Bicycle control apparatus that communicates power and data over a single transmission path

#The present invention is directed to bicycles and, more particularly, to a bicycle signal processing device that operates more reliably in the bicycling environment.

#Many bicycle signal processing systems have been developed. A typical system often gathers and displays information related to bicycle speed, cadence, distance traveled and the like. Such systems usually include a magnet mounted to a wheel spoke, a magnet mounted to one of the pedal cranks, and magnet sensors mounted to the bicycle frame for sensing the passage of the magnets as the wheel and crank revolve. An electrical pulse is generated every time a magnet passes its associated sensor (e.g., once per wheel or crank revolution). The speed of the bicycle can be calculated based on the number of pulses received from the wheel sensor per unit of time and the circumference of the wheel. Similarly, the distance traveled can be calculated based on the number of pulses received over a length of time and the circumference of the wheel. The cadence can be calculated based on the number of pulses received from the crank sensor per unit of time. One or more switches ordinarily are provided for entering operating parameters (e.g., the wheel circumference), for selecting what information is displayed to the rider, and for starting and stopping various timers used for calculating the desired information.

#More sophisticated systems have the ability to display information related to the state of the bicycle transmission. For example, some bicycles have a plurality of front sprockets that rotate with the pedal cranks, a plurality of rear sprockets that rotate with the rear wheel, and a chain that engages one of the front sprockets and one of the rear sprockets. A front derailleur is mounted to the bicycle frame for shifting the chain among the plurality of front sprockets, and a rear derailleur is mounted to the bicycle frame for shifting the chain among the plurality of rear sprockets. Manually operated switches or levers may control the front and rear derailleurs. Position sensors (e.g., potentiometers or contact sensors) are mounted to the switches or levers so that the front and rear sprockets currently engaged by the chain may be determined by the positions of the corresponding switches or levers. Such information may be displayed to the rider so that the rider may operate the transmission accordingly. Even more sophisticated systems use small electric motors to control the bicycle transmission. The motors may be controlled manually by the foregoing switches or levers, or automatically based on bicycle speed and/or cadence.

#FIG. 1 is a side view of a bicycle that includes a particular embodiment of a signal processing device according to the present invention;

#FIG. 2 is an oblique view of the handlebar mounted components of the signal processing device;

#FIG. 3 is a detailed block diagram of a particular embodiment of a signal processing device according to the present invention;

#FIG. 1 is a side view of a bicycle 10 that includes a particular embodiment of a signal processing device 12 (FIG. 3) according to the present invention. Bicycle 10 has a frame 14, a front fork 18 rotatably supported in a head tube 22 of frame 14, a front wheel 26 rotatably supported by fork 18, a handlebar 30 for rotating fork 18 (and hence front wheel 26) in the desired direction, and a rear wheel 34 rotatably supported at the rear of frame 14. A pair of crank arms 38, each supporting a pedal 42, are mounted to an axle 46 that is rotatably supported in a lower portion of frame 14. A plurality of front sprockets 50 are mounted to the right side crank arm 38 for rotating with the right side crank arm 38, and a plurality of rear sprockets 54 are mounted to the rear wheel 34 for rotating with rear wheel 34. A chain 58 engages one of the front sprockets 50 and one of the rear sprockets 54. A front derailleur 62 is mounted to frame 14 in close proximity to the plurality of front sprockets 50 for moving chain 58 among the plurality of front sprockets 50, and a rear derailleur 66 is mounted to frame 14 in close proximity to the plurality of rear sprockets 54 for moving chain 58 among the plurality of rear sprockets 54. A front braking unit 70 is mounted to fork 18 for braking front wheel 26, and a rear braking unit 74 is mounted to the rear of frame 14 for braking rear wheel 34. Front braking unit 70 is connected to a Bowden-type control cable 78 that is connected to a brake lever assembly 82 mounted on the right side of handlebar 30 as shown in FIG. 2. Similarly, rear braking unit 74 is connected to a Bowden-type control cable 88 that is connected to a brake lever assembly 92 mounted on the left side of handlebar 30.

#As shown in FIGS. 1-3, a display housing 100 that is part of a computer control unit having an LCD display 104 is coupled to a mounting bracket 108 attached to handlebar 30. As shown in FIG. 3, display housing 100 houses a backlight 112 for display 104, a processor 116 for controlling the operation of display 104, a real time clock (RTC) circuit 120 for providing timing information, a battery 124 for providing backup power for the data stored in processor 116, a receiver circuit 128 for receiving data in a manner described below, a power circuit 132 for receiving power in a manner described below, a resistance (e.g., resistor) R8 coupled to processor 116, and a switch 138 having a terminal 142 coupled to a node 144 between resistance R8 and processor 116 for selecting the information displayed on display 104. The other terminal 146 of switch 138 is connected to a ground potential.

#Mounting bracket 108 houses serially connected resistances (e.g., resistors) R1 and R2, a buffer amplifier 150 having an input terminal 154 connected to a node 156 between resistances R1 and R2, a voltage regulator 158 for supplying a regulated voltage to buffer amplifier 150, a voltage regulator 162 for supplying a regulated voltage to resistance R1, and a connector 166. Connector 166 includes an external output terminal 170 connected to an output terminal 174 of buffer amplifier 150, a power/data input terminal 178 for communicating power to voltage regulators 158 and 162 in mounting bracket 108 and to power circuit 132 in display housing 100 and for communicating data to receiver circuit 128 in display housing 100, and a ground terminal 182 for providing a ground potential to the components in mounting bracket 108 and display housing 100. External output terminal 170, power/data input terminal 178 and ground terminal 182 have exposed contact surfaces 170a, 178a and 182a, respectively.