Abstract:
A chain shifting apparatus senses bias of pre-set peak pedal force to incrementally move a derailleur cable in a first direction, and to store spring energy. A governor apparatus senses peak cadence to move the cable in a second direction. A cam action from a pedalled-sprocket communicates a timing instant for shifting under low chain transmitting force. A derailleur cable motion distributor communicates single cable up-shift and down-shift instruction from a finger shift and from spring-loaded automatic collet actions to route chains onto available front or rear sprocket sets.

Description:
Cross-References to Related Applications: U.S. Pat. No. 5,407,396 (from Ser. No. 08/181,294), and Docket R395 of 28 Mar. 1995 &#34;Derailleur Cable Collet&#34; 
     Statement as to rights to inventions made under Federally-sponsored research and development: None 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to bicycle chain shifting apparatus in which derailleur chain guides are positioned by cable movement. The invention moves derailleur cables to comply with rider-selected pedal pressure and pedal-cadence rate. 
     2. Description of Related Art 
     Automatic shifting a derailleur-equipped bicycle involves these problems: 
     1. Manually shifting a derailleur system demands a greater level of expertise and technique than many riders are willing to develop. However, completely automatic chain shifters also limit the utility of bicycles so equipped. 
     2. Imperfect timing of a chain shifting event may occur while the chain is at high stress, causing unnecessary mechanical wear to the chain and sprockets, and inducing an unnecessary loss-of-balance risk for a rider. 
     3. Transferring optimum power from a rider to the bicycle pedal system requires multiple attention of the rider to pedal force and pedal-rate cadence while steering and balancing the vehicle. 
     An automatic bicycle transmission (U.S. Pat. No. 4,598,920) sensed the angular velocity of a rear bicycle wheel and guided a pedalled chain onto a smaller driven sprocket as angular velocity increased, or larger driven sprocket as angular velocity decreased. 
     A &#34;Chain Shifter&#34; (U.S. Pat. No. 5,407,396), cited as a reference, automatically adjusts cable movement in response to pedal pressure peaks and low force patterns. 
     A &#34;Derailleur Cable Collet&#34; of Docket R395 automatically adjusts cable movement in response to pedal pressure and pedal velocity whose threshold presets may be electrically overridden by transducer inputs through other decision logic apparatus. 
     SUMMARY OF THE INVENTION 
     This sprocket ratio changer is a bicycle shifting apparatus using mechanically stored energy to grasp and move a derailleur cable. 
     A biased beam senses pedal pressure and collects pedal work from a draw-chain for storage in a spring. Movement of the biased beam communicates changing levels of draw-chain pressure during a pedalling cycle. A trigger plate senses movement beyond a threshold position, and releases a sear of the compressed spring module to move a collet that grips and moves a derailleur cable. 
     Communication from the trigger may pass through a pedal-position sensor to time release of the spring energy into the collet. 
     A speed sensor communicates with a ring on a pedalled sprocket to measure cadence rate. The sensor output moves a velocity rod that presses against a pre-set velocity-threshold trigger plate position. The spring-held energy collection, storage, and release for cadence shifting actuate and oppositely-directed cable movement apparatus to provide automatic derailleur changing functions for pedal cadence similar to those for pedal pressure. 
     Advantages of the invention over prior art include 
     1. A rider may let the automatic shifting feature operate or may use manual shifting capability. 
     2. Timing of a high-tension chain shift is automatically coordinated with the minimum chain force of a rider&#39;s pedal-stroke. Equipment wear and rider risk are reduced. 
     3. Rider attention need not be distracted by needs to manually direct derailleur to shift chain among sprocket options. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     
         ______________________________________FIG. 1 Diagram of Sprocket-Ratio Changer MethodFIG.2 Draw-chain, with Sprockets and Biased Third Wheel1.   draw-chain      13.    second tension path3.   pedalled sprocket                15.    third tension path5.   pedal           17.    beam7.   chain loop      19.    frame9.   wheel-driving sprocket                21.    biasing spring11.  Third wheelFIG. 3. Bias Beam with Measuring and Collecting Members23.  measuring point 31.    collector bar25.  threshold box   33.    spring and latch module27.  measuring rod   35.    cable moving module                39.    colletFIG. 4. Spring and Latch Module41.  Storage Spring  51.    First Seap Apparatus43.  Spring Loading rod                53.    Derailleur Cable Core45.  Collet Drawbar  54.    Derailleur Cable Cover46.  Rocker Arm      107.   Second Sear Shaft47.  Slot Bearing    108.   Sear Shaft Notch w Face48.  Travel Limit Point                111.   Timed Sear Latch w Face49.  First Latch Pawl                112.   Timed Sear RodFIG. 5. Draw-Spring Collet Module56.  Collet Box      62.    Pulling Loop57.  Compression Block                63.    Draw Spring60.  Draw Bar Extensions                64.    Down-Shift Module61.  Frame Connection                65.    Up-Shift ModuleFIG. 6. Pedal Force Threshold Apparatus66.  Force-Setter Ball-handle                73.    Trigger rod67.  Setter shaft    75.    Forked beam end69.  Roller Fulcrum  76.    Measuring rod block71.  Threshold Trigger Plate                77.    Front Derailleur lever72.  Force-Ratio Beam                78.    Compensator ForkFIG. 7. Threshold Box with Pedal Force Apparatus74.  Adjusting ScrewFIG. 8. Threshold Box with Cadence Apparatus85.  Cadence Setter Ball                91.    Cadence Trigger Plate87.  Cadence Shaft   93.    Velocity rod88.  Cadence Roller  95.    Velocity rod blockFulcrum89.  Cadence Ratio Beam                97.    Bottom of Ratio Beam                98.    Cadence trigger RodFIG. 9. Pedalled Governor and Timing Sear93.  Velocity Rod    104.   Sear Timing Cam99.  Encased Governor                105.   Timing Roller100. Gear            106.   Sear Timing Rod101. Tooth ring      109.   A Frame-Mounted                       Bearing103. Velocity Rod HolderFIG. 10. Contained Flyball Governor102. Flyball Action  117.   Flyball Bearing113. Bearing and Bracket                119.   Flexible SealFIG. 11. Sear Delay Communication and Toggles121. Trigger Rod, Force                127.   Trigger Rod, Cadence123. Sear Delay Rod, Force                129.   Toggle switch, Force125. Sear Delay Rod, 131.   Toggle switch, CadenceCadenceFIG. 12. Toggle Cam Sequence121. Frame-Sliding Rod                143.   Cam Spring, Compressed133. Toggle-Cam      145.   Toggle at First Position135. First Cam Face  147.   Holding Spring Release137. Cam Return Spring                149.   Holding Spring Hook139. Cam Holding Spring                151.   Toggle at Second Position141. Channel         153.   Rotary Cam142. Toggle Cam Module                155.   Cam Follower                156.   Toggle-return camFIG. 13. Cable Motion Distributor53.  First Derailleur Cable                161.   A Core SliderCore56.  First Derailleur Cable                163.   A Centering SpringCover157. A Distributor   165.   A Carrier Box Arm158. An outer wall   167.   A Distributor Box Arm159. A Carrier Box   169.   A Second Cable Core                171.   A Second Cable CoverFIG. 14. Front Derailleur Lever with Compensator Fork19.  Frame           177.   Chain Guide77.  Front Derailleur Lever                179.   Hinge Connection78.  Compensator Fork                181.   First Spacer Lobe173. Second Cable    183.   Second Spacer Lobe175. Parallel Diagonal                185.   Third Spacer LobeFIG. 15. Second Sear Notch Face and Latch107. Second Sear Shaft                110.   Shift Timing Latch Mount108. Sear Shaft Notch w                111.   Timed Sear Latch wFace                   FaceFIG. 16. Module Communication11.  Third wheel     99.    Encased Governor17   Biased beam     98.    Cadence trigger33.  Spring &amp; Latch modules                123.   Sear delay64.  Downshift collet module                142.   Toggle cam module65.  Upshift collet module                157.   Distributor71.  Threshold trigger plate                169.   Cable to rear derailleur78.  Compensator fork                171.   Cable to front derailleur______________________________________ 
    
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A sprocket ratio-changer measures biased deflection of a draw chain (FIG. 2-1) and cadence of a pedalled sprocket (FIG. 2-3) from the instant force and velocity of a rider&#39;s pedal (FIG. 2-5). 
     The pedalled sprocket converts a rider&#39;s pedal force into chain tension communicated by the draw-chain portion of a total chain loop (FIG. 2-7). A first tension path of the draw-chain passes from a wheel-driving sprocket (FIG. 2-9) to the pedalled sprocket. 
     A third-wheel (FIG. 2-11), such as a pulley or sprocket, is biasly pressed against the draw-chain to alter its first tension path into a combination second tension path (FIG. 2-13) and a third tension path (FIG. 2-15). 
     The third wheel is mounted on a first end of a beam (FIG. 2-17) whose second end rotates on a first end bearing connected to the frame (FIG. 2-19). A biasing spring (FIG. 2-21) is connected to the beam and to the frame and provides a bias force to angular movement of the beam. 
     An surface area of the beam is extended perpendicularly to provide an area on which a measuring point (FIG. 3-23) is perpendicular to threshold box (FIG. 3-25) and the point locates a bearing for a first end of a measuring rod (FIG. 3-27) that communicates with a pedal force threshold apparatus (FIG. 6) within the threshold box (FIG. 7). 
     The operation of this draw-chain biasing means presses the biased third wheel against a point on the first path of the draw chain to generate a second path from the wheel-driving sprocket to a third path to the pedalled sprocket. 
     An energy collector bar (FIG. 3-31) communicates oscillating motion from a bearing point on the beam to a spring and latch module (FIG. 3-33) which contains apparatus for mechanical storage of energy. 
     Note. A pedalled vehicle typically receives a non-uniform driving-force pattern into the pedals. A resultant variation in stress within the draw-chain reacts against the biased beam to generate an oscillation. Work from the movement of a force provides energy for storage and for subsequent movement of derailleur cables. 
     The energy storage modules communicate with a cable moving module (FIG. 3-35) that contain collets (FIG. 4-39) which convert spring driven motion into cable motion. 
     A preferred energy collector is the spring and latch module (FIG. 4) holding a storage spring (FIG. 4-41). A spring loading rod (FIG. 4-43) connects a collet drawbar (FIG. 4-45) at the base of the spring, through the center of the spring to a rocker arm (FIG. 4-46) that includes a slot bearing (FIG. 4-47) which hosts one end of the energy collector bar (FIG. 4-31). 
     The collecting bar draws the collet drawbar against the spring and past a travel limit point (FIG. 4-48) where a first latch-pawl (FIG. 4-49) biasly slides behind the drawbar to hold the spring compression. Without the spring reaction, the end of the collecting bar oscillates within the slot bearing. 
     A first sear apparatus (FIG. 4-51) draws the first latch pawl from the path of the collect draw-bar to release the spring driven draw bar. Draw bar movement compresses the collet (FIG. 4-39) around the derailleur cable core (FIG. 4-53) and moves it through its cable cover (FIG. 4-54) by one increment. 
     A preferred draw-spring collet module (FIG. 5) contains, in a collet box (FIG. 5-56), a compression block (FIG. 5-57), cable-guide fittings (FIG. 5-58), cable pulling assemblies (FIG. 5-59), draw-bar extensions (FIG. 5-60), and frame connection (FIG. 5-61). 
     The draw bar extension connects the collet draw-bar (FIG. 5-45) of the spring and latch module (FIG. 4-33) to a pulling loop (FIG. 5-62) of a draw spring (FIG. 5-63) through which the derailleur cable core (FIG. 5-53) passes. 
     The collet draw-bar of the spring module rigidly connects to the draw bar extension, permitting the storage spring travel limit point (FIG. 4-48) to influence static compression of the draw springs: 
     Storage springs that are held in compression communicate through the draw bar extensions a fixed dimension for two draw springs and a compression block. This dimension holds each draw springs in slight compression. 
     End-to-end compression of a draw springs with large pitch expands the spring&#39;s inside diameter. Without compression the draw springs inside diameter is approximately equal to the outside diameter of the cable core, offering a &#34;sliding fit&#34; of small, but measurable resistance. When drawn in tension, the large pitch is extended against the resistance to draw a tight grip on the cable core. 
     When a sear action releases the drawbar, the storage spring grips the cable and communicates an increment of linear motion. 
     Recocking the spring and latch module reinvests a compression in the spring that makes cable motion free. 
     The pedal force threshold box (FIG. 3-25) faces an oscillating movement plane of the bias beam (FIG. 2-17) and receives its communication through the measuring rod (FIG. 3-27). 
     A force-setter ball-handle (FIG. 6-66) and setter shaft (FIG. 6-67) provide motion through the top of the threshold box to enter pedal force shifting point values. 
     The shaft connects to a roller-fulcrum (FIG. 6-69) which moves between a cantilever-suspended elastic threshold trigger plate (FIG. 6-71) and a force-ratio beam (FIG. 6-72). A trigger rod (FIG. 6-73) extends perpendicularly from a free end of the trigger plate, and passes through the box&#39;s vertical wall and connects to the sear apparatus (FIG. 4-51) of the spring and latch module. 
     The ratio beam is connected to one side of the box near its top by an adjusting screw (FIG. 6-74). A forked bottom end (FIG. 6-75) of the force-ratio beam straddles the measuring rod and communicates with a rod block (FIG. 6-76) of the measuring rod. 
     A front derailleur lever (FIG. 14-77) communicates a vertical position change for a compensation fork (FIG. 6-78) to occur concurrently with adjustment of horizontal position of front chain guides. The fork is hinged to the lever and extends into the threshold box to oscillate with the measuring rod block. The lever lifts and lowers the compensator to match a thickness spacer between the measuring rod block and the ratio beam that is proportional to the change in pedal force for each front sprocket (FIG. 2-9) over which the chain travels. 
     A cadence setter ball (FIG. 8-85) and shaft (FIG. 8-87) extend into a second portion of the threshold box (FIG. 7) to adjust a cadence roller fulcrum (FIG. 8-88) between a cadence ratio beam (FIG. 8-89) and a cadence trigger plate (FIG. 8-91). A velocity rod (FIG. 8-93), communicates governor output position to the velocity threshold apparatus. 
     When the velocity rod block (FIG. 8-95) contacts a bottom fork (FIG. 8-97) of the ratio beam with sufficient force, the biased cantilevered trigger plate releases its stored energy into a cadence trigger rod (FIG. 8-98) that communicates with a sear apparatus of a second spring and latch module that drives a second draw-spring collet. 
     Within threshold box (FIG. 8-27) threshold apparatus for pedal force actions &#34;shifts down&#34; the ratio of pedalled revolutions to wheel revolutions to reduce the proportion of wheel turns for each pedalled sprocket revolution. Oppositely, threshold apparatus for cadence actions &#34;shifts up&#34; the ratio of wheel revolutions for each pedalled sprocket revolution. 
     The velocity rod (FIG. 9-93) communicates to an encased governor (FIG. 9-99), that is driven by a gear (FIG. 9-100) turned by a tooth ring (FIG. 9-101) on the inside surface of a front set of pedalled sprockets. The flyball action (FIG. 10-102) moves a velocity-rod holder (FIG. 10-103). 
     Bicycle safety is enhanced if chain shifting from one sprocket to another is executed while the chain is transmitting a minimum stress. A parallel logic shift-timing apparatus mounts a sear-timing cam (FIG. 9-104) on an inward-facing surface of the pedalled sprocket, to actuate a timing roller (FIG. 9-105) that communicates a sear timing rod (FIG. 9-106) movement to the spring and latch module (FIG. 4). 
