US3895333A

US3895333A - Relay coil with open washer

Info

Publication number: US3895333A
Application number: US517579A
Authority: US
Inventors: Robert C Cressman
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1974-10-23
Filing date: 1974-10-23
Publication date: 1975-07-15
Anticipated expiration: 1992-07-15

Abstract

A relay switch is activated to a stay-on position or to a stayoff position by alternative operation of two axially aligned solenoid coils. The coils are wound on a single spool having two coil bays separated by a spacer. The spacer divides the spool into the two bays and contains a disc of magnetic material to keep the two magnetic circuits separated. The spool for prior art solenoid pairs were made up of separate spools which had to be assembled or had an insert molded magnetic disc and such spools were difficult and costly to produce. Now a two bay is first molded separately and the magnetic disc is then mounted to the spool center to complete and separate the magnetic circuits. The improved magnetic disc is in the form of a split ring which is opened at the split and which can be closed about and around a hollow core of the spool and about a magnetic plunger within the hollow core.

Description

United States Patent [191 Cressman July 15, 1975 l l RELAY COIL WITH OPEN WASHER Robert C. Cressman, East Greenwich, R].

[75] Inventor:

[73] Assignee: General Electric Company, New

York, NY.

22 Filed: on. 23, 1974 211 Appl. No.: 517,579

Sterenbuch el al..,. 335/299 X Schweitzer 336/176 X Primary ExaminerG. Harris Attorney, Agent. or Firm-l aul E. Rochford [57] ABSTRACT A relay switch is activated to a stay-on position or to a stay-off position by alternative operation of two axially aligned solenoid coils. The coils are wound on a single spool having two coil bays separated by a spacer. The spacer divides the spool into the two bays and contains a disc of magnetic material to keep the two magnetic circuits separated. The spool for prior art solenoid pairs were made up of separate spools which had to be assembled or had an insert molded magnetic disc and such spools were difficult and costly to produce. Now a two bay is first molded separately and the magnetic disc is then mounted to the spool center to complete and separate the magnetic circuits. The improved magnetic disc is in the form of a split ring which is opened at the split and which can be closed about and around a hollow core of the spool and about a magnetic plunger within the hollow core.

5 Claims, 6 Drawing Figures BACKGROUND OF THE INVENTION It is known that relay switches of the latching type operate very satisfactorily when a relatively low voltage is employed in activating a magnetic plunger within a relay to two at rest positions. Such relays use lowvoltage for control circuits but the circuits which are controlled are themsleves at line voltage or may be at higher voltages. For such low voltage activation, a first solenoid coil causes one actuation of the magnetic plunger to one of the at rest positions and a second solenoid coil causes a reverse action of the plunger within the switch to a second at rest position. The movement of the plunger controls the higher voltage switching according to teachings well known in the art. Such relay switching is taught in the US. Pat. No. such as 2.841.669 and the arrangements of circuits containing such relays are taught in the U.S. Pat. Nos. such as 3.l 18.039. 3,207,955 3,493.8l7, and 3,758,828. Prior art US. Pat. Nos. such as 1,236,357 and 2,453,725 teach slotted end pieces on coil supports.

When operated in a conventional fashion, latching type relay switches have two stable at rest positions and the switching elements can be moved to either of these positions by the energization of one of the two controlling solenoid coils. Because of the small sizes of the units which are used in remote control relay operation the solenoids themselves are quite limited in size and the magnetic field by which they are operated is quite limited. An important element defining the magnetic field in which the device operates is the magnetic element separating the two fields of the adjacent relay coils.

When properly formed. the spool itself is made ofin sulating nonmagnetic material. The spool also has at its midpoint a magnetic separating element which is effective in separating the fields of the two solenoids of the spools and which is part of the magnetic path of each solenoid.

In prior art devices. the separating element has been a metal ring having magnetic properties and this ring has been built into the spool by separate molding of separate spools, assembling the spools and ring on a hollow non-magnetic tube and crimping the tube ends to hold the assembled parts in place. To improve on this costly assembly technology. conventional insert molding manufacturing technology was then employed. However, the insert molding has sometimes produced damage to the tools forming the spool itself because of misalignment of the magnetic ring and impacting of the tools into the metal ring. In other cases. the insert molding has not worked well so that the needed metal magnetic rings are not properly enclosed and insulated.

It is highly desirable in the formation of a spool having the two coil base and having a magnetic spacer that these spacers be adequately aligned to provide separation of one of the magnetic fields from the other, and accordingly to avoid the movement of the plunger in some fashion which is not the intended or controlled fashion prescribed for the unit. In the operation of such a device. it is also important that there be an adequate insulating wall between the magnetic element and the coil as there is vibration attendant to the movement of the plunger within the spool and there is accordingly a chance that the magnet wire of the winding will shear its insulating coating and will make contact with the 2 metal magnetic spacer. Accordingly, it is desirable that the magnetic material be adequately insulated by disposition at its surface of an insulating layer of adequate thickness.

OBJECTS OF THE INVENTION It is accordingly one object of the present invention to provide a low cost reliable relay switch.

Another object is to provide an improved reliable solenoid arrangement for a relay switch at lower cost.

Another object of the invention is to provide an improved spool for the solenoid coils of a double acting remote control switch.

A further object is to provide an improved method of assembly of the spool of a solenoid unit for a remote control unit.

Other objects will in part be apparent and in part pointed out in the description which follows.

SUMMARY OF THE INVENTION A relay coil is formed by providing a two bay spool of non-magnetic material having a ring of magnetic ma terial spaced between the two bays of the spool. The spool itself is of insulating and non-magnetic material, has a hollow core which accomodates a magnetically actuatable plunger and is preferably molded with four integral flanges. Two end flanges define the outer ends of the coil bays. The two center flanges are spaced to accomodate a split ring of magnetic material therebetween. The split ring is split at one side and is partially split or internally notched at the opposite side to permit the ring to be hinged closed at the notch. In the opened condition in which the ring is formed. the split ring is mounted by insertion between the center flanges ofthe spool and the ring is then closed to form a grip about the hollow center shaft of the spool.

The manner in which objects of the invention may be achieved will be made clear by reference to the accompanying drawing in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an arrangement of magnetic solenoids on a two bay spool as used in connection with a remote control relay.

FIG. 2 is a side elevation of the spool of a solenoid such as that illustrated in FIG. 1.

FIG. 3 is a vertical section of the spool shown in FIG. 4 and taken along the line 33 of FIG. 4.

FIG. 4 is a side elevation similar to that of FIG. 2 showing a center magnetic element in place.

FIG. 5 is a vertical section similar to that of FIG. 3 but taken along the line 5-5 of FIG. 2.

FIG. 6 is an enlarged and more detailed vertical section of the spool of FIG. 3 but taken along the axis of the spool.

DESCRIPTION OF THE PREFERRED EMBODIMENT Considering first the perspective view of FIG. 1, a spool 10 is made up of a hollow core 12 on which are integrally formed four flanges 14, I6, 18. and 20. The

flanges

14 and 20 are end flanges and are formed integrally with the ends of the hollow shaft 12 of the spool. The center flanges 16 and 18 are formed as a relatively closely spaced pair, generally at the central section of the hollow shaft 12. A first solenoid winding 22 and a second solenoid winding 24 are formed by winding magnet wire on the spool in the

respective bays

26 and 28 of the spool.

A ring 30' composed of a magnetic material is formed in the general shape of a washer but a washer which is split or has a radial opening at one side 32'. The side opening gives the ring 30 the form of a split ring washer. the split being formed by severing the side 32' of the washer to form the confronting edges 34' and 36.

For convenience of reference in describing the ring. it is indicated to be ring 30' when it is on its open condition, and as being ring 30 in its closed condition. Similarly the several portions of open ring 30' are referred to by primed numerals and these same portions of ring 30 are referred to by unprimed numerals.

A notch 38' is formed in the hinged section 40' of ring 30' preferably the split ring 30' is formed directly from sheet stock in the opened formation so that opening of the ring to the form seen in FIG. I is not necessary. The hinged section 40 is not actually provided with the conventional hinge but rather is partially severed at notch 38' to leave a relatively thinner webb 42' at the outer edge of section 40'. This notching permits the ring metal at the webb 42' to be bent or hinged into the closed position once the ring 30 has been placed between the spaced flanges I6 and 18 of the spool 10 of the relay coil. A curved indentation 43' below opposite notch 40 is designed to prevent folding of the metal at the thinner webb section 42' and in addition results in a full rounded edge when the ring 30' is folded into place.

The arrangement of a hollow shaft 12 of spool 10 and the end flanges l4 and 20 to provide the overall configuration of a conventional spool is illustrated in FIG. 2. These end flange portions of spool 10 are molded integrally with hollow shaft 12. The two spaced center flanges I6 and 18 are also formed integrally with the formation of the spool so that the several flanges have the proper spacing to form the two

bays

26 and 28 to receive the magnetic wire winding and also a proper spacing to receive the magnetic ring 30. A magnetic ring 30' is shown in FIG. 1 in the pre-assembly opened position so that it can be mounted over the hollow center shaft portion 12 of the spool and can then be closed in place as ring 30 between the center flanges I6 and 18. In FIG. I, the ring 30 is also shown in place in between flanges 16 and I8.

In FIG. 3. the ring 30' is shown in phantom in its open position and the same ring 30 is also shown in solid lines in its closed position in the same figure. As noted above. for convenience of reference the closed ring is referred to as ring 30 and the open ring is referred to as ring 30'. The portions of the ring are also indicated in the drawings with a prime where they pertain to parts of the open ring.

A separator 44 extends up radially from the hollow core I2 of spool 10. Separator 44 provides a guide against which the edges 36 and 34' of the open ring may bear as ring 30' is closed about the hollow shaft 12. Similarly. a radially extending boss 46 provides a guide for a notch 38' to position the ring 30' prior to closure about the hollow core I2. Once the ring 30 is closed into place, it has the appearance illustrated in the side elevation of FIG. 4. The disposition of the ring about the radial spacer 44 and radial boss 46 is illustrated in the FIG. 3 which is a crossection of FIG. 4 taken along the line 3--3 of FIG. 4. The actual configurations of the hollow core 12, of flanges l4, l6, l8, and 20, as well as of radially extending spacer 44 and boss 46 may be seen in a vertical section of FIG. 6. FIG. 6 is a sectional view of spool I0 taken along the longitudinal axis of the hollow core 12.

In actual practice. the spool 10 is formed of a thermoplastic material by molding within a suitable cavit to form all of the described portions of hollow shaft and flanges simultaneously. Also the split ring 30' may be formed by punching the element out of suitable strip stock of a magnetic material such as a strip of malleable iron or cold-rolled steel. After the open split ring is formed in the form illustrated in the lower portion of FIG. I it is mounted in place as illustrated in phantom in FIG. 3. The ring 30' is then closed into place about the hollow shaft 12, the guide 46, and spacer 44.

It has been found that a split ring such as 30' may be very conveniently and reliably inserted between the spaced flanges I6 and 18 of a spool of a non-magnetic insulating material and may then be closed into place securely and reliably. Because of curved indentation 43' opposite notch 38'. no folding of the metal takes place and there is no outward flexing or distortion of the closely spaced flanges l6 and 18. When so mounted it provides very satisfactory termination of the magnetic field emanating from each solenoid coil such as 22 and 24. In other words. with the ring 30 in place. the magnetic fleld of one solenoid such as 22 is terminated and separated from the magnetic field of the other solenoid such as 24. Accordingly. in the actual operation of a relay containing a pair of coils such as 22 and 24 as illustrated in FIG. 1, the solenoids can function separately and satisfactorily in first imparting one motion to a plunger disposed within hollow core 12 and then reversing the motion of the plunger by operation of the other solenoid of the coil.

Prior art spools had been formed with the magnetic ring insert molded within the spool to have the general form illustrated in FIG. 1. However, difficulty of manufacture and damage to the molding tools have been experienced due to the difficulty of placement of the metal ring prior to the insert molding. The cost and reliability of the manufacture have accordingly and been adversely affected. Because the molding can be carried in accordance with this invention without the insert molding of the magnetic piece. the molding is carried out without damage or interference with the tool. Accordingly, it is also done at lower cost. In addition, the split ring 30' can be conveniently and reliably mounted to the spool 10 between the spaced

flanges

16 and 18 with great reliability as well as economy. In this way, effective control of the formation of the solenoid coil and avoidance of costly damage to the forming tools is achieved.

What is claimed and sought to be secured by Letters Patent of the United States are:

1. A coil comprising:

a. a spool of insulating and non-magnetic material.

b. said spool having a hollow center shaft in which a magnetic plunger may be operatively associated and magnetically moved,

c. said spool having two aligned relay coil bays one at each end of said spool.

0. said bays being defined by an end flange at each end of said hollow center shaft and by a parallel pair of center flanges,

e. said center flanges being spaced to receive an annular piece of magnetic material therebetween f. and a ring of magnetic material at the center of said spool disposed between said center flanges,

g. said ring having a radial slot through one side thereof and a diametrically opposite weakened section opposite said radial slot whereby said ring may be closed on said spool by hinging at said weakened section from an open ring configuration in which it is formed.

2. The coil of claim 1 wherein the weakened section is an internally notched section.

3. The coil of claim 1 wherein the weakened section of the open ring is internally notched and externally dished to facilitate deformation in hingelike fashion.

4. A notched ring for closure into and about a conforming receptacle comprising a metal split ring a. said ring having an open annular ring form b. the opening of the ring having generally radial edges and said edges being spaced to permit mounting over a tubular shaft.

c. a curved inner surface having a notch opposite said opening and adapted to close at said notch into conforming circular relation to said tubular shaft d. said curved outer surface forming a circular outer surface on closure of said ring at said notch.

5. The ring of claim 4 in which the ring has a curved outer surface and the curved outer surface has a curved indentation opposite the notch

Claims

1. A coil comprising: a. a spool of insulating and non-magnetic material, b. said spool having a hollow center shaft in which a magnetic plunger may be operatively associated and magnetically moved, c. said spool having two aligned relay coil bays one at each end of said spool, d. said bays being defined by an end flange at each end of said hollow center shaft and by a parallel pair of center flanges, e. said center flanges being spaced to receive an annular piece of magnetic material therebetween, f. and a ring of magnetic material at the center of said spool disposed between said center flanges, g. said ring having a radial slot through one side thereof and a diametrically opposite weakened section opposite said radial slot whereby said ring may be closed on said spool by hinging at said weakened section from an open ring configuration in which it is formed.

4. A notched ring for closure into and about a conforming receptacle comprising a metal split ring, a. said ring having an open annular ring form, b. the opening of the ring having generally radial edges and said edges being spaced to permit mounting over a tubular shaft, c. a curved inner surface having a notch Opposite said opening and adapted to close at said notch into conforming circular relation to said tubular shaft, d. said curved outer surface forming a circular outer surface on closure of said ring at said notch.

5. The ring of claim 4 in which the ring has a curved outer surface and the curved outer surface has a curved indentation opposite the notch.