Bicycle front derailleur with removable chain guide

Abstract

Bicycle front derailleur (10) comprising: a base element (12) configured and suitable to be attached to a bicycle frame (100), a chain guide (16) configured and suitable to engage a chain, a connecting structure (18) which connects the chain guide (16) to the base element (12) such that the chain guide (16) can move with respect to the base element (12), and a fastening structure (20) which removably fastens the chain guide (16) to the connecting structure (18) and / or the connecting structure (18) to the base element (12), wherein the fastening structure (20) comprises a first fastening element (20a) with a first part (26) and a second part (28), wherein the first part (26) of the first fastening element (20a) comprises a head portion (30) and a shaft portion (32) with an external thread, wherein the second part (28) of the first fastening element (20a) comprises a head portion (34) and a cylindrical portion (36) with an internal thread, wherein the internal thread is arranged in a through hole of the cylindrical portion (36), wherein the shaft portion (32) with external thread is received in the cylindrical portion (36) with internal thread.

Description

REFERENCE

[0001] This application claims priority to U.S. Application No. 13 / 780,482, filed February 28, 2013. The entire disclosure of that application is hereby incorporated by reference. FIELD OF THE INVENTION

[0002] The present invention relates to a bicycle front derailleur and, more particularly, to a bicycle front derailleur with a removable or detachable chain guide. BACKGROUND OF THE INVENTION

[0003] Bicycle front derailleurs are well-known and typically feature a chain guide that moves a chain from one chainring to another in response to rider input. Furthermore, there is a constant need to improve these bicycle front derailleurs.

[0004] French patent application FR 2 415 037 A1 discloses a rear or front derailleur for bicycles in which the support of the connecting rods of a four-bar linkage is formed by two parallel arms perpendicular to the frame and the crankset, between which the heads of the front and rear connecting rods are frictionally inserted, which rotate about axes transverse to the arms and are fixed to the latter by screwing.

[0005] The American patent application US 2011 / 0 218 067 A1 discloses a front derailleur of a bicycle comprising a retaining ring arranged at a lower end of a seat post, the retaining ring comprising two coupling seats, the coupling seat comprising a connecting rod set having a first, a second, a third and a fourth connecting rod, a shaft and the guide loop, the coupling seat comprising a first hole formed at a lower end of one side thereof such that a first screw is inserted through a first bore of the guide loop.

[0006] The German utility model DE 79 30 350 U1 further discloses an adjustment mechanism for a derailleur for sprockets arranged on a pedal crank, in particular on bicycles.

[0007] US 2006 / 0 189 422 A1 discloses a bicycle derailleur motor unit comprising a motorized front derailleur mounting member and a motor unit. The front derailleur mounting member is configured to be mounted to a bicycle frame. The front derailleur mounting member includes a front derailleur mounting portion configured to be connected to a front derailleur linkage and a motor unit mounting portion.

[0008] DE 10 2005 050 988 A1 shows a front derailleur consisting of a derailleur housing, a tube clamp, and a chain guide hinged to parallelogram arms. The shifting movement is transmitted to the chain guide by a cable via a pivoting transmission element. The shifting torque is supported on the frame tube by the derailleur housing, which is equipped with a support extension. The transmission element is pivotally attached to the derailleur housing with a pivot pin. The return spring is arranged around the pivot pin and is supported on the derailleur housing via a spring stop.

[0009] DE 29 48 378 A1 shows a bottom bracket sprocket shifting mechanism with an actuating element in the form of a four-bar linkage or a deformable parallelogram, which comprises two pivot arms pivotably mounted at their ends on two support members, the support members forming the other two arms of the deformable parallelogram. The support member is provided with a clamp for attachment to a tubular part of the bicycle frame, while the support member accommodates the fork, which, in a conventional manner, surrounds the load side of the chain in front of the chain wheels of different diameters of the bottom bracket.

[0010] US 2009 / 0 111 625 A1 shows a bicycle gear shift comprising a carrier element configured for mounting on a bicycle frame, a drive element for driving a bicycle chain, and at least one articulated arm for movably connecting the drive element to the carrier element. The articulated arm is connected to at least a portion of the carrier element and the drive element so that it can rotate about a corresponding axis of rotation via at least one corresponding connecting pin extending along the axis of rotation. At least one first rolling element is operatively arranged in the radial direction between the connecting pin, one of the articulated arms, the portion of the carrier element, and the drive element. OVERVIEW OF THE INVENTION

[0011] When a mechanic or professional performs maintenance on a bicycle front derailleur, it may be necessary to disassemble the bicycle front derailleur or at least remove part of it from a bicycle requiring maintenance without opening the chain.

[0012] An object of the present invention is accordingly to provide an improved bicycle front derailleur whose chain guide is detachably or releasably connected to the other parts of the bicycle front derailleur.

[0013] To achieve the present object, a bicycle front derailleur is provided, comprising a base member configured and adapted to be attached to a bicycle frame, a chain guide configured and adapted to engage a chain, a connecting structure connecting the chain guide to the base member such that the chain guide can move with respect to the base member, and a fastening structure removably fastening the chain guide to the connecting structure and / or the connecting structure to the base member.The fastening structure comprises a first fastening element with a first part and a second part, wherein the first part of the first fastening element has a head portion and a shaft portion with an external thread, wherein the second part of the first fastening element has a head portion and a cylindrical portion with an internal thread, wherein the internal thread is arranged in a through hole of the cylindrical portion, wherein the shaft portion with an external thread is received in the cylindrical portion with an internal thread.

[0014] Furthermore, a bicycle front derailleur is provided, which comprises a base member configured and suitable for being attached to a bicycle frame, a chain guide configured and suitable for engaging a chain, a connecting structure connecting the chain guide to the base member such that the chain guide can move relative to the base member, a fastening structure removably fastening the chain guide to the connecting structure and / or the connecting structure to the base member, and an electric motor unit operatively coupled to the connecting structure to move the chain guide. The fastening structure is formed by a first fastening element, a second fastening element, and a third fastening element, wherein the connecting structure comprises a first coupling element and a second coupling element.wherein one of the first coupling element and the second coupling element comprises one of the first fastening element, the second fastening element, and the third fastening element, and the other of the first coupling element and the second coupling element comprises the other two of the first fastening element, the second fastening element, and the third fastening element. The first coupling element connects the base element and the connecting structure, wherein the fastening structure removably fastens the chain guide to the connecting structure, and wherein a first part of the first, second, and / or third fastening element has a shaft portion and a head portion, wherein the shaft portion of the first part is screwed into a second part having a through hole such that one of the chain guide and the connecting structure is clamped between the head portion of the first part and the second part.

[0015] Further advantageous embodiments can be found in the dependent claims of the attached set of patent claims.

[0016] The invention, together with additional features and advantages thereof, will be explained in more detail by the description given hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a bicycle front derailleur mounted to a bicycle frame, in accordance with a preferred embodiment of the present invention; Fig. 2 is a perspective view of the bicycle front derailleur of the Fig. 1, the mounting portion thereof not being shown; Fig. 3 is a perspective view of the bicycle front derailleur of the Fig. 1, which shows an exploded view of a fastening structure; Fig. 4 is a cross-sectional view of a fastener that secures a portion of the chain guide to the connecting structure.

[0017] Like reference characters refer to the same or similar parts throughout the several views. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Selected embodiments are explained below with reference to the drawings. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the embodiments are provided for illustrative purposes only and not for the purpose of restricting or limiting the invention as defined by the appended claims and their equivalents.

[0019] With reference to Fig. 1, a bicycle front derailleur 10 essentially comprises a base member 12 having a mounting portion 14, a chain guide 16, a connecting structure 18, and a fastening structure 20 that removably or detachably fastens the chain guide 16 to the connecting structure 18. The mounting portion 14 is removably attached to the base member 12. In a further embodiment, the mounting portion 14 may be designed as a one-piece structure with the base member 12. The mounting portion 14 is clamped or fastened to a bicycle frame 100 in order to fasten the bicycle front derailleur 10 to the bicycle frame 100. It can be seen that the threaded fastening of the mounting portion 14 in Fig. 1 is not shown. Although the mounting portion 14 is illustrated as a clamp member in this embodiment, any type of mounting portion that secures the bicycle front derailleur 10 to the frame 100 may be used within the scope of this invention.

[0020] The connecting structure 18 connects the chain guide 16 to the base member 12 such that the connecting structure 18 allows the chain guide 16 to move relative to the base member 12. In a preferred embodiment, the connecting structure 18 includes a first coupling element 22 and a second coupling element 24. The chain guide 16 is removably attached to the first and second coupling elements 22 and 24 by means of the attachment structure 20. With reference to Fig. 2 to 3, the fastening structure 20 includes a first fastening element 20a, a second fastening element 20b, and a third fastening element 20c. In another embodiment, the fastening structure (e.g., any one or more fastening elements) may removably attach the fastening structure 18 to the base member 12.

[0021] As seen in Fig. 3 to 4, the first, second, and third fastening elements 20a, 20b, and 20c each comprise a first part 26 and a second part 28. Preferably, the first part 26 comprises a head portion 30 and a shaft portion with an external thread (hereinafter referred to as the "shaft portion") 32, and the second part 28 comprises a head portion 34 and a cylindrical portion with an internal thread (hereinafter referred to as the "cylindrical portion") 36. The shaft portion 32 is received or screwed into the cylindrical portion 36, and a portion of the chain guide 16 is clamped between the first part 26 and the second part 28. In a further embodiment, the connecting structure 18, and in particular one or both of the first and second coupling elements 22 and 24, can be clamped between the first part 26 and the second part 28.In particular, the shaft portion 32 of the first part 26 is screwed into the cylindrical portion 36 such that the portion of the chain guide 16 is clamped between the head portion 30 of the first part 26 and the distal end of the cylindrical portion 36 of the second part 28. In a preferred embodiment, as shown in . Fig. 3 to 4, the head portion 30 of the first part 26 has a projecting portion 26a which is received in a threadless portion 36a of the cylindrical portion 36.

[0022] As seen in Fig. 3, in a preferred embodiment, the first part 26 and the second part 28 have a tool engagement portion 37, such as an outer engagement surface (see head portion 34 of the second part 28) or a tool engagement opening (see head portion 30 of the first part 26).

[0023] In a preferred embodiment, the first coupling element 22 has pivot openings 22a and 22b defined therein. The pivot opening 22a enables pivotable attachment of the first coupling element 22 to the base element 12, and the pivot opening 22b enables pivotable attachment of the first coupling element 22 to the chain guide 16. In a preferred embodiment, the first fastening element 20a is received in and extends through the pivot opening 22b, and a pivot opening 16a is formed in the chain guide 16. In a preferred embodiment, the second coupling element 24 has pivot openings 24a and 24b defined therein. The pivot opening 24a ensures pivotable attachment of the second coupling element 24 to the base element 12, and the pivot opening 24b enables pivotable attachment of the second coupling element 24 to the chain guide 16.

[0024] In a preferred embodiment, the second fastening element 20b is received in and extends through the pivot opening 24b and a pivot opening 16b is formed in the chain guide 16. In a preferred embodiment, the first coupling element 22 also has pivot openings 22c and 22d defined therein. In a further embodiment, these pivot openings may be defined as a separate third coupling element. The pivot opening 22c enables pivotable attachment of the first coupling element 22 to the base member 12 and the pivot opening 22d enables pivotable attachment of the first coupling element 22 to the chain guide 16. In a preferred embodiment, the third fastening element 20c is received in and extends through the pivot opening 22d and a pivot opening 16c is defined in the chain guide 16.

[0025] With the arrangement as described above, shown in Fig. 4, the second coupling element 24 is pivotally arranged around the cylindrical portion 36 and is positioned between the chain guide 16 and the head portion 34 of the second part 28. Although only the second fastening element 20b in Fig. 4, it will be apparent to those skilled in the art that a similar arrangement exists between the first and third fastening elements 20a and 20c and the chain guide 16 and the first coupling element 22.

[0026] It should be appreciated that the bicycle front derailleur 10 may comprise between one and four fastening elements. In a preferred embodiment, as shown in Fig. 2, the derailleur has first, second, and third fastening elements 20a, 20b, and 20c. It will be apparent to those skilled in the art that the first and second coupling elements 22 and 24 (the connecting structure 18), which connect the base member 12 and the chain guide 16, form a four-bar linkage between the base member 12 and the chain guide 16, which allows movement of the chain guide 16 and thus a shifting operation. The connecting structure 18 may have third and / or fourth coupling elements, or the first coupling element 22 may have additional pivot points or openings for more than one additional fastening element. Any combination of coupling elements and fastening elements to form a joint, preferably a four-bar linkage, is to be considered within the scope of the present invention. Furthermore, as in Fig. As can be seen in Figures 2 to 3, the chain guide 16 includes a series (preferably a pair) of flanges or projections 42a and 42b. The pivot openings 16a and 16b are defined in the flange 42a, and the pivot opening 16c is defined in the flange 42b.

[0027] In a preferred embodiment, a first bushing 38a is arranged in a radial direction between the cylindrical portion 36 of the first fastening element 20a and the first coupling element 22. A second axis 38b is arranged in a radial direction between the cylindrical portion 36 of the second fastening element 20b and the second coupling element 24. A third bushing 38c is arranged in a radial direction between the cylindrical portion 36 of the third fastening element 20c and the first coupling element 22. As shown in Fig. 3, in this embodiment of the invention, the second part 28 of the first fastening element 20a may have an elongated cylindrical portion 36b disposed between the head portion 34 and the cylinder portion 36. As seen in Fig. 2, a spring 39 is mounted on the elongated cylindrical portion 36b.

[0028] As seen in Fig. 2, in a preferred embodiment, the bicycle front derailleur 10 includes an electric motor unit 40 having a motor 40a. The electric motor unit is operatively coupled to the connecting structure 18 to move the chain guide 16. More specifically, the electric motor unit 40 may be operatively coupled to one of the first coupling element 22 or the second coupling element 24, or both. Preferably, the electric motor unit 40 is mounted to the base member 12. However, this is not a limitation, as the electric motor unit 40 may be mounted elsewhere.

[0029] For the purpose of understanding the scope of the present invention, the term "comprising" and its derivatives, as used herein, are to be understood as open terms that specify the presence of the recited features, elements, components, groups, integers, and / or steps, but do not exclude the presence of other unspecified features, elements, components, groups, integers, and / or steps. The above also applies to words with similar meanings, such as the terms "comprising," "having," "having," and their derivatives. As used above to describe the embodiment(s), the following directional terms "front," "rear," "top," "bottom," "vertical," "horizontal," "below," and "transverse," as well as any other directional or positional specifications, refer to those of a bicycle equipped with the bicycle front derailleur.Accordingly, these terms used to describe bicycle front derailleurs are intended to be relative to a bicycle in a normal riding position on a flat surface. Furthermore, the terms "part," "section," "segment," "member," or "element," when used in the singular, may have the plural meaning of a single part or a plurality of parts. Finally, the extent terms, such as "substantially," "by," and "approximately," as used herein, mean a reasonable amount of variation from the modified term so that the end result is not significantly altered.

[0030] While certain features of the invention are set forth below in claim form, the inventors contemplate the various aspects of the disclosure under all possible claim numbers and forms. For example, while only one aspect of the invention has been recited as a functional claim, other features may also be set forth as functional claims or in other forms, such as embodied in machine-readable media. Accordingly, the applicant reserves the right to file additional claims after the filing of the application to pursue such additional claim forms or other features of the invention.

[0031] Accordingly, although exemplary embodiments of the invention have been described herein, it should be understood that the terms used herein are descriptive rather than limiting, and that various changes, modifications, and substitutions may be made by those skilled in the art without departing from the spirit and scope of the invention.

Claims

[1] Bicycle front derailleur (10) comprising: a base element (12) configured and suitable to be attached to a bicycle frame (100), a chain guide (16) configured and suitable to engage a chain, a connecting structure (18) which connects the chain guide (16) to the base element (12) such that the chain guide (16) can move with respect to the base element (12), and a fastening structure (20) which removably fastens the chain guide (16) to the connecting structure (18) and / or the connecting structure (18) to the base element (12), wherein the fastening structure (20) comprises a first fastening element (20a) with a first part (26) and a second part (28), wherein the first part (26) of the first fastening element (20a) comprises a head portion (30) and a shaft portion (32) with an external thread, wherein the second part (28) of the first fastening element (20a) comprises a head portion (34) and a cylindrical portion (36) with an internal thread, wherein the internal thread is arranged in a through-hole of the cylindrical portion (36), wherein the shaft portion (32) with external thread is received in the cylindrical portion (36) with internal thread. [2] Bicycle front derailleur (10) according to claim 1, wherein the attachment structure (20) removably attaches the chain guide (16) to the connecting structure (18). [3] Bicycle front derailleur (10) comprising: a base element (12) configured and suitable to be attached to a bicycle frame (100), a chain guide (16) configured and suitable to engage a chain, a connecting structure (18) which connects the chain guide (16) to the base element (12) such that the chain guide (16) can move relative to the base element (12), a fastening structure (20) which removably fastens the chain guide (16) to the connecting structure (18) or the connecting structure (18) to the base element (12), and an electric motor unit (40) operatively coupled to the connecting structure (18) to move the chain guide (16), wherein the fastening structure (20) is formed by a first fastening element (20a), a second fastening element (20b) and a third fastening element (20c), wherein the connecting structure (18) comprises a first coupling element (22) and a second coupling element (24), wherein one of the first coupling element (22) and the second coupling element (24) comprises one of the first fastening element (20a), the second fastening element (20b) and the third fastening element (20c), and the other of the first coupling element (22) and the second coupling element (24) comprises the other two of the first fastening element (20a), the second fastening element (20b) and the third fastening element (20c), wherein the first coupling element (22) connects the base element (12) and the connecting structure (18), wherein the fastening structure (20) removably fastens the chain guide (16) to the connecting structure (18), and wherein a first part (26) of the first, second and / or third fastening element (20a, 20b; 20c) has a shaft portion (32) and a head portion (30), wherein the shaft portion (32) of the first part (26) is screwed into a second part (28) having a through hole such that one of the chain guide (16) and the connecting structure (18) is clamped between the head portion (30) of the first part (26) and the second part (28). [4] Bicycle front derailleur (10) according to claim 3, wherein one of the first coupling element (22) and the second coupling element (24) is operatively coupled to the electric motor unit (40) and comprises two of the first fastening element (20a), the second fastening element (20b) and the third fastening element (20c). [5] Bicycle front derailleur (10) according to claims 1 to 4, wherein the fastening structure (20) comprises the first fastening element (20a) having the first part (26) and the second part (28), and wherein one of the chain guide (16) and the connecting structure (18) is clamped between the first part (26) and the second part (28). [6] Bicycle front derailleur (10) according to claims 1 to 3, wherein the connecting structure (18) has a first coupling element (22) and wherein one of the chain guide (16) and the first coupling element (22) is clamped between the first part (26) and the second part (28) of the first fastening element (20a). [7] Bicycle front derailleur (10) according to claim 5, wherein the fastening structure (20) further comprises a second fastening element (20b) having the first part (26) and the second part (28), wherein the connecting structure (18) further comprises a second coupling element (24) such that a four-bar linkage is formed between the base element (12) and the chain guide (16), and wherein one of the chain guide (16) and the second coupling element (24) is clamped between the first part (26) and the second part (28) of the second fastening element (20b). [8] Bicycle front derailleur (10) according to claim 6, wherein the second part (28) of the first fastening element (20a) further comprises a head portion (34), wherein the first coupling element (22) is pivotally arranged around a cylindrical portion (36) of the second part (28) of the first fastening element (20a) and is positioned between the chain guide (16) and the head portion (34) of the second part (28) of the first fastening element (20a). [9] Bicycle front derailleur (10) according to claim 6 or 7, wherein the second part (28) of the first fastening element (20a) further comprises a head portion (34), wherein the first coupling element (22) is pivotally arranged around a cylindrical portion (36b) of the second part (28) of the first fastening element (20a) and is positioned between the chain guide (16) and the head portion (34) of the second part (28) of the first fastening element (20a), wherein the second part (28) of a second fastening element (20b) further comprises the head portion (34), and wherein a second coupling element (24) is pivotally arranged around a cylindrical portion (36) of the second part (28) of the second fastening element (20b) and is positioned between the chain guide (16) and the head portion (34) of the second part (28) of the second fastening element (20b). [10] Bicycle front derailleur (10) according to claims 6, 7 or 8, wherein the fastening structure (20) further comprises a third fastening element (20c) having the first part (26) and the second part (28), and wherein one of the chain guide (16) and the first coupling element (22) is clamped between the first part (26) and the second part (28) of the third fastening element (20c). [11] The bicycle front derailleur (10) according to claim 10, wherein the second part (28) of the first fastening element (20a) further comprises a head portion (34), wherein the first coupling element (22) is pivotally arranged around a cylindrical portion (36) of the second part (28) of a third fastening element (20c) and is positioned between the chain guide (16) and the head portion (34) of the second part (28) of the first fastening element (20a), wherein the second part (28) of a second fastening element (20b) further comprises a head portion (34), wherein the second coupling element (24) is pivotally arranged around a cylindrical portion (36) of the second part (28) of the second fastening element (20b) and is positioned between the chain guide (16) and the head portion (34) of the second part (28) of the second fastening element (20b),wherein the second part (28) of the third fastening element (20c) further comprises a head portion (34), and wherein the first coupling element (22) is pivotally arranged around a cylindrical portion (36) of the second part (28) of the third fastening element (20c) and is positioned between the chain guide (16) and the head portion (34) of the second part (28) of the third fastening element (20c). [12] Bicycle front derailleur (10) according to one of claims 6 or 8; further comprising one or more of a) a first bushing (38a) arranged in a radial direction between a cylindrical portion (36) of the first fastening element (20a) and the first coupling element (22), b) a second bushing (38b) arranged in a radial direction between a cylindrical portion (36) of a second fastening element (20b) and the second coupling element (24), and c) a third bushing (38c) arranged in a radial direction between a cylindrical portion (36) of the third fastening element (20c) and the first coupling element (22). [13] Bicycle front derailleur (10) according to one of claims 1 to 3 or 5 to 11, wherein the chain guide (16) is clamped between one or more of a) the first part (26) and the second part (28) of the first fastening element (20a); b) the first part (26) and the second part (28) of a second fastening element (20b); and c) the first part (26) and the second part (28) of the second fastening element (20b) and the first part (26) and the second part (28) of a third fastening element (20c). [14] Bicycle front derailleur (10) according to one of claims 3, 4, 6, 8 or 12, further comprising an electric motor unit (40) which is configured and provided to move the chain guide (16) and is operatively coupled to the first coupling element (22). [15] Bicycle front derailleur (10) according to one of claims 1 to 13, further comprising an electric motor unit (40) configured and provided to move the chain guide (16) and operatively coupled to the connecting structure (18). [16] Bicycle front derailleur (10) according to claim 14 or 15, wherein the electric motor unit (40) is mounted on the base member (12).

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