Patent Application
20180366287
This technology relates to an apparatus that shifts a bolted pressure switch assembly between OPEN and CLOSED conditions under the biasing forces of springs.
Electrical switches are often used to act as a main disconnect for commercial and industrial applications. The switch has to make and break the current at the contacts safely to ensure electrical connection and disconnection of the circuit. Since the switches are to make and break on load, an operating mechanism is incorporated before the contacts so as to first store the energy inside the mechanism by means of spring-linkage system, and to then let the mechanism release the stored energy to the contacts to make or break the current at some pre-determined velocities. Traditionally, an external handle is connected to the mechanism shaft and the energy to the mechanism is supplied manually by human effort.
In embodiments described below, an apparatus includes an electrical switch assembly and a cam assembly. The switch assembly includes a first contact supported for movement into and out of electrical connection with a second contact. The cam assembly deflects a spring into a stressed condition. The cam assembly also moves the first contact into electrical connection with the second contact under a bias of the spring upon return deflection of the spring from the stressed condition. The apparatus further includes a motor having an output member. A linkage interconnects the output member with the cam assembly to deflect the spring into the stressed condition in response to movement of the output member.
In distinction from a manually operated handle, the motor can provide greater amounts of energy to be stored in the spring. Additionally, the motor can be actuated by wireless or other actuation means located remotely from the switch assembly for enhanced user safety.
In the given examples, the apparatus further includes a frame having an outer periphery configured for fitting within a switchboard cubicle. The motor and linkage are contained within the outer periphery of the frame to ensure a proper fit within the switchboard cubicle.
The apparatus illustrated in the drawings includes parts that are examples of the elements recited in the claims. The illustrated apparatus thus includes examples of how a person of ordinary skill in the art can make and use the claimed invention. These examples are described to meet the enablement and best mode requirements of the patent statute without imposing limitations that are not recited in the claims.
As shown in
The apparatus 10 is sized and shaped for installation in a switchboard (not shown) which, as known in the art, includes a cubicle for containing a switch assembly. The switch assembly 12 of
This particular example of a switch assembly 12 is known as a bolted pressure switch assembly. As shown in
The actuator mechanism 18 is operatively interconnected with the motor 24 and the linkage 28, but is otherwise configured as known in the art. As shown partially in
In operation, the shaft 50 is rotated from a first position to a second position. The shaft 50 can be rotated either manually by use of the handle 20 or automatically by use of the motor 24 and the linkage 28. When the shaft 50 is rotating toward the second position, the cam assembly 52 first compresses one of the springs 54, and then latches the compressed spring 54 in a stressed condition. The shaft 50 is next rotated back to the first position. When the shaft 50 is rotating back toward the first position, the compressed spring 54 remains latched, and the cam assembly 52 compresses the other spring 54 to a stressed condition. However, the cam assembly 52 does not latch the other spring 54 in the compressed condition. Instead, the cam assembly 52 releases the other spring 54 to snap back from the compressed condition. The return movement of the other spring 54 drives the cam assembly 52 to shift the switch assembly 12 from the OPEN condition to the CLOSED condition under the bias of the released spring 54. The actuator mechanism 18 further includes a release button 58 (
As best shown in
The linkage 28 includes first, second and third links 80, 82 and 84. The first link 80 is anchored to the end section 72 of the frame 34, and is movable pivotally about an axis 85. The second link 82 interconnects the first and third links 80 and 84 through couplings having respective pivotal axes 87 and 89. The third link 84 interconnects the second link 82 with the rotatable shaft 50 at the cam assembly 52. The pivotal axes 85, 87 and 89 in the linkage 28 are all parallel to the rotational axis 55 of the shaft 50.
This example of a motor 24 is a linear actuator having a fluid piston-cylinder 100 with an output shaft 102 that is driven to reciprocate along an axis 105. A bracket 106 is fixed to the upper side section 70 of the frame 34. The motor 24 is supported on the bracket 106 for pivotal movement about an axis 107 that also is parallel to the axis 55 at the rotatable shaft 50. The output shaft 102 is coupled to the second link 82 for movement about another parallel pivotal axis 109.
When the motor 24 is actuated to extend the output shaft 102 outward from the piston-cylinder 100, the output shaft 102 moves the linkage 28 from the condition of
The linkage 28 can be disconnected if the handle 20 is to be used instead of the motor 24. This can be accomplished, for example, by disconnecting second link 82 from the third link 84. However, in distinction from the handle 20, the motor 24 can provide greater amounts of energy to be stored in the springs 54. Additionally, the motor 24 can be actuated in the forgoing manner by the use of any suitable actuation means known in the art, including wireless or other actuation means that can be located remotely from the switch assembly 12 for enhanced user safety.
Another embodiment is shown partially in
This written description sets for the best mode of carrying out the invention, and describes the invention so as to enable a person of ordinary skill in the art to make and use the invention, by presenting examples of the elements recited in the claims. The detailed descriptions of those examples do not impose limitations that are not recited in the claims, either literally or under the doctrine of equivalents.
