CA1104049A - Method of stitching radial tires to inhibit belt edge distortion - Google Patents
Method of stitching radial tires to inhibit belt edge distortionInfo
- Publication number
- CA1104049A CA1104049A CA304,428A CA304428A CA1104049A CA 1104049 A CA1104049 A CA 1104049A CA 304428 A CA304428 A CA 304428A CA 1104049 A CA1104049 A CA 1104049A
- Authority
- CA
- Canada
- Prior art keywords
- belt
- carcass
- assembly
- edges
- bead portions
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Tyre Moulding (AREA)
Abstract
METHOD OF STITCHING RADIAL TIRES
TO INHIBIT BELT EDGE DISTORTION
Abstract of the Disclosure A simple but effective method of air stitching, avoiding use of hard roller stitchers at and between the lateral edges of the restrictor belt, minimizes or eliminates the displacement of the cord or wire ends at the edge or edges of the belt. The restrictor belt, or belt-tread assembly is first disposed about the car-cass. The carcass is then shaped only sufficiently to contact a narrow zone of the belt, and the transfer ring or other device is removed, thereby leaving the belt supported only by the carcass and free of external restraint. Thereafter the shaping of the carcass expands the axial width of contact then extending progressively outward of the respective edges. The shaping pressure within the carcass then is sufficient alone to cohere the carcass to the belt.
TO INHIBIT BELT EDGE DISTORTION
Abstract of the Disclosure A simple but effective method of air stitching, avoiding use of hard roller stitchers at and between the lateral edges of the restrictor belt, minimizes or eliminates the displacement of the cord or wire ends at the edge or edges of the belt. The restrictor belt, or belt-tread assembly is first disposed about the car-cass. The carcass is then shaped only sufficiently to contact a narrow zone of the belt, and the transfer ring or other device is removed, thereby leaving the belt supported only by the carcass and free of external restraint. Thereafter the shaping of the carcass expands the axial width of contact then extending progressively outward of the respective edges. The shaping pressure within the carcass then is sufficient alone to cohere the carcass to the belt.
Description
The present invention has to do with the manu-facture of tires and particularly with methods of building improved pneumatic tires. Still more particularly, the invention provides a method of combining a radial tire carcass with an inextensible belt or belt-tread assembly which affords improvement in the lateral force characterist-ics of the tire and particularly the advantage of reduced belt flaring, that is, the displacement of the cord endings of the belt eages in the shoulder regions of the tire which improvement is revealed by x-ray examination of the tire.
Furtherr in addition to advantages in quality attained by the invention, there is an unusual but welcome improvement in that the time required in the building machine cycle can be reduced.
In accordance with one aspect of this invention there is provided a method of building a radial p1y tire having an endless inextensihle circumferential belt therein of predetermined width between its lateral edges comprising building a radial ply carcass, placing said carcass on -~
shaping means having means to engage the bead portions of the carcass and move them coaxially toward each other . .
symmetrically with a mid-plane of the carcass normal to the tire axis and means to expand the tire carcass concurrently with the movement of the bead portions toward the mid-plane;
forming a belt or belt and tread assembly in endless inexten-sible cylindrical form; disposing said belt or said assembly coaxially about said carcass by means of a transfer ring;
operating said shaping means to move the bead portions toward each other and to expand the carcass radially to contact the belt or the assembly only in a narrow circumfer-ential zone; then removing entirely the restraint afforded by the transfer ring and leaving the belt or the assembly supported only by the carcass; then moving the respective bead portions closer to the mid-plane a distance sufficient to allow the carcass to axially extend its contact progress-ively outwardly from said narrow zone to or very nearly to the respectively associated belt edges such that the cir-cumferential contact between the carcass and the belt or the assembly is progressively extended axially outwardly from said ~one to the respective belt edges.
In accordance with another aspect of this invention there is provided a method of applying an endless inextens-ible belt or belt tread assembly to a radial tire carcass having bead portions comprising disposing said belt or said asse~bly about said carcass, shaping said carcass to expand radially into contact with said belt or said assembly in a narrow central circumferential zone, then before further shaping the carcass removing all radial and lateral restraint from said belt or said assembly, and thereafter further ` shaping the carcass by moving the bead portions thereof axially inward to extend said narrow zone axially outwardly s~mmetrically to the respectively associated la~eral edges of the belt or of the belt-tread assembly.
To acquaint persons skilled in the arts most closely ; related to the present invention, certain preferred embodiments thereof illustrating a best mode now contem-plated for putting the invention into practice are described herein by and with reference to the annexed drawings forming a part of the specification. The embodiments shown and ~- described herein are illustrative and as will become apparent to those~ skilled in these arts can be modified in numerous ways within the spirit and scope of the invention defined in the claims hereof.
In the drawings:
.
Furtherr in addition to advantages in quality attained by the invention, there is an unusual but welcome improvement in that the time required in the building machine cycle can be reduced.
In accordance with one aspect of this invention there is provided a method of building a radial p1y tire having an endless inextensihle circumferential belt therein of predetermined width between its lateral edges comprising building a radial ply carcass, placing said carcass on -~
shaping means having means to engage the bead portions of the carcass and move them coaxially toward each other . .
symmetrically with a mid-plane of the carcass normal to the tire axis and means to expand the tire carcass concurrently with the movement of the bead portions toward the mid-plane;
forming a belt or belt and tread assembly in endless inexten-sible cylindrical form; disposing said belt or said assembly coaxially about said carcass by means of a transfer ring;
operating said shaping means to move the bead portions toward each other and to expand the carcass radially to contact the belt or the assembly only in a narrow circumfer-ential zone; then removing entirely the restraint afforded by the transfer ring and leaving the belt or the assembly supported only by the carcass; then moving the respective bead portions closer to the mid-plane a distance sufficient to allow the carcass to axially extend its contact progress-ively outwardly from said narrow zone to or very nearly to the respectively associated belt edges such that the cir-cumferential contact between the carcass and the belt or the assembly is progressively extended axially outwardly from said ~one to the respective belt edges.
In accordance with another aspect of this invention there is provided a method of applying an endless inextens-ible belt or belt tread assembly to a radial tire carcass having bead portions comprising disposing said belt or said asse~bly about said carcass, shaping said carcass to expand radially into contact with said belt or said assembly in a narrow central circumferential zone, then before further shaping the carcass removing all radial and lateral restraint from said belt or said assembly, and thereafter further ` shaping the carcass by moving the bead portions thereof axially inward to extend said narrow zone axially outwardly s~mmetrically to the respectively associated la~eral edges of the belt or of the belt-tread assembly.
To acquaint persons skilled in the arts most closely ; related to the present invention, certain preferred embodiments thereof illustrating a best mode now contem-plated for putting the invention into practice are described herein by and with reference to the annexed drawings forming a part of the specification. The embodiments shown and ~- described herein are illustrative and as will become apparent to those~ skilled in these arts can be modified in numerous ways within the spirit and scope of the invention defined in the claims hereof.
In the drawings:
.
-2-,-, , FIG. 1 illustrates a prior art step of positioning a belt tread assembly on a shaped radial carcass;
FIG. 2 illustrates the step of the prior art process in w~ich the carcass is shaped outwardly into increasingly wide contact progressing outwardly from the mid-circumferential plane with the belt and/or tread assembly which is restrained by the rigid transfer ring employed to dispose the assemb.ly about the carcassi :
FIG. 3, the belt and tread assembly is illustrated '~' completely without restraint, the trans~er ring having been removed while the.carcass and belt tread assembly remain in the relatlon therebetween illustrated in Fig. l;
~ ~ r . ~ ~
, .
~.
-2a-:. ~
FIG. ~ illustrates the mode o~ hard roller stitching heretofore in use wherein a pair o~ stitcher rolls are brought into contact with the tire starting at the mid-circumferential plane o~ the tire~ the indiYidual stitchers 5 being moved outwardly oppositel~ and gradually as the tire is rotated so as to consolidate the belt and tread onto the carcass in the ~amiliar manner;
FIG 5 illustrates the stitching step in accordance with the invention wherein a similar pair of hard roll stitchers are brought into contact with the tire to initiate the stitching at or slightly outward of the respective lateral edges of the inextensible bel-t itself and progress thence outwardly to the lateral edges of the tread.
In carrying out the invention~ a carcass 10 which includes at least one ply having cords or wires extending parallel to the axis and at least two bead cores 12 about which the respective axial ends of the ply in cyllndrical form are wrapped and secured~ is built ~ollowing any known procedure. Normally~ the carcass includes also an ,~
air-impervious liner.
e carcass is placed on shaping means o~ known construction having means 15 to engage the bead portions of the carcass and to move them coaxiall~ toward each other symmetrically with respect to a mid-plane 20 normal to the tire axis~ and means to expand the carcass~ ~or ` examplea to introduce pressurized air within the chamber ~` of the carcass to in*late ita concurrently with movement o~ the bead portions toward the mid-plane.
An inextensible bel-t or a belt-tread assembly B in endless cylindrical form prepared by known procedures and having a predetermined wid-th from one a to the other b lateral belt edge, measured parallel to the -tire axis is then disposed coaxially about the carcass, as by means of a rigid transfer ring 25 such -that their respective mid-planes are coplanar, or offset axially a predetermined small distance.
The shaping means is then operated to move the respective bead portions toward each other and concurrently to expand the carcass -to contact the belt or the assembly only in a narrow circumferen-tial zone. As is indicated in Fig. 1, this contact may be considered as the con-tact of a circular arc with a s-traight~line in a representative radial plane.
In accordance with the invention~ the next step of the process is that of removing entirely all of the external restraint acting on the belt or assembly leaving ~he assembly ;
~itself supported only by the carcass. In Fig. ~, this is represent~ed by removal of or absence of the transfer ring ; 25 completely from contact with the belt tread assembly B.
,. ~
, 20 Then, af-ter the transfer ring or like external restrain-t ..
;~ has been removed, in accordance with the invention, the ~; respective bead portions of the carcass are moved closer to the mid-plane 20 of the carcass each by a distance sufficient that the inflation pressure existing in the carcass shapes the carcass progressively outwardly symmetrically from the mid-plane of the carcass into cohesive con-tact :......................... ~ , ~: :
;:
:- - . .
... .
with the belt to the respectlve edges ~ b, of the belt, This permits the pressure within the carcass to stitch the carcass to the belt rather than require the belt to be stitched externally to the carcass. ~he belt at this stage as illustrated in Fig, 3~ remains essentially parallel to the axis and undeformed. Then, in a ~urther aspect of the improved procedure~ roller stitching is applied to the belt tread assembly with the important difference that the s-titchers 30 contact the tread axially outward of the respective belt edges~ as illustrated in Fig. 5~ and stitch from that position axially outwardly ; toward the lateral edges of the tread, It is particularly `~ important that the roller stitching of the assembly on the carcass is not performed between the belt edges. It is 1~ believed that this arrangement is particularly efPective .
in avoiding the so-called flaring of the belt edges wherein at least one of the edges suffe~s from displacement and de~ormation of the cord endings at that edge, The carcass-- to-belt adherence is thus obtained solely by the fluid pressure acting outwardly in the carcass to press the carcass against the inextensible belt~
Notably~ although the pause in the operating cycle of the tire building machine to accommodate removal of the transfer ring adds to the floor-to-floor time required for building the tire~ the omission of a large fraction o~ the time required for roller stitching heretofore practiced pro~ides a net gain in floor~to-floor time in the building of the tire~
FIG. 2 illustrates the step of the prior art process in w~ich the carcass is shaped outwardly into increasingly wide contact progressing outwardly from the mid-circumferential plane with the belt and/or tread assembly which is restrained by the rigid transfer ring employed to dispose the assemb.ly about the carcassi :
FIG. 3, the belt and tread assembly is illustrated '~' completely without restraint, the trans~er ring having been removed while the.carcass and belt tread assembly remain in the relatlon therebetween illustrated in Fig. l;
~ ~ r . ~ ~
, .
~.
-2a-:. ~
FIG. ~ illustrates the mode o~ hard roller stitching heretofore in use wherein a pair o~ stitcher rolls are brought into contact with the tire starting at the mid-circumferential plane o~ the tire~ the indiYidual stitchers 5 being moved outwardly oppositel~ and gradually as the tire is rotated so as to consolidate the belt and tread onto the carcass in the ~amiliar manner;
FIG 5 illustrates the stitching step in accordance with the invention wherein a similar pair of hard roll stitchers are brought into contact with the tire to initiate the stitching at or slightly outward of the respective lateral edges of the inextensible bel-t itself and progress thence outwardly to the lateral edges of the tread.
In carrying out the invention~ a carcass 10 which includes at least one ply having cords or wires extending parallel to the axis and at least two bead cores 12 about which the respective axial ends of the ply in cyllndrical form are wrapped and secured~ is built ~ollowing any known procedure. Normally~ the carcass includes also an ,~
air-impervious liner.
e carcass is placed on shaping means o~ known construction having means 15 to engage the bead portions of the carcass and to move them coaxiall~ toward each other symmetrically with respect to a mid-plane 20 normal to the tire axis~ and means to expand the carcass~ ~or ` examplea to introduce pressurized air within the chamber ~` of the carcass to in*late ita concurrently with movement o~ the bead portions toward the mid-plane.
An inextensible bel-t or a belt-tread assembly B in endless cylindrical form prepared by known procedures and having a predetermined wid-th from one a to the other b lateral belt edge, measured parallel to the -tire axis is then disposed coaxially about the carcass, as by means of a rigid transfer ring 25 such -that their respective mid-planes are coplanar, or offset axially a predetermined small distance.
The shaping means is then operated to move the respective bead portions toward each other and concurrently to expand the carcass -to contact the belt or the assembly only in a narrow circumferen-tial zone. As is indicated in Fig. 1, this contact may be considered as the con-tact of a circular arc with a s-traight~line in a representative radial plane.
In accordance with the invention~ the next step of the process is that of removing entirely all of the external restraint acting on the belt or assembly leaving ~he assembly ;
~itself supported only by the carcass. In Fig. ~, this is represent~ed by removal of or absence of the transfer ring ; 25 completely from contact with the belt tread assembly B.
,. ~
, 20 Then, af-ter the transfer ring or like external restrain-t ..
;~ has been removed, in accordance with the invention, the ~; respective bead portions of the carcass are moved closer to the mid-plane 20 of the carcass each by a distance sufficient that the inflation pressure existing in the carcass shapes the carcass progressively outwardly symmetrically from the mid-plane of the carcass into cohesive con-tact :......................... ~ , ~: :
;:
:- - . .
... .
with the belt to the respectlve edges ~ b, of the belt, This permits the pressure within the carcass to stitch the carcass to the belt rather than require the belt to be stitched externally to the carcass. ~he belt at this stage as illustrated in Fig, 3~ remains essentially parallel to the axis and undeformed. Then, in a ~urther aspect of the improved procedure~ roller stitching is applied to the belt tread assembly with the important difference that the s-titchers 30 contact the tread axially outward of the respective belt edges~ as illustrated in Fig. 5~ and stitch from that position axially outwardly ; toward the lateral edges of the tread, It is particularly `~ important that the roller stitching of the assembly on the carcass is not performed between the belt edges. It is 1~ believed that this arrangement is particularly efPective .
in avoiding the so-called flaring of the belt edges wherein at least one of the edges suffe~s from displacement and de~ormation of the cord endings at that edge, The carcass-- to-belt adherence is thus obtained solely by the fluid pressure acting outwardly in the carcass to press the carcass against the inextensible belt~
Notably~ although the pause in the operating cycle of the tire building machine to accommodate removal of the transfer ring adds to the floor-to-floor time required for building the tire~ the omission of a large fraction o~ the time required for roller stitching heretofore practiced pro~ides a net gain in floor~to-floor time in the building of the tire~
Claims (4)
1. A method of building a radial ply tire having an endless inextensible circumferential belt therein of predetermined width between its lateral edges comprising building a radial ply carcass, placing said carcass on shaping means having means to engage the bead portions of the carcass and move them coaxially toward each other symmetrically with a mid-plane of the carcass normal to the tire axis and means to expand the tire carcass con-currently with the movement of the bead portions toward the mid-plane; forming a belt or belt and tread assembly in endless inextensible cylindrical form; disposing said belt or said assembly coaxially about said carcass by means of a transfer ring; operating said shaping means to move the bead portions toward each other and to expand the carcass radially to contact the belt or the assembly only in a narrow circumferential zone; then removing entirely the restraint afforded by the transfer ring and leaving the belt or the assembly supported only by the carcass; then moving the respective bead portions closer to the mid-plane a distance sufficient to allow the carcass to axially extend its contact progressively outwardly from said narrow zone to or very nearly to the respectively associated belt edges such what the circumferential con-tact between the carcass and the belt or the assembly is progressively extended axially outwardly from said zone to the respective belt edges.
2. A method as claimed in Claim 1, further including roller stitching the assembly to the carcass only in the further zones which extend axially outward of the respective belt edges, and omitting any roller s stitching of the assembly or the belt on the carcass between said belt edges.
3. A method as claimed in Claim 1, including adhering the carcass to the belt solely by fluid pressure acting outwardly in the carcass to press the carcass outwardly against the inextensible belt.
4. A method of applying an endless inextensible belt or belt tread assembly to a radial tire carcass having bead portions comprising disposing said belt or said assembly about said carcass, shaping said carcass to expand radially into contact with said belt or said assembly in a narrow central circumferential zone, then before further shaping the carcass removing all radial and lateral restraint from said belt or said assembly, and thereafter further shaping the carcass by moving the bead portions thereof axially inward to extend said narrow zone axially outwardly symmetrically to the respectively associated lateral edges of the belt or of the belt-tread assembly.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US81973777A | 1977-07-28 | 1977-07-28 | |
| US819,737 | 1986-01-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1104049A true CA1104049A (en) | 1981-06-30 |
Family
ID=25228910
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA304,428A Expired CA1104049A (en) | 1977-07-28 | 1978-05-30 | Method of stitching radial tires to inhibit belt edge distortion |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1104049A (en) |
-
1978
- 1978-05-30 CA CA304,428A patent/CA1104049A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |