WO1999067125A1

WO1999067125A1 - Bicycle pedal crank

Info

Publication number: WO1999067125A1
Application number: PCT/IT1999/000182
Authority: WO
Inventors: Dario Corsi; Gabriele Agabiti; Michele Ponsele'
Original assignee: Pacific Electronic Instruments S.A.
Priority date: 1998-06-25
Filing date: 1999-06-23
Publication date: 1999-12-29
Also published as: ITPS980011A0; ITPS980011A1; AU4646399A; IT1306419B1

Abstract

The invention relates to a pedal crank for bicycles which has been designed for replacing pedal cranks of different lengths. The subject pedal crank, in particular, can be fitted to cyclists having different physical characteristics, as well as to racing or mountain bikes, or to the type of the running path. The crank is provided with a recess (3) for engaging therein a cam element (4), or the like, in which is formed a threaded attachment (9) for the pedal pivot pin which, upon assembling, will lock this insert in the seat or recess therefor. By turning through 180 degrees the cam insert, or replacing it by other difference eccentricity cams, it is possible to change the equivalent length of the pedal crank. The cam or eccentric insert, in particular, could be also engaged at the pivot pin of the central driving assembly or on the two end portions of the pedal crank to be locked by screws or any other suitable locking means.

Description

BICYCLE PEDA CRANK

BACKGROUND OF THE INVENTION

The present invention relates to a pedal crank for bicