Pulley assembly for belt drives

Abstract: The device for connecting parts having holes with different centre-to-centre distances consists of a threaded connecting element (11), such as a bolt or a nut, and a bush (12) whose internal diameter (D12) is greater than the diameter (D10) of the bolt shank or of a threaded shank associated to the the nut; if used for fitting vehicle wheels, a bolt (11) may be inserted into the holes (F) in the wheel (4), with the bush (12) snapped onto the base of the bolt head (13) from below, and the bolt then screwed into the corresponding threaded hole (S) in the axle hub (3), the difference between the centre-to-centre distance of the holes (F) in the wheel (4) and that of the threaded holes (S) in the vehicle axle hub (3) being compensated by the play created by the difference between the diameter of the bush and that of the bolt.

Description: The present invention concerns a device for connecting a wheel to a hub in accordance with the preamble of claim 1. Motor vehicle wheels have a plurality of holes, usually from three to five, distributed along the circumference of a circle whose centre is the centre of the wheel; on a plate (commonly known as "hub"), attached and perpendicular to the axle, there is a plurality of threaded holes corresponding to the holes in the wheel; the wheel is held to the axle hub by retaining bolts inserted through the holes in the wheel and screwed into the threaded holes in the hub. The configurations of the holes in the wheel and hub differ from one motor vehicle make to another, and even from one model to another, depending on design choices made in response to functional and aesthetic requirements. The differences consist not only in the number of holes in the wheel (and of the corresponding threaded holes in the hub) but also in the centre-to-centre distance between one hole and another in the wheel (or between two corresponding threaded holes in the hub). Basically, the radius of the circle, along whose circumference the holes in the wheel are arranged, may differ from that of the threaded holes in the axle hub. It is known from document WO 93/17883 a wheel with a rim and a dish whose diameter, width, shape and arrangement fit into different vehicles. The wheel has at least one opening in the flange through which wheel fasteners that match the most different hole circles can be introduced. An adapter ring centred in the wheel is provided with at least one fixed hole circle that allows the wheel to be secured to the corresponding hub by means of bolts or nuts. Document DE 8813513-U relates to a nut with a pressure ring which is provided with a spherically shaped underside for engagement with a depression complementary thereto in a component to be secured. In order to permit a simple and secure mounting of the pressure ring and to guarantee a clearly reproducible holddown force, the pressure ring is formed as a closed ring and means are provided for connecting the nut with the ring which prevents a separation and loss. Thereby the nut and the ring are rotatable relative to one another about a nut axis and are shiftable relative to one another transversely of the nut axis. At present, it is not possible to fit wheels with holes whose centres are at a given distance from each other to vehicles whose axle hubs have holes whose centres are at a different distance from each other, even if the difference is minimal. The aim of the present invention is to solve the problem just mentioned by providing a device which enables parts having holes with different centre-to-centre distances to be bolted to one another. According to the invention the device of the above-mentioned type comprises the features of the characterising portion of claim 1. One of the advantages of the present invention is that it allows wheels to be fitted to motor vehicle axle hubs even in those cases where the centre-to-centre distance between the holes for the retaining bolts in the wheel differs from that between the holes in the axle hub into which the retaining bolts are to be screwed. This advantage applies not only in those cases where the distance between the centres of the holes in the wheel is greater than that of the holes in the axle hub but also where, on the contrary, the holes in the axle hub are further apart than those in the wheel. In the preferred embodiment, applied to motor vehicle wheels, used hereafter as a non-restrictive example to describe the invention, the differences between the centre-to-centre distances between the holes in the two parts to be joined are of a few millimetres, a significant measurement if considered in relation to the dimensions concerned, namely centre-to-centre distances in the order of 10 2 millimetres and wheel and axle hub hole diameters in the order of 10 1 millimetres. Obviously, these values may vary according to the size of the parts concerned. The technical characteristics of the invention are laid out in the claims below and the advantages of the disclosure are apparent from the detailed description which follows, with reference to the accompanying drawings, which illustrate a preferred embodiment of the invention by way of example and in which: Fig. 1 is a schematic perspective view of a possible application of the present invention; Fig. 2 is a side view, with parts shown in cross section and others cut away, of an embodiment of the invention, applied to a motor vehicle wheel; Fig. 3 is a side view, with parts shown in cross section, of a device embodying the present invention and consisting of a bolt and bush assembly; Fig. 4 is a view in cross-section of a bush forming part of the device illustrated in Fig. 3; Fig. 5 is a side view, with parts shown in cross section and others cut away, of a device embodying the present invention and consisting of a nut and bush assembly. The invention will now be described with reference to the drawings listed above which illustrate preferred embodiments of the invention used for fitting wheels to the axle hubs of motor vehicles. The device illustrated in Figs. 2 to 4, for connecting parts having holes with centre-to-centre distances that do not match exactly, comprises a bolt 11 and a bush 12. The bolt has a head 13, used as a grip for tightening or slackening the bolt itself, and a shank 10 threaded complementarily with respect to a first hole S1 and a second hole S2 in a first plurality of holes S made in a first part 3 to be connected; in the example illustrated, the first part 3 is a hub 3 attached to an axle 31, shown only partially and schematically. The shank 10 has a diameter D10 which is smaller than a first diameter (DF) of a first hole F1 and a of a second hole F2 in a second plurality of holes F made in a second part 4 which, in the example illustrated, is a wheel 4 to be connected to the hub 3. The first threaded hole S1 and the second threaded hole S2 are spaced apart by a first distance IS which differs from a second distance IF between the first hole F1 and the second hole F2 in the wheel 4. The bush 12, which in the illustration has the shape of a truncated cone, has an internal diameter D12 that is smaller than the diameter D13 of the head 13 of the bolt 11 and larger than the diameter D10 of the shank 10 of the bolt itself by a value equal to the difference DI between the first distance IS (between the centres of the threaded holes S in the hub) and the second distance IF (between the centres of the holes F in the wheel). This arrangement makes it possible for at least two bolts to pass through the first hole F1 and the second hole F2 and to be screwed, respectively, into the first threaded hole S1 and the second threaded hole S2 in the axle hub 3. In the case of a motor vehicle, there are obviously more than two holes in the wheel and more than two threaded holes in the axle hub and, in practice, the device embodying the present invention (labelled 1 as a whole) causes the bolt to be shifted inwards or outwards in relation to the hole F through which it passes. For example, if the centre-to-centre distance IS between the threaded holes S in the axle hub is smaller than the centre-to-centre distance IF between the holes F in the wheel, the bolts will be shifted towards the inside of the wheel. The bush 12 has an annular seat 14 designed to accommodate the head 13 of the bolt 11 in such a way that the latter can rotate while being held firmly in the direction R of the bolt axis A and allowed play in a direction V perpendicular to the axis A by an amount not smaller than the difference DI between the first centre-to-centre distance IS and the second centre-to-centre distance IF. The annular seat 14 has a curved rim, obtainable by chamfering for example, designed to be snapped onto a corresponding rim of the head of the bolt 11 so as to make it easier for the device 1 to be fitted and holding the bolt 11 to the bush 12. Figure 5 shows an embodiment of the invention wherein a bush 12, similar to that of the embodiment described above, is associated with a nut 13'; the connection between the nut 13' and the bush 12 is comparable to that in the embodiment described above, between the bush 12 and the head 13 of the bolt 11. Obviously, to be able to connect two parts, the nut 13' must be screwed onto a corresponding threaded shank, not illustrated in Fig. 5, which may form part of the hub (or other part be connected) or which may be screwed into a hole in the hub itself (or in another part to be connected). The internal diameter D12 of the bush 12 is greater than the external diameter D13' of the nut 13' so as to provide the play necessary to connect parts each with at least two holes at a distance from each other different from the distance between the two corresponding holes in the other part. The invention described can be subject to modifications and variations without thereby departing from the scope of the inventive concept as defined by the claims.

Claims: A device for connecting a wheel (4) to a hub (3), said wheel (4) presenting at least two holes (F1, F2) having diameter (DF) and being spaced apart by a centre-to-centre distance (IF); said hub (3) presenting at least two threaded holes (S1, S2) having diameter (DS) and being spaced apart by a centre-to-centre distance (IS) different from the centre-to-centre distance (IF) of the holes (F1, F2) of the wheel (4); each threaded hole (S1, S2) of the hub (3) being associated to a corresponding hole (F1, F2) of the wheel (4); the device comprising a connecting element (11), including a shank (10) connected to a head (13) or a shank (10) associated to a nut (13'), said shank (10) being threaded complementarily with respect to said threaded holes (S1, S2) of the hub (3), said shank (10) or said nut (13') having a diameter (D10, D13') smaller than the diameter (DF) of the holes (F1, F2) of the wheel (4), the device being characterized in that it comprises, associable with the connecting element (11), a bush (12) having an internal diameter (D12) that is smaller than the external diameter (D13) of the head or of a portion of the nut remote from the hub, the internal diameter (D12) being larger than the diameter (D10) of the shank (10) or the external diameter (D13') of a portion of the nut (13') adjacent to the hub (3) by a value not smaller than the difference between the centre-to-centre distance (IS) of the threaded holes (S1, S2) of the hub (3) and the centre-to-centre distance (IF) of the holes (F1, F2) of the wheel (4), making it possible for two shanks (10) to pass through the corresponding holes (F1, F2) of the wheel (4) and to be screwed into the corresponding threaded holes (S1, S2) of the hub (3). The device according to claim 1, characterized in that the said bush (12) has the shape of a truncated cone and presents an annular seat (14) designed to accommodate the head (13) of the connecting element (11) in such a way that the latter can rotate while being held firmly in the direction (R) of the axis (A) of the element (11) and allowed play in a direction (V) perpendicular to the axis by an amount not smaller than the difference (DI) between the first centre-to-centre distance (IS) and the second centre-to-centre distance (IF). The device according to claim 2, for connecting parts with holes having different centre-to-centre distances, characterized in that the said annular seat (14) has a curved rim designed to be snapped onto a corresponding rim of the head (13) of the element (11).

Inventors: BERNONI CLAUDIO, BERNONI, CLAUDIO
Applicants: O Z S P A, O.Z. S.P.A.
Application year: 1995
Main classification: F16B5
IPC codes: F16B5, B60B3, F16B43