US2933573A

US2933573A - Electric switch

Info

Publication number: US2933573A
Application number: US781526A
Authority: US
Inventors: Pierce W Strider
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-12-19
Filing date: 1958-12-19
Publication date: 1960-04-19
Anticipated expiration: 1977-04-19
Also published as: FR1242778A; GB896143A; DE1223930B; CH361320A

Description

April 19, 1960 P. w. STRIDER guzcmc SWITCH 2 Sheets-Sheet 1 Filed Dec. 19, 1958 Pierce W Stride 1N VENTOR.

April 19, 1960 P. w. STRIDER ELECTRIC swrrcn 2 Sheets-Sheet 2 Filed Dec. 19, 1958 Pierce n. .Syn'abr IN VEN TOR. mm

W Wing.

nited States This invention relates to switches and more particu larly to electromagnetic switches for controlling a plurality of circuits.

An object of the invention is to provide an electromagnetically operative switch for controlling a plurality of separate circuits, the switch having a number of structural improvements over prior switches to serve somewhat similar purposes and the method of assembling an electromagnetic switch.

Series-parallel switches, double throw, double pole switches and separate circuit switches are old and well known. A switch constructed in accordance with this invention may be used in any of the above mentioned capacities and others. Yet, the switch is comparatively simple in its construction and easily assembled during manufacture.

The switch has a base and a cover, each of which are preferably made of electrically insulating material. The base has two pairs of binding posts, each of which are provided with pairs of contacts located in parallel spaced planes. The switch cover contains a solenoid structure including a fixed coil and an armature. There is at least one additional pair of binding posts and contacts, and preferably two additional pairs of binding posts and contacts carried by the cover of the switch. The armature has three conductive washers which function as three movable contacts cooperable with the fixed contacts in the base and the cover respectively. The movable contacts are so proportioned with reference to the spacing of the contacts of the pairs in the cover that the armature may be assembled as a unit in the cover of the switch that is, the armature plus the three movable contacts simply dropped into the cover, making high speed production possible. After having the armature disposed in the cover, the base of the switch may be attached to the cover thereby automatically positioning the pairs of contacts that are carried by the base, operatively with respect to the movable contact washers on the armature. For this reason and also for compactness, the locations of the contacts with respect to each other in the switch, and the size of each movable contact assumes importance.

The three movable contacts assembled on the armature are held spaced from each other by means of nonconductive spacers, and the washers that form the movable contacts are free to rotate on the spindle so that different areas of the movable and fixed contacts engage during successive operations of the switch. A significant improvement exists in the way that the movable contacts are related to each other, to the armature and the fixed contacts in the switch. A pair of heavy duty fixed contacts are carried by the cover and these are bridged by one of the movable contacts when the solenoid is energized. There is a first spring which reacts on the armature in such a way that the spring is compressed when the solenoid is energized. In addition, there is a second spring which reacts on the armature circuits may be controlled, two at 2,933,573 Patented Apr. 19, 1960 and at least the movable contact which bridges the fixed contacts in the cover. This second spring is considerably heavier than the first spring, but becomes compressed when the armature is electromagnetically moved to one of its positions. When deenergized, the armature is released and the light spring moves the entire armature to the rest position. However, it is the heavy spring which reacts on at least one of the movable contacts which causes the initial separation of the movable contact of the armature by a quick snap action from the fixed contacts in the switch cover. This rapid movement of the movable contact with respect to the armature, as opposed to movement with the entire armature caused by the lighter gauge spring, minimizes the possibility of arcing thereby contributing to longevity of the contacts.

As indicated previously the switch may be used in a number of ways, one of which is as an ordinary double throw double pole switch of the electromagnetically operated type. An important specific use of the switch is in connection with storage batteries for motor vehicles. The switch may have its contacts connected with the cells of a battery to connect them alternately in series and parallel. For example, a 12 volt automotive storage battery containing six cells,-may have the cells connected alternately in series and in parallel so that the motor vehicle may have available for consumption current impressed at 6 or 12 volts respectively. Such systems are known in the art, and the benefit obtained is to have the high voltage available for starting while the motor vehicle may operate on the design 6 volt source during all other phases of motor vehicle operation.

Although the series-parallel arrangement for the cells of a storage battery is a possible use of the invention, the switch is so constructed that it may be used wherever plural circuits must be sequentially controlled. A preferred form of the invention has four pairs of contacts at the inner ends of four pairs of binding posts, terminals or the like. The armature has three movable contacts, preferably Washers, adapted to move in a Way that the rest position for the switch has two of the contacts bridging two pairs of fixed contacts. When the switch is in the energized position, that is, when the electromagnetic coil is energized, the two normally closed pairs of contacts are opened by movement of the armature and movable contacts carried by the armature. In addition, one of the movable contacts that was used to bridge a pair of fixed contacts, bridges another pair of fixed contacts, and a third movable contact washer bridges a final pair of contacts in the switch. Accordingly, it is noted that the three movable contacts control four pairs of fixed contacts so that four individual a time, with only three movable contacts and four sets of fixed contacts.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation shown and described, as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure l is a perspective view of the switch constructed in accordance with the invention.

Figure 2 is a top view of the switch in Figure 1.

Figure 3 is a bottom view of the switch in Figure 1.

Figure 4 is a sectional view taken on the line 44 of Figure 2.

Figure 5 is a sectional view taken on the line 55 of Figure 2.

In the accompanying drawings there is a switch which may be used for general or specific purposes. The switch is constructed of a cover 12 having a cavity 14, and a base-16 to which the cover is attached, for example by nuts and bolts 18 passed through aligned openings in flange 20 of cover 12 and base 16. A gasket 22 is located between the confronting surfaces of the flange 20 and base 16.

There is a shallow-cavity 24 in base 16, which confronts cavity 14 when the base and cover are assembled. Four

binding posts

30, 31, 32 and 33 respectively are attached to the base 16, portions of the binding posts protruding beyond the outer surface or side of the base, and portions of each binding posts projecting through openings in the base 16. The binding posts are in pairs with the first pair consisting of

posts

30 and 31, and a second pair consisting of

binding posts

32 and 33. A first pair of

fixed contacts

35 and 36 are integral with the inner ends of

binding posts

30 and 31, and a second pair of

fixed contacts

37 and 38 are integral with the inner extremities of

binding posts

32 and 33. All of these fixed contacts may be made as heads on the binding posts and ground where necessary so that flat contact surfaces are obtained. The first pair of

contacts

35 and 36 are coplanar, and the second pair of contacts are coplanar but located in the plane spaced from and parallel to the plane containing the first

fixed contacts

35 and 36. The four described

contacts

35, 36, 37 and 38 are at least partly disposed in cavity 24 of the base 16. The binding posts may be made in any known fashion, for example as screw threaded shanks with holding nuts 40 thereon backed by washers and adapted to accommodate additional nuts for holding eyelets at the ends of wires.

A third pair of

binding posts

41 and 42 are attached to the cover 12, passing through openings in the built up

bosses

44 and 45 at the sides of cover 12. Nuts 46 backed by lock washers and pliable washers are on binding

posts

41 and 42. Additional nuts may be placed on binding

posts

41 and 42 in order to hold eyelets at the ends of conductors or to hold any other type of connecting part of a conductor, for instance a part of a bus bar having a hole in it. The inner ends of the

binding posts

41 and 42 have a third pair of

contacts

48 and 49 respectively thereon. These may be formed as heads of the binding posts and are located Within a pair of

channels

50 and 52 and the walls of cavity 14. The channels are in the cover 12 to prevent the binding posts from rotating during assembly. The same holds true for

contacts

35 and 36, inasmuch as they are in channels 39 in a wall of cavity 24. The second pair of

contacts

37 and 38 have flat edges which abut shoulders 53 in cavity 24 thereby preventing

binding posts

32 and 33 fromrotating during manufacturing assembly.

Contacts

48 and 49 are coplanar and in a plane parallel and spaced from the planes containing the first and second pairs of contacts. The fourth pair of contacts 73 and 59 are located in the plane between the

plane containing contacts

48 and 49 and the plane containing the second pair of

contacts

37 and 38 respectively. The fourth pair of contacts 73 and 59 are located in cavity 14, and are at the inner ends of

binding posts

74 and 61 respectively. The fourth pair of fixed contacts 73 and 59 have their

binding posts

60 and 61 pass through holes in the side wall of cover 12 and held in place by nuts 62 backed by washers and adapted to receive conductors, for example conductor 63 (Figure 6). Contacts 73 and 59 are formed as heads on the binding posts and are located in channels 65 and 66 in the walls of cavity 14.

There are electromagnetic means for bridging the aaaaws various pairs of contacts. These electromagnetic means consist preferably of a solenoid 70 having a coil 71 in cavity 14 at one end thereof. One end of the coil has a wire 72 extending therefrom which is secured to head 58 at the inner extremity of binding post 60. The binding post 60 is passed through an opening in the wall of cover 12 and has a nut 75 thereon. Head 60 is located in a channel 76 (Figure 8) in the wall of cavity 14. The opposite end of the coil has a wire 79 extending from it and attached to the top binding post 80. By impressing a voltage across binding

posts

80 and 60, the solenoid coil 71 is energized. The solenoid has asolenoid structure 81 enclosing the coil 70, and an insulating partition 82 extends across the bottom of the solenoid structure. The bore 83 in coil 71 has a plunger stop 84 at one end and within the field of the coil when the coil is energized. The armature 85 of the solenoid is constructed of a plunger-86 having a lower reduced shank 87. -The armature is reciprocably disposed in the bore 83 and is attracted inwardly of the coil when the coil is energized. Accordingly, the rest position of the armature is established by spring 38 which reacts on a part of the solenoid structure 81 and the plunger 86 in a manner which will be described in more detail subsequently. When in the rest position, though, the first and second pairs of

contacts

35, 36 and 37, 38 respectively are bridged. These same contacts are opened when the solenoid is energized.

There are three movable contacts, consisting of a first contact 90, a second contact 91 and a third contact 92. Further, each of the movable contacts is preferably made of a conductive washer mounted on shank 87 in such a way that the washers are capable of freely rotating or reasonably freely rotating. The lower extremity of shank 87 has a fastener, for instance washer 93 held in place by peening a reduced extension of the shank 87 thereover. There are four insulating

spacers

94, 95, 96 and 97 assembled on the shank 87 and held in place by washer 93. Spacer 94 has a central upwardly opening recess 98 in which a second spring 99.is seated. This second spring is considerably stronger than spring 88 which seats on the nearest spacer 97. Flange 100 protrudes from the main body of spacer 94 and forms a lower stop for contact 90. A comparatively light spring 102 is disposed on contact and seats against a part of the opposing surface of spacer 95. The spring 102 lightly holds contact 90 downwardly, while spring 99 bears quite forcibly against spacer 94 and spacer 96 against which it bears. The spacer has a cylindrical part 104 slidably disposed an and concentrically arranged with respect to a part of spacer 96. The intermediate contact 91 is located between portions of

spacers

95 and 96. Spacer 97 has an undercut part 106 which cooperates with an adjacent surface of spacer 96 to form an annular groove within which a part of contact 92 is disposed.

In operation of the switch, control current is applied across

terminals

60 and 80 in order to energize the coil of the solenoid. This elevates the armature 85 causing the three movable contacts on the armature to move from the rest position to the second position. When the control current is discontinued, the armature returns to the rest position.

When in the rest position movable contact 90 which is considered the first movable contact, bridges the first

fixed contacts

35 and 36. Spring 102 yields against the pres sure exerted between the armature plunger and the contact 90, pressing the latter against the first pair of fixed

contacts

35 and 36. Therefore, the tolerances between the movable contacts on the armature may be quite large. Further, the second movable contact 91 bridges the second pair of fixed

contacts

37 and 38 so that two individual circuits may be controlled that is, closed simultaneously. One or more individual circuits that are connected with the third and fourth pairs of fixed contacts, are opened at this time. 7

When coil 71 is energized the armature is withdrawn into the bore 83' compressing'the comparatively light spring 88. Movable contact 92 engages the third pair of fixed

contacts

48 and 49 causing spacer% and spacer 95 to move toward washer 93 thereby compressing the comparatively heavy spring 99. Accordingly, spring 99 is placed under a compressive load when the armature is withdrawn into the solenoid bore. Further, the intermediate or second movable contact 91 bridges the fourth pair 73 and 59 of fixed contacts. This means that

contacts

37 and 38 are no longer bridged by movable contact 91, and that the first pair of

contacts

35 and 36 are no longer bridged by the first movable contact 90.

At the instant that the solenoid coil 71 is deenergized the first action is for the heavily loaded spring 99 to very quickly expend its stored potential energy in a direction to forcibly push the armature plunger 86 outwardly from bore 83 so that the movable contact 92 is snapped away from the

third pair

48 and 49 of fixed contacts. The fixed

contacts

48 and 49 are heavy duty, high capacity contacts, and the action of the heavier spring 99 is mainly responsible for opening or unbridging the contacts very quickly. Spring 88, which is a lighter gauge spring also helps, but the principal purpose of spring 88 is merely to return the entire armature assembly with its movable contacts, to the rest position at which the first and second vpairs of fixed contacts are again bridged by movable contacts 90 and 91. Switch is now prepared for another cycle of operation identical to that described above.

The foregoing is considered as illustrative only or the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. An electromagnetic switch for a plurality of circuits comprising an insulating base, a first pair of binding posts having first fixed contacts at their inner ends, a

second pair of contacts having second fixed contacts at their inner ends, said binding posts extending from one side of said base, said fixed contacts being locked on the opposite side of said base, said first contacts being coplanar and said second contacts being coplanar with the planes containing said contacts spaced from each other, a third pair of binding posts having third fixed contacts at their inner ends and disposed in a plane parallel and .spaced from the planes occupied by said first and second contacts, a cover, means securing said cover to said base, a solenoid in said cover and having a coil structure and an armature, a first and a second and a third movable contact carried by said armature, a first spring reacting on said armature and said structure andurging said armature to a rest position at which said first and said second movable contacts bridge said first and said second fixed contacts and said third movable contact is spaced from said third contacts, a second spring reacting on said armature and said third movable contact, said third movable contact in addition to being movable with said armature also being movable with respect to said armature against the opposition of said second spring, said armature and said movable contacts being movable in response to energization of said coil structure to a 'position at which said first and second movable contacts are spaced from said first and second fixed contacts and said third fixed contacts bridged by said third movable contact and said first and second springs are compressed, said second spring having a greater strength than said first spring and forcibly snapping said third contact away from said third fixed contacts by sliding the movable third contact with respect to the armature when said coil structure .is deenergized and 'at the same time said first .6 spring returns the armature and contacts carried thereby to said rest position.

2. An electromagnetic switch for a plurality of circuits comprising an insulating base, a first pair of binding posts having first fixed contacts at their inner ends, a second pair of contacts having second fixed contacts at their inner ends, said binding posts extending from one side of said base, said fixed contacts being located on the opposite side of said base, said first contacts being coplanar and said second contacts being coplanar with the planes containing said contacts spaced from each other, a third pair of binding posts having third fixed contacts at their inner ends and disposed in a plane paral lel and spaced from the planes occupied by said first and second contacts, a fourth pair of binding posts, a fourth pair of fixed contacts in a plane parallel to and spaced from the plane containing said third fixed contacts, a cov er, means securing said cover to said base, a solenoid in said cover and having a coil structure and an armature, a first and a second and a third movable contact carried by said armature, a first spring reacting on said armature and said structure and urging said armature to a rest position at which said first and said second movable contacts bridge said first and said second fixed contacts and said third movable contact is spaced from said third contacts, a second spring reacting on said armature and said third movable contact, said third movable contact in addition to being movable with said armature also being movable with respect to said armature against the opposition of said second spring, said armature and said movable contacts being movable in response to energization of said coil structure to a position at which said first and second movable contacts are spaced from said first and second fixed contacts and said third and fourth fixed contacts bridged by said third and second movable contacts respectively, and said first and second springs are compressed, said second spring having a greater strength than said first spring and forcibly snapping said third contact away from said third fixed contacts by sliding the movable third contact with respect to the armature when said coil structure is deenergized and at the same time said first spring returns the armature and contacts carried thereby to said rest position.

3. An electromagnetic switch for a plurality of circuits comprising an insulating base, a first pair of binding posts having first fixed contacts at their inner ends, a second pair of contacts having second fixed contacts at their inner ends, said binding posts extending from one side of said base, said fixed contacts being located on the opposite side of said base, said first contacts being coplanar and said second contacts being coplanar with the planes containing said contacts spaced from each other, a third pair of binding posts having third fixed contacts at their inner ends and disposed in a plane parallel and spaced from the planes occupied by said first and second contacts, a fourth pair of binding posts, a fourth pair of fixed contacts in a plane parallel to and spaced from the plane containing said third fixed contacts, a cover, means securing said cover to said base, a solenoid in said cover and having a coil structure and an armature, a first and a second and a third movable contact carried by said armature, a first spring reacting on said armature and said structure and urging said armature to a rest position at which said first and said second movable contacts bridge said first and second fixed contacts and said third movable contact is spaced from said third contacts, a second spring reacting on said armature and said third movable contact, said third movable contact in addition to being movable with said armature also being movable with respect to said armature against the opposition of said second spring, said armature and said movable contacts being movable in response to energization of said coil structure to a position at which said first and second movable contacts are spaced from said first and second fixed contacts and said third and fourth fixed contacts bridged dressers by said third and second movable contacts respectively and said first and second springs are compressed, said second spring having a greater strength than said-first spring and forcibly snapping said third contact away from said third fixed contacts by sliding the movable third contact with respect to the armature when said coil structure is deenergized and at the same time said first spring returns the armature and contacts carried thereby to said rest position, said cover having a cavity in which said third and fourth fixed contacts and f said coil structure are located, said movable contacts each consisting of a conductive washer, said third movable contact washer being of a diameter that is smaller than the spacing of said fourth fixed contacts so that said armature with said movable contacts assembled thereon may be inserted as a unit into said cavity. I

'4. In an electromagnetically operated switch which has a coil, an armature movable axially in response to energization of said coil, a base and a cover enclosing said armature and coil, said base and cover constituting means by which to support a plurality of fixed contacts, a first pair of fixed contacts enclosed by said cover and base, a second pair of fixed contacts enclosed by said cover and spaced from said first pair of fixed contacts, a third pair of fixed contacts spaced from said first and said second pairs of fixed contacts, the contacts of each pair being coplanar with the pairs in three separate planes, at least two pairs of said fixed contacts being spaced at a different radial distance from the axis of the coil, movable contacts premounted on said armature and adapted to bridge selectively said fixed contacts alternately in response to movement of said armature between the rest and energized positions respectively, at least one pair of contacts being unbridged while the other pairs of contacts are bridged by said movable contacts, said armature and contacts thereon being slidably receivable in the cover with the fixed contacts in position, and a plurality of springs reacting on said armature and at least one of the movable contacts for compressing when said armature is electromagnetically moved by energization of said coil and for rapidly and forcibly mechanically returning the armature to the rest position when said coil is deenergized.

5. The switch of claim 4 wherein one of said springs is comparatively light and the other of said springs is comparatively heavy in spring rate so that the heavier spring more forcibly moves said one of said movable contacts with respect to said armature whereby said one of said contacts is rapidly unseated from its bridging position across a pair of said fixed contacts.

6. The switch or" claim 5 wherein there is another set of fixed contacts enclosed within said cover and base,

said movable contacts consist of three washers of at ieast two difierent diameters, the largest diameter washer being movable between two pairs of fixed contacts so that one of said two pairs of fixed contacts has the contacts thereof bridged in the rest position and the energized positions of said armature respectively, another pair of said fixed contacts being bridged by a smaller diameter washer movable contact, and the remaining pairs of fixed contacts being carried by said base which is sep arable from said cover so that said armature with the movable contact washers thereon may be assembled as a unit in said cover with the smaller diameter washer contact passing the pair of fixed contacts that are carried by said cover and that are bridged by said larger diameter washer contact.

In an electromagnetically operated switch having a coil, a base and a cover enclosing said coil, said base and cover constituting means for supporting a plurality of fixed contacts, first fixed contact means enclosed by said cover and base, second fixed contact means enclosed by said cover and axially spaced from said first fixed contact means, a third fixed contact means axially spaced from said first and second fixed contact means,

bridging selective fixed contact means, said armature being responsive to energization and de-energization of the coil for alternately displacing the armature mounted contacts to communicate with selected fixed contact means. i

.8. An electromagnetically operated switch comprising a cover housing having a coil and an armature-receiving chamber, a plurality of fixed contacts supported in said housing in axially spaced relation to each other and at radially different locations, a housing base member having a plurality of fixed contacts supported thereon in axially spaced relation to :each other and at radially different locations, an armature supported for axial displacement between limits in the armature-receiving chamber, a plurality of contacts for cooperatively and selectively engaging the fixed contacts mounted on the armature, said armature-mounted contacts having preselected radial lengths for communicating with corresponding fixed contacts and avoiding other fixed contacts during armature displacement.

9. An electromagnetically operated switch comprising a cover housing having a coil, a plurality of fixed contacts supported in said housing in axially spaced relation to each other and at radially different locations, a housing base member having a plurality of fixed contacts supported thereon in axially spaced relation to each other and at radially different locations, an armature supported for axial displacement between limits upon energization and de-energization of said coil, said armature having a plurality of axially spaced contacts for cooperatively and selectively engagingthe fixed contacts in a predetermined order upon displacement of the armature, selected armature supported contacts having radii to avoid contact with at least one fixed contact in the path of travel of said armature having the contacts mounted thereon.

10. An electromagnetically operated switch comprising a cover housing having a coil and an armaturereceiving chamber, a first pair of fixed coplanar con tacts and a second pair of fixed coplanar contacts axially spaced from each other, said first and second pairs of fixed contacts being located at difierent radial distances from the longitudinal axis of the coil, a base member for said housing having a third pair of fixed coplanar contacts and a fourth set of coplanar contacts, said third and fourth pairs of contacts being located at difierent radial distances from the longitudinal axis of the coil with the base member mounted on the housing, and an armature slidably displaceable in said chamber and having premounted thereon at least three contact members for coperatively engaging selected pairs of fixed contacts in the housing and base member upon energization and deenergization of the coil.

11. The method of assembling an electromagnetic switch for controlling a plurality of circuits, the switch having a coil and a cylindrical cavity and a plurality of axially spaced fixed contacts positioned at selective radial distances from the axis of the switch to which contact binding posts are connected, and a pre-assembl'ed armature axially movable in response to energization and deenergization of the solenoid and having a plurality of axially spaced contacts thereon to cooperatively engage with the axially spaced fixed contacts, the step of assembling the switch by inserting the preassembled armature into the cylindrical cavity with the plurality of axially spaced contacts thereon.

12. The method of assembling electromagnetic switches for controlling a plurality of circuits, the switch having a cover housing in which a coil is retained forming an axial armature-receiving cylindrical cavity, and a plurality of axially spaced fixed contacts selectively positioned and radially spaced selectively from the axis of the cylindrical cavity to which contact binding posts are connected and an armature slidably receivable in the cover housing cylindrical cavity and having pre-mounted thereon a plurality of axially spaced contacts each of which will cooperatively engage with a pre-selected fixed contact upon cnergization and de-energization of the coil, the step of inserting the armature with all the contacts premounted thereon into the armature-receiving cylindrical cavity With the fixed contacts remaining in position.

13. The method of assembling electromagnetic switches for controlling a plurality of circuits, the switch having a cover housing in which a coil is retained forming an armature-receiving cylindrical cavity, and a plurality of axially spaced fixed contacts selectively positioned and radially spaced selectively from each other, and an armature slidably receivable in the cover housing with a plurality of pre-mounted and axially spaced contacts thereon for cooperatively engaging with pre-selected fixed contacts upon displacement of the armature, and a base member having axially spaced and radially offset fixed contacts mounted thereon, the step of inserting the armature with all the contacts preniounted thereon into the cover housing, and mounting the base member with premounted contacts on the housing.

References Cited in the file of this patent UNITED STATES PATENTS 985,509 Carpenter Feb. 28, 1911 1,019,045 Horton Mar. 5, 1912 1,844,731 Whittingham Feb. 9, 1932 2,006,690 Blake July 2, 1935 2,266,536 Cooper Dec. 16, 1941