GB1588173A

GB1588173A - Vehicle wheel/pneumatic tyre arrembly

Info

Publication number: GB1588173A
Application number: GB4155477A
Authority: GB
Original assignee: Continental Gummi Werke AG
Current assignee: Continental AG
Priority date: 1976-10-09
Filing date: 1977-10-06
Publication date: 1981-04-15
Also published as: AT355923B; CH622995A5; FR2366940B2; LU78269A1; ATA716577A; DE2645760A1; FR2366940A2; IT1113632B

Abstract

On a vehicle wheel with a pneumatic tyre and with folded-over rim flanges which are subdivided in each case into two sub-sections (32, 33) which are bent with respect to one another, the bead seat face (31) which is assigned to the foot of the tyre bead (21) and adjoins the rim flanges axially inwards is formed cylindrically, or only slightly conically, at an oblique angle ( gamma ) in an order of magnitude of approximately 5 DEG in cross-section with respect to the axis of the tyre. This results in an improved sealing effect of the tyre beads and greater security against the tyres being thrown off under the effect of laterally occurring impacts. <IMAGE>

Description

(54) A VEHICLE WHEEL/PNEUMATIC TYRE ASSEMBLY (71) We, CONTINENTAL GUMMI WERKE AKTIENGESELLSCHAFT, of Continental Haus/Postfach 169, 3000 Hannover, Germany (Fed Rep); a German body corporate 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: The present invention relates to a vehicle wheel/pneumatic tyre assembly, each bead of the tyre being reinforced with a core ring, being supported on a respective bead seating surface of the wheel rim and abutting against a respective tyre bead retaining rim flange. The present invention comprises an improvement in or modification of the vehicle wheel/pneumatic tyre assembly described and claimed in our co-pending application No. 33635/75, Serial No. 1513780.

Vehicle wheels with offset wheel flanges as in our UK Patent Specification No.

1513780 cause the resilience of the mounted tyres to come into effect to a particularly wide extent and, on account of the stepped course of inclination, also absorb extreme cross-sectional deformations of the side walls of the tyre. Therefore, with pneumatic tyres having a relatively shallow crosssection they are distinguished by pleasantly felt, surprisingly soft, resilience even at high travelling speeds, without this advantage having to be paid for with compromises to the assembly conditions or with other disadvantages.

While the low height of the wheel rim flanges, which is a result of their offset design. was helpful in practice to the requirement of facilitating tyre assembly as an additional side effect, it appeared in the course of the aims for further simplification appropriate for the supporting surfaces of the tyre beads to be formed clearly to be conically flared outwards at an angle of inclination of from 10 to 20 relative to the axis of rotation of the wheel. The expectations connected herewith have in fact been fulfilled to the full extent. But it has been found that under certain conditions considerable losses in travelling safety could occur; since under the influence of considerable blows impacting the side wall of the tyre directly above the wheel flanges in an axial direction, it was possible to push the tyre off the rim and to cause sudden dangerous pressure losses. Hence the object of the invention is based on improving the assembly described and claimed in co-pending application No. 33635/75, Serial No.

1513780, and ensure the pressuretight seat of the tyre on the rim whilst maintaining its required travel and deflection behaviour in all conceivable cases of stress against shedding and any yielding leading to any loss of air.

According to the present invention there is provided an assembly comprising a pneumatic tyre and a vehicle wheel having a rim comprising tyre bead seating surfaces and tyre bead retaining rim flanges, the rim having a cylindrical portion adjacent a bead seat, in which the two tyre beads, which are each reinforced with a core ring, are each supported on a respective bead seating surface and abut against a respective tyre retaining rim flange, wherein the flanges each have a radially inner part and a radially outer part and wherein the flange parts make acute angles with a circumferential plane, the angle made by the radially outer part with the circumferential plane being greater than the angle made by the radially inner part with the circumferential plane, and in which the tyre bead seating surfaces of the rim radially supporting the tyre beads are each cylindrical or are flared conically outwardly and form an angle with the axis of rotation of the wheel of less than 10 .

Preferably the tyre bead seating surfaces of the rim radially supporting the tyre beads each form an angle with the axis of rotation of the wheel of approximately 5".

Angles of inclination of up to 10 are already known in other connections and different conditions. The particular starting conditions prevailing in connection with yehicle wheel assemblies mentioned in the introductory portion of the speculation, however, compel the departure from a hitherto valid point of view and to adopt a new evaluation gauge. While the low rim flanges do facilitate, the fact that the tyre beads are, when mounted on such rim, located in a relatively far outwardly lying range (when viewed in radial direction) represents a drawback, which fact became evident only after extensive driving tests had been carried out. Since otherwise than in the case of conventional wheels with wheel flanges of conventional height, blows impacting the side of the tyres do not act dampened over the elastic lever arm of the side wall section but moreover, onto the less resilient bead region, so that the tyre already under unexpectedly low stresses is caused to carry out yielding movements.

With the cylindrical or only slightly conical shape of the bead supporting surfaces in accordance with the invention these tendencies to movement are not suppressed. The invention on the other hand provides a greater backlash which permits temporary detachment of the tyre bead from the wheel flanges without impairing the sealing effect.

An embodiment of the invention is shown schematically in the drawing, in which the single Figure is a fragmentary cross-section of a vehicle wheel/pneumatic tyre assembly which contains a wheel having a rim 3 and a pneumatic tyre 2. The rim 3 has a cylindrical portion adjacent bead seat 31. The tyre bead 21, reinforced with an embedded core ring 4, is supported on bead seat 31 of the rim 3 and, under the action of the internal air pressure, is pressed firmly thereon in an biaxial direction against the wheel rim flange forming the outer definition of the rim. The wheel flange in turn is formed by a radially inner part 32 inclined at an angle of inclination a of about 15 to a circumferential plane and a radially outer part 33 inclined at a substantially greater angle of inclination ss of about 55" to the circumferential plane, which results in its cranked cross-sectional shape shown. The bead seat 31 of the rim radially supporting the tyre bead 21 forms an angle y with the axis of rotation of the wheel of about 5".

WHAT WE CLAIM IS: 1. An assembly comprising a pneumatic tyre and a vehicle wheel having a rim comprising tyre bead seating surfaces and tyre bead retaining rim flanges, the rim having a cylindrical portion adjacent a bead seat. in which the two tyre beads, which are each reinforced with a core ring, are each supported on a respective bead seating surface and abut against a respective tyre bead retaining rim flange, wherein the flanges each have a radially inner part and a radially outer part and wherein the flange parts make acute angles with a circumferential plane, the angle made by the radially outer part with the curcumferential plane being greater than the angle made by the radially inner part with the circumferential plane, and in which the tyre bead seating surfaces of the rim radially supporting the tyre beads are each cylindrical or are flared conically outwardly and form an angle with the axis of rotation of the wheel of loess than 10 .

2. An assembly as claimed in claim 1 in which the tyre bead seating surfaces of the rim radially supporting the tyre beads each form an angle with the axis of rotation of the wheel of approximately 5".

3. An assembly of a pneumatic tyre and a vehicle wheel, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. each form an angle with the axis of rotation of the wheel of approximately 5". Angles of inclination of up to 10 are already known in other connections and different conditions. The particular starting conditions prevailing in connection with yehicle wheel assemblies mentioned in the introductory portion of the speculation, however, compel the departure from a hitherto valid point of view and to adopt a new evaluation gauge. While the low rim flanges do facilitate, the fact that the tyre beads are, when mounted on such rim, located in a relatively far outwardly lying range (when viewed in radial direction) represents a drawback, which fact became evident only after extensive driving tests had been carried out. Since otherwise than in the case of conventional wheels with wheel flanges of conventional height, blows impacting the side of the tyres do not act dampened over the elastic lever arm of the side wall section but moreover, onto the less resilient bead region, so that the tyre already under unexpectedly low stresses is caused to carry out yielding movements. With the cylindrical or only slightly conical shape of the bead supporting surfaces in accordance with the invention these tendencies to movement are not suppressed. The invention on the other hand provides a greater backlash which permits temporary detachment of the tyre bead from the wheel flanges without impairing the sealing effect. An embodiment of the invention is shown schematically in the drawing, in which the single Figure is a fragmentary cross-section of a vehicle wheel/pneumatic tyre assembly which contains a wheel having a rim 3 and a pneumatic tyre 2. The rim 3 has a cylindrical portion adjacent bead seat 31. The tyre bead 21, reinforced with an embedded core ring 4, is supported on bead seat 31 of the rim 3 and, under the action of the internal air pressure, is pressed firmly thereon in an biaxial direction against the wheel rim flange forming the outer definition of the rim. The wheel flange in turn is formed by a radially inner part 32 inclined at an angle of inclination a of about 15 to a circumferential plane and a radially outer part 33 inclined at a substantially greater angle of inclination ss of about 55" to the circumferential plane, which results in its cranked cross-sectional shape shown. The bead seat 31 of the rim radially supporting the tyre bead 21 forms an angle y with the axis of rotation of the wheel of about 5". WHAT WE CLAIM IS:

1. An assembly comprising a pneumatic tyre and a vehicle wheel having a rim comprising tyre bead seating surfaces and tyre bead retaining rim flanges, the rim having a cylindrical portion adjacent a bead seat. in which the two tyre beads, which are each reinforced with a core ring, are each supported on a respective bead seating surface and abut against a respective tyre bead retaining rim flange, wherein the flanges each have a radially inner part and a radially outer part and wherein the flange parts make acute angles with a circumferential plane, the angle made by the radially outer part with the curcumferential plane being greater than the angle made by the radially inner part with the circumferential plane, and in which the tyre bead seating surfaces of the rim radially supporting the tyre beads are each cylindrical or are flared conically outwardly and form an angle with the axis of rotation of the wheel of loess than 10 .