US3665228A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Modular design-double insulated field
Assignee: GW Murphy Industries Inc
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Filing: 1970-05-15
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Granted: 1972-05-23
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Expires: 1990-05-15
Abstract
Abstract In a power tool, an electric motor is mounted on an electrically conductive frame by an electrically insulating shield member which directly insulates the motor from the frame and also shields the motor field magnets against spark-gap conduction of electricity to the frame, preventing possible shock to the user.
Inventors
- 👤 Anthony Jacyno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:23
CPC Classifications
B; B23; B23B; B23B45/00; B23B45/02; H; H02; H02K; H02K1/00; H02K1/06; H02K1/12; H02K1/18; H02K1/185; H02K7/00; H02K7/14; H02K7/145
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
164 words
A power tool including an electric motor having a stator member, electrically conductive frame means, insulating shield means positioned between said frame means and the stator of said motor, and mounting means carried by said shield means for securing said motor on said frame, said insulating shield means shielding against spark jump from the motor to the frame means, said insulating shield means comprising a longitudinal tube section shell of insulating material with integral radially inwardly depending arm members, inwardly and outwardly projecting opposing integral pins in axial alignment extending from opposing sides of each arm member on an axis parallel with the axis of said tube section with all of said pins on the same approximate axis, a bore in the stator of said motor parallel to and spaced from the axis of the motor shaft and receiving the inwardly projecting pins of said insulating shield means and receiver means in said frame receiving the outwardly projecting pins of said insulating shield means.
Claim 2
Dependent Claim
164 words
A power tool including an electric motor having a stator member, electrically conductive frame means, insulating shield means positioned between said frame means and the stator of said motor, and mounting means carried by said shield means for securing said motor on said frame, said insulating shield means shielding against spark jump from the motor to the frame means, said insulating shield means comprising a longitudinal tube section shell of insulating material with integral radially inwardly depending arm members, inwardly and outwardly projecting opposing integral pins in axial alignment extending from opposing sides of each arm member on an axis parallel with the axis of said tube section with all of said pins on the same approximate axis, a bore in the stator of said motor parallel to and spaced from the axis of the motor shaft and receiving the inwardly projecting pins of said insulating shield means and receiver means in said frame receiving the outwardly projecting pins of said insulating shield means.
Claim 3
Dependent Claim
55 words
The device of claim 1 wherein said frame means comprises first and second stamped sheet metal members of generally planar configuration which are at least in part mirror images of one another and which include means rEceiving said mounting means between said stamped sheet members for holding said shield means relative to said frame means.
Claim 4
Dependent Claim
154 words
A power tool including an electric motor having a stator member, electrically conductive frame means, insulating shield means positioned between said frame means and the stator of said motor, and mounting means carried by said shield means for securing said motor on said frame, said insulating shield means shielding against spark jump from the motor to the frame means, said insulating shield means comprising a pair of shield portions having cooperating joint surfaces for slidably joining said shield portions to provide the shield means, each shield portion including pin means projecting in the direction of joining movement of said shield portions and received by axially sliding movement in pin receivers in said motor during joining movement of said shield portions to form the shield, and including means for locking said shield means to said frame, the frame including abutment means receiving the shield member and locking said shield portion against separation from each other.
Claim 5
Dependent Claim
154 words
A power tool including an electric motor having a stator member, electrically conductive frame means, insulating shield means positioned between said frame means and the stator of said motor, and mounting means carried by said shield means for securing said motor on said frame, said insulating shield means shielding against spark jump from the motor to the frame means, said insulating shield means comprising a pair of shield portions having cooperating joint surfaces for slidably joining said shield portions to provide the shield means, each shield portion including pin means projecting in the direction of joining movement of said shield portions and received by axially sliding movement in pin receivers in said motor during joining movement of said shield portions to form the shield, and including means for locking said shield means to said frame, the frame including abutment means receiving the shield member and locking said shield portion against separation from each other.
Claim 6
Dependent Claim
13 words
The device of claim 3 wherein said joint surfaces are cooperating stepped surfaces.
Claim 7
Dependent Claim
15 words
The device of claim 3 wherein said shield means has cylindrical inner and outer surfaces.
Claim 8
Dependent Claim
92 words
A power tool including an electric motor having a stator member, electrically conductive frame means, insulating shield means positioned between said frame means and the stator of said motor, and mounting means carried by said shield means for securing said motor on said frame, said insulating shield means shielding against spark jump from the motor to the frame means, said shield means comprising two engaged, partially overlapping members longitudinally slidable to accommodate motor stators of different longitudinal lengths, said mounting means being formed of insulating material and integral with said shield means.
Claim 9
Dependent Claim
92 words
A power tool including an electric motor having a stator member, electrically conductive frame means, insulating shield means positioned between said frame means and the stator of said motor, and mounting means carried by said shield means for securing said motor on said frame, said insulating shield means shielding against spark jump from the motor to the frame means, said shield means comprising two engaged, partially overlapping members longitudinally slidable to accommodate motor stators of different longitudinal lengths, said mounting means being formed of insulating material and integral with said shield means.
Claim 10
Dependent Claim
101 words
A power tool including an electric motor having a stator member, electrically conductive frame means, insulating shield means positioned between said frame means and the stator of said motor, and mounting means carried by said shield means for securing said motor on said frame, said insulating shield means shielding against spark jump from the motor to the frame means and being comprised of two engaged, partially overlapping members longitudinally slidable with respect to each other, said mounting means being integral with said overlapping members and comprising insulating pin means located radially inwardly of the outermost peripheral extent of said overlapping members.
Claim 11
Dependent Claim
101 words
A power tool including an electric motor having a stator member, electrically conductive frame means, insulating shield means positioned between said frame means and the stator of said motor, and mounting means carried by said shield means for securing said motor on said frame, said insulating shield means shielding against spark jump from the motor to the frame means and being comprised of two engaged, partially overlapping members longitudinally slidable with respect to each other, said mounting means being integral with said overlapping members and comprising insulating pin means located radially inwardly of the outermost peripheral extent of said overlapping members.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |