Abstract:
An elevator car door opening and closing apparatus is taught having a clutch assembly carried by each car door for coupling with a landing door locking and unlocking assembly whereby the car and landing doors open and close simultaneously. The clutch assembly includes a four bar mechanical expanding and collapsing parallelogram linkage which engages, unlocks, and opens the landing door. Mechanical linkage is also attached to the parallelogram linkage whereby the elevator car doors may only be forced opened a limited amount if the car is stalled between landing sites.

Description:
RELATED APPLICATIONS 
     This is a non-provisional application based upon an earlier filed provisional application Ser. No. 60/248,918 filed Nov. 15, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention generally relates to elevator car door opening and closing apparatus. More specifically the present invention relates to an elevator car door opening apparatus wherein the active door operating mechanism is carried upon the elevator car and car door and an inexpensive, landing door unlocking and opening mechanism is attached to the landing door. A mechanical elevator car door locking mechanism is included which is inherently disabled when the car is within a reasonable distance of a landing site but which otherwise only permits the doors to be opened by an amount insufficient for passengers, within the car, to exit. 
     PRIOR ART 
     Heretofore complex and expensive landing door opening mechanisms have been attached to the landing door at each individual landing site. An example of such a mechanism may be found in U.S. Pat. No. 5,690,188, for an “Elevator Door System” issued to Takakusaki et al. on Nov. 25, 1997 wherein simple, inexpensive car door opening roller assemblies are placed on the car doors and complex, expensive, vane assemblies are placed on each landing site door. This arrangement can prove very costly in a high rise building having a large number of floors served by multiple elevators since the expensive vane assemblies must be provided on each and every landing site door. 
     BRIEF SUMMARY OF THE PRESENT INVENTION 
     The present invention overcomes the shortcomings of the referenced prior art by placing relatively inexpensive landing door opening roller assemblies on the landing doors and placing a more efficient clutch assembly on the elevator car door that engages the landing door roller assembly when the car doors are opened thereby opening both car and landing doors simultaneously in a more efficient and economical manner. Therefore, the more expensive clutch assembly need only be provided on the elevator car and not on each and every landing site door; a definite economical advantage in high rise buildings having a large number of landing sites served by one or more elevator cars. 
     The present invention teaches a new and improved clutch assembly, attached to the elevator car door comprising an assembly of mechanical links that form an expanding and collapsing mechanical parallelogram that is linked to the car door opening mechanism. The mechanical parallelogram is configured such that two parallel sides thereof provide a pair of vertically oriented gripping links that move laterally toward or away from each other as the mechanical parallelogram expands or collapses. A cam wheel, operated by the door opening mechanism, expands and/or collapses the mechanical parallelogram. 
     As the elevator car approaches and stops at a landing site, a pair of rollers attached to the landing door&#39;s locking mechanism enters the slot between the vertically oriented gripping links of the mechanical parallelogram. As the elevator doors begin to open, by action of the car door opening mechanism, the cam wheel is caused to rotate thereby collapsing, or closing, the vertical gripping links upon the landing door rollers coupling the landing door to the elevator car door and unlocking the landing doors. With the landing doors unlocked and coupled to the elevator car doors, the car doors and landing doors are opened simultaneously by the car door opening mechanism. 
     By reversing the elevator car door opening mechanism, the elevator car doors and the landing doors are simultaneously closed and the gripping links are expanded or opened, by the reverse rotation of the cam wheel, thereby releasing their grip upon the landing door rollers whereby the landing doors are again locked and the elevator car is free to move on to another landing site. 
     In the event of an emergency such as an unexpected electrical power failure, the door opening system, as taught and disclosed herein, further provides a simple and economical way to prevent the opening of the elevator car doors, by onboard passengers, beyond a predetermined amount if the elevator car is not within reasonable distance of a landing zone. 
     If the elevator car is not within a reasonable distance of a landing site the landing door locking and unlocking rollers will not be between the vertical gripping links of the mechanical parallelogram. Therefore, if the passengers, in a stalled elevator car, push the car doors open, the gripping links, of the mechanical parallelogram will close or collapse toward each other farther than possible when the landing door locking and unlocking rollers are present. The additional travel of the mechanical parallelogram gripping links may be advantageously used to mechanically activate, by appropriate mechanical linkage, a car door latch mechanism that will limit the amount of car door separation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 presents a view looking downward on the top of a typical elevator car, embodying the present invention, stopped at a landing site. 
     FIG. 2 presents an elevational, view of a pair of elevator car doors in the closed configuration and embodying the present invention. 
     FIG. 3 presents an elevational view of a pair of elevator car doors in the open configuration and embodying the present invention. 
     FIG. 4 presents a pictorial view of the elevator door power drive assembly of the present invention. 
     FIG. 5 presents an elevational view of the right side car door embodying the present invention. 
     FIGS. 5A through 5C illustrates the operation of an elevator car door safety latch. 
     FIG. 6 presents an enlarged elevational view of the door opening clutch assembly shown in FIG.  5 . 
     FIG. 7 presents an exploded view of the elements comprising the car door opening clutch assembly as illustrated in FIGS. 5 and 6. 
     FIG. 8 presents a plan view of the landing door opening rollers about to be engaged by the elevator door opening clutch assembly. 
     FIG. 9 presents an elevational view taken along line  9 — 9  in FIG.  6 . 
     FIG. 10 presents an elevational view taken along line  10 — 10  in FIG.  6 . 
     FIG. 11 presents an elevational view taken along line  11 — 11  in FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 presents a top view of a typical elevator car  10  positioned at a typical landing site and embodying the present invention. As illustrated, in FIG. 1, the elevator car doors  12  and  13  are in alignment with landing doors  14  and  15  respectively. A door opening clutch assembly  18 , attached to each car door  12  and  13 , is in engaging alignment with a pair of landing door unlocking and opening roller assemblies  21 . 
     When car  10  stops at a given landing, car doors  12  and  13  are opened by means of clutch assemblies  18  which, because of their engagement with roller assemblies  21  on landing doors  14  and  15  also unlock and open landing doors  14  and  15 . 
     Referring now to FIG. 2, car doors  12  and  13  are illustrated in their closed position. A door opening power drive assembly  40  is affixed to the top of car  10 . Referring now to FIG. 4, drive assembly  40  preferably comprises an electric motor  42  coupled to a speed reducing torque multiplier  44  preferably having a speed reduction ratio of 29 to 1. Although any speed reducing apparatus may be used it is preferable that a “cyclo” or cyclodial type speed reducer be used. A suitable cyclo speed reducer has been found to be Cyclo Speed Model CNHX-4100Y-29 marketed by Sumitomo Machinery Corporation of America. The cyclo speed reducer operates by the action of an eccentric cam mounted on the input shaft of the speed reducer. The eccentric cam rotates within a bore inside a cyclodial disc forcing the cyclodial disc to roll inside a ring gear housing. As the input shaft, and the eccentric cam, rotate, the cyclodial disc advances a given distance in the opposite direction thereby producing a speed reduction. The amount of speed reduction is determined by the specific design of the cyclodial disc and the ring gear housing. The primary advantage of the cyclodial speed reducer is that it has no elements operating in shear as in a typical geared speed reducer. In a cyclodial speed reducer all moving elements operate in compression. Thus a valuable benefit is realized, namely long life and no catastrophic failure is possible. Further, because of the rolling action, the cyclo speed reducer is more quiet than speed reducers using gears. This is particularly important for a device mounted on top of an elevator car where because of its box like structure, can amplify sounds to the passengers within the car. 
     Attached to output shaft  46  of speed reducer  44  is a typical door actuating arm  48  having a typical counter weight  41  attached thereto as illustrated. However, any other traditional drive assembly, such as the belt drive assemblies as illustrated in U.S. Pat. Nos. 4,926,975 and 5,690,188, may be used in combination with the present invention. 
     The continuing detailed description of the present invention will be further described as it applies to the right hand elevator door  13  and its associated landing door  15 . However, it is to be understood that the invention, hereinbelow, may be equally applied to the left hand door  12 , as also illustrated in the figures, by one skilled in the relevant art. 
     Referring now to FIGS. 2,  5 , and  6 , door drive link  20  is pivotally attached to pivot pin  43  of actuating arm  48  of power drive assembly  40 . Link  20  is pivotally attached to door opening link  22  at pivot  23 . Door opening link  22  is pivotally attached to the car body at pivot  24 . Link  22  is also pivotally attached to rotatable cam link  60 , of clutch assembly  18 , at pivot  51 . Rotatable cam link  60  is pivotally attached to clutch mounting plate  62  by pivot pin  54 . Clutch mounting plate  62  is typically attached to door  13 , as illustrated in FIG. 5, by any convenient means. FIG. 7 provides an exploded view of clutch assembly  18  as applied to door  13 . 
     To open doors  12  and  13 , power drive assembly  40  is energized whereby actuating arm  48  rotates counterclockwise, as viewed in FIG. 2, thereby causing link  20  to translate to the left whereby link  22  rotates, counterclockwise about pivot  24  dragging door  13  to its open position as illustrated in FIG.  3 . To close doors  12  and  13 , the process is simply reversed. 
     Referring now to FIGS. 2,  3 ,  5 ,  6 ,  7 ,  9  and  10 . Clutch assembly  18 , preferably, comprises a base or mounting plate  62  which is affixed to the hoist side of elevator door  13 . Pivotally attached to base plate  62  are a pair of laterally disposed, diagonal links  71  and  72 . Diagonal links  71  and  72  are pivotally attached to base plate  62  by pivot pins  74  and  76  respectively such that links  71  and  72  are free to rotate in a plane parallel to the plane of base plate  62 . Pivotally attached to the opposite ends of diagonal links  71  and  72  are vertical links  78  and  79  as illustrated in FIG.  6 . Thus links  71 ,  72 ,  78 , and  79  form a movable parallelogram whereby the theoretical area, therein, may be expanded and/or collapsed. Link  79  is provided a cam follower, or roller,  77  projecting into the plane of rotation of links  71  and  72 . Similarly vertical link  78  includes pin  73  extending into the plane of rotation of links  71  and  72 . 
     Cam wheel  60  is pivotally attached to base plate  62  by pivot pin  54  whereby cam link  60  is free to rotate within the plane of links  71  and  72  between base plate  62  and vertical links  78  and  79  as illustrated in FIGS. 9 and 10. Cam wheel  60  has two cam surfaces  63  and  64 . Both cam surfaces  63  and  64  are of a circular configuration concentric about pivot  54  with surface  64  being of a larger radius than surface  63 . A camming ramp, or step,  66  acts as a transition from surface  63  to surface  64 . Extending radially outward from cam surface  63  is arm  61 . The function of cam surfaces  63  and  64 , ramp  66 , and arm  61  will be described more fully below. 
     When car doors  12  and  13  are in there respective closed position, as illustrated in FIG. 2, all elements of clutch assembly  18 , on car door  13 , are positioned as shown in FIGS. 5 and 6. Cam arm  61  is in engagement with pin  73  on vertical link  78  thereby preventing tension spring  65  from collapsing the collapsible parallelogram formed by links  71 ,  72 ,  78 , and  79 . Cam follower  77 , on vertical link  79 , is in engagement with, or slightly removed from cam surface  63  and immediately adjacent to ramp  66  between cam surfaces  63  and  64 . 
     As car door  13  begins to open, by virtue of the horizontal force applied by link  22  through cam wheel  60  and pivot  54 , cam wheel  60  begins to rotate clockwise on door  13  (counterclockwise on door  12 ) see FIG.  2 . As cam wheel  60  rotates clockwise, cam arm  61  rises releasing its hold on pin  73  and ramp  66  engages cam follower  77 , on vertical link  79 , and with the assistance of tension spring  65 , forces vertical link  79  downward and vertical link  78  upward thereby causing vertical links  78  and  79  to move laterally toward one another by action of the collapsing parallelogram formed by links  71 ,  72 ,  78 , and  79 . 
     Referring now to FIGS. 1,  8  and  11 . If elevator car  10  is in a landing zone, or safely close to a landing, door unlocking and opening rollers  26  and  27 , of roller coupling assembly  21 , will be positioned between vertical links  78  and  79  of clutch assembly  18  as illustrated. As shown in FIG. 11, rollers  26  and  27  are typically positioned side by side with roller  26  rigidly affixed to assembly  21  while roller  27  is permitted to move laterally approximately one quarter of an inch. When coupling assembly  21  is positioned between vertical links  78  and  79  each roller,  26  and  27 , is typically provided approximately one quarter of an inch clearance between roller surface and vertical links  78  and  79  respectively. Thus when the collapsing parallelogram formed by links  71 ,  72 , 78 , and  79  closes upon rollers  26  and  27  vertical link  79  need only translate one quarter of an inch to engage roller  26  however, vertical link  78  must not only translate one quarter of an inch to engage roller  27  but it must also translate an additional quarter of an inch pushing roller  27  to its lateral stop to firmly grip coupling assembly  21 . Therefore, in order to provide the additional travel required by vertical link  78  lateral links  71  and  72  are eccentrically pivoted about pivots  74  and  76  respectively, whereby link  78  will move faster and laterally further than link  79  by virtue of the longer pivot radius about pivots  74  and  76 . 
     As roller  27  is pushed toward roller  26  by vertical link  79  door unlatching link  30  is caused to move vertically thereby unlatching door locking lever  34  permitting the door to open. 
     When elevator car doors  12  and  13  close, by action of power drive  40 , cam wheel  60 , on door  13 , will rotate counterclockwise, as viewed in FIGS. 5 and 6, whereby cam arm  61  will engage pin  73 , on vertical link  78 , and by overcoming the force of tension spring  65  force vertical link  78  downward causing vertical links  78  and  79  to separate releasing their grip upon door opening rollers  26  and  27  and thereby returning clutch assembly  18  to its closed door configuration permitting elevator car  10  to move on to another landing. Roller  27  being pivotally biased to separate from roller  26 , because of the weight of link  30  upon lever arm  36 , will separate from roller  26  thereby causing the landing door locking lever  34  to engage and lock the landing door from being forced open. 
     In the event Elevator car  10  stops outside a landing zone, for example as a result of a power failure, elevator car doors  12  and  13  might be pushed open by passengers inside the car by overcoming the resisting torque of power drive assembly  40 . However, it is desirable that car doors  12  and  13  be pushed open only to a given position to permit air ventilation within the car. Clutch  18  further acts to limit the car door opening as described in greater detail below. 
     FIG. 5 illustrates an optional feature that may be added to the present invention. Attached to a door suspension assembly  32  of car door  13  by pivot  58  is latching arm  56 . Latching arm  56  is connected to vertical link  78  of clutch assembly  18  by link  52  as illustrated. 
     Referring additionally to FIGS. 5A,  5 B, and  5 C. If car  10  stops outside a landing zone, rollers  26  and  27 , of landing door coupling assembly  21 , will not be positioned between vertical links  78  and  79  of clutch assembly  18 . Thus if car doors  12  and  13  are forced open, clutch assembly  18  will function as described above whereby cam wheel  60  will rotate clockwise, by action of links  22 , and  20 , and actuating arm  48  of power drive assembly  40  whereby arm  61  of cam wheel  60  will rotate clockwise and upward, as viewed in FIGS. 5 and 6, thereby releasing its hold upon pin  73 . Vertical links  78  and  79 , now being unrestricted, and being drawn together by action of tension spring  65  may close more fully than when roller coupling assembly  21  is therebetween. 
     Upon collapse of the parallelogram formed by links  71 ,  72 ,  78 , and  79 , vertical link  78  is permitted to move further upward than it would if a landing door coupling assembly  21  was therebetween, thereby, similarly, forcing latching link  52  further upward causing latch  56  to rotate counterclockwise about pivot  58 . As door  13  moves further, latching link  56  progressively rotates downward, as illustrated in FIGS. 5A,  5 B, and  5 C until latch  56  travels over center, as illustrated in FIG. 5C, whereby latch  56  will engage bracket  57  attached to door rail  59  thereby preventing further opening of door  13 . 
     Preferably vertical links  78  and  79  also includes roller engaging plates  68  and  69 , respectively, having diverging end flanges as illustrated in the figures. The diverging end flanges, of plates  68  and  69  serve to guide rollers  26  and  27 , of roller coupling assembly  21 , there between, see FIGS. 8 and 11, when the elevator car is reengaging the hoistway rollers  26  and  27  after manual disengagement for maintenance purposes. 
     Although the preferred embodiment as disclosed herein teaches an elevator having two car doors with two associated landing doors wherein a separate clutch assembly is included for each car door, the clutch assembly as described and claimed herein may also be effectively used on an elevator car having a single car door with a single associated landing door. Further the clutch assembly, as taught and claimed herein, may be used on an elevator car having two car doors wherein a single clutch assembly is positioned on one “master” door and the second car door is “slaved” to the master door and operated by means such as cables, gears or mechanical linkages. 
     It should be further understood, by those skilled in the art, that various other changes, modifications, omissions and/or additions in form and detail of the preferred embodiment taught herein may be made therein without departing from the spirit and scope of the claimed invention.