Elevator car door operating and locking device
United States Patent 1191 Dew hu rst 1 1 Apr. 22, 1975 1 ELEVATOR CAR DOOR OPERATING AND LOCKING DEVICE [75] Inventor: Alan Dewhurst, Hounslow, England [73] Assignee: Dewhurst &amp; Partner Limited.  
 Hounslow, Middlesex. England [221 Filed: June 18, 1973 [211 App]. No; 370.854  
 [30] Foreign Application Priority Data June 19, 1972 United Kingdom .1 28617/72 [52] U.S. Cl. .t 187/52: 49/139. 187/57 [51] Int. Cl B66b 13/16 [58] Field of Search 187/51, 52, 56 57, 58,  
 [56] References Cited UNITED STATES PATENTS 1,709,301 4/1929 Bassctt t. 187/52 2.458.402 1/1949 Myers 187/56 X 2.998.245 8/1961 Adams 49/139 3,344,556 10/1967 Edwards 49/139 X 3.406.484 10/1968 Atke et a1. 187/52 X 3.439.454 4/1969 Strctton 49/139 X Primary E.\&#39;amitterRiChard A. Schacher Assistant Examiner-James L. Rowland Attomqv. Agent, or Firm-Lawrence E. Laubscher [57] ABSTRACT Apparatus for operating a car door on an elevator includes a linkage mechanism which normally locks the car door when in the closed position. To enable the car door to be opened manually in the event of a power failure, bias means are provided to urge the linkage mechanism out of the locking position. electromagnetic means including a fixed solenoid and moving armature being provided for energization to prevent such movement of the linkage mechanism under the action of the bias means during normal operation.  
 3 Claims, 2 Drawing Figures PATEi-HEUAFRZZ m5 87 8,919 sumap z F/G.Z  
 ELEVATOR CAR DOOR OPERATING AND LOCKING DEVICE BACKGROUND OF THE IN\&#39;ENTION This invention relates to apparatus for operating a car door on an elevator car. and in particular to electri cally powered car door operator apparatus.  
  It is clearly dsirable for safety reasons that during normal operation ofele\ ator apparatus. the car door he held in the closed position when the car is travelling between floors. In a known form of car door operator apparatus a linkage mechanism is arranged to adopt a locking position when the car door is closed and is retained in this position. until energi7ation of the drive means to open the door. by a detent cam arrangement.  
  However. in many applications it is frequently re quired that if the elevater apparatus becomes inoperable whilst the car is in use. due for example to a power failure. the door should be released to allow manual opening by the elevator occupants. either to enable escape or at least to ensure adequate ventilation and relief of claustrophobic conditions whilst awaiting rescue.  
 SUMMARY OF THE INVENTION It is an object of the present invention to provide uparatus for operating a car door on an elevator which normally adopts a locking position on closure of the car door but which allows the car door to be opened manually in the event of a failure of the power supply to the apparatus.  
  The invention provides car door operator apparatus on an elevator car comprising drive means. a linkage mechanism operable by said drive means to open and close the car door and arranged to adopt a locking position at least on closure of the car door so as to lock the car door in the closed position. mechanical bias means arranged to urge said linkage mechanism out of said locking position. and electromagnetic means including a fixed solenoid and an armature mounted on said drive means for movement with said linkage mechanism and for magnetic coupling with said solenoid when said linkage mechanism is in the locking position so that movement of said armature is restrained on energization of said solenoid whereby to prevent movement of said linkage mechanism under the action of said bias means.  
 BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate. by way of example only. a preferred embodiment of the invention. In the drawings:  
  FIG. I is a front view illustrating schematically the general layout ofthe car door operator apparatus of the preferred embodiment; and  
  FIG. 2 is a detailed front view ofthe drive system of the embodiment of FIG.  
 DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. I, the drive means I comprises an electric motor 2 coupled by means of a belt drive (not shown) to free&#39;turning wheel 3 which itself is coupled to drive the wheel 4. the whole assembly being mounted on a base 5 supported on the top of the lift car (not shown). The linkage mechanism comprises first and second radius arms 6 and 7 mounted for rotation with the wheel 4. the outer end of the radius arm 6 being provided with a roller 8 received between the side walls of a vertical channel member 9 attached rigidly to the car door 10.  
  The apparatus is shown in FIG. I with the car door 10 in the closed position. and to open the car door radius arms 6 and 7 are driven by the motor 2 in a counterclockwise direction (as seen in the drawings). The roller 8 thus moves in a semi-circle indicated by II driving the channel member 9 and car door 10 to the right (as seen in the drawings) to open the car door.  
  It will be appreciated that when the car door is in the closed position with the radius arms 6 and 7 in a horizontal position and therefore lying in a line parallel with the direction of movement of the car door. the car door is prevented from opening by the radius arm 6. Thus. when the radius arms are in the horizontal position the linkage mechanism is in the locking position.  
  When the radius arms 6 and 7 are inclined to the horizontal. on the other hand. the mechanism is not in a locking position since in this situation a sufficient opening force applied to the door acts to rotate the radius arm 6 and wheel 4 and the door can therefore be opened.  
  The bias means comprises a lever I2 spring biased in a counterclockwise direction (as seen in the drawing) about the pivot point I3, the lever being arranged so that when the linkage mechanism moves into the doorclosed position as shown in the drawing. the radius arm 7 depresses the lever I2 against the action of the bias. Thus. if the linkage mechanism is in the door-closed position and the motor 2 is tie-energized. in the absence of any restraining force the lever 12 pushes the radius arm 7 upwards to turn the radius arms 6 and 7 in a counterclockwise direction to a nonhorizontal position.  
  FIG. 2 is a front view showing the drive system in greater detail with the apparatus in the door-open position. The electromagnetic means comprises an armature plate 20 rigidly bolted to a spoke of the wheel 3. and a fixed solenoid 21 mounted so that when the wheel is in the position corresponding to the doorclosed position of the apparatus. the armature plate 20 is adjacent the pole face 22 of the core of the solenoid 21.  
  The lever I2 is formed by a bell crank lever having first and second arms 30 and 31 respectively. the arm 30 being provided with a roller 32 for engagement by the radius arm 7 (as illustrated in FIG. I). The bell crank lever is securely fastened to a shaft 13 which is journalled in support 33 mounted on the base 5 and provided with a robust spring (not shown) housed in the housing 34 and arranged to urge the bell crank lever in a counterclockwise direction (as seen in the drawing). A stop post 35 projecting forwardly from the support 33 is engagable by detents 36 and 37 formed on the arms 30 and 31 of the bell crank lever to define the limits of angular movement of the bell crank lever. In normal operation. the solenoid 2I is energized by the control system for the elevator apparatus when the doors are in the closed position. thereby preventing the drive means and linkage mechanism from moving out of the locking position under the action of the spring biased level 12. When there is a power failure with the elevator doors closed. however. the solenoid is deenergized. thereby allowing the spring biased lever 12 to push the radius arms 6 and 7 out of the horizontal locking position and allowing the doors to be opened by hand.  
  Preferably. the solenoid is connected for energization by the power supply for the drive motor 2 so that the solenoid is de-energized whenever there is a failure in the power supply to the drive motor.  
 What is claimed is:  
 l. Elevator car door operating means. comprising a. linkage means for opening and closing the car door. said linkage means being arranged to adopt a locking position at least on closure of the car door so as to lock the car door in the closed position;  
 b. drive means for operating said linkage means to open and close the car door. said drive means including an electric drive motor. and power supply means for energizing said electric drive motor.  
 c. mechanical bias means for urging said linkage means out of said locking position; and  
 d. electromagnetic means for normally restraining movement of said linkage means from said locking position. including an armature mounted on said drive means for movement with said linkage means. and a stationary solenoid arranged opposite said armature when said linkage means is in the locking position. said solenoid being electrically connected with said power supply means. whereby upon the occurrence of a power failure with the elevator door closed. the solenoid is de-energized. thereby permitting said mechanical bias means to displace said linkage means out of the locking position.  
  2. Apparatus as claimed in claim I wherein said drive means comprises at least one wheel rotatable to operate said linkage mechanism and said armature comprises a plate otterro-magnetic material secured to said wheel.  
  3. Apparatus as claimed in claim I wherein said linkage mechanism comprises first and second radius arms mounted for rotation by said drive means and an elon gate guide member secured to said car door and wherein said mechanical bias means comprises a spring biased lever. the outer end olsaid first radius arm being slidingly connected with said guide member and said spring biased lever being mounted for engagement by said second radius arm on movement of said linkage mechanism into said locking position for rotation against the action of the spring bias.