Patent US3797585A successfully refreshed from Google Patents.
US3797585A
Expired / Lapsed
US
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Apparatus for generating a pressure wave in an elongated body operatively connected to a drop hammer
Assignee: Individual
•
Filing: 1972-10-18
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Granted: 1974-03-19
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Expires: 1992-10-18
Abstract
Abstract When driving piles into the ground the drop hammer should act upon the head of the pile through the intermediation of an elastically deformable cap. The resistance of the ground will vary from one occasion to the other and will furthermore often vary during the driving of an individual pile. This makes it desirable to change the elastic properties of the cap, which to that end is designed to enclose a body of gas and a body of liquid, means being provided for adjusting the volume and the pressure of the gas by governing the flow of liquid from one chamber to another within the cap.
Inventors
- 👤 B Ludvigson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:22
CPC Classifications
E; E02; E02D; E02D7/00; E02D7/20; E02D13/00; E02D13/10; E02D7/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
108 words
A device for generating a pressure wave in an elongated body, one end of which, the ''''head'''' is acted upon by a drop hammer through the intermediation of a cap permitting an elastic deformation in the direction of impact, said cap comprising a cylinder and a piston biased by an elastic body enclosed in the cylinder and operable therein by the action of the drop hammer, the improvement of means defining at least two chambers within the cap a body of liquid within said chambers and means for selectively governing the flow of liquid between the chambers for governing the volume and the pressure of the elastic body.
Claim 2
Independent Claim
108 words
A device for generating a pressure wave in an elongated body, one end of which, the ''''head'''' is acted upon by a drop hammer through the intermediation of a cap permitting an elastic deformation in the direction of impact, said cap comprising a cylinder and a piston biased by an elastic body enclosed in the cylinder and operable therein by the action of the drop hammer, the improvement of means defining at least two chambers within the cap a body of liquid within said chambers and means for selectively governing the flow of liquid between the chambers for governing the volume and the pressure of the elastic body.
Claim 3
Dependent Claim
57 words
The device as claimed in claim 1 in which two pistons are operable towards and away from each other in the cylinder, a first one acted upon by the hammer and the other acting upon the elongated body, said pistons defining between themselves a first chamber enclosing the elastic body and a selected portion of the liquid.
Claim 4
Dependent Claim
82 words
The device according to claim 2 in which the second piston is provided with a first passage for communication with said first chamber, and with two second passages for communication with a second chamber and with the first passage, the flow governing means being located intermediate all three passages to govern flow through them, each of the second passages being provided with a non-return valve, one being devised to prevent flow to the first chamber, and the other to permit flow thereto.
Claim 5
Dependent Claim
30 words
The device according to claim 2 in which the flow governing means includes a reversible pump for transferring liquid from the first chamber to the second chamber, and vice versa.
Claim 6
Dependent Claim
30 words
The device according to claim 2 in which the first piston is designed as a hollow cylinder open towarDs the second chamber and adapted to receive a gaseous elastic body.
Claim 7
Dependent Claim
59 words
The device according to claim 2, in which the first piston is provided with an enlarged portion defining a third chamber within the cylinder, the flow govering means comprising a reversible pump for transferring liquid between the first and the second chambers and a further pump being provided for transferring liquid from the first chamber to the third chamber.
Claim 8
Dependent Claim
51 words
The device according to claim 6 in which an annular valve member operable by the liquid pressure is fitted in the third chamber, cooperating with the enlarged portion of the first piston for govering flow of liquid between the second and the third chamber past said enlarged portion of the piston
Claim 9
Dependent Claim
36 words
The device according to claim 6, in which an annular valve member mechanically operable by the drop hammer is fitted within the hollow first piston for opening a passage between the second and the third chamber.
Claim 10
Dependent Claim
42 words
The device according to claim 8, in which an automatically operating valve member is fitted in the hollow, first piston to define the portion of the second chamber containing the elastic body from the main portion of the chamber containing the liquid.
References Cited (Backward Citations)
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US3417828A
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US3606296A
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US3721095A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |