The subject of the invention is a power unit for a roller shutter, in particular a slatted roller shutter installed on the outside of the window. Wherein the roller shutter curtain comprising a series of slats, articulated on their longer edges. This unit can also be used for a roller shutter comprising a movable curtain of a small thickness, for example made of fabric. The power unit according to the invention is intended in particular for use in roller shutters installed on roof windows.

Prior art. It is known from the patent description PL 191038 B1, derived from PCT Application Publication No. WO 00/29706, a power unit for the "Screen device", which has a shaft with drive wheels for moving the roller shutter slats during its unwinding or winding, and has a tubular bar on which such a wound roller shutter is stored. Inside the tubular bar, a drive shaft connected by a toothed or belt gear is located, with a shaft provided with drive wheels, and connected by a spring to a tubular bar. During unwinding of the roller shutter, the tubular bar is driven from the roller shutter slats pulled by a shaft provided with drive wheels, and during unwinding the winding diameter of the roller shutter decreases and the rotational speed of the tubular bar increases. The drive shaft has a constant speed, usually smaller than the tubular bar, therefore, the spring connecting these elements inhibits the movement of the tubular bar tightening the roller shutter. The disadvantage of this solution is the need to bring external driving means to the shaft with drive wheels and to the shaft inside the tubular bar (as indicated in the description), and this requires additional space next to the window for the motor or for the gear transferring hand operation. It is known from the patent description EP 1637693 B1 to provide a solution of the driving means in which the shafts: the drive shaft and the wound roller shutter storing shaft are connected by a belt transmission and a differential planetary gear unit. Roller shutter drives, in particular for thin roller shutters, for example textile roller shutters, are also known, equipped with an electric motor built in the wound roller shutter storing shaft.

Background of the invention. A roller shutter power unit, in particular for the slatted roller shutter, comprising a winding shaft, which is used to store a movable curtain which is composed of slats articulated to one another on their longer edges, and comprises a drive shaft used to move the movable curtain, is characterized in that the drive shaft and the winding shaft are driven by separate electric motors, referred to as the "driving motor" and the "winding motor", respectively. At least one of the two motors has a rotational speed regulated by the controller, depending on the stage of winding of the movable curtain on the winding shaft. The roller shutter comprises the power unit according to the invention, is designed in particular for a roof window in which, due to its inclination in the roof slope and the variable inclination angle of the sash in its open positions, it is difficult or impossible to unwind the movable curtain using gravity. The roller shutter, located outside of the window, has a cassette for storage of the movable curtain in its wound state, placed in particular at the top of the window, in particular on the upper frame member. The roller shutter is connected to the movable curtain guides, placed along the side frame members and the window sash frame. The ends of both shafts, i.e. the winding shaft and the drive shaft, are bearing mounted in the cassette side plates. The drive shaft is located just upstream of the inlet of the movable curtain to the guides. During the movable curtain unwinding, the drive shaft slides subsequent slats into the guides and is supported by the winding shaft that unwinds the stored slats of the movable curtain. When moving in the opposite direction, i.e. winding of the movable curtain, the drive shaft introduces its slats to the cassette, where they are wound on the winding shaft.

Preferably, the electric motor with the rotational speed controlled during the movement of the movable curtain is the winding motor. The rotational speed of the driving motor can be constant or adjustable by the user or the roller shutter manufacturer. The adjustable rotational speed of the driving motor can refer to the full range of movements of the movable curtain, for the use of different speeds of unwinding and winding. This motor can have at least two stages of adjustable rotational speed and there may also exist stageless adjustment of the driving motor rotational speed. The rotational speed of the driving motor adjustable, at least in two stages, in particular by the manufacturer, can only be used in the final sections of movement of the movable curtain to reduce this speed when the movable curtain is moved to its extreme positions. It is also possible to program a small retraction of the movable curtain after reaching the extreme position, fully unwound, in order to obtain alignment of the positions of slats.

