BICYCLE RIM AND METHOD OF MANUFACTURING

Abstract

A bicycle rim for bicycles with a rim body with a visible surface perceptible in proper operation, wherein a supporting structure of the rim body is made from fibrous composite materials of prepreg layers is disclosed. The rim body includes rim flanks disposed opposite one another, a rim well, and a rim base. The visible surface is formed by a thin non-woven layer on the supporting structure, so as to form directly during manufacturing, an optically appealing, visible surface on the rim body, involving no postprocessing. The non-woven layer forms on the rim body, an outer layer of a composite layer. The composite layer includes a prepreg layer and the non-woven layer.

Claims

1. A bicycle rim for bicycles, comprising: at least one rim body with a visible surface perceptible in proper operation; wherein a supporting structure of the rim body is manufactured from fibrous composite materials consisting of prepreg layers; wherein the rim body comprises rim flanks disposed opposite one another, a rim well, and a rim base; the visible surface is formed by a thin, non-woven layer on the supporting structure, so as to form during manufacturing, an optically appealing, visible surface on the rim body; and the non-woven layer on the rim body is an outer layer of a composite layer, which comprises at least one prepreg layer and the non-woven layer.

2. The bicycle rim according to claim 1, wherein the composite layer comprises two prepreg layers with reinforcing fibers in different orientations, and the non-woven layer.

3. The bicycle rim according to claim 1, wherein at least one prepreg layer comprises unidirectional reinforcing fibers.

4. The bicycle rim according to claim 1, wherein the non-woven layer provides less than 10% or less than 5% of the stability of the rim body.

5. The bicycle rim according to claim 1, wherein the thickness of the non-woven layer is less than 5% of the wall thickness of the supporting structure of the rim body, and/or wherein the thickness of the non-woven layer is less than 0.1 mm.

6. The bicycle rim according to claim 1, wherein the weight per unit area of the fibrous material of the non-woven layer is 8 grams per square meter +/?50%.

7. The bicycle rim according to claim 1, wherein the prepreg layers comprise continuous fibers cut to the layer size.

8. The bicycle rim according to claim 1, wherein the non-woven layer is configured as a non-woven prepreg comprising randomly disposed non-woven fibers of different lengths, and resin.

9. The bicycle rim according to claim 1, wherein the non-woven proportion of the non-woven layer is 40%+/?20%.

10. A method of manufacturing a bicycle rim having at least one rim body, the supporting structure of which is manufactured from a fibrous composite material of prepreg layers, wherein the rim body comprises rim flanks disposed opposite one another, a rim well, and a rim base, comprising: forming a perceptible (visible) surface on the rim body which is visible in proper operation, a composite layer of a thin, non-woven layer and at least one prepreg layer is inserted into the manufacturing mold so that the non-woven layer bears against the manufacturing mold, so that the visible surface is formed by the thin non-woven layer, and the supporting structure is formed by the prepreg layers, so as to form during manufacturing an optically appealing, visible surface on the rim body, and that the non-woven layer on the rim body is an outer layer of a composite layer, which comprises at least one prepreg layer and the non-woven layer.

11. The method according to claim 10, wherein the composite layer is first formed by way of joining at least one prepreg layer with the non-woven layer, and wherein for forming the composite layer, at least one prepreg layer is placed on a backing and the non-woven layer is placed on top and then pressed onto it.

12. The method according to claim 10, wherein the composite layer is vacuum impregnated prior to placement in the manufacturing mold.

13. The method according to claim 10, wherein the composite layer is pressed onto the manufacturing mold full-surface, and wherein after placing/inserting the composite layer in the manufacturing mold, reinforcement layers are placed/inserted in the manufacturing mold.

14. The method according to claim 10, wherein the manufacturing mold loaded with the prepreg layers and the non-woven layer and optionally with reinforcement layers, is evacuated, and wherein the manufacturing mold is placed in a press device and heated.

15. The method according to claim 10, wherein for manufacturing a rim, a prepreg layer (and no non-woven layer) is applied directly on the ring part forming the rim well, and wherein after removing the rim, spoke holes are inserted.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The figures show in:

[0050] FIG. 1 a schematic illustration of a mountain bike with bicycle rims according to the invention;

[0051] FIG. 2 a schematic illustration of a racing bicycle with bicycle rims according to the invention;

[0052] FIG. 3 a bicycle rim according to the invention;

[0053] FIGS. 4a, 4b a non-woven layer and two prepreg layers in manufacturing the bicycle rim according to the invention;

[0054] FIGS. 5a-5c various steps in manufacturing a rim according to the invention for a bicycle; and

[0055] FIG. 6 a perspective view of a bicycle rim according to the invention.

DETAILED DESCRIPTION

[0056] The FIGS. 1 and 2 illustrate a mountain bike respectively a racing bicycle 100, each equipped with bicycle rims 1 according to the application. The mountain bike respectively racing bicycle 100 comprise a front wheel 101 and a rear wheel 102 each, where bicycle rims 1 according to the application respectively rims are used. The two wheels 101, 102 are provided with spokes 109 to connect the rims 1 with the hubs 110. To this end, the rim 1 is provided with spoke holes 25. The mountain bike respectively racing bicycle 100 comprise a handlebar 30 and a frame 103 each.

[0057] A bicycle 100 has a frame 103 with frame components 40, a handle 106 with a handlebar 30, a saddle 107, a fork respectively suspension fork 104, and the mountain bike may be provided with a rear wheel damper 105. A pedal crank 112 with pedals serves for driving.

[0058] Optionally the pedal crank 112 and/or the wheels may be provided with an electrical auxiliary drive. The hub 110 of the wheels may be attached to the frame by means of a clamping system such as a through axle or a quick release.

[0059] FIG. 3 shows a bicycle rim respectively rim 1 as a bicycle component in a schematic cross section. The rim 1 is configured as a hollow rim and has a hollow space 29 in the interior of the rim 1 between the radially inwardly rim base 23 and the radially outwardly rim well 24. On the sides, rim flanks 21 and 22 are provided, extending convex between the rim base 23 and the radially outwardly rim flanges 26 and 27. The rim 1 has a component body respectively rim body 2, whose supporting structure 3 is provided by prepreg layers 5. The radially outwardly side 24a of the rim well 24 between the rim flanges 26 and 27 is as a rule not visible in proper use, since this is where the tire plus optionally a tube is/are received.

[0060] Therefore, the visible surface 8 extends on the inner surface 28 from the rim flange 26 across the rim base 23 up to the other, opposite rim flank 22. This visible surface 8 is again provided by a non-woven layer 9 (see FIGS. 4a and 4b), extending over the inner surface 28 and across the rim flanks 21, 22 and the rim base 23 up to and including the rim flanges 26, 27. The thin and lightweight non-woven layer 9 preferably has an end weight of less than 10 grams. In particular, the weight proportion of the non-woven layer (resin plus fibers) is relative to the total weight of the rim 1 less than 2% or even less than 1.5% and may be less than 1% or less than 0.5%.

[0061] Surprisingly, the non-woven layer 9 achieves considerable improvement of the optical quality of the rim 1 removed from the manufacturing mold 50 and to reduce the quantity of defects on the visible surface 8 to such an extent that postprocessing is not necessary as a rule, thus reducing the manufacturing costs and increasing the quality of the rim 1.

[0062] The supporting structure 3 is formed by a number of prepreg layers 5. The supporting structure 3 provides the majority of the stability of the rim body 2. The non-woven layer 9 only provides a very low proportion of 5%, 10% or maybe 15% of the stability of the rim body 2. The predominant part (80%, 90% or more) of the stability of the supporting structure 3 respectively the rim body 2 is provided by the prepreg layers 5 from fibrous composite materials 4. A minimum wall thickness 3b of the supporting structure 3 is formed in the convex region of the rim flanks 21 and 22, while in the region of the rim base 23, additionally inserted reinforcement layers 12 achieve a higher maximum wall thickness 3c of the supporting structure 3, other than crossing points such as the connecting points of the rim well 24 and the rim flanks 21, 22.

[0063] Basically, the outer layer 11 provides the visible surface 8 by way of a non-woven layer 9. The prepreg layers 5a and 5b follow toward the inside, forming the supporting structure 3 of the rim body 2. Further reinforcement layers 12 may be comprised inside.

[0064] FIG. 4a shows a schematic, perspective illustration of a non-woven layer and two prepreg layers 5a and 5b, which are joined together to form a composite layer 10, which is thereafter inserted into a manufacturing mold 50 to manufacture a bicycle rim 1.

[0065] FIG. 4b shows a schematic and sectional side view of the composite layer 10 on a backing 60. Firstly, a (first) prepreg layer 5a is positioned on the backing 60. Thereafter, a second prepreg layer 5b is disposed on the first prepreg layer 5a. Finally, the non-woven layer 9, which is very lightweight and thin and therefore difficult to drape, is placed, as wrinkle-free as possible, to form a composite layer of three layers, the composite layer 10. The stacked prepreg layers 5a, 5b and the non-woven layer 9 are pressed to one another. It is possible to vacuum impregnate the composite layer 10 so as to form a very homogeneous and very closely joined composite layer.

[0066] For producing large quantities, the composite layer 10 may be manufactured by way of automatically feeding prepreg layers 5a (and 5b) and at least one non-woven layer 9, which are unwound from separate rolls, and assembled and pressed together. Then, the composite layer 10 may be cut to the sizes required.

[0067] Using prepregs for the fiber layers 5a and 5b and the non-woven layer 9, causes these layers to adhere to one another, thus enabling a simple way of joint draping in the manufacturing mold 50.

