Patent Application
20100236912
Embodiments are generally related to electrical switching devices and methods. Embodiments are also related to snap action electrical switches Embodiments are additionally related to snap action springs.
Electrical switches typically operate to open and close an electrical circuit by moving one or more contacts between contact positions. Most “snap action” switches, for example, employ a snap disc disposed in a housing such that the snap disc is sensitive to an applied force. The snap disc generally possesses a convex surface that changes shape to an inverted configuration due to a snap action when the applied force attains a preset threshold. Snap disc switches also may include a movable connecting member and a movable contact arm engaged with the snap disc such that when the snap disc changes configurations between first and second shapes, the movable contact is moved between the open and closed contact positions.
The majority of prior art electrical snap action switches utilize an electrical contact that is located between a metal snap action plate and metal pins (or conductors on a printed circuit board). The presence of several metal-based components and the extended travel of such components can increase the susceptibility of component failure. Additionally, such snap action switches are not easily adjustable when selecting the threshold set point and the operating characteristics of the snap action switch cannot be changed easily. Furthermore, the cost for packaging such metal-based components increases, which further enlarges the size of the final snap action switch assembly and the complexity of the resulting system, may cause a reduction in reliability.
Based on the foregoing, it is believed that a need exists for an improved snap action switch apparatus having a non-metal interchangeable spring for providing a customized spring force. It is also believed that a need exists for an improved snap action spring that offers a high reliability, is easy to assemble, and is inexpensive, as described in greater detail herein.
The following summary is provided to facilitate an understanding of some of the innovative features unique to the embodiments disclosed and is not intended to be a full description. A full appreciation of the various aspects of the embodiments can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
It is, therefore, one aspect of the present invention to provide for an improved snap action switch apparatus.
It is another aspect of the present invention to provide for an improved snap action switch apparatus having a non-metal interchangeable spring for providing customized spring force.
It is a further aspect of the present invention for an improved snap action spring.
The aforementioned aspects and other objectives and advantages can now be achieved as described herein. A snap action switch apparatus is disclosed, which includes a non-metal interchangeable spring for providing customized spring force. The apparatus further includes one or more mutually spaced fixed contact elements and one or more movable contact elements that can move between a normally closed position and a normally open position. An actuating member can be provided for moving the contact elements between the closed position and the open position. The non-metal interchangeable spring can be utilized for performing a snap action operation and is capable of supplying a force needed to maintain the movable contacts in at least one position. A switch mechanism (e.g., a push button) eliminates the applied force to change the movable contacts to the normally open position. The non-metal interchangeable spring can be utilized to achieve a customized spring force in order to easily change and modify the operating characteristics of the snap action switch apparatus.
The non-metal interchangeable spring comprises a dome spring (e.g., rubber) and/or arc shaped spring (e.g., plastic). The dome spring acts as a compressed spring and applies the force to the switch apparatus. The arc-based spring can be anchored to a base (e.g., plastic) at one end and can be attached to the movable contact at the other end. The molded shape of the arc-based spring can be utilized as a normal state. The non-metal interchangeable spring (domed spring and/or arc based spring) can reduce the amount of metal components thereby reducing the cost associated with the production of the snap action switch apparatus. Accordingly, the snap action switch apparatus of the present invention employs the non-metal interchangeable spring that offers high reliability and requires minimal metal components thereby providing a compact and simple structure.
The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the embodiments and, together with the detailed description, serve to explain the embodiments disclosed herein.
The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope thereof.
The movable contact element 165 can move to the closed position 155 for connecting the fixed contact element 180 in an electrically conductive manner. The dome spring 140 is capable of supplying a force to maintain the snap action switch apparatus 100 in normally closed position 155 or in the normally open position 175. The dome shaped spring 140 described herein may be configured from a material such as, for example, rubber, depending upon design considerations. It can be appreciated that other types of materials may be utilized in place of the suggested material. A switch mechanism 120 (e.g., a push button) can be utilized to eliminate the acting force and make the snap action switch apparatus 100 to retain the normally open position 175.
The dome spring 140 possesses a generally circular periphery and is received within a recess, having a corresponding circular periphery so as to maintain a normally upwardly convex configuration. It can be appreciated, of course, that other shapes may be utilized to implement the dome spring 140. The characteristics of the dome spring 140 are a function of various design parameters such as, for example, diameter, thickness, radius of curvature, and stiffness of material that can be selected depending upon design considerations. When the dome spring 140 is pressed, it flexes in a snap action movement so that a portion of the dome spring 140, typically the central portion, presses against the actuating member 130 and thereby establishes an electrical connection between the fixed contacts 180 and 190 and the movable contacts 160 and 165. When pressure is removed, the dome spring 140 snaps back to a stable position and thereby break contact with the fixed contacts 180 and 190.
The dome spring 140 can be supported by a thin web, which provides the necessary elasticity to permit the dome spring 140 to be depressed and actuate the snap action switch apparatus 100. When the applied pressure by the switch mechanism 120 is removed, the thin web can facilitate the dome spring 140 to spring back to its original position. The switch mechanism 120 and the dome spring 140 can spring back out of engagement as a result of the elasticity associated with the dome spring 140 when the actuating force is removed.
The dome spring 140 and the actuating member 130 can return to their original positions upon removal of the external force. The actuating member 130 located within the internal cavity of the switch apparatus 100 can be extended around the fixed terminals 180 and 190 in sufficiently spaced apart relationship with respect thereto so that the snap action switch 100 can have sufficient gap and creep age distance between and among the actuating member 130 and the fixed contacts 180 and 190, and other parts electrically connected thereto. The snap action switch apparatus 100 can provide excellent characteristics with respect to electrical insulation.
The arc shaped spring 210 provides snap action movement in response to changes in force exerted upon the arc shaped spring 210. The molded shape of the arc shaped spring 210 can be utilized as a normal state. The arc shaped spring 210 described herein may be configured from a flat, resilient material such as, for example, plastic, depending upon design considerations. It can be appreciated that other types of materials may be utilized in place of the suggested material. The switch mechanism 120 can be located above the arc shaped spring 210 and can be depressed in a snap action manner.
The arc shaped spring 210 is configured to be compressed to a certain point based upon the orientation of the spring 210 in the switch apparatus 200 and then the compression is released as the spring 210 is moved through an arc of motion. Also, the spring 210 generates a constant upward pressure on the actuating member 130, which can allow the spring 210 to return to its original (default) position following activation.
Note that detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art to variously employ the present invention.
The non-metal interchangeable spring (e.g., dome spring 140 and the arc based spring 210) can be utilized to achieve a customized spring force in order to change and modify the operating characteristics of the snap action switch apparatus 100 and 200. The non-metal interchangeable spring can reduce the amount of metal components thereby reducing the cost associated with the production of the snap action switch apparatus. Accordingly, the snap action switch apparatus 100 and 200 of the present invention employs the non-metal interchangeable spring that offers high reliability and requires minimal metal components thereby providing a compact and simple structure.
It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also, that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
