# US 10,864,694 B2 · Bead apex rubber-forming method, and bead apex rubber-forming device

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- Number: US 10,864,694 B2
- Document ID: US10864694B2
- Status: Granted
- Kind: B2
- Application number: 15/896,992
- Filed: 2018-02-14
- Published: 2018-11-01
- Granted: 2020-12-15
- Earliest claimed: 2012-05-16
- Assignees: Sumitomo Rubber Industries, Ltd.; Nakata Engineering Co., Ltd.
- Applicants: Sumitomo Rubber Industries, Ltd.; Nakata Engineering Co., Ltd.
- Inventors: Hiroyuki Onimatsu; Naoyasu Nakao; Hiroyuki Takahashi
- Web page: https://patentgrep.com/patent/US10864694B2

## CPC

- B29D 30/48: Bead-rings or bead-cores (from wire B21F37/00); Treatment thereof prior to building the tyre
- B29C 48/12: Articles with an irregular circumference when viewed in cross-section, e.g. window profiles
- B29C 48/30: Extrusion nozzles or dies (extrusion characterised by the shape or cross-section of the extruded article B29C48/03)
- B29C 48/37: Gear pumps
- B29C 48/395: using screws surrounded by a cooperating barrel, e.g. single screw extruders
- B29C 48/92: Measuring, controlling or regulating
- B29D 30/0681: {Parts of pneumatic tyres; accessories, auxiliary operations}
- B29D 2030/482: {Applying fillers or apexes to bead cores}
- B29D 2030/487: {Forming devices for manufacturing the beads}
- B29K 2021/00: Use of unspecified rubbers as moulding material
- B29K 2105/246: {Uncured, e.g. green}
- B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00)
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS

## Abstract

The present invention forms bead apex rubber with good precision on the outer circumferential surface of the bead core. A molding process, in which unvulcanized rubber is made to flow into a bead apex molding chamber that is surrounded by surfaces that include the outer circumferential surface of a circular bead core and the bead apex rubber is formed directly on the outer circumferential surface of the bead core that is rotating around the core axis, is provided. The molding process comprises: a tip forming step that forms the leading end of the bead apex rubber; a middle section forming step that sequentially forms the bead apex rubber to be continuous with the leading end; and a joining step to join the back end and the leading end of the bead apex rubber by inflowing the unvulcanized rubber therebetween.

## Claims

### Claim 1

A bead apex rubber forming device to form the bead apex rubber continuously in a full circle on an outer circumferential surface of an annular bead core having a core axis, wherein the bead apex rubber forming device comprises
a bead core holding means for holding the bead core rotatably around the core axis,
a rubber extruder having a gear pump for extruding unvulcanized rubber from a rubber discharge port depending on an on-off action of the gear pump, and
a molding head fixed to the rubber extruder,
the molding head comprises
a bead apex molding chamber being surrounded by the outer circumferential surface of the bead core,
a first inner wall surface of the molding head on one side of a core axis direction, and
a second inner wall surface of the molding head on another side of the core axis direction,
the first inner wall surface being provided with a rubber inflow port connected with the rubber discharge port via a rubber flow channel to feed the unvulcanized rubber from the rubber extruder to the bead apex molding chamber,
the bead apex molding chamber extending in a circumferential direction of the outer circumferential surface, and being openable and closable in the circumferential direction by front and rear shutters on a front portion and a rear portion respectively of the bead apex molding chamber in a bead core rotating direction in relation to the rubber inflow port,
the molding head further comprising
the front shutter,
the rear shutter positioned between a rear end of the bead apex molding chamber in the bead core rotating direction and the rubber inflow port so that a portion for entering a previously-extruded tip of the bead apex rubber is formed in the bead apex molding chamber and between the rear end of the bead apex molding chamber and the rear shutter, and
a cutter to cut the bead apex rubber off from the rubber in the rubber flow channel,
the cutter being slidable along a cutter-guiding groove formed on the first inner wall surface,
the rear shutter being slidable along a shutter-guiding groove of the molding head,
wherein
the rubber inflow port and the shutter-guiding groove are open in a bottom-surface of the cutter-guiding groove that is opposite to the bead apex molding chamber in a thickness direction of the cutter-guiding groove, and
the opening of the rubber inflow port and the opening of the shutter-guiding groove are arranged side by side in the circumferential direction.

### Claim 2 (depends on 1)

The bead apex rubber forming device as set forth in claim 1, wherein the shutter-guiding groove is inclined at an angle toward a front end of the bead apex molding chamber in the bead core rotating direction.

### Claim 3 (depends on 1)

The bead apex rubber forming device as set forth in claim 1, wherein a distance along the first inner wall surface between the opening of the shutter-guiding groove and the opening of the rubber inflow port is not more than 1 mm.

### Claim 4 (depends on 1)

The bead apex rubber forming device as set forth in claim 1, wherein an angle of the shutter-guiding groove with respect to the circumferential direction is smaller than an angle of the rubber flow channel with respect to the circumferential direction.