WO1989009156A1

WO1989009156A1 - Steering rod for a bicycle

Info

Publication number: WO1989009156A1
Application number: PCT/SE1989/000158
Authority: WO
Inventors: Holger Rosenblad; Lars-Göran ROSENBLAD
Original assignee: Husqvarna Inventor Ab
Priority date: 1988-03-24
Filing date: 1989-03-28
Publication date: 1989-10-05
Also published as: SE460784B; AU3361389A; SE8801082D0; SE8801082L

Abstract

A bicycle headset consisting of an upright member (1), which is rotatably journalled in the bicycle frame and is joined to the front fork for turning it and thereby for turning the front wheel of the bicycle, and a mounting member (7) having a mounting point (9) at which the handlebars (8) are removably mounted. At the top of the upright member it has a lateral portion (3), which extends transverse to the upright member. The mounting member consists of a separate unit having a mounting surface (18) which bears against a mounting surface (17) on the lateral portion (3) of the upright member (1). The mounting member is removably secured to the lateral portion (3) by means of a fastener (24). The mounting surface (18) of the mounting member is oriented in such a way, that it is displaced relative to a position of symmetry directly beneath the mounting position of the mounting member. The mounting member may be adjusted between a number of different positions relative to the lateral portion, in part by moving the mounting member relative to the mounting surface and securing it by means of the said fastener, and in part by turning the mounting member 180° about an axis (24), which extends transverse to the common general plane of the mounting surfaces.

Description

Steering rod for a bicycle

Field of the Invention:

The present invention relates to a bicycle headset con¬ sisting in part of an upright member, which is rotatably journalled in the bicycle frame and is joined with the front fork for turning it and thereby also turning the front wheel of the bicycle, and in part of a mounting member having a mounting point at which the handlebars are removably mounted, in addition to which the upright member has at its top a portion directed laterally rela¬ tive to the upright member.

Background Art:

Once a more or less correct frame size is chosen, a bicycle is adjusted to suit its user normally by verti¬ cally adjusting the saddle and the handlebars. Posi¬ tioning the handlebars at the correct height is gene¬ rally not a problem, but acheiving the correct distance between the saddle and the handlebars is complicated by the fact that the angle which the front fork and, thereby, the fork retaining sleeve, make with the horizontal is for reasons of steering geometry generally less than the angle of the saddle retaining tube. The fork retaining sleeve and the saddle retaining tube thus converge upwardly. This means that simultaneous raising of both the saddle and the handlebars will lessen the horizontal distance between them, whereas lowering them has the opposite effect. This is therefore the opposite of what would be desirable. The normal solution is for the cyclist to test a headset having a transverse por¬ tion with a suitable length, which may require the purchase of several units before a satisfactory result is achieved. This may be defensible in the case of com- petitive cycling, but for the every-day cyclist such a solution is too expensive and provides no simple possibility to adjust to two different users of the same bicycle.

The object of the present invention is to eliminate the above-mentioned problems by making it possible to adjust the mounting point for the handlebars relative to the longitudinal axis of the steering tube.

The Solution:

The stated object is achieved by means of a bicycle headset according to the present invention, which is characterized in that the mounting member is composed of a separate unit having a mounting surface which bears against a mounting surface on the lateral portion of the upright unit, and of fastening means, by which the moun¬ ting member is removably secured to the lateral portion; in that the mounting surface of the mounting member is so oriented, that it is displaced relative to a position of symmetry directly beneath the mounting point of the mounting member; and in that the mounting member is adjustable between a number of different positions rela¬ tive to the lateral portions, in part by moving the mounting member relative to the mounting surface of the upright unit and securing it by means of said fastening means, and in part by turning the mounting member 180° about an axis, which extends transverse to the common, principal plane of the mounting surfaces.

Brief Description of the Drawings:

A pair of exemplifying embodiments of the invention will now be described below with reference to the accompany- ing drawings, in which Fig. 1 is a partially broken side view of a first embodiment of a bicycle headset; Fig. 2 is a top view of the bicycle headset according to Fig. 1; and Fig. 3 is a side view of the bicycle headset with a mounting position reversed in relation to the position in Figs. 1 and 2. Figs. 4 and 5 show an alternative embodiment of the bicycle headset, where Fig. 5 is a section taken along the line V-V in Fig. 4.

Best mode of carrying out the Invention:

The bicycle headset according to the present invention is composed of an upright member 1 in the shape of a steering tube 2 having a lateral portion 3, whose principal extension is angled relative the longitudinal axis of the upright unit 1, which, for reasons of steering geometry, does not extend exactly vertically, but rather forms an angle of 70-72° relative to the horizontal. For the sake of simplicity, the steering tube 2 is shown broken and extends in the conventional manner through a sleeve-shaped portion of the bicycle frame and is securely joined with the front fork, in which the front wheel is rotatably journalled in a con¬ ventional manner. The steering tube 2 and the front fork are together journalled so as to be able to turn rela¬ tive to the sleeve-shaped portion of the bicycle frame. In practice, a tubular portion at the top of the fork is normally journalled in the sleeve-shaped portion of the bicycle frame so that the fork can normally not be dis¬ placed axially relative to the frame, whereas the steering tube 2 is secured in the fork and is adjustable vertically, i.e., the axial direction of the steering tube 2, for adjusting the height of the handlebars of the bicycle. This height adjustment thus leads to an undesirable change in the position of the handlebars relative to the saddle because of the required steering geometry. The lateral portion 3 is composed either of a portion forming an integral unit with the steering tube or, as shown in the example, a separate unit having a conical, downward facing cavity 4, into which a- cor¬ responding conical portion 5 of the steering tube extends. The lateral portion 3 is prevented from turning relative to the steering tube 2 by means of a screw 6, for example, a counter-sunk socket head cap screw, which is threaded in an internal portion of the steering tube in a conventional manner. The conical surfaces are pre- ferrably provided with lengthwise extending grooves.

The headset also has a mounting member 7 formed as a separate unit, which, according to the invention, may be mounted on the lateral portion 3 of the headset in different alternative adjustment positions. The mounting member 7 is intended to form a mount for the handlebars 8 which, for reasons of space, are indicated only by a broken portion, namely, the portion which is connected to the mounting member. The handlebars 8 may be of a conventional type adapted to the cycling style of the user. The mounting member 7 has a fastening arrangement in the shape of a opening 9 which extends through the fastening arrangement and has a shape which is adapted to the cross-sectional shape of the handlebars, usually a cylindrical shape, but other shapes are also possible. The mounting member is of the clamping type and is divi¬ ded into two portions 10, 11 to make it easier to turn the handlebars without threading the handlebars through the fastening arrangement 9 for reasons which will be described in greater detail below. Clamping action is made possible by the mounting member having surfaces 12, which face one another and which are arranged with a gap between them on one side of the fastening arrange¬ ment 9, which may be changed somewhat in order to change the diameter of the opening 9, whereby clamping action arises. On the other side of the opening the portions 10, 11 are separated by surfaces 13 and are held pressed against one another. Secure clamping is provided by means of a clamping screw 14, which extends through a hole 15 in the one portion 10 of the mounting member 7 and is screwed into a corresponding hole 16 in the -other portion 11. The head of the screw rests in a counterbore in the portion 10 and creates clamping pressure by the head bearing against a shoulder in the hole 15. As is shown in both Fig. 1 and Fig. 2, the lateral por¬ tion 3 of the upright member 1 has an upward facing mounting surface 17 for the mounting member 7. This mounting surface 17 extends mainly in a plane in the longitudinal direction of the lateral portion, in the illustrated example, mainly horizontally. The mounting member 7 has a corresponding downwardly facing mounting surface 18, but extends over a smaller distance in the said principal plane than the upwardly facing mounting surface. In the illustrated example, the two mounting surfaces are provided with transverse grooves, whereby the mounting surfaces 17, 18 are recessed and do not extend all the way out to the side surfaces 19, 20, 21,

22 of the lateral portion 3 and the mounting member 7, respectively, but rather have protective edge portions

23 so that there are no sharp portions with the risk of injury due to the exposed part of the mounting surface 17.

The mounting member 7 is held together with the lateral portion 3 of the upright member 1 by means of a fastener 24, which holds the mounting member 7 securely together with the lateral portion 3 but which makes it possible to loosen the mounting member 7 from the portion 3 for adjustment in a way which will be described in greater detail below. In the illustrated example, the fastener

24 consists of a screw which extends through a hole 25 through the two portions 10, 11 of the mounting member 7, and the head of the screw rests in a countersunk portion against a shoulder in the upper portion 10 of the mounting member. The lateral portion 3 also has an elongated opening 26 — a so called long-hole — through which the screw 24 extends, whereby the lateral portion 3 has a surface 27, which faces away from its mounting surface 17, i.e., faces downward, of a recess 28 in the lateral portion. This surface forms a shoulder and a bearing surface for a threaded nut 29 on the screw 24, 6 so that the screw 24 thus extends somewhat beyond the surface 27.

Tightening the nut 29 ensures in part that the two por¬ tions 10, 11 of the mounting member are held together, and in part that the mounting member is secured to the lateral portion 3 of the upright member 1 by the two mounting surfaces 17, 18 being pressed against each other, whereby the parts are clamped together and are locked in place. The mounting member may be given a chosen position relative to the upright unit 1 within a predetermined adjustment region by the mounting surface 18 of the mounting member 7 being placed against a desired place on the mounting surface 17 in order to achieve a desired position for the handlebars 8, which is chosen at a suitable distance from the saddle of the bicycle, so that the most correct and comfortable riding pasture is made possible for the user. The adjustment possibility in the horizontal direction thus makes it possible to choose the distance from the center 30 of the mounting arrangement 9 of the mounting member 7 to the imagined longitudinal axis 31 of the upright unit 1. Changing this distance is made possible within a first adjustment interval by directly moving the mounting member 7 relative to the lateral portion 3, and in particular by placing the mounting surface 18 of the mounting member at a predetermined position on the upwardly facing mounting surface 17. This is done by loosening the fastener 21 by loosening the nut 29 some¬ what, so that the mounting surfaces 17, 18 can separate somewhat so as to make it possible to move the mounting member 7 relative to the upwardly facing mounting sur¬ face 17. The screw 24 is thereby carried along in the movement in the long-hole 26, and when a chosen position has been assumed, the nut 29 is once again tightened. A conceivable re-adjusted position for the mounting member 7 is shown in Fig. 1 with dash-dotted line, in which only the contour of the mounting member is drawn. If the adjustment region described above is not enough, for example, in order to achieve less of a distance between the center 30 of the mounting arrangement 9 and the longitudinal axis 31 of the upright member l, one may according to the invention turn the mounting member 10 180^β about an axis which is perpendicular to the co mom general plane of the mounting surfaces 17, 18. In practice, this axis is represented by the screw 24, whose nut 29 is loosened, whereupon it becomes possible to turn the mounting member about the fastener 24, so that the mounting arrangement 9 is located on the opposite side of the screw 24. This effect is achieved by the mounting surface 18 of the mounting member 7 being located at a position which is displaced relative to a vertical position of symmetry through the center 30 of the mounting arrangement 9. This reversed position is shown in Fig. 3, which also shows how the adjustment region has been increased so as to be greater than the extension of the mounting surface 17. When the mounting member 7 is turned, the handlebars 8 must also be tur¬ ned around, which is made possible without having to draw the handlebars through the opening in the mounting member. Instead, the screw 14 and also the screw 24 are loosened enough that the two portions 10, 11 of the mounting member may be separated, whereupon at least the screw 14 is caused to leave the hole 16 in the lower portion 11, so that the handlebars may be guided through the space between the two surfaces 12; alterna¬ tively, so that the upper portion 10 of the mounting member may be completely removed, whereupon the handle¬ bars are turned and are replaced in the opening 9 of the mounting member. Thereafter, the two portions 10, 11 of the mounting member are secured to one another and -clamp the handlebars 8 by the screw 14 being screwed in and tightened, and also by the screw 24 being screwed in and the nut 29 being tightened, with the mounting member located at the desired position. At the same time the handlebars are turned, the mounting member is of course located at a chosen position relative to the mounting surface 17, so that a desired position for the center 30 of the mounting arrangement is achieved relative to the longitudinal axis 31 of the upright member 1. As Fig. 3 shows, this center 30 may be located near the longitudi¬ nal axis 31 of the upright unit, and may in principle even be allowed to be located beyond the longitudinal axis 31. This center should, however, lie in front of the longitudinal axis 31. The horizontal distance between the said center 31 and the turning axis 24 of the mounting member 7 should thus not exceed the hori¬ zontal distance over the mounting surface 17 between the said turning axis 24 (in its position closest to the longitudinal axis 31) and the longitudinal axis.

The embodiment according to Figs. 4 and 5 differs from that according to Figs. 1-3 by the screw 24 extending through the long-hole 26 being replaced by two screws 32, 33. The long-hole may in this way be deleted, and an individual tensioning of in part the two parts of the mounting member against each other, and in part the mounting member against the lateral portion 3. The moun¬ ting member here is provided with a sleeve portion 34, which encompasses the portion 3, whereupon the screw 33 is screwed into the sleeve portion and bears against a surface 35 on the underside of the portion 3.

The invention is not limited to the exemplifying embodi¬ ment described above and shown in the drawings, but may be varied within the scope of the following patent claims. It is for example envisioned that the shape- based locking using grooves may be replaced with fric¬ tion locking, i.e., that the mounting surfaces 1-7, 18 have a certain friction. It is also possible for the surfaces to be completely smooth, although this would require severe tightening of the mounting member rela¬ tive to the upright member. It is conceivable that this may be complemented using guide edges which only permit gliding of the surfaces in the direction of adjustment and only when the nut 29 is loosened enough to allow the described turning. The sides of the lateral portion may for example be provided with a graduated scale, with one scale member on the one side and another scale member on the other side of the lateral portion. The one scale is placed in the region of interest when the mounting member faces backwards, but the other member is used when the mounting member faces forwards. An index is provided on the mounting member across from this scale.

Claims

10Claims :

1. Bicycle headset consisting in part of an upright member (1) , which is rotatably journalled in the bicycle frame and is joined with the front fork for turning it and thereby also turning the front wheel of the bicycle, and in part of a mounting member (7) having a mounting point (9) at which the handlebars (8) are removably mounted, in addition to which the upright member has at its top a portion (3) directed laterally relative to the upright member, c h a r a c t e r i z e d in that the mounting member is composed of a separate unit having a mounting surface (18) which bears against a mounting surface (17) on the lateral portion (3) of the upright unit (1), and of fastening means (24, 33), by which the mounting member is removably secured to the lateral portion (3) ; in that the mounting surface (18) of the mounting member is so oriented, that it is displaced relative to a position of symmetry directly beneath the mounting point of the mounting member; and in that the mounting member is adjustable between a number of dif¬ ferent positions relative to the lateral portions, in part by moving the mounting member relative to the mounting surface of the upright unit and securing it by means of said fastening means, and in part by turning the mounting member 180" about an axis (24) , which extends transverse to the common, principal plane of the mounting surfaces.

2. Bicycle headset according to claim 1, c h a r a c t e r i z e d by said axis (24) being for¬ med of the fastening means for the mounting member -(7) . 11

3. Bicycle headset according to claim 2, c h a r a c t e r i z e d by the mounting member (7) being divided into two portions (10, 11) , which together form the mounting point (9) for the handlebars (8) .

4. Bicycle headset according to claim 3, c h a r a c t e r i z e d by said two portions (10, 11) being held together by the fastening means (24) for the mounting member (7) .

5. Bicycle headset according to claim 4, c h a r a c t e r i z e d by the fastening means (24) being composed of a screw, which extends through the mounting member (7) and through an elongated hole in the lateral portion (3) of the upright member (1) .

6. Bicycle headset according to claim 5, c h a r a c t e r i z e d by the mounting surface (17) of the lateral portion (3) being longer than the moun¬ ting surface (18) of the mounting member (7) .

7. Bicycle headset according to claim 6, c h a r a c t e r i z e d by the two mounting surfaces (17, 18) having transverse grooves.

8. Bicycle headset according to claim 7, c h a r a c t e r i z e d by the grooves being delimited at their ends by flat edge portions (23) .

9. Bicycle headset according to claim l, c h a r a c t e r i z e d by the mounting member (3) being formed with a sleeve portion (34) , into which the fastening means (33) is secured, whereby the fastening means bears against a surface (35) in the lateral- por¬ tion (3) .