Abstract:
A door coupler ( 4 ) comprising gripping elements ( 14,15 ) moved by a linkage ( 2 ) and designed to grip a counterpart ( 17,18 ) on the landing door, and a lock catch ( 10 ) which has a closed position and an open position. The releasing movement of the lock catch ( 10 ) from the closed position into the open position is allowed when a gripping element is pressed against a counterpart.

Description:
This application is a Continuation of prior PCT International Application No. PCT/FI97/00137 which has an International filing date of Feb. 28, 1996 which designated the United States of America, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a door -coupler and to a locking device for a car door of an elevator. 
     DESCRIPTION OF THE BACKGROUND ART 
     In elevators provided with automatic doors, the coupling between the car door and the landing door is generally implemented using a door coupler which is mounted on the car door and which, by means of its gripping elements, engages counterparts mounted on the landing door. The door coupler and the counterparts are so fitted relative to each other that, when the elevator car is moving past the landing door, the counterparts on the landing door pass between the gripping elements of the door coupler. When the car is at a landing and the car doors are moving, the door coupler is in engagement with the counterparts. In this way, the landing door moves together with the car door when the latter is moved by a power means connected to the car door. Often the gripping elements are metal vanes projecting from the door coupler towards the landing door and forming a kind of vertical slot which is open towards the landing door. The counterparts used often consist of rollers mounted on the landing door and projecting from the door towards the elevator shaft, the axle of the rollers being mounted in a position perpendicular to the plane of the door. In conjunction with the door coupler or the car door itself there is a locking device which closes the car door so that it cannot, at least without special measures, be opened except when the elevator car is near a landing, i.e. when the elevator car is within the so-called door zone. The locking system of an elevator door must be reliable and durable. The locking of an elevator door should not produce any disturbing noise. 
     There are various arrangements for locking the elevator door in a manner that is reliable and suited for use with an elevator door. For instance, a locking system operated by a separate electromechanical actuator requires that the elevator has a separate subsystem or a parallel system for the control of door operation that takes care of locking and unlocking the door. A locking system using a separate electromechanical actuator always involves an additional cost corresponding to the price of the actuator. 
     There are also mechanical locking systems in which the actuating force for locking the door is taken from the motion of the elevator car or the car door. In such systems the landing zone is indicated and/or the operation of the lock is controlled by means of a separate slide or other sign provided in the elevator shaft at each landing and immovably fixed in place with respect to the elevator shaft. Mounting such slides or signs in the elevator shaft at each landing requires plenty of installation time. A long installation time means high labor costs. 
     Often the locking arrangement occupies a large space and therefore the placement of the locking devices more or less dictates the design of the door or door suspension of the elevator car. 
     SUMMARY OF THE INVENTION 
     To meet the need to achieve a simple, mechanically operated locking device for the door of an elevator car which is applicable for use in a modern elevator environment and in modern elevator technology and is cheap to manufacture and advantageous in respect of space utilization, easy to install, noiseless in operation and is integrated with the door coupler, a new type of door coupler and a new type of locking system are presented as an invention. 
     The advantages achieved by the invention include the following: 
     the locking device is cheap to manufacture. 
     being integrated with the door coupler, the locking device permits the application of a simpler door concept. Integrating the door coupler with the locking system simplifies the installation. 
     since the locking is controlled by the operation of the door coupler, in other words, by the presence or absence of a counterpart attached to a landing door within the reach of a gripping element of the door coupler, the elevator shaft need not be provided with separate control devices or signs to indicate door zones. 
     the locking device is of a construction that does not take up much space, so it is not difficult to accommodate it even in thin structures. 
     the locking device is easy to install in conjunction with the door and, being mechanically controlled, requires no electric actuating equipment. 
     the door remains locked when outside landing zones, the locking is not affected by possible disturbances in the electrical system of the elevator. 
     if in the event of a power failure the elevator has stopped between floors, the door can be opened after the elevator has been moved manually to a landing. 
     the equipment does not produce any extra noise when the elevator is running or when the car door is being locked or unlocked. 
     the locking and unlocking of the car door of the elevator is dependent on the opening and closing of the door both mechanically and in respect of time. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the following, the invention is described in detail by the aid of an example embodiment by referring to the attached drawings which are given by way of illustration only, and thus are not limitative of the present invention, and in which 
     FIGS. 1 and 2 present a door coupler applying the invention together with a locking system when the car is outside the landing zone, and 
     FIGS. 3 and 4 present a door coupler applying the invention together with a locking system when the car is within the landing zone. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the description, parts are designated by using terms such as left, right, upper, lower, etc. These terms refer to the corresponding directions in the figures, and so do the expressions “clockwise” and “counterclockwise”. The use of these directions and terms to explain the invention should not be construed to limit the scope of the claims. 
     A door coupler  4  with a lock applying the invention and its operation are described by referring to FIGS.  1 - 4 . FIGS. 1 and 2 present a situation where the elevator car is outside the landing zone and the door coupler vanes  14  and  15  cannot meet the rollers constituting the counterparts on the landing doors. FIGS. 3 and 4 present a situation where the elevator car is within the landing zone and the vanes  14 , 15  engage the rollers  17 , 18  on the landing door when the doors are opened. The door coupler  4  is mounted on the car door suspension plate  1 . The car door suspension plate  1  is provided with supporting rollers and usually also counter rollers, which run along a guide rail or other suitable guide surface on the overhead supporting beam fixed to the elevator car. Thus, supported by the suspension plate(s), the door is suspended from the overhead supporting beam. 
     The door coupler vanes  14  and  15 , between which the rollers  17  and  18  (shown in FIG. 4) attached to the landing door will go when the door coupler engages the landing door, are attached to a linkage system  2  actuated by the car door drive. Connected to the linkage  2  is also a lock catch  10  that locks the car door. The lock catch engages a detent immovable relative to the car door, mounted e.g. on the overhead beam supporting the door, or possibly a door panel moving in the opposite direction. The car door actuator opens and closes the car door. It also opens and closes the landing door, which is coupled to the car door via the door coupler. The car door actuator is e.g. a rope drive acting in the directions of the opening and closing movements of the door and attached to the door coupler  4 . Instead of a rope drive, the door actuator may be some other type of drive means, such as a hydraulic cylinder, that produces a driving force acting in the direction of the car door movement. The doors are actually moved by means of the door coupler. The rope drive is connected to the linkage  2  via connection point  3  on the operating lever  5  as indicated by box  100 . Due to the action of the rope drive, the operating lever  5  tends to turn, within the limits of its range of motion, in the direction of the rope pull about its pivot  6 , which is immovable in relation to the door coupler  4  (and to the suspension plate  1  supporting the door coupler). The operating lever  5  is connected to the suspension plate  1  via pivot  6 , permitting a turning movement. The motion of the operating lever  5  about its pivot  6  produces via the linkage  2  an appropriate movement of both the lock catch  10  and the vanes  14  and  15 . The movement appropriate in each case depends on whether the elevator is within a door zone or not. The information as to whether the elevator is within a door zone is obtained on the basis of the presence of landing door rollers in the gap between the vanes  14  and  15 . Therefore, the height of the gap between the vanes  14  and  15  must be substantially equal to the height of the door zone. 
     FIG. 1 shows close and open arrows which start from the connection point  3 . The close arrow indicates the direction (to the left in the figure) in which the rope drive pulls the door when it is being closed, while the open arrow indicates the direction (to the right in the figure) in which the rope drive pulls the door when it is being opened. The close arrow also indicates the direction of the closing movement of the door and the open arrow the direction of its opening movement. In FIG. 1, the angle through which the operating lever  5  turns counterclockwise about pivot  6  when the rope drive is trying to open the door is indicated by a sector  6   a  depicted at pivot  6 . The turning movement of some other parts  7 , 8 , 9  in the linkage caused by the turning of the operating lever  5  is indicated by sectors  7   a , 8   a , 9   a  shown on the appropriate parts. These parts  7 , 8 , 9  of the linkage turn about pivots  7   b , 8   b , 9   b  immovable with respect to the door coupler. These pivots  7   b , 8   b , 9   b  that are immovable in relation to the door coupler are indicated in the figures with a filled (blackened) circle. All other pivots and connection points that are immovable with respect to the door coupler are also indicated by filled circles. Pivots and connection points moving with the parts of the linkage are indicated with an empty (white) circle. FIG. 2 shows the positions of the parts of the linkage, the door coupler vanes  14  and  15  and the lock catch  10  in which they have ended up as a result of the action of the linkage  2  caused by the motion of the operating lever. 
     In the following is a description of how the kinetic effect resulting from the operating lever  5  turning through sector  6   a  is transmitted in the linkage  2 . The operating lever  5  is connected to the linkage via three movable pivots  5   x,    5   y  and  5   z.  Below the operating lever  5  there is a supporting lever  21  which is turnably connected to an immovable pivot  21   a  and which has movable pivots  21   x  and  21   y  on it. The lever arms between pivots  21   a  and  21   x  and between pivots  6  and  5   x , respectively, are of equal length. Similarly, the lever arms between pivots  21   a  and  21   y  and between pivots  6  and  5   y , respectively, are of equal length. The left vane  14  is connected to the operating lever  5  and to the supporting lever  21  via pivots  5   x  and  21   x.  Connected to the operating lever  5  and the supporting lever  21  is a synchronizing bar  16  via pivots  5   y  and  21   y  in such manner that pivots  5   x ,  21   x ,  5   y  and  21   y  constitute the corner points of a rhomboid, so that the left vane  14  and the synchronizing bar  16  are parallel to each other, the lever arms between pivots  21   a  and  21   x  and between  6  and  5   x  are parallel to each other and the lever arms between pivots  21   a  and  21   y  and between  6  and  5   y  are parallel to each other. In fact, as far its movements are concerned, the synchronizing bar  16  corresponds to the vane of an ordinary door coupler corresponding to vane  15 , and this vane  15 , which acts as a slide vane actuating the lock, is a detached surface structure of the synchronizing bar  16  which, when departing from the immediate vicinity of the synchronizing bar  16 , prevents the lock catch  10  from being released. Connected to the operating lever  5  at pivot  5   z  is the left end of a first rod  22 , which connects the operating lever  5  to an upper triangular lever  7 . The rod has between its ends a joint  22   a  that permits bending of the rod. The upper triangular lever  7  is held by an immovable pivot  7   b.  Around this pivot  7   b , the upper triangular lever has pivots  7   x , 7   z  and a connection point for a draw-spring  23  which move with the triangular lever. Connected to the uppermost pivot  7   z  is the right-hand end of the rod  22 . When the rod  22  moves right as the operating lever  5  is turning in the clockwise direction, the triangular lever  7  also turns clockwise. This clockwise turning motion is assisted by the draw-spring  23 , which applies a pull at the connection point  7   y  on the right, acting in a downward direction towards the point  23   a  of connection of the draw-spring on the suspension plate. No draw-spring  23  would be needed if the rod had no joint  22   a.  The clockwise rotation of the first triangular lever  7  causes the left-hand pivot  7   x  on the triangular lever  7  to move upwards, thus drawing the right-hand movable pivot  8   y  of a second triangular lever  8  upwards by means of a second rod  24 , causing triangular lever  8  to turn counterclockwise about pivot  8   b , with the result that the left-hand pivot  8   x  moves right. The first end of the second rod  24  is connected to pivot  7   x  and the second end to pivot  8   y . The pivots  8   b , 8   x , 8   y  of triangular lever  8  are located near the corners of the triangular lever  8 . 
     In fact, the above description of the movements of the various parts of the linkage applies both inside and outside the landing zone and the movements take place in consequence of the operating lever  5  turning through an angle corresponding to sector  6   a  when the door control reference, in other words the pull produced by the door drive, changes from the close direction to the open direction. 
     Now, referring to FIGS. 1 and 2, a situation will be described where the elevator car is outside the landing zone, and then, referring to FIGS. 3 and 4, a situation where the elevator car is within the landing zone. 
     Connected by its first end to pivot  8   x  on triangular lever  8  is a third rod  25 . Via a pivot  25   a  between its ends, the third rod  25  is turnably attached to the right-hand end of a substantially L-shaped locking lever  11 . The locking lever  11  remains substantially stationary, and this is ensured by a compression spring  12  which applies an upward pressure to the left-hand end of the locking lever, which in turn presses the lock catch  10  towards the locked position. The drawings show the springs  12  and  23  only in FIG.  1 . As the triangular lever  8  causes the first end of the rod  25  connected to pivot  8   x  to move right, the rod  25  turns about pivot  25   a,  with the result that the second end of the rod moves left and, via a fourth rod  26 , applies a force to pivot  27   a  between the ends of the first suspension lever  27  of vane  15 , causing said lever  27  to turn left. The first end of the fourth rod  26  is connected via pivot  25   x  to the second end of the third rod  25 , while the second end of the fourth rod  26  is connected to pivot  27   a  on the first suspension lever  27 . Vane  15  is connected to the door coupler via two suspension levers  27  and  28 . The first suspension lever  27  and the second suspension lever  28  are turnably connected to the suspension plate  1  supporting the door coupler via the pivots  27   x  and  28   x  at their first ends, which are immovable in relation to the door coupler. The second ends of the suspension levers  27  and  28  are connected to vane  15  via pivots  27   y , 28   y . The two suspension levers  27  and  28  are of the same length. Pivots  27   y ,  28   y ,  27   x  and  28   x  are so disposed relative to each other and to the suspension plate  1  that, when the suspension levers  27 , 28  are turning, vane  15  remains aligned in a vertical direction. Thus, the motion of the linkage will not release the lock when the car is outside the landing zone, but merely causes vane  15  to move to the left. The compression spring  12  ensures that the vane will move to the left. Due to the force applied by the compression spring to the locking lever  11 , pivot  25   a  remains stationary while pivot  25   x  is moving. 
     Referring to FIGS. 3 and 4, a situation is now described where the elevator car is in a landing zone and the locking of the car door is released. 
     FIG. 3 shows a sector  6   a  at pivot  6  to indicate the angle through which the operating lever  5  first turns in the counterclockwise direction to release the lock, and another sector  6 A through which the operating lever  5  subsequently turns to permit the door coupler  4  to engage the rollers  17 , 18  on the landing door. 
     In the manner described above, the action of the linkage produces, among other things, turning movements of the triangular levers  7  and  8 , as indicated by the sectors  7   a  and  8   a  depicted on top of said levers. Since the right-hand vane  15 , when the elevator car is within the landing zone, is pressed against the right-hand roller  18 , some of the various parts of the linkage move in a different way than when the car is outside the landing zone as stated above. Roller  18  is, so to speak, a fixed roller, in other words, it is the one of the rollers that remains substantially immovable in the horizontal direction relative to the landing door when the door coupler vane is pressed against it. On the other hand, roller  17  can move through some distance relative to the landing door, so the movement produced by the pressure applied to this roller by door coupler vane  14  can be used to release the lock of the landing door. As vane  15  is pressed against roller  18 , this prevents it from moving to the left. An important movement in respect of the desired operation is the clockwise turning movement of the third rod  25  about pivot  25   x  through an angle indicated by sector  25 A that takes place as a result of the counterclockwise rotation of triangular lever  8 . 
     FIG. 4 shows the positions of the parts of the linkage  2 , the door coupler vanes  14  and  15  and the lock catch  10  in which they have ended up as a result of the action of the linkage caused by the operating lever moving through an angle corresponding to sector  6   a.  Connected to pivot  8   x  on triangular lever  8  is the first end of rod  25 , whose lower end is connected to the fourth rod, and the pivot  25   x  at its end acts as the fulcrum of its turning movement when its upper end is moved to the right by the triangular lever. Since the movement of the right-hand vane  15  and therefore also the movement of suspension lever  27  is prevented, the pivot  25   x  at the right-hand end of the fourth rod acts as a substantially immovable fulcrum for the turning movement of the third rod  25 . In this situation, the effect of the compression spring  12  on lever  11  is outbalanced by the supporting force indirectly received by pivot  25   x . Consequently, the pivot between the ends of the third rod to which the L-shaped locking lever  11  is connected is drawn through a certain distance to the right. The pull resulting from the movement of the locking lever  11  releases the lock catch  10 , thus permitting the opening movement of the car door to be started. At the same time, a safety switch  13  provided in conjunction with the lock catch  10  is opened. From the safety switch, an electric signal indicating whether the car door is locked or not is supplied to the safety circuit and, if necessary, to the control system of the elevator. After the lock has been released, the operating lever will turn further through a distance corresponding to sector  6 A as shown in FIG.  3 . This movement of the operating lever causes the right-hand door coupler vane  14  to move into contact with the right-hand roller  17  on the landing door and finally the door coupler rollers  17 , 18  to be pressed between the door coupler vanes  14 , 15 , resulting in complete coupling between the landing door and the car door. The operating lever is free to turn through sector  6 A because lever  22  is provided with a joint  22   a  that permits the rod to bend so that its motion towards triangular lever  7  after the release of the lock is substantially completely received by the bending of the rod  22 . 
     It is obvious to a person skilled in the art that different embodiments of the invention are not limited to the examples described above, but that they can be varied within the scope of the claims presented below.