Plastic article or earthenware shaping or treating: apparatus – Reshaping – resizing or vulcanizing means for tire – tire...
Reexamination Certificate
1999-03-15
2001-03-06
Mackey, James P. (Department: 1722)
Plastic article or earthenware shaping or treating: apparatus
Reshaping, resizing or vulcanizing means for tire, tire...
C425S046000, C425S195000
Reexamination Certificate
active
06196818
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
This invention generally relates to pneumatic tire molds and, more particularly, to the connection between the die ribs that form the tire tread pattern and the mold sections of a pneumatic tire mold. Specifically, the present invention discloses tire mold sections that each have at least one dovetailed groove that slidingly receives a plurality of dovetailed die ribs with the die ribs cooperating to form a continuous, 360 degree die when a plurality of mold sections are fit together to form a tire mold.
2. Background Information
Pneumatic tire molds must have inwardly-projecting continuous dies that form the continuous tire tread on a pneumatic tire during the molding process. These inwardly-projecting dies are formed by combining a plurality of die ribs that are each individually connected to a section of the tire mold. Although the exact number of die ribs and mold sections vary in specific applications, approximately nine mold sections and approximately seventy to seventy-five die ribs are used to form the continuous, 360 degree die in at least one example of a tire mold. A typical pneumatic tire uses three or four of these continuous dies to form the tread pattern of the tire.
Most tire tread patterns include repetitive elements that allow repetitive die ribs to be used to form the continuous, 360 degree tread die of the tire mold. The repetitive die ribs may be formed by any of a variety of molding methods or machining methods known in the art. One molding method that is used to form the die ribs is lost wax casting. Lost wax casting uses a wax representation of the final die rib that is coated with an appropriate material. The wax is melted out of the coating leaving a hollow mold. Although this method allows the intricate projections for the sipes and blades of the tread pattern to be formed on the die ribs, the method does not allow holes to be formed in the molded piece. Such holes have been used in the art to receive pins that connect the die ribs to the mold sections.
In prior art molds, the mold makers had to machine holes into each of the die ribs so that they could be connected to the mold sections. For a typical tire mold, the mold makers had to machine 210 to 300 of the die ribs as well as machining corresponding holes into the mold sections. One typical method of connecting the die ribs to the mold sections is depicted in FIG.
7
. The configuration depicted in
FIG. 7
includes a prior art die rib
10
connected to a prior art mold section
12
. Mold section
12
is formed with a longitudinal rectangular shaped groove
14
into which the base
16
of die rib
10
is inserted. Various projections
18
that form the sipes and blades in the pneumatic tire tread pattern project from die rib
10
and are configured to abut the inner surface
20
of mold section
12
. In the past, a machinist drilled a pair of holes
22
in mold section
12
that were configured to align with a pair of holes
24
that were drilled into die rib
10
. A pair of pins
26
were then used to connect die rib
10
to mold section
12
. Although this connection configuration is not overly complicated, it is time consuming when repeated on 210 to 300 die ribs. It is thus desired in the art to provide a die rib and mold section configuration that allows the die ribs to be quickly and easily connected to the mold sections without the machining steps.
SUMMARY OF THE INVENTION
In view of the foregoing, it is an objective of the present invention to provide a mold section and die rib for a pneumatic tire mold that are configured to slide together and automatically form a secure connection without additional connection elements.
Another objective of the present invention is to provide a mold section that accepts die ribs that may be formed by typical molding methods such as lost wax casting.
Another objective of the present invention is to provide a mold section having at least one longitudinal groove into which at least one die rib is slidingly received with a groove and die rib forming an interference fit in a direction substantially perpendicular to the longitudinal direction of the groove.
Another objective of the present invention is to provide a mold section having a female dovetailed groove and a die rib having a male dovetailed base that is slidingly received in the female dovetailed groove of the mold section.
Another objective of the present invention is to provide a pneumatic tire mold having a plurality of die ribs that are connected to a plurality of mold sections with an interference fit.
Another objective of the present invention is to provide an effective, safe, inexpensive and efficient device that achieves all the enumerated objectives, provides for eliminating difficulties encountered with prior devices, and solves problems and obtains new results in the art.
These and other objectives and advantages of the present invention are achieved by the combination of a mold section and a die rib for a pneumatic tire mold, the combination including a mold section having a body with an interface; a body defining at least one longitudinal groove that opens up the inner surface; the groove having a mouth and a body, the width of the mouth being smaller than the largest width of the body; and a die rib having a body and a base; the base being slidingly received in the groove.
Other objectives and advantages of the present invention are achieved by a die rib for a pneumatic tire mold, the die rib including a body; and a base connected to the body, the base having a male dovetailed cross section.
Yet other objectives and advantages of the present invention are achieved by a mold section for a pneumatic tire mold, the mold section including a body with an inner surface; the body defining at least one longitudinal groove that opens at the inner surface; and the groove having a mouth and a body, the width of the mouth being smaller than the largest width of the body.
REFERENCES:
patent: 3664406 (1972-05-01), Mawson et al.
patent: 3852006 (1974-12-01), Irie
patent: 3893794 (1975-07-01), Acda
patent: 4531902 (1985-07-01), Stuhldreher et al.
patent: 4552522 (1985-11-01), Van Melle
patent: 4708609 (1987-11-01), Yoda et al.
patent: 4856976 (1989-08-01), Rook et al.
patent: 5163501 (1992-11-01), Tanaka et al.
patent: 5208044 (1993-05-01), Miyata et al.
patent: 5429172 (1995-07-01), Hand
patent: 5564492 (1996-10-01), Preiss
patent: 5730204 (1998-03-01), Shimmell
Coleman Richard E.
Glasenapp William A.
Bridgestone Firestone Research, Inc.
Kingsbury Thomas R.
Mackey James P.
Sand Michael
LandOfFree
Mold section and die ribs for tire curing mold does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Mold section and die ribs for tire curing mold, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mold section and die ribs for tire curing mold will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2489498