Patent US3596561A successfully refreshed from Google Patents.
US3596561A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic clamping arrangements for injection moulding machines
Assignee: Stubbe Maschinenfabrik GmbH
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Filing: 1969-01-08
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Granted: 1971-08-03
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Expires: 1989-01-08
Abstract
Abstract A mold-clamping plate is attached to one end of a tubular piston rod the other end of which is attached to an annular piston. The piston is slidably mounted in an outer cylinder and surrounds a concentric inner cylinder along which it is slidable. Hydraulic pressure applied to the full area face of the piston moves the clamping plate to a clamping position. Hydraulic pressure applied to the annular face of the piston via the space between the piston rod and the outer cylinder moves the clamping plate to a nonclamping position and during this movement oil is transferred from the full-face side of the piston to the space between the piston rod and the inner cylinder, being returned during the next clamping stroke of the piston. Feed and transfer of oil is controlled by hydraulic flow control valves operated under control of electrical switches.
Inventors
- 👤 Heinrich Keller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:40
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/64; B29C45/67; B29C45/6764
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
236 words
A hydraulic clamping mechanism for an injection moulding machine comprising coaxial outer and inner cylinders, a double acting annular piston disposed in the annular space between the cylinders and operable by relative movement witH respect to the cylinders to open and close the mould, one end face of the piston constituting a movable wall of a closing-pressure chamber at one end of the annular space and the other end face of the piston being secured to a tubular piston rod which extends through the other end of the annular space and divides it into an openingpressure chamber and a storage chamber, and control means operable during a mould-closing operation to connect the closingpressure chamber, the opening-pressure chamber and the storage chamber with each other and with a first source of hydraulic pressure to effect closure of the mould and displacement of hydraulic fluid from the opening pressure chamber and the storage chamber directly to the closing-pressure chamber, operable during a mold-clamping operation, after the mould has been closed, to connect the closing-pressure chamber to said first source of hydraulic pressure and the opening-pressure chamber and the storage chamber to exhaust, and operable during a mold-clamping operation to connect the opening-pressure chamber with said first source of hydraulic pressure and the closing-pressure chamber and the storage chamber with each other and to exhaust, hydraulic fluid displaced from the closing-pressure chamber being passed directly to the storage chamber.
Claim 2
Dependent Claim
236 words
A hydraulic clamping mechanism for an injection moulding machine comprising coaxial outer and inner cylinders, a double acting annular piston disposed in the annular space between the cylinders and operable by relative movement witH respect to the cylinders to open and close the mould, one end face of the piston constituting a movable wall of a closing-pressure chamber at one end of the annular space and the other end face of the piston being secured to a tubular piston rod which extends through the other end of the annular space and divides it into an openingpressure chamber and a storage chamber, and control means operable during a mould-closing operation to connect the closingpressure chamber, the opening-pressure chamber and the storage chamber with each other and with a first source of hydraulic pressure to effect closure of the mould and displacement of hydraulic fluid from the opening pressure chamber and the storage chamber directly to the closing-pressure chamber, operable during a mold-clamping operation, after the mould has been closed, to connect the closing-pressure chamber to said first source of hydraulic pressure and the opening-pressure chamber and the storage chamber to exhaust, and operable during a mold-clamping operation to connect the opening-pressure chamber with said first source of hydraulic pressure and the closing-pressure chamber and the storage chamber with each other and to exhaust, hydraulic fluid displaced from the closing-pressure chamber being passed directly to the storage chamber.
Claim 3
Dependent Claim
36 words
A clamping mechanism according to claim 1, in which the opening-pressure chamber is disposed between the piston rod and the outer cylinder and the storage chamber is disposed between the piston rod and the inner cylinder.
Claim 4
Dependent Claim
53 words
A clamping mechanism according to claim 1, in which a hydraulic fluid transfer passage is provided disposed within the inner cylinder, the transfer passage having an outlet at one end and external to the outer cylinder and communicating at the other end with the end of the storage chamber remote from the piston.
Claim 5
Dependent Claim
40 words
A clamping mechanism according to claim 1, in which the control means connects the closing-pressure chamber during a mold-clamping operation to a second source of higher pressure than said first source to which it is connected during a mould-closing operation.
References Cited (Backward Citations)
US3452397A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |