Patent US3645342A successfully refreshed from Google Patents.
US3645342A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Percussion hammer
Assignee: Vulcan Iron Works Inc
•
Filing: 1970-06-01
•
Granted: 1972-02-29
•
Expires: 1990-06-01
Abstract
Abstract There is provided a percussion hammer of the type used for driving piles and the like, and including a differential diameter piston defining a ram reciprocally positioned within a differential diameter cylinder. An anvil is mounted for limited movement in one end of the cylinder positioned in the path of the ram to receive percussion blows therefrom. Valve means are provided for controlling the inlet of working fluid and the exhaust of the working fluid from the cylinder so as to cycle the ram through power and return strokes. Safety means are provided for rendering the valve inoperative to cycle the ram when the percussion hammer is out of engagement with a pile.
Inventors
- 👤 George C Wandell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:36
CPC Classifications
E; E02; E02D; E02D7/00; E02D7/02; E02D7/06; E02D7/10
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
140 words
A percussion hammer adapted to rest on a pile and comprising a housing having defined therein a differential diameter cylinder; a piston of corresponding different diameters mounted in said cylinder and defining a ram; an impact anvil mounted for limited movement in one end of said cylinder positioned in the path of said ram, said anvil being supported in an upper position when the hammer rests on a pile and dropping to a lower position when the hammer is out of engagement with a pile; valve means for controlling the inlet and exhaust of working fluid into the space in said cylinder between the differential diameters of said cylinder and said piston to cycle said ram through power and return strokes; and safety means including passage means bypassing said piston when said hammer is out of engagement with a pile.
Claim 2
Dependent Claim
140 words
A percussion hammer adapted to rest on a pile and comprising a housing having defined therein a differential diameter cylinder; a piston of corresponding different diameters mounted in said cylinder and defining a ram; an impact anvil mounted for limited movement in one end of said cylinder positioned in the path of said ram, said anvil being supported in an upper position when the hammer rests on a pile and dropping to a lower position when the hammer is out of engagement with a pile; valve means for controlling the inlet and exhaust of working fluid into the space in said cylinder between the differential diameters of said cylinder and said piston to cycle said ram through power and return strokes; and safety means including passage means bypassing said piston when said hammer is out of engagement with a pile.
Claim 3
Dependent Claim
104 words
A percussion hammer as set forth in claim 2 wherein said piston has a working stroke between an upper position in which said ram is raised above said impact anvil, and an intermediate position wherein said ram strikes said impact anvil when said hammer rests on a pile so that said anvil is in its upper position, and a lower position wherein said ram rests on said impact anvil when said hammer is out of engagement with a pile so that said anvil is in its lower position; and wherein said passage means bypasses said piston when said ram is in said lower position.
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) | 1975-02-28 | 1975-08-30 | 1976-02-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-28 | 1979-08-30 | 1980-02-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-28 | 1983-08-30 | 1984-02-29 | $7700.00 | Window Closed / Lapsed |