JPS6015741Y2 - bicycle handle stem - Google Patents

Description

[Detailed description of the invention] This invention relates to the improvement of a handle stem used when attaching a handle to a bicycle frame, and an object of the present invention is to provide a handle stem that can be easily attached and detached and has high strength. With the goal.

On a bicycle frame? ) A handle stem is used to attach the steering wheel, but the handle attachment part of a conventional handle stem is formed by forming a short cylindrical part 2 with a cut 1 at the upper front end of the handle stem, as illustrated in FIG. By tightening bolts 3 and nuts 4 provided at the cutout 1, the diameter of the short cylindrical portion 2 is reduced, and the handle inserted through the cylindrical portion 2 is fixed to the stem. Ta.

However, in such a conventional handle stem, the cut 1 of the short cylindrical portion cannot be opened wide, so the handle must be inserted into the short cylindrical portion 2 from the end thereof.

Therefore, the handle cannot be attached or detached with the grip or brake lever attached to the handle or with the tape wrapped around the handle.

In order to eliminate this inconvenience, the upper half of the cylindrical part 2 is separated, the handle is sandwiched between it and the lower half, and both halves are connected with bolts from above when the handle is removed, and the handle is sandwiched. A structure such as that described in Japanese Utility Model Publication No. 52-3783 has been considered in the past, but such a structure had a problem in terms of strength.

In other words, the force applied to the steering wheel during normal driving is not very large as only part of your body weight is applied from above, but when you press the pedals forcefully, for example when climbing a steep slope, the force applied to the steering wheel becomes stronger with your arms. As you step on the pedal while pulling, a large diagonal upward force is applied to the handlebar.For this reason, with a handlebar stem that holds down the handlebar from above, a large force is applied to the bolt that tightens the handlebar. Frequently, the bolts broke.

It is difficult to make this bolt thicker because the mounting part is small.

Furthermore, as described in the specification and drawings of French Patent No. 39294, a separate support piece is attached to the front end of the handlebar stem, but this is because the handlebar attachment sometimes causes the support piece to wobble. Therefore, the handlebar mounting cannot be operated in a stable state.

The handle stem of the present invention overcomes these drawbacks of conventional handle stems.

The present invention will be explained below with reference to the drawings.

Figures 2 and 3 show the upper part (handle attachment part) of the handle stem of the present invention.

Since the structure of the lower part (the part inserted into the frame) is the same as the conventional one, illustration and explanation will be omitted, and the structure of the handle attachment part will be explained below.

Connecting rod (pipe can also be used) 6 extending forward from the vertical pipe 5
At the front end of the connecting rod 6, an upper support piece 7 is formed integrally with the connecting rod 6, and the center portion of the lower surface 7a is recessed upward into a semi-cylindrical shape.

A vertical through hole 8 is bored in the front end of the upper support piece 7.

A vertical screw hole 14 is formed at the rear end of the upper support piece 7 .

The center part of the upper surface 11a of the lower support piece 11 fixed under the upper support piece 7 by bolts 9 and 10 is recessed downward into a semi-cylindrical shape, and the center part of the lower surface of the upper support piece 7 is recessed downward. Together with the recess, it forms a cylindrical portion.

A screw hole 12 is provided at the front end (right end in the drawing) of the lower support piece 11 in the vertical direction, into which a bolt 10 inserted from above into the through hole 8 at the front end of the upper support piece 7 is screwed. .

A screw hole 14 is provided at the rear end of the upper support piece 7 at a position opposite to the through hole 13 of the piece 11 when the lower support piece 11 is stacked thereon, and the bolt 9 inserted into the through hole 13 is inserted into the screw hole 14. I try to screw them together.

Since a gap 15 is formed between the upper surface of the rear end of the lower support piece 11 and the lower surface of the rear end of the upper support piece 7, the through hole 1
By strongly screwing the bolt 9 inserted into the screw hole 14 into the screw hole 14, the diameter of the cylindrical portion surrounded by the recess on the lower surface 7a of the upper support piece and the recess on the upper surface 11a of the lower support piece is slightly reduced. The handle inserted into the handle can be strongly held between the upper and lower support pieces 7.11.

Next, a procedure for attaching a handle to the bicycle handle stem of the present invention constructed as described above will be explained.

First, with the lower support piece 11 removed from the upper support piece 7, hold the handle in your hand by bringing the center part of the handle into contact with the recessed part of the lower surface 7a of the upper support piece. Next, place the lower support piece 11 under the upper support piece 7 with the handle in between, and insert the bolt 10 inserted into the through hole 8 of the upper support piece.
are screwed into the screw holes 12 at the front end of the lower support piece, the bolts 9 inserted from below into the through holes 13 of the lower support piece are screwed into the screw holes 14 at the base of the upper support piece, and each bolt is tightened.

This allows the handlebar to be firmly fixed to the handlebar stem.

To remove the handle from the stem, do the opposite.

This operation of attaching and detaching the handle can be carried out extremely easily with the grip, tape, or brake lever still attached to the handle.

In addition, since the upper support piece 7 is formed integrally with the connecting rod 6, even if the pedal is strongly depressed and a strong diagonal upward force is applied to the stem via the handlebar, the connecting rod 6 remains strong.
Because it is exposed to the heat, it exhibits sufficient strength and provides great durability and reliability.

In this way, the present invention allows the handlebar to be attached with the lower support piece 11 fixedly attached to the upper support piece 7, so the attachment can be carried out easily and quickly with stable operation, making it practical. The above is valid.

[Brief explanation of drawings]

Fig. 1 is a side view showing the upper part of a conventional handle stem, Fig. 2 is a partially cutaway upper side view showing an embodiment of the handle stem of the present invention, and Fig. 3 is a perspective view of the upper part of the handle stem. . 5: Vertical pipe, 6: Connecting rod, 7: Upper support piece, 7a: Lower surface, 8: Through hole, 9, 10: Bolt, 11: Lower support piece, 11a: Upper surface, 12: Screw hole, 13: Through hole , 14:
Screw hole, 15: Gap.

Claims (1)

[Scope of utility model registration request] At the front end of the connecting rod 6 extending forward from the upper end of the vertical pipe 5, the central part of the lower surface 7a is recessed upward into a semi-cylindrical shape, and a through hole 8 is bored in the vertical direction at the front end. , an upper support piece 7 having a screw hole 14 formed at the rear end is integrally formed, and a bolt 10 inserted into the through hole 8 from above is screwed into the screw hole 12 formed at the front end. A separate lower support piece 11 is provided which is coupled to the lower surface of the support piece 7, and the center part of the upper surface 11a of the lower support piece 11 is shaped in half so that the center part of the upper support piece corresponds to the semi-cylindrical recess. The bolt 9 can be freely screwed into the threaded hole 14 of the upper support piece 7 through a vertical through hole 13 formed at the rear end of the lower support piece 11 and recessed downward into a cylindrical shape,
When the lower surface of the front end of the upper support piece 7 and the upper surface of the front end of the lower support piece 11 are in contact with each other, the gap between the upper surface of the lower support piece 11 and the lower surface of the upper support piece 7 at the rear end of the lower support piece 11 A bicycle handlebar stem having a gap 15 formed in the form of a gap 15.