Bicycle compression ring assembly and installation procedure for said assembly

Abstract

The invention describes a bicycle compression ring assembly (1) configured to connect a bicycle headset bearing (RS) between the fork tube (H) and the frame (C). The assembly (1) comprises: an open outer ring (2) with a tapered inner wall (21); and an open inner ring (3) with a tapered outer wall (31). The tapered length of the outer wall (31) of the inner ring (3) and the tapered length of the inner wall (21) of the outer ring (2) have essentially the same taper, so that when the assembly (1) is mounted, the inner ring (3) fits into the outer ring (2) like a wedge, thereby compressing it against the bearing (RS).

Description

Bicycle compression ring assembly and installation procedure for said assembly Technical sector The present invention belongs to the field of bicycles, and more particularly to the elements used for the connection between the fork and the frame of a bicycle. A first aspect of the present invention is directed to an improved bicycle compression ring assembly relative to conventional compression rings. A second aspect of the present invention is directed to a procedure for installing the aforementioned compression ring assembly. State of the art A bicycle's steering system typically comprises a fork that rotates relative to the frame. As shown in Fig. 1, the fork (H) consists of a stanchion whose upper end is connected to the stem (P) and whose lower end branches into two arms, between which the front wheel (RD) is located. The fork stanchion (H) passes through the inside of a front tube of the frame (C) and is rotatably connected to it via a set of components commonly referred to as the "headset." The components of the headset are designed to prevent play between the frame (C) and the fork stanchion (H) while simultaneously allowing for substantially friction-free rotation to enable efficient and safe bicycle handling. Fig. 2 shows a longitudinal section of a conventional bicycle's steering system, illustrating the components that make up the steering.As can be seen, the fork leg (H) passes through the inside of the frame's head tube (C), connected to it by means of two bearings, the upper (RS) and lower (RI). In the case of the upper bearing (RS), the attachment to the frame (C) and fork (H) is achieved by friction, compressing the outer race of the bearing (RS) against the frame (C) and the inner race of the bearing (RS), via an annular piece called the "compression ring" (AC), against the fork (H). For this purpose, the compression ring (AC) is an open ring with a conical wall that acts as a wedge, thus ensuring sufficient compression force to prevent displacement of the upper bearing (RS). This configuration is shown in greater detail in the close-up view of Fig. 3, where the forces applied to the assembly during the assembly process are also represented by arrows.As can be seen, preload is applied essentially by pushing the frame (C) downwards relative to the fork (H), which has the effect of wedging the compression ring (AC) between the inner race of the upper bearing (RS) and the fork steerer tube (H). The compression ring (AC) may also have openings (A) to allow cable routing on high-end bicycles, as shown in the perspective view of Fig. 4. Fig. 4 also shows the open section (TA) of the compression ring (AC) which allows it to slightly increase or decrease its diameter to fit into position. One drawback of this system is the reduced contact area between the upper bearing (RS) and the compression ring (AC). In fact, the upper bearing (RS) and the compression ring (AC) typically only have a small section of tapered wall (PC) that remains in contact after the preload force (FP) is applied. Figure 5 shows how, when the preload force (FP) is applied, the compression ring (AC) slides relative to the upper bearing (RS) along the tapered wall (PC), slightly reducing its diameter, so that the vertical walls of both elements separate. Consequently, a gap (HU) is created between the vertical walls of both elements. The contact area is reduced to the tapered wall (PC), which is approximately 2 millimeters long. While this solution is adequate for most situations, when additional elements are introduced that add play to the steering, for example, when a fork angle adjustment system is implemented in the frame, instability can occur, causing play and noise. For this reason, there is a need in this field for an improved compression ring capable of ensuring a sufficiently firm and stable fixation of the upper bearing. Document TWM619006U describes an assembly for connecting a bearing between the fork tube and the bicycle frame, which has an outer ring without a circumferential opening. Summary of the invention The inventors of the present invention have overcome the aforementioned drawbacks by means of a compression ring assembly consisting of two rings, an inner and an outer ring, which fit together via complementary conical surfaces. In this way, the inner ring acts like a wedge, compressing the outer ring against the bearing. Furthermore, the outer ring has a cylindrical outer surface, so that it makes contact with the entire inner surface of the bearing's inner raceway. This solution significantly increases the contact surface between the compression ring assembly of the invention and the inner race of the bearing, thereby improving the firmness of the connection. In this document, the terms "upper," "lower," and similar terms are interpreted according to the natural orientation of the bicycle during use, which coincides with the orientation shown in the figures accompanying this document. In this document, the terms "inner," "outer," and the like are interpreted, unless the context clearly indicates otherwise, in accordance with the radial direction relative to the fork leg. In this document, the term "longitudinal" refers to the longitudinal direction of the fork leg. First aspect: compression ring assembly A first aspect of the present invention relates to a bicycle compression ring assembly configured to connect a bicycle headset bearing between the fork steerer tube and the frame. As mentioned above, this compression ring assembly replaces the conventional one-piece compression ring. The compression ring assembly of the present invention comprises the following elements: a) Outer ring It is an open outer ring comprising an inner wall and an outer wall. The inner wall comprises at least one conical section. The outer wall comprises a cylindrical wall configured to bear against an inner race of the bicycle's steering bearing. b) Inner ring It is an open inner ring comprising an outer wall and an inner wall. The outer wall comprises at least one conical section. The inner wall comprises a cylindrical wall configured to rest against an outer surface of the fork tube. These two rings are configured so that, when fitted into position, they generate a radial force that compresses the inner ring against the fork tube and the outer ring against the bearing, completely filling the gap and causing the tube, compression rings, and bearing to work together. To achieve this, the tapered section of the outer wall of the inner ring and the tapered section of the inner wall of the outer ring have essentially the same taper. Thus, when the assembly is mounted, the inner ring fits into the outer ring like a wedge and compresses it against the bearing. Preferably, the taper angle of the conical section of the inner wall of the outer ring and of the conical section of the outer wall of the inner ring is between 20° and 30°. The inventors of this application have found that this range of angles is particularly suitable for facilitating the fitting of the outer ring into the inner ring and the sliding of one over the other until reaching the final assembly position. In principle, both rings can be formed as a single piece, and naturally, in both cases they have an open section to allow their diameter to vary slightly so they can fit into position. In this case, the outer wall of the inner ring and the inner wall of the outer ring are typically entirely conical. However, in a particularly preferred embodiment of the invention, the inner ring is divided into a first portion and a second portion physically separated and configured to be installed in essentially diametrically opposed positions to each other. In this case, preferably the outer wall of the first portion of the inner ring is cylindrical, and the inner wall of the outer ring section into which this first portion of the inner ring fits is also cylindrical. More preferably, the outer wall of the second portion of the inner ring is conical, and the inner wall of the outer ring section into which this second portion fits is also conical. Thus, in this configuration, the second portion of the inner ring acts as a wedge, compressing the assembly to firmly secure the bearing. In either case, the rings that make up the described compression ring assembly may have an essentially constant cross-section along their entire diameter. However, to provide space for cables to pass into the fork tube, the inner wall of the outer ring may include a first, thin-walled recess. Similarly, also to allow cables to pass into the fork tube, the outer wall of the inner ring may include a second, thin-walled recess. Furthermore, by appropriately selecting the relative radial positions of the inner and outer rings, it is possible to align the reduced-thickness gap of one with the open section of the other. This results in a wider conduit for cable passage. Specifically, the rings can be arranged so that the second gap of the inner ring and the first gap of the outer ring are positioned radially to coincide, respectively, with the radial position of an open section of the outer ring and the radial position of an open section of the inner ring. Furthermore, openings and open sections whose radial positions coincide can have similar radial extensions. Thus, each cable duct takes the form of an annular section of the largest possible size. Specifically, the second opening of the inner ring and the first opening of the outer ring can have radial extensions that coincide, respectively, with the radial extension of the open section of the outer ring and the radial extension of the open section of the inner ring. Second aspect: installation procedure A second aspect of the present invention relates to a method for installing a bicycle compression ring assembly as described in the preceding paragraphs. This method essentially comprises the following steps: 1. Fit the outer ring into the bearing so that the cylindrical outer wall of the outer ring contacts the inner race of the bearing. 2. Insert the inner ring into the outer ring in a longitudinal direction, so that the conical outer wall of the inner ring rests against the conical inner wall of the outer ring. 3. Apply a preload in the longitudinal direction on the inner ring, so that the inner ring is pushed further into the outer ring and the sliding of the conical outer surface of the inner ring against the conical inner surface of the outer ring causes a radially outward oriented force that compresses the outer ring against the inner race of the bearing. According to a particularly preferred embodiment, the method of the invention further comprises the step of aligning the position of the second hole in the inner ring with the open section of the outer ring and the position of the first hole in the outer ring with the open section of the inner ring. Brief description of the figures The details of the invention are shown in the accompanying figures, which are not intended to limit the scope of the invention: Figure 1 shows a view of the front portion of a bicycle according to the prior art. Figure 2 shows a longitudinal section of the steering mechanism of a bicycle according to the prior art. Fig. 3 schematically shows the procedure for installing a conventional compression ring on a bicycle according to the prior art. Fig. 4 shows a perspective view of the conventional compression ring already installed on a bicycle according to the prior art. Figure 5 shows a longitudinal section illustrating how the conventional compression ring fits with the steering bearing of a bicycle according to the prior art. Figure 6 shows a longitudinal section illustrating a first embodiment of the compression ring assembly of the present invention installed on a bicycle. Fig. 7 shows the first embodiment of the compression ring assembly according to the present invention where the inner ring is a single piece. Fig. 8 shows a second embodiment of the compression ring assembly according to the present invention where the inner ring is formed by two pieces. Detailed description of the invention The invention is described below with reference to Figures 6-8, which show a preferred embodiment of bicycle compression ring assembly (1). In particular, Figures 6 and 7 show a first embodiment of a bicycle compression ring assembly (1), respectively mounted and unmounted. The assembly (1) comprises an outer ring (2) and an inner ring (3). Both rings (2, 3) are open, i.e., they are not completely closed circles but have open sections (TA2, TA3). Specifically, the inner ring (2) comprises an open section (TA2), and the outer ring (3) comprises an open section (TA3). These open sections allow the ring (2, 3) to slightly increase or decrease its diameter when it is inserted into its position in the direction of the bicycle. The outer ring (2) has a radially inner wall (21) of conical shape and a radially outer wall (22) of cylindrical shape. The cylindrical outer wall (22) has a diameter configured to fit into the inner race of the upper bearing (RS) of the bicycle's steering head. In addition to these two walls (21, 22), the outer ring (2) also has a flange (24) located on its upper wall that projects radially outward relative to the outer wall (22). When the assembly (1) is installed, this flange rests against the upper side of the bearing (RS) in the axial direction, thus preventing the assembly (1) formed by the two compression rings (2, 3) from moving downwards when preload is applied. The inner ring (3) has a radially outer wall (31) that is conical in shape and a radially inner wall (32) that is cylindrical in shape. The cylindrical inner wall (32) has a diameter configured to fit over the fork bar (H, not shown in Fig. 6). The tapered walls (21, 31) of the outer ring (2) and inner ring (3) are configured to interlock. Specifically, the tapered walls (21, 31) increase in diameter longitudinally as they ascend. This allows the inner ring (3) to be lowered longitudinally and inserted into the outer ring (2). Once the tapered walls (21, 31) are in contact, applying a downward longitudinal force firmly locks the inner ring (3) into the outer ring (2). As a result, the inner ring (3) radially pushes the outer ring (2) outward, compressing it against the inner race of the upper bearing (RS). Indeed, since the inner wall (32) of the inner ring (3) rests against the yoke (H, not shown in Fig. 6), its diameter cannot be reduced despite its open section (TA3).Therefore, as its conical outer wall (31) moves downwards, it slides against the conical inner wall (21) of the outer ring (2), pushing the outer ring (2) radially outwards. For this to occur, the taper angle of both conical walls (21, 31) is usually essentially the same. This configuration significantly increases the contact surface between the compression ring assembly (1) and the upper bearing (RS). The contact surface between the two rings (2, 3) is also much larger compared to the mere 2 millimeters of contact in the prior art. This results in a more rigid and secure connection. Both rings (2, 3) also have recesses (23, 33) to facilitate the passage of cables into the fork tube (H). Specifically, the inner wall (21) of the outer ring (2) comprises a first recess (23) of reduced thickness, and the outer wall (31) of the outer ring (3) comprises a second recess (33) of reduced thickness. That is, both rings (2, 3) have reduced thickness in these recesses (23, 33) thanks to a recess in their respective inner (21) and outer (31) walls. Thanks to this configuration, if the position of the holes (23, 33) of one of the rings (2, 3) is aligned with the position of the open section (TA2, TA3) of the other ring (2, 3), a wide conduit for cable passage is achieved. This configuration is shown in Fig. 7, where the first hole (23) of the outer ring (2) aligns with the position of the open section (TA3) of the inner ring (3), and the second hole (33) of the outer ring (3) aligns with the position of the open section (TA2) of the outer ring (2). In this particular embodiment, the radial extension of the first hole (23) also aligns with the radial extension of the open section (TA3), and the radial extension of the second hole (33) aligns with the radial extension of the open section (TA2). The installation of a compression ring assembly (1) according to this first embodiment of the invention in the upper bearing (RS) of a bicycle steering system would be carried out as follows. First, the outer ring (2) is inserted into the bearing (RS) so that the cylindrical outer wall (22) of the outer ring (2) contacts, or is at least adjacent to, the inner race of the bearing (RS). Next, the inner ring (3) is inserted into the outer ring (2) by sliding it longitudinally downwards as shown in Fig. 6. Once inserted, the conical outer wall (31) of the inner ring (3) contacts the conical inner wall (21) of the outer ring (2). Finally, the inner ring (3) is pushed downwards as shown in Fig. 6.The thrust force, or preload, can be applied directly to the inner ring (3), or indirectly by compressing the steering assembly in a known manner. In either case, the effect of this longitudinal force, which tends to draw the inner ring (3) into the outer ring (2), is that the tapered surfaces (21, 31) slide over one another. Since the diameter of the inner ring (3) is fixed by the fork tube (H), it is the outer ring (2) that slightly increases in diameter, pushing radially against the inner race of the upper bearing (RS). The result is that the fork tube (H), the two compression rings (2, 3), and the bearing (RS) are joined together in a single, tight unit. Fig. 8 shows a second preferred embodiment of the compression ring assembly (1) also formed by an outer ring (2) essentially the same as in the previous preferred embodiment and an inner ring (3) which, in this case, is divided into two physically separate portions: a first portion (3a) and a second portion (3b). The first portion (3a) has a greater radial extent than the second portion (3b), in this example approximately 180°, and both walls, inner (31) and outer (32), of this first portion (3a) are cylindrical. Consequently, the section of inner wall (21) of the outer ring (2) into which this first portion (3a) of the inner ring (3) fits is also cylindrical. The second portion (3b) has a smaller radial extent, in this example around 40°–60°. The inner wall (32) of the second portion (3b) is cylindrical, while the outer wall (31) of the second portion (3b) is conical. Consequently, the section of the inner wall (21) of the outer ring (2) into which this second portion (3b) of the inner ring (3) fits is also conical. This configuration works essentially the same way as the preferred embodiment described above. The outer ring (2) is first inserted in a manner similar to that described above. Next, the first portion (3a) of the inner ring (3) is inserted so that its cylindrical outer wall (31) coincides with the cylindrical section of the inner wall (21) of the outer ring (2). Since both elements contact each other via parallel cylindrical walls, the first portion (3a) of the inner ring (3) fits easily and completely inside the outer ring (2). The second portion (3b) of the inner ring (3) is then inserted in the position where its conical outer wall (31) coincides with the conical section of the inner wall (21) of the outer ring (2). This second portion (3b) of the inner ring (3) is pushed longitudinally (vertically downwards, as shown in Fig.8) to cause its conical outer wall (31) to act as a wedge that compresses the outer ring (2) against the bearing (RS).

Claims

1. A bicycle compression ring assembly (1) configured to connect a bicycle headset bearing (RS) between the fork tube (H) and the frame (C), characterized in that it comprises: - an outer ring (2) comprising an inner wall (21) and an outer wall (22), wherein said inner wall (21) comprises at least one conical section and said outer wall (22) comprises a cylindrical wall configured to bear against an inner race of the bicycle headset bearing (RS); - an open inner ring (3) comprising an outer wall (31) and an inner wall (32), wherein said outer wall (31) comprises at least one conical section and said inner wall (32) comprises a cylindrical wall configured to bear against an outer surface of the fork tube (H),wherein the tapered section of the outer wall (31) of the inner ring (3) and the tapered section of the inner wall (21) of the outer ring (2) have essentially the same taper such that, when the assembly (1) is mounted, the inner ring (3) fits into the outer ring (2) like a wedge and compresses it against the bearing (RS), characterized in that the outer ring (2) is an open outer ring (2) comprising an open circumferential section (TA2) that allows its diameter to vary slightly to fit properly into position.

2. Bicycle compression ring assembly (1) according to claim 1, wherein the taper angle of the tapered section of the inner wall (21) of the outer ring (2) and of the tapered section of the outer wall (31) of the inner ring (3) is between 20° and 30°.

3. Bicycle compression ring assembly (1) according to any of the preceding claims,where the inner ring (3) is divided into a first portion (3a) and a second portion (3b) physically separated and configured to be installed in essentially diametrically opposite positions.

4. Bicycle compression ring assembly (1) according to claim 3, wherein the outer wall (31) of the first portion (3a) of the inner ring (3) is cylindrical and the inner wall (21) of the outer ring section (2) into which said first portion (3a) of the inner ring (3) fits is also cylindrical.

5. Bicycle compression ring assembly (1) according to any of claims 3-4, wherein the outer wall (31) of the second portion (3b) of the inner ring (3) is conical and the inner wall (21) of the outer ring section (2) into which said second portion (3a) fits is also conical.

6. Bicycle compression ring assembly (1) according to any of the preceding claims,wherein the inner wall (21) of the outer ring (2) comprises a first recess (23) of reduced thickness configured to allow the passage of cables into the fork tube (H).

7. Bicycle compression ring assembly (1) according to any of the preceding claims, wherein the outer wall (31) of the inner ring (3) comprises a second recess (33) of reduced thickness configured to allow the passage of cables into the fork tube (H).

8. Bicycle compression ring assembly (1) according to claim 7 when the latter depends on claim 6.wherein the second hole (33) of the inner ring (3) and the first hole (23) of the outer ring (2) are arranged in radial positions configured to coincide respectively with the radial position of an open section (TA2) of the outer ring (2) and with the radial position of an open section (TA3) of the inner ring (3).

9. Bicycle compression assembly (1) according to claim 8, wherein the second hole (33) of the inner ring (3) and the first hole (23) of the outer ring (2) have radial extensions that coincide respectively with the radial extension of the open section (TA2) of the outer ring (2) and with the radial extension of the open section (TA3) of the inner ring (3).

10. Method of installing a bicycle compression ring assembly (1) according to any of the preceding claims.the method comprising the following steps: - fitting the outer ring (2) into the bearing (RS) so that the cylindrical outer wall (22) of the outer ring (2) contacts the inner race of the bearing (RS); - inserting the inner ring (3) into the outer ring (2) in a longitudinal direction, so that the conical outer wall (31) of said inner ring (3) rests against the conical inner wall (21) of the outer ring (2); and - applying a preload in the longitudinal direction on the inner ring (3),so that said inner ring (3) is further inserted into the outer ring (2) and the sliding of the conical outer surface (31) of the inner ring (3) against the conical inner surface (21) of the outer ring (2) causes a radially outward oriented force that compresses the outer ring (2) against the inner race of the bearing (RS).

11. Method according to claim 10 wherein the bicycle compression ring assembly (1) conforms to any of claims 8 or 9, comprising the step of aligning the position of the second recess (33) of the inner ring (3) with the open section (TA2) of the outer ring (2) and the position of the first recess (23) of the outer ring (2) with the open section (TA3) of the inner ring (3).

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