US2988614A - High speed reversing switch - Google Patents

High speed reversing switch Download PDF

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Publication number
US2988614A
US2988614A US807195A US80719559A US2988614A US 2988614 A US2988614 A US 2988614A US 807195 A US807195 A US 807195A US 80719559 A US80719559 A US 80719559A US 2988614 A US2988614 A US 2988614A
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United States
Prior art keywords
pressure
switch
oil
contacts
reversing switch
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Expired - Lifetime
Application number
US807195A
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English (en)
Inventor
Grebe Otto
Bopp Karl
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Licentia Patent Verwaltungs GmbH
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Licentia Patent Verwaltungs GmbH
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/02—Details
    • H01H33/28—Power arrangements internal to the switch for operating the driving mechanism
    • H01H33/30—Power arrangements internal to the switch for operating the driving mechanism using fluid actuator
    • H01H33/34—Power arrangements internal to the switch for operating the driving mechanism using fluid actuator hydraulic
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V33/00—Structural combinations of lighting devices with other articles, not otherwise provided for
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D27/00—Lighting arrangements
    • F25D27/005—Lighting arrangements combined with control means

Definitions

  • the present invention relates to circuit breakers. More particularly, the present invention relates to high-speed reversing switches adapted for high currents and a great frequency of operation.
  • D.C.-current motors for driving heavy rolls or drums and conveying devices.
  • the sense of rotation of the motor must be very frequently reversed.
  • the process for reversing the sense of rotation is initiated by reversing the polarity of the D.C.-current motor. In order to effect this, it is necessary to interrupt comparatively great currents.
  • the requirements of automatic control call for a speedy operation of this reversing process, and the circuit making and breaking of the elevated currents has to be effected in a comparatively short time, for example, in the order of 50 milliseconds.
  • quick reversing switches comprising a rocking lever mounted on a rotatable shaft.
  • the rocking lever is actuated, thereby turning the shaft by a certain angle.
  • the shaft bears further levers which are provided with contacts for making the desired circuit connections.
  • the known quick reversing switches suiier from great disadvantages.
  • a comparatively great deadtime occurs between the input signal produced by switching in the intermediate relays on the one hand and the moment in which the contacts are lifted.
  • the entire switching time is composed of the time used for switching the intermediate relay, the time which is required for raising the magnetic field of the quick reversing switch to the desired value and the flying time proper of the contacts, the latter being determined by the interval between the moment in which the contacts are first lifted and the moment in which the movement is ended.
  • This total switching time must not exceed a predetermined length following the particular requirements of automatic control. Accordingly, the flying time of the contacts should be very short. This, in turn, calls for elevated accelerating forces and, furthermore, results in a high speed of the movement of the contacts.
  • Still a further object of the present invention is to provide a quick reversing switch adapted for high currents and great frequency of operation in which the locking device is rarely used, thereby greatly lengthening its service life.
  • the highspeed reversing switch of the type adapted for operation of high currents and with a great frequency of operation of the present invention, which switch comprises and is actuated by a hydraulic driving system, whose operation is controlled by an electromagnetic control system.
  • hydraulic-mechanical locking means for stopping the operation of the hydraulically operated switch.
  • the hydraulic driving system comprises an oil pump having a capacity capable of providing but a small fraction of the pressure medium which is needed for the operation of the high-speed reversing switch.
  • the other, large portion needed for that purpose is furnished by at least one pressure reservoir provided according to the invention in the hydraulic driving system.
  • FIGURE 1 is a diagram illustrating the total switching time and the ratio of the switching time of the intermediate relays, the flying time of the contacts and the dead time in conventional high-speed reversing switches.
  • FIGURE 2 is a diagram illustrating the total flying time and the ratio of the switching time of the relays, of the flying time, and the dead time in the greatly improved high speed reversing switch of the present invention.
  • FIGURE 3 is a side elevational view, partly in section, of the high speed reversing switch of the present invention.
  • the time interval t -t designated as the dead time is much ,greater than the time interval t t constituting the flying time.
  • the exciting voltage and the exciting current (i and u) are also shown in the diagrams.
  • the high-speed reversing switch of the presentinvention comprises the electric motor 1, the oil sump 39, and the oil pump 2.
  • the pipe conduit system '4 branches 01? after the oil pump as at 5, one branch leading to the pressure relief valve 6, the other branch leading to the pressure control device 7, comprising the cylinder 711 housing the piston 7b, the latter being connected to a counter pressure spring 7c.
  • the pipe conduit system also connects the oil pump 2 and the valve 6 and the control device 7 with check valve 10. It further communicates with the cylinders 29 and 36, respectively via the pressure reservoirs 13 and 14 and the electromagnetic control valves 35 and 28, respectively.
  • the valves 28 and 35 comprise magnetic coils 45 and 46, respectively, supplied with'current from an accumulator 47a.
  • the cylinders 29 and 36 house pistons 12 and- 11,
  • rocking lever 31 ending in a downwardly projecting pin 29 and having, at its uppermost end, the contact 24 with lateral contact faces 24a and 24b.
  • This rocking switch lever is fulcrumed at 31a and bears a' transverse beam 30, the latter hearing, at its respective outer ends, the faces 39a and 30b-adapted to come into contact with the pistons 11 and- 12, respectively.
  • the fixed contacts 23 and 25 connected with the terminal32 and 37, respectively, and adapted to contact the contact faces 2 4a and 24b, respectively.
  • the flexible wire 33 is connected with its one end to the rocking lever 31 leading; with its other end to the terminal 34.
  • a locking device 15 adapted for arresting the movement of rocking lever 31 and communicating the pipe conduit system 4. It comprises the cylinder 16a housing piston '16, the latter being connected with one end of the counter pressure spring 17 and bearing at its other end a rod 19 upwardly projecting in the direction in which there extends the downwardly projecting pin 20 of the rocking switch lever 31.
  • the rod 19 can be connected withthe contacts 21 and 22 of an alarm circuit, further comprising a suitable current source as, e.g. the accumulator 47, and a signal device, e.g. the signal lamp 48, connected in series with the accumulator 47.
  • the high-speed reversing switch of the present invention operates in the following manner:
  • the oil pump 2 is driven by the electric motor 1, pressing the pressure medium, for example pressure oil, from the oil sump 39 into the pipe conduit system 4.
  • the pressure relief valve 6 determines the maximum pressure of operation in the system.
  • the pressure control device 7 is gauged to a certain maximum pressure. If this pressure is exceeded, the piston 7b is pressed against the influence of spring 70 and its end plate 7d closes the contacts 8 and 9 of the first alarm circuit- T e ch ck v lve aasaeia, e
  • the pressure reservoirs 13 and 14 are adapted to supply additional pressure oil which may be temporarily needed for the switching operation.
  • the pressure reservoirs 13 and 1,4 are charged with pressure oil by the continuously running oil pump during the intervals between the switching operations.
  • the pressure oil thus supplied to the pressure-reservoir cylinders pushes the. pistons 42 ands? upwardly, thereby tensioning the pressure springs 44) and 41;
  • the pressure reservoirs are discharged, i.e. the
  • the rocking lever is swivelled in one direction or the other towards the contacts 23' and 25', respectively, by means of the pistons 11 and 12, pushing the left or the right end, respectively, of the transverse beam 30' upwardly. Thereby contact is established by the contact facesZa and 2412 with the contacts 23 or 25 and the terminals-32 or 37, respectively, according to the position of the rocking lever-31.
  • the movement 'of the rocking switch lever 31 is controlled by the control switch 26.
  • the electromagnetic valve 28 is opened and admits oil to the cylinder 29, thereby pushing the piston 12 in upward direction and moving the rocking lever into the position shown in thedrawing in which contact is made with terminal 32.
  • the main current-then flows from the terminal 32, via the fixed contact 23, the'movable main contact 24- and the flexible wire 33 to the terminal 34.
  • the contact lever 27 can'assume only one of the two afore-described positions, i.e. either the position as indicated by the bold line or the position as indicated by the dashed line in FIGURE 3, the change from the opening and closing. ofvalves 28 and 35 or vice versa is effected by one and the same switching operation.
  • the magnetic coils 45 and 46 are excited with current supplied by the accumulator 47a.
  • the locking device 15 protects the reversing switch against any false operation in case the oil pressure should be too low.
  • piston 16 of the locking'device is pushed against the influence of the counter pressure spring 17 in the direction of arrow 18 and is thereby kept in the position shown in FIGURE 3 of the drawings. Accordingly, oil is admitted to the two cylinders 36 and 29. If the pressure falls below a certain, predetermined minimum not capable of satisfactorily effecting a hydraulic driving of the switch, the spring 17 pushes the piston 16 in the opposite direction of the arrow 18, thereby causing the rod 19 to project into the path of the pin 20 of the rocking switch lever -31, thus arresting its movement. Any switching operation is thereby made impossible until the minimum pressure has again been reached. In the latter instance the increased pressure pushes the piston 16 with the shaft 19 out of the path of pin 20, thereby allowing the movement of the rocking lever.
  • the high-speed reversing switch of the present invention ofiers considerable advantages over any of the devices known 'in the art.
  • the control system with the electromagnetic valves 28 and 35 consumes but a very small amount of electric energy. It is, for example, possible to effect the control of the hydraulic switch with an, input of 1 watt and even less and, hence, intermediate relays for switching the controlled current can be dispensed with. Furthermore, the time needed by a small magnet of, for example, 1 watt in order to respond is very small and, in addition, the hydraulic driving means of the present invention need an infinitely small time in order to respond and effect the driving. As a consequence, the total switching time of the high-speed reversing switch of the present invention is as follows, and as illustrated in the diagram of FIGURE 2.
  • the total switching time is designated by t
  • the dead time is represented by the small time interval t -t which is determined by the time needed for response by the small control magnet, and the time needed by the hydraulic driving means in order to become effective. Since the latter is negligibly small, it is not indicated in the diagram.
  • the diagram shows that the flying time t, of the contact 24 is considerably greater as shown by the time interval t I than the corresponding interval shown in the diagram of FIGURE 1, even though the total switching time is considerably shorter.
  • the flying time t of the contact 24 is considerably greater as shown by the time interval t I than the corresponding interval shown in the diagram of FIGURE 1, even though the total switching time is considerably shorter.
  • a further advantage resides in the provision of the locking device of the invention, which has been described further above and which is also hydraulically-mechanically operated. Since the locking shaft or rod 19 is projected into the path of the rocking lever with the projecting pin 20 only whenever the oil pressure falls below a predetermined medium level, it is only rarely used. Consequently, the wear of this locking device is much smaller than the wear of the locking devices of the known high-speed reversing switches.
  • the service life of the entire switch is shortened by the reduced service life of the locking device, which has to come into operation after each individual switching operation.
  • the armature is mechanically locked after each switching operation, in order to be able to switch off the exciting coils for the comparatively great magnets with a view to obtain a comparatively short relative switching-in period.
  • the switch of the present invention it is unnecessary to effect a locking after each switching operation. As a result, the service life of the entire switch is not impaired by the frequent wear of the locking device as in the known high-speed reversing switches.
  • the continuously operating oil pump 2 may have a much smaller conveying capacity sufiicient for the current consumption.
  • the greater amount of pressure oil needed for impelling one of the two pistons 11 and 12 can be supplied by one of these two pressure reservoirs.
  • a pressure pump of comparatively small capacity is much cheaper, both as to production and operation.
  • the service life of the pressure oil itself is tremendously lengthened because the small conveying capacity of the oil pump results in a reduced circulation of the oil and a smaller friction of the oil produced by the pumping operation. Less heat is, therefore, imparted to the oil.
  • the lengthening of its service life resulting therefrom is obvious if it is kept in mind that a lowering of the medium operational temperature of the oil by only 8% lengthens its service life by 50%.
  • a high-speed reversing switch of the type adapted for operation at high currents and with a great frequency of operation comprising a movable contact arm capable of assuming two switching positions, a hydraulic driving system for alternating the position of said movable contact arm between said two positions, and an electromagnetic control system including two solenoid valves and means for energizing them mutually exclusively for actuating said hydraulic driving system.
  • a high-speed reversing switch of the type adapted for operation at high currents and with a great frequency of operation comprising a movable contact arm, a hydraulic driving system for actuating said movable contact arms, hydraulic locking means dependent upon the by draulic pressure in said system but independent from the position of said arm for arresting said hydraulic driving system and said movable contact arm, and an electromagnetic control system for actuating said hydraulic driving system.
  • a high-speed reversing switch of the type adapted for operation at high currents and with a great frequency of operation comprising a hydraulic driving system, a rocking switch lever driven by said hydraulic driving system, locking means dependent upon the hydraulic pressure in said system and operating independent from anaemia the-position of saidlever engageable with said'rocking switch lever, to arrest the movement thereof said locking meansbeing operated by, said hydraulic driving system and an electromagnetic control system for said hydraulic driving system.
  • a high-speed reversing switch of the type adapted for operation at high currents and v.with a great frequency of operation comprising a hydraulic driving system, a rocking switch lever driven by said hydraulic driving system and having a downwardly projecting pin portion, locking means engageable with said rocking switch lever comprising cylinder and piston means, a rod connected to said piston means, a pressure spring urging said rod into the path of movement of the projecting pin portion of said rocking switch lever, and a pipe conduit system for the pressure medium of said hydraulic driving.
  • said'hydraulic'driving system comprising an oil pump having a capacity capable of. providing a predetermined, small fraction of the oil pressure needed for driving said rockingswitch lever, andat least one pressure reservoir furnishing the remaining, large portion of pressure oil needed" for actuating said rocking switch lever.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Devices That Are Associated With Refrigeration Equipment (AREA)
  • Measuring Fluid Pressure (AREA)
US807195A 1958-04-18 1959-04-17 High speed reversing switch Expired - Lifetime US2988614A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEL30221A DE1119376B (de) 1958-04-18 1958-04-18 Elektrischer Schnellumschalter fuer hohe Stroeme und Schalthaeufigkeit

Publications (1)

Publication Number Publication Date
US2988614A true US2988614A (en) 1961-06-13

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Application Number Title Priority Date Filing Date
US807195A Expired - Lifetime US2988614A (en) 1958-04-18 1959-04-17 High speed reversing switch

Country Status (6)

Country Link
US (1) US2988614A (de)
BE (1) BE576959A (de)
CH (1) CH368218A (de)
DE (1) DE1119376B (de)
FR (1) FR1219587A (de)
GB (2) GB897235A (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3296394A (en) * 1965-01-28 1967-01-03 Rocco Iezzi Air powered current reversing contactor

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT231977Y1 (it) * 1993-09-22 1999-08-10 Zanussi Elettrodomestici Apparecchio frigorifero con lampada perfezionata
EP0651217A1 (de) * 1993-10-27 1995-05-03 Liebherr-Hausgeräte Gmbh Beleuchtung für den Kühlraum eines Kühl- oder Gefrierschrankes

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2251503A (en) * 1938-09-30 1941-08-05 Honeywell Regulator Co Refrigeration control system
US2308261A (en) * 1939-12-06 1943-01-12 Gen Electric Fluid pressure control system
US2464237A (en) * 1943-05-24 1949-03-15 Allis Chalmers Mfg Co Fluid pressure actuated switch
US2555898A (en) * 1949-01-28 1951-06-05 Allis Chalmers Mfg Co Fluid operating and braking system for circuit interrupters
US2861144A (en) * 1957-07-08 1958-11-18 Gen Electric Stored energy type closing device for an electric circuit breaker

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2251503A (en) * 1938-09-30 1941-08-05 Honeywell Regulator Co Refrigeration control system
US2308261A (en) * 1939-12-06 1943-01-12 Gen Electric Fluid pressure control system
US2464237A (en) * 1943-05-24 1949-03-15 Allis Chalmers Mfg Co Fluid pressure actuated switch
US2555898A (en) * 1949-01-28 1951-06-05 Allis Chalmers Mfg Co Fluid operating and braking system for circuit interrupters
US2861144A (en) * 1957-07-08 1958-11-18 Gen Electric Stored energy type closing device for an electric circuit breaker

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3296394A (en) * 1965-01-28 1967-01-03 Rocco Iezzi Air powered current reversing contactor

Also Published As

Publication number Publication date
FR1219587A (fr) 1960-05-18
DE1119376B (de) 1961-12-14
GB1018495A (de) 1966-01-26
GB897235A (en) 1962-05-23
BE576959A (fr) 1959-07-16
CH368218A (de) 1963-03-31

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