Electricity: circuit makers and breakers – Multiple circuit control – Pivoted contact
Reexamination Certificate
1999-12-30
2001-11-06
Scott, J. R. (Department: 2832)
Electricity: circuit makers and breakers
Multiple circuit control
Pivoted contact
C200S018000, C200S293000, C218S001000, C218S153000
Reexamination Certificate
active
06313416
ABSTRACT:
TECHNICAL FIELD
The present invention relates generally to switches and, more particularly, to fusible and non-fusible switches which have modular assemblies of interchangeable components.
BACKGROUND OF THE INVENTION
Switches are usually mounted in an enclosure and incorporate an insulating base to carry an incoming line base for each phase. The circuit for each phase is completed through a pivotal knife blade which engages a corresponding contact to electrically connect the line current to the load. Switches can be fusible or non-fusible. In fusible switches the blade engages a contact which is electrically connected to a fuse clip having a fuse seated thereon. The fuse is then electrically connected to the load. U.S. Pat. Nos. 4,302,643, and 5,777,283, commonly assigned to the Square D Company, disclose a fusible switch utilizing the above-mentioned construction. The disclosures of such patents are hereby incorporated herein by reference. In non-fusible switches the blade engages a contact which is directly electrically connected to the load.
Switches, and particularly fusible switches, are used in switchboards to disconnect and distribute power for commercial and industrial applications. The need arises to distribute more power through enclosures which are the same size or smaller. This requires increasing the electrical rating of the switch to carry a higher voltage and current density while decreasing the size of the enclosure housing and mounting mechanism housing the electrical parts.
Among the problems caused by decreasing the space requirements of a switch is the additional components within the switch, including the components necessary for: mounting different types of fuses; hinging the blade; engaging the end of the blade; providing springing capability to the blade hinge, blade jaw, and fuse clip; mounting the line lug and load lug; connecting the fuse clips and blade jaws with the line lug and load lugs; connecting the line bases; mounting the rotor mechanism; providing a rotor cam stop; providing a mounting mechanism housing; and, connecting the mounting mechanism to the switch. Multiple parts and multiple connecting hardware has resulted in increased cost, increased inventory, increased assembly time and complexity of assembly, and has reduced the flexibility for field replacement of interior components and conversion from a fusible to non-fusible switch and vice-versa. Further, decreasing the space requirements of a switch has decreased the efficiency of the switching mechanism.
Accordingly, there is a need for an effective and efficient means for providing a switch assembly. One of the requirements for such a switch includes that the part count must be reduced and made such that parts that were once unique to a single element, are now compatible with multiple elements and uses. This will reduce inventory, supply and assembly problems. Further, the switch assembly must be economical to manufacture, the switch must be capable of being assembled easier and faster to reduce cost, field assembly and retrofit must be simplified, and the switch must have more widespread application.
SUMMARY OF THE INVENTION
The switch assembly of the present invention provides a limited number of components for both a fusible and a non-fusible switching assembly, and further provides for the interchangeability of many of these components. Additionally, these components are easier to manufacture and assemble, and require less mounting hardware than prior switching assemblies. As such, the present invention provides a switch assembly that is less expensive, more efficient, requires less inventory, and is easily retrofitted between from a fusible switch assembly to a non-fusible switch assembly, and vice versa.
According to one aspect of the present invention, the base switching assembly includes an insulating base, a blade, a blade hinge member, a first contact member, and a line terminal. The blade has a first pivoting member at one end thereof, and the blade hinge member has a bottom wall integral with opposing sidewalls. The bottom wall of the blade hinge member is secured to the insulating base. At least one of the sidewalls has a second pivoting member which mates with the first pivoting member of the blade to allow for rotation of the blade about the pivot position made therebetween. Like the blade hinge member, the first contact member also has a bottom portion integral with opposing sidewalls, and the bottom portion is similarly secured to the insulating base. The opposing sidewalls electrically engage and disengage the blade in response to pivoting movement of the blade. The line terminal contacts and is secured to the bottom portion of the first contact member to provide electrical communication therewith.
According to another aspect of the present invention, the above-recited base switching assembly can be modified into a fusible switch by adding a minimum amount of components, including: a second contact member, a third contact member, a second insulating base, a fusible member, and a load terminal. The second contact member and the third contact member each have a substantially planar bottom portion and opposing sidewalls integral with the bottom portion. The bottom portion of the second contact member contacts the bottom wall of the blade hinge member. The bottom portion of the third contact member is secured to the second insulating base. The first portion of the fusible member is removably secured to the opposing sidewalls of the second contact member, and the second portion of the fusible member is removably secured to the opposing sidewalls of the third contact member. As such, the second contact member is electrically connected with the third contact member. Finally, the load terminal contacts and is secured to the bottom portion of the third contact member to provide electrical communication therewith.
According to another aspect of the present invention, the base switching assembly can be modified to a non-fusible switch by adding a single component, a load terminal. The load terminal contacts and is secured to the bottom portion of the blade hinge member to provide electrical communication therewith.
According to another aspect of the present invention, the blade hinge member, first contact member, second contact member, and third contact member are each adapted to: engage and disengage the blade, mate with the first pivoting member of the blade to allow for rotation of the blade about the pivot position made therebetween, and are also each adapted to removably secure the fusible member thereto. In a preferred embodiment, the blade hinge member and the first, second, and third contact members are identical and interchangeable components, and thus reduce the number of unique components for the assembly.
According to another aspect of the present invention, first, second, third and fourth spring clips are employed. The first spring clip is removably connected to the blade hinge member to assist in retaining the blade to the blade hinge member; the second spring clip is removably connected to the first contact member to assist in engaging the blade; the third spring clip is removably connected to the second contact member to assist in securing the first end of the fusible member; and, the fourth spring clip is removably connected to the third contact member to assist in securing the second end of the fusible member. In a preferred embodiment the first, second, third, and fourth spring clips are geometrically identical and interchangeable components, and thus reduce the number of unique components for the assembly.
According to another aspect of the present invention, a rotor element is adapted to rotate about a notch in the sidewall of the insulating base. The rotor has a sleeve which engages the blade, such that rotation of the rotor causes the blade to engage and disengage itself from the first contact member. The rotor further includes mating members at the first and second ends thereof for connection to additional rotor elements to provide simultaneous rotation
Abroy Hamid S.
Leppla John Kenneth
Golden Larry I.
Scott J. R.
Shrout Larry T.
Square D Company
Stacey David R.
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