US3922122A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for molding an embossed pattern on the peripheral band of a toroidal article, in particular on tire treads
Assignee: Industrie Pirelli SpA
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Filing: 1974-12-09
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Granted: 1975-11-25
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Expires: 1994-12-09
Abstract
Abstract An apparatus is disclosed for molding an embossed pattern on the peripheral band of a toroidal article, particularly on the tread of a tire, having a mold with upper and lower sidewall sections for pressing the sidewalls of the article and an intermediate section with a plurality of segments for pressing the peripheral band of the article when the mold is closed. The apparatus has driving means to move the segments radially in consequence of their axial displacements, a press to open and close the mold and means for admitting and discharging a curing fluid to cure the article. The driving means are characterized by being able to cause a compression stress between the connected faces of at least two contiguous segments when the mold is assembled and being able to cause a reduction in the stress during molding and curing. This allows the article to be molded and cured outside of the press.
Inventors
- 👤 Franco Bottasso
- 👤 Antonio Pacciarini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:26
CPC Classifications
B; B29; B29D; B29D30/00; B29D30/06; B29D30/0601; B29D30/0605; B29D30/0645; B29D2030/0647
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
206 words
In an apparatus for molding an embossed pattern on the peripheral band of a toroidal article, in particular on the tread of a tire, said apparatus comprising a mold having upper and lower sidewall sections arranged to press the sidewalls of the article, and an intermediate section comprising a plurality of segments arranged to press the peripheral band of the article itself, when the mold is closed, driving means for radially moving said segments in consequence of their axial displacements, a press for opening and closing the mold, means for admitting and discharging a curing fluid at a suitable temperature and pressure with respect to said article to obtain curing of said article, the improvement which comprises said driving means having means for originating a compression stress between the connected faces of at least two contiguous segments when the mold is assembled before molding and curing and having means for oRiginating a reduction of said stress during molding and curing while always maintaining said connected faces of said contiguous segments in direct mutual contact whereby molding and curing can be effected outside of said press and locking means for mutually engaging said upper and lower sidewall sections with said driving means when the mold is assembled.
Claim 2
Dependent Claim
206 words
In an apparatus for molding an embossed pattern on the peripheral band of a toroidal article, in particular on the tread of a tire, said apparatus comprising a mold having upper and lower sidewall sections arranged to press the sidewalls of the article, and an intermediate section comprising a plurality of segments arranged to press the peripheral band of the article itself, when the mold is closed, driving means for radially moving said segments in consequence of their axial displacements, a press for opening and closing the mold, means for admitting and discharging a curing fluid at a suitable temperature and pressure with respect to said article to obtain curing of said article, the improvement which comprises said driving means having means for originating a compression stress between the connected faces of at least two contiguous segments when the mold is assembled before molding and curing and having means for oRiginating a reduction of said stress during molding and curing while always maintaining said connected faces of said contiguous segments in direct mutual contact whereby molding and curing can be effected outside of said press and locking means for mutually engaging said upper and lower sidewall sections with said driving means when the mold is assembled.
Claim 3
Dependent Claim
93 words
The apparatus of claim 1 wherein said driving means for originating said compression stress comprise at least an annular section which surrounds said plurality of segments, said section having an inner diameter such that an interference of pre-established value occurs between the inner surface thereof and the corresponding faces of said segments when the mold is closed before molding and curing, said pre-established value of the interference being at least that which prevents separation of the connected faces of said contiguous segments when the vulcanizing pressure acts inside the article in the mold.
Claim 4
Dependent Claim
35 words
The apparatus of claim 2 wherein the pre-established value of the interference is variable by means capable of carrying out an adjustment of the axial position of said annular section with respect to said segments.
Claim 5
Dependent Claim
56 words
The apparatus of claim 3 wherein the means for carrying out an adjustment of the axial position of said annular section comprise a frame on which said lower sidewall section rests, when the mold is assembled, connecting means connecting said annular section to said frame, and adjustment washers inserted between said annular section and said frame.
Claim 6
Dependent Claim
44 words
The apparatus according to claim 2 further comprising an upper plate, movable in the direction of the mold axis, said plate being arranged to move said segments and to lock itself to the annular section by said locking means when the mold is assembled.
Claim 7
Dependent Claim
65 words
The apparatus of claim 5 wherein said locking means comprise a ferrule rotating on said upper plate and provided with a number of radial teeth and a cylindrical housing provided with a number of teeth, connected to said annular section and containing said mold, wherein locking is accomplished by the sliding contact of the teeth of the cylindrical housing with the teeth of the ferrule.
Claim 8
Dependent Claim
72 words
The apparatus of claim 6 wherein said teeth have mutually facing surfaces shaped along lines parallel to one another and inclined with respect to a plane perpendicular to the mold axis and further wherein means are provided to cause the mutual engagement of said teeth in order to vary the axial position of said segments with respect to said annular section and consequently the value of the compression stress exerted on same.
Claim 9
Dependent Claim
35 words
The apparatus of claim 5 wherein chambers are formed inside said annular section and said plate to permit circulation of said fluid at a suitable temperature and pressure to vulcanize the article in the mold.
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) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |