# Patent

## Title
Electrically powered bumper cars comprising multiple drive wheels and integral hub motors

## Abstract

“Bumper car” amusement rides are disclosed. An exemplary bumper car comprises a frame, a seat, multiple drive wheels, a motor controller, and at least one rider control. The seat is configured to hold and position at least one rider of the bumper car. The car is electrically powered from an internal and/or external power source. Each drive wheel comprises a respective hub motor that, when supplied with the electrical power from the source, rotates the respective drive wheel relative to the frame and propels the bumper car. The controller is connected to the source and to the hub motors. The controller is configured: (a) to limit a maximal current supplied by the source to the hub motors during a surge-current situation to a preset maximum, and (b) to ramp down the maximal current over a preset time interval during the surge-current situation. The at least one rider control is interconnected with the source and the hub motors and is configured to be manipulated by a rider for maneuvering the bumper car.

## Background
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 11/372,398, filed on Mar. 8, 2006 now U.S. Pat. No. 7,607,500, which is incorporated herein by reference in its entirety.


FIELD
This disclosure pertains to amusement rides, especially of a type known as “bumper cars.” More specifically, the disclosure pertains to, inter alia, electrically powered bumper cars of which the drive wheels are driven by a particular type of motor called a “hub motor.”
BACKGROUND
Amusement rides known as “bumper cars” have been known and enjoyed for many years. (For example, certain models in the past were known as “Dodgem Cars” and “Glidabouts.”) A modern bumper car is a self-propelled, steerable vehicle usually intended to carry one or two riders around in an arena or the like without having to confine the vehicles to a track. The vehicles are individually equipped with compliant but resilient shock-absorbing structures (“bumpers”), mounted usually around the periphery of the vehicle, that allow the bumper cars to engage in collisions and the like without injury to the riders or damage to the cars, and without tipping the cars over. An exemplary type of bumper is disclosed in U.S. Pat. No. 5,516,169 to Falk et al., incorporated herein by reference. Whereas most types of conventional bumper cars are electrically powered, some are powered by small gasoline engines.
Many conventional electrically powered bumper cars are “externally” powered, i.e., powered by electrical current supplied to the bumper cars from a stationary source such an electrified floor or electrified floor and ceiling. An exemplary electrified floor is disclosed in U.S. Pat. No. 6,581,350 to Dean, incorporated herein by reference. In the '350 patent, direct-current electrical power is conducted from the floor to the cars via electrical pickups (“shoes” or “brushes”) beneath the cars that remain in sliding contact with the floor as the cars are being driven around on the floor.
One type of conventional bumper car is driven using a gasoline motor. Use of a gasoline motor allows the bumper car to be operated on a non-electrified surface, but the motor itself and the required mechanical linkages from the motor to the drive wheels on the car are mechanically inefficient. Also objectionable are the facts that a gasoline motor requires fossil fuel to run and produces environmentally unfriendly exhaust.
One type of conventional bumper car that operates on an electrified floor comprises a frame to which are mounted the bumpers and a body including a seat for the rider. Also mounted to the frame, below the level of the seat, are driving wheels and stabilizing wheels (e.g., caster wheels). The driving wheels move the bumper car around the floor while the stabilizing wheels stabilize the car relative to the floor. Also mounted to the frame is a DC electric motor that runs continuously while the bumper car is being driven. Driving power from the motor is selectively delivered to the driving wheels via respective hydrostatic transmissions. The respective amounts of driving power delivered by the transmissions to the wheels are individually controlled by mechanisms, such as respective control levers, that are coupled to the transmissions, mounted to the frame, and manipulated by the rider. The rider steers the car by selectively applying, via the control levers gripped by the rider's hands, driving power to each driving wheel. In this type of bumper car, the manner in which driving power produced by the motor is delivered to the driving wheels is mechanically inefficient. The inefficiency is masked because the bumper car can draw as much current as it ever needs from the conductive floor.
Another conventional type of electrically powered bumper car utilizes a DC motor coupled via a gear box and chain-drive to a drive wheel. Steering is achieved by turning, via a first control, the entire mechanism of motor, gear box, and drive wheel. Motion and braking of the bumper car is achieved by manipulating a second control that turns the motor on and off. As noted above, normal use of a bumper car is characterized by a large number of rapidly executed starts, stops, directional maneuvers, and “bumps” into other bumper cars and walls. Driving the bumper car into a stationary wall or into another car can cause an abrupt stall (halt in rotation) of the motor even though power is still being delivered to the motor. At the moment of a stall, the motional emf of the motor drops to substantially zero, which causes the motor to draw a very large current (surge current) that is limited only by the inductance and resistance of the motor windings. Draw of surge current also occurs during starts of the bumper car from a stopped position and during rapid transitions from forward to reverse and vice versa. The large number of such draws of surge current accompanying normal use of the bumper car causes very high power consumption, as well as overheating and premature failure of the motor. Also, the manner of coupling the motor to the drive wheel is mechanically inefficient, and the steering mechanism in this type of bumper car is incapable of executing 360° spins “on a dime,” as currently desired in bumper-car rides.
Another type of conventional electrically powered bumper car comprises a small DC motor to which are coupled two gear boxes. Each gear box drives a respective drive wheel via a respective drive belt or chain. Forward, reverse, and steering motions of the car are achieved by manipulation of controls coupled to the gear boxes. In the course of driving the bumper car in rapid start, stop, and reverse maneuvers, surge current being delivered to the motor is reduced by use of hydraulic motion limiters in the controls. The motion limiters impose limits on the rate at which the rider can change motion of the car (e.g., impose a time delay in shifting from forward to reverse). This mechanism is complicated and inherently reduces the responsiveness of the car. Hence, this mechanism is used mainly on small, low-mass bumper cars intended to be ridden by very light-weight riders (namely, small children). Loads imposed by larger and heavier riders result in unacceptable rates of power consumption and render the bumper cars too unresponsive for acceptance by older children and adult riders.
Therefore, there is a need for bumper cars providing substantially improved maneuverability and other performance features that riders increasingly expect from such amusement rides.
SUMMARY
The need articulated above is satisfied by any of various electrically powered bumper cars as disclosed herein. Some embodiments receive electrical power from an on-board source such as one or more batteries. Such cars are termed “internally electrically powered.” Other embodiments receive electrical power from an external source such as an electrically conductive floor. The latter are termed “externally electrically powered.” Yet other embodiments are powered by both internal and external sources of electrical energy. For example, high-current power for propelling the car can be supplied by an external source, while low-current power for operating one or more on-board devices such as the motor controller can be supplied by an internal source.
An exemplary embodiment of a bumper car comprises a frame, a seat, multiple drive wheels each comprising a respective “hub motor,” a motor controller configured to control the electrical power being delivered from a source to the hub motors, and at least one rider control. The seat is attached to the frame and configured to hold and position at least one rider of the bumper car. The drive wheels are mounted to the frame. Each hub motor that, when supplied with electrical power from the source, rotates the respective drive wheel relative to the frame and thus propels the bumper car. The motor controller is connected to the source and to the hub motors. The motor controller is configured to perform at least the following: (a) limit a maximal current, supplied by the source to the hub motors during a surge-current situation, to a preset maximum, and (b) ramp down the maximal current, over a preset time interval, during the surge-current situation. The at least one rider control is interconnected with the source, the hub motors, and the motor controller. The at least one rider control is configured to be manipulated by a rider for propelling and maneuvering the bumper car.
The motor controller desirably is further configured to limit a steady-state current, supplied to the hub motors during actual running of the motors, to a preset value that is lower than the maximal current.
Alternatively, the motor controller is configured to perform at least two of the following: (a) limit a maximal current, supplied by the source to the hub motors during a surge-current situation, to a preset maximum, (b) ramp down the maximal current, over a preset time interval, during the surge-current situation, and (c) limit a steady-state current, supplied to the hub motors during actual running of the motors, to a preset value that is lower than the maximal current.
The bumper car desirably further comprises a bumper mounted to and extending substantially circumferentially around the frame, for cushioning impacts of the bumper car with other objects.
An internal source of electrical power can comprise at least one battery. If multiple batteries are used, they desirably are arranged in pairs, wherein each pair is connected so as to provide, in a selectable individual manner, electrical power to the hub motors. Thus, when one pair is supplying the electrical power to the hub motors, the other pair can be off-line (not supplying electrical power to the hub motors), and vice versa. Bumper cars comprising multiple, selectably usable battery sets desirably further comprise a battery-selector switch interconnected with the battery sets. In one embodiment the battery-selector switch has a first selectable position allowing electrical power to be drawn from the first battery set to the hub motors, and a second selectable position allowing electrical power to be drawn from the second battery set to the hub motors.
In externally powered embodiments, electrical power is supplied by, for example, an electrically conductive floor on which the car is driven. Desirably, especially for personal safety reasons, the floor is powered to deliver low-voltage (e.g., 24 VDC), high-current to the car. For such a purpose, each car driven on the floor includes one or more conductive “brushes” that extend downward from the car (typically beneath the car) to the conductive surface of the floor. In this regard, reference is made to U.S. Pat. No. 6,581,350 to Dean, incorporated herein by reference.
The rider control can have any of various configurations such as joysticks, dual potentiometer controls, or other suitable configuration. In one embodiment two joysticks are used. In this embodiment the multiple drive wheels comprise a left drive wheel and a right drive wheel. A first joystick is connected so as to control operation of the left drive wheel, and a second joystick is connected so as to control operation of the right drive wheel. The first joystick desirably is situated to be manipulated by the left hand of the rider, and the second joystick desirably is situated to be manipulated by the right hand of the rider, independently of the first joystick.
By way of example, with respect to a bumper car configured to run on 24 VDC (either internally or externally supplied), the respective hub motors are configured to run on the 24 VDC for rotating the respective drive wheels. The motor controller is configured: (a) to limit the maximal current supplied to the hub motors during a surge-current situation to a preset maximum in the range of 25 to 30 amps, (b) to limit the steady-state current, supplied to the hub motors during actual running of the motors to a preset value in the range of 5 to 20 amps, and (c) during the surge-current situation to ramp down the maximal current to the steady-state current over a preset time interval in the range of 1 to 3 seconds.
According to another aspect, methods are provided for propelling and steering a bumper car. An embodiment of such a method comprises providing a bumper car with first and second drive wheels powered by first and second hub wheels, respectively, that are integral with the first and second drive wheels, respectively. The method includes controllably delivering electrical power to the hub motors. Thus, the hub motors are energized in a selective manner serving to propel the bumper car and to perform steering of the bumper car, while: (a) limiting a maximal current supplied by the source to the hub motors, during a surge-current situation, to a preset maximum, and (b) ramping down the maximal current over a preset time interval during the surge-current situation. It also is desirable to control delivery of electrical power from the source to the first and second hub motors in a manner that limits a steady-state current, supplied to the hub motors during actual running of the motors, at a preset value that is lower than the maximal current.
The foregoing and additional features and advantages of the subject apparatus and methods will be more apparent from the following detailed description, which proceeds with reference to the accompanying drawings.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the external features of a bumper car according to a representative embodiment.
FIG. 2 is a plan view of the frame of the bumper car of FIG. 1.
FIG. 3 is a plan view of an internally electrically powered embodiment including the frame shown in FIG. 2 and also showing batteries, hub motors, controller, and other components mounted to the frame.
FIG. 4 is a perspective view showing the manner, with respect to the embodiment of FIG. 3, in which the hub motors and batteries are connected to a particular type of controller. The figure also depicts an exemplary manner in which active-low control switches can be connected to the controller for controlling operation of the hub motors.
FIG. 5(A) provides certain details of an exemplary manner, with respect to internally or externally powered embodiments, in which a joystick can be connected to the controller for controlling operation of the hub motors. Normally, two joysticks would be connected, one for each respective hub motor. Also shown are throttle zones associated with the particular joystick illustrated.
FIG. 5(B) provides certain details of an exemplary manner, with respect to internally or externally powered embodiments, in which dual potentiometers can be connected to the controller for controlling operation of the hub motors. Also shown are throttle zones associated with the dual potentiometers.
FIG. 6 is an exemplary electrical schematic wiring diagram, showing connections of the hub motors and joysticks to the controller in internal or externally powered embodiments.
FIG. 7 is an electrical schematic wiring diagram that is essentially a continuation of FIG. 6, showing interconnections of the batteries, radio receiver, and solenoids in an internal electrically powered embodiment of a bumper car.
FIG. 8 is an electrical schematic wiring diagram depicting interconnections for an external electrically powered embodiment of a bumper car.



DETAILED DESCRIPTION
This disclosure is set forth below in the context of representative embodiments that are not intended to be limiting in any way. Words of relative position, such as “vertical,” “horizontal,” “above,” “below,” “over,” “under,” “front,” “rear,” and the like are used to facilitate comprehension of structure by using as a frame of reference a bumper car in a normal-use position. However, these terms are not to be construed as imposing any absolute relationships that persist under all conceivable situations.
Bumper cars as described herein are configured to address the following considerations:
First, to provide maximal maneuverability, the bumper cars are provided with two drive wheels, instead of one as in certain conventional bumper cars. The drive wheels desirably are spaced apart from each other on a horizontal axis. The horizontal axis desirably is bisected by a vertical axis passing substantially through a center of gravity of the bumper car and rider. (It is not necessary that the vertical axis intersect the horizontal axis, but these axes desirably are situated such that differential rotation of one drive wheel relative to the other drive wheel provides a desired highly responsive maneuverability of the cars, including 360° turns “on a dime,” e.g., about the vertical axis.)
Second, to provide maximal mechanical efficiency, each drive wheel is driven by a respective integral “hub motor.” Each hub motor is a combination of an electric motor and a gear train (typically a planetary gear train) in the hub of the respective drive wheel so as to couple the motor directly to the drive wheel. Use of hub motors eliminates the need for external gear trains, transmissions, clutches, chains, belts, and/or other efficiency-robbing mechanical couplings between the motor and respective drive wheel. Thus, each drive wheel is integral with its respective hub motor, yielding a substantially greater mechanical efficiency with which the cars are driven. Such high efficiency correspondingly reduces the power appetite of the bumper car, which is highly desirable in a battery-powered or other internally electrically powered bumper car.
Third, each bumper car is powered by a source of electrical power. The source can be internal or external to the car. An example internal source comprises one or more devices each conventionally (and in a general sense) called a “battery,” wherein substantially all known batteries produce direct-current (DC) electrical power. Hence, a “battery” as referred to herein encompasses any of various portable sources of electrical power. In general, the portable source of electrical power is mounted to the frame, either directly or indirectly. An example external source is an electrified floor on which the car is driven, wherein the car obtains power from the floor via one or more “brushes” or other sliding contacts extending from the car to the floor. The brushes make electrical contact with the floor sufficiently to provide an uninterrupted flow of electrical power from the floor to the car under any of various conditions and situations including stationary cars, cars being driven, cars being bumped into one another, cars being stalled, and cars undergoing turning and other directional maneuvers.
Fourth, delivery of electrical power from the source to the hub motors is controlled using a motor controller that provides, for each hub motor, respective limits on starting/surge current (maximum current draw by the motor when starting, including after a stall), surge time (a defined time period during which current flow up to the surge limit is allowed), and steady-state current (after elapse of the surge time, the maximum current allowed during actual running of the hub motor). Thus, the hub motors are driven only when necessary to achieve a desired motion of the car and are operated under controlled current-draw conditions (including during motor-stall situations) that substantially reduce power consumption compared to conventional electrically powered bumper cars.
As noted earlier above, at the moment a voltage is applied to a brushed DC motor that is not turning (e.g., during a stall or at rest, both being conditions in which motional emf of the motor is zero), the motor draws a very large current (a “surge” current) that is limited only by the inductance and resistance of the motor windings. As the motor armature begins to turn and picks up speed, the motional emf increases and opposes the flow of current to the motor, which causes the current to fall rapidly from the surge level toward a steady-state value that depends upon the particular motor and the mechanical load being driven by the motor. The surge current being drawn by a stalled or starting motor, especially under mechanical load, can be very high and can cause rapid heating of the motor. A bumper car under normal-use conditions is subjected to a large number of starts and stops in short periods of time. The electrical source powering the motor(s) must be able to provide the large number of starts and stops required during normal operation of the bumper car. In addition, these many starts and stops must be provided in a manner that does not cause overheating or other damage to the motor(s). The embodiments described below address these concerns.
Turning first to FIG. 1, general features of a representative embodiment of a bumper car 10 are shown. The bumper car 10 includes a frame 12 (not detailed, but see FIG. 2), a circumferential bumper 14, a molded body 16, a seat 18, and hand controls 20a, 20b placed so as to be easily reached and manipulated by a rider while seated in the seat. The seat 18 includes a seat belt 22 that restrains the rider in the seat. The body 16 includes depressions 24 that accommodate the rider's lower legs and feet when the rider is seated in the seat 18. The seat belt 22 desirably fits loosely to the rider so that the pivot point of the rider's body is from the rider's seat, not the rider's neck. The depressions 24 position the rider's legs and feet so that the rider's legs can act as stabilizers in a natural manner.
Regarding the frame 12 and body 16, it is possible to integrate the body and frame in a single unit rather than having a separate body that is attached to the frame; such a single unit would still be regarded as a “frame.” Also, although in this embodiment the seat is configured to hold one rider, in other embodiments the bumper car can be configured to hold more than one rider. In addition although the seat is depicted in this embodiment as being a separate component that is mounted to the body (or frame), in other embodiments the seat is integral with the body or frame. For example, the body 16 can be molded or formed so as to define a seat. In all these various configurations, the seat nevertheless is “attached” to the frame.
FIG. 2 is a plan view of the frame 12 with the body and bumper removed. The frame 12 in this embodiment comprises an annular portion 30, a front cross member 32, a rear cross member 34, outside bottom supports 36, middle bottom supports 38, center bottom supports 40, battery-mount members 42, and motor-mount members 44. The frame 12 also comprises a rear caster mount 46 and a front caster mount 48. A respective caster wheel 50, 52 or analogous structure is mounted to the underside of each of the front and rear caster mounts 46, 48, respectively. For durability, the frame 12 desirably is made of mild steel, wherein the various members are welded together and/or connected together by mechanical fasteners. A desirable finish for the frame is a powder-coat finish.
In this embodiment the caster wheels 50, 52 desirably are each swivel-mount and four inches in diameter. It will be understood that other types and sizes of “caster wheels” alternatively could be used.
FIG. 3 is a plan view showing the frame 12 of FIG. 2 to which are mounted, in this embodiment, first and second drive wheels 60, 62, two solenoids 66a, 66b, a motor controller 68, and a radio receiver 70 for receiving on-off signals from a remote radio transmitter (not shown). Other components outlined in FIG. 3 are discussed later below.
This embodiment is internally electrically powered using four sealed batterieds 64a-64d. Each of the batteries 64a-64d in this embodiment desirably is a 12 VDC, 32 Amp-hour, sealed type. The batteries 64a-64d are connected for alternating use in pairs; i.e., when one pair is “on,” the other pair is “off.” In FIG. 3 the first pair consists of batteries 64a, 64b, and the second pair consists of batteries 64c, 64d. In each pair the batteries are connected together in series, which configures each pair to produce a net 24 VDC output for driving the hub motors in the drive wheels 60, 62. By connecting the batteries 64a-64d for alternating use in pairs each consisting of multiple batteries, the mass of each battery can be sufficiently low for convenience and ease of handling during maintenance activity, and the bumper car can be operated without running down a particular pair of batteries all the time. It will be understood, however, that use in this embodiment of four batteries in this manner is exemplary, and is not intended to be limiting in any way. Providing direct current from one or more batteries carried about in a bumper car can be achieved in any of various ways, and the particular manner that is selected will reflect prevailing concerns of weight, convenience, and the power requirements of the particular drive wheels.
Each drive wheel 60, 62 comprises a respective hub motor 72, 74 that, in this embodiment, is a brushed 24-volt DC hub motor with an integral brake and integral tire 76, 78. Thus, each drive wheel 60, 62 is integral with its respective hub motor 72, 74. In accordance with achieving intuitive control during driving, the first drive wheel 60 desirably is located on the left side of the frame, and the second drive wheel 62 74 desirably is located on the right side.
An exemplary hub motor is XTi® type 280-1342M manufactured by Assembled Products Corp., Rogers, Ark., which is configured to be driven using 24 VDC. This specific type of hub motor has a solid rubber tire having a diameter of eight inches. The stated diameter is not intended to be limiting. For this particular hub motor, the 8-inch tire diameter was deemed advantageous in view of certain factors such as the maximum rotational velocity (150 rpm) exhibited by this motor when driven at maximal power and a concern with limiting the maximal driving velocity of the car. (An 8-inch diameter drive wheel rotating at 150 rpm provides a car-drive velocity of 3,770 in/min=3.57 ml/hr.) Therefore, depending upon the desired driving velocity of the car, the maximal rotational velocity of the hub motor at full power, and the particular hub motors that are commercially available, an appropriate diameter of the driving wheel can be selected. For example, a hub motor having a lower maximal rotational velocity and a correspondingly larger tire diameter could be used, so long as the motor is able to provide sufficient motive power to the bumper car at an acceptable rate of power consumption. The tire need not be solid; alternatively, it can be pneumatic, for example.
The hub motors 72, 74 also desirably have integral brakes that are actuated whenever power to the motors is interrupted. Thus, the integral brakes operate in a fail-safe mode in which the brakes are off whenever power is being supplied to the motors and the brakes are on whenever power is not being supplied to the motors. This is especially desirable because the brakes, when on, prevent the car from moving while a rider is either exiting or entering the bumper car. Further desirably, the brakes are configured with an override feature (e.g., a manually operated control on each hub motor) to allow the cars to be moved when “off,” such as during an emergency situation. Since these types of integral brakes draw a certain amount of power to maintain them in an “off” state whenever the hub motors are “on,” the power consumption of the brakes in the hub motors should be taken into consideration in determining the amount of DC power to be provided by the battery or batteries. For example, the brakes on the exemplary hub motors noted above draw about 0.8 amp at 24 VDC.
DC power to the hub motors 72, 74 in this embodiment is supplied by a selected pair of batteries via a respective controller (or via a respective channel of a single controller 68). As noted above, a stalled motor normally draws maximal current until power to the motor is disconnected. This situation could have serious power-dissipation consequences for a semiconductor-based controller being used to control the motor. The controller 68 desirably is semiconductor-based but is configured to control each bi-directional load (i.e., each respective hub motor that can move in forward and reverse directions) while simultaneously limiting the following parameters for each load: starting/surge current, steady-state current, and surge time. By imposing these limitations, both the controller 68 and the motors 72, 74 escape the hazards of surge currents.
For this particular bumper-car embodiment, exemplary levels for the controller parameters are as follows (at 24 VDC): starting/surge current: 25 amps, steady-state current: 10 amps, and surge time: 2 seconds to drop from 25 to 10 amps. Representative ranges for a car sized to carry an adult rider are 25-30 amps for starting/surge current (approximately 15 amps for a smaller car for small-child riders), 5-20 amps for steady-state, and 1-3 seconds surge time. If a surge-current or otherwise high-current situation is detected by the controller 68, the controller reduces, over a preset amount of time, the power delivered to the respective load. Thus, maximal current supplied to the hub motors during a surge-current situation is: (a) limited to a preset maximum appropriate for the particular hub motors, and (b) automatically ramped down, rather than abruptly shut off, over a preset time interval during the surge-current situation. (The longer the time interval, the more time consumed in reducing the current from a surge level to the steady-state level.) Also, steady-state current supplied to the hub motors during actual running of the motors is limited to a preset value that is lower than the surge maximum.
Example types of controllers offering such performance are triac-based controllers, chopper-based controllers, and full-bridge-based controllers. In the case of a triac-based controller, a respective triac can be used to control each motor, or a respective triac can be used to control each rotational direction of each motor. Each triac can be controlled using, for example, a control IC (integrated circuit) or a microcontroller. Many chopper circuits utilize chopper MOSFETs that control the rate and duration of application of current to the motor. This type of circuit can incorporate a “soft-start” feature, in which the motor is set in motion over a period of time, rather than instantly, by application of periodic bursts of current to the motor, and surge currents are avoided by initially allowing the chopper MOSFET to conduct for only short periods of time. The full-bridge-based controller circuit achieves forward, reverse, and braking control of the motor, typically using four MOSFETs that are controlled using a microcontroller. The MOSFETs apply packets of current to the motor in a manner by which the frequency and duration of the packets are controlled by the microcontroller.
An exemplary controller 68 is the “Dual30” two-channel controller manufactured by Courtney Electronics, Greenland, Ark. This particular controller can independently control two hub motors 72, 74, connected as shown in FIG. 4, and allows the current limits and surge times to be programmed into the controller using a computer. The controller 68 has a seven-pin connector 80 as well as high-current lugs 82, 84 (“C1” and “C2”) for connecting to the first motor 72 and high-current lugs 86, 88 (“C3” and “C4”) for connecting to the second motor 74. The controller 68 also has high-current lugs 90, 92 for receiving power from the high-current power source (e.g., batteries 64). In the seven-pin connector 80, the first pin 94 is ground, the second pin 96 is “WIPER1” (analog 0-5 VDC)/SWITCH1 (active-low digital), the third pin 98 is “WIPER2” (analog 0-5 VDC)/SWITCH2 (active-low digital), the fourth pin 100 is SWITCH3 (active-low digital), the fifth pin 102 is SWITCH4/INH (active-low digital), the sixth pin 104 is Vk (programming supply voltage), and the seventh pin 106 is Vdd (logic voltage +5 VDC). The INH pin (fifth pin 102) can be used to inhibit output to both channels simultaneously. To inhibit all outputs (“inhibit” mode), a connection is made from the INH pin 102 to logic ground (first pin 94). Opening this connection will cause the controller 68 to exit the inhibit mode.
It will be understood that the low-current DC voltages (e.g., +5 VDC logic voltage) can be supplied by an on-board power supply (battery) regardless of whether the high-current power for the hub motors is internal or external. In other embodiments the low-current DC voltages can be provided by voltage-dividing the voltage (e.g., 24 VDC) supplied by the high-current supply.
In general, the controller 68 can be used with any of various input schemes, such as a joystick-based input scheme, a dual-potentiometer input scheme, or an active-low switch input scheme. An exemplary active-low switch input scheme is shown in FIG. 4, in which two double-throw switches 107, 109 are used, one for each motor 72, 74, respectively. The switch 107 effectively comprises two single-throw switches 107a, 107b, and the switch 109 effectively comprises two single-throw switches 109a, 109b. In this scheme, “C1,” “C2,” “C3,” and “C4” are controlled by active-low inputs SWITCH1 (second pin 96), SWITCH2 (third pin 98), SWITCH3 (fourth pin 100), and SWITCH4 (fifth pin 102), respectively. SWITCH1 and SWITCH2 correspond to switches 107a and 107b, respectively, and SWITCH3 and SWITCH4 correspond to switches 109a and 109b, respectively. To “activate” any given input, a connection is made from the corresponding input pin to logic ground (GND, first pin 94). If both inputs corresponding to a particular motor are driven low (e.g., SWITCH1 and SWITCH2 for the first motor 72), a switch fault is detected, and the output to that motor is inhibited.
For this particular bumper-car embodiment, a joystick-based input scheme is desirable because it provides directional and speed controls in a manner that is familiar to most riders. For example, any joystick that produces two analog outputs may be used so long as the controller 68 is properly programmed. An exemplary joystick connection for the first motor 72 is shown in FIG. 5(A), in which “P1” is the first pin 94, “P2” is the second pin 96, “P3” is the third pin 98, and “P7” is the seventh pin 106 of the connector 80. This figure also depicts the available throttle zones of the joystick. In one embodiment, an exemplary joystick (two per car) is model 50-7604-10, manufactured by Happ Controls, Elk Grove, Ill. This type of joystick has respective connecting pins that are denoted “common,” “normally open,” and “normally closed.” The common and normally open pins are used, as discussed later with respect to FIG. 6.
An exemplary dual-potentiometer input scheme is shown in FIG. 5(B), which also depicts the available throttle zones. In this mode, each motor 72, 74 is controlled by a respective center-off variable analog input. WIPER1 (second pin 96) and WIPER2 (third pin 98) are the throttle inputs for the first motor 72 and second motor 74, respectively. This throttle option provides control of direction as well as speed.
An electrical schematic of an embodiment of a circuit by which joysticks 110, 112, the controller 68, and the hub motors 72, 74 are interconnected is provided in FIG. 6. Also shown are a ground block 114, the first solenoid 66a, and the second solenoid 66b. The first motor 72 has a red-insulated lead 116 and a black-insulated lead 118 for forward and reverse operation, respectively, a positive-power lead 120, and a negative-power lead 122. Similarly, the second motor 74 has a red-insulated lead 124 and a black-insulated lead 126 for forward and reverse operation, respectively, a positive-power lead 128, and a negative-power lead 130. On the controller, the “C1” lug 82 is connected to the red-insulated lead 116 of the first motor 72, the “C4” lug 88 is connected to the red-insulated lead 124 of the second motor 74, the “C2” lug 84 is connected to the black-insulated lead 118 of the first motor 72, and the “C3” lug 86 is connected to the black-insulated lead 126 of the second motor. (For joystick operation, “C1” is the FORWARD output lug for the first motor 72, “C2” is the REVERSE output lug for the first motor, “C3” is the FORWARD output lug for the second motor 74, and “C4” is the REVERSE output lug for the second motor.) Further with respect to the controller 68, the “−” power lug 90 is connected to the first pin 94 and to the ground block 114, and the “+” power lug 92 is connected to outputs of the first and second solenoids 66a, 66b. The “+” power lug 92 also is connected via lead 120 to the first motor 72 and via lead 128 to the second motor 74. The ground block 114 is also connected, via a ground conductor 132, to the first joystick 110, to the second joystick 112, to the first motor 72 via lead 122, and to the second motor 74 via lead 130.
On the first (left-hand) joystick 110, the two “common” (COM) terminals are connected to the ground conductor 132, the front normally open (N.O.) terminal is connected via a conductor 133 to pin 96 (P2) on the controller 68, and the rear N.O. terminal is connected via a conductor 134 to pin 98 (P3) on the controller. Similarly, on the second (right-hand) joystick 112, the two COM terminals are connected to the ground conductor 132, the front N.O. terminal is connected via a conductor 135 to pin 102 (P5) on the controller 68, and the rear N.O. terminal is connected via a conductor 136 to pin 100 (P4) on the controller. As noted above, the normally closed (N.C.) terminals on the joysticks 110, 112 are not used in this embodiment.
With respect to an internally powered embodiment of bumper car, an electrical schematic of an exemplary scheme of the wiring of the batteries 64a-64d and associated electrical components is shown in FIG. 7, which is basically a continuation of FIG. 6. As noted earlier above, this embodiment is internally electrically powered using four batteries 64a, 64b, 64c, 64d. The batteries are arranged in two pairs, the first pair consisting of batteries 64a and 64b, the second pair consisting of batteries 64c and 64d. In each pair, the respective batteries are connected in series by a respective conductor 140a, 140b (to produce a net 24 VDC output from each pair). The pairs of batteries are individually selectable for use, by manipulating a battery-selector switch 142, in powering the bumper car. Thus, during normal-use conditions in a commercial setting, such as at the beginning of a day in which a ride operator makes the cars available for rides by paying riders, the bumper cars consume power from one pair of batteries during, say, the morning hours, and power from the other pair of batteries during the afternoon hours. Recharging of the batteries can be conducted after-hours.
As noted above, in alternative internally powered embodiments, two batteries can be used, wherein each battery is used in place of a respective pair of batteries used in the depicted embodiment. Yet further embodiments can employ only a single battery. Also, the battery or batteries are not limited to 12 or 24 VDC output. Other voltage outputs can be used as appropriate for the particular bumper car (and hub motors of the car), the conditions under which the car will be used, and the prevailing level of battery technology. Changing the battery voltage likely will necessitate a change in the specifications of the hub motors 72, 74; however, such a change is readily accommodated in view of the various types of hub motors that currently are commercially available.
Referring further to FIG. 7, the respective “+” power terminals 144a, 144b of the pairs of batteries are connected to respective input lugs of a main fuse block 146. Positive voltage passing through the main fuse block 146 is supplied to respective power-input lugs 148a, 148b of the starter solenoids 66a, 66b, which have respective power-output lugs 150a, 150b connected together (see also FIG. 6) to deliver “+” power to the controller 68 and hence to the motors 72, 74. The “−” power terminals 152a, 152b of each pair of batteries are connected in parallel to the ground block 114 and to the radio receiver 70 (specifically to a “−” power input 154 and a switch input 156). A switch output 158 of the radio receiver 70 is connected via a first circuit breaker 160 to a first pole 162 of the battery-selector switch 142. A second pole 164 of the battery-selector switch 142 is connected via a second circuit breaker 166 to a “+” power input 168 of the radio receiver 70. Thus, the radio receiver 70 receives “+” and “−” operating power from the batteries via the power inputs 154, 168.
The radio receiver 70 functions as a radio-actuated switch. Whenever the radio receiver 70 receives a respective signal from a remote radio transmitter (not shown), the radio receiver opens or closes an internal switch that breaks or makes, respectively, an electrical connection between the switch input 156 and the switch output 158. Thus the bumper car (as well as other cars in the vicinity, if desired) can be turned on and off remotely (and simultaneously, if desired). Desirably, in the manner of a “fail safe” configuration, the radio receiver 70 opens its internal switch (thereby turning power to the car off) in a situation in which power delivery to the radio receiver is off. If desired, the car can be provided with a bypass switch (not shown, but desirably manually operated) that overrides the radio receiver.
Further with respect to the battery-selector switch 142, a pin 162a is connected to a “−” coil input 166 of the second solenoid 66b, and a pin 162a is connected to a “−” coil input of the first solenoid 66a. The first solenoid 66a receives “+” coil power via a “+” coil input 170 that is connected to the power-input lug 148a. Similarly, the second solenoid 66b receives “+” coil power via a “+” coil input 172 that is connected to the power-input lug 148b. Thus, the respective coils of the solenoids 66a, 66b receive constant “+” power from the main fuse block 146 but switched “−” power from the battery-selector switch 142. Furthermore, via the second pole 164, the radio receiver 70 always receives “+” power, supplied by either the pin 164a or the pin 164b of the battery-selector switch 142. Thus, the battery-selector switch 142 is a DPDT switch providing selective control of the particular pair of batteries being used for powering the car, without interrupting power to the radio receiver 70.
The batteries are recharged by connection of a conventional recharging unit (not shown) to a charging-plug assembly 174. The recharging-plug assembly 174 comprises two plugs 176, 178. Each plug 176, 178 has a respective first pin 176a, 178a connected to “−” battery power via the ground block 114 as shown, and a respective second pin 176b, 178b connected to “+” battery power via the main fuse block 146 as shown. Application of charging power to the plug 176 recharges the pair of batteries 64c, 64d, and application of charging power to the plug 178 recharges the batteries 64a, 64b. 
Testing under normal actual-use conditions has revealed that bumper cars within the scope of the instant disclosure, configured according to the representative embodiment, and having new batteries with a full charge operating under normal-use circumstances, will provide approximately 100 ride cycles (each being 2 minutes in duration, with an approximately 30-second pause between each cycle to allow exchange of riders) per pair of batteries. Thus, the four batteries 64a-64d can supply adequate power to the bumper car for approximately 200 2-minute ride cycles per full battery charge. This is two to six times the usable life, per charge, of conventional battery-powered bumper cars.
Although the bumper cars can be powered either externally or externally, internal power offers substantial latitude in terms of locations and conditions of use of the cars. For example, internal power allows the bumper cars to be used on various surfaces not limited to conductive floors and the like. That said, it is nevertheless is possible for bumper cars having hub motors as described herein to obtain power from a conductive floor or analogous means. Another advantage of internal power such as a battery pack is that the delivered power is substantially free of potentially harmful voltage fluctuations, spikes, and the like.
If the cars are powered externally, such as via a conductive floor, desirably either the bumper cars include circuitry for filtering the delivered power or the external power supply itself (i.e., supplying power to the floor) is filtered sufficiently for use by the motor controller.
FIG. 8 is a schematic diagram of key power components in an embodiment of an externally powered bumper car 200 (dashed-lines). This embodiment is intended for operation on a conductive floor 201, such as described in U.S. Pat. No. 6,581,350, incorporated herein by reference. The floor 201 includes segments 205, 207 that are selectively connected to a low-voltage high-current DC power supply 203, for example a ±24VDC power supply. As the car 200 is situated on the floor surface 201, brushes extending from the underside of the car extend to and make electrical contact with the floor segments 205, 207, thereby delivering power from the floor to the car. The depicted embodiment includes two positive brushes 202 and two negative brushes 204. Also shown are the two hub motors 206. The drawing does not depict the joysticks or casters. The brushes are arranged as two sets each including a positive brush 202 and a negative brush 204. Each set of brushes is connected to a respective rectifier array 208a, 208b. Use of multiple positive brushes 202 and negative brushes 204 ensures continuous electrical contact of the car 200 with the floor 201. The car 200 can include a radio switch 70 as described above, a breaker 210, a fuse block 212, and a relay 214, which are similar to the breaker 166, fuse block 146, and relay 66a described above. Thus, DC power is provided to the hub motors 206 from an outboard source as if the power source were an on-board source.
Whereas the subject bumper cars and other aspects have been described above in the context of representative embodiments, the invention is not limited to those embodiments. On the contrary, the subject bumper cars and other aspects are intended to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention, as defined by the appended claims.

## Claims

1. A bumper car, comprising:
a frame comprising an annular portion, a first cross member, and a second cross member, the first and second cross members extending laterally across the interior of the annular portion;
a seat attached to the frame;
multiple drive wheels mounted to the frame, each drive wheel comprising a respective hub motor that, when supplied with the electrical power from a power source, rotates the respective drive wheel relative to the frame and propels the bumper car, the respective hub motor comprising an electric motor located in a hub of the respective drive wheel;
a bumper that circumferentially surrounds the frame and drive wheels of the bumper car; and
at least one rider control electrically interconnected with the power source and the hub motors.

2. The bumper car of claim 1, wherein the power source is an external power source.

3. The bumper car of claim 2, wherein the external power source comprises a conductive floor and a power supply providing electrical power to the floor.

4. The bumper car of claim 3, further comprising at least one brush extending from the car to the floor and configured to make electrical contact of the car with the electrical power provided to the floor.

5. The bumper car of claim 1, wherein the power source is an internal power source.

6. The bumper car of claim 5, wherein the internal power source comprises at least one battery.

7. The bumper car of claim 6, wherein:
the internal power source comprises multiple batteries; and
the multiple batteries are arranged in pairs, each pair being connected so as to provide, in a selectable individual manner, electrical power to the hub motors, such that, when one pair is supplying the electrical power to the hub motors, the other pair is not supplying the electrical power to the hub motors, and vice versa.

8. The bumper car of claim 6, wherein:
the source of electrical power comprises a first battery set and a second battery set; and
the sets are connected so as to provide, in a selectable individual manner, electrical power to the hub motors, such that, when the first battery set is supplying the electrical power to the hub motors, the second battery set is not supplying the electrical power to the hub motors, and vice versa.

9. The bumper car of claim 8, further comprising a battery-selector switch interconnected with the battery sets, the battery-selector switch having a first selectable position allowing electrical power to be drawn from the first battery set to the hub motors, and a second selectable position allowing electrical power to be drawn from the second battery set to the hub motors.

10. The bumper car of claim 1, further comprising:
a motor controller connected to the source and to the hub motors, the motor controller being configured (a) to limit a maximal current, supplied by the source to the hub motors during a surge-current situation, to a preset maximum, and (b) to ramp down the maximal current, over a preset time interval, during the surge-current situation; and
wherein the motor controller is further configured to limit a steady-state current, supplied to the hub motors during actual running of the motors, to a preset value that is lower than the maximal current.

11. The bumper car of claim 1, wherein the at least one rider control comprises a respective joystick.

12. The bumper car of claim 11, wherein:
the multiple drive wheels comprise a left drive wheel and a right drive wheel;
the at least one rider control comprises a first joystick and a second joystick; and
the first joystick is connected so as to control operation of the left drive wheel, and the second joystick is connected so as to control operation of the right drive wheel.

13. The bumper car of claim 1, wherein:
the source produces 24 VDC electrical power;
the respective hub motors are configured to run on the 24 VDC for rotating the respective drive wheels; and
a motor controller configured (a) to limit the maximal current supplied to the hub motors during a surge-current situation to a preset maximum in a range of 25 to 30 amps, (b) to limit the steady-state current, supplied to the hub motors during actual running of the motors to a preset value in a range of 5 to 20 amps, and (c) during the surge-current situation to ramp down the maximal current to the steady-state current over a preset time interval in a range of 1 to 3 seconds.

14. A bumper car, comprising:
a frame comprising an annular portion, a first cross member, and a second cross member, each of the first and second cross members extending laterally across the interior of the annular portion;
a seat attached to the frame;
a connection to a power source;
multiple drive wheels mounted to the frame between the first and second cross members, each drive wheel comprising a respective hub motor that, when supplied with electrical power from the power source, rotates the respective drive wheel relative to the frame and propels the bumper car, the respective hub motor comprising an electric motor located in a hub of the respective drive wheel;
a bumper that circumferentially surrounds the frame and drive wheels of the bumper car; and
at least one rider control electrically interconnected with the power source and the hub motors.

15. The bumper car of claim 14, wherein the connection to a power source comprises one or more brushes extending from the bumper car to a conductive surface on which the car is driven.

16. A bumper car, comprising:
frame means for holding and supporting components of the bumper car, the frame means comprising an annular portion, a first cross member, and a second cross member, the first and second cross members extending laterally across the interior of the annular portion;
seat means for holding and positioning a rider while riding in and maneuvering the bumper car;
power means for supplying electrical power to the car;
drive-wheel means for propelling the bumper car, the drive-wheel means comprising hub-motor means for actuating, when said hub-motor means are supplied with electrical power from said power means, said drive-wheel means to propel the bumper car, each hub-motor means comprising an electric motor means located in a hub of the respective drive-wheel means;
a bumper that circumferentially surrounds the frame means and drive-wheel means of the bumper car; and
control means, manipulatable by the rider, for supplying electrical power to said hub-motor means to propel the bumper car and to maneuver the bumper car.

17. The bumper car of claim 16, further comprising:
motor-controller means for controlling the supplying of electrical power from said power means to said hub-motor means while (a) limiting a maximal current, supplied by said power means to said hub-motor means, during a surge-current situation to a preset maximum, and (b) ramping down the maximal current, over a preset time interval, during the surge-current situation; and
wherein said motor-controller means controls the supplying of electrical power to said hub-motor means further while limiting a steady-state current, supplied to said hub-motor means, to a preset value that is lower than the maximal current.

18. The bumper car of claim 17, wherein said power means comprises battery means.

19. The bumper car of claim 18, wherein said power means comprises at least one brush extending from the car to an electrically energized surface on which the car is driven.

20. The bumper car of claim 17, wherein said control means comprises at least one joystick means.

21. The bumper car of claim 17, wherein:
said drive-wheel means comprises first and second drive wheels; and
said hub-motor means comprises first and second hub motors associated with the first and second drive wheels, respectively;
wherein said motor-controller means is for controlling the supplying of electrical power from said power means to the first and second hub-motors.

22. A method for propelling a bumper car, comprising:
providing a bumper car with a frame and first and second drive wheels powered by first and second hub motors, respectively, that are integral with the first and second drive wheels, respectively, each hub motor comprising an electric motor located in a hub of the respective drive wheel, the bumper car further comprising a bumper that circumferentially surrounds the frame and the drive wheels of the bumper car, the frame of the bumper car comprising an annular portion, a first cross member, and a second cross member, the first and second cross members extending laterally across the interior of the annular portion;
providing electrical power to the bumper car;
controlling delivery of the electrical power to the first and second hub motors so as to energize the hub motors in a selective manner serving to propel the bumper car, while (a) limiting a maximal electrical current to the hub motors, during a surge-current situation, to a preset maximum, and (b) ramping down the maximal current over a preset time interval during the surge-current situation, the delivery of the electrical power further being selectively activated or deactivated via a remote signal transmitted from a remote radio transmitter.

23. The method of claim 22, wherein the electrical power is provided from an internal power supply carried by the car.

24. The method of claim 22, wherein the electrical power is provided from an external power supply.

25. The method of claim 24, wherein controlling delivery of electrical power to the first and second hub motors further comprises limiting a steady-state current, supplied to the hub motors during actual running of the motors, at a preset value that is lower than the maximal current.

26. The method of claim 25, further comprising steering the bumper car while propelling the bumper car.

27. The method of claim 26, wherein steering is performed by controlling respective amounts of electrical current delivered to the first and second hub motors so as to produce corresponding rotational velocities of the first and second drive wheels.

28. A method for propelling and maneuvering a bumper car, comprising:
providing a bumper car with a frame and first and second drive wheels powered by first and second hub motors, respectively, that are integral with the first and second drive wheels, respectively, each hub motor comprising an electric motor located in a hub of the respective drive wheel, the bumper car further comprising a bumper that circumferentially surrounds the frame and the drive wheels of the bumper car, the frame of the bumper car comprising an annular portion, a first cross member, and a second cross member, the first and second cross members extending laterally across the interior of the annular portion;
providing electrical power to the bumper car;
controlling delivery of the electrical power to the first and second hub motors so as to energize the hub motors in a selective manner serving to propel the bumper car, the delivery control including at least two of (a) limiting a maximal current supplied by the source to the hub motors, during a surge-current situation, to a preset maximum, (b) ramping down the maximal current over a preset time interval during the surge-current situation, and (c) limiting a steady-state current, supplied to the hub motors during actual running of the motors, at a preset value that is lower than the maximal current, the delivery of the electrical power further being selectively activated or deactivated via a remote signal transmitted from a remote radio transmitter; and
steering the bumper car by controlling respective amounts of electrical current delivered to the first and second hub motors so as to produce corresponding rotational velocities of the first and second drive wheels.

29. The bumper car of claim 1, wherein the drive wheels are located between the first cross member and the second cross member.

30. The bumper car of claim 1, wherein the frame further comprises a battery mount member extending from the first cross member to the second cross member and that is configured to support a battery.

31. The bumper car of claim 1, wherein the frame further comprises one or more supports that extend from the first cross member toward the front of the annular portion and that are angled inwardly toward a midline of the annular portion as they extend from the first cross member toward the front of the annular portion.

32. The bumper car of claim 1, wherein the frame further comprises first and second members extending from the first cross member to the second cross member, wherein a first of the multiple drive wheels is mounted between the first member and a first side of the annular portion, and a second of the multiple drive wheels is mounted between the second member and a second side of the annular portion opposite the first side of the annular portion.

33. The bumper car of claim 1, wherein the first and second cross members extend from respective locations on a left side of the annular portion to respective location on a right side of the annular portion.