CA1118826A - Change-over switch for tap-changing regulating transformers - Google Patents
Change-over switch for tap-changing regulating transformersInfo
- Publication number
- CA1118826A CA1118826A CA000321547A CA321547A CA1118826A CA 1118826 A CA1118826 A CA 1118826A CA 000321547 A CA000321547 A CA 000321547A CA 321547 A CA321547 A CA 321547A CA 1118826 A CA1118826 A CA 1118826A
- Authority
- CA
- Canada
- Prior art keywords
- change
- crankshaft
- pair
- over switch
- contacts
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
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
- H01H9/0005—Tap change devices
- H01H9/0027—Operating mechanisms
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H3/00—Mechanisms for operating contacts
- H01H3/22—Power arrangements internal to the switch for operating the driving mechanism
- H01H3/30—Power arrangements internal to the switch for operating the driving mechanism using spring motor
- H01H3/3052—Linear spring motors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/50—Means for increasing contact pressure, preventing vibration of contacts, holding contacts together after engagement, or biasing contacts to the open position
- H01H2001/508—Means for increasing contact pressure, preventing vibration of contacts, holding contacts together after engagement, or biasing contacts to the open position with mechanical means to prevent return/reverse movement of movable contact once opening or closing cycle has started
Landscapes
- Mechanisms For Operating Contacts (AREA)
- Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
- Transmission Devices (AREA)
- Supporting Of Heads In Record-Carrier Devices (AREA)
Abstract
Abstract of the Disclosure A spring-drive for load change-over switches of tap-changing regulating transformers. The drive is intended for use in connection with change-over switches having main arcing contacts and current-carrying contacts engaged and disengaged in a pre-determined sequence during change-over operations. The drive includes at least one compression spring arranged between a first slide operable by an eccentric driven by a drive shaft, and a second slide driving the change-over switch by the intermediary of a crankshaft. The crankshaft is adapted to be arrested at the end of each operating cycle when the current-carrying contacts of the change-over switch are in engagement by a pair of pawls each engaging one of a pair of recesses forming part of the crankshaft.
To avoid malfunction of the drive mainly due to changes in temperature of its surroundings, a pair of additional recesses form-ing part of the crankshaft are provided. Each pair of additional recesses is arranged ahead of one of the pair of recesses as seen in the direction of motion of the crankshaft so that the crankshaft may be arrested by one of the pair of pawls when the crankshaft is in a position that corresponds to the closed position of the main arcing contacts, but short of the maximal travel thereof that corresponds to the closed position of the current-carrying contacts.
To avoid malfunction of the drive mainly due to changes in temperature of its surroundings, a pair of additional recesses form-ing part of the crankshaft are provided. Each pair of additional recesses is arranged ahead of one of the pair of recesses as seen in the direction of motion of the crankshaft so that the crankshaft may be arrested by one of the pair of pawls when the crankshaft is in a position that corresponds to the closed position of the main arcing contacts, but short of the maximal travel thereof that corresponds to the closed position of the current-carrying contacts.
Description
~ 2 ~
Back~round o~ the Invention This invention relates to spring-drives for change-over switches for tap-changing regulating transformers. It relates more particu-larly to spring-drives ~or change-over swit~hes referred to as Jansen type switches, because Jansen was the first to disclose this type of switches. Jansen type change~-over switches are well known in the art and disclosed in many U.S.patents such as, ~or instance, in U.S.patent 3~176,089; March 30,1965 to A.Bleibtrau et al for LOAD TAP CHANGERS FOR TRANSFO~MERS; U.S.patent 3,250,864;
10 May 10,1966 to A.Bleibtreu et al for REGULATING TRANSFORMERS
HAVIN& A LARGE NUMBER OF TAPS; U.S.patent 3,858,016; December 31, 1974 to Ernst Baumgartner for SPRING-LOADED SNAP-ACTION STEPPINE-SWITCH-OPERATING MECHANISM, and many other patents.
This invention relates to a spring-drive for change-over switches of the Jansen type which will be described below in more detail, and solves the problem of achieving proper operation of change-over switches for a wide range of ambient temperatures, in-cluding temperatures which may be considered as normal temperatures, and temperatures well below normal temperatures, i.e. extreme colds 20 Jansen type change-over switches are designed to operate their contacts in predetermined sequences and in predetermined inter-~vals of time which results in egtinction o~ the switching arcs atzeros of the curretlt under interruption. When a Jansen type change-over switch is operated under extreme climatic condistions, particularly at very low temperatures, the viscosity o~ the oil in whlch it9 constituent parts are immersed increases and this changes entirely the physical conditions for which the switch has been originally designed. To be more speci~ic, the change-over tlmes of the change-over switch are too slow, or are greatly re-3~ duced from normal conditions, and the change-over switch may possibly not reach its end position when its current-carrying contacts engage and, there~ore, not be latched in said end position.
