"TUBULAR GEARMOTOR AND ROLLER SHUTTER ASSEMBLY AND METHOD FOR SETTING THE END POSITIONS THEREOF"
The present invention relates to assemblies or installations comprising a tubular gearmotor and a roller shutter member actuated by such gearmotor for closing openings in buildings and/or for the protection from sunlight. The roller shutter member can be for example a roller blind, a rolling shutter, a sunblind and the like fitted to windows or doors.
The general structure of these known assemblies comprises an electric motor and a gear reduction unit, in the following jointly referred to as a gearmotor, an electromagnetic brake unit and a unit for setting the limit (end) positions, all the above components being housed inside a single tubular member on/from which the roller shutter member is wound/unwound. The drive shaft of the reduction gear protrudes from one end of the tubular member while the other end is firmly secured to an anchor member or fixture such as for example the masonry housing the roller shutter box of a roller blind.
The drive shaft of the reduction gear transmits the rotary motion to the winding tube of the roller shutter member through a pulley to which it is keyed. In the known devices, the motor is usually a single-phase asynchronous motor equipped with two windings in order to obtain the rotation in both directions. The tubular member on which the roller shutter member is wound and which contains all the components is known as tubular gearmotor.
After the tubular gearmotor and the roller shutter member have been installed, the unit for setting the limit positions is used for defining the (winding and unwinding) end positions of the roller shutter member, i.e. the end positions that shall be reached when the control switch has been actuated.
For setting the two limit positions there are known mechanical devices comprising two microswitches, one for each rotating direction, which are controlled (e.g. opened to stop the motor) in accordance with the angular position of the tube through an arrangement of thread rods located inside the limit switch unit, such a device being mechanically controlled by the rotation of the annular crown of the winding tube. The setting of the limit positions is achieved by manually causing the motor rotation through external setting screws laterally located on the crown or
through equivalent means. Such a setting method is long and does not allow a great accuracy.
Gearmotors with electronic setting of the limit positions have been suggested which nevertheless require additional cabling for the connection to an external programming keyboard and are therefore not compatible with existing roller shutter assemblies.
It is therefore an object of the present invention to overcome the drawbacks and limitations of the prior art methods and roller shutter - gearmotor assemblies so as to render the setting of the limit positions a very simple and quick operation. The above objects of the present invention are achieved through a method as claimed in claim 1. In accordance with a further aspect, the present invention comprises a roller shutter member/tubular gearmotor assembly as claimed in claim 7. Additional advantageous features are recited in the dependent claims.
Particularly, thanks to the present invention the setting of the limit positions is accomplished in a quick and simple manner, and quite safely for the operator.
The invention will now be disclosed hereinbelow with reference to the attached drawings of a preferred but non limiting embodiment, in which:
Fig. 1 is a schematic view of a window to which a roller shutter/gearmotor assembly according to the invention has been fitted; Fig. 2 is a block diagram of the control system.
Throughout the figures the same references have been used to indicate components that are equal or substantially implement equivalent functions.
With reference to Figures 1 and 2, a tubular member 5 housing a gearmotor assembly 1 and the other components, on which a roller shutter member 2 e.g. a roller-blind is wound, is mounted at the top of a window 3, usually inside a roller shutter box that can be either protruding from or incorporated inside the masonry. As better illustrated in the enlarged detail of Fig. 1 , on the gearmotor there is located a push-button S which constitutes a control input to a microprocessor 10 which controls the gearmotor, as better illustrated in detail hereinbelow. Reference S will be used to indicate the microprocessor input as well as the push-button generating a signal to such input. Of course additional control inputs to the microprocessor can be provided.
In a known manner, the microprocessor 10 is responsive to a single closing of the switch S, or to a predetermined number of closings occurring within a given time
interval. A cable 4 outcoming from the gearmotor assembly comprises four insulated electric conductors, respectively one for the rising and one for the descending motion of the member 2, a common conductor and an earth or ground conductor.
A switch S1 , for instance a wall-mounted switch, is provided to control the winding and the unwinding of the roller shutter 2, by properly feeding the motor of the gearmotor 1. In normal operation, by keeping the switch S1 pressed for a proper length of time, the bottom end of the roller shutter 2 can be positioned at any desired position between the two extreme positions defined as top and bottom limit positions. In the following, the terms motor and gearmotor are used to briefly indicate also the shaft of the gearmotor.
With particular reference now to the block diagram of Fig. 2, the assembly control unit 8 comprises a microprocessor 10 connected to the gearmotor 1 (as a matter of fact to the motor of this latter) to cause the motor rotation, and therefore the winding and unwinding of the roller shutter 2, and a memory M. The actuation of the gearmotor 1 is implemented through the switch S1 connected to the control unit 8. For simplicity sake, no supply connection has been shown in the Figure. The memory M connected to the microprocessor 10 is, for example, of the EEPROM type (electrically erasable programmable ROM) in which programs and data have been stored at the factory and in which the limit position information will be stored after the assembly has been installed. The control input S, which is preferably but not exclusively implemented as a push-button, is an input through which controls can be directly applied to the microprocessor 10.
The method according to the invention for setting (adjusting) the roller member limit positions, i.e. for storing in the control system the end positions at which the motor will be disabled even in the case a pressure is maintained on the switch S1 , shall be illustrated in the following. This setting is usually accomplished after the assembly has been installed, and possibly repeated later on to compensate changes caused by the settling of the assembly with time.
The switch S1 is firstly positioned so as to cause the gearmotor to rotate in a selected direction, for example for causing an upward rotation. Since the limit positions have not yet been stored, this action does not really cause the starting of the gearmotor 1 : this operation is equivalent to merely enabling the rotation of the motor in a given direction, which could be accomplished also by other means. Then the
operator presses the push-button S, which causes the starting of the motor and the consequent raising of the roller shutter 2, and keeps it pressed until the desired top limit position is reached, i.e. the position at which the roller shutter is wound as much as possible (compatibly with the constraints of the window arrangement) around the tube 5. At this point the operator releases the push-button S thus stopping the motor.
Then the operator presses the push-button S three times, one after the other, thus generating a sequence of three pulses on the control input of the microprocessor, thus causing the top limit position (or more generally the first limit position) to be stored in the memory M of the control system. The first limit position is preferably stored in the memory M as a reference position.
Then, the operator moves the switch S1 to the position allowing the rotation of the gearmotor downwards and presses the push-button S until the bottom limit position is reached, i.e. the position at which the roller shutter abuts against the windowsill 3 (or the floor in the case of a French window). At this point, the operator releases the push-button S thus stopping the motor and, by pressing the push-button S three times, one after the other, causes the second limit position to be stored in the memory M of the control system, the position being in the present case the bottom position. The second limit position is preferably stored as a predetermined rotation counted from the reference position defined by the first limit position. At this point the setting is complete and from now on, the rotation of the motor started by an actuation of S1 , if not stopped before reaching an end position, will automatically and quite precisely be stopped at one of the two set limit positions.
Should it become necessary to correct or change the setting of the limit positions, for example because of one or more of the above mentioned reasons, the stored set values can be erased from the memory, for example by uninterruptedly pressing the push-button S for 5 seconds. After such an operation, the system is restored to a condition similar to that preceding the setting operation, and new limit positions can be set and stored as disclosed above.
Although the present invention has been illustrated with reference to an actually preferred embodiment, it is generally subjected to other applications and modifications which fall within the scope of the invention, as it will be evident to the skilled of the art.