A HUB UNIT FOR AN INLINE SKATE WHEEL
The present invention relates to inline skate wheels and particularly to a hub unit for such a wheel.
Wheels for inline skates and other types of wheel skates exist in a large number of different brands and types. Such wheels of standard type are usually provided with a through-bore with two radial collars and an arrangement supported in small rolling bearings and positioned between the bore in the wheel and an axle. The two collars in the bore has made it necessary to mount the bearings, which are supporting the wheel, from opposite sides of the wheel bore, which has necessitated that both sides of the wheel are accessible, and it has further meant that it is very difficult to position the two bearings in the positions, where they have the exact mutual spacing and particularly, where they are accurately aligned. The alignment problem cannot even be overcome with use of exactly dimensioned spacing devices positioned between the bearings.
The purpose of the present invention is to propose a hub unit for an inline skate wheel, which is built as a closed unit, uniting the bearings in exact mutual positions in axial direction and also exactly aligned, for ascertaining that the above problems are eliminated, and this has been achieved in that the hub unit has been designed in accordance with the accompanying claim 1.
Hereinafter, the invention will be further described with reference to the accompanying drawings illustrating slightly different embodiments of an inline skate wheel hub according to the present invention.
Fig. 1 shows in perspective a cross section through an inline skate wheel, with a hub unit in accordance with the present invention.
Fig. 2 is a planar cross section of the hub unit according to Fig. 1 and in bigger scale.
Fig. 3 is a perspective view of the hub unit shown in Fig. 2
Fig. 4 is a further perspective view of the hub unit shown in Fig. 3, viewed from a direction different from that in Fig. 3
Fig. 5 is an exploded perspective view of components of the hub unit shown in Fig. 2,
Fig. 6 is a further exploded perspective view with the bearing unit separated from the rest of the hub unit parts.
Fig. 7 is an exploded perspective view of a two-part embodiment of the hub unit according to the invention, and
Fig. 8 is an exploded perspective view of a slightly modified embodiment of the hub unit according to the invention.
In Fig. 1 is shown a cross section through an inline skate wheel 1, with a centrally located hub unit 2, according to the invention.
The hub unit 2 shown in Fig. 1 is shown in bigger scale and in a planar cross sectional view in Fig. 2. The hub unit 2 incorporates, as can be seen from this view, a hollow sleeve 3 forming an inner bearing ring, and having spaced apart race tracks 4 for a number of rolling bodies 5, here shown as balls. Each row of balls 5 cooperates with an outer bearing ring 6 having an appropriate, corresponding race track The hub unit 2 further incorporates an external socket 7, which encloses the outer ring 6 of one first of the bearings and via a radial flange portion 7a has an axially extending sleeve portion 7b of smaller diameter and encircling the inner bearing ring sleeve 3. At its end remote from the part 7 enclosing the outer ring of one first of the two bearings, this sleeve portion 7b terminates in a circular end edge 7c projecting into an axial groove 8 in the outer ring 6 of the other bearing, and at a short distance from the axial inner wall of said groove 8. Adjacent the circular end edge 7c, the sleeve portion 7b is provided with radially flexing connecting means 9 adapted to be coupled to corresponding means 10 provided on a connecting bush 11, arranged to enclose the outer ring 6 of the other bearing when the hub unit is in mounted position, or in a position for storage or transport, the side of the connecting means 9 facing the other
bearing abutting the bearing side-face, thereby defining the built-in clearance in the bearing system.
The hub unit 2 according to the invention therefore can be assembled with the bearings in exact positions and exactly aligned and thereupon be stored, transported and finally mounted in an inline skate wheel without any need - or possibility - to displace the bearings or other components of the hub unit.
When mounting the hub unit in an inline skate wheel or the like, the connecting bush 11 is removed in a manner further described hereinafter, whereupon the other parts of the hub unit can be pushed in from one side of the bore in the wheel with its flexing end edge 7c being bent radially inwards until its radial flange portion 7a abuts a collar in the wheel bore, while simultaneously the flexible end edge flex outward and interconnecting means snap around the other collar of the wheel to lock the bearing unit axially to the wheel. Then the connecting bush 11 is positioned from the opposite side of the wheel bore over the outer ring of the other bearing and in the wheel bore, down to wheel shoulder, and is rotated to lock the interconnecting means 9 of the circular end edge 7c.
Figs. 3 and 4 show perspective cross sectional drawings, seen from different angles, of the complete hub unit according to Fig. 2. For allowing the interconnecting means 9 on the circular end edge 7c to pass through the bore in a wheel up to the wheel collar, it is required that that portion is somewhat flexible, thus that it can be bent inwards when passing the most narrow portion of the bore. This can preferably be achieved in that the axially extending sleeve portion 7b is provided with axially extending slots 12, giving the sleeve portion 7b a comb-like, radially flexible structure, allowing it to flex away radially when being pushed into the wheel bore and to flex back to normal position when reaching the correctly mounted position. As can be further seen in those two figures, the connecting means 9 of the sleeve portion 7b are preferably designed as a number of hook-like projections, extending radially outwards from at least some of the fingers 13 formed between adjacent slots 12 in the sleeve portion 7b. The corresponding means 10 provided on the connecting bush 11, and adapted to be coupled to the hook-like connecting means 9, are preferably short, axially extending inclined ramps arranged to interlock with the
hook-like projections 9 when the connecting bush 11 is applied and rotated to cause an engagement of the same type as a bayonet joint.
The outwardly facing sides of both bearings are provided with bearing seals 14 of any appropriate type, fitted e.g. in ordinary grooves in the outer bearing ring 6.
Fig. 5 shows in perspective the hub unit 2 in perspective and with the connecting bush 11 removed from the rest of the hub unit. The shape and positioning of the hook-like connecting means 9 and the inclined ramps 10 can be better seen in this view.
Fig. 6 is another perspective view from another direction than that shown in Fig. 5 and in a somewhat smaller scale, and this view differs from that according to Fig. 5 in that the different components forming the hub unit are shown separate from each other.
In Fig. 7 is shown a further embodiment of the hub unit for an inline skate wheel or the like according to the invention, and which is designed mainly for simplify manufacturing, and wherein the external socket 7' is divided into two parts 15, 16, each having axially extending fingers 15a, 16a. Both these sets of axially extending fingers 15a, 16a are arranged in comb-like manner with a spacing mainly corresponding to the width of the fingers, thus that the fingers 15a, 16a, when the two halves 15, 16 have been pushed into each other, together form a surface with a number of very thin slots, which slots provide a sealing effect as a labyrinth, whereby contaminants appearing in the environment, e.g. under a wheel change, or the like, can be prevented from entering the hub unit. Both parts 15, 16 can be produced from plastic material by means of an appropriate moulding technique.
Although the hub unit formed in two pieces is shown in Fig. 7 with two comb-like halves it is also possible to make the socket as two substantially semi-cylindrical parts, which are joined at assembly.
Fig. 8 finally shows an alternative hub unit for a wheel, particularly an inline skate wheel, where the hub unit 7" is designed substantially in the same manner as the embodiment shown in Fig. 5. In this specific case, the hub unit is provided with a tapering axle
extension 3", which is provided with an external thread and which can be fitted in a cantilever manner to the frame of a inline skate or the like. This tapering axle extension can be an integral part of the inner bearing ring or can be a separate part fitted to the bearing ring, and for weight reduction purposes and for giving the component a visual appearance of light weight.
The experienced user of inline skates use different wheels and therefore need to exchange the wheels often, whereby it is vital that this exchange is possible in a simple manner.
For dismounting a wheel with a hub unit according to the invention the following steps must be taken:
1) First the connecting bush 11 is rotated in opposite direction to its rotation at locking, to a given position.
2) By doing so the inclined ramps of 10 pass over the hooks of 9 and force them to flex inwards, to such an extent that their outer diameter becomes smaller than the bore of the wheel.
3) Then the outer bearing ring is pressed from the side of bush 11 so that the whole unit is extracted from the wheel
4) The wheel is finally turned and bush 11 is pressed outwards.
The hub unit as shown and described is a self-contained unit with factory defined and unchangeable settings, and the advantages gained therewith are
lower friction, giving a longer free spinning time, i.e. the unloaded wheel is rotating much longer than a wheel having a conventional three piece bearing arrangement with two loose bearings pushed into the bore in the wheel and having a spacer positioned therebetween,
a better load supporting ability,
longer service life (following the exact and unchangeable factory settings), and
a sound when the wheel is rotated, which is more appealing to the user, experienced as a whining rather than a rattling noise.
The invention is not limited to the method and the members as illustrated in the accompanying drawings and described with reference thereto, but modifications and variants are possible within the scope of the attached claims.