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Publication numberUS3902572 A
Publication typeGrant
Publication dateSep 2, 1975
Filing dateNov 28, 1973
Priority dateNov 28, 1973
Also published asCA1010586A1, DE2456146A1
Publication numberUS 3902572 A, US 3902572A, US-A-3902572, US3902572 A, US3902572A
InventorsWilliam M Ostrander
Original AssigneeWestinghouse Electric Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Elevator system
US 3902572 A
Abstract
An elevator system having speed control apparatus providing first, second and third acceleration modes which provide progressively higher maximum speeds for an elevator car. Control circuitry associated with each landing to be served by the elevator car is successively enabled in response to the location and movement of the elevator car, with the number of floors from the last stop of the elevator car to the floor of the next stop being used to select one of the three acceleration modes. Protective apparatus responsive to the voltage across the armature circuit of the elevator drive motor is also provided which stops the elevator car when the rate of change of this voltage exceeds a predetermined magnitude, or the magnitude and polarity of the voltage indicates the elevator car is traveling at or above a predetermined speed in a direction opposite to the travel direction selected by the control circuitry.
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Description  (OCR text may contain errors)

United States Patent 1 Ostrander 51 Sept. 2, 1975 I ELEVATOR SYSTEM William M. Ostrander. Hackensack, NJ.

[75] Inventor:

[73] Assignee: Westinghouse Electric Corporation,

Pittsburgh. Pa.

[22] Filed: Nov. 28, 1973 [21] Appl. No.: 419,759

Primary Examiner-Robert K. Schaefer Assistant Examiner-W. E. Duncanson, Jr. Attorney, Agent, or FirmD. R. Lackey SWITCHING CONTACTS CIRCUIT DIRECT CONTACTS PATTERN PERV CONTROL 42 CALLS CAR POSITION SIGNALS D l RE CTION CONTACTS [57] ABSTRACT An elevator system having speed control apparatus providing first, second and third acceleration modes which provide progressively higher maximum speeds for an elevator car. Control circuitry associated with each landing to be served by the elevator car is successively enabled in response to the location and movement of the elevator car. with the number of floors from the last stop of the elevator car to the floor of the next stop being used to select one of the three acceleration modes. Protective apparatus responsive to the voltage across the armature circuit of the elevator drive motor is also provided which stops the elevator car when the rate of change of this voltage exceeds a predetermined magnitude, or the magnitude and polarity of the voltage indicates the elevator car is traveling at or above a predetermined speed in a direction opposite to the travel direction selected by the control circuitry.

12 Claims, 8 Drawing Figures l6 i 26(DlRECT DRIVE) 62 5TH FLOOR 1- t "T 4ULL |U| T ELI-5UL 4TH FLOOR 77/77 4TH FL 0 l qmslsu w owu) Y 5TH FLOOR AL H.s. SLOWDOWN s2 3RD FLOOR W \F G 0 FLOOR i .SLCWDOWN T 4TH FLOOR BL7 '-(H.s SLOWDOWN PATENTEU SEP 2 975 sumau s LONG RUN ZFLOOR RUN TlME- FIG. 2

AP los IFLOOR RUN ELEVATOR SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates in general to elevator systems. and more specifically to speed control and protective apparatus for elevator systems.

2. Description of the Prior Art It is conventional in elevator systems to use a direct current motor for driving the traction sheave. A source of direct current voltage having a magnitude which is varied in accordance with an error signal derived from signals representing the actual and desired speeds of the elevator car is connected to the drive motor. With a maximum car speed of about 350 feet per minute. the direct current drive motor is usually connected to the traction sheave via a reduction gear arrangement. such as a worm gear. With car speeds of about 400 feet per minute. and above. the direct current drive motor is usually directly connected to the traction sheave.

The floor selectors in common usage are those of the notching type. used for medium and slow speed applications. and those of the synchronous type. used for high speed elevator applications. The notching selector is commonly used with geared machines. and the synchronous selector is commonly used with the gearless machines.

The notching selector moves in one floor steps. actuated by tape mounted cams or magnetic plates disposed in the hoistway and cooperative switches or inductors. respectively. carried by the elevator car. The carriage of the notching selector notches or steps as the car trav els through the hoistway. until the selector notches into a landing or floor for which a car call has been registered. or a hall call has been registered in the service direction of the elevator car. The presence of such a hall call. or car call. enables the slowdown circuits associated with this landing. the car slows down according to a speed profile provided by a speed pattern generator. and levels into the floor by landing plates or cams located at the floor and cooperative landing inductors or switches carried by the elevator car. U.S. Pat. Nos. 1.979.679 and 1.981.601 are illustrative of selectors of the notching type.

The synchronous selector is a scaled down or miniature version of the associated elevator system. including a carriage arrangement which moves proportional to the travel of the elevator car. Separate carriage systems are used for up and down travel and each carriage system includes two separately driven carriages. the synchronous and the advanced carriages. The synchronous carriage moves proportional to the movement of the elevator car. The advanced carriage moves out ahead of the synchronous carriage for a distance equivalent to the slowdown distance of the car. representing the advanced or effective car position. A call for a floor at which the elevator car should stop. stops the advanced carriage at the location on the selector which corresponds to this floor. and the movement of the synchronous carriage toward the stopped carriage aetuates contacts and control circuitry for controlling the slowdown of the elevator car. The car levels into the floor via inductor plates disposed in the hoistway and cooperative landing inductors carried by the car. U.S. Pat. Nos. 2.657.765 and 3.160.232 are illustrative of selectors of the synchronous type.

The regulator systems used with the geared and gearless types of elevator systems often differ substantially due to the differences in car speeds. With the slower geared elevator systems the regulator is commonly of the type which utilizes a voltage produced across at capacitor to develop a pattern or desired voltage for com parison with a signal responsive to actual car speed. to obtain an error signal for controlling the magnitude of the direct current voltage applied to the direct current drive motor. This type of regulator will be referred to a regulator of the electronic type. U.S. Pat. Nos. 2.508.179. 2.620.898 and 3.599.755 are directed to regulators of this type.

The high speed gearles systems. which operate with the synchronous type floor selector may utilize a drag magnet regulator. in which actual car speed and the pattern or desired speed are electromagnetically related to provide a resultant or error signal which controls the speed and position of the elevator car. This type of regulator will be referred to as the electromagnetic regulator. U.S. Pat. Nos. 2.874.806 and 3.207.265 describe drag magnet regulators and also inductor leveling of the elevator car at a landing.

The notching selector and electronic regulator used with the geared elevator systems is less costly than the synchronous selector and electromagnetic regulator used with the gearless elevator systems. and it would therefore be desirable to extend their usage into the lower end of the gearles speed range. such as gearless elevator systems which operate at about 500 feet per minute. This extension of notching selectors and electronic regulators to higher speed elevator systems. however. must be made without a significant degradation in operating performance. such as floor-to-floor time. and the system should meet the same high standards of safety now met by the presently used geared and gearless elevator control systems.

SUMMARY OF THE INVENTION Briefly. the present invention is a new and improved elevator system which successfully extends the use of notching type selectors. electronic regulators. and switch type landing and leveling systems. to elevator systems which operate at a rated speed as high as 500 feet per minute. This higher speed usage of these operating elements has been made without a significant reduction in floor-to-floor time. and with no compromise in operating safety.

More specifically. suitable floor-tofloor time has been achieved. even for one and two floor runs where the elevator ear does not reach maximum operating speed before slowdown is initiated. by providing first. second and third modes of operation which control acceleration of the elevator car to first. second and third progressively higher speeds. First and second slowdown indicators are provided in the hoistway for each floor. for each direction in which the floor may be approached by the elevator car. The first indicator initiates slowdown when the elevator car is in the third operating mode. The second indicator is used during the third operating mode as another slowdown point. and it also initiates slowdown when the elevator car is in the first operating mode. Counting means counts the notches or steps made by the selector from the last car stop to the next car stop. at least to distinguish and determine when the elevator car is making a two floor run. and the counting means is operatively connected to prepare the elevator system for a two floor run when the notching means is notched or stepped into the second floor from the last stop of the elevator car. When the elevator car is making a two floor run, the second operating mode is automatically selected. and the first slowdown indicator is prevented from initiating slowdown, as it does for runs which are longer than two floors. When the floor selector notches into the second floor from the last car stop, timing means is started which continues acceleration of the elevator car for a predetermined period of time, with the elevator car passing the first slowdown indicator without circuit effect. At the end of this predetermined time, slowdown is initiated. The predetermined period of time is adjustably selected to bring the car promptly to the desired landing, providing a floor-to-floor time which does not differ significantly from those obtainable with electromagnetic regulators and synchronous floor selectors.

New and improved safety arrangements are disclosed which monitor the voltage across the armature circuit of the elevator drive motor, and which stop the elevator car when the polarity and magnitude of this voltage indicates the elevator car is moving above a predetermined speed in a direction opposite to the direction selected by the direction circuits. The car is also stopped when the rate of change of this voltage reaches a predetermined magnitude, indicating acceleration of the elevator car above a desired magnitude. The protective circuitry also monitors the car speed and the condition of the car doors, stopping the elevator car when the doors start to open when the speed of the elevator car is above a predetermined magnitude.

BRIEF DESCRIPTION OF THE DRAWINGS The invention may be better understood, and further advantages and uses thereof more readily apparent, when considered in view of the following detailed description of exemplary embodiments, taken with accompanying drawings, in which:

FIG. 1 is a partially schematic and a partially block diagram of an elevator system which may be constructed according to the teachings of the invention;

FIG. 2 is a graph illustrating the operating characteristics of the elevator system of FIG. I when constructed according to the teachings of the invention;

FIG. 3 is a schematic diagram ofa speed pattern generator constructed according to the teachings of the invention;

FIGS. 4, 5 and 6 are schematic diagrams of control apparatus constructed according to the teachings of the invention. which apparatus cooperates with the speed pattern generator shown in FIG. 3 to control the elevator system shown in FIG. 1; and

FIGS. 7 and 8 are schematic diagrams of protective apparatus constructed according to the teachings of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings and FIG. I in particular, there is shown an elevator system 10 of the variable voltage, gearless traction type which may be constructed according to the teachings of the invention. Elevator system 10 includes an elevator car 12 connected to a counterweight 14 via a suitable roping arrangement 16 which is reeved over a traction sheave 18. The elevator car 12 is suspended in the hatch or (ill hoistway of a structure or building to serve a plurality of landings or floor therein. of which five. the second through the six floors, are illustrated.

The traction sheave is driven by a direct current motor 20 having an armature 22 and a field winding 24. The armature 22 is directly connected to the traction sheave 18 via a drive shaft 26. The field winding 24 of the drive motor 20 is connected to a source 28 of constant direct current potential.

A source of direct potential is provided for energizing the elevator drive motor 20 to move the elevator car 12 in accordance with the requirements of the elevator system. This source may be a motor-generator set which includes a generator 30 having an armature 32 driven at a substantially constant speed by a motor (not shown). Generator 30 also includes a shunt field winding 34, a regulating field winding 36, and an interpole field winding 37.

The generator 30 has its armature 32 connected in a loop circuit with the armature 22 of the elevator drive motor 20. The interpole field winding 37 of the generator 30 is also connected in the loop circuit for energization.

The shunt field winding 34 of the generator 30 is preferably connected across the terminals of the armature 32 of the generator 30 via switching contacts shown generally at 38, which are arranged to reversibly connect winding 34 to the generator armature 32.

The regulating field winding 36 accurately controls the output voltage developed by generator 32, and thus accurately controls the speed of the elevator drive motor 20 and the position of the elevator car 12. The regulating field winding 36 is energized from a power modulator 40, which is energized by a source 42 of alternating potential, via contacts from the direction circuits, shown generally at 44. Up and down direction relays IR and 2R, which are part of the supervisory control shown generally at 46, and which will be hereinafter described, control the direction of the elevator car, and contacts of these direction relays connect the power modulator 44 to properly energize regulating winding 36 to achieve the desired travel direction of the elevator car 12. The supervisory control 46 selects the travel direction in response to registered car and hall calls, and the location of the floors associated therewith relative to the position of the elevator car 12. A suitable power modulator using grid controlled rectifiers of gaseous-discharge type (thyratrons) are disclosed in US. Pat. Nos. 2,508,179 and 2,620,898, while a suitable modulator using solid state components is disclosed in US. Pat. No. 3,470,434, all of which are assigned to the same assignee as the present application.

The power modulator is controlled by an error signal derived by comparing a signal from a pattern generator 48, which represents the desired speed of the elevator car, with a feedback signal responsive to the actual speed of the elevator car. Pattern generator 48 receives its energy from a source 49 of alternating potential. A tachometer generator 50 driven by the motor armature 22, as indicated by broken line 52, is the preferred arrangement for obtaining the feedback signal because it provides continuous direct measurement of the speed of the elevator drive motor. First and second derivative damping, as well as filtering of the output signal from tachometer generator 50 is provided by a circuit shown generally at 54, and this compensated tachomcter signal is summed in opposition to the signal from the pattern generator 48 in a circuit 56 which includes appropriate contacts from the direction relays IR and 2R, which will be hereinafter described. The resultant signal obtained in circuit 56, which uses contacts of the direction relays to obtain a signal responsive to the difference between the actual and desired car speeds. i.c.. error signal, is applied to the power modulator to control the magnitude of the direct current potential applied to the regulating field winding 36 via the direction contacts 44. As disclosed in U.S. Pat. No. 3,620,898, first derivative damping may be obtained by differentiating the voltage across the armature 22 of the motor 20, while second derivative damping may be obtained by differentiating the voltage across the interpole field winding 37.

The supervisory control 46 additionally includes a floor selector of the notching type, such as described in U.S. Pat. No. 1,979,679, which is stepped or notched in response to indicators AL and BL disposed in the hoistway. These indicators may be cams for operating switches. carried by the car, magnetic plates for operating inductor relays carried by the car, or permanent magnets for operating magnetically responsive switches. such as reed switches, carried by the elevator car. The switches, inductor relays, or Red switches are mounted on the elevator car 12 in a control panel shown generally at 60. The indicators AL and BL are disposed in different vertical lanes in the hoistway in order to actuate two notching switches AL and BL al ternately from floor-to-floor and thus prevent contact bounce from falsely notching the floor selector.

Slowdown of the elevator car is responsive to indicators SUL and 4UL disposed in the hoistway for each floor which may be approached when the car is traveling upwardly, and in response to indicators SDL and 4DL (not shown) disposed in the hoistway for each floor which may be approached when the car is traveling downwardly. As will be hereinafter explained, indicators SUL and SDL are high speed slowdown indicators. while indicators 4UL and 4DL are medium or intermediate speed slowdown indicators. The SUL and SDL indicators for a given floor are disposed about 12.5 feet from its associated floor, when the maximum rate of speed of the elevator car is about 500 feet per minute, and the 4UL and 4DL indicators are disposed about 4.5 feet from the associated floor to provide another slowdown point when the car is slowing from the 500 feet per minute maximum speed. As indicated in FIG. 1, it is possible for the medium speed slowdown indicator, such as 4UL, for one floor to be between the high and medium speed slowdown indicators, such as SUL and 4UL. associated with an adjacent floor. A control arrangement for ignoring the intervening medium speed slowdown indicator will be hereinafter described.

Leveling of the elevator car 12 at a landing may be performed by leveling cams 62 associated with each floor or landing, which may be mounted on a suitable tape 64 which extends the length of the hoistway. Switches lDL and lUL carried by the elevator car coperate with a cam 62 when the elevator car arrives in the leveling zone for stopping at the associated landing. and will perform releveling of the elevator car should the car overshoot or move away from the landing due to rope stretch. Actuation of both switches lDL and lUL indicates the elevator car is within i0.5 inch of floor level, while movement of the elevator car up or down from this position closes switch lDL or lUL, respectively, to energize the re-leveling control in the direction required to re-level the car 12 with the floor level.

FIG. 2 is a graph illustrating speed profile patterns of an elevator car using new and improved control circuitry constructed according to the teachings of the invention. Car speed is plotted on the ordinate versus time which is on the abcissa. When the elevator car is making a one floor run, the car accelerates along curve portion until reaching a predetermined medium speed, indicated by curve portion 72. At about 4.5 feet from the floor, i.e., the proper distance to slow the car from the selected medium speed according to a predetermined deceleration schedule, which distance is indicated by hoistway indicators 4UL or 4DL, the car decelerates smoothly into the leveling zone along curve portion 74.

On a run of more than 2 floors, the elevator car accelerates along curve portion 70 until reaching the rated speed of the elevator system, such as 500 feet per minute, respresented by curve portion 76. At about 12.5 feet from the floor at which the elevator car is to stop, as indicated by the indicator SUL or SDL. associ ated with this floor, the elevator car decelerates smoothly into the leveling zone along curve portion 78.

The elevator ear cannot reach a rated maximum speed of 500 feet per minute, represented by curve portion 76., on a two floor run. Thus. when the high speed slowdown indicator SUL or SDL is reached the car decelerates along curve portion to the one floor run speed. represented by curve portion 72', and upon reaching the medium speed slowdown indicator 4UL or 4DL associated with this floor, it decelerates into the floor along curve portion 82. This slowdown profile is undersirable as it unduly lengthens the time required to make a two floor run.

The present invention counts the notches or steps of the notching selector from the last Stop of the elevator car, and when the circuitry associated with the floor associated with the second notch from the last stop indicates the elevator car may be making a two floor run, a third operating mode is automatically provided when the circuitry associated with this second landing from the last stop indicates the elevator car should stop at this landing. The third operating mode ignores the high speed slowdown indicator 5UL or SDL, maintaining the acceleration of the car along curve portion 70 for a predetermined period of time selected to enable the car to reach a speed which will permit the desired smooth slowdown profile into the leveling zone of the floor, and provide the desired floor-to-floor time. The broken curve 84 indicates a modified two floor run obtained by following the teachings of the invention.

As an aid to understanding the drawings, the relays are identified as follow s:

A Brake Monitor Relay ACC Acceleration Relay ADT Monitor Relay-Acceleration CPR Protective Relay (JR-4 Pattern Voltage Relay-Mediuni Speed GR4B Pattern Voltage Relay GR4T Pattern Voltage Time Relay CR6 Pattern Voltage Relay-High Speed GR6T Pattern Voltage Time Relay LD Leveling Relay LU Leveling Relay M Running Relay N Notching Relay NA Notching Relay for Alternate Floors NB Notehing Relay for Intervening Floors OVD Monitor Relay Motor Armature Current for Down Travel OVU Monitor Relay Monitor Armature Current for Up Travel SAOl Selector Relay Associated With Lower Terminal SAOT Selector Relay Associated with Upper Terminal X Relay Counts First Notch of Selector Y Relay Counts Second Notch of Selector YT Two Floor Run Time Relay Z Two Floor Run Relay 1R Up Direction Relay 1C Up Direction Relay 2R Down Direction Relay 2C Down Direction Relay 6R Potential Switch 6P Potential Switch 22R Running Relay 23R Running Relay 29R Safety Circuit Relay 32R Running Relay 34R Master Slowdown Relay 38R Car Call Slowdown Relay 39R Notching Relay 39A Notching Relay With Delayed Dropout 40R Car Door Relay R Master Car Door Relay R Overspeed Relay H Hand Control Relay R Running Relay T Door Non-interference Time Relay C Master Call Relay 80D Attendant Relay Down 80U Attendant Relay Up 81D Down Travel Direction Relay 8lU Up Travel Direction Relay 81R Travel Direction Relay 438R Corridor Call Slowdown Relay Contacts associated with these relays are identified by hyphenated reference characters, with the associated relay identification to the left of the hyphen. and the contact identification to the right of the hyphen. The relay contacts are shown in their normal position when the relay is dc-energized.

FIG. 3 is a schematic diagram of a new and improved pattern generator 48 which provides first, second and third speed patterns for runs of one, two, and more than two floors, respectively. When the elevator car is making a one floor run, the speed pattern generator 48 provides the one floor run pattern shown in FIG. 2. If the circuits of the landing or floor associated with the first notch of the floor selector following the stop of the elevator car have not been set to request the elevator car to stop but the circuits of the landing associated with the second notch following the last stop of the elevator car are set to request the car to stop. the speed pattern generator 48 provides the speed pattern illustrated with the broken line in FIG. 2. Counting means counts the number of notches following the last stop of the elevator car, and on the second notching of the floor selector the pattern generator prepares for a two floor run immediately, whether or not the elevator car is to stop at this second floor after the last stop. If a stop is not made for this floor. the floor selector automatically provides a speed profile associated with a long run.

More specifically. the desired speed pattern signal is provided across an energy storage device, such as eapacitor 100, which includes terminals 101 and 103 connected to its upper and lower plates, respectively. The acceleration portion of the speed pattern profiles shown in FIG, 2 is provided by controlling the rate at which capacitor is charged. The deceleration portion of the speed pattern profiles is provided by controlling the rate at which capacitor 100 is discharged. A source of direct current potential, provided by source 49 of alternating potential, full-wave bridge rectifier 102, and filter capacitor 104, has an output terminal 107 connected to selector arm AP of an adjustable resistor 106, and its other output terminal 113 is connected to terminal 103 of capacitor 100 via a resistor 120. Resistor is part of a voltage divider network, as will be hereinafter described. A regulated or constant source of direct current potential, as provided by resistor 108 and Zener diode 110, has its output terminals 111 and 113 connected across a voltage divider network which includes serially connected resistors 112, 114, 116, 118, and 120. Resistors 114, 116, and 118 are adjustable, having selector arms IS, 225 and LS. respectively. Resistors 122 and 124 are serially connected across resistors 112 and 114, with resistor 122 being of the adjustable type, having a selector arm HS.

Capacitor 100 has its terminal 103 directly connected to junction 126 between resistors 118 and 120, and its terminal 101 is selectively connected to provide the desired charging and discharging rates at the appropriate times during a one floor, a two floor, and a longer run. of the elevator car.

When the contacts of the door interlock relays close, which are shown generally at 128, indicating the elevator car and hatch doors are closed, and the acceleration relay ACC picks up to close its contacts ACC-1, capacitor 100 starts to charge along curve portion 70 shown in FIG. 2. The rate at which capacitor 100 charges, and thus the basic acceleration rate, is selected by arm AP of resistor 106.

If a one floor run is to be made. the medium speed relay GR4 will be picked up, and both the high speed run relay GR6 and the two floor run relay Z will be denergized. Thus, a circuit will be established from terminal 101 of capactir 100 to selector arm IS of resistor 114 through contacts ACC-1- the door interlock contacts 128, contacts 2-2, GR6-2, and GR4-1, and diode 130. Diode 130 is poled to clamp the voltage across capacitor 100 to the value selected by arm IS of resistor 114. This voltage represents the medium or intermediate speed illustrated by curve portion 72 in FIG. 2. When relay GR4 drops in response to the elevator car passing indicator 4UL or indicator 4DL in the hoistway, the acceleration relay ACC also drops and capacitor 100 discharges to a lower voltage setting selected by contact ACC-3 and additional contacts which will be hereinafter described.

Ifa two floor run is to be made. both the medium and high speed relays CR4 and GR6 will pick up. This arrangement completes a circuit from terminal 101 of ca pacitor 100 to arm HS of resistor 122 via contact ACC- 1, the door interlock contacts 128. contacts GR6-l, and diode 132. Diode 132 is poled to clamp the voltage across capacitor 100 to the setting selected by arm HS of resistor 122. which setting determines the maximum speed to which the elevator car will be accelerated. such as 500 feet per minute. On a two floor run. however, there is not enough time to accelerate the car to a maximum speed of 500 feet per minute. with the high speed slowdown indicator UL or SDL dropping the high speed relay GR6 shortly after the car exceeds the speed magnitude for a one floor run. Without the two floor run relay Z. the car would decelerate to the one floor run speed illustrated by curve portion 72 in FIG. 2. as the dropping of relay GR6 drops the acceleration relay ACC. contacts ACC-Z and ACC-3 close and the circuit from arm 18 of resistor 114 to terminal 101 is completed via a diode 134. and contacts GR4-2, ACC-2 and ACC-3. Capacitor 100 discharges through resistor 120. and through adjustable resistors 136 and 138 until the voltage across its terminals reaches the voltage setting of selector arm of resistor 114. Resistors 136 and 138 are of the adjustable type having selector arms D and DT. respectively. Terminal 113 of the power supply is connected directly to one side of resistor 136. and also to its selector arm D via normally closed contact GR4-4 relay GR4. The other side of resistor 136 is connected to arm DT of resistor 138. One side of resistor 138 is connected to terminal 101 of capacitor 100 via normally closed contact ACC-3.

The two floor run relay Z. however. is energized when the selector notches into the second landing from the last stop of the elevator car. and it is energized for a predetermined period of time following the notching of the selector into the second floor. Thus. when the elevator car is to stop at the second landing from the last stop of the elevator car. relay GR6 drops when the car passes hatch indicator SUL or SDL. which for a maximum car speed of 500 feet per minute is disposed about 12.5 feet from the floor at which the car is to land. However. the dropping of relay GR6 has no immediate circuit affect. as contacts Z-l of the energized Z relay shunt the now open GR6-1 contacts to maintain acceleration of the car along curve portion 70 shown in FlG. 2. Contact Z-2 in the medium speed clamping circuit is open at this point in time. Contact Z-3 of the two floor run relay. which contact is shown in FIG. 4, maintains cncrgization of the acceleration relay ACC despite the opening of contact GR6-4. When the predetermined period of time for extending the acceleration period of the elevator car expires, relay Z drops. the acceleration relay ACC drops. and capacitor 100 discharges toward the voltage level selected by arm 15 of resistor 114. by the circuit hereinbefore described. This time period for energizing the two floor run relay Z is preferably selected to enable the elevator car to reach the speed setting of arm lS at about the same time. or just shortly before. the car reaches hatch indicator 4UL or 4DL. depending upon car direction. which indicators are located about 4.5 feet from their associated floor for a 500 foot per minute maximum car speed elevator system. Thus. the deceleration curve for a two floor run. illustrated by the broken curve in FIG. 2, will be smooth. or substantially smooth. having at the most a slight flattening as it reaches curve portion 72' of FIG. 2. and it substantially shortens the time for a two floor run. compared with the time required for a two floor run if the car were to start decelerating from the high speed slowdown indicator SUL. or indicator SDL. On a run longer than two floors. the two floor run relay Z will pick up and drop out without circuit affect. as the indicator 5UL or 5DL for the second floor from the last stop will not drop out the speed pattern relay GR6. The elevator car continues to accelerate to the maximum speed determined by the setting of arm HS of resistor 122. which is indicated by curve portion 76 in FIG. 2. From this maximum speed, the slowdown is prompt and smooth along curve portion 78 shown in FIG. 2. being initiated when the elevator car is 12.5 feet from the floor of the stop by hatch indicator SUL or indicator SDL.

When the elevator car is 4.5 feet from the floor at which it is to stop. relay GR4 drops due to the hatch indicator 4UL or indicator 4DL. contact GR4-2 opens to open the circuit from terminal 101 of capacitor to the speed setting arm 1S. and contact GR4-3 closes to connect terminal 101 of capacitor 100 to arm 225 of resistor 116 via contacts ACC-3. GR4-3. GR4T-l. 34R-1. 22R-1. and diode 140. The function of relays GR4T. 34R and 22R will be described when a complete system operation is set forth. The capacitor 100. therefore. discharges from the voltage setting of arm [5 of resistor 114 to the voltage selected by arm 228 of resis tor 116. Capacitor 100 discharges through resistors 120, 136 and 138. but at a higher rate than when decelerating to the 18 speed setting. as contact GR4-4 of relay GR4 is now closed. to shunt a portion of resistor 136 via its selector arm D.

When the elevator car reaches the leveling zone. which is about 3 inches from the floor as determined by the length of the cams 62 shown in FIG. 1, one of the leveling switches lDL or lUL will open to drop its associated leveling relay LD or LU. and when either of the leveling relays LD or LU drops out. relay 22R drops to open its contacts 22R-l in the 22S selector arm circuit of resistor 116. Capacitor 100 then discharges to the setting of arm LS of resistor 118, with terminal 101 of capacitor 100 being connected to arm LS via diode 142. and contacts GR4-3 and ACC-3. Arm LS selects the landing speed in the leveling zone.

When the elevator car is within i0.5 inch of the floor. both leveling switches 1UL and 1DL will be open by cam 62, both leveling relays LU and LD will be denergized. and relay 6P drops to close its contact 6P-1.

Contact 6P-1 slows the elevator car to a stop by completing a circuit from selector arm LS of resistor 118 to terminal 103 of capacitor 100 which includes an adjustable resistor 144 having a selector arm LSS. contacts 6P-l and 23R-1. Arm LS of resistor 118 is connected to arm LSS of resistor 144, and one side of resistor 144 is connected to terminal 103 of capacitor 100 via contacts 6P-1 and 23R-1. The voltage across capacitor 100 is thus reduced from that between arm LS and terminal 113 of the power supply. to that appearing between arms LS and LSS and junction 126 of the voltage divider. which voltage brings the car to a stop and the brake is then applied.

In describing the operation of the elevator system. FIGS. 1 through 6 will be referred to. lt will be assumed that the elevator car is parked at a floor with the brake applied. and with the doors open. The master slowdown relay 34R shown in FIG. 6 will be energized through the normally closed contact 45R-1 of the master door relay 45R (not shown), which is tie-energized until the doors are signaled to close. The 34R relay is II II energized while the doors are open to keep leveling cffective. Contacts 80U-I and SOD-I are associated with up and down relays (not shown) for attendant service. either of which will drop 34R should attendant wish to leave immediately after a stop. On automatic operation, the holding circuit of master slowdown relay 34R is broken when relay 70T drops. With master slowdown relay 34R de-energized, both leveling relays LU and LD are energized via contacts 34R-8 and 34R-9, respectively, even though the elevator car is at a floor and switches IUL and IDL are held in their open position by cam 62, as illustrated in FIG. 1. With the brake applied, the brake monitor relay A (not shown) is energized, with the door non-interference time expired, the non-interference relay 70T (not shown) is deenergized, its contact 70T-l in the circuit of the master call relay 80C (FIG. 6) is closed, and its contact 70T-2 in the holding circuit of master slowdown relay 34R is open. Relay YT (FIG. 4) is energized, and relay 22R (FIG. 6) is energized via the closed contacts LU-S, LD-S and the closed contacts of the door interlocks, shown generally at 150.

Assume now that a travel direction for the elevator car is established, such as manually by an attendant operated car switch 80U or 80D, or automatically by circuits which compare the floor destination of a car call, or the floor at which a hall call is registered, with the location of the elevaror car. If the car direction selected by the operator, or automatic circuits, is up, the up direction relay SIU and master direction relay 81R are both picked up, and if the direction is down. the down direction relay 81D and the master direction relay 81R are picked up. These direction relays are not shown since their operations are well known in the art.

When a car direction is established, indicated by relay 81R picking up, its contact SIR-l in FIG. 6 closes to pick up the master call relay 80C. If the direction selected was up, contact SOC-I in FIG. plus contact SSR-l, which is closed when the ovcrspeed relay 55R (not shown) is energized. indicating there is no overspced condition, plus contacts SlU-l, LU-l, 2R-I and 2C-l pick up the up direction relay 1C, provided that the upper travel direction limit switch UL is closed, indicating that the car is not already at the uppermost landing served by car. Its contacts IC-I and 1C-2 close to pick up relay 6P via either contacts LU-4 or LD-3, which are both closed, and it also picks up relay 6R. When relay 6P picks up, its contact ()P-l opens and capacitor 100 charges slightly to the voltage appearing at arm LS of resistor 118 to provide an initial pattern voltage sufficient to hold the car when the brake is lifted. Relay 6R closes its contact 6R-2 and the up direction relay IR picks up. Contact IR-Z of the up direction relay 1R located in FIG. 5 picks up relay 65R via the now closed contact SOC-2 of the master call relay 80C. Contact 65R-2 closes to seal in around contact 80C-2. Relay 32R also picks up. Contact lR-3 in FIG. 6 picks up relay GR4B through the closed contact 34R-2 of master slowdown relay, or through the closed medium speed slowdown switch 4UL which cooperates with the 4UL indicator disposed in the hatch, through contact 34R-4, through the now closed contact 65R-3 of the running relay 65R, and through closed door interlocks 150.

Contact GR4B-2 closes to enable relay (3R4. Contacts GR4B-3 and GR4B-4 close in the LU and LD relay circuits, respectively. Contact GR4B-I closes to pick up relay 23R in FIG. 5.

When the directional relay 1R picks up, the brake is released and the brake monitor relay A drops, opening it contact A-Z in FIG. 6, and timing relay GR4T drops after a delay to close its contact GRdT-Z and pick up relay GR4.

It will first be assumed that there are no car or corridor calls for the first two floors adjacent the elevator car, and thus the elevator car will make a run of more than two floors, which is referred to as a long run. When relay GR4 picks up for more than a one floor run, relay GR6 also picks up. Contact GR6-4 in FIG. 4 closes to pick up the acceleration relay ACC, and contact GR6-3 closes to pick up running relay M.

When the running relay R picks up it closes its contact 65R-1 in FIG. 4 to prepare the two floor run portion of the supervisory control 46. However, since this portion of the circuit has no affect on the operation of the elevator system when the elevator car is making a long run, its description will be delayed until the two floor run is described.

When relays GR6 and ACC pick up, contacts GR6-I and ACC-I close, and the pattern generator 48 shown in FIG. 3 provides a pattern which accelerates the elevator car along curve portion of FIG. 2 to the maximum car speed, which is selected by arm HS of resistor I22. The first notching of the selector occurs before the car moves away from the floor, and the second and subsequent notchings of the selector are in response to the AL and BL cams in the hoistway. When the elevator car passes notching indicator AL in the hatch, it momentarily drops a relay NA (not shown), and when the elevator car passes notching indicator BL in the hatch it momentarily drops a relay NB (now shown). Contacts NA-Z and NB-2 of these two notching relays, which contacts are shown in FIG. 4, drop the master notching relay N each time either notching relay NA or notching relay NB notches to the next floor. During the short notching period, indicated by the de-energized condition of relay N, normally closed contacts of relay N pick up notching relays 39R and 39A (not shown). Notching relay 39R drops when notching relay N picks up following the completion of the notching of the selector, and notching relay 39A drops after a short delay following the picking up of relay N. Thus, contacts N-2 and 39A-I of notching relays N and 39A in FIG. 6 are both closed for a short period of time following a notching or stepping of the floor selector as it notches into the next floor. Contact 23R-3 is closed, which occurred when relay GR E'B picked up. If there is a reason to stop at the floor associated with this new notch of the floor selector, the master slowdown relay 34R will pick up. For example, relay 3 3R will pick up if: (a) contact 438R-I is closed, indicating there is a hall call for this floor, (b) contact 38R-I are closed indicating a car call for this floor, (c) contacts 2C-4 and SID-2 are closed, indicating the car is traveling downwardly and there are no calls ahead of the car. (d) contacts 1C-4 and SlU-Z are closed indicating the car traveling upwardly and there are no calls ahead, or (e) either contacts SAOT-I or SAOl-l are closed. indicating that the selected floor is the upper or lower terminal floor, respectively.

When master slowdown relay 34R picks up, its contact 34R-I in FIG. 3 prepares the 22S slowdown circuit of the pattern generator, its contacts 34R2, 34R-3, 34R-5 and 34414 in FIG. 6 render the slowdown switches 4UL. 4DL, 34Rl in FIG. 3 prepares the 22S slowdown circuit of the pattern generator. its contacts 34R-2, 34R-3. 34R-5 and 34R-6 in FIG. 6 render the slowdown switches 4UL. 4DL. SUL and SDL. respectively, effective. its contacts 34R-4 and 34R-7 in FIG. 6 open to prepare relays GR4, GR4B and GR6 for drop out, its contacts 34R-8 and 34R-9 prepare leveling relays LU and LD for dropout. and its contact 34R- 10 seals itselfin through the closed contacts 65R-4 and 70T-2 of the running and non-interference time relays 65R and 70T, respectively.

When the elevator car reaches the high speed slowdown indicator SUL in the hatch when going upwardly, or the SDL hatch indicator when going downwardly, the switch carried by the elevator car with the sane reference characters in FIG. 6 opens to drop relay GR6. Timing relay GR6T starts to time out when contact GR6-6 opens, with the time being long enough for the elevator car to pass an intervening 4UL or 4DL indicator for the floor preceding the one which the elevator car is to stop. For example, as shown in FIG. I. if the elevator car is going upwardly and the SUL indicator for the 4th floor opens switch SUL, relay GR6T will remain energized, shunting switches 4UL and 4DL with its closed contacts GR6T-I and GR6T-2 until the indicator 4UL associated with the third floor is passed. When relay GR6T times out and drops, it prepares the 4UL switch to be actuated by the 4UL indicator associated with the fourth floor.

When relay GR6 drops at the high speed slowdown indicator SUL, or SDL, its contact GR6-4 in FIG. 4 opens to drop the acceleration relay ACC. The running relay M does not drop when contact GR6-3 opens. as the running relay M seals itself in via its contact M-l.

When the acceleration relay ACC drops, contacts ACC-l and ACC-3 in the pattern generator 48 of FIG. 3 open and close, respectively, to decelerate the car towards the voltage selected by arm IS of resistor 114 of the pattern generator. When the elevator car reaches the 4UL indicator in the hoistway, the switch 4UL shown in FIG. 6 opens to drop relays GR4 and GR4B. Contact GR4-2 opens and contact GR4-3 closes to discharge capacitor 100 towards the voltage selected by arm 225 of resistor I16. Assume the elevator car is traveling upwardly. When it reaches cam 62, about 3 inches from the floor level. switch lDL opens and leveling relay LD drops. Contact LD-S of relay LD in FIGv 6 opens to drop relay 22R. and relay 80C drops via the contact 22R-5 in the holding circuit of relay 80C. Contact 22R-l of relay 22R in the pattern generator 48 of FIG. 3 opens to discharge capacitor 100 towards the voltage selected by the arm LS of resistor 118. At onehalf inch from the floor level cam 62 opens switch lUL (FIG. 6) and leveling relay LU drops. Contacts LU-4 and LD-3 in FIG. 5 are now both open. which drops relay 6P to start the brake setting. The pattern is now controlled by the LSS potentiometer, which is set for zero Speed. The car stops before the brake sets. When the brake is fully set, brake monitor relay A picks up. Its contact A-l in FIG. 5 opens and relays 1R, 1C and 6R all drop. When the directional relay lR drops, contacts 1R-2 in FIG. 5 open and relays 23R. 32R and 65R all drop out. Relay 70T starts the door open noninterference time and then times out and drops.

If the elevator car should overshoot the landing while going in the up direction. switch IDL will go off of cam 62 and close its contacts. picking up leveling relay LD.

As shown in FIG. 5, contact LD-4 will close and pick up the down direction relay 2C via contact LU-2 of the up leveling relay LU, contact 22R-4 of running relay 22R, and contact CPR-l of a protective relay CPR. 5 which will be hereinafter described. Relays 2R. P and 6P all pick up. the brake is picked up. the brake monitor relay A drops, and the car levels back to the landing via the voltage at arm LS of resistor 118. When switch IDL opens. relays LD. 2R, 2C. P and 6P, all drop out, the brake is applied. and the brake monitor relay A is energized. It will be obvious from the drawings that if the car is traveling downwardly and overshoots the floor, how the elevator car re-levels back to the floor, using the switch lUL and the up leveling relay LU.

On a two floor run, relay N of FIG. 4 drops out on the first notching of the selector following a stop of the car, which occurs while the car is preparing to leave the landing, closing its contact N-l and notching relay 39R (not shown) picks up to close its contact 39R-l. Thus. on the first notch or step of the floor selector. relay X is energized. counting to one. Contact X-l closes to seal in relay X. and contact X-2 closes to prepare the circuit of relay Y. Upon the next notching of the floor selector. responsive to passing an indicator in the hatch. contacts NA-I or NB-l of the notching relays close to energize relay Y, counting to two. Relay Y seals itself in via contact Y-I. and it opens its contact Y-2 to start the timed dropout of timing relay YT. It also closes its contact Y-3 to energize the two floor run relay Z for the timing period of relay YT. When relay YT times out and drops, relay Z is de-energized. The circuit effect of relay Z during a two floor run was hereinbeforc described when the pattern generator 48 was described, with its contact Z-I bypassing contact GR6-l to prevent the elevator car from initiating slowdown when it passes the SUL or SDL hatch indicator. it opens the medium speed circuit IS via its contact Z-2, and it maintains the energization of acceleration relay ACC via its contact Z-3. The timing period of relay YT is selected to continue the speed pattern along the acceleration curve 70 until reaching a speed magnitude at which slowdown will be smooth and will bring the cl evator car into the desired floor without undue delay.

On a one floor run, when the floor selector notches into the floor adjacent the last stop of the elevator car, which occurs as the car prepares to leave the floor. the request to stop associated with this notch picks up the master slowdown relay 34R. Its contact 34R-7 in FIG. 6 opens and relay GR6 does not pick up when relay GR4 picks up. Thus, relay M does not pick up. When relay GR4 picks up, the acceleration relay ACC picks up via contacts GR4-5 and M-2. and the car accelerates to the speed setting of arm IS of resistor 114 of the speed pattern generator 48.

FIGS. 7 and 8 are schematic diagrams of protective apparatus constructed according to the teachings of the invention. FIG. 7 is a schematic diagram ofa protective circuit 160, which is also illustrated in block form in FIG. 1, which circuit is powered by a source 162 of alternating potential. Protective circuit 160 is connected to the portion of the loop circuit of the elevator drive motor which is shown generally within the dashed rectangle I64 in FIG. 7. Circuit 164 includes the motor armature winding 22 and the generator interpole field winding 37.

A voltage divider, including resistors 166 and 168, is connected across the armature circuit 164, with resistor 168 being an adjustable resistor having a selector arm 170. The magnitude and polarity of the voltage appearing between arm 170 and junction 172 is responsive to the rotational speed and rotational direction of motor 20. A transformer 174 having a primary winding 176 connected to source 162, includes two secondary windings 178 and 180 connected to full-wave bridge rcctifiers 182 and 184, respectively. The direct current output voltage of bridge rectifier 182 is filtered via capacitor 192 and resistor 194, and the direct current output voltage of bridge rectifier 184 is filtered by capacitor 196 and resistor 198.

The positive output terminal of bridge rectifier 182 is connected to the negative output terminal of bridge rectifier 184 at junction 188, and this junction is connected to the junction 172 between the interpole field winding 37 and armature 22 of the drive motor 20. The negative output terminal 186 of bridge rectifier 182 is connected to selector arm 170 of resistor 168 via relay OVD and resistor 216, and the positive output terminal 190 of bridge rectifier 184 is connected to selector arm 170 via relay OVU and resistor 218. Normally closed contact GR4-7 of relay CR4 and normally open contact 22R-2 of relay 22R are serially connected across resistor 216, while normally closed contact GR4-8 and normally open contact 22R-3 are connected across resistor 218.

When the drive motor is not rotating, the elevator car is stationary at a landing, both relays OVU and OVD are picked up due to the output voltage of the serially connected bridge rcctifiers 182 and 184. When the motor 20 starts to rotate in a direction to move the elevator car in an upward direction, the voltage at selector arm 170 becomes increasingly more positive as the motor speed increases, until a motor speed is reached which generates a voltage sufficient to reduce the voltage across relay OVU to the point where it will drop out. Contact GR4-8 is open during this period of time, and contact 22R-3 is closed. The positive voltage at selector arm 170 has no adverse affect on the condition of relay OVD, and it remains energized. Upon slowdown. when relay GR4 drops out at 4.5 feet from the floor, resistor 218 is shunted to enable relay OVU to pick up at substantially the same output volt age from motor 20 at which it dropped out.

In a similar manner, if drive motor 20 starts to rotate in a direction to lower the elevator car, the voltage at junction 172 becomes increasingly more positive as the elevator drive motor increases in speed until relay OVD drops out. Relay OVU remains energized.

Contacts GR4-7 are open and contacts 22R-2 are closed during the acceleration period. When the motor decelerates, Contact GR4-7 opens 4.5 feet from the floor and relay OVD will pick up at substantially the same motor speed at which it dropped out.

Protective circuit 160 additionally includes a circuit 200 which monitors the rate of change of motor voltage, and thus monitors the acceleration rate of the motor and elevator car. A capacitor 202 is connected from one side of the motor armature 22, at junction 171, to one end of a two branch parallel circuit 201 which includes serially connected resistors 204 and 206 in one branch, and serially connected capacitor 212 and resistor 214 in the other branch. Resistor 204 is adjustable, having a selector arm 208. The remaining side of the parallel circuit 201 is connected to the remaining side of the motor armature 22 atjunction 172. A bridge rectifier 210 has its input terminals connected across capacitor 212, and a monitoring relay ADT is connected across the output terminals of the bridge rectifier 210.

Capacitor 202 blocks current flow from the motor armature circuit when the voltage across the armature is static, and it passes current in direct proportion to the rate of change of motor armature voltage. Thus, during acceleration of the drive motor and'elevator car, capacitor 212 charges to a magnitude proportional to the rate of change of armature voltage. If the rate of change of armature voltage exceeds a predetermined magnitude, which is selected by adjustment of resistor 204, relay ADT will pick up.

P10. 8 is a schematic diagram which illustrates how contacts of relays OVD, OVU and ADT are utilized to provide new and improved protective functions. A pretective relay CPR is connected between busses L+ and L via a plurality of contacts and switches which monitor various functions of the elevator system. Relay CPR has a normally open contact CPR-1 in FIG. 5 connected such that the elevator car will not run should relay CPR become deenergized.

Relay CPR is connected serially with belt switches, shown generally at 230, which are closed as long as the belts which they are associated with are not broken, normally open contacts OVD-1 and OVU-l of the motor voltage monitoring relays, normally closed contact ADT-l of the acceleration monitoring relay, and its own normally open contact CPR-2. A normally open pushbutton 232 is connected across contact CPR- 2. Normally open contacts 2R-5 and lR-5 of the up and down direction relays 2R and IR, respectively, are serially connected across contacts OVD-l and OVU-1. Normally open contacts 40R-l of the door monitoring relay 40R and normally closed contact H-1 of the hand control relay 60H are serially connected from the junction 234 between contacts OVD-l and OVU-1 to the junction 236 between contacts 2R-5 and 1R-5.

When the elevator car is stationary at a landing, both relays OVU and OVD are energized, the hand control relay 60H is dropped out when the elevator is on automatic control, the door relay 40R is dropped out when the car doors are open, the direction relays IR and 2R are dropped out, and relay ADT is dropped out. Closing pushbutton 232, which is actuated by maintenance personnel in the machine room when the elevator system is initially placed in operation, picks up relay CPR via a circuit which includes the belt switches 230, contacts OVD-1, OVU-1, and ADT-1. Contact CPR-2 closes to seal in relay CPR and maintain its energized condition after the pushbutton 232 returns to its normally open condition.

When the elevator drive motor prepares to move in the upward direction, the door relay 40R picks up and its contact 40R-1 closes and the up direction relay 1R picks up and contact lR-S closes. As the elevator drive motor 20 increases its rotational speed. a point is reached where relay OVU drops out. opening its contact OVU-1. Relay CPR remains energized, however. via the closed contacts 40R-1, 60H -1 and lR-S, which shunt the now open contact OVU-l.

When the elevator drive motor rotates in a direction to cause the elevator car to move downwardly, relays 2R and 40R will be picked up to shunt contacts OVD-l with closed contacts 2R-5, 40R-1 and 60H-1. Thus. when the drive motor reaches the speed where relay OVD-l drops out. the circuit through relay CPR is maintained.

If the car up direction relay IR is picked up but the polarity of the motor armature voltage indicates downward travel. relay OVD will drop out when the motor armature voltage reaches a predetermined magnitude. which is selected to be higher than the motor armature voltage developed during normal re-leveling. When relay OVD drops out with the up direction relay lR picked up. relay CPR drops out and the elevator car will make an emergency stop and it cannot be restarted until maintenance personnel correct the system malfunction and manually actuate pushbutton 232 to again pick up the protective relay CPR.

In like manner. if the down direction relay 2R is energized and relay OVU drops out. indicating the presence of a predetermined motor armature voltage magnitude having a polarity indicating rotation ofthe motor for up travel of the elevator car. relay CPR will drop out.

The armature voltage magnitude which will drop out one of the relays OVU or OVD is selected to indicate a motor rotational speed and thus car speed which is above that at which the doors are set to prc-open. Should the doors pre-open when the motor armature voltage is sufficient to dropout either relay OVU or OVD. relay CPR will drop out as contact 40R-l will be open. as will contacts OVD-l or OVD-2. and the energizing circuit for relay CPR will be broken.

When the elevator car is operated on hand control. the hand control relay 60H picks up and opens its contact 6OH-1. The maximum car speed on hand control is below the car speed at which OVU or OVD pick up. Should the elevator car exceed this maximum hand control speed and pick up one of the relays OVU or OVD. relay CPR will drop out and the elevator car will make an emergency stop.

I claim as my invention:

1. An elevator system comprising:

a structure having a plurality of floors and a hoistway.

an elevator car mounted for movement in the hoistway of said structure.

motive means for moving said elevator car relative to the structure to serve said floors.

said motive means including speed control means having first. second and third modes of operation which control acceleration of said elevator car to first. second and third progressively higher speeds. respectively,

slowdown indicator means disposed in said hoistway for initiating slowdown of said elevator car at a selected floor.

and notching selector means responsive to runs of said elevator car of one floor. two floors. and more than two floors. selecting said first. second and third modes of operation. respectively. of said speed control means.

said notching selector means including means for counting at least certain of the notchings thereof. with said counting means selecting the second ac celerator mode when the elevator car is making a run of two floors by modifying the effect of said slowdown indicator means.

2. The elevator system of claim 1 wherein the speed control means includes energy storage means. with the acceleration of the elevator car during each of the first. second and third operating modes of the speed control means being responsive to the voltage across said en- (it l ergy storage means. said energy storage means being charged toward the same target voltage at the same charging rate for each of the first. second and third operating modes.

3. The elevator system of claim 2 wherein the slowdown indicator means includes at least first and second spaced slowdown indicators disposed in the hoistway associated with each floor for each direction in which the elevator car may approach the floor.

and wherein the speed control means includes means for controlling the deceleration of the elevator car according to the voltage across the same energy storage means which controls the acceleration of the elevator car. including first slowdown circuit means discharging the energy storage means towards a first predetermined lower voltage when the elevator car passes the first slowdown indicator associated with the floor at which the elevator car is to stop. and second slowdown circuit means discharging the energy storage means towards a sec ond predetermined lower voltage when the elevator car passes the second slowdown indicator associated with the floor at which the elevator ear is to stop.

4. The elevator system of claim 3 wherein the second slowdown indicator for a given floor is located between the first and second slowdown indicators associated with an adjacent floor. and means successively enabling the first and second slowdown circuit means. with the time period between the enabling of the first and second slowdown circuit means being selected such that the first and second slowdown circuit means are responsive to the first and second slowdown indicators associated with the floor at which the elevator car is to stop. while ignoring the intervening second slowdown indicator for the adjacent floor.

5. An elevator system comprising:

a structure having a plurality of floors and a hoistway.

an elevator car mounted for movement in the hoistway of said structure.

motive means for moving said elevator car relative to the structure to serve said floors.

said motive means including speed control means having first. second and third modes of operation which control the acceleration of said elevator car to first. second and third progressively higher speeds. respectively.

notching selector means responsive to runs of said elevator car of one floor. two floors. and more than two floors. selecting said first. second and third modes of operation. respectively. of said speed control means.

said notching selector means including means for counting at least certain of the notchings thereof to determine when the elevator car is making a run of one floor. two floors. or more than two floors. control circuits for said floors.

means modifying the control circuit of a floor from a first condition to a second condition when the elevator car should stop at this floor.

said notching selector means including means successively enabling the control circuits of said floors responsive to the location and travel direction of the elevator car.

means responsive to the enabling of the control circuit of the next adjacent floor to the floor of the last stop of the elevator car when said control circuit is in its second condition. for selecting the first operating mode.

and means responsive to the enabling of the control circuit of the second floor from the last stop of the elevator car. when the control circuit of this floor is in its second condition. for selecting the second operating mode.

said notehing selector means selecting the third operating mode when the elevator ear does not stop within two floors of its last stop.

6. An elevator system comprising:

a structure having a plurality of floors and a hoistway.

an elevator car mounted for movement in the hoistway of said structure.

motive means for moving said elevator car relative to the structure to serve said floors. said motive means including speed control means having first. second and third modes of operation which control the acceleration of said elevator car to first. second and third progressively higher speeds. respectively. said speed control means including energy storage means. with the acceleration of the elevator car during each of the first. second and third operating modes of the speed control means being responsive to the voltage across said energy storage means. said energy storage means being charged toward the same target voltage at the same charging rate for each of the first. second and third operating modes. notehing selector means responsive to runs of said elevator car of one floor. two floors. and more than two floors. selecting said first. second and third modes of operation. respectively. of said speed control means. said notehing selector means including means for counting at least certain of the notehing thereof to determine when the elevataor car is making a run of one floor. two floors. or more than two floors.

first and second voltage clamping means for clamping the voltage across said energy storage means to voltages corresponding to the maximum operating speeds of the elevator car for the first and third operating modes. respectively. and means maintaining the charging of said energy storage means to a voltage higher than the voltage of the first voltage clamping means. but less than the voltage of the second voltage clamping means. for the second operating mode.

7. The elevator system of claim 6 wherein the means maintaining the charging of the energy storage means to a voltage higher than the voltage of the first voltage clamping means includes timing means for continuing the charging of the energy storage means for a predetermined period of time after the energy storage means has reached the magnitude of the first voltage clamping means.

8. An elevator system comprising:

a structure having a plurality of floors and a hoistway.

an elevator ear mounted for movement in the hoistway of said structure.

motive means for moving said elevator car relative to the structure to serve said floors.

said motive means including speed control means having first. second and third modes of operation which control the acceleration of said elevator car to first. second and third progressively higher speeds. respectively.

notehing selector means responsive to runs of said elevator car of one floor. two floors. and more than two floors. selecting said first. second and third modes of operation. respectively. of said speed control means. said notehing selector means including means for counting at least certain of the notchings thereof to determine when the elevator car is making a run of one floor. two floors. or more than two floors.

control circuits associated with each of the floors.

and notehing means successively enabling said control circuits of the floors in the travel direction of the elevator car in response to the position of the elevator car relative to the floors.

said means for counting the notchings being responsive to said notehing means for determining when the control circuit associated with at least a second floor from the last stop is enabled by said notehing means.

9. The elevator system of claim 8 including slowdown indicator means disposed in the hoistway to signify the slowdown point for each floor when the elevator car is to stop at the associated floor. slowdown means responsive to the slowdown indicating means of a specific floor when the control circuits of that floor indicate the elevator car should stop at that floor. and timing means initiated in response to the means for counting detecting that the control circuit being enabled is associated with the second floor from the last stop of the elevator car. said timing means delaying the slowdown of the elevator car in the event it is to stop at this floor. notwithstanding the clevator car passing the slowdown indicator means in the hoistway associated with this floor.

10. The elevator system of claim 9 wherein the slowdown indicator means includes high and intermediate speed slowdown indicators for each floor. for each direction in which the elevator car may approach the floor. and the slowdown means includes first and second slowdown means responsive to the high and intermediate speed slowdown indicators. respcctively. with the maximum speed of the elevator car and spacing of the floors being such that the intermediate speed slowdown indicator for one floor is between the high and intermediate speed slowdown indicators associated with an adjacent floor. and including means delaying the response of the second slowdown means to the intermediate speed slowdown indicator once slowdown is initiated by the first slowdown means in response to the high speed slowdown indicator. until the intervening intermediate speed slowdown indicator of the adjacent floor has been passed by the elevator car.

11. An elevator system comprising:

a structure having a plurality of floors and a hoistway.

an elevator car mounted for movement in the hoistway of said structure.

motive means for moving said elevator car relative to the structure to serve said floors. first and second slowdown indicators spaced in the hoistway for each floor. for each service direction in which said elevator car may serve the floor.

control means initiating slowdown of said elevator car to stop the elevator car at a predetermined floor in response to the second slowdown indicator for that floor and service direction for a run of one floor.

said Control means initiating slowdown of said elevator car to stop the elevator car at a predetermined evator car to make a two floor run.

12. The elevator system of claim 11 wherein the means which overrides the first slowdown indicator associated with the stopping floor of a two floor run, overrides the first slowdown indicator for the second floor from the last stop of the elevator car on every run of more than one floor. regardless of the length of the run.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3643762 *Nov 16, 1970Feb 22, 1972Inventio AgMethod and apparatus for controlling an elevator for medium to high running speed
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4042068 *Jun 25, 1975Aug 16, 1977Westinghouse Electric CorporationElevator system
US4116306 *Apr 29, 1977Sep 26, 1978Elevator IndustriesElevator car generator-motor-brake control unit apparatus and method
US4308936 *Feb 19, 1980Jan 5, 1982Westinghouse Electric Corp.Elevator system
US4337848 *Apr 10, 1981Jul 6, 1982Inventio AgStart control device, especially for an elevator
US4351416 *Nov 17, 1980Sep 28, 1982Mitsubishi Denki Kabushiki KaishaElevator control device
US5399948 *Jan 21, 1993Mar 21, 1995Yang; Tai-HerGovernor circuit for universal series (or compound) motor
US7377363 *Feb 24, 2003May 27, 2008Otis Elevator CompanyElevator with variable drag for car and counterweight
US7438158 *Jan 27, 2005Oct 21, 2008K.A. Schmersal Holding KgSafety monitoring device with instantaneous speed determination for a lift car
US20130075199 *Nov 19, 2012Mar 28, 2013Tuukka KauppinenMethod for limiting the loading of an elevator assembly, and an elevator assembly
Classifications
U.S. Classification187/293, 187/287
International ClassificationB66B1/28, B66B5/06, B66B1/30, B66B1/24, B66B1/52, B66B1/16
Cooperative ClassificationB66B1/30, Y02B50/142, Y02B50/125, B66B1/285
European ClassificationB66B1/30