Search

EP-4527726-B1 - BICYCLE STEM

EP4527726B1EP 4527726 B1EP4527726 B1EP 4527726B1EP-4527726-B1

Inventors

  • HENRY, GILLES
  • PROUST, FABIEN
  • CERVANTES, FRANCISCO

Dates

Publication Date
20260513
Application Date
20240913

Claims (12)

  1. A bicycle handlebar stem comprising: a handlebar stem body (9) to which a bicycle handlebar (3) can be fixed, and a base (19) designed to be fixedly connected to the steering pivot (8) of a bicycle (1), wherein the handlebar stem body (9) is connectable to the base (19); characterized in that the handlebar stem body (9) is detachably connectable to the base (19) by means of a bayonet fitting comprising at least one radial finger (37a, 37b) and at least one groove (46a, 46b), and wherein the bayonet fitting makes it possible to connect the handlebar stem body (9) to the base (19) by pushing the handlebar stem body (9) against the base (19), along an engagement axis (A), and then by rotating the handlebar stem body (9) relative to the base (19), about the engagement axis (A), each groove (46a, 46b) comprising a circumferential segment (36a, 36b) in the form of a circular arc about the engagement axis (A) and an axial segment (26a, 26b) parallel to the engagement axis (A), and each radial finger (37a, 37b) can be engaged and slide in the groove (46a, 46b) which corresponds to it, the bicycle handlebar stem further comprising a hook (33) mounted on the handlebar stem body (9) and designed to catch in a first notch (38) formed in the base (19) in order to immobilize the handlebar stem body (9) in a use position in which the handlebar stem body (9) is rotationally fixed to the base (19) about the engagement axis (A) and translationally fixed to the base along the engagement axis (A).
  2. The bicycle handlebar stem of claim 1, wherein each groove (46a, 46b) has an overall L shape.
  3. The bicycle handlebar stem of claim 1 or 2, wherein: the handlebar stem body (9) is hollow and the base (19) is designed to be engaged inside the handlebar stem body (9); and each radial finger (37a, 37b) projects into the handlebar stem body (9) and each groove (46a, 46b) is formed in the periphery of the base (19).
  4. The bicycle handlebar stem of claim 2 or 3, wherein: when each radial finger (37a, 37b) is engaged in the groove (46a, 46b) which corresponds to it and when the hook (33) is in an unhooked position, the handlebar stem body (9) can be rotated relative to the base (19), about the engagement axis (A), between the use position in which the radial finger (37a, 37b) is at one end of the circumferential segment (36a, 36b) and a disconnection position in which the radial finger (37a, 37b) is at the other end of the circumferential segment (36a, 36b) in line with the axial segment (26a, 26b); in the use position, the axial movement of the handlebar stem body (9) relative to the base (19) is prevented by the engagement of the radial finger (37a, 37b) in the circumferential segment (36a, 36b); from the disconnection position, the handlebar stem body (9) can be disconnected from the base (19) by sliding the radial finger in the axial segment (26a, 26b) so as to bring the radial finger (37a, 37b) out of the groove (46a, 46b).
  5. The bicycle handlebar stem of claim 4, wherein the hook (33) is designed to catch in a second notch (39) formed in the base (19) in order to immobilize the handlebar stem body (9) in the disconnection position.
  6. The bicycle handlebar stem of claim 4 or 5, wherein the use position and the disconnection position are angularly spaced by a rotational angle of 90°.
  7. The bicycle handlebar stem of claim 1 to 6, wherein: the handlebar stem body (9) comprises a fixing foot (41) of cylindrical overall shape about a first axis of revolution (B1); the base (19) comprises a fixing head (49) of cylindrical overall shape about a second axis of revolution (B2); the fixing foot (41) and the fixing head (49) are designed to be coaxially engaged in one another.
  8. The bicycle handlebar stem of claim 7, wherein: the fixing foot (41) comprises a sleeve (44) having the first axis of revolution as central axis (B1); and the fixing head (49) is designed to be coaxially engaged in the sleeve (44).
  9. The bicycle handlebar stem of claim 8, wherein: the handlebar stem body (9) comprises a central rod (30) extending in the centre of the sleeve (44) along the first axis of revolution (B1); the hook (33) is partially accommodated inside the central rod (30); a central hole (43) is formed in the fixing head (49) for receiving the central rod (30) when the fixing head (49) is engaged in the sleeve (44); and the first and/or the second notch (38, 39) is formed in the lateral wall (45) delimiting the central hole (43).
  10. The handlebar stem of claim 8 or 9, further comprising a clamping system for clamping the sleeve (44) against the fixing head (49) when the fixing head (49) is engaged in the sleeve (44).
  11. A bicycle comprising a handlebar (3), a steering pivot (8), and a handlebar stem according to any one of claims 1 to 10, the handlebar stem connecting the handlebar (3) to the steering pivot (8).
  12. The bicycle according to claim 11, comprising a front wheel and a handlebar stem according to claim 6, wherein, in the use position, the handlebar (3) is oriented perpendicular to the median plane of the front wheel and, in the disconnection position, the handlebar (3) is oriented parallel to the median plane of the front wheel.

Description

technical field The invention relates to a bicycle stem. This stem can be mounted on any type of bicycle. Background A bicycle stem is a component that connects a bicycle's handlebars to the steering pivot, also known as the fork steerer tube, at the top of the bicycle's fork. Some bicycles are equipped with a stem that allows the handlebars to be rotated 90° relative to the steering pivot, positioning them parallel to the median plane of the bicycle's front wheel. This eliminates the handlebars protruding beyond the front wheel, making the bicycle easier to store. Stems of this type are described, for example, in patent documents. NL 2005592 A And DE 102011054696 A1 However, these stems do not allow the handlebars to be quickly detached from the rest of the bicycle. Detaching the handlebars could prove useful for preventing the bicycle from being used (and thus reducing the risk of theft) or for facilitating its storage. Other examples of stems are described in the patent documents. CN 213831982 U , US 2020/277020 A1 , CN 109018151 A , CN 1631709 A , TW 201118000 A And CN 110435803 A . There is therefore a need for a bicycle stem that not only allows for simple modification (i.e., without having to dismantle any parts and without special tools) of the orientation of the handlebars relative to the steering pivot, but also allows for simple and quick detachment of the handlebars from the rest of the bicycle, while ensuring a robust and reliable mechanical connection between the handlebars and the steering pivot in the position of use. General presentation A bicycle stem according to the invention comprises a base adapted to be fixedly connected to the bicycle's steering pivot and a stem body to which the bicycle handlebars can be attached. The stem body is detachably connectable to the base by means of a bayonet fitting. The bayonet fitting allows the stem body to be connected to the base by pushing the stem body against the base, along an engagement axis, and then by rotating the stem body (in a first direction of rotation) relative to the base, around the engagement axis. Thus, the stem body The stem, and with it the handlebars, can be easily and quickly attached to the rest of the bicycle. This feature is referred to below as a "quick-release." Conversely, the bayonet fitting allows the stem body to be disconnected (i.e., detached) from the base by rotating the stem body (in the opposite direction to the initial rotation) around its pivot point and pulling the stem body axially away from the base. Thus, the stem body, and with it the handlebars, can be easily and quickly detached from the rest of the bicycle. This feature is referred to below as "quick release." Furthermore, the bayonet mount allows for easy adjustment of the handlebar orientation relative to the steering pivot, as explained in detail below. Finally, the bayonet mount offers the advantage of being both simple and robust. To reinforce the connection between the stem body and the base in the riding position, without compromising the quick-release mechanism, the bicycle stem also includes a hook mounted on the stem body. This hook is designed to engage in a first notch in the base to lock the stem body in the riding position. In the riding position, when the hook is engaged in the first notch, the stem body is fixed to the base, preventing rotation around the axis of engagement and translation along the axis of engagement. In other words, by engaging the hook in the first notch, the relative position between the stem body and the base is fixed, allowing the bicycle to be ridden. In some embodiments, the stem body is hollow and the base is adapted to be engaged inside the stem body. The bayonet fitting according to the invention comprises at least one radial finger and at least one groove. Each groove includes a circumferential segment in the form of an arc around the engagement axis and an axial segment parallel to the engagement axis. For example, each groove has the general shape of an L. Each radial finger can be engaged and slid into its corresponding groove. In some embodiments, each radial finger protrudes inside the hollow stem body and each groove is formed at the periphery of the base. The invention also relates to a bicycle comprising handlebars, a steering pivot, and a stem according to the invention, the stem connecting the handlebars to the steering pivot. The bicycle may have two or more wheels (bicycle, tricycle, etc.), be motorized or not (electric-assist bicycle, pedelec, moped, etc.), be foldable or not; the invention is not limited to any particular type of bicycle. Other features and advantages of the invention will become apparent from the detailed description that follows. This detailed description refers to the accompanying drawings. Brief description of the drawings The accompanying drawings are schematic and not necessarily to scale; their primary purpose is to illustrate the principles of the invention. In these dr