US2381300A - Timing relay - Google Patents

Description

7, 1945. I K. MAHNKE 2,381,300

TIMING RELAY Filed March 13, 1943 2 Sheets-Sheet l INVENTOR Karl Mafmke. BY

A'ITORNEY Patented Aug. 7, 1945 2,381,300 TIMING RELAY Kurt Mahnke, Forest Hills, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application March 13, 1943, Serial No. 479,073

7 Claims.

My invention relates to electromagnetic devices and more particularly to electromagnetic time limit devices of the direct current type.

Electromagnetic time limit devices are 'well known in the electrical art. Those depending on alternating current are usually expensive synchronous devices and are quite accurate but those depending on direct current if of the inductive type have only a short variable time constant and if of the motor operated type are expensive and also are not reliable as to the time constant obtained.

One object of my invention is the provision of a direct current time limit device having a relatively long time constant and a device that shall be cheap and easily manufactured.

Another object of my invention is the provision of a direct current time limit relay that shall include means for adjusting the length of the time constant and which shall have a relatively long time constant.

These objects specifically stated are merely illustrative because many other and more specific objects will become apparent from a study of the following specification and the accompanying drawings, in which:

Figure 1 is a front view of my relay;

Fig. 2 is a side view, with certain parts broken away to show some details, of the subject-matter shown in Fig. 1;

Fig. 3 is a circuit diagram showing my invention schematically as used with a direct current motor; and

Fig. 4 is a circuit diagram showing my invention schematically as used with an alternating current motor.

In Figures 1 and 2 of the drawings, l designates the base upon which all the elements of my novel device are mounted. This base I is, as shown, suitably connected to the cross bars 2 and 3 for mounting the base in a vertical position on a control panel board, or other structure. My device has general utility but was devised with particular reference to the needs of the United States Navy. This novel structure, in addition to being inexpensive, simple and reliable, is compact and is not materially affected by shocks to which war vessels, on which my device finds use, are often subjected.

A face plate 4 is disposed in spaced relation to the base I and is, as shown, rigidly secured to the base I. This face plate has an opening 5 through which the pinion 6 projects. This pinion 5 is keyed to shaft 1 to rotate with shaft 1 but may be axially adjusted on this shaft. The purpose of this adjustment is to obtain proper positioning of thedisc relative to the other parts of my device and to obtain some slight variation in the time constant of my device.

Shaft 'l is freely rotatable in members 8 and 9. Member 8 is adjustably mounted in the base I and held to its adjusted position by the lock nuts 9. Member 9 is rigidly secured to the face plate 4 by the bolts I0 and is held in spaced relation to face plate 4 by the spacers l I. The spacing and adjustment of members 8 and 9 are such that shaft I is very freely rotatable in the members 8 and 9.

The bolts II! also hold a pair of brackets I2 and 13 of insulating material for holding the flexible, and thus movable, contact member 58 and the rigid contact member 51, respectively. The face plate 4 is also provided with a stud shaft l5 upon which is mounted, for free rotation, the gear sector H5. The gear teeth ll of this sector 16 meshes with the pinion 6.

The sector I6 is provided with a switch actuating stud 18, which stud, made of suitable insulation, operates to close the circuit at contact members 51 and 58 when the sector is rotated to its extreme counterclockwise position. A spring 20 of suitable characteristics and under any adjusted tension is disposed between the adjusting means I4. This adjusting means comprises the bracket 49, stud bolt 48, and nut 41. The plate 9 is also provided With'a plurality of holes 45 so that rough adjustments of the tension of spring 20 may be made by shifting the upper attachment of the spring and for a finer adjustment the nut 41 may be operated to different positions on the bolt 48.

The spring 20 normally actuates the sector IE to its extreme counterclockwise position so that the sector 16 normally rests against the righthand side of stop 2|. When in this position to engage stop 2!, the contact members 5'! and 58, acted upon by stud [8, are closed.

From the foregoing description of the face plate 4 and the description of the elements secured to it, it is apparent that the entire face plate assembly may be removed as a unit by merely removing the screws 22 and 23.

