WO2009105819A1

WO2009105819A1 - A hanger for a skateboard truck

Info

Publication number: WO2009105819A1
Application number: PCT/AU2009/000222
Authority: WO
Inventors: Chris Northwood
Original assignee: Titanium Truck Technologies Pty Ltd
Current assignee: Titanium Truck Technologies Pty Ltd
Priority date: 2008-02-27
Filing date: 2009-02-27
Publication date: 2009-09-03
Anticipated expiration: 2010-08-27
Also published as: US20110012318A1

Abstract

A hanger (2) for a skateboard truck includes: a body and an axle (4, 12) integrally formed with the body, wherein in use, the axle (4, 12) is prevented from disengaging the body.

Description

A HANGER FOR A SKATEBOARD TRUCK

Field of the invention

The present invention relates to skateboard trucks, and more particularly, hangers for a skateboard truck.

In this specification, where a document, act or item of information or knowledge in relation to the prior art is referred to or discussed, such a reference or discussion is not an admission that the document, act or item of knowledge or information, or any combination thereof, was at the priority date, part of the common general knowledge or known to be relevant to an attempt to solve any problem with which this specification is concerned.

Background of the invention

A skateboard truck is the component, which lies between the skateboard wheels and bearings on the one hand and the skateboard on the other hand. The skateboard is the platform whereby the person user or skateboard rider is carried and supported.

Presently, skateboard trucks are generally constructed from five (5) distinct and separate components being the axle, the hanger, the baseplate, the bushes and the central bolt. The bushes and the central bolt when combined in use ^'in the hanger, is known in the art as the "kingpin".

Generally, skateboard trucks utilise a two-piece hanger/axle assembly.' Typically, this involves the use of two types of material such as a steel material axle, which is cast or cold pressed into another metal alloy hanger to create a two-piece hanger unit.

As a result of the above-mentioned arrangement, such two-piece hanger/axle assemblies have an inherent problem. The problem being is that as a result of normal usage by the skateboard rider, the axles work away and move free from the hanger. As a result of this problem, the entire skateboard truck can therefore be rendered useless. Summary of the invention

According to the present invention, there is provided a hanger for a skateboard truck, including: a body, an axle integrally formed with the body, wherein in use, the axle is prevented from disengaging the body.

Preferably, the axle includes a first member and a second member, the first member and second member being spaced apart.

Preferably, wherein the first member and the second member each have a threaded portion adapted to retain a wheel.

Preferably, the axle and the body are uniformly constructed from a titanium based material. In this case it is preferred that the titanium based material is in the range of about 50% -100% by weight titanium. It is further preferred that the titanium based material includes a titanium based composite of about 90% titanium.

Preferably, the body includes an annular portion adapted to receive a kingpin. In this case, it is preferred that the annular portion includes an aperture.

Preferably, the body includes a pivot point adapted to movably engage about a base plate.

Preferably, the body includes at least one cavity region.

Preferably, the hanger is adapted to withstand a maximum yield strength of up to 815.773 Mpa.

Preferably, the hanger has a maximum breaking strength located about a first edge of the body and a second edge of the body. In this case, it is preferred that the maximum breaking strength of the first edge of the body and the second edge of the body, is each in the order of 906.124 Mpa. It will accordingly be seen that manufacturing the hanger with an integrated axle this prevents the axle from working away and moving free from the body.

Brief description of the drawings In order that the invention may be readily understood and put into practical effect, reference will now be made to the accompanying drawings, in which:-

Figure 1 is a perspective view of the hanger for a skateboard truck, according to a first preferred embodiment of the invention.

Figure 2 is a top plan view of the hanger for a skateboard truck of Figure 1 , according to a second preferred embodiment of the invention.

Figure 3 is a side perspective view of the hanger for a skateboard truck bf Figure 2, according to a third preferred embodiment of the invention.

Figure 4 is an inverted side perspective view of the hanger for a skateboard truck of Figure 2, according to a fourth preferred embodiment of the invention.

Figure 5 is an inverted top perspective view of the hanger for a skateboard truck of Figure 2, according to a fifth preferred embodiment of the invention.

Figure 6 is a front perspective view of the hanger for a skateboard truck of Figure 2, according to a sixth preferred embodiment of the invention.

Figure 7 is a perspective view of the hanger for a skateboard truck of Figure 6, rotated about 180^* anti-clockwise about a vertical axis, according to a seventh preferred embodiment of the invention.

Figure 8 is a side perspective view of the hanger for a skateboard truck of Figure 6, rotated about 90^°, anti-clockwise about a vertical axis, according to an eighth preferred embodiment of the invention. Figure 9 is a perspective view of the hanger of a skateboard truck, indicating stress test representations, according to a ninth preferred embodiment of the invention.

Description of preferred embodiments of the invention

By referring to Figures 1 to 9, the hanger 2 includes an axle which is defined by a combination of a first member 4 and a second member 12. The first member 4 and the second member 12 are spaced apart within a body having a first end 18 and a second end 22 respectively.

The first member 4 and the second member 12 both function to each hold and retain a spinning wheel (not show in the drawings) for a skateboard as a whole.

As the first member 4 and second member 12 are integrally formed with the body at each of the its first end 18 and second end 22 respectively, the axle which is constituted by the combination of the first member 4 and the second member 12, does not spin or rotate within the hanger 2.

By specifically referring to Figure I₁ the first member 4 is provided with a threaded portion 6 at its end which is adapted to receive or retain a first spinning wheel usually a ball bearing type (which is not shown in the drawings). The second member 12 is also provided with a threaded portion 14 at its end which is adapted to receive or retain a second spinning wheel usually a bait bearing type (which is not shown in the drawings).

The hanger 2 is also provided with a cavity 8 and cavity 20, which both serve to function of reducing the weight of the hanger 2 as a whole.

Traditional hangers in the art which use steel and alloy composites are heavy and weigh about 240 grams plus or minus (+/-) 20 grams whereas, the present hanger 2 weighs in the order of about 160 grams, a reduction of about 80 grams in weight as compared to prior art hangers. By specifically referring to Figure 2, the annular portion 26 can be seen more clearly which extends or protrudes from the curved region of the body 24 by way of a cavity wall 30, descending from the curved region of the body 24. The annular portion 26 is also provided with an aperture 16, which is defined within a first annular recess 28.

Both features aperture 16 and the first annular recess 28 serve to function by receiving the "kingpin" (which is not shown in drawings) or some other similar . fastening arrangement so that the hanger 2 can be ultimately fastened to a base plate (also not shown in the drawings).

By specifically referring to Figure 3, the annular portion 26 is seen extending from the cavity wall 30. As a result of this cavity wall 30, there is a cavity 32, which provides a space to receive the "kingpin" or other fastening arrangement as described earlier.

By referring to Figure 4, the hanger 2 is provided with a cavity.8 and cavity 2O₁ which functions to reduce the overall weight of the hanger 2. The annular portion 26 on the inverted side or bottom side is provided with a second annular recess 34, which surrounds the aperture 16. The second annular recess 34 is also provided with an annular edge 36. The second annular recess 34 and annular edge 36 serve to function to receive the "kingpin" on the inverted side of the hanger 2. The annular portion 26 extends to a smooth region 38, which further extends to an arcuate bridge 40 which, in turn integrally forms with the pivot point 10.

The pivot point 10 functions to act as a means to allow the hanger 2 to movably engage about a base plate (not shown in the drawings) when a skateboard truck is installed on a skateboard (also not shown in the drawings) to provide steering and maneuvering capability for the skateboard as a whole:

Turning to Figure 5, the. body is also provided with a first edge 42, a second edge 44, a third edge 46 and a fourth edge 48 respectively. Located Inside the cavity 20 toward the second end of the body 22, there is located a first internal wall 50, which indicates the integrally formed nature of the axle including, the second member of the axle 12 forming part of the body at the second end 22. Towards the first end of the body 18, there is provided a second Internal wall 52.

Turning now to Figure 6, the annular portion 26 is provided with a groove 54 and a smooth edge 56 on its outer edge. The pivot point 10 is provided with a first recess 58 and second recess 60.

Turning now to Figure 7, the ourved region of the body 24 extends to an external edge 62, which in turn, integrally forms with the curved wall 64 which further extends to the pivot point 10.

Turning now to Figure 8, the first member of the axle 4 Is provided with an end 66. The body toward the second end 22 is also provided with an external edge 68. The body is also provided with an internal wall 70. _. In this Figure 8, the groove 54 can be seen forming part of the annular portion 26.

Turning to Figure 9, is a representation of the Finite Element Analysis ("FEA") stress tests performed on the hanger 2. There are two (2) types of FEA stress tests being: (1 ) breaking of the hanger 2 and (2) bending of the hanger 2.

In respect of the first test of breaking the hanger 2, there are only two regions of the hanger 2, where the body breaks as a result of stress test. The first region being the first edge of the body 42 and the second edge of body 44 (referring to Figure 5) and regions 82, 86, 84 and 80 (by referring to Figure 9) each have a . maximum breaking strength of 906.124 Mpa.

In relation to the second test of bending the hanger 2, the bending regions are near, surround or adjacent to the breaking regions of the first edge of the body 42 and second edge of the body 44 (by referring to Figure 5) and regions 82,86,84 & 80 (by referring to Figure 9). These regions commence bending to maximum yield strength in of about 679.621 Mpa . As part of the FEA stress test, it has been found that the hanger 2 is adapted to withstand a maximum yield strength of up to 815.773 Mpa, which far exceeds the pressures and stresses applied by ordinary usage of skateboarders.

As seen in Figure 9, there are no stress points on the first member of the axle 4 and the second member of the axle 12. As a result of the FEA stress test, it was observed that the least stress or pressure was applied to the first member of the axle 4 and the second member of the axle 12.

Further, the vast majority of the hanger 2 other than the breaking regions which are defined by the first edge of the body 42 and second edge of the body 44 described above, indicated that there was no breaking or bending. Such regions include: the first member of the axle 4 and the second member of the axle 12; the first end of the body 18 and the second end of the body 22; the pivot point 10; the annular portion 26; the second annular recess 34; the annular edge 36; the smooth region 38 and the arcuate bridge 40. Such regions are known to "yield" meaning that they are able to withstand the various pressures applied without bending or breaking.

It should be noted that the normal stresses applied to a hanger in the normal course of events is in the order of 373 Mpa. It therefore can be appreciated by the person skilled in the art that the FEA stress tests performance of the hanger 2 for the first and second tests far exceed the normal stresses which would normally be applied by ordinary skateboard usage riders to the hanger 2.

The hanger 2 is best known to be manufactured by way of a computer numerical control or "CNC Milling" based upon a solid piece of titanium metal, or titanium composite material, which forms the basis of the hanger 2.

In order to manufacture the hanger 2, the following manufacturing method is used. A solid piece of "64 Titanium" commercially available titanium composite is used. The term "64" refers to 6% per cent by weight Aluminium and 4% by weight Vanadium. It is preferred that the titanium based composite used for manufacture of the hanger 2 is about 90% titanium by weight. It however should be mentioned . that a titanium-based material of from about 50% to100% titanium can also be used.

Therefore a range of titanium based materia! of about 50% titanium composite to about to 100% titanium is suitable to use to manufacture the hanger 2.

During CNC Milling, the computer controller that reads the G-code instructions, . drives a machine tool, a powered mechanical device typically used to fabricate components by the selective removal of material. The CNC Milling process is numerically directed interpolation of a cutting toot in the work envelope of a machine. The operating parameters of the CNC Milling process can be altered by way of a software load program.

The thread portion 6 and 14 are applied to the first member of the axle 4 and the second member of the axle 14 by way of known machining.

As the body of the hanger 2 and the axle are integrally formed of the same or uniform titanium based material whether the 100% form or a 64 titanium composite type, such a construction is a change or variation in the construction of previous hangers. Previously constructed hangers would have combined two types of material, such as an alloy metal hanger with a steel base axle. There has not been any hangers known to the present Applicant that uses entirely titanium based composite to a high percentage for both the body and integrally formed axle.

One advantage of embodiments of the present invention is that by manufacturing the hanger with an integrated axle, this prevents the axle from working away and moving free from the body. Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognised that departures can be made within the scope of the invention, which is not to be limited to the details described herein, but is to be accorded the full scope of the appended claims so as to embrace any and all equivalent devices, products, apparatus, methods and processes.

'Comprises/comprising' when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

In the claims, each dependent claim is to be read as being within the scope of its parent claim or claims, in the sense that a dependent claim is not to be interpreted as infringed unless its parent claims are also infringed.

Claims

1. A hanger for a skateboard truck, including: a body, an axle integrally formed with the body, wherein in use, the axle is prevented from disengaging the body.

2. The hanger according to claim 1 , wherein the axle includes a first member and a second member, the first member and second member being spaced apart.

3. The hanger according to claim 2, wherein the first member and the seoond member each have a threaded portion adapted to retain a wheel.

4. The hanger according to any one of claims 1 to 3, wherein the axle and the body are uniformly constructed from a titanium based material.

5. The hanger according to claim 4, wherein the titanium based material is in the range of about 50% -100% by weight titanium.

6. The hanger according to claim 5, wherein the titanium based material includes a titanium based composite of about 90% titanium.

7. The hanger according to any one of claims 1 to 6, wherein the body includes an annular portion adapted to receive a kingpin.

8. The hanger according to claim 7, wherein the annular portion includes an aperture. .

9. The hanger according to any one of claims 1 to 8, wherein the body includes a pivot point adapted to movably engage about a base plate.

10. The hangeraccording to any one of claims 1 to 9, wherein the body includes at least one cavity region. - H -

11. The hanger according to any one of claims 1 to 10, wherein the hanger is. . adapted to withstand a maximum yield strength of up to 815.773 Mpa.

12. The hanger according to any one of claims 1 to 11 , wherein the hanger has a maximum breaking strength located about a first edge of the body and a second edge of the body.

13. The hanger according to claim 12, wherein the maximum breaking strength of the first edge of the body and the second edge of the body, is each in the order of 906.124 Mpa,

14. A hanger substantially as hereinbefore described with reference to at least one of the accompanying drawings.

15. A method substantially as hereinbefore described.