U.S. patent application number 15/930677 was filed with the patent office on 2020-08-27 for quiet motorized window treatment system.
This patent application is currently assigned to Lutron Technology Company LLC. The applicant listed for this patent is Lutron Technology Company LLC. Invention is credited to David A. Kirby, Robert C. Newman, JR..
Application Number | 20200270942 15/930677 |
Document ID | / |
Family ID | 1000004824298 |
Filed Date | 2020-08-27 |
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United States Patent
Application |
20200270942 |
Kind Code |
A1 |
Kirby; David A. ; et
al. |
August 27, 2020 |
QUIET MOTORIZED WINDOW TREATMENT SYSTEM
Abstract
A motorized window treatment system may include a roller tube, a
covering material windingly attached to the roller tube, and a
drive assembly that may be at least partially disposed within the
roller tube. The drive assembly may include a motor having a drive
shaft that is elongate along a longitudinal direction and a drive
gear attached to the drive shaft such that a toothed portion of the
drive gear is cantilevered with respect to the drive shaft. The
drive assembly may include a gear assembly having a pair of
intermediate gears on opposed sides of the drive gear. Rotation of
the drive gear may be transferred through the pair of intermediate
gears, a connecting gear, a planetary gear set, a cage, and an
idler to the roller tube. Rotation of the roller tube may cause the
covering material to move between an open position and a closed
position.
Inventors: |
Kirby; David A.;
(Zionsville, PA) ; Newman, JR.; Robert C.;
(Emmaus, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lutron Technology Company LLC |
Coopersburg |
PA |
US |
|
|
Assignee: |
Lutron Technology Company
LLC
Coopersburg
PA
|
Family ID: |
1000004824298 |
Appl. No.: |
15/930677 |
Filed: |
May 13, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15461962 |
Mar 17, 2017 |
10689905 |
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15930677 |
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14490327 |
Sep 18, 2014 |
9598901 |
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15461962 |
|
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61879305 |
Sep 18, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E06B 9/72 20130101; H02K
11/33 20160101; F16H 1/46 20130101; H02K 2207/03 20130101; F16H
1/22 20130101; E06B 2009/725 20130101; H02K 2203/03 20130101; H02K
7/116 20130101 |
International
Class: |
E06B 9/72 20060101
E06B009/72; H02K 7/116 20060101 H02K007/116; H02K 11/33 20060101
H02K011/33; F16H 1/46 20060101 F16H001/46 |
Claims
1. A drive assembly comprising: a motor having a drive shaft that
defines a drive shaft rotational axis, the drive shaft defining a
distal end that is spaced from the motor, wherein the drive shaft
defines a drive shaft diameter; a drive gear that engages the
distal end of the drive shaft, the drive gear having a toothed
portion adapted to rotate about the drive shaft rotational axis,
wherein the toothed portion of the drive gear is spaced from the
distal end of the drive shaft along the drive shaft rotational
axis; and a gear assembly operatively coupled to the toothed
portion of the drive gear such that actuation of the motor causes
the drive gear to rotate the gear assembly.
2. The drive assembly of claim 1, wherein the toothed portion of
the drive gear defines a root diameter that is less than the drive
shaft diameter, and wherein the toothed portion of the drive gear
defines a channel that receives the distal end of the drive
shaft.
3. The drive assembly of claim 1, wherein the toothed portion
comprises less than 12 gear teeth, and wherein the gear teeth are
helical.
4. The drive assembly of claim 1, wherein the drive assembly is
operatively coupled to a roller tube for rotating the roller tube
about a longitudinal axis defined by the roller tube.
5. The drive assembly of claim 4, wherein the drive shaft extends
parallel to the longitudinal axis of the roller tube.
6. The drive assembly of claim 1, wherein the distal end of the
drive shaft is spaced from the motor by a first distance and the
toothed portion is spaced from the motor by a second distance that
is greater than the first distance.
7. The drive assembly of claim 1, wherein the toothed portion is
comprised of plastic and the drive gear further comprises a
coupling portion that extends from the toothed portion and mates
with the drive shaft so as to operatively couple the drive gear to
the drive shaft, the coupling portion comprising a non-plastic
portion that operatively couples the toothed portion to the
coupling portion.
8. The drive assembly of claim 1, wherein the gear assembly
comprises a pair of intermediate gears disposed on opposed sides of
the toothed portion of the drive gear, a planetary gear set that is
operatively coupled to the roller tube, and a connecting gear that
is operatively coupled to the pair of intermediate gears.
9. The drive assembly of claim 8, wherein the gear assembly further
comprises a cage that rotatably captures one or more shafts of the
planetary gear set such that rotation of the planetary gear set
causes the cage to rotate, and wherein the cage is connected to the
roller tube via an idler such that rotation of the cage causes the
roller tube to rotate about the longitudinal axis.
10. The drive assembly of claim 1, wherein the gear assembly is
operably coupled to the roller tube such that actuation of the
motor causes the roller tube to rotate about the longitudinal
axis.
11. A motorized window treatment system comprising: an elongate
roller tube defining a longitudinal axis; a covering material
windingly attached to the roller tube; a drive assembly that is
operatively coupled to the roller tube for rotating the roller tube
about the longitudinal axis, the drive assembly including: a motor
having a drive shaft that defines a drive shaft rotational axis,
the drive shaft defining a distal end that is spaced from the
motor, wherein the drive shaft defines a drive shaft diameter; a
drive gear that engages the distal end of the drive shaft, the
drive gear having a toothed portion adapted to rotate about the
drive shaft rotational axis, wherein the toothed portion of the
drive gear is spaced from the distal end of the drive shaft along
the drive shaft rotational axis; and a gear assembly operatively
coupled to the toothed portion of the drive gear such that
actuation of the motor causes the gear assembly to rotate.
12. The motorized window treatment system of claim 11, wherein the
toothed portion defines a root diameter that is less than the drive
shaft diameter.
13. The motorized window treatment system of claim 11, wherein the
toothed portion of the drive gear comprises a plurality of gear
teeth that are helical gear teeth.
14. The motorized window treatment system of claim 11, wherein the
distal end of the drive shaft that is spaced a first distance from
the motor, and wherein the toothed portion of the drive gear is
spaced a second distance from the motor, and wherein the second
distance is greater than the first distance.
15. The motorized window treatment system of claim 11, wherein the
drive gear is cantilevered with respect to the distal end of the
drive shaft, and wherein the drive gear defines a channel that
receives a portion of the drive shaft.
16. The motorized window treatment system of claim 11, wherein the
drive gear further comprises a coupling portion that extends from
the toothed portion and mates with the drive shaft so as to
operatively couple the drive gear to the drive shaft, the coupling
portion comprising a non-plastic portion that operatively couples
the toothed portion to the coupling portion.
17. The motorized window treatment system of claim 11, wherein the
gear assembly is configured to be operatively coupled to the roller
tube such that actuation of the motor causes the roller tube to
move the covering material between an open position and a closed
position.
18. The motorized window treatment system of claim 11, wherein the
covering material is a screen.
19. The motorized window treatment system of claim 11, wherein the
gear assembly comprises a pair of intermediate gears disposed on
opposed sides of the toothed portion of the drive gear, a planetary
gear set that is operatively coupled to the roller tube, and a
connecting gear that is operatively coupled to the pair of
intermediate gears.
20. The motorized window treatment system of claim 19, wherein the
gear assembly further comprises a cage that rotatably captures one
or more shafts of the planetary gear set such that rotation of the
planetary gear set causes the cage to rotate, and wherein the cage
is connected to the roller tube via an idler such that rotation of
the cage causes the roller tube to rotate about the longitudinal
axis.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/461,962, filed Mar. 17, 2017, which is a
continuation of U.S. patent application Ser. No. 14/490,327, filed
Sep. 18, 2014, which issued as U.S. Pat. No. 9,598,901 on Mar. 21,
2017, which claims priority to U.S. provisional patent application
No. 61/879,305, filed Sep. 18, 2013, the disclosures of which are
incorporated herein by reference in their entireties.
BACKGROUND
[0002] A motorized window treatment system may include a covering
material wound onto a roller tube. The covering material may
include a weighted hembar at a lower end of the covering material,
such that the covering material extends vertically (e.g., hangs) in
front of a window. Motorized window treatments may include a drive
system that is coupled to the roller tube to provide for tube
rotation, such that the lower end of the covering material can be
raised and lowered (i.e., moved in a vertical direction) by
rotating the roller tube. The drive system may include a motor
having a drive shaft and a gear train that is operatively coupled
to (e.g., in communication with) the drive shaft and roller tube
such that actuation of the motor causes the roller tube to rotate.
The motor may be a direct current (DC) motor powered by a DC power
source or an alternating current (AC) motor powered by an AC power
source.
[0003] The torque capability and efficiency of a DC motor may vary
depending on the motor speed. While the particular values of motor
speed, torque capability, and efficiency may vary for different DC
motors, certain characteristics may be shared by most DC motors.
For example, motor speed and motor torque capability may vary
linearly, and inversely, throughout the entire range of motor
speeds including very low speeds approaching zero. Motor efficiency
may generally reach peak efficiency under light-duty conditions
(e.g., relatively low torque capability at a motor speed greater
than 50% of maximum motor speed). When a DC motor operates at a
peak efficiency (e.g., at greater speeds), the motor may generate
undesired noise. Manufactures may operate the motor at a slower
speed and a lower efficiency, to reduce a noise level of the
motor.
SUMMARY
[0004] A motorized window treatment system may include a roller
tube, a covering material, and a drive assembly. The covering
material may be windingly attached to the roller tube such that
rotating the roller tube causes the covering material to move
between a first position and a second position. The first position
and the second position may include one or more positions between
and including an open position and a closed position.
[0005] The drive assembly may be operatively coupled to the roller
tube for rotating the roller tube about a longitudinal axis. The
drive assembly may include a motor, a drive gear, and/or a gear
assembly. The motor may include a drive shaft that is elongate
parallel to a longitudinal axis of the roller tube. The drive shaft
may define a drive shaft rotational axis. The drive shaft may
include an end that is distal from the motor. The drive shaft may
define a drive shaft diameter.
[0006] The drive gear may be attached to the drive shaft. The drive
gear may define a rotational axis. The drive gear rotational axis
may be in a coaxial relationship with the drive shaft rotational
axis. The drive gear may include a toothed portion distal from the
end of the drive shaft. The toothed portion of the drive gear may
be adapted to rotate about the drive gear rotational axis. The
toothed portion of the drive gear may define a root diameter. The
root diameter may be less than the drive shaft diameter. The
toothed portion may be spaced from the drive shaft along the drive
shaft rotational axis. The toothed portion may include eight or
more and twelve or less gear teeth. The gear teeth may be helical
gear teeth. The toothed portion may be plastic. The drive gear may
include a coupling portion. The coupling portion may extend from
the toothed portion. The coupling portion may mate with the drive
shaft to operatively couple the drive gear to the drive shaft. The
coupling portion may include a non-plastic portion. The non-plastic
portion may operatively couple the toothed portion to the coupling
portion.
[0007] The gear assembly may be operatively coupled to the toothed
portion of the drive gear and operatively coupled to the roller
tube such that actuation of the motor causes the roller tube to
rotate about the longitudinal axis. The gear assembly may include a
pair of intermediate gears. The pair of intermediate gears may be
disposed on opposed sides of the toothed portion of the drive gear.
The gear assembly may include a planetary gear set. The planetary
gear set may be operatively coupled to the roller tube. The gear
assembly may include a connecting gear. The connecting gear may be
operatively coupled to the pair of intermediate gears and the
planetary gear set.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1A is a perspective view of an example motorized window
treatment system that includes a roller tube and a covering
material windingly attached to the roller tube.
[0009] FIG. 1B is an exploded view of the example roller tube shown
in FIG. 1A, the motorized window treatment system including a drive
assembly at least partially disposed within the roller tube and
configured to rotate the roller tube so as to cause the covering
material to move between a closed position and an open
position.
[0010] FIG. 2A is a top perspective view of the example drive
assembly shown in FIG. 1B, the drive assembly including a motor, a
drive gear coupled to the motor, and a gear assembly operatively
coupled to the drive gear and the roller tube such that actuation
of the motor causes the roller tube to move the covering material
between the open position and the closed position.
[0011] FIG. 2B is a top plan view of the example drive assembly
shown in FIG. 2A.
[0012] FIG. 2C is a detailed view of the example drive gear and
gear assembly of the drive assembly shown in FIG. 2B, the gear
assembly including gear a pair of intermediate gears disposed on
opposed sides of the drive gear, a planetary gear set that is
operatively coupled to the roller tube, and a connecting gear that
is operatively coupled to the pair of intermediate gears and the
planetary gear set.
[0013] FIG. 2D is a cross-section of the example drive gear and the
gear assembly shown in FIG. 2C, the drive gear including a toothed
portion that is cantilevered with respect to a drive shaft of the
motor and is spaced from the drive shaft of the motor along a
longitudinal direction.
[0014] FIG. 3 is a cross-section of an example drive gear that
includes a plastic toothed portion and a coupling portion having a
non-plastic portion and a plastic portion.
DETAILED DESCRIPTION
[0015] FIGS. 1A and 1B depict an example motorized window treatment
system 10 that includes a roller tube 18 and a covering material 22
windingly attached to the roller tube 18. The motorized window
treatment system 10 includes a housing 14 (e.g., a pocket or a
headrail) that is configured to be coupled to or otherwise mounted
to a structure. For example, the housing 14 may be configured to be
mounted to (e.g., attached to) a window frame, a wall, or other
structure, such that the motorized window treatment system 10 is
mounted proximate to an opening (e.g., over the opening or in the
opening), such as a window for example. The motorized window
treatment system 10 may further include a rotational element, such
as a roller tube 18 that is elongate along a longitudinal direction
L, and that is rotatably mounted (e.g., rotatably supported) within
the housing 14. The longitudinal direction L may be referred to as
a first direction. The roller tube 18 may define a longitudinal
axis 12. The motorized window treatment system 10 may include a
covering material 22 that is windingly attached to the roller tube
18, such that rotation of the roller tube 18 causes the covering
material 22 to wind or unwind from the roller tube 18 along a
transverse direction T that extends perpendicular to the
longitudinal direction L. The transverse direction T may be
referred to as a second direction. For example, rotation of the
roller tube 18 may cause the covering material 22 to move between a
raised (e.g., open) position and a lowered (e.g., closed) position
along the transverse direction T.
[0016] The covering material 22 may include a first end (e.g., a
top or upper end) that is coupled to the roller tube 18 and a
second end (e.g., a bottom or lower end) that is coupled to a
hembar 24. The hembar 24 may be configured, for instance weighted,
to cause the covering material 22 to hang vertically. Rotation of
the roller tube 18 may cause the hembar 24 to move toward or away
from the housing 14. The housing 14 may be made of any suitable
material, such as plastic or metal. It should be appreciated,
however, that the housing 14 may be made from any material, or from
any combination of materials. The covering material 22 may be any
suitable material, or form any combination of materials. For
example, the covering material 22 may be "scrim," woven cloth,
non-woven material, light-control film, screen, and/or mesh. The
covering material 22 may be any type of shade. For example, the
covering material 22 may be a roller shade as illustrated, a soft
sheer shade, a drapery, or a cellular shade.
[0017] As shown in FIG. 1A, the motorized window treatment system
10 may include a battery compartment 26. The battery compartment 26
may be configured to retain a plurality of batteries 28. The
battery compartment 26 may be spaced from the roller tube 18 as
illustrated. The battery compartment 26 may be disposed within the
roller tube 18. The batteries 28 may be configured to power a drive
assembly, a microprocessor, and/or any other electrical component
of the motorized window treatment system 10. The motorized window
treatment system 10 may be hard wired.
[0018] As shown in FIG. 1B, the motorized window treatment system
10 may include a drive assembly 30, a control circuit 31
electrically connected to the drive assembly 30, a first idler 32a,
and a second idler 32b. The drive assembly 30, the control circuit
31, the first idler 32a, and the second idler 32b may at least
partially be disposed within the roller tube 18. For example, the
control circuit 31 may include a microprocessor and may be mounted
to a printed circuit board (PCB). The drive assembly 30 and the
control circuit 31 may be powered by the batteries 28. The drive
assembly 30 may be coupled to the first idler 32a such that when
the drive assembly 30 is actuated, the first idler 32a is driven by
the drive assembly 30 to thereby cause the roller tube 18 to
rotate. The second idler 32b may be passive and may rotate as the
first idler 32a is driven by the drive assembly 30. The drive
assembly 30 and control circuit 31 may be configured to allow for
control of the rotation of the roller tube 18. A user of the
motorized window treatment system 10 may control the rotation of
the roller tube 18 to move the covering material 22 to a desired
position. The drive assembly 30 may include a sensor that monitors
the position of the covering material 22, so that the control
circuit 31 knows the position of the covering material 22 relative
to one or more limits (e.g., an upper limit and/or a lower limit)
of the covering material 22 at any given time. The drive assembly
30 may be locally controlled (e.g., with a push button) and/or
remotely controlled (e.g. wirelessly controlled with an infrared
(IR) or radio frequency (RF) remote control device). The control
circuit 31 may include an RF transceiver or receiver, and/or an
antenna that may be enclosed within the housing 14 or coupled to an
exterior portion of the housing 14. Examples of drive assemblies
and control circuits for motorized roller shades are described in
greater detail in U.S. Pat. No. 6,983,783, issued Jan. 10, 2006,
entitled "Motorized Shade Control System." U.S. Pat. No. 7,723,939,
issued May 25, 2010, entitled "Radio-Frequency Controlled Motorized
Roller Shade," and U.S. Pat. No. 7,839,109, issued Nov. 23, 2010,
entitled "Method Of Controlling A Motorized Window Treatment," the
entire contents of each of which are hereby incorporated herein by
reference. It should be appreciated, that the drive assembly 30 may
be configured to rotate rotational elements other than a roller
tube 18. For example, the drive assembly 30 can be configured to
rotate a drive shaft that winds up lift cords as disclosed in U.S.
Pat. No. 8,950,461, issued Feb. 10, 2015, entitled "Motorized
Window Treatment," the entire contents of which is hereby
incorporated herein by reference.
[0019] As shown in FIG. 1B, the drive assembly 30 and the control
circuit 31 may be disposed within a drive housing 200. The drive
housing 200 may include a first section 202 and a second section
204. The first section 202 and the second section 204 may fit
together along a split line 232 to house the drive assembly 30 and
the control circuit 31. The drive assembly 30 may be supported in
the drive housing 200 by one or more of the following non-rotating
support parts. The drive assembly 30 may include a collar 218 that
is disposed between the motor 34 and a gear assembly. The collar
218 may rest in a molded channel of the drive housing 200. The
drive assembly 30 may include one or more disks 212, 216 that
support the rotating elements of the drive assembly 30 within the
drive housing 200. The disk 216 may include a plurality of tabs 214
that engage a plurality of slots in the drive housing 200. The disk
212 may be disposed within one or more channels in the drive
housing 200. The drive assembly 30 may include a ring gear 120 with
a plurality of tabs 210 that engage a plurality of slots 208 in the
drive housing 200.
[0020] As shown in FIG. 1B, the first idler 32a may be connected to
a cage 220 that engages one or more planetary gears. The cage 220
may be spaced from the first idler 32a such that the drive housing
200 may be supported by a shaft 224 connecting the first idler 32a
to the cage 220. The cage 220 may include a plurality of slots 222.
Each of the plurality of slots 222 may accept a respective
planetary gear shaft such that rotation of the one or more
planetary gears rotates the cage 220 and the first idler 32a. The
shafts of the planetary gears may be rotatably captured within the
slots 222, such that the shafts of the planetary gears cause the
cage 220, the first idler 32a, and the roller tube 18 to rotate
about the longitudinal axis 12 as the shafts of the planetary gears
rotate about the longitudinal axis 12.
[0021] FIGS. 2A-2D depict an example drive assembly 30. As shown in
FIGS. 2A and 2B, a drive assembly 30 may include a motor 34 having
a drive shaft 38 that is elongate along the longitudinal direction
L. In accordance with the illustrated orientation of the motorized
window treatment system 10, the longitudinal direction L extends
parallel to a longitudinal axis 12 of the roller tube 18. The drive
shaft 38 may define a drive shaft rotational axis 206. The drive
shaft 38 may include a distal end 230 that is spaced from the motor
34. The distal end 230 may be a first distance D1 from the motor
34. An intermediate gear 70 may be a second distance D2 from the
motor 34. The second distance D2 may be longer than the first
distance D1. The drive assembly 30 may include a drive gear 42 that
is attached (e.g., fixedly attached) to the drive shaft 38 and may
include a gear assembly 46. The gear assembly 46 may be operatively
coupled to (e.g., in communication with) the drive gear 42 and the
roller tube 18 such that actuation of the motor 34 transmits
rotation of the drive shaft 38 through the gear assembly 46 and to
the roller tube 18. For example, the gear assembly 46 may be
operatively coupled to the drive gear 42 and the roller tube 18,
such that actuation of the motor 34 causes the roller tube 18 to
move the covering material 22 between a first position (e.g., an
open position) and a second position (e.g., a closed position). The
drive assembly 30 may be configured such that the motor 34 can
operate at an efficient speed while remaining below a noise
threshold (e.g., maintaining satisfactory decibel levels). For
example, the drive assembly 30 may be configured so that the motor
34 can be operated at a more efficient speed as compared to the
known drive assemblies while a noise level of the motorized window
treatment system remains below 33 dBa.
[0022] The drive gear 42 may include a coupling portion 50 and a
toothed portion 54 that extends from the coupling portion 50 along
the longitudinal direction L. As shown in FIG. 2D, the coupling
portion 50 may define a channel 58 that is elongate along the
longitudinal direction L and is configured to receive the drive
shaft 38 to thereby operatively couple (e.g., couple) the drive
gear 42 to the drive shaft 38. The coupling portion 50 and the
toothed portion 54 may be made of a non-metal material (e.g., a
plastic material). The drive gear 42 may be made of any
material.
[0023] As shown in FIG. 2D, the drive gear 42 may be attached to
the drive shaft 38, such that the toothed portion 54 is spaced from
the distal end 230 of the drive shaft 38. The toothed portion 54
may be spaced from the motor 34 (e.g., by approximately the second
distance D2 along the longitudinal direction L). The toothed
portion 54 may be cantilevered with respect to the drive shaft 38
along the longitudinal direction L. For example, the teeth of the
toothed portion 54 may be supported outwardly from the drive shaft
38. As shown in FIG. 2D, the toothed portion 54 may be cantilevered
with respect to the drive shaft 38, such that the toothed portion
54 is spaced from the drive shaft 38 along the longitudinal
direction L and does not overlap the drive shaft 38. The drive
shaft 38 may define a drive shaft diameter Ds. The toothed portion
54 may define a root diameter DR. The root diameter DR may be less
than or equal to the drive shaft diameter Ds. The drive gear 42 may
define a rotational axis in a coaxial relationship with the drive
shaft rotational axis 206. When compared to a non-cantilevered
drive gear, the smaller or cantilevered drive gear 42 may move
slower and may reduce transmitted vibrations and noise levels. A
portion of the toothed portion 54 may overlap the drive shaft 38
such that a majority of the toothed portion 54 is cantilevered with
respect to the drive shaft 38.
[0024] The toothed portion 54 of the drive gear 42 may include
between eight and twelve (e.g., eight or more and twelve or less)
gear teeth 60. As shown in FIGS. 2C and 2D, each gear tooth 60 may
define a helical gear tooth. The toothed portion 54 may have any
number of gear teeth 60. The gear teeth 60 may have any gear
configurations (e.g., a gear configuration other than helical). For
example, the toothed portion 54 may have thirteen or more teeth and
may define standard straight gear teeth.
[0025] As shown in FIGS. 2A-2C, the gear assembly 46 may be
operatively coupled to (e.g., in meshed communication with) the
toothed portion 54 of the drive gear 42 and the roller tube 18 via
the first idler 32a, such that actuation of the motor 34 transmits
rotation of the drive shaft 38 to the roller tube 18. As shown in
FIG. 2C, the gear assembly 46 may include a pair of intermediate
gears 70 disposed on opposed sides of the toothed portion 54 of the
drive gear 42, a planetary gear set 74 that is coupled to the
roller tube 18 (e.g., via the first idler 32a), and a connecting
gear 78 that is operatively coupled (e.g., in meshed communication
with) both the (e.g., the pair of) intermediate gears 70 and the
planetary gear set 74.
[0026] The intermediate gears 70 may each include a first gear
portion 82 and a second gear portion 86 that extends from the first
gear portion 82 along the longitudinal direction L. The first gear
portions 82 may include a plurality of helical gear teeth 90 and
the second gear portions 86 may include a plurality of standard
straight gear teeth 94. The gear teeth 90 and the gear teeth 94 may
have any gear configurations. As shown in FIG. 2C, the gear teeth
90 of the first gear portions 82 may mesh with the helical gear
teeth 60 of the drive gear 42, such that when the drive gear 42 is
driven by the motor 34, rotation of the drive gear is transmitted
to the intermediate gears 70.
[0027] The intermediate gears 70 may be disposed adjacent the drive
gear 42. For example, as shown the intermediate gears 70 are
disposed on opposed sides of the drive gear 42, such that the first
gear portions 82 of the intermediate gears 70 are operatively
coupled to the toothed portion 54 of the drive gear 42, and such
that respective axles 226 of the intermediate gears 70 are aligned
with respect to each other along the transverse direction T. Any
forces acting on the toothed portion 54 by one of the pair of
intermediate gears 70 may be offset by corresponding forces acting
on the toothed portion 54 by the other of the pair of intermediate
gears 70. Each intermediate gear 70 may apply an equal and opposite
force to the toothed portion 54 of the drive gear 42 so as to
reduce the load on the cantilevered toothed portion 54 and reduce
or otherwise prevent flexing of the toothed portion 54. A drive
gear may be prone to flexing under the load of one intermediate
gear. Flexing of the drive gear may cause a whining noise. The
corresponding (e.g., equal and opposite) forces from a pair of
intermediate gears may reduce the noise of the drive gear and gear
assembly.
[0028] As shown in FIGS. 2B and 2C, the connecting gear 78 may
include a first gear portion 100 and a second gear portion 104 that
is spaced from the first gear portion 100 along the longitudinal
direction L. The first gear portion 100 may include a plurality of
standard straight gear teeth 108 and the second gear portion 104
may include a plurality of standard straight gear teeth 112. The
gear teeth 108 and 112 may have any gear configurations. As shown
in FIG. 2C, the gear teeth 108 of the first gear portion 100 may
mesh with the gear teeth 94 of the pair of intermediate gears 70
such that when the pair of intermediate gears 70 are driven by the
drive gear 42, rotation of the pair of intermediate gears 70 is
transmitted to the connecting gear 78.
[0029] The planetary gear set 74 may include a ring gear 120 and a
plurality of planetary gears 124 that are operatively coupled
(e.g., in meshed communication with) the ring gear 120 and the
second gear portion 104 of the connecting gear 78. The planetary
gears 124 may be rotatably coupled to the first idler 32a and may
be disposed within the ring gear 120 such that the planetary gears
124 and first idler 32a together rotate around the ring gear 120.
For example, as shown, each planetary gear 124 includes a shaft
228. The shaft 228 of each planetary gear 124 may be disposed in a
corresponding slot 222 of the cage 220. The shafts 228 of the
planetary gears 124 may freely rotate in the slots 222, such that
the shafts 228 are rotatably captive in the slots 222.
[0030] The ring gear 120 may include a plurality of internal gear
teeth 128 (see FIG. 1B) and each planetary gear 124 may include a
plurality of gear teeth 132 that mesh with the gear teeth 128 of
the ring gear 120 and with the gear teeth 112 of the second gear
portion 104 of the connecting gear 78 such that when the connecting
gear 78 is driven by the pair of intermediate gears 70, rotation of
the connecting gear 78 is transmitted to the planetary gears 124.
The planetary gears 124 and the first idler 32a may rotate around
the ring gear 120 in response to rotation of the connecting gear
78. The second gear portion 104 may act as a sun gear to the
planetary gears 124. The illustrated planetary gear set 74 includes
three planetary gears 124 that are rotatably coupled to the first
idler 32a. It should be appreciated that the planetary gear set 124
is not limited to three planetary gears 124, and that the planetary
gear set 74 may be alternatively configured to include any number
of planetary gears 124.
[0031] The pair of intermediate gears 70, planetary gear set 74,
and connecting gear 78 may be made from any material. For example,
the pair of intermediate gears 70, planetary gear set 74, and
connecting gear 78 may be made from a plastic material. The pair of
intermediate gears 70, connecting gear 78, ring gear 120, and
planetary gears 124 may include any number of gear teeth, so long
as the gears of the gear assembly mesh together.
[0032] In use, actuation of the motor 34 may cause the drive gear
42 to rotate. Rotation of the drive gear 42 may be transferred
through the gear assembly 46 and to the roller tube 18. The
cantilevered toothed portion 54 of the drive gear 42 may reduce the
noise (e.g., decibel levels) of the drive assembly 30. Reducing the
noise of the drive assembly 30 may allow the motor 34 to be
operated at a higher and/or more efficient speed. Disposing the
intermediate gears 70 on opposed sides of the toothed portion 54 of
the drive gear 42 may allow the intermediate gears 70 to offset
forces applied by the intermediate gears 70 to the cantilevered
toothed portion 54 of the drive gear 42. For example, a first one
of the intermediate gears 70 may offset any forces transferred to
the cantilevered toothed portion 54 by the other one of the
intermediate gears 70. Offsetting any forces transferred may reduce
fatigue of the cantilevered toothed portion 54 and may allow the
drive assembly 30 to be operated with a reduced (e.g., without)
risk of failure. When the drive assembly 30 is quieter and/or
operated at more efficient speeds, less energy may be required to
operate the motorized window treatment system 10. When the drive
assembly 30 is powered by batteries, more efficient operation may
prolong battery life.
[0033] FIG. 3 depicts an example drive gear 142 that may be
implemented in the motorized window treatment 10 (e.g., in place of
the drive gear 42). As shown, the drive gear 142 may include a
plastic toothed portion 154 and a coupling portion 150 having a
non-plastic portion 152 and a plastic portion 151. The drive gear
142 may include a coupling portion 150 and a toothed portion 154
that extends from the coupling portion 150 along the longitudinal
direction L. As shown in FIG. 3, the coupling portion 150 may
define a channel 158 that is elongate along the longitudinal
direction L and may be configured to receive the drive shaft 38 to
thereby couple the drive gear 142 to the drive shaft 38. The
toothed portion 154 may be made of a plastic material. The coupling
portion 150 may include a plastic portion 151 and a non-plastic
portion 152. The plastic portion 151 may define the channel 158 and
may couple the drive gear 142 to the drive shaft 38. The
non-plastic portion 152 may be made of rubber and may couple the
toothed portion 154 to the plastic portion 151. The plastic portion
151 may include a coupling member 153. The non-plastic portion 152
may be overmolded onto the coupling member 153 to thereby couple
the plastic portion 151 to the non-plastic portion 152. As shown in
FIG. 3, the non-plastic portion 152 may isolate the toothed portion
154 from the drive shaft 38 to reduce the noise (e.g., the decibel
levels) of the drive assembly. The toothed portion 154 may be
attached to the non-plastic portion 152 using any known methods.
The non-plastic portion 152 may be made of materials other than
rubber.
[0034] The drive gear 142 may be coupled to the drive shaft 38 such
that the toothed portion 154 is cantilevered with respect to the
drive shaft 38 along the longitudinal direction L. As shown in FIG.
3, the entire toothed portion 154 may be cantilevered with respect
to the drive shaft 38 such that the entire toothed portion 154 is
spaced from the drive shaft 38 along the longitudinal direction L
by at least the non-plastic portion 152 of the coupling portion
150. The drive shaft 38 may define a drive shaft diameter Ds. The
toothed portion 154 may define a root diameter DR. The root
diameter DR may be less than or equal to the drive shaft diameter
Ds.
[0035] The toothed portion 154 of the drive gear 142 may include
between eight and twelve (e.g., eight or more and twelve or less)
gear teeth 160. As shown in FIG. 3, each gear tooth 160 may define
a helical gear tooth. The toothed portion 154 may have any number
of gear teeth 160, and the gear teeth 160 may have any gear
configurations. For example, the toothed portion 154 may have
thirteen or more teeth and may be standard straight gear teeth.
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