US3898314A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of molding rubber articles
Assignee: Teledyne Mid America Corp
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Filing: 1973-10-17
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Granted: 1975-08-05
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Expires: 1993-10-17
Abstract
Abstract An improved method of molding rubber articles in which uncured rubber is preheated to a soft, workable condition in a warm-up mill located immediately adjacent to an injection press. The warm uncured rubber is transferred to the press and then by a press plunger mechanism into cavities of a mold cavity plate. The plunger mechanism and cavities are coated with Teflon to prevent sticking of the rubber. A mold lid with pressure pins then is placed on the cavity plate and pressed in an auxiliary press to displace rubber within the cavities and to form openings through the rubber articles being produced. The displaced rubber is forced into a groove formed between the cavity plate and lid surrounding the cavity formation at the parting line between the lid and cavity plate, and the rubber in the groove forms a circumferential rib around the molded article. The rubber in the cavities is cured at the desired temperature for the required amount of time while maintained under pressure. After curing, the mold lid is removed and the molded rubber articles are removed from the cavities by an air ejector mechanism. Air nozzles are inserted into the openings formed by the pressure pins and a blast of high pressure air breaks the bond between the molded articles and cavity plate. Threaded tips preferably are formed on the air nozzles to grip the molded articles and lift them from the mold plate. The gripped articles then are knocked off the nozzle tips and deposited on a conveyor.
Inventors
- 👤 Herman S Church
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:35
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/40; B29C45/42; B29C45/4225; B29C45/02; B29C45/43; B29K; B29K2021/00; Y; Y10; Y10S; Y10S264/00; Y10S264/66; Y10S425/00; Y10S425/102
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
361 words
IN A RUBBER MOLDING METHOD OF THE TYPE WHEREIN A SUPPLY OF UNCURED RUBBER IS MAINTAINED IN A POT CHAMBER AT A HEATED TEMPERATURE BELOW CURING TEMPERATURE TO RETAIN THE UNCURED RUBBER IN A SOFT, WORABLE CONDITION, THEN A CHARGE OF THE HEATED UNCURED RUBBER IS TRANSFERRED TO A MOLD CAVITY FORMED PARTIALLY BY A LOWER MOLD ELEMENT, THEN THE TRANSFERRED CHARGE OF UNCURED RUBBER IS SEPARATED FROM THE SUPPLY OF UNCURED RUBBER IN THE POT CHAMBER, THEN A MOLD LID IS PLACED ON THE LOWER MOLD ELEMENT TO ENCLOSE, PRESS, AND DISPLACE THE UNCURED RUBBER IN THE CAVITY, AND THEN THE ENCLOSED CHARGE OF UNCURED RUBBER IS CURVED WHILE UNDER PRESSURE IN THE CAVITY AT CURING TEMPERATURE TO FORM A MOLDED RUBBER ARTICLE, THE IMPROVEMENTS INCLUDING THE STEPS OF INSERTING PIN MEANS INTO THE CHARGE OF UNCURED RUBBER DURING MOLD CLOSURE OF SAID CHARGE OF UNCURED RUBBER FOR CARRYING OUT THE DISPLACEMENT OF RUBBER IN THE MOLD CAVITY AND TO HOLD THE RUBBER UNDER COMPRESSION IN THE CAVITY, THEREBY FORMING AT LEAST A SINGLE VOID IN THE RUBBER ARTICLE BEING MOLDED BY THE PIN MEANS WHEN THE MOLD LID IS PLACED ON THE LOWER MOLD ELEMENT PRIOR TO CURING, FORMING A CIRCUMFERENTIAL RIB ON THE RUBBER ARTICLE UPON INSERTION OF THE PIN MEANS BY DISPLACING RUBBER OUTWARDLY FROM THE CAVITY AND SURROUNDING THE MOLD CAVITY AT THE PARTING LINE BETWEEN THE MOLD LID AND LOWER MOLD ELEMENT, REMOVING THE MOLD LID AND PIN MEANS FROM THE LOWER MOLD ELEMENT AND RUBBER ARTICLE, RESPECTIVELY, AFTER CURING, INSERTING AIR NOZZLE MEANS DOWNWARDLY INTO THE VOID FORMED IN THE RUBBER ARTICLE AND GRIPPING THE MOLDED RUBBER ARTICLE WITHIN THE VOID, INJECTING AIR FROM THE NOZZLE MEANS THROUGH THE VOID AGAINST THE BOTTOM OF THE MOLD CAVITY TO ASSIST IN STRIPPING THE ARTICLE FROM THE LOWER MOLD ELEMENT, REMOVING THE MOLDED RUBBER ARTICLE FROM THE LOWER MOLD BY MOVING THE AIR NOZZLE MEANS RELATIVE TO THE LOWER MOLD ELEMENT, RETAINING THE ARTICLE ON THE AIR NOZZLE MEANS WHILE MOVING THE AIR NOZZLE MEANS, AND REMOVING AUTOMATICALLY THE GRIPPED ARTICLE FROM THE AIR NOZZLE MEANS AFTER REMOVAL OF THE ARTICLE FROM THE LOWER MOLD ELEMENT.
Claim 2
Dependent Claim
361 words
IN A RUBBER MOLDING METHOD OF THE TYPE WHEREIN A SUPPLY OF UNCURED RUBBER IS MAINTAINED IN A POT CHAMBER AT A HEATED TEMPERATURE BELOW CURING TEMPERATURE TO RETAIN THE UNCURED RUBBER IN A SOFT, WORABLE CONDITION, THEN A CHARGE OF THE HEATED UNCURED RUBBER IS TRANSFERRED TO A MOLD CAVITY FORMED PARTIALLY BY A LOWER MOLD ELEMENT, THEN THE TRANSFERRED CHARGE OF UNCURED RUBBER IS SEPARATED FROM THE SUPPLY OF UNCURED RUBBER IN THE POT CHAMBER, THEN A MOLD LID IS PLACED ON THE LOWER MOLD ELEMENT TO ENCLOSE, PRESS, AND DISPLACE THE UNCURED RUBBER IN THE CAVITY, AND THEN THE ENCLOSED CHARGE OF UNCURED RUBBER IS CURVED WHILE UNDER PRESSURE IN THE CAVITY AT CURING TEMPERATURE TO FORM A MOLDED RUBBER ARTICLE, THE IMPROVEMENTS INCLUDING THE STEPS OF INSERTING PIN MEANS INTO THE CHARGE OF UNCURED RUBBER DURING MOLD CLOSURE OF SAID CHARGE OF UNCURED RUBBER FOR CARRYING OUT THE DISPLACEMENT OF RUBBER IN THE MOLD CAVITY AND TO HOLD THE RUBBER UNDER COMPRESSION IN THE CAVITY, THEREBY FORMING AT LEAST A SINGLE VOID IN THE RUBBER ARTICLE BEING MOLDED BY THE PIN MEANS WHEN THE MOLD LID IS PLACED ON THE LOWER MOLD ELEMENT PRIOR TO CURING, FORMING A CIRCUMFERENTIAL RIB ON THE RUBBER ARTICLE UPON INSERTION OF THE PIN MEANS BY DISPLACING RUBBER OUTWARDLY FROM THE CAVITY AND SURROUNDING THE MOLD CAVITY AT THE PARTING LINE BETWEEN THE MOLD LID AND LOWER MOLD ELEMENT, REMOVING THE MOLD LID AND PIN MEANS FROM THE LOWER MOLD ELEMENT AND RUBBER ARTICLE, RESPECTIVELY, AFTER CURING, INSERTING AIR NOZZLE MEANS DOWNWARDLY INTO THE VOID FORMED IN THE RUBBER ARTICLE AND GRIPPING THE MOLDED RUBBER ARTICLE WITHIN THE VOID, INJECTING AIR FROM THE NOZZLE MEANS THROUGH THE VOID AGAINST THE BOTTOM OF THE MOLD CAVITY TO ASSIST IN STRIPPING THE ARTICLE FROM THE LOWER MOLD ELEMENT, REMOVING THE MOLDED RUBBER ARTICLE FROM THE LOWER MOLD BY MOVING THE AIR NOZZLE MEANS RELATIVE TO THE LOWER MOLD ELEMENT, RETAINING THE ARTICLE ON THE AIR NOZZLE MEANS WHILE MOVING THE AIR NOZZLE MEANS, AND REMOVING AUTOMATICALLY THE GRIPPED ARTICLE FROM THE AIR NOZZLE MEANS AFTER REMOVAL OF THE ARTICLE FROM THE LOWER MOLD ELEMENT.
Claim 3
Dependent Claim
46 words
The method defined in claim 1 including the step of locating a warm-up mill adjacent the pot chamber supply of heated uncured rubber; heating a charge of uncured rubber in the warm-up mill; and transferring the heated charge of uncured rubber directly to the pot chamber.
Claim 4
Dependent Claim
55 words
The method defined in claim 1 including the further step of forming projection means on the lower portion of the rubber article by displacing rubber outwardly from the cavity adjacent the bottom surface thereof, said projection means assisting in retaining the rubber article in the lower mold element when the mold lid is removed therefrom.
Claim 5
Dependent Claim
47 words
The method defined in claim 1 including the step of coating the mold cavity with a layer of material having nonsticking properties with respect to the uncured rubber, said coating material adhering to the mold cavity and remaining adherred to said mold cavity after repeated molding operations.
Claim 6
Dependent Claim
246 words
IN A RUBBER MOLDING METHOD OF THE TYPE WHEREIN A SUPPLY OF HEATED UNCURED RUBBER IS ENCLOSED AND PRESSED IN A MOLD CAVITY FORMED BY A MOLD ELEMENT AND A MOLD LID TO DISPLACE THE RUBBER IN THE CAVITY, AND THEN THE ENCLOSED CHARGE OF RUBBER IS CURED WHILE HELD UNDER PRESSURE TO FORM A MOLDED RUBBER ARTICLE, THE IMPROVEMENT INCLUDING THE STEPS OF INSERTING PIN MEANS INTO THE CHARGE OF UNCURED RUBBER DURING MOLD CLOSURE OF SAID CHARGE OF UNCURED RUBBER FOR CARRYING OUT THE DISPLACMENT OF RUBBER IN THE MOLD CAVITY AND TO HOLD THE RUBBER UNDER COMPRESSION IN THE CAVITY, AND FOR FORMING A VOID EXTENDING THROUGH THE RUBBER ARTICLE BEING MOLDED BY THE PIN MEANS WHEN THE MOLD LID AND PIN MEANS FROM THE MOLD TO CURING, REMOVING THE MOLD LID AND PIN MEANS FOR THE MOLD ELEMENT AND RUBBER ARTICLE, ARTICLE AND AN END OF THE VOID POSE A PORTION OF THE RUBBER ARTICLE AND AN END OF THE VOID FORMED THEREIN, INSERTING AIR NOZZLE MEANS IN THE VOID FORMED THEREIN, INSERTING AIR NOZZLE MEANS INTO THE VOID RUBBER ARTICLE WITHIN THE VOID, INJECTING AIR FROM THE NOZZLE MEANS THROUGH THE VOID AGAINST THE BOTTOM OF THE MOLD CAVITY TO ASSIST IN STRIPPING THE ARTICLE FROM THE MOLD ELEMENT, MOVING THE AIR NOZZLE MEANS RELATIVE TO THE MOLD ELEMENT, AND RETAINING THE ARTICLE ON THE AIR NOZZLE MEANS WHILE THE AIR NOZZLE MEANS TO REMOVE THE ARTICLE FROM THE MOLD ELEMENT.
Claim 7
Dependent Claim
246 words
IN A RUBBER MOLDING METHOD OF THE TYPE WHEREIN A SUPPLY OF HEATED UNCURED RUBBER IS ENCLOSED AND PRESSED IN A MOLD CAVITY FORMED BY A MOLD ELEMENT AND A MOLD LID TO DISPLACE THE RUBBER IN THE CAVITY, AND THEN THE ENCLOSED CHARGE OF RUBBER IS CURED WHILE HELD UNDER PRESSURE TO FORM A MOLDED RUBBER ARTICLE, THE IMPROVEMENT INCLUDING THE STEPS OF INSERTING PIN MEANS INTO THE CHARGE OF UNCURED RUBBER DURING MOLD CLOSURE OF SAID CHARGE OF UNCURED RUBBER FOR CARRYING OUT THE DISPLACMENT OF RUBBER IN THE MOLD CAVITY AND TO HOLD THE RUBBER UNDER COMPRESSION IN THE CAVITY, AND FOR FORMING A VOID EXTENDING THROUGH THE RUBBER ARTICLE BEING MOLDED BY THE PIN MEANS WHEN THE MOLD LID AND PIN MEANS FROM THE MOLD TO CURING, REMOVING THE MOLD LID AND PIN MEANS FOR THE MOLD ELEMENT AND RUBBER ARTICLE, ARTICLE AND AN END OF THE VOID POSE A PORTION OF THE RUBBER ARTICLE AND AN END OF THE VOID FORMED THEREIN, INSERTING AIR NOZZLE MEANS IN THE VOID FORMED THEREIN, INSERTING AIR NOZZLE MEANS INTO THE VOID RUBBER ARTICLE WITHIN THE VOID, INJECTING AIR FROM THE NOZZLE MEANS THROUGH THE VOID AGAINST THE BOTTOM OF THE MOLD CAVITY TO ASSIST IN STRIPPING THE ARTICLE FROM THE MOLD ELEMENT, MOVING THE AIR NOZZLE MEANS RELATIVE TO THE MOLD ELEMENT, AND RETAINING THE ARTICLE ON THE AIR NOZZLE MEANS WHILE THE AIR NOZZLE MEANS TO REMOVE THE ARTICLE FROM THE MOLD ELEMENT.
Claim 8
Dependent Claim
32 words
The method defined in claim 5 including the step of removing the gripped article from the air nozzle means after removing the article from the mold element by engaging kicker plate means.
Claim 9
Dependent Claim
41 words
The method defined in claim 5 including the step of forming a circumferential rib on the rubber article by displacing rubber outwardly from the cavity and surrounding the mold cavity at the parting line between the mold lid and mold element.
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) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |