US3124723A - Stutz - Google Patents

Description

March 10, 1964 K. STUTZ 3,124,723

METHOD FOR THE AUTOMATIC SELECTION OF THE SPEED OF ESCALATORS Filed June 5, 1959 United States Patent Ofiice 3,124,723 Patented Mar. 10, 1964 3,124,723 METHOD FOR THE AUTOMATIC SELECTION OF THE SPEED OF ESCALATORS Karl Stutz, Hinterbramberg 6, Lucerne, Switzerland Filed June 3, 1959, Ser. No. 817,930 Claims priority, application Switzerland June 5, 1958 11 Claims. (Cl. 317-142).

This invention relates to a method for the automatic selection of the speed, adapted to the frequency of the passengers, of escalators, and to a device for carrying out the method.

It is known to set escalators in operation automatically on the approach of passengers, by means of floor contacts or light barriers. Two-speed drive arrangements have also already been proposed for escalators, wherein the increased speed is switched on by a switch clock at with increased .traflic.

Furthermore escalators have already been equipped with passenger-counting arrangements, for statistical purposes, wherein for example a cam moved by a roller of the loaded steps directly actuates a mechanical counting mechanism, or actuates, through a contact, an electrical impulse-counting mechanism.

' Now the invention relates to a method for the auto matic selection of the speed, adapted to the sfirequency of the passengers, of escalators, in which method, according to the passenger frequency at the given moment, the lower or higher conveying speed is selected automatically. According to the invention the impulses instigated by the passengers serve for the measurement of the frequency. The novelty according to the inventionconsists in that the duration of time between two passenger impulses or the frequency of the number of passengers is compared with a predetermined, settable, normal value, whereupon, in dependence upon the departure of the compared values, a switch command is issued for the lower or higher speed.

The device for carrying out the method is characterised in that a measuring arrangement is provided, which measures the duration of time between two impulses or the frequency of the passengers, and compares this with a settable, critical value, and further in that a switch arrangement is provided, which varies the conveying speed in dependence upon the difference between the two compared values.

An example of embodiment of the inventon is illustrated by reference to a circuit diagram in the accompanying drawing.

In the drawing, and designate the poles of a source of direct current. Between these poles there are interposed an impulse contact 1 and a relay 2. The impulse contact 1 has .a trigger device (not shown), which is installed in the escalator and is interrupted for a short time by every person using the escalator. It can be actuated for example by a roller of the loaded escalator step. The relay 2 possesses an off contact 2.1 and a switch-over contact 2.2. Connected in parallel with the impulse contact 1 and the relay 2 there is a gas-tilled relay tube 3 with anode 12, cold cathode 13 and starter electrode 14, the oifcontact 2.1 being connected into the anode lead 15 and a resistance 6 being connected into the cathode lead 16. "The switch-over contact 2.2 is connected through a lead v17 with the starter electrode 14. Furthermore a variable resistance is inserted into the current circuit of the switch-over contact 2.2. 4 designates a condenser, through which the starter electrode is connected with the pole.

The cathode lead 16 is connected through a variable resistance 7 with the grid 18 of a negatively biassed vacuum triode 10, the anode 19 of which is connected through a relay 1-1 with the pole of the source of direct current and the cathode 20 of which is connected through a resistance 9 with the pole of the source of direct current. A condenser 8 is connected between the grid 18 and this negative pole of the source. The relay 11 possesses a switch-over contact 11.1, through which, according to choice, a coil 12 or "13" of a relay switch is energised. The coil 12 serves for switching on the high conveying speed and the coil 13' for switching on the low conveying speed.

The condenser 4, with the variable resistance 5, forms a settable time norm, while the R-C member consisting of the variable resistance 7 land the condenser 8 serves for the delaying of the switch-over of the speeds on variation of the passenger frequency.

The arrangement as described works as follows: Every time a passenger passes the measuring point, the impulse contact 1 imparts an impulse to the relay 2, whereupon the contacts 2.1 and 2.2 are shifted over for a short time. The condenser 4 is then discharged to zero potential, whereby the anode circuit of the relay tube 3 is interrupted. The relay tube 3, if lit up, is thereby extinguished. Thus the time norm is set back to the zero position. After the impulse the condenser 4 is charged up afresh through the resistance 5. When its potential has reached the value of the lighting potential of the starter electrode of the tube 3, the latter lights up. This time is used as time norm, and is set to about 2 seconds, corresponding to a mean passenger frequency. If the frequency is higher, an impulse follows a preceding one beiiore the tube 3 lights up, so that the tube 3 never lights up at all. Thus the voltage drop on the resistance 6 is always zero also.

If the passenger frequency is low, the tube lights up periodically, and rectangular impulses occur on the resistance 6, which impulses are the longer in relation to the period duration, the lower is the passenger frequency. On the condenser 8 there occurs a voltage equal to the mean value of these rectangular impulses. Thus this voltage is a measure for the deviation orf the time duration between two passenger impulses and the time norm. It controls the current in the vacuum triode 10, which is negatively biasse-d by the resistance 9. The relay 11 pulls up at a certain voltage on the condenser 8, or drops off when this certain voltage is not reached. When pulled up it switches on the relay switch 13' for the low travelling speed, and when dropped off it switches on the switch 12'. for the high speed.

By the resistance 7 the change-over of the speed on variation of the passenger frequency can be delayed by a settable time.

.Instead of .the R-C combination 4, 5 the time norm can also be established through an electromechanical relay with predeterminably delayed action for controlling the igniting of the tube 3.

What I claim is:

1. An arrangement for automatically varying the speed of an escalator between predetermined values, depending upon the passenger frequency, comprising, in combination, relay switch means movable by energization between a normal and an alternative position and adapted to be operatively connected with the escalator and to cause, when in said normal position, escalator operation at a predetermined speed, and to cause, when in said alternative position, escalator operation at a predetermined lower speed; circuit means including a source of electric energy and normally open main contact means positioned and adapted to be actuated once for every passenger traveling on the escalator; and time comparator means controllable by closing of said main contact means and including a timing circuit establishing a predetermined reference time period, for comparing the actual intervals between consecutive actuations of said main contact means with said predetermined reference time period, and for delivering an energizing voltage to said relay switch means so as to move the latter to said alternative position only when said actual intervals are longer than said predetermined reference time period.

2. An arrangement for automatically controlling two switch devices adapted to be connected with an escalator and to vary the speed thereof between predetermined values, depending upon the passenger frequency, comprising, in combination, a first relay switch adapted to cause, when energized, operation of the escalator connected therewith at a predetermined speed; a second relay switch adapted to cause, when energized, operation of the escalator connected therewith at a predetermined lower speed; circuit means including a source of electric energy and normally open main contact means positioned and adapted to be actuated and closed for a brief moment once for every passenger traveling on the escalator; first switch means in circuit with said source and operatively connected with said main contact means and including timing means for delivering a control voltage pulse only a predetermined reference time period after actuation of said main contact means, but incapable of delivering said control voltage pulse if said actuation occurs after a preceding actuation before the end of said predetermined reference time period; second switch means controllable by said control voltage pulses for connecting, upon application of said control voltage pulses, a source of electric energy with said second relay switch so as to energize the latter, and for connecting, when deenergized, said source with said first relay switch so as to energize the latter, so that when the passenger frequency is small said control voltage pulses are delivered and said second relay switch operates to cause said predetermined lower escalator speed, while when the passenger frequency is higher and the intervals between actuations of said main contact means are shorter than said reference time period, no control voltage pulse is delivered and said first relay switch operates to cause said predetermined higher escalator speed.

3. An arrangement as claimed in claim 2, wherein said first switch means comprises a relay tube having a starter electrode, an anode and a cathode, a time relay means having a coil connected to be energized by closing said main contact means, and a timing condenser connected in circuit with said starter electrode, said time relay means causing, when deenergized, charging of said timing condenser and ignition of said tube when said condenser, a predetermined reference time period after actuation of said main contact means, is charged to the ignition potential of said tube, and said time relay means causing, when briefly energized, discharge of said timing condenser and non-conductivity of said tube.

4. An arrangement as claimed in claim 3, wherein said first switch means comprise an adjustable resistor in series with said condenser for adjusting the charging rate thereof.

5. An arrangement as claimed in claim 2, wherein said second switch means comprise a triode and control relay means controllable by the output of said triode, the control grid of said triode being connected with said relay tube to be controlled by a control voltage derived therefrom when said relay tube is condutcive, and a capacitor being connected in the circuit between said triode and said relay tube for rendering said control voltage depending upon the ratio between the intervals separating said control voltage pulses and said predetermined reference time period, said control relay means causing, when energized, energization of said second relay switch, and causing, when deenergized, energization of said first relay switch.

6. An arrangement as claimed in claim 5, wherein a variable time delay means is connected between said relay tube and said triode.

7. An arrangement as claimed in claim 6, wherein said variable time delay means is a variable resistor.

8. An arrangement for automatically varying between predetermined values the speed of conveyor means carrying objects along a predetermined path, depending upon the conveyed object frequency, comprising, in combination, relay switch means movable by energization between a normal and an alternative position and adapted to be operatively connected with the conveyor means and to cause, when in said normal position, operation of said conveyor means at a predetermined speed, and to cause, when in said alternative position, operation of said conveyor means at a predetermined lower speed; circuit means including a source of electric energy and normally open main contact means positioned and adapted to be actuated once for every individual object being conveyed by said conveyor means; and time comparator means controllable by closing of said main contact means and including a timing circuit establishing a predetermined reference time period, for comparing the actual intervals between consecutive actuations of said main contact means with said predetermined reference time period, and for delivering an energizing voltage to said relay switch means so as to move the latter to said alternative position only when said actual intervals are longer than said predetermined reference time period.

9. An arrangement for automatically controlling two switch devices adapted to be connected with a conveyor means carrying objects along a predetermined path and to vary the speed thereof between predetermined values, depending upon the conveyed object frequency, comprising, in combination, a first relay switch adapted to cause, when energized, operation of the conveyor means connected therewith at a first predetermined speed; a second relay switch adapted to cause, when energized, operation of the conveyor means connected therewith at a second predetermined lower speed; circuit means including a source of electric energy and normally open main contact means positioned and adapted to be actuated and closed for a brief moment once for every individual object being conveyed by said conveyor means; first switch means in circuit with said source and operatively connected with said main contact means and including timing means for delivering a control voltage pulse only a predetermined reference time period after actuation of said main contact means, but incapable of delivering said control voltage pulse if said actuation occurs after a preceding actuation before the end of said predetermined reference time period; second switch means controllable by said control voltage pulses for connecting, upon application of said control voltage pulses, a source of electric energy with said second relay switch so as to energize the latter, and for connecting, when deenergized, said source with said first relay switch so as to energize the latter, so that when the conveyed object frequency is small said control voltage pulses are delivered and said second relay switch operates to cause said second predetermined lower conveyor speed, while when the conveyed object frequency is higher and the intervals between actuations of said main contact means are shorter than said reference time period, no control voltage pulse is delivered and said first relay switch operates to cause said first predetermined conveyor speed.

10. An arrangement for automatically controlling two switch devices adapted to be connected with an escalator and to vary the speed thereof between predetermined values, depending upon the passenger frequency, comprising, in combination, a first relay switch adapted to cause, when energized, operation of the escalator connected therewith at a predetermined speed; a second relay switch adapted to cause, when energized, operation of the escalator connected therewith at a predetermined lower speed; circuit means including a source of electric energy and normally open main contact means positioned and adapted to be actuated and closed for a brief moment once for every passenger traveling on the escalator; first switch means in circuit with said source and operatively connected with said main contact means and including timing means for delivering a control voltage pulse only a predetermined reference time period after actuation of said main contact means, but incapable of delivering said control voltage pulse if said actuation occurs after a preceding actuation before the end of said predetermined reference time period, said first switch means comprising a relay tube having a starter electrode, an anode and a cathode, a time relay means having a coil connected to be energized by closing said main contact means, and a timing condenser connected in circuit with said starter electrode, said time relay means causing, when deenergized, charging of said timing condenser and ignition of said tube when said condenser, a predetermined reference time period after actuation of said main contact means, is charged to the ignition potential of said tube, and said time relay means causing, when briefly energized, discharge of said timing condenser and non-conductivity of said tube, said first switch means further comprising an adjustable resistor in series with said condenser for adjusting the charging rate thereof, said time relay means having a first normally closed relay contact in the anode circuit of said tube, and a change-over contact connected between the terminals of said source, said timing condenser and said adjustable resistor in such a manner that, when said time relay means is deenergized, said timing condenser and adjustable resistor are connected in series between said terminals so that said condenser is charged, while, when said time relay means is briefly energized, said condenser is discharged and said anode circuit is interrupted so as to extinguish said tube; second switch means controllable by said control voltage pul es for connecting, upon application of said control voltage pulses, a source of electric energy with said second relay switch so as to energize the latter, and con necting, when deenergized, said source with said first relay switch so as to energize the latter, so that when the passenger frequency is small said control voltage pulses are delivered and said second relay switch operates to cause said predetermined lower escalator speed, while when the passenger frequency is higher and the intervals between actuations of said main contact means are shorter than said reference time period, no control vol age pulse is delivered and said first relay switch operates to cause said predetermined higher escalator speed.

11. An arrangement as claimed in claim 10, wherein said second switch means comprise a triode and control relay means controllable by the output of said triode, the control grid of said triode being connected with said relay tube to be controlled by a control voltage derived therefrom when said relay tube is conductive, and a capacitor being connected in the circuit between said triode and said relay tube for rendering said control voltage dependent upon the ratio between the intervals separating said control voltage pulses and said predetermined reference time period, said control relay means causing, when energized, energization of said second relay switch, and causing, when deenergized, energization of said first relay switch.

References Cited in the file of this patent UNITED STATES PATENTS 1,985,563 FitzGerald Dec. 25, 1934 2,567,928 Farmer Sept. 18, 1951 2,602,888 Audier July 8, 1952 2,650,301 Farmer Aug. 25, 1953

Claims (1)

1. AN ARRANGEMENT FOR AUTOMATICALLY VARYING THE SPEED OF AN ESCALATOR BETWEEN PREDETERMINED VALUES, DEPENDING UPON THE PASSENGER FREQUENCY, COMPRISING, IN COMBINATION, RELAY SWITCH MEANS MOVABLE BY ENERGIZATION BETWEEN A NORMAL AND AN ALTERNATIVE POSITION AND ADAPTED TO BE OPERATIVELY CONNECTED WITH THE ESCALATOR AND TO CAUSE, WHEN IN SAID NORMAL POSITION, ESCALATOR OPERATION AT A PREDETERMINED SPEED, AND TO CAUSE, WHEN IN SAID ALTERNATIVE POSITION, ESCALATOR OPERATION AT A PREDETERMINED LOWER SPEED; CIRCUIT MEANS INCLUDING A SOURCE OF ELECTRIC ENERGY AND NORMALLY OPEN MAIN CONTACT MEANS POSITIONED AND ADAPTED TO BE ACTUATED ONCE FOR EVERY PASSENGER TRAVELING ON THE ESCALATOR; AND TIME COMPARATOR MEANS CONTROLLABLE BY CLOSING OF SAID MAIN CONTACT MEANS AND INCLUDING A TIMING CIRCUIT ESTABLISHING A PREDETERMINED REFERENCE TIME PERIOD, FOR COMPARING THE ACTUAL INTERVALS BETWEEN CONSECUTIVE ACTUATIONS OF SAID MAIN CONTACT MEANS WITH SAID PREDETERMINED REFERENCE TIME PERIOD, AND FOR DELIVERING AN ENERGIZING VOLTAGE TO SAID RELAY SWITCH MEANS SO AS TO MOVE THE LATTER TO SAID ALTERNATIVE POSITION ONLY WHEN SAID ACTUAL INTERVALS ARE LONGER THAN SAID PREDETERMINED REFERENCE TIME PERIOD.

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