US1975821A - Overload switch - Google Patents

Overload switch Download PDF

Info

Publication number
US1975821A
US1975821A US536423A US53642331A US1975821A US 1975821 A US1975821 A US 1975821A US 536423 A US536423 A US 536423A US 53642331 A US53642331 A US 53642331A US 1975821 A US1975821 A US 1975821A
Authority
US
United States
Prior art keywords
contact
switch
armature
circuit
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 - Lifetime
Application number
US536423A
Other languages
English (en)
Inventor
Wright Stanley Robert
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US1975821A publication Critical patent/US1975821A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/04—Oxygen-containing compounds
    • C08K5/10—Esters; Ether-esters
    • C08K5/101—Esters; Ether-esters of monocarboxylic acids
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H57/00—General details of gearing
    • F16H57/08—General details of gearing of gearings with members having orbital motion
    • F16H57/10—Braking arrangements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10—Operating or release mechanisms
    • H01H71/12—Automatic release mechanisms with or without manual release
    • H01H71/44—Automatic release mechanisms with or without manual release having means for introducing a predetermined time delay
    • H01H71/443—Automatic release mechanisms with or without manual release having means for introducing a predetermined time delay with dash-pot
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H83/00—Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current
    • H01H83/12—Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current operated by voltage falling below a predetermined value, e.g. for no-volt protection

Definitions

  • This invention relates to overload switches.
  • the object of the invention is the provision of improvements in such switches and the inven tion consists broadly in the arrangement that upon the occurrence of a relatively low overload the switch is operated after a time ⁇ interval in opposition to a retarding device and .upon the occurrence of a relatively hig overload said switch is operated instantly independently of said retarding device.
  • Fig. 1 is an elevation of an overload switch arrangement in accordance with the invention
  • Fig. 2 is a plan of the same
  • Fig. 3 is an elevation at a different angle from Fig. 1 of a portion of the same,
  • Fig. 4 is a sectional elevation of a dash p'ot included in the same.
  • Fig. 5 is a developed diagrammatic view of a modified arrangement in which protection is also given against voltage failure.
  • Fig. 6 is a similar view of a still further modified arrangement.
  • Figs. '7 and 8 illustrate to an enlarged scale in two different positions a lock out element employed in the switches of Fig. 6.
  • Figs. 9 and 10 illustrate in two positions a modification of the arrangement shown in Figs. 6 to 8.
  • Fig. 11 is a front elevation of another overload, no volt switch arrangement in accordance with the invention.
  • Fig. 12 is a plan of the same
  • Fig. 13 is an end elevation of the same
  • Fig. 14 is a circuit diagram illustrating the way in which the arrangement of Figs. 11-13 is employed when two wire control is required.
  • Fig. 15 is a similar diagram illustrating the way in which said arrangement is employed when three wire control may be employed.
  • Fig. 16 is a sectional elevation 01' another overload no v'olt switch arrangement in accordance with the invention.
  • Fig. 17 is a circuit diagram illustrating the way in which the arrangement of Fig. 16 is employed.
  • the arrangement therein illustrated comprises three upright coils 1 for the three phases to be controlled, having magnetic plungers 2 and disposed symmetrically around the iron stem 3 of an upright oil dashpot 4 having a brass plunger.
  • the upper ends of the three plungers 2 have reduced stems 5 55 extending from them and these stems together with the iron dashpot stem 3 are fixed as shewn to a common linking plate 6 so that the three coil plungers and the dashpot plunger are constrained to move as one piece...
  • armature 7 On the top of the three coils is located a plate armature 7.
  • This armature 7 has three holes in it through which the coil-plunger stems 5 pass and a. central hole through which the dashpot stem 3 passes.
  • Three short brass sleeves 8 extend downwards from said armature in such a posi tion that their bores form continuations ot the three former holes so that the coil-plunger stems .5 also pass through said brass sleeves.
  • Coil springs 9 surrounding said brass sleeves normally hold the armature 7 a given distance above the top of the coils 1 but if a downward force of con-' siderable magnitude is applied to said armature said springs will be compressed, said brass sleeves passing into the clearance between the coil-plunger stems 5 and the coils.
  • Three contacts 10 are mounted on the edge of the armature 7 in such a way that their contacting surfaces face outwardly or away from the axis of the dash-pot stem 3.
  • the respective terminals 10a connected to these contacts 10 are mounted on 30 the top of the armature 7 and the contacts, when said armature is in the normal position engage with respective fixed contacts 11.
  • the pairs of contacts 10, 11 are connected in series with one another in the coil circuit of a main contactor or 35 similar isolating switch.
  • a suitable mounting for the device may consist of a triangular plate 12 on whose upper face the lower ends of the coils 1 are mounted and on whose lower face the upper end of the dash-pot cylinder 4 is mounted, said plate 12 having holes in it for giving access to the plungers and the dash-pot stem.
  • the dash-pot has a. variable time lag period after which it's plunger 13 moves freely for permitting the coil plungers 2. to engage with the brass sleeves 8.
  • the bore of the cylinder 4 or dash-pot proper is enlarged toward 1 the upper end as shown so that a clearance is pro- 1 vided outside the circumferential periphery of the piston or plunger when it reaches this enlarged portion of the bore.
  • This piston is formedin the well known way with a downwardly extending skirt and this skirt .has a number of relatively large side holes 14 formedthrough it at a given distance from the top.
  • Top holes 15 are also formed through the top portion of the piston and a washer 16 is located on this top portion so as to restrict the flow of oil through these top holes when the plunger 13 is being lifted but to permit of 4 free flow when said plunger is sinking.
  • the side holes 14 When the plunger is at the bottom of its stroke the side holes 14 will be closed by the wall of the cylinder 4 and the initial upward movement will be slow as governed by the restricted flow of oil through the top holes 15.
  • the side holes 14 When however the plunger has been lifted to a given levelthe side holes 14 will register with the enlarged portion of the cylinder bore so that oil with be free to rush through these side holes and the plunger will then rise freely.
  • a screwed rod 17 is screwed from the outside 1 through the centre of the bottom of the cylinder ,4. and the upper end of this rod forms a stop limiting the downward movement of the plunger 13 and therefore determining the distance the piston moves at the slow rate or in other words the period of the time lag.
  • this time lag period may obviously be preselected.
  • coils 1 and plungers 2 having reduced stems 5 are provided as before.
  • the stems 5 pass through a fixed guide plate 18, and a common horizontal wrought iron plate armature 19 is located underneath the three coils.
  • Extending upwardly from this armature is another vertical stem 20 which also passes through a hole in the guide plate 18.
  • the coils and plungers may be arranged symmetrically around the stem 20 as centre.
  • the common armature 19 is connected, by
  • dash-pot 4a may be similar in all respects to the dash-pot 4 described in connection with the preceding arrangement.
  • a start push button 26 is provided which short circuits all the four switches 21, 22 so that when this push button is depressed the main contactor winding 23 is energized and the motor is started.
  • the normal current in the three windings will be sufficient to lift the three plungers so that the three plunger switches 21 will close but this normal current will be insufiicient to lift the common armature 19 in opposition to the dash-pot 4a so that the armature switch 22 will remain closed. All four switches 21, 22 being closed therefore the start switch 26 will be short circuited and the contactor winding 23 will remain energized when said short switch is released.
  • the reference 27 designates a stop switch by depression of which the circuit of the winding 23 will be at any time deenergized, thereby oausing the wholearrangement to return to the original position.
  • Fig. 6 this illustrates a somewhat different arrangement in which the separate parallel circuit for the start switch may be dispensed with.
  • this arrangement there are only the three switches 21, one of these (the centre one according to the drawings) being common as shown to one of the plunger stems 5 and to the armature stem 20.
  • Each of these switches 21 has a lower contact pivoted about point a: and an upper contact pivoted about point y, which upper contact rests upon said lower contact.
  • the three plunger stems 5 act directly to lift the lower contacts and the upper contacts are accordingly lifted by means of said lower contacts.
  • the armature stem acts directly to lift the upper contact of the switch to which it appertains.
  • each switch 21 has a tall piece as shown which interlocks with a tail piece on the upper contact of the switch 21 immediately to the left in such a way that said upper contact cannot fall so long as said lower contact of the former switch is held up. (As the drawing is a developed diagrammatic drawing it has not been possible to illustrate thisinterlock in the case of the two switches which appear as being outside in said drawing.)
  • Each of the three switches 21 is provided with a weight biased lock-out element 28 (Figs. '7 and 8) pivoted, about an axis 2, on the upper contact, which, immediately the two contacts are sufiiciently separated to break circuit, is free to rotate under the influence of its biasing weight from the position of Fig. '7 to insert an insulating piece 29 between them as in Fig. 8.
  • a common resetting arm 30 is provided upon operation of which any of these lock-out elements are reset.
  • start switch 26a is an ordinary switch and is connected in series with the three switches.
  • start switch 26a When however the start switch 26a is opened so that all the contacts drop together. they will remain in contact with one another so that the circuit is ready to be re-establlshed immediately by reclosure of said start switch.
  • Figs. 6-8 may be modified as in Figs. 9 and 10.
  • each right hand switch element has a tail piece which engages under a tail piece on the left hand switch element of the switch immediately to its right.
  • Each of these right hand tail pieces is upwardly biased by means of a spring 31 and since the left hand tailpieees rest on the right hand tail pieces it will be seen that all the tail pieces are upwardly biased with one equal force. Normally these upwards biases bal ance each other by the engagement of the opposite contacting surfaces of the switch elements as shown in Fig.
  • a single switch is provided in place of the three plunger switches.
  • the movable contact of thisswitch takes the form of a V shape plate 34 pivoted about a horizontal axis X-X in its plane and passing say through'the apex of the V parallel to an imaginary line joining the extremities of the two arms.
  • the stems 5 of the three plungers 2 are formed with collars 35 which engage each with an insulating end of a respective rocking element 36 pivoted between its ends about a horizontal axis in such a way that when said plungers 2 are pulled down the said insulating ends of said pivoted elements 36 are pulled down and the remote ends ofsaid pivoted elements are accordingly pushed up.
  • This arrangement is provided with an armature 19, armature stem 20, divided rod 24a, 241) spring 25 and dashpot 4a all functioning precisely as in Figs. 5 and 6, the arrangement being such that when the armature 19 is lifted the stem 20 135 lifts the V shaped bridging contact 34.
  • the V shape bridging contact 34 is biased by means of a spring 3'7 about its axis in such a way that the extremities of its two arms bear down upon the remote ends of the two outer rocking 140 elements 36 and the crutch portion of said bridging contact 34 bears down on the remote end of the third rocking element 36.
  • the remote ends of said two outer rocking elements 36 carry contact pieces 360. which are engaged by similar 14,5 contact pieces 34a on the extremities of the bridging contact 34 and the contact pieces 36a. are connected through the pivotal bearings of the respective elements 36 with fixed terminals 38. These terminals 38 are connected in series with 150 switch 26a across lines L3, L1.
  • the contactor accordingly closes its contacts 23a; the motor is started, the three coils 1 energized and the three plungers 2 and their stems 5 accordingly raised to their up'position.
  • This will permit the remote ends of the rocking elements 36 to be pressed down by means of the V shaped bridging contact 34, contact being main- 25 tained throughout between the contact pieces 34a and the contact pieces 36a so that the circuit of the main contactor winding 23 will remain 'unbroken.
  • Fig. 15 illustrates a slightly modified arrangement in which three wire control may be em- 56 ployed. In thislarmngement the relays 39, 40
  • aiidanadditional contact 235 is provided on the main contactor which opens and closes according as the main contacts 23a of said main contactor open and close.
  • This additional contact 231) short circuits a start push button 26a connected in series with the V shape bridging contact 34 and the main contactor winding 23 across lines L3, L2.
  • said main contactor 60 winding 23 is energized by a circuit which is maintained upon closure of the contactor 23b independently of said start push button.
  • the bridging contact 34 moves down in engagement with the remote contact bearing ends of the rocking element 36 thereby maintaining the contactor winding circuit and said bridging contact is opened upon failure of any one phase. In this case, it is clear that once the contactor is opened its winding 23 cannot be again energized until the start push button 26a is depressed.
  • reference 27a designates a stop push button.
  • the device comprises a plate 34a. pivoted about an axis XX and biased downwards by means of a spring 41 toward bridging engagement with a pair of fixed contacts respectively connected to the terminals 38 (Figs. 17).
  • a pivoted trip arm 42 When the plungers 2 are down the collars 35 on the plunger stems 5 bear down each upon one end of a pivoted trip arm 42 thereby causing the remote end of said arm to rise to the up position.
  • the remote end of any of these three trip arms 42 being at the up position the plate 34a is lifted and held at the circuit breaking position.
  • a second bridging contact 345 is also provided which is biased downwardly to a position at which it bridges two other contacts respectively connected to the terminals 38.
  • This contact 34?) is carried by an arm 43 to which is attached a plate 44 which the collars 35 engage and lift, thereby lifting said contact 34b to the contact breaking position, when the plungers 2 are at the up position.
  • a catch 45 is pivotally mounted on a fixed part and biased about its axis 46 by a spring 47 so that it presses against the edge of said plate 44, and also against the collar 35 of one of the plungers 2 so that only when the said collar 35 is down and said plate 44 is up can said clutch 45 click inwards thereby preventing said plate 44 and therefore said contact 341) from releasing to the closed or down position.
  • each of said armature members being responsive to operate said circuit interrupting mechanism upon failure of voltage in its associated winding
  • said latter armature being responsive to a circuit interrupting mechanism, an armature member associated with each of said windings, each of said armature members being responsive upon failure of voltage in its associated winding to effect operation of said circuit interrupting mechanism, an armature member common to said windings and responsive to eflect operation of said circuit interrupting mechanism, said latter armature being responsive after a given period of delay upon given current conditions in any one orall of said windings and being also responsive substantially instantaneously upon given increased current conditions in any or all of said windings.
  • a protective device operable to effect interruption of said circuit, a plurality of electromagnetic windings connected in difierent phases of said circuit, an armature member common to said windings and responsive under the action thereof to operate said switch mechanism for interruption of said circuit upon overload conditions in any or all of the phases thereof, and means for delaaiing response of said armature member under low overload conditions in said circuit and for permitting immediate .response thereof under heavy overload conditions in said circuit.
  • a switch including a plurality of terminal contacts and a cooperating bridging contact, a plurality of windings to be supplied with currents of unlike phase, means under the control oi said windings for effectirig bridging of said terminal contacts by said bridging contact upon energization or deenergization 01 said windings simultaneously and for also efiecting unbridging of said terminal contacts by said bridging contact upon deenergization 01' any one of said windings with the other of said windings energized, and an armature member common to said windings and responsive to eflfect unbridging of said terminal contacts by said bridging contact upon given overload current values in any or all of said windings.
  • a normally clgsed circuit interrupting mechanism means under the control of said windings for maintaining said circuit interrupting mechanism in closed position upon simultaneous energization of all of said windings, and for effecting opening of said circuit interrupting mechanism upon failure of no voltage in any one of said windings with the other of said windings energized, and an armature member common to said windings and responsive under the action thereof to efiect opening of said circuit interrupting mechanism, said armature member being responsive after. a given period of delay upon given overload conditions in any or all of said windings, and being also responsive substantially instantaneously upon given increased overload conditions in any or all of said windings.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Breakers (AREA)
US536423A 1930-05-28 1931-05-11 Overload switch Expired - Lifetime US1975821A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB16442/30A GB355738A (en) 1930-05-28 1930-05-28 Improvements in or relating to overload switches

