US3838741A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pile hammers
Assignee: Individual
•
Filing: 1972-05-09
•
Granted: 1974-10-01
•
Expires: 1992-05-09
Abstract
Abstract Power hammer for driving piling, and the like, free of valve mechanism likely to require attention and comprising a working cylinder having an anvil at the lower end of the same and a ram operative as a piston in the cylinder, cooperative with the anvil and surrounding walls of the cylinder to form an expansion chamber, the ram having a flow passage extending from an annular groove near the top, down through the lower end to said expansion chamber and the cylinder having pressure supply and exhaust ports to register with said flow passage and to be uncovered by the ram, in lower and upper positions of the ram in the cylinder and whereby the essential functions of the hammer are automatically effected in the normal operation of the ram. Pressure controlled valves may be added to automatically hold desired pressures and release opposing pressures on the ram.
Inventors
- 👤 C Pepe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:13
CPC Classifications
E; E02; E02D; E02D7/00; E02D7/02; E02D7/06; E02D7/10
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
411 words
A power hammer comprising: a normally upright cylinder having an upper end and a lower end; an anvil at the lower end of the cylinder, the anvil having an upper face; fluid pressure supply connections having a plurality of equally spaced inlet ports opening in through the side of the cylinder; a ram in said cylinder operating in cooperative relation with the anvil, said ram being movable between a lower position, wherein the ram is against the anvil, and an upper position, wherein the ram is away from the anvil and adjacent the upper end of the cylinder; the cylinder including an expansion chamber at the lower end thereof; the ram having an upper end and a lower end, an annular groove in the side thereof, a passage in the interior thereof and a plurality of openings in the groove connecting the groove and the passage, the passage extending from the said plurality of openings through the lower end of the ram to communicate with the expansion chamber, and the annular groove having upper and lower ends; and upper and lower sealing means located, respectively, adjacent the upper and lower ends of the annular groove for establishing a pressure fluid seal between the ram and the cylinder; the annular groove being located so as to register with the inlet ports in the lower position of the ram to thereby supply pressure fluid through the openings and the passage to the expansion chamber to lift the ram and operate the same as a piston, said upper and lower ends of the annular groove being spaced apart to provide the groove with a length great enough to admit sufficient pressure fluid to the expansion chamber, as the ram is lifted and before the sealing means cut off communication between the openings in the ram and the inlet ports, to lift the ram to the upper position thereof; the cylinder having an exhaust port through the side thereof which is covered by the ram when the ram is in the lower position and uncovered to communicate with the expansion chamber when the ram is in the upper position, the exhaust port being spaced upwardly from the lower end of the cylinder a distance sufficient to permit expansion of the pressure fluid in the expansion chamber to raise the ram and enable the expanded pressure fluid to be exhausted from the expansion chamber to allow the ram to fall freely downward and strike the anvil.
Claim 2
Dependent Claim
411 words
A power hammer comprising: a normally upright cylinder having an upper end and a lower end; an anvil at the lower end of the cylinder, the anvil having an upper face; fluid pressure supply connections having a plurality of equally spaced inlet ports opening in through the side of the cylinder; a ram in said cylinder operating in cooperative relation with the anvil, said ram being movable between a lower position, wherein the ram is against the anvil, and an upper position, wherein the ram is away from the anvil and adjacent the upper end of the cylinder; the cylinder including an expansion chamber at the lower end thereof; the ram having an upper end and a lower end, an annular groove in the side thereof, a passage in the interior thereof and a plurality of openings in the groove connecting the groove and the passage, the passage extending from the said plurality of openings through the lower end of the ram to communicate with the expansion chamber, and the annular groove having upper and lower ends; and upper and lower sealing means located, respectively, adjacent the upper and lower ends of the annular groove for establishing a pressure fluid seal between the ram and the cylinder; the annular groove being located so as to register with the inlet ports in the lower position of the ram to thereby supply pressure fluid through the openings and the passage to the expansion chamber to lift the ram and operate the same as a piston, said upper and lower ends of the annular groove being spaced apart to provide the groove with a length great enough to admit sufficient pressure fluid to the expansion chamber, as the ram is lifted and before the sealing means cut off communication between the openings in the ram and the inlet ports, to lift the ram to the upper position thereof; the cylinder having an exhaust port through the side thereof which is covered by the ram when the ram is in the lower position and uncovered to communicate with the expansion chamber when the ram is in the upper position, the exhaust port being spaced upwardly from the lower end of the cylinder a distance sufficient to permit expansion of the pressure fluid in the expansion chamber to raise the ram and enable the expanded pressure fluid to be exhausted from the expansion chamber to allow the ram to fall freely downward and strike the anvil.
Claim 3
Dependent Claim
39 words
The invention of claim 1 wherein: the anvil has crossed V-section grooves in its upper face opposed to the lower end of the ram to provide clearance for the pressure fluid admitted down through the passage in the ram.
Claim 4
Dependent Claim
77 words
The invention of claim 1 including: valve means biased to its open position mounted near the upper end of the cylinder; said valve means being open to atmosphere on the downstroke of the ram to prevent vacuum build-up and retardation of the downstroke; said valve means closing on the upstroke of the ram when the pressure generated is sufficient to overcome the bias to thereby build up an air cushion and pressure source for the subsequent downstroke.
Claim 5
Dependent Claim
72 words
The invention of claim 3 including: second valve means biased to its open position mounted near the lower end of the cylinder; said second valve means being open to atmosphere to relieve back pressure on the downstroke of the ram; said second valve means closing as the pressure beneath the ram is sufficient to overcome the bias and remaining closed on the upstroke until the pressure fluid exits through the exhaust port.
Claim 6
Dependent Claim
69 words
The invention of claim 1 including: valve means biased to its open position mounted near the lower end of the cylinder; said valve means being open to atmosphere to relieve back pressure on the downstroke of the ram; said valve means closing as the pressure beneath the ram is sufficient to overcome the bias and remaining closed on the upstroke until the pressure fluid exits through the exhaust port.
Claim 7
Dependent Claim
16 words
The invention of claim 5 wherein said valve means is spring biased to its open position.
Claim 8
Dependent Claim
48 words
The invention of claim 1 wherein: there are two such exhaust ports spaced apart in a vertical direction such that when the lower of said exhaust ports is closed, the pressure fluid is exhausted through the upper exhaust port to thereby obtain a longer stroke of the ram.
Claim 9
Dependent Claim
94 words
The invention of claim 7 including: a first spring-opened, pressure-closed valve mounted in the cylinder at a level adjacent the upper face of the anvil; a second spring-opened, pressure-closed valve mounted in the cylinder adjacent the upper end thereof; a pressure fluid, supply connection extending to said inlet ports and having a branch extending to the cylinder above the ram and having pressure regulating means therein for reducing the downward pressure of the pressure fluid on the ram as opposed to the greater upward pressure of the pressure fluid used for lifting the ram.
Claim 10
Dependent Claim
16 words
The invention of claim 8 including means for precluding flow of pressure fluid in the branch.
Claim 11
Dependent Claim
94 words
The invention of claim 1 including: a first spring-opened, pressure-closed valve mounted in the cylinder at a level adjacent the upper face of the anvil; a second spring-opened, pressure-closed valve mounted in the cylinder adjacent the upper end thereof; a pressure fluid, supply connection extending to said inlet ports and having a branch extending to the cylinder above the ram and having pressure regulating means therein for reducing the downward pressure of the pressure fluid on the ram as opposed to the greater upward pressure of the pressure fluid used for lifting the ram.
Claim 12
Dependent Claim
253 words
A power hammer comprising: a normally upright cylinder having a head, an upper end and a lower end; an anvil at the lower end of the cylinder; a ram in said cylinder operating in cooperative relation with the anvil, said ram being movable between a down position, wherein the ram is against the anvil and an up position, wherein the ram is away from the anvil and adjacent the upper end of the cylinder, said ram having: an upper end and a lower end; an annular groove in the outer perimeter of the side thereof; a passage in the interior from the top to the bottom; and a plurality of openings connecting the annular groove and the passage; a tube mounted in the head of the cylinder and carrying vertically spaced upper and lower piston valve elements positioned within the passage to register with the annular groove in the down and up positions of the ram; the lower piston valve element being in register with the annular groove in the down position of the ram; the upper piston valve element being in register with the annular groove in the up position of the ram; a first fluid connection in the cylinder in register with the annular groove in the down position of the ram and communicating with the lower end of the cylinder; and a second fluid connection in the cylinder in register with the annular groove in the up position of the ram and communicating with the upper end of the cylinder.
Claim 13
Dependent Claim
253 words
A power hammer comprising: a normally upright cylinder having a head, an upper end and a lower end; an anvil at the lower end of the cylinder; a ram in said cylinder operating in cooperative relation with the anvil, said ram being movable between a down position, wherein the ram is against the anvil and an up position, wherein the ram is away from the anvil and adjacent the upper end of the cylinder, said ram having: an upper end and a lower end; an annular groove in the outer perimeter of the side thereof; a passage in the interior from the top to the bottom; and a plurality of openings connecting the annular groove and the passage; a tube mounted in the head of the cylinder and carrying vertically spaced upper and lower piston valve elements positioned within the passage to register with the annular groove in the down and up positions of the ram; the lower piston valve element being in register with the annular groove in the down position of the ram; the upper piston valve element being in register with the annular groove in the up position of the ram; a first fluid connection in the cylinder in register with the annular groove in the down position of the ram and communicating with the lower end of the cylinder; and a second fluid connection in the cylinder in register with the annular groove in the up position of the ram and communicating with the upper end of the cylinder.
References Cited (Backward Citations)
US1184687A
Cited
US1424188A
Cited
US1791582A
Cited
FR759573A
Cited
FR855214A
Cited
US2459484A
Cited
US2797664A
Cited
DE1189471B
Cited
US3105359A
Cited
US3442338A
Cited
US3453657A
Cited
US3547207A
Cited
US3606930A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-30 | 1978-04-01 | 1978-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-30 | 1982-04-01 | 1982-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-30 | 1986-04-01 | 1986-10-01 | $7700.00 | Window Closed / Lapsed |