JPS6237835Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to the improvement of a handlebar stem for attaching a handlebar to the fork tube of a bicycle frame, and is particularly useful for bicycles for attaching a handlebar having an irregular cross-section used for competition bicycles. It is intended to provide a handle stem.

Competition bicycles, especially those used for track sprint competitions, are designed to reduce air resistance as much as possible, and for this reason, the handlebars are shaped as shown in Figures 1 and 2. ing. That is, the cross section of the portion 1 that is exposed to strong winds while driving is made into a Daruma shape as shown in FIG.
Or it may be oval. The attachment part 2 to the handle stem at the center of the handle is formed to have a circular cross section like a normal handle. However, the handle having the portion 1 with such an irregular cross section,
Since the long axis of the portion 1 with the irregular cross section is larger than the outer diameter of the attachment portion 2, the handle stem is inserted from the end with the portion 1 of the irregular cross section holding the handle in the conventional handle stem. It becomes impossible to install it.

For this reason, in the past, part 1 of such an irregular cross section
As shown in Fig. 3, the handle stem for attaching a handle has a holding piece 5 that can separate a part of the handle attachment part 3, and the handle is attached with this holding piece 5 removed, and then the holding piece is removed. Piece 5
The handle was fixed to the handle stem by tightening the handle to the stem body 4 with bolts 6, 6. However, a handle stem in which the handle attachment part is divided into two parts is not only cumbersome to manufacture, but also has poor strength because the bolts 6, 6 partially support stress such as twisting applied to the handle. It has the disadvantage of being weak.

The present invention aims to provide a handle stem that does not have the above-mentioned drawbacks.

Hereinafter, the present invention will be explained with reference to drawings showing embodiments.

FIG. 4 shows a state in which the handle attachment portion of the handle stem of the present invention is divided. Stem body 4
The handle attachment portion 3 provided at the tip of the protruding arm 7 is provided with an attachment hole 8 having a Daruma-shaped cross section and passing through it in the lateral direction. The mounting hole 8 is a circular hole 8a having an inner diameter into which the handle mounting portion 2 (FIG. 1) can be fitted without rattling, and a notch 8b having a U-shaped cross section is continuously formed. This notch 8b has a small diameter portion 10 through which the rod portion 9a of the bolt 9 can be inserted.
a, and a large diameter portion 1 into which the head 9b of the bolt 9 can be fitted.
A washer piece 11 with a circular hole 10 made of 0b
, a nut piece 13 having a screw hole 12 into which the bolt 9 is screwed, and a through hole 14 through which the rod portion 9a of the bolt 9 passes, and the washer piece 11 and the nut piece 1
3 and an elastic rubber piece 15 held between the two are inserted. Washer piece 11, nut piece 13, and elastic rubber piece 15
This means that the outer shape is such that it can be fitted into the notch 8b without wobbling, and one side is a circular arc surface 11a, 1 with a radius that matches the inner peripheral surface of the circular hole 8a of the mounting hole 8.
3a and 15a.

Next, a procedure for fixing the handle to the handle stem of the present invention configured as described above will be explained.

To attach the handle, first insert the handle into the attachment hole 8 from the end, and position the attachment part 2 at the center of the handle in the circular hole part 8a of the attachment hole 8. When performing this work, the washer piece 11, nut piece 13, elastic rubber piece 15, and bolt 9 are kept out of the mounting hole 8. Therefore, even if a part of the handle has a Daruma-shaped cross section as shown in Fig. 2 or an oval part as shown in Fig. 5, it can be used to fill the entire cross section of the mounting hole 8. , the handle can be inserted freely from the end. Once the handle attachment part 2 is located inside the circular hole part 8a, first remove the washer piece 1.
1 and the nut piece 13 so that the elastic rubber piece 15 is sandwiched between the three pieces 11, 13, 15.
into the notch 8b. Next, the washer piece 11
The tip of the rod portion 9a of the bolt, which has passed through the circular hole 10 and the through hole 14 of the elastic rubber piece 15, is screwed into the threaded hole 12 of the nut piece 13, and the bolt 9 is tightened. By tightening the bolt 9, the distance between the washer piece 11 and the nut piece 13 is narrowed, and the elastic rubber piece 15 between the two pieces 11 and 13 is compressed and deformed. In this state, the elastic rubber piece 15 tends to bulge toward the circular hole 8a of the attachment hole 8, so that the outer circumferential surface of the attachment part 2 of the handle is pressed by the elastic rubber piece 15. Therefore, by strongly tightening the bolt 9, the handle can be fixed to the handle attachment portion 3 of the handle stem. When removing the handle,
In the reverse order of the above, pull out the bolt 9 and attach the washer piece 11, nut piece 13, and elastic rubber piece 15 to the notch 8.
After pulling it out from b, the handle can be pulled out from the mounting hole 8.

In the above-mentioned embodiment, an example was shown in which the outer surface of the attachment part 2 of the handle was directly pressed by the elastic rubber piece 15, but as shown in FIG. A pressing plate 16 curved in an arc is provided between the three pieces 11, 13, 15 inserted into the hole 8b and the handle attachment part 2 inserted into the circular hole 8a. The attachment portion 2 of the handle may be pressed through the handle. The inner surface 16a of the pressing plate 16 is formed with a groove that engages with a groove formed on the outer circumferential surface of the mounting portion 2. Since the upper and lower edges of the press plate 16 mounted in this manner are in contact with the edges of the notch 8b, the press plate 16 does not move when the handle is fixed, and completely prevents the handle from moving in the twisting direction. It can be prevented.

The bicycle handlebar stem of the present invention is constructed and used as described above, and therefore, it can be used as a handlebar stem for attaching a handlebar having an irregular cross section, as compared to the conventional handlebar stem in which the handlebar mounting part is divided into two parts. There are advantages.

1. It is easy to manufacture as it eliminates the trouble of accurately manufacturing divided parts as in the past. Note that the washer piece 11, the nut piece 13, which is inserted into the notch 8b,
Making the elastic rubber piece 15 is easier than making a conventional handle stem as shown in FIG.

2. The handle attachment part 3 is integrated, and there is no need to worry about the strength of the handle, as no stress is applied to the bolts, etc. for fixing the handle due to twisting of the handle.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an example of a handle having an irregular cross section, Fig. 2 is an enlarged cross-sectional view taken along line A-A in Fig. 1,
Fig. 3 is a side view showing an example of a conventional handle stem, and Fig. 4 and subsequent figures show examples of the present invention.
Fig. 4 is an exploded perspective view of the handle attachment part, Fig. 5 is a side view showing the state when the handle is inserted, Fig. 6 is a perspective view showing the assembled state, and Fig. 7 is B--B in Fig. 6.
B sectional view and FIG. 8 are side views of the handle attachment part showing another embodiment. 1: Part, 2: Mounting part, 3: Handle mounting part,
4: Stem body, 5: Holding piece, 6: Bolt, 7:
Projecting arm, 8: Mounting hole, 8a: Round hole, 8b: Notch, 9: Bolt, 9a: Rod, 9b: Head, 1
0: circular hole, 10a: small diameter part, 10b: large diameter part, 1
1: Washer piece, 11a: Arc surface, 12: Screw hole, 1
3: Nut piece, 13a: Arc surface, 14: Through hole,
15: Elastic rubber piece, 15a: Arc surface, 16: Pressing plate, 16a: Inner surface.

Claims (1)

[Scope of utility model registration request] The handle attachment portion 3 at the end of the stem body 4 has a circular hole portion 8a and a notch portion 8b continuous with the circular hole portion 8a.
forming a laterally penetrating mounting hole 8 consisting of;
A circular arc surface 1 that can freely enter and exit the notch 8b and whose side surface on the circular hole 8a side coincides with the inner circumferential surface of the circular hole 8a.
A washer piece 11 labeled as 1a and a nut piece 13 of the same shape
and an elastic rubber piece 15 held between both pieces 11 and 13.
The washer piece 11 has a circular hole 10 through which the bolt 9 is inserted, the nut piece 13 has a screw hole 12 into which the bolt 9 is screwed, and the elastic rubber piece 15 has a through hole 14 through which the bolt 9 is inserted. A bicycle handle stem that is equipped with each.