US2671836A

US2671836A - Electromagnetic relay

Info

Publication number: US2671836A
Application number: US152594A
Authority: US
Inventors: Ernest G Anger; Robert C Mierendorf
Original assignee: Square D Co
Current assignee: Schneider Electric USA Inc
Priority date: 1950-03-29
Filing date: 1950-03-29
Publication date: 1954-03-09
Anticipated expiration: 1971-03-09

Description

ELECTROMAGNETIC RELAY Filed March 29, 1950 x1. /j INVENTORS.

1 7716.97 6. in er: fiaZer? CfM'ereruZorf Patented Mar. 9, 1954 ELECTROMAGNETIC RELAY Ernest G. Anger, Wauwatosa, and Robert C.

Mierendorf, Milwaukee, Wis.,

assignors to Square D Company, Detroit, Mich, a corporation of Michigan Application March 29, 1950, Serial No. 152,594

12 Claims. 1

This invention relates to an electromagnetic relay and more particularly to an electromagnetic relay which is especially designed to close an electric circuit controlled by the relay with certainty and with no faulty operation of the electric circuit occurring due to unwanted momentary opening of the relay contacts immediately after closure thereof.

One object of the present invention is the provision of an electromagnetic relay which is especially useful for triggering an associated elec trical circuit and which comprises a bridging contact element carrying a pair of movable contacts which cooperate with a pair of fixed contacts, the spacing between one of the fixed contacts and one of the movable contacts being different from that between the other of the fixed contacts and the other of the movable contacts so as to nullify the effect of initial contact bounce.

Another object of the present invention is the provision of a relay in accordance with the preceding objects and in which a core is magnetized by an energizing coil and attracts a movable armature, the armature having a movable interior member which prevents any momentary tendency of the armature to move toward deenergized position immediately after reaching the limit of the energized stroke.

Another object of the present invention is the provision of an electromagnetic relay in accordance with the preceding objects in which the movable contacts are closed upon the fixed contacts in accordance with the movement of an armature, the armature having an internal weight which operates to compress a spring as the armature reaches fully energized position, the spring transmitting its energy to the armature to prevent its movement away from the core immediately upon reaching the fully energized position.

Other objects and features of the invention will be readily apparent to those skilled in the art from the specification and appended drawing illustrating certain preferred embodiments in which:

Figure 1 is a front elevational view of the device of the present invention.

Figure 2 is an enlarged view around the lines III[ of Figure 1.

Figure 3 is a detailed sectional view along the lines III-I1I of Figure 2.

The device of the present invention comprises a metallic mounting plate I provided with suitable apertures for firmly fixing the device to a surface, to which there is secured, as by welding, one leg of an inverted, generally U-shaped bracket member 2 which cooperates with an L- shaped bracket member 3 attached thereto by suitable studs 4 to mount an energizing coil 5 in position. The

brackets

2 and 3 are of magnetic material to provide an exterior path for the magnetic flux. The energizing coil 5 has terminals e and 1 which may be connected in an energizing circuit, while suspended from bracket 2 within the coil '5 is a core of magnetic material 8, which mounts a sleeve member 9 about which the energizing coil 5 is disposed. The core 8 has a central opening through which extends an armature rod H for reciprocatory motions therethrough.

Upon the lower end of the armature rod II, as viewed in Figure 2, is mounted an armature assembly generally designated by the numeral l2. The exterior of the armature assembly [2 comprises an inverted, generally cup-shaped member I3 through which the armature rod ll projects. A bushing l4 and movable weight l5 are provided about a portion of the armature rod II within the cup-shaped member [3. A washer I1 is provided to close the open end of the cup-shaped member [3, the washer l1 fitting against one end of the bushing i4 and clamping the member l3 on the rod ll through the nut [8. A spring l6 about the bushing l4 and between the base of member 12 and the weight l5 biases the weight against the washer I! in the normal position of the parts.

The upper end of the armature rod ll carries a movable contact assembly [9, studs 2| serving to clamp a base 22 of insulating material to the upper end of the armature rod II, the studs 2| cooperating with a suitable bracket 23 to accomplish this purpose. Mounted along the u per edge of the insulating base member 22 is a movable contact structure shown particularly in Figure 3, this structure consisting of a fixed outer enclosure of general U shape 24 having inwardly directed retaining flanges and which is fixedly secured to the base member 22. A spring 25 is disposed within the U-shaped member 24 and supplies contact pressure by biasing a bridging contact element 26 away from the insulating base 22, the ends of the bridging element 26 being provided with

movable contacts

21 and 28. Disposed in position to cooperate with the

contacts

21 and 28 are fixed

contacts

29 and 30 mounted on insulating plate 33 and having terminals 32 and 3| respectively, projecting through the plate for connection to the circuit to be controlled.

The fixed contacts are mounted at different distances from the under surface of plate 33 as by the spacing washers 34 above contact 29 so that the distance between the movable contacts 28 and the fixed contact 30 is greater than the distance between the other movable contact 21 and the fixed contact 28.

The operation of the device will now be described. When the energizing coil 5 is deenergized, the armature and the contacts occupy the position indicated by full lines in the Figure 2, the armature being fully retracted away from the core member 8 and the movable contacts 2'! and 28 occupying a position which is generally horizontal as viewed in Figure 2. When the energizing coil 5 is energized, the armature assembly I2 is attracted toward the fixed core 8 and moves upwardly to decrease the air gap therebetween. As the armature assembly approaches the fixed core member 8, the contact 21 will first strike against the contact 29 with animpact which may cause the contact 21 to rebound from the contact 29, tilting the conducting bar 26 against the bias of the spring 25. The spring 25, however, will cause the

contacts

21 and 29 to rapidly reclose and to finish bouncing before contacts 28 and 38 engage to close the circuit through the relay. When the electrical circuit connected between the terminals 3| and 32 is one which requires an instantaneous pulse of current, it will be seen that the relay of the present invention will provide just such pulse at the instant when the contact 28 closes upon fixed contact 30, as the rebound between the movable contact 21 and the fixed contact 23 has already occurred and these contacts are once again together. Consequently, in a circuit requiring just such a pulse, the current will flow through the aforementioned electrical route between the terminals 3 I and 32 and subsequent bounce between contacts!!! and 30 will be of no consequence. It has been found that this type of relay is particularly effective in controlling the conduction of anignitron and prevents variation in firing due to erratic duration of bounce of the standard contact construction.

As the armature assembly i2 closes upon the core 8, the armature rod ll carries the base member l2 upward until the U-shaped member 24' is in position indicated by dotted lines in Fig ure 2, in which case the conducting bar 26 is at an angle with respect to the horizontal as viewed in-F'igure 2, the spring 25 exerting a force upon the conducting bar 26 which tends to firmly hold the movable contact against the fixed contacts.

If the energizing coil 5 should be located in an energizing circuit subject to transient low voltage conditions, or in a circuit in which a resonating reactor is employed which would tend to reverse the direction of current flow through the energizing coil momentarily after energization of the coil 5, the armature i2 might tend to drop out immediately after closing upon the core member 8. The relay of the present invention has, there fore, been provided with the movable weight l5 which acquires kinetic energy as the armature member I2 is moved toward the core member 8 when the energizing coil 5 is energized, and at the end of the upward stroke of the armature assembly I2 the movable weight dissipates this kinetic energy in the spring l5, resulting in a force being exerted upon the inner surface of the cup-shaped member [3 just following the instant at which the armature assembly reaches the upwardmost portion of its stroke. This upward thrust is exerted to aid in maintaining the contacts closed should any instantaneous deenergization of the energizing core '5 tend to occur at this critical instant.

It will, therefore, be seen that the device of the present invention provides the particularly advantageous result of closing an associated electrical circuit with certainty and insuring that a controlled electrical circuit receives a pulse of energy independent of any contact bounce or any momentary adverse conditions in the circuit controlling the energizing coil employed. As has been earlier indicated, the device of the present invention has been found to be of particular advantage in controlling the electrical circuit of ignitors. used tofire ignitrons, and especially in such a circuit where. a resonating reactor is employed in' series with the energizing coil, the movable weight as previously described overcoming the effect of the resonating reactor which might tend to open the contacts by deenergization of the energizing coil just after the armature has reached its fully operated position.

While certain preferred embodiments of the invention have beenspecifically disclosed, it is understood that the invention is not limited thereto, as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims:

What is claimed is:

1. In an electromagnetic relay, fixed contacts, movable contacts cooperating with said fixed contacts, an armature, an energizing coil for effecting movement of said armature upon energization and deenergization of said energizing coil, means connecting said armature to said movable contacts, said armature comprising an outer en-.

closure having an internal spring and an internal Weight, said weight being movable relative to said outer enclosure and acting to compress said internal spring immediately after said armature reaches its fully operated position whereby the kinetic energy of said movable weight is utilized to prevent an immediate movement of said armature away from its operated position.

2. In an electromagnetic relay, fixed contacts, movable contacts cooperating with said fixed contacts, an armature, an energizing coil for effecting movement of said armature upon energization and deenergization of said energizing coil, means connecting said armature to said movable contacts, said armature comprising a cylindrical outer member having a spring and movable weight therein, said spring being interposed between said movable weight and the end of said cylindrical outer member nearest said movable contacts, said weight acting to compress said internal spring immediately after said armature reaches its fully operated position whereby the kinetic energy of said movable weight is utilized to prevent an immediate movement of said armature away from its operated position.

3. In an electromagnetic relay, fixed contacts, movable contacts cooperating with said fixed contacts, an armature, an elongated rod connecting said armature to said movable contacts, an energizing coil for eifecting movement of said armature upon energization and deenergization of said energizing coil, said armature comprising an outer cylindrical shell having an internal spring and an internal movable weight, said elongated rod extending into the interior of said outer shell, said internal spring and weight being disposed about the section of said elongated rod which extends into said cylindrical shell and guided thereby, the weight moving relative to said outer cylindrical shell and acting to compress said internal spring immediately after said armature reaches its fully operated position whereby the kinetic energy of said movable weight is utilized to prevent an immediate movement of said armature away from its operated position.

4. In an electromagnetic relay, fixed contacts, movable contacts cooperating with said fixed contacts, an armature member, an energizing coil for effecting movement of said armature upon energization of said energizing coil, an elongated rod having one end connected to said movable contacts and one end to said armature member, said armature member including a bushing surrounding at least a section of said rod, a spring surrounding a first section of said bushing, a movable weight surrounding a second section of said bushing, said second section being contiguous to said first section and further from the end of said elongated rod connected to said movable contacts than said first section, and a hollow cylindrical shell surrounding said bushing, spring and weight, one end of said spring abutting against an inner end surface of said cylindrical shell while the other end of said spring abuts against said movable weight, said movable weight being movable relative to said cylindrical shell and acting to compress said internal spring immediately after said armature member reaches its fully operated position whereby the kinetic energy of said movable weight is utilized to prevent an immediate movement of said armature away from its operated position.

5. In an electromagnetic relay, an energizing coil, an armature adapted for reciprocatory motion relative to said energizing coil upon energization and deenergization of said coil, a bridging conducting member having a pair of movable contacts thereon, means for moving said member and movable contacts in response to the movement of said armature including a resilient mounting therefor, fixed contacts cooperating with said movable contacts, the open circuit gap between one of said fixed contacts and one of said movable contacts normally being different than that between the other of said fixed contacts and the other of said movable contacts whereby said one of said movable contacts closes upon its 00- operating fixed contact before the other of said movable contacts closes upon its associated fixed contact as said armature moves to fully operated position, said resilient mounting biasing the movable contacts against the stationary contacts when closed, said armature comprising an outer enclosure having an internal spring and an internal weight, said weight being movable relative to said outer enclosure and acting to compress said internal spring immediately after said armature reaches its fully operated position whereby the kinetic energy of said movable weight is utilized to prevent an immediate movement of said armature away from its operated position.

6. In an electromagnetic relay, an energizing coil, an armature adapted for reciprocatory motion relative to said energizing coil upon energization and deenergization of said coil, a bridging conducting plate having spaced contacts thereupon, means for moving said conducting plate and contacts carried thereby in response to the movement of said armature, a bracket and a centrally disposed spring for normally positioning said conducting plate in a predetermined plane, fixed contacts for cooperating with the movable contacts, the distance between one of said fixed contacts and the movable contact with which it cooperates normally being different than the distance between the other fixed contact and its cooperating movable contact so that said one set of contacts engages first as the armature moves toward closed position, said conducting plate moving out of said predetermined plane against the bias of said spring as said armature moves to fully operated position upon energization of said energizing coil, said armature comprising an outer enclosure having an internal spring and an internal weight, said weight being movable relative to said outer enclosure and acting to compress said internal spring immediately after said armature reaches its fully operated position whereby the kinetic energy of said movable weight is utilized to prevent an immediate movement of said armature away from its operated position.

'7. In an electromagnetic relay, an energizing coil, an armature adapted for reciprocatory motion relative to said energizing coil upon energization and deenergization of said energizing coil, a bridging conducting member having a pair of movable contacts thereon, means for moving said member and movable contacts in response to the movement of said armature including a re silient mounting therefor, fixed contacts cooperating with said movable contacts, the open circuit gap between one of said fixed contacts and one of said movable contacts normally being different than that between the other of said fixed contacts and the other of said movable contacts whereby said one of said movable contacts closes upon its cooperating fixed contact before the other of said movable contacts closes upon its associated fixed contact as said armatue moves to fully operated position, said resilient mounting biasing the movable contacts against the stationary contacts when closed, said armature comprising a cylindrical outer member having a spring and movable weight therein, said spring being interposed between said movable weight and the end of said cylindrical outer member nearest said movable contacts, said weight acting to compress said internal spring immediately after said armature reaches its fully operated position whereby the kinetic energy of said movable weight is utilized to prevent an immediate movement of said armature away from its operated position.

8. In an electromagnetic relay, an energizing coil, an armature adapted for reciprocatory motion relative to said energizing coil upon energization and deenergization of said coil, a bridging conducting plate having spaced contacts thereupon, means for moving said conducting plate and contacts carried thereby in response to the movement of said armature, a bracket and spring for normally positioning said conducting plate in a predetermined plane, fixed contacts for cooperating with said spaced contacts, the distance between one of said fixed contacts and the movable contact with which it cooperates normally being different than the distance between the other fixed contact and its movable contact so that said one set of contacts engages first as the armature moves toward closed position, said conducting plate moving out of said predetermined plane against the bias of said spring as said armature moves to fully operated position upon energization of said energizing coil, said armature comprising a cylindrical outer member having a spring and movable weight therein, said spring being interposed between said movable weight and the end of said cylindrical member nearest said movable contacts, said weight acting to compress said internal spring immediately after said armature reaches its fully operated position whereby the kinetic energy of said movable weight is utilized to prevent an immediate movement of said armature away from its operated position.

9. In an electromagnetic relay, an energizing coil, an armature adapted for reciprocatory motion relative to said energizing coil upon energization and deenergization of said coil, a pair of fixed contacts, electrical conducting means for bridging the space between said fixed contacts, said last mentioned means comprising a strip of conducting material having a centrally disposed resilient mount, said fixed contacts being spaced both laterally and in the direction of movement of said movable contacts, means connecting said armature to said bridging means whereby said bridging means is moved in response to the move ment of said armature, said bridging means moving into contact with said fixed contacts against the bias of its resilient mounting as said armature moves to operated position upon energization of said energizing coil, said armature comprising a cylindrical outer member having a spring and movable weight therein, said spring being interposed between said movable weight and the end of said cylindrical member nearest said movable contacts, said weight acting to compress said internal spring immediately after said armature reaches its fully operated position whereby the kinetic energy of said movable weight is utilized to prevent an immediate movement of said armature away from its operated position.

10. In an electromagnetic relay, an energizing coil, an armature member adapted for recipro catory motion relative to said energizing coil upon energization and deenergization of said coil, a bridging conducting member having a pair of movable contacts thereon, means for moving said member and movable contacts in response to the movement of said armature including a resilient mounting therefor, fixed contacts coopcrating with said movable contacts, the open circuit gap between one of said fixed contacts and one of said movable contacts normally being different than that between the other of said fixed contacts and the other of said movable contacts whereby said one of said movable contacts closes upon its cooperating fixed contact before the other of said movable contacts closes upon its associated fixed contact as said armature member moves to fully operated position, said resilient mounting biasing the movable contacts against the stationary contacts when closed, said means for moving said conducting plate comprising an elongated rod having one end connected thereto and one end to said armature member, said armature member comprising a bushing surrounding at least a section of said rod, a spring surrounding a first section of said bushing, a movable weight surrounding a second section of said bushing, said second section being contiguous to said first section and further from the end of said elongated rod connected to said movable contacts than said first section, and a hollow cylindrical shell surrounding said bushing, spring and weight, one end of said spring abutting against an inner end surface of said cylindrical shell While the other end of said spring weight being movable relative to said cylindrical shell and acting to compress said internal spring immediately after said armature reaches its fully operated position whereby the kinetic energy of said movable weight is utilized to prevent an immediate movement of said armature away from its operated position.

11. In an electromagnetic relay, an energizing coil, an armature adapted for reciprocatory motion relative to said energizing coil upon energization and deenergization of said coil, a bridging conducting plate having spaced contacts thereupon, means for moving said conducting plate and contacts carried thereby in response to the movement of said armature, a bracket and spring for normally positioning said conducting plate. in a predetermined plane, fixed contacts for cooperating with said spaced contacts, the distance between one of said fixed contacts and the movable contact with which it cooperates normally being diiferent than the distance between the other fixed contact and its cooperating movable contact so that said one set of contacts engages first as the armature moves toward closed position, said conducting plate moving out of its predetermined plane against the bias of said spring as said armature moves to fully operated position upon energization of said energizing coil, the mass of said conducting plate being proportioned to the strength of said mounting spring and the difierence in distances between one fixed contact and the other fixed contact and their cooperating movable contacts so that rebounding movement of the bridging means after engaging the first of said fixed contacts has ceased when the second of the pair of fixed contacts is engaged by said bridging means, an armature comprising a cylindrical outer member having a spring and movable weight therein, said spring being interposed between said movable weight and the end of said cylindrical member nearest said movable contacts, said weight acting to compress said internal spring immediately after said armature reaches its fully operated position whereby the kinetic energy of said movable weight is utilized to prevent an immediate movement of said armature away from its operated position.

12. In an electromagnetic relay, an energizing coil, an armature adapted for reciprocatory motion relative to said energizing coil upon energization and deenergization of said coil, a pair of fixed contacts, electrical conducting means for bridging the space between said fixed contacts, said last mentioned means comprising a strip of resiliently mounted conducting material, said fixed contacts being spaced both laterally and in the direction of movement of said movable contacts, means connecting said armature to said bridging means whereby said bridging means is moved in response to movement of said armature, said bridging means moving into contact with said fixed contacts against the bias of its resilient mounting as said armature moves to operated position upon energization of said energizing coil, the mass of said bridging means being proportioned to the strength of the resilient mount of said bridging means and the displacement of said fixed contacts in the direction of motion so that rebounding movement of the bridging means after engaging the first of the pair of fixed contacts has ceased when the second of the pair of fixed contacts is en aged by said bridging means, an armature comprising a cylindrical outer mem- References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re. 20,094 Wilms et a1 Sept. 1, 1936 Number Number Name Date Ferguson Sept. 26, 1911 Horton Mar. 5, 1912 Granberg June 4, 1940 Borgkvist Apr. 15, 1941 Ayers et a1 Jan. 6, 1948 Austin July 19, 1949 Shaw Nov. 15, 1949 Johnson Nov. 22, 1949 FOREIGN PATENTS Country Date Great Britain Dec. 15, 1927