US4445675A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Work-clamping unit for use in machine tools
Assignee: Aioi Seiki Inc
•
Filing: 1981-11-18
•
Granted: 1984-05-01
•
Expires: 2001-11-18
Abstract
Abstract A work-clamping unit includes a base plate in which hydraulic cylinders are totally embedded, each cylinder including a piston vertically movable beneath the top surface of the base plate, the piston being adapted to carry a clamping member detachably connected thereto so as to transmit a clamping force from the piston to the clamping member, the base plate additionally including an oil path for feeding hydraulic pressure to each of the cylinders.
Inventors
- 👤 Ichiro Kitaura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:02
CPC Classifications
B; B25; B25B; B25B5/00; B25B5/06; B25B5/061; Y; Y10; Y10S; Y10S269/00; Y10S269/90
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
260 words
A work-clamping unit for use in machine tools, said work-clamping unit comprising: a base plate made of steel and provided with a top surface and a bottom surface; said base plate including a plurality of separate and identical hydraulic cylinders totally embedded therein, and a stopper means provided on the bottom surface of the base plate in engagement with recesses in said hydraulic cylinders; said hydraulic cylinders being disposed in a given regular pattern, with each of said separate cylinders spaced a given regular distance longitudinally and transversely from each adjacent one of said separate cylinders, respectively; each of said hydraulic cylinders including a piston vertically movable beneath said top surface of said base plate, and an oil chamber for actuating said piston downward, said stopper means in engagement with recesses provided in said piston, said piston having means for enabling a clamping member to be secured thereto so as to effect a unitary movement of said piston and said clamping member; said stopper means provided to prevent rotation of said piston when said clamping member is secured to said piston and to fasten said cylinder to said base; said top surface having openings for said clamping members to pass through, each of said openings being concentric with each of said hydraulic cylinders; and said base plate including an oil path for supplying each of said hydraulic cylinders with hydraulic pressure, said oil path being communicated with at least a hydraulic supply port, said oil path communicating in series with said oil chambers; hydraulic pressure from one cylinder to another.
Claim 2
Dependent Claim
260 words
A work-clamping unit for use in machine tools, said work-clamping unit comprising: a base plate made of steel and provided with a top surface and a bottom surface; said base plate including a plurality of separate and identical hydraulic cylinders totally embedded therein, and a stopper means provided on the bottom surface of the base plate in engagement with recesses in said hydraulic cylinders; said hydraulic cylinders being disposed in a given regular pattern, with each of said separate cylinders spaced a given regular distance longitudinally and transversely from each adjacent one of said separate cylinders, respectively; each of said hydraulic cylinders including a piston vertically movable beneath said top surface of said base plate, and an oil chamber for actuating said piston downward, said stopper means in engagement with recesses provided in said piston, said piston having means for enabling a clamping member to be secured thereto so as to effect a unitary movement of said piston and said clamping member; said stopper means provided to prevent rotation of said piston when said clamping member is secured to said piston and to fasten said cylinder to said base; said top surface having openings for said clamping members to pass through, each of said openings being concentric with each of said hydraulic cylinders; and said base plate including an oil path for supplying each of said hydraulic cylinders with hydraulic pressure, said oil path being communicated with at least a hydraulic supply port, said oil path communicating in series with said oil chambers; hydraulic pressure from one cylinder to another.
Claim 3
Dependent Claim
26 words
A work-clamping unit as defined in claim 1, wherein said base plate is provided with T-shaped grooves in said top surface on which workpiece are clamped.
Claim 4
Dependent Claim
38 words
A work-clamping unit as defined in claim 1, wherein said piston in said hydraulic cylinder can be optionally made inoperative under hydraulic pressure by replacing said clamping member with a plug secured to said means in said piston.
Claim 5
Dependent Claim
35 words
A work-clamping unit as defined in claim 1, wherein said piston comprises a body portion and a rod portion with a shoulder interposed, said shoulder being adapted to limit the upward movement of said piston.
Claim 6
Dependent Claim
29 words
A work-clamping unit as defined in claim 1, further comprising a spring located under said piston so as to allow said piston to return when hydraulic pressure is withdrawn.
Claim 7
Dependent Claim
15 words
A work-clamping unit as defined in claim 1, wherein said means is a threaded hole.
Claim 8
Dependent Claim
19 words
A work-clamping unit as defined in claim 1, wherein said stopper means supports the spring pressing said piston upward.
Claim 9
Dependent Claim
29 words
A work-clamping unit as defined in claim 1, wherein said base plate is produced separately from the table of a machine tool, and is fastened thereto when in use.
Claim 10
Dependent Claim
21 words
A work-clamping unit as defined in claim 1, wherein said base plate is constituted by the table of a machine tool.
Claim 11
Dependent Claim
33 words
A work-clamping unit as defined in claim 1 wherein said piston is provided with a projection which extends into a recess of said stopper means so as to prevent rotation of said piston.
References Cited (Backward Citations)
US2421957A
Cited
US3700227A
Cited
US3830485A
Cited
DE2421644A1
Cited
US4174828A
Cited
US4179106A
Cited
US4275983A
Cited
US4286778A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-01 | 1987-10-31 | 1988-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-01 | 1991-10-31 | 1992-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-01 | 1995-10-31 | 1996-05-01 | $7700.00 | Window Closed / Lapsed |