The shaft 1, shown more clearly in the cut away portion of Fig. 2, is provided with a disc 24 of aluminum, copper, silver, or some other conducting metal. This disc 24 is loosely mounted on the shaft and is held in operative relation to the pinion 6, and thus the shaft 1, by the friction clutch disc 25. This friction disc 25 is biased against the disc 24 and thus the pinion 6 by the suitably loaded compression spring 26 disposed between the friction member 25 and washer 21 loosely mounted on shaft 1 and held in axial position on shaft 1 by the pin 28. It will be noted that the shaft and all the parts on it may be removed as a unit, after removal of the face plate 4, without affecting the position of the other elements of the relay.

By means of suitable studs n the base I, I mount four coils, 66, 68, 69 and having their axes normal to the disc 24. These coils are con nected in series to a suitable source of direct current, a shown in Fig. 3 and as represented by the rectifier 11 in Fig. 4. To vary the flux density of the flux disposed transverse the disc 24 the adjustable resistor or rheostat 61 is provided.

Disposed on the lower right-hand position of the base I is a voltage responsive solenoid 29. This solenoid has a rectangular C-sh'aped construction with the coil 53 of the solenoid disposed within the C. An armature 30 is disposed within the coil and is axially moved toward the right with a rapid movement when the coil is energized. The armature is guided within the coil by suitable facing U-shaped non-magnetic guides 3| and 32. This provides for free movement of the armature.

Th'e left-hand end of the armature is provided with a rod 33 guided for horizontal movement by the lugs 34 and 35. This rod is provided with a projecting bent arm 36 disposed to engage pin 31 on the lower arm 38 of the sector l6, A spring 39 of considerable strength and under tension is hooked to the rod at 40 and to a stud 4| on the base I. When the solenoid coil is deenergized the armature moves to the left under the action of spring 39. Thi spring 39 is selected sufiiciently strong to overcome spring so that when the solenoid coil is deenergized arm 36 acting on pin 31 rotates sector |6 rapidly clockwise without rotating disc 24 through pinion 6. The friction disc permits this kind of operation.

When the solenoid coil 53 is energized arm 36 is moved to the right without affecting or operating on pin 31 to alter the position of pin 31 on the lower projection 38. The sector I6 is thus freed to be actuated counterclockwise by the spring 20. The speed of operation of the section I6 in the counterclockwise direction is delayed by the eddy currents in disc 24 caused by the density of the flux disposed transverse of the disc 24.

Since the distance of the disc 24 from the adjacent ends of the coils 66, 68, 69 and 10 may be varied by the axial movement of the pinion 6 by the nuts 9', since the position of stop l8 on the sector |6 may be changed angularly, and since the current strength of the coils 66, 68, 69 and 10 may be varied by rheostat 61, and further since the tension of spring 26 is adjustable, and also since the gear ratio between the disc 24 and sector l6 can be changed, it is apparent that; the time of movement of sector l6 in the counterclockwise direction may be varied over a very wide range.

In many applications and particularly on board ship many automatically restarting motors are connected to the same source of supply. In the event of a voltage failure it is imperative, when voltage returns to the supply system, that the motors or other loads be not connected to the supply at the same time. The preferred operation is the reconnection of the various loads to the supply in a definite sequence. By using one of my relays for each of the loads and adjusting my timing relays for the respective loads for different time constants, the required sequence may be obtained.

Assuming that motor M, Fig. 3, is in one load unit as above mentioned. For normal operation of load unit M, switch 5| is closed whereupon a circuit is established from bus 50 through switch 5|, conductor 52, solenoid coil 53 and conductor 54 to bus 55.

The armature 30 is thus rapidly moved to the right releasing the sector I6 to the control of spring 20 and the action of coils 66, 68, 69 and 10, which are also energized by the closure of switch 5|. Afte a definite time, depending on the adjustments of nuts 9', nut 41, and rheostat 61, contact members 51 and 58 are closed.

Closure of contact members 51 and 58 establishes a circuit from energized conductor 52 through coil 56 of relay 56, contact members 51 and 58, strip 59 and conductor 60 to bus 55. Operation of relay 56 closescontact members 6| and 62. The relay is held in by contact members 6| and the coil 63 of the line switch is energized and the motor M is thus connected to the buses 50 and 55 by contact members 64 and 65.

In the event of a voltage failure, all the parts move to the position shown in Fig. 3 except that switch 5| is closed. When voltage returns on the buses 50 and 55, the sequence above described is reenacted.

In the showing in Fig. 4, when switch 1| is closed a circuit is established from bus 10' through switch 1|, conductor 12, contact members 13, coil 53, and conductor 14 to bus 15. Another circuit is established from conductor 12 through contact members 16, rectifier 11 to energized conductor 14. From the direct current terminals of the rectifier the coils 66, 68, 69 and 10 are thus energized.

After a predetermined time, contact members 51 and 58 close whereupon a circuit is established from energized conductor 12 through coil 18 of the line contacto 19, strip 59 and conductor to lens 15.

Operation of line contactor 19 causes the closure of contact members BI, 82, 83 and 84. The motor is thus energized and the line contactor is held in by the circuit through contact members 84. Opening of contact members 13 and 16 removes the energization from the time limit relay.

Upon voltage failure, the condition of the circuits is again as shown in Fig. 4 except switch 1| is closed. When the voltage comes back on the buses the cycle above recited is repeated.

From the foregoing, it will be apparent that I have provided a simple and eflicient time limit device which, when properly designed, can produce any selected time constant from one second to twenty-five seconds, or more, particularly if the gear ratio between disc and sector is increased.

Since both coil 53 and the magnets 66, 68, 69 and 10 are deenergized simultaneously, the relay will reset very fast. The disc is then turned rapidly in clockwise direction by spring 39, without being retarded. Whether or not the clutch 25 slips is not very important for this operation' However, the clutch 25 is of particular value if, instead of the coils, permanent magnets are used for damping. In this case, spring 20 should be too weak to overcome clutch friction and spring 39 should be strong enough to exceed clutch friction.

My invention is not limited to the use of electromagnets but the reference characters 66, 68, 69 and 10 may as well designate permanent magnets.

My invention is not limited to the specific showing made but is only limited by the scope of the claims hereto appended.

I claim as my invention:

1. A time limit device of the direct current type comprising in combination, a source of direct current, a plurality of coils connected to said source of direct current, a base for the coils, said coils being mounted on the base with their axes in parallel relation and so that the ends of the coils fall in substantially the same plane, a rotatably mounted disc disposed a given distance from the ends of said coils and rotatable in a plane parallel to the plane defined by the ends of said coils, disc operating means including biasing means for normally biasing said disc to a given angular position, electromagnetic means having a spring-biased element for operating said disc when said electromagnetic means is deenergized to another angular position through said disc operating means, means operable by said electromagnetic means, when said electromagnetic means is energized, to release said disc operating means to thus release said disc for rotation to its first given angular position, said disc, being in the magnetic field of said coils, is thus retarded in its rotation to a selected speed for a selected period of time; and switching means operable by said disc at the end of its rotation to its first angular position.

2. A time limit device of the direct current type comprising in combination, a source of direct current, a plurality of coils connected to said source of direct current, a base for the coils, said coils being mounted on the base with their axes in parallel relation and so that the ends of the coils fall in substantially the same plane, a rotatably mounted disc disposed a given distance from the ends of said coils and rotatable in a plane parallel to the plane defined by the ends of said coils, means for adjusting the distance of the disc from the ends of the coils, disc operating means including biasing means for normally biasing said disc to a given angular position, electromagnetic means having a spring-biased element for operating said disc through said disc operating means to another angular position when said electromagnetic means is deenergized, means operable by said electromagnetic means, when said electromagnetic means is energized, to release said disc operating means to thus release said disc for rotation to its first given angular position, said disc, being in the magnetic field of said coils, is thus retarded in its rotation to a selected speed for a selected period of time, and switching means operable by said disc at the end of its rotation to its first angular position.

3. A time limit device of the direct current type comprising in combination, a source of direct current, a plurality of coils connected to said source of direct current, a base for said coils, means for adjusting the current traversing said coils to thus alter the fiux density at the ends of said coils, said coils being mounted on the base with their axes in parallel relation and so that the ends of the coils fall in substantially the same plane, a rotatably mounted disc disposed a given distance from the ends of said coils and rotatable in a plane parallel to the plane defined by the ends of said coils, disc operating means including biasing means for normally biasing said disc to a given angular position, electromagnetic means having a spring-biased element for operating said disc through said disc operating means to another angular position when said electromagnetic means is deenergized, means operable by said electromagnetic means, when said electromagnetic means is energized, to release said disc operating means to thus release said disc for rotation to its first given angular position, said disc, being disposed in the magnetic field of said coils, is thus retarded in'its rotation to a selected speed for a selected period of time, and switching means operable by said disc at the end of its rotation to its first angular position.

4. A time limit device of the direct current type. comprising in combination, a source of direct current, a plurality of coils connected to said source of direct current, a base for said coils, means for adjusting the current traversing said coils to thus alter the flux density at the ends of said coils, said coils being mounted on the base with their axes in parallel relation and so that the ends of the coils fall in substantially the same plane, a rotatably mounted disc disposed a given distance from the ends of said coils and rotatable in a plane parallel to the plane defined by the ends of said coils, disc operating means including biasing means for normally biasing said disc to a given angular position, means for adjusting the biasing force of said .disc biasing means, electromagnetic means having a spring-biased element for operating said disc through said disc operating means to another angular position when said electromagnetic means is deenergized, means operable by said electromagnetic means, when said electromagnetic means is energized, to release said disc operating means to thus release said disc for rotation to its first given angular position, said disc, being disposed in the magnetic field of said coils, is thus retarded in its rotation to a selected speed for a selected period of time, and switching means operable by said disc at the end of its rotation to its first angular position.

5. A time limit device of the direct current type comprising in combination, a source of direct current, a plurality of coils connected to said source of direct current, a base for said coils, means for adjusting the current traversing said coils to thus alter the flux density at the ends of said coils, said coils being mounted on the base with their axes in parallel relation and so that the ends of the coils fall in substantially the same plane, a rotatably mounted disc disposed a given distance from the ends of said coils and rotatable in a plane parallel to the plane defined by the ends of said coils, means for adjusting the distance of the disc from the ends of the coils, disc operating means including biasing means for normally biasing said disc to a given angular position, electromagnetic means having a spring biased element for operating said disc through said disc operating means to another angular position when said electromagnetic means is deenergized, means operable by said electromagnetic means to release said disc operating means to thus release said disc for rotation to its first given angular position, said disc, being disposed in the magnetic field of said coils, is thus retarded in its rotation to a selected speed for a selected period of time, and switching means operable by said disc 'at the end of its rotation to its first angular position.

6. A time limit device of the direct current,

type comprising in combination, a source of direct current, a plurality of coils connected to said source of, direct current, a base for said coils, means for adjusting the current traversing said coils to thus alter the flux density at the ends of said coils, said coils being mounted on the base with their axes in parallel relation and so that the ends of the coils fall in substantially the same plane, a rotatably mounted disc disposed a given distance from the ends of Sflildi coils and rotataliilev in a plane parallel to the plane defined by the ends of said coils, disc operating means including biasing means for normally biasing said disc to a given angular position, means for adjusting the biasing force of said disc biasing means, electromagnetic means having a spring-biased element for operating said disc: through said disc operating means to another angular position when said electromagnetic means is deenerg'imd, means operable by said electromagnetic means to release said disc operating means to thus release said: disc for rotation to its first given angular position, said being disposed in the magnetic field oi! said coils, is thus retarded in its rotation to a selected speed for a selected period of time, and switchhug means operable by said disc at the end of its rotation to its firstangular position.

7. A time limit device of the direct current type comprising combination, a source of direct current, a plurality 0t coils connected to said sum-cc of direct current, a base for said coils, means for adjusting the current traversing said coils to thus alter the flux density at the ends of said coils, said coils being mounted on the base with their axes in parallel relation and so that the ends of the coils fall in substantially the same plane, a rotatably mounted disc disposed a given distance from the ends of said coils and rotatable in a plane parallel to the plane defined by the ends of said coils, means for adjusting the distance of the disc from the ends of the coils, disc operating means including biasing means for normally biasing said disc to a given angular position, means for adjusting the biasing force: of said disc biasing means, electromagnetic meansv having a spring-biased element for operating said disc through said disc operating means to another angular position when said electromagnetic means is deenerglzed, means. operable by said electromagnetic means to release said disc operating means to thus release said disc for rotation to its first given angular position, said disc, being disposed in the magnetic field of saidcoils, is thus retarded in its rotation to a selected speed for a selected period of time, and switching means operable by said disc at the end of its rotation to its first angular position.

KURT MAHNKE.

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