Back~round o~ the Invention This invention relates to spring-drives for change-over switches for tap-changing regulating transformers. It relates more particu-larly to spring-drives ~or change-over swit~hes referred to as Jansen type switches, because Jansen was the first to disclose this type of switches. Jansen type change~-over switches are well known in the art and disclosed in many U.S.patents such as, ~or instance, in U.S.patent 3~176,089; March 30,1965 to A.Bleibtrau et al for LOAD TAP CHANGERS FOR TRANSFO~MERS; U.S.patent 3,250,864;
10 May 10,1966 to A.Bleibtreu et al for REGULATING TRANSFORMERS
HAVIN& A LARGE NUMBER OF TAPS; U.S.patent 3,858,016; December 31, 1974 to Ernst Baumgartner for SPRING-LOADED SNAP-ACTION STEPPINE-SWITCH-OPERATING MECHANISM, and many other patents.
This invention relates to a spring-drive for change-over switches of the Jansen type which will be described below in more detail, and solves the problem of achieving proper operation of change-over switches for a wide range of ambient temperatures, in-cluding temperatures which may be considered as normal temperatures, and temperatures well below normal temperatures, i.e. extreme colds 20 Jansen type change-over switches are designed to operate their contacts in predetermined sequences and in predetermined inter-~vals of time which results in egtinction o~ the switching arcs atzeros of the curretlt under interruption. When a Jansen type change-over switch is operated under extreme climatic condistions, particularly at very low temperatures, the viscosity o~ the oil in whlch it9 constituent parts are immersed increases and this changes entirely the physical conditions for which the switch has been originally designed. To be more speci~ic, the change-over tlmes of the change-over switch are too slow, or are greatly re-3~ duced from normal conditions, and the change-over switch may possibly not reach its end position when its current-carrying contacts engage and, there~ore, not be latched in said end position.
-2-. .
The contacts of a Jansen type change-over swi~ch are operated by energy storage devices, such as pre~loaded springs. The energy content of, and the sequence of operations effected by, the springs of energy storage devices, are determined by normal temperature conditions, and cannot be altered to cope with con-ditions imposed by excessively low temperatures~ If the energy content of the energy storage device were increased to cope with abnormally low temperatures, the tap-change-over switch would operate too ~apidly under normal temperature conditions. The open-ing of two contacts supposed to operate sequentially may occur with~in the same half cycle on the current wave.
The principal object of the present invention is to further de-velop the a~orementioned spring-drives ~or load-~ap-changers in such a way that they remain operative, even if their previous per-formance was imper~ect due to prevalence of extremely low temperatures. Thws the spring-drives ~or the load-tap-changers re main operative, even at extremely low temperatures and even if the previous operation thereof had to remain incomplete. To achieve this end it is not necessary, or possible, to change the per~or-mance characteristics of the spring energy storage device which islayed out for normal rather than e~tremely low ambient temperatures.
As is well known in the art, load-tap-changers inclucle main arcing contacts and current-carrying contact, The former are de-signed to perform switching operations and to carry the entire load for limited periods o~ time. The latter are not designed to per~orm any switching operations, or to wi~hs~and arcing. They are designed to shunt out the main arcing contacts after completion of a switching operation, and to carry load currents ~or indefinite periods of time. The invention is based on the fact that load-tap-3U changers can be operated, particularly a~ low ambient temperatures,if their main arcing contacts are closed, but their current--carrying contacts, which should be closed, are not closed. Under such circumstances excess heat is generated at the main arcing contacts, and is dissipated by the body of oil surrounding the main arcing contacts, so that no impermissible heating of the main arcing contacts occurs~ The gradual heating of thQ oil by heat generated at the main arcing contacts raises the temperature of the surrounding oil to such an extent that a normal operation can now take place, i.e. the tap-changing switch may reach its ulti-mate or end position wherein the current-carrying contacts are in engagem~nt and shunt out the main atcing contacts. The heating of the body of oil in which the change-over switch is immersed is accelerated by the heat generated in various resistors connected to arcing contacts of the switch~other than the main arcing con-tacts thereof.
Summary of the Invention A spring-driYe for load change-over switches of tap-changing regulating transformers according to this invention is intended for application in connection with change-over switches having main arcing contacts and current-carrying contacts. These contacts are disengaged and engaged in a predetermlned sequence during change-over operations. The spring-drive proper - which is prior art - includes one or more compression springs. This~pring or these springs are arranged between a pair of slides, i.e. a first slide and a second 91ide. The first slide is operable by an eccentric clriven by a drive shaft. The second slide is driving said change-over switch by the intermediary of a crank mechanism and is adapted to be arrested by a pair oE pawls each engaging one of a pair o~
reces9es forming part oE said crank mechanism. That engagement occurs at the end o~ each operating cycle of said change-over switch when said current-carrying contact thereof are in engagement.
The novel feature provided by the present invention consists in a pair of additional recesses forming part of said crank mechanism.
Each of said pair of additional recesses is arranged ahead of one ~ 6 of said palr o~ recesses forming part o said crank mechanism when seen in the direction of motion of said crank mechanism so that said crank mechanism may be arrested by engagement o~
one of said additional recesses by one of said pair of pawls.
Such an arrest of said crank mechanism may take place when it or said second slide is in a position that corresponds to the position of engagement o~ the fixed and the movable main arcing contacts of said change-over switch, but short of the maximal travel thereof when the fixed and the movable current-carrying 10 coQtacts of said change-over switch are in engagement. Thus any reversal o~ the movement of the change-over switch is avoided once its fixed and movable main arcing contacts are in engagement.
- Brief Descri~tion of the Draw~ngs '::
- Fig.l is a -top-plan view of the 9pring-drive according to this invention;
Fig.2 is a longitudinal section along I-I of Fig.l also showing the crank-sha~t for operating the movable contacts of the change-over switcho Description o~ Preferred Embodiment As set ~orth in the above referred-to patents, e,g. U.S.
patent 3,176,069, any Jansen type switch includes two component switches, namely a ~lector switch and transfer or change-over switch, The selector switches serve the purpose o selecting a part~cular tap on a tapped tran9former wind:Lng intended to be connected into an electric circuit. Selector switches do not carry any load currents at the time a particular tap is selected, i.e~ they are not requirefl to interrupt life or current-carry-ing clrcuits, nor to close on such circuits, This task is per-~ormed by the transfer or change-over swltches. The latter per-form all switching operations under load. Therefore all arcingis restricted to the transfer or change-over switches, the selector switches merely selecting the particular transformer tap to which the load is to be transferred, ~ 2~
TransEer or change-over switches comprise a plurality of stationary contacts which are preferabLy arranged along a sector of a circle.On each end of a line of stationary contacts a pair of such ~ontacts is directly connected ~o contiguous taps of a trans~ormer winding. These contacts are the current-carrying contacts of the change-over switch. They are not capable of performing any switching operations wherein an arc is drawn, but are capable of carrying load currents for inde~lnite periods of time. Considering; a line of fi~ed contacts of a change-over switch, there is a pair o~ fixed contacts that is arranged inwardly of the fixed current-carrying contacts. These contacts are also directly connected to two contiguous taps of a transformer winding, i.e. without interposition of any resistorsO They are re~erred-to as the main arcing contacts of the change-over switch because thy are capable of performing switching operations wherein an arc ls drawn and involving the full load current for which the change-over switch is designed.
Further considering a line of fixed contacts of a change-over switch, a number of arcing contacts is arranged inwarclly of the main arcing contacts. These contacts are referred-to as auxiliary arcing contacts and are designed to switch load currents reduced in magnitude by resistors inserted into their respective circuitO Each fixed current-carrying contact is en-gaged by, and disengaged from, a movable current-carrying contact, each ~ixed main arcing contact is engaged by, and flisengaged from, a movable main arcing contact, and each fixed auxiliary arcing contact is engaged by, and disengaged from, a movable au~iliary arcing contact. The sequences of diqe~gagements and engagements of ~he a~orementioned kind of contacts and the timing thereof is determined by fixed programs.
The present invention is more particularly concerned with the drive of the movable contacts of a transfer or change-over switch or, to be more specific, with the operation of the drive ~Li3L1~8Z6 shaft of such a switch. How the rotary motion o~ such a shaft is translated into the required sequential motion o~ the movable con-tacts of the switch is well known ln the art,is adequately des-cribed in ~he above U.S.patents and,therefore,does not need to be repeated in the present context.
Referring now to Figs~] and 2,numeral 10 has been applied to in-dicate a cup-like housing supporting straight guide bars 11 which, in turn,support slides 12 and 13.Slide 12 is a spring loading slide and slide 13 a s~epping slide as will become apparent from what lO follows.Slide 12 is provided with flanges 14 and 15, and slide 13 is provided with flanges 16 and 17.0ne or more helically wound comPression springs 18 are lnterposed between slides 12 and 13.The ends of springs 18 abut against bushings 19 slidably mounted on guide bars ll.Slides 12 and 13 are arranged in such a way that com-pression springs 18 are positioned between the right flange 15 of slide 12 and the left flange 1~ of slide 13,thus allowing loading Of springs 18 by relative movement of slides 12 and 13.Slide 12 is provided on the upper surface thereof with a paIr of projections or abutments 20,which cooperate with an eccentric 21,i.e.a cam whose 20 axis of revolution is displaced ~rom its center so that it is capable of imparting reciprocating motions to slide 12.Eccentric 21 ls driven by drive shaft 22.Sllde 13 ls connected to a shaft to which reference numeral 23 has been applied.Shaft 23 forms together with parts 24,25 and 26-to be described below in greater detail-a crankshaft. The motions of shaft 23 are transmitted to the movable contact of the change-over switch not shown in the drawing.
A9 iS well known in the art, a rotary motion of sha~t 23 ln one direction results in sequential openlngs and closings of the contacts o~ the change-over switch and in a change-over from a 30 ~irst tap to a second tap, and a rotary motion of shaft 23 in the other direction results in sequential openings and closings Of the contacts of the change-over switch and in a change-over from said second tap to said first tap. In ~he operation of the movable contacts of the change-over switch the operating times of its constituent movable contacts may also overlap.
When at the end of a closing operation of a change-over switch the main arcing contacts and the current-carrying contacts are closed, this is effected sequentially, i.e. Eirst the former engage, and thereafter the latter engage. The shaft 23 which operates the contacts of the change-over switch is pro-vided with a cam 24. The latter supports a bolt 25 keyed by a key 26 to it~ Bolt 25 engages a groove 27 provided on the lower side of slide `13. The cam 24 is provided with locking flanges 28 and 29 having recesses which may be engaged selectively by pawls to which numerals 30 and 31 have been applied. Pawls 30 and 31 are spring-loaded, as clearly shown in Fig.l. Cam 24 is further provided with additional locking flanges 281 and 291, respectively having recesses which are engaged by pawls 30 and 31 when and if the operating stroke of the change-over switch is incomplete, as will be explained below in greater detail.
The operation of the structure shown in Figs.l and 2 is as 2Q follows:
Operating shaft 22 drives by means oE eccentric 21 slide 12 to its left limit position shown in Figs.l and 2. This causes loading of compression spring or springs 18 by the right flange 15 o~ slide 12. Slide 13 iæ retained in posltion by cam 24 and locking flange 28 and a recess therein engaged by pawl 30. Thus the pressure of springs 18 on the left flange 16 of slide 11 is increased~ i.e. energy is stored in spring 18. When slide 12 reaches its left limit position a dog 36 on slide 12 engages pawl 30 and causes a rotary motion thereof in counterclockwise direction (Fig.l~, resulting in disengagement of pawl 30 from locking flange 28. This~ in turn, frees cam 24, bolt 25 and slide 13. Slide 13 now moves under the action of spring 18 from right .
The contacts of a Jansen type change-over swi~ch are operated by energy storage devices, such as pre~loaded springs. The energy content of, and the sequence of operations effected by, the springs of energy storage devices, are determined by normal temperature conditions, and cannot be altered to cope with con-ditions imposed by excessively low temperatures~ If the energy content of the energy storage device were increased to cope with abnormally low temperatures, the tap-change-over switch would operate too ~apidly under normal temperature conditions. The open-ing of two contacts supposed to operate sequentially may occur with~in the same half cycle on the current wave.
The principal object of the present invention is to further de-velop the a~orementioned spring-drives ~or load-~ap-changers in such a way that they remain operative, even if their previous per-formance was imper~ect due to prevalence of extremely low temperatures. Thws the spring-drives ~or the load-tap-changers re main operative, even at extremely low temperatures and even if the previous operation thereof had to remain incomplete. To achieve this end it is not necessary, or possible, to change the per~or-mance characteristics of the spring energy storage device which islayed out for normal rather than e~tremely low ambient temperatures.
As is well known in the art, load-tap-changers inclucle main arcing contacts and current-carrying contact, The former are de-signed to perform switching operations and to carry the entire load for limited periods o~ time. The latter are not designed to per~orm any switching operations, or to wi~hs~and arcing. They are designed to shunt out the main arcing contacts after completion of a switching operation, and to carry load currents ~or indefinite periods of time. The invention is based on the fact that load-tap-3U changers can be operated, particularly a~ low ambient temperatures,if their main arcing contacts are closed, but their current--carrying contacts, which should be closed, are not closed. Under such circumstances excess heat is generated at the main arcing contacts, and is dissipated by the body of oil surrounding the main arcing contacts, so that no impermissible heating of the main arcing contacts occurs~ The gradual heating of thQ oil by heat generated at the main arcing contacts raises the temperature of the surrounding oil to such an extent that a normal operation can now take place, i.e. the tap-changing switch may reach its ulti-mate or end position wherein the current-carrying contacts are in engagem~nt and shunt out the main atcing contacts. The heating of the body of oil in which the change-over switch is immersed is accelerated by the heat generated in various resistors connected to arcing contacts of the switch~other than the main arcing con-tacts thereof.
Summary of the Invention A spring-driYe for load change-over switches of tap-changing regulating transformers according to this invention is intended for application in connection with change-over switches having main arcing contacts and current-carrying contacts. These contacts are disengaged and engaged in a predetermlned sequence during change-over operations. The spring-drive proper - which is prior art - includes one or more compression springs. This~pring or these springs are arranged between a pair of slides, i.e. a first slide and a second 91ide. The first slide is operable by an eccentric clriven by a drive shaft. The second slide is driving said change-over switch by the intermediary of a crank mechanism and is adapted to be arrested by a pair oE pawls each engaging one of a pair o~
reces9es forming part oE said crank mechanism. That engagement occurs at the end o~ each operating cycle of said change-over switch when said current-carrying contact thereof are in engagement.
The novel feature provided by the present invention consists in a pair of additional recesses forming part of said crank mechanism.
Each of said pair of additional recesses is arranged ahead of one ~ 6 of said palr o~ recesses forming part o said crank mechanism when seen in the direction of motion of said crank mechanism so that said crank mechanism may be arrested by engagement o~
one of said additional recesses by one of said pair of pawls.
Such an arrest of said crank mechanism may take place when it or said second slide is in a position that corresponds to the position of engagement o~ the fixed and the movable main arcing contacts of said change-over switch, but short of the maximal travel thereof when the fixed and the movable current-carrying 10 coQtacts of said change-over switch are in engagement. Thus any reversal o~ the movement of the change-over switch is avoided once its fixed and movable main arcing contacts are in engagement.
- Brief Descri~tion of the Draw~ngs '::
- Fig.l is a -top-plan view of the 9pring-drive according to this invention;
Fig.2 is a longitudinal section along I-I of Fig.l also showing the crank-sha~t for operating the movable contacts of the change-over switcho Description o~ Preferred Embodiment As set ~orth in the above referred-to patents, e,g. U.S.
patent 3,176,069, any Jansen type switch includes two component switches, namely a ~lector switch and transfer or change-over switch, The selector switches serve the purpose o selecting a part~cular tap on a tapped tran9former wind:Lng intended to be connected into an electric circuit. Selector switches do not carry any load currents at the time a particular tap is selected, i.e~ they are not requirefl to interrupt life or current-carry-ing clrcuits, nor to close on such circuits, This task is per-~ormed by the transfer or change-over swltches. The latter per-form all switching operations under load. Therefore all arcingis restricted to the transfer or change-over switches, the selector switches merely selecting the particular transformer tap to which the load is to be transferred, ~ 2~
TransEer or change-over switches comprise a plurality of stationary contacts which are preferabLy arranged along a sector of a circle.On each end of a line of stationary contacts a pair of such ~ontacts is directly connected ~o contiguous taps of a trans~ormer winding. These contacts are the current-carrying contacts of the change-over switch. They are not capable of performing any switching operations wherein an arc is drawn, but are capable of carrying load currents for inde~lnite periods of time. Considering; a line of fi~ed contacts of a change-over switch, there is a pair o~ fixed contacts that is arranged inwardly of the fixed current-carrying contacts. These contacts are also directly connected to two contiguous taps of a transformer winding, i.e. without interposition of any resistorsO They are re~erred-to as the main arcing contacts of the change-over switch because thy are capable of performing switching operations wherein an arc ls drawn and involving the full load current for which the change-over switch is designed.
Further considering a line of fixed contacts of a change-over switch, a number of arcing contacts is arranged inwarclly of the main arcing contacts. These contacts are referred-to as auxiliary arcing contacts and are designed to switch load currents reduced in magnitude by resistors inserted into their respective circuitO Each fixed current-carrying contact is en-gaged by, and disengaged from, a movable current-carrying contact, each ~ixed main arcing contact is engaged by, and flisengaged from, a movable main arcing contact, and each fixed auxiliary arcing contact is engaged by, and disengaged from, a movable au~iliary arcing contact. The sequences of diqe~gagements and engagements of ~he a~orementioned kind of contacts and the timing thereof is determined by fixed programs.
The present invention is more particularly concerned with the drive of the movable contacts of a transfer or change-over switch or, to be more specific, with the operation of the drive ~Li3L1~8Z6 shaft of such a switch. How the rotary motion o~ such a shaft is translated into the required sequential motion o~ the movable con-tacts of the switch is well known ln the art,is adequately des-cribed in ~he above U.S.patents and,therefore,does not need to be repeated in the present context.
Referring now to Figs~] and 2,numeral 10 has been applied to in-dicate a cup-like housing supporting straight guide bars 11 which, in turn,support slides 12 and 13.Slide 12 is a spring loading slide and slide 13 a s~epping slide as will become apparent from what lO follows.Slide 12 is provided with flanges 14 and 15, and slide 13 is provided with flanges 16 and 17.0ne or more helically wound comPression springs 18 are lnterposed between slides 12 and 13.The ends of springs 18 abut against bushings 19 slidably mounted on guide bars ll.Slides 12 and 13 are arranged in such a way that com-pression springs 18 are positioned between the right flange 15 of slide 12 and the left flange 1~ of slide 13,thus allowing loading Of springs 18 by relative movement of slides 12 and 13.Slide 12 is provided on the upper surface thereof with a paIr of projections or abutments 20,which cooperate with an eccentric 21,i.e.a cam whose 20 axis of revolution is displaced ~rom its center so that it is capable of imparting reciprocating motions to slide 12.Eccentric 21 ls driven by drive shaft 22.Sllde 13 ls connected to a shaft to which reference numeral 23 has been applied.Shaft 23 forms together with parts 24,25 and 26-to be described below in greater detail-a crankshaft. The motions of shaft 23 are transmitted to the movable contact of the change-over switch not shown in the drawing.
A9 iS well known in the art, a rotary motion of sha~t 23 ln one direction results in sequential openlngs and closings of the contacts o~ the change-over switch and in a change-over from a 30 ~irst tap to a second tap, and a rotary motion of shaft 23 in the other direction results in sequential openings and closings Of the contacts of the change-over switch and in a change-over from said second tap to said first tap. In ~he operation of the movable contacts of the change-over switch the operating times of its constituent movable contacts may also overlap.
When at the end of a closing operation of a change-over switch the main arcing contacts and the current-carrying contacts are closed, this is effected sequentially, i.e. Eirst the former engage, and thereafter the latter engage. The shaft 23 which operates the contacts of the change-over switch is pro-vided with a cam 24. The latter supports a bolt 25 keyed by a key 26 to it~ Bolt 25 engages a groove 27 provided on the lower side of slide `13. The cam 24 is provided with locking flanges 28 and 29 having recesses which may be engaged selectively by pawls to which numerals 30 and 31 have been applied. Pawls 30 and 31 are spring-loaded, as clearly shown in Fig.l. Cam 24 is further provided with additional locking flanges 281 and 291, respectively having recesses which are engaged by pawls 30 and 31 when and if the operating stroke of the change-over switch is incomplete, as will be explained below in greater detail.
The operation of the structure shown in Figs.l and 2 is as 2Q follows:
Operating shaft 22 drives by means oE eccentric 21 slide 12 to its left limit position shown in Figs.l and 2. This causes loading of compression spring or springs 18 by the right flange 15 o~ slide 12. Slide 13 iæ retained in posltion by cam 24 and locking flange 28 and a recess therein engaged by pawl 30. Thus the pressure of springs 18 on the left flange 16 of slide 11 is increased~ i.e. energy is stored in spring 18. When slide 12 reaches its left limit position a dog 36 on slide 12 engages pawl 30 and causes a rotary motion thereof in counterclockwise direction (Fig.l~, resulting in disengagement of pawl 30 from locking flange 28. This~ in turn, frees cam 24, bolt 25 and slide 13. Slide 13 now moves under the action of spring 18 from right .
3.;3..~38~i to left. This movement results in a movement o~ crankshaft 23, and consequently of the con~acts of the change-over switch.
After completion of thls movement spring-'biased pawl 31 engages a recess in the other locking flange 29, thus arresting slide 13 ln the new position thereof. This completes the ~ap-changing operation and the energy s-torage device is readied to perform another tap-changing operation. This subsequent operation is initiated by a motion of slide 12 effected by con-tinued rotation of operating shaft 22 and eccentric 21.
The gist of this invention resides in the provision of ad'ditional locking flanges 281 and 289 in cam 24 of which each has a recess for engagement by pawls 30 and 31. Locking flanges 281 and 289 and their respective recesses are positioned shortly ahead of locking flanges 28 and 29 as seen in the direction of Operation of crankshaft 23. Considering the positions of the parts shown in Figs.l and 2, and assuming that a tap-changing impulse is received, but that this occurs during a period of extreme cold, when the viscosity of the oil surrounding the constituent parts of the change-over switch is very high. Under such conditions the slide 13 may not be capable to move shaft 23 to its end or limit position. Hence pawl 31 would not be capable of engaging locking flange 29. In such a case locking flange 291 'becomes operative by receiving pawl 31, since locking flange 291 is positioned ahead of locking flange 29 in the direction of movement o~ cam 24. When pawl 31 engages locking ~lange 291, crankshaft 23,24,25,26 and slide 13 are stopped, or arrested, though they have not reached their limit positions. The addition-al locking flanges 281 and 291 are arranged in such a way that t'hey become effective when, and if, the crankshaft 23,24,25,26 has closed the main arcing contacts, but not the current-carrying contacts of the change-over switch.
~ _g _ ~113826 The progres~lve change of the shape of the recesses in locking ~langes 28 and 29 and in additional locking flanges 281 and 291 cooperating with pawls 30 and 31, respectively, assures that at normal operating conditLons, i.e. at normal temperatures, the operation of pawls 31 and 30 and locklng flanges 28,29 are not af~ected by the presence of the additional locking flanges 281 and 291 and their recesses. In other words, at normal temperatures pawls 30 and 31 will engage the recesses in ~langes 28 and 29 and not be affected by the recesses in flanges 281 and 291. If a tap-changing impulse is received at a time when pawl 30 is about to be disengaged from the recess in locking flange 28, the locking flange 281 remains ineffective since pawl 30 is sufficiently pivoted counterclockwise by eccentric 21 and abutment 36 and held for a su~Eiciently long period o~ time in that position not to engage locking flange 281.
It will be apparent that the above described operation will be repeated iQ an analog fashion when slide 13 is held in its left end or limit position by locking flanges 29, or 291, respectively, and slide 12 is moved by eccentric 21 so far to the right that pawl 31 initiates the change-over switch operation by its disengagement ~rom flanges 29 dr 291, respectively O
I claim as my invention
After completion of thls movement spring-'biased pawl 31 engages a recess in the other locking flange 29, thus arresting slide 13 ln the new position thereof. This completes the ~ap-changing operation and the energy s-torage device is readied to perform another tap-changing operation. This subsequent operation is initiated by a motion of slide 12 effected by con-tinued rotation of operating shaft 22 and eccentric 21.
The gist of this invention resides in the provision of ad'ditional locking flanges 281 and 289 in cam 24 of which each has a recess for engagement by pawls 30 and 31. Locking flanges 281 and 289 and their respective recesses are positioned shortly ahead of locking flanges 28 and 29 as seen in the direction of Operation of crankshaft 23. Considering the positions of the parts shown in Figs.l and 2, and assuming that a tap-changing impulse is received, but that this occurs during a period of extreme cold, when the viscosity of the oil surrounding the constituent parts of the change-over switch is very high. Under such conditions the slide 13 may not be capable to move shaft 23 to its end or limit position. Hence pawl 31 would not be capable of engaging locking flange 29. In such a case locking flange 291 'becomes operative by receiving pawl 31, since locking flange 291 is positioned ahead of locking flange 29 in the direction of movement o~ cam 24. When pawl 31 engages locking ~lange 291, crankshaft 23,24,25,26 and slide 13 are stopped, or arrested, though they have not reached their limit positions. The addition-al locking flanges 281 and 291 are arranged in such a way that t'hey become effective when, and if, the crankshaft 23,24,25,26 has closed the main arcing contacts, but not the current-carrying contacts of the change-over switch.
~ _g _ ~113826 The progres~lve change of the shape of the recesses in locking ~langes 28 and 29 and in additional locking flanges 281 and 291 cooperating with pawls 30 and 31, respectively, assures that at normal operating conditLons, i.e. at normal temperatures, the operation of pawls 31 and 30 and locklng flanges 28,29 are not af~ected by the presence of the additional locking flanges 281 and 291 and their recesses. In other words, at normal temperatures pawls 30 and 31 will engage the recesses in ~langes 28 and 29 and not be affected by the recesses in flanges 281 and 291. If a tap-changing impulse is received at a time when pawl 30 is about to be disengaged from the recess in locking flange 28, the locking flange 281 remains ineffective since pawl 30 is sufficiently pivoted counterclockwise by eccentric 21 and abutment 36 and held for a su~Eiciently long period o~ time in that position not to engage locking flange 281.
It will be apparent that the above described operation will be repeated iQ an analog fashion when slide 13 is held in its left end or limit position by locking flanges 29, or 291, respectively, and slide 12 is moved by eccentric 21 so far to the right that pawl 31 initiates the change-over switch operation by its disengagement ~rom flanges 29 dr 291, respectively O
I claim as my invention
Claims (3)
1. A spring-drive for load change-over switches of tap-changing regulating transformers, said spring-drive being intended for use in connection with change-over switches having main arcing contacts and current-carrying contacts engaged and disengaged in a predetermined sequence during change-over operations, said spring-drive including at least one compression spring arranged between a first slide operable by an eccentric driven by a drive shaft, and a second slide driving said change-over switch by the intermediary of a crankshaft, said crankshaft being adapted to be arrested by a pair of pawls each engaging one of a pair of recesses forming part of said crankshaft at the end of each operating cycle of said crankshaft when said current-carrying contacts of said change-over switch are in engagement, wherein the novel feature consists in a pair of additional recesses form-ing part of said crankshaft, each of said pair of additional recesses being arranged ahead of one of said pair of recesses as seen In the direction of motion of said crankshaft so that said crankshaft may be arrested by engagement of one of said additional recesses by one of said pair of pawls when said crank-shaft is in a position that corresponds to the closed position of the main arcing contacts of said change-over switch, but short of the maximal travel thereof that corresponds to the closed position of the current-carrying contacts of said change-over switch.
2. A spring-drive as specified in claim 1 including means for preventing said pair of pawls from engaging said recesses in said additional locking flanges and arresting said crankshaft when said spring is capable of moving said second slide to the full end position thereof in which the current-carrying contacts of said change-over switch are in engagement.
3. A spring-drive as specified in claim 2 wherein said second slide and said change-over switch are interconnected by a crankshaft having a cam, and wherein said cam is provided with a pair of recesses adapted to arrest said crankshaft at end positions thereof and with a pair of additional re-cesses adapted to arrest said crankshaft in positions short of said end positions thereof.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2806282A DE2806282C2 (en) | 1978-02-15 | 1978-02-15 | Diverter switch for step switches of step transformers |
| DEP2806282.0-32 | 1978-02-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1118826A true CA1118826A (en) | 1982-02-23 |
Family
ID=6031976
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000321547A Expired CA1118826A (en) | 1978-02-15 | 1979-02-15 | Change-over switch for tap-changing regulating transformers |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS54118523A (en) |
| AT (1) | AT365370B (en) |
| BE (1) | BE874101A (en) |
| CA (1) | CA1118826A (en) |
| DE (1) | DE2806282C2 (en) |
| FR (1) | FR2417885A1 (en) |
| GB (1) | GB2014794B (en) |
| NL (1) | NL184858C (en) |
| SE (1) | SE420963B (en) |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4011019C1 (en) * | 1990-04-05 | 1991-12-05 | Maschinenfabrik Reinhausen Gmbh, 8400 Regensburg, De | |
| DE4034126C1 (en) * | 1990-10-26 | 1992-03-05 | Maschinenfabrik Reinhausen Gmbh, 8400 Regensburg, De | |
| DE19510809C1 (en) * | 1995-03-24 | 1996-07-04 | Reinhausen Maschf Scheubeck | Load switching device for stepping switch |
| DE19847745C1 (en) * | 1998-10-16 | 2000-01-05 | Reinhausen Maschf Scheubeck | Tapping switch for interruption-free switchover between different winding tappings of a tapped transformer |
| DE19855860C1 (en) * | 1998-12-03 | 2000-02-17 | Reinhausen Maschf Scheubeck | Mechanical energy store for transformer stepping switch has spring tensioning carriage and switch carriage mounted on parallel guide rods each provided with guide roller on one side and guide surface on opposite side |
| DE19913814C1 (en) * | 1999-03-26 | 2000-04-20 | Reinhausen Maschf Scheubeck | Energy store for electrical stepping switch has reciprocating slide used for tensioning energy storage springs acting on driven element coupled to driven shaft via cog mechanism for rotation in single direction |
| DE10050932C1 (en) * | 2000-10-13 | 2002-06-13 | Reinhausen Maschf Scheubeck | Spring energy store for electrical stepping switch uses tensioning spring(s) between linearly displaced carriage and linearly displaced driven piece for rotation of switch drive shaft |
| DE10062679C2 (en) * | 2000-12-15 | 2003-08-14 | Reinhausen Maschf Scheubeck | Step switch with switching monitoring |
| DE102005027524B3 (en) * | 2005-06-15 | 2006-10-12 | Maschinenfabrik Reinhausen Gmbh | Power accumulator for on-load tap changer, has lift and leaping carriages with three linear bearings, and cam follower coinciding with actuator such that leaping carriage is pushed into new final position by rotation of eccentric plate |
| DE102005027527B3 (en) | 2005-06-15 | 2006-08-17 | Maschinenfabrik Reinhausen Gmbh | Energy storage device e.g. for load-tap changer switch for transformer, has first and second rollers which are moved in stages by step-change slide |
| DE102010046280B3 (en) * | 2010-09-22 | 2011-11-10 | Maschinenfabrik Reinhausen Gmbh | power storage |
| DE102011013749B4 (en) | 2011-03-12 | 2015-03-19 | Maschinenfabrik Reinhausen Gmbh | OLTC |
| DE202012101475U1 (en) | 2012-04-20 | 2013-07-23 | Maschinenfabrik Reinhausen Gmbh | OLTC |
| DE102012103489B4 (en) | 2012-04-20 | 2015-11-12 | Maschinenfabrik Reinhausen Gmbh | On-load tap-changer and its use for voltage regulation in a distribution transformer |
| DE202012101476U1 (en) | 2012-04-20 | 2013-07-23 | Maschinenfabrik Reinhausen Gmbh | OLTC |
| DE102012104379A1 (en) | 2012-05-22 | 2013-11-28 | Maschinenfabrik Reinhausen Gmbh | Power storage for an on-load tap-changer |
| DE102012105152B4 (en) | 2012-06-14 | 2015-11-12 | Maschinenfabrik Reinhausen Gmbh | On-load tap-changer for uninterrupted switching between different winding taps of a tapped transformer |
| DE102012107900A1 (en) | 2012-08-28 | 2014-03-06 | Maschinenfabrik Reinhausen Gmbh | Power storage for an on-load tap-changer |
| JP6013875B2 (en) * | 2012-10-29 | 2016-10-25 | 株式会社ダイヘン | Energy storage device for on-load tap changer |
| DE102013103360A1 (en) | 2013-04-04 | 2014-10-09 | Maschinenfabrik Reinhausen Gmbh | Method for performing a switching operation in an on-load tap-changer |
| DE102015103928B4 (en) | 2015-03-17 | 2021-11-04 | Maschinenfabrik Reinhausen Gmbh | Energy storage for an on-load tap-changer and on-load tap-changer with energy storage |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1956369B2 (en) * | 1969-11-08 | 1971-10-21 | POWER STORAGE FOR LOAD CHANGEOVER FROM TAP SWITCHES FOR CONTROL TRANSFORMERS |
-
1978
- 1978-02-15 DE DE2806282A patent/DE2806282C2/en not_active Expired
-
1979
- 1979-02-12 NL NLAANVRAGE7901079,A patent/NL184858C/en not_active IP Right Cessation
- 1979-02-12 BE BE193407A patent/BE874101A/en not_active IP Right Cessation
- 1979-02-13 SE SE7901231A patent/SE420963B/en unknown
- 1979-02-13 AT AT0110879A patent/AT365370B/en not_active IP Right Cessation
- 1979-02-14 JP JP1509779A patent/JPS54118523A/en active Granted
- 1979-02-15 CA CA000321547A patent/CA1118826A/en not_active Expired
- 1979-02-15 GB GB7905358A patent/GB2014794B/en not_active Expired
- 1979-02-15 FR FR7903898A patent/FR2417885A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| AT365370B (en) | 1982-01-11 |
| FR2417885B1 (en) | 1983-07-29 |
| SE420963B (en) | 1981-11-09 |
| GB2014794A (en) | 1979-08-30 |
| JPS54118523A (en) | 1979-09-14 |
| FR2417885A1 (en) | 1979-09-14 |
| BE874101A (en) | 1979-05-29 |
| GB2014794B (en) | 1982-03-03 |
| ATA110879A (en) | 1981-05-15 |
| NL7901079A (en) | 1979-08-17 |
| SE7901231L (en) | 1979-08-16 |
| NL184858B (en) | 1989-06-16 |
| JPS625326B2 (en) | 1987-02-04 |
| DE2806282B1 (en) | 1979-08-02 |
| DE2806282C2 (en) | 1980-04-10 |
| NL184858C (en) | 1989-11-16 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |