Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H3/00—Mechanisms for operating contacts
  • H01H3/02—Operating parts, i.e. for operating driving mechanism by a mechanical force external to the switch
  • H01H3/04—Levers
  • H01H3/06—Means for securing to shaft of driving mechanism
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H3/00—Mechanisms for operating contacts
  • H01H3/02—Operating parts, i.e. for operating driving mechanism by a mechanical force external to the switch
  • H01H3/20—Operating parts, i.e. for operating driving mechanism by a mechanical force external to the switch wherein an auxiliary movement thereof, or of an attachment thereto, is necessary before the main movement is possible or effective, e.g. for unlatching, for coupling
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H3/00—Mechanisms for operating contacts
  • H01H3/54—Mechanisms for coupling or uncoupling operating parts, driving mechanisms, or contacts
  • H01H3/58—Mechanisms for coupling or uncoupling operating parts, driving mechanisms, or contacts using friction, toothed, or other mechanical clutch

Definitions

• the invention relates generally to an electrical power distribution switch and more particularly to an actuating mechanism for this type of switch.
• Switches which are actuated by rotation of an external operating shaft are well known. See, for example, U.S. Patent No. 4,467,161. Such switches typically have a rocker arm movable between three positions: two closed positions and an intermediate open position. A plurality of contacts are mounted on the rocker arm, and positions of mechanical equilibrium for the shaft and for the rocker arm corresponding to the three switch positions are provided by an operator so that rotation of the external shaft causes snap action movement of the rocker arm from one position to another. It is desirable that such a switch include actuating means which enable reversal of the shaft but prevent rapid reversal thereof, and prevent the switch from accidentally being shifted from one closed position to the other when it is desired to shift the switch from a closed position to the open position.
• It 'a further object of the invention to provide an actuating mechanism which enables an electrical power distribution switch to be thrown from one position to an adjacent position with a single stroke of the handle, and which enables the switch to be advanced to the next position by further strokes of the handle without removal of the handle from the shaft.
• FIG. 1 is a diagrammatical view of an electrical power distribution switch in accordance with the invention
• FIG. 2 is a side elevational view of the actuating mechanism of the switch of FIG. 1;
• FIG. 3 is a bottom view of the actuating mechanism of FIG. 2;
• FIG. 4 is a fragmentary sectional view taken substantially along line 4-4 in FIG. 2, looking in the direction of the arrows; and
• FIG. 5 is a fragmentary sectional view taken substantially along line 5-5 in FIG. 2, looking in the direction of the arrows.
• the invention is generally embodied in an actuating mechanism 10 for use in an electrical power distribution switch 12 wherein opening and closing of the switch is accomplished by rotation of an external operating shaft 14 connected to a spring-loaded operator 16.
• a switch of this type is described and illustrated in more detail in U.S. Patent No. 4,467,161 which is commonly assigned with the present application and incorporated herein by reference.
• the operator 16 may be of known construction such as that disclosed in U.S. Patent No. 3,403,565, which is commonly assigned with the present application and incorporated herein by reference.
• the illustrated switch 12 includes a sealed housing 18 containing a dielectric such as oil or a suitable gas.
• a seal 19 (FIG. 3) prevents leakage of dielectric fluid around the shaft 14.
• a set of three movable contacts 20a, 20b and 20c is mounted on a rocker arm 22 which is supported for rotation within the housing 18.
• the rocker arm 22 is rotatable between a first closed position wherein the movable contacts 20a, 20b and 20c engage a first set of fixed contacts 24a, 24b, 24c, a second closed position where the movable contacts engage a second set of fixed contacts, 26a, 26b and 26c, and an open position between the closed positions.
• One of the closed positions is normally a tie or ground position.
• a worker rotates the external operating shaft 14.
• the operator 16 rotates the rocker arm 22 with a snap action motion from one position to an adjacent position.
• the ⁇ operator 16 provides a position of mechanical equilibrium at each of the three switch positions.
• the actuating mechanism 10 employs an elongated handle 24 connected to the shaft 14 by a ratchet mechanism 26 which prevents undesirable rapid reversal of the shaft rotation while enabling deliberate reversal thereof without removal of the handle 24 from the shaft 14.
• the ratchet mechanism 26 also enables the switch 12 to be thrown from one closed position to the other closed positi ⁇ n by reciprocated movement of the handle 24, without removal of the handle 24 from the shaft 14.
• the actuating mechanism 10 preferably includes remotely operable means 46 for reversing the rachet mechanism 26 as described below.
• the shaft 14 is fixed to a lock plate 28.
• the handle 24 is pivotably attached to the external end of the shaft 14 by a bolt 27.
• a socket 29 on one end of the handle 24 receives the end of the shaft 14.
• the handle 24 has a movable ratchet pin 30 mounted thereon with a beveled end 32 extendable into apertures 34 in the lock plate 28.
• the pin 30 is parallel to the shaft 14 and biased toward the lock plate 28 by a coil spring 36 which is compressed between a first washer 40 abutting a surface on the handle 24, and a second washer 42 abutting a transverse key 44 extending through the pin 30.
• Engagement between the beveled end 32 of the pin 30 and one of the apertures 34 in the lock plate 28 prevents relative rotation between the handle 24 and the shaft 14 in one direction while permitting such relative rotation in the opposite direction.
• Manipulation of the pin 30 in this manner is facilitated by an elongated direction indicator 46 having a point 48 on one end to indicate the direction of the ratchet and an eye 50 on its opposite end for engagement by a hook or other manipulation means.
• detent means are provided in the form of a slot 51 in the handle 24 for receiving the transverse key 44.
• the spring force urges the key 44 into the detent slot 51, thus preventing rotation of the pin 30.
• the illustrated actuating mechanism 10 is particularly suitable for use on a switch located in an underground vault wherein the switch may be thrown by a worker positioned above the switch with a hookstick.
• the handle 24 has an eye 52 on its movable end. Positioning of the eye 52 at the end of the handle 24 provides a maximum mechanical advantage.
• the illustrated actuating mechanism 10 includes switch position indicators 54 attached to the lock plate 28.
• the position indicator 54 at the top of the switch 12 indicates the position of the switch 12 and will be readable by a worker throwing the switch from above the vault.
• Shifting of the switch 12 from a particular position to an adjacent position requires a predetermined angular displacement of the rocker arm 22.
• Such predetermined displacement of the rocker arm 22 is effected by similar angular displacement of the external shaft 14.
• the spacing of the apertures 34 in the lock plate 28 is substantially identical to the spacing of the three switch positions of the rocker arm 22 and shaft 14. That is, in the preferred embodiment, the open position of the switch 12 is located 60° from each of the closed positions and the apertures 34 in the lock plate 28 are spaced at 60° intervals.
• the actuating mechanism 10 includes a frame 56 which provides stops 58, 60 for the handle 24 that allow angular displacement of the handle 24 through an arc slightly greater than the spacing of the apertures 34 (and of the switch positions) but less than twice the spacing thereof.
• the reason for allowing greater than 60° displacement of the handle 24 is that although throwing the switch 12 nominally requires rotation of the shaft 60°, slightly greater rotation of the shaft 14 may be required in practice.
• the pin 30 When the switch 12 is in an equilibrium position with the pin 30 engaging an aperture 34 and the direction indicator point 48 aiming away from the nearer handle stop 58 or 60, if the handle is pivoted to the nearer stop, the pin 30 is disengaged from the aperture 34 and does not engage any other apertures, nor does it effect similar motion of the lock plate.
• the handle 24 must be advanced from the stop 58 or 60 in the direction of the indicator point 48 until the pin 30 re-engages the aperture 34 before the lock plate 28 will rotate with the handle. Accordingly, the maximum angular displacement of the lock plate 28 in a single stroke of the handle 24 is less * than the range of motion of the handle between the stops 58, 60.
• the switch 12 may be thrown from the open position to a closed position, or from a closed position to the open position, in a single stroke of the handle 24; but the switch 12 may not be thrown from a closed position to a closed position with a single stroke of the handle 24.
• the switch 12 may be thrown from a closed position to closed position by three strokes of the handle 24: a first stroke in a first rotational direction; a second stroke in the opposite rotational direction which shifts the ratchet pin 30 from one aperture 34 to an adjacent aperture; and a third stroke in the original direction.
• the frame 56 of the actuating mechanism 10 comprises two generally U-shaped members 66, 68 which are fixed to the switch housing 18.
• the frame 56 includes top and bottom walls 62, 64, each of which has an elongated slot 70 therein for receiving a radially-projecting tab 72 on the lock plate 28 to serve as a stop for the lock plate.
• a first set of notches 74 is provided on the periphery of the lock plate at 60° intervals corresponding to each of the three switch positions for engagement by a padlock.
• a padlock shackle can be passed through the opening 78 and the notch 76 in the bottom wall 64 and one of the notches 74.
• a second set of notches 80 is also provided on the periphery of the lock plate at intervals corresponding to the three switch positions for engagement with a sliding bolt lock.
• a sliding bolt lock could be fastened to the side wall 82 of the frame 56 so that its sliding bolt would pass through a circular hole 84 in the side wall 82 for engagement with one of the notches 80 in lock plate 28.
• the present invention provides a novel and improved actuating mechanism for throwing an electrical power distribution switch. While a preferred embodiment is described and illustrated herein, there is no intent to limit the scope of the invention to this or any particular embodiment.
• the actuating mechanism of the invention could be used in a two-position switch rather than the three-position switch described herein. In other embodiments of the invention, the actuating mechanism might have a different frame and/or a different orientation.

Landscapes

• Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)

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ID=24961962

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Family Cites Families (18)

• 1986
  • 1986-05-22 EP EP19860903875 patent/EP0222011A1/de not_active Withdrawn
  • 1986-05-22 WO PCT/US1986/001114 patent/WO1986007186A1/en unknown

Non-Patent Citations (1)

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