Publications (1)

Publication Number Publication Date
US1975821A true US1975821A (en) 1934-10-09

Family

ID=10077399

Family Applications (1)

Application Number Title Priority Date Filing Date
US536423A Expired - Lifetime US1975821A (en) 1930-05-28 1931-05-11 Overload switch

Country Status (4)

Country Link
US (1) US1975821A (en(2012))
BE (1) BE379657A (en(2012))
FR (1) FR716959A (en(2012))
GB (1) GB355738A (en(2012))

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150070113A1 (en) * 2013-09-11 2015-03-12 Siemens Industry, Inc. Tripping mechanisms for two-pole circuit breakers
CN114012775A (zh) * 2021-12-07 2022-02-08 江苏集萃智能制造技术研究所有限公司 一种高性能移动机器人关节模组

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150070113A1 (en) * 2013-09-11 2015-03-12 Siemens Industry, Inc. Tripping mechanisms for two-pole circuit breakers
US8988174B1 (en) * 2013-09-11 2015-03-24 Siemens Industry, Inc. Tripping mechanisms for two-pole circuit breakers
CN114012775A (zh) * 2021-12-07 2022-02-08 江苏集萃智能制造技术研究所有限公司 一种高性能移动机器人关节模组

Also Published As

Publication number Publication date
BE379657A (en(2012))
GB355738A (en) 1931-08-28
FR716959A (fr) 1931-12-30

Similar Documents

Publication Publication Date Title
US1975821A (en) Overload switch
US2246298A (en) Latch checking means for circuit breaker mechanisms
US1314332A (en) Electrical safety device
US1330094A (en) Circuit-breaker
US1289656A (en) Time-element circuit-breaker.
US1980736A (en) Electroresponsive device and apparatus
US1768452A (en) Time-delay controlling device and system
US2295691A (en) Overload protective device
US2701828A (en) Electrically operated switch and sectionalizer
US2036736A (en) Voltage failure protection device
US2385293A (en) Device for overcoming effects of shocks
US2506744A (en) Retarded circuit breaker after reclosing
US1976781A (en) Circuit controlling device
US2792529A (en) Automatic load pickup switch
US2994753A (en) Circuit breaker
US2593225A (en) Polyphase circuit interrupter
US2769054A (en) Automatic reclosing circuit breakers
US2060481A (en) Electric switch
GB370122A (en) Improvements in or relating to voltage failure protection devices
US2709731A (en) Circuit breaker
US2655575A (en) Automatic reclosing circuit breaker
US2891121A (en) Repeating circuit interrupter with selectable reclosing time
US2870289A (en) Circuit interrupter
US2752451A (en) Circuit interrupter
US2295307A (en) High speed reclosing mechanism