US3579741A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Machine and clamp force control system therefor
Assignee: Lester Engineering Co
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Filing: 1968-11-04
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Granted: 1971-05-25
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Expires: 1988-11-04
Abstract
Abstract A machine such as a diecasting or injection molding machine having a frame with a bed and movable die plate supporting relatively movable molds or dies, such molds or dies being closed by a clamp cylinder to obtain a clamping tonnage, die height adjustment which is operative to control the relative position of the relatively movable dies or molds, and a control system which measures the force or tonnage exerted by the clamp and compares the measured tonnage against a preset or predetermined tonnage which then automatically energizes the die height adjustment mechanism so that the clamp tonnage will be substantially the same and correct for each cycle of operation of the machine and will not vary due to mold growth or shrinkage as temperatures change.
Inventors
- 👤 William H Schwartz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:10
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/76; B29C45/7653; B22; B22D; B22D17/00; B22D17/20; B22D17/32; B29C45/1751
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
93 words
A machine having a frame, a bed and movable die plate mounted on said frame adapted to support relatively Movable dies, power means operative to move such dies together, die height adjustment means, means operative to measure the force exerted on said frame by said power means, and means operative to compare such measured force against a predetermined optimum force to obtain a differential, and means responsive to said differential to energize said die height adjustment means for opening or closing the dies to make the measured force equal to the optimum force.
Claim 2
Dependent Claim
93 words
A machine having a frame, a bed and movable die plate mounted on said frame adapted to support relatively Movable dies, power means operative to move such dies together, die height adjustment means, means operative to measure the force exerted on said frame by said power means, and means operative to compare such measured force against a predetermined optimum force to obtain a differential, and means responsive to said differential to energize said die height adjustment means for opening or closing the dies to make the measured force equal to the optimum force.
Claim 3
Dependent Claim
18 words
A machine as set forth in claim 1 wherein said die height adjustment means comprises a motor-driven screw.
Claim 4
Dependent Claim
33 words
A machine as set forth in claim 1 wherein said means operative to measure the force exerted by said power means comprises strain cell transducers mounted on the longitudinal elements of said frame.
Claim 5
Dependent Claim
46 words
A machine as set forth in claim 1 wherein said means operative to measure the force exerted by said power means comprises strain cell transducers mounted on the longitudinal elements of said frame, said strain cell transducers being mounted on opposite sides of each longitudinal element.
Claim 6
Dependent Claim
49 words
A machine as set forth in claim 1 wherein said means operative to compare such measured force against a predetermined force comprises a load to set point comparator operative to give an increase or decrease command to said die height adjustment means when said relatively movable dies are open.
Claim 7
Dependent Claim
30 words
A machine as set forth in claim 1 wherein said die height adjustment means comprises a worm-driven screw, and a high torque reversible hydraulic motor operative to drive said worm.
Claim 8
Dependent Claim
43 words
A machine as set forth in claim 1 wherein said die height adjustment comprises a reversible hydraulic motor-driven screw, a double-solenoid valve operative to control said motor and the direction of rotation thereof, each solenoid being selectively energized according to the comparison obtained.
Claim 9
Dependent Claim
38 words
A machine as set forth in claim 1 wherein said relatively movable dies include a fixed and movable die, the latter including two relatively movable elements the spacing of which is controlled by said die height adjustment means.
Claim 10
Dependent Claim
36 words
A machine as set forth in claim 1 wherein said frame includes four longitudinal members, strain cells mounted on each member, and a digital indicator operative to measure the long on each member or all members.
Claim 11
Dependent Claim
76 words
A clamp force control system for machines of the type having relatively movable mold portions, means operative to sense the clamp force exerted on such mold portions, means operative to compare such force to obtain a differential to a predetermined optimum force, and means responsive to said differential to adjust the position of such mold portions in the machine for opening or closing the mold portions to make the measured force equal to the optimum force.
Claim 12
Dependent Claim
76 words
A clamp force control system for machines of the type having relatively movable mold portions, means operative to sense the clamp force exerted on such mold portions, means operative to compare such force to obtain a differential to a predetermined optimum force, and means responsive to said differential to adjust the position of such mold portions in the machine for opening or closing the mold portions to make the measured force equal to the optimum force.
Claim 13
Dependent Claim
27 words
A system as set forth in claim 10 wherein said last mentioned means includes a reversible hydraulic motor-driven screw to adjust the position of such mold portions.
Claim 14
Dependent Claim
22 words
A system as set forth in claim 11 including a double-solenoid valve operative to control the extent and direction of rotation thereof.
Claim 15
Dependent Claim
18 words
A system as set forth in claim 12 including a flow control valve leading to said double-solenoid valve.
Claim 16
Dependent Claim
34 words
A system as set forth in claim 10 wherein said first mentioned means includes strain cells on the frame elements of the machine, and means to record the load on each or all elements.
Claim 17
Dependent Claim
18 words
A system as set forth in claim 14 including strain cells mounted on opposite sides of each element.
Claim 18
Dependent Claim
25 words
A system as set forth in claim 15 wherein the two strain cells on each element are connected together to form a full four-leg bridge.
Claim 19
Dependent Claim
20 words
A system as set forth in claim 10 wherein said last mentioned means comprises a load to set point comparator.
Claim 20
Dependent Claim
17 words
A system as set forth in claim 17 wherein said set point is obtained on a dial.
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) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |