CAR DOOR LOCKING DEVICE

FIELD OF THE INVENTION

The present invention relates generally to elevator door control devices, in particular for opening and closing automatic car doors and landing doors and for blocking movement of the car door when appropriate.

BACKGROUND OF THE INVENTION

Elevators doors usually include a car door assembly and a landing door assembly at each landing level of the elevator system. The door assemblies are parallel to each other and usually include a plurality of sliding door panels.

The panels of an automatic car door are movable by a motor. The car door is equipped with a coupling device to unlock and open landing doors when the motor opens the car door while the car is at a landing position, i.e. level with a landing door at a given landing floor. Generally, the coupling device does not prevent the car doors from being forced open by passengers during transit.

Consequently, devices have been proposed offering secure locking of the car doors to prevent such car doors from opening unless specifically instructed to open by control systems. For certain elevators, technical norms are now requiring inclusion of car door locking devices. There currently exist two types of car door locking devices: electromagnetic doors locks and mechanical door locks. Electromagnetic door locks utilise sensors and actuators to lock the car doors during transit of the car. Mechanical door locks are relatively complicated to operate. Indeed, due to the intricate nature of the mechanisms needed to ensure correct opening only within door zones and to mechanically incorporate the logic of such systems due to the large number of elements involved, current systems are complicated.

SUMMARY OF THE INVENTION

The present invention proposes to associate a car door locking function to coupling devices in order to provide a simple and reliable operation, that is advantageously able to keep car doors either locked or unlocked (depending on the situation), irrespective of whether the elevator system is electrically powered or not.

An embodiment of the invention consists of a control device for doors of an elevator system, comprising a coupling system for coupling a car door with a landing door and operable to open and close the car door and the landing door at a landing position of the car, a car door locking mechanism for locking the car door shut and permitting the unlocking of the car door in response to the coupling system reaching an opening position, and a blocking device to block the coupling system from reaching the opening position when outside the landing position of the car. Such dispositions provide a simple device able to securely lock car doors outside of door zones, and the reliable opening of car doors inside of door zones.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a perspective view of an elevator system incorporating a device according to an embodiment to the present invention.

Figure 2 illustrates in more details the front view of the car as shown in figure 1 , showing in more details the top portion of the car.

Figure 3 illustrates a control device according to an exemplary embodiment of the invention in a position adopted when all doors of the elevator are closed.

Figure 4 illustrates the device of Figure 3 in a position corresponding to a blocked attempt to manually open the car door of the elevator while the car is not in a door zone.

Figure 5 illustrates the device of Figure 3 in a position adopted when the car is in a door zone and the car door and a landing door of the elevator are open.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Figure 1 schematically illustrates portions of an elevator system 1 fitted with a control device 8 according to an embodiment of the invention. The elevator system 1 comprises a car 2 disposed for travelling vertically within a hoistway between a plurality of floors. Each floor has an independent landing door, for example constituted by two panels 4 sliding either telescopically in the same direction, or apart in opposite directions. The car 2 also has a door comprising a set of panels 3 which may open centrally or telescopically, and are substantially the same size as the landing door panels 4.

Figure 2 shows in more detail the top portion of the car 2 as it was schematically illustrated in figure 1.

Each car door panel 3 is fixed to a respective hanger 3a which is itself slidably connected to a guide rail 3b fixed to the upper portion of the car 2.

The car door panels 3 being of the automatic type, an actuating motor 5 cooperates with the car door panels 3 for opening and closing them in response to inputs from a controller. In the illustrated embodiment, the motor 5 is coupled to an endless belt (or chain) 6 running between a motor pulley 5a driven by the motor 5 and a free pulley 6a. The belt 6 is disposed laterally across the car 2, above the car door panels 3, and is operable to displace the car door panels 3 laterally to open or close them. The landing door panels 4 are slidably mounted on a guide rail fixed to the walls of the landing.

The control device 8 has a coupling device 10 to cause the landing door panels 4 to open and close together with the car door panels 3 in response to a driving action by the motor 5 and belt 6 when the car 2 is disposed inside a so-called 'door zone'. The door zone is a zone vertically

adjacent to each landing door opening, having a vertical extension defined by a length of first and second cam member 21 , 22 belonging to the coupling device 10 as detailed hereunder.

The coupling device 10 permits the opening and locking of the car door panels 3. In the embodiment shown in figures 2-5, it has a support plate

20 for mounting on the hanger 3a of one of the car door panels. The coupling device 10 is itself, and through itself the car door panels 3, displaced by the motor 5 by means of the belt 6.

The coupling device 10 can be formed of a deformable parallelogram assembly with first and second cam members 21 , 22 of substantially the same dimensions, positioned vertically parallel to each other. The two cam members 21 , 22 have a substantially L-shaped cross section, each having a respective support part 21a, 22a parallel to the doors and a respective cam surface 21b, 22b perpendicular to the support part. The cam surfaces of the two members 21 , 22 face away from one another.

The two cam members 21 , 22 are pivotally connected together on their upper portions by a first link 23, and on their lower portions by a second link 24. The links 23, 24 extend substantially parallel to each other and are articulated to the support plate 20 between the two cam members 21 , 22. By virtue of its geometry, the whole deformable assembly is able to deform while always maintaining the two cam members 21 , 22 in a substantially vertical orientation. The first link 23 has an extension 23a articulated thereon for cooperating with the belt 6. In response to an opening command, the actuating belt 6 pulls the extension 23a to the left of figures 3-5, which first urges the deformable assembly to the position shown in figure 5, in which the two cam members 21 , 22 are spaced-apart with a maximum distance D between their cam surfaces 21b, 22b. Subsequently, further traction by the belt 6 opens the car door by pulling the support plate 20 to the left. In response to a closing command, the belt 6 actuates the extension 23a to the right, which first closes the car door and then collapses the deformable assembly to the contracted position shown in figure 3, in which the two cam

surfaces 21 b, 22b are at a minimum distance c/from each other and vertically offset.

The coupling device further comprises a pawl 26 pivotally mounted to the support plate 20 for cooperating with a notch 23x provided at an end of the first link 23. In the illustrated example, the pawl 26 is a substantially straight member mounted pivotally through its median portion on a pivot axis perpendicular to the support plate 20. A biasing element (not shown) biases the pawl 26 counter clockwise as seen in figures 3-5. When the car door is closed, a butting member 29, fixed to the rail or to the car frame maintains the pawl 26 in the position shown in figures 3-4 against the biasing element. Once the parallelogram assembly has been fully deployed to the spaced- apart position of figure 5 and the car doors 3 have initiated the opening movement, thus taking the pawl 26 away from the butting member 29, the pawl 26 is biased to rotate so that its upper end 26a engages the notch 23x at the end of the first link 23. This maintains the parallelogram assembly rigidly in its spaced-apart position, corresponding to an opening position of the coupling device, until the car door is again closed.

At each landing level, the landing door is fitted with a landing door locking mechanism 50 of which an exemplary embodiment is depicted (in a mirror image) in the upper parts of figures 3-5.

This landing door locking mechanism 50 has a latch 54 pivotally mounted at 55 to a support plate 4a attached to the hanger of a landing door panel 4. The latch 54 has an engagement portion 51 for cooperating with a corresponding portion belonging to the other landing door panel 4 (or the lintel supporting the landing door), and a counterweight 54a disposed on the other side of the pivot point 55 with respect to the engagement portion 51. The action of the counterweight 54a is to bring the latch 54 into the default locking position shown in figures 3-4.

The landing door locking mechanism 50 further comprises two rollers, one 53 pivotally mounted to the support plate 4a and the other one 56 pivotally mounted to the latch 54 on the same side of the pivot point 55 as the counterweight 54a. In the default locking position of the latch 54, the two

rollers 53, 56 are approximately at the same horizontal level and have between them an interval L broader than c/and slightly narrower than D.

The mutual positioning of the coupling device 10 and of the landing door locking mechanism 50 is such that when the car travels across the corresponding landing level (with the doors closed and the coupling device 10 in the position illustrated by figure 3), the two cam surfaces 21b, 22b move vertically between the two rollers 53, 56 without interfering with them. However, if a door opening command occurs while the car is in the door zone, the deployment of the parallelogram assembly of the coupling device 10 pulls the cam surfaces 21 b, 22b apart while they dwell in the gap between the two rollers 53, 56. The cam surface 22b pushing the roller 56 tilts the latch 54 out of the default locking position (figure 5), thus unlocking the landing door panels 4. Then, the cam member 22 entrains the roller 56 to open the landing door as the car door is opened by the motor 5 and belt 6. Likewise, when the car door is being closed, the cam member 21 pushes the roller 53 to close the coupled landing door, and then the movement of the parallelogram assembly back towards the contracted position releases the latch 54 which is returned to the default locking position by its counterweight 54a. It is appreciated that the door zone is defined by the alignment of the cam members 21 , 22 with the rollers 53, 56.

In accordance with an embodiment of the invention, the control device 8 includes, in addition to the coupling device 10 mounted on the hanger 3a, further mechanical means 30, 40 for locking the car doors shut and enabling them to be released in specified circumstances. A car door locking mechanism 30 permits the locking of the car door when the parallelogram assembly of the coupling device 10 is in its contracted position, and the unlocking of the car door when the coupling device 10 is its opening position.

In the illustrated embodiment, the car door locking mechanism 30 has a lever 32 pivotally mounted at 31 on the support plate 20 of the coupling device. The end of the lever 32 away from the coupling device 10 has a lug

33 to cooperate with a catch 34 located on a fixed portion of the car 2 or on

the opposite car door panel 3. The lug 33 and the catch 34 thus form a lock for the car door. The lever 32 is free to rotate about its extremity 31 , and returns to its at-rest position naturally under gravity, whereby the lug 33 cooperates with the catch 34. The car door locking mechanism 30 may be fitted with an electrical contact to electrically check the correct locking of the car door, for example in order to prevent movements of the car 2 when the car door locking mechanism 30 is not safely locked.

The bottom portion of the support part 21a of the first cam member 21 has a lateral extension 27 away from the second cam member 22 towards the car door locking mechanism 30. The end of this extension 27 bears an actuation roller 27a which contacts the lever 32 of the car door locking mechanism 30 when the parallelogram assembly of the coupling device 10 approaches its spaced-apart position shown in figure 5, due to the resulting upward movement of the first cam member 21. In the final phase of the deployment of the parallelogram assembly, the roller 27a lifts the lever 32 out of engagement with the catch 34. The locking lever 32 is then maintained in its lifted, disengaged position while the car door panels 3 are moved away from or towards each other by the motor. Once the door has been closed, the return of the parallelogram assembly into its contracted position lowers the roller 27a, whereby the lever 32 falls back into the at-rest position in which the lug 33 engages the catch 34.

The control device 8 according to the invention further includes a blocking device 40 to block the coupling device 10 from reaching its opening position when the car 2 is not inside a landing position, i.e. when the car is not in a door zone. The coupling device 10 is preferably, though not necessarily, positioned between the car door locking mechanism 30 and the blocking device 40.

The blocking device 40 is arranged to be brought in a position able to engage the parallelogram assembly of the coupling device 10 so as to block it from reaching its spaced-apart position when the car 2 is not in a door

zone, thereby preventing the door panels 3 from opening when the car 2 is not opposite a landing.

In particular, according to the present exemplary embodiment, the blocking device 40 takes the form of a third cam member 41 pivotally connected to upper and lower links 42, 43. The upper and lower links 42, 43 are articulated to the support plate 20 at 42a, 43a to form another articulated parallelogram assembly with the third cam member 41.

The third cam member 41 is thus suited to be displaced in a substantially circular motion to approach and recede from the second cam member 22 of the coupling device 10 while always maintaining a substantially vertical orientation. The bottom part of the second cam member 22 comprises an abutment 28 which extends horizontally towards the blocking device 40. The abutment 28 serves as a support for the blocking device 40, and thus defines a rest position for the blocking device 40 relative to the second cam member 22 (figures 3-4). Moreover, this configuration of the blocking device 40 allows the third cam member 41 to displace horizontally to contact the coupling device 10 as a result of the vertical position of the abutment 28 of the second cam member 22.

The third cam member 41 may also have an L-shaped cross-section with a support part 41a parallel to that of the first and second cam members 21 , 22 and a cam surface 41 b facing the cam surface 22b of the second cam member 22.

When the third cam member 41 rests on the abutment 28, the horizontal distance between the cam surfaces 41 b and 22b varies between a minimum distance c/' and a maximum distance D' depending on the position of the parallelogram assembly of the coupling device 10.

The minimum distance d' may be defined by the horizontal dimension of the support part 22a of the second cam member, as shown in figure 4. It is selected to be smaller than the diameter A of the roller 56 of the landing door locking mechanism 50: d'<A.

The maximum distance D\ which applies when the parallelogram assembly of the coupling device 10 is in its contracted position as shown in figure 3, is defined by the relative horizontal positions of the parallelogram assemblies of the coupling device 10 and of the blocking device 40 and by the height of the abutment 28. It is selected to be sufficiently larger than the diameter δ of the roller 56 (D'>A) so that, when the car travels across a landing level, with the doors closed and the coupling device 10 in the position illustrated by figure 3, the two cam surfaces 22b, 41b move vertically on both sides of the roller 56 without interfering with it. In the embodiment shown in figures 3-5, the support part 22a of the second cam member is provided with a projection or hook 44 in front of the third cam member 41 , and the rear side of the cam surface 41 b of the third cam member is correspondingly provided with a catch 45 horizontally aligned with the hook 44. The deployment of the parallelogram assembly of the coupling device

10 from its contracted position causes the distance between the cam surfaces 41b and 22b to be lowered from the maximum distance D' shown in figure 3. If the deployment is effected while the car 2 is not in a door zone (figure 4), the minimum distance c/'will be reached, thus causing the hook 44 to engage the catch 45 as shown. This engagement prevents the third cam member 41 from moving up under the pressure applied by the second cam member 22. As the third cam member 41 is also prevented from moving down by the abutment 28, the second cam member 22 cannot continue its movement downward and away from the first cam member 21. In other words, the coupling device 10 is blocked from reaching its opening position.

On the other hand, if the deployment of the parallelogram assembly of the coupling device 10 is effected while the car 2 is in a door zone (figure 5), the roller 56 of diameter A>d' sitting between the cam surfaces 41b and 22b maintains a sufficient distance between the second and third cam members 22, 41 to keep the hook and catch 44, 45 out of engagement. The deployment of the coupling device 10 can be completed up to the opening position shown in figure 5 to release the lever 32 and unlock the car door.

Of course, it will be understood that the catch and hook 44, 45 are interchangeable between the second cam member 22 and the third cam member 41 , or indeed that various alternative dispositions preventing the third cam member 41 from relative vertical movement when in direct contact with the second cam member 22 may be used. Also, the illustrated roller 56 may be replaced by any element associated with the landing or the landing door and able to keep the blocking device 40 away from the coupling device 10. This can, for example, be a fixed element protruding out of the landing to interact with the blocking device 40 when the car 2 is in the door zone. As long as the elevator is electrically powered, the motor 5 maintains a biasing force to keep the car door shut when the car 2 is located between landing levels, the deployment of the coupling device 10 being enabled only when the car is in a door zone.

It can be useful to enable opening of the car door in circumstances where power supply is missing, in order to evacuate passengers. However, such an opening of the door should only be allowed if the car is in front of a landing.

The coupling device is further provided with a biasing member which, in the embodiment illustrated in figures 3-5, is in the form of a helical spring 25 fixed on the two links 23, 24 of the parallelogram assembly at positions denoted by asterisks in figures 3 and 5. Alternatively, the biasing member may have its ends attached to the cam members or one end attached to the support plate 20. The spring 25 is arranged to bias, in the absence of any other restraint or input from the motor 5, the deformable parallelogram assembly of the coupling device towards its spaced-apart position.

The spring 25 thus serves to move the coupling device 10 to its opening position when power is lost. As indicated previously, this opening position will only be reached if the car 2 is within a door zone, the passengers then being able to open both the car door and the landing door by manually pulling apart the car door panels 3. Otherwise, the blocking device 40 and the car door locking mechanism 30 keeps the car door locked shut.

It will be appreciated that the blocking device 40 described hereabove in the form of a cam member 41 can be embodied by any member or configuration able to block the coupling device 10 from reaching its opening position. For example, the blocking device 40 may again comprise a vertically oriented third cam member, substantially as described hereabove, and mounted in a slot disposed for horizontal displacement, such cam member being biased towards the coupling device 10 by a spring or the like. These dispositions would allow the third cam member to move horizontally forward and backwards towards the second cam member 22 to block full deformation of the coupling device 10. Of course, it also allows the retreating of the third cam member in the cases when an element, such as the roller 56, comes to interpose itself in between the blocking device 40 and the coupling device 10 when within a door zone.

By means of the above-described dispositions, a control device for car and landing doors of an elevator system has been described. Such a device effectively, simply, and reliably allows the secure locking of the car door when the car is not at a door zone. Conversely, when the car is found within a door zone, these dispositions will allow the opening of the car door under any conditions. This device further functions irrespective of whether the elevator system is under power or not.

While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.