US3898121A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for molding hollow rubber articles
Assignee: Dunlop Ltd
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Filing: 1973-09-19
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Granted: 1975-08-05
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Expires: 1993-09-19
Abstract
Abstract An apparatus for molding a hollow rubber article in a pair of female molding cavities, the apparatus having means to pre-work the rubber without curing before the molding step, the mold cavities having locking sprue grooves and the mold having means to pressurize it with gas and means to bring the mold cavities together to join the parts of the article. The apparatus enables satisfactory joining of the article parts without need for adhesive or undue pressure at joining stage.
Inventors
- 👤 Eric Holroyd
- 👤 Anthony G Goodfellow
- 👤 James N Mcglashen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:45
CPC Classifications
B; B29; B29C; B29C33/00; B29C33/0022; B29C33/34; B29C43/00; B29C43/02; B29C43/04; B29C43/10; B29C45/00; B29C45/02; B29C69/00; B29C69/004; B29C2791/00; B29C2791/001; B29K; B29K2021/00; B29L; B29L2031/00; B29L2031/54; Y; Y10; Y10T; Y10T156/00; Y10T156/17; Y10T156/1702; Y10T156/1744
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
89 words
A MOULDING APPARATUS COMPRISING AT LEAST ONE PAIR OF FEMALE MOULD CAVITIES MEANS TO FORM MOULDED HALVES FROM RUBBER IN SAID CAVITIES SAID CAVITIES BEING PROVIDED WITH LOCKING SPRUE GROOVES TO PREVENT DISPLACEMENE OF SAID MOULDED HALVES MEANS TO MECHANICALLY WORK SAID RUBBER WITHOUT ANY SUBSTANTIALLY CURING PRIOR TO ITS BEING FORMED INTO SAID HALVES MEANS TO PRESSURISE SAID MOULD WITH GAS AND MEANS TO BRING EACH PAIR OF FEMALE MOULD CAVITIES TOGETHER CONTAINING SAIDD MOULDED HAVLES WHREEBY SAID HALVES CAN CAN BE JOINED TOGETHER UNDER HEAT AND PRESSURE.
Claim 2
Dependent Claim
89 words
A MOULDING APPARATUS COMPRISING AT LEAST ONE PAIR OF FEMALE MOULD CAVITIES MEANS TO FORM MOULDED HALVES FROM RUBBER IN SAID CAVITIES SAID CAVITIES BEING PROVIDED WITH LOCKING SPRUE GROOVES TO PREVENT DISPLACEMENE OF SAID MOULDED HALVES MEANS TO MECHANICALLY WORK SAID RUBBER WITHOUT ANY SUBSTANTIALLY CURING PRIOR TO ITS BEING FORMED INTO SAID HALVES MEANS TO PRESSURISE SAID MOULD WITH GAS AND MEANS TO BRING EACH PAIR OF FEMALE MOULD CAVITIES TOGETHER CONTAINING SAIDD MOULDED HAVLES WHREEBY SAID HALVES CAN CAN BE JOINED TOGETHER UNDER HEAT AND PRESSURE.
Claim 3
Dependent Claim
39 words
An apparatus according to claim 1, in which said means to mechanically work said rubber comprises a feederscrew coupled to a transfer moulding chamber through which said rubber is passed prior to being formed in said female mould cavities.
Claim 4
Dependent Claim
139 words
An apparatus according to claim 1, in which said pair of female mould cavities are located in a rotary mould, said mould having an upper and a lower platen, each platen containing one of said pair of female mould cavities, a male former and a blank cavity, said mould having two forming positions; in said first forming position the male former of each platen being located within the female mould cavity of the other platen thereby defining the halves to be moulded, and in said second forming position the female mould cavities of the two platens being in correspondence with each other thereby enabling the moulded halves to be joined together, and the male former of each platen being located in the blank cavity of the other platen; said platens being rotatable between said first and second forming positions.
Claim 5
Dependent Claim
29 words
An apparatus according to claim 1, in which male formers are provided whereby said rubber halves are formed and defined between said male formers and said female mold cavities.
Claim 6
Dependent Claim
25 words
An apparatus according to claim 1, in which said means to form the rubber havles in the female mold cavities is a transfer molding mechanism.
Claim 7
Dependent Claim
25 words
An apparatus according to claim 1, in which said means to form the rubber halves in the female mold cavities is an injection molding mechanism.
Claim 8
Dependent Claim
25 words
An apparatus according to claim 1, in which said means to form the rubber halves in the female mold cavities is a compression molding mechanism.
Claim 9
Dependent Claim
74 words
An apparatus according to claim 1, in which is provided two press molds, each containing two opposed sets of said female cavities, and two feed chambers being provided between said two press molds, each feed chamber being movable in and out of one of the press molds whereby when one feed chamber is located within its press mold the other feed chamber is in the ''''out'''' position where it can be charged with rubber.
Claim 10
Dependent Claim
27 words
An apparatus according to claim 1, in which said means to pressurize the mold with gas introduces the gas over the equators of the female mold cavities.
Claim 11
Dependent Claim
65 words
An apparatus according to claim 1, in which said locking sprue grooves are shaped to give the sprues a cutaway surface whereby gas entering the mold will pass over the lip of the formed half and onto the surface of the half which is to be the interior of the article, but will not enter between the shell and the wall of the mold cavity.
Claim 12
Dependent Claim
35 words
An apparatus according to claim 1, in which said locking sprue grooves are shaped to provide a sprue which consists of a thicker portion connected to its half of the article by a thinner portion.
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 |