US3201538A

US3201538A - Snap acting electric toggle switch

Info

Publication number: US3201538A
Application number: US263472A
Authority: US
Inventors: Jr William W De Vore
Original assignee: Harvey Hubbell Inc
Current assignee: Harvey Hubbell Inc
Priority date: 1963-03-07
Filing date: 1963-03-07
Publication date: 1965-08-17
Anticipated expiration: 1982-08-17

Description

2 Sheets-Sheet l W. W. DE VORE, JR

SNAP ACTING ELECTRIC TOGGLE SWITCH Aug. 17, 1965 Filed March 7, 1965 All@ 17, 1965 w. w. DE voRE, JR 3,201,538

SNAP ACTING ELECTRIC TOGGLE SWITCH Filed March 7, 1963 2 Sheets-Sheet 2 HTTRNEYS.

United States Patent O7 3,201,538 SNAP ACTING ELECTRIC TOGGLE SWITCH William W. De Vore, Jr., Palos Verdes Estates, Calif., assigner to Harvey Hubbell, Incorporated, Bridgeport, Conn., a corporation of Connecticut Filed Mar. 7, 1963, Ser. No. 263,472 9 Claims. (Cl. 200-67) This invention relates to electrical switches, and, more particularly, to switches of the D.C. type.

Snap action electrical switches are widely used and `well known items of electrical equipment used in electrical power transmission and control apparatus. For normal A C. usage, these switches are simple, inexpensive and reliable. However, they have not been particularly successful when employed for D.C. use because the snap action of the switch contacts is not suliiciently crisp, as it is not independent of the relatively slow actuating handle movement. Therefore, if the handle of the standard snap action switch is moved slowly from one eX- treme position to another extreme position, the separation action of the electrical contacts of the switch also takes place in a relatively slow fashion. This is referred to in the art as slow make and break This is not a problem when lswitching A.C., because the alternating characteristics of this type of current assist in extinguishing any 'arc that might be formed between the contacts during engagement and disengagement. However, when D.C. is being switched, the electrical arc which may be produced will persist for a considerable period of time and finally be extinguished only by virtue of the increased impedance due to its length. This may result in serious burning of the contacts of the switch and may even result in welding` of the movable to the stationary contacts.

It is, accordingly, the primary object of this invention to provide an improved snap action electrical switch. Other objects are to provide such aswitch having a crisp snap action substantially independent of the actuator handle movement, having a simple and reliable construction, and which is relatively inexpensive to manufacture. v

The above objects of this invention are generally achieved by providing in a toggle type electrical switch, a bearing race on the actuator handle of the switch that is mounted for joint movement therewith, and an independent bearing member which is operatively connected to the movable electrical contacts of the switch and in compressively spring-loaded engagement with the race. The -construction and arrangement of these switch elements is such that tilting of the race, by selective y manual pivotal movement of the handle, initially compresses a lspring that forms part of the mounting of the bearing member, and on further tilting of the handle a toggling point is reached where the energy stored in the compressed spring is quickly released and impels the bearing member along the race, crisply tripping the Contact switching mechanism independently of the handle.

Other objects, features and advantages will become apparent from the following description, the appended claims and the figures of the attached drawings, wherein: .f

FIG. 1 is a plan view of a switch constructed in accordance with this invention; n FIG. 2 is a side elevation of the switch of FIG. 1,` partially cut away to show the internal construction;

FIG. 3 is an end elevation of the switch of FIG. 2;

FIG. 4 is an enlarged longitudinal cross section of the switch of theinvention;

FIG. 5 is a cross section taken substantially along the line 5-5 of FIG. 5; t FIG. 6 is a perspective view showing the arrangement j 3,2l,53 Patented Aug. l?, 1965 ICAC of contacts and terminals for providing a four-way switch;

FIG. 7 is an enlarged fragmentary side elevation of another embodiment of the invention with portions cut away to show a modified form of switch mechanism; and

FIG. 8 is a cross section taken substantially along line 8-8 of FIG. 7.

By reference to the drawings, particularly FIGS. 1-5, it will be noted that the improved switch comprises a housing including a body 10 and a cover 12 of electrical insulating material. A mounting yoke 14 of standard design is positioned on the upper surface of the cover and the switch, including its internal elements, is held together in assembled relationship by screws 16 which pass through body 10 and cover 12 and are threadedly anchored in suitably tapped holes in yoke 14.

A pair of internal wall-like spaced

side frames

18, 20 are firmly positioned and retained between the body 10 and the cover 12 by means of suitable notches 19 Aformed in body 10 and shoulders 21 formed on cover 12. The side frames 18, 2l) are made of a rigid material, such as a metal, and include aligned keystone shaped openings 22, 24, respectively. Pivotally mounted within the openings 22, 24 and suspended between the

side frames

18, 20 is a generally U-shaped toggle bar 26. Each of the

horizontal extremities

28, 30 of the toggle bar 26 constitutes an actuating arm and passes through corresponding slots in one of two movable

contact guide plates

32, 34, mounted between a side frame and an outer wall of body 10. The guide plates are made of an insulating material and though their function will be more fully described below, at this point it should be realized that they are mounted on actuating

arms

28, 30 for joint pivotal movement therewith and that they form part of the contact switching mechanism.

A slotted actuating rod 36 having a generally conical bearing head 38 ts slidably over the horizontal portion of toggle bar 26, which is an actuating arm for the rod 36, and is urged upwardly therefrom by means of a coil spring 40 which is compressed between the toggle bar 26 and an vannular shoulder 42 von the under side of head 38. The conical head 38 of the actuating rod 36 slidably bears against a rigid partial cylindrical race 44. Race 44 is pivotally mounted relative to the switch housing on a pivot 46 between and supported by the two

side frames

18, 20. The race 44 is rigidly secured to the lower extension 48 of a standard toggling actuator handle 50, whereby the handle also is pivotally mounted by pivot 46. Handle 50 projects through an opening in cover 12 and is accessible from the exterior of the switch housing. Movement of the handle Stb in either direction of pivoting causes the race 44 to jointly pivot about pivot 46. Pivoting of the handle results in interrelated and controlled movement of the bearing race 44, bearing head Sti-actuator rod 36, actuator bar 26 and

contact guide plates

32, 34, with associated contact means, in a manner to be described.

In the illustrated switch, the lswitching action is achieved by means of a pair of movable contact arm assemblies 52. One such assembly is mounted on either side of the switch within the switch housing and outside the

side frames

18 and 20. Each assembly 52 includes one of the movable

contact guide plates

32 or 34, and two electrically conductive strip-like contact arms 56a, 56b, which are identical and mounted onV either side of a guide plate byl rivets 58 or other suitable means. The extremities of each of the electrical contact arms 56a, Sb extend beyond the edges of the guide plate and are flared laterally away from each other, as is best illustrated in FIGS. 1 and 2, so that each pair is positioned =to springingly engage a lixed electrical contact which may be disposed between them.

The operation of the togglingmechanismof this invention to eliect snap acting switching will be best understood by reference to FIGS. 4 and 5, where it will be seen that actuator rod 36-head 33 are disposed in a well 36 having spaced upper diverging wall portions 38. As the handle Si? is selectively manually displaced from the left hand position shown in FIG. 4 to its right hand position, the race 44 jointly pivots clockwise about its pivot 46. The curvature of race 44 and bearing head 38 are such that this initially dcprcsses the conical head 33 axially against the reaction of spring 40, and also compresses the spring. At this time, the head 38 bears against right-hand wall portion 38. Subsequently, on further pivotal movement of race 44, it passes a dead center or toggling over center position, where a tangent to the inner surface of the race 44 is perpendicular to the longitudinal axis of the actuating rod 36. At this time, the energy stored in the compressed spring 40 is suddenly released and impels the conical head 38 to the left along the race 44 into contact with the left-hand wall portion 3S'. Simultaneously, the actuating rod 36 and the toggle bar 26 are rapidly pivoted in a counterclockwise direction about the pivot points formed by bar 26 resting within the openings 22, 24 on side frames 1S, 20. Accordingly, contact arm assemblies 52, comprising the movable

contact guide plates

32, 34 and their attached electrical contact arms 56a and 56h, are simultaneously pivoted from their dotted line FIG. 4 position to the solid line positions illustrated in FIG. 2.

It is important to note that the speed of movement of the contact arm assemblies 52 is completely independent of handle movement, and rapidly commences once the handle has passed the toggling overcenter position. The actual angular movement of the race 44 required for actuation of the actuating rod 36 will depend upon the geometry of the particular switch, i.e., the dimensions, configuration and disposition ofthe toggling elements. In one operative embodiment, these elements are. so designed that a 24 displacement of the handle puts the mechanism into the toggling position. At this point, a simultaneous action occurs which involves release of the stored energy in the spring, together with a rapid 54 rotation of the toggle bar 26 and contact arm assemblies. An identical, but reversed, action takes place when the handle is returned from its FIG. 2 right-hand to its FIG. 4 left-hand position.

The improved snap-acting toggling mechanism described may be incorporated into a variety of electrical switches, A.C. or D.C., where crisp snap-acting contact engagement and disengagement are desired. In FIGS. 1-6 it`i`s illustrated as incorporated into a so-called fourway switch. In such a switch, on each side there are provided a pair of spaced adjacent stationary contacts at each end, and a pair of movable contacts carried by one of the contact arm assemblies 52.

The fixed electrical contacts ofthe illustrated embodiment are best illustrated in FIG. 6. At one end of the switch (upper in FIG. 6) a pair of xed contactfterminal assemblies 60 are mounted on the housing, each comprising a pair of parallel, aligned, vertically spaced contacts 66a and 66h, which are chamfered on their outermost surfaces, as illustrated, so as to readily enter between a pair of adjacent spaced contact arms 56a, 56h carried on a contact arm assembly. Each assembly 60 includes a conductor-mounting terminal screw 61 positioned on a terminal mounting ange 63 having an upper flared lip 63a and a lower ared lip 63h. The mounting flanges extend through openings in the end of switch body 1t) and portions 60 of assemblies 60 are engaged by shoulders 65 on the body and by shoulders 67 on cover 12 to position and mount the assemblies.

The

guide plates

32 and 34 are hexagonal-shaped and have portions extending Within the spaced

xed contacts

60a and 60b at all times, so that, upon actuation of the switch handle and toggling of the mechanism, the tlared ends of the contact arms 56a, 5611 are guided over the chamfered edges of the lxed contacts to form a good electrical contact therewith. The advantage of this construction is that the electrical contacts are self-aligning which simplifies manufacturing and improves service reliability. Each of the movable contact arm assemblies is connected to the same electrical contact assembly 6), i.e., either the upper or lower contact 60a, 60h, regardless of which position the contact arm assemblies may be in.

The opposite end of the switch (lower in FIG. 6) includes a novel cross-over contact-terminal arrangement for achieving the reversing characteristics of a four-way switch. This isv illustrated in FIG. 6 and comprises a right hand contact-terminal assembly 62 and a left hand contact-terminal assembly 64. Each of these contactterminal assemblies includes an identical terminal mounting ange 66 having an upper tiared lip 66a and a lower ared lip 66h. The lower lips 66b fit over an upwardly projecting shoulder 68 on body 10 (FIG. 2) and the

assemblies

62 and 64 are secured in place by means of a downwardly projecting shoulder 70 on cover 12. Each of

assemblies

62, 64 includes a pair of upper fixed

contacts

72a, 72b, which are generally similar to contacts 69a, 6tlb and arranged to be engaged on their opposite sides by the ared ends of the electrical contact arms 56a, 56b when the contact arm assemblies are in the FIG. 2 position. Each of the

assemblies

62, 64 also includes a. horizontally extending

cross-over arm

74, 76, which are Ioffset `relative to the longitudinal extent of the switch and carry at their ends a

U-shaped Xed contact

78, 80, respectively. Contacts 78, are positioned directly below the upper ixed contacts of

assemblies

62, 64 in such a manner as to be engaged by the electrical contact arms 56a, 56h, when they are in the position shown in FIG. 6.

The horizontal portions of the

cross-over arms

74, 76 also offset from one another, as illustrated in FIGS. 1 and 6, for purposes of electrical isolation. This isolation is further improved by insertion of an insulating plate 75 (FIG. 4) between the cross-over arms. The arms 74', 76 are secured to their respective mounting plates 66 by the terminal screws 61 which pass through straps 74', 76 of the arms.

Arms

74, 76 are positioned in a lateral notch 75' formed in lbody 10, as shown in FIG. 4, and upon wiring of the switch and tightened of screws 61', the

arms

74, 76 cooperate with lips 66a, 66b to positively lock the

assemblies

62, 64 into position.

The construction and arrangement of the

contactterminal assemblies

60, 62 and 64 are such that a fourway switch, cross-over, Contact disposition is provided by simply constructed contact-terminal assemblies that are readily assembled in the housing and retained in position by the cap-body assembly.

Inl view of the foregoing, it will be apparent that an improved four-way switch construction having improved snap-acting toggling mechanism has been provided.

An embodiment of this invention is illustrated in FIGS. 7 and 8, where a modified toggling mechanism is shown. In this embodiment, the conical head 38 of FIGS. l5 is replaced by a spherical ball which is supported on the upper end of the coil spring 40. In place of an actuating rod 36 of FIGS. 1-5, the toggle bar 26' is provided with an integral upwardly extending tongue 92 positioned within the coil spring 40. The toggle bar is thus actuated by the coil spring 40 and the tongue 92 as the ball 90 travels along the race. All common elements to the FIGS. 1-6 modification shown in FIGS. 7 and 8 are designated by the same reference numeral with a prime added. The basic mechanics of the operation of the toggling mechanism are similar to those of the switch illustrated in FIGS. 1-5.

It will be apparent to those skilled in this art that a number of variations and modifications may be made in this invention.V For example, a partial cylindrical race has been disclosed. However, the shape of the race need not be restricted to a partial cylindrical surface, though that is the preferred form, but may be of various other congurations, for example, spherical or even planar. Other variations will also occur which will fall within the spirit and scope of this invention, Accordingly, the foregoing description is to be construed as illustrative only, rather than limiting. The invention is limited `only by the scope of the following claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1l. A snap action switch which comprises housing means; rigid bearing race means pivotally mounted within said housing means; means for mounting and selectively pivoting said bearing race means; toggle bar means pivotally mounted within said housing means and spaced from said bearing race means; means for pivotally mounting said toggle bar means about an axis parallel to the axis of pivoting of said bearing race means; bearing means contacting said bearing race means and positioned between said bearing race means and said toggle bar means; resilient means intermediate said toggle bar means and said bearing means compressively urging said bearing means against said bearing race means into contact therewith; means for moving said bearing means relative to and in response to pivoting of said bearing race means; means for pivoting said toggle bar means in response to movement of said bearing means relative to said bearing race means; and electrical switchingcontact means actuated by said toggle bar means.

2. The switch of claim 1 wherein said resilient means comprises a coil spring.

3. The switch of claim 1 wherein said toggle bar means comprises a substantially U-'shaped member having a first horizontal actuating arm extending from one arm of the U and a second horizontal actuating arm extending from the other arm of the U, said U-shaped member being pivoted on said actuating arms.

4. The switch of claim 3 wherein said housing means supports rst and second parallel spaced side frame means,

` each of said side frame means dening an opening therein for receiving andpivotally mounting one ofk said horizontal actuating arms.

S. The switch of claim l wherein said electrical switching contact means comprises a first movable contact arm rigidly aliixed to said rst actuating arm and a second movable contact arm rigidly aflxed to said second actuating arm, whereby said Contact arms pivot jointly with said U-shaped member.

6. The switch of claim 1 wherein said resilient means comprises a coil spring and said means for pivoting said toggle bar means comprises a lever arm extending from said toggle bar means in a direction perpendicular to its axis of pivoting and positioned within said coil spring.

7. The switch of claim 6 wherein said lever arm is an integral part of said toggle bar means and wherein said bearing means is a separate ball bearing.

8. The switch of claim 6 wherein said lever arm is slidable relative to said toggle bar means in a direction perpendicular to its axis of rotation.

9. The switch of claim S wherein said lever arm is integrally connected with said bearing means and said coil spring is compressively retained between said bearing means and said toggle bar means.

Retferences Cited bythe Examiner UNITED STATES PATENTS 1,546,496 7/25 Leppert 200--15 1,821,180 9/31 Gaynor 20G-67 1,918,282 7/33 Meuer 20G-168 2,648,731 8/ 5 3 Despard 200-67 2,734,115 2/56 Dupre 200-168 2,743,330 4/ 56 Ludwig 20G-67 BERNARD A. GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner.

Claims

1. A SNAP ACTION SWITCH WHICH COMPRISES HOUSING MEANS; RIGID BEARING RACE MEANS PIVOTALLY MOUTED WITHIN SAID HOUSING MEANS; MEANS FOR MOUNTING AND SELECTIVELY PIVOTING SAID BEARING RACE MEANS; TOGGLE BAR MEANS PIVOTALLY MOUNTED WITHIN SAID HOUSING MEANS AND SPACED FROM SAID BEARING RACE MEANS; MEANS FOR PIVOTALLY MOUNTING SAID TOGGLE BAR MEANS ABOUT AN AXIS PARALLEL TO THE AXIS OF PIVOTING OF SAID BEARING RACE MEANS; BEARING MEANS CONTACTING SAID BEARING RACE MEANS AND POSITIONED BETWEEN SAID BEARING RACE MEANS AND SAID TOGGLE BAR MEANS; RESILIENT MEANS INTERMEDIATE SAID TOGGLE BAR MEANS AND SAID BEARING MEANS COMPRESSIVELY URGING SAID BEARING MEANS AGAINST SAID BEARING RACE MEANS INTO CONTACT THEREWITH; MEANS FOR MOVING SAID BEARING MEANS RELATIVE TO AND IN RESPONSE TO PIVOTING OF SAID BEARING RACE MEANS; MEANS FOR PIVOTING SAID TOGGLE BAR MEANS IN RESPONSE TO MOVEMENT OF SAID BEARING MEANS RELATIVELY TO SAID BEARING RACE MEANS; AND ELECTRICAL SWITCHING CONTACT MEANS ACTUATED BY SAID TOGGLE BAR MEANS.