WO2002081291A2

WO2002081291A2 - Bicycle seat post and stem

Info

Publication number: WO2002081291A2
Application number: PCT/US2002/010911
Authority: WO
Inventors: Chuck Dunlap
Original assignee: Yeti Cycling, Llc
Priority date: 2001-04-04
Filing date: 2002-04-04
Publication date: 2002-10-17

Abstract

A seat post comprises a head with tapered openings therein, and correspondingly tapered wedge members adapted to fit therein. Clamp members cooperate with the wedge members to define seat rail receiving clamps, whereby a through bolt and nut are tightened to secure the seat rail to the head. A bicycle stem includes a wedge member and corresponding indentation defined in a lower portion of a hollow stem tube, carried on a stem body. The stem body included a bolt that engages the wedge via a through bore from the upper portion of the stem body into the indentation, whereby the wedge may be pulled tighter into the indentation. The wedge has a fork tube engaging surface profile on a face opposite the face engaging the indentation.

Description

BICYCLE SEAT POST AND STEM

Background of the Invention This invention relates to seat posts, and more particularly for a seat post for a bicycle or the like for enabling securing of a seat to the bicycle, and to a bicycle stem.

In bicycle construction, some manner of engagement between the bicycle handle and the front wheel forks must be employed in order to enable the rider to steer the bicycle. Also, some manner to mount the seat to the bicycle is required.

Summary of the Invention In accordance with the invention, a seat post assembly includes a head with left and right tapered openings and corresponding tapered wedge members which fit in the head tapers. Clamps cooperate with the wedge members to define seat rail receiving clamps, and a through bolt and nut tightened the head/wedge/clamp structure to secure the seat rail to the head. In accordance with another aspect of the invention, a bicycle stem employs a vertically aligned bore in the stem which is adapted to engage with a bicycle fork tube. Within the bore is an indentation, adapted to receive a correspondingly shaped wedge therein. The wedge is threadably engaged by a bolt member, the bolt passing through the stem. On tightening or loosening of the bolt, the wedge is pulled into or out of the indentation. The wedge includes a fork tube engaging portion to tightly engage the fork tube to secure the stem and fork tube, when the bolt is tightened.

Accordingly, it is an object of the present invention to provide an improved seat post. It is a further object of the present invention to provide an improved seat post which resists rotation.

It is yet another object of the present invention to provide an improved an improved seat post employing tapered wedge parts which resist rotation.

It is also an object of the present invention to provide an improved bike stem.

It is a further object of the present invention to provide an improved bike stem employing a substantially vertically moving wedge member.

It is yet another object of the present invention to provide an improved bike stem clamp mechanism for attaching the handle bars of a bike to a steerer tube.

The subject matter of the present invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, both the organization and method of operation, together with further advantages and objects thereof, may best be understood by reference to the following description taken in connection with accompanying drawings wherein like reference characters refer to like elements.

Both the organization and method of operation, together with further advantages and objects thereof, may best be understood by reference to the following description taken in connection with accompanying drawings wherein like reference characters refer to like elements.

Brief Description of the Drawings

FIG. 1 is a perspective view of the seat post assembly according to the invention;

FIG. 2 is an end view of the seat post assembly of FIG. 1 taken in the direction of arrow 2 in FIG. 1 ; FIG. 3 is a side view of the seat post assembly of FIG. 1 taken in the direction of arrow 3 in FIG. 1 ;

FIG. 4 is a top view of the seat post assembly of FIG. 1 taken in the direction of arrow 4 in FIG. 1 ;

FIG. 5 is an exploded perspective view of the seat post assembly of FIG. 1 ;

FIG. 6 is an exploded view of the seat post assembly of FIG. 2 ;

FIG. 7 is an exploded side view of the seat post assembly of FIG. 3; FIG. 8 is an exploded top view of the seat post assembly of FIG. 4 ;

FIG. 9 is a perspective view of the seat post assembly illustrating seat rails 38 in phantom, showing their cooperation with the wedges and clamps; FIG. 10 is a side view showing a seat schematically in a manner as would be mounted to with the seat post clamp;

FIG. 11 is an exploded perspective view of the bicycle stem according to the present invention; FIG. 12 is a top exploded view of the bicycle stem;

FIG. 13 is a side exploded view of the bicycle stem;

FIG. 14 is an end exploded view of the bicycle stem taken in the direction of arrow 4 of FIG. 11;

FIG. 15 is a bottom exploded view of the bicycle stem;

FIG. 16 is a solid top exploded partial perspective view of the bicycle stem; FIG. 17 is a solid top exploded complete perspective view of the bicycle stem;

FIG. 18 is a solid bottom exploded complete perspective view of the bicycle stem;

FIG. 19 is another solid top exploded part perspective view of the bicycle stem taken from a different angle from the view of FIG. 17; and

FIG. 20 is another solid top exploded part perspective view of the bicycle stem taken from a different angle from the view of FIG. 18.

Detailed Description The seat post system according to a preferred embodiment of the present invention comprises wedge shaped parts that lock into tapered holes, for resisting rotation.

The bike stem system according to a preferred embodiment of the present invention comprises a wedge member and corresponding indentation defined in a hollow stem. The stem body includes a bolt that engages the wedge, whereby the wedge may be pulled tighter into the indentation. The wedge has a tube engaging surface on a face opposite the face engaging the indentation, whereby a secure engagement between the tube and the stem is provided by tightening the bolt.

Referring to FIG. 1, a perspective view of the seat post in assembled form and to FIG. 5, an exploded perspective view of the seat post, an elongate tubular post member 12, adapted to be received and secured to a bicycle frame (not shown) for example, has a head 14 secured thereto, typically by gluing or other suitable manner. The head includes an opening 16 that passes therethrough, and which carries 'an inwardly tapered portion at each side of the opening, being wider at the outermost edge and tapering inwardly and narrower towards the center of the head. A pair of correspondingly tapered wedge members 18 are provided, with the taper of the wedges being such that it cooperates with the taper of the head. A transverse slot 20 is defined in the wider face of the wedge 18, such that the slot faces outwardly when the wedges are installed. A corresponding pair of outer clamp members 22 cooperate with the wedges, the clamp members having transverse slots 24 defined in the inwardly oriented faces thereof. A through bore is defined in the wedges and the clamp members, whereby a bolt 26 may be passed through the clamps, wedges and head, threadably engaging a nut member 28, which may be provided with a seat in the clamp so as to fit flush into the clamp member.

When assembled, from left to right in FIG. 6, the structure comprises the bolt 26, clamp 22, wedge 18, head 14, another wedge 18, another clamp 22 and nut 28. The bolt is suitably tightened, pulling the tapered wedges and clamps together with the head, for secure engagement. The tightening of the through bolt pulls the outer clamps against the seat rails, and pulls the wedges together towards each other. The wedges lock into the tapered hole in the head. The slots 20 and 24 define receiving openings for the rail of a seat, whereby the clamping action of the wedges and clamp members and the head result in the seat being secured to the head. The assembly is highly resistant to rotation about the arc 30 (FIG. 3) . Such rotation is undesirable as it alters the feel of the seat and rider comfort/performance.

Referring again to FIG. 6, it may be noted that the wedges 18 are thicker at a lower portion 32 thereof, while the upper part above the slot 20 is slightly narrower. This allows a slight opening 36 (FIG. 2) between the clamp and wedge, for superior gripping of the seat rail even with rail size variations .

FIGs. 9 and 10 are perspective and side views respectively, illustrating seat rails 38 in phantom, showing their cooperation with the wedges and clamps. A schematic seat 40 is shown in FIG. 10, as an example.

In the preferred embodiment, the seat post clamp is employed in a bicycle. The post 12 is received and suitably secured to the bicycle frame (FIG. 10) .

Referring now to FIG. 11, an exploded perspective view of the bicycle stem according to the present invention, the bicycle stem includes an elongate stem body 112, which is horizontally aligned in the drawing. The leftmost end of the stem body in the figure engages with a handle bar receiving clamp 114, which cooperates with handle bar clamp jaw portion 116 and threaded bolts 118, to clamp a handle bar tube (not shown) . The bolts 118 fit through holes 120 in the clamp jaw portion 116 and are received in corresponding threaded holes 122 in the clamp 114. The inner faces of the clamp 114 and clamp jaw 116 have arcuate shapes so as to cooperate with the shape of a handle bar to allow clamping thereof when the bolts 118 are tightened. At the end of stem body 112 opposite from the clamp 114, a vertically aligned tube portion 124 is defined. At the top of the body 112, near the tube portion, a vertical through bore 126 is defined for receiving threaded bolt 128. An arcuate tapered indentation 130 is formed in the inner face of the tube portion, from the bottom thereof (relative to the orientation of FIG. 11) , extending upwardly part way up the vertical length of the tube. The indentation 130 is formed at the side of the tube where it meets the stem body 112. A wedge member 132, having a tapered profile that is a counterpart to the profile of the indentation 130 is removably receivable in the indentation, inside of the tube portion 124.

Referring to FIG. 16, which is a solid top exploded partial perspective view of the bicycle stem, looking down into the tube portion 124, it may be observed that wedge member 132 has a vertical bore 134 therein. Bore 134 is suitably threaded so as to threadingly engage the threads of bolt 128 when the stem is assembled. The inner face (that is, the face that is oriented towards the inside of the tube 124) of the wedge has an arcuate profile, but unlike the other face of the wedge, is not tapered.

When the stem is assembled, a fork tube 136 (shown in FIG. 13 in phantom, for illustrative purposes, representing the engagement point on the body of the bicycle) of a bicycle is received inside tube 124. Bolt 128 is positioned in hole 126, and wedge member 132 is brought up into the tapered indentation 130. The bolt is engaged with the threaded bore 134 in the wedge. The non-tapered arcuate face of the wedge engages the fork tube 136. Upon tightening of the bolt, the wedge is pulled into the indentation 130, and, as a result of the tapered profiles of the wedge and the indentation, the wedge is urged into tight engagement with the fork tube. Thereby, the bike stem is securely held to the fork tube of the bike. The handle bar 140 of the bike (shown in phantom in FIG. 13) is then clamped between clamp 114 and jaw portion 116, secured by cooperation of the bolts 118 and holes 120 and 122.

Bolts 118 may also operate to secure the clamp portion to the stem body 112, by engagement with threaded holes (not show) in the stem body. Alternatively, clamp portion 114 may be secured to the stem body by any suitable means, or may be defined as a unitary portion of the stem body.

The various drawing figures provide views of the bicycle stem from different angles, to assist in the understanding of the operation and structure thereof. Accordingly an improved seat post and bicycle stem are provided. The stem enables easy secure clamping to the bicycle, while also enabling easy loosening and removal for adjustment, replacement, or repair. While preferred embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that many changes and modifications may be made without departing from the invention in its broader aspects. The appended claims are therefore intended to cover all such changes and modifications as fall within the true spirit and scope of the invention.

Claims

Claims What is claimed is:

1. A seat post, comprising: a head member having a first tapered portion; and a seat rail receiving wedge member having a second taper, said second taper for cooperating with said first taper to mount said wedge member to said head member.

2. A seat post according to claim 1, further comprising a clamp member adapted to clamp the seat rail to said wedge member.

3. A seat post according to claim 2, further comprising a tightening member for tightening engagement of said clamp member and said wedge member to the seat rail and said wedge member to said head member.

4. A seat post according to claim 3, wherein said tightening member comprises a through bolt passing through said head member, said wedge member and said clamp member, and further comprising a corresponding nut tightening member for cooperating with said through bolt to urge said wedge member against said head member and said clamp member against said wedge member.

5. A seat post according to claim 1, further comprising a tightening member for tightening engagement of said wedge member to said head member.

6. A seat post, comprising: a head member having at least a first tapered portion; and first and second seat rail receiving wedge members, at least one of said wedge members having a second taper, said second taper for cooperating with said first taper to mount said wedge members to said head member.

7. A seat post according to claim 5, further comprising first and second clamp members adapted to clamp the seat rail to said wedge members.

8. A seat post according to claim 7, further comprising a tightening member for tightening engagement of said clamp members and said wedge members to the seat rail and said wedge members to said head member.

9. A seat post according to claim 8, wherein said tightening member comprises a through bolt passing through said head member, said wedge members and said clamp members, and further comprising a corresponding nut tightening member for cooperating with said through bolt to urge said wedge members against said head member and said clamp members against said wedge members .

10. A seat post according to claim 5, further comprising a tightening member for tightening engagement of said wedge members to said head member.

11. A bicycle, comprising: a seat post having a head member, said head member having a first tapered portion; and a seat rail receiving wedge member having a second taper, said second taper for cooperating with said first taper to mount said wedge member to said head member.

12. A bicycle according to claim 11, further comprising a clamp member adapted to clamp the seat rail to said wedge member.

13. A bicycle according to claim 12, further comprising a tightening member for tightening engagement of said clamp member and said wedge member to the seat rail and said wedge member to said head member.

14. A bicycle according to claim 13, wherein said tightening member comprises a through bolt passing through said head member, said wedge member and said clamp member, and further comprising a corresponding nut tightening member for cooperating with said through bolt to urge said wedge member against said head member and said clamp member against said wedge member.

15. A bicycle according to claim 11, further comprising a tightening member for tightening engagement of said wedge member to said head member.

16. A bicycle according to claim 11, wherein said wedge member comprises first and second wedge portions, wherein said head member includes a second tapered portion, said first and second wedge portions cooperating with said first and second tapered portions.

17. A bicycle according to claim 16, further comprising first and second clamp members adapted to clamp the seat rail to said first and second wedge member portions.

18. A bicycle stem, comprising: a stem body having a tapered indentation defined therein; and a wedge member having a portion with a counterpart tapered shape to the tapered indentation.

19. The bicycle stem according to claim 18, wherein said wedge member has a bolt receiving portion and wherein said stem body carries a bolt, for engaging the bolt receiving portion of said wedge member.

20. The bicycle stem according to claim 18, wherein said wedge member has a bicycle part engaging profile on a face opposite the portion having the counterpart tapered shape.

21. The bicycle stem according to claim 20, wherein said part engaging profile comprises an arcuate profile .

22. The bicycle stem according to claim 21, wherein said arcuate profile comprises a circular profile .

23. A bicycle stem, comprising: a stem body having a tubular member with a tapered indentation defined in an interior portion thereof, wherein an engaging member receiving bore is defined into the tapered indentation; a wedge member having a portion with a counterpart tapered shape to the tapered indentation and an engaging member receiving portion therein, said wedge member having a profile on a portion thereof adapted to mate with a profile of a bicycle attachment part; and an engagement member for passing through said receiving bore and meeting said engaging member receiving portion, for adjustably setting the position of said wedge member.

24. The bicycle stem according to claim 23, wherein said tubular member tapered indentation has a greater dimension on a longitudinal axis thereof, and where said longitudinal axis is oriented substantially vertically relative to a bicycle frame.

25. The bicycle stem according to claim 23, wherein said engagement member and said engagement member receiving portion of said wedge member threadably cooperate with one another.

26. The bicycle stem according to claim 23, wherein said engagement member comprises a threaded bolt and said engagement member receiving portion of said wedge member comprises a corresponding threaded bore .

27 . A bicycle , comprising : a frame having a stem engaging member; a stem body for receiving said stem engaging member, and having a tapered indentation defined therein; a wedge member having a portion with a counterpart tapered shape to the tapered indentation adjustably received in said tapered indentation; and a securing member for securing said wedge relative to said stem body.

28. The bicycle according to claim 27, wherein said stem body receives said wedge member in a substantially vertical relation relative to said stem engaging member.

29. The bicycle according to claim 27, wherein said stem engaging member comprises a tubular portion.

30. The bicycle stem according to claim 27, wherein said tapered indentation has a greater dimension on a longitudinal axis thereof, and where said longitudinal axis is oriented substantially vertically relative to said bicycle frame.

31. The bicycle stem according to claim 27, wherein said securing member and said wedge member threadably cooperate with one another.

32. The bicycle stem according to claim 27, wherein said securing member comprises a threaded bolt and said wedge member carries a corresponding threaded bore therein.