US2410325A - Delayed action relay - Google Patents

Description

Oct. 29, 1946. YARDENY I 2,410,325

DELAYED ACTION RELAY Original Filed Sept. 20, 1940 8 F1 chi O 16 4 Z* MW 17 i 2; 4

MCHEL M YA RDENY INVENTOR Q 5; 1 Many ATTORNEY Patented Oct. 29, 1946 UNITED STATES PATENT OFFICE DELAYED ACTION RELAY Michel N. Yardeny, New York, N. Y.

Original application September 20, 1940, Serial No. 357,660. Divided and this application September 11, 1943, Serial No. 502,055

2 Claims. 1

My invention relates to delayed action relays and has particular reference to relays in which the movable part of the relay is retarded in its movement.

This is divisional application of my United States application, Serial No. 357,660, filed September 20, 1940, now Patent No. 2,342,717, granted February 29, 1944. In this application, I disclosed as a part of my electrical control system, a relay in which the armature or movable part of the relay moves rapidly toward the magnet part of the relay when it is magnetized, thereby rapidly closing the circuit of a motor by the relay contacts, but is released slowly when relay is demagnetized, thereby allowing other parts of the control system to attain stable condition of rest before the motor is finally deenergized. Such delayed action is particularly important and useful when the motor in the system is stopped by dynamic braking or by other method in which current is required to accomplish the stopping. The delayed action relay is used in such an arrangement to deenergize the motor after electrical con-- ditions have been established for stopping the motor. In my system, as described in the foregoing application, the motor is stopped when the control device, operated by the motor, reaches a desired position in which a larger current is sent through the system, and the increased current is used to trip the relay and, at the same time, to stop the motor. It is evident that under such condition it is essential that a certain interval of tim should elapse after the relay is deenergized to allow the motor to be completely stopped before t e current is shut oil" by the relay.

The principle itself of delayed action relay is not new but previously known relays of that type were of rather complicated construction, involving the use of dash pots and other mechanical and electrical mechanisms to accomplish delayed action.

The high cost of such relays, as well as their relatively large sizes, render them unsuitable for certain applications in which small and inexpensive relays are required. With this object in view, have developed a delayed action relay which is of approximately the same size and cost as an ordinary quick-acting relay, the delayed action being obtained by the simple expedient of applying a layer of a non-drying viscous sticky or gummy substance to the face of the relay magnet and/or to the face of the relay armature. My relay therefore, acts quickly when magnet is energized, but because of high viscosity of the gummy substance, separation of the armature from the magnet takes an appreciable interval of time, sufficient for many purposes for which delayed action relays may be used.

My invention is more fully described in the accompanying specification and drawing in which:

Fig. l is a plan view of my relay;

Fig. 2 is a diagram of electric connections of a relay with two coils;

Fig. 3 is a fractional View on enlarged scale of the gummy layer.

My relay can be built in a variety of shapes and types to suit different requirements, and in Fig. 1 is shown by way of an example a construction which can be used with my invention. The relay consists of an iron core I with two coils or windings 2, 3 (although, of course, one coil can be used if desired), with leads 4, 5, 4', 5. An armature 6, also of iron, is mounted on a spring I, rigidly supported at 8. An insulation block 9 is fastened to the armature and engages a light spring l0 supported at I l and connected to a lead 12 of an electric circuit which is controlled by the relay. Spring I0 is provided with a contact point l3 which engages a similar contact point M on another contact spring l5 supported on a post [6 and having a lead [1, forming part of the controlled circuit. The contacting surfaces of the core I and armature 6 are provided with layers I8, [9 of a viscous non-drying gummy substance, such as solution of latex in kerosene, vinyl alcohol, emul- .ion of latex with protein glue, etc. which materially retards separation of the contacting surfaces. Action of the gummy substance is more clearly shown in Fig. 3. The layers l8, l9 adhere together when the armature B is attracted, and when the core I is demagnetized, the gummy substance breaks up into separate strings or filaments 2!), gradually becoming thinner until they finally break apart. This process of viscous stretching of the filaments consumes a certain amount of time.

Such delayed action may be needed in a variety of applications to electric circuits, one of which is illustrated by way of an example inFig. 2. The relay coils 2, 3 are wound in the opposite directions so that the core l is magnetized only when one of the coils 2, 3 is energized by closing one of the switches l, 22, for instance, 2 I with the main switch 23 also closed as well as a starting push button 24. The armature 6 then becomes attracted to the core I, the layers l8 and I9 joining each other. As a result, current from the battery 25 will flow through one of the reversing field windings 26, 21, and th motor will rotate in a. corresponding direction. For stopping the motor,

the second switch 22 is closed thereby energizing both field windings and stopping the motor by the opposing currents and electromotive forces. As soon as the motor is stopped, however, it may be desirable to disconnect the motor circuit even if the switches are left closed. This is accomplished by the provision of the two opposing relay windings 2 and 3 which demagnetize the relay core I when energized at the same time causing the motor circuit to be disconnected. It is very important, however, that the motor should be completely stopped by the opposing currents before its circuit is interrupted, and the relay, therefore, must be of delayed action type. This purpose is satisfactorily accomplished by the use of the adhesive cement I8, I9,

I have found that good results are obtained by using a gummy substance prepared with rubber, preferably latex dissolved in a non-evaporating solvent, such as kerosene. A layer of such a composition lasts under ordinary operating conditions for over a year, which is quite sufficient ior ordinary purposes, The layer, when it becomes ineflective, can be easily repaired or renewed by the application of fresh composition. I have found that good results are obtained when the thickness of such a layer is from about .010 to about .030 inch.

It is understood that my delayed action relay may be further modified without departing from the spirit of the invention, as set forth in the appended claims.

I claim as my invention:

1. A delayed action relay comprising a stationary member and a movable member, one of the members being arranged to be energized for causing mutual attraction between the members while one of the members is energized, a portion of each member being arranged to contact a corresponding portion of the other member in response to one of the members being energized, and a layer of an adhesive viscous substance applied to one of the contacting portions for retarding separation of the movable member from the stationary member in response to deenergizing the energized member.

2. A delayed action relay comprising a stationary electromagnet including a core and a movable armature, means for energizing the electromagnet for causing attraction between the armature and the core while the electromagnet is energized, the armature being arranged to contact the core in response to being attracted by the core, and a layer of an adhesive viscous substance applied to at least one of the contacting surfaces for retarding separation of the armature from the core in response to deenergizing the electromagnet.

MICHEL N. YARDENY.

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