BACKGROUND INFORMATION

The subject matter disclosed herein relates to a switching device including a mechanical switching element which physically moves within a chamber between a closed and an open position. More specifically, a guide for the switching element is disclosed, which acts to retain the switching element in a desired physical orientation within the chamber.

As is known to those skilled in the art, switching devices are components in an electrical circuit that may be controlled between an “ON” and an “OFF” state. In the ON state, the switching device establishes an electrical connection between contacts and allows electrical current to flow through the switching device from a power source to an electrical load. In the OFF state, the switching device breaks the electrical connection between contacts, preventing the electrical current from flowing through the switching device. Switching devices may be used, for example, as a circuit breaker, motor protection device, contactor to supply power to one or more branch circuits, or the like. The switching device may be manually or automatically actuated. A mechanical switch or electronic actuator is provided which moves between two states. In one state, the mechanical switch or electronic actuator causes the switching device to establish the electrical connection, and, in the other state, the mechanical switch or electronic actuator causes the switching device to break the electrical connection.

Typically, the mechanical switch or electronic actuator will cause a plunger to move a switching element within the switching device in a first direction as the switch or actuator transition from a first state to a second state. When the mechanical switch or electrical actuator, transition back from the second state to the first state, a spring causes the switching element to return to its original position. The switching element moves within a channel defined within the switching device.

However, these switching devices are not without certain challenges. During normal operation, the potential exists for the switching element to “bounce”. As the spring returns the switching element to its original position, the force of the switching element impacting the other contact to close the circuit may cause a small amount of recoil. In particular, after many cycles and as the spring wears, the force applied by the spring may weaken, such that the spring does not immediately hold the switching element against the contact when closing the circuit. During this recoil, the switching element is no longer mechanically held between the plunger and the spring in its desired orientation within the channel. The switching element may move side-to-side, front-to-back, or even rotate within the channel. Movement of the switching element may, at a minimum, reduce the surface area of contacts that establish a physical connection, accelerating wear between contacts, or, in a worst case, cause failure of the switching device.

Potential movement of the switching element within the switching device is not limited to normal wear of the switching device. During commissioning, for example, a control circuit that is not yet operating correctly may cause a rapid cycling of state in the switching device between the ON and OFF states. This rapid cycling may simulate a bounce condition, where the plunger and spring are not always holding the switching element in place and the switching element may move or rotate within the channel. Similarly, a sharp force applied to the housing of the switching element, for example, during transport, may cause a vibration or impulse force to the device during which the spring compresses enough for the switching element to move or rotate within the channel. Such a force received by the switching device during shipping may result in premature failure of the device.

Thus, it would be desirable to provide an improved switching device in which undesired movement of the switching element is reduced.

It would also be desirable to provide a guide for the switching element which positively retains the switching element in a desired orientation within the switching device.

BRIEF DESCRIPTION

According to one embodiment of the invention, a guide for a switching element includes a front member, a rear member, a first side member, and a second side member. The front member is configured to extend longitudinally along a front side of the switching element, and the rear member is configured to extend longitudinally along a rear side of the switching element. The front member includes a first seat configured to receive a lower surface of the switching element and a first tab configured to retain the switching element within the guide. The rear member includes a second seat configured to receive the lower surface of the switching element and a second tab configured to retain the switching element within the guide. The first side member has a front edge and a rear edge, where the first side member extends between a first end of a lower portion of the front member and a first end of a lower portion of the rear member. The second side member has a front edge and a rear edge, where the second side member extends between a second end of the lower portion of the front member and a second end of the lower portion of the rear member. The first side member includes a first guide portion protruding outward from the front edge of the first side member and a second guide portion protruding outward from the rear edge of the first side member. The second side member incudes a third guide portion protruding outward from the front edge of the second side member, and a fourth guide portion protruding outward from the rear edge of the second side member. An opening is defined between the first side member and the second side member, where the opening is configured to receive a spring between the first and second side members. The spring engages the lower surface of the switching element, the lower portion of the front member, and the lower portion of the rear member when it is inserted into the opening.

According to another embodiment of the invention, a switching device includes a plunger, a spring, a switching element, and a guide for the switching element. The plunger is configured to move reciprocally along an axis between a first position and a second position, and the spring is configured to be selectively compressed as the plunger is moved reciprocally along the axis. The switching element is positioned between the plunger and the spring. The spring is seated, at least in part, against the switching element, and the switching element receives a force applied by the spring in a direction toward the plunger. The guide includes an upper portion defining a seat for the switching element, at least one tab located on the upper portion, and a lower portion defining an opening in which an end of the spring is seated. The at least one tab is configured to retain the switching element within the guide, and the end of the spring is seated in part against the switching element and in part against the guide.

According to still another embodiment of the invention, a guide for a switching element includes an upper portion, a lower portion, and at least one tab located on the upper portion. The upper portion defines a seat for the switching element, and the at least one tab is configured to retain the switching element within the guide. The lower portion defines an opening in which an end of a spring is seated, where the end of the spring is seated in part against the switching element and in part against the guide.

These and other advantages and features of the invention will become apparent to those skilled in the art from the detailed description and the accompanying drawings. It should be understood, however, that the detailed description and accompanying drawings, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.

