QUICKLY DETACHABLE AND ROTATABLE BICYCLE HANDLEBAR STEM

Abstract

The invention relates to a handlebar stem, which permits simple and quick loosening and twisting, as well as simple and safe resetting and fastening of said stem with the handlebar attached thereto. The problem of the invention is to provide a particularly simple, theft-proof and versatile alternative involving low manufacturing costs, and which can also easily be retrofitted. A stem set according to the invention comprises a stem and at least one locking device, which can be fixedly clamped to the steerer tube. According to the invention, the stem set is arranged, such that when mounted on the steerer tube, the locking device fixedly connected to the steerer tube prevents the stem from being pulled off the steerer tube. However, this can also be achieved, for example, by the stem engaging around and/or behind the locking device and/or the locking device engaging around and/or behind the stem.

Claims

1. A stem set for a bicycle with a round steerer tube, wherein the stem set comprises a stem with at least one releasable clamping clip adapted to enclose the steerer tube, and at least one clamping means for reversible and releasable clamping of the at least one clamping clip on the steerer tube; wherein the at least one clamping clip is arranged such that, in a position in which the at least one clamping clip is clamped on the steerer tube by the at least one clamping means, rotation of the stem about the steerer tube is prevented and, in a released position, rotation of the stem about the steerer tube is not prevented; wherein the at least one clamping means has a hand-grip section for manual movement, wherein the movement of the hand-grip section in a first direction or in a direction of rotation causes reversible clamping of the at least one clamping clip on the steerer tube by way of the clamping means; wherein the movement of the hand-grip section in a second direction or in a direction of rotation, causes reversible clamping release of the at least one clamping clip on the steerer tube, or is configured such that by way of the at least one clamping means, the at least one clamping clip is switchable from the clamped position to the released position or from the released position to the clamped position; wherein in the stem set has at least one locking device, which is fixedly connectable to the steerer tube; wherein the at least one locking device prevents the stem from being pulled off the steerer tube by limiting the movement of the stem along the steerer tube; and wherein the at least one locking device has a first locking device preventing pull-off which engages behind the stem, or the stem has at least one securing element, which engages behind the first locking device in order to prevent pull-off.

2. The stem set according to claim 1, wherein the at least one locking device or the stem has at least one first projection or at least one first recess for limiting the rotation of the stem on the steerer tube relative to the at least one locking device, when the stem set is mounted on the steerer tube; wherein the at least one first projection or the at least one first recess in the released position of the at least one clamping clip limits the rotation of the stem about the steerer tube to an angle of rotation of less than 360°.

3. The stem set according to claim 2, wherein the stem set is adapted, when mounted on the steerer tube in the released position of the at least one clamping clip, to allow for rotation of the stem about the steerer tube relative to the at least one locking device in a first direction of rotation into the rotational position of the stem relative to the at least one locking device predetermined by the limitation, but prevents rotation of the stem about the steerer tube relative to the at least one locking device in a second direction of rotation opposite the first direction of rotation without dismantling the stem set.

4. The stem set according to claim 3, wherein the at least one first recess or the at least one first projection, when the stem set is mounted on the steerer tube in the released position of the at least one clamping clip, allows for rotation of the stem about the steerer tube relative to the at least one locking device of at least 10°, and limits rotation of the stem about the steerer tube relative to the at least one locking device to less than 360°, such that rotation by 360° is feasible only upon dismantling the stem set.

5. The stem set according to claim 1, further comprising at least one locking member on the stem or on the at least one locking device, wherein the at least one locking member has a return member, the return member being arranged to pretension the at least one locking member in a first position and allow movement of the at least one locking member into a second position against a force exerted by the return member; wherein the stem set is arranged such that, in the released position of the at least one clamping clip, the at least one locking member in its first position does not restrict rotation of the stem, when the stem set is mounted on the steerer tube relative to the at least one locking device in a first direction of rotation, when moving the at least one locking member into the second position due to the parts of stem and the at least one locking device rotating relative to one another, but restricts rotation in a second direction of rotation opposite the first direction of rotation together with the at least one first recess or the at least one first projection, however, allows rotation after manually moving the at least one locking member into the second position.

6. The stem set according to claim 1, wherein, in the clamped position of the at least one clamping clip, the at least clamping means prevents rotation of the stem about the steerer tube up to a torque of 150 Nm being applied to the stem or wherein, in the clamped position of the at least one clamping clip, the stem is non-positively connected to the steerer tube, wherein the required torque for rotating the stem around the steerer tube is at least 150 Nm.

7. The stem set according to claim 1, wherein the at least one locking device encloses the steerer tube or has a tensioning screw, wherein the at least one locking device clamps on the steerer tube by means of the tensioning screw, such that rotation about and translation along the steerer tube is prevented, at least at a torque of less than 150 Nm or a translational force of less than 250 N.

8. The stem set according to claim 1, wherein the at least one locking device is arranged on the steerer tube directly below the stem.

9. A bicycle with the round steerer tube having the stem set according to claim 1 mounted on the steerer tube.

10. The stem set according to claim 1, for use on a single one piece round steerer tube of the bicycle.

11. The stem set according to claim 1, wherein the movement of the hand-grip section is accomplished by a human hand and without the use of tools.

12. The stem set according to claim 1, wherein the clamping means is one of a toggle clamp, a wing nut, a wing screw, a knurled screw and a tommy screw.

13. The stem set according to claim 1, wherein the at least one locking device is clamped to the steerer tube.

14. The stem set according to claim 1, wherein the at least one locking device is arranged on the steerer tube above the stem and is located between the stem and a first end of the steerer tube, and wherein the first end is opposite a second end closest to a blade of a fork.

15. The stem set according to claim 2, wherein the at least one first recess or the at least one first projection is formed or arranged such that the limitation, when being struck, defines a predetermined rotational position of the stem relative to the at least one locking device.

16. The stem set according to claim 5, wherein the at least one locking member fully prevents rotation of the stem when the at least one locking member is in the second position.

17. The stem set according to claim 7, wherein the tensioning screw is a direct or indirect tensioning screw.

18. The stem set according to claim 8, wherein the at least one locking device is located between the stem and the upper bearing cone.

19. The bicycle according to claim 9, wherein the round steerer tube is a single one piece steerer tube.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0035] The following purely schematic drawings and their description are intended to make it easier to understand the invention and do not restrict the invention. In the drawings:

[0036] FIG. 1a shows a lateral view of a first embodiment of a stem set according to the invention, when mounted on a steerer tube;

[0037] FIG. 1b shows a section through the stem of the stem set shown in FIG. 1a;

[0038] FIG. 1c shows a cross-section through a locking mechanism of the stem set shown in FIG. 1a;

[0039] FIG. 2a shows a lateral view of a second embodiment of a stem set according to the invention, when mounted on a steerer tube; and

[0040] FIG. 2b shows a cross-section through a locking mechanism of the stem set shown in FIG. 2a.

DETAILED DESCRIPTION

[0041] FIG. 1 a shows a lateral view of a stem set according to the invention, when mounted on a steerer tube 1. A ring-shaped securing device 3 is clamped on the steerer tube 1. Above this, a stem 2 is arranged on the steerer tube. The steerer tube 1 is nevertheless also shown for illustrative purposes, in the area where it is enclosed and hidden by the stem set. The steerer tube 1 ends slightly above the end of the stem 2. A fork is located at the opposite end of the steerer tube, which is not shown here.

[0042] The stem has clamping clips 5, with which it can be releasably clamped on the steerer tube 1 with the aid of the clamping means 9, which is configured as a wing screw. It further comprises a securing element 7, which is configured as hook-shaped and encloses the locking mechanism, which is clamped on the steerer tube 1 below the stem 2. The locking mechanism 3 has a nose-shaped projection 7, which limits rotation of the stem about the steerer tube 1 relative to the locking mechanism 3.

[0043] FIG. 1b shows a section through the stem in FIG. 1a. Clearly visible here are the clamping clips 9, which can be moved toward one another with the wing screw 9 in order to clamp the stem 2 on the steerer tube in a releasable manner. Visible is also that a thread 4 is provided on a clamping clip, into which thread 4, the wing screw 9 engages with its thread. Visible is also that a through-hole was combined in the other clamp with a larger blind hole allowing for a shoulder to be formed upon which, the wing screw protruding into the blind hole is supported. This blind hole makes it possible to exchange the wing screw 9 for a screw with a simple head, which can then be countersunk in the blind hole. For example, an Allen screw may be used in this case. This enhances safety, especially against sabotage, however, requires the use of a tool for transitioning between the clamped and released position of the stem.

[0044] FIG. 1c represents a cross-section through the locking mechanism 3 in FIG. 1a. Two grub screws 8 can be seen here, by means of which the locking mechanism 3 may be clamped onto a steerer tube, as shown in FIG. 1a. The projection 7 arranged on the surface of the locking mechanism is indicated by a dashed line.

[0045] In combination with FIG. 1, it can be seen that with the locking mechanism clamped on the steerer tube 1 by means of the grub screws 8, and with the wing screw 9 loosened, the stem can be rotated roughly 315° on the steerer tube, but cannot be removed from the steerer tube. Moreover, the stem can be clamped in any of the allowed rotational positions on the steerer tube by means of the wing screw, such that rotation around the steerer tube is no longer possible. It is also apparent that if the locking mechanism 3 is appropriately aligned before it is clamped on the steerer tube by means of the grub screws 8, a certain position, in particular the straight-ahead riding position, can be defined by the projection 7 by turning the stem until it strikes the projection, and thereby determine this position. Thus, in order to assume the preset position, it is important that the projection 7 be struck from the preset direction.

[0046] FIG. 2a shows a view identical to FIG. 1a, however, of an alternative embodiment of a stem set mounted on a steerer tube 1. Here, the steerer tube 1 protrudes slightly upward above the stem 2. A fork is located at the opposite end of the steerer tube, not shown here. A ring-shaped securing device 3 is clamped on the steerer tube 1. Above this, on the steerer tube, a stem 2 is arranged. The steerer tube 1 is nevertheless shown for illustrative purposes, including in the area where it is enclosed and hidden by the stem set.

[0047] The stem 2 has clamping clips 5, with which it can be releasably clamped on the steerer tube 1 with the aid of the clamping means 9, which is configured as a wing screw. It further has a securing element 7, which is configured as hook-shaped and encloses the locking mechanism clamped on the steerer tube 1 below the stem 2

[0048] FIG. 2b shows a cross-section through the locking mechanism 3 of FIG. 2a, wherein the sectional plane in FIG. 2a extends just below the setback 10, wherein the top view in FIG. 2a is seen from below, as indicated there by corresponding arrows on the dashed line of intersection. This also shows the extension of the setback 10, which is guided over roughly 100° on the outer circumference. Two grub screws 8 are likewise shown, by means of which it [unclear referent, likely the locking mechanism] can be clamped onto a steerer tube, as shown in FIG. 2a.

[0049] As can be seen in FIG. 2a, a securing element 7 of the stem extends in the setback 10, which is configured in the shape of a hook, and engages around the locking mechanism clamped on the steerer tube 1 below the stem 2.

[0050] Given that the setback 10, in which the securing element 7 engages, is only configured over a limited angular range, the freedom of rotation of the stem on the steerer tube is limited with respect to the securing device 3, in this case to approx. 90°. Depending on the mounting orientation of the securing device 3 on the steerer tube 1, a stop thus provided can make the straight-ahead riding position safe and easy to find.

[0051] Each of the figures shows a simple stem. However, the invention may also be used with more complex stems, e.g., those having a tilt and/or height adjustment.

REFERENCE NUMERAL LIST

[0052] 1 Steerer tube

[0053] 2 Stem

[0054] 3 Locking mechanism

[0055] 4 Thread

[0056] 5 Clamp clip

[0057] 6 Securing element

[0058] 7 Projection

[0059] 8 Locking mechanism clamp

[0060] 9 Clamping device

[0061] 10 Setback