US4103591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for a hydraulically driven percussion hammer
Assignee: Individual
•
Filing: 1976-08-30
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Granted: 1978-08-01
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Expires: 1996-08-30
Abstract
Abstract Device for a hydraulically driven percussion hammer for activating a tool, comprising a differential piston with corresponding cylinder, where the piston's largest surface is closest to the percussion tool, and where the smallest working surface is in direct hydraulic connection with an air tank. The largest working surface is above a multiple valve in connection with a hydraulic pressure medium. The valve is adjustable from an admission position with closed return duct to a position where the admission is blocked and the return duct is open. The piston chamber above the piston's small working surface has a feed duct with back pressure valve for a hydraulic pressure medium.
Inventors
- 👤 Olav L. Reiersdal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:23
CPC Classifications
B; B25; B25D; B25D9/00; B25D9/14; B25D9/145
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
393 words
An hydraulically driven percussion device for actuating a tool, comprising means defining a cavity having first, second and third coaxial cylindrical regions of which the first and second regions are of smaller diameter than the third region, a differential piston having first and second end portions and an intermediate portion fitted slidingly in the first, second and third regions respectively of the cavity, the first end portion having two ends, one of which is further from the second end portion than is the other, and the intermediate portion having two end surfaces, one of which is further from the first end portion and gains the intermediate portion to the second end portion and the other of which is further from the second end portion and gains the intermediate portion to the first end portion, the piston having two working surfaces of which a first is constituted by said one end of the first end portion and of which the second is constituted by said one end surface of the intermediate portion, the area of the second working surface being greater than the area of the first working surface, means defining a cylinder which is coaxial with the three coaxial cylindrical regions of said cavity and has one end in direct communication with said first region of the cavity, a second piston fitted slidingly in said cylinder, resiliently compressible means effective on said second piston to urge said second piston toward said one end of said cylinder source means for supplying hydraulic fluid under pressure, first duct means for placing said source means in communication with said first region of the cavity whereby the resiliently compressible means are placed in hydraulic pressure-transmitting relationship with said first working surface, a check valve for preventing flow of hydraulic fluid from said first region towards said source means, second duct means for placing said source means in communication with the second working surface, and a multiple way valve defining a discharge outlet and having a first position in which the source means communicate with the second working surface via said second duct means and both the source means and the second duct means are shut off from the discharge outlet and a second position in which the source means are shut off from the second working surface and the second duct means communicate with said discharge outlet.
Claim 2
Dependent Claim
393 words
An hydraulically driven percussion device for actuating a tool, comprising means defining a cavity having first, second and third coaxial cylindrical regions of which the first and second regions are of smaller diameter than the third region, a differential piston having first and second end portions and an intermediate portion fitted slidingly in the first, second and third regions respectively of the cavity, the first end portion having two ends, one of which is further from the second end portion than is the other, and the intermediate portion having two end surfaces, one of which is further from the first end portion and gains the intermediate portion to the second end portion and the other of which is further from the second end portion and gains the intermediate portion to the first end portion, the piston having two working surfaces of which a first is constituted by said one end of the first end portion and of which the second is constituted by said one end surface of the intermediate portion, the area of the second working surface being greater than the area of the first working surface, means defining a cylinder which is coaxial with the three coaxial cylindrical regions of said cavity and has one end in direct communication with said first region of the cavity, a second piston fitted slidingly in said cylinder, resiliently compressible means effective on said second piston to urge said second piston toward said one end of said cylinder source means for supplying hydraulic fluid under pressure, first duct means for placing said source means in communication with said first region of the cavity whereby the resiliently compressible means are placed in hydraulic pressure-transmitting relationship with said first working surface, a check valve for preventing flow of hydraulic fluid from said first region towards said source means, second duct means for placing said source means in communication with the second working surface, and a multiple way valve defining a discharge outlet and having a first position in which the source means communicate with the second working surface via said second duct means and both the source means and the second duct means are shut off from the discharge outlet and a second position in which the source means are shut off from the second working surface and the second duct means communicate with said discharge outlet.
Claim 3
Dependent Claim
24 words
A percussion device as claimed in claim 1, wherein said source means are operative to maintain a constant pressure in said first duct means.
Claim 4
Dependent Claim
344 words
An hydraulically driven percussion device for actuating a tool, comprising means defining a cavity having first, second and third coaxial cylindrical regions of which the first and second regions are of smaller diameter than the third region, a differential piston having first and second end portions and an intermediate portion fitted slidingly in the first, second and third regions respectively of the cavity, the first end portion having two ends, one of which is further from the second end portion than is the other, and the intermediate portion having two end surfaces, one of which is further from the first end portion and surrounds the second end portion and the other of which is further from the second end portion and surrounds the first end portion, the piston having two working surfaces of which a first is constituted by said one end of the first end portion and of which the second is constituted by said one end surface of the intermediate portion, the area of the second working surface being greater than the area of the first working surface, an air tank positioned above the first region of the cavity and in communication therewith, source means for supplying hydraulic fluid under pressure, first duct means for placing said source means in communication with said first region of the cavity whereby the gas in the cylinder is placed in direct hydraulic pressure-transmitting relationship with said first working surface, a check valve for preventing flow of hydraulic fluid from said first region towards said source means, second duct means for placing said source means in communication with the second working surface, and a multiple way valve defining a discharge outlet and having a first position in which the source means communicate with the second working surface via said second duct means and both the source means and the second duct means are shut off from the discharge outlet and a second position in which the source means are shut off from the second working surface and the second duct means communicate with said discharge outlet.
Claim 5
Dependent Claim
344 words
An hydraulically driven percussion device for actuating a tool, comprising means defining a cavity having first, second and third coaxial cylindrical regions of which the first and second regions are of smaller diameter than the third region, a differential piston having first and second end portions and an intermediate portion fitted slidingly in the first, second and third regions respectively of the cavity, the first end portion having two ends, one of which is further from the second end portion than is the other, and the intermediate portion having two end surfaces, one of which is further from the first end portion and surrounds the second end portion and the other of which is further from the second end portion and surrounds the first end portion, the piston having two working surfaces of which a first is constituted by said one end of the first end portion and of which the second is constituted by said one end surface of the intermediate portion, the area of the second working surface being greater than the area of the first working surface, an air tank positioned above the first region of the cavity and in communication therewith, source means for supplying hydraulic fluid under pressure, first duct means for placing said source means in communication with said first region of the cavity whereby the gas in the cylinder is placed in direct hydraulic pressure-transmitting relationship with said first working surface, a check valve for preventing flow of hydraulic fluid from said first region towards said source means, second duct means for placing said source means in communication with the second working surface, and a multiple way valve defining a discharge outlet and having a first position in which the source means communicate with the second working surface via said second duct means and both the source means and the second duct means are shut off from the discharge outlet and a second position in which the source means are shut off from the second working surface and the second duct means communicate with said discharge outlet.
Claim 6
Dependent Claim
29 words
A percussion device as claimed in claim 3, wherein the source means are operative to maintain a constant pressure of hydraulic fluid in said first region of the cavity.
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) | 1981-07-31 | 1982-01-30 | 1982-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-31 | 1986-01-30 | 1986-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-31 | 1990-01-30 | 1990-08-01 | $7700.00 | Window Closed / Lapsed |