Patent Publication Number: US-6659514-B2

Title: Swinging elevator hatchway door interlock

Description:
FIELD OF THE INVENTION 
     The present invention relates to elevator systems that employ swinging hatchway doors. In particular, the present invention provides an electromechanical interlock that locks and unlocks a swinging elevator hatchway door and provides a means for determining when the hatchway door is locked. 
     DESCRIPTION OF RELATED ART 
     Elevator systems typically employ hatchway doors and car doors. It is imperative that hatchway doors be locked at all times, unless an elevator car is located at the same landing area as the hatchway door. Moreover, before an elevator car leaves a landing area at which a hatchway door was opened, the elevator system must verify that the hatchway door is locked. Various interlock devices exist for use with sliding hatchway doors, however, there has been heretofore no true electromechanical interlock system (i.e. “a device that has two related interdependent functions, which are: (a) to prevent the operation of the driving machine by the normal operating device unless the hoistway door is locked in the closed position; and (b) to prevent the opening of the hoistway door from the landing side unless the car is within the landing zone and is either stopped or being stopped.” (see ASME A-17.1b-1998 incorporated herein by reference)) for swinging hatchway doors. 
     SUMMARY OF THE INVENTION 
     The present invention provides a true electromechanical interlock for use with swinging hatchway doors that swing between opened and closed positions. In one embodiment, the interlock comprises a pivotal hook that is pivotally mounted on a swinging elevator hatchway door. The pivotal hook is preferably, but not necessarily, mounted on the interior surface (i.e. the shaft, or hoistway, facing surface) of the door. The pivotal hook protrudes in a generally perpendicular direction from the interior surface of the swinging hatchway door. The pivotal hook has a beak end and rotates between a locked and unlocked position. An electrical conductor is mounted on the beak end. A spring or other means biases the pivotal hook toward the locked position. The lug preferably, but not necessarily, has an inclined surface for slidably engaging the beak end when the door swings from the open position to the closed position. The lug also has a locking surface for engaging the beak end when the hook is in the locked position and an attempt to open the door is made. When the pivotal hook is in the locked position, the electrical conductor engages electrical contacts, which may be disposed on an electrical contact assembly, to close an electrical circuit. The closing of the electrical circuit indicates that the pivotal hook is in the locked position and thus, the door is locked closed. A solenoid having an extendable pin is mounted adjacent to the beak end of the pivotal hook so that when the solenoid is energized, the extendable pin extends and contacts the hook, thereby pivoting the pivotal hook from the locked position to the unlocked position. When the solenoid is not energized, the solenoid pin is retracted and the biasing means pivots the pivotal hook to the locked position when the hatchway door is in the closed position. The lug, electrical contact assembly, and solenoid may be mounted on a mounting plate, which in turn can be mounted in an elevator hoistway or on an elevator hatchway door jamb. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 depicts a pivotal interlock hook and mounting bracket for use with the present invention. 
     FIG. 2 is a perspective view of the pivotal hook depicted in FIG.  1 . 
     FIG. 2A is a perspective view of an electrical conductor that may be mounted on the pivotal hook. 
     FIG. 3 depicts an electromechanical interlock according to the present invention wherein the interlock is in a locked position. 
     FIG. 4 depicts an electromechanical interlock according to the present invention wherein the interlock is in an unlocked position. 
     FIG. 5 depicts a perspective view of a portion of an electrical contact assembly for use with the present invention. 
     FIG. 6 depicts a fire resistant box for housing some of the components of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As is shown in FIGS. 1 and 2, a bracket  1  is used to mount a pivotal hook  2  to a swinging elevator hatch way door  19 . The pivotal hook  2  has a beak end  3  and a fulcrum end  4 . The fulcrum end  4  is pivotally secured to the bracket  1  with a pin  5 . The hook pivots about an axis of rotation that is created by the pin  5 . The pivotal hook  2  may be manufactured from any suitable material, such as phenolic plastic. A spring  7 , mounted in a slot  6  and abutting a shoulder  14 , biases the hook in a counter-clockwise direction (as oriented in FIG.  1 ). The beak end  3  has an outboard surface  8 , which may be comprised of several contiguous planar surfaces, as is shown in FIG.  1 . An electrical conductor  9  (see also FIG. 2A) is disposed on the outboard surface  8  of the beak end  3 . (See FIGS.  1  &amp;  2 ). Brass pin escutcheons  10  may be disposed within two holes  9   a  and  9   b  provided on the conductor  9 . The beak end  3  also has an inboard surface  11 , which may also be comprised of several contiguous planar surfaces, as is shown in FIG.  1 . 
     As is shown in FIG. 3, a lug  20  is mounted to a mounting plate  21 , which in turn may be mounted to a door jamb or other suitable secure surface or structure. The lug  20  preferably has an inclined surface  22  for engaging the outboard surface  8  and conductor  9  on the beak end  3  when the elevator hatchway door swings from an open position to a closed position. In the embodiment depicted, the spring  7  abuts the shoulder  14  to bias the pivotal hook  2  in a counter-clockwise direction so that when the hatchway door swings closed the outboard surface  8  of the beak end  3  slides up the inclined surface  22  of the lug  20 . After the outboard surface  8  slides past the inclined surface  22  of the lug  20 , the pivotal hook  2  pivots to a locked position, as is shown in FIG.  3 . If the hatchway door starts to swing toward an open position, the inboard surface  11  of the beak end  3  will engage a locking surface  25  of the lug  20 , thereby preventing the door from swinging open. In the locked position, the brass pin escutcheons  10  on the conductor  9  engage electrical contacts  15  on an electrical contact assembly  16  (which can be either a separate structure, as is shown in the drawings, or can be an integral part of the lug  20 ). When the pin escutcheons  10  engage the electrical contacts, a closed electric circuit is formed. This circuit can then act to signal an elevator controller that the hatchway door is locked. 
     A solenoid  30 , or other electromechanical device, is mounted beneath and between the lug  20  and the electrical contact assembly  16 . The solenoid has an extendable pin  31  for engaging the outboard surface  8  of the beak end  3  when the solenoid  30  is energized and for pivoting the pivotal hook  2  (clockwise in FIG. 3) to an unlocked position. As shown in FIG. 4 the pivotal hook pivots to a point where the inboard surface  11  will not engage the locking surface  25  of the lug  20  when the hatchway door is opened. The solenoid  30  may also have a manual release mechanism  35  for unlocking the interlock in the event of a power failure or other malfunction. The manual release mechanism  35  may comprise a push button assembly for manually extending the solenoid pin  31  so that the hook may be pivoted manually to the unlocked position. 
     The pivotal hook  2  may be mounted to a swinging elevator door via a bracket  1  and the lug  20 , electrical contact assembly  16 , and solenoid  30  may be mounted to a mounting plate  21  that is in turn mounted to a door jamb or other suitable structure associated with the elevator hoistway. As is shown in FIG. 6, the plate  21  containing the lug  20 , electrical contact assembly  15 , and solenoid  30  may be enclosed in a fire resistant box  40 . The fire resistant box  40  preferably contains an opening  45  through which the beak end  3  protrudes when the interlock is in a locked position. A contact switch  50  may also be mounted to a surface on the fire resistant box. The contact switch  50  contacts the hatchway door and provide a means for determining when the hatchway door is closed. 
     In some embodiments it may be desirable to mount the hook to a doorjamb or other suitable hatchway structure and the other components to the hatchway door. Moreover, the present invention may be readily modified for use with sliding hatchway doors. In addition, the invention may be modified for use on an elevator cab door as well as a hatchway door. 
     The hook may be manufactured from a conducting material and thus the outer surface of the beak end is itself the conductor. While the lug is shown having an inclined surface, not all embodiments require an inclined surface. However, in some embodiments it may be desirable to match the incline angle of the inclined surface of the lug with the angle formed by one or more outboard surfaces on the beak end that engages the lug when the door opens or closes. (See FIG.  4 ).