US2185748A - Elevator system - Google Patents

Description

0- F. KEBELMAN 2,185,748

ELEVATOR SYSTEM Filed Afig. 27, 19:56 4 Sheets-Sheet 1 JTRACTION SHEAVE HOISTING ROPE5 ilk ELEVATOR CAR -UP odwu E\HATCHWAY DOOR AR HERE uem GAR MOVING LIGHT CAR GATE/ [b8 HALL BUTTON mm! LM M INVENTOR ATTORNEY Jan. 2, 1940- F. L. KEBELMAN ELEVATOR SYSTEM 4 SheetS-Sheet 3 Filed Aug. 27, 1956 BLQ H54 FM LMIMW INVENTOR I ATTORNEY BY I II a Jan. 2, 1940. F. L. KEBELMANQ ELEVATOR SYSTEM 4 Sheets-Sheet 4 Filed Aug. 27, 1956 w W. 6 3 w 4 5 II n U WT i M M M m B T k? a & Q Q I Z 9 P w? l 1 n l &? & 1 l l l I I l l I md mnr Q m N g? w u w m LL 0 :l H Av m M J oT LTw -iv -LT? u M m MT l a lllLwT I W1 LMWMM INVENTOR in... Jan. 2, 1940 UNITED" STATES ELEVATOR SYSTEM Frank as. Kebelman, Rockville Centre,

anignor to Otis Elevator Company, New York, N. Y., a corporation of New Jersey Application August 27, 1938, Serial No. 98,111

4 Claims.

The invention relates to elevator systems- In certain types of elevator installations. such as those for handling freight, service demands are not as frequent as in other types. Such installa- 5 tions do not require elaborate methods of control and may be of relatively low car speed. These and other factors contribute to minimizing the cost of the installation.

Various simplified controls have been provided for such installations. Among these are systems in which the users and prospective users of the car control the operation of the car themselves. Push buttons are provided at the landings and in the car for controlling the starting and stopping of the car. These push buttons are arranged to control the operation of the car directly, dispensing with floor relays or equivalent devices and thus effecting considerable saving. With such con- 1 trol, the user maintains the push button depressed until the desired landing is reached. It is desirable and the usual practice that the hatchway doors of such installations be of the solid type. Vision panels have been provided in these doors in order that the prospective users at the landings may judge the position of the car in controlling the stopping of the car. The invention is especially directed to elevator systems of this character. l

' The principal object of the invention resides in the improvement of such elevator systems.

One feature of the invention is to stop the car automatically at the landing at which a push button is depressed.

Another feature of the invention is to signal the arrival of the car to the ospective user as the stop is made so that the push button may be released.

With these features embodied in an elevator system of the above character, the vision panels in the hatchway doors-may be omitted, decreasing the cost of the installatibn as well as providing improved operation.

In carrying out the invention, according to the embodiment to be described, a push button is located at each landing for operation by the prospective users to call the car. A signal lamp is also located at each landing for advising the prospective user oi the arrival of the car. An up push button and a down push button are provided in 50 the car for operation by Ompants of the car to send the to the destination. Another signal lamp is located at each landing for advising prospective users when the car is in motion. The control apparatus is so arranged that. upon a ill push button at a landing being depressed. the "car moving" light at each landing is illuminated and the car is started toward the landing at which the push button is located. Upon the arrival of the car at. the landing, it is brought to a stop automaticaliy. Incident to the stoppin operation, 5 the car moving lights are extinguished and the car here light at the landing at which the stop is being made is illuminated, advising the prospective user that the push button may be released. Should the car be positioned at the landing at 10 which the push button is pressed, the car here" light at the landing is lighted immediately, indicating that the car is at the landing. When the car is at a landing or has been. brought to the landing, the prospective user may enter the car 15 and press the push button for the direction in which his desired destination lies. Upon the arrival of the car at the landing desired, the push button is released and the car is brought to a stop.

A general idea of the invention. the mode of 0 carrying it out which is at present preferred, and various features and advantages thereof can be gained from the above statements. Other features and advantages of the invention will be apparent from the following description and 25 appended claims.

In the drawings:

Figure 1 is a simplified schematic representation of an elevator installation in accordance with the invention;

Figure 2 is a view of. the front of a push button box at a landing;

Figure 3 is a diagrammatic representation of the control panel, showing particularly the relationship of the coils and contacts of the various 35 electromagnetic switches mounted thereon; and

Figure 4 is a simplified wiring diagram of the power and control circuits; and

Figure 4a is a key sheet for Figure 4 showing the electromagnetic switches in spindle form with 40 the contacts and coils arranged on the spindles in horizontal alignment with the corresponding contacts and coils in the wiring diagram.

For a general understanding of the invention, reference may be had to Figure 1. wherein various parts of the system, chosen to illustrate the principles of the invention, are indicated either by reference characters or by legends. The elevator car is raised and lowered by means of a hoisting motor. This motor drives a traction sheave over which Pass the hoisting ropes for the car and counterweight. An electromechanical brake is provided and is applied to effect the final stopping operation and to hold the car when at rest.

slotted cam llii carried by the car. when the car is stopped at a floor as illustrated, the operating arm oi the switch upon which the roller is mounted is in neutral position. When the car leaves a floor in the upward direction the cam moves the arm into an operative position on one side oi neutral, and when the car leaves the iioor in the down direction the cam moves the arm to I the corresponding operative position on the other side oi neutral. As the car arrives at a floor, the operating arm oi the switch ior that iioor is moved irom operative position to neutral, causing the opening oi the switch at slow down distance irom the floor level. This causes the car to be brought to a stop at the floor level.

4 push button, hereinaiter termed hall button", is provided at each landing to call the car. The "car here" light and "car moving'light ior each landing are preferably associated with the push button in the same operating box. A iront view oi such arrangement is illustrated in Figure 2. The contacts oi the push button are operated by meansoi a knob ill which extends through an aperture in the iace plate ill ior the box. The lights are arranged behind Jewels III and I" provided in the iace plate. These Jewels are preierably oi distinctive colors, such as red ior the "car moving" light and green ior the "car here light. These lights may also be marked "Car here" and "Car moving" as indicated. The push buttons in the car are designated "Up" and "Down, the p" push button being operated to cause upward travel oi the car and the "Down" push button being operated to cause downward travel oi the car. An emergency stop button it is also provided in the car.

A horizontally sliding car gate and hatchway doors oi the bi-parting vertically sliding type have been illustrated. Mechanism has also been illustrated ior locking the hatchway doors in closed position. This mechanism is the same ior each door and comprises a bell crank lever ill. one arm oi which cooperates with a catch I" on the door to latch the door against opening. The other arm of the lever is provided with an operating roller I81. The roller is adapted to be engaged by a retiring cam I68 carried by the car to move the lever out oi the path oi movement oi the catch on the door, permitting the door to be moved to open position. The cam is retracted by means oi a magnet I22 carried by the elevator car.

Reierence may now be had to Figure 4, which illustrates diagrammatically the various control and power circuits. No attempt is made in this ilgure to show the coils and contacts oi the electromagnetic switches in their associated positions, a "straight" or "across line diagram being employed. In this type oi diagram the coils and contacts-oi the switches are separated so as to make the connections to the supply linesas simple and direct as possible. The numerals employed in designating the various elements in the circuits are arranged in sequence, the lowest numeral, l I, which indicates one blade oi the main line switch, occurring in the upper leit hand' corner oi the iigure. The succeeding numbers iollow in numerical sequence irom leit to right down oi the sheet oi drawings.

The circuits are illustrated ior live floors. It is to be understood, however, that the invention is applicable to installations oi other numbers oi floors. The invention is applicable to installations having either direct current or alternating current power supply. A three-phase alternating current power supply has been illustrated in which the supply mains are designated 1, II and III. The blades oi the main line switch ior connecting the system to the supply mains are designated I i, II and I.

The elevator hoisting motor is shown as a threephase squirrelcage induction motor. The rotor oi this motor is designated I3! and its stator windings iii, in and Ill. The release coil oi the electromechanicalbrake is designated I". Two sets oi door contacts are illustrated, those oi one set being closed when their respective doors are closed and the others being closed only in the event that their respective doors are closed and locked. The contacts oi each set are arranged in. series relation and are represented on the diagram by a single set oi contacts. Those which are closed when the doors are closed are designated SI and are termed "door sequence contacts", while those which are closed only when the doors are closed and locked are designated 4i and are termed "door lock contacts". The gate contacts are designated 40. Door lock contacts are indicated in Figure 1 but door sequence and gate contacts are not'shown in that iigure as their arrangement is well understood. The contacts oi the various saiety devices have not been illustrated in the interests oi simplicity.

The up push button in the car is designated I1 and the down push button in the car is designated .42. The hall buttons are designated H2. ll. II, II and I! ior the ilrst to the iiith floors respectively. The floor stop switches are designated I I, II, It, 12 and Ill ior theiirst to the iiith iioors respectively. The "car here" lights are designated iii, I02. til, 16 and N ior the first to the iiith floors respectively and the "car moving" lights are designated 20, II, II, It and il ior the hut to the iiith floors respectively.

The floor stop switches are illustrated diagrammatically in Figure 4. The switches ior intermediate iioors are oi the same construction. Each switch comprises a pair oi bridging contacts ior cooperating with three stationary contacts and a pair oi making contacts biased to engaged position but maintained separated mechanically when the car is away irom the floor ior which the switch is provided. when the car is at an intermediate floor, the floor stop switch operating cam on the car has engaged the roller oi the iloor stop switch ior that door and moved theoperating arm 'to neutral. In this position, the bridging contacts are disengaged irom the stationary contacts and the making contacts are released so that they are in engagement. This is the position oi the parts oi the third iioor stop switch 84, the circuits being shown ior the condition where the car is stopped at the third floor. The bridging contacts II and are disengaged irom stationary contacts II, II and II and the making contacts 81 are engaged. The car being above the second floor, the floor stop switch ior that door is in'position where its brldg-- ing contacts II and or engage contacts I! and O4 and its making contacts llil are mechanically held in separated condition. Similarly, the car being below the iourth iioor, the iioor stop switch ior that iloor is inposition where its bridging contacts l1 and I4 engage contacts I! and I8 and its making contacts II are mechanically held in separatedoondition. The iioor stop switches ior the mains I and II to provide the desired voltage for operating the electromagnetic switches. Assuming 220 volt electromagnetic switches, in order that 110 volt lamps may be used the circuit for the car moving" lamps is taken from the midpoint of the secondary winding ii of the transformer, while a voltage regulating resistance 60 is provided for the car here" lamps.

The electromagnetic switches have been designated as follows:

AN-Auxiliary non-interference switch D-Down direction switch DC-Door contact relay N-Non-interference switch P--Potential switch TTime switch U-Up direction switch Throughout the description which follows, these letters, in addition to reference numerals, will be applied to parts of the above designated switches. For example, coil U53 indicates that the coil is provided for the up direction switch. In a similar manner the coil of the retiring cam magnet is designated CMI22. Therelationship of the coils and contacts of the switches may be seen from Figure 3, where the switches are arranged, in so far as practical, in alphabetical order. The relationship of these coils and contacts may also be seen from Figure 4a. where these switches are arranged in alphabetical order and are shown in spindle form. The positions of the coils and contacts in the wiring diagram may be found by referring to Figure 4a where the coils and contacts are positioned on the spindles in horizontal alignment with the corresponding elements of the wiring diagram. Thus, by first locating any coil or contact on thespindle diagram, the corresponding element of the wiring diagram may be readily found. The switches are illustrated in Figure! 50 in deenergized condition.

Assume that the car is standing idle at the third floor with the hatchway door and car gate closed, the circuits being illustrated in. accordance with this assumption. Under such conditions, door sequence contacts 33 are in engagement, connecting coil DC34 of the door contact relay across the secondary winding 5 of the transformer. separating its contacts DC35, and maintaining coil T3! of the time switch deenergized..

Assume further that. the use of the car is de-' sired at the fifth floor. Upon the prospective user pressing the fifth floor hall button 51, a circuit is completed through contacts TI23 for coil CM|22 of the cam magnet to retract the retiring cam, locking the hatchway door at the third floor. This causes the engagement of door lock contacts, completing a circuit for coil U53 of the up direction switch. This circuit is from the left hand side of the secondary winding l5 of the transformer through emergency stop button 30, door lockcontacts 4|, contacts Y45 and 5| of' the floor stop switch for the fifth floor, coil U53, contacts D54, contacts N55, contacts This relay is therefore operated,

other side of winding IS.

The up direction switch, upon operation, en-

gages contacts Ul6, completing a circuit for the "car moving" lights 26, 2|, 2!, 23 and 24 at the respective floors. The lighting of this light at the fifth floor advises the prospective user that he has obtained control of the car. The lighting of these lights at other floors advises later prospective users at these floors that the car is in use. The up direction switch also separates its interlock contacts UIOS in the circuit for coil DIOB of the down direction switch. It engages contacts U124 and UI 2T, preparing circuits for the stator windings of the elevator hoisting motor for upward car travel and for the brake release coil. It

also engages contacts U36, completing a circuit through the fifth fioor stop switch for coil Pl'lv of the potential switch.

The potential switch, upon operation, engages contacts Pl l6 and Pl2l, completing the circuits for the stator windings of the elevator hoisting motor and the brake release coil This causes the brake to be released and the car to be started in the up' direction.

The potential switch also separates contacts PM in the circuit common to the "car here lights. These contacts are provided to prevent the lighting of a car here light at a floor when the hall button at that fioor is being depressed as the car passes the floor. It engages contacts P63, PI I3 and PI H! in parallel with contacts T56, TI H and Tl23 respectively. It also engages contacts P2! to effect the energization of coil T3! of tion until it arrives at a certain distance fromthe fifth floor. When this point is reached, the fioor stop switch for the fifth floor is moved into position disengaging its bridging contacts from stationary contacts 45 and 5!. Thisdeenergizes coil U53 of the up direction switch and coil P4! of the potential switch. The resultant separation of contacts Pll6, Pl2l, UIM and Ul 2| causes the deenergization of the stator windings of the elevator hoisting motor and of brake release coil I26, causing the brake to be applied to bring the car to a stop at the fifth floor landing.

The separation of contacts U|6 breaks the circuit for the car moving" lights.- The reengagement of contacts P6I together with the engagement of making contacts 62 of the fifth floor stop switch as the car comes to a stop completes the circuit for car here" light 64 at the fifth floor. This light. is thereupon illuminated, advis-.

ing the prospective user of the arrival of the car at the floor. Thus he may release the hall button. The release of the hall button breaks the circuit for the car here light at the fifth floor and also for coil .CMIZZ of the retiring cam magnet. This magnet permits the retiring cam tobe extended to unlock the door and effect the separation of door lock contacts ll.

The car cannot be operated by hall buttons after the car moving lights are extinguished and the stop has been made, owing to contacts P63 and Pl|3 being separated. Contacts P63, Pl [3 and PI I9 separate to open the by-pass circuits across time switch contactsT56, Till and Tl23 respectively at the same time that contacts 4 aromas a door and car gate to be opened without the possibility of interference.

The opening of the hstchway door and gate causes the separation or door sequence contacts it and gate contacts 40 respectively. The separation oi contacts a breaks the circuit for coil DC of the door contact relay, which drops out to reengage contacts DC". This reestablishes the circuit for coil Tll oi the time switch,

maintaining contacts T68, Till and TI" separated. Upon the prospective user entering the car and the closing of the hatchway door and car gate, gate contacts 40 and door sequence contacts ll reengage. The reengagement of contacts I8 reestablishes the circuit for coil DC of the door contact relay, which operates to separate contacts DC", again deenergizing coil I'll oi the time switch. Thus time is provided for the occupant of the car to press the button to start the car toward his desired destination without the pouibility of interference from hall buttons.

Assume that the occupant oi the car desires the car to travel to the second floor. To efleet such operation, he presses down button 42 in the car. This completes a circuit for coil AN 0! the auxiliary non-interference switch. This switch operates toengage contacts ANN to complete a circuit for coil N2! of the non-interference switch. The non-interference switch operates to engage contacts N32, establishing a seli-' holdingcircuit, and to separate contacts Nil and NI II in the circuits from the hall buttons to the coils oi the direction switches. The auxiliary non-interference switch also engages contacts ANlill to complete a circuit for coil CM!!! of the retiring cam magnet, attracting the retiring cam to eflect the locking oi the iiith floor hatchway door and the reengagement of door lock contacts ll. This completes a circuit for coil Dllll o! the down direction switch. This circuit is through emergency stop button lll, door lock contacts ll, contacts 104 and llll oi the floor stop switch for the first floor, coil Dllll, contacts Ullis, down button 42 and gate contacts ll.

The down direction switch, upon operation, engages contacts Dll to complete a circuit for the "car moving lights. It separates interlock contacts D" in the circuit for coil U88 0! the up direction switch and engages contacts DI" and DI, preparing the circuits for the stator windings of the elevator hoisting motor for downward car travel and for the brake release coil. It also engages contacts DIM to complete a circuit for coil P41 0! the potential switch.

The potential switch engages contacts Pl II and PIII, completing the circuits for the stator windings of the elevator hoisting motor and brake release coil to eflect the starting of the car in the down direction. The engagement of contacts P2! causes reenergization or the coil or the time switch.

The down button in the car is maintained depressed until the car arrives at its stopplna distance from the second floor. -When this point is reached the button is released, breaking the circuittorccilDlllloithedowndireotionswitch,

-. causing ma switch to drop out to i deenergise the hoisting motor and brake release coil. Thus the brake is applied to bring the car to a stop at the second floor landing. The separation oi' contacts m1 breaks the circuit for the "carjmcvmg" lights. The separation of contacts Dlilt breaks the circuit for coil P4! of the potential switch. The consequent separation or contacts P21 deenergizes coil Til oi the time switch.

The releaseoi the down button also breaks the circuit for coil AN or the auxiliary non-interierence switch. which drops out to separate its contacts AN" and ANlIll. Coil Nil 0! the noninterierence switch is maintained energized alter the separation of contacts AN" by contacts N82. The separation of contacts ANlIll breaks the circuit for coil CMlII oi the retiring cam magnet, releasing the retiring cam to unlock the second iioor hatchway door. Thus the door and gate may be moved to open position to permit the occupant of the car to leave the car. The separation of gate contacts 40 upon the opening or the car gate breaks the circuit for coil N" o! the non-interference switch, causing the reengagement 0! contacts N" and NI II. The separation oi door sequence contacts is upon the opening of the hatchway door deenergizes coil DC" of the door contact relay, which reengages contacts DC" to reenergize coil Til oi the time switch. Thus non-interference from the halls after the deenergiaation oi the non-interference switch N is maintained by time switch T, contacts TI! and Ti l l of which are separated. Upon the reclosure oi the car gate and hatchway door and the expirationo! the time interval provided by the time switch, deenergized as a result of the reengagement of door sequence contacts 3! to eilect the operation of door contact switch DC,

the car may again be operated by hall buttons.

It is believed it will be understood from the above description that when the-car is available for operation by hall buttons, it is started in the down direction in response to the pressure of a hall button for a floor below the one at which the-car is positioned, and is started in the up direction in response to the pressing of a hall button for a iioor above the one at which the car is positioned. In order that the circuits for the direction switch cells may be readily seen when the hall button is pressed for an intermediate floor. assume that with the car positioned at the third door the fourth floor hall button ll is pressed. This completes a circuit for cell U53 oi the up direction switch through stop button 30, door lock contacts II, the iioor stop switch II for the ilith floor, coil Ull, contacts nu, contacts N" and contacts, Tl! as bei'ore, thence through contacts II and ll of the iioor stop switch for the fourth door, push button ll, and

gate contacts ll. Assume that instead or the fourth door hall button the second floor hall button II is pressed. This completes a circuit for coil Dill oi the down direction switch through stop button ll, door lock contacts ll, floor stop switch ill for the first floor. coil DI"; contacts UIIII. contacts Nllt, contacts Till, and thence through contacts 02 and ll 0! the floor stop switch for the second floor. push button ti, and gate contacts ll. In either case. upon the arrival of the car at the floor at which the button is pressed, it is automatically stopped and the "car here" light at that door is illuminated.

' It the hall button should be pressed at the door at which the car is positioned, the car is not .startedandinsteadacircuitisestablishediorthe u the third floor. hall button it with the car at the third floor establishes a circuit for car here" light 90 at the third floor through stop contacts iii, door lock contacts ll, resistance", contacts PM, contacts 81, light 90, push button 83, and gate contacts 40. The lightingoi the "car here light upon pressing of the button advises the prospective user that the car is already at that iloor.

It is believed that it will also be understood from the above description that the pressing of the up push button in the car under conditions where the car is at a floor below the fifth floor causes the car to be started in the up direction and that the car continues to travel in the up direction until this button is released. When the occupant of the car desires to have the car travel to the terminal floor, he maintains the operated button pressed until the terminal floor is reached and the stop is made by the opening of the floor stop switch for the terminal floor. When the car is to make a stop at an intermediate floor, the button is released as the car arrives at its stopping distance from the desired landing. The floor stop switches for floors which the car must pass to travel to a destination have no eflect upon the operation of the car upon being swung from one operative position to the other as the car passes" the floor, the circuit for the coil of the operated direction switch being maintained by the push button which is being held pressed.

Several of the .control featuresillustrated are in the nature of refinements and may be omitted if not desired for a particular installation. This may include time switch T, contacts P63, Pll3 and PI is by-passing the time switch contacts,

and the control for the time switch involving door sequence contacts 33, door contact relay DC and contacts P21. The non-interference switch N and its control may be omitted or replaced by a manually operable non-interference button in the car connected in the place of contacts N55 and NIH). The door lock contacts 4| may be replaced by door sequence contacts. The retiring cam and its operating magnet and the control for the magnet may be omitted, particularly where the door lock contacts are omitted. This includes the omission of not only contacts AN I but also one pair of contacts of each hall button, permitting single contact hall buttons to be used. Contacts P6! of the potential switch may also be omitted. Where no car gate is provided, gate contacts 40 are omitted.

By way of a resume, it will be seen that in accordance with the principles of the invention, the car may be called from a floor to any other floor by pressing a single hall button at the calling floor. If the calling floor is above the iloor at which the car is positioned, the car starts automatically in the up direction, and it it is below the floor at which the car is positioned the car starts automatically in the down direction. The hall button is maintained pressed until the car arrives at the calling floor, where it automatically stops. While the hall button is pressed, a car moving light is lighted at each floor, advising prospective users that the car is in use or is answering a call. When the car stops at the calling floor, the car moving lights are extinguished and a car here" light is illuminated at the floor at which the stop is made. This advises the prospective user that the car has arrived at the floor so that the button may be released and the hatchway door and car gate may be opened. When the car is occupied, the occupant maysend the car to the desired floor by pressing either anup button or a down button,

depending upon the direction or the floor to which he desires to have thecar travel. This button is maintained pressed until the car arrives at the desired lloorfwhe'reupon it'is released and the car is brought to a stop.

What is claimed is: M

1. A control system for an elevator car com prising; a plurality oi! manually operable controls, one at each or a plurality of landings; means responsive to the operation of a control at a landing other than the one at which the car is positioned and the manual maintaining of said control operated for causing the car to travel to and stop at such landing; a plurality of signals, one at'each of said landings; and means operable, when the control operated is the one at the landing at which the car is located, to give said signal at that landing to indicate that the car is already at the landing and, when the control operated is one at some other landing, to give said signal at such other landing as the car arrives at that landing to indicate the arrival of the car at the landing.

2. A control system for an elevator car comprising; a plurality of manually operable controls, one at each of a plurality of landings; means responsive to the operation of a control at a landing, other than the one at which the car is located, for starting the car toward the landing at which the control is located and for bringing it to that landing provided the control is maintained operated, the release of said control prior to the car arriving at a predetermined distance from such landing causing the car to come to a stop before the landing is reached; means responsive to the arrival of the car at said predetermined distance from said landing at which said operated control is located for causing the car to come to a stop at said landing; a signal at each landing; and means for causing the giving of the signal at the landing at which the stop is made as the car is stopped at that landing, advising the person operating said control at that landing that the control may be released.

3. A control system for an elevator car comprising; a plurality of push buttons, one at each of a plurality of landings; a plurality of signals, one at each of said landings; means responsive to the pressing of any one of said push buttons,' other than the one at the landing at which the push button is located, and the manual holding of said push button depressed until said signal at the landing at which such push button is located is given for bringing the car from the landing at which it is located to the landing at which said push button is located; and means responsive to the arrival of the car at a certain distance from said landing for causing the car to come to a stop at said landing and for causing said signal at said landing to be given so that said push button may be released, said push button upon being released causing the giving of said signal to be discontinued.

4. A control system for an elevator car comprising; a plurality of push buttons, one at each of a plurality of landings; a plurality of signal lamps, one at each of said landings; means responsive to the pressing of any one of said push buttons, other than the one at the landing at which the car is positioned, and the manual holding of said push button depressed until said signal lamp at the landing at which the push button is located is lighted for causing the car last named means acting when thc push button to tragvel to such landing; and means responsive at the landing at which the car is positioned is to the arrival of the car at such landing for pressedto cause said signal lamp atthatlanding bringing the cartoastopandi'or causing said tobelightedtoindicate that thecarisalready signal lamp at said landing to be lighted to inat the landing. 5 dicate thatthe car has arrived at that landing FRANK LOUIS so. that said push button may be released. said

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