Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
  • H01H9/16—Indicators for switching condition, e.g. "on" or "off"

Definitions

• the present invention relates to a control device comprising a spring means for controlling switching means, a position indicator shaft for indicating the position of the switching means, a control shaft, arranged in the spring means and surrounding the position indicator shaft, for charging the spring means, and a release spring means for returning the switching means to the previous switching state.
• Such a device is a substantial part of a switching device, used in internal and external switch plants.
• Control devices are used to switch a switching device between the "Open” and “Closed” positions.
• Switching devices mounted on poles have also lately been provided with earthing functions, resulting in extremely high reliability requirements set on the position indication used in the devices.
• the (normally) energized conductors of an electric circuit built on pole lines are most commonly earthed by means of a separate, transportable earthing means.
• the advantage of this is that the earthing means is visible.
• the use of a transportable earthing means is difficult and laborious and requires the presence of an electrician during the mounting and dismounting of the earthing.
• the present trend is towards switching devices earthed by means of an earthing device, such as so-called knives, attached to the switching means, by turning them to the earthing position.
• the position of the earthing device is then visible even in air-isolated devices.
• the new SFS6 gas-isolated switching devices make it difficult to catch sight of the switching means, and consequently the position of the switching devices is indicated by means of a position indication mechanically coupled to the switching device.
• Three-position switching devices provided with a separate operating shaft and, if needed, also a control device for earthing are currently often used in internal switch plants. Similarly, a separate control device and operating shaft is used for the control of "Open” and “Closed” positions. Hazardous use of switching devices is prevented by locks and blocking.
• Two/three-position control devices provided with one control spring (torsion spring) have lately become commercially available, the positions of these control devices being “Earthed” - "Open” - “Closed”. In these control devices, only an intermediary locking in the device distinguishes a two-position control device from a three- position control device. The intermediary locking prevents the switching motion "Open” - "Earth” in the control device.
• Control devices open and close a switching device by spring force.
• the advantage of spring force is the opening and closing speed, which is important in the operation of the switching device.
• the springs used in the device can be pressure springs, draw-springs or torsion springs. Pressure and draw- springs are usually operated by a so-called throw-open mechanism, the spring being pressed or drawn to a given stress state at its dead point. Having passed the dead point, the spring is released and provides thus a rapid and linear control motion.
• Torsion springs are used in e.g. so-called two-spring control devices in which one spring, a so-called release spring, can be pre-charged for rapid release from e.g. a fuse switch.
• Load disconnectors provided with such a control device are consequently called fuse load disconnectors. It is extremely important to be able to control these to open when such a switching device is controlled against short-circuit owing to erroneous control.
• a further problem in known devices is that a second spring (release spring), released by using a fuse switch or in some other way, directly affects the control shaft of the switching means. In this case impaired operation of the release spring causes an imperfect switching motion in the switching device creating various risk situations.
• the object of the present invention is to eliminate prior art disad- vantages and provide a completely novel solution which prevents manual control devices from operating incorrectly and disturbing operation, and ensures safe operation of a switching device even if the release spring operates defectively. This object is achieved by the control device characterized in the claims of the present invention.
• the device of the present invention is mainly characterized in that the control shaft is arranged to comprise two parts: an outer spline shaft and an inner spline shaft; the parts of the control shaft being interlinked by connecting means arranged in a rotating disc attached to the outer spline shaft and a rotating plate attached to the inner spline shaft, and that the rotational motion of the control shaft is arranged to generate in the rotating disc and the rotating plate a motion in the direction of the control shaft for separating the discs one from the other in order to break the connection between the connecting means.
• the control arrangement of the control device is also characterized in that the release spring means is arranged to charge the spring means.
• the invention provides significant advantages. It prevents injuries and equipment damage due to remote or fuse release under uncontrolled circumstances and enables faulty switching against short-circuit without harm to operators or equipment.
• the invention also ensures that a switching device operates continuously irrespective of the operation of the release spring. It ensures that the transfer motion transmitted to the control shaft is always sufficient to accomplish a perfect switching motion.
• all control, disconnection and charging motions take place from around one control shaft.
• the motions are mere rotational motions except for the axial disconnection motion of the rotating disc, in accordance with the invention.
• No auxiliary levers or shafts are used in the control device of the invention, resulting in an extremely simple, reliable and inexpensive device structure.
• the present control device can easily be modified for different switching devices and the particular switching angles required. This can be effected by the release spring module used in the device by changing the positioning of the wedge surfaces and the locking devices without any major structural changed to the device.
• the invention is characterized by a principle according to which disconnection during a charging motion is achieved by changing the rotational motion of the transmission surfaces on the periphery of a lifting disc into an axial motion in a lifting plate and a rotating disk.
• a separate so-called torque disc including cogs and pressure springs, has been constructed in order for the rotating disc to be able to move in the direction of the longitudinal axis of the device and simultaneously act as a torque transmitter.
• cogs is not at all substantial, the axial motion may equally well be achieved by one motion surface and one release spring.
• the motion surface is preferably able to transmit both torque and axial motion. Such a surface could be e.g. a circular surface, ground even, having sides that are cut even and surrounded by a corresponding sleeve or opening.
• the so-called lifting plate used in the control device of the invention is anchored to the frame of the device. This may be accomplished in different ways, such as by using a separate screw or other supplementary part, an anchor part cast on the lifting plate, or the like. It is essential that by means of the anchoring point the lifting plate is arranged not to rotate in the control device in such a way that the lifting plate is under no circumstances able to rotate to- gether with the charging or disconnection motions occurring in the control device. However, the lifting plate has to be able to move axially.
• the mechanical fastening of the lifting disc to the position indicator shaft or any other shaft transmitted directly from the control spring can be designed in various ways, such as by a cylindrical cog, a screw, a profile surface, by welding, etc. It is essential that the lifting disc always rotates in the same way as the position indicator shaft.
• Figure 1 shows a distribution pattern of the control device according to the invention
• Figure 2 is a detail drawing of the equipment components attached to the outer spline shaft shown as a distribution pattern
• FIG. 3 is a detail drawing of the equipment components attached to the inner spline shaft shown as a distribution pattern.
• the Figures show a preferred embodiment of the invention.
• Such a control device comprises a spring means, known per se, disposed in a control device casing 1.
• the spring means controls switching means whose switching state is transmitted to position indication (not shown) by a position indicator shaft 2.
• the position indicator shaft is surrounded by a control shaft whose rotational motion is used to charge the spring means for generating a fast release and switching in the switching device.
• an outer end 3 of the control shaft is provided with e.g. a lever or other suitable, preferably manually driven control means.
• the control shaft may also be motor-driven by e.g.
• the same charging motion as is used for charging the spring means to achieve switching, is preferably used to charge a second spring means, i.e. a release spring means 4, in the device.
• a second spring means i.e. a release spring means 4
• the purpose of such a release spring means is to return the coupling means to "Open" position in case of malfunction.
• control shaft is preferably divided into two parts at the outer end 3 of the shaft, the two parts being an outer spline shaft 5 and an inner spline shaft 6.
• a torque disc 7 is attached to the outer spline shaft substantially rigidly and arranged to control the rotating disc 8 in such a manner that control cogs 9 extend from the torque disc to receiving openings 10 in the rotating disc.
• the rotating disc 8 in turn, is attached to a rotating plate 11 , secured non-rotatably to the inner spline shaft 6 through projections 12 disposed in the rotating disc, the projections being arranged in slots 13 disposed in the rotating plate.
• a gripping means 14 in the rotating plate 11 is arranged to control the motion of a tightening arm 15, a tightening means 16 arranged in the charging arm being arranged to tighten the release string 4 in the device.
• the release spring is locked by a blocking means (not shown) which can be controlled by a fuse device or a relay, manually or by a magnetic controller as the spring means in turn is released and directs the energy charged therein to charging the control spring.
• the position indication shaft 2 in the device turns and directs the position indication to a new position.
• a lifting disc 17, rigidly attached to the position indicator shaft 2 has turned to a new position simultaneously forcing a lifting disc 18, arranged in the centre of the rotating disc, to an axial motion as at least one transmission surface 19 arranged in the lifting disc hits at least one sliding surface 20 arranged in the lifting plate surface facing the lifting disc.
• the release mechanism of the control shaft according to the invention is one of the most critical parts of the present invention.
• the purpose of the lifting parts of the embodiment of the present device is thus to release the coupling between manual control and the release spring when the charging is complete.
• the transmission and sliding surfaces are thus positioned in such a way that they do not meet until at the end of the control motion in order to minimize friction.
• the advantage is the ability to utilize the kinetic energy of the spring energy of the initial stage.
• the wedge surfaces of the transmission and sliding surfaces 19 and 20 are formed to have only an about 30° inclination, and consequently an advantageous power transmission is achieved to the power directed upwards from the rotational power.
• the friction of the wedge surfaces can be reduced by advantageous material choices and good surface quality, and possibly by the use of lubricant grease.
• Another essential function of the invention is provided by the rotating plate 11 : when the control device is being charged from "Open" position to "Closed" position, the rotating plate must rotate with the charging motion since only the rotating plate charges the spring means. The control motion is transmitted from the control means only to the rotating disc 8 from which the motion is further transmitted or is not transmitted to the rotating plate depending on the particular case.
• the lever is turned in order to manually control the control shaft towards “Closed” position, the release spring 4 being in an uncharged state (in a two-position version the procedure is otherwise the same, but control is impossible in the "Earth” direction).
• the torque is transferred via the outer spline shaft 5 from its centre to the grooved torque disc 7.
• the control clogs 9 in the torque disc transmit the rotational motion further via the receiving openings to the sleeve-like rotating disc 8.
• the rotat- ing disc comprises the projections 12 which rest in the slots 13 of the rotating plate 11. The projections and slots co-operate to turn the rotating plate around the longitudinal axis of the device.
• the rotating plate 11 transmits the torque further from its grooved centre via the inner spline shaft 6 to the spring means controller (to the grooved centre of the release disc of the controller device). At the same time the turning motion of the rotating plate is transmitted via e.g. a therein arranged gripping means 14 to a release spring tightening arm 15 and from there further to a tightening means 16 which charges the device as the lever of the tightening means of the release spring is simultaneously locked into its operating position.
• the release spring 4 is preferably anchored at one end to the frame of the device.
• the position of the end of the spring can be moved in order to carry out different pre-tightenings.
• the rotational motion of the tightening means 16 starts to tighten the release spring from its centre. As the rotational motion reaches the point about 1 to 2° before the release of the spring means, the bent lever of the tightening arm 15 is locked into a locking mechanism (not shown in the Figure) provided in the device.
• the position indicator shaft and the lifting disc arranged therein remain substantially stationary.
• the spring means is released inside the control device controlling the switching device and the position indicator shaft preferably 80° clockwise in the present embodiment.
• the lifting disc 17, and its transmission surface 19, secured to the position indicator shaft 2 rotates by essentially the same angle and at the end of the rotational motion the transmission surfaces hit the corresponding sliding surfaces 20 of the lifting disc 18 disposed above the transmission surfaces.
• the rotating plate 11 is physically detached from the rotating disc 8, the release spring carrying it along for substantially the same 1 to 2° which was the difference in locking and release.
• the release spring 4 pre-charges the spring means towards “Open” position by said 1 to 2°.
• the locking stops the release spring and the rotating plate.
• the rotating disc 8 rises about 5 mm and presses together pressure springs 23 surrounding the control cogs 9 of the torque disc 7.
• the motion is rendered possible by means of the control cogs of the torque disc, whereby they sink deeper into the receiving openings 10 of the rotating disc inside the rotating disk during the pressing stage.
• the rotating disc is now completely independent of the operation of the release spring 4 in such a manner that when the release spring is released manually or e.g. by fuse-backup, the rotating plate rotates as the tightening arm 15 of the release spring pushes the gripping means of the rotating plate.
• the rotating plate now charges the spring means with the rotating disc remaining stationary. The charging ends as the control device is released.
• the release spring operates expressly as an "Open" spring.
• the release spring 4 If the release spring 4 is not released, but remains in a charged state behind locking, the projections 12 of the risen rotating disc 8 will get into contact with upwards bent pegs 24 during a counterclockwise rotation. In this case the charging motion may be finished "manually", the spring means controlling the switching device to "Open” position. The transmission and sliding surfaces then withdraw from their overlapping position and the rotating disc descends owing to the pressure springs 23. The projections of the rotating disc descend into the slots of the rotating plate.
• the rotating disc 8 can be controlled complete normally counterclockwise as an "empty motion" until its projections get into contact with the upwards bent pegs 24 of the rotating plate.
• the release spring has charged the control spring and it has been released and switched the switching device to "Open” position, the transmission and sliding surfaces are withdrawn from an overlapping position as above.
• the rotating disc is not able to directly descend since the slots of the rotating plate are at "Open” position and the rotating disc is still near “Closed” position.
• the pressure springs of the rotating disc press the rotating disc against the surface of the rotating plate, but this does not prevent a counterclockwise "empty control motion". As the pressure springs reach the slots, they press the rotating disc in position.
• control device can be controlled quite normally, either back in "Closed” direction or in "Earth” direction (three-position control device).
• "Earth” direction no disconnection motion takes place, but the projections of the rotating disc remain normally in their notches.

Landscapes

• Mechanisms For Operating Contacts (AREA)
• Mechanical Control Devices (AREA)
• Lock And Its Accessories (AREA)
• Massaging Devices (AREA)
• Valve Device For Special Equipments (AREA)
• Iron Core Of Rotating Electric Machines (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8547123

Family Applications (1)

Country Status (7)

Citations (1)

• 1996
  • 1996-11-25 FI FI964687A patent/FI101435B1/fi not_active IP Right Cessation
• 1997
  • 1997-11-24 DE DE69729894T patent/DE69729894T2/de not_active Expired - Lifetime
  • 1997-11-24 ES ES97913215T patent/ES2224225T3/es not_active Expired - Lifetime
  • 1997-11-24 AU AU50549/98A patent/AU5054998A/en not_active Abandoned
  • 1997-11-24 EP EP97913215A patent/EP1010188B1/en not_active Expired - Lifetime
  • 1997-11-24 WO PCT/FI1997/000716 patent/WO1998024101A1/en active IP Right Grant
• 1999
  • 1999-05-25 NO NO19992506A patent/NO318040B1/no not_active IP Right Cessation

Patent Citations (1)

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