QUIET MOTORIZED WINDOW TREATMENT SYSTEM
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.
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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.
BACKGROUNDA 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.
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.
SUMMARYA 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.
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.
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.
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.
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.
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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
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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
As shown in
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
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.
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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.
The ring gear 120 may include a plurality of internal gear teeth 128 (see
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.
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.
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
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
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.
Type: Application
Filed: May 13, 2020
Publication Date: Aug 27, 2020
Applicant: Lutron Technology Company LLC (Coopersburg, PA)
Inventors: David A. Kirby (Zionsville, PA), Robert C. Newman, JR. (Emmaus, PA)
Application Number: 15/930,677