US2437756A

US2437756A - Electromagnetic timing relay

Info

Publication number: US2437756A
Application number: US627261A
Authority: US
Inventors: Theodore F Rosing; Edwin W Seeger
Original assignee: Cutler Hammer Inc
Current assignee: Cutler Hammer Inc
Priority date: 1945-11-07
Filing date: 1945-11-07
Publication date: 1948-03-16
Anticipated expiration: 1965-03-16
Also published as: GB627723A

Description

March. 16, 1-948. 'r. F. ROSINGY ETAL 2,437,756

I ELECTROMAGNETIC TIMING RELAY Filed Nov. 7, 1945 PULL. 0F COIL Z! PULL PuLL 0F COIL a0 CURRENT CURRENT PULL.

Patented Mar. 16, 1948 2,437,756 ELEGTROYMAGNETIC TIMING RELAY Theodore F. Rosina,

poratlon of Delaware Whitefish Bay, W. Sceger, Wauwatosa, Wis Cutler-Hammer, 1110.,

and Edwin ass gnors to Milwaukee, Wis., a cor- Appllcatlon November 7, 194?), Serial No. 622,281 I d lJlaims. (Cl. 175-320) The invention relates to a timing relay and is particularly applicable to a relay which is adapted to respond selectively in accordance with the lapse of time after initiation of commutation of the energizing cm'rent.

It is often desirable to provide relay means for the control of two succeeding functions with a time interval between the two functions.

An object of the present invention is to provide a relay having an oscillating element with means to move the latter in one direction upon simultaneous energization of two electromagnets connected in series with each other and to thereafter cause the oscillating element to move in the opposite direction after a given interval of time following the initial movement.

Another object is to provide a balanced electroprovide a relay, the time is not appreciably atlected energizing current.

advantages will hereinafter 3 Figure 1 is a diagrammatic showing of a relay with the associated strumentalities.

Fig. 2 shows the pull of the relay coils as a function of the energizing current.

power supply and control ina Fig. 3 shows the current in the difi'erent aranches 01' the energizing circuit upon closure )f the circuit as a function of elapsed time after :losure for two values of the supply voltage, vhile Fig. 4 shows the relation he two coils as a function losure.

between the pull of of elapsed time after he relay has a lever l2, atatively supported by a stationary pivot l3. ach end or the lever I2 is provided with a me:-

its completion. The

5 transient period.

5 of the coil 2| netizalale armature l4 and lb, respectively. The lever is normally biased to its center position by a centering spring 16. Attached to the lever is also a movable contact arm l7, arranged to cooperate with stationary contacts 13 and la, respectlvely, upon rotation of the lever in opposite directions.

.A magnetizing coil 253 of relatively low resistance and low inductance cooperates with the armature l4, tending when magnetized, to attract the latter, and a magnetizing coil 2| of relatively high resistance and relatively low 1nductance, but higher than that similarly with the armature 15. A condenser 22 is connectedin shunt with the coil 2!. The tractive force of the two coils upon their respective armatures is such, that with the same current flowing through the two coils, the pull of the coil 2| exceeds that of the coil 20 and rotates the lever in a clockwise direction to cause engagement of contacts H and I9.

When the switch I I is open the relay lever is in the position shown. Upon closure of the switch current flows from line L through switch coils 20 and 2| to line L A part of the current by-passes the coil 2| through the condenser 22 to charge the latter. Hence, during the initial rise of the current to its final value, the ratio of energization of the coil 2| is less relative to that of coil 20, than that obtaining when the current is constant, the ratio referred to decreasing with increasing charge of the condenser 22, thereby deflecting an increasingly greater portion of the total current through the coil 2|, until the pull is greater than that of coil 20. Thereupon the lever is revolved clockwise to disengage the contacts and I8 and engage the contacts I1 and I9.

As aforestated, the diagram, Fig. 2, shows the pulls of the coils 20 and 2|, respectively, for different steady currents flowing through the respective coils.

Fig. 3 shows the current in the various parts of the circuit as a function of the time elapsed after curves 1". I and I are the currents in the coils 20 and 2| and the condenser 22, respectively, at various intervals after the closure of the control switch for a given line voltage, resulting in a given steady current after the If the voltage of the supply circult is reduced to two-thirds, the currents in the aforementioned elements are reduced to twothirds of the former values, as shown by curves I'zo, 1'21 and I'az, respectively. Fig. 4 shows the pm! of the two magnets in relation to-the elapsed of coil 20, cooperates supply voltage.

' charged condenser curves P and P3 again refer to a given line voltage, while the pull curves F and P'n show 7 the respective pulls for substantially two-thirds of the aforementioned line voltage. It will be seen from Fig. 4 that for either voltage the pull of the coil 26! predominates over that oi the coil prior to the moment indicated bya in the din gram and it will also be apparent that the interval from the time of closure of the circuit to the moment A changes little with variations of the It will also. be apparent from the foregoing that the response of the relay is also subject to elapsedtime upon opening of the circuit.

Thus it the contacts El and it are engaged while current is flowing through the windings or even when underthis condition two coils are equal and the relay is in its center position and the current is interrupted, the discharges through the coil 2i, thereby temporarily maintaining its current above the value of the decaying line current passing through coil 29. The resulting clockwise torque tends to rotate the relay to complete the circuit between contacts H and it or maintain this circuit for a time dependent upon the capacity of the condenser 22 and of the inductance of the coil 2 l We claim:

1. In a timing system, a relay-comprising an oscillatable armature normally biased to aneutral position, a pair of direct current electromagnets acting upon said armature and tending to move it in opposite directions respectively, the windings of said electromagnets being connected in series with each other for normally passing the same energizing current therethrough, said electromagnets being so constructed and calibrated that the operating efiect of one of the same upon said armature for any given current exceeds the eflect of the other, and means electrically connected in parallel with the winding of said one of said electromagnets to delay the rate of change of the current therein relative to the rate or change of said energizing current upon transient changes thereof.

2. In a timing system, a relay comprising an oscillatable armature normally biased to a neutral position, a pair of direct current electromagnets acting upon said armature and tending to move it in opposite directions respectively, the windings of said electromagnets being connected in series with each other for normally passing the same energizing current therethrough, said electromagnets being so constructed and calibrated the pulls oi the current that the operating efiect'oi one or the same upon said armature for any given current exceeds the eflect of the other, and means electrically connected in parallel with the winding of one of said electromagnets to delay the rate of change or the current therein relative to the rate oi chan e of said energizing current upon transient changes thereof. 4

3. In a timing system, a relay comprising an oscillatable armature normally biased to a neutral position, a pair of direct current electromagnets acting upon said armature and tending to move it in opposite directions respectively, the windings of said electromagnets being connected in series with each other for normally passing the same energizing current therethrough, said electromagnets being so constructed and calibrated that the operating effect of one of the same upon said armature for any given current exceeds the efiect of the other, and a condenser connected in parallel with the winding of said one of said electromagnets to delay the rate of change of the current therein relative to the rate of change of said energizing current .upon transient changes thereof.

4. In a timing system, a relay comprising an oscillatable armature normally biased to a neutral position, means operated by said armature for selectively ccmmutating an electric circuit upon' movement of said armature from said neutral position, a pair of direct current electromagnets acting upon said armature and tending to move it in opposite directions respectively, the windings of said electromagnets being connected in series with each other for normally passing the same energizing current therethrough, said electromagnets being so constructed and calibrated that the operating effect of one of the same upon said armature for any given current exceeds the efiect or the other, and a capacitor connected in parallel with the winding of said one of said electromagnets to delay the rate of change of the therein relative to the rate or. change of said energizing current upon' transient changes thereof.

THEODORE F. ROSING. EDWIN W. SEEGER.

REFERENCES CITE UNITED STATES PATENTS Number Name 7 Date 1,748,862 Brown Feb. 25, 193( 2,394,294; Guiseppe Feb. 5, 194(