US3598497A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power-operated unit for drilling and similar purposes
Assignee: Atlas Copco AB
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Filing: 1969-09-02
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Granted: 1971-08-10
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Expires: 1989-09-02
Abstract
Abstract A drilling unit is arranged which has power means for moving the drill axially. When, during rapid feed motion, the drill engages a workpiece, a cutoff valve blocks off a passage for a speedcontrolling hydraulic fluid flow. The fluid must now pass a metering valve. This results in a slower working feed.
Inventors
- 👤 Bengt Ebbe Harald Nyman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:20
CPC Classifications
B; B23; B23Q; B23Q5/00; B23Q5/22; B23Q5/26; B23Q5/261; B23Q5/263; B23Q5/265; Y; Y10; Y10T; Y10T408/00; Y10T408/16; Y10T408/17; Y10T408/172; Y10T408/65; Y10T408/675; Y10T408/6757
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
255 words
A power-operated unit for drilling and similar purposes comprising a first part adapted to be mounted in a frame or the like, a second part movably carried by said first part and rotatably carrying a tool element such as a drill, a motor for rotating said tool element, means for feeding and retracting said second part with respect to a workpiece, and hydraulic control means for controlling the rate of movement and dividing a feed motion into a high-speed approach feed and a low speed working feed which control means comprises a conduit system having a first and a second branch connected in parallel, and means for providing a hydraulic fluid flow proportional to the feed speed through said conduit system, said first branch being restricted so as to limit the flow there through and said second branch incorporating a valving element which is capable of cutting off the flow therethrough when a sudden reduction in the pressure in the hydraulic fluid flow occurs due to engagement of the tool element with the workpiece and, when in open condition during approach feed, is loaded towards the open position by the pressure of the hydraulic fluid downstream of said valving element working on a first surface thereof and loaded towards closed position by means of hydraulic fluid in a fluid chamber working on a second surface thereof, the fluid in said fluid chamber being connected to the fluid in said second branch by means of a leak passage and being resiliently loaded by a piston element.
Claim 2
Dependent Claim
255 words
A power-operated unit for drilling and similar purposes comprising a first part adapted to be mounted in a frame or the like, a second part movably carried by said first part and rotatably carrying a tool element such as a drill, a motor for rotating said tool element, means for feeding and retracting said second part with respect to a workpiece, and hydraulic control means for controlling the rate of movement and dividing a feed motion into a high-speed approach feed and a low speed working feed which control means comprises a conduit system having a first and a second branch connected in parallel, and means for providing a hydraulic fluid flow proportional to the feed speed through said conduit system, said first branch being restricted so as to limit the flow there through and said second branch incorporating a valving element which is capable of cutting off the flow therethrough when a sudden reduction in the pressure in the hydraulic fluid flow occurs due to engagement of the tool element with the workpiece and, when in open condition during approach feed, is loaded towards the open position by the pressure of the hydraulic fluid downstream of said valving element working on a first surface thereof and loaded towards closed position by means of hydraulic fluid in a fluid chamber working on a second surface thereof, the fluid in said fluid chamber being connected to the fluid in said second branch by means of a leak passage and being resiliently loaded by a piston element.
Claim 3
Dependent Claim
24 words
A unit according to claim 1 in which said piston element comprises an elastic membrane which is loaded by gas in a closed chamber.
Claim 4
Dependent Claim
20 words
A unit according to claim 1 in which a spring is arranged to bias said valving element towards open position.
Claim 5
Dependent Claim
20 words
A unit according to claim 2 in which a spring is arranged to bias said valving element towards open position.
Claim 6
Dependent Claim
183 words
A unit according to claim 1 in which said second part comprises a power unit for carrying and rotating a toolholder for the tool element, a feed piston rigidly connected to said power unit for advancing the same, and a return piston coaxial with said first piston and rigidly connected therewith, and in which working unit said first part comprises a first cylinder in which said feed piston is reciprocable, a second cylinder in which said return piston is reciprocable, an annular space surrounding said second cylinder, and elastic membrane sealingly dividing said annular space into an air chamber and an hydraulic fluid reservoir, an air-distributing valve connected to a source of compressed air, to said first cylinder at the rear of said feed piston and to said air chamber, said hydraulic conduit system being connected between the second cylinder in front of the return piston and the hydraulic fluid reservoir and said air-distributing valve having a position for pressurizing the first cylinder and simultaneously venting the air chamber and a position for venting the first cylinder and simultaneously pressurizing the air chamber.
Claim 7
Dependent Claim
18 words
A unit according to claim 5 in which an adjustable restriction valve is disposed in said first branch.
Claim 8
Dependent Claim
75 words
A unit according to claim 6 in which a check valve is disposed in said second branch between said valving element and said hydraulic fluid reservoir to permit flow only in the direction from the second cylinder to the fluid reservoir, said check valve being bypassed by a passage controlled by an adjustable restriction valve and a check valve, the latter permitting flow only in the direction from the fluid reservoir to the second cylinder.
References Cited (Backward Citations)
US3336821A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-09 | 1975-02-08 | 1975-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-09 | 1979-02-08 | 1979-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-09 | 1983-02-08 | 1983-08-10 | $7700.00 | Window Closed / Lapsed |