 of 26 a conventional type that responds only to peaks in signal 171 27 whereby only peak torques are recognized. By way of example, 2g circuitry 180 may include a torque level discriminator employing 2g such conventional elements as Schmitt trigger circuitry, in order to convert the torque signal 171 into a tri-stable switching 33. signal. Instability may be avoided by detecting only peak signals 32 in the sensed output torque, and a counter that counts out the 33 above mentioned cyclically occurring torque fluctuations may be 34 used in the circuitry, such as at 151 to prevent erratic 3 5 shi f ting .
36 The sensed torque signal 171 as processed through circuitry 37 180 is applied via a lead 173 to a switching circuit 174 that in . CVO 99/24735 PCT/US97/20492 1 analogy to shifting element 72 shown in Fig. 3 effects selective 2 switching of the third and fourth ratchets 46 and 48. To this 3 end, switching circuit 174 responds to the processed torque 4 signal occurring at 173 by supplying switching signals to ratchet shifter actuators 196 and 197. By way of example, such actuators 6 may include solenoid drivers, and the switching circuit 174 may 7 include a solenoid driver selector which may in effect be a 8 shifting element analogous to the shifting element 72 in the 9 mechanical version of Fig. 3.
In this respect, solenoid driver 196 alternatively energizes 11 spaced electromagnets 200 and 201 having the ratchet shifter 90 12 for the third ratchet 46 located therebetween. Similarly, 13 solenoid driver 197 alternatively energizes spaced electromagnets 14 202 and 203 having the ratchet shifter 91 for the fourth ratchet 48 located therebetween. By way of example, solenoid driver 197 16 may be a high-low driver, shifting transmission 130 among high 17 and low gears, and solenoid driver 196 may be an intermediate 1g solenoid driver, shifting the transmission to and from an i9 intermediate gear.
Accordingly, third ratchet 46 is switched to and is retained 21 in its disabled state by energization of electromagnet 200 via 22 driver 196. Similarly, fourth ratchet 48 is switched to and is 23 retained in its disabled state by energization of electromagnet 24 202 via driver 197.
Conversely, third ratchet 46 is switched to and is retained 26 in its enabled state by energization of electromagnet 201 via 27 driver 196. Fourth ratchet 48 is switched to and is retained in 2g its enabled state by energization of electromagnet 203 via driver 29 197.
According to an embodiment of the invention, the ratchet 31 shifters 90 and 91 are or include permanent magnets so that 32 electromagnets 200, 201, 202, 203, can be energized to either 33 attract or repel their corresponding ratchet shifter 90 or 91.
34 Preferably, ;solenoids or electromagnets 200 to 203 have soft iron cores so that each ratchet shifter 90 or 91 will remain at the 36 last electromagnet that has attracted it, until its opposite 37 electromagnet is energized. In such case, the mentioned 1 energization of electromagnets may not be necessary for retaining 2 a switched ratchet in a switched state, since the permanent 3 magnetism of a ratchet shifter 90 or 91 may perform such 4 retention on the soft iron core of the adjacent electromagaet.
In practice, the switching pattern illustrated by switching 6 blocks 47 and 49 may be implemented in solenoid driver selector 7 174 and solenoid drivers 196 and 197 to effect gear shifting in 8 a manner explained above with reference to Figs. 2 et seq.
9 Solenoid driver selector 174 may be progra,a~ed for that purpose or for any other desired switching pattern.
11 The countervailing ratchet switching actions may be gives 12 a bistable character by the above mentioned circuitry 180.
13 Alternatively or additionally, bent springs 205 and 206~having 14 configurations similar to one of the bumps 87 and 88 illustrated in Figs. 4 to 6 may be provided in order to enhance the bistable 16 character of each ratchet shifting operation. In this respect, 17 in the mechanical version of Fig. 3, the spring 95 provides a 18 sustained force to move ratchet shifters 90 and 91 until a 19 ratchet shifting operation has been completed. In the electromechanical version, an extended electromotoric force or 21 EMF maybe provided by aaalogy and/or springs 205 and 206 may 22 serve to complete the motion of ratchet shifters 90 and 91, 23 respectively, during the short delays when pawls move among their 24 positions exemplified in Figs. 8 and 9. for instance.
In analogy to the manual shift arrester 123 such as shown 26 in Fig. 12, the embodiment of Fig. 13 may include a shift 27 arrester, such as in the form of a switch 223 between torque 28 sensor 151 and solenoid driver selector 174. Such switch is 29 normally closed or biased to its closed position wherein gear shifting occurs in response to sensed output torque changes.
31 Alternatively, switch 223 is opened, such as by the type of 32 cable pull 53 shown in Fig. 12 or by another manually exerted 33 force 153. In this manner, supply of shifting signals to the 34 solenoid , drivers may be interrupted, whereby the electromechanical transmission 130 is manually arrested in any 36 then prevailing shift position. Switch 223 may be released to 37 its closed position whereby automatic switching of transmission 1 130 is resumed.
2 The automatic transmission 130 may be electrified with 3 batteries and/or the kind of generating system used for bicycle 4 lights.
The embodiments of Figs. 3 and 13 employ several ball, 6 needle or other bearings which may be of_a conventional type.
Although planetary gear or hub type integral transmissions g have been shown in detail and are preferred, the principles of 9 the subject invention and of its embodiments of Figs. 2 etc. may also be applied to derailleur type of shiftable transmissions.
11 By way of example, Fig. 14 shows an automatic transmission 12 230 wherein a derailleur type of transmission 231 is substituted 13 for the first planetary gear system 31 of gear type transmissions 14 30 and 130.
Derailleur transmissions are well known and include the 16 tension wheel and the jockey wheels (not shown) around the chain 1~ 24 at the rear wheel 28, and the freewheel and gear cluster (not 1g shown) in the area of sprocket wheel 25. The sprocket input again 19 has been shown as 25, as in Fig. 2.
The torque sensing and transmission shifting system, 21 including the secondary planetary system 32 and torque sensor 51, 22 again may be provided according to a preferred embodiment of the 23 invention; this time to (a) apply the rear wheel or output torque 24 152 of the derailleur transmission 231 to the wheel hub 40 and to (b) sense such output torque and shift the derailleur, such 26 as indicated by dotted lice 154.
2~ Within the scope of the invention, a derailleur type of 28 transmission system may be electrified, such as in the manner 29 disclosed above with respect to Fig. 13. In either case, a derailleur or derailleurs is or are shifted instead of the 31 ratchets 46 and 48.
32 Within the scope of the invention, the transmission may be 33 hybrid, such as either automatic and manual or automatic gear 34 type and derailleur manual.
Although the invention and its various aspects are herein 36 disclosed with the aid of detailed embodiments, the invention 37 clearly neither is limited to such details. nor to any disclosed *rB

1 modes of carrying out the invention. Rather, this disclosure and 2 also the following parts thereof reveal a broad applicability of 3 the invention and a variability going clearly beyond the elements 4 mentioned herein as an aid to an acquisition of understanding.
5 Accordingly, the exemplary term "such as" need to be thought as 6 being present before each specific or numerical statement or 7 indication.
g From one aspect thereof, the invention shifts a shiftable 9 bicycle transmission by automatically sensing output power torque 10 of that transmission, automatically converting sensed output 11 power torque to transmission shifting motion, and automatically 12 shifting that shiftable transmission with said transmission 13 shifting motion.
14 To this end, a shiftable bicycle driving power transmission 15 30, 130, 230 may have a transmission shifting element, such as 16 72, 154 or 174, and comprises a bicycle output power torque 17 sensor 51, 151, and an output power torque-to-transmission 1g shifting motion converter 68, 74, 180, having a output power 19 torque input coupled to the output power torque sensor, such as 20 at 52 or 171, and having a transmission shifting motion output 21 73, 173. The transmission shifting element 72, 174 is coupled 22 to the transmission shifting motion output of that converter.
23 The output power torque may be sensed mechanically, and the 24 output power torque sensor 51 may be a mechanical output power 25 torque sensor 34, 52, 68. Alternatively, the output power torque 26 may be sensed electrically, such as at 151 employing strain gages 27 134. The output power torque preferably is sensed inside the 2g transmission, and the output power torque sensor 51, 134, 151 29 preferably is inside the transmission 30, 130, 230.
A variable corresponding to the output power torque may be 31 developed in the transmission, and the output power torque is 32 sensed from that variable. The output power torque sensor 51, 33 151 may include sun gear 34, strain gages 134 or other means for 34 sensing a variable corresponding to the output power torque in the transmission 30, 130, 230, and a spring 68, strain gage 36 reference amplifier 151, torque level discriminator 180 or other 37 means for sensing that output power torque from that variable.

1 A planetary gear 32 may be included in transmission 30 or 2 230, and the above mentioned variable may be derived from such 3 planetary gear. The output power torque sensor 51 may be coupled 4 to that planetary gear, such as indicated at 52 in Figs. 2, 3 and 14. Such output power torque sensor 51 may be coupled to a sun 6 gear 34 of that planetary gear 32, or, the above mentioned variable may otherwise be derived from such sun gear 34 of g planetary gear 32.
g First and second planetary gears 31 and 32 may be variably coupled in series in the transmission, and the above mentioned 11 variable may be derived from one of these planetary gears, such 12 as from the second planetary gear 32. The transmission may 13 include first and second planetary gears 31 and 32 variably 14 coupled in series, and the output power torque sensor 51 is coupled to one of such planetary gears, such as to the second 16 planetary gear 32.
1~ The shifting of the transmission may include reversing 1g transmission of power torque through the first planetary gear, i9 such as from the ring gear 37 to the planet gears 35 in one shift position (e.g. when third and fourth ratchets 46 and 48 are 21 deactivated). and conversely from these planet gears 35 to that 22 ring gear 37 in another shift position (e.g. When third and 23 fourth ratchets 46 and 48 are activated as means for reversing 24 that transmission of power).
The above mentioned variable may impose a strain on an 26 element in the transmission, and .the output power torque may be 27 sensed from that strain. By way of example, the output power 2g torque sensor may include a strain gage 134 on an element in the 29 transmission, such as shown in Fig. 13. Such element may be a shaft 15 on which strain is imposed, and strain gage 134 may be 31 mounted on that shaft.
32 Another example of such an element is the spring 68 shown 33 in Fig. 3 on Which strain is imposed, such as from sun gear 34 34 via coupling 52. The output power torque sensor 51 may include a spring 68 coupled to part of the transmission 30.
36 A derailleur 231 and gears 32 may be included in the 3~ transmission, such as shown in Fig. 14, and output torque may be 1 sensed from such gears 32. The derailleur may then be shifted 2 with the above mentioned transmission shifting motion, such as 3 indicated at 154 in Fig. 14, Which shows a derailleur 231 and 4 gears 32 between that derailleur and an output 40 of transmission 230. The output power torque sensor 51 is coupled to these 6 gears, such as at 52, and the transmission shifting element 154 7 is coupled to the derailleur. Gears 34, 36, 38 may be arranged 8 in a planetary system.
g The transmission may be shifted in upshifts and in downshifts, and a hysteresis 190, 191 may be imposed on the 11 automatic shifting as between such upshif is and downshifts, such 12 as shown in Fig. 7. Upshif t shifters and downshift shifters may 13 include the cam 74 acting on shifting element 72 and ratchets 46 14 and 48, and means for imposing hystereses may include cam 80 with bumps 87, 88, etc.
16 Energy of the sensed output torque may be stored, such as 17 in spring 68 mechanically or in a circuit 180 electronically, and 1g such stored energy may be metered in the automatic conversion of 19 sensed output power torque to transmission shifting motion. Such stored energy may particularly be metered to retard upshifts in 21 the shifting of the shiftable transmission 30, 130, 230. By way 22 of example, such metered energy release may be effected by 23 auxiliary planetary gearing 110 with one-Way clutch 100, which 24 also may impose a hysteresis of sorts. Upshifts preferably are retarded relative to downshifts. By way of example, upshif is are 26 retarded while converting sensed output power torque to 27 transmission shifting motion. Transmission 30, 130 may include 28 upshift shifters and downshift shifters 90, 91 and shift 2g retarders 87, 88, 100, 180.
Pursuant to a preferred embodiment of the invention, sensed 31 output power torque is automatically converted to the 32 transmission shifting motion in steps corresponding to shift 33 positions of the transmission, such as (1), (2), (3), and such 34 shiftable transmission is automatically shifted by automatically shifting that transmission with such transmission shifting motion 36 in these steps. The output power torque-to-transmission shifting 37 motion converter of the transmission may include a step-action 1 converter 74, 80. 180 having a stepped transmission shifting 2 motion output at 73 or 173.
3 Ia this or any other manner within the scope of the 4 invention, the automatic transmission preferably has distinct shifting positions, such as (1), (2), (3), corresponding to 6 different output power torques, and such conversion of output 7 power torque preferably is automatically detained until the g sensed output power torque has achieved a value corresponding to 9 a distinct shifting position of that transmission. The conversion of output power torque is automatically released 1l whenever the sensed output power torque has achieved a value 12 corresponding to a distinct shifting position of the 13 transmission, and such shiftable transmission is automatically 14 shifted upon release of that conversion by applying a transmission shifting motion to that transmission. In this 16 respect, the transmission shifting element 72, 174 has distinct 17 shifting positions corresponding to different output power 1g torques applied to the transmission, and the converter may have 19 a detent 87, 88 adapted to detain output power torque-to-transmission shifting motion conversion and thereby shifting of 21 the transmission until sensed output power torque has achieved 22 a value corresponding to a distinct shifting position of the 23 transmission shifting element, such as also implemented by 24 circuit 180.
The transmission shifting element may be a translatory 26 transmission shifting element 72, and its output power torque 27 input is a rotary output power torque input 34, 52, 70, 74 28 coupled to an output power torque sensor 51, 68. The 29 transmission shifting motion output may be a translatory transmission shifting motion output 73 coupled to that rotary 31 output power torque input. The traaslatory transmission shifting 32 element 72 may be coupled to that traaslatory transmission 33 shifting motion output 73.
34 The transmission typically has distinct lower and higher shif tiag positions corresponding to different output power 36 torques, and the conversion of output power torque is 37 automatically detained until the sensed output power torque has 1~V0 99/24735 PCT/US97/20492 1 achieved a value corresponding to a distinct shifting position 2 of that transmission. The conversion of output power torque is 3 automatically released whenever the sensed output power torque 4 has achieved a value corresponding to a distinct shifting position of the transmission. Preferably, such conversion of 6 output power torque is detained and is thereafter released at a 7 hysteresis so that output power torque is released at different 8 shift points for shifts from a lower shifting position to a 9 higher shifting position than for shifts from a higher shifting position to a lower shifting position, and such as shown by Way 11 of example in Fig. 7. The shiftable transmission is 12 automatically shifted at such different shift points.
13 Shift points for shifts from a lower shifting position to 14 a higher shifting position preferably are lower in teems of output power torque than shift points for shifts from a higher 16 shifting position to a lower shifting position, such as seen in 17 gig. 7, for instance. The transmission shifting element 72 1g preferably has distinct lower and higher shifting positions 19 corresponding to different lower and higher output power torques, respectively, applied to the transmission, ann the converter 74, 21 80 has a decent 87, 88, 100 adapted to detain output power 22 torque-to-transmission shifting motion conversion and thereby 23 shifting of the transmission at different shift points for shifts 24 from a lower shifting position to a higher shifting position than for shifts from a higher shifting position to a lower shifting 26 position.
27 The shiftable bicycle transmission 30, 130, 230 may be 2g arrested in any shifting position. By way of example, a manual 29 shift position arrester 123, 223 may be coupled to the transmission, such as by a coupling of the shift position 31 arrester to torque sensor 51, 151, etc.
32 This extensive disclosure with many examples in and from the 33 mechanical and electric arts demonstrates the broad scope of the 34 invention axed of its various aspects and embodiments, rendering apparent or suggesting to those skilled in the art various 36 modifications and variations within the spirit and scope of the 37 invention.

Claims

I/WE CLAIM:

1. A method of shifting a shiftable bicycle transmission, comprising in combination:
automatically sensing output power torque of said transmission;
automatically converting sensed output power torque to transmission shifting motion; and automatically shifting said shiftable transmission with said transmission shifting motion.

2. A method as in claim 1, wherein:
said output power torque is sensed mechanically.

3. A method as in claim 1, wherein:
said output power torque is sensed electrically.

4. A method as in claim 1, wherein:
said output power torque is sensed inside said transmission.

5. A method as in claim 1, 2, 3 or 4, wherein:
a variable corresponding to said output power torque is developed in said transmission; and said output power torque is sensed from said variable.

6. A method as in claim 5, wherein:
skid variable is developed with the aid of a gear element in said transmission.

7. A method as in claim 5, wherein:
a planetary gear is included in said transmission; and said variable is derived from said planetary gear.

8. A method as in claim 7, wherein:
said variable is derived from a sun gear of said planetary gear.

9. A method as is claim 5, wherein:
first and second planetary gears are variably coupled in series in said transmission; and said variable is derived from one of said planetary gears.

10. A method as in claim 9, wherein:
said shifting includes reversing transmission of power torque through said first planetary gear.

11. A method as in claim 9, wherein:
said variable is derived from said second planetary gear.

12. A method as in claim 5, wherein:
said variable imposes a strain on as element in said transmission; and said output power torque is sensed from said strain.

13. A method as in claim 12, wherein:
said element is a shaft on which said strain is imposed.

14. A method as in claim 12, wherein:
said element is a spring on which said strain is imposed.

15. A method as in claim 1, 2, 3 or 4, wherein:
a derailleur and gears are included in said transmission;
said output torque is sensed from said gears; and said derailleur is shifted with said transmission shifting motion.

16. A method as in claim 15, wherein:
said gears are arranged in a planetary system.

17. A method as in claim 1, 2, 3 or 4, wherein:
said transmission is shifted in upshifts and in downshifts; and a hysteresis is imposed on said automatic shifting as between said upshifts and downshifts.

18. A method as in claim 1, 2, 3 or 4, wherein:
energy of said sensed output torque is stored; and said stored energy is metered in the automatic conversion of sensed output power torque to transmission shifting motion.

19. A method as in claim 18, wherein:
said stored energy is metered to retard upshifts in the shifting of said shiftable transmission.

20. A method as in claim 1, 2, 3 or 4, wherein:
said transmission is shifted in upshifts and in downshifts; and said upshifts are retarded relative to said downshifts.

21. A method as in claim 20, wherein:
said upshifts are retarded while converting sensed output power torque to transmission shifting motion.

22. A method as is claim 1, 2, 3 or 4, wherein:
said sensed output power torque is automatically converted to said transmission shifting motion in steps corresponding to shift positions of said transmission; and said shiftable transmission is automatically shifted by automatically shifting said transmission with said transmission shifting motion in said steps.

23. A method as in claim 22, wherein:
said transmission is shifted in upshifts and in downshifts; and said upshifts are retarded relative to said downshifts.

24. A method as in claim 23, wherein:
said upshifts are retarded while converting ceased output power torque to transmission shifting motion.

25. A method as in claim 1, 2, 3 or 4, wherein:
said transmission has distinct shifting positions corresponding to different output power torques;
said conversion of output power torque is automatically detained until said sensed output power torque has achieved a value corresponding to a distinct shifting position of said transmission;
said conversion of output power torque is automatically released whenever said sensed output power torque has achieved a value corresponding to a distinct shifting position of said transmission; and said shiftable transmission is automatically shifted upon release of said conversion by applying a transmission shifting motion to said transmission.

26. A method as in claim 1, 2, 3 or 4, wherein:
said transmission has distinct lower and higher shifting positions corresponding to different output power torques;
said conversion of output power torque is automatically detained until said sensed output power torque has achieved a value corresponding to a distinct shifting position of said transmission;
said conversion of output power torque is automatically released whenever said sensed output power torque has achieved a value corresponding to a distinct shifting position of said transmission;
with said conversion of output power torque being detained and being released at a hysteresis so that output power torque is released at different shift points for shifts from a lower shifting position to a higher shifting position than for shifts from a higher shifting position to a lower shifting position; and said shiftable transmission is automatically shifted at said different shift points.

27. A method as in claim 26, wherein:
shift points for shifts from a lower shifting position to a higher shifting position are lower in terms of output power torque than shift points for shifts from a higher shifting position to a lower shifting position.

28. A method as in claim 1, 2, 3 or 4, wherein:
said shiftable bicycle transmission is arrested in any shifting position.

29. A method as in claim 1, 2, 3 or 4, wherein:
input power torque applied to said transmission is equalized by coupling each foot of a bicycle rider to a pedal of the bicycle.

30. A shiftable bicycle driving power transmission having a transmission shifting element, comprising in combination:
a bicycle output power torque sensor; and an output power torque-to-transmission shifting motion converter having an output power torque input coupled to said output power torque sensor and having a transmission shifting motion output;
said transmission shifting element coupled to said transmission shifting motion output of said converter.

31. A transmission as in claim 30, wherein:
said output power torque sensor is a mechanical output power torque sensor.

32. A transmission as in claim 30, wherein:
said output power torque sensor is an electromechanical output power torque sensor.

33. A transmission as in claim 30, wherein:
said output power torque sensor is inside said transmission.

34. A transmission as in claim 30, 31, 32 or 33, wherein:
said output power torque sensor includes means for sensing a variable corresponding to said output power torque in said transmission; and means for sensing said output power torque from said variable.

35. A transmission as in claim 30, 31, 32 or 33, wherein:
said output power torque sensor includes a gear element in said transmission.

36. A transmission as in claim 30, 31, 32 or 33, wherein:
said transmission includes a planetary gear; and said output power torque sensor is coupled to said planetary gear.

37. A transmission as in claim 36, wherein:
said output power torque sensor is coupled to a sun gear of said planetary gear.

38. A transmission as in claim 36, wherein:
said transmission includes first and second planetary gears variably coupled in series; and said output power torque sensor is coupled to one of said planetary gears.

39. A transmission as in claim 38, including:
means for reversing transmission of power torque through said first planetary gear coupled to said transmission shifting element.

40. A transmission as in claim 38, wherein:
said output power torque sensor is coupled to said second planetary gear.

41. A transmission as in claim 30, 31, 32 or 33, wherein:
said output power torque sensor includes a strain gage on an element in said transmission.

42. A transmission as in claim 41, wherein:
said element is a shaft; and said strain gage is mounted on said shaft.

43. A transmission as in claim 30, 31 or 33, wherein:
said output power torque sensor includes a spring coupled to part of said transmission.

44. A transmission as in claim 30, 31, 32 or 33, including:
a derailleur and gears between said derailleur and an output of said transmission;
said output power torque sensor is coupled to said gears; and said transmission shifting element is coupled to said derailleur.

45. A transmission as in claim 44, wherein:
said gears are in a planetary system.

46. A transmission as in claim 30, 31, 32 or 33, wherein:
said transmission includes upshift shifters and downshift shifters; and means for imposing a hysteresis on said upshift and downshift shifters.

47. A transmission as in claim 30, 31, 32 or 33, wherein:
said bicycle output power torque sensor includes a sensed output torque energy storing device; and said output power torque-to-transmission shifting motion converter includes a stored energy metering device.

48. A transmission as in claim 47, wherein:
said stored energy metering device is a unidirectional upshift retarding device.

49. A transmission as in claim 30, 31, 32 or 33, wherein:
said transmission includes upshift shifters and downshift shifters; and shift retarders selectively coupled to said upshift shifters.

50. A transmission as in claim 30, 31, 32 or 33, wherein:
said converter is a step-action converter having a stepped transmission shifting motion output.

51. A transmission as in claim 50, wherein:
said transmission includes upshift shifters and downshift shifters; and means for imposing a hysteresis on said upshift and downshift shifters.

52. A transmission as in claim 50, wherein:
said transmission includes upshift shifters and downshift shifters; and shift retarders selectively coupled to said upshift shifters.

53. A transmission as in claim 30, 31, 32 or 33, wherein:
said transmission shifting element has distinct shifting positions corresponding to different output power torques applied to said transmission;
said converter has a detent adapted to detain output power torque-to-transmission shifting motion conversion and thereby shifting of said transmission until sensed output power torque has achieved a value corresponding to a distinct shifting position of said transmission shifting element.

54. A transmission as in claim 30, 31, 32 or 33, wherein:
said transmission shifting element is a translatory transmission shifting element;
said output power torque input is a rotary output power torque input coupled to said output power torque sensor;
said transmission shifting motion output is a translatory transmission shifting motion output coupled to said rotary output power torque input; and said translatory transmission shifting element is coupled to said translatory transmission shifting motion output.

55. A transmission as in claim 30, 31, 32 or 33, wherein:
said transmission shifting element has distinct lower and higher shifting positions corresponding to different lower and higher output power torques, respectively, applied to said transmission; and said converter has a detent adapted to detain output power torque-to-transmission shifting motion conversion and thereby shifting of said transmission at different shift points for shifts from a lower shifting position to a higher shifting position than for shifts from a higher shifting position to a lower shifting position.

56. A transmission as in claim 30, 31, 32 or 33, including:
a manual shift position arrester coupled to said transmission.

57. A transmission as in claim 56, including:
a coupling of said shift position arrester to said torque sensor.

58. A transmission as in claim 30, 31, 32 or 33, including:
foot-to-pedal couplings from each foot of a bicycle rider to each bicycle pedal, associated with said transmission.