GB1573953A

GB1573953A - Wheel rim and method ofmaking thereof

Info

Publication number: GB1573953A
Application number: GB1368577A
Authority: GB
Original assignee: Kelsey Hayes Co
Current assignee: Kelsey Hayes Co
Priority date: 1976-04-05
Filing date: 1977-03-31
Publication date: 1980-08-28
Also published as: BR7702130A; DE2714646A1; JPS52152002A; DE2714646C2; CA1125815A; IT1084620B; FR2347211B1; MX143755A; FR2347211A1

Description

(54) WHEEL RIM AND METHOD OF MAKING THEREOF (71) We, KELSEY-HAYES COM PANY, a Corporation organised and existing under the laws of the State of Delaware, United States of America, of 38481 Huron River Drive, Romulus, Michigan 48174, United States of America, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to an improved wheel rim and to a method of constructing such a wheel rim.

A wheel rim construction should be designed to permit easy mounting of the tyre, yet should also ensure against movement of the tyre bead relative to the wheel rim once mounted and inflated. Various wheel rim configurations have been proposed for achieving this purpose. In addition to the aforenoted desired results, the wheel rim should permit easy disassembly of the tyre for servicing or replacement. Substantially all of the prior wheel rim constructions have been a compromise to achieve all of these effects. It is also desirable if the rim will co-operate with the tyre bead in such a way as to prevent the tyre from leaving the rim in the event of a "run flat" condition. That is, it is desirable if the tyre will be retained on the rim even though it is fully deflated so that the owner may drive the vehicle to a place where it may be serviced.

According to the invention there is provided a wheel rim having a pair of axially spaced tyre bead retaining flanges, an annular well portion intermediate the flanges, and a bead seat adjacent each flange having an annular surface for supporting a bead of a tyre, each bead seat having a radially outwardly projecting protuberance extending completely around the circumference of the bead seat in the area to be engaged by the bead of a tyre to be provided on the rim, the protuberance being formed by an annular ridge so rising from the bead seat surface as to increase the thickness of bead seat and having an inclined surface extending upwardly in an axial outer direction and terminating in a generally radially extending portion facing the adjacent flange. Preferably a plurality of the ridges are provided spaced axially of the rim.

Another aspect of the invention provides a method of making a wheel rim having a tyre bead retaining flange and an adjacent bead seat for supporting a bead of a tyre comprising the step of positioning the rim between a pair of opposed forming rolls, said forming rolls having the surface configuration corresponding to the defined configuration of the bead seat, and forming by means of a recessed surface discontinuity in one of the rolls, through deflection of the metal of the wheel rim, a circumferential surface protuberance of the bead seat that is adapted to interlock with the rubber of a tyre bead through deflection of the latter when the tyre is mounted on the wheel rim, the cross-section of the discontinuity in the roll being such that the protuberance is formed as a ridge projecting from the bead seat surface to increase the thickness of the bead seat and having an inclined surface extending upwardly in an axial outer direction and terminating in a generally radially extending portion facing the adjacent flange.

The invention will be described, by way of example, with reference to the accompanying drawings, wherein: FIGURE 1 is a partial cross-sectional view of a wheel rim embodying the invention with an associated tyre; FIGURE 2 is an enlarged cross-sectional view of the area encompassed by the circle 2 in Figure 1; and FIGURE 3 is a cross-sectional view showing the method of forming of the wheel rim bead seat.

Referring to the drawing, there is shown a drop centre wheel rim 11 having an annular wall providing a drop centre portion 12. At the axial outer periphery of the wheel 11, a first tyre bead seat portion 13 is formed, and terminates in a radially outwardly extending flange 14. At the axial inner side of the drop centre 12, an elongated flange 15 is formed that terminates in a second tyre bead seat portion 16 which also terminates in a radially outwardly extending flange 17.

A pneumatic tyre 18, preferably of the tubeless type, is mounted on the wheel rim Il. The tyre 18 has inner and outer beads 19 and 21 that co-operate with the wheel bead seats 13 and 16, respectively.

In order to ensure against accidental displacement of the tyre bead portions 19 and 21 from the bead seats 13 and 16, an improved retention means is provided, which may be best understood by reference to Figure 2. In Figure 2 only the bead seat portion 13 is described and illustrated in detail. It is to be understood that the bead seat portion 16 is of substantially identical construction. The tyre bead 19 has a heel portion that contacts the upper surface of the rim bead seat 13 over a substantial portion of its length. Three inclined surface protuberances in the form of upstanding ridges 22, 23 and 24 are formed completely around the circumference of the portion of the bead seat 13 contacted by the tyre bead 19. The ridges 22, 23 and 24, which so rise from the bead seat surface as to increase the thickness of the bead seat, have substantially the same shape and are of a generally right triangular configuration in cross-section. The included angle between the hypotenuse and the generally radially extending leg is substantially 60". At least the upper surface of the bead seat portion 13 is inclined at a slight (substantially 5 ) angle to wheel axis. The radially extending sides of the ridges lie at substantially right angles to a wheel axis and thus are slightly displaced from a right angle with respect to the upper surface of the bead seat portion 13. A somewhat similar protuberant ridge 25 is formed axially inwardly of the portion of the bead seat 13 contacted by the heel of the tyre bead 19. The reason for the provision of this additional ridge 25 will become apparent.

The ridges 22, 23 and 24 have been found to deflect into the rubber of the tyre bead 19 to provide a mechanical interlock therewith. Because of the configuration, inflation and seating during mounting and dismounting affords no difficulty. The interlock is, however, sufficient to provide a run flat operation and to prevent axial separation during high cornering loads.

The method of forming the wheel rim 11 may be best understood by reference to Figure 3. An initial forming of the rim 11 is accomplished prior to a final rolling operation. In this final rolling operation, the rim 11 is positioned between a plurality of rolls, only those associated with the bead seat portion 13 being illustrated for ease of understanding. It is to be understood that the bead seat 16 is formed in a similar manner. The formation of the remainder of the wheel rim 11 is conventional and need not be described.

As is conventional in wheel forming operation, the rim 11 is positioned between an outer roll 27 and an inner roll 28. The rolls 27 and 28 have facing surfaces that will, with suitable allowance for spring back, result in the desired configuration of the bead seat 13. Unlike previously proposed arrangements, however, the roll 27 is formed with discontinuities or reliefs 29, 31, 32 and 33 for forming the ridges 22, 23, 24 and 25, respectively. The reliefs 29, 31, 32 and 33 are of slightly greater depth than the resulting ridges 22, 23, 24 and 25, to permit the spring back and to afford sufficient clearance for metal deformation. It has been found that during the rolling operation the pressure exerted by the roll 28 is sufficiently great as to cause the metal of the wheel rim 11 permanently to deflect into the grooves 29, 31, 32 and 33, of the roll 27.

It has been previously noted that the ridge 25 does not contact the tyre bead 19.

The ridge is formed to provide a surface of upset material at the axial inner periphery of the bead seat portion 13. The ridge 25 in effect constitutes a dam that prevents inward displacement of the metal of the rim during the rolling operation to ensure sharp definition of the ridges 22, 23, 24.

WHAT WE CLAIM IS: 1. A wheel rim having a pair of axially spaced tyre bead retaining flanges, an annular well portion intermediate the flanges, and a bead seat adjacent each flange having an annular surface for supporting a bead of a tyre, each bead seat having a radially outwardly projecting protuberance extending completely around the circumference of the bead seat in the area to be engaged by the bead of a tyre to be provided on the rim, the protuberance being formed by an annular ridge so rising from the bead seat surface as to increase the thickness of bead seat and having an inclined surface extending upwardly in an axial outer direction and terminating in a generally radially extending portion facing the adjacent flange.

2. A wheel rim as claimed in claim 1, wherein a plurality of axially spaced annular protuberances are provided, each comprising an annular ridge having an inclined surface extending upwardly in an axial outer direction relative to the bead seat and terminating in a generally radially extending portion facing the adjacent flange.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the axial outer periphery of the wheel 11, a first tyre bead seat portion 13 is formed, and terminates in a radially outwardly extending flange 14. At the axial inner side of the drop centre 12, an elongated flange 15 is formed that terminates in a second tyre bead seat portion 16 which also terminates in a radially outwardly extending flange 17. A pneumatic tyre 18, preferably of the tubeless type, is mounted on the wheel rim Il. The tyre 18 has inner and outer beads 19 and 21 that co-operate with the wheel bead seats 13 and 16, respectively. In order to ensure against accidental displacement of the tyre bead portions 19 and 21 from the bead seats 13 and 16, an improved retention means is provided, which may be best understood by reference to Figure 2. In Figure 2 only the bead seat portion 13 is described and illustrated in detail. It is to be understood that the bead seat portion 16 is of substantially identical construction. The tyre bead 19 has a heel portion that contacts the upper surface of the rim bead seat 13 over a substantial portion of its length. Three inclined surface protuberances in the form of upstanding ridges 22, 23 and 24 are formed completely around the circumference of the portion of the bead seat 13 contacted by the tyre bead 19. The ridges 22, 23 and 24, which so rise from the bead seat surface as to increase the thickness of the bead seat, have substantially the same shape and are of a generally right triangular configuration in cross-section. The included angle between the hypotenuse and the generally radially extending leg is substantially 60". At least the upper surface of the bead seat portion 13 is inclined at a slight (substantially 5 ) angle to wheel axis. The radially extending sides of the ridges lie at substantially right angles to a wheel axis and thus are slightly displaced from a right angle with respect to the upper surface of the bead seat portion 13. A somewhat similar protuberant ridge 25 is formed axially inwardly of the portion of the bead seat 13 contacted by the heel of the tyre bead 19. The reason for the provision of this additional ridge 25 will become apparent. The ridges 22, 23 and 24 have been found to deflect into the rubber of the tyre bead 19 to provide a mechanical interlock therewith. Because of the configuration, inflation and seating during mounting and dismounting affords no difficulty. The interlock is, however, sufficient to provide a run flat operation and to prevent axial separation during high cornering loads. The method of forming the wheel rim 11 may be best understood by reference to Figure 3. An initial forming of the rim 11 is accomplished prior to a final rolling operation. In this final rolling operation, the rim 11 is positioned between a plurality of rolls, only those associated with the bead seat portion 13 being illustrated for ease of understanding. It is to be understood that the bead seat 16 is formed in a similar manner. The formation of the remainder of the wheel rim 11 is conventional and need not be described. As is conventional in wheel forming operation, the rim 11 is positioned between an outer roll 27 and an inner roll 28. The rolls 27 and 28 have facing surfaces that will, with suitable allowance for spring back, result in the desired configuration of the bead seat 13. Unlike previously proposed arrangements, however, the roll 27 is formed with discontinuities or reliefs 29, 31, 32 and 33 for forming the ridges 22, 23, 24 and 25, respectively. The reliefs 29, 31, 32 and 33 are of slightly greater depth than the resulting ridges 22, 23, 24 and 25, to permit the spring back and to afford sufficient clearance for metal deformation. It has been found that during the rolling operation the pressure exerted by the roll 28 is sufficiently great as to cause the metal of the wheel rim 11 permanently to deflect into the grooves 29, 31, 32 and 33, of the roll 27. It has been previously noted that the ridge 25 does not contact the tyre bead 19. The ridge is formed to provide a surface of upset material at the axial inner periphery of the bead seat portion 13. The ridge 25 in effect constitutes a dam that prevents inward displacement of the metal of the rim during the rolling operation to ensure sharp definition of the ridges 22, 23, 24. WHAT WE CLAIM IS:

1. A wheel rim having a pair of axially spaced tyre bead retaining flanges, an annular well portion intermediate the flanges, and a bead seat adjacent each flange having an annular surface for supporting a bead of a tyre, each bead seat having a radially outwardly projecting protuberance extending completely around the circumference of the bead seat in the area to be engaged by the bead of a tyre to be provided on the rim, the protuberance being formed by an annular ridge so rising from the bead seat surface as to increase the thickness of bead seat and having an inclined surface extending upwardly in an axial outer direction and terminating in a generally radially extending portion facing the adjacent flange.

3. A wheel rim as claimed in claim 2,

wherein an axially innermost ridge is positioned in an area of the bead seat not engaged by the bead of a tyre to be mounted thereon.

4. A wheel rim as claimed in any preceding claim, wherein the or each ridge is integrally formed with the bead seat and extends upwardly from its surface.

5. A wheel rim as claimed in any preceding claim, wherein the or each ridge has a triangular axial cross-section.

6. A wheel rim as claimed in claim 5, wherein the cross-section of the ridge is of generally right triangular configuration.

7. A wheel rim as claimed in claim 6, wherein the included angle between the hypotenuse and the generally radially extending side is substantially 600.

8. A wheel rim as claimed in any preceding claim, wherein the upper surface of the bead seat is inclined at substantially 5".

9. A method of making a wheel rim having a tyre bead retaining flange and an adjacent bead seat for supporting a bead of a tyre comprising the step of positioning the rim between a pair of opposed forming rolls, said forming rolls having the surface configuration corresponding to the defined configuration of the bead seat, and forming by means of a recessed surface discontinuity in one of the rolls through deflection of the metal of the wheel rim, a circumferential surface protuberance of the bead seat that is adapted to interlock with the rubber of a tyre bead through deflection of the latter when the tyre is mounted on the wheel rim, the cross-section of the discontinuity in the roll being such that the protuberance is formed as a ridge projecting from the bead seat surface to increase the thickness of the bead seat and having an inclined surface extending upwardly in an axial outer direction and terminating in a generally radially extending portion facing the adjacent flange.

10. A method as claimed in claim 9, wherein a plurality of axially spaced recessed surface discontinuities are provided in the outermost roll.

11. A method of making a wheel rim substantially as herein described with reference to the accompanying drawings.

12. A wheel rim constructed and arranged substantially as herein described with reference to and as illustrated in the accompanying drawings.