US3019308A

US3019308A - Electric switch

Info

Publication number: US3019308A
Application number: US675349A
Authority: US
Inventors: Gilbert S Ellithorpe
Original assignee: Littelfuse Inc
Current assignee: Littelfuse Inc
Priority date: 1957-07-31
Filing date: 1957-07-31
Publication date: 1962-01-30
Anticipated expiration: 1979-01-30

Description

Jan. 30, 1962 G. s. ELLITHORPE 3,019,308

ELECTRIC SWITCH Filed July 51, 1957 2 Sheets-Sheet 1 $5 45,13 39 INVENTOR.

E4; wvwmik'w Jan. 30, 1962 G,'S. ELLITHORPE 3,019,308

ELECTRIC SWITCH Filed July 31, 1957 2 Sheets-Sheet 2 W 66 INVENTOR.

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United States Patent i 3,019,308 ELECTRIC SWITCH Gilbert 5. Ellithorpe, Waterman, Ilh, assignor to Littelfuse, Incorporated, Des Plaines, 111., a corporation of Illinois Filed July 31, 1957, Ser. No. 675,349 6 Claims. (Cl. 200-11) This invention is directed generally to electric switches and more particularly to a rotary type multiple position electric switch.

The principal object of this invention is to provide an improved electric switch wherein a rigid contact bar or contactor member is laterally moved in an operating plane with respect to contacts for performing the switching function and wherein the contact bar or contactor member is also moved normal to said operating plane for lowering and raising the same into and out of engagement with the contacts as the contact bar or contactor member is moved in said operating plane. This provides a quick make and break action and also a wiping action to minimize arcing and pitting of the contacts, to eliminate deterioration of the insulation adjacent the contacts, to maintain the contacts clean and operative, and to increase the expected life of the switch. In accordance with this invention, the movement of contact bar or contactor member in a direction normal to the operating plane of movement thereof is simply and inexpensively accomplished by cam means engaged by the contact bar or contactor member.

Further objects of this invention reside in the details of construction of the electric switch and in the'cooperative relationships between the component parts there of.

Other objects and advantages of this invention will becomeapparent to those skilled in the art upon reference to the accompanying specification, claims and drawings in which:

FIG. 1 is a perspective view of the electric switch of this invention looking from one end thereof;

FIG. 2 is an end elevational view of the electric switch looking from the other end thereof;

FIG. 3 .is a vertical sectional view through the electric switch taken substantially along the line 3-3 of FIG. 2;

FIG. 4 is an exploded perspective view of the contact bar and the carrier member which is utilized in the electric switch illustrated in FIGS. 1 to 3;

FIG. 5 is a perspective view of the mechanism for rotating the carrier member;

FIG. 6 is a vertical sectional view through the electric switch taken substantially along the line 66 of FIG. 3

FIG. 7 is a partial sectional view similar to FIG. 6, but illustrating the carrier member in a different position;

FIG. 8 is a vertical sectional view taken substantially along the line 8-8 of FIG. 7;

FIG. 9 is a substantially horizontal sectional view taken substantially along the line 9--9 of FIG. 6; and

FIG. 10 is a substantially horizontal sectional view taken substantially along the line 1010 of FIG. 6.

Referring first to FIGS. 1 to 3, the preferred form of the electric switch of this invention is generally designated as 10 and it is shown to be a rotary type, multiple-position electric switch. It includes a hollow base member 11 formed of electrical insulating material such as Bakelite or the like. The base 11 has a cavity 12 which is substantially pie-shaped in configuration. The smaller end of cavity 12 is provided with circularly shaped cavity 13. One end, 14, of the hollow base member 11 is closed by an end wall and the other end is open. The open end of the base member 11 is provided with a flange 15 and a bracket 16 closes the open 7 3,019,308 Patented Jan. 39, 1952 "ice end of the base member 11 and is held in place on the base member 11 by fingers 17 struck therefrom and clinched over the flange '15 of the base member 11. The bracket 16 is provided with a pair of ears 18 provided with holes 19 for mounting the electric switch. One of the ears 18 is provided with an extension 20 to which is secured a clip 21 by a screw 22 for holding wires leading to the contacts of the electric switch.

The closed end wall 14 of the base member 11 is provided with a rectangular slot 25 anda communicating opening 26 for receiving a first contact member 27. This contact member 27 after being inserted in the rectangular slot 25 is clinched over as illustrated in FIG. 3 to hold the same in place, the contact member 27 being interiorly provided with a fiat surface 28 forming a first contact. The outer end of the contact member 27 extends outwardly to form a terminal connection. The end wall 14 of the insulating base 11 is provided with a second rectangular slot 29 and a communicating open ing 30 for receiving a second contact member 31. The contact member 31 is also inserted throughthe slot 29 and is secured in place by clinching the same over on the end wall 14. The inner end of the contact member 31 carries a first contact 32 and the outer end thereof extends outwardly for forming a terminal connection. The end wall 14 of the insulating base 11 is also provided with a third rectangular slot 33 and a communicating opening 34 for receiving a third contact member 35. Here, also, the third contact member 35 is inserted through the rectangular slot 33 and is clinched in place on the end wall 14. The inner end of the contact member 35 carries a third contact 36 and the outer end thereof extends outwardly to form a connecting terminal. The communicating

openings

26, 30 and 34 communicating with the

rectangular slots

25, 29 and 33 are provided for the purpose of facilitating insertion of the

contact members

27, 31 and 35 in the end wall 14. The first, second and

third contacts

28, 32 and 36 respectively, are laterally arranged in a common plane and are laterally spaced from each other.

Arranged within the cavity 12 of the insulating base member 11 is a carrier member 38 which is also preferably made of electrical insulating material such as Bakelite or the like. This carrier member 38 is provided at its lower end with a cylindrical portion 39 which is journalled for rotation in the cylindrical cavity portion 13 of the insulating base 11. Thus the carrier member 39 may be rotated in a plane which is parallel to the plane including the

contacts

28, 32 and 36. The carrier member 38 is also slidably carried by the insulating base member 11 for movement in a direction normal to said plane. Adjacent its upper end, the carrier member 38 is provided with a slot 40 which is utilized for the purpose of rotating the carrier member. The carrier member 38 is also provided with a pair of side faces 41 and with a fulcrum portion 42 arranged between the side faces 41. The lower end of the carrier member 38 is also provided with a notch 43. A hole 44 is pro vided in the carrier member 38, the. hole 44 opening into the face of the carrier 38 which is opposite from the face carrying the fulcrum portion 42 and the notch 43.

A rigid contact bar or contactor member 46 is arranged between the carrier member 38 and the closed end 14 of the insulating base member 11. This contact bar 46, as here illustrated, is made of electrically conductive material, such as brass or the like, and is provided with a recess 47 which engages over the fulcrum portion 42 of the carrier member 38 so that the contact bar 46 is pivotally mounted with respect to the carrier member 38 for movement in a direction normal to the plane containing the

contacts

28, 32 and 36. The contact bar 46 is provided with a pair of ears 48 which engage the side faces 41 of the carrier member 38 and with an ear 49 which engages in the notch 43 in the carrier member 38. By reason of this construction, the contact bar 46 is rotated in an operating plane which is parallel to the plane containing the

contacts

23, 32 and 36 when the carrier member 38 is rotated and by reason of the fulcrum or pivotal connection between the carrier member 3% and the contact bar 46, the contact bar 46 may be pivoted in a direction normal to the operating plane. The contact bar 46 is provided with a dimple 50 which forms a contactor which continuously engages the first contact 28 to provide an electrical connection between the first contact 28 and the contact bar 46.

The contact bar 46 also carries a contact or contactor 51 which is moved to a first or intermediate position be tween the

contacts

32 and 36, or a second position where it engages the contact 32, or a third position where it engages the contact '36. Thus, when the contact bar 46 is in the first or intermediate position, the electrical circuits are broken and when the contact bar 46 is moved to the second position, a circuit is completed between the

contact members

27 and 31 and when the contact bar 46 is moved to the third position, a circuit is complete between the contact member 27 and the contact member 35. The upper end of the contact bar 46 is also provided with a cam follower means 52 which is adapted to engage a cam means 65 formed on the end wall 14 of the insulating base member 11 for moving the contact bar 46 in a direction normal to the operating plane as the contact bar 46 is rotated in the operating plane.

The electric switch of this invention is operated by a knob 54 secured to a shaft 55 which is journalled for rotation in a bearing 56 formed in the bracket 16. An operating member 57 which is arranged between the can rier member 38 and the bracket 16 is staked to the inner end of the shaft 55 as indicated at 58. The free end of the operating member 57 is provided with a finger 59 which extends into the slot 40 in the carrier member 38. The axes of rotation of the shaft 55 and the carrier 38 are concentric and thus as the shaft 55 is rotated by manipulating the knob 54, the carrier member 38 is correspondingly rotated. The operating member 57 is provided with a retaining hole 60 which receives a ball 61, the ball 61 engaging the bracket 16. A spring 62 is arranged in the hole 44 in the carrier member 38 between the carrier member 38 and the ball 61. The spring 62 operates to press the ball 61 against the bracket 16 and to move the carrier member 38 toward the end wall 14 of the insulating base member 11. In so doing, the spring 62 resiliently urges the contact bar 46 toward and against the

contacts

28, 32 and 36.

The cam means 65 formed on the front wall 14 of the insulating base 11 is provided with a central high dwell 66 and spaced low dwells 67 and cam surfaces 68 therebetween, as shown more clearly in FIG. 9. The central high dwell 66 is preferably provided with a central notch 69. The cam means 65 are engaged by the cam follower 52 formed on the upper end of the contact bar 46. When the cam follower 52 of the contact bar 46 is engaging the high dwell 66 of the cam means 65 and/or the notch 69 therein, the contact bar 46 is pivoted rearwardly so as to retract the contact 51 from alignment with the

contacts

32 and 36, this being shown in full lines in FIGS. 9 and 10. This represents the first, or intermediate, position of the electric switch. When the knob 54 is manipulated to move the contact bar 46 from the first, or intermediate, position to the second position, the cam follower 52 rides down the cam surface 68 toward the low dwell 67 as shown in broken line in FIG. 9. Accordingly, when the contact bar 46 is rotated in its operative plane from the first position toward the second position, the contact bar 46 is moved in a direction normal to the operating plane by the spring 62 so as to lower the contact 51 of the contact bar 46 into engagement with the second contact 32 as the contact bar 46 is rotated into the second position. During this movement, the contact 51 is lowered into engagement with the contact 32 and the follower 52 is lifted otf of the cam surface 63 when the contact 51 engages the contact 32. This provides a positive make of the contacts. Continued movement in the operating plane to the ultimate second position causes the contact 51 to slide on the contact 32 to provide a wiping contact action.- There is thus provided a positive making of the contact along with a wiping action. Likewise as the contact bar 46 is being moved from the second position to the first, or intermediate position, the contact 51 is raised out of engagement with the second contact 32. This movement of the contact 51 in the operating plane and in a direction normal to the operating plane provides a quick make and break action and also a wiping action between the

contacts

51 and 32. This minimizes arcing and pitting of the contacts, eliminates deterioration of the insulation adjacent to the contacts and maintains the contacts clean and operative at all times. When the contact bar 46 is moved between the first, or intermediate position, and the third position where the contact 51 engages the con tact 36, a similar action takes place and a further de* tailed description is not considered necessary. The low dwells 67 on the cam means 65 and the notch 69 in the high dwell 66 operate effectively to maintain the contact bar 46 in any one of its selected three positions. The spring 62 at all times insures adequate contact pressure and also allows movement of the carrier member 38 and pivotal movement of the contact bar 46 in a direction normal to the operating plane of the contact bar 46. I

In order positively to assure positive positioning of the contact bar 46 in any of its selected three positions, the bracket 16 is preferably provided with three recesses 72, 73 and 74 which are adapted to be engaged by the ball 61, the ball 61 engaging respectively in the recesses 72, 73 and 74 as the contact bar 46 is rotated to its first, sec-' 0nd and third positions. While the electric switch of this invention has been specifically disclosed as a three-posi tion, rotary type electric switch, this invention is applicable to electric switches having more or fewer posi tions and to electrical switches of the sliding or recipro eating type as distinguished from the rotary type.

While for purposes of illustration, one form of this invention has been disclosed, other forms thereof may become apparent to those skilled in the art upon reference to this disclosure and, therefore, this invention is to be limited only by the scope of the appended claims.

I claim as my invention:

1. An electric switch comprising an insulating base member, a first contact carried by the base member, a second contact carried by the base member and laterally spaced from the first contact, a rigid contact bar continuously engaging the first contact and laterally movable in an operating plane between a first position Where the contact bar is laterally spaced from the second contact and a second position where the contact bar engages the second contact, a carrier member movable in a plane parallel to said operating plane and in a direction normal to said operating plane, means for mounting the contact bar on the carrier member for movement thereby in said operating plane and including means for pivotally mounting the contact bar for movement in a direction normal to said operating plane, spring means urging the carrier member in a direction normal to said operating plane and hence said contact bar in said direction toward the contacts, and cam means on the base member engaged by the contact bar for moving the contact bar normal to said operating plane when the contact bar is laterally moved into and out of said second position for lowering and raising the contact bar into and out of engagement with the second contact with a wiping action upon such lateral movement of the contact bar.

2. A multiple position electric switch comprising an insulating base member, a first contact carried by the base member, second and third contacts carried by the base member and laterally spaced from each other and from the first contact, a rigid contact bar continuously engaging the first contact and laterally movable in an operating plane between a first position where the contact bar is laterally arranged between and spaced from the second and third contacts, a second position where the contact bar engages the second contact, and a third position where the contact bar engages the third contact, a carrier member movable in a plane parallel to said operating plane and in a direction normal to said operating plane, means for mounting the contact bar on the carrier member for movement thereby in said operating plane and including means for pivotally mounting the contact bar for movement in a direction normal to said operating plane, spring means urging the carrier member in a direction normal to said operating plane and hence said contact bar in said direction toward the contacts, and cam means on the base member engaged by the contact bar for moving the contact bar normal to said operating plane when the contact bar is laterally moved into and out of said second and third positions for lowering and raising the contact bar into and out of engagement with the second and third contacts with a wiping action upon such lateral movement of the contact bar.

3. A rotary type electric switch comprising an insulating base member, a first contact carried by the base member, a second contact carried by the base member and laterally spaced from the first contact, a rigid contact bar continuously engaging the first contact and laterally rotatable in an operating plane between a first position where the contact bar is laterally spaced from the second contact and a second position where the contact bar engages the second contact, a carrier member rotatable in a plane parallel to said operating plane and slidable in a direction normal to said operating plane, means for mounting the contact bar on the carrier member for rotation thereby in said operating plane and including means for pivotally mounting the contact bar for movement in a direction normal to said operating plane, spring means urging the carrier member in a direction normal to said operating plane and hence said contact bar in said direction toward the contacts, and cam means on the base member engaged by the contact bar for moving the contact bar normal to said operating plane when the contact bar is laterally rotated into and out of said second position for lowering and raising the contact bar into and out of engagement with the second contact with a wiping action upon such lateral rotation of the contact bar.

4. A rotary type multiple position electric switch comprising an insulating base member, a first contact carried by the base member, second and third contacts carried by the base member and laterally spaced from each other and irom the first contact, a rigid contact bar continuously engaging the first contact and laterally rotatable in an operating plane between a first position where the contact bar is laterally arranged between and spaced from the second and third contacts, a second position where the contact bar engages the second contact, and a third position where the contact bar engages the third contact, a carrier member rotatably and slidably mounted in the base member and rotatable in a plane parallel to said operating plane and slidable in a direction normal to said operating plane, means for mounting the contact bar on the carrier member for rotation thereby in said operating plane and including means for pivotally mounting the contact bar for movement in a direction normal to said operating plane, spring means urging the carrier member in a direction normal to said operating plane and hence said contact bar in said direction toward the contacts, and cam means on the base member engaged by the contact bar for moving the contact bar normal to said operating plane when the contact bar is laterally rotated into and out of said second and third positions for lowering and raising the contact bar into and out of engagement with the second and third contacts with a wiping action upon such lateral rotation of the contact bar.

5. A rotary type multiple position electric switch comprising a hollow insulating base member closed at one end and open at its other end, a first contact carried by the closed end of the base member, second and third contacts carried by the closed end of the base member and laterally spaced from each other and from the first contact, a rigid contact bar continuously engaging the first contact and laterally rotatable in an operating plane between a first position where the contact bar is laterally arranged between and spaced from the second and third contacts, a second position where the contact bar engages the second contact, and a third position where the contact bar engages the third contact, a carrier member rotatably and slidably mounted in the base member and rotatable in a plane parallel to said operating plane and slidable in a direction normal to said operating plane, means for mounting the contact bar on the carrier member for rotation thereby in said operating plane and including means for pivotally mounting the contact bar for movement in a direction normal to said operating plane, a bracket closing the open end of the base member, spring means interposed between the bracket and the carrier member urging the carrier member in a direction normal to said operating plane and hence said contact bar in said direction toward the contacts, cam means on the closed end of the base member engaged by the contact bar for moving the contact bar normal to said operating plane when the contact bar is laterally rotated into and out of said second and third positions for lowering and raising the contact bar into and out of engagement with the second and third contacts with a wiping action upon such lateral rotation of the contact bar, and means rotatably carried by the bracket for rotating the carrier member.

6. A rotary type multiple position electric switch comprising a hollow insulating base member closed at one end and open at its other end, a first contact carried by the closed end of the base member, second and third contacts carried by the closed end of the base member and laterally spaced from each other and from the first contact, a rigid contact bar continuously engaging the first contact and laterally rotatable in an operating plane between a first position where the contact bar is laterally arranged between and spaced from the second and third contacts, a second position where the contact bar on gages the second contact, and a third position where the contact bar engages the third contact, a carrier member rotatably and slidably mounted in the base member and rotatable in a plane parallel to said operating plane and slidable in a direction normal to said operating plane, means for mounting the contact bar on the carrier member for rotation thereby in said operating plane and including means for pivotally mounting the contact bar for movement in a direction normal to said operating plane, a bracket closing the open end of the base member, spring means interposed between the bracket and the carrier member urging the carrier member in a direction normal to said operating plane and hence said contact bar in said direction toward the contacts, cam means on the closed end of the base member engaged by the contact bar for moving the contact bar normal to said operating plane when the contact bar is laterally rotated into and out of said second and third positions for lowering and raising thecontact bar into and out of engagement with the second and third contacts with a wiping action upon such lateral rotation of the contact bar, and means rotatably carriedby the bracket for rotating the carrier member, said bracket having three recesses therein, and said spring means including a ball selectively received in said recesses for fixing rotation of said carrier member and said contact bar in said three positions of rotation.

References Cited in the file of this patent Henry Sept. 29, 1942 8 Hasselbaum Sept. 9, 1947 Ellithorpe Ian. 25, 1949 Crowley May 16, 1950 Tregoning July 28, 1953 Frerer Apr. 18, 1954 FOREIGN PATENTS Germany May 27, 1919 Germany June 22, 1923