     A second sear shaft (FIG. 4-107) extends beyond the collet drawbar (FIG. 4-45) and through the end of the module. A sear shaft notch with face (FIG. 15-108) of a second-sear rod is separated by a small distance from the timed sear latch with face (FIG. 15-111). This second sear is attached to the spring and latch module as a frame-mounted bearing (FIG. 9-109). 
     When a trigger action from within the pedal force threshold apparatus draws the first latch pawl away from the spring&#39;s travel, a timed sear latch (FIG. 4-111) stops the spring and collet drawbar (FIG. 4-45) from further travel until the timed sear rod (FIG. 9-112) communicates an instant of time when the pedalled sprocket is at a position of minimum force communication. 
     A series logic shift timing apparatus, suitable for velocity-paced shifting routes the trigger rod (FIG. 7-73) from the threshold box to a frame-sliding rod (FIG. 11-121), mounted on the frame and connected to a toggle-cam. At the time of threshold triggering, a toggle cam (FIG. 12-133) is depressed and a toggle switch (FIG. 11-129) on the inner face of the pedalled sprocket is moved from toggle, first position [B] (FIG. 12-145) to toggle, at second position [D] (FIG. 12-151) where it actuates a rotary cam (FIG. 12-153) against a cam-follower (FIG. 12-155) to communicate movement through a sear delivery rod to the first position pawl. A cam-holding spring (FIG. 12-139) retains the cam in a toggle moving condition until the toggle&#39;s movement releases its holding spring hook (FIG. 12-149). A toggle return cam repositions the toggle arm after it has actuated the rotary cam. 
     The single derailleur cable core (FIG. 13-53) communicates shifting instruction of the draw spring collet box. A distributor (FIG. 13-157) converts the first cable core (FIG. 13-53) motion into separate derailleur shifting motions of first cable core (FIG. 13-53A) and second cable core (FIG. 13-169): 
     A first cable cover (FIG. 13-56) terminates at an outer wall (FIG. 13-158) and routes the first core through that distributor wall and through a first wall of a carrier box (FIG. 13-159) to a core slider (FIG. 13-161). The carrier box slides within the distributor and transmits unrestricted first cable core motion through an arm (FIG. 13-165) and continuation of first cable core (FIG. 13-53) motion. 
     The first cable core connects to a core slider (FIG. 13-161) that slides within the carrier box. The slider is also connected to a second cable core and to an open pitch centering spring (FIG. 13-163), having bias strength in both compression and tension against a carrier box second wall. 
     A second cable cover (FIG. 13-171) connects directly to the first wall of the carrier box, and travels without restriction through a hole in the distributor case and on to a derailleur for the pedalled sprocket (FIG. 2-3) . 
     When a cable-core moving instruction from the collets exceeds the travel limits of the rear wheel derailleur, the core slider moves against a bias of the spring to move the cable core of the front derailleur (FIG. 13-169). 
     The pedalled sprocket (front) derailleur (FIG. 14) connects to the front cable core (FIG. 14-169). Cable movement draws the front derailleur lever (FIG. 14-77) to move the front chain guide (FIG. 14-177) diagonally. A horizontal vector shifts the chain; and a vertical vector lifts a hinge (FIG. 14-179) and compensator fork (FIG. 14-78) that fits through the bottom of the pedal force threshold box. A first, second or third spacer lobe (FIGS. 14-181, 182 &amp; 183) are positioned between the measuring rod block (FIG. 6-76) and the ratio-beam end (FIG. 6-75) as means to compensate for pedal force-to-chain force ratios that change as the chain is fitted to front sprockets of different diameters. 
     FIG. 15 shows detail of a second sear shaft (FIG. 15-107) that extends from the collet drawbar (FIG. 15-45). A notch (FIGS. 4-108 &amp; 15-108) in the shaft and a second sear-latch (FIG. 4-111 &amp; 15-111) are mounted (FIG. 15-110) at the base of pedal-force spring and latch set. 
     FIGS. 1 and 16 summarizes communication among modules within the sprocket ratio changer to illustrate a unity in purpose for the subsystems and their components.