Mechanical hoistway access control device

A mechanical hoistway access control device for an elevator landing door includes a first and a second base plates mounted on the hoistway side of a landing door panel and arranged in parallel with one another, a slider slidably arranged between the first and second base plates and configured to move in conjunction with a car door and configured to protrude out from a door closing side end of the landing door by a first elastic member to take an extended position when the landing door is opened with no elevator car at the landing, and a latch attached to the landing door and configured to engage with the slider to keep the slider in the extended position once the slider protrudes out from the door closing side end of the landing door.

TECHNICAL FIELD

The present invention relates generally to a device for mechanically preventing engagement of an elevator landing door switch during elevator maintenance and inspection.

BACKGROUND ART

In general, an elevator landing door switch for preventing intrusion of a person in a hoistway through a landing door is provided on each landing door. The landing door switch is configured to be released by mechanically interlocking with an elevator car door when the elevator car door is opened on arrival of the elevator car at a landing. When one of the landing door switches is released, operation of the elevator car is interrupted. Once the elevator door is closed, the landing door switch is closed (i.e. electrically connected) accordingly, and the elevator system resumes operation of the elevator car. With such a configuration, not only can landing doors of an elevator be prevented from being opened improperly from the outside, but the operation of the elevator car can be interrupted appropriately when a landing door is opened on purpose or accidentally, thereby unforeseen accidents can be avoided in advance.

When a maintenance person enters a hoistway during maintenance and inspection of an elevator, a landing door switch is released by unlocking its lock device from the landing and opening the landing door manually, as known in the art. Therefore, the elevator car does not travel when the landing door is open.

However, in some elevators, the elevator car may resume operation once the landing door is completely closed during elevator maintenance, regardless of whether a maintenance person is in the hoistway. Further, even if the elevator has a safety switch in addition to the landing door switches, there is always a chance that a maintenance person may forget to operate the safety switch, since the method of operating a safety switch differs depending on types of elevators.

Therefore, there exists in the art a need for providing a safety device of an elevator which can reliably stop operations of the elevator car at the time of elevator maintenance and inspection. There also exists in the art a need for providing a safety device for elevators capable of retrofitting for any type of elevators.

SUMMARY OF INVENTION

According to one aspect of the present invention, a mechanical hoistway access control device for an elevator landing door is disclosed. The mechanical hoistway access control device includes a first and a second base plates mounted on the hoistway side of a landing door panel and arranged in parallel with one another, a slider slidably arranged between the first and second base plates and configured to move in conjunction with a car door and configured to protrude out from a door closing side end of the landing door by a first elastic member to take an extended position when the landing door is opened with no elevator car at the landing, and a latch attached to the landing door and configured to engage with the slider to keep the slider in the extended position once the slider protrudes out from the door closing side end of the landing door.

In some embodiments, the slider further comprises a tapered end oriented in a door closing direction of the landing door, and a cutout portion formed in the lower portion of the slider immediately behind the tapered end. The cutout portion is configured to engage with a corresponding receiver attached to a position adjacent to the door closing side end of the landing door panel when the landing door is closed after the landing door is once opened with no elevator car at the landing. The engagement of the cutout portion with the receiver mechanically locks opening and closing of the landing door.

In some embodiments, the mechanical hoistway access control device includes a landing door switch that locks the landing door when the landing door is closed.

In some embodiments, the slider includes a linkage member configured to be engaged with a car cam provided on the car door to move the slider in the door opening direction with the landing door to keep the slider in a retracted position during normal operation of the elevator car.

In some embodiments, the linkage member is a roller rotatably attached near a door opening side end portion of the slider on the hoistway side surface.

In some embodiments, the slider includes a latch groove provided in the upper side of the intermediate portion of the slider. The latch groove is configured to engage with the latch when the slider is in the extended position.

In some embodiments, the latch has a L-shaped configuration and is disposed at a position such that a shorter side portion of the L-shaped configuration is oriented in a door closing direction of the landing door and a longer side portion of the L-shaped configuration is oriented in the downward direction and overlaps with a door closing side portion of the slider to slidably hold the door closing side portion of the slider between the longer side portion of the latch and the landing door. The latch is pivotally attached to the landing door in the vicinity of a corner section of the L-shaped configuration. The latch groove is configured to engage with the shorter side portion of the latch when the slider is in the extended position.

In some embodiments, the shorter side portion of the latch has a thickness portion protruding against the landing door. The thickness of the thickness portion is slightly larger than the thickness of the slider. The thickness portion has a lower edge configured to be in slidable contact with the slider.

In some embodiments, the first elastic member is attached at one end to the latch near the corner section of the L-shaped configuration and attached at the other end to the slider near a door opening side end portion of the slider. The slider is held in a retracted position under a tension by the first elastic member so that the slider protrudes out from the door closing side end of the landing door when the landing door is opened with no elevator car at the landing.

In some embodiments, a second elastic member is attached at one end to the latch near the longer side end of the L-shaped configuration and attached at the other end to the first base plate arranged in the lower position than the second base plate near the intermediate portion of the first base plate. The second elastic member biases the latch in the latching direction.

In some embodiments, the mechanical hoistway access control device is disposed in proximity to the landing door switch.

In some embodiments, the first and the second base plates, the slider and the latch are formed of a steel plate.

In some embodiments, the first and the second base plates, the slider and the latch are disposed on a base member, and the mechanical hoistway access control device is attached to the upper portion of the landing door through the base member.

In some embodiments, the first elastic member is a spring.

In some embodiments, the second elastic member is a spring.

These and other aspects of this disclosure will become more readily apparent from the following description and the accompanying drawings, which can be briefly described as follows.

DESCRIPTION OF EMBODIMENTS

FIG. 1shows the arrangement of a mechanical hoistway access control device (MHAD)1in accordance with the present invention located on a landing door2, which is viewed from a hoistway.

InFIG. 1, the landing door2includes two door panels3and their respective door hangers4that are provided on the upper portion of the door panels3so as to support the door panels3on their respective door rails5. When the landing door2is opened and closed, each door panel3slides to the right and left by means of a plurality of door rollers disposed within the corresponding door hanger4which move in the horizontal direction on the corresponding door rail5. Two door rails5are fixed at the position on a door frame16on each floor of a building. Although the present invention will be described with reference to a landing door with lateral opening, it is to be understood that the present invention may be installed on a landing door with central opening.

Each landing door2is generally provided with a landing door switch6. As shown inFIG. 1, the landing door switch6is generally placed on the door hanger4. As is well known, each landing door switch6at each landing is electrically connected in series with each other with respect to an elevator control device, and the control device is configured to operate the elevator car only when the control device detects that all the landing door switches6are completely closed.

InFIG. 1, a mechanical hoistway access control device (MHAD)1in accordance with the present invention is disposed on the door hanger4below the landing door switch6. However, the MHAD1may be disposed on the door hanger4above the landing door switch6. It should be understood that the MHAD1may be placed at any appropriate position on the door hanger4, provided that it does not intervene normal operation of the elevator.

Next, the configuration of the MHAD1in accordance with the present invention will be described with reference toFIG. 2.

FIG. 2is a schematic view of a portion of the landing door2viewed from a hoistway. According to one embodiment of the present invention, the MHAD1is provided with two base plates7a,7b, a slider8, a latch9, a first elastic member10, and a second elastic member11. In one example, the slider8may be formed of a steel plate and slidably arranged between two base plates7a,7b, which are arranged in parallel with each other and attached to a predetermined position on the door hanger4. Likewise, two base plates7a,7bmay be formed of a steel plate. In one example, each of the two base plates7a,7bmay be fixed to the door hanger4by welding, adhesives, fasteners, bolts, etc.

FIG. 2shows a state in which the slider8is disposed in a retracted position which does not protrude from the door closing side end12of the landing door2. The door closing side end of the slider8(i.e. the left end of the slider8inFIG. 2) includes a tapered end13and a cutout portion14formed in the lower portion (i.e. the floor side) of the slider8immediately behind the tapered end13. The tapered end13is oriented in a door closing direction of the landing door2. The cutout portion14is formed such that when the slider8is arranged in the extended position, as will be described later, the cutout portion14engages with a corresponding receiver15attached to the landing door frame16adjacent to the door closing side end12of the landing door2.

The latch9having a substantially L-shaped configuration is disposed at a position such that the shorter side end9aof the L-shaped configuration is oriented in the door close direction of the landing door2and the longer side end9bof the L-shaped configuration is oriented in the downward direction and overlaps with a door closing side portion of the slider8. The latch9is pivotally attached to the door hanger4in the vicinity of the corner section of the L-shaped configuration. The latch9is arranged to slidably hold the door closing side portion of the slider8between the longer side portion9bof the latch9and the door hanger4. Further, the shorter side portion9aof the latch9has a thickness portion protruding against the door hanger4, the thickness of which is slightly larger than the thickness of the slider8. The lower edge9cof the thickness portion (shown by broken line inFIG. 2) is configured to be in slidable contact with the slider8so as to prevent the slider8from coming off upwardly.

A latch groove16having a predetermined length is provided in the upper side of the intermediate portion of the slider8. As will be described later, the latch groove16is configured to engage with the shorter side portion9aof the latch9when the slider8protrudes out from the door closing side end12of the landing door2, i.e. when the slider8is in the extended position.

The first elastic member10(e.g. a spring) is attached at one end to the latch9near the corner portion of the L-shaped configuration and attached at the other end to the slider8near the door opening side end portion of the slider8(i.e. the right end side of the slider8inFIG. 2). As will be described later, the slider8is held in the retracted position under a tension by the first elastic member10so that the slider8protrudes out from the door closing side end12of the landing door2when a maintenance person opens the landing door2manually during elevator maintenance and inspection.

Furthermore, the second elastic member11(e.g. a spring) is attached at one end to the latch9near the longer side end9bof the L-shaped configuration and attached at the other end to the lower base plate7baround the intermediate portion. InFIG. 2, the second elastic member11biases the latch9in a counterclockwise direction, i.e., biases the latch in the latching direction.

A roller17is rotatably attached near the door opening side end portion of the slider8on the hoistway side surface of the slider8. The roller17is arranged such that during normal operation of the elevator car the roller17is pushed in the door opening direction (i.e. to the right inFIG. 2) by the car cam18provided on the car door (not shown) in a known manner, and thereby the slider8as well as the entire MHAD1moves in the door opening direction with the landing door2while maintaining the retracted position.

In another embodiment, two base plates7a,7b, the slider8and the latch9are disposed in the predetermined position on a base member formed of a sheet metal. In this case, the MHAD1may be installed in any desired position on the door hanger4though the base member. The base member may be fixed to the door hanger4by welding, adhesives, fasteners, bolts, etc.

The operation of the MHAD1in accordance with the present invention will now be described with reference toFIGS. 2 to 14.

When the elevator car arrives at a landing during normal operation, the car cam18provided on the car door engages with a cam follower provided on the landing door2for opening and closing the landing door2in response to the movement of the car door, in a known manner. At this moment (FIG. 2), the car cam18also engages with the roller17on the slider8.

As is well known, in response to the movement of the car door in the door opening direction (FIG. 3), the car cam18releases (unlocks) the landing door switch6(FIG. 1) via the cam follower and pushes the cam follower in the door opening direction together with the roller17of the slider8. As a result, the landing door2is opened in conjunction with the car door while the slider8is held in the retracted position by the car cam18(FIG. 3).

During door closing operation, the car door moves in the door closing direction (i.e. to the left inFIG. 4). In response to the movement of the car door in the door closing direction (FIG. 4), the car cam18pushes the cam follower in the door closing direction, thereby closing the landing door2in conjunction with the car door. At this moment, the landing door2is closed while the slider8is held in the retracted position by the car cam18.

On the other hand, when a maintenance person enters a hoistway during maintenance and inspection of an elevator, the landing door2is opened manually by unlocking the door switch6from the landing using a key, as known in the art.

When the landing door2is moved in the door opening direction (to the right inFIG. 5) with no elevator car at the landing, the slider8protrudes out from the door closing side end12of the landing door2to the door closing direction, as shown inFIG. 6, by a tension of the first elastic member10.

In response to the movement of the landing door2in the door opening direction, when the slider8protrudes up to a position where the latch groove16is immediately below the shorter side portion9aof the latch9as shown inFIG. 6, the latch9is pivoted by a tension of the second elastic member11in the counterclockwise direction (i.e., into a latching direction) and thereby the latch9engages with the latch groove16as shown inFIG. 7. By providing the second elastic member11, the engagement of the latch9with the latch groove16is ensured. However, it should be understood that the second elastic member11may be omitted. In this case, the shorter side portion9aof the latch9may have a certain weight so that the shorter side portion9aof the latch9engages with the latch groove16by its own weight.

As shown inFIG. 8, once the slider8protrudes up to a position where the shorter side portion9aof the latch9comes in contact with the door opening side end16bof the latch groove16(i.e. the right end of the latch groove16inFIG. 8), the slider8does not protrude further in the door closing direction and maintains the position (i.e. the extended position) as shown inFIGS. 8 and 9until the landing door2is closed.

As shown inFIG. 10, when a maintenance person closes the landing door2from inside the hoistway during maintenance and inspection, the tapered end13of the slider8comes in contact with the receiver15which is attached to the landing door frame16adjacent to the door closing side end12of the landing door2. Then, the slider8is pushed by the force of closing the landing door2back to the position where the shorter side portion9aof the latch9comes in contact with the door closing side end16aof the latch groove16(as shown by the broken circle A).

As shown inFIG. 11, the latch9fixing the slider8in the position (as shown by the broken circle A) ensures that the tapered end13of the slider8runs upon the receiver15(as shown by the broken circle B) when the tapered end13is pushed against the receiver15by the force of closing the landing door2. At this moment, since the slider8slightly moves upward, the spacing between two base plates7a,7b, the length of each plate7a,7b, and the position of either longitudinal ends of each plate7a,7bmay be determined so that the slider8does not get detached from the MHAD1when the tapered end13runs upon the receiver15. Optionally, a roller19may be provided at the door opening side end (the right end inFIG. 11) of the lower base plate7band/or at the door closing side end (the left end in the figure) of the upper base plate7a, in order to maintain better contact with the slider8.

As shown inFIG. 12, as soon as the tapered end13runs on the receiver15, the tapered end13drops downward by the weight of the slider8and then the cutout portion14engages with the receiver15(as shown by the broken circle B).

Then, as shown inFIG. 13, the door opening side end14bof the cutout portion14engages with the receiver15while the shorter side end9aof the latch9comes in contact with the door closing side end16aof the latch groove16. Therefore, the opening and closing of the landing door2is mechanically locked, leaving a slight gap between the door closing side end12of the landing door2and the landing door frame16.

When unlocking or disengaging the slider8from the receiver15, the latch9is turned from its latched position as shown inFIG. 13to the unlatched position as shown inFIG. 6, and the slider8is moved from the extended position to the retracted position either from the inside or the outside of the hoistway manually using a corresponding key. Once the landing door2is completely closed manually from the outside of the hoistway after the maintenance and inspection of the elevator, the landing door switch is closed to enable normal operation of the elevator.

By mechanically locking the opening and/or closing of the landing door2leaving a slight gap between the landing door2and the door frame16during elevator maintenance and inspection, the engagement of the landing door switch6is mechanically blocked. Thus, the MHAD1of the present invention can securely block operations of an elevator car during maintenance and inspection of the elevator system, regardless of the model of elevator installed. Moreover, according to one embodiment of the present invention, since the door opening operation of the landing door2is also locked at the same time during elevator maintenance, the risk of a third person falling into the hoistway at the time of elevator maintenance can also be prevented. In particular, since the MHAD1of the present invention can mechanically block complete closing of the landing door2, it ensures a temporary stop of the elevator car during maintenance and inspection of the elevator, even if a maintenance person has forgotten to activate a safety switch of the elevator.

The mechanical MHAD1of the present invention has a relatively compact, lightweight design applicable to almost all existing elevator systems having a car cam driven landing door, i.e. having a landing door operable in conjunction with a car door by means of a car cam. Furthermore, since the MHAD1of the present invention is configured to “mechanically” prevent the engagement of a landing door switch without using electrical equipment, any electrical control and complex wirings to hoistway is not required. Therefore, the MHAD1in accordance with the present invention can be retrofitted to almost all existing elevator systems.

In another embodiment of the present invention, the slider8′ may not include a tapered end13or a cutout portion14. As shown inFIG. 14, the slider8′ does not engage with the stopper15′ attached to the landing door frame16but just comes in contact with the stopper15′ when the slider is in the extended position. The slider8′ is configured such that a maintenance person can freely open and close the landing door2during maintenance and inspection of the elevator, while preventing the landing door2and thus the landing door switch6from being completely closed.

Although the present invention has been described with reference to the configuration of the MHAD1made of a steel plate, the components of the MHAD1may be made of any members such as a bar or a rod-like member. Further, it should be understood that the composition of the MHAD1is not limited to the steel plate, and that the MHAD1can be manufactured using various materials such as carbon fiber, metal alloy, the combination of any known materials, and the like.

While the present invention has been particularly shown and described with reference to the exemplary embodiments as illustrated in the drawings, it will be recognized by those skilled in the art that various modifications may be made without departing from the spirit and scope of the invention as disclosed in the accompanying claims.