US3837410A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary impact drill
Assignee: Individual
•
Filing: 1973-05-23
•
Granted: 1974-09-24
•
Expires: 1993-05-23
Abstract
Abstract A rotary impact drill includes spaced-apart front and rear bearings in which a hammer is rotatably and axially reciprocably supported for working against an anvil which is also supported in the same front bearing as the hammer. A coupling member is secured to the rear end of the shaft portion of the anvil for coupling to a power-driven drive shaft, and such coupling member also secures an axial thrust bearing to such shaft portion, with such thrust bearing being located between the rear bearing and a retainer. A spring is compressed between the hammer and the thrust bearing for normally biasing the hammer toward the anvil. A cam on the drill cooperates with a cam follower on the housing for reciprocating the hammer toward and away from the anvil in cooperation with the spring.
Inventors
- 👤 R Maxwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:50
CPC Classifications
B; B23; B23B; B23B45/00; B25; B25D; B25D11/00; B25D11/06; B25D11/10; B25D11/102
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
349 words
A rotary impact drill comprising a drive assembly having a drive shaft; a drive-impact unit having a housing detachably secured to said assembly and a drive member axially detachably coupled to said drive shaft; said housing having axially spaced apart front and rear radial thrust roller bearings in a uniform diameter bore therethrough and having a spacer tube therebetween; said drive member having integral shaft and anvil portions respectively including a coupling member at the end of said shaft portion for coupling to said drive shaft and a chuck at the end of said anvil portion for gripping a masonry drill and the like; said shaft portion having a non-circular cross-section portion adjacent said anvil portion; a hammer rotatably and axially reciprocably supported in said bore and having a complemental non-circular cross-section bore axially but non-rotatably slidable on said non-circular cross-section portion and having a peripheral groove therearound of which the side facing said anvil portion has a stepped cam surface including circumferentially successive helically and generally axially extending surfaces; a cam follower in said housing extending radially into said peripheral groove for engagement by said helically extending surface; spring means biasing said hammer toward said anvil operative to permit yielding movement of said hammer away from said anvil portion during rotation of said hammer and drive member while said helically extending surface is engaged with said cam follower and to drive the hammer axially into impacting contact with said anvil portion as said generally axially extending surface passes said cam follower; said impact blows thus repeatedly delivered to said anvil portion by said hammer being transmitted to the masonry drill gripped by said chuck; the improvement comprising: SAID hammer being rotatably and axially reciprocably supported in said front and rear bearings and said anvIl portion also being rotatably supported in said front bearing; axial thrust bearing means retained on said shaft portion by said coupling member and being disposed in axial thrust relation between said rear bearing and a retainer in said bore, and said spring means being compressed between said hammer and said axial thrust bearing means.
Claim 2
Dependent Claim
349 words
A rotary impact drill comprising a drive assembly having a drive shaft; a drive-impact unit having a housing detachably secured to said assembly and a drive member axially detachably coupled to said drive shaft; said housing having axially spaced apart front and rear radial thrust roller bearings in a uniform diameter bore therethrough and having a spacer tube therebetween; said drive member having integral shaft and anvil portions respectively including a coupling member at the end of said shaft portion for coupling to said drive shaft and a chuck at the end of said anvil portion for gripping a masonry drill and the like; said shaft portion having a non-circular cross-section portion adjacent said anvil portion; a hammer rotatably and axially reciprocably supported in said bore and having a complemental non-circular cross-section bore axially but non-rotatably slidable on said non-circular cross-section portion and having a peripheral groove therearound of which the side facing said anvil portion has a stepped cam surface including circumferentially successive helically and generally axially extending surfaces; a cam follower in said housing extending radially into said peripheral groove for engagement by said helically extending surface; spring means biasing said hammer toward said anvil operative to permit yielding movement of said hammer away from said anvil portion during rotation of said hammer and drive member while said helically extending surface is engaged with said cam follower and to drive the hammer axially into impacting contact with said anvil portion as said generally axially extending surface passes said cam follower; said impact blows thus repeatedly delivered to said anvil portion by said hammer being transmitted to the masonry drill gripped by said chuck; the improvement comprising: SAID hammer being rotatably and axially reciprocably supported in said front and rear bearings and said anvIl portion also being rotatably supported in said front bearing; axial thrust bearing means retained on said shaft portion by said coupling member and being disposed in axial thrust relation between said rear bearing and a retainer in said bore, and said spring means being compressed between said hammer and said axial thrust bearing means.
Claim 3
Dependent Claim
76 words
The rotary impact drill of claim 1 wherein said retainer in said bore for said axial thrust bearing means comprises a snap ring engaged in an internal groove in said bore in rearwardly-spaced relation to said rear bearing; said aixial thrust bearing means comprising a ring having an inner peripheral portion between said coupling member and a shoulder on said shaft portion, and an outer peripheral portion between said rear roller bearing and said snap ring.
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) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |