US20080090488A1

US20080090488A1 - Drive unit for mobile assembly

Info

Publication number: US20080090488A1
Application number: US11/541,312
Authority: US
Inventors: Bruce D. Lightner
Original assignee: Dancing Helix LLC
Current assignee: Dancing Helix LLC
Priority date: 2006-09-29
Filing date: 2006-09-29
Publication date: 2008-04-17

Abstract

A drive unit for driving a mobile assembly where the mobile assembly includes a mobile and a rotational coupling unit for storing and delivering energy to the mobile and where the mobile assembly has an oscillating period. The drive unit includes a motor for connecting to the mobile assembly, a power source, a motor driver for providing power from the power source to the motor and a control unit for controlling the motor driver to provide drive-pulse impulses to the motor with a low duty cycle and with a pulse period tailored to the mobile assembly.

Description

TECHNICAL FIELD

The present invention relates to an electromechanical drive unit that imparts rotary motion to suspended items such as mobiles, toys and kinetic sculptures.

BACKGROUND OF THE INVENTION

It is popular these days for people to have many different types of items in homes, offices and other places that, when watched, bring a feeling of calmness and relaxation or which draw attention and interest. These items include aquariums, computer screen-savers with an aquarium or other pleasing image, fountains and waterfalls and they all provide rhythmical wave patterns that can lead to a state of greater relaxation, a sense of peace and calmness. They produce an effect that is similar to the effect of being out at the ocean and watching the waves.
Currently Feng Shui, the Chinese art of creating balanced and healthy living environments, has found acceptance in modern American interior design. They define rhythmically moving mobiles as Chi or energy generating. There is a need for mobiles that operate in pleasing rhythmical ways and that therefore align with Feng Shui's ideas of rhythmical movement of objects and things hanging to create healthier and happier living space.
U.S. Pat. No. 6,832,944 is for a motor driven helix-shaped mobile, commonly marketed under the name Dancing Helix®, having parallel ribs aligned and clamped onto a vertical spine that functions as a slow-wave discrete-element torsional transmission line. The spine is attached to a motor which turns ON and OFF at variable intervals, causing the spine to twist, affecting an apparent spiral motion through the length of spine as the ribs rotate. The motor ON and OFF sequencing is set to coordinate with the length and material of the spine and the attached ribs and weights. In a typical operation for oscillatory motion, the motor is set to a 3 minute ON and 3 minute OFF 50% duty-cycle. Further, the motor includes a gear drive to lower the revolutions per minute of the motor so that the rotational speed of the mobile is at a pleasant speed. The mobile for battery operation typically is powered by 2 D batteries that have a one month battery life for typical operation.
Many other rotational mobiles are popular and have been available for years. The helix-shaped mobile in U.S. Design Pat. D505,639 entitled Kinetic Sculpture, the circular-shaped mobile in U.S. design Pat. D500,964 entitled Circular Shaped Kinetic Sculpture, the diamond-shaped mobile in U.S. Design Pat. D500,702 entitled Diamond Shaped Kinetic Sculpture, the helix-shaped mobile in U.S. design Pat. D497,833 entitled Kinetic Sculpture and in the helix-shaped mobile in U.S. design Pat. D487,034 entitled Kinetic Sculpture are typical. These mobiles are kinetic when powered by wind in a windy location. However, for still-air indoor use they are static and do not move. The helix-shaped mobile of U.S. Design Pat. D497,833 for example, operates in the wind with the inner and outer mobiles rotating in opposite directions under wind power. Such mobiles, however, are not designed to reverse direction and do not oscillate when driven indoors by conventional rotary motors.
While there have been many mobiles produced, there is a need for improved drive units for driving dynamic mobiles resulting in mobile apparatus that are both pleasing and interesting while reducing power consumption when driven by battery power.

SUMMARY OF THE INVENTION

The present invention is a drive unit for driving a mobile assembly where the mobile assembly includes a mobile and includes a rotational coupling unit for storing and delivering energy to the mobile. The mobile assembly has an oscillating period with rotation in a first direction (for example clockwise) followed by rotation in a second direction (for example counter-clockwise). The drive unit includes a motor for connecting to the mobile assembly, a power unit supplying electrical power, a motor driver for providing power from the power source to the motor and a control unit for controlling the motor driver to provide drive pulses to the motor with a duty-cycle and with a drive-pulse period tailored for the mobile assembly.
In the present invention, the drive unit converts electrical energy into motion of the mobile assembly. The power unit in one embodiment is a battery. The coupling unit is an elastomer, spring or other flexible material for storing and releasing energy and for suspending the mobile from the drive unit. The drive unit period is ON in order to store rotational energy into the coupling unit and to drive the mobile and is OFF in order to allow rotational energy stored in the flexible coupling unit to drive the suspended mobile. The suspended mobile oscillates with rotation alternately in a first direction followed by rotation in a second direction.
The coupling unit functions as a speed changer where the higher rotational speed of the motor is reduced by the coupling unit to a lower rotational speed of the mobile without need for speed reducing gears.
In an embodiment where the power unit is a battery, the drive unit operates with low duty-cycle drive pulses to conserve energy and hence produce long battery life.
The rotation of the coupling unit is determined by the coactions of the drive unit and the suspended mobile. A rotational drive pulse from the drive unit causes the motor to transfer energy to or from the coupling unit. Also, the momentum of the suspended mobile results in the transfer of energy to or from the coupling unit. The mobile assembly, including the mobile and the coupling unit, exhibits oscillating periods. The drive pulses from the drive unit are tailored for the mobile assembly. The tailoring is done so that the observation period by human observers is a pleasant experience. If the observation period is between a few seconds and five minutes, then several oscillations over the observation period are desirable.
In one preferred embodiment where the mobile assembly has a one-cycle response period in response to a pulse from the drive unit, the drive-pulse period, measured as the period between drive pulses from the drive unit, is tailored to be greater than the one-cycle response period of the mobile assembly.
In one preferred embodiment, low duty-cycle drive pulses from the motor driver have drive-pulse periods that are one or more times longer than the oscillating periods of the mobile assembly.
In one preferred embodiment, the drive-pulse period, measured as the period between drive pulses from the drive unit, is tailored to cause oscillation of the mobile assembly.
The foregoing and other objects, features and advantages of the invention will be apparent from the following detailed description in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a schematic block diagram of a mobile apparatus including a drive unit for driving a mobile assembly where the mobile assembly includes a dynamic coupling unit attached to a mobile.

FIG. 2 depicts a graph of one embodiment of the ON/OFF timing of the drive unit of FIG. 1.

FIG. 3 depicts a graph of the energy storage in one embodiment of a dynamic coupling unit of FIG. 1.

FIG. 4 depicts a mobile apparatus with a drive unit driving two nested mobile assemblies, each assembly having a coupling unit and a mobile.

FIG. 5 depicts the drive unit of FIG. 4 with one mobile element rotating in one direction and the other mobile element rotating in the opposite direction.

FIG. 6 depicts a mobile apparatus with a drive unit driving two vertically cascaded mobile assemblies, each assembly having a coupling unit and a mobile.

FIG. 7 is a schematic representation of a series connection of a plurality of cascaded mobile assemblies.

FIG. 8 is a schematic representation of a series connection of a plurality of nested and cascaded mobile assemblies and mobile apparatus.

FIG. 9 is a front view of a mobile apparatus with a 28-rib slow-wave discrete-element torsional transmission line mobile in a stationary position with the drive unit OFF.

FIG. 10 is a front view of the drive unit of FIG. 9 with the mobile in a moved position when the drive unit is ON.

FIG. 11 depicts a schematic block diagram of a drive unit employing an analog control unit.

FIG. 12 depicts a schematic block diagram of a drive unit employing a digital control unit for driving in one direction.

FIG. 13 depicts a schematic block diagram of a drive unit employing a digital control unit for driving in two directions.

FIG. 14 depicts a graph depicting the one cycle impulse response of the outer assembly and of the inner assembly of FIG. 4.

FIG. 15 depicts a graph of the interactive response of the outer assembly and the inner assembly of FIG. 4 for three successive drive pulses from the motor.

FIG. 16 depicts an alternate drive-pulse pattern for the drive unit of FIG. 1.

FIG. 17 depicts another alternate drive-pulse pattern for the drive unit of FIG. 1.

DETAILED DESCRIPTION

In FIG. 1, a motorized oscillating mobile apparatus 33 includes a drive unit 2 that drives a mobile assembly 30 including a dynamic coupling unit 31 and a mobile 10. The mobile 10 is intended to be an artistic object that attracts attention and is pleasing to watch, particularly when moving. In one preferred embodiment, the drive unit 2 includes a low duty-cycle impulse motor 43 having a short ON drive period and a long OFF non-drive period whereby the amount of energy utilized to drive the mobile 10 is conserved. Typically, the motor 43 operates on conventional size batteries such as two C batteries. During the ON period, a drive pulse from the drive unit 2 rotationally drives the dynamic coupling unit 31 in one direction and causes the coupling unit 31 to wind and to store energy from the drive pulse. The dynamic coupling unit 31 thereafter supplies energy by unwinding and rotationally driving the mobile 10. The momentum of the mobile 10 continues the rotation until the dynamic coupling unit 31 becomes wound in the opposite direction. When fully wound in the opposite direction until the mobile 10 stops, the dynamic coupling unit 31 reverses direction and unwinds, again driving the rotation of the mobile 10. The oscillation of the mobile 10 and the coupling unit 31 periodically continues back and forth in a first direction and in then in a second direction. The motor 43 periodically impulses energy into the mobile assembly 30.
In one preferred embodiment, the dynamic coupling unit 31 is a polyurethane or other elastomer cord, which “winds up” when rotated in one direction by the drive unit 2 or the mobile 10 and which “unwinds” when not driven to rotate the mobile 10. The rotation of the mobile 10 and the coupling unit 31 oscillates both in a positive rotation (+R), for example clockwise, and in a negative rotation (−R), for example counterclockwise. The motor 43 impulse period, the motor duty-cycle, the elasticity of the dynamic coupling unit 31 and the weight and dimensions of the mobile 10 interact to cause the mobile 10 to oscillate, rotating first in one direction and then to rotate in the opposite direction. During the operation, the mobile 10 repeatedly switches rotation direction where the frequency of switching rotational direction is pleasing to a viewer. Typically, the switching of direction occurs in less than a minute or so for viewing pleasure. However, any dynamic operation and any time period desired may be used.
With respect to the motor 43, the energy transferred to or from the coupling unit 31 is positive or negative in value as a function of the direction of rotation of the motor 43 during the ON pulse relative to the direction of the stored energy in the coupling unit 31. If the motor 43 rotates in the same direction as the stored potential energy in the coupling unit 31, the potential energy stored in the coupling unit 31 is increased (positive). If the motor 43 rotates in the opposite direction as the stored potential energy in the coupling unit 31, the potential energy stored in the coupling unit 31 is decreased (negative).
Similarly, the energy to or from the coupling unit 31 has a positive or negative effect as a function of the direction of rotation of the mobile 10 relative to the direction of the stored potential energy in the coupling unit 31. If the mobile 10 rotates in the same direction as the direction that created the stored potential energy in the coupling unit 31, the potential energy stored in the coupling unit 31 is increased (positive). If the mobile 10 rotates in the opposite direction as the direction that created the stored energy in the coupling unit 31, the potential energy stored in the coupling unit 31 is decreased (negative).
As the suspended mobile 10 rotates in one direction, comes to a stop and then rotates in the other direction, the coupling unit 31 stores rotational potential energy from the momentum of the mobile 10 and then converts the stored energy back into kinetic energy driving the mobile 10.
From time to time, the motor 43 is pulsed and energy is transferred to the mobile assembly 30. Depending upon the power of the drive motor, the duration of the drive motor pulse, the period between drive motor pulses, the mass and other parameters of the suspended mobile 10 and the elasticity of the coupling unit 31, the suspended mobile 10 will rotate back and forth through a varying number of degrees, anywhere from a partial revolution to multiple revolutions.
The period between drive motor pulses affects the kinetic effect of the forward and reverse rotational oscillations of the suspended mobile 10. Long periods between drive motor pulses allow the oscillations to decay substantially and thus produces one kinetic effect. Shorter periods between drive motor pulses will produce different kinetic effects as a function of when the motor pulses occur relative to the oscillation of the suspended mobile assembly 30. The coupling unit 31 functions as a speed changer where the higher rotational speed of the motor 43 is reduced by the coupling unit 31 to a lower rotational speed of the mobile 10 without need for speed reducing gears. The coupling unit 31 is silent and essentially frictionless in operation in contrast to speed reducing gears that tend to be noisy and have friction.
In operation, the suspended mobile 10 oscillates by rotating, first in one direction and then in the reverse direction, with steadily decaying amplitude. As the suspended mobile 10 first rotates in one direction and then the other direction, the flexible coupling unit 31 stores rotational potential energy and then converts the potential energy into rotational kinetic energy while the suspended mobile 10 rotates in one direction, stops and then rotates in the opposite direction.
Tailoring the period between drive motor pulses affects the kinetic effect of the forward and reverse rotational oscillation of the suspended mobile 10. Long periods which allow the oscillation of the mobile 10 to decay substantially produce one kinetic effect. Shorter periods between drive motor pulses produce a different kinetic effect. Synchronizing the drive motor pulses with the rotational oscillation of the suspended mobile 10 produce still a different kinetic effect.
The drive unit sends pulses to the drive motor 43 so as to transfer energy to the mobile assembly 30. The mobile assembly 30 has rotational periods. Bu controlling the phase of the mobile assembly's rotational period, the drive motor's direction, the pulse of rotational energy from the motor 43 will either speed or slow the rotation of the mobile assembly 30. By controlling the timing of the motor pulse relative to the phase of the mobile assembly 30, different oscillating kinetic effects are established.
Reversing the rotation of drive motor 43 between forward and reverse directions produces still other kinetic effects. Depending upon the effect desired, the motor reversing is controlled to occur at selected times relative to the phase of the rotational oscillation of the mobile assembly 30.
By periodically pulsing the drive motor 43, the battery operated rotary drive unit can keep a large kinetic sculpture in constant motion for long time periods. In one embodiment of the invention, a four-foot plastic kinetic sculpture weighing 10 pounds was kept in constant motion for more than one year using 10 watt-hours of battery storage (for example, 4 AA alkaline batteries).
In the present invention, the motor 43 is any type of motor that is capable of rotating a shaft connected to the coupling unit 31. For example, “DC motors”, “AC motors” and “stepper motors” are used together with appropriate drive circuits and configurations for such motors. Also, the motors include gearing or other mechanisms for satisfying power and speed requirements. While DC motors have been described in certain embodiments, the invention applies to any type of motor.
In FIG. 2, a timing diagram for the drive unit 2 of FIG. 1 is shown. For the FIG. 2 timing diagram, drive unit 2 is an impulse motor with a T_ONperiod and a T_OFFperiod forming a whole period T. Typically, T_ONis small compared with T_OFF, for example, 1 second and 60 second, respectively. With such timing, the drive unit 2 has a small duty-cycle of 1/60 or about 1.67%. Accordingly, with such a small duty-cycle, the battery life of drive unit 2 is very high. For example, the battery life of the 50% duty-cycle motor of U.S. Pat. No. 6,832,944 has been found to be from 1 to 2 months and a battery life for a 1.67% duty-cycle motor is approximately 30 times longer, that is, from 30 to 60 months. While differences in power requirements may change the battery life depending on the weight of the mobile and other parameters, none-the-less the low duty-cycle motor has a much longer battery life which, in general, is substantially longer than 12 months and will often exceed 24 months depending on the mobile.
In FIG. 3, a graph is shown depicting the rotation of the coupling element 31 in response to being driven by drive unit 2 of FIG. 1 with the driving pulse of FIG. 2. The ON pulse starts at t0 and continues for 1 second until t1. The ON pulse between t0 and t1 winds the coupling element 31 by rotation of drive shaft 2-1 a number of turns as a function of the speed of the drive unit 2 and starts the mobile rotating in a first direction. For an 8 revolutions per second drive unit 2, a 1 second pulse winds the coupling element approximately 8 turns. When the drive unit 2 is OFF at t1 and drive shaft 2-1 is held stationary, the coupling element begins to unwind and continues to drive the mobile in the same first direction. At about t2, the coupling element is unwound to its starting state and continues winding in the same first direction as the result of the momentum force of the mobile 10 until fully counter-wound at t3. At t3, the coupling element begins to unwind and drives the mobile in the opposite second direction. At about t4, the coupling element is again unwound to its starting state and continues winding in the same second direction until fully wound at t5. At t5, the coupling element begins to unwind and drives the mobile in the first direction. At about t6, the coupling element is unwound to its starting state and continues winding in the first direction until fully counter-wound at t7. At t7, the coupling element begins to unwind and drives the mobile in the second direction. At about t8, the coupling element is unwound to its starting state and continues winding in the second direction until fully wound at t9. At t9, the coupling element begins to unwind in the first direction until at t10, a new drive pulse from the motor fully winds the coupling element at t11 and the oscillating process continues as before with added energy from the drive pulse between t10 and t11.
In FIG. 3, the coupling element 31 has oscillating periods with rotation in a first direction (for example clockwise) followed by rotation in a second direction (for example counter-clockwise). The periods shown are t1 to t5 and t5 to t9.
The drive unit 2 and mobile assembly 30 of FIG. 1 operate generally in the manner described in connection with FIG. 2 and FIG. 3 for many different types of mobiles. For each mobile 10, the motor parameters including drive-pulse duty-cycle and torque, and the coupling element 31 parameters, including elasticity, are tailored to achieve a pleasant oscillating operation.
In the present application, the term “one-cycle impulse response” for a mobile assembly means the response time for one cycle of a mobile assembly after the mobile assembly has been driven by a drive unit with a single drive pulse. Typically, the drive pulse has a short duration of, for example, one second. The “one-cycle impulse response” is the amount of time that elapses until the mobile assembly, including the mobile and coupling unit, has fully wound in a first direction to a momentary stop and then has fully unwound and wound in the opposite direction to a momentary stop. It has been observed that for small mobiles of less than approximately 24 inches in radial diameter, the appearance of the oscillations are pleasant when the “one-cycle impulse response” is less than five minutes. Typically, the “one-cycle impulse response” is less than one minute. When mobile assemblies are series or parallel connected, both for cascaded connections and nested connections, the mobile assemblies farther from the drive unit have a pleasant appearance when the “one-cycle impulse response” is different (typically greater) than for mobile assemblies closer to the drive unit. If the “one-cycle impulse responses” of connected mobile assemblies are substantially different, then the combined response of the connected mobile assemblies driven by a low duty-cycle drive unit tends to produce pleasant counter revolutions.
In FIG. 4 and FIG. 5, a motorized oscillating mobile apparatus 33 includes a first outer mobile assembly 30-1 and a second inner mobile assembly 30-2 series connected with assembly 30-2 nested within mobile assembly 30-1. The first outer mobile assembly 30-1 includes a mobile 10-1 having a design of the outer mobile of U.S. Pat. D497,833 and a first coupling element 31-1. The coupling element 31-1 connects between the drive shaft 2-1 of drive unit 2 and the mobile 10-1. The second inner mobile assembly 30-2 includes a mobile 10-2, like and smaller than mobile 10-1, having a second coupling element 31-2. The coupling element 31-2 is series connected between mobile 10-1 and the mobile 10-2. The assemblies 30-1 and 30-2 are series connected and different in a number of respects. Generally, the outer mobile 10-1 is heavier and larger than the inner mobile 10-2. Also, the coupling unit 31-1 has a greater turning resistance than the coupling unit 31-2 and requires a greater force to wind then the force required for winding the coupling unit 31-2.
The operation of the FIG. 4 motorized oscillating mobile apparatus 33 starts generally with the outer mobile assembly 30-1 operating as described in connection with FIG. 1 and FIG. 2. The inner mobile assembly 30-2 initially follows the outer mobile assembly 30-1. However, because the assemblies 30-1 and 30-2 are different, the motorized operation soon results in the mobile 10-1 having a rotation in the opposite direction as the rotation direction for mobile 10-2. The mobiles 10-1 and 10-2 reverse direction of rotation at different times so that at times the mobiles 10-1 and 10-2 are rotating in the same direction and at other times in opposite directions with periodic different times for switching direction.
In one specific implementation of the FIG. 4 motorized oscillating mobile apparatus 33, the outer mobile 10-1 is a 17 inch (43 cm) kinetic helix-shaped sculpture and the inner mobile is a 14 inch (36 cm) kinetic helix-shaped sculpture of the U.S. Pat. D497,833 type. Each of the mobile assemblies 30-1 and 30-2 of FIG. 4 are the same as described in connection with FIG. 6 and have the same impulse responses. The dynamic appearance of the mobile apparatus 33 of FIG. 4 is the same as the dynamic appearance of the mobile apparatus 33 of FIG. 6, except that FIG. 6 is cascaded and FIG. 4 is nested.
The operation of the FIG. 4 and FIG. 5 motorized oscillating mobile apparatus 33 starts with the outer mobile assembly 30-1 operating as described in connection with FIG. 1 and FIG. 2. The inner mobile assembly 30-2 initially follows the outer mobile assembly 30-1. However, because the assemblies 30-1 and 30-2 are different in weight, diameter and elasticity of the coupling element and produce different amounts of momentum, the motorized operation soon results in the mobile 10-1 having a rotation in the opposite direction as the rotation for mobile 10-2. The mobiles 10-1 and 10-2 reverse direction of rotation at different times so that at times the mobiles 10-1 and 10-2 are rotating in the same direction and at other times in opposite directions with each having periodic different times for switching direction.
In FIG. 6, a motorized oscillating mobile apparatus 33 includes a first top mobile assembly 30-1 connected in series and cascaded with a second mobile assembly 30-2. The mobile assembly 30-1 includes a mobile 10-1 having a design of U.S. Pat. D497,833 and a first coupling element 31-1 like described in FIG. 4. The coupling element 31-1 connects between the drive shaft 2-1 of drive unit 2 and the mobile 10-1. The second cascaded lower mobile assembly 30-2 includes a mobile 10-2 like mobile 10-1 and has a second coupling element 31-2. The coupling element 31-2 connects in series between mobile 10-1 and the mobile 10-2. The series connected and cascaded assemblies 30-1 and 30-2 are different in a number of respects. The coupling unit 31-1 is less elastic than the coupling unit 31-2 and requires a greater force to wind then the force required for the coupling unit 31-2.
The operation of the FIG. 6 motorized oscillating mobile apparatus 33 starts with the upper mobile assembly 30-1 operating as described in connection with FIG. 1 and FIG. 2. The lower mobile assembly 30-2 initially follows the upper mobile assembly 30-1. However, because the assemblies 30-1 and 30-2 are different with different once-cycle impulse responses and are connected in series, the motorized operation soon results in the mobile 10-1 having a rotation in the opposite direction as the rotation for mobile 10-2. The mobiles 10-1 and 10-2 reverse direction of rotation at different times so that at times the mobiles 10-1 and 10-2 are rotating in the same direction and at other times are rotating in opposite directions with periodic different times for switching direction of rotation.
In one specific implementation of the FIG. 6 motorized mobile assembly 30-1, the mobile 10-1 is a 17 inch (43 cm) kinetic helix-shaped sculpture of the U.S. Pat. D497,833 design. Such kinetic helix-shaped sculptures are available, for example, from Twirly Things (www.twirlythings.com) under the name, Double Cosmix™ Helix Copper 17″. The outer mobile 10-1 is made of sheet copper and measures approximately 17 inches (43 cm) in height and in diameter and weights approximately 300 grams. The inner mobile 10-2 is another kinetic helix-shaped sculpture made of sheet copper and measures approximately 14 inches (36 cm) in height and in diameter and weights approximately 100 grams. The coupling element 31-1 is a 1.5 mm stretchy polyurethane cord. The cord for coupling element 31-1 is tied or otherwise fastened into an elongated loop where each of the two sides of the loop has a 1.5 mm diameter and has a length of approximately 2.5 inches (6.4 cm). The polyurethane cord of coupling element 31-1 loops at one end around a hook 5-1 of motor shaft 2-1 and loops at the other end around a hook 5-2 rigidly affixed to mobile 10-1. The coupling element 31-2 is a 0.7 mm polyurethane cord. The cord for coupling element 31-2 is tied or otherwise fastened into an elongated loop where each of the two sides of the loop has a 0.7 mm diameter and has a length of approximately 1 inch (2.54 cm). The polyurethane cord of coupling element 31-2 loops at one end around an inner hook (not shown) of outer mobile 10-1 and loops at the other end around a hook 5-3 rigidly affixed to mobile 10-2.
The stretchy cord used for the coupling elements 31-1 and 31-2 and in other embodiments of coupling units 31 is available as polyurethane elastic beading cord from numerous sources including Pepperell Braiding Company, Inc. (www.pepperell.com) which manufactures and sells polyurethane elastic cord in various diameters. The cords are sold under the trade mark Stretch Magic®.
In the FIG. 6 example described, an drive pulse of 2 seconds from a 1.92 revolution/second motor, resulted in a 34 second impulse response for the 17 inch kinetic helix-shaped mobile assembly 30-1. An drive pulse of 2 seconds from a 1.92 revolution/second motor, resulted in a 46 second impulse response for the 14 inch kinetic helix-shaped mobile assembly 30-2.
FIG. 7 is a schematic representation of a motorized oscillating mobile apparatus 33 including a series connection of a plurality of cascaded mobile assemblies 30-1, . . . , 30-p including the coupling units 31-1, . . . , 31-p, respectively, and the mobiles 10-1, . . . 10-p, respectively. Additionally, in FIG. 7, any one or more of the mobile assemblies 30-1, . . . , 30-p may include other nested mobile assemblies (not shown). In FIG. 7 all of the mobile assemblies 30-1, . . . , 30-p are series connected with the drive unit 2.
FIG. 8 is a schematic representation of motorized oscillating mobile apparatus 33-1. , , , . 33-Z. The mobile apparatus 33-1 includes a series connection of a plurality of nested mobile assemblies 30-1, . . . , 30- n 1, . . . , 30- m 1 operating together with cascaded mobile assemblies 30-1, . . . , 30-p. Each mobile assembly includes a mobile (10-1, . . . , 10- n 1, , , , ) and a coupling unit (31-1, . . . , 31- n 1, . . . ). The mobile assembly 30- n 1 includes a mobile apparatus 33-2 nested within the mobile 10- n 1. The mobile apparatus 33-1 is series connected with one or more mobile apparatus including mobile apparatus 33-Z. In FIG. 8 all of the mobile assemblies 30-1, . . . , 30- n 1, . . . , 30- m 1 are series connected with the drive unit 2-1. However, the mobile assembly 30-p is parallel connected with mobile 30- n 1 and mobile assemblies such as mobile assembly 30- m 1 series connected with mobile 30- n 1. FIG. 8 is schematic and indicates that any series and parallel combination of cascaded and nested mobile assemblies and mobile apparatus is possible in addition to the combination explicitly shown.
FIG. 8 is a multiple drive unit mobile apparatus including one or more drive units (2-1, . . . , 2-Z) for driving one or more mobile assemblies (30-1, . . . , 30- n 1, . . . , 30- m 1 and 30-1, 30-p) where each mobile assembly includes a mobile (10-1, . . . , 10- n 1, , , , ) and a rotational coupling unit (31-1, . . . , 31- n 1, . . . ) for storing and transferring energy to and from the mobile. In FIG. 8, each of said drive units (2-1, . . . , 2-Z, . . . ) includes a motor (41 see FIG. 1) for connecting to the one or more mobile assemblies, a power source (40 see FIG. 1), a motor driver (42 see FIG. 1) for providing power from the power source to the motor, a control unit (41 see FIG. 1) for controlling the motor driver to provide drive pulses to the motor with a drive-pulse duty cycle and a drive-pulse period tailored for one or more of the mobile assemblies causing the one or more mobiles to rotate with mobile rotational speeds. The one or more control units control the one or more motor drive units to rotate the one or more coupling units with motor drive speeds where the motor drive speeds are greater than the mobile rotational speeds whereby the one or more coupling units function as speed changers.
FIG. 9 and FIG. 10 depict a motorized oscillating mobile apparatus 33 that includes a mobile assembly 30 where the kinetic-helix mobile 10 is of the type described in U.S. Pat. No. 6,832,944 and marketed under the name Dancing Helix®. The kinetic-helix mobile 10 in operation forms a three-dimensional, rotating and counter-rotating (clockwise and counter-clockwise) helix formed by a slow-wave discrete-element torsional transmission line. The coupling unit 31 in FIG. 9 and FIG. 10 is combined with the slow-wave discrete-element torsional transmission line 3 of U.S. Pat. No. 6,832,944 to form the mobile assembly 30. The number of ribs attached to the spine 1 and the distance between ribs in mobile 10 can vary and these variations will affect the over all length of the mobile. Mobile lengths are typically from 3 to 15 feet, but mobiles of 30 feet or more are possible. One requirement is that the spine 1 be strong enough to support the weight of the ribs while being elastic enough to allow rotation of the spine by the ribs. The rotational period of the mobile 10 is much longer than the period of the coupling device 31 since the elasticity of the coupling device 31 is much greater than the elasticity of the spine of the mobile 10.
In the present application, the term “one-cycle impulse response” for a kinetic-helix mobile 10 means the response time for one cycle of the mobile (without coupling element) after the mobile has been driven by a drive unit with a single drive pulse. Typically, the drive pulse has a short duration of, for example, one second. The “one-cycle impulse response” is the amount of time that elapses until the mobile has fully wound in a first direction to a momentary stop and then has fully unwound and wound in the opposite direction to a momentary stop.
In one embodiment, the rotational speed of mobile 10 is generally within a range of from 5 to 30 rpm with between 16 to 20 rpm being optimum for 11 inch ribs. For longer ribs, the speed tends to be slower, for example, a 21 inch rib can use a speed of 8 rpm. The longer the rib, the faster the speed of a bead or other rib weight at the end of a rib and hence the greater the momentum and the torsion forces on the spine 1.
The speed of the drive unit 2 in one embodiment is 8 revolutions per second and hence is much faster than the targeted speed of from 16 to 20 rpm for mobile 10. The drive unit 2 with its higher speed stores energy into the coupling unit 31 of FIG. 9 and FIG. 10 using a sufficient number of pulses to supply energy into coupling unit 31 to achieve the desired rotational speed and appearance of mobile 10.
In FIG. 10, a frontal view of the 28-rib embodiment of mobile 10 in FIG. 9 is shown in a moving position with the drive unit 2 having been ON to energize the coupling unit 31. The FIG. 10 view is a snapshot in an instant of time since the mobile 10 is in continuous rotation. The ribs 3 ₁, 3 ₂, . . . , 3 ₂₈and the rib weights 4 _1L, 4 _2L, . . . , 4 _28Land the rib weights 4 _1R, 4 _2R, . . . , 4 _28Lhave been rotated on spine 1. The shape formed for each of the rib weights 4 _1L, 4 _2L, . . . , 4 _28Lis that of a helix and the shape formed for each of the rib weights 4 _1R, 4 _2R, . . . , 4 _28Rso that together a dynamic three-dimensional helix is formed.
The impulse response of a typical 28 rib kinetic-helix mobile 10 is approximately 24 seconds. In response to an drive pulse from a motor (ON for about 1 second) a traveling wave propagates down the spine rotating the ribs and winding the spine until the ribs stop. Then, the traveling wave propagates up the spine rotating the ribs in the opposite direction as the spine unwinds until again the spine is stopped. The complete downward and upward propagation is the impulse response of the mobile and, in the example described, is approximately 24 seconds.
In one embodiment, the coupling unit 31 used with the kinetic-helix mobile 10 is 5 inch (12.7 cm) 1.5 mm polyurethane elastic cord. Together, the mobile assembly formed of the combined coupling unit 31 and the kinetic-helix mobile 10 is 32 seconds for downward propagation and 31 seconds for upward propagation for a total impulse response of 63 seconds.
A number of different mobile assemblies have been described in both series and parallel connected combinations in the present specification. Of course, many different other series and parallel combinations are possible and can be employed.
FIG. 11 depicts a schematic block diagram of a drive unit 2 for use with the mobile assembly 30 of FIG. 1 to form a mobile apparatus 33 of FIG. 1. The drive unit 2 of FIG. 11 employs an analog control unit 41. The drive unit 2 includes a DC motor 43 and a motor driver 42. A power unit 40 supplies power to the control unit 41 and motor driver 42. Control unit 41 and motor driver 42 control the electrical current to motor 43. For power units 40 that are battery implemented, control unit 41 controls motor 43 for low duty-cycle operation with a short ON drive period and a long OFF non-drive period whereby the amount of energy utilized to drive the motor 43 is conserved.
For FIG. 11, typical component values are set forth in the following TABLE 1.

TABLE 1

B	Battery	3–6 volts
SW1	ON/OFF Switch
R1, R4	1M Ω Resistor
R2–R3	1K Ω Resistor
C1
47 μF Capacitor
D1	1N5817 Schottky Diode
D2	1N4148 Fast Diode
Q1	BCV27 NPN Transistor
Q2–Q6	CD4007UB Dual Complementary Pair Plus Inverter

In FIG. 11, the operation of drive unit 2 is as follows. Switch SW1 is a toggle switch which remains OPEN or CLOSED until toggled to the other state by a user. When switch SW1 is OPEN for a long period, transistor Q2 is in a conducting state and capacitor C1 is discharged and no power is delivered to the motor 43.
When switch SW1 is CLOSED, the voltage from battery B is applied to motor 43 in pulses controlled by the control unit 41. The timing circuit of control unit 41 alternates between two different metastable states, one long and one short. During the short state C1 is charged quickly, from near 0V to about 2.5V, by current flowing mainly through R2 and D1. At that time, Q2 switches ON, reversing the states of the two CMOS inverters (Q3/Q4 and Q5/Q6). At that time, C1 begins discharging, much more slowly, through R1, from battery voltage down to about 2.5V. At that time, Q2 turns OFF and the cycle is repeated. During the time that C1 is charging, R3 conducts current into the base of Q1 which will in turn conduct battery current through the collector-emitter switch connection of Q1 in series with the motor for conducting current through the motor 43, driving it in one direction. During the time C1 is discharging, the voltage on R3 is near zero and the base of Q1 inhibits collector-emitter switch conduction of Q1 and therefore the motor 43 will be OFF. Providing R1 is much larger than R2, the motor 43 ON time is controlled by the resistor and capacitor timing circuit formed by the combination R2 and C1. The motor 43 OFF time is controlled by the resistor and capacitor timing circuit formed by the combination R1 and C1. The diode D2 is an optional protective rectifier diode connected in parallel with the inductive load represented by the motor 43. D1 safely dissipates stored inductive energy whenever the motor 43 is switched OFF.
FIG. 12 depicts a schematic block diagram of a drive unit 2 for use with the mobile assembly 30 of FIG. 1 to form a mobile apparatus 33 of FIG. 1. The drive unit 2 of FIG. 12 employs a digital control unit 41. The drive unit 2 includes a DC motor 43 and a motor driver 42. A power unit 40 supplies power to the control unit 41 and motor driver 42. Control unit 41 and motor driver 42 control the electrical current to motor 43. For power units 40 that are battery implemented, control unit 41 controls motor 43 for low duty-cycle operation with a short ON drive period and a long OFF non-drive period whereby the amount of energy utilized to drive the motor 43 is conserved.
For FIG. 12, typical component values are set forth in the following TABLE 2.

	TABLE 2

	B	Battery 4.5 volts
	SW1	Momentary ON/OFF Switch
	R1	22K Ω Resistor
	R2–R3	1K Ω Resistor
	R4
	1 Ω Resistor
	D1	LED
	D2	1N4148 High Conductance Fast Diode
	Q1	BCV27 NPN Darlington Transistors
	U1	ATtiny15L 8-bit Microcontroller

In FIG. 12, the operation is as follows. The interface unit 41-1 includes a momentary contact switch SW1 for actuation by a user. When switch SW1 is momentarily toggled, microcontroller U1 is switched to one of one or more modes of operation. A typical mode is for low duty-cycle of operation.
In FIG. 12, the ON time and the OFF time are controlled by the PB4 output from microcontroller U1. The PB4 output connects through current limiting resistor R3 to the control base of transistor Q1. During the ON time, the transistor Q1 is held to a conducting state by the PB4 output thus allowing the motor to have drive current. The drive current results from the voltage of battery B applied across motor 43, conducting transistor Q1 and sense resistor R4. The drive current drives motor 43 in one direction. During the OFF time, the transistor Q1 is held non-conducting by the PB4 output thus preventing any motor drive current, the diode D2 is an optional protective rectifier diode connected in parallel with the inductive load represented by the motor 43. D1 safely dissipates stored inductive energy whenever the motor 43 is switched OFF.
The resistor R4 is a current sensor that provides an analog input to the PB3 pin of microcontroller U1. The voltage on the PB3 pin from the resistor R4 is proportional to the instantaneous current through motor 43. The current sensing function is optional. By monitoring the instantaneous current of DC motor 43, the microcontroller U1 determines how much potential energy has been transferred by the drive unit 2 to the mobile assembly 30 (see FIG. 1). The current sensor is also used in some embodiments to detect if DC motor 43 is stalled and to detect when the DC motor 43 begins to rotate. Further, the current sensor is used in some embodiments to count the number of times the DC motor has rotated. By using a current sensor, the logic/timer unit 41-2 in some modes automatically adapts to changing conditions. For example, the changing conditions include varying battery voltages and mobile assemblies of different sizes (different masses).
In FIG. 12, the resistor R1 provides an inverted input to the inverted RST pin of microcontroller U1 for resetting microcontroller U1. When power from battery B is first applied to U1 the low logic level on the inverted RST pin causes all the internal circuitry in U1 to be reset. After a short period of time R1 conducts battery B voltage to the inverted RST pin, ending the reset period. At that point U1 begins to execute its stored program.
In FIG. 12, the interface unit 41 includes resistor R2 and light emitting diode (LED) D1 connected to the PB1 pin of microcontroller U1. The LED is used to signal a user as to the state or mode of drive unit 2. For example, no output indicates an OFF state, a slow BLINK indicates a normal drive mode, a fast blink indicates a more powerful drive mode and five rapid blinks with a long pause indicates a low battery condition.
FIG. 13 depicts a schematic block diagram of a forward and reverse drive unit 2 for use with the mobile assembly 30 of FIG. 1 to form a mobile apparatus 33 of FIG. 1. The drive unit 2 of FIG. 13 employs a digital control unit 41. The drive unit 2 includes a DC motor 43 and a motor driver 42. A power unit 40 supplies power to the control unit 41 and motor driver 42. Control unit 41 and motor driver 42 control the electrical current to motor 43 to drive motor 43 in forward or reverse directions. For power units 40 that are battery implemented, control unit 41 controls motor 43 for low duty-cycle operation with a short ON drive period and a long OFF non-drive period whereby the amount of energy utilized to drive the motor 43 is conserved.
For FIG. 13, typical component values are set forth in the following TABLE 3.

	TABLE 3

	B	Battery 4.5 volts
	SW1	Momentary ON/OFF Switch
	R1	22K Ω Resistor
	R2–R6	1K Ω Resistor
	D1	LED
	D2	1N4148 High Conductance Fast Diode
	Q1, Q2	BCV27 PNP Darlington Transistors
	Q3, Q4	BCV27 NPN Darlington Transistors
	U1	ATtiny15L 8-bit Microcontroller

In FIG. 13, the operation and configuration are as follows. The interface unit 41-1 includes a first function device F1 for providing inputs from a user. In the described embodiment, a momentary contact switch SW1 is an example of device F1. The switch SW1 is actuated by a user. When switch SW1 is momentarily toggled, microcontroller U1 is switched to one of one or more modes of operation. A typical mode is for low duty-cycle operation. The mode selection function F1, providing mode input control by a user, is implemented in many other ways. In other embodiments, keyed inputs (keypad, keyboard and other manually keyed devices), voice sensors, optical devices and other conventional input mechanisms are employed.
In FIG. 13, the ON time and the OFF time are controlled by the PB1, PB2, PB3 and PB4 outputs from microcontroller U1. The PB1, PB2, PB3 and PB4 outputs connect through current limiting resistors R6, R5, R4 and R3 to the control gates of transistors Q1, Q2, Q3 and Q4, respectively. During the ON time, for conduction in a first direction through motor 43, the collector-emitter switch connections of Q1 and Q4 are held conducting by PB1 and PB4 and the collector-emitter switch connections of Q2 and Q3 are held non-conducting by PB 2 and PB3. The drive current in the first direction results from the voltage of battery B applied across motor 43 and conducting transistors Q1 and Q4. During the ON time, for conduction in a second direction through motor 43, the collector-emitter switch connections of Q2 and Q3 are held conducting by PB2 and PB3 and the collector-emitter switch connections of Q1 and Q4 are held non-conducting by PB1 and PB4. The drive current in the second direction results from the voltage of battery B applied across motor 43 and conducting transistors Q2 and Q3. During the OFF time, all of transistors Q1, Q2, Q3 and Q4 are held non-conducting by the PB1, PB2, PB3 and PB4 outputs.
In FIG. 13, the interface unit 41 includes resistor R2 and light emitting diode (LED) D1 connected to the PB1 pin of microcontroller U1. The LED is used to signal a user as to the state or mode of drive unit 2 and is energized whenever PB1 is energized.
In alternate embodiments of FIG. 13, an expanded or larger microcontroller U1 x with more pins X3, X4, . . . , Xx, . . . , Xn is added to provide addition functions F3, F4, . . . , Fx, . . . , Fn.
In one alternate embodiment of FIG. 13, the current sensor function Fx is provided using 1Ω resistor Rx. The resistor Rx, like the resistor R4 in FIG. 12, is a current sensor that provides an input to the Xx pin of expanded microcontroller U1 x. The input to the Xx pin from the resistor Rx is proportional to the instantaneous current through motor 43. The current sensing function is optional and has the same functions as resistor R4 in FIG. 12.
In FIG. 13, the resistor R1 provides an inverted input to the inverted RST pin of microcontroller U1 for resetting microcontroller U1. When power from battery B is first applied to U1 the low logic level on the inverted RST pin causes all the internal circuitry in U1 to be reset. After a short period of time R1 conducts battery B voltage to the inverted RST pin, ending the reset period. At that point U1 begins to execute its stored program.
In FIG. 13, the display function F1 implemented by resistor R2 and light emitting diode (LED) D1 are connected to a different pin (not shown) than PB1 pin of microcontroller U1 x. In such case, the LED is used to signal a user as to the state or mode of drive unit 2 independently of the state of PB1. For example, a no output indicates an OFF state, a slow BLINK indicates a one direction drive mode, a fast blink indicates a two direction drive mode and five rapid blinks with a long pause indicate a low battery condition. The display function F1 is implemented in other embodiments as a digital display using any conventional digital output device.
In FIG. 13, an optional one of the functions F3, F4, . . . , Fn, for example F3, is an activity sensor. The activity sensor F3 detects the presence or absence of motion by persons and/or objects within proximity to the mobile apparatus. Typically, the activity sensor F3 is an infrared (or microwave) motion detector circuit. In one embodiment, the mobile apparatus remains powered OFF when no motion is detected. The activity sensor F3 is useful in situations where the mobile apparatus is installed in environments where motion of the mobile might set off an intrusion-detection alarm system operating with motion sensors.
In FIG. 13, an optional one of the functions F3, F4, . . . , Fn, for example F4, is a remote control device. The remote control device F4 is used to inhibit/enable operation of the mobile apparatus. Typically, the remote control device F4 receives signals from a hand-held infra-red (IR) or radio frequency (RF) remote transmitter. The remote control device F4 includes a compatible IR detector or RF receiver. The IR detector or RF receiver provides an input to the X4 pin of microcontroller U1 x and functions to toggle the motor driver ON and OFF. This feature is useful in situations where the present invention is installed in environments where the motion of the mobile might set off after-hour intrusion-detection alarm systems based on motion sensors.
In the several embodiments of FIG. 11, FIG. 12 and FIG. 13 the transistors Q1 through Q6 all function as ON/OFF switches. For bipolar transistors, the switch connection conduction path is the collector-emitter path and the control input is a base. For MOS transistors, the switch connection conduction path is the source-drain path and the control input is a gate. All of the ON/OFF switches described may be implemented using any type of transistor or semiconductor device such as NPN/PNP, nFET/pFET, jFET and SCR devices and may be implemented with any other technology including reed switches, relays and other well-known switching devices. Regardless of the particular technology, the ON/OFF switches have switch connections with ON states for conduction and OFF states for non-conduction controlled by control inputs for switching between the ON states and the OFF states.
In FIG. 14, the single-cycle impulse responses of the mobile assemblies 30-1 and 30-2 of FIG. 4 are shown. In particular, when the outer (O) mobile assembly 30-1, including coupling element 31-1 and mobile 10-1, without the mobile assembly 30-2 attached, is hung from the drive unit 2 and receives a 1 second drive pulse at 8 revolutions per second, the coupling element 31 -1 is completely wound (8 turns) to a fully-wound, momentarily-stopped position. In a response period of 30 seconds, the mobile assembly 30-1 unwinds to its initial position and thereafter fully winds in the opposite direction to a momentarily-stopped position at 60 seconds. The impulse response, I_O, of mobile assembly 30-1 is represented by the broken line in FIG. 14. Similarly, the impulse response, I_I, of mobile assembly 30-2 is represented by the solid line in FIG. 14. When the mobile assembly 30-2, including coupling element 31-2 and mobile 10-2, without being attached to the mobile assembly 30-1, is hung from the drive unit 2 and receives a 1 second drive pulse at 8 revolutions per second, the coupling element 31-2 completely winds from a rest position to a fully wound, momentarily stopped position. In a response period of 25 seconds, the mobile assembly 30-2 unwinds to its initial position and thereafter fully winds in the opposite direction to a momentarily-stopped position at 50 seconds.
In an example of the operation, a first one of the mobile assemblies rotates in a first direction during certain times and a second one of the mobile assemblies counter rotates in a second (opposite) direction during the same certain times. After a pleasant period, usually less than five minutes and typically less than one minute, counter oscillations occur with each of the mobile assemblies reversing direction. The times of reversal of direction are typically not synchronized so that the periods of counter revolution are of variable duration.
If the “one-cycle impulse response” of series connected mobile assemblies are substantially the same, then the combined response of the series connected mobile assemblies frequently does not produce pleasant counter oscillations, but rather, the series connected mobile assemblies for long durations appear to be synchronized and rotating in the same direction.
In FIG. 15, the combined responses of the mobile assemblies 30-1 and 30-2 of FIG. 4 are shown when driven by drive unit 2 having a 47 second period between 1 second drive pulses of 8 revolutions per second. With such a drive unit 2 operation, note that the outside mobile 10-1 reverses direction at about 25, 60 and 100 seconds. Similarly, the inside mobile reverses direction at 40, 90 and 120 seconds. Accordingly, the mobiles 10-1 and 10-2 are rotating in the same direction from 0 to 25 seconds, from 40 to 60 seconds and from 90 to 100 seconds while rotating in opposite directions from 25 to 40 seconds, from 60 to 90 seconds and so on.
The appropriate dynamic properties of the coupling units 31 in the various embodiments of the invention are most easily determined by experimentation although mathematical and engineering specification using well understood principles of physics may also be employed. The length of the cord, the diameter of the cord, the number of strands (one or more and in the loop embodiment, two), the elasticity of the polyurethane, the tensile strength of the cord and other factors vary the dynamic properties of the coupling units 31. Each of these variables may be modified to achieve the desired dynamic operation. Of course, elastomers other than polyurethane may be employed. In general, for multiple coupling units connected in series, the coupling units closest to the motor are stronger and more firm requiring a greater force to turn and have a shorter impulse response period than coupling units farther from the motor.
In FIG. 15, a timing diagram for the drive unit 2 of FIG. 1 is shown for operation with the mobile apparatus 33 of FIG. 4. For the FIG. 15 timing diagram, drive unit 2 is an impulse motor with TON small compared with T_OFF, for example, 1 second and 47 seconds, respectively. With such timing, the drive unit 2 has a small duty-cycle of 1/47 or about 2.1%. Accordingly, with such a small drive-pulse duty-cycle, the battery life of drive unit 2 is very high which, in general, is substantially longer than 12 months.
FIG. 16 depicts an alternate drive pulse pattern for the motor of FIG. 1. A sequence of five 1 second drive pulses is used over a 60 second drive-pulse period to deliver more power from a motor to a coupling element. The timing of each drive pulse and the drive-pulse period is readily controlled, for example, by changing the digital program in the microcontroller U1 and U1 x of FIG 13.
FIG. 17 depicts another alternate impulse pattern for the motor of FIG. 1 where different drive pulse widths are employed, where both positive and negative drive pulses are created at near random intervals. The timing of each drive pulse and the drive-pulse periods are readily controlled, for example, by changing the digital program in the microcontroller U1 and U1 x of FIG. 13. The positive and negative drive pulses of FIG. 17 rely on the ability to control motor current in two directions as described, for example, in connection with the motor driver 42 in FIG. 13.
While the invention has been particularly shown and described with reference to preferred embodiments thereof it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention.

Claims

1. A drive unit for driving one or more mobile assemblies where each mobile assembly includes a mobile and includes a rotational coupling unit for storing and transferring energy to and from the mobile and where each mobile assembly has an oscillating period, said drive unit comprising,

a motor for connecting to the one or more mobile assemblies,

a power source,

a motor driver for providing power from the power source to the motor,

a control unit for controlling the motor driver to provide drive pulses to the motor with a drive-pulse duty cycle and a drive-pulse period tailored for oscillating one or more of the mobile assemblies.

2. The drive unit of claim 1 wherein said motor is a DC motor.

3. The drive unit of claim 1 wherein said power source is a battery and said duty cycle is less than 20 percent.

4. The drive unit of claim 1 wherein the control unit controls said pulses for causing a first one of the mobile assemblies to rotate in a first direction during certain times and a second one of the mobile assemblies to counter rotate in a second direction during said certain times.

5. The drive unit of claim 1 wherein said control unit includes an analog logic and timer unit for controlling the drive-pulse duty cycle and the drive-pulse period.

6. The drive unit of claim 5 wherein said analog logic and timer unit includes,

a first resistor and capacitor timing circuit for controlling a control signal for an ON period and a second resistor and capacitor timing circuit for controlling the control signal for an OFF period,

an ON/OFF switch having a switch connection in series with said motor for controlling the current through said motor and having a control input for receiving the control signal to enable the current through the switch connection during the ON period and for inhibiting the current through the switch connection during the OFF period.

7. The drive unit of claim 1 wherein said control unit includes a digital logic and timer unit for controlling the drive-pulse duty cycle and the drive-pulse period.

8. The drive unit of claim 7 wherein said digital logic and timer unit is a programmable microcontroller having one or more digital outputs for controlling said motor driver.

9. The drive unit of claim 8 wherein said motor driver includes one or more ON/OFF switches having one or more switch connections in series with said motor for controlling the current through said motor and having one or more control inputs controlled by said one or more digital outputs.

10. The drive unit of claim 9 wherein said motor driver includes,

first and second ones of said ON/OFF switches having first and second ones of said switch connections in series with said motor for conducting current through said motor and having first and second ones of said control inputs controlled by first and second ones of said digital outputs for enabling or blocking the current through the motor in a first direction,

third and fourth ones of said ON/OFF switches having third and fourth ones of said switch connections in series with said motor for conducting current through said motor and having third and fourth ones of said control inputs controlled by third and fourth ones of said digital outputs for enabling or blocking the current through the motor in a second direction.

11. The drive unit of claim 1 wherein said control unit includes a programmable microcontroller as a digital logic and timer unit, said programmable microcontroller having one or more digital inputs for receiving input signals for controlling said motor driver.

12. The drive unit of claim 11 wherein said control unit includes an interface unit providing user input and outputs signals.

13. The drive unit of claim 11 wherein said motor driver includes a current sensor for providing a current sensing input to said programmable microcontroller.

14. The mobile apparatus of claim 1 wherein said control unit controls the motor drive unit to rotate the coupling unit with a motor driver speed where the motor drive speed is greater than the mobile rotational speed whereby the coupling unit functions as a speed changer.

15. A drive unit for driving a mobile assembly where the mobile assembly includes a mobile and includes a rotational coupling unit for suspending the mobile and for storing and transferring energy to and from the mobile, said drive unit comprising,

a motor for connecting to the coupling unit for rotationally driving the mobile assembly,

a battery power source,

a motor driver for providing power from the power source to the motor,

a control unit for controlling the motor driver to provide drive pulses to the motor with a drive-pulse duty cycle and a drive-pulse period causing the motor drive unit to rotate the coupling unit with a motor drive speed and causing the mobile to rotate with a mobile rotational speed where the motor drive speed is greater than the mobile rotational speed whereby the coupling unit functions as a speed changer.

16. The drive unit of claim 15 wherein said control unit includes an analog logic and timer unit for controlling the drive-pulse duty cycle and the drive-pulse period and wherein said analog logic and timer unit includes,

17. The drive unit of claim 15 wherein said control unit includes a digital logic and timer unit for controlling the drive-pulse duty cycle and the drive-pulse period and wherein said digital logic and timer unit is a programmable microcontroller having one or more digital outputs for controlling said motor driver.

18. The drive unit of claim 17 wherein said motor driver includes one or more ON/OFF switches having one or more switch connections in series with said motor for controlling the current through said motor and having one or more control inputs controlled by said one or more digital outputs for controlling ON and OFF states of the ON/OFF switches.

19. A mobile apparatus including one or more drive units for driving one or more mobile assemblies where each mobile assembly includes a mobile and includes a rotational coupling unit for storing and transferring energy to and from the mobile, each of said drive units comprising,

a motor for connecting to the one or more mobile assemblies,

a power source,

a motor driver for providing power from the power source to the motor,

a control unit for controlling the motor driver to provide drive pulses to the motor with a drive-pulse duty cycle and a drive-pulse period tailored for one or more of the mobile assemblies causing the one or more mobiles to rotate with mobile rotational speeds.

20. The mobile apparatus of claim 19 wherein one or more of said control units controls one or more motor drive units to rotate one or more coupling units with motor drive speeds where the motor drive speeds are greater than the mobile rotational speeds whereby one or more coupling units function as speed changers.