GB2469290A

GB2469290A - Bicycle handlebar stem

Info

Publication number: GB2469290A
Application number: GB0906013A
Authority: GB
Inventors: Henry Rosenthal; Mark Anthony Reynolds
Original assignee: Renthal Ltd
Current assignee: Renthal Ltd
Priority date: 2009-04-07
Filing date: 2009-04-07
Publication date: 2010-10-13
Anticipated expiration: 2029-04-07
Also published as: GB2469290B; GB0906013D0

Abstract

For attaching a handlebar 30 to a front wheel steering tube 40, a clamp is provided which comprises two separate clamp members (10, 20). Each member provides a part cylindrical clamping surface (12, 22) for mounting opposedly to the other to clamp the handlebar 30 there between in a first clamping plane. Each member also has a respective collar clamp portion with opposing clamp jaws (14, 16 and 24, 26) extending in a plane substantially perpendicular to the first clamping plane in order to clamp around the steering tube 40.

Description

BICYCLE HANDLEBAR CLAMP

[0001] The present invention relates to a clamp for attaching a handlebar to a front wheel steering tube of a bicycle, particularly but not exclusively a mountain bicycle.

BACKGROUND

[0002] A handlebar clamp for a mountain bike typically clamps a central section of the handlebar at a location which lies in front of an upper end of the front wheel steering tube in the direction of travel of the bike. Therefore, the clamp connects to a substantially horizontally arranged handlebar in a first, substantially vertically disposed clamping plane, meaning that opposing clamping members or jaws are brought together in such a plane, but also connects, rearward of the handlebar connection, to the substantially vertically arranged stem in a second, substantially horizontally disposed clamping plane. Such a handlebar clamp is nowadays often referred to as "a stem", but in this document the more conventional term "clamp", which makes clear the function of this component is used.

[0003] Most known handlebar clamps for mountain bikes comprise two separate clamp members, each member providing a part cylindrical clamping surface for mounting opposedly to the other to clamp the handlebar there between in the aforesaid first clamping plane. One of the clamp members also extends to provide a split collar clamp for connecting to the stem in the second clamping plane. Thus, the split collar clamp is provided as a rear portion of only one of the clamp members, which portion has opposing clamp jaws arranged in a plane substantially perpendicular to the first clamping plane where the handlebar is held.

[0004] In the design of mountain bikes, particularly for competitive racing, but also more generally, minimising the weight of all components is desirable.

[0005] An object of the present invention is to provide an improved design of handlebar clamp for mountain bikes which is lighter in weight in any currently available but does not compromise the strength of the overall clamped connection made with the handlebar and the steering tube.

BRIEF SUMMARY OF THE DISCLOSURE

[0006] According to the present invention a bicycle handlebar clamp comprises two separate clamp members, as specified above, each providing a part cylindrical clamping surface for mounting opposedly to the other to clamp the handlebar there between, but is characterised in that each of these two clamped members has a respective collar clamp portion with opposing clamp jaws extending in a plane substantially perpendicular to the plane of clamping of the handlebar.

[0007] Thus, in preferred embodiments of the invention, the clamp is split into two similar parts (or members) which in use are an upper part and a lower part, each part having a completely separate collar clamp portion for encircling the steering tube, but providing half of the clamp portion for the handlebar as these respective halves cooperate to engage around the handlebar.

[0008] Surprisingly, providing the collar clamp portion for clamping the steering tube as two separate parts, namely the rearward portion of each one of the two clamp members does not diminish the strength of the overall clamped connection when both the clamp members are securely clamped to the handlebar and to the steering tube. By providing such a design of clamp it is possible to reduce the overall amount of material of the clamp, which is typically made of aluminium, and thereby reduce the overall weight.

Moreover, an added advantage to this design is that it is easier to manufacture two separate clamp members having the specified features, each with part of the handlebar clamp and each with a respective steering tube clamp, than manufacturing two members where one only has a larger, stronger steering tube clamp portion. Ease of manufacture tends to reduce costs of the finished product.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The invention is described further, by way of example, with reference to the accompanying drawings, in which: [0010] Figure 1 is a partial, perspective, exploded view of a practical embodiment of a clamp in accordance with the invention showing how it is to be connected to a handlebar and a steering tube of a bicycle; [0011] Figure 2 is an enlarged partial perspective view corresponding to figure 1 but showing the clamp fully assembled onto the handlebar and steering tube to connect same; [0012] Figure 3 is a top plan view of the upper clamp member of the clamp shown in figures 1 and 2; [0013] Figure 4 is a corresponding side view of the upper clamp member shown in figure 3; [0014] Figure 5 is a corresponding underside view of the upper clamp member shown in figure 3; [0015] Figure 6 is a top plan view of the lower clamp member shown in figures 1 and [0016] Figure 7 is a corresponding side view of the lower clamp member shown in figure 6; and [0017] Figure 8 is a corresponding underside view of the lower clamp member shown in figure 6

DETAILED DESCRIPTION

[0018] As illustrated, a practical embodiment of the clamp according to the invention comprises a first clamp member 10, which for purposes of this description is the upper clamp member shown in figures 1 and 2, and shown separately in figures 3, 4 and 5, and a second clamp member 20, which again for purposes of this description is the lower clamp member shown in figures 1 and 2, and shown separately in figures 6, 7 and 8.

[0019] The upper clamp member 10 has a front portion which provides an arcuate (or more accurately a part cylindrical) clamping surface 12 and a rear portion which provides a split collar clamp arrangement, namely respective opposing clamp jaws 14, 16. Between the front and rear portions is a central section 18 of enlarged height.

[0020] The lower clamp member 20 similarly has a front portion which provides a part cylindrical clamping surface 22 and a rear portion which provides a split collar clamp arrangement, namely respective opposing clamp jaws 24, 26. Again, just as for the upper clamp member, between the front and rear portions of the lower clamp member is a central section 28 of enlarged height.

[0021] As shown in figures 1 and 2, in use of the clamp, the upper and lower clamp members 10, 20, are brought together so that their respective central sections 18, 28 are in abutment and their respective part cylindrical clamping surfaces 12, 22 are disposed in opposition to clamp around a central section of a handlebar 30. Bolts 32 secure the central sections 18, 28 to each other and bolts 34 secure respective front ends of the upper and lower clamp members 10, 20 so that the clamp is secured around the handlebar 30 in this clamping disposition.

[0022] The clamp jaws 14, 16 of the upper clamp member 10 and the clamp jaws 24, 26 of the lower clamp member 20 are used to clamp around an upper end of a bike steering tube 40 by means of respective bolts 36 which urge respective opposing ends of jaws 14, 16 and of jaws 24, 26 towards each other in known manner. As shown, when the bike is upright, the steering tube 40 extends generally vertically while the handlebar 30 extends generally in a horizontal direction, but is offset at a spacing to the front of the steering tube 40. The respective clamp jaws 14, 16 and 24, 26 are spaced apart in their clamping locations on the steering tube 40. In other words, a gap remains between these clamp connections. It will be apparent that the plane of the clamp connections provided by the respective clamp jaws 14, 16 and 24, 26 to the steering tube 40 is substantially perpendicular to the plane of the clamp connection to the handlebar 30 by the clamping surfaces 12, 22.

[0023] It is apparent from the drawings that material is cut away from the central sections 18, 28 of the respective clamp members 10, 20 such that only flanking regions are brought into abutment as the handlebar 30 is clamped. This removal of material, as well as the gap provided between the split collar clamping jaws 14, 16 and 24, 26, minimises the weight of the overall clamp 10, 20. Compared to known mountain bike clamps it may be only 75% of the weight of same, for example about 150g instead of 200g, yet provides the same overall strength once the fully assembled connection is made, and the respective clamp members 10, 20 and their clamping jaws 14, 16 and 22, 26 are tightly clamped by means of the bolts 32, 34, 36 as shown in figure 2.

[0024] The invention is not restricted to the details of any foregoing embodiments and variations are possible, as will be apparent to any person skilled in the art, within the scope of the appended claims. For example, a gap between the split collar portions 14, 16 and 24, 26 of the respective clamp members 10, 20 is not essential, merely preferred.

[0025] Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of them mean "including but not limited to", and they are not intended to (and do not) exclude other components. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0026] Features described in conjunction with a particular embodiment or example of the invention are to be understood to be applicable to any other embodiment or example described herein unless incompatible therewith.

Claims

CLAIMS1. A bicycle handlebar clamp for attaching a handlebar to a front wheel steering tube, the clamp comprising two separate clamp members, each member providing a part cylindrical clamping surface for mounting opposedly to the other to clamp the handlebar there between in a first clamping plane, characterised in that each member also has a respective collar clamp portion with opposing clamp jaws extending in a plane substantially perpendicular to the first clamping plane in order to clamp around the steering tube.
2. A bicycle handlebar clamping arrangement comprising a front wheel steering tube and a handlebar which is clamped thereto by means of a clamp comprising two separate clamp members, each member providing a part cylindrical clamping surface mounted opposedly to the other and clamping the handlebar there between in a first clamping plane, and each member also having a respective collar clamp portion with opposing clamp jaws extending in a plane substantially perpendicular to the first clamping plane and clamping around the steering tube.
3. A clamping arrangement according to claim 2 wherein respective collar clamp portions of the two clamp members are spaced apart in their location of clamping around the steering tube.
4. A bicycle handlebar clamp for attaching a handlebar to a front wheel steering tube substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.
5. A bicycle handlebar clamping arrangement substantially as hereinbefore described with reference to and as illustrated in figures 1 and 2 of the accompanying drawings.