US1934500A - Automatically operated elevator door - Google Patents

Description

Nov. 7, 1933. G. K. HEARN El AL 1,934,500

AUTOMATICALLY OPERATED ELEVATOR DOOR Filed Feb. 28, 1951 ATTORNEY Patented Nov. 7, 1933 UNITED STATES AUTOMATICALLY OPERATED ELEVATOR DGOR George K. Hearn, Chicago, 111., Paul B. Barten, New York, N. Y., Edgewcod, Pa.,

and William F. Eames,

assignors to Westinghouse Electric and Manufacturing Company, a corporation of Pennsylvania Application February 28, 1931. Serial No. 519,008

15 Claims. (Cl. 18731) Our invention relates to systems of control for automatically operated elevator doors and more particularly to door-control systems employed in elevator installations in which the elevator cars are automatically stopped level with the floor landings.

One object of our invention is to provide for stopping an elevator car immediately after it travels past a floor landing at which a stop is to be made by that car, when the regular stop ping means fails, and for which the car door and the corridor door have started to open.

Another object of our invention is to provide for indicating to the car attendant that the additional means for stopping the car after it has run by a stop at which the doors havestarted to open, is not operating or is not in good working condition.

It is also an object of our invention to provide, in an elevator system having automatically operated doors, means for stopping and reversing the car at a landing without the automatically operated doors opening at that landingi For an illustration of one of the various forms our invention may take, reference may be had to the accompanying drawing, in which the sole figure is a diagrammatic representation of an elevator system embodying our invention.

Referring more particularly to the drawing, we have illustrated therein an elevator car C as suitably suspended by a cable Co which passes over a hoisting drum D to a suitable counter weight C20. The hoisting drum D is directly coupled to and operated by the armature EM of an elevator motor EM.

The control system for the elevator motor Eli l is illustrated as being of the variable-voltage type wherein the armature El /I of the motor EM is connected in loop circuit with the armature 3? of a generator G. The generator G is provided with a separately excited field winding and a series field winding ESF. The armature G of the generator G is suitably driven by means of a driving motor M, illustratedas of a shunt wound type having its armature M and its field winding MF connected in shunt relation to a source of power designated by the supply conductors L1 and L2.

The direction and speed of operation of the motor EM is suitably controlled by controlling'the direction and value of the excitation current supplied to the separately excited field winding of the generator G. v

The direction of the excitation current for the field winding GF is suitably controlled bymeans of an up direction switch 1 and a down direction switch 2, while the value of the current supplied to the hold winding G)? is controlled by means of an intermediate speed relay 3 and a high-speed relay i.

A car switch CS is mounted upon tl e elevator car C to be actuated by the attendant on the car for controlling the operation of the direction switches 1 and 2 and the speed relays 3 and l to movethe car in either direction atthe desired speed.

A control system of any suitable type may be employed for automatically stopping the car 0 level with the floors past which it moves when the car switch CS is moved to its car stopping position. As a suitably system or" control, we have illustrated a system or" the automatic inductor landing type which is disclosed in the copendlng application of E. M. Bouton, Serial No. 731,921, filed August 14, 1924, and assigned to the Westinghouse Electric & Mfg. Company.

The inductor landing system includes an up high speed inductor relay EU and an up intermediate speed relay SU for causing the car to be automatically decelerat ed from its high and intermediate speeds, respectively, and a stopping inductor relay S for automatically bringing the decelerated car to astop at an exact level with the floor when the car is travelling upwardly. Similarly, a down high speed inductor relay HD, a down intermediate speed inductor relay SD and the automatic stopping relay S will cause the car to slow down and stop at the floors when it is travelling downwardly.

It is assumed that each of the floor landings past which the car moves will be provided with a set of inductor plat for cooperation with the inductor relays as the car approaches predetermined points in advance or" the landing to cause the car to stop thereat, when the car switch CS is centered for a stop. We have illustrated the inductor plates for one floor landing as comprising an up high speed inductor plate HU an up intermediate speed inductor plate SU and a stopping inductor plate S for successively operating the inductor relays SUand S as the car, moving upwardly approaches the floor level at which the inductor plates are disposed. When the car is travelling downwardly the high speed inductor plate HD, the intermediate speed inductor plate SD, and the stopping inductor plate S will successively operate the inductor relays HD, SD and S, respectively, as the car approaches the floor landing at which the plates are disposed, to decelerate the car and stop it at that landing.

As shown, the car C is provided with a door or collapsible gate 11, for protecting passengers While the car is moving. The means for opening and closing the car door comprises a lever 12 and a pair of electromagnets l3 and 14 which are electrically connected to the supply conductors L1 to L2 by a door relay 15. When the door relay 15 is energized, the car door closes. When the door relay is deenergised, the car door opens. A pair of car-door contact segments b and c are so disposed on the car switch CS and connected to the coil of the car door relay that the relay may be energized or deenergized by operating the car switch.

Inasmuch as 'ie corridor doors and operator therefor are well known in the art, they have not been illustrated in the accompanying drawing, it being understood that corridor doors and operators of any suitable type may be employed, such as the individually actuated corridor doors disclosed in application Serial No. 420,092, filed Jan. 11, 1930, and assigned to Westinghouse Electric Elevator Company, or the corridor doors shown in Patent No. 1,370,111 to I. R. Jackson, Jr. as being operated by an operator on the car door. In the present application the car door is illustrated provided with a shoe or channel member 16 die-- posed to engage a projecting member (not shown) on the corridor door at a landing when the car arrives thereat and thereby cause the corridor door at that landing to open and close with the car door. The shoe 16 should be long enough to engage the corridor door and start it to open when the car is approaching the floor but still about six inches from the floor level.

The system is illustrated as applied to an elevator installation in which the corridor door and the car door start to open when the car arrives within a predetermined distance of the landing at which it is to stop, to save time in making the call at the landing. In order to accomplish this, a second circuit for controlling the car door relay 15 is extended through a pair of contact members 0 on the intermediate speed relay 3. The second circuit is disposed in parallel relation to the circult through the contact segments 2) and c on the car switch CS. Hence, if the car switch is moved to the stop position when the car is running, the car door relay will not be deenergized for the following stop until the intermediate speed relay 3 opens at a predetermined distance from the landing thereby opens the second circuit for the coil of the car door relay.

In elevator systems provided with means for automatically stopping the car level with the floor at a landing and f or automatically opening the car door and corridor door for the stop at that landing, if the doors open automatically but the car fails to stop, a very dangerous condition of operation will exist. This is particularly true in systems of the type in which the car is first slowed down by a decelerating means, next the corridor door and the car door automatically start to open and then the slowly moving car is brought to rest level with the floor, with the doors fully open, because, if the passengers attempt to get into or out of the slowly moving car as soon the doors open, but the car fails to stop, they may be caught by the doors closing when the car continues past the landing.

In order to have positive protection against the failure of the automatic stopping means, such as the inductor relay S, in landing, we have provided an auxiliary safety means for stopping the car before it travels sufliciently far beyond the floor level to cause the doors to close, when the automatic car stopping means fails to open the control circuit and stop the car.

As a suitable auxiliary stopping means, we have illustrated a time limit relay TE that is disposed to open 1e car control circuit at a second point predetermined time after the automatic stopping means should open it. Hence, if the automatic stopping means does not stop the car at the floor, the operation of the time element rewiil stop it a predetermined time thereafter. The predetermined time may be so set that the car will travel only few inches beyond the point where it is normally stopped by the automatic stopping means before it is stopped by the auxiliary stopping means when the automatic means fails to Work.

Inasmuch as the doors open at a point when the car is only a few inches from the floor where it will be normally stopped by the automatic stopping means, the auxiliary stopping means may be controlled by the opening of the doors to operate at such a 1::redetermined time thereafter that its operation will occur at a predetermined time after the automatic stopping means should, and normally does, operate. In order to accomplish this, the relay TE is controlled by a door contact relay 1'! which deenergized by the opening of the door contacts 18 and 19 when the doors start to open. A da pot is) is connected to the relay TE for delaying its operation for a predetermined time after the doors start to open, which time should be sufficient, as above explained, to permit the automatic stopping means to function. A more complete explanation of the operation of these relays will be given later in an assumed operation of the system.

Inasmuch as the automatic stopping means comprising the stopping inductor relay S seldom fails to work, the reaches a point where it will be stopped by the auxiliary stopping means. Under such circumstances the auxiliary stopping means may get out of condition and stick or fail to operate effectively without the car attendant being aware of its disabled condition. Therefore, we have connected the circuit for the door operating relay 15 through the contact members a of the time element relay TE in such manner that the car attendant cannot reclose the doors after a stop unless the time element relay has moved to its car stopping position. Hence, when the car attendant finds that he cannot reclose the doors after a stop has been made, that is an indication to him that the aimiliarv stopping means is not wo king properly.

.As further 7-: to keep doors closed while the car is moving, a third parallel cii cult is provided for the door operating relay which extends through a re .stor The res should be so proportioned that tl..

relay 15 cannot be energized throi. after it has been. energized though tl members b of the relay 1'? or the contact members a. of relay TE by the operation o the car switch, it will energized until it is We ergized by the opening of both the ca" switch and the intermediate speed relay 3. f the door is forced open while the car iilOVil'lH, it will be reclosed immediately.

In the operation of elevators, it occasionally happens that the car attendant runs car 1 t a floor and then desires to return to it to pick: up or let oil passengers.

usually stops before it iii:

car and reverse it at the next floor without SEW-J it to open its contact members b to deenergize the ing the automatic doors to open, the contact segments b and c onthe car switch CS are so extended inwardly that the switch arm 21 may be disposed thereon without engaging the car switch contact segments d and e, thereby maintaining a parallel circuit for the coil of the door operating relay 15 through the contact members b on the door contact relay 17, to hold the doors closed without energizing either of the direction switches l and 2. With this arrangement of the contact segments and circuits, if the car attendant throws the switch across the center position'to a position upon the first part of the door contact segment for the reverse position, before the doors start to open, the door operating relay 15 will remain energized and keep the doors closed while the car comes to a stop. Then a further movement of the car switch in the same direction will cause the car to reverse without the doors opening, and return to the floor at which the car attendant desires to stop.

The following assumed operation of our invention is given to explain it more fully.

Assuming that the car is standing at a fioor landing with the corridor door and the car door in their open position and that the car attendant, desiring to move the car upwardly, moves the arm 21 on the switch CS in a counter-clockwise di-' rection until the contact segment 9' engages the contact segment 0, then the door relay 15 will be energized to cause the doors to close by the completion of a circuit for energizing the door operating relay 15, which circuit extends from the supply conductor L1 through conductors 25, 26 and 27, the contact members a of relay TE, conductors 28 and 29, the coil of relay 15, conductors 30, 31 and 32, the contact segments 0 and y of the car switch CS, and conductor 33 to the supply conductor L2.

The energization of the door relay 15 causes door electro magnet 13, and to close its contact members a to thereby complete a circuit for en ergizing the door-closing electro-magnet 14 to close the car door, which circuit extends from supply conductor L1 through conductor 35, the

coil of electro-magnet 14, conductor 36, the contact members a of relay 15 and conductor 37 to supply conductor L2. The energization of the electro-magnet 14 causes its armature to pull upi lay 17 to operate the relay TE, which circuit extends irorn the supply conductor Ll through conductor 25, the door contact members 18 and 19, conductor 40, the 'coil of relay 17, and conductor 41 to the supply conductor L2.

The closing of the contact members 5 on the energized door contact relay 17 completes a circuit in parallel to that through the contact members a of the relay TE for energizing the relay 15, which circuit extends from a junction point 42 on conductor 26 through conductor 43, the contact members 5 of relay l7 and conductor 44 to a junction point 45 with conductor 29 and thence through the coil of relay 15 to the supply conductor L2, as previously described.

The closing of the contact, members a on the energized relay 17 completes a circuit for energizing the time element relay TE, which circuit extends from the supply conductor L1 through conductors 25, 26 and 43 the contact members a of relay 17, conductor 46, the coil of relay TE, and conductors 47 and 41, to the supply conductor L2. 7 The energization of the time element relay TE causes its contact members a to open and its contact members b to close. The opening of the contact members a opens the circuit through the relay TE for the door-operating relay 15. However, it will be noted that, although the contact membersa on the relay TE open the circuit first completed for the relay 15, the parallel circuit for the relay previously completed through the closing of the contact members b of the relay 17 will maintain the relay 15 in an energized condition until the car switch CS and the intermediate speed relay 3 are operated to deenergize it.

The closing of the contact members I) on the relay TE closes a safety gap in the car control circuit so that the car may be started by the car attendant moving the car switch CS to a position to energize the up direction switch.

Assuming now that the car attendant continues the movement of the switch arm 21 in a counterclockwise direction, then the contact segment a on the arm will engage the contact segment e of the car switch CS and thereby complete a circuit for energizing the up direction switch 1 to move the car upwardly, which circuit extends from supply conductor Ll through conductors 25 and 50, contact segments a and e of the car switch CS, conductor 51, the coil of up direction switch 1, conductors 52 and 53, the contact members 5 of relay TE and conductors 54 and 55 to the sup ply conductor L2.

The energization of the up direction switch 1 closes its contact members a to complete a selfholding circuit therefor, which extends from the supply conductor L1 through conductors 25 and 56, the contact members on thestopping inductor relay S, conductors 57 and 58, the contact members a of up direction switch 1, the coil of up direction switch 1, and thence through conductor 52 to the supply conductor'L2 as previously described.

The closing of the contact members I) and c on the up direction switch 1 completes a circuit for energizing the field winding GF of the generator G to cause the hoisting motor EM to move the car upwardly, which circuit extends from supply conductor L1 through conductor 60, the contact members b of up direction switch 1, conductor 62, the field winding GF, conductors 63 and 64, the contact members 0 of up direction switch 1, conductor 65, resistors R1 and R2 and conductor 66 to the supply conductor L2.

As the car attendant continues the movement of the car switch CS in a counterclockwise direction the contact segment a on the arm 21 engages the contact segment g and completes a circuit for energizing the intermediate speed relay 3 to increase the speed or the car, which circuit extends from supply conductor Ll through conductors 25 and 50, the contact segments a and g of car switch CS, conductors 67,-the'coil of intermediate speed relay 3, and conductors 68, 69, and 70, to supply conductor L2.

The closing of the contact members a on the energized relay 3 completes a self-holding circuit for that relay extending from the supply conductor L1 through conductors 25 and 72, the contact members of inductor SD, conductor 73,

the contact members of inductor SU, conductor 74, the contact members a of relay 3, the coil of relay 3 and conductors 68, 69 and 70 to the supply conductor L2. Hence, the intermediate speed relay 3 will remain energized until the inductor relay SU is operated to open the holding circuit therefor.

The closing of the contact members I) on the intermediate speed relay 3 eliminates the resistor R1 from the circuit of the field winding GF and thereby causes the car to run at its intermediate speed.

The closing of the contact members 0 of the intermediate speed relay completes a circuit leading from the coil of the door operating relay 15 to the supply conductor L2 which is in parallel relation to that through the car switch CS so that the door operating relay 15 cannot be deenergized by the centering of the car switch CS until the intermediate speed relay 3 is deenergizcd. This parallel circuit extends from the coil of the relay 15 through conductor 30, junction point 75, conductor 76, contact members 0 of relay 3 and conductor '70 to supply conductor L2.

As the car attendant continues the movement of the car switch CS to operate the car at high speed, a circuit is completed for energizing the high speed relay 4, which circuit extends from the supply conductors L1 through conductors 25 and 50, the contact segments a and i, the car switch CS, conductors '78, the coil of relay 4, conductors 68, 69 and '7 to supply conductor L2.

The closing of the contact members a on the high speed relay 4 completes a self-holding circuit for that relay extending from the supply conductor L1 through conductors 25 and '79, the contact members of induction relay HD, conductor 80, the contact members of induction relay HU, conductor 81, the contact members a of relay 4, conductor the coil of relay 4 and conductors 68, 69 and '70 to supply conductor L2. Hence, the high speed relay will remain energized until it is deenergized by the opening of the contact members on the inductor relay HU.

The closing of the contact members b on the relay 4 eliminates the resistor R2 from the circuit for the field winding GE and thereby causes the car to run at high speed.

Assuming now that the car attendant centers the car switch CS to a stop at the next landing on his upward trip, then the centering of the car switch completes a circuit for energizing the inductor relays HU, SU and S, so that they will be operated to decelerate and stop the car at the next landing, which circuit extends from supply conductor L1 through conductors 25 and 50, the contact segments a and of car switch CS, conductor 84, then in parallel through the coils of the inductor relays HU, SU, and S and conductors 85 and 55 to the supply conductor L2.

is the car approaches the next landing, the inductor relay HU passes the inductor plate EU and is operated thereby to open its contact members thereby deenergizing the high speed relay l and thus causing the resistor R2 to be reinserted in the circuit previously described for the generator GF to decelerate the car to its intermediate speed.

As the car continues its approach to the landing, the inductor relay SU passes the inductor plate SU and is operated thereby to open its contact members to deenergize the intermediate speed relay 3. The opening of the contact memhere D on the intermediate speed relay 3 re inserts the resistor R1 in the circuit for the field winding GF and thereby decelerates the car to its low speed.

Inasmuch as the centering of the car switch CS opened the circuit through that switch for the door-operating relay 15, the opening of the contact members 0 on the intermediate speed relay 3 opens the parallel circuit for the coil of the door operating relay 15 and thereby causes it to be deenergized to effect the opening of the doors.

The opening of the contact members a of the deenergized door relay 15 deenergizes the electromagnet 14 which has held the car door in its closed position.

The closing of the contact members I) of the deenergized door relay l5 completes a circuit for energizing the door operating electro-magnet 13 to operate the door lever 12 to open the door, which circuit extends from supply conductor L1 through conductor 87, the coil of the electromagnet 13, conductor 88, the contact members I) of door relay l5 and conductor 37 to the supply conductor L2. Hence the car door 11 is opened while the car is approaching its stopping point, level with the floor landing. Inasmuch as the s is already within a few inches of the floor el, the operating shoe 16 on the car door 11 the corridor door (not shown) at g and cause it to open along with the cor Zoo T.. e opening of the car door opens the circuit for the door contact relay 1'? and thereby deenergizes that relay.

The opening of contact members a on the deenergized relay 1? deenergizes the time element relay TE but, by reason of the dash-pot 20, that relay does not open until after the expiration of a predetermined time, conlrolled by the setting of the dash-pot.

As the car arrives at the final stopping point, the inductor relay S comes opposite the inductor plate S and is operated to open its contact members. The opening of the contact members on the relay S opens the self-holding circuit for the up direction switch 1, thereby stopping the car level with the floor.

The delayed opera ion of the relay TE now takes place and its contact members I) open, but inasmuch as the inductor relay S has already stopped the car, the operation of the relay TE has no effect upon it.

Assuming new that the stop has been compleged and that the car attendant, desiring to continue his upward trip, again moves the car switch in a counter-clockwise direction, then the doors will be closed, the up direction switch 1, the intermediate speed relay 3, and the high speed relay 4 will be energized successively, and operate as previously described to cause the car to run at high speed.

Assuming further that the car attendant centers the ear switch CS to make a stop at an approaching floor then the inductor relays HU, SU and S will be energized as previously described to stop the car at that floor. As the car passes the inductor plate EU, the inductor relay HU operates and deenergizes the high speed relay 4 to decclerate the car to its intermediate speed. As the car passes the inductor plate SU, the inductor relay SU operates and deenergizes the intermediate speed relay 3 to decclerate the car to its low speed. The deenergized relay 3 also causes the doors to open. The opening of the doors deenergizes the door contact relay 17 which, in turn, deenergizes the time element relay TE and prepares it to open the car control circuit at a predetermined time thereafter, all as previously described.

Now, with the car slowed down to its slow speed for the stop, the doors opening and the time element relay deenergized, let it be assumed that the stopping inductor relay S sticks and fails to work, then the car will fail to stop and will con tinue past the floor level at its slow speed. At this point, the predetermined time for which the dash pct 20 has been set expires and the deener gized relay TE operates to open its contact mem bers 12 thereby opening the car control circuit and stopping the car. Assuming that the relay TE has been correctly adjusted, the car is s'opped a few inches below the floor level and before the shoe 16 on the car door has moved beyond the projection (not shown) on the corridor door, then the corridor door will be maintained in its open position and will not close upon any person who may have tried to enter the slowly moving car before it was stopped.

Assuming now that the stopping inductor relay S has been repaired and the car attendant again moves the switch in the counter-clockwise direction to continue the upward trip, then the doors will be closed and the up direction switch 1 and the speed relays Sand 4 will be operated as previously described to run the car at high speed.

Assuming further that the car attendant centers the car switch CS to make his stop at an approaching floor and that the inductor relays operate accurately and thereby stop the car level with the floor but that the auxiliary stopping device comprising the time element relay TE sticks or fails to operate when it is deenergized. Under these conditions nothing abnormal in the operation of the car will happen until the operator tries to close the doors and leave the floor at which the car has stopped. "Thereupon, he will find that he cannot close the car door and the corridor door because the contact members a of the sticking relay TE are open, thereby preventing the door operating relay 15'from being energized to close the doors. The fact that he cannoteffect the closing of the doors will warn him that the auxiliary stopping means comprising the time element relay TE is out of order.

Assuming now that the relay TE has been repaired and that the car attendant is operating the car in an upward direction but passes a floor at which he should make a stop and then, suddenly realizing that he should have stopped, moves the car switch CS in a clockwise direction to stop the car and reverse it at the next floor. Under such conditions, he desires to stop the car and reverse it at the next landing without causing the automatically operated doors to open at that landing. Thereupon, he moves the car switch arm 21 in a clockwise direction across the center until. it rests upon the contact segments 6 and z of the car switch. .In this position, the contact segment a on the switch arm 21 engages the contact segment 2 of the switch, while the contact segment 9' of the arm engages the contact segment b.

The engagement of the contact segments a and z of the car switch completes a circuit for energizing the inductor relays to stop the car at the next landing, as previously described.

The engagement oithe contact segments 7' and b on the car switch completes a circuit for main taining the door operating relay in its energized condition to hold the doors closed while the stop is made, which circuit extends from supply conductor Ll, through conductors 25, 26 and 43, the

contact members b of relay 1?, conductors 44 and 29, the coil of relay 15, conductors 30 and 31, the contact members I) and 7 of car switch CS and conductor 33 to supply conductor L2.

In this connection, it should be noted that the car switch may be actuated at any time previous to the actual opening of the doors to maintain the doors closed at a stop. Thisis made possible by the contact members b on the relay 1'7 reg closed until the doors open and thereby ntaining a partially completed circuit :1 which the door operating relay 15 may iaed or maintained in an energized condition by operation of the car switch.

Assuming that the inductor relays HU, SU and S operate as previously described and stop the car level with the landing and that thereupon the car attendant continues the movement of the car switch in a clockwise direction, then the contact segment a on the switch arm 21 will move off the contact segment a and engage the contact segment d thereby completing a circuit for energizing the down direction witch 2 for returning the car to the landing that was passed, which circuit extends from supply conductor Ll through conductors 25 and 50, the contact segments a and d of car switch CS, conductor 91 th coil of down direction switch 2, conductors 52 and 53, the contact members I) of relay TE and conductors E i and 55 to supply conductor L2.

The closing of the contact members a on the energized down direction switch 2, completes a self-holding circuit for that switch extending from supply conductor Ll, through conductors 25 and 56, the contact members of stopping inductor relay 5, conductors 5'7 and .92, contact members a and the coil of down direction switch 2, and through conductor 52 as previously de scribed to supply conductor L2. The closing of the contact members I) and c on the energized down direction switch 2 completes a circuit for energizing the field winding GF to operate the car downwardly, which circuit extends from the supply conductor Ll through conductors 60 and 93, the contact members b on down direction switch 2, conductor 63, the field winding GF, conductors 62 and 94, the contact members 0 of down direction switch 2, conductor 65, resistors R1 and R2 and conductor 66 to the supply concluctor L2.

As the car attendant continues the movement of the car switch CS'in a clockwise direction the contact segment a will engage the contact segment 17 thereon, thereby completing a circuit for energizing intermediate speed relay 3 to operate the car at its intermediate speed as previously described.

A further movement of the car switch in the clockwise direction will cause the contact segment (2 to engage the contact segment h thereon, thereby completing a circuit for energizing the speed relay i, to operate the car at high speed as previously described.

Assuming now that the car attendant centers the car switch CS to stop the car at the floor which he overran, then the inductor relays HD, SD and S will be energized by a circuit extending from the supply conductor Ll through conductors 25 and 50, the contact segments a and e of car switch CS, conductor 84, in parallel through the coils of the inductor relays I-ID, SD and S and thence through conductors and 55 to the supply conductorL2. As the car approaches the stop the inductor relay HD passes the inductor relay plate HD' and is operated thereby to deenergize the high speed relay 4. to decelerate the car.

As the car continues its downward approach to the passed floor, the inductor relay SD the inductor plate and is operated thereby, to decnergize the intermediate speed relay 3 to decelerate the car to its low stopping speed. As the car approaches closer to the stopping point the stopping inductor relay S comes to the inductor plate S and is operated thereby to open the circuit to the down direction switch, thus causing the car to stop level with the floor.

It will also be apparent from the circuits so far described, that the car attendant may stop the car at a iloor and hold "he doors shut by moving the switch arm almost but not quite to the center position and that he may then restart the car in the same direction, without opening the doors, by reversing the movement of the switch arm 21, or he may reverse the car, without opening the doors, by moving the switch arm across the center position to the reversing position.

For instance, assuming that the car is moving upwardly with the switch arm 21 on the contact segments 2', g, e and c, and that the car attendant moves the car switch arm almost but not quite to the center position, then the switch arm will be off the car running contact segments but will be on the inductor relay contact segments .2 and the door contact segment 0. In this position the inductor relays will be energized to stop the car and the door operating relay 15 will remain energized to hold the doors shut. Assuming now that the car attendant deaides to restart the car in its up direction without opening the doors, he may do so by simply returning the switch arm to the point where it re-engages the contact members i, g and e.

Assuming, however, that the car attendant decides to reverse the direction of the car after making the last mentioned stop, without opening the doors, then he simply moves the switch arm from the contact segments 2 and 0, across the center, to the contact segments d and b. In this position the doors will remain closed and the car will start in the opposite or down direction, This latter operation is made possible because of the contact members b on the relay 1'7 and the fact that it takes time for the doors to actually start to open after the door operating relay 15 is deenergized. When the switch arm 21 moves across the center, the door operating relay 15 is deenergized but, by reason of the time lag in the opening of the doors, the contact members b on relay 17 remains closed long enough after the door relay 15 is deenergized to permit that relay to be reenergized by the switch arm engaging the door contact segment b before the doors open.

Therefore, it will be seen that we have provided an elevator door control system in which if the doors start to open and the car fails to stop, an aitixiliary stopping device will automatically effect the stopping of the car before it proceeds far enough beyond the floor level to injure anybody who may have stepped into the open doorway. It will also be se n that we have provided door control system having an auxiliary automatic safety device with means whereby the operation of the auxiliary device will be tested at every stop and that we have also provided a system in which a car may be stopped at floor and restarted or reversed to return to another floor, without opening the automatically operated doors associated therewith.

While we have illustrated and described only one specific embodiment of our invention, we are aware of the fact that it may be changed and modified in many ways and therefore we do not desire to be limited to the embodiment of the invention illustrated and described.

We claim as our invention:

1. In an elevator, the combination with means for operating an elevator car past a landing, and a door for closing the opening to said car, of means operably responsive to the opening of said door for stopping said car and means for delaying the operation of said stopping means for a predetermined time after said door starts to open.

2. In an elevator, provided with means for operating an elevator car past a landing at a corridor, automatic means for stopping the car at the landing, means for setting said automatic stopping means into operation, a door for closing the opening to said car, an auxiliary stopping means operably responsive to the opening of said door for stopping said car, and means for preventing the oper lion OI said auxiliary stopping means until after the expiration of a predetermined time after the automatic means should have stopped the car.

3. In an elevator, means for operating an elevator car past a landing, automatic means for stopping the car, means for setting said automatic stopping means to stop said car at said landing, a door for closing the opening to the canineans for starting the door to open as the car approaches the stop to be made, and auxiliary means operably responsive to the opening of the door for stopping the car within a predetermined time after said stopping means has been set to operate.

4. In an elevator, means for operating an elevator car past a landing, automatic means for slopping the car, means for setting said automatic stopping means to stop said car at said landing, a door for closing the opening to the car, means for starting the door to open as the car approaches the stop to be made, auxiliary means operably responsive to the opening of the door for stopping the car, and means for delaying the operation of the auxiliary stopping means fora predetermined time after said automatic stopping means should have operated when set fora stop.

5. In an elevator, means for operating an elevator car past a landing, automatic means for decelerating the car, automatic means for stopping the car, control means for conditioning the decelerating means and the automatic stopping means to decelerate the car and stop it at the landing, a door for closing the opening to said car, means operably responsive to the operation of said decelerating means for opening said door, and an auxiliary means operably responsive to the opening of said door for stopping said car within a predetermined time after it should have con stopped by the automatic stopping means.

6. In an elevator, means for operating an elevator car past a landing, automatic means for decelerating the car, automatic means for stopping the car, control means for conditioning the decelerating means and the automatic stopping means to decelerate the car and stop it at the landing, a door for closing the opening to said car, means operably responsive to the operation of said decelerating means for opening said door,

and an auxiliary means operably responsive to the opening of. said door for stopping said car and means for delaying the operation of the auxiliary stopping means until after the automatic stopping means should have stopped the car.

7. In an elevator, provided with means for operating said car past a landing, a control circuit for controlling said operating means, automatic means for opening said control circuit to stop said car, a door for closing the opening to said car, means for controlling the opening and the closing of said door, means for setting the automatic means to effect the stopping of the car and for operating the door controlling means to open the door for a stop at thelanding, and a time element relay operably responsive to the opening of said door for opening said control circuit within a predetermined time after the automatic stopping means should open said circuit to stop the car.

8. In an elevator, the combination with means for operating an elevator car past a landing, automatic means for stopping the car at the landing, a door for closing the opening to said oar, means for opening said door, means for closing said door, and means for setting the automatic stopping means and the door opening means into operation for a stop at the landing, of an auxiliary stopping means operaloly respon sive to the opening of the door for stopping said car within a predetermined time after said automatic stopping means should stop said car, and means operably responsive to a failure of operation of said auxiliary stopping means for preventing the reclosing of said door.

9. In an elevator, the combination with means for operating an elevator car past a plurality of landin s, automatic means for stopping said car, at a landing, means for reversing the direction or" operation of said car, a door for closing an opening to said car, means normally responsive to operation of the car to make a stop at a landing for opening said door at said landing and means for controlling the automatic stopping means, the reversing means and the door operating means to stop the car and reverse it at the landing without opening said. door.

10. In an elevator, means for operating an elevator car past a landing, automatic means for decelerating the car for a stop, automatic for stopping the decelerated car, control means for conditioning the decelerating means and the automatic stopping means to decelerai'e the car and stop it at the landing, meansior reversing the direction of operation of said car, a door for closing an opening to said car, means normal- 1y responsive to said decelerating means for opening the door at the landing and means connected with said control means for retaining the door in its closed position when the car is stopped and reversed at the landing.

11. In an elevator, means for operating an elevator car past a landing, automatic means for decelerating the car for a stop, automatic means for stopping the decelerated car, means for controlling the decelerating means and the automatic stopping means, a door for closing an opening to said car, and means for opening said door, door opening means being connected to the decelerating means and to the control means in such manner that, with the control means in one position, the door will open automatically when the car stops at the landing and, with the control means in another position, the door will remain closed when the car stops at the landing.

12. In an elevator, means for operating an elevator past a landing, automatic means for decelerating the car, automatic means for stopping the decelerated car, means for reversing the direction of operation of the car, means for controlling the decelerating means, the stopping means and the reversing means, a door for closing an opening to said car, and means for opening said door, said door-opening means being connected to the decelerating means and to the control means in such manner that movement of the control means to one position will cause the car to stop and the door to open automatically at the landing, and movement of the control means to another position will cause the car to stop and the door to remain closed at the landing and an additional movement of the control means in the same direction will cause the car to reverse and move in an opposite direction.

18. In an elevator control system, an elevator car, a motor for driving said car, and control mechanism including means for starting said car, a first stopping means, a second stopping means arranged to stop said motor in the event of failure of said first stopping means, and mechanism responsive to a failure of one of said stopping means for rendering said starting means ineffective.

14. In an elevator control system, an elevator car, a motor for driving said car, a door for .said car and closing mechanism therefor, and control mechanism including a first stopping means, a second stopping means for stopping said motor upon failure of said first stopping means, and mechanism responsive to failure of one of said stopping means for preventing operation of said door closing mechanism.

15. In an elevator control system, an elevator car, a motor for driving said car, a door for said car, and a controller including means for opening and closing said door, mechanism responsive to operation of said means to open said door for stopping said motor, and means responsive to failure of said stopping means for preventing operation of said means to close said door.

GEORGE K. I-IEARN. PAUL B. BARTON. WILLIAM F. EAMES.

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