US3818255A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bearing assembly for power tools having a plastic housing
Assignee: Singer Co
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Filing: 1973-07-30
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Granted: 1974-06-18
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Expires: 1993-07-30
Abstract
Abstract A bearing assembly for a power tool, such as a drill, having a plastic housing in which is mounted a universal motor. The motor has an armature and a stator, with the armature shaft disposed axially in the housing and having a fan affixed thereto. Cooling apertures are formed in a motor chamber in the housing in axially spaced relationship to each other on either side of the fan to permit ventilating air to enter and to exit the housing to cool the motor. A first bearing means journals one end of the armature shaft in the housing. An improved second bearing journals the other end of the armature shaft adjacent a second chamber which may be in communication with the motor chamber. The improved bearing includes a plurality of circumferentially spaced axial apertures that are formed to permit the flow of ventilating air from the second chamber therethrough, drawn by the fan in the motor chamber, to cool the second bearing and the housing.
Inventors
- 👤 R Wagner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:56
CPC Classifications
B; B25; B25F; B25F5/00; B25F5/008; H; H02; H02K; H02K5/00; H02K5/04; H02K5/16; H02K5/167; H02K5/1672; H02K9/00; H02K9/02; H02K9/04; H02K9/06
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
178 words
A bearing assembly for a power tool comprising: a. a housing formed of plastic, b. a universal motor having a stator and an armature mounted in the housing, c. a shaft for the armature disposed axially in the housing and having a fan affixed thereto, d. apertures formed in the housing in axially spaced relationship on either side of the fan to permit ventilating air to enter and to exit the housing to cool the motor, e. a first bearing means connected in the housing to journal one end of the armature shaft, f. a second bearing means to journal the other end of the armature shaft, g. a motor chamber formed in the housing in communication with said apertures, h. a second chamber formed in the housing adjacent the second beAring means, and i. a plurality of apertures formed in the second bearing means to permit circulatoin of the ventilating air through the second bearing means from the second chamber, drawn by the fan in the motor chamber, to cool the second bearing means and the housing.
Claim 2
Dependent Claim
178 words
A bearing assembly for a power tool comprising: a. a housing formed of plastic, b. a universal motor having a stator and an armature mounted in the housing, c. a shaft for the armature disposed axially in the housing and having a fan affixed thereto, d. apertures formed in the housing in axially spaced relationship on either side of the fan to permit ventilating air to enter and to exit the housing to cool the motor, e. a first bearing means connected in the housing to journal one end of the armature shaft, f. a second bearing means to journal the other end of the armature shaft, g. a motor chamber formed in the housing in communication with said apertures, h. a second chamber formed in the housing adjacent the second beAring means, and i. a plurality of apertures formed in the second bearing means to permit circulatoin of the ventilating air through the second bearing means from the second chamber, drawn by the fan in the motor chamber, to cool the second bearing means and the housing.
Claim 3
Dependent Claim
48 words
The combination claimed in claim 1 wherein: a. a gear chamber formed in the housing adjacent to the second chamber and remote from the motor chamber, and b. means formed on the second bearing means to define a grease seal between the motor chamber and the gear chamber.
Claim 4
Dependent Claim
86 words
The combination claimed in claim 2 wherein: a. a recess formed in the housing, b. the second bearing means seated within said recess, c. the apertures of the second bearing means defining axial slots, d. an annular flange formed on the second bearing means to extend radially above the axial slots and to define a grease seal to prevent the passage of grease from the gear chamber, and e. a plurality of radial projections on the second bearing means formed alternately with the ventilating apertures thereon.
Claim 5
Dependent Claim
37 words
The combination claimed in claim 1 wherein: a. the second chamber having an external aperture to draw secondary air from outside the housing into and through the second chamber to cool the second bearing and the housing.
Claim 6
Dependent Claim
48 words
The combination claimed in claim 1 wherein: a. the second chamber having an aperture radially above the second bearing and in communication with the motor chamber to draw ventilating air from the motor chamber for passage through the second bearing prior to discharge from the housing discharge aperture.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-17 | 1977-12-17 | 1978-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-17 | 1981-12-17 | 1982-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-17 | 1985-12-17 | 1986-06-18 | $7700.00 | Window Closed / Lapsed |