Abstract:
An improved elevator door system for reducing vibration and noise in opening/closing a car door and a hatch door and allowing fast operation by releasing a landing door lock device before the car door moves. The elevator door system includes a hatch door; a car door; a motor for providing rotating force to open and close the hatch door and the car door; power transmitting means; a rack for possibly moving horizontally by the power transmitting means; a pinion engaged with the rack for rotating by horizontal movement of the rack; clutch connected to the pinion for transmitting or cutting off power toward the hatch door; and door lock engaged with the clutch, the door lock positioned in a lock release state in which the hatch door is movable when the clutch transmits power, while positioned in a lock state for fixing position of the hatch door when the clutch cuts off power.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to an elevator door system for opening and closing a car door in an elevator system in connection with and together with a hatch door in each floor, and more particularly to an improved elevator clutch device for releasing a landing door lock device before operating the car door so to reduce vibration and noise in opening/closing the car door and hatch door as well as enable the elevator moving fast. 
     2. Description of the Prior Art 
     As well known to the skilled, the elevator system includes a car door installed to an elevator car moving through hoistway in a building, and a hatch door installed to a hall leading to the hoistway in each floor of the building. Therefore, in order that passengers board on or off the elevator, both of the car door and the hatch door should be opened. In addition, power is required to open the car and hatch doors, the elevator system employs only one driving source in the elevator so to open/close the car door and the hatch door together without using separate driving power sources in consideration of economy. Therefore, the elevator system needs another device for operating the car door and the hatch door together. 
     In order to open/close the car door and the hatch door together with use of one driving power source installed in the elevator, the elevator system commonly employs a clutch device for connecting the car door and the hatch door so to open/close together when the elevator stops at a floor. On the other hand, if the hatch door is opened by hand when the elevator car is not on a suitable position, there can be a risk of a person or matter to fall into the hoistway through the hatch door. Therefore, a landing door lock device is essential to the elevator system in order to lock the hatch door not opened by hand, and to unlock the hatch door only when the car door starts opening in state that the elevator car stops in a designated position. 
     FIG. 1 is a front view for showing a clutch device and a belt-type door driving unit employed in the conventional elevator system viewed from the hatch door. FIG. 2 is a front view for showing the landing door lock device of the hatch door installed to the elevator system viewed from the car door. FIG.  3  and FIG. 4 show states of the landing door lock device respectively locked and unlocked by the elevator clutch device. The conventional elevator clutch device in relation with such landing door lock device of the hatch door is explained with reference to the accompanying drawings. 
     Referring to FIG. 1 at first, a driving motor  2  is mounted to a car frame  1 . The driving motor  2  drives a driving pulley  4  at a reduced rotating ratio through a belt  3 . In addition, the driving pulley  4  circulates a timing belt  6  connected to a driven pulley  5 . Left and right car doors  7 ,  7 ′ are integrally hung on hanger plates  8 ,  8 ′, which are movably suspended on a rail  9  mounted on the car frame  1 . Furthermore, one hanger plate  8  is configured to be directly led by the timing belt  6 . On the other hand, though not shown in the figure, the car doors  7 ,  7 ′ are connected to each other through a separate rope. When one door  7  moves, the rope moves the other door  7 ′ to an opposite direction at the same time such that the car doors open. 
     In addition, a clutch device  10  is shown in FIG.  3  and FIG. 4 as a conventional landing door lock device. As shown in FIGS. 3 and 4, the clutch device  10  includes a fixed clutch bar  12  and a movable clutch bar  13  mounted parallel vertically to a base  11  fixed to the hanger plate  8  of one car door  7 . Clutch arms  14 ,  14 ′ are mounted beside the movable clutch bar  13  in order to move the movable clutch bar  13  in parallel to the fixed clutch bar  14 . In addition, a cam plate  15  is fixedly mounted to a portion of the car frame  1 , and an interlocking roller  16  is connected to the movable clutch bar  13 . The cam plate  15  and the interlocking roller  16  are interlocked to change a space between the fixed and movable clutch bars  12 ,  13  according to position of the car door  7 . 
     When the car doors  7 ,  7 ′ are closed, the interlocking roller  16  is seated on the cam plate  15 , whereby the movable clutch bar  13  of the clutch device  10  is lifted upward. Because the movable clutch bar  13  moves in linkage with the clutch arms  14 ,  14 ′, the space between the fixed and movable clutch bars  12 ,  13  is broadened with the movable clutch bar  13  lifted. When the elevator car moves vertically, the fixed and movable clutch bars  12 ,  13  move with the space broadened. In addition, when the elevator car moves vertically, a lock release roller  21  of the landing door lock device  20  mounted to one hanger plate  18  of the hatch doors  17 ,  17 ′in each floor shown in FIG. 2 passes through the broadened space between the fixed and movable clutch bars  12 ,  13 . When the elevator car stops at a hall in a certain floor, the lock release rollers  21  of the landing door lock device  20  are positioned between the fixed and movable clutch bars  12 ,  13  as shown in FIG.  3 . Of course, before the car door opens, space between the fixed and movable clutch bars  12 ,  13  is in broaden state, and at that time the latch  22  of the landing door lock device  20  is hooked up the locker  23 . Therefore, the hatch doors  17 ,  17 ′ are maintained not to be opened by hand. 
     When the car doors close as shown in FIG. 3, the driving motor  2  shown in FIG. 1 is activated such that the car doors  7 ,  7 ′ are led by the timing belt  6 . Then, one car door  7  at which the clutch device  10  is installed moves to an opening direction (left in the drawing). Therefore, as shown in FIG. 4, the interlocking roller  16  comes down along the cam plate  15  so that the movable clutch bar  13  moves downward. At this time, the movable clutch bar  13  is particularly geared with the clutch arms  14 ,  14 ′ so to reduce distance to the fixed clutch bar  12 . If the space between the fixed and movable clutch bars  12 ,  13  is narrowed, the lock release rollers  21  of the landing door lock device  20  interposed therebetween become upright from their inclined state (FIG.  3 ). According to that, as shown in FIG. 4, the latch  22  fixed in a locking state by the lock release rollers  21  becomes released from the locker  23 . Therefore, from that time, the hatch door becomes led by the car door and opened at the same time with the lock release rollers  21  restrained in a narrowed space between the fixed and movable clutch bars  12 ,  13 . Closing process of the hatch door and the car door is contrary to the above opening process. 
     In addition, a micro switch  24  is installed in the landing door lock device  20 . The micro switch  24  is in contact with an actuator  25  attached to the latch  22  when the landing door lock device  20  is in a locking state, while the micro switch  24  is turned off when the landing door lock device  20  is in an unlocking state. Therefore, when contacting with the micro switch  24 , the actuator  25  activates the micro switch  24  so to inform that the landing door lock device  20  is in the locking state. 
     However, in such conventional technique, a spatial gap is created because the clutch device should move a certain distance in order to release the landing door lock device of the hatch door after the car begins to open. Due to the spatial gap, when an initial opening speed is set fast, mechanical collision may arise in the release process of the landing door lock device. In addition, because the hatch door is hardly controlled in a process of closing up the car door, the hatch doors close with colliding with each other due to the speed of the car door. Such mechanical collision of the doors and severe vibration and noise caused therefrom may cause uneasiness of passengers and shorten lift cycle of the elevator system. 
     Therefore, the conventional elevator sets up speed of the car door slow in order to prevent mechanical collision and vibration and noise therefrom, which causes decreasing capacity of the elevator and inconvenience of passengers boarding on/off the elevator. 
     SUMMARY OF THE INVENTION 
     Therefore, the present invention is designed to overcome the above problems of the prior art. An object of the present invention is to provide an improved elevator door system for opening and closing car doors and hatch doors at the same time which minimizes collision, vibration and noise in the door opening/closing process and enables door speed to be set fast by means of releasing a landing door lock device of the hatch door in advance before the car door starts opening in consideration that a factor of the problem is a gap between the conventional clutch device and the landing door lock device of the hatch door. 
     In order to accomplish the object, the present invention provides an elevator door system comprising: a hatch door mounted on each floor in a building through which passengers board on/off an elevator; a car door installed to an elevator car through which passengers board on/off the elevator; a motor mounted on the elevator car for providing rotating force to open and close the hatch door and the car door; power transmitting means for converting the rotating force to power in order to move the hatch door to an opening or closing position; a rack connected to the power transmitting means for possibly moving horizontally in accordance with the power transmitting means; a pinion engaged with the rack for rotating by horizontal movement of the rack; clutch means connected to the pinion for transmitting or cutting off power toward the hatch door; and door lock means engaged with the clutch means, the door lock means positioned in a lock release state in which the hatch door is movable when the clutch means transmits power, while positioned in a lock state for fixing position of the hatch door when the clutch means cuts off power. 
     The elevator door system may include rack locking means for locking or unlocking the rack in relation to the pinion. 
     In the elevator door system, the clutch means may include a pair of clutch bars extended vertically parallel with facing each other, the clutch bars being movable near to or far from each other; a pair of clutch arms having first clutch arm pivoted to upper ends of the clutch bars and second clutch arm pivoted to lower ends of the clutch bars, the clutch arms moving a pair of the clutch bars near to or far from each other; and a pair of links, one ends of which are connected to the first clutch arm, the other ends of which are connected to the pinion in order to transmit rotating force of the pinion to the first clutch arm. 
     In the elevator door system, the rack lock means may include the rack having a horizontal elongated opening perforated therein; a guide rod which is movable horizontally in the elongated opening; a lock lever for possibly rotating to a position of restraining movement of the guide rod or a position of releasing movement of the guide rod, the lock lever having a hook for restraining the guide rod; a roller provided to one end of the lock lever; and a plate having a plane portion and an inclined portion for providing travel surface to the roller. 
     The rack lock means may further include a spring for biasing the lock lever to a position of restraining the guide rod. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings, in which like components are referred to by like reference numerals. In the drawings: 
     FIG. 1 is a front view for showing a conventional elevator door system viewed from the hatch door; 
     FIG. 2 is a front view for showing the conventional elevator door system viewed from the car door; 
     FIG. 3 is a front view showing that the landing door lock device of the hatch door and the clutch device of the conventional elevator are locked; 
     FIG. 4 is a front view showing that the landing door lock device of the hatch door and the clutch device of the conventional elevator are unlocked; 
     FIG. 5 is a front view for showing an elevator door system according to the present invention viewed from the hatch door; 
     FIG. 6 is a front view showing that the elevator clutch device and the landing door lock device of the hatch door according to the present invention are locked; and 
     FIG. 7 is a front view showing that the elevator clutch device and the landing door lock device of the hatch door according to the present invention are unlocked. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
     Referring to FIG. 5 at first, the driving motor  2  is installed to the car frame  1  like the conventional art. The driving motor  2  drives the driving pulley  4  at a reduced rotating ratio through the belt  3 . In addition, the driving pulley  4  circulates the timing belt  6  connected to the driven pulley  5 . Left and right car doors  7 ,  7 ′ are integrally hung on hanger plates  8 ,  8 ′, which are movably suspended on the rail  9  mounted on the car frame  1 . Unlike to the prior art, the hanger plate  8 , of the car door  7  is not directly connected to the timing belt  6 , but connected to the timing belt  6  through an element of a clutch device described below so to be led by the element. On the other hand, though not shown in the figure, the car doors  7 ,  7 ′ are connected to each other through a separate rope. When one door  7  moves, the rope moves the other door  7 ′ to an opposite direction at the same time such that the car doors open. 
     FIG. 6 is a front view showing that the elevator clutch device  30  and the landing door lock device  20  of the hatch door are locked, while FIG. 7 is a front view showing that the elevator clutch device  30  and the landing door lock device  20  of the hatch door are unlock. Referring to the figures, a pair of clutch bars  32 ,  32 ′ are installed to a base  31  fixed to the hanger plate  8  of one car door  7 . A pair of the clutch bars  32 ,  32 ′ are mounted vertically in parallel, between which lock release rollers  21  of the landing door lock device  20  used for locking the hatch doors  17 ,  17 ′ may be interposed (FIG.  2 ). In addition, both ends of the clutch bars  32 ,  32 ′ areinterconnected by clutch arms  33 ,  33 ′. The clutch arms  33 ,  33 ′ are rotatably combined to the base  31  such that the clutch bars  32 ,  32 ′may be linked by rotation of the clutch arms  33 ,  33 ′ so to change space between the clutch bars . In addition, the upper clutch arm  33  is connected to a pinion  34  through a pair of links  35 ,  35 ′. The pinion  34  is also engaged with a rack  36 , which can be directly led by the timing belt  6 . Therefore, when the rack  36  is moving linearly by the timing belt  6 , the pinion  34  becomes rotated, and then the clutch arms  33 ,  33 ′ linked with the links  35 ,  35 ′ are also rotated so to change space between the clutch bars  32 ,  32 ′. 
     The rack  36  has a horizontal elongated opening  37 , through which a guide rod  38  combined to the base  31  is inserted. The guide rod  38  horizontally moves in the horizontal elongated opening  37  according to movement of the rack  36 . A region in which the guide rod  38  moves within the horizontal elongated opening  37  is corresponding to a clutching region where the landing door lock device locks or unlocks the hatch doors  17 ,  17 ′. The guide rod  38  has a shape of reversed “L”, and the dashed portion extended vertically in FIG.  6  and FIG. 7 is extended downward at the rear of the rack  36  and combined with the base  31 . 
     A rack lock lever  39  is rotatably attached to one side of the rack  36  by a pivot pin  39 b fixed to the rack  36 . The rack lock lever  39  has a hook  39   a  in one end thereof, the other end of which is connected to an interlocking roller  40 . The interlocking roller  40  is positioned on the cam plate  41  when the car doors  7 ,  7 ′ are closed. At this time, the cam plate  41  consists of a plane portion horizontally extended in a slightly higher position than the pivot pin  39   b  of the rack lock lever  39 , and an inclined portion sloped downward from one end of the plane portion. While the rack  36  moves in the clutching region, the interlocking roller  40  either rides on the plane portion of the cam plate  41  or descends along the inclined portion. When the rack  36  moves in the clutching region during a door opening process, the guide rod  38  moves from one end of the horizontal elongated opening  37  (left end in the drawing paper). 
     When the interlocking roller  40  is moving downward along the inclined portion of the cam plate  41 , the rack lock lever  39  rotates on the pivot pin  39   b  so that the hook  39   a  in one end of the rack lock lever  39  may shut and fix the guide rod  38  in one end of the horizontal elongated opening  37 . If the hook  39   a  of the rack lock lever  39  fixes the guide rod  38 , the state that space between the clutch bars  32 ,  32 ′ is narrowed by rotation of the pinion  34  engaged with the rack  36  can be maintained through the door opening/closing process. In addition, it is preferred that a spring  42  for pressing the rack lock lever  39  is provided in order to maintain the state of restraining the guide rod  38 . The cam plate  41  is fixed to the car frame  1 , and thus not moves laterally in the door opening/closing process. 
     In the clutch device described above, both of a pair of the clutch bars  32 ,  32 ′ are configured to be movable in linkage with the pinion  34  and the link  35 . In addition, the rack  36  moves with being engaged with the pinion  34  in the clutching region, which corresponds to a distance of the guide rod  38  to move in the horizontal elongated opening  37 . At this time, rotating angle of the pinion  34  is preferably about 90 degrees, or less. 
     Further more, the micro switch  24  and the actuator  25  are installed in the landing door lock device  20  of the hatch door. Same as the prior art, the micro switch  24  is in contact with an actuator  25  when the landing door lock device  20  is in a locked state. At this time, the actuator  25  activates the micro switch  24  so to inform that the landing door lock device  20  is in the locked state. 
     The elevator door system as constructed above will be explained in detail in conjunction with run of the elevator car. In state that the car doors  7 ,  7 ′ are closed and the elevator car is movable, the hatch doors  17 ,  17 ′ are, of course, locked by the landing door lock device  20  as described above. In this state, the rack  36  is positioned in a direction to which the door is closed and the guide rod  38  is positioned in a left end of the horizontal elongated opening  37  formed in the rack  36 . In addition, at this time, the interlocking roller  40  is on the cam plate  41 , and thus the hook  39   a  of the rack lock lever  39  is departing from a right end of the horizontal elongated opening  37 . In addition, the pinion  34  is engaged with left end of gear  36 a formed in the rack  36 , and space between a pair of the clutch bars  32 ,  32 ′ is widest. When the elevator car moves vertically in the hoistway, the lock release rollers  21  of the landing door lock device  20  for locking the hatch doors  17 ,  17 ′ can pass through the broaden space between the clutch bars  32 ,  32 ′. 
     When the elevator car moves and stops at a certain floor, the lock release rollers  21  of the landing door lock device  20  which is locking the hatch doors  17 ,  17 ′ in the corresponding floor become interposed into the wide space between the clutch bars  32 ,  32 ′. Because the space between the clutch bars  32 ,  32 ′ is sufficiently wide, the latch  22  of the landing door lock device  20  is continuously locked by the locker  23 . Therefore, the hatch doors  17 ,  17 ′ cannot be still opened by hand. 
     If the driving motor  2  is activated to open the door in the closed state as shown in FIG. 5, the timing belt  6  circulates by the driving motor to a corresponding direction, and the rack  36  connected to the timing belt  6  thus moves to a door-open direction. While region in which the rack  36  moves can be classified into an initial clutching region of gearing a pair of the clutch bars  32 ,  32 ′ for unlocking the hatch doors  17 ,  17 ′ and a door moving region in which the doors substantially moves. 
     That is, the clutching region corresponds a region where the guide rod  38  connected to the base  31  fixed to the car door  7  moves from a left end (FIG. 6) of the horizontal elongated opening  37  and then is hooked on and restrained at a right end (FIG. 7) toward a door opening direction. In such clutching region, the car doors  7 ,  7 ′ and the hatch doors  17 ,  17 ′ do not open, while the rack  36  moves. Moreover, in the clutching region, the pinion  34  rotates about  90  degrees according to movement of the rack  3 ( 6  as shown in FIG. 7, and the space between a pair of the clutch bars  32 ,  32 ′ becomes narrow by linkage of the links  35 ,  35 ′ and the clutch arms  33 ,  33 ′. Of course, the guide rod  38 , at this time, moves from the left end to right end of the horizontal elongated opening  37 . 
     If the space between the clutch bars  32 ,  32 ′ becomes narrow, the lock release rollers  21  of the landing door lock device  20  interposed therebetween become upright from their inclined state as shown in FIG. 7, which makes the latch  22  escaped from the locker  23  so to unlock the hatch doors  17 ,  17 ′. Therefore after that, the rack  36  leads the car door  7  restrained to a door opening direction by the guide rod  38  hooked in the right end of the horizontal elongated opening  37 , and the car doors  7 ,  7 ′lead the hatch doors  17 ,  17 ′ unlocked by the lock release rollers  21  interposed between the clutch bars  32 ,  32 ′. According to that, the car doors  7 ,  7 ′ and the hatch doors  17 ,  17 ′ may open simultaneously. 
     On the other hand, the rack lock lever  39  attached to and moving together with the rack  36  rotates while the interlocking roller  40  slides downward along the cam plate  41 , in FIG.  7 . While the rack lock lever  39  rotates, the guide rod  38  is restrained between the right end of the horizontal elongated opening  37  and the hook  39   a  of the rack lock lever  39 , resulting that restraint relation between the rack  36  and the car door  7  can be maintained. At this time, the spring  42  helps the rack lock lever  39  continuously restraining the car door  7  securely. 
     Such restraint relation between the rack  36  and the car door  7  is maintained in the door closing process until the interlocking roller  40  of the rack lock lever  39  climbs on the cam plate  41  again. In addition, because the guide rod  38  is fixed to the right end of the horizontal elongated opening  37  of the rack  36 , space between a pair of the clutch bars  32 ,  32 ′ is not widened in the door closing process. That is, the elevator door system of the present invention prevents the clutch device  30  from moving freely, which improves safety. 
     The door closing process is contrary to the door opening process. That is, after the car doors  7 ,  7 ′ and the hatch doors  17 ,  17 ′ are closed completely, the hatch doors  17 ,  17 ′ are then locked again. After that the elevator car may move vertically. 
     As described above, the present invention improves the clutch device for opening or closing the car door and the hatch door simultaneously, in which the hatch door is unlocked before opening the door and locked again after closing the door in order to make the door opening/closing operation smooth and stable. 
     In addition, the elevator door system of the present invention may provide agreeableness and convenience in passenger transportation by minimizing noise at the start of opening door and at the end of closing door and reducing time for the door opening/closing process. 
     Therefore, the present invention is effective to remove uneasiness of passengers and lower breakdown ratio of the system, and facilitates efficiency of passenger transportation by shortening the door opening/closing time such that time of passengers getting on/off the elevator car can be reduced. 
     The elevator door system according to the present invention has been described in detail. 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.