CS265274B1 - Forks, in particular for bicycles and a method for making them - Google Patents

Abstract

The fork consists of tubular arms, provided at the lower end with a pre-existing base arranged in front of the tubular arm and provided with cutouts for mounting the wheel. The character of the fork consists in the fact that the base forms a single unit with the tubular arm and consists of two abutting side walls in the rear part passing into the wall of the tubular arm. The essence of the manufacturing method consists in bending the lower end of the tubular arm by the edge of the lower wall into an imaginary extension of the opposite edge of the straight part of the arm and pressing the bent part, lying outside the extension of the straight part of the arm.

Description

BACKGROUND OF THE INVENTION The invention relates to a fork, in particular for bicycles, consisting of tubular arms provided at the lower end with a representative base / arranged in front of the tubular arm and provided with a recess for receiving the wheel. The invention also relates to a method of manufacturing a fork.

In the existing wheel fork designs, the fork legs are bent at the bottom and are provided with slots for gripping the wheel. These fork designs do not exhibit sufficient rigidity and are therefore not used in off-road bikes, especially croissant bikes. To increase the rigidity of the forks, the forks are constructed from supporting tubular arms, at the lower ends of which the exemplary bases are welded or brazed, in which cut-outs are provided for gripping the wheels. These forks suit in terms of strength, but at the expense of increased labor and manufacturing costs, which is mainly due to operations to attach the socket to the fork arms.

It is an object of the present invention to provide a fork structure which is characterized by increased rigidity and is easy to manufacture.

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The fork according to the invention is characterized in that the wheel bearing bead forms a unit with the tubular arm and consists of two side walls abutting one another, each of which passes into the tubular arm wall at the rear. The rear edge of the cap lies in a plane tangent to the tubular arm. One side wall extends tangentially with its outer surface into the outer surface of the tubular arm.

The principle of the method of manufacturing this fork is that the lower end of the tubular arm is bent so that the axis of the arm intersects its bent lower wall and the lower edge of the wall lies in an imaginary extension of the flat opposite wall of the tubular arm. lying on the opposite side of this intended extension to the axis of the straight portion of the tubular arm.

The advantage of the fork according to the invention is its easy manufacture and the possibility of its automatic production, while its stiffness reaches the stiffness of the cross forks with additionally fixed sockets.

An example of a fork according to the invention is shown in the accompanying drawings, wherein Fig. 1 shows a front view of the fork, Fig. 2 shows a side view of the fork of Fig. 1, Fig. 3 shows a section AA of Fig. 1, Fig. 4 shows a bottom view 1, 5 shows a front view of the fork blank, prior to pressing the socket, FIG. 6 shows a bottom view of an alternative embodiment of the fork. FIG.

The tubular arm 2 of the fork is terminated at its lower end by a socket 1. The wall of the tubular arm 2 is on one side

265 274 are bent so that its lower end lies roughly in the imaginary extension of the wall of the tubular arm 2 on the opposite side. The base 1 is integral with the tubular arm 2, so that the wall of the market arm 2 merges into the two side walls J of the base 1. The side walls 2 of the base 1 abut one another.

In the embodiment of the fork according to Figures 1 to 4, the outer surface 2 of one of the side walls 2 is tangent to the outer surface of the tubular arm 2, while the second side wall 2 of the cap 1 forms a rear edge 1 on contact with the tubular arm 2. the outer surface of the tubular arm 2, the rear edge 1 of the cap 1 in the case of the side wall 2 of the cap 1 is only an imaginary line at the point where the side wall 2 passes in plan view into the contour of the tubular arm 2. 2. to store the wheel.

One alternative embodiment of the fork is shown in Fig. 6, wherein the side walls 2 are symmetrical to a plane passing through the axis of the tubular arm 2.

All embodiments of the fork according to the invention are easy to manufacture by bending the straight tubular arm at the lower end, as seen in the blank of Figure 5.

After bending, the lower edge of the bottom wall lies in an imaginary extension of the straight opposite wall of the tubular arm, and then the bent end is compressed so that the trailing edge of the representative cap lies in the imaginary extension of the front straight wall of the tubular arm.

Claims (4)

1 »Forks, in particular for bicycles, comprising tubular arms provided at the lower end with a representative base. arranged in front of the tubular arm and provided with a cut-out for receiving the wheel, characterized in that the cap (1) forms one unit with the tubular arm (2) 265 274 and consists of two abutting side walls (3) / in the rear part merging into the wall of the tubular arm (2). Fork according to claim 1, characterized in that the rear edge (4) formed between the base (1) and the tubular arm (2) passes into the outer surface of the tubular arm (2) above the base (1). O Fork according to Claims 1 and 2, characterized in that one side wall (3) passes with its outer surface (5) tangentially into the outer surface of the tubular arm (2). 4o A method of manufacturing a fork, characterized in that the lower end of the tubular arm is bent such that the axis of the arm intersects its bent lower wall and the lower edge of the wall lies in an imaginary extension of the flat opposite wall of the tubular arm; on the opposite side of this intended extension from the straight portion of the tubular arm.