Background of the Invention

This invention relates to accessories for vehicles, especially bicycles, and is particularly directed to a combination of a generator and lamp circuit for a bicycle, with the additional features of a rechargable battery, a charging circuit for the battery, and a speedometer and odometer.

In the past, it has been conventional, to pro¬ vide generators for bicycles, for operating one or more lamps on the bicycle. Such systems are disclosed, for example, in U. S. Patent No. 4,069,451, Rouse; U. S. PAT¬ ENT No. 3,753,000, Newman; U. S. Patent No. 3,792,307, Baker; U. S. Patent No. 3,894,281, Bloomfield and U. S. Patent No. 2,299,762. In the systems of these references, generators are provided which may be rotated by shaft elements engaging the rim of the wheel. The circuits disclose various features, such as the use of AC genera¬ tors, the use of DC generators, rectification of the output of the generator, and the provision of batteries which may be employed to separately energize the lamps. Further, the Rouse patent discloses the provision of fil¬ tering and limiting devices for the generator, and the Newman reference discloses the use of a rectifier in com¬ bination with a DC generator for charging the battery when the lamps are not connected. Rectifier circuits of this type are generally employed in series with the load, in view of the belief that the use thereof is superior to the provision of mechanical switches.

In accordance with the present invention, however, it is desired to provide as efficient a system as possible , as well as as economical a system as possible , for the fabrication and use of lighting circuit of a bicycle. For this purpose , therefore , it has been found that electro¬ mechanical switches are in fact superior to electrical rectifiers , in view of the significantly reduced voltage drop thereacross in use, and the reliability of present day mechanical switching contacts. Therefore, in accordance with the invention , the voltage applied to the lamps of a bicycle may be significantly higher (or, alternatively, the output of the generator may be employed to supply the lamps at a lower voltage) than in the past, where semiconductor diodes have been employed. In addition, by employing AC power to the lamps, a still greater increase in efficiency is provided. Diodes are used in accordance with the invention, only for the charging of the battery and voltage detection, and are not employed in the rectification of power currents, so that the efficiency of the system is maintained at the highest possible levels.

It has also been known in the past to provide speedometers and/odometers for use in bicycles, such devices being powered by means of an electric generator. Such systems are disclosed, for example, in U. S. Patent No. 4,156,190, Chittenden; U. S. Patent No. 3,784,913, Maass; U. S. Patant No. 3,898,563, Erisman and U. S. Patent No. 4,007,419. In each of these references, the signal applied to the speedometer or odometer is related to the angular displacement of the wheel of the bicycle, whereby the device is useful only for bicycles of a given wheel size, i.e., major modifications are necessary for use of the device on bicycles of different wheel sizes.

Summary of the Invention

The present invention is therefore directed to the provision of a combined generator, rechargable battery, charging circuit, speedometer and odometer for a vehicle, especially a bicycle, that does not have the above disad¬ vantages. While the system of the invention may be pro¬ vided for a complete unit, it will be apparent that it is sufficiently versitile that the required speedometer and odometer capabilities may be readily and easily adapted to bicycles that already incorporate generators and lamps or other output devices, and that rechargable battery systems may also be incorporated into such existing systems with a minimum of cost and effort.

Briefly stated, in accordance with the invention, it is necessary to provide an AC or pulse generator, pref¬ erably an AC generator, for the bicycle, and the gene¬ rator be mounted such that the cycles correspond to incre¬ ments of distance along the tire or rim of the bicycle. Such arrangements are conventionally provided, for example, by engaging a rider with the side of the wheel of the bi¬ cycle , for turning the rotor of the generator.

In accordance with the invention, a rechargable battery is provided for lighting the lamps or other load of the bicycle when the generator output voltage is in¬ adequate, the lamps or load being energized by way of mechanical contact. When the output voltage of the generator is sufficiently high, in dependence upon the selected load, a detection circuit effects the closure of mechanical contacts so that the generator output voltage energizes the load, and maintains the contacts in a hold position until such time as the speed of the bicycle re¬ duces to a determinate level. The rechargable battery is also charged by the AC generator, when the output

voltage therof is -sufficiently high, although the re¬ charging current may proceed by way of semiconductor diodes. Currents in this case may be. adequately low that the efficiency of the system is not greatly impaired.

In addition, the wave form of the AC voltage may be shaped and amplitude and limited to provide pulses for operating a speedometer and odomete circuit, the rectified output of the battery, for the recharging function, being employed for the operating voltage for the speedometer and odometer circuits.

The system of the invention thereby does not entail the use of complicated circuit configurations, is adapted to the use of conventional integrated circuits, and may be readily incorporated into existing systems.

Thus, in an existing system having an alterna¬ ting current generator and lamps, it is merely necessary to change the connections of two wires of the existing system to install a recharging circuit, odometer and speed¬ ometer fabricated in accordance with the invention. The efficiency of the system, avoiding the use of rectifiers for the lamp load, thereby reduces the energy required on the part of the bicycle rider, and enables brighter light and/or light at lower speeds, than is existing systems which employ semiconductor devices in series with the lamp load on the bicycle circuit.

Brief Description of the Drawings

In order that the invention will be more clearly understood, it will now be disclosed in great¬ er detail with reference to the accompanying drawings, wherein:

Fig. 1 is a block diagram of an electrical system for a ^' bicycle, in accordance with the invention,

including a generator, one or more lamploads , a re¬ chargable battery and charging circuits for the battery, and a speedometer/odometer and display system;

Fig. 2 is a circuit diagram of the portion of the circuit of Fig. 1 including the generator and lamp loads, as well as the battery, recharging circuit, and automatic switching systems for the generator;

Fig. 3 is a detailed circuit diagram of an embodiment of the portions of the circuit of Fig. 1 including the odometer circuit, speedometer circuit and the display circuits; and

Fig. 4 is a circuit diagram of a modification of the circuit of Fig. 3, wherein a substantially non¬ volatile souce of power is provided for the odometer circuit, whereby the parameter of distance traveled may be stored at times when the normal battery is not functioning.

Detailed Disclosure of the Invention

The system in accordance with the invention is comprised essentially of two sub-systems. The first of these, which incorporates devices which may already have been provided on the bicycle, includes an AC gene¬ rator, a rechargable battery, one or more lamps or other devices that will be energized by either the battery or the generator, and a charging and control circuit. The second major portion of the system includes those cir¬ cuits which are concerned with the display of speed of the bicycle, and/or the distance that the bicycle has traveled. The first of these sub-systems will initially be disclosed, in accordance with a preferred embodiment of the invention, with reference to Figs. 1 and 2.

Power Generation, Control and Lighting

As illustrated in Figs. 1 and 2, the system in accordance with the invention is comprised of an AC generator 10. This generator may be of a type that is conventionally employed on bicycles, having,, for example, a shaft fitted with a friction element or the like for engaging the side of a tire of the bicycle in order to effect the rotation of the rotor of the generator. These features are of importance to the present invention, as will be apparent from the following paragraphs, since, within a reasonably high degree of accuracy, a cycle of the alternating output of thegenerator will correspond to a determinable distance of travel of the bicycle. Further, although the system may therafter be designed on the basis of a bicycle having a given wheel diameter, the accuracy of the system will not be seriously impaired even though the system is employed without modification on bicycles having any conventional wheel diameter. It is therefore stressed again that the generator 10 is an AC generator. One of the ^* terminals of the generator is connected to a point of reference potential, referenced herinafter as the gound of the system. The other terminal thereof is connected by the output line 11 to a voltage regulator and charging circuit 12. A rechargable battery 13, such as a nickel-cadmium battery, has its negative terminal grounded and its positive terminal connected to a lead 14, which serves as the battery output of this portion of the system, and is connected to the cathode of a diode 15 within the voltage regulator circuit. The anode of a further diode 16 is connected to the generator line 11, the cathode of this diode being connected by way of a resistor 17 to the anode of the diode 15. The cathode

of the diode or rectifier 16 is connected to a Zener diode 18, and thence to reference ground. In this circuit, it is apparent that the diode 15 prevents dis¬ charge of the battery by way of the generator, and the combination of the diode 16 and Zener diode inhibit charging current from being applied to the battery until the positive peaks of the generator output are slightly above the battery voltage. The resistor 17 serves as a current limiting resistor. While this element is illus¬ trated as being a passive element, it is apparent that the efficiency of the system would be improved by the use of a dynamic device.

The output of the generator, on line 11, is also applied to a voltage sampling circuit 20, an auto¬ matic switch 21, and to one fixed contact of a single- pull double-throw switch 22. The voltage sensing circuit includes a relay having a coil 25 , the normally closed and normally open contacts 26 and 27 therof con¬ stituting the automatic switch 21. The two contacts of the relay are serially connected.

One end of the coil 25 is grounded. The gene¬ rator output line 11 is connected to the cathode of a diode 28 and thence to the other end of the coil of the relay by way of a Zener diode 29. Thus, only negative peaks of the generator output are coupled to the coil of the relay, the Zener voltage of the diode 29 deter¬ mining therby the energizing voltage to be applied to the relay to effect operation of the automatic switch. This level may be arbitrarily determined on the basis that the voltage must be adequate at this time to en¬ able the energization of the lamps on the bicycle at a reasonable illumination level. This level may, and preferably is, below the output voltage of the recharg¬ able batteries. As is conventional, a capacitor may be

connected in shunt with the winding of the coil 25.

The battery line 14 is connected to the other terminal of the normally closed contact 26, and the generator output line 11 is connected to the other termi¬ nal of the normally open contact 27. Further, the cen¬ ters of these two contacts are connected to the other fixed contacts of the switch 22, the movable contact of the switch being connected to a line 30. With these interconnections it is apparent that, in the position of the switch 22 as illustrated, the battery voltage will be applied to the line 30 when there is insufficient generator output for the lamps, and the generator output line 11 will be interconnected with the line 30 when the voltage thereon is above the threshold level of the voltage sampling circuit. Further, in the non-illustrated position of the switch 22, the battery 13 will always be disconnected from the lamps, and the generator output line 11 will be connected to the lamp line 30 when the voltage out¬ put of the generator is adequate.

It will further be noted that the generator output is connected to the line 30 by way of mechanical switch contacts, whereby losses occasioned by semicon¬ ductor switches or the like are not present in the sys¬ tem in accordance with the invention.

The common line of the contacts 26 and 27 is also connected to the coil 25 of the relay by way of serially connected diodes 33 and 34, in that order, poled to pass current when the voltage at the common contact is negative. It is a consequence, once the relay has been initially energized, this current path will maintain the energization of the relay by the generator. This holding effect is at a lower voltage

than that required to initially energize the relay. Thus, initially it was necessary to sense a voltage such as required by the light voltage, plus the inter¬ nal generator voltage drop assuming a load was connected to the circuit. As soon as the lights are lit by the AC generator, there is a voltage drop due to the internal resistance of the AC generator, so that it is now nec¬ essary to sense a new voltage with a new set of criteria. In this circuit, the diode 34 could be replaced by a series of diodes, or by a Zener diode (connected in the opposite direction) to change the detection criteria. A negative voltage regulator 35, i.e., a Zener diode, is connected between referenced potential and the junc¬ tions of the diodes 33 and 34. This Zener diode clamps the negative half cycle of the AC input to insure that it does not go above the specified limits of the Zener diode. This function protects the relay coil against over voltage and also serves in conjunction with the pos¬ itive clamping circuit to regulate the voltage supplied to the lights.

The switch 22 may be employed, for example, in the event that the batteries are removed from the cir¬ cuits, or are discharged. The line 30 is connected to the from lamp 36 of the bicycle by way of a switch 37 , as well as to a back light 38 of the bicycle by way of a switch 39. It is preferable by employ separate switches for the lamps , in order to save electricity when it is not necessary, for example, to have the front lamps on. If desired, an external charging circuit 40 of conven¬ tional nature may be connected to the battery line 30, for example, employing a tip jack, if it may be desired to charge the batteries from some other source of power, such as from AC house current.

Speedometer/Odometer Circuit

As illustrated in Figs. 1 and 3, the generator line 11 and the positive output voltage line 30 are also applied to the speedometer/odometer circuit. The posi¬ tive voltage on line 30 is employed as a positive oper¬ ating voltage for this circuit, while the generator output voltage on line 11 is employed as a signal vol¬ tage since the cycles of this voltage are a measure of the distance traveled by the bicycle. Thus, as discussed above, if the generator is directly driven by the rim of a bicycle wheel, the AC cycles of the generator out¬ put will occur at intervals corresponding to the dis¬ tance traveled by the bicycle, independently of the wheel size of the bicycle.

The line 11 is first applied to an input con¬ ditioner (amplifier, li iter and filter) circuit 50, This circuit may employ diodes connected to limit the potential applied to the speedometer to potentials be¬ tween the ground reference and the positive supply, as well as resistance-capacitance low pass filter elements. A transistor may be employed to amplify the AC voltage, with an output diode clamp also being employed. The out¬ put of this circuit is connected to a divider and decoder 51, as well as to a speed counter and latch 52. The line 30 is connected to the speedometer circuit by way of an isolating diode 53, for the supply of the minimum current operating semiconductor devices of the circuit. A display switch 54, however, may be employed for disconnecting the display devices, since these devices, such as light- emitting diodes, may otherwise drain the battery to an undersirable extent. If low current display devices, such as LCDs are employed, however, this switch may be omitted if desired.

In the circuit diagram of Fig. 3, the device numbers of commercially available integrated circuits are shown, along with the pin numbers of these devices, in order that the circuit of the invention will be more clearly understood. The devices may, for example, be CMOS devices as illustrated, for low current operation. _ It will, of course, be apparent that other devices may be employed, the circuit of Fig. 3 being organized on the basis of presently available components.

The design of the circuit in accordance with the invention may proceed on the basis that the circuit should indicate the speed of the bicycle at a minimum value, for example, one-tenth of a mile an hour. A signal at this speed, from the generator, has a very low voltage, and this is. the reason that the amplifier has been provided in the input condition in the circuit. The filter is required in order to remove noise from the generator output, and the limiter is necessary since the output of the generator, at higher speeds, may exceed the safe operating voltages for the circuits. It will, of course, be apparent that conventional circuitry may be employed for these purposes. The outputs of the input conditioner is applied, as illustrated in Fig. 3, to a buffer in chip 60 (a 4023) , the output of this buffer being applied to a 14-stage decoder/divider 61 for division. This divider, in one embodiment of the invention, is con¬ nected to provide output divisions at counts of 4096, 512 and 216, and these outputs are connected to three input NAND gate in the IC chip 60, to provide an output with a division of 4864. The pulse output of this NAND is thence applied to a distance counter 62 in the form of a re- settable counter chips -63 (4553). The counter 63 thereby counts a number of pulses applied thereto, which corresponds to 1/4864 of the frequency of the generator. This division

corresponds to one-tenth of a mile, in accordance with the above example, based upon the size of the generator, the size of the rotary drive for the generator, and the size of the wheel, and the distance traveled. In the given example, this division will provide an accuracy of about 2 1/2%. A further factor in the division would have en¬ abled increased accuracy, for example, up to about 0.2%. The counter 63 is connected to provide counts at the lowest, central and most significant bits, at terminals 15, 1 and 2 respectively, of a three-digit decimal number. These output pulses are applied to a pulse selector switch 65, for example, a quad and/or select gate 66 (Type 4019) at terminals 7, 5 and 3 respectively. (It will be apparent that the circuit illustrated is multi¬ plexed in conventional manner, in order to provide a seven-segment display output) .

The above portion of the circuit further in¬ cludes a reset switch 67 connected to the distance counter 63, for resetting the odometer portion of the circuit to zero or any desired fixed base.

The speedometer portion of the circuit includes a speed counter and latch 52 in the form of a counter 70 (a Type 4553) connected to count the generator output pulses from the input conditioning circuit, that occur within a given period as determined by a timer 71. The timer may comprise a Type 555 timer 72 connected as a free running multivibrator, the output at terminal 3 thereof providing a latch for the counter 70. A dif¬ ferentiating circuit 73 connected to the output of the 555 latch 72 provides a reset pulse on line 74 for the counter 70. The timer circuit, in the above example of the invention , is connected to provide an approximately, 0.7 second pulse every 0.701 seconds. Initially, the latching of the speed counter effects the store and dis-

play of information within the speed counter, i.e., the count of the previous cycle, the differentiator thereby resetting this counter to zero after the data therein has been applied to the output circuit. Thus, when the reset signal drops, the counter 70 is enabled approximately 0.7 seconds to count the number of genera¬ tor cycles applied thereto. After this 0.7 seconds, the latch voltage drops to enable the transfer of this number of counts to the counter memory, with the conse¬ quent reset of the counter upon receipt of the reset volts. The output of the counter 70, in the form of pulses corresponding to the least, central and most significant bits of a three-digit decimal number are applied to the.-- terminals 6, 4 and 2 of the switching device 66.

In the circuit of Fig. 3, for convenience, the switch 64 is shown as having separate portions 65A and 65B, the portion thereof 65A controlling the display of the digit at any instant. This switch has a further section 65B for controlling the BCD counts stored in the counters. The BCD output of the switch 80 is applied, on lines W, X, Y and Z to a BCD to seven-segment conver¬ ter 84 (Type 4543), while the decimal enable outputs are applied by way of driver transistors to the seven-segment display devices (such as LEDs) 82. The seven-segment output signals from the decoder 84 are also applied to these display devices, in the conventional multiplex fashion. The manual switch 81, connected to the switches 66 and 80, enables either the display of the odometer count, or the speedometer count.

It will of course be apparent that many modifications may be made in the system as above disclosed,

Thus , the resistor in the charging circuit may be re¬ placed by a transistor or integrated circuit enabling the application of a constant charging current to the bat¬ tery. Further, the timing circuit of the timer of Fig. 3 may be replaced by a linear or non-linear integrated circuit. Further, non-linear circuit decoding may be intro¬ duced into the decoder circuit of the odometer in order to improve accuracy, and also to eliminate some of the discrete components.

While the invention has been described with reference to the three-digit display, it is of course apparent that more or less digits may be employed, as desired, and that the division ration may be reduced in order to display, for example, lOOths of a mile or lOOOths of a mile.

Further, as illustrated in Fig. 4, a backup battery 90 may be connected to the divider circuit 51 and distance counter 62 of the odometer, in order to simulate a non-volatile mempxy, whereby the backup battery will be charged while the generator voltage is sufficiently high, but the storage in the counter circuits will be maintained over long periods of time even though the bicycle is not in use. Further it is alternately, of course, a non-volatile memory may be employed. Further, it is of course apparent that changes in the division ration will enable display of the dis¬ tance and speed in units of the metric system. If de¬ sired, suitable conventional switches may be employed to enable alternate display in the metric system. Mul¬ tiple displays may of course be provided also, to simul¬ taneously show distance and speed. As a further modifi¬ cation , means may be provided for producing a signal cor¬ responding to a determined speed or distance, for comparison with the outputs of the odometer and speedometer

counters to produce an audible or visual signal when the speed or distance are above or below determined levels. Alternatively, such outputs can be employed for serving other functions. Further, a solid state Hall Effect switch may be employed for sensing suitable magnets mounted on a rotary member of the bicycle, or electro¬ magnetic or Eddy current sensors may be employed and mounted to sense uneven metal surfaces such as gear teeth or sprockets on the rotary member, for the speedometer- odomete function. It is apparent that the present inven¬ tion therefore covers each such variation and modifica¬ tion as falls within the true spirit and scope of the invention.

V.HAT IS CLAIMED IS:

1. A circuit for providing a display of a distance related function for a vehicle, comprising a AC generator for producing a voltage having a wave-for with a cycle that is directly proportional to distance traveled by the vehicle, means producing a direct operating voltage for said circuit from said voltage having said wave-form, and means for counting the number of cycles of said vol¬ tage having said wave-form for providing said display.

2. The circuit of claim 1 wherein said function is speed, wherein said means for counting comprises means for periodically counting the number of cycles of said wave form in a determined time period, and means for dis¬ playing said count.

3. The circuit of claim 2 comprising means for producing pulses from said wave form for application to

O PI >- ipo