Patent US6004490A successfully refreshed from Google Patents.
US6004490A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of using an improved clamping unit in an injection molding machine
Assignee: Industrial Technology Research Institute
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Filing: 1995-08-24
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Granted: 1999-12-21
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Expires: 2015-08-24
Abstract
Abstract A clamping unit and method thereof, in which a servo-motor mounted on a rear platen is used for driving two ball screws with pre-load hydraulic cylinders so as to acuate the outward-bending toggle mechanism to provide mold-opening and mold-clamping functions; by using a limited space, a servo-motor mounted on the movable platen is used for driving a nut to turn so as to cause the screw and the ejector bar to be moved back and forth; finally, an electric motor on the rear, platen will drive a mold-adjusting mechanism, and a servo-motor mounted on the platen is also operated so as to complete the mold adjustment quickly and automatically.
Inventors
- 👤 Lang-Fu Tsai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:42
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/64; B29C45/66; B29C45/661; B29C45/40; B29C45/4005; B29C2045/4036
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
251 words
A method of producing an object using injection molding machine, comprising the following steps: (a) providing an injection molding machine having a clamping unit, said clamping unit comprising: (i) a machine base; (ii) a front platen mounted on said machine base; and (iii) a plurality of tie bars parallel to each other and fixedly mounted to said front platen; a rear platen and a movable platen both of which are also mounted on said machine base, said movable platen being movable sleeved about said tie bars, and said rear platen and said movable platen being coupled together by a pair of outward-bending toggle mechanisms; (b) placing a mold in which an object is to be made inside said clamping unit; (c) using a servo-motor mounted on said rear platen to actuate a plurality of ball screws, said ball screws being adapted to drive said outward-bending toggle mechanism via a balancing means so as to perform mold-opening and mold-claming functions; wherein said balancing means including a plurality of sealed and intercommunicating pre-load hydrolic cylinders which are able to apply a balanced force to said ball screws so as to provide a balanced clamping force, to minimize a screw pitch error between said ball screws and to absorb an impact during mold opening; (d) determining a clampind force required to operate said clamping unit; (e) using said ball screw to set said clamping force so as to operate said clamping unit; (f) injecting an injectable material into said mold to form an object.
Claim 2
Independent Claim
251 words
A method of producing an object using injection molding machine, comprising the following steps: (a) providing an injection molding machine having a clamping unit, said clamping unit comprising: (i) a machine base; (ii) a front platen mounted on said machine base; and (iii) a plurality of tie bars parallel to each other and fixedly mounted to said front platen; a rear platen and a movable platen both of which are also mounted on said machine base, said movable platen being movable sleeved about said tie bars, and said rear platen and said movable platen being coupled together by a pair of outward-bending toggle mechanisms; (b) placing a mold in which an object is to be made inside said clamping unit; (c) using a servo-motor mounted on said rear platen to actuate a plurality of ball screws, said ball screws being adapted to drive said outward-bending toggle mechanism via a balancing means so as to perform mold-opening and mold-claming functions; wherein said balancing means including a plurality of sealed and intercommunicating pre-load hydrolic cylinders which are able to apply a balanced force to said ball screws so as to provide a balanced clamping force, to minimize a screw pitch error between said ball screws and to absorb an impact during mold opening; (d) determining a clampind force required to operate said clamping unit; (e) using said ball screw to set said clamping force so as to operate said clamping unit; (f) injecting an injectable material into said mold to form an object.
Claim 3
Dependent Claim
126 words
The method of producing an object using an injection molding machine according to claim 1, wherein: (a) said outward-bending toggle mechanism comprises a driving arm, a front arm, a rear arm, a rear-platen arm, and a movable-platen arm; (b) said rear-platen arm is fixedly connected to said rear platen, and said movable-platen arm is fixedly connected to said movable platen; (c) said front arm, said rear arm and said driving arm are commonly and privotably connected via a first pin; (d) said driving arm is pivotably connected to said rear platen via a second pin; (e) said rear arm is pivotably connected to said rear-platen arm via a third pin; and (f) said front arm is pivotably connected to said movable-platen arm via a fourth pin.
Claim 4
Dependent Claim
254 words
The method of producing an object using an injection molding machine according to claim 2, wherein said clamping force is provided according to the following steps: (a) calculating an extension distance of said tie bars according to the following formula: ##EQU4## wherein F is the predetermined clamping force, δ x is the extension distance of the tie bar, E is Young's modulus, A is the cross-sectional area of the tie bar, L is the length of the tie bar; and (b) adjusting a distance between said movable platen and said rear platen a distance δ m according to the following set of formulas: ##EQU5## wherein A is the length of the front arm, B is the length of the rear arm, D is the length of the driving arm, E is the axial distance between the second shaft pin and the third shaft pin, H is the axial distance between the second shaft pin and the fourth shaft pin, δ x is the extension distance of the tie bar, δ is a parameter for calculating θ, φ is the angle between the driving arm and ball screw, θ is the angle between the rear arm and a vertical line passing through the third shaft pin, ψ 0 is the angle between the front arm and the ball screw, θ 0 is the angle between the line connecting said third and fourth shaft pins and a vertical line passing through the third shaft pin, K b is the distance between shaft pin and shaft pin.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-12-20 | 2003-06-21 | 2003-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-12-20 | 2007-06-21 | 2007-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-12-20 | 2011-06-21 | 2011-12-21 | $7700.00 | Window Closed / Lapsed |