The present invention relates to an automatic sliding-door power-drive assembly.

More in detail, the present invention relates to a power drive assembly for supporting and automatically moving sliding doors. Use to which the following description will make explicit reference without this implying any loss of generality.

As is known, a sliding door is a door structure which is installed over a through opening in a general wall, and essentially consists of one or, more often, two rectangular-shaped sliding shutters, which are vertically fixed to/suspended from the wall with the capability to horizontally movable, while remaining on their vertical laying plane, so as to be movable to and from a closed position, in which the sliding shutter(s) are arranged at the opening in the wall, usually adjacent to each other, so as to completely close/ obstruct such opening in order to prevent people and/or things from transiting.

On the other hand, the automatic sliding-door power drive-assemblies are rigidly anchored to the wall, immediately above the opening on which the sliding door is located, and are structured to directly support the sliding shutter(s) and also be able to move the sliding shutter(s) horizontally to and from the closed position, while keeping them on their vertical laying plane.

More in detail, the automatic sliding-door power-drive assemblies generally comprise: a straight load-bearing longitudinal member, which is adapted to be fixed in a horizontal position grazing the wall, immediately above the opening on which the sliding door is located; a series of shutter-supporting carriages which are fixed on the longitudinal member with the possibility to slide freely along the longitudinal member, parallel to the longitudinal axis of the same longitudinal member, and are provided with a protruding appendage that cantilevered projects downwards from the longitudinal member and is structured to support the sliding shutter of the door, while keeping the same shutter substantially coplanar to the longitudinal supporting member; and finally an electrically-operated carriage drive system which is directly fixed on the longitudinal member and is capable of moving the shutter-supporting carriages back and forth along the load-bearing longitudinal member, so as to synchronously move the sliding shutter(s) parallel to the longitudinal axis of the longitudinal member.

More in detail, automatic sliding-door power-drive assemblies currently on the market are provided with a longitudinal driving belt which is looped and tightened around two substantially coplanar return pulleys that are fixed in an axially rotatable manner on the longitudinal member, close to the two axial ends of the longitudinal member; and with an electric motor which is attached to the longitudinal member, close to one of the two return pulleys, and is connected to such a return pulley by means of a mechanical gear reducer which allows the electric motor to drive the return pulley into rotation.

The single shutter-supporting carriages are fixed to the upper straight section or to the lower straight section of the driving belt, so as to follow the movements of the belt; whereas the electric motor is able to drive the return pulley into rotation in both rotation directions, so as to move the two straight sections of the driving belt back and forth in opposition to each other, thus synchronously moving the shutter-supporting carriages back and forth along the longitudinal member.

In most power-drive assemblies, in particular, the load-bearing longitudinal member is provided with two horizontal flat shelves that cantilevered project from the wall, one above the other, while remaining parallel to the ground. The lower shelf is provided with a straight rail along which the shutter-supporting carriages slide, while the upper shelf supports the carriage drive system.

In addition, the above-mentioned power-drive assemblies are moreover provided with a removable protective casing that cantilevered projects from the upper shelf and extends downwards so as to be arranged straddling the lower shelf, thus to close the space in front of the rail on which the shutter-supporting carriages slide.

The above-mentioned power-drive assemblies are finally provided with an electronic control unit which controls the electric motor and is suspended below the upper shelf of the longitudinal member, beside the electric motor; and with a presence sensor which is fixed outside the protective casing by means of self-tapping screws, more or less in the middle of the load-bearing longitudinal member, and is connected to the back-located electronic control unit by means of a long electric cable, so as to control opening and closing of the door.

Unfortunately, location of the presence sensor on the protective casing creates many problems during initial installation and subsequent maintenance of the power-drive assembly.

During the operations of calibrating and/or maintaining the power drive assembly, in fact the installer technician must remove the protective casing to continuously access all the components fixed to the longitudinal member, and at the same time must repeatedly operate the power-drive assembly under normal operating conditions. Operation quite uneasy to perform and which necessarily requires the simultaneous presence of two people, considering that the presence sensor is integral with the protective casing and that the protective casing is not attached to the longitudinal member.

Aim of the present invention is to simplify and speed up the installation and routine and/or extraordinary maintenance of the apparatus.

In compliance with the above aims, according to the present invention there is provided an automatic sliding-door power-drive assembly as defined in claim 1 and preferably, though not necessarily, in any one of the dependent claims.

The present invention will now be described with reference to the accompanying drawings, which show a non-limiting embodiment thereof, in which:

• figure 1 is a perspective view, with parts in section and parts removed for clarity, of a sliding door equipped with an automatic sliding-door power-drive assembly realized in accordance with the teachings of the present invention;
• figure 2 is a front view, with parts removed for clarity, of the sliding door in figure 1;
• figures 3 and 4 are two side views, with parts removed for clarity, of the automatic sliding-door power-drive assembly in Figure 2, sectioned along section line A-A; whereas
• figures 5 and 6 are two perspective views of some components of the power-drive assembly shown in figure 1.

With reference to figures 1, 2, 3 and 4, reference numeral 1 indicates as a whole an automatic sliding-door power-drive assembly which is designed to support and horizontally move the sliding shutter(s) of a sliding door.

More in detail, the automatic sliding-door power-drive assembly 1 is structured so as to be rigidly fixed/attached on wall P, where the sliding door 100 is located, just above the sliding door 100 to be driven, and is able to support the sliding shutter(s) 101 forming said sliding door 100.

In the example shown, in particular, the sliding door 100 is preferably provided with two substantially rectangular, flat sliding shutters 101 which are fixed to/suspended from the power drive assembly 1 so as to be vertically arranged and locally substantially coplanar and adjacent to each other; and the power-drive assembly 1 is structured so as to move the two sliding shutters 101 in a horizontal direction d locally parallel to the laying plane of the sliding shutters 101, so as to move the two sliding shutters 101 preferably in opposition to each other, to and from a closed position (see figure 2) in which the two sliding shutters 101 are stationary at the opening on wall P, preferably closely shut to each other, so as to substantially completely close/obstruct such opening and prevent people and/or things from transiting.

Preferably, though not necessarily, the two sliding shutters 101 of door 100 are furthermore designed so that their straight bottom edge rests in axially sliding manner on a horizontal straight rail (not shown) extending, grazing the ground, substantially coplanar to the laying plane of the two sliding shutters 101.

Therefore, the automatic sliding-door power-drive assembly 1 is structured to at least partly support the two sliding shutters 101 of sliding door 100, and to horizontally move the two sliding shutters 101 in direction d to and from the closed position, while keeping the two sliding shutters 101 on their laying plane.

More in detail, with reference to figures 1, 2, 3 and 4, the automatic sliding-door power-drive assembly 1 comprises:

• a straight load-bearing longitudinal member 2 which is arranged in substantially horizontal position, above the sliding door 100 to be driven;
• a plurality of shutter-supporting carriages 3, each of which is slidingly mounted on the longitudinal member 2 with the capability to slide freely along the longitudinal member 2 parallel to the longitudinal axis L of longitudinal member 2, preferably substantially along the whole length of the longitudinal member 2, and is furthermore structured to be rigidly fixed to the body of a respective sliding shutter 101 underneath; and
• a carriage moving device 4 which is rigidly fixed on the longitudinal member 2 and is structured to move the various shutter-supporting carriages 3 back and forth along the longitudinal member 2.

More in detail, the load-bearing longitudinal member 2 is adapted to be anchored/fixed in rigid manner on wall P in a substantially horizontal position and also locally substantially grazing the wall P, immediately above the opening on which the sliding door 100 is located, so as to be substantially coplanar to the two sliding shutters 101.

The load-bearing longitudinal member 2 is preferably moreover provided with two flat projecting shelves 5, 6 which are arranged parallel to and facing each other, so as to cantilevered extend from wall P one above the other while remaining substantially parallel to the ground, i.e. horizontal, when the longitudinal member 2 is fixed in horizontal position on wall P. Preferably, the top flat shelf 6 of longitudinal member 2 is also wider than the bottom flat shelf 5, so as to cantilevered extend beyond the edge of the bottom flat portion 5 of the longitudinal member 2.

The shutter-supporting carriages 3 rest on the lower shelf 5 of the longitudinal member 2 with the capability to freely slide along the lower shelf 5, parallel to the longitudinal axis L of longitudinal member 2, preferably substantially along the whole length of the longitudinal member 2.

More in detail, with reference to figures 1, 2, 3 and 4, in the example shown, the shutter-supporting carriages 3 are preferably fitted in an axially sliding manner on a straight rail 7 which is located on the upper face of the bottom flat shelf 5 of longitudinal member 2, and which extends parallel to the longitudinal axis L of longitudinal member 2, preferably substantially along the whole length of the longitudinal member 2.

In other words, the shutter-supporting carriages 3 are located inside the straight channel laterally delimited by the two flat projecting shelves 5 and 6 of longitudinal member 2, with the capability to move inside the channel parallel to the longitudinal axis L of longitudinal member 2.

In addition, with reference to figures 2, 3 and 4, each shutter-supporting carriage 3 is preferably provided with a projecting bottom appendage 8 that cantilevered extends downwards from the longitudinal member 2, or better from the bottom flat shelf 5 of longitudinal member 2, and is structured to be rigidly fixed to the body of the corresponding sliding shutter 101 preferably, though not necessarily, by means of anchoring screws.

Preferably the projecting bottom appendage 8 is moreover structured to keep the same sliding shutter 101 locally substantially coplanar with, or in any case substantially parallel to, the load-bearing longitudinal member 2.

With reference to figures 1, 2, 3 and 4, the carriage moving device 4 is instead suspended/fixed below the upper shelf 6 of longitudinal member 2, so as to face the shutter-supporting carriages 3, and is preferably designed so as to move the shutter-supporting carriages 3 in a synchronous manner back and forth along the longitudinal member 2, thus to move the sliding shutters 101 parallel to the longitudinal axis L of longitudinal member 2 in opposition to each other.

More in detail, the carriage moving device 4 is preferably fixed/attached in a rigid and stable, though easily removable manner, below the top flat shelf 6 of longitudinal member 2, and preferably comprises:

• two pulleys 9 and 10, which are fixed in axially rotatable manner on the longitudinal member 2, preferably close to the two axial ends of longitudinal member 2, so as to be substantially coplanar to each other and have the respective rotation axes 9a and 10a locally substantially perpendicular to the longitudinal axis L of longitudinal member 2;
• a driving belt 11 which is looped and tightened around the two pulleys 9 and 10 so as to form two adjacent straight sections, which are locally substantially parallel to the longitudinal axis L of the longitudinal member 2, and locally substantially face the bottom flat shelf 5 of the longitudinal member 2; and
• an electric motor 12 which is fixed on the longitudinal member 2 close to return pulley 10, and is mechanically connected to pulley 10 so as to drive it into rotation about the rotation axis 10a.

More in detail, the return pulley 9 is preferably fixed in axially rotatable manner on a supporting bracket 13 that cantilevered extends downwards from the lower face of upper shelf 6 of longitudinal member 2, and is preferably structured so as to be fixed/attached to the upper shelf 6 of longitudinal member 2 in a rigid and stable, though easily removable manner.

More in detail, the supporting bracket 13 is preferably provided at the top with a coupling head which is shaped/structured so as to engage and lock in a rigid and stable, though easily removable manner, inside a longitudinal straight groove 14 which preferably has a substantially T-shaped cross section and extends along the lower face of the top flat shelf 6 of longitudinal member 2 parallel to the longitudinal axis L of longitudinal member 2, preferably along the whole length of longitudinal member 2.

With reference to figures 3 and 4, similarly to pulley 9, also return pulley 10 is preferably fixed in axially rotatable manner on a second supporting bracket 15 which cantilevered extends downwards from the lower face of the upper shelf 6 of longitudinal member 2, and is preferably fixed to the upper shelf 6 of the longitudinal member 2 in a rigid and stable, though easily removable manner.

More in detail, the supporting bracket 15 is preferably provided at the top with a coupling head which is shaped/structured to engage and lock inside the longitudinal groove 14 on the lower face of the top flat shelf 6 of longitudinal member 2 in a rigid and stable, though easily removable manner.

In addition, the supporting brackets 13 and 15 of the carriage moving device 4 are preferably designed so as to keep, when they are fixed to the upper shelf 6 of longitudinal member 2, the two return pulleys 9 and 10 substantially facing the bottom flat shelf 5 of longitudinal member 2, with the respective rotation axes 9a and 10a locally substantially perpendicular to the longitudinal axis L of longitudinal member 2, and also substantially horizontal, i.e. perpendicular, to the laying plane of the sliding shutters 101.

Therefore, the return pulleys 9 and 10 and the driving belt 11 preferably lie on a substantially vertical reference plane which is locally substantially parallel to the longitudinal axis L of longitudinal member 2, and the two horizontal straight sections of driving belt 11 are vertically offset one above the other.

Depending on to the sliding shutter 101 that the shutter-supporting carriages 3 must support, the shutter-supporting carriages 3 are fastened to the lower straight section or to the upper straight section of the driving belt 11 by means of a screw-clamp, so as to follow the movements of belt 11; whereas the electric motor 12 is able to drive pulley 10 into rotation about the rotation axis 10A in both rotation directions, so as to move the two straight sections of the driving belt 11 back and forth in opposition to each other, thus synchronously moving the shutter-supporting carriages 3 back and forth along the load-bearing longitudinal member 2.

With reference to figures 1, 2, 3 and 4, in the example shown, in particular, the electric motor 12 is preferably cantilevered fixed on the supporting bracket 15, coaxial to the rotation axis 10a of pulley 10; and the return pulley 10 is preferably angularly rigidly fitted directly onto the end of the drive shaft of the electric motor 12, so as to be driven into rotation by the electric motor 12 without the interposition of speed reducers.

In other words, the supporting bracket 15 is preferably structured to keep, when the top coupling head is firmly fixed on the upper shelf 6 of longitudinal member 2, the electric motor 12 with its drive shaft locally substantially facing the lower shelf 5 of longitudinal member 2, and with the rotation axis substantially horizontal and locally substantially perpendicular to the longitudinal axis L of longitudinal member 2, i.e. perpendicular to the laying plane of the sliding shutters 101.

With reference to figure 1, the automatic sliding-door power-drive assembly 1 furthermore comprises an electronic control unit 17 which is adapted to control the electric motor 12, and is preferably suspended/fixed below the upper shelf 6 of the longitudinal member 2, preferably in a rigid and stable, though easily removable manner.

More in detail, the electronic control unit 17 is preferably suspended/fixed below the upper shelf 6 of longitudinal member 2 by means of one or more supporting brackets (not shown), each of which is preferably provided with a top coupling head which is shaped/ structured to engage and lock in a rigid and stable, though easily removable manner, inside the longitudinal groove 14 on the bottom face of the upper shelf 6 of longitudinal member 2.

In addition, with reference to figures 1, 3 and 4, the automatic sliding-door power-drive assembly 1 is additionally provided with a longitudinal protective casing 18 which is fixed on the longitudinal member 2, to cover the front portion of the longitudinal member 2 substantially for the whole length of the longitudinal member 2, so as to hide the shutter-supporting carriages 3, the carriage moving device 4, and the electronic control unit 17.

More in detail, the longitudinal casing 18 is preferably fixed on the upper shelf 6 of the longitudinal member 2, preferably in a rigid and stable, though easily removable manner, and cantilevered extends downwards so as to be arranged straddling the lower shelf 5 of longitudinal member 2, in order to close the space in front of rail 7 on which the shutter-supporting carriages 3 slide.

In the example shown, in particular, the longitudinal casing 18 preferably consists of a substantially C-shaped straight section bar which has the upper longitudinal edge structured so as to couple in a rigid and stable, though easily removable manner, onto the top flat shelf 6 of the longitudinal member 2, preferably also forming an extension of the upper shelf 6 of longitudinal member 2, and then cantilevered projects downwards so as to step over the lower shelf 5 of longitudinal member 2 and place the lower longitudinal edge thereof substantially below the bottom flat shelf 5 of longitudinal member 2, in a more or less horizontal position.

With reference to figure 1, the automatic sliding-door power-drive assembly 1 is finally moreover provided with a presence sensor 19 which is stably located immediately outside the longitudinal casing 18, preferably vertically aligned to the center of the opening on wall P.

The presence sensor 19 is an electronic device 19 of known type, which is capable of detecting the presence of things and/or people in the immediate nearby of the sliding door 100, and it is connected to the electronic control unit 17 located behind the longitudinal casing 18 preferably by means of an electric cable (not shown), so as to communicate to the electronic control unit 17 when it is required to move the shutter-supporting carriages 3 for opening and/or closing the sliding door 100 .

More in detail, with reference to standard EN 16005, the presence sensor 19 may preferably be a uniand/or bi-directional opening sensor, an opening and safety sensor, or a safety sensor.

With reference to figures 3, 4, 5 and 6, unlike the currently known automatic sliding-door power drive-assemblies, the presence sensor 19 is however rigidly fixed/attached to the load-bearing longitudinal member 2 by means of an intermediate supporting bracket 20 which is rigidly fixed directly on the longitudinal member 2 and is structured to step over/get around the longitudinal casing 18 and keep the presence sensor 19 stably suspended outside the longitudinal protective casing 18.

More in detail, supporting bracket 20 cantilevered extends downwards from the upper shelf 6 of longitudinal member 2 so as to cantilevered project below the longitudinal casing 18, and is substantially hook-shaped so as to then extend again upwards while remaining locally substantially grazing the outer surface of the longitudinal casing 18; and the presence sensor 19 is rigidly fixed directly on the distal end of the supporting bracket 20, outside the longitudinal casing 18 and close to the same.

Preferably the supporting bracket 20 is furthermore structured so as to couple on the longitudinal member 2, or better on the upper shelf 6 of longitudinal member 2, in a rigid and stable, though easily removable manner.

More in detail, with reference to figures 3, 4, 5 and 6, the supporting bracket 20 is preferably provided at the top with a coupling head 21 which is shaped/ structured to engage and lock, in a rigid and stable, though easily removable manner, inside the longitudinal groove 14 on the lower face of the top flat shelf 6 of longitudinal member 2.

In addition to the above description, preferably the supporting bracket 20 is divided into an unmovable portion 22 which is rigidly fixed to the load-bearing longitudinal member 2, and into a movable portion 23 which directly supports the presence sensor 19 and is movably mounted on the unmovable portion 22; and moreover comprises a locking device 24 which is designed to lock the movable portion 23 to the unmovable portion 22 selectively and in a rigid and stable, though easily releasable manner.

More in detail, the unmovable portion 22 of supporting bracket 20 cantilevered extends downwards from longitudinal member 2, or better from the upper shelf 6 of longitudinal member 2, and is preferably fixed on the longitudinal member 2 in a rigid and stable, though easily removable manner.

In other words, the unmovable portion 22 of supporting bracket 20 incorporates the coupling head 21 which is shaped/structured to engage and lock in a rigid and stable, though easily removable manner, into the longitudinal groove 14 on the top flat shelf 6 of longitudinal member 2.

The movable portion 23 of supporting bracket 20 is instead preferably coupled in floating manner to the unmovable portion 22, so as to be able to move, with respect to the unmovable portion 22, to and from an operating position (see figures 3 and 5) in which the movable portion 23 arranges the presence sensor 19 immediately in front of the longitudinal casing 18, at the minimum distance from the outer surface of longitudinal casing 18 and preferably also substantially at the height of the lower shelf 5 of longitudinal member 2, in such a position to allow the proper functioning of the presence sensor 19.

The locking device 24 is instead designed so as to lock the movable portion 23 to the unmovable portion 22 selectively and in a rigid and stable, though easily releasable manner, when the movable portion 23 is in the operating position.

More in detail, in the example shown, the locking device 24 preferably comprises one or more permanent magnets 25 which are rigidly and unmovably fixed on the unmovable portion 22 and/or on the movable portion 23 of the supporting bracket 20, and are structured so as to magnetically lock the movable portion 23 in a rigid manner to the unmovable portion 22 when the movable portion 23 is in the operating position.

With reference to figures 3 and 4, in the example shown, in particular, the movable portion 23 of supporting bracket 20 is preferably coupled in floating manner to the unmovable portion 22, so as to be able to move, with respect to the unmovable portion 22, between a raised position (see figures 3 and 5) in which the movable portion 23 arranges the presence sensor 19 in front of the longitudinal casing 18, at the minimum distance from the outer surface of longitudinal casing 18 and preferably also substantially at the height of the bottom flat shelf 5 of longitudinal member 2; and a lowered position (see figures 4 and 6) in which the movable portion 23 arranges the presence sensor 19 at the maximum distance from the outer surface of longitudinal casing 18, preferably vertically spaced apart below the longitudinal casing 18, so as to allow/ facilitate the detachment/removal of longitudinal casing 18 from the longitudinal member 2.

More in detail, in the example shown, the movable portion 23 of supporting bracket 20 is preferably pivotally connected/hinged to the unmovable portion 22, so as to be able to at least rotate with respect to the unmovable portion 22 about a rotation axis R substantially horizontal and parallel to the longitudinal axis L of the load-bearing longitudinal member 2.

The locking device 24 instead is structured to selectively lock the movable portion 23 to the unmovable portion 22 in a rigid and stable, though easily releasable manner, when the movable portion 23 is in the raised position.

More in detail, in the example shown, the locking device 24 preferably comprises one or more permanent magnets 25 which are rigidly and unmovably fixed to the movable portion 23 of supporting bracket 20, and are structured so as to be able to magnetically attached to the unmovable portion 22 of supporting bracket 20 when the movable portion 23 is in the raised position.

Obviously, in a different embodiment, the permanent magnets 25 could be rigidly and unmovably fixed to the unmovable portion 22 of the supporting bracket 20, and be structured so as to be able to magnetically attach to the movable portion 23 of supporting bracket 20 when the movable portion 23 is in the raised position.

With reference to figures 3, 4, 5 and 6, in the example shown, in particular, the unmovable portion 22 of supporting bracket 20 preferably comprises a plate-like element 26 which extends perpendicular to the upper shelf 6 of longitudinal member 2 and parallel to the longitudinal axis L, and is provided, close to the lower side edge, with two adjacent straight slits 27 which extend aligned to each other, along a reference axis R locally parallel to the longitudinal axis L of the load-bearing longitudinal member 2.

Preferably the movable portion 22 of supporting bracket 20 is instead provided with two plate-like tabs 28, each of which freely slidingly engages a respective straight slit 27 of plate-like element 26, so as to allow the movable portion 22 to rotate freely with respect to the plate-like element 26 about axis R, and optionally to translate vertically with respect to the plate-like element 26.

Preferably the locking device 24 in turn comprises two permanent magnets 25 which are preferably substantially shaped like a cylindrical pad, and each of which is rigidly fixed to the distal end of a respective plate-like tab 28, so as to abut on the body of the plate-like element 26 when the movable portion 23 is in the raised position (see figures 3 and 5). Preferably each permanent magnet 25 is moreover fixed to the corresponding plate-like tab 28 by means of a pass-through anchor bolt 29 that engages a centring hole 30 made on the body of the plate-like element 26, when the permanent magnet 25 stably abuts on the body of the plate-like element 26.

Operation of automatic sliding-door power-drive assembly 1 is clearly inferable from the above description, and does not require further explanations.

The advantages associated with fixing the presence sensor 19 to the load-bearing longitudinal member 2 by means of supporting bracket 20 are remarkable.

Firstly, the presence sensor 19 is now completely released from the longitudinal protective casing 18 and remains in position even when the longitudinal casing is removed, thus allowing a single person to quickly perform any calibration and/or maintenance operation on the power drive assembly 1 without any hindrances.

Furthermore, the fact that supporting bracket 20 is divided into an unmovable portion 22 rigidly fixed to the load-bearing longitudinal member 2 and into a movable portion 23 directly supporting the presence sensor 19, allows the longitudinal casing 18 to be quickly removed without being hindered by the presence of the presence sensor 19. Finally, using the permanent magnets 25 makes locking the movable portion 23 on the unmovable portion 22 of the supporting bracket 20 highly simple and quick, with the advantages this involves.

Finally, it is apparent that changes and variations may be made to the automatic sliding-door power-drive assembly 1 without departing from the scope of the present invention.

For example, if the automatic sliding-door power-drive assembly 1 must drive a sliding door provide with only one sliding shutter, it may be provided with only one shutter-supporting carriage 3 which supports such a sliding shutter.