AU637236B2 - Double disk construction for automobile wheel of light alloy - Google Patents

Description

Our Ref: 364547 6)3723 AU STRALI A patents Act (1990) COMPLETE SPECIFICATION FORM

(ORIGINAL)

Application Number: Lodged:

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0 500 p Complete Specilfication Lodged: Accepted: Published: Priority: Related Art: Applicant Address for Service: Crimson Company Limited Sugigamachi N1,RA-C ITY

JAPAN

ARTHUR S. CA.VE CO.

Patent Trade Mark Attorneys Level 10, 10 Barrack Street SYDNEY NSW 2000

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0 Ok 0 Compl&: specification for the invention entitled "Double diskA cnctrv-,7n for automobile wheel of light alloy".

The following statement is a full description of this invention, including the best method of performing it known to me:- 5020 1

SPECIFICATION

DOUBLE DISK CONSTRIUCTION FOR AUTOMOBILE WHEEL' OF LIGHT ALLOY B3ACKGRIOUND OF THE INVENTION Generally, an automobile wheel of light alloy In the form of an assembly of a wheel disk and a tire supporting wheel rim Is known, said wheel disk being Interchangeably fitted on the hub of an axle.

It has been common practice to form a number of vent holes In the Intermediate region between the boss and the peripheral rib of the wheel disk to distribute them to thereover, thereby providing a quasi-wire spoke configuration or other artistic pattern on the surface of the wheel disk.

Such artistically designed pattern has become the test sel ling point for interchangeable wheels, which Lendt .o be manufactured on a diversified small- and medlum-quant~y production basts.

However, conventional wheel disks used In light alloy 5 wheelIs for automobiles are of single construction consisting of a single flat disk, as found In Japanese Patent Application Disclosure No. 227601/1984; thus, the artistic pat terns formed thereon are lacking In three-dimensional effect and dignity.

2 That is, In the single construction, in designing said artistic patterns, there -is no way but to thicken the disk Itself, to bend all or part of the disk or to expose ribs on the surface of.the disk. As a result, the resulting artistic design Is unavoidably monotonous. Further, In relation to various automobiles having Interchangeable wheels mounted thereon, there Is a limit to the obtainment of an artistic pattern full of Interest and variety, which Is expected to be In harmony with the design of the car body.

As for measures to be taken to solve such problems, it would be contemplated to mount a separate wheel cap on the entire surface of a wheel disk. With such arrangement, however, even If a beautiful artistic pattern can be imparted to the wheel, cap, the wheel cap is nothing but an accessory part to the wheel disk, and since It is attached to the wheel disk afterward, It does not add to the strength of the wheel disk Itself. Wheel disks are required- to have a sufficient strength to support wheel rims.

Thus, I hdve previously proposed Japanese Patent Application Disclosure No. 185302/1983, wherein the wheel d isk is of double construction consisting of a front wall and a rear wall, the opposed walls being Integrally cast in spindle form, so that support members for the rear wall can be seen through vent holes distributed over the front wall.

Thus, despite the fact that the wheel disk Is made of 3 light alloy, there is an advantage that an artistic pattern depicting a quasi-wire spoke configuration having a threedimensional dignified effect can be obtained; thus, it serves to solve the above problems to some extent.

However, the wheel disk of said known invention Is a one-piece casting of light alloy and in this sense it does not differ much from a wheel disk of single construction; it cannot be produced by forging or other plastic processing means which are effective for increasing the strength of the wheel disk.

,*so s..o Further, since it is of one-piece construction, once it **6 Is produced the artistic pattern of the wheel disk cannot be changed by changing the combination of said front wall and said rear wall; thus, a wheel disk having an artistic pattern full of variety can hardly be manufactured on a diversified small- and medium-quantity production basis.

:Not only in Japanese Patent Application Disclosure No.

227501/1984 but also in applicant's Japanese Patent- Application Disclosure No.185302/1983, the boss of the wheel disk is adapted to be attached to the hub of the axle by a .j plurality of screw clamp devices extending parallel with the p wheel rotation axis.

In this respect, It may be said that means for integrally rotatably attaching the boss of a wheel disk to the hub of an axle throhgh a separate adapter rlate.

However, in this case also, the situation rema.'ns unchanged 4 in that the plurallty of screw clamping devices for attaching the boss of the' wheel disk to the adapter plate still extend parallel with the wheel rotation axis.

Therefore, supposing that the diameter of the wheel disk is constant, the PCD (Pitch Circle Diameter) of the screw clamping devicei for &ttachlng the boss to the hub of the axle directly or Indirectly through the adapter plate becomes excessively large and correspondingly thereto the boss of the wheel disk has to be given as large a diameter as possible since It needs the strength for attachment.

If so, the Intermediate region between the boss and the ooI peripheral rib of, the wheel disk Is limited In area, with the result that the degree of freedom for providing said artistic pattern In said region Is correspondingly limited; thus, the length of qlasi-wlre spokes forming such artistic pattern Is unavoidably decreased.

In the case of the means for attaching the boss of the wheel disk to the hub of the axle directly or lndire-ctly through the adapter place by screw clamping devices extending parallel with the wheel rotation axis, the horizontal component of an external foice imparted from the road to the wheel produces tensile stresses in said screw clamping devices and shearing stresses also In said screw clamping devices; thus, loads acting In all directions cannot be effectively dispersed or absorbed.

As a result, when It Is desired to mount wheels on 4WD AMD/0659a 5 cars or 4WS cars. It is very difficult to establish a wheel mount state which provides durabili -y and copes with complicated actions required of the wheels for said cars and changes in the direction of external forces on the wheels.

SUMMARY OF THE INVENTION The present invention seeks to overcome the aforementioned problems.

More particularly, the present invention seeks to provide a wheel disk for automobile wheels of light alloy, wherein the wheel disk is of split type comprising two parts, a main disk and a sub-disk opposed thereto, said sub-disk being superposed from the front onto the surface of the main disk, whereupon the two disks are integrally attached together at their bosses by a plurality of screw clamping devices and at their peripheral edges by a separate plurality of screw clamping devices so that they are rotatable as a unit, said two disks being put together in t.

such a manner that a space surrounded by three planes respectively containing the intermediate regions of the two r 44 disks and the wheel rotation axis is bridged by a three-dimensional truss of substantially triangular cross-section with the plane containing said wheel rotation axis defining one side of the triangle, whereby, unlike a w conventional wheel disk of single construction in the form of a flat disk or conventional wheel cap to be fitted thereon, the wheel disk is given a sufficient strength to function as a support member and the durability thereof is AMD/0659a -6increased.

The present invention also seeks to provide an arrangement wherein the main disk has a number of vent holes in the intermediate region between the boss and the peripheral edge thereof, said vent holes being distributed in a definite artistic pattern, while the sub-disk adapted to be superposed from the front onto the surface of said main disk and attached thereto has its intermediate region formed at its corresponding positions with a number of vent holes which differ from the vent holes of the main disk in size and shape and distribution, whereby coupled with the bridge construction forming said three-dimensional truss, with the result that a three-dimensional dignified artistic pattern creating the impression that the wheel is a wire spoke wheel despite the wheel disk itself being of light alloy manifests itself on the wheel disk.

i The invention also seeks to provide an arrangement wherein the sub-disk prepared as a separate part is superposed from the front onto the surface of the main disk "and the two disks are then removably attached together at their bosses by a plurality of screw clamping devices and at their peripheral edges by another plurality of screw clamping devices, so that such main disks and sub-disks can be recombined so as to allow the artistic pattern derived from the two disks to be changed at any time afterward to provide artistic patterns full of variety, the wheel disk being adapted to be manufactured on a diversified small- and medium-quantity production basis.

In that case, in addition to forming the opposed AMD/0659a -7intermediate portions of the two disks with many vent holes different in the shape of the openings and their distribution, the surface of one of the two disks may be left intact to expose the as-cast surface or other non-processed surface while the surface of the other disk may be plated, cut, painted or otherwise processed; thus, by recombination of said disks, the artistic patterns can be made more variegated.

The present invention also seeks to provide an arrangement wherein a wheel disk is of split type comprising two parts, a main disk and a sub-disk which are opposed to each other, thus allowing the two disks to be mass-produced nriot only be casting light alloys but also by forging or other plastic processing means which are effective to increase the strength, and facilitating production and providing various configurations in which all or part of the S" tire supporting wheel rim integrally projects from the main disk or sub-disk.

The present invention also seeks to provide an arrangement wherein the case where a separate adapter plate is interposed between the two disks when the latter are put together and attached to the hub of an axle, the 8 superposed surfaces of said two disks are made In the form of conical tapered surfaces, and a separate plurality of screw clamping devices whlch extend through the conical tapered surfaces to attach the bosses of the two disks to the adapter plate are inclined so that their axes Intersect the wheel rotation axis with their heads directed toward the wheel rotation axis, whereby the PCD of the screw clamping devices is decreased by an amount corresponding to the angle of inclination and hence the diameter of the boss of the

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,sub-disk in the wheel disk can be correspondingly decreased, a fact which means that the Intermediate region between the see* boss and the peripheral edge Is given a relatively large area, allowing said artistic pattern to be derived therefrom without limitation, and allowing the quaal-wire spokes to extend longer.

The screw clamping devices In the Inclined state ensures 4 that external forces acting horizontally and vertically of the wheel from the road are efficiently dispersed or absorbed, so that the wheel disk can be stably and durably mounted on 4W? and 4WS cars whose wheels are required to make complicated movements.

BRIEF DESCRIPTION OF THE DRAWINGS Figs. 1 through 5 show a basic embodiment of ar.

automobile wheel according to the present invention; Fig. 1 is a front view of the wheel; Fig. 2 is a sectional view taken along the line 2-2 in 9 Fig. 1 Fig. 3 is a sectional- view showing the wheel attached to the hub of an axle; Fig. 4 is a front view of an adapter plate; Fig. B Is a fragmentary perspective view of the adapter plate; Fig. 6 Is a front view of another adapter plate to be used Interchangeably with the adapter plate of Fig. 4; Fig. 7 Is a sectional view showing a first modification e. of an automobile wheel according to the Invention; Figs. 8 through 10 are half-cutaway sectional views showing second through fourth modifications of automobile wheels according io the invention; and Figs. 11 and 12 are sectional views showing fifth and sixth modifications.

DESCRIPTION OF TIE PREFERRED EMBODIMENTS The arrangement of the Invention will now be described with reference to the accompanying drawings. Flgs,- 1 through 6 show a built-up automobile wheel according to the basic embodiment of the invention. The reference character P denotes a tire supporting rim, and D denotes a wheel disk *g serving as a support member therefor and consisting of a main disk 21 positioned on the back side (rear side) of the wheel and a sub-disk 22 positioned on the front side (forward side).

The sub-disk 22 Is superposed from the front onto the 10 surface of the main disk 21 and they are Integrally attashed together, thereby formlng'the wheel disk D of double construction. The wheel disk D has the wheel rim R Integrally attached thereto, thereby com:pletlng the wheel as a three-piece type automobile wheel.

Speaking of the main disk 21 of the wheel disk D, It is made of aluminum alloy or other metal alloy, preferably by forging or other plastic processing, and Its circular 23 peripheral edge/of given diameter Is formed with a number of threaded holes 24 In radial-line symmetry relation to each S* other for receiving third screw clamping devices to be later described. The numeral 25 denotes a boss disposed at the center of the main disk and adapted to be removably attached to the hub 26 of an axle for rotation therewlth through a separate adapter plate A.

The numeral 27 denotes an intermediate region defined a between the boss 25 and peripheral edge 23 of the main disk 21 and formed with a number of vent holes 28 havlng-a given size and shape and distribution, whereby the artistic pattern manife'sting themselves on the intermediate region 27 A has a quasi-wire spoke configuration as shown In Fig. 1.

That is, the crossing ribs delimiting the vent holes 28 are arranged in mesh configuration creating the Impression :hat the wheel is a wire spoke wheel. However, the artistic pattern is not limited to such quasi-wire spoke conf guration.

11 The adapter plate A is used for Interchangeably attaching the wheel disk D to the hub 26 of the axle and it Is a circular type having an axle clearing port 29 and is formed of light alloy preferably by forging or other plas, c processing. The numeral 30 denotes a plurality of first sc-ew clamping devices for attaching the adapter plate A to the hub 26 of the axle. As is clear from Fig. 3, each device 30 consists of a known stud bolt Integrally extending forwardly from the hub and a fixing nut engaged therewith.

'A 0*, 6 These devices extend parallel with the wheel rotation axis 0-0.

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The numeral 31 denotes a plurality (t total of five in the figuer) of projections continuously integrally extending from the surface of the adapter plate toward the front (forward) and In radial-I ne symmetry relation to each *oo: other, with a plurality of grooves 32 each defined between Uadjacent projections 31. Thus, on the surface of the adapter plate A, the projections 31 and grooves 32 alternate wIth each other.

The top surfaces (front surfaces) of the projections 31 are machined to define concave conical slope surfaces 33 flush with each other, and threaded holes 35 for receiving second screw claming devices 34 are formed at the respective centers of the projections 31 so thea they are orthogonal to tile associated conical slope surfaces 33. Each of the second acrew clampln devices 34 is In the form of a headed 12 bolt, as shown in Fig. 3.

On the other hand, the bottom surfaces of the grooves 32 are non-conical flat surfaces 36 continuous with the surface of the adapter plate A, and holes 37 for receiving first screws clamping devices 30 are formed at the centers of the grooves 32.

In that case, the PCD (Pitch Circle Diameter) of the holes 37 for receiving first screw clamping devices varies from car naker to car maker'and from car type to car type. Thus, as can be suggested from a comparison between Figs. 4 and 6, several types of adapter plates are prepared 8 a including 'ne adapter plate A whose holes 37 for receiving the first screw clamping devices 30 have a large PCD dl, and another adapter plate A whose holes 37 for receiving the first screw clamping devices 30 h-ve a small PCD d2. They are selectively used to attach the wheel disk D indirectly to the hub 26 of the axle.

However, it goes without saying that the threaded holes 36 for receiving the second screw clamping devices 34 have a fixed PCD d3 wtlch Is common with all adapter plates A.

With this arrangement, even If PCD of the first screw

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clamping devices 30 varies from car maker to car maker and from car type to car type, there is no need to produce and store several types of wheels; it is only necessary to change said adapter plate A and it becomes possible to attach the wheel disk D to the hub 26 of the axle. This 13 arrangement is very useful.

At any rate, the outer peripheral surfaces of the projections 31 extending from the surface of the adapter plate A are superposed and functions as male side fitting surfaces 38, maintaining the intimate contact provided by the spigot Joint configuration.

When the adapter plate A has been attached to the hub 26 of the axle, as is clear from Fig. 3, the flat surfaces 36 of the adapter plate A are In a plane orthogonal to the wheel rotation axis 0-0, while the concave conical slope surfaces 33 are In a plane crossing the wheel rotation axis 0-0 at a given angle.

Corresponding to the surface shape of the adapter plate A, the back surface (rear surface) of the main disk 21 1s formed with a plurality of convex conical slope surfaces 39 adapted to engage said concave conical slope surfaces 33 of the adapter plate A, said surfaces 39 being in radial-line symmetry relation to each other. Formed through 'hic S* respective centers of said convex conical slope surfaces 39 are holes 40 fdr receiving the clamping devices 34 aligned S with the threaded holes 36 for receiving the second screw

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clamping devices 34 In the adapter plate A.

The back surface (rear surface) of the boss 26 of the main disk 21 is formed with notches 41 for receiving the first screw clamping devices 30 at positions corresponding to the grooves 32 of the adapter plate A, said notches 14 alternating with the convex conical slope surfaces 39.

That Is, the fixing nuts to be engaged from the front with the stud bolts In the first screw clamping devices are received In said notches 41 of the main disk 21, thereby preventing interference between the back surface of the main disk 21 and the fixing nuts, as shown In Fig. 3.

Speaking of the sub-disk 22 of the wheel disk D, it is made of light alloy by forging or other plastic processing methods and having substantially the same diameter as the S main disk 21. The numeral 42 denotes the peripheral edge of the sub-disk 22, where holes 44 are distributively formed for receiving the third screw clamping devices 43 aligned .5 wl th the threaded holes 24 In the peripheral edge of the main disk 21.

Each of the third-screw clamping devices 43 consists of a headed bolt extending parallel with the wheel rotation axis 0-0, and a fixing nut engaged therewith. The peripheral edge 23 of the main disk 21, the peripheral edge 42 of the sub-disk 22 and an attaching leg 45 inwardly extending from'the wheel rim R are removably attached together.

The numeral 46 denotes a boss forming the center of the sub-disk 22 and formed with holes 47 for receiving the second screw clamping devices 34; it goes without saying that said holes 47 are aligned with the holes 40 for receiving said clamping devices 34.

15 In that case, the surface of the boss 25 of the main disk 21 is processed to form a concave conical slope surface 48, while the back surface of the boss 46 of the sub-disk 22 Is processed to form a convex conical slope surface 49. The boss 46 of the sub-disk 22 is superposed from the front onto the boss 25 of the main disk 21, whereupon they are removably attached together by the second screw clamping devices 34.

That Is, as Is clear from Fig. 3, tie second screw S clamping devices 34 each consisting of a headed bolt are passed through the receiving holes 47 of the sub-disk 22 and the receiving holes 40 of the main disk 21 and then screwed 9.

into the threaded holes 35 of the adapter plate A. The second screw clamping devices 34 extend orthogonal to the conical slope surfaces'33 and 39 of the adapter plate A and main disk 21 a- 1 the conical slope surfaces 48 and 49 of the t main disk 21 and sub-disk 22, so that each screw axis P-P cross the wheel rotation axis 0-0 at a fixed angle O-with Its head assuming the inclined state directed toward the wheel rotation hxis.

Therefore, the horizontal and vertical laod applied from the road to the wheel can be effectively dispersed or absorbed by the second screw clamping devices 34 In the inclined state. When subjected to a centrifugal force due to the rotation of the wheel, the second screw clamping devices 34 In the inclined state are forced further into the 16 thr-eaded holes 35 of thle adapter plate A; thus, there Is no danger of them being accidentally loosened.

The numeral 51 denotes thle Intermediate region between thle boss 46 and peripheral edge 42 of the sub-disk 22, said Intermediate region being opposed to thle Intermediate region 27 of thle main disk 21 and being formed with a number of vent holes 52 whose size and shape and distribution differ from those of thle vent hole 28. Thus, the artistic pattern derived from the Intermediate region 51 of thle sub-disk 22 differs from the artistic pat tern derived from thle Intermediate region 27 of thle main disk 21.

That Is, wi th thle quasi-wire spoke conf iguration taken as an example, thle crossing ribs partitioning thle vent holes 28 In thle main disk 21 on the back side (rear side) can be seen through thle vent -holes 52 of thle sub-dtsk 22 posi tioned on thle front side (forward side). The pattern of mesh configuration Is Intentionally changed between thle two disks 21 and 22. The artistic pattern to be Imparted to Mte Intermediate region 51 of thle sub-disk 22 Is not limited to the Illustrated quasi-wire spoke configuration so long as thle artistic pattern changes.

-in that case, If ei ther tile surf ace of the Intermediate region 27 of the main disk 21 or the surface of thle Inter-mediate region 51 of the sub-disk 22 Is exposed as a Cast surface or other non-processed surface while cutting, palining or o therwi se processing thle otiher surface to thereby 17 make these surfaces different from each other In external appearance, the artistic patterns crn be further variegated.

The sub-disk 22 Is superposed from the front onto the surface of the main disk 21 and they are attached together at their bosses 46 and 26 by the second screw clamping devices 34 cnd at their peripheral edges 42 and 23 by the third screw clamping devices 43, as described above. In the attached state, as shown in Figs. 2 and 3, the space surrounded by the three planes respectively containing the intermediate regions 27 and 51 and wheel rotation axis 0-0 Is bridged by a three-dimensional truss r;f substantially triangular cross-section with the plare containing the wheel 9.

rotation axis defining one side of the triangle.

The apexes of each triangle are marked with X, Y and Z, and as suggested therefrom, a given clearance Is secured between the intermediate region 27 of the main d'sk 21 and the intermediate region 51 of the sub-disk 22. This arrangement In which the two disks 21 and 22 are ati-ached .together In the superposed state forming a three-dimensional truss, Is effective to Increase the strength of the structure and Is superior In the three-dimensional effect eee9•9 and dignity derived from the Intermediate regions 27 and 51.

In addition, the numeral 53 in Fig. 3 denotes a center cap removably fitted from the front to the boss 46 of th. subdisk 22.

In the basic embodiment shown In Figs. 1 through 5, the 18 tire supporting wheel rim R is formed with the attaching leg extending inwardly therefrom and engaged with the peripheral edge 23 of the main disk 21, and then the third screw clamping devices 43 attaching the peripheral edge 23 of the main disk 21 to the peripheral edge 42 of the subdisk 22 is utilized to fix the two disks 21 and 22 together.

However, the arrangements shown In first through sixth modifications shown In Figs. 7 through 12 which are different from said basic embodiment may be used so long as the invention Is applied to a built-up type automobile wheel In which the wheel rim 11 Is attached to the wheel disk D.

In the first modification shown in Fig. 7, the rear rim S. 54. forming the tire supporting wheel rim R continuously extends rearward from the peripheral edge 23a of the main disk 21a, while the Inward attaching leg 45a of the front rim 66. which is separate from the rear rim 54 is held between the peripheral edge 23a of the main disk 21a and the peripheral edge 42a of the sub-disk 22a, and In thi-s state the three are removably attached together by the third screw clamping devlces 43a.

That is, the three pieces, the main disk 21a integral with the rear rim 54, the sub-disk 22a and the front rim 56 cooperate with each other to form a bul t-up type automobile wheel. The character 56. denotes a seal ring fixed between the front rim 55 and the rear rim 54.

With thin arrangement, in changing the amount of offset 19 of the wheel, as suggested by chain lines in Fig. 7, this can be very easily attained simply by exchanging the front rim 65, In the second modification shown In Fig. 8, the rear rim 54b of the wheel rim R extends rearward from the peripheral edge 23b of the main disk 21b while the front rim 56b continuously integrally extends forward from the peripheral edge 42b of the sub-disk 22b, and the two disks 21b and 22b are removably attached together at their peripheral edges 4, 23a and 42b by the third screw clamping devices 43b: thus, the wheel is made of two pieces.

Fig. 9 shows the third modification, wherein the whole of the tire supporting wheel rim R continuously extinds from the peripheral edge 23c of the main dlsk 21c, and the peripheral edge 42c of- the sub-disk 22c Is engaged from the front with the peripheral edge 23c of the sub-disk 22c, wheieupon the two disks are removably attached together at the peripheral edges 23c and 426 also by the third clamping devices 43c. Therefore, In this case also, the wheel is made of two p.eces.

The fourth modification shown In Fig. 10 Is a partially modified version of the third modification described above,.

wherein the third screw clamping devices 43d for attaching the two disks 21d and 22d at their peripheral edges 23d and 42d are headed bolts not combined with nuts, said bolts being passed from the front thr .uon the sub-disk 22d and 20 screwed Into the peripheral edge 23d of the main disk 21d.

Further, in the basic. embodimeit shown in Figs. 1 through 5, the second screw clamping devices 34 for attaching the two disk 21 and 22 at their bosses 25 and 46 are inclined such that the screw axis P-P crosses the wheel rotation axis 0-0 at a given angle 0 with the head directed toward the wheel rotation axis. However, as shown in the fifth modification In Fig. 11, the second screw clamping devices 34e may extend parallel with the wheel rotation axis 0-0.

4e That Is, the surfaces of the boss 25e of the main disk 21e to be superposed on the adapter plate A and on the subdisk 22e are non-conical surfaces which are orthogonal to the wheel rotation axis 0-0.

In the sixth modification shown in Fig. 12, the adapter plate A used in the basic embodiment shown In Figs. 1 through 5 and the first screw clamping devices 30 for attachment to the hub 26 of the axle are omitted, whi le the second screw claming devices 34f extending parallel with the wheel rotation'axis 0-0 are each composed of a stud bolt set in the hub 26 ol the axle to extend forwardly theref'om and

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a fixing nut engaged therewith, said second screw clamping devices 34f being utilized to attach the two disks !1f and 22f simultaneously to the hub 26 of the axle.

As In the fifth and sixth modifications shown In Figs.

11 and 12, even if the bosses 26e, 46e, 26f and 46f of the 21 disks 21e, 22e, 21f and 22f are attached to the hub 26 of the axle directly or indirectly through the adapter plate A by the second screw clamping devices 34e and 34f extending parallel with the wheel rotation axis 0-0, the intended object of the Invention can be attained. However, if the second screw clamping devices 34 are Inclined at a given angle 0 with respect to the Wheel rotation axis 0-0 with the head 60 directed toward the wheel rotation axis, as is clear from the basic embodiment shown in Figs. I through 6, the PCD d3 of the second screw clamping devices 34 Is decreased by the amount by which the head 50 is Inclined toward the wheel rotation axis.

As a result, with the diameter of the wheel disk D I taken to be constant, the diameter of the boss 46 of the sub-rf'sk 22 in the wheel disk D can be minimized. Despite this minimization, the sufficient strength of attachment to the hub 26 of the axle by the second screw clamping devices 34 can be maintained. Further, tie area of the intermediate region 61 is increased by an amount corresponding to the minimization ?nd hence the degree of freedom for imparting S said artistic pattern to the intermediate region 51 is Increased. For example, there is an effect that the length of the quasi-wire spokes extending from the boss 46 to the peripheral edge 42 can be Increased. Such effect can also be attained in the case of the arrangements of the first through fourth modifications shown In Figs. 7 through 22 The rest of the arrangement of each of the first through sixth modifications shown In Figs. 7 through 12 Is substantially the same as In the basic embodiment shown In Figs. 1 through 6; thus, a detailed description thereof Is omitted with only alphabetic characters suffixed to the reference numerals used In the basic embodiment.

In brief, in the present invention, sub-disk 22 Is formed separate from the main disk 21, and with the sub-disk 22 superposed on the surface of the main dlsk 21, the space surrounded by three planes respectively containing the Intermediate regions 27 and 51 of the opposed two disks 21 gee% and 22 and the wheel rotation axis 0-0 Is bridged by a three-dimensional truss of triangular cross-section, as uggelted by the reference characters X, Y and Z.

Therefore, there is an effect that unlike the conventional wheel disk of single construction and its accessory wheel I* cap described at the outset, the strength of the wheel disk o o D to function as a support member for the wheel rim II can be greatly increased, Taking part in the attainment of such effect is the fact ee,: that the sub-disk 22 and the main disk 21 are fixed together at their bosses 46 and 26 by the second screw clamping devices 34 and at their peripheral edges 42 and 23 by the third screw clamping devices 34. The increase in the strengih of the wheel cannot be attained by the wheel cap, which Is an accessory part to be attached afterward.

2.3 Furthermore, the wheel disk D of the present invention Is of double construction*, and because of the threedimensional truss of triangular cross-section, a beautiful artistic pattern full of the three-dimensional effect and dignity of a wire spoke wheel can be derived from the intermediate regions 27 and 51 of the two disks 21 and 22 despite the fact that tile wheel disk is made of light alloy.

Particularly, the intermediate regions 27 and 51 of the two disks 21 and 22 are formed with a number of vent holes 28 and 52, respectively, differing In size and shape and distribution, and the sub-disk 22 and main disk 21 are removably attached together by the second and third screw clamping devices 34 and 43. Therefore, by preparing various main disks 21 and sub-disks 22 differing in artistic pattern provided by the vent holes 28 and 52 and recombining the pair afterward, it Is possible to enrich the variety of •:se artis' pattern exhibited on the surface of the wheel and se* it becomes easier to harmonize the artistic design wTth the Sdesign of the car body.

Further, since the main disk 21 and tile sub-disk 22 are Independent of each other and cooperate with each oither to

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form the wheel disk D of double construction when attached together, they can be produced of light alloy by casting and also by forging and other plastic processing means which are advantageous for increasing the strength. Further, as Is suggested from the basic embodiment and the first through 24 sixth modifications, the wheel disk can be formed to be continuous and Integral w-ith ail or part of the tire supporting wheel rim 11 wi thou. any trouble. In this respect also, the Invention Is very useful for manufacture of Interchangeable wheels on a diversified small- and mediumquantity basis.

I've V6040.

Claims (14)

1. A wheel disk for an automobile wheel, comprising a first disk which is to be visible from the outside of the wheel and a second disk which is to lie behind the first disk, each disk having a central boss, a peripheral region for supporting a wheel rim, and an intermediate region between the boss and the peripheral region, means being provided for removably fixing the peripheral region of the first disk to the peripheral region of the second disk and for removably fixing the boss of the first disk to the boss of the second disk, the intermediate region of the first disk being formed with holes through which the intermediate region of the main disk is visible, the first nd second disks being superposed so that a space surrounded by three planes respectively containing the intermediate regions and the wheel rotation axic: is bridged by a three-dimensional truss of substantially triangular cross-section.

2. A wheel disk as claimed ir ,aim 1, further comprising an adapter pla'te removably fixed to the bosses, the adapter plate being attached to the hub of an axle.

3. A wheel disk as claimed in claim 2, in which the adapter plate is removably attached to the hub of an axle by screw clamping devices extending parallel with the wheel rotation axis, the adapte. plate and the bosses having mutually superposed conical surfaces, inclined screws clamping devices passing through the conical surfaces and being inclined such that their respective axes intersect the whee' rotation axis, with their heads directed towards the wheel rotation axis.

4. A wheel disk as claimed in any preceding claim, in which the intermediate region of the second disk has holes.

5. A wheel disk ns claimed in claim 4, in which the holes in the first disk differ from the holes in the second disk in size and/or shape and/or distribution.

6. A wheel disk as claimed in any preceding claim, in which the holes are formed such that the intermediate region resembles spokes.

7. A wheel disk as claimed in any preceding claim, in which the first and second disks are each of a light alloy. J 0 6, AMD/0659a 26

8. An automobile wheel comprising a wheel disk according to any preceding claim, the wheel rim being supported by the said peripheral regions of the said first and second disks.

9. An automobile wheel as claimed in claim 8, i' which at least part of the wheel is integral with one of the first and second disks.

An automobile wheel as claimed in claim 8 or 9, in which the peripheral region of at least one of the first and second disks is connected to the wheel rim by screw clamping devices constituting the means for removably fixing the peripheral regions together.

11. An automobile wheel of light alloy therein the boss of a wheel disk is attachable to the hub of an axle directly or indirectly via an adapter plate, the wheel rim being supported by the peripheral edge of the wheel disk so that they rotate as a unit, a number of holes being distributively formed in the intermediate region between the boss and peripheral edge, thereby im'arting a pattern to the surface of the wheel disk, the wheel disk comprising a main disk and a sub-disk separately prepared, and the intermediate regions of the main disk and of the sub-disk corresponding to the intermediate region o)f the wheel disk being formed with holes, the holes in the sub-disk differing from the holes in the main disk in size and/or shape and/or distribution, the sub-disk being superposed from the front onto the surface of the main disk so that a space surrounded by three planes respectively containing the intermediate regions and the wheel rotation axis is bridged by a three-dimensional truss of substantially triangular cross-section, with the plane containing the.wheel rotation axis defining one side of the triangle, the two disk being removably attached together at their bosses by a plurality of screw clamping devices and at their peripheral edges by a separate plurality of screw clamping devices so that they are rotatable as a unit.

12. An automobile wheel as claimed in claim 11, wherein the adapter plate is removably attachable to the hub of the axle by a plurality of screw clamping devices extending parallel .o oo OoO e o o oooo ~~a K L~) N ~'Kr a AMD/0659a 27 with the whcl rotation axis; the sup -posed surfaces of the boss of the main disk and the ar ,er plate and the superposed surfaces of the boss of tnLe sub-disk and the boss of the main disk being formed as conical slope surfaces; and the screw clamping devices for attaching the bosses of the two disks pass through the conical slope surfaces and are inclined such that their respective axes intersect the wheel rotation axis at an angle, with their heads directed towards the wheel rotation axis.

13. A wheel disk substantially as described with reference to, and as shown in Figures 1 to 3 or any of Figures 7 to 12 of the accompanying drawings.

14. An automobile wheel substantially as described with reference to, and as shown in, Figures 1 to 6 or any of Figures 7 to 12 of the accompanying drawings. DATED this 30th day of December, 1992. CRIMSON COMPANY LIMITED By Its Patent Attorneys DAVIES COLLISON CAVE o e o -r t 0 AMD/0394a 2g ABSTRACT The present invention relates to a double disc configuration of an automobile wheel constructed of light alloy, designed to improve the durability of the wheel rim and the impart an aesthetically pleasing three-dimensional effect. The wheel disc is formed of main disc (21) and a sub-disc (22) opposed thereto. The intermediate region (51) of the sub-disc (22) corresponding to the intermediate region (27) of the mra:n diai (21) is formed with a number of vent holes (52) diffeing .from the vent holes (28) of the main disc (21) in size, shape and distribution. The sub-disc (22) is superposed from the front onto the surface of the main disc (21) such that the space surrounded by three places respectively containing the intermediate *i a regions (27, 51} of the two discs (21, 22) is bridged by a three-dimensional truss of substantially triangular cross-section with the plane containing the wheel rotation axis defining one side of the triangle. The discs (21,22) are then removably attached together at their bosses (25,46) by a plurality of screw clamping devices (34) and at their peripheral edges (23,42) by a separate plurality of OS screw clamping devices (43) so that they are rotatable as a unit. S s