US 3922510 A
A snap action rocker switch in which the pivotable rocker handle imparts linear motion to contact carrier of a slide switch. Snap action is imparted to rocker handle and contact carrier by U-shaped wire spring mounted between the rocker handle and the brackets upon which it is pivotally mounted. Spring is arranged to provide over-the-center snap action without imparting additional contact pressure to contacts of the switch.
Description (OCR text may contain errors)
United States Patent [191 Arthur Nov. 25, 1975 SNAP ACTION ROCKER SWITCH  Inventor: Ronald H. Arthur, Fort Lauderdale,
 Assignee: AMF Incorporated, White Plains.
 Filed: Oct. 17, 1974  Appl. No: 515,493
 US. Cl. 200/76; 200/16 D; 200/67 A; 200/67 PK  Int. Cl. ..H01H 15/18  Field of Search l. 200/76, 67 C, 67 A, 16 D, 200/16 R, 67 PK, 154
 References Cited UNITED STATES PATENTS 3,457,383 7/1969 Roberts, Jr. et al. l. 200/67 C FOREIGN PATENTS OR APPLICATIONS 729,000 4/1955 United Kingdom ZOO/76 Primary Examiner-David Smith, Jr. Attorney, Agent, or FirmGeorge W. Price; John Hv Gallagher  ABSTRACT A snap action rocker switch in which the pivotable rocker handle imparts linear motion to contact carrier of a slide switch, Snap action is imparted to rocker handle and contact carrier by U-shaped wire spring mounted between the rocker handle and the brackets upon which it is pivotally mounted. Spring is arranged to provide over-the-center snap action without impart ing additional contact pressure to contacts of the switch.
5 Claims, 4 Drawing Figures US. Patent Nov. 25, 1975 7 FIG. 4
SNAP ACTION ROCKER SWITCH BACKGROUND OF THE INVENTION held in a housing shell. The contact carrier is free to 1 move parallel to the path containing the stationary contacts so that the sliding contact selectively makes and breaks contact with different pairs of the stationary contacts as it moves along the path, thus providing a switching action. A rocker handle is the actuator for the sliding contact carrier.
The described type of slide switch has become extremely popular and extensively used because it is relatively easy and inexpensive to manufacture. However, one difficulty that has been encountered in the use of some inexpensive slide switches is that they usually do not include a positive snap or keeper mechanism to maintain the sliding contact in positive engagement with the stationary contacts. If the sliding contact undesirably tends to move off one stationary contact so as to be on the verge of breaking that contact. while at the same time tending to move toward another stationary contact so as to be on the verge of making that contact, serious damage may be caused to the contacts as a result of arcing.
In my US. Pat. No. 3,737,60l issued Feb. 24, 1972, I disclose in FIG. I a rocker handle snap action slide switch which positively maintains the sliding contact carrier in either one of its two switch positions. In that switch, an over-the-center spring member is disposed between the underside of a pivoted rocker handle and the top portion of the slidable contact carrier. The spring is a flat blade-like member which is maintained under compressive forces so as to provide an over-thecenter type of snap action to the contact carrier as it is slid along the path by the rotating rocker handle.
While the snap action switch of my earlier patent has operated satisfactorily in many applications, I have found that the useful life of that type of switch often is not as long as desired. It has been found that because the flat snap spring exerts a downward force on the contact carrier, the contact pressure between the sliding contact and stationary contacts has been significantly increased, thus increasing the wear of the contacts and reducing the useful life of the switch. Additionally, the downward force urges the bottom of contact carrier into frictional contact with the upper surface of the insulating board having the stationary contacts thereon. This results in abrasive action be tween the contact carrier and insulating board and creates contaminating dust and grit which adversely affects the contacts. Additionally, the frictional contact between the contact carrier and insulating board tends to prevent a crisp or smart snapping action.
SUMMARY OF THE INVENTION In accordance with the present invention a snap action slide switch having a rocker handle actuator is provided with an over-the-center spring member in engagement with the pivotable rocker handle and in engagement with bracket members upon which the rocker handle is mounted. In this manner a snap action is imparted to the rocker handle and thus to the contact 2 carrier and sliding contact, but the spring is not in engagement with the contact carrier and thus does not exert thereon the excessive downwardly directed force which has been found to contribute to excess wear of the contacts.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the snap action rocker switch of the present invention;
FIGS. 2 and 3 are, respectively, side and transverse sectional views of the switch of FIG. 1, and;
FIG. 4 is a perspective view of the compression spring utilized in the switch of this invention.
DETAILED DESCRIPTION OF THE INVENTION The switch 10 is comprised of three stationary contacts l2, l3 and 14 which protrude above the top surface of a planar insulating board 17. The stationary contacts are in conductive contact with respective terminal pins 12, I3 and 14. A sliding contact 18 is formed from a thin strip of copper and is fashioned in the form of a spring. Sliding contact 18 is received within a recess 20 in a plastic contact carrier 22. Contact carrier 22 is reciprocally movable horizontally to cause sliding contact 18 to selectively connect stationary contact 13 with either one of the other stationary contacts 12 or 14. Contact carrier 22 includes a slide operator 24 which extends upwardly.
Switch housing 27 is an elongated three sided shell having an aperture 28 through its top surface through which slide operator 24 protrudes. The length of aperture 28 defines the extreme limits of the sliding motion of contact carrier 22. Switch housing 27 includes along both of its bottom edges a plurality of tabs 29 which are staked over the bottom surface of planar insulating board 17 to hold the switch together as an integral unit.
Attached to the top surface of switch housing 27 is a handle mounting member 30. Member 30 has a bottom portion 31 with an aperture 33 therein through which slide operator 24 protrudes. Aperture 33 may or may not contribute to defining the extreme limits of movernent of contact carrier 22. Handle mounting member 30 may be permanently attached to switch housing 27 by any convenient means such as spot welding, or by means of bent tabs, or it may be an integral part of switch housing 27.
Handle mounting member 30 also includes vertically extending side brackets 36 which carry a pivot pin 37 at their top ends. A rocker handle 40 is pivotally mounted on pivot pin 37. The bottom portion of rocker handle 40 is comprised of a recess 42 which forms two actuator fingers 44 and 45 at opposite sides of the bottom portion. Fingers 44 and 45 are constructed and arranged to slidably engage the left and right vertical side surfaces 48 and 49 of slide operator 24. As rocker handle pivots about pivot pin 37, fingers 44 and 45 impart a horizontal motion to slide operator 24 to cause contact carrier 22 and sliding contact [8 to slide across stationary contacts l2, l3 and 14, thereby selectively making and breaking connections therebetween.
The positive snap type action on the movement of rocker handle 40 is provided by a wire spring member 55 which generally has the shape of an inverted Side legs 56 or spring 55 are parallel and curved or bowed in a direction transverse to their lengths, as best seen in FIG. 4. A horizontal crossover section 58 joins side legs 56. The bottoms of side legs 56 have short horizontal segments 57 that extend outwardly in opposite 3 direction from the respective side legs.
Spring 55 is shown in its mounted position in FIGS. 2 and 3 wherein it is seen that crossover section 58 is received in a groove 61 in the underside of rocker handle 40 and the horizontal segments 57 at the bottoms of legs 56 are received within respective slots 63 in side brackets 36 of handle mounting member 30. Wire spring 55 is so constructed and arranged as to be in constant compression, in a generally vertical direction, as illustrated, between rocker handle 40 and side brackets 36.
Groove 61 is located on handle 40 so that when handle 40 is at some intermediate position between its two extreme positions, halfway for example, groove 61 is at its closest proximity to slots 63. At that position spring 55 is in maximum compression storing maximum energy. As handle 40 moves to either side of that intermediate position, spring 55 releases at least a portion of its stored energy to produce a snap action to move handle 40 and positively hold it at one of its extreme positions. By way of actuator fingers 44 and 45 of handle 40 acting on slide operator 24, contact carrier 22 likewise is moved with a snap action to its corresponding extreme positions. At the two extreme positions of contact carrier 22, the horizontal crossover portion 58 of compression spring 55 is on opposite sides of a vertical plane which contains pivot pin 37 and the slots 63 in side brackets 36. Thus, during the pivoting of rocker handle 40 from one of its extreme positions the compressive force on spring 55 increases until the point of centrality of crossover section 58 is reached. As rotation of handle 40 continues, the compressive force then diminishes to a minimum at the other extreme position of rocker handle 40 and contact carrier 22. This provides the over-the-center snap type action to hold contact carrier 22 at its extreme positions thus to assure positive and firm contact between sliding contact 18 and selected pairs of the stationary contacts l2, l3, 14.
It will be seen that the compressive force stored in spring 55 is not acting on contact carrier 22 because the spring is held in compression between rocker handle 40 and side brackets 36. Consequently, no additional contact pressure is present between the sliding and stationary contacts.
From the above description it is seen that a positive over-the-center snap type action is provided for a rocker handle which actuates a slide switch and that the means for providing the desired snap action is comprised of an inexpensive U-shaped wire spring whose legs are curved or bent. The spring is simple to manufacture and to install.
The compressive force provided by spring 55 may be changed by substituting a spring of different dimensions and/or different material, or by relocating the places in side brackets 36 where the short horizontal segments 57 are supported and about which spring 55 pivots. That is, instead of slots 63 in side brackets 36, a series of circular holes may be provided for adjustably locating the short horizontal segments 57 of spring 55.
Spring 55 is illustrated in FIG. 4 in its preferred embodiment. Other embodiments of a compression spring may be employed between rocker handle 40 and one or both mounting brackets 36. As one example, a spring which is comprised of essentially onehalf of spring 55 may be employed. In that embodiment there would be just one horizontal segment 57 received in one slot 63 in a side bracket 36, and just one-half of the crossover section 58 would be received within groove 61 in the underside of handle 40.
While the present invention has been described in its preferred embodiment it is to be understood that other modifications and embodiments may be arrived at without departing from the scope of the present invention.
What is claimed is:
1. In an electrical switch having a plurality of stationary contacts disposed along a path and having a sliding contact movable along said path by a contact carrier for selectively engaging stationary contacts, said contact carrier being movable along said path between extreme switching positions by a rocker member which is pivotally mounted between side brackets that are fixedly mounted relative to said movable contact carrier, the improvement of spring means for providing a positive snap action to the pivoting of said rocker member and to the sliding of the contact carrier between its extreme switching positions, said means and action being provided without imparting additional contact pressure to the stationary and sliding contacts, said improvement comprising a compression spring mounted between said rocker member and at least one of said side brackets,
the location of the mounting of the spring to said rocker member falling on opposite sides of a plane passing through the pivotal axis of the rocker member and the location of the mounting of the spring to a bracket when the rocker member is pivoted to place the contact carrier in its extreme switching positions, thereby to provide an over-the-center snap action to rotation of the handle and the sliding of the contact carrier.
2. in an electrical switch having a plurality of stationary contacts disposed along a path and having a sliding contact movable along said path by a contact carrier for selectively engaging stationary contacts, said contact carrier being movable along said path between extreme switching positions by a rocker handle which is pivotally mounted between side brackets that are fixedly mounted with respect to said movable contact carrier, the improvement of means for providing a positive snap action to the pivoting of said rocker member and to the sliding of the contact carrier between its extreme switching position, said snap action being provided without imparting additional contact pressure to the stationary and sliding contacts, said improvement comprising a compression spring mounted between said rocker member and at least one of said side brackets,
a recessed portion in the end region of the rocker handle which is disposed between said brackets, said recessed portion providing spaced actuator fingers for engagement with said contact carrier, spring receiving means located in the recessed portion of the handle intermediate said actuator fingers,
spring receiving means in at least one of said brackets,
said compression spring being mounted in compression between the spring receiving means of said rocker handle and said bracket,
the spring receiving means in the handle and in the bracket being constructed and arranged to be at their closest proximity when said contact carrier is intermediate its extreme switching positions. whereby the spring is under maximum compression at said intermediate position and under less compression at said extreme positions, thereby imparting an overthe-center snap type switch action to said rocker handle and to said contact carrier.
3. The electrical switch claimed in claim 2 wherein said compression spring is a wire spring member hav ing a generally U-shaped configuration that includes two parallel side legs joined by a crossover portion,
said side legs being curved intermediate their end regions,
the ends of the side legs at the open end of the U- shaped configuration including short segments that extend transversely to said side legs,
the crossover portion of said spring member being received at one of said spring receiving means and the short segments on the side legs of the spring member being received by said other spring receiving means.
4. In a slide switch having a contact carrier for carrying a sliding contact along a path containing a plurality of stationary contacts, said sliding contact being slidable between first and second switching positions in response to corresponding actuation by a rocker handle which is supported between fixed side brackets and pivotable about a pivot axis, said contact carrier having a protruding slide operator and the rocker handle having at its portion which is adjacent said slide operator spaced actuator fingers for respectively engaging opposite sides of said protruding slide operator, thereby providing actuating means to slide the contact carrier upon pivotable motion of the rocker handle, the improvement of providing a snap type action to the pivoting of said rocker handle without adding contact pressure to said contacts, said improvement comprising,
a spring disposed between said brackets and mounted in compression between a spring receiving location on the rocker handle and one or more spring receiving locations on one or more of said brackets,
the spring receiving location on said handle being intermediate said actuator fingers and facing the contact carrier,
said spring receiving locations being constructed and arranged to be at their closest proximity and aligned in a plane containing the pivotal axis ofthe handle when the contact carrier is intermediate its extreme positions,
whereby said spring is in maximum compression at said intermediate position and is in lesser compression at said extreme positions, thereby to provide an over-the-center snap type switching action.
5. In a slide switch having a contact carrier for carrying a sliding contact along a path containing a plurality of stationary contacts, said sliding contact being slidable between first and second switching positions in response to actuation by a rocker handle which is supported between fixed side members and pivotable about a pivot axis, said contact carrier having a protruding slide operator and the rocker handle having at its portion which is adjacent said slide operator spaced actuator fingers for respectively engaging opposite sides of said protruding slide operator thereby providing actuating means to slide the contact carrier upon pivotable motion of the rocker handle, the improvement of providing a snap type action to the pivoting of said rocker handle without adding contact pressure to said contacts, said improvement comprising,
a wire spring member having a generally U-shape that includes two side legs joined by a crossover portion,
the ends of the side legs at the open end of the U- shape including short segments that extend transversely to the side legs,
said side legs being curved intermediate their end re gions,
said wire spring member being supported in compression between said side members and said rocker handle,
said rocker handle having spring receiving means disposed intermediate its spaced actuator fingers for receiving said crossover portion of the spring memher,
said side members having apertures therein for receiving a respective transversely extending short segment at the other end of the spring member.