Motor end cap

• US 4,801,833 A
• Filed: 10/21/1987
• Issued: 01/31/1989
• Est. Priority Date: 12/12/1985
• Status: Expired due to Term

• Current Assignee: Eaton Tennessee, Inc.
• Original Assignee: Eaton Stamping Company
• Inventors: Dye, Clifford L.
• Primary Examiner(s): Skudy, R.
• Application Number:
  US07/111,114
• Time in Patent Office: 468 Days
• Field of Search: 310/40 MM, 310/51, 310/43, 310/89, 310/90, 310/68 C, 310/91, 310/71, 310/42, 310/239, 310/240, 310/241, 310/245, 310/247, 310/298, 310/242, 337/380, 361/23, 361/24, 361/25, 29/596, 29/597
• US Class Current: 310/239
• CPC Class Codes: H01R 39/38 Brush holders
• CPC Class Codes: H02K 5/148 Slidably supported brushes

Abstract

An end cap for small electric motors using brushes, the end cap being molded of a synthetic plastic dielectric material. Brush-receiving guides are defined on the end cap by homogeneous cantilevered fingers which are deflectable to grip the brush therein during assembly of the end cap to a motor casing. Electric conductor and connector retainers are homogeneously defined on the end cap to provide conductor strain relief, a circuit breaker retainer is homogeneously included in the cap configuration, and tie bolt ears are of such configuration as to cooperate with the motor casing to resist deflection.

Claims

1. In an electric motor having a tubular casing having ends wherein an armature is rotatably supported within the casing upon end caps mounted upon the casing ends, the improvement comprising, at least one of the end caps being molded of a synthetic plastic dielectric material, an inner surface defined on said one end cap, armature bearing means defined on said end cap defining a bearing axis, a plurality of brush-holding means defined upon said end cap inner surface about said axis, said brush-holding means including a pair of spaced parallel cantilevered fingers homogeneously formed of the material of the end cap having a length extending substantially parallel to said bearing axis, each finger having an outer free end, an inner lateral edge disposed toward said bearing axis, an outer lateral edge remote from said bearing axis, and an inner side, said inner sides of said pair of fingers being in spaced opposed relation to each, other, an elongated recess defined in each of said fingers'"'"' inner sides having a length projecting toward said bearing axis, the recesses of a pair of fingers being in opposed relation and defining a brush-receiving guide, said fingers'"'"' outer free ends being in spaced relation to each other and adapted to be deformable whereby temporary deformation of said fingers toward each other will frictionally grip a brush within said guide to prevent brush movement therein, and a spring anchor projection homogeneously formed of the material of said one end cap adjacent and spaced from said outer lateral edges of a spaced pair of said fingers, said spring anchor projection being in alignment with said brush-receiving guide defined in said spaced pair of fingers.

2. In an electric motor as in claim 1, said spring anchor projection being of a planar configuration having a free outer end located a distance from said end cap inner surface substantially equal to the distance of said fingers'"'"' outer free end from said end cap inner surface.

3. In an electric motor having a tubular casing having ends wherein an armature is rotatably supported within the casing upon end caps mounted upon the casing ends, the improvement comprising, at least one of the end caps being molded of a synthetic plastic dielectric material, an inner surface defined on said one end cap, armature bearing means defined on said end cap defining a bearing axis, a plurality of brush-holding means defined upon said end cap inner surface about said axis, an axially extending peripheral flange defined on said end cap extending from said inner surface, an elongated electric conductor-receiving notch defined in said peripheral flange, a pair of parallel spaced ribs homogeneously defined of the material of said end cap projecting from said end cap inner surface adjacent said conductor-receiving notch, said ribs defining elongated conductor-receiving recesses therebetween having a length transversely disposed to the length of said notch whereby a conductor entering said end cap through said notch and located within a rib-defined recess is bent transversely to the length of said notch to provide strain relief of the conductor, an elongated resilient circuit breaker retainer hook homogeneously extending from said end cap inner surface formed of the end cap material, said retainer including a free end, a hook shoulder defined on said free end, a circuit breaker receiving cradle homogeneously defined on said end cap of the material thereof in opposed relation to said retainer hook, said hook shoulder and retainer maintaining a circuit breaker within said cradle upon said retainer being temporarily deflected to permit a circuit breaker to be located between said hook shoulder and end cap inner surface.

4. In an electric motor having a tubular casing having ends wherein an armature is rotatably supported within the casing upon end caps mounted upon the casing ends, the improvement comprising, at least one of the end caps being molded of a synthetic plastic dielectric material, an inner surface defined on said one end cap, armature bearing means defined on said one end cap defining a bearing axis, a plurality of brush-holding means defined upon said one end cap inner surface about said axis, a casing end engaging edge defined upon said one end cap, a plurality of tie rod receiving ears defined on said one end cap homogeneously formed of the material thereof and extending outwardly from the casing and engaging edge, said ears each including an axially extending inner surface extending outwardly beyond said edge and adjacent thereto conforming in configuration to the configuration of the motor casing and extending in the direction of the casing whereby upon placing said one end cap upon a motor casing end such that the casing end engages the end cap edge said ears inner surfaces overlap and engage the exterior surface of the casing adjacent the casing end and the casing supports said ears against inward deflection toward the casing, and a tie rod connected to each ear at a location outward of said inner surface of the associated ear imposing a bending force on the associated ear endeavoring to bend the ear toward the casing.

5. In an electric motor as in claim 4, said tie rods interconnecting the end caps each having an outer end having a self-tapping thread defined thereon, and a hole defined in each ear of said one end cap receiving a thread of at least one of said tie rods.