US3723585A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of electroformed molds
Assignee: Individual
•
Filing: 1970-03-06
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Granted: 1973-03-27
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Expires: 1990-03-06
Abstract
Abstract A pattern for a pair of separable metal molds for a giant plastic article is prepared by a method in which a parting frame at the location of the contemplated parting line is secured to two sections representing the two parts of the mold. The pattern is immersed in an electrolyte and a metallic envelope is electroformed about the pattern. Insulated protrusions extending from the parting frame are not coated, whereby accurate identification of various zones of the envelope is feasible. Copper is a preferred metal for the major thickness of the electroformed molds, but nickel is desirably first plated onto the pattern and thus is the metal contacting the hot plastic. The surfaces of the envelope are modified to permit construction of heat transfer conduits, desirably by a second stage of electroforming. The periphery of the parting frame is removed, thereby permitting the two portions of the electroform to function as two portions of a mold. Each portion is anchored into a box. A polyurethane foam insulating foundation is positioned between a box wall and a contoured wall of the mold. The relatively thin contoured walls of the electroformed halves of the mold are not readily distorted because they are anchored into their boxes.
Inventors
- 👤 F Nussbaum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:50
CPC Classifications
B; B29; B29C; B29C33/00; B29C33/56; B29C33/565; B29C33/02; B29C33/04; B29C33/38; B29C33/3842
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
65 words
The method of claim 1 in which heat transfer conduits are applied subsequent to the withdrawal of the copper-enveloped pattern from the electrolyte by steps including the step of applying wax strips and bonding a copper envelope over the wax strips and copper envelope by a further step of electroforming, and melting the wax to remove the wax from the thus formed heat transfer conduits.
Claim 2
Independent Claim
272 words
A method of preparing a two-section mold for producing a giant organic plastic article including the steps of: preparing a master having external surfaces corresponding generally to the external surfaces of the giant organic plastic article to be produced; determining the parting line between the two parts of the mold, and designating a rigid rectangular frame having parallel faces as the parting frame; cutting the master having the external surfaces corresponding to the external surfaces of the plastic article, such cutting being at the parting line, and securing the two halves of the master to opposite faces of the parting frame, such composite being designated as a pattern; immersing the pattern in an electrolyte and electroforming a metallic envelope about the pattern to form contoured walls on the interior of the envelope of said electroformed metal, said metal being copper, nickel, or mixtures thereof; withdrawing the enveloped pattern from the electrolyte; providing two boxes, each having peripheral frame members and a rear plate; anchoring the electroformed metallic envelope to the rectangular peripheral frame members of the two boxes; positioning an insulating foundation having a pore volume of about 25 percent by forming in place a polyurethane plastic foam between exterior surface portions of the metallic envelope and the rear plate of each box; removing the periphery of the parting frame by cutting through the two parallel faces thereof to separate the envelope into two portions, each portion having a contoured wall extending from a flat matching parallel face portion and being anchored to its box; removing the two boxes and their contoured walls from the pattern to provide a two section mold.
Claim 3
Dependent Claim
73 words
The method of claim 3 in which a plurality of identifying protusions are secured to the pattern prior to the electroforming and said protrusions are insulated so that they are not electroformed, whereby the processing subsequent to the electroforming until the removal of the pattern from the two section mold can be performed with accurate knowledge of the location of the insulated protrusions and the related locations of various portions of the pattern.
Claim 4
Dependent Claim
155 words
The method of claim 3 wherein heat transfer conduits are applied subsequent to the withdrawal of the enveloped pattern but prior to the positioning of the insulating foundation, said application of heat transfer conduits including steps providing a plurality of meltable wax rods positioned on the rear face of each contoured wall, the rods having extensions adapted to align with openings providing flow paths from the exterior of the peripheral frame member of the box through independent conduits having zones contacting the rear face of the contoured wall to outlets exterior of a peripheral frame member, providing the plurality of heat transfer conduits with the adaptation permitting differential heat transfer of various zones of the contoured wall, applying silicone rubber to the rear of the contoured wall and around the exposed portions of the wax rods, and melting the wax rods to remove the wax and to form the conduits for the heat transfer liquid.
Claim 5
Dependent Claim
70 words
A method as set forth in claim 3 wherein heat transfer conduits are applied subsequent to the withdrawal of the enveloped pattern but prior to the positioning of the insulating foundation, said application of heat transfer conduits including the steps of providing wax rods on the exterior surface of the contoured wall, spraying silicone rubber on the wax rods, and melting the wax rods to provide the heat transfer conduits.
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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) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |