Abstract:
An elevator car ( 1 ) includes, a support frame ( 8 ) of a cable-driven elevator system without a machine room, with a compact driving pulley driving machine ( 7 ), combine with a brake, integrated in this car ( 1 ) and/or its support frame ( 8 ). This is to provide an elevator car which can be preassembled outside of an elevator shaft as a unit ready to be installed, with as many functional parts as possible. To this end, the elevator car ( 1 ) has the following feathers: the driving machine ( 7 ) is equipped with a permanent magnet-excited synchronous motor as the driving source; the operating electronics of the driving machine and the control electronics required for the operation of the entire elevator system from a common, interactive functional unit in the form of an electronic central unit ( 10 ); and the electronic central unit ( 10 ) is permanently connected to the elevator car and/or its support frame.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   Applicants claim priority under 35 U.S.C. §119 of GERMAN Application No. 100 37 394.1 filed on 29 Jul. 2000. Applicants also claim priority under 35 U.S.C. §365 of PCT/DE01/02877 filed on 26 Jul. 2001. The international application under PCT article 21(2) was not published in English. 

   BACKGROUND OF THE INVENTION 
   Field of the Invention 
   The invention pertains to an elevator car with a driving pulley driving machine integrated into this elevator car and/or its support frame. 
   Known elevator cars of this type are disclosed in EP 1 028 082 A2, FR 2 640 604 B1, WO 97/11020 and WO 00/64798. 
   The invention aims to develop an elevator car of this type in such a way that as many functional parts as possible of an elevator system without a machine room are already completely preassembled together with the elevator car in the form of a unit that can be installed into the elevator shaft at the construction site. 
   In addition, the utilization of a small, compact driving machine on or on top of the elevator car should reduce the space requirement to a minimum. In this respect, a reduction in the required materials and the weight should be achieved, in particular, by integrating the driving machine into the components of the elevator car, preferably its support frame. 
   One basic solution of this problem consists of a driving machine of the initially described type which is realized in accordance with the characteristics disclosed in the present invention. 
   The invention also aims to attain other cost savings in addition to a comprehensive constructive integration of the driving machine into the components of the elevator car or its support frame, respectively, namely by combining all electronic operating and control elements required for the operation of the elevator system into a common functional unit, i.e., an electronic central unit, and by arranging this central unit on the elevator car. This central unit should contain those electronic control and operating elements which serve for the operation of the elevator system including the operation of the elevator doors, as well as for the operation and the control of the driving machine that, for example, is realized in the form of a permanent magnet-excited synchronous motors including the brake connected to said driving machine. The control electronics required for instances in which the driving machine should be operated by a battery in case of an emergency preferably also form part of the electronic central unit according to the invention. 
   One particular advantage of this embodiment of the invention can be seen in the fact that nearly the entire operating and control electronics of the elevator system can be prefabricated at the factory together with the elevator car. This makes it possible to realize a particularly cost-efficient manufacture of an elevator system without a machine room. 
   Particularly practical and advantageous embodiments of the invention form the objects of the dependent claims. 
   The central unit according to the invention is connected to a power distribution and switching station that is stationarily arranged outside the elevator shaft by means of cables that are connected to the elevator car and a bus interface. 
   A battery for realizing an emergency power supply is provided on the power distribution/switching station. Such a battery may also be provided on the elevator car in order to additionally improve the safety in case the cable connection between the control unit and the switching station is interrupted in the emergency mode. The electronic central unit comprises, in particular, also those electronic means which are required for changing over the driving machine into the battery mode in case of an emergency. 
   An emergency occurs if the main power supply fails and the driving machine comes to a standstill between the elevator doors of two floors. 
   In order to enable the persons trapped in the elevator car to release themselves without external assistance, the design of the elevator car in accordance with the invention, i.e., the arrangement of the driving mechanism including the electronic central unit on the elevator car, makes it possible to realize emergency release means that lead into the interior of the elevator car. These means consist of a mechanical device for releasing the brakes of the driving machine which are automatically engaged in a spring-loaded fashion if the power fails. These means may, in particular, consist of a cable with an actuating handle which leads from the brake of the driving machine into the interior of the elevator car. The motor brake can be released by pulling on the actuating handle. If the weight of the occupied elevator car and its counterweight are not in equilibrium, the elevator car tends to move upward or downward due to the lack of equilibrium. One prerequisite for ensuring that the elevator car does not carry out any fast uncontrolled movements is a generator mode function of the driving machine in the emergency mode, wherein the motor windings are short-circuited in the generator mode. 
   The following measures may be taken in order to ensure that the elevator car automatically assumes a position in which the persons situated in the elevator car can conventionally exit the elevator car through an open elevator door on a floor in case of an emergency release. 
   When actuating the means required for activating the emergency release, these means can, after being activated, be mandatorily locked in a position in which the brake cannot be engaged again independently of a permanent actuation by the person initiating the emergency release. In this case, the locking means may cooperate with a sensor that is rigidly connected to the elevator car and able to sense the elevation of the elevator car within the elevator shaft. As soon as this sensor detects an elevation of the elevator car at which the elevator doors can be opened so as to enable the passengers to exit on a floor, the emergency release means that ensure that the brake remains disengaged are unlocked, in particular, by an actuator that is directly connected to the sensor. Subsequently, the emergency release means leading into the elevator car are reset into their starting position in which they are able to activate another emergency release. 
   With respect to the guidance of the cable, it needs to be observed that, if the driving machine is arranged on the elevator car, the elevator cable is looped around the driving pulley over a sufficiently large angle of more than 180°. This can be achieved with additional deflection sheaves arranged on the elevator car in the vicinity of the driving pulley of the driving machine. In this respect, various embodiments of deflection sheaves used for this and other purposes may be considered. Two particularly practical arrangements are described in greater detail below. 
   The central unit according to the invention also provides most of the previously described advantages if it is stationarily arranged at an arbitrary location of the elevator shaft rather than movably on the elevator car. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Advantageous embodiments of the invention are illustrated in the figures and described in greater detail below. 
     The figures show: 
       FIG. 1  a schematic representation of an elevator car that is suspended and guided in its center of gravity and on the roof of which a driving machine and an electronic central unit are arranged; 
       FIG. 2  a schematic representation of an elevator car that is realized in accordance with the piggyback principle, wherein the driving machine and an electronic central unit are arranged on the rear cabin wall; 
       FIG. 3  a schematic representation of the guidance of an elevator cable in a first embodiment in which a driving mechanism is arranged on the roof of an elevator car; 
       FIG. 4  a schematic representation of the guidance of an elevator cable in a second embodiment in which a driving machine is arranged on the roof of an elevator car; 
       FIG. 5  a circuit diagram for the arrangement and wiring of an elevator [driving] machine on an elevator car together with an electronic central unit, and 
       FIG. 6  an enlarged representation of the part of an emergency release mechanism which corresponds to the detail VI in FIG.  5 . 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   In both types of elevator systems shown in  FIGS. 1 and 2 , an elevator car  1  is suspended on an elevator cable  2  that is stationarily fixed on both ends. Between the two stationary ends, the elevator car  1  and a conventional counterweight  3  are suspended on this elevator cable  2 . Between the elevator car  1  and the counterweight  3 , the elevator cable  2  extends over a stationarily arranged deflection sheave  4 . On the counterweight  3 , the elevator cable  2  is guided in a deflection sheave  5  arranged on said counterweight. 
   On the elevator car  1 , the elevator cable  2  is guided in a driving pulley  6  of a driving machine  7  that is rigidly connected to the elevator car. 
   The differences between the embodiments shown in  FIGS. 1 and 2  are discussed below. 
   In the embodiment according to  FIG. 1 , in which the elevator car  1  is suspended in the vertical direction referred to its center of gravity, the driving machine  7  is situated on the roof of the elevator car  1 , namely in a support frame  8  of the elevator car. 
   In the embodiment according to  FIG. 2 , in which the elevator car  1  is suspended and guided in accordance with the piggyback principle, the driving machine  7  is situated on a carrier of a support frame  9  of the elevator car. 
   In both embodiments, a driving machine according to DE 197 39 899 A1 may respectively be provided, wherein the essential components of the motor and gear housing are respectively replaced with the corresponding support elements of the elevator car  1 . 
   An electronic central unit  10  is respectively provided on the elevator car  1  together with the driving machine  6  in both embodiments, wherein the function of this electronic central unit is described in greater detail below with reference to FIG.  4 . 
     FIG. 3  shows one embodiment of the guidance of the elevator cable  2 , wherein the elevator cable  2  is guided without intersecting and looped around the driving pulley  6  by an angle of more than 180°. In this embodiment, the driving machine  7  with the driving pulley  6  is arranged in a lateral region of the roof of the elevator car  1 . Two deflection sheaves  11  and  12  are provided on the roof of the elevator car  1  adjacent to one another, namely in the same plane as the driving pulley  6 . Both deflection sheaves  11  and  12 , over which the elevator cable  2  respectively extends in front of and behind the driving pulley  6  viewed in the cable direction—however, on the same side of the driving machine  7  referred to the width of the elevator car—are positioned such that the elevator cable  2  is looped around the bottom of said deflection sheaves. The diameters and elevations of the deflection sheaves  11 ,  12  are chosen such that the elevator cable  2  leads to the driving pulley  6  and away from this pulley without intersecting. The elevator cable  2  extends directly to a stationary mounting point in the elevator shaft from the deflection sheave  11 . From the deflection sheave  12 , the elevator cable  2  extends to a second stationary mounting point in the elevator shaft over a deflection sheave  13  that is stationarily arranged in the elevator shaft and another deflection sheave  5  that is arranged on the counterweight  3 . The guidance of the elevator cable  2  over the driving pulley  6  with the aid of the deflection sheaves  11  and  12  ensures that the transmission of the torque generated by the driving pulley  6  cannot be impermissibly lowered by a temporary decrease in the elevator cable tension while the elevator car  1  moves downward. In this embodiment of the elevator cable guidance, the elevator cable respectively extends onto the driving pulley  6  and at least the deflection sheaves  11 ,  12  of the elevator car  1  linearly. 
     FIG. 4  shows an alternative embodiment of the guidance of the elevator cable  2 , in which the elevator cable  2  is looped around the driving pulley  6  by at least 270°. The driving machine  7  with the driving pulley  6  is also arranged in a lateral region of the roof of the elevator car  1  in this case. A deflection sheave  12 ′ is arranged in the opposite lateral region of the elevator car roof in the plane of the driving pulley  6 . The elevator cable  2  that extends downward from a stationary mounting point in the top region of the elevator shaft is looped around the driving pulley  6  by at least 270° and then extends into the lower region of the deflection sheave  12 ′ arranged in the opposite lateral region of the elevator car roof. Analogous to the embodiment shown in  FIG. 3 , the elevator cable extends from the latter-mentioned deflection sheave to a second stationary mounting point in the top region of the elevator shaft over a stationary deflection sheave  13  and the deflection sheave  5  arranged on the counterweight. In this embodiment of the elevator cable guidance, the elevator car  1  is centrally suspended. The driving pulley  6  and the deflection sheave  12 ′ can be integrated into the support frame that carries the elevator car. In the embodiment of the elevator cable guidance shown in  FIG. 4 , no deflection sheaves is situated [directly] above the elevator car. This is desirable and even required in certain instances for safety reasons. 
   The driving pulley and the deflection sheaves may be realized with a smaller width in all instances, in which the elevator cable is looped around the driving pulley  6  and the deflection sheaves on the elevator car by less than 360°. The driving pulley and the deflection sheaves are correspondingly wider if the elevator cable is looped around the respective pulley or sheave more than once. 
   The circuit diagram according to  FIG. 5  shows the driving machine  7  that is rigidly arranged on the elevator car  1  or its support frame, respectively, as well as its functional elements, namely a permanent magnet-excited synchronous motor  7 ′, a brake  7 ″, a planetary gear  7 ′″ and the driving pulley  6 . The driving machine  7  is connected to and controlled by the electronic central unit  10  that is also rigidly arranged on the elevator car  1 . In this case, the electronic central unit  10  contains a servo controller for the synchronous motor  7 ′ of the driving machine  7  which, in particular, is functionally integrated into the elevator system electronics. 
   The electronic central unit  10  serves, in particular, as a conventional elevator car computer. The control electronics for the door drive of the elevator system are also integrated into the central unit  10 . A so-called service panel  15  for use by service personnel operating on top of the elevator car  1 , as well as a conventional operating panel  16  arranged in the interior of the elevator car, are also connected to the central unit  10 . 
   The electronic central unit  10  is connected to the power supply and switching station  17  that is stationarily arranged in the elevator shaft via a trailing line and a bus interface situated in this switching station  17 . At lest one outside panel  18  for operating the elevator is connected to the switching station  17 . A battery  19  for the emergency mode of the elevator system is situated on or in the switching station  17 . For this purpose, the battery power source is connected to the central unit  10  via the trailing line that extends between the central unit  10  and the switching station  17 . An additional battery may also be arranged on the elevator car  2  [sic] in order to enable the elevator to operate in the emergency mode if the trailing line becomes defective. 
   In case of a malfunction of the elevator system which causes the occupied elevator car  1  to come to a standstill between two floors equipped with elevator doors, an emergency release device  20  is provided in the interior of the elevator car  1 . This device consists of a cable with a handle  21  on the end that leads into the interior of the elevator car  1 , wherein the other end of the cable is coupled to the brake  7 ″ of the driving machine  7 . The brake  7 ″ can be disengaged against the force of a spring by pulling on the handle  21 . The emergency release cable cooperates with a locking device  22  in order to ensure that tension does not have to be permanently applied to the handle  21  for maintaining the disengaged state of the brake  7 ″ after the emergency release has been activated. This locking device comprises a rotatable disk  23  that is rigidly connected to the emergency release cable. This disk  23  is provided with a projection  24 . When the disk  23  is turned by pulling on the emergency release cable, a lever  25  that holds the cable in the disengaged position of the brake is locked in position by the projection  24 . The lever  25  is arranged such that it can be pivoted about an axis  26 . 
   If the weight of the occupied elevator car and the counterweight are not in equilibrium, the elevator car  1  automatically moves upward or downward when the brake  7 ″ is disengaged. In this type of emergency mode, the synchronous motor  7 ′ acts as a generator brake. 
   The lever  25  is shown in the locked position in FIG.  5 . This lever  25  cooperates with a sensor  27 . In the embodiment shown, this mechanical sensor  27  is rigidly connected to the elevator car  1  and senses the inside contour of the elevator shaft in order to determine a position of the elevator car  1  in which the persons trapped therein are able to exit through an open elevator door. A projection  28  on the inner wall of the elevator shaft may serve as a marking in this case. Once this projection  28  is reached, the sensor  27  unlocks the lever  25  against the force of a compression spring  29 . This causes the disk  23  to be released and the brake engagement springs that are tensioned while the brake is disengaged cause the brake to engage. 
   The lever is unlocked by the sensor  27  due to the fact that an electromagnet  30  provided therein displaces a plunger  31  in the direction in which the compression spring  29  is compressed. The plunger  31  engages on the compression spring  29  with an annular collar  32 . An extension of the plunger  31  which extends beyond the annular collar  32  is coupled to a lever  33  that is rigidly connected to the disk  23 . When the compression spring  29  is compressed by the plunger  31 , the disk  23  is automatically displaced into a position that corresponds to the engaged position of the driving machine brake  7 ″ by the lever  33 . 
   In the normal mode of the elevator system, the emergency release device remains inactive and cannot be unintentionally activated. It would, in principle, also be conceivable that the emergency release device is unintentionally activated, for example, by pulling on the emergency release lever  22 . Such an unintentional activation is prevented due to the fact that the electromagnet  30  within the sensor  27  causes the plunger  31  to mandatorily hold the disk  23  in a position in which the cable cooperating with the handle  21  cannot open or hold open the driving machine brake  7 ″ in the normal mode of the elevator system. If the emergency release device  20  is activated by pulling the handle  21  after the elevator comes to a standstill due to a malfunction, the electromagnet  30  also ensures that the brake is not prevented from stopping the elevator car  1  in a position that is predetermined by the sensor  27  if the handle  21  is permanently pulled. This is achieved due to the fact that the plunger  31  is moved into the engaged position of the brake—in the previously described fashion—by pivoting the lever  33  under the influence of the electromagnet  30  that acts as an actuator.