EP0221826A1 - End stop device for automatically operating roller blinds, roller shutters and other lifting means with rollers - Google Patents

Abstract

1. End-of-stroke device for automatically stopping the drum (1) intended for winding and unwinding the mobile member of a blind, roller shutter or other lifting apparatus, of the type comprising two threaded rods (5, 6) which are angularly connected to the drum (1) and on which are engaged two sliding nuts (7) retained angularly so that the rotation of said rods effects, in opposite directions, the axial displacement of these nuts which, once suitably positioned, successively assume a fixed end of stroke (position 0), provoking actuation of the contactors (12) adapted to ensure stop of the drum at one and the other of the two ends desired for the stroke of the mobile member, characterized in that with each of the two sliding nuts (7) is associated an unlocking mechanism (13-15-17) adapted momentarily to cause angular immobilization of the nut (7) in question to cease so that the latter rotates with respect to its threaded rod (5, 6) under the effect of elastic means (14) and thus returns as far as the fixed end-of-stroke with a view to a new adjustment.

Description

The present invention relates to limit switch devices intended to equip blinds, roller shutters or other lifting devices with a view to ensuring, in combination with an electric switch with manual actuation, the automatic stopping of the rotating drum for the moving and unwinding of the movable member of said devices.

We know that in their conventional construction, devices of this type include two threaded rods which are angularly linked to the rotating drum and on each of which is engaged a sliding nut, angularly immobilized so that the rotation of the aforementioned drum and the rods causes the longitudinal displacement of said nuts along them. Each of these sliding nuts is associated with a stop which is actuated when the envisaged nut arrives at one of the ends of its alternating travel and which, by means of a push-button, acts on an electrical contactor inserted on the circuit. power supply to the drum drive motor so as to stop it.

Things are arranged so that the two sliding nuts move in opposite directions, so that with an adequate initial positioning of both of these two nuts, it can be obtained that the drum stops automatically when the movable member (canvas, apron or the like) of the controlled device arrives at either end of its travel.

The difficulty therefore lies in the initial adjustment of the device as a function of the total stroke of the movable member, it being observed that in almost all cases, the nuts are practically inaccessible, the device being most often housed inside the rotating drum. Also, in order to facilitate the adjustment operation, have the limit switches of the above-mentioned type been made to comprise two independent clutch release mechanisms, the operation of which by the installer makes it possible, on the one hand, to temporarily dissociate the threaded rod corresponding drum, on the other hand to act on the stop or the push associated with it in order to close the corresponding contactor.

It is therefore understandable that if the manufacturer takes care to deliver his devices with the two sliding nuts in the disengaged position and pressing against their stop, the installer only has to operate the reversing switch in one direction to bring the member movable at one of the ends desired for its stroke and to restore things by actuating the declutching mechanism, the operation being repeated in the same way for the opposite end of the stroke of the movable member. In other words, it is by successively bringing the movable member to the two ends of its travel using the motor and by acting each time on the corresponding declutching mechanism that the initial adjustment of the limit switches.

A difficulty remains: in the event that he made a false maneuver during the initial adjustment or if he wishes to modify it thereafter, the operator ignores the exact positioning of the sliding nuts, so that the new adjustment requires a succession of particularly delicate maneuvers.

It is to this drawback that the present invention mainly intends to remedy, which essentially consists in associating with each of the two sliding nuts an unlocking mechanism capable of temporarily stopping the angular immobilization of the nut considered so that under the effect of elastic return means, the latter rotates relative to its threaded rod and thus returns until the end of its travel for which it bears against its stop.

In order for such a system to function in practice, it is obviously necessary to give the threaded rods a rapid pitch, capable of allowing the nuts to move longitudinally while rotating under the effect of the elastic return means. The latter can very simply be produced in the form of a spring engaged around the threaded rod to bear on the one hand against a fixed point, on the other hand against the corresponding transverse face of the nut, which spring is compressed when this nut moves away from its stop.

Furthermore, it is of course essential that each of the two unlocking mechanisms operates, in addition to the release of the nut associated therewith, the actuation of the electrical control switch, so that the drum drive motor can be supplied despite the fact that the nut is pressed against its stop.

Structurally, each unlocking mechanism advantageously comprises a cage which is made angularly integral with the corresponding sliding nut while allowing the longitudinal displacement thereof. This cage is angularly immobilized by a clamp placed under the dependence of an operating part with angular or axial movement, provided easily accessible as in the case of the declutching mechanism of conventional devices.

• Fig. 1 et 2 sont deux coupes longitudinales schématiques d'un dispositif suivant l'invention.
• Fig. 3 est une coupe transversale agrandie de ce dispositif suivant le plan indiqué en III-III en fig. 1, sur laquelle on a fait apparaître en I-I et II-II les plans de coupe des fig. 1 et 2.

The appended drawing, given by way of example, will allow a better understanding of the invention, the characteristics which it presents and the advantages which it is capable of providing:

• Fig. 1 and 2 are two schematic longitudinal sections of a device according to the invention.
• Fig. 3 is an enlarged cross section of this device along the plane indicated in III-III in FIG. 1, on which we have shown in II and II-II the section planes of FIGS. 1 and 2.

In this drawing, it has been assumed that the end-of-travel device is mounted inside the rotating drum 1 which provides for the unwinding and unwinding of the fabric of a blind device. This drum 1 is driven in rotation by an electric motor (not shown) which is itself enclosed by said drum and whose manual control in both directions of rotation is ensured by an inverter switch suitably connected to the supply circuit. electric of said motor, the limit switch device shown being intended to automatically cut the power to this motor when the fabric arrives at one or the other of the two ends of its race.

The device is entirely housed inside a tubular frame 2 which at one of its ends (on the left in fig. 1 and 2) is supported by a fixed bush 3, which contains a reducing mechanism whose entry is angularly linked to the drum 1. The output shaft of this mechanism drives, in opposite directions, two pinions 4 wedged on threaded rods 5 and 6 oriented parallel to one another. On each rod 5 and 6 is engaged a sliding nut 7 and it is understood that if it is assumed that each nut 7 is angularly retained, the rotation of the two rods in opposite directions causes the longitudinal displacement of said nuts themselves in opposite directions (an identical result would be obtained using two threaded rods rotating in the same direction but provided with opposite threads).

Each of the two nuts 7 cooperates, at one end of its longitudinal travel (on the left in FIGS. 1 and 2), with a stop 8 engaged in sliding action on a smooth part with smaller diameter of the corresponding rod 5, a return spring 9 being associated with said burée 8. Each stop 8 is integral with a crank pin 8 a which is made integral, for example by means of a pin, with a plunger 10 oriented longitudinally, parallel to the two rods Threaded 5 and 6. Each tappet 10 is associated, opposite the socket 3, with a tilting paddle 11 for actuating a microswitch 12 connected to the electrical supply of the drive motor so as to open the circuit thereof when the pallet 11 is not pushed back by the corresponding pusher 10.

The angular retention of each of the two sliding nuts 7 is ensured by a cage 13 of circular section. As shown in fig. 1, the internal wall of each cage 13 comprises, over at least part of its length, a longitudinal notch 13 a in which is engaged a projection or lateral tooth of the nut 7 envisaged. Assuming that the cages 13 are immobilized angularly, it is understood that the cooperation of the aforementioned tooth and the slot 13 prohibits the nut 7 turn on itself while allowing it to move axially along the corresponding threaded rod 5 or 6.

It should be observed that the pitch of the threaded part of each rod 5 or 6 is very rapid (threads very inclined relative to the axis), and that each sliding nut 7 is associated with a spring 14 which is engaged on the rod considered between the nut 7 and the annular bottom of the cage 13 envisaged. This spring 14 is thus compressed when the nut 7 with which it is associated moves away from the bush 3 (displacement from left to right in FIG. 1).

The angular immobilization of each cage 13 is operated by a clamp mechanism comprising a helical spring 15 (fig. 3) which is wound on the thinned end of said cage turned towards the side of the micro-contacts 12. One of the ends of each spring 15 is moored at a fixed point formed by a cylindrical flange 16 a secured to a transverse partition 16 of the tubular frame 2, while the opposite end is introduced into a notch 17 a made in an operating bar 17, oriented parallel to the pushers 10 and to the threaded rods 5 and 6.

The radial pressure applied by the turns of each spring 15 on the end of the corresponding cage 13 well ensures the angular retention of the latter. On the other hand, when the envisaged bar 17 is pivoted, these turns deviate and angularly release the cage 13 which can then rotate on itself, the spring 15 thus playing the role of an unlocking mechanism for the nut 7 associated with it.

Opposite the spring or clamp 15, each bar 17 is equipped with a small operating lever 18, accessible from the outside of the drum 1 of the blind device. The opposite end of each of these bars, supported by the partition 16, carries, beyond the latter, a sloping ring which cooperates with an inclined shoe integral with one or the other of the two pallets 11, so that the angular operation of each of the bars 17 simultaneously controls the spring 15 when unlocking and actuating the corresponding micro-contact 12.

Consequently, the operation and the mode of use of the limit switch device can easily be deduced from the foregoing explanations.

If during the first installation of the blind device the two sliding nuts 7 are assumed to be in position 0 corresponding to the pressing of said nuts against their stop 8, to adjust the first limit switch, the installer operates angularly one of the two levers 18, which has the effect of releasing the corresponding cage 13 and actuating the micro-contact 12 envisaged. The electric motor of the blind device can be powered by the manual change-over switch in order to bring the fabric to the desired end of travel.

During this operation, the sliding nut 7 of the cage 13 which has remained angularly immobilized has moved along its threaded rod 5 or 6 by compressing the spring 14 which is associated with it. This nut is positioned and the installer can return the lever 18 to the normal operating position.

The operations are repeated in the same way for the opposite limit switch, that is to say operation of the other lever 18, actuation in the opposite direction of the reversing switch and return of the lever 18 in the normal position. The two nuts 7 are then positioned and will automatically cut off the power to the electric motor each time they come to bear against their stop 8, in the same manner as in conventional limit switch devices.

In the event of an error or false operation during the adjustment operations, or if the blind device must, after disassembly, be installed on a window having dimensions which imply different limit switches for the fabric, it is sufficient to operator to operate the two levers 18 to return the sliding nuts to position 0, that is to say resting against their stop 8, and be able to carry out a new positioning identical to that described above.

Indeed, the angular actuation of each lever 18 causes, not only the control of the corresponding micro-contact 12 by allowing the supply of the electric motor through the manual change-over switch, but also that of the clamp mechanism associated with the cage 13 envisaged. The release of this cage 13 by opening the helical spring 15 operates the automatic return of the nut towards its stop 8 by rotation of said nut and of its cage 13 around the threaded rod 5 or 6; this return is ensured under the effect of the compressed spring 14 during the preceding stroke of the nut considered and it can occur as a result of the rapid pitch of the threading of the rods 5 and 6.

It goes without saying that one could imagine other means for operating the angular immobilization of the cages 13 and the release of these under the effect of the bars 17. It will be noted that the latter are capable of being operated axially at place and place of the above-mentioned angular control.

It is also understood that the actuation of the contactors 11 can be carried out independently of resetting to 0 using the pushers 10, for example by means of an appropriate circuit.

Claims (4)

1. Limit switch device for automatically stopping the drum (1) intended for winding and unwinding the movable member of a blind, rolling shutter or other lifting device, of the type comprising two threaded rods ( 5, 6) which are angularly linked to the drum (1) and on which are engaged two sliding nuts (7) angularly retained so that the rotation of said rods operates, in opposite directions, the axial displacement of these nuts which a once suitably positioned successively affect a fixed end position (position 0) by causing the actuation of the contactors (12) capable of ensuring that the drum stops at either of the two ends desired for the travel of the movable member, characterized in that each of the two sliding nuts (7) is associated with an unlocking mechanism (13-15-17) able to temporarily stop the angular immobilization of the nut (7) considered in order that this one turns relative to its tig e threaded (5, 6) under the effect of elastic means (14) and thus returns to the fixed end of travel for a new adjustment. 2. Device according to claim 1, characterized in that each threaded rod (5, 6) has a thread with rapid pitch. 3. Device according to any one of claims 1 and 2, characterized in that each sliding nut (7) is mounted inside a cage (13) of which it is made angularly integral and which is immobilized angularly through a clamp mechanism (15) actuated by means of a bar (17) accessible from outside the lifting device. 4. Device according to claim 3, characterized in that the clamp mechanism is formed by a helical spring (15) whose turns are wound around the cage (13) and whose ends are attached one to the bar actuation (17), the other at a fixed point (16 a ).

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