In the first embodiment of controlling the movement of the movable curtain of the roller shutter, the power unit control system calculates the angle of rotation of the drive shaft, calculated from one of the two extreme positions of the movable curtain. The angle of rotation of the drive shaft is measured by an encoder, i.e. a transducer for measuring the rotational movement of the motor by calculating the number of pulses sent by a magnet installed on the rotating driving motor pin, read by the sensor fixed in the roller shutter cassette, in particular in the motor set housing comprising the main components: an electric motor and a toothed gear. In addition, the controller calculates the current supplied to both motors: the driving motor and the winding motor.

The readings of the number of pulses from the driving motor are calculated in the controller as the driving force from this motor is transferred by the gear which results in that the number of rotations of the motor and the shaft driven by this motor are different. The number of rotations of the drive shaft calculated in the controller indicates how many movable curtain slats are placed inside the cassette and should be wound on the winding shaft. From the number of slats wound on this shaft, the controller calculates the actual diameter of the movable curtain outer layer wound on the winding shaft, and according to this diameter it determines the required number of rotations of the winding shaft, necessary to maintain the peripheral speed for the actual winding diameter compatible with the linear speed of the movable curtain slats moved by the drive shaft. The control system also calculates the rotation angle of the winding shaft, similarly to the drive shaft, by calculating the number of pulses sent by the magnet installed on the rotating pin of the winding motor. The difference of angles of rotation of the shafts: the winding shaft and the drive shaft calculated by the controller, in relation to the angle of rotation of the drive shaft, is also used to control the winding motor, as this difference of rotation angles indicates whether the actual rotational speed of the winding shaft is appropriate for cooperation with the drive shaft, and in case of any discrepancy, the speed of the winding motor is increased or decreased accordingly.

Calculation of current supplied to the motors: the driving motor and the winding motor, is used to protect the roller shutter and its power unit against overloads that may occur during movement of the roller shutter movable curtain. In the case of excessive resistance to motion or blocking of the movable curtain, the current supplied to the motors increases, and if they reach the maximum admissible values, the power supply to the electric motors is switched off.

In the second control embodiment, the rotational speed of at least one of the electric motors is controlled based on the current calculation of the motor driving the shaft, which cooperates with the movable curtain in the chosen direction of movement of the movable curtain, as second in order. The controlled motor is preferably the winding motor and to control its rotational speed calculations of current are used: in the driving motor, during the unwinding of the movable curtain, and in the winding motor during its winding. During the unwinding of the movable curtain, the lower resistance to motion of the drive shaft, and thus the lower current in the driving motor, signals that the unwinding of the movable curtain from the winding shaft is too fast, which may lead to uncontrolled stacking of slats inside the cassette. In this case, the control system reduces the rotational speed of the winding motor. Increasing current in the driving motor indicates that the winding motor is working too slowly which results in that the movable curtain is tightening between the winding and drive shaft. In this case, the control system increases the rotational speed of the winding motor in order to release the movable curtain faster. During the winding of the movable curtain on the winding shaft, low current in the winding motor indicates that the motor must be accelerated to wind on the winding shaft all slats inserted into the cassette by the drive shaft and thus avoid uncontrolled stacking of these slats in the cassette. The increase of the current in the winding motor signals that its speed and thus rotational speed of the winding shaft should be reduced as the movable curtain is overtightened between the shafts: the winding shaft and the drive shaft.

The shafts placed in the roller shutter cassette: the winding shaft and the drive shaft are hollow and the electric motors: the driving motor and the winding motor driving both shafts, are located inside this shafts. Each of these two motors is part of the motor set, respectively: the driving motor or the winding motor, that has also a toothed gear to reduce the motor speed to the speed needed to drive the shafts. The motor and gear of the motor set are placed in a cylindrical housing, having at one end a collar by means of which the motor set is mounted in one of the side plates of the cassette. The gear shaft pin protrudes at the opposite end of each motor set, with the driver mounted transferring the driving force from the motor set to the shaft, respectively: the driving motor or the winding motor. The drive shaft cooperating on its periphery with the surfaces - external to the window - of the individual slats of the movable curtain, has seats for the slats moved by this shaft. The seats are concave and their shape is adapted to the convex surfaces of the movable curtain slats, located on the side - external to the window - of these slats. Preferably, between the adjacent seats for the movable curtain slats, the drive shaft comprises hooks. During the cooperation of the drive shaft with the movable curtain, these hooks enter gaps between its slats, stretching slightly flexible connectors of adjacent seats. The use of hooks increases the efficiency of transferring the driving force of the individual slats of the movable curtain. It is sufficient to locate the seats for the movable curtain only at the ends of the drive shaft. In particular, these seats are part of the drive wheels which are monolithic with the ends of the drive shaft and are used for its sliding bearing mounting in the cassette. In the second variant, the drive wheels with seats for the slats of the movable curtain are mounted on both ends of the drive shaft and they are separated elements from the shaft ends used for bearing mounting.

Advantageous effects of the invention. The use for the roller shutter drive, in particular the slatted roller shutter, of two electric motors located inside the shafts: the drive shaft and the winding shaft, and controlling their rotational speeds, eliminates the use of complicated and expensive mechanical gear sets. It also eliminates tightening of the roller shutter by means of springs between the drive and winding shafts, and maintaining the unnecessary spring tension while the roller shutter does not move. The motors located inside the two shafts also reduce the dimensions of the roller shutter, in particular the width, which is important when embedding of a set of windows placed next to each other on the roof. In addition, two motors instead of one big motor allow better and more flexible use of the power of both cooperating motors.

An embodiment of the invention. The subject of the invention is illustrated in the embodiment as a power unit for a roof window slatted roller shutter, in the drawing, of which the individual figures show:

• Fig. 1 - Roof window, closed, with a roller shutter partially covering the window - in axonometric view.
• Fig. 2 - The roller shutter cassette - in cross-section with the plane passing through the axes of the shafts: the drive shaft and the winding shaft.
• Fig. 3 - The roller shutter cassette - in cross-section with a vertical plane.
• Fig. 4 - Diagram of the control system of the power unit motors.

The roof window slatted roller shutter has movable curtain 1, comprising slats 11, in a number appropriate to the length of the roof window, articulated to one another on the longer edges of the slats by flexible connectors 12. In the open position of the roller shutter, slats 11 of movable curtain 1 are stored in cassette 2, by winding on the winding shaft 3. Cassette 2 also includes drive shaft 4 that moves slats 11 of movable curtain 1. Roller shutter cassette 2 is mounted on the roof window 5, on upper frame member 51. Roof window also comprises a sash 52 with window pane 53b, embedded in a frame 54 of this sash. The complete sash is fixed in the frame by means of common hinges suitable for the window opening function as a tilting window, i.e. opened by turning the sash about an axis located slightly above half the height of the window, or as hinged window, i.e. opened by turning the sash around the axis at the top of the frame, or also with a double set of hinges, for opening the window in both indicated functions.

The supporting elements of cassette 2 in the roller shutter according to the invention are two side plates: motor plate 21 and bearing plate 22. Motor winding unit 6 is attached to the motor plate 21, in the cylindrical housing of which winding motor 61 and planetary winding gear 62 are embedded, and motor power unit 7 is also mounted, in the cylindrical housing of which driving motor 71 and planetary drive gear 72 are located. In order to unify the roller shutter units, both motor sets 6, 7 have identical construction, whereas differentiation by separate references in the drawing of the present description is due to the fact that each motor set drives a shaft that performs a different function in the roller shutter. Motor set housings 6, 7 have flanges 63, 73, by means of which these sets are fixed to motor plate 21 of the cassette. Flanges 63, 73 are placed in the seats of the motor plate 21, accessible from the outside of cassette 2, and secured with screws (not shown in the drawing). The cylindrical part of winding motor set 6 passes through a port in motor plate 21, and a distal section of the motor set protruding from the motor plate is placed inside winding shaft 3. Similarly, the cylindrical part of motor power unit 7 passes through a port in motor plate 21, and a distal section of the motor set is arranged in the interior of drive shaft 3. Both motor sets 6, 7 have encoders, i.e. transducers for measuring the rotation of motors; in case of winding unit 6 it is winding encoder 64, and in case of motor power unit 7, it is drive encoder 74. Each of the encoders comprises a magnet mounted on the shaft of winding motor 64 or driving motor 7, rotating along with the motor shaft, and of a pulse reader embedded inside the casing of the winding unit: winding motor set 6 or motor power unit 7.

Around the openings through which motor sets 6, 7 pass, the motor plate has monolithic cylindrical pins 23, on which the sliding ends of the shafts are bearing mounted: winding shaft 3 and drive shaft 4. Both shafts: winding shaft 3 and drive shaft 4, in the middle part, have polygonal tube 31 (identical in order to unify parts), and the driving force of motors: winding motor 61 and driving motor 71 for these shafts is transferred by drivers 32, mounted on gear pins protruding from motor set: winding motor set 6 and motor power unit 7. The shape of the circumferential surface of drivers 32 is adapted to the internal contour of polygonal tube 31. Drivers 32 are made of plastic and are mounted by means of metal inserts 33 on the gear pins.

On the opposite to motor plate 21 side of cassette 2, there is a bearing plate 22 equipped with two bearing pins 24 detachably mounted in it, placed in the seats of bearing plate 22, accessible from the outside of cassette 2, and secured with screws (not shown in the drawing). Pin bearing elements 22 cooperating with shafts enter inside cassette 2, and the ends of shafts: winding shaft 3 and driving shaft 4 are sliding bearing mounted on these pin elements.

The ends of the shafts: winding shaft 3 and drive shaft 4, cooperating with cylindrical pins 23 of motor plate 21 and with bearing pins 24 of bearing plate 22, are different in both shafts due to their functions, but identical at both ends of each shaft. In winding shaft 3, there are bearing ends 34 embedded in the interior of polygonal tube 31 which on their protruding outer ends, have cylindrical openings cooperating with pins 23 of motor plate 21, and with bearing pins 24 of bearing plate 22. Bearing ends 34 are used for sliding bearing mounting of winding shaft 3 in roller shutter cassette 2.

Drive ends 41 for a dual function are placed in drive shaft 4. The first of this function is bearing mounting of drive shaft 4 in cassette 2, in the same way as the function of bearing ends 32 in winding shaft 3. The second function is to transfer the driving force from this shaft to individual slats 11 of movable curtain 1, and this function at each drive end 41 is fully provided by a portion of the drive end, formed into the shape of drive wheel 42, protruding from polygonal tube 31. Each of the two drive wheels 42, at its circumference, has concave seats 43, with a shape adapted to the convex surfaces of slats 11 of movable curtain 1, the slats being displaced by drive wheels 42 from cassette 2 to the guides 8, or to the opposite side, from guides 8 to cassette 2. Drive wheels 42 between their seats 43 have protruding hooks 44 which, during the cooperation of drive wheels with slats 11 of movable curtain 1, enter between adjacent slats 11, slightly stretching flexible connector 12 that connects slats, which ensures better, because shaped, transfer of the drive to slats 11 of movable curtain 1. Flexible connector 12 on both edges has profiles entering the recesses at the edges of slats 11 of the movable curtain. Slat 11 located in the movable curtain of in the highest position of all, is connected to winding shaft 3 via limit switch 13, which has a profile on one of its edges entering the recess at the edge of slat 11, identical to that in flexible connector 12. On the other edge, limit switch 13 has a profile entering recess 35 in polygonal tube 31 of winding shaft 3.

Roller shutter slats 11, covering roof window 5, are fixed with their ends in guides 8: right guide and left guide and are displaced in these guides during covering or uncovering the window. The upper ends of guides 8 are connected by the side plates of cassette 2, one with motor plate 21 and the second with bearing plate 22. The lower ends of both guides 8 are connected to frame 54 of sash 52 in the lower corners of this frame. Cassette 2 with the upper frame member 51 of window frame 5 is articulated via axis 28, the connections of guides 8 to the bottom corners of frame 54 of sash 52 are also articulated. This makes it possible to adjust the position of guides 8 to the position of sash 54 in a closed or open window at various stages of opening. In the closed window position (drawing, Fig. 1), guides 8 are arranged parallel to side frame members 54 of sash frame 52. In the open window as tilting window, guides 8, the upper part of the frame, i.e. above the hinges, and the lower part of sash 52 (below the hinges) form a triangle, however due to the variability of the position of the window sash and the roller shutter guides, these guides are compensated for their length.

Roller shutter cassette 2, in addition to the previously discussed parts and subassemblies has also central cover 25, comprising an upper and a lower part located between its side plates: motor plate 21 and bearing plate 22, connected to these plates by means of screws. In the upper part of central cover 25, photovoltaic panel 26 is installed, which generates electric current for motors 61 and 71, while constituting an independent source of electricity, or auxiliary power supply for another source, for example for home electricity network. The side plates of cassette 2, i.e. motor plate 21 and bearing plate 22 have side covers 27 on the outside of the cassette.

The drive unit control system calculates the angle of rotation of drive shaft 4, calculated from one of the two extreme positions of movable curtain 1.

The angle of rotation of this shaft is measured with drive encoder 74, by calculating the number of pulses sent by a magnet installed on the rotating pin of driving motor 71, read by a sensor installed in the housing of motor power unit 7. The control system also calculates the rotation angle of winding shaft 3, similarly to drive shaft 4, by calculating the number of pulses sent by the magnet of winding encoder 64, installed on the rotating pin of winding motor 71. The readings of the number of pulses from the encoders: drive encoder 74 and winding encoder 64 are transmitted to controller 9, where in speed control modules 91, separate for driving motor 71 and winding motor 61, the rotational speeds of the motors: driving motor 71 and winding motor 61 as well as the shafts: drive shaft 4 and winding shaft 3 are calculated. In addition, controller 9 in current control modules 93, separate for driving motor 71 and winding motor 61, calculates the current supplied by controller 9 to both of these motors.

On the basis of information on the rotational speed of drive shaft 4, processor 9 calculates how many slats 11 of movable curtain 1 are inside cassette 2 and should be wound on winding shaft 3, on the basis of which it calculates the current diameter of the outer mobile layer of curtain 1 wound on winding shaft 3, according to this diameter it determines the required number of rotations of winding shaft 3 and winding motor 61 necessary to maintain the circumferential speed, for the current winding diameter, according to the linear speed of movement, of drive shaft 4, slat 11 of movable curtain 1. The difference between the angles of rotation of the shafts: drive shaft 3 and the winding shaft 4, in relation to the angle of rotation of drive shaft 4, is also used to control winding motor 61, as this difference in rotation angles indicates whether the actual rotational speed of winding shaft 3 is appropriate for cooperation with drive shaft 4, for the current stage of winding of the movable curtain on winding shaft 3. In case of a discrepancy processor 93 calculates the respectively increased or decreased rotational speed of winding motor 61. Information on the calculated rotational speed of motors: driving motor 71 and winding motor 61 is transferred to control systems 94, separate for both motors, which regulate the current of motors 61, 71, according to the required rotational speed.

The current supplied to motors: driving motor 71 and winding motor 61, measured in current control modules 93, is used to protect the roller shutter and its power unit against overloads that may occur when moving movable curtain 1. In the case of excessive resistance to motion or blocking of the movable curtain, the current absorbed by motors 61, 71 increases, and if they reach the maximum admissible values, the power supply to the electric motors is switched off.