[0068] As can be seen in FIG. 4a, the reinforcing fibers 6 of the two prepreg layers 5a and 5b run transverse to one another and thus on the whole allow increased stability of a bicycle rim 1 thus manufactured. The matrix material used is a resin material 7, so that no additional resin is needed for the composite layer 10 nor otherwise. The non-woven layer 9 comprises a fibrous material 16 in the shape of non-woven fibers 17. The non-woven fibers may be formed by short-fiber and/or long-fiber reinforcing fibers. The non-woven fibers 17 are homogeneously distributed over the surface of the non-woven layer 9, and disposed randomly and actually disordered relative to one another, and not woven nor braided.

[0069] FIG. 4b schematically shows the two prepreg layers 5a and 5b and disposed on the second prepreg layer 5b, the non-woven layer 9, which forms the visible outer surface of the finished component. It can be clearly seen that the thickness 9a of the non-woven layer 9 is considerably less than the wall thickness 3a of the supporting structure 3, which is formed by the prepreg layers 5a and 5b. In the exemplary embodiment, the thickness 9a of the non-woven layer 9 is less than 1/10 of the wall thickness 3a of the supporting structure 3, which in this case is formed only of the two prepreg layers 5a and 5b. Thus, the non-woven layer 9 provides only very little of the total weight of the bicycle rim 1.

[0070] FIGS. 5a bis 5c show three successive steps in manufacturing a rim, the bicycle rim 1. FIG. 5a schematically illustrates the two moldings 51 and 52 of the manufacturing mold 50. The composite layer 10 is inserted in the molding 51, such that the non-woven layer 9 covers the contact surface with the molding 51. Thus, the non-woven layer 9 provides what later is the outer, visible surface 8 of the finished rim 1, which is perceptible respectively visible in normal operation. After covering the first molding and the second molding and the ring part 53, the manufacturing mold 50 is closed, so as to obtain the condition shown in FIG. 5b. The interior of the rim 1 schematically shows an inflatable tube 18, which is pumped up to generate the required counterpressure from the inside.

[0071] The outside surfaces are provided on the rim flanks 21 and 22 and the rim base 23, with a (continuous or two-part right/left) non-woven layer 9, which is provided to form on what is to be the rim 1, the surface 8 of which can be directly seen from the outside.

[0072] After heating and curing the fibrous composite material, the manufacturing mold 50 can be opened. Then, the ring part 53 respectively its segments are removed radially outwardly, and the finished rim 1 can be taken out of the manufacturing mold 50.

[0073] Thereafter, the rim body 2 may be provided with spoke holes 25, and any excess resin may be removed. There is no need for extensive refinishing of the visible outer surface. FIG. 6 shows a schematic, perspective illustration of a rim 1. FIG. 6 shows the rim body 2 of the rim 1, schematically showing on the right the outer, non-woven layer 9 and the two prepreg layers 5a and 5b of the composite layer 10, and a reinforcement layer 12.

[0074] Overall, the invention provides high quality bicycle rims, the supporting structure of which is formed by prepreg layers 5. A high quality, visible outer surface 8 is provided by a thin, non-woven layer 9. The quantity of any optical defects is largely reduced, so as to provide the visible surface 8 largely without any postprocessing to the surface.

[0075] While a particular embodiment of the present bicycle rim and method of manufacturing have been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.

LIST OF REFERENCE NUMERALS

[0076] 1 bicycle rim, rim, bicycle component [0077] 2 rim body, component body [0078] 3 supporting structure [0079] 3a wall thickness [0080] 3b minimum wall thickness [0081] 3c maximum wall thickness [0082] 4 fibrous composite material [0083] 5 prepreg layer [0084] 5a first prepreg layer [0085] 5b second prepreg layer [0086] 6 reinforcing fibers [0087] 7 resin material [0088] 8 visible surface [0089] 9 non-woven layer [0090] 9a thickness of 9 [0091] 10 composite layer [0092] 11 outer layer of 10 [0093] 12 reinforcement layer [0094] 13 layer size [0095] 16 fibrous material of 9 [0096] 17 non-woven fibers [0097] 18 inflatable tube [0098] 21 rim flank [0099] 22 rim flank [0100] 23 rim base [0101] 24 rim well [0102] 24a radially outside surface [0103] 25 spoke hole [0104] 26 rim flange [0105] 27 rim flange [0106] 28 inner surface, visible surface [0107] 29 hollow space [0108] 30 handlebar [0109] 40 frame component [0110] 50 manufacturing mold [0111] 51 molding [0112] 52 molding [0113] 53 ring part [0114] 60 backing [0115] 100 bicycle [0116] 101 wheel, front wheel [0117] 102 wheel, rear wheel [0118] 103 frame [0119] 104 fork, suspension fork [0120] 105 rear wheel damper [0121] 106 handlebar, handle [0122] 107 saddle [0123] 109 spoke [0124] 110 hub [0125] 112 pedal crank