Background Art Forerunner of this invention is a manual gear shifter for a multi- speed bicycle. Basically, a manual gear shifter (see Fig. 14 & 14A) consists of a mechanical shifter 53 such as a lever shift, grip shift, or index shift 54 and a shift cable 6 attached to the derailleur 4. A multi speed bicycle consist of seven or more cogs 9 at the rear and two or more chain ring 3 attached to the pedal. Selecting proper gearing is done by lever shifting, hand gripping or index shifting. A gear, like a lever, is a means of changing the rate at which work is done. The rate of change is called the ratio. On a bicycle, the ratio is determined by relative sizes of the crank set chain rings 3 and the freewheel sprockets or cogs 9. The average cyclist produces 1/8 horsepower on a steady basis with maximum efficiency when pedaling at a cadence of 55 to 85 revolutions per minute (rpm). The purpose of the gears is to maintain an efficient cadence, and the key to using gear in such manner is anticipation.

However, there are some factors that prevent you not to shift when needed. For example: 1. You are not aware that the terrain is slightly changing.

2. Your both hands must hold the handle bar due to the terrain.

3. The biker is too"lazy"to change gear.

4. The biker ignores the change in the cadence pace.

Given these non-shifting gear scenarios, the biking efficiency will be reduced and more irrelevant physical stress will be incurred.

Moreover, a manual gear shifter in a multi-speed bicycle reduces power efficiency because one hand is at the shift lever during shifting.

Recently, some manufacturers have introduced two kinds of non- modular automatic gear shifter in the market but all of them have a common mode of construction, that is, built-in. A built-in automatic gear shifter has several drawbacks such as: 1. It cannot be retrofitted or transferred to any other bicycle; 2. It is expensive and custom built; 3. It has complex design; and 4. It will make the bike inoperable once the built-in automatic gear shifter malfunctions.

With these kinds of automatic gear shifter, the frame of the bicycle has been completely modified in order to accommodate the electromechanical gadgets for this purpose. A special set of drive train such as derailleur and rear hub is used. Other design approach is a complete revision on the chain ring. Replacement parts are not interchangeable with these different types of automated gear shifter.

Many bike users want to try an automated gearing feature but the newly introduced types are very costly because they have to purchase a whole new set of bike to avail of such feature.

Disclosure of Invention The modular automatic gear shifter is easily operable because it makes use of a central processing unit in conjunction with electro- mechanical gadgets. Likewise, it is very convenient to use and install as it can be attached to any multi-speed bicycle without any alteration to the latter's original set up. It is a bolt on, a retrofit accessory that will function as automatic transmission like in car. The module will operate by itself for the function of automatic gear shifting in place of the traditional hand operated gear shifting lever mechanism on manual multi speed bicycle. The module will select automatically the proper gear ratio relative to the biker's cadence pace. The design of this module is called the Open Loop, it can accommodate different number of cogs/sprockets thru programming during set up. Override switches are incorporated and placed at the handle bar for override function through remote infrared light. A low power hi je i efficiency's usedtMo replenish drained power from battery. In the event of module malfunction, bike owner will not have to worry about the operability of his bike. The module can be simply be detached and reconnect the shift cable and use it again as manual.

Brief Description of Drawings Fig. 1 is the general overview how the module is attached to a bike.

Fig. 2 is the close-up view of the module as attached to a bike.

Fig. 2A is the close-up view of the built-in dynamo that serves both as a cadence/speed sensor and as a battery charger.

Fig. 3 is the perspective view of the module showing some control buttons.

Fig. 4 is the basic block diagram using a hall effect transistor.

Fig. 5 is the basic block diagram using a dynamo.

Fig. 6 is the flowchart during the set-up mode.

Fig. 7 is the flowchart for the software during run mode.

Fig. 8 is the simplified representation of the open loop design while Fig. 8A is the more detailed representation of the open loop design.

Fig. 9 is a look up table for the E value of encoder with respect to each cog while Fig. 9A is for the revolution per minute (RPM) relative to voltage output.

Fig. 10 is the perspective view of M1 assembly showing the DC torque motor mechanism while Fig. 10A is the side view of said assembly.

Fig. 11 is a graphical representation of the relationship between applied voltage and time to energize torque motor Ml.

Fig. 12 is a locational drawing of the built-in dynamo and optional hi-tech dynamo.

Fig. 13 is an overview of the remote control module attached to the handle bar.

Fig. 14 & 14A are the drawings of the background or prior art.

Best Mode of Carrying Out the Invention Fig. 1 shows where the module 1 is placed in a bicycle and clamped at chain stay tube 2.

Fig. 2 is a closer perspective of the module 1 showing imaginary components inside the enclosure. The module 1 has an exposed drive gear 16 that is coupled to chain ring 3. While the chain ring 3 rotates, the drive gear pulley 17 rotates which in turn causes the eventual rotation of the pulley 18 via belt 21. The slotted disk 15 that it will also rotate as the pedal 8 moves. The hall effect transistors 19, 110 19a are mounted on the opposite of the slotted disk 15 which will serve as speed or cadence sensors. Its output is then fed to CPU 13 for processing Fig. 2a is basically the same as Fig. 2 except for the built-in dynamo 11 that serves both as a cadence/speed sensor and as a battery charger. The pulley 18 is coupled with the built-in dynamo 11 through the 115 dynamo shaft 11b.

Fig. 3 is a perspective view of the module 1 showing control switches such as"UP"button 31,"DOWN"button 32,"ENTER"button 33, mode select switch 34. This also shows where the shift cable 6 is attached to the upper side of the module 1.

120 Fig. 4 is a basic schematic diagram showing the hall effect transistors 19a, 19 being used as cadence sensors. The output of the hall effect transistors l9a, 19 are fed to the CPU 13 for logical decisions. The optional dynamo 11a is the source of power to replenish battery 14 to prolong its stored energy. Torque motor assembly 12 consisting of the 125 torque motor 30 and encoders 21,22 are ganged together. Cadence preset select switch 23/51 is a user option to select the rhythmic pattern of pedaling whether in fast pace or slow pace. The toggle switch 26/34 enables the user to select either set-up mode or run mode. The UP button switch 24/31 and DOWN button switches 27/32 determine the 130 direction of the DC torque motor 30 during set up. If the desired functions have already been selected, the"enter"button switch 25/33 should be pressed to finish the set up. Reset switch 52 is to initialize the CPU 13. An overload sense circuit is incorporated to monitor the current flowing in the torque motor driver 30 in which will interrupt the CPU 13 135 in the event of over current. Over current is possible when reset switch 52 is pressed while the shift cable 6 is attached. The correct procedure in using the reset switch 52 is by removing first the shift cable from the module 1 The infrared (IR) sensor 28 receives the infrared signal from the remote control module 10 attached to the handle bar 47 whenever the 140 up switch 44 or down switch 45 therein are pressed.

Fig. 5 is the same as Fig. 4 except that a built-in dynamo 11 is used as a cadence/speed sensor instead of the hall effect transistors 19a, 19.

Fig. 6 is the flow chart of set-up procedure. It describes how to first use the module 1 through programming sequence prior to actual use.

145 During the set up mode, the bike should be suspended in such a way that its rear wheel 50 can be rotated freely.

Fig. 7 is the basic flow chart of the computer software that will run the CPU 13 during the run mode. The basic flow starts from M2 speed sensor 61. The decision block 62 determines whether there is a"nuisance 150 pedaling"which may refer to back and forth pedaling, stalling, or other irrelevant action. If there is no nuisance pedaling 62, it goes through a decision 63 that compares cadence preset against the actual speed read by the sensor 61 consisting of any of the following: hall effect transistors 19, 19a, built-in dynamo 11 or optional dynamo 11a. Less than value (<) will 155 proceed to command block 64 then goes through decision 67. Decision 67 will command the M1 motor index 71 for Ccw rotation. For greater than (>) value will proceed to command block 65 then goes through decision 68. Decision 68 will command the M1 motor index 71 for Cw rotation.

For equal value (=), there is no change 83 in gear shifting. Once M1 160 motor 79 has moved, Cw 78 encoder and Ccw encoder 80 also move since they are ganged together to act as a position indicator. Encoder values go to memory block 77 that is then compared to the E value 81 stored during programming/set up. Decision 72 compares the value of memory block 77 and E value 81 to send signal to Ml index motor 165 command 71 and motor brake command 75 when E value 81 is one gear less than or one gear greater than the programmed E value 81. Block 82 will register the current gear position as interpreted from the stop signal of decision 72. A decision routine 69 monitors the activity of the pedal that will disable the override command 70 when pedal is not moving. On 170 the other hand, if the pedal is moving, it will enable the override logic gate 73 to allow signal coming from decision 74 to become valid when there is a signal from the remote control module 10 transmitted to the infra-red (IR) sensor 28. A decision block 76 will determine which switch button has been pressed. Decision block 76 will give command to either 175 command block 64 (less than the preset cadence pace value) or command block 65 (greater than the preset cadence pace value). The terminator block 83 shows no gear change or end of routine.

Fig. 8 is a simplified representation of the so-called open loop design. It shows the encoders 21,22 and the torque motor assembly 12 180 which are ganged together. Their function is to pull the shift cable 6 and the latter pulls the derailleur 4 and eventually will shift the chain 5. The selected cog 9 has a certain memory value through encoders 21,22 which is then interpreted by the CPU 13 as memory location. Illustration shows how encoders 21,22 can accommodate different number of cogs 9 185 through programming. Two encoders 21,22 are used for the reason that there is a slight variation from Cw to Ccw of the torque motor assembly 12 and vice-versa due to the spring effect of derailleur 4.

Fig. 8A is the more detailed representation of the open loop design.

It is basically the same as Fig. 8 except that it further demonstrates the 190 versatility of the design to accommodate different number of cogs for future upgrades. P1 indicates the existing cog usage while P2 shows expandable capability to accommodate more cogs which can be achieved through programming during set up mode prior to usage.

Fig. 9 is the look up table showing sample E values from the two 195 encoders 21,22 with respect to each cog. On the other hand, Fig. 9A presents the possible voltage output of built-in dynamo 11 depending on RPM.

In Fig 10, the DC torque motor 30 is coupled to a gear head 41 with a certain reduction ratio to amplify the output torque. A drive gear 200 35 is attached at the gear head shaft 41a. The drive gear 35 drives a bigger gear 36 where a lead screw 40 is inserted at its center. Lead screw 40 is held both by stationary end supports 38,38a. A threaded block 39 is mounted on the slider 43 moving portion of the slide bearing 42. The slider 43 is where the shift cable 6 is attached. Transfer of power starts 205 from the DC torque motor 30, drive gear 35, bigger gear 36, lead screw 40, threaded block 39, slider 43, and finally to the shift cable 6. The encoders 21,22 (potentiometer) are coupled at the gear head shaft 41a. In this way, any movement from the DC torque motor 30 will be registered by the encoders 21,22. Fig. 10A is just the side view of the same DC 210 torque motor assembly 12.

Fig. 11 illustrates the applied voltage to energize the DC torque motor 30 at run mode. It also shows when to apply a momentary brake to stop the DC torque motor 30 instantly. Fig. 11A shows the decrease of applied voltage relative to time to energize the DC torque motor 30. This 215 is to decelerate the DC torque motor 30 during set up mode.

Fig. 12 shows the location of optional hi-tech dynamo lla attached to the fork tube 48 as compared to the built-in dynamo 11 within the module 1 attached to the chain stay tube 2. The invention may use either an optional hi-tech dynamo lla or built-in dynamo 11 depending on their 220 availability, size and shape. The inventor prefers the use of Dymotec S12/S6 as an optional hi-tech dynamo lla because it has the efficiency of a top quality hub dynamo (more than 60%), causing almost insignificant resistance while riding. It reaches full light output at 10 kilometer per hour (kph) and is almost silent. Because of the new technology, the 225 magnetic circuit principle is only about 4.5 watts of pedal power compared to the conventional dynamos with an approximate pedal power of 15 watts.

Fig. 13 shows the remote control panel 10 mounted at the right side of the handle bar 47. This consists of the"UP"button 44 and 230"DOWN"button 45 serving as override switches. The primary function of the remote control panel 10 is to select a desired cog 9 instantly. All signals are transmitted to the module 1 via infrared light 46. The other parts in the remote control panel 10 are the watch battery and transmitter IC chip.

235 Industrial Applicability By virtue of its being modular in nature, this automatic gear shifter can be separately manufactured and subsequently added on any kind, brand or size of manual multi-speed bicycle available in the market today.

240 The idea is that it is an optional accessory that can be easily attached to the bicycle without any change in the latter's original set up. Thus, a person who already owns a manually operated multi-speed bicycle does

not have to buy a new bike with automatic gear shifter feature. He or she must only purchase a modular automatic gear shifter and install it on his or her bike. A bike already having this modular automatic gear shifter devise makes the biker free from shifting gears like in vehicles equipped with automatic transmission.