U.S. patent application number 10/894136 was filed with the patent office on 2005-02-10 for asymmetric drive motor for a barrier operator or the like.
This patent application is currently assigned to The Chamberlain Group, Inc.. Invention is credited to Fitzgibbon, James J., Laird, Edward T..
Application Number | 20050029974 10/894136 |
Document ID | / |
Family ID | 28040132 |
Filed Date | 2005-02-10 |
United States Patent
Application |
20050029974 |
Kind Code |
A1 |
Fitzgibbon, James J. ; et
al. |
February 10, 2005 |
Asymmetric drive motor for a barrier operator or the like
Abstract
An asymmetrical drive motor and apparatus with the asymmetric
drive motor driving a barrier. The asymmetric drive motor drives
the barrier at different drive powers according to direction, time
of travel, safety requirements of speed. The drive power is
controlled by electrically changing the capacitance value for a
permanent split capacitor motor.
Inventors: |
Fitzgibbon, James J.;
(Batavia, IL) ; Laird, Edward T.; (Lombard,
IL) |
Correspondence
Address: |
FITCH EVEN TABIN AND FLANNERY
120 SOUTH LA SALLE STREET
SUITE 1600
CHICAGO
IL
60603-3406
US
|
Assignee: |
The Chamberlain Group, Inc.
|
Family ID: |
28040132 |
Appl. No.: |
10/894136 |
Filed: |
July 19, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10894136 |
Jul 19, 2004 |
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10373524 |
Feb 24, 2003 |
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6774594 |
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10373524 |
Feb 24, 2003 |
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10102122 |
Mar 20, 2002 |
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6777902 |
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Current U.S.
Class: |
318/280 ;
318/108 |
Current CPC
Class: |
H02P 25/04 20130101;
H02P 1/44 20130101; H02P 1/445 20130101; E05Y 2400/31 20130101;
H02P 25/24 20130101 |
Class at
Publication: |
318/280 ;
318/108 |
International
Class: |
H02P 001/00 |
Claims
1. A barrier movement arrangement comprising: a motor having a
first power output and a second power output, for moving a barrier
between open and closed positions; first apparatus for enabling the
first power output; second apparatus for enabling the second power
output, the second power output being greater than the first; and a
controller responsive to sensed barrier movement conditions for
controlling the first apparatus to enable the motor at the first
power output when predetermined conditions are sensed and for
controlling the second apparatus to enable the motor at the second
power output when predetermined other conditions are sensed.
2. A barrier movement arrangement in accordance with claim 1
comprising apparatus for sensing expected barrier movement
direction and wherein the controller responds to the sensed
condition that a barrier is to be moved toward the open position
for controlling the second apparatus to enable the motor at the
second power output.
3. A barrier movement arrangement according to claim 1 comprising
apparatus for sensing an expected direction of barrier movement and
wherein the controller responds to a sensed condition that the
barrier is to be moved toward the closed position for controlling
the first apparatus to enable the first power output to start and
move the door.
4. A barrier movement arrangement according to claim 1 comprising
the ability to sense obstructions to barrier movement wherein the
controller responds to sensed obstructions by reversing a direction
of travel of the barrier and by controlling the second apparatus to
enable the motor at the second power output.
5. A barrier movement arrangement according to claim 1 comprising
the ability to sense barrier movement speed after the motor has
been started and the controller responds to barrier movement speed
after the motor has been started to control the second apparatus to
enable the motor at the second power when the sensed barrier
movement speed is below a predetermined value.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is related to a movable barrier and
more particularly, to a motor for driving a movable barrier such as
a garage door.
[0003] 2. Background Description
[0004] Movable barrier operators and, more particularly, garage
door operators are well known and have become very sophisticated to
provide users with increased convenience and security. The amount
of drive power for such a barrier operator is usually selected
based on a trade off between the need for power to start and
continue the door's motion and the noise and vibration generated by
the motor, as well as the availability of electrical power.
Generally, it is desirable to have a higher power to open the door
due to ice and snow freezing the door down. Also, during safety
initiated operations larger amounts of power may be desired to
reverse or stop the barrier. A problem is. that a higher power
motor usually create larger levels of noise and vibration and
require more electrical power and thus, generate more heat to
operate for the same level of mechanical power.
[0005] For example, in a situation where the door has become
extremely heavy such as when the door's counter balance spring has
broken and the door is required to reverse, a low power motor which
is adequate to keep a door in motion may not have enough power to
overcome both the inertia of motion and the extreme weight of the
door. Typically, in selecting a drive motor for a barrier operator,
safety. takes precedence over noise and vibration or operational
electrical efficiency and, the motor is selected to open the garage
door in all situations.
[0006] By contrast selecting a high power motor allows the operator
to have S enough power to lift the door even when the door's spring
has broken. In this situation the high power operator has the
ability to open the door but is often more inefficient and has
higher levels of, noise and vibration.
[0007] The typical motor used in such a garage door operators is a
single phase motor. A single-phase motor may be classified as a
split phase motor, a permanent split capacitor (PSC) motor, a
capacitor start-induction run motor or a capacitor start-capacitor
run motor. Further, most single-phase induction motors require a
switching arrangement for starting the motor, e.g., switching start
windings, a start capacitor, a run capacitor or a combination
thereof, to assist the motor in reaching full speed. Capacitor
start motors have a start capacitor that is only used to start the
motor.
[0008] Thus, there is a need for a motor than can have higher power
during intervals that require it, yet switch to a lower power, to
reduce electrical power requirement and noise and vibration.
SUMMARY OF THE INVENTION
[0009] The present invention is an asymmetric drive motor and
apparatus with the asymmetric drive motor for opening and closing a
moveable barrier. The asymmetric drive motor may drive for example,
a garage door open at a first drive power and closed at a second
drive power. The first drive power is greater than the second drive
power. A motor control circuit receives control commands and
controls the motor to provide the first drive power if barrier is
being opened and at the second drive power if the barrier is being
closed.
[0010] Accordingly, the asymmetric motor of the present invention
has improved power control for selecting higher power or lower
power. Further, momentary application of higher power is available
if needed at the start of travel for example to overcome inertia or
ice that may have frozen the barrier shut. In emergency situations
such as when the barrier has encountered an object on closing
higher power is available to quickly open the barrier. Further, a
power can be adjusted in the motor depending on the load driven by
the motor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The foregoing and other objects, aspects and advantages will
be better understood from the following detailed preferred
embodiment description with reference to the drawings, in
which:
[0012] FIG. 1 shows an example of a movable barrier operator or
garage door operator (GDO) according to the present invention;
[0013] FIG. 2 shows a first preferred embodiment of asymmetric
drive motor according to the present invention, which acts as a
hybrid permanent split capacitor/capacitor start single phase motor
with more power in one direction than in an opposite direction;
[0014] FIG. 3 is a second preferred embodiment asymmetric drive
garage door motor which is substantially similar to the embodiment
of FIG. 2;
[0015] FIG. 4 is a third preferred embodiment asymmetric drive
motor substantially similar to the first two embodiments of FIGS. 2
and 3 with like elements labeled identically;
[0016] FIG. 5 is an example of a controller controlling an
asymmetric drive motor such as in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] Referring now to the drawings, and more particularly, FIG. 1
shows an example of a movable barrier operator or garage door
operator (GDO) according to the present invention, generally
referred to by numeral 100. The preferred GDO 100 includes a
preferred embodiment asymmetric drive motor 150 (FIG. 5) and a
control circuit 208 (FIG. 5) controlling GDO operation in a head
unit 102 that is mounted to the ceiling of a garage 104. A rail 106
extends from the head unit 102. A trolley 108 is releasably
attached to the rail 106 and includes an arm 110 extending to a
multiple paneled garage door 112 positioned for movement along a
pair of door rails 114 and 116. The GDO system 100 includes at
least one hand-held remote control transmitter unit 118 adapted to
send signals to an antenna 120 on the head unit 102. Signals from
the antenna 120 are provided to the control circuit in the head
unit 102. An external remote control pad 122 is positioned on the
outside of the garage and includes multiple buttons thereon for
communicating via radio frequency transmission with the control
circuit in the head unit 102. A wall switch module 124 is mounted
on a wall of the garage. The wall switch module 124 is a wired
remote control connected to the control circuit in the head unit
102 by a wire 126. The wall switch module 124 may include a light
switch 130, a lock switch 132 and a command switch 134. An optical
emitter 138, preferably emitting an infrared (IR) beam, is
connected via a power and signal line 140 to the control circuit in
the head unit 102. An optical detector 142, disposed opposite the
optical emitter 138 and receiving the IR beam, also is connected by
a wire 144 to the control circuit in the head unit 102. The optical
detectors 133 and 142 serve to sense if an obstruction is present
in the barrier opening.
[0018] FIG. 2 shows a first preferred embodiment of asymmetric
drive motor 150 according to the present invention, which acts a
hybrid permanent split capacitor/capacitor start single phase motor
with more or less drive power being selected by a controller of
head unit 102. The motor 150 includes two coils or windings 152,
154 in the stator. The common connection of the two windings 152
and 154 is connected to ground or a neutral reference voltage
terminal. Capacitor 158 is permanently connected across terminals
at the opposite ends of the two windings 152, 154. A second
capacitor 160 and parallel bleed resistor 162 are series connected
with a relay 164 across first capacitor 158. Line current is
provided through a light relay 166 to a direction relay 168 which
selectively passes line current directly to either side of
capacitor 158 and one of windings 152, 154. In this embodiment
providing line current to winding 152 drives the garage door
operator in the up direction. Down relay 170 passes line current to
the motor at winding 154 only when the motor is driving the garage
door down to close it.
[0019] When the garage door operator is activated to drive the door
down, e.g., by pressing a button on a remote; the control circuit
closes light relay 166; direction relay 168 remains in the position
shown of FIG. 2; down relay 170 is closed; and, higher power relay
164 remains in its open position as shown in FIG. 2. Alternating
line current is provided to coil 154 at capacitor 158. Capacitor
158 passes a current out of phase with the line current to coil
152. As a result, the motor 150 drives the garage door down at a
first drive power level, e.g., 1/2 horsepower (hp). When the garage
door operator is activated, again, the control circuit closes light
relay 166. However, direction relay 168 switches to the up
position, down relay 170 remains open as shown in FIG. 2 and high
power relay 164 is closed. Since directional relay is in the up
position, line current is provided to coil 152 at capacitor 158 and
capacitor 158 provides a current out of phase with the line current
to inductor 154. With higher power relay 164 closed, effectively,
capacitors 158 and 162 are in parallel to increase the drive power
of the motor, e.g., from 1/2 hp to 3/4 hp. Thus, the motor 150
drives the garage door open with 50% more power than is available
for driving the garage door closed.
[0020] The control circuit may be programmed to keep the high power
relay 164 closed for substantially the entire travel of the garage
door, keep the high power relay 164 closed for a period of time or,
as determined by the sensed speed of the motor 150. Thus, the high
power relay 164 may be closed for a period of time to initially
open the garage door. When the high power relay 164 opens, bleed
resistor 162 discharges any charge remaining on second capacitor
160. Alternately, the control circuit 200 (FIG. 5) which includes a
motor rotation sensor 226 may sense motor speed and keep the high
power relay closed when the door is opening and until the motor
reaches a pre-selected speed for a start capacitor-like operation.
Also, in emergency situations, e.g., when an object is encountered
by the closing garage door or an obstruction is sensed by optical
detectors the controller may reverse the travel of the door. At
such direction reversal the high power relay 164 is activated when
the motor 150 reverses to drive the motor at high power for opening
the garage door to recover from the emergency. In addition, the
high power relay 164 may be closed to recover from a falling door
situation, i.e., when the control circuit detects the door is
falling, the motor is activated to keep it from hitting the
floor.
[0021] FIG. 3 is a second preferred embodiment asymmetric drive
garage door motor 180 which is substantially similar to the
embodiment of FIG. 2. Accordingly, in FIG. 3 like elements are
labeled identically. In this embodiment the second capacitor 182
and parallel bleed resistor 184 are series connected with higher
power relay 186 across the direction relay 168 and down relay 170.
Since the higher power relay 186 is energized when the motor 180 is
raising the garage door, operation is substantially identical to
the above description for operation of the motor 150 of FIG. 2,
especially for lowering the garage door. When the door is closed
and a button on a remote is pressed to cause the control circuit to
activate the motor to open the door, the control circuit closes
light relay 166 and switches direction relay 168 in its up
position; down relay 170 remains open; and, high power relay 184 is
closed. Again, with both the high power relay 186 closed and the
direction relay 168 in its up position, the second capacitor 180 is
essentially in parallel with the first capacitor 158, boosting
power of the motor substantially as in the embodiment of FIG. 2.
When higher power relay 184 is opened, any remaining charge across
second capacitor 180 discharges through bleed resistor 182. With
this embodiment also, the higher power relay 184 may be closed then
opened again at the beginning of the opening door travel or during
an emergency situation. Alternately, higher power relay 184 may be
held on until the motor 180 reaches a selected minimum speed.
[0022] FIG. 4 is a third preferred embodiment asymmetric drive
motor 190 substantially similar to the first two embodiments of
FIGS. 2 and 3 with like elements to FIG. 2 labeled identically. In
this embodiment both the first capacitor 192 and the second
capacitor 160 are switched in by power relays 196 and 164,
respectively. Each capacitor 192, 160 has a parallel respective
bleed resistor 194, 162. Thus, this embodiment has three selectable
drive power levels determined by the first capacitor 192, the
second capacitor 160 and the sum of the two capacitors 160, 192.
The power level is selected by closing the appropriate one of power
relay 164, 196 or the combination thereof. This embodiment may
provide increased power on demand, e.g., selecting both capacitors
160, 192 when initially opening the garage door. Also, power can be
controlled and provided as needed, e.g., when one capacitor 160 or
192 is switched in and the control circuit detects that the garage
door is slowing down, the other capacitor 192, 160 may be switched
in or substituted to boost motor drive. In response to the
additional drive power, the drive motor 190 drives the door back to
the minimum speed and then reduces power by opening one of switches
164 and 192.
[0023] FIG. 5 is an example of a controller 200 controlling an
asymmetric drive motor 150 such as in FIG. 2. The controller 200 is
powered by a power supply 202 that converts alternating current
from an alternating current source, such as 110 volt AC, to
required levels of DC voltage. The controller 200 is mounted in the
head unit, e.g., head unit 102 of FIG. 1, with antenna 120 attached
to receiver 204 which is coupled via a line 206 to supply
demodulated digital signals to a microcontroller 208. The
microcontroller 208 is also coupled by a bus 210 to a non-volatile
memory 212, which stores user codes, and other digital data related
to the operation of the control unit 200. Emitter 138 and infrared
detector 142 form an obstacle detector 214 and power and signal
lines 140, 144 form an obstacle detector bus 216 connected to
microcontroller 208. The obstacle detector bus 218 includes lines
140 and 144. The wall switch module 124 is connected via wire 126
to the microcontroller 208. The microcontroller 208, in response to
switch closures and received codes, sends signals over a relay
logic line 220 to a relay logic module 222 connected to asymmetric
drive motor 150 which has a power take-off shaft (not shown) from
the rotor coupled to the transmission of the garage door operator
100 of FIG. 1. A tachometer 226 is coupled to the asymmetric drive
motor 150 and provides an RPM signal on a tachometer line 228 to
the microcontroller 208; the tachometer signal provides an
indication of the speed at which the door is being driven. The
apparatus also includes up and down limit switches 230,
respectively sensing when the door 112 is fully open or fully
closed. The limit switches 230 are connected to microcontroller 208
by leads 232. A light 234 is controlled by microcontroller 208
through logic module 222.
[0024] Accordingly, the asymmetric motor of the present invention
has improved power control for selecting higher power or lower
power depending on a direction of travel of the garage door.
Further, momentary application of higher power is available if
needed at the start of travel for example to overcome inertia or
ice that may have frozen the garage door shut. Higher power is
available in emergency situations such as when the door has
encountered an object on closing, higher power is available to
quickly open the door. Further, a power can be adjusted in the
motor depending on the load driven by the motor and depending on
the sensed speed of the motor. In the preceding embodiments the
switches for controlling motor activation are shown as relays. Such
relays may be replaced by other devices such as semiconductor
triacs in other embodiments.
[0025] The embodiments described include a motor having a pair of
windings with a neutral tap at a common winding terminal. The
control principles discussed herein are not limited to such a
winding configuration, but may apply to any motor configuration
capable of producing two or more levels of power output. For
example, but not by limitation, the motor could comprise multiple
serially energized windings which can be individually removed from
providing substantial motive force by switching arrangements such
as by shorting across the terminals of individual windings.
Further, the increase of power output as well as phase shifting
could be performed by reactive components other than capacitors,
such as inductors.
[0026] Having thus described preferred embodiments of the present
invention, various modifications and changes will occur to a person
skilled in the art without departing from the spirit and scope of
the invention. It is intended that all such variations and
modifications fall within the scope of the appended claims.
Examples and drawings are, accordingly, to be regarded as
illustrative rather than restrictive.
* * * * *