US3693702A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure casting machine with pressure increase system
Assignee: Individual
•
Filing: 1970-05-26
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Granted: 1972-09-26
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Expires: 1990-05-26
Abstract
Abstract A pressure casting machine having a moulding piston slidable in a cylinder and a pressure-increase system having a stepped piston and serving to increase the pressure in the moulding cylinder towards the end of the working stroke of the moulding piston, the pressure line leading to the working chamber of the moulding cylinder being closed by means of a valve when the pressureincrease system is in operation, wherein the annular face of the pressure-increase piston is free from pressure and the large face of the said piston is actuated by a predetermined pressure through a feed line controlled by a valve.
Inventors
- 👤 Rolf Piekenbrink
- 👤 Albert Reinhardt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 18:08
CPC Classifications
B; B22; B22D; B22D17/00; B22D17/20; B22D17/32
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
200 words
A pressure casting apparatus comprising a moulding cylinder, a moulding piston slidably disposed at least partially within said moulding cylinder thereby defining a working chamber and a retraction chamber within said moulding cylinder, means for supplying fluid under pressure to said working chamber to thereby actuate said moulding piston in its working stroke; and pressureincrease means for increasing the pressure in the working chamber towards the end of said working stroke responsive to a predetermined moulding pressure, said pressure-increase means comprising a pressure-increase cylinder, a pressure-increase piston slidably disposed within said pressure-increase cylinder, said pressure-increase piston being stepped and having a large face, a small face, and an annular face, said large face thereby defining a pressure chamber, said small face thereby defining a high pressure chamber and said annular face thereby defining an annular chamber, means for maintaining said annular chamber at atmospheric pressure, separate means for supplying fluid pressure to said pressure chamber responsive to said predetermined moulding pressure, means for adjusting said pressure supplied to said pressure chamber to provide a predetermined final moulding pressure, and closure valve means for closing said means for supplying pressure to said working chamber when said pressureincrease means is in operation.
Claim 2
Dependent Claim
200 words
A pressure casting apparatus comprising a moulding cylinder, a moulding piston slidably disposed at least partially within said moulding cylinder thereby defining a working chamber and a retraction chamber within said moulding cylinder, means for supplying fluid under pressure to said working chamber to thereby actuate said moulding piston in its working stroke; and pressureincrease means for increasing the pressure in the working chamber towards the end of said working stroke responsive to a predetermined moulding pressure, said pressure-increase means comprising a pressure-increase cylinder, a pressure-increase piston slidably disposed within said pressure-increase cylinder, said pressure-increase piston being stepped and having a large face, a small face, and an annular face, said large face thereby defining a pressure chamber, said small face thereby defining a high pressure chamber and said annular face thereby defining an annular chamber, means for maintaining said annular chamber at atmospheric pressure, separate means for supplying fluid pressure to said pressure chamber responsive to said predetermined moulding pressure, means for adjusting said pressure supplied to said pressure chamber to provide a predetermined final moulding pressure, and closure valve means for closing said means for supplying pressure to said working chamber when said pressureincrease means is in operation.
Claim 3
Dependent Claim
32 words
A pressure casting machine as claimed in claim 1, wherein said separate means for supplying pressure to the pressure-increase means comprises a pressurized fluid feed line and a pressure-regulating or pressure-reducing valve.
Claim 4
Dependent Claim
19 words
A pressure casting machine as claimed in claim 2, wherein a pressure reservoir is connected to the feed line.
Claim 5
Dependent Claim
33 words
A pressure casting machine as claimed in claim 1, wherein said separate means for supplying pressure further comprises a switching valve responsive to the pressure in the working chamber of the moulding cylinder.
Claim 6
Dependent Claim
41 words
A pressure casting machine as claimed in claim 1, wherein the closure valve means also serves as a valve to connect the working chamber and said high-pressure chamber when the pressure line to the working chamber is blocked and vice versa.
Claim 7
Dependent Claim
28 words
A pressure casting machine as claimed in claim 1, wherein the closure valve means is operable by the pressure in the high pressure chamber of the pressure-increase means.
Claim 8
Dependent Claim
70 words
A pressure casting machine as claimed in claim 5, wherein the closure valve means has a valve member which is actuated by the pressure in the high pressure chamber of the pressure-increase means and has holes which are closed by the walls of the bore which receives it and which effect the connection between the working chamber of the moulding cylinder and the high-pressure chamber of the pressure increase means.
Claim 9
Dependent Claim
59 words
A pressure casting machine as claimed in claim 7, further comprising a tappet which moves when a predetermined pressure level is reached in the chamber into which the moulding piston is retracted to return the vale member to the position in which it isolates the working chamber of the moulding cylinder from the high-pressure chamber of the pressure-increase means.
Claim 10
Dependent Claim
53 words
A pressure casting machine as claimed in claim 1, wherein the pressure increase piston has a valve surface and a control sleeve is slidably arranged in a cylinder chamber located in front of the said valve surface, the said sleeve constituting a valve seating facing the valve surface of the pressure increase piston.
Claim 11
Dependent Claim
36 words
A pressure casting machine as claimed in claim 9, wherein the pressure increase piston has a projection which engages with the control sleeve and carries on its front end a stop member for the control sleeve.
Claim 12
Dependent Claim
44 words
A pressure casTing machine as claimed in claim 10, wherein the projection is hollow and in the part adjacent the valve surface of the pressure increase piston has holes for the flow of pressurized fluid conveyed to the working chamber of the mould cylinder.
Claim 13
Dependent Claim
33 words
A pressure casting machine as claimed in claim 11, wherein passages for the pressurized fluid conveyed to the working chamber of the mould cylinder are provided between said projection and the control sleeve.
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) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |