Temperature control in an electric motor
First Claim
Patent Images
1. An electric motor having brush gear, comprising:
- (A) a brush which bears on a commutator of the motor;
(B) an input terminal for supplying power to the brush;
(C) a PTC resistor;
(D) means for coupling the PTC resistor in series between the input terminal and the brush; and
(E) an end cap having an aperture extending therethrough through which the PTC resistor may be moved between a position outside the end cap and the coupling means.
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Accused Products
Abstract
An electric motor incorporates a positive temperature coefficient resistor 18 between a supply terminal and a brush. The resistor can be inserted from outside the motor through an aperture 17 in an end cap 2. A body 19 of heat conducting material, also insertable from outside the end cap, can be provided and held against to resistor 18 to alter its effective thermal mass and so adjust its operating characteristics.
25 Citations
19 Claims
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1. An electric motor having brush gear, comprising:
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(A) a brush which bears on a commutator of the motor; (B) an input terminal for supplying power to the brush; (C) a PTC resistor; (D) means for coupling the PTC resistor in series between the input terminal and the brush; and (E) an end cap having an aperture extending therethrough through which the PTC resistor may be moved between a position outside the end cap and the coupling means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An electric motor having a brush gear, comprising:
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(A) a brush which bears on a commutator of the motor; (B) an input terminal for supplying power to the brush; (C) means for coupling a PTC resistor in series between the input terminal and the brush when a PTC resistor is inserted into the coupling means; and (D) an end cap having an aperture extending therethrough through which a PTC resistor may be inserted into the coupling means from a position outside the end cap. - View Dependent Claims (10, 11, 12, 13)
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14. An electric motor having brush gear, comprising:
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(A) a brush which bears on a commutator of the motor; (B) an input terminal for supplying power to the brush; (C) means for coupling a PTC resistor in series between the brush and the input terminal when a PTC resistor is placed in the holding means; and (D) an end cap having an aperture formed therein through which the PTC resistor may be moved between a position outside the end cap and the coupling means, the coupling means including two conductive leaves coupled to the input terminal and the brush, respectively, the conductive leaves being located on respective opposite sides of the aperture for releasably receiving therebetween a PTC resistor insertable through the aperture from outside the end cap to complete a series connection between the input terminal and the brush. - View Dependent Claims (15, 16)
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17. An electric motor having brush gear, comprising:
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(A) a brush which bears on a commutator of the motor; (B) an input terminal for supplying power to the brush; (C) means for coupling a PTC resistor in series between the brush and the input terminal when a PTC resistor is placed in the coupling means; and (D) an end cap having an aperture formed therein through which the PTC resistor may be moved between a position outside the end cap and the coupling means;
the holding means including a resilient conductive leaf held in the end cap and extending along one side of the aperture and being electrically connected to the input terminal and an opposing leaf held in the end cap and extending along an opposite side of the aperture. - View Dependent Claims (18, 19)
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Specification