US3681635A - Carbon brush for use in electric motors - Google Patents

Carbon brush for use in electric motors Download PDF

Info

Publication number
US3681635A
US3681635A US121019A US3681635DA US3681635A US 3681635 A US3681635 A US 3681635A US 121019 A US121019 A US 121019A US 3681635D A US3681635D A US 3681635DA US 3681635 A US3681635 A US 3681635A
Authority
US
United States
Prior art keywords
face
carbon brush
pressure member
trailing
recess
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
US121019A
Other languages
English (en)
Inventor
Erich Bayer
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.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
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 Robert Bosch GmbH filed Critical Robert Bosch GmbH
Application granted granted Critical
Publication of US3681635A publication Critical patent/US3681635A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R39/00—Rotary current collectors, distributors or interrupters
    • H01R39/02—Details for dynamo electric machines
    • H01R39/58—Means structurally associated with the current collector for indicating condition thereof, e.g. for indicating brush wear

Definitions

  • An elon gated brush body has a trailing end face and a [58] held of Search 10/219, leading end face which contacts a rotating collector.
  • a 310/ 245'249 recess extends from the trailing towards the leading 56 R f d end face and is provided with a bottom surface which e erences I e is domed in direction away from the leading end face UNITED STATES PATENTS and towards the trailing end face.
  • a pressure member of insulating material is slidably accommodated in the recess, and it is as well as the recess are stepped so that they are respectively provided with a stop and a shoulder which will abut when the pressure member moves towards the leading end face by a predetermined distance.
  • a biasing spring urges the pressure member in that direction so that its forward end face abuts against the bottom surface of the recess but with the stop and shoulder remaining out of abutment until such time as the leading end face of the brush body, upon wearing away due to engagement with the rotating collector, reaches the level of the bottom surface and penetrates into the recess whereupon the pressure member emerges from the recess almost instantaneously and moves into abutment with the collector, thereby lifting the brush body off the collector.
  • the present invention relates generally to a carbon brush for use with electric motors, and more particularly to an improved carbon brush which is intended to prevent damage to electric motors that could occur under certain circumstances.
  • the bottom wall of the recess itself converges forwardly in the direction towards the leading end face of the carbon brush body, that is it has a somewhat conically tapering configuration such as that produced by forming a bore with a spiral drill.
  • the narrowest point of the forwardly converging bottom wall thus is also the point which is foremost, that is closest to the leading end face of the brush body. If, now, the brush body has worn away until it reaches the recess, initially a pinhole will open where the wear line intersects with the leading tapered end of the bottom wall of the recess. As wear further continues, this hole increases in size until it is large enough for the end of the pressure member to pass through and move into engagement with the collector to thereby lift the carbon brush off the same.
  • a further disadvantage of the prior-art constructions is the configuration of the closure plate or closure member which closes the open end of the recess at the trailing end of the carbon brush body. Conventionally it is either located within the recess itself and held by part of the compacted carbon, or it is soldered to the trailing end face of the carbon brush body. Neither construction is entirely satisfactory for this member which constitutes an abutment for the'biasing means which biases the pressure member to operative position.
  • the present invention therefore has as its general object to provide an improved carbon brush of the type under discussion.
  • the present invention has as one of its objects to provide an improved carbon brush of the type under discussion in which-when wear of the carbon brush body has progressed to a predetermined extent-the pressure member will rapidly and with great reliability emerge from its recess and will lift the worn carbon brush body out of engagement with the collector.
  • Still another object of the invention is to provide an improved closure member constituting an abutment for the biasing means.
  • a carbon brush for use in electric motors which, briefly stated, comprises in one embodiment an elongated brush body having a leading end face adapted to contact a rotating collector, and a trailing end face.
  • a recess extends from the trailing towards the leading end face and has a bottom surface.
  • a pressure member is slidably accommodated in the recess and has a forward end surface, with both surfaces being so configurated that in response to wearing-away of the leading end face to the level of the bottom surface, the forward end surface will become exposed over its entire cross-sectional area substantially at once.
  • Biasing means acts upon the pressure member and urges the gorward end surface into abutment with the bottom surace.
  • FIG. 1 is a partly sectioned elevation illustrating a carbon brush according to one embodiment of the invention
  • the carbon brushbody itself is identified with reference numeral 1 and in conventional form has essentially the outline of an elongated'rectangle. It has two parallel major surfaces 2 and 3, and two parallel minor surfaces 4 and S which connect the major surfaces, all surfaces extending longitudinally of the brush body 1. Also in conventional manner the leading end face 6 of the body] is configurated as a fragment of a hollow cylindrical surface, as illustrated in FIG. 2.
  • the trailing end portion of the body 1 is configurated as most clearly visible from FIGS. 1 and 2. More specifically, the surfaces 4 and are provided with inclined facets 7 and 8which converge in direction towards the leading end face 6 from the trailing end face of the body 1.
  • a closure and abutment plate or member 9 may be made of sheet brass or the like, and is provided with an upwardly extending collar 10 surrounding an opening through which an electrical conductor 11 passes which is soldered into this opening.
  • the lateral ends 12 and 13.0f this closure member 9 are downwardly angled as shown in FIGS. 1 and 2, in such a manner that they abut against thefacets 7 and 8 to which they are solder-connected.
  • these portions 12 and 13 form with the facets 7 and 8 a substantially dove-tailed connection.
  • a recess 14 extends into the brush body 1 from the illustrating the 7 portion of the recess 14, constituted bythe marginal 19 and 21 there is a cylindrical stop or bead 20 which projects outwardly and is adapted to cooperate with the shoulder from which it is, however, normally spaced in direction towards the trailing end face of the body 1,
  • Biasing means is provided, here illustrated in form of a helical pressure spring 22 which surrounds the portion 21 and bears with its opposite ends upon the stop and the plate 9, respectively.
  • FIG. 1 illustrates the brush according to the present invention as it appears when it is new or at least when it is not yet significantlyworn.
  • FIG. 3 I have illustrated the appearance of the brush when it has worn to the extent permissible without causing the danger of damage to the cooperating collector 23 which is diagrammatically shown in FIG. 3 for purposes of orientation.
  • the leading end face 6 of the body 1 has been worn away so that it has reached the forwardly located circumferential marginal zones of the bottom face 17 in the recess 14.
  • a breakthrough will occur alongan annular line corresponding to the foremost circumferential zone of the bottom face 17.
  • the bottom surface 17 of the portion 16 is domed in direction towards the leading end face of the body 1, which is to say that its outer circumferential marginal zone is located axially forward of its middle or center zone, as clearly evident from F IG. 1.
  • a pressure member 18 consisting of electrically insulating material is loosely slidably accommodated in the recess 14. Its lower cylindrical portion 19 is located in the portion 16 of the recess 14, and the slightly rearwardly tapering portion 21 is located in the remainder of the recess 14. At the juncture between the portions reliably prevented because when the recess becomes exposed, it becomes exposed almost instantaneously over its entire cross-sectional area with the bottom face l7 disappearing in its totality almost at once.
  • FIGS. 4 and 5 essentially resembles that of FIGS. 1-3. It differs from that embodiment only in that the pressure member 118 is provided with a stop or bead 120 which tapers conically in the direction towards the leading end face of the carbon brush body. correspondingly, the abutment surface on the shoulder also tapers in the same sense. This provides for an improved guidance function for the member 118 as the same moves to its extended position shown in FIG. 5.
  • the carbon brush according to the present invention can be produced very simply, and in particular it is easy to produce the abutment for the pressure spring acting upon the pressure member, due to the fact that there is the dovetail-shaped interengagement between the closure plate and the trailing portion of the body 1.
  • the bottom wall 17 due to the particular configuration of the bottom wall 17, the danger of delay in lifting-off of the carbon brush 1 from the collector 23 is avoided, and the provision of the shoulder and stop in the recess and on the pressure member precludes undesired projecting of the pressure member out of the recess beyond a certain extent, that is beyond the extent necessary to provide lifting-off of the carbon brush, and this in turn eliminates the danger of jamming or skewing of the pressure member between the carbon brush and the collector and thus avoids further possibilities of malfunctions.
  • a carbon brush for use in electric motors comprising an elongated brush body having a leading end face adapted to contact a rotating collector, and a trailing end face; a stepped recess extending from said trailing towards said leading end face and having a wider first portion extending inwardly from said trailing end face, a narrower second portion extending inwardly from said first portion, a shoulder at the juncture of said portions, and a bottom surface domed in direction towards said trailing end face; a correspondingly stepped pressure member slidably accommodated in said recess and having first and second sections located in the respective portions, a stop, and a forward end surface, said surfaces being so configurated that in response to wearing away of said leading end face to the level of said bottom surface, said forward end surface will become exposed over its entire cross-sectional area substantially at once; biasing means acting upon said pressure member and urging said forward end surface into abutment with said bottom surface, said stop being normally spaced from said shoulder but being adapted to bear upon the same
  • biasing means being a biasing spring accommodated in said recess; and further comprising cooperating abutment portions on said pressure member and in the region of said trailing end face and against which said biasing spring bears.
  • a carbon brush as defined in claim 2 said pressure member having a cylindrical portion in the region of said trailing end face, and said spring being a helical spring surrounding said cylindrical portion.
  • a stepped recess extending from said trailing towards said leading end face and having a wider first portion extending inwardly from said trailing end face, a narrower second portion extending inwardly from said first portion, a shoulder at the juncture of said portions, and a bottom surface domed in direction towards said trailing end face;
  • a correspondingly stepped'pressure member composed of electrically insulating material slidably accommodated in said recess and having a cylindrical first section and a second section located in the respective portions, a stop, and a forward end surface, said surfaces being so configurated that in response to wearing away of said leading end face to the level of said bottom surface, said forward end surface will become exposed over its entire cross-sectional area substantially at once; and an abutment member overlying said trailing end face and embracing said rear end portion in clasping relationship;
  • a carbon brush for use in electric motors comprising an elongated brush body having a leading end face adapted to contact a rotating collector, and a rear end portion having a dove-tail shaped cross-section and provided with a trailing end face; a recess extending from said trailing towards said leading end face and having a bottom surface; a pressure member slidably accommodated in said recess and having a forward end surface, said surfaces being so configurated that in response to wearing away of said leading end face to the level of said bottom surface, said forward end surface will become exposed over its entire cross-sectional area substantially at once; biasing means; and an abutment member for said biasing means, said abutment member being substantially C-shaped and embracing and clasping said rear end portion in interlocking engagement therewith, said biasing means acting upon said pressure member and urging said forward end surface into abutment with said bottom surface.

Landscapes

  • Motor Or Generator Current Collectors (AREA)
US121019A 1970-03-21 1971-03-04 Carbon brush for use in electric motors Expired - Lifetime US3681635A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE7010521U DE7010521U (de) 1970-03-21 1970-03-21 Abschaltkohlebuerste.

Publications (1)

Publication Number Publication Date
US3681635A true US3681635A (en) 1972-08-01

Family

ID=6610361

Family Applications (1)

Application Number Title Priority Date Filing Date
US121019A Expired - Lifetime US3681635A (en) 1970-03-21 1971-03-04 Carbon brush for use in electric motors

Country Status (5)

Country Link
US (1) US3681635A (enExample)
JP (1) JPS501401B1 (enExample)
DE (1) DE7010521U (enExample)
FR (1) FR2083855A5 (enExample)
GB (1) GB1325793A (enExample)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0023537A1 (de) * 1979-07-21 1981-02-11 REKOFA Wenzel GmbH & Co KG. Kohlebürste mit Abschaltvorrichtung
US4316186A (en) * 1980-02-06 1982-02-16 Eltra Corporation Brush wear detection and warning system
US4344072A (en) * 1979-12-10 1982-08-10 Harper Jr Harold L Worn brush indicator
US4536670A (en) * 1981-12-14 1985-08-20 Morganite Incorporated Electrical brushes with wear sensors
DE4304527A1 (de) * 1993-02-15 1994-08-18 Miele & Cie Abschaltkohlebürste für Kollektormotoren, insbesondere für einen Staubsauger-Gebläsemotor
US5402027A (en) * 1992-12-22 1995-03-28 Johnson Electric S.A. Brush assembly for an electric motor
FR2776847A1 (fr) * 1998-03-24 1999-10-01 Bosch Gmbh Robert Balai de collecteur pour des moteurs electriques a collecteur
US6087754A (en) * 1997-09-10 2000-07-11 Robert Bosch Gmbh Cut-out brush for electric hand tool
US6552467B1 (en) * 2000-04-21 2003-04-22 Valeo Electrical Systems, Inc. Integral noise filter within brush of electric motor
US20080100170A1 (en) * 2006-09-29 2008-05-01 Herbert Rehm Carbon brush with wear-protecting means
US20080142351A1 (en) * 2005-05-13 2008-06-19 Black & Decker Inc. Angle grinder
CN100414785C (zh) * 2003-12-12 2008-08-27 乐金电子(天津)电器有限公司 具有过载电流阻断功能的整流子电机的电刷组装体
US20090189479A1 (en) * 2008-01-25 2009-07-30 Energy Conversion Systems Holdings, Llc Brush Assembly
RU2375796C2 (ru) * 2005-12-30 2009-12-10 Шунк Коленштоффтехник Гмбх Угольная щетка с отключающим устройством
US20130293059A1 (en) * 2010-10-22 2013-11-07 Robert Bosch Gmbh Carbon brush with disconnection apparatus
US10818450B2 (en) 2017-06-14 2020-10-27 Black & Decker Inc. Paddle switch

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0023537A1 (de) * 1979-07-21 1981-02-11 REKOFA Wenzel GmbH & Co KG. Kohlebürste mit Abschaltvorrichtung
US4344072A (en) * 1979-12-10 1982-08-10 Harper Jr Harold L Worn brush indicator
US4316186A (en) * 1980-02-06 1982-02-16 Eltra Corporation Brush wear detection and warning system
US4536670A (en) * 1981-12-14 1985-08-20 Morganite Incorporated Electrical brushes with wear sensors
US5402027A (en) * 1992-12-22 1995-03-28 Johnson Electric S.A. Brush assembly for an electric motor
DE4304527A1 (de) * 1993-02-15 1994-08-18 Miele & Cie Abschaltkohlebürste für Kollektormotoren, insbesondere für einen Staubsauger-Gebläsemotor
US6087754A (en) * 1997-09-10 2000-07-11 Robert Bosch Gmbh Cut-out brush for electric hand tool
AT412046B (de) * 1998-03-24 2004-08-26 Bosch Gmbh Robert Kommutierungsbürste für elektrische kommutatormaschinen
FR2776847A1 (fr) * 1998-03-24 1999-10-01 Bosch Gmbh Robert Balai de collecteur pour des moteurs electriques a collecteur
US6552467B1 (en) * 2000-04-21 2003-04-22 Valeo Electrical Systems, Inc. Integral noise filter within brush of electric motor
CN100414785C (zh) * 2003-12-12 2008-08-27 乐金电子(天津)电器有限公司 具有过载电流阻断功能的整流子电机的电刷组装体
US8087976B2 (en) 2005-05-13 2012-01-03 Black & Decker Inc. Trigger assembly for angle grinder
US20080142351A1 (en) * 2005-05-13 2008-06-19 Black & Decker Inc. Angle grinder
US20080146126A1 (en) * 2005-05-13 2008-06-19 Black & Decker Inc. Angle grinder
US20080146127A1 (en) * 2005-05-13 2008-06-19 Gallagher William F Angle grinder
US8716618B2 (en) 2005-05-13 2014-05-06 Black & Decker Inc. Angle grinder
US7722444B2 (en) 2005-05-13 2010-05-25 Black & Decker Inc. Angle grinder
US8087977B2 (en) 2005-05-13 2012-01-03 Black & Decker Inc. Angle grinder
RU2375796C2 (ru) * 2005-12-30 2009-12-10 Шунк Коленштоффтехник Гмбх Угольная щетка с отключающим устройством
US20080100170A1 (en) * 2006-09-29 2008-05-01 Herbert Rehm Carbon brush with wear-protecting means
US20090189479A1 (en) * 2008-01-25 2009-07-30 Energy Conversion Systems Holdings, Llc Brush Assembly
US20130293059A1 (en) * 2010-10-22 2013-11-07 Robert Bosch Gmbh Carbon brush with disconnection apparatus
US10818450B2 (en) 2017-06-14 2020-10-27 Black & Decker Inc. Paddle switch

Also Published As

Publication number Publication date
GB1325793A (en) 1973-08-08
DE7010521U (de) 1971-08-26
FR2083855A5 (enExample) 1971-12-17
JPS501401B1 (enExample) 1975-01-17

Similar Documents

Publication Publication Date Title
US3681635A (en) Carbon brush for use in electric motors
US3156761A (en) Connector assembly
US4246508A (en) Brush holder assemblies for small electric motors
US2323736A (en) Attachment plug
US3664012A (en) Method of making a commutator
GB1151636A (en) Brush Holder for an Electric Commutator Motor
US1390607A (en) Electric contact device
US1491426A (en) Electromagnetic clutch
US2469337A (en) Control apparatus for switches and the like
US2985857A (en) Variable transformer
US1502785A (en) Pushbutton switch
GB1174557A (en) End Face Commutator
US1948268A (en) Motor brush
US2474601A (en) Brush mechanism
US2914689A (en) Motor brush assembly
US2870355A (en) Electrical brush arrangement
US1821405A (en) Dynamo electric machine
US2341135A (en) Electrical protecting system
US3191085A (en) Brush holder for electric commutator machine
US1132473A (en) Circuit-controller.
GB1147327A (en) Dynamo-electric machine
GB591183A (en) Improvements in electric contacts
US3477483A (en) Knife clamp
US2421795A (en) Armature brush
GB1394278A (en) Electrical switch assembly