Patent Publication Number: US-9834986-B2

Title: Architectural covering having a drive mechanism

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the national stage application of International Patent Application No. PCT/NL2013/000009, filed Feb. 27, 2013, entitled “Architectural Covering Having a Drive Mechanism”, which claims priority to Netherlands Patent Application No. 1039407, filed Feb. 27, 2012, entitled “Architectural Covering Having a Drive Mechanism For Extending and Retracting a Covering Member Between Opposite First and Second End Positions,” which are hereby incorporated by reference herein in their entireties. 
     FIELD 
     The invention relates to an architectural covering having a drive mechanism for extending and retracting a covering member between opposite first and second end positions. 
     BACKGROUND 
     It is known for such a drive mechanism to include an electric motor unit that has a stationary end and a rotating end. The rotating end being arranged for rotating a winding core for receiving wound layers of a flexible element. It has further been proposed for such a drive mechanism to also include a spring assist module for compensating the masses of the architectural covering between its opposite first and second end positions. 
     In a known architectural covering, as disclosed in applicant&#39;s international patent application published as WO 2010/089118, the spring assist module is required to be positioned at an outer end of the roller tube because its stationary central shaft requires a fixed connection to one of the mounting brackets. As a consequence the motor unit is arranged at an inward end of the spring assist module and is difficult to reach for adjustment or control. It would for instance be desirable when adjusting the end position limits, that it would not be necessary to disassemble the spring assist and motor units from the roller blind to enable such adjustments. 
     SUMMARY 
     Accordingly it is an object of the present invention to propose an improved drive mechanism for an extendable and retractable covering member of an architectural covering. In a more general sense it is thus an object of the invention to overcome or ameliorate at least one of the disadvantages of the prior art. It is also an object of the present invention to provide alternative structures which are less cumbersome in assembly and operation and which moreover can be made relatively inexpensively. Alternatively it is an object of the invention to at least provide the public with a useful choice. 
     To this end the invention provides an architectural covering having a drive mechanism for extending and retracting a covering member between opposite first and second end positions as defined in one or more of the appended claims. By housing the communication electronics, such as setting of first and second end positions and/or a remote control receiver, in a separate motor head it has become possible to access the appropriate controls without any disassembling. This has been enabled while retaining a fixed attachment for the spring assist module in the proximity of an outside end of a winding core, such as a blind roller. Mechanical changes to an electric motor unit that typically has a driving end and a stationary end are thereby also avoided. This keeps manufacturing costs low as standardized mass produced motor units can be employed as before. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantageous aspects of the invention will become clear from the appended description and in reference to the accompanying drawings, in which: 
         FIG. 1  is an isometric view of a motor head for use in a mechanism for extending and retracting an architectural covering; 
         FIG. 2  is an exploded isometric view of the motor head of  FIG. 1 ; 
         FIG. 3  shows s motor unit and the motor head in an exploded arrangement; 
         FIG. 4  shows the individual elements of  FIG. 3  in an assembled condition; 
         FIG. 5  shows the motor unit and motor head with a spring assist module interposed there between in an exploded arrangement; 
         FIG. 6  shows the spring assist module of  FIG. 5 ; 
         FIG. 7  shows the spring assist module of  FIG. 5  in an exploded arrangement; 
         FIG. 8  is an exploded arrangement similar to  FIG. 5  but now with additional buffer couplings interposed at opposite ends of the spring assist module; 
         FIG. 9  is an isometric view of the buffer coupling of  FIG. 8 ; 
         FIG. 10  is an exploded view of the buffer coupling of  FIG. 9 ; and 
         FIG. 11  shows a roller shade including the mechanism for extending and retracting in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     A motor head  1  for a drive mechanism of an architectural covering, such as roller shade  100  in  FIG. 11 , is shown in  FIG. 1 . The motor head  1  has a housing  3 , an outer end member  5 , and an inner end member  7 . The outer end member  5  has coupling features  9  for engaging a mounting bracket, such as mounting brackets  102 ,  104  of  FIG. 11 . Further the outer end member  5  is provided with an entrance opening  11  for electrical wires  13 . Journalled for rotation between the outer end member  5  and the housing  3  is a rotatable collar  15 . Protruding from the inner end member  7  is an electrical connector plug  17 . As illustrated in the exploded view of  FIG. 2  the electrical wires  13  connect to a printed circuit board (PCB)  19 , which in turn connects to the connector plug  17 . The printed circuit board ( 19 ) is accommodated in the housing  3  of the motor head  1 , and may include at least a selection of end position limit switches, a switch for setting the first and second end positions, electronic communication means, and/or a remote control receiver. Such devices are conventionally accommodated in the same unit that also houses an electric motor unit. According to the invention the motor head  1  does not include an electric motor unit, but merely provides external electrical control for such an electric motor unit. Hence the motor head  1  provides for an electrical interface with an electric motor unit that enables control of motor end positions and/or remote communication. 
     The rotatable collar  15  is journalled for rotation about stationary stub axle  21 , via bearing ring  23 . The stationary stub axle  21  is stationary held to the outer end member  5  by appropriate complementary mating formations  21 A,  21 B. The housing  3  accommodates the printed circuit board  19  and is stationery affixed to the stub axle  21  by means of a screw  25  and a nut  27 . Upon assembly of the motor head  1 , the inner end plug  7  also connects to the stationary housing  3  through mating ribs and serrations. Further the inner end plug  7  is provided with a coupling protrusion  29  for a stationary central shaft, as will be explained herein below. 
     Motor head  1  is shown in  FIG. 3  in an exploded arrangement with an electric motor unit  31 . The electric motor unit  31  has a stationary end  33  and a rotatable driving end  35 . Protruding from the stationary end  33  is an electrical connector socket  37  that is connectable directly, or indirectly, to the connector plug  17 . The driving end  35  is provided with external ribs  35 A to engage mating formations of an inner wall of a winding core, such as blind roller  106  shown in  FIG. 11 . For clarity no winding core or blind roller is shown in  FIG. 3 , but such elements are conventional and well known to the skilled person. Similarly the rotatable collar  15  is also provided with ribs  15 A for engaging mating formations on a surrounding winding core. To prevent the stationary end  33  of the motor unit  31  from sagging against the interior of a rotating winding core, an optional bearing collar clip  39  may be mounted in the vicinity of the stationary end  33  of the motor unit  31 . The outer circumference of the bearing collar clip  39  may be provided with protrusions  39 A for engaging the interior wall of a winding core similar to the ribs  15 A and the ribs  35 A. 
     In one arrangement optionally to the invention as shown in  FIG. 4  the motor head  1  may be directly coupled to the electric motor unit  31 . The bearing collar clip  39  may then be clipped around the connection between the motor unit  31  and the motor head  1 . 
     In  FIG. 5  another optional arrangement of the motor head  1  and motor unit  31  is shown. In the arrangement of  FIG. 5  a spring assist module  41  is interposed between the motor head  1  and the motor unit  31 . This spring assist unit is generally similar to the units described in applicant&#39;s published international patent application WO 2010/089118. For the present description it will therefore be sufficient to briefly describe the components that form the spring assist unit  41 . A helically wound torsion spring  43  at one end engages a first plug member  45  that in turn can drivingly engage a winding core (such as blind roller  106  in  FIG. 11 ). The first plug member  45  is rotatably journalled about a stationary central shaft  49 . Another end of the helically wound torsion spring  43  engages a second plug member  47 , which is designed to allow free rotation with respect thereto of a surrounding winding core. However that second plug member  47  non-rotatably engages splines on the stationary central shaft  49 . The stationary central shaft  49  is hollow, so that electrical conduits may extend through its center. Rotatably surrounding the stationary shaft  49  adjacent to the second plug member  47 , is a bearing web  51  that is designed to engage an inside of a surrounding winding core, when present. At the opposite end of the spring assist module  41  and beyond the first plug member  45 , a shaft coupling  53  is non-rotatably fitted to the stationary shaft  49 . At the same end it is seen that electrical connector sockets  37 A extend from the shaft coupling  53  to connect to the connector plug  17  of the motor head  1 . A connector plug  17 A extends from the stationary shaft  49  at an opposite end of the spring assist module  41  for coupling to the connector sockets  37  of the motor unit  31 . 
     As shown in more detail in  FIGS. 6 and 7  the spring assist module  41  has an electric cable  55  extending through the hollow interior of the splined stationary shaft  49 . One end of the cable  55  is provided with the connector sockets  37 A, while the other end of cable  55  is provided with the connector plug  17 A. It will be clear to the skilled person that it would also be possible to form the electrical conduit integrally within the hollow interior of the stationary shaft  49 . Similarly the electrical connector plugs and sockets may also be integrated with the ends of the stationary shaft  49 . The shaft coupling  53  may be fixedly clamped to the stationary shaft  49  by a first set screw  59  engaging a nut  59 A in the shaft coupling  53 . The shaft coupling  53  may also be clamped to the coupling protrusion  29  of the inner end member  7  of the motor head  1  by a second set screw  61 , engaging a corresponding nut  61 A in the shaft coupling  53 . In a still further elaborated optional arrangement, illustrated in  FIG. 8 , additional buffer coupling  63  are interposed at each opposite end of the spring assist module  41 . One of the buffer couplings  63  may be an integral part of the electric motor unit  31  and thus may form the stationary end (such as  33  in  FIGS. 3, 4 and 5 ) attached to an electric motor  65 . The motor head  1  is merely schematically represented in  FIG. 8 , but may be similar in shape to the motor head shown in the other Figures. The buffer coupling  63  is shown in more detail in  FIGS. 9 and 10 . The buffer coupling  63  includes a first connector  67  that can non-rotatably engage the splined stationary central shaft  49  and be clamped thereto by a set screw  69  that engages a nut  69 A positioned in a cavity of the first connector  67 . A second connector  71  is adapted to non-rotatably engage either one of the electric motor  65 , or the exposed end  57  of the shaft coupling  53 . Suitable formations on confronting faces of the first and second connectors  67 ,  71  engage complementary formation of a resilient block member  73 , interposed between these confronting faces. The resilient block member  73  can conveniently be a rubber part or some other resilient configuration. Again all of the first connector  67 , the resilient block member  73 , and the second connector  71  have a central through bore to allow an electrical connecting cable  75  to extend there through. The addition of buffer couplings  63  assists in absorbing torque changes and start and stop impacts of the motor unit  31  and spring assist module  41  that would otherwise be transmitted to the motor head  1 . 
       FIG. 11  shows one type of architectural covering in which the extending and retraction mechanism of the present invention may be employed. This architectural covering is in the form of a roller blind  100  that has a blind roller  106  that is mounted for rotation between opposite first and second mounting brackets  102 ,  104 . A flexible screening material such as a shade cloth  108  is windable to and from the blind roller  106  to be extended within or be retracted from an architectural opening (not shown in  FIG. 11 , but conventional). To assist in unwinding the shade cloth  108  from the roller  106  a weight bar  110  is attached to the bottom of the shade cloth  108 . The extension and retraction mechanism according to the various embodiments described herein above may be entirely accommodated with the hollow interior of the blind roller  106 , which acts as a winding core for a flexible element in the form of shade cloth  108 . The motor head  1  of the various embodiments will have its outer end member  5  non-rotatably engaged by one of the mounting brackets  102  or  104 . The electrical wires  13  extending from the outer end member  5  can thereby easily connect to a power source or electrical switchgear. Alternatively or additionally mechanical switches or optical eyes provided in the motor head can be positioned within reach of an external tool or operation device. 
     Accordingly a mechanism is disclosed for extending and retracting an architectural covering member  108  between opposite first and second end positions. The mechanism includes an electric motor unit  31  having a stationary end  33  and a rotating end  35  for rotating a winding core, such as a roller blind shaft  106 , for receiving wound layers of a flexible element, such as a sheet of flexible material  108  thereon, and a spring assist module  41 . The mechanism further includes a motor head  1 , separate from the electric motor unit  31 , providing external electrical control for the motor unit  31  and an electrical interface between the motor head  1  and the motor unit  31 . A printed circuit board  19  accommodated in the motor head  1  may include at least one of end position limit switches, a switch for setting the first and second end positions, electronic communication means, or a remote control receiver. The electrical interface may include an electrical connector plug  17 ;  17 A, an electrical socket  37 ;  37 A, and/or an electrical cable  55 ;  75 . 
     The spring assist module  41  may include a helically wound torsion spring  43  that is selected from a predefined range of incremental lengths to best ensure a constant operating force. This can be achieved by taking into account the relevant physical parameters of the architectural covering and the mechanism for extending and retracting, as described in applicant&#39;s published international patent application WO 2010/089118. 
     It is also clear from the foregoing description that the spring assist module  41  and buffer coupling  63  may constitute a modular kit of self-contained parts that each may selectively be combined individually with the motor unit  31  and motor head  1  in any number between zero and two. 
     It is thus believed that the operation and construction of the present invention will be apparent from the foregoing description. To the skilled person in this field of the art it will be clear that the invention is not limited to the embodiments represented and described here, but that within the framework of the appended claims a large number of variants are possible. Also kinematic inversions are considered inherently disclosed and to be within the scope of the present invention. The terms comprising and including when used in this description or the appended claims should not be construed in an exclusive or exhaustive sense but rather in an inclusive sense. Expressions such as: “means for . . . ” should be read as: “component configured for . . . ” or “member constructed to . . . ” and should be construed to include equivalents for the structures disclosed. The use of expressions like: “critical”, “preferred”, “especially preferred” etc. is not intended to limit the invention. In this regard, the terms in the foregoing description and the appended claims, such as “upper”, “lower”, “right”, and “left”, have been used only as relative terms to describe the relationships of the various elements. Features which are not specifically or explicitly described or claimed may be additionally included in the structure according to the present invention without deviating from its scope.