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US4918348A Expired / Lapsed US ⏱️ 0.0 years remaining

Brush wear indicator

Assignee: Prestolite Electric Inc
•
Filing: 1988-12-14
•
Granted: 1990-04-17
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Expires: 2008-12-14
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Abstract

Abstract An apparatus for detecting the wear of a motor brush includes a spring that biases the brush towards an extended position. A portion of the spring moves along a path towards the extended position as the brush wears, wherein the spring portion makes mechanical contact with a portion of an electrical signal generating device that is disposed in the path to indicate a given amount of brush wear has occurred.

Inventors

  • 👤 Alan H. Fitzsimmons
  • 👤 Joe K. Hammer

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 09:11
CPC Classifications
H; H01; H01R; H01R39/00; H01R39/02; H01R39/58

Claims Analysis

Total Claims: 33
Claim 1
Independent Claim 143 words
Apparatus for indicating brush wear for an electrical appliance, by providing an electrical signal indicating that a brush is worn down to a point of extending brush wear, comprising: a wearable brush moveable toward a contact point in the appliance, said brush deteriorating at said contact point during operation of the appliance; spring means for biasing said brush toward said contact point, said spring means including a portion moveable along a path during at least some of the time said brush is moved during wear of said brush; and electrical signal generator means having a member disposed in said path for making mechanical contact with said portion of said spring means when said brush is worn down to a point of extended brush wear, said electrical signal generator means for generating an electrical signal in response to the making of said mechanical contact.
Claim 2
Dependent Claim 143 words
Apparatus for indicating brush wear for an electrical appliance, by providing an electrical signal indicating that a brush is worn down to a point of extending brush wear, comprising: a wearable brush moveable toward a contact point in the appliance, said brush deteriorating at said contact point during operation of the appliance; spring means for biasing said brush toward said contact point, said spring means including a portion moveable along a path during at least some of the time said brush is moved during wear of said brush; and electrical signal generator means having a member disposed in said path for making mechanical contact with said portion of said spring means when said brush is worn down to a point of extended brush wear, said electrical signal generator means for generating an electrical signal in response to the making of said mechanical contact.
Claim 3
Dependent Claim 26 words
Apparatus according to claim 1 wherein said spring means includes a coil spring biased for retracting, said coil spring forcing said brush toward said contact point.
Claim 4
Dependent Claim 43 words
Apparatus according to claim 1 wherein said spring means includes a coil spring and wherein said portion includes a surface of said coil spring moveable along said path during at least some of the time said brush is moved toward said contact point.
Claim 5
Dependent Claim 22 words
Apparatus according to claim 2 wherein said coil spring includes an end secured in a fixed position with respect to the appliance.
Claim 6
Dependent Claim 50 words
Apparatus according to claim 2 and further including a connector plate secured in a fixed position with respect to the appliance, and wherein said coil spring includes a first end secured to said connector plate and a second end which coils as said brush is moved toward said contact point.
Claim 7
Dependent Claim 41 words
Apparatus according to claim 5 and further including electrical conductor means having at least one flexible conductor, one end of said conductor being secured to said connector plate and the other end of said one conductor being secured to said brush.
Claim 8
Dependent Claim 23 words
Apparatus according to claim 1 wherein said member includes an electrical contact for making mechanical contact with said portion of said spring means.
Claim 9
Dependent Claim 53 words
A brush wear indicator according to claim 7 wherein said portion of said spring means carries an electrical signal and wherein said electrical signal is received by said electrical contact upon mechanical contact of said electrical contact with said portion of said spring means to generate an electrical signal at said electrical contact.
Claim 10
Dependent Claim 21 words
Apparatus according to claim 5 wherein said connector plate includes tongue means for holding said first end to said connector plate.
Claim 11
Dependent Claim 117 words
A brush assembly for an electrical appliance which has an armature rotatable relative to a frame of the appliance and which has a means for generating an electrical signal to indicate brush wear, comprising a connector plate replaceably securable to the frame of the appliance; a brush movably mounted with respect to said connector plate; and spring means secured to said connector plate for biasing said brush for movement relative to said connector plate, said spring means having a portion moving along a path as said brush is moved relative to said connector plate and providing a contact surface for making mechanical contact with the generating means of the electrical appliance at a point along said path.
Claim 12
Dependent Claim 117 words
A brush assembly for an electrical appliance which has an armature rotatable relative to a frame of the appliance and which has a means for generating an electrical signal to indicate brush wear, comprising a connector plate replaceably securable to the frame of the appliance; a brush movably mounted with respect to said connector plate; and spring means secured to said connector plate for biasing said brush for movement relative to said connector plate, said spring means having a portion moving along a path as said brush is moved relative to said connector plate and providing a contact surface for making mechanical contact with the generating means of the electrical appliance at a point along said path.
Claim 13
Dependent Claim 51 words
