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US4019845A
Expired / Lapsed
US
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Control system for injection-molding machine
Assignee: Kloeckner Werke AG
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Filing: 1976-04-21
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Granted: 1977-04-26
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Expires: 1996-04-21
Abstract
Abstract An injection-molding machine has a drive ram with a pressurizable chamber that can be connected either to the high-pressure side or the low-pressure side of a source of fluid under pressure. A control system operating this machine has a pressure-reducing valve with an inlet port connected to the high-pressure side of the source, an outlet port connected through a cut-off valve and a throttle to the chamber of the ram, and a pilot port pressurizable to control the pressure at this outlet port. A pressure-relief valve has an inlet port connected to the pressurizable ram chamber, an outlet port connected to the low-pressure side of the pressure source, and a pilot port pressurizable to control the pressure differential across this pressure-relief valve. A pressure-control valve has an outlet side connected to the low-pressure side of the source and an inlet side and is operable to maintain a first predetermined pressure differential between its inlet and outlet sides in an injection mode and to maintain a certain predetermined pressure differential between its inlet and outlet sides in a clamping mode. A check valve has one side connected to the pilot port of the pressure-reducing valve and another side connected to the pilot port of the pressure-relief valve for fluid flow only from the former to the latter. A function-control valve has a first connection coupled to the inlet side of the pressure-control valve and a second and third connection each coupled to a respective one of the pilot ports. This function-control valve is operable between a filling position connecting the pilot port of the pressure-relief valve to the pressure-control valve and an injecting/holding position connecting the pilot port of the pressure-reducing valve to the pressure-control valve.
Inventors
- 👤 Hans Birkhofer
- 👤 Arno Stohr
- 👤 Werner Schrammel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:33
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/76; B29C45/82
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
247 words
In combination with an injection-molding machine having a drive ram with a pressurizable chamber and with a source of fluid under pressure having a high-pressure side and a low-pressure side, a control system comprising: a pressure-reducing valve having an inlet port connected to the said high-pressure side, an outlet port connected to said chamber, and a pilot port, means operable in said pressure-reducing valve whereby the pressure at said pilot port determines the pressure at said outlet port; a pressure-relief valve having an inlet port connected to said chamber, an outlet port connected to said low-pressure side, and a pilot port, means operable in said pressure-relief valve whereby the pressure at said inlet port of said pressure-relief valve is determined by the pressure at its said pilot port; a pressure-control valve having an outlet side connected to said low-pressure side and an inlet side and having means operable to maintain a first predetermined pressure differential between said inlet and outlet sides in an injecting mode and to maintain a second predermined pressure differential between said inlet and outlet sides in a clamping mode; and function-control means including a valve having a first connection coupled to said inlet side and second and third connections each coupled to a respective one of said pilot ports and operable between a filling position connecting said pilot port of said pressure-relief valve to said pressure-control valve and an injecting/holding position connecting said pilot port of said pressure-reducing valve to said pressure-control valve.
Claim 2
Dependent Claim
247 words
In combination with an injection-molding machine having a drive ram with a pressurizable chamber and with a source of fluid under pressure having a high-pressure side and a low-pressure side, a control system comprising: a pressure-reducing valve having an inlet port connected to the said high-pressure side, an outlet port connected to said chamber, and a pilot port, means operable in said pressure-reducing valve whereby the pressure at said pilot port determines the pressure at said outlet port; a pressure-relief valve having an inlet port connected to said chamber, an outlet port connected to said low-pressure side, and a pilot port, means operable in said pressure-relief valve whereby the pressure at said inlet port of said pressure-relief valve is determined by the pressure at its said pilot port; a pressure-control valve having an outlet side connected to said low-pressure side and an inlet side and having means operable to maintain a first predetermined pressure differential between said inlet and outlet sides in an injecting mode and to maintain a second predermined pressure differential between said inlet and outlet sides in a clamping mode; and function-control means including a valve having a first connection coupled to said inlet side and second and third connections each coupled to a respective one of said pilot ports and operable between a filling position connecting said pilot port of said pressure-relief valve to said pressure-control valve and an injecting/holding position connecting said pilot port of said pressure-reducing valve to said pressure-control valve.
Claim 3
Dependent Claim
44 words
The system defined in claim 1, further comprising a cut-off valve between said outlet port of said pressure-reducing valve and said chamber, said cut-off valve being closable to block fluid flow from said pressure-reducing valve to said chamber and openable to permit such flow.
Claim 4
Dependent Claim
30 words
The system defined in claim 2, further comprising a second pressure-reducing valve connected in series with said cut-off valve between said outlet port of said pressure-reducing valve and said chamber.
Claim 5
Dependent Claim
27 words
The system defined in claim 3, further comprising a shunt valve connected across said second pressure-reducing valve, said shunt valve being openable to bypass said cut-off valve.
Claim 6
Dependent Claim
26 words
The system defined in claim 1, further comprising a shunt valve connected across said pressure-relief valve, said shunt valve being openable to bypass said pressure-relief valve.
Claim 7
Dependent Claim
55 words
The system defined in claim 1, further comprising a program means connected to said function-control means and to said pressure-control valve for operating said function-control means to connect said pilot port of said pressure-reducing valve to said pressure-control valve and thereupon switching same from said injecting position to said holding position after a predetermined interval.
Claim 8
Dependent Claim
71 words
The system defined in claim 6, further comprising a cut-off valve connected between said outlet port of said pressure-reducing valve and said chamber, said cut-off valve being openable to permit fluid flow from said pressure-reducing valve to said chamber and closable to block said flow, said program means being connected to said cut-off valve to close same on connection of said pressure-control valve through said function-control means to said pressure-relief valve.
Claim 9
Dependent Claim
285 words
In combination with an injection-molding machine having a drive ram with a pressurizable chamber and with a source of fluid under pressure having a high-pressure side and a low-pressure side, a control system comprising: a pressure-reducing valve having an inlet port connected to said high-pressure side, an outlet port, and a pilot port pressurizable to control the pressure at said outlet port; a cut-off valve between said outlet port and said chamber openable for fluid flow therebetween and closable to block such flow; a throttle between said cut-off valve and said pressure-reducing valve; a pressure-relief valve having an inlet port connected to said chamber, an outlet port connected to said low-pressure side, and a pilot port pressurizable to control the pressure differential across said inlet and outlet ports of said pressure-relief valve; a pressure-control valve having an outlet side connected to said low-pressure side and an inlet side and openable to maintain a first predetermined pressure differential between said inlet and outlet sides in an injecting mode and to maintain a second predetermined pressure differential between said inlet and outlet sides in a clamping mode; a check valve having one side connected to said pilot port of said pressure-reducing valve and another side connected to said pilot port of said pressure-relief valve and for fluid flow only from the former to the latter; and a function-control valve having a first connection coupled to said inlet side and second and third connections each coupled to a respective one of said pilot ports and operable between a filling position connecting said pilot port of said pressure-relief valve to said pressure-control valve and an injecting/holding position connecting said pilot port of said pressure-reducing valve to said pressure-control valve.
Claim 10
Dependent Claim
285 words
In combination with an injection-molding machine having a drive ram with a pressurizable chamber and with a source of fluid under pressure having a high-pressure side and a low-pressure side, a control system comprising: a pressure-reducing valve having an inlet port connected to said high-pressure side, an outlet port, and a pilot port pressurizable to control the pressure at said outlet port; a cut-off valve between said outlet port and said chamber openable for fluid flow therebetween and closable to block such flow; a throttle between said cut-off valve and said pressure-reducing valve; a pressure-relief valve having an inlet port connected to said chamber, an outlet port connected to said low-pressure side, and a pilot port pressurizable to control the pressure differential across said inlet and outlet ports of said pressure-relief valve; a pressure-control valve having an outlet side connected to said low-pressure side and an inlet side and openable to maintain a first predetermined pressure differential between said inlet and outlet sides in an injecting mode and to maintain a second predetermined pressure differential between said inlet and outlet sides in a clamping mode; a check valve having one side connected to said pilot port of said pressure-reducing valve and another side connected to said pilot port of said pressure-relief valve and for fluid flow only from the former to the latter; and a function-control valve having a first connection coupled to said inlet side and second and third connections each coupled to a respective one of said pilot ports and operable between a filling position connecting said pilot port of said pressure-relief valve to said pressure-control valve and an injecting/holding position connecting said pilot port of said pressure-reducing valve to said pressure-control valve.
Claim 11
Dependent Claim
65 words
The combination defined in claim 8 wherein said pressure-relief valve and said pressure-control valve each have a housing and a piston subdividing same into a pair of compartments one of which has the respective pilot port and the other of which has the other ports of the respective valve, each piston being formed with a small-diameter orifice permitting limited fluid flow between the respective compartments.
Claim 12
Dependent Claim
34 words
The combination defined in claim 8 wherein said function-control valve is a four-way valve having a port constituting a fourth connection and unable to communicate with any of said first, second, or third connections.
References Cited (Backward Citations)
SU185044A1
Cited
GB652360A
Cited
US2789541A
Cited
US3537356A
Cited
US3695800A
Cited
US3911677A
Cited
US3894824A
Cited
US3840312A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |