Patent Application
20070278187
The preferred embodiments of the visible open indicator for high voltage vacuum interrupters and switches of the present invention, as well as other objects, features and advantages of this invention, will be apparent from the following detailed description, which is to be read in conjunction with the accompanying drawings wherein:
The present invention provides visual indication of the position of high voltage contacts sealed in a vacuum bottle for switches and interrupters. The contacts cannot be viewed directly through the nontransparent wall of the vacuum bottle and, therefore, it is necessary to locate the visual indicator on the outside of the bottle. The housings for some prior art switches are constructed of solid dielectric materials, such as ethylene propylene diene monomer (“EPDM”) rubber, and position indicators on the outside of the housing indicate when the switch is in the open or closed position. In order to move the indicator, numerous components in the linkage (
The present invention improves the reliability by moving the viewing window closer to the vacuum bottle and using fewer connections between the vacuum bottle actuating element and the indicator. In preferred embodiments, maximum reliability is provided by moving the viewing window as close to the vacuum bottle as the electrical field will allow. This reduces the number of actuating mechanism components between the vacuum bottle contacts and the viewing window to a minimum. Consequently, the risk of a connection failure or a false reading is significantly reduced.
The visible open indicator of the present invention is used with high voltage vacuum interrupters and switches that include a high voltage contact in a vacuum bottle. The vacuum bottle is provided with an actuating element that opens and closes the contact. The actuating element has a shaft that extends outside the vacuum bottle and passes through one or more seals, which maintain the vacuum inside the bottle. An actuating mechanism, which is external to the vacuum bottle, operatively connects to the actuating element. (See U.S. Pat. Nos. 5,667,060; 5,808,258; and 5,864,942 to Luzzi.) The actuating mechanism includes a linkage that has a plurality of components and that can be connected to a handle for manual opening and closing the contacts and/or a motor operator. The actuating mechanism is enclosed in a housing and provided with a viewing window that allows the actuating mechanism to be viewed through the wall of the housing. The viewing window is sealably installed in an aperture in the wall of the housing using methods well know to those skilled in the art, preferably using a sealant such as an epoxy.
An indicator is attached to the actuating mechanism and aligned so that its location corresponds to the location of the viewing window. When the actuating mechanism closes the contacts, the indicator is moved towards the vacuum bottle. When the actuating mechanism opens the contacts, the indicator is moved away from the vacuum bottle. In a preferred embodiment, the indicator is provided with a first indicating portion or indicia for the open contact position and a second indicating portion or indicia for the closed contact position. Most preferably, the first indicia is a green indicator for an open contact and a red indicator for a closed contact. The viewing window and the indicator are designed so that the first indicating portion is visible through the viewing window when the contact is open and the second indicating portion is visible through the viewing window when the contact is closed.
In another preferred embodiment, the actuating mechanism includes an assembly that connects the indicator to the actuating element and a first end connected to the actuating element and a second end connected to a handle. The assembly includes a connector and an insulated rod and, more preferably, a connector, a screw and an insulated rod. The indicator is preferably attached to the first connector at a minimum distance from the actuating element. This reduces the number of actuating mechanism components between the actuating element and the indicator and provides greater reliability. The housing for the actuating mechanism can be constructed from a solid dielectric material; preferably, a hard rubber material and, most preferably, EPDM rubber. The aperture for the viewing window is formed either when the housing is fabricated using methods well know to those skilled in the art, such as injection molding, or after the housing is formed by cutting or drilling an opening that extends through the wall of the housing.
The visible open indicator of the present invention can be used with either a high voltage vacuum interrupter or a high voltage switch, which has an inlet connection with a first centerline for the high voltage source. The viewing window is located in an aperture in the actuating mechanism housing that is connected to the interrupter or switch. The aperture/viewing window has a second center line that is less than 6 inches from the first centerline and, preferably, less than 5 inches. Of course, actual distances may vary.
A viewing window 42 extends through the housing 14 so that, when the actuating mechanism opens or closes the contact 28, the red portion 44 or green portion 46 of the indicator 40 is aligned with the viewing window 42 and shows the position of the contact 28. In a preferred embodiment, the housing 14 is made from a solid dielectric material and the viewing window 42 is located in an aperture 41 in the wall 43 of the housing 14. The viewing window 42 is located as close as possible to the centerline of the inlet connection 29 for the load in order to minimize the number of components in the actuating mechanism 30 between the actuating element 22 and the indicator 40. Preferably, the distance (L) between the centerline of the viewing window 42 and the centerline of the inlet connection 29 is less than 6 inches and most preferably less than 5 inches.
Thus, while there have been described the preferred embodiments of the present invention, those skilled in the art will realize that other embodiments can be made without departing from the spirit of the invention, and it is intended to include all such further modifications and changes as come within the true scope of the claims set forth herein.
This application claims priority from provisional application Ser. No. 60/809,696, filed on May 31, 2006.
| Number | Date | Country | |
|---|---|---|---|
| 60809696 | May 2006 | US |