A brush assembly according to claim 10 wherein said spring means includes a coil spring having a bias for retracting, said bias forcing said brush to an extended position, and wherein said coil spring includes a coil portion moveable along said path as said brush is moved toward said extended position.
Claim 14
Dependent Claim 19 words
A brush assembly according to claim 11 wherein said coil spring includes an end secured to said connector plate.
Claim 15
Dependent Claim 44 words
A brush assembly according to claim 10 and further including electrical conductor means having at least one flexible conductor, one end of said one conductor being secured to said connector plate and the other end of said one conductor being secured to said brush.
Claim 16
Dependent Claim 17 words
A brush assembly according to claim 13 wherein said electrical conductor means includes a pair of conductors.
Claim 17
Dependent Claim 34 words
A brush assembly according to claim 10 wherein said connector plate includes an elongated arm and a support wall disposed normal to said elongated arm, and wherein said spring means includes a coil spring.
Claim 18
Dependent Claim 21 words
Apparatus according to claim 15 wherein said elongated arm includes tongue means for holding said coil spring to said connector plate.
Claim 19
Dependent Claim 160 words
A motor having a brush wear indicator comprising an armature; a brush assembly support structure including an opening; a brush assembly including; (i) a connector plate secured to said support structure relative to said opening; (ii) a brush movably disposed with respect to said connector plate and slidably mounted within said opening for movement toward a contact point, said brush deteriorating at said contact point upon operation of the appliance; (iii) spring means for biasing said brush toward the contact point, said spring means having a portion moving along a path as said brush is moved toward the contact point during wear of said brush; and electrical signal generator means including a member disposed in said path for making mechanical contact with said portion of said spring means when said brush is worn down to a point of extended brush wear, said electrical signal generator means for generating an electrical signal indicative of said brush being at a predetermined wear.
Claim 20
Dependent Claim 160 words
A motor having a brush wear indicator comprising an armature; a brush assembly support structure including an opening; a brush assembly including; (i) a connector plate secured to said support structure relative to said opening; (ii) a brush movably disposed with respect to said connector plate and slidably mounted within said opening for movement toward a contact point, said brush deteriorating at said contact point upon operation of the appliance; (iii) spring means for biasing said brush toward the contact point, said spring means having a portion moving along a path as said brush is moved toward the contact point during wear of said brush; and electrical signal generator means including a member disposed in said path for making mechanical contact with said portion of said spring means when said brush is worn down to a point of extended brush wear, said electrical signal generator means for generating an electrical signal indicative of said brush being at a predetermined wear.
Claim 21
Dependent Claim 18 words
A motor according to claim 17 wherein said brush assembly support structure is formed from an insulative material.
Claim 22
Dependent Claim 16 words
A motor according to claim 17 wherein said brush assembly support structure is molded from plastic.
Claim 23
Dependent Claim 22 words
A motor according to claim 15 wherein said brush assembly support structure includes an end head surrounding a portion of said armature.
Claim 24
Dependent Claim 27 words
A motor according to claim 17 wherein said spring means includes a coil spring biased for retracting, said coil spring forcing said brush toward said contact point.
Claim 25
Dependent Claim 44 words
A motor according to claim 17 wherein said spring means includes a coil spring and wherein said portion includes a surface of said coil spring moveable along said path during at least some of the time said brush is moved toward said contact point.
Claim 26
Dependent Claim 18 words
A motor according to claim 21 wherein said coil spring includes an end secured in a fixed position.
Claim 27
Dependent Claim 34 words
A motor according to claim 21 wherein said coil spring includes a first end secured to said connector plate and a second end which coils as said brush is moved toward said contact point.
Claim 28
Dependent Claim 42 words
A motor according to claim 24 and further including electrical conductor means having at least one flexible conductor, one end of said conductor being secured to said connector plate and the other end of said one conductor being secured to said brush.
Claim 29
Dependent Claim 24 words
A motor according to claim 17 wherein said member includes an electrical contact for making mechanical contact with said portion of said spring means.
Claim 30
Dependent Claim 51 words
A motor according to claim 26 wherein said portion of said spring means carries an electrical signal and wherein said electrical signal is received by said electrical contact upon mechanical contact of said electrical contact with said portion of said spring means to generate an electrical signal at said electrical contact.
Claim 31
Dependent Claim 33 words
A motor according to claim 17 wherein said connector plate includes an elongated arm and a support wall disposed normal to said elongated arm, and wherein said spring means includes a coil spring.
Claim 32
Dependent Claim 35 words
A motor according to claim 17 and further including brush wear indicator means connected to said electrical signal generator means and responsive to generation of said electrical signal for generating an indication of brush wear.
Claim 33
Dependent Claim 22 words
A motor according to claim 28 wherein said elongated arm includes tongue means for holding said coil spring to said connector plate.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-04-16 1993-10-16 1994-04-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-04-16 1997-10-16 1998-04-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-04-16 2001-10-16 2002-04-17 $7700.00 Window Closed / Lapsed

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