Bead setting apparatus with retractable flange

An apparatus and method of setting a bead ring against the plies of a tire carcass on the shoulder of a building drum includes a carrier member with a retractable bead support flange. As the carrier member pushes the bead firmly against the carcass plies, the bead support flange is also pushed against the carcass plies, and the flange partly retracts under the pressure. Then, a fluid operated piston drives the support flange further away from the carcass plies, leaving the bead ring almost unsupported, but pressed firmly against the carcass plies on the building drum. The carrier member then retracts away from the building drum, leaving the bead ring in place on the building drum shoulder and ready to have the carcass ply end portions wrapped around it.

FIELD OF THE INVENTION 
This invention relates to the art of building pneumatic tires, and more 
particularly to an improved apparatus and method of setting a bead ring 
against the plies of a tire carcass that overhang the shoulder of a 
building drum. 
BACKGROUND OF THE INVENTION 
One apparatus and method of setting a bead ring against the plies of a tire 
carcass is shown in U.S. Pat. No. 3,871,942 to V. E. Henley et al., 
assigned to the assignee of the present invention. The bead setting 
apparatus of that patent, shown in FIG. 7 and described in column 6, lines 
49 to 66, has a thin cylindrical flange on which the bead ring is 
supported before it is pushed against the carcass plies on the drum 
shoulder by a radially extending plate located behind the bead ring. Since 
the supporting cylindrical flange extends only part way within the inside 
edge surface of the bead ring, this flange does not touch the carcass 
plies or the drum shoulder, or otherwise interfere with the bead setting 
apparatus as it drives the bead ring against the carcass plies. 
However, in order to obtain a tight wrapping of the carcass plies around 
the building drum shoulder during the expansion of the drum and the 
subsequent setting of the bead ring, it has been found desireable to 
lengthen the cylindrical flange of the bead setting apparatus. With such a 
longer flange, extending fully across the inside surface of the bead ring 
and protruding toward the shoulder of the building drum, the bead setting 
apparatus is moved in close to the drum during its expansion. With the 
apparatus so positioned, the carcass plies will be forced laterally around 
the drum facing edge of the long flange as they are pulled radially 
outwardly by the expanding drum. These plies will thus be wrapped more 
tightly against the shoudler of the drum and will conform more to the 
contour of the shoulder, thus insuring better cord length control. 
While a long bead carrying flange helps in wrapping the carcass plies 
around the drum shoulder, it makes the actual setting of the bead ring 
more difficult. In the past, an inflatable push-off bladder has been used 
to push the bead ring off its long flange and against the carcass plies on 
the shoulder of the building drum. Such a bladder, however, cannot provide 
the required force to push the bead ring off the long cylindrical flange 
when the bead ring fits snugly over the flange. On the other hand, when 
the bead ring fits loosely on the flange, it is likely to become canted 
and positioned off center when it is seated against the carcass plies on 
the building drum. The push-off bladder itself can also contribute to the 
improper and insecure positioning of the bead ring, because it does not 
present a solid back-up surface for the bead ring and does not push hard 
enough on the bead ring, especially during the final stages of the bead 
setting. 
SUMMARY OF THE INVENTION 
The foregoing problems in setting a bead ring against the plies of a tire 
carcass are overcome by an improved apparatus that includes an annular 
carrier member encircling the axis of a tire building drum, bead ring 
support flange encircling the building drum axis and mounted on the 
carrier member and extending axially from the carrier member toward the 
tire building drum shoulder, and means for moving the carrier member 
axially toward the tire building drum shoulder. The improvement resides in 
a bead ring support flange that is axially slidable with respect to the 
carrier member, and in the means for sliding this bead ring support flange 
with respect to the carrier member in a direction axially away from the 
tire building drum. Preferably, the means for sliding the support flange 
is a fluid operated annular piston slidable within an annular chamber in 
the carrier member. 
The invention also resides in an improved method that includes the steps of 
carrying the bead ring on the support flange of a carrier member to a 
first position spaced axially from the building drum shoulder, and then 
expanding the building drum to cause the end portions of carcass plies on 
the drum to be drawn around the drum facing edge of the support flange and 
toward the end face of the building drum. The improvement resides in the 
steps of moving the carrier member further toward the drum from its first 
position to press the bead ring and the support flange against the carcass 
ply end portions and also to press the carcass ply end portions against 
the end face of the building drum; sliding the support flange on the bead 
ring carrier member axially away from the tire building drum to release 
the hold that the carrier member has on the bead ring; and then moving the 
carrier member axially away from the tire building drum, leaving the bead 
ring pressed against the end portions of the carcass plies overhanging the 
building drum shoulder. Preferably, the bead ring support flange slides on 
the carrier member axially away from the tire building drum a short 
distance as the result of the forward movement of the carrier member 
toward the building drum which presses the support flange against the 
carcass plies, and then the support flange is slid further away from the 
tire building drum by a fluid operated piston or other movement means 
independent of the means that moves the bead ring carrier member. 
An object of the foregoing improved bead setting method and apparatus is to 
provide a tire bead ring set firmly, concentrically, and squarely against 
the carcass ply end portions overhanging the building drum shoulder. 
Another object of the invention is to provide a firm and accurate setting 
of the bead ring while at the same time insuring that the carcass ply ends 
are wrapped tightly around the drum shoulder and conforming to the contour 
of the soulder. This insures a square and concentric setting of the bead 
with respect to the outside diameter of the drum. Since the drum supports 
the ply, this insures a square and concentric setting. 
These and other objects, advantages, and features of the invention will be 
more apparent from the attached drawings and the following detailed 
description of a preferred embodiment of the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT 
As best seen in the sectional views of FIGS. 2, 3 and 4, the bead setting 
apparatus 2 includes an annular carrier member 4 and a cylindrical bead 
ring support flange 6. The carrier member 4 is in turn made of several 
parts including a main body ring 8, a front ring member 10, and a chamber 
cover plate 12. Machine screws 13 (FIG. 1) secure the front ring member 10 
to the chamber cover plate 12. 
As shown in FIG. 2, a machine screw 14 secures the main body ring 8 to a 
carrier member support beam 16. There are two such machine screws 14 and 
support beams 16 at diametrically opposed locations on the circumference 
of the bead setting apparatus, as illustrated in FIG. 1 by the dotted-line 
heads of machine screws 14. 
An annulus-shaped chamber 18 extends circumferentially around the main body 
ring 8 and houses an annular piston 20. Compressible O-rings 22 and 
teflon-filled bronze rings 24 are housed within grooves in the sides of 
the piston 20, providing an airtight, sealed engagement between the piston 
20 and the walls of chamber 18. The left-hand end of chamber 18, as viewed 
in FIGS. 2, 3, and 4, is closed off by the chamber cover plate 12, secured 
to the main body ring 8 by machine screws 26 (FIG. 3), which are disposed 
at a plurality of locations around the circumference of the bead setting 
apparatus, as indicated in FIG. 1. The connection between the cover plate 
12 and the chamber 18 is sealed airtight by O-rings 28. 
As shown in FIG. 3, the piston 20 is connected to the cylindrical flange 6 
by rods 30, spaced at intervals around the circumference of the apparatus 
as indicated in FIG. 1. Each rod 30 is surrounded by a sleeve 32 that 
slides within a bearing member 34 mounted on the main body ring 8. Outside 
the bearing member 34, the rod 30 is connected by nuts 36 to the end of 
the cylindrical flange 6. On the other side of piston 20, the rod 30 has 
an enlarged head sliding with a bearing member 40 mounted on the cover 
plate 12. The head 38 keeps the rod 30 axially aligned with the opening in 
bearing member 34 and keeps it from jamming during its movement. O-ring 
seal 42 in the head 38 and an O-ring seal 44 surrounding the sleeve 32 
keep the fluid in chamber 18 from leaking past either end of the rod 30. 
The chamber cover plate 12 has several fluid passageways 46 located around 
its circumference, as shown in FIG. 1. As best seen in FIG. 4, each fluid 
passage-way 46 is connected to an air supply line 50, and the passageway 
46 directs air pressure from this supply line against the piston 20 in 
chamber 18. At the other end of chamber 18 on the other side of piston 20 
is located an air supply fitting 52. The piston 20 is moved backward or 
forward in the chamber 18 to retract or extend the bead ring support 
flange 6 by either feeding pressurized air through air supply line 50 
while using fitting 52 as a vent to the atmosphere, or conversely feeding 
pressurized air through fitting 52 and using the line 50 as a vent to the 
atmosphere. 
To move the bead ring carrier member 4 toward and away from its associated 
tire building drum, there is provided a combination of pneumatic and 
hydraulic pressure cylinders, shown schematically in FIG. 5. Piston 54 in 
air cylinder 56 is connected by rod 58 to a cross-member 60, extending 
between the two support beams 16. Air presssure supplied to the cylinder 
56 thus supplies the primary power to move the annular carrier member 4 
toward or away from the building drum. The cylinders 62 are supplied with 
hydraulic fluid and rods 64 connected to the pistons 66 inside the 
cylinders 62 act as stops against pins 68 connected to the support beams 
16. When the air pressure in cylinder 56 moves the carrier member 4 toward 
the building drum, the rods 64, backed by the hydraulic pressure in 
cylinders 62, engage the pins 68 and stop the carrier member 4 at a first 
position spaced a short distance away from the end of the building drum. 
Then, later when the carcass ply ends on the shoulder of the building drum 
are ready to receive the bead ring, the hydraulic pressure in the 
cylinders 62 is released, allowing the carrier member 4 to move in against 
the shoulder of the building drum for the purpose of setting the bead 
ring. 
The operation of the bead setting apparatus 2 is illustrated in FIGS. 6 
through 10. First, the carrier member 4 with its slidable flange 6 are 
moved by the above described pressure cylinders to a first position shown 
in FIG. 6. In this position the bead ring B is supported on flange 6 which 
is held fully extended from the carrier member 4 by air pressure in 
chamber 18 supplied through the fittings 52. Also, the carrier member 4 
and flange 6 hold the bead ring B spaced axially a short distance from the 
end face 70 of building drum 72. The hydraulic pressure in cylinders 62 
(FIG. 5) holds the carrier member 4 from further movement toward the 
building drum 72. 
Then, the building drum 72 is expanded in diameter to a position shown in 
FIG. 7. During this expansion, the end portions E of carcass plies C on 
the building drum 72 are drawn around the drum facing edge 74 of the bead 
ring support flange 6 and toward the building drum end face 70. This 
action wraps the carcass ply ends E around building drum shoulder 76, so 
that the carcass plies conform to the shape of the shoulder. 
After expansion of building drum 72, the pressure in hydraulic cylinders 62 
(FIG. 5) is released, and the pneumatic cylinder 56 moves the carrier 
member 4 to the position shown in FIG. 8. In this position, both the bead 
ring B and the support flange 6 are pressed against the carcass ply ends 
E, and the carcass ply ends E are in turn forced flush against the end 
face 70 of building drum 72. Under this pressure, the support flange 6 
slides a short distance on the carrier member 4 axially away from the tire 
building drum 72. This causes the annular piston 20 to be forced back in 
chamber 18, in spite of the air pressure still supplied through the 
circumferentially spaced fittings 52 (FIG. 4). Because the support flange 
6 retracts as the carrier member 4 presses the bead ring B against the 
carcass ply ends E, the bead ring B is squeezed between the front ring 
member 10 of the carrier member 4 and the carcass ply ends E. This causes 
the bead ring B to be firmly adhered to the tacky, uncured rubber of the 
carcass plies. Also, because the bead ring B is still fully supported at 
this point by the flange 6, the bead ring B is accurately positioned on 
the carcass plies. 
While the carrier member 4 continues to press the bead ring B against the 
carcass plies, air pressure is introduced through line 50 while the 
passage in line 52 is vented to the atmosphere (FIG. 4). This moves the 
annular piston 20 all the way to the back of chamber 18, causing the 
flange 6 to retract to the position shown in FIG. 9. In this position the 
flange 6 will be barely, if at all, in contact with the bead ring B, and 
thus the hold that the carrier member 4 and flange 6 have on the bead ring 
B will be released. Put another way, the tacking force holding the bead 
ring B to the carcass plies on the building drum will be much greater than 
the frictional forces holding the bead ring B to the front ring member 10 
and flange 6. Thus, when the carrier member 4 is moved back away from the 
building drum to the position shown in FIG. 10, the bead ring B will 
remain firmly in place on the carcass plies adjacent the end face 70 and 
shoulder 76 of the building drum 72. 
When the carrier member 4 is withdrawn away from the building drum, as 
shown in FIG. 10, the flange 6 is returned to its original position by 
reversing the air pressures on the opposite sides of the piston 20 in 
chamber 18. The bead setting apparatus 2 is then ready to receive another 
bead ring for placement on the carcass plies of the next tire to be built 
on building drum 72. 
While one embodiment of the present invention has been shown and described, 
modifications and other embodiments will of course be apparent to those 
skilled in the art, while remaining within the scope of the appended 
claims.