U.S. patent application number 11/541312 was filed with the patent office on 2008-04-17 for drive unit for mobile assembly.
This patent application is currently assigned to Dancing Helix LLC. Invention is credited to Bruce D. Lightner.
Application Number | 20080090488 11/541312 |
Document ID | / |
Family ID | 39303590 |
Filed Date | 2008-04-17 |
United States Patent
Application |
20080090488 |
Kind Code |
A1 |
Lightner; Bruce D. |
April 17, 2008 |
Drive unit for mobile assembly
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.
Inventors: |
Lightner; Bruce D.; (La
Jolla, CA) |
Correspondence
Address: |
DAVID E. LOVEJOY, REG. NO. 22,748
102 REED RANCH ROAD
TIBURON
CA
94920-2025
US
|
Assignee: |
Dancing Helix LLC
|
Family ID: |
39303590 |
Appl. No.: |
11/541312 |
Filed: |
September 29, 2006 |
Current U.S.
Class: |
446/236 |
Current CPC
Class: |
G09F 19/02 20130101 |
Class at
Publication: |
446/236 |
International
Class: |
A63H 1/00 20060101
A63H001/00 |
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, 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.
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.
Description
TECHNICAL FIELD
[0001] 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
[0002] 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.
[0003] 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.
[0004] U.S. Pat. No. 6,832,944 is for a motor driven helix-shaped
mobile, commonly marketed under the name Dancing Helix.RTM., 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.
[0005] 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.
[0006] 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
[0007] 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.
[0008] 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.
[0009] 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.
[0010] 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.
[0011] 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.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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
[0016] 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.
[0017] FIG. 2 depicts a graph of one embodiment of the ON/OFF
timing of the drive unit of FIG. 1.
[0018] FIG. 3 depicts a graph of the energy storage in one
embodiment of a dynamic coupling unit of FIG. 1.
[0019] FIG. 4 depicts a mobile apparatus with a drive unit driving
two nested mobile assemblies, each assembly having a coupling unit
and a mobile.
[0020] 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.
[0021] 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.
[0022] FIG. 7 is a schematic representation of a series connection
of a plurality of cascaded mobile assemblies.
[0023] FIG. 8 is a schematic representation of a series connection
of a plurality of nested and cascaded mobile assemblies and mobile
apparatus.
[0024] 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.
[0025] 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.
[0026] FIG. 11 depicts a schematic block diagram of a drive unit
employing an analog control unit.
[0027] FIG. 12 depicts a schematic block diagram of a drive unit
employing a digital control unit for driving in one direction.
[0028] FIG. 13 depicts a schematic block diagram of a drive unit
employing a digital control unit for driving in two directions.
[0029] FIG. 14 depicts a graph depicting the one cycle impulse
response of the outer assembly and of the inner assembly of FIG.
4.
[0030] 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.
[0031] FIG. 16 depicts an alternate drive-pulse pattern for the
drive unit of FIG. 1.
[0032] FIG. 17 depicts another alternate drive-pulse pattern for
the drive unit of FIG. 1.
DETAILED DESCRIPTION
[0033] 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.
[0034] 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.
[0035] 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).
[0036] 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).
[0037] 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.
[0038] 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.
[0039] 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.
[0040] 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.
[0041] 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.
[0042] 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.
[0043] 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.
[0044] 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).
[0045] 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.
[0046] 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.sub.ON period and a T.sub.OFF period forming a whole
period T. Typically, T.sub.ON is small compared with T.sub.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.
[0047] 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.
[0048] 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.
[0049] 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.
[0050] 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.
[0051] 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.
[0052] 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.
[0053] 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.
[0054] 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.
[0055] 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.
[0056] 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.
[0057] 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.TM. 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.
[0058] 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.RTM..
[0059] 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.
[0060] 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.
[0061] 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-n1, . . . , 30-m1
operating together with cascaded mobile assemblies 30-1, . . . ,
30-p. Each mobile assembly includes a mobile (10-1, . . . , 10-n1,
, , , ) and a coupling unit (31-1, . . . , 31-n1, . . . ). The
mobile assembly 30-n1 includes a mobile apparatus 33-2 nested
within the mobile 10-n1. 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-n1, . . . , 30-m1 are series connected with the drive unit
2-1. However, the mobile assembly 30-p is parallel connected with
mobile 30-n1 and mobile assemblies such as mobile assembly 30-m1
series connected with mobile 30-n1. 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.
[0062] 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-n1, . . . , 30-m1 and 30-1,
30-p) where each mobile assembly includes a mobile (10-1, . . . ,
10-n1, , , , ) and a rotational coupling unit (31-1, . . . , 31-n1,
. . . ) 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.
[0063] 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.RTM.. 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.
[0064] 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.
[0065] 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.
[0066] 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.
[0067] 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.sub.1, 3.sub.2, . . . , 3.sub.28
and the rib weights 4.sub.1L, 4.sub.2L, . . . , 4.sub.28L and the
rib weights 4.sub.1R, 4.sub.2R, . . . , 4.sub.28L have been rotated
on spine 1. The shape formed for each of the rib weights 4.sub.1L,
4.sub.2L, . . . , 4.sub.28L is that of a helix and the shape formed
for each of the rib weights 4.sub.1R, 4.sub.2R, . . . , 4.sub.28R
so that together a dynamic three-dimensional helix is formed.
[0068] 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.
[0069] 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.
[0070] 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.
[0071] 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.
[0072] For FIG. 11, typical component values are set forth in the
following TABLE 1.
TABLE-US-00001 TABLE 1 B Battery 3 6 volts SW1 ON/OFF Switch R1, R4
1M .OMEGA. Resistor R2 R3 1K .OMEGA. Resistor C1 47 .mu.F Capacitor
D1 1N5817 Schottky Diode D2 1N4148 Fast Diode Q1 BCV27 NPN
Transistor Q2 Q6 CD4007UB Dual Complementary Pair Plus Inverter
[0073] 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.
[0074] 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.
[0075] 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.
[0076] For FIG. 12, typical component values are set forth in the
following TABLE 2.
TABLE-US-00002 TABLE 2 B Battery 4.5 volts SW1 Momentary ON/OFF
Switch R1 22K .OMEGA. Resistor R2 R3 1K .OMEGA. Resistor R4 1
.OMEGA. Resistor D1 LED D2 1N4148 High Conductance Fast Diode Q1
BCV27 NPN Darlington Transistors U1 ATtiny15L 8-bit
Microcontroller
[0077] 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.
[0078] 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.
[0079] 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).
[0080] 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.
[0081] 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.
[0082] 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.
[0083] For FIG. 13, typical component values are set forth in the
following TABLE 3.
TABLE-US-00003 TABLE 3 B Battery 4.5 volts SW1 Momentary ON/OFF
Switch R1 22K .OMEGA. Resistor R2 R6 1K .OMEGA. 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
[0084] 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.
[0085] 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.
[0086] 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.
[0087] In alternate embodiments of FIG. 13, an expanded or larger
microcontroller U1x with more pins X3, X4, . . . , Xx, . . . , Xn
is added to provide addition functions F3, F4, . . . , Fx, . . . ,
Fn.
[0088] In one alternate embodiment of FIG. 13, the current sensor
function Fx is provided using 1.OMEGA. 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 U1x.
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.
[0089] 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.
[0090] 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 U1x. 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.
[0091] 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.
[0092] 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 U1x 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.
[0093] 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.
[0094] 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.sub.O, of mobile assembly 30-1 is represented
by the broken line in FIG. 14. Similarly, the impulse response,
I.sub.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.
[0095] 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.
[0096] 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.
[0097] 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.
[0098] 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.
[0099] 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.sub.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.
[0100] 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 U1x of FIG
13.
[0101] 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 U1x 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.
[0102] 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.
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