Abstract:
A motor-drive system for retractable covering having a headrail with a horizontally disposed roller supporting a top edge of a flexible fabric material includes an electric motor mounted within a housing and interconnected to the roller to selectively rotate the roller in opposite directions while minimizing noise created from vibrations within the system. This system includes motor mounts within the housing which separate and absorb vibrations of the motor within the housing and a drive disk of a moderately soft material, which is firm enough to transfer torque from the motor to the roller while being soft enough to absorb vibrations which would otherwise be transmitted from the motor to the roller. An interconnect mounting the drive disk to the drive shaft of the motor is also made of a third relatively soft material, which is harder than the drive disk to more ably transmit torque but soft enough so as not to unduly transmit noise.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a continuation of co-pending U.S. patent application Ser. No. 13/675,539 (the “&#39;539 Application”) filed on Nov. 13, 2012, now U.S. Pat. No. 9,410,371 and entitled “Noise-Dampening Motor Drive System For Retractable Covering For Architectural Openings”, which is a continuation of U.S. patent application Ser. No. 12/685,927 (the “&#39;927 Application”) filed on Jan. 12, 2010, now U.S. Pat. No. 8,307,878 and entitled “Noise-Dampening Motor Drive System For Retractable Covering For Architectural Openings”, which claims benefit under 35 U.S.C. §119(e) to U.S. provisional patent application No. 61/144,467 (the “&#39;467 Application”) filed on Jan. 14, 2009 and entitled “Noise Dampening Motor Drive System For Retractable Covering For Architectural Openings”. The &#39;539, &#39;927 and &#39;467 Applications are hereby incorporated by reference into the present application in their entireties. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Field of the Invention 
         [0003]    The present invention is directed to motorized retractable coverings for architectural openings and more particularly to a system for minimizing noise created when an electric motor is used to reversibly drive a roller about which a fabric for the covering can be wrapped and unwrapped. 
         [0004]    Description of the Relevant Art 
         [0005]    Coverings for architectural openings such as windows, doors, archways, and the like, have assumed numerous forms for many years. Many such coverings are retractable and have a headrail in which a rotatable roller is horizontally disposed and supports a flexible fabric that depends from the roller. Depending upon the direction of rotation of the roller, the fabric is either wrapped or unwrapped from the roller. The roller can be rotated with a control system that might be manual using control cords or the like or might be motor driven and operable from a remote location particularly where the architectural opening is not easily accessible. 
         [0006]    Motor driven coverings for architectural openings have previously been louder in operation than desirable. Accordingly, attempts have been made to reduce the noise which is typically vibratory in its source. 
         [0007]    For example, the drive shaft from the motor or its gear-reduction unit typically carries a drive disk. The drive disk is operatively engaged with the roller in the headrail of the covering to rotate the roller in one direction or the other. The connection between the drive shaft and the drive disk has been made of a soft material to reduce the vibration that might otherwise be transferred from the drive shaft of the motor to the drive disk. 
         [0008]    The present invention has been developed to further minimize the noise created in a motor-driven covering for an architectural opening. 
       SUMMARY OF THE INVENTION 
       [0009]    Pursuant to the present invention, a covering for an architectural opening includes a headrail in which a reversibly rotatable roller is horizontally mounted. The roller supports the top edge of a flexible fabric material that can be wrapped around or unwrapped from the roller depending upon the direction of rotation of the roller. 
         [0010]    The roller is reversibly rotated by an electric drive system that includes an electric motor and a gear-reduction unit mounted within a housing so as to be horizontally positioned within the roller. A drive shaft emanating from the motor/gear-reduction unit operatively carries a drive disk that is engaged with the roller to rotate the roller in reversible directions. The housing for the motor is rigidly supported on the headrail to resist torque applied thereto by resistance to rotation of the roller. 
         [0011]    In order to dampen vibrations that naturally occur when an electric motor rotationally drives a relatively heavy roller and suspended fabric, resilient grommets are positioned within the housing at opposite ends of the motor and its gear-reduction unit with the grommets being slightly larger in diameter than the motor and gear-reduction unit so as to engage an inner wall of the housing and maintain a small separation of the housing from the motor and gear reduction unit. The drive disk operatively connected to the drive shaft from the motor is also made of a relatively soft material which dampens vibration but is firm enough to transfer torque from the drive shaft to the roller whereby the decibel level emanating from vibration of the drive unit when the motor is driven is maintained at an acceptable level. 
         [0012]    Other aspects, features and details of the present invention can be more completely understood by reference to the following detailed description of a preferred embodiment, taken in conjunction with the drawings and from the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a fragmentary isometric of a motor-driven retractable covering for an architectural opening incorporating the motor-mounting system of the present invention. 
           [0014]      FIG. 2  is an exploded fragmentary isometric showing the end of the headrail with the motor-drive unit mounted thereto. 
           [0015]      FIG. 3A  is a view similar to  FIG. 2  with the motor-drive unit itself further exploded. 
           [0016]      FIG. 3B  is a fragmentary isometric showing a portion of the headrail, the roller, and battery pack for driving the motor. 
           [0017]      FIG. 4  is an exploded isometric of the drive unit. 
           [0018]      FIG. 5  is an enlarged section taken along line  5 - 5  of  FIG. 1 . 
           [0019]      FIG. 6A  is a section taken along line  6 A- 6 A of  FIG. 5 . 
           [0020]      FIG. 6B  is a longitudinal vertical section through the roll bar showing the electrical connection of a drive module to the motor and battery pack. 
           [0021]      FIG. 7  is an enlarged section taken along line  7 - 7  of  FIG. 6A . 
           [0022]      FIG. 8  is a section similar to  FIG. 7  with the roll bar having been rotated slightly to show shock absorption features of the invention. 
           [0023]      FIG. 9  is a diagrammatic of the electrical circuitry for the covering of  FIG. 1 . 
           [0024]      FIG. 10  is a section taken along line  10 - 10  of  FIG. 6B . 
           [0025]      FIG. 11  is an isometric looking at one side of the outer component of the rear motor mount. 
           [0026]      FIG. 12  is an isometric looking at the other side of the outer component of the rear motor mount. 
           [0027]      FIG. 13  is an isometric looking at one side of the inner component of the rear motor mount. 
           [0028]      FIG. 14  is an isometric looking at the other side of the inner component of the rear motor mount. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]    Referring to  FIG. 1 , a covering  10  for an architectural opening is shown including a headrail  12  having end caps  14  and  16  at opposite ends of the headrail and with a roller  18  ( FIG. 3B ) interiorly of the headrail that is horizontally disposed and supports a top edge of a flexible fabric shade material  20  having a ballast  22  along the lower edge. The fabric material can be any flexible material adapted to be rolled around a roller, but the material illustrated has a backing sheet  24  to which is attached a plurality of horizontally disposed vertically spaced loops of material  26  simulating a Roman shade. At the right end of the headrail (even though it could be anywhere along the length of the headrail), a remote sensor  28 , which might be RF or IR for operating a reversible motor  30  ( FIG. 4 ) carried within the headrail from a remote location, is seen incorporated into the headrail. 
         [0030]      FIG. 2  shows the drive system for the present invention which is mounted on the end cap  16  at the right end of the headrail as seen in  FIG. 1  with the end cap having an inwardly directed mounting shaft  32  seen in  FIG. 3A  with a mounting ring  34  on its distal end. The mounting ring has a plurality of radiating longitudinally extending fins  36  and diametrically opposed catch tabs  38  which are beveled for a purpose to be described hereafter. A mounting hub  40  with longitudinally-extending radiating ribs  42  and an end plate  44  is rotatably seated on the mounting shaft for a purpose to be described hereafter. 
         [0031]    The drive unit, as seen in  FIG. 3A , includes a two-piece housing  46  having identical components  46   a  and  46   b  which might be made of a slightly flexible but substantially rigid plastic material that when assembled is substantially cylindrical in configuration and defines an internal cylindrical cavity  48  ( FIG. 6A ). The end of the housing adjacent to the right end cap  16  has diametrically opposed longitudinally extending flexible arms  50  having rectangular holes  52  therethrough that can be slid over the beveled catch tabs  38  until the tabs project into the holes of the flexible arms so that the housing  46  is releasably secured to the mounting ring  34  and prevented from rotation by receipt of the catch tabs in the holes of the flexible arms. Releasable catches  54  are also provided in surfaces of the two components  46   a  and  46   b  of the housing and fasteners  56  can further be used to positively secure the two components of the housing together. 
         [0032]    Projecting from the distal end of the housing  46  is a drive shaft  58  ( FIG. 4 ) which is operatively connected to a drive disk or coupler  60  which is reversibly rotatable by the reversible motor  30  and a gear-reduction unit  62  of which the drive shaft forms a part. The motor/gear-reduction unit is positioned horizontally within the housing as possibly seen best in  FIG. 4  with the reversible motor being axially aligned with the gear-reduction unit. The drive shaft  58  can be seen to be of non-circular cross-section. Three longitudinally-extending pins  64  are also circumferentially spaced around the drive shaft at the distal end of the gear-reduction unit with the pins serving a function to be described hereafter. 
         [0033]    At opposite ends of the motor/gear-reduction unit  30 / 62 , as best seen in  FIGS. 4, 6A and 6B , front  66  and rear  68  motor mounts or bushings are provided. The front motor mount or bushing is made of a resilient material that is relatively soft in comparison to the motor/gear-reduction unit and further is of generally circular transverse cross-section with the diameter of the cross-section being slightly greater than the diameter of the motor/gear-reduction unit. The outer diameter of the front motor mount is substantially commensurate with the diameter of the internal cylindrical cavity  48  of the housing  46  when it is assembled so that the housing circumferentially engages the resilient front motor mount and is thereby maintained in a slightly spaced relationship from the motor/gear-reduction unit. The front motor mount preferably has a durometer rating in the range of 50 A to 70 A with a preferred rating of 64 A. 
         [0034]    A motor rotated timing pin  70  extends axially from the opposite or rear end of the motor/gear-reduction unit  30 / 62  from the drive shaft  58  and passes through the rear motor mount  68 . The motor/gear-reduction unit has an axial substantially oblong, non-circular extension  72  supported in the rear motor mount so that the motor/gear-reduction unit is supported at this end by the rear motor mount and at the opposite end by the three circumferentially spaced longitudinally extending pins  64 , which support the front motor mount  66 . 
         [0035]    The rear motor mount  68  is a two-piece motor mount having an internal hard and rigid component  73  and an external relatively soft component  75 . The hard component includes a main body  77  having a substantially ovular or otherwise non-circular recess  79  in a front surface thereof which correlates in size and cross-sectional shape to the axial extension  72 . At the top and bottom of the main body are identical diametrically opposed fingers  81  of generally trapezoidal cross-section having a rearwardly opening seat  83  also of generally trapezoidal cross section adapted to receive and be keyed to the relatively soft component of the rear motor mount as will be described hereafter. The hard component is thereby received on the non-circular axial extension  72  of the motor/gear-reduction unit so that it is nonrotatable relative thereto. 
         [0036]    The relatively soft component  75  of the rear motor mount  68  is one piece having an outer partially segmented substantially cylindrical wall  85  with the segments of the wall being diametrically opposed and forming a gap  87  therebetween adapted to slidably receive the hard component  73 . In order to key the hard inner component to the relatively soft outer component, each segment of the outer component has an inwardly directed rib  89  of substantially trapezoidal transverse cross-section, which defines a generally V-shaped slot  91  on opposite sides of the rib so that the rib can be received in a corresponding rearwardly opening seat  83  of the hard inner component. In this manner, the hard component can be slid into the open left end of the outer component until a plate  93  at the end of each substantially trapezoidal seat engages the end of the outer component which positively positions the hard component relative to and within the outer component. As can also be appreciated, the relatively soft outer component also has a longitudinally-extending groove  95  in the top and bottom surface with those grooves receiving inwardly directed lugs  97  ( FIGS. 4, 6B and 10 ) formed on the inner surface along the longitudinal top and bottom center of the upper and lower housing components  46   a  and  46   b  respectively so that when the outer component of the rear motor mount is seated within the housing  46 , the entire rear motor mount is prevented from rotating relative to the motor/gear-reduction unit. The outer segmented cylindrical wall  85  of the outer component is also divided into two axially related half segments  85   a  and  85   b  with the rear segment  85   b  being of slightly smaller diameter than the front segment to assist in mounting the rear motor mount within the housing  46 . A passage  99  also extends through the rear segment to receive the shaft  70  of the motor/gear-reduction unit. 
         [0037]    As mentioned, the inner component  73  is rigid and hard and can be made of plastic or metal. The outer relatively soft component  75  would preferably be of a plastic material having a durometer rating in the range of 30 A to 50 A with the most preferable durometer rating being 38 A. Having the relatively hard component fitted within and cooperating with the relatively soft outer component, a resistance to rotation of the motor relative to the housing  46  is obtained while still absorbing any vibration, which create noise in operation of the motor. 
         [0038]    It has also been found that static electricity will build up when the shade material  20  of a covering  10  incorporating the present invention passes into and out of the headrail  12  for the covering. That static electricity can adversely effect the operation of the motor  30 . To shield or insulate the motor from any such static electricity, a sleeve  101  ( FIG. 4 ) made of a flexible heat-shrink plastic material is shrunk around the housing  46  for the motor/gear-reduction unit  30 / 62  which provides a static electricity barrier to prevent malfunctioning of the motor. 
         [0039]    The hub  40  ( FIG. 3A ) consists generally of a cylindrical body having the longitudinally-extending circumferentially spaced ribs  42  and the end plate  44  at the proximal end thereof. The hub also has longitudinally-extending and radially inwardly directed grooves  80  which slidably receive the fins  36  of the mounting ring  34  as the hub is advanced past the mounting ring into a seated position on the mounting shaft  32  where it is free to rotate. The hub further includes inwardly directed longitudinally-extending grooves  82  adapted to slidably receive the catch tabs  38  of the mounting ring so the hub can be slid over and past the mounting ring. 
         [0040]    It will therefore be appreciated that the mounting shaft  32  and mounting ring  34  are rigidly mounted on the end cap  16  with the hub  40  being rotatably mounted on the mounting shaft. The housing  46  is mounted on the mounting ring and secured thereto with the locking engagement of the flexible arms  50  with the catch tabs  38 . The housing, therefore, projects axially along the length of the headrail  12  so that the drive disk  60  at the distal end of the housing and the housing itself are positioned for receipt within the roller  18  as will be described hereafter with the drive disk being operatively engaged with the roller in supporting relationship to effect reversible rotation thereof via energy provided by the motor  30 . The opposite or left end of the roller is rotatably supported on the left end cap  14  in a conventional manner, which is not illustrated. 
         [0041]    The headrail  12 , which is probably best viewed in  FIG. 3B , has a relatively flat back wall  84 , a flat top wall  86 , and an arcuate front wall  88 . The back wall has a pair of guide channels  90  each of L-shaped cross-section adapted to slidably receive and retain a battery pack  92  for providing energy to the motor  30 . The battery pack includes a pair of longitudinally-extending batteries  94  that are supported on a bracket  96  having guide arms  98  for slidable receipt in the channels  90  so that the battery pack can be slid into position and will remain in position on the rear wall of the headrail so as to be out of sight. At one end of the bracket  96 , an electrical connector  100  protrudes from the battery pack and is adapted to receive an electrical connector on a flat wire conductor  102  seen for example in  FIGS. 3A and 9 , which is operatively connected to the motor in a manner to be described hereafter. A control module  104  is also slidably mounted on the back wall  84  of the headrail in the same manner as the battery pack as is probably seen best in  FIG. 3B . The control module is operatively connected to other components of the covering for controlling its operation as will be explained later. It is of importance to note that control modules for remotely operable retractable coverings for architectural openings have typically been mounted inside a head rail adjacent to an end cap and in this position the width of the fabric had to be limited relative to the overall length of the head rail as the control module itself prevented positioning the edge of the fabric closely adjacent to the end cap. By mounting the control module on the back wall of the head rail as in the present invention, the width of the fabric can be made to be substantially commensurate with the length of the head rail as the lateral edges of the fabric can be positioned closely adjacent to the end caps. Making the width of the fabric substantially commensurate with the length of the head rail allows the fabric to cover a greater portion of the architectural opening than is otherwise permissible with a given length of head rail. 
         [0042]    Referring again to  FIG. 4 , at the distal end of the motor/gear-reduction unit  30 / 62 , the front motor mount  66 , as mentioned previously, is positioned and has holes  106  in its proximal end adapted to receive the three longitudinally-extending circumferentially spaced pins  64 . These holes can be seen, for example, in  FIGS. 7 and 8  and become slightly ovular in cross-section ( FIG. 8 ) when stretched so that the circular cross-section of the pins can move relative to the motor/gear-reduction unit in a circumferential direction a small amount within the holes. This helps to absorb vibration when the motor is energized or de-energized, as will become more clear hereafter. 
         [0043]    The front motor mount  66  further includes a large centered axial passage  108  that receives an interconnect  110  as seen best possibly in  FIG. 4  with the interconnect having a proximal shaft  112  extending through the front motor mount and being secured thereto with a snap ring  114 . The proximal shaft has an axial hole  116  ( FIG. 6A ) that receives the non-circular drive shaft  58  of the motor/gear-reduction unit  30 / 62  with the transverse configuration of the drive shaft and the hole  116  being the same and in the disclosed embodiment of D-shape. In this manner, the rotation of the drive shaft is transferred to the interconnect. The interconnect further includes a flat abutment plate  118  adapted to abut against the proximal face of the drive disk  60  and a pair of forwardly and longitudinally extending support legs  120  that are receivable in diametrically opposed passages  122  through the drive disk. The support legs have an enlarged cap  124  on their end so that the resilient drive disk can be inserted onto the interconnect and retained in position. The drive disk further includes a pair of diametrically opposed radially opening grooves  126  of generally trapezoidal transverse cross-section with these grooves adapted to cooperate with the roller  18  as will be explained hereafter in transferring rotation from the motor drive shaft to the roller. 
         [0044]    The interconnect  110  is preferably made of a material that is rigid enough to transfer torque from the drive shaft  58  to the drive disk  60 . While some plastics would be suitable, metals have been found desirable with zinc being the preferred metal. As mentioned, the drive disk is made of a resilient and relatively soft material having a durometer rating preferably in the range of 55 A to 65 A so that there is enough rigidity in the disk to drive the roller while providing a cushioned interface between the drive shaft and the roller. Accordingly, through the soft drive disk vibrations of the relatively hard motor  30  and its drive shaft  58  are reduced significantly while the interconnect and drive disk have enough rigidity to acceptably transfer torque from the drive shaft to the roller. 
         [0045]    The front  66  and rear  68  motor mounts are also made of resilient, relatively soft materials, as mentioned previously, with the durometer rating of the front motor mount being preferably in the range of 50 A to 70 A while the durometer rating of the outer portion of the rear motor mount is preferably in the range of 30 A to 50 A. 
         [0046]      FIG. 6A  is a longitudinal section through the roller  18  showing the motor/gear-reduction unit  30 / 62 , the front motor mount  66 , the interconnect  110 , the drive disk  60 , and the roller  18 , which is operatively engaged with the drive disk. The roller, which is possibly best seen in  FIG. 3B , is generally cylindrical in configuration having a radially inwardly directed longitudinally-extending projection  128  that is adapted to be received in one of the diametrically opposed grooves  126  in the drive disk. This assures a unitary rotation of the roller with the drive disk and with the motor. 
         [0047]    Referring again to  FIGS. 7 and 8 , as mentioned previously, the front motor mount  66  has the holes  106  for receiving the circumferentially spaced pins  64 , which are circular in cross-section, and this relationship between the pins and the motor mount provide a system for absorbing vibration that might otherwise exist when the motor is energized and de-energized.  FIG. 7  shows the pins in the holes when the motor is not being driven, and  FIG. 8  shows the pins shifted to one side of the holes, which become distorted into an ovular shape when the motor is driven in one direction, and it can thereby be seen that that movement is absorbed and cushioned as the pins shift relative to the holes in which they are received. 
         [0048]    The operation of the covering is best appreciated by reference to  FIG. 9  where various components of the covering are shown diagrammatically along with their interconnection. It will first be appreciated that the battery pack  92  mounted on the back wall  84  of the headrail  12  is connected with a flat cable  130  to one end of the control module  104 , which is also mounted on the back wall of the headrail. The control module on an opposite end is connected both to the remote sensor  28  by one flat cable  132  and to an electrical mounting plate  134  with the flat cable  102 , which is also seen in  FIG. 6B . The flat cable  102  going to the electrical mounting plate is electrically connected through the plate to a pair of electrical wires  136  connected to the motor  30  with one of those wires being seen in  FIG. 6B . The electrical plate also interconnects the control module with a timing arm  138  mounted on the end of the rotatable timing pin  70 , which rotates with the motor so that the timing arm intercepts a signal in a conventional manner to count rotations of the timing pin so that any covering having this operating system can be preset through its control module to extend or retract a predetermined amount to cover or uncover an architectural opening in which the covering is mounted depending upon the number of rotations of the timing pin. Such systems are commonly known in the art and, accordingly, a further description thereof is not deemed necessary. 
         [0049]    With the control system as shown in  FIG. 9 , it will be appreciated that information received by the sensor  28 , either from a remote control (not shown) or through a manual switch  140  provided on the remote sensor, can be transmitted to the control module  104  which is energized by the battery pack  92 . That information is used to drive the motor  30  and its gear-reduction unit  62  in one direction or another, which not only rotates the roller  18  about which the fabric  20  for the covering is wrapped or unwrapped, but also counts the rotations of the roller so that the covering can be extended a predetermined amount from the roller to precisely cover the architectural opening in which the covering is mounted. 
         [0050]    It will be appreciated from the above that the motor-drive system utilized in the covering of the present invention has been designed to minimize vibration that creates noise during operation of the electric motor. There are two distinct shock-absorbing components of the motor drive system with one of those components being the drive disk  60 , and the other the front  66  and rear  68  motor mounts. Considerable effort has been given to arriving upon the most desirable durometer rating for these components of the system, as simply making the components harder for better torque transfer or softer for more sound absorption was found not to be the full answer. Rather, various durometer combinations for the components were determined to fall in the ranges mentioned previously, which generated a decibel output of approximately 58 decibels, which was a level found to be acceptable and superior to prior art systems. 
         [0051]    Although the present invention has been described with a certain degree of particularity, it is understood the disclosure has been made by way of example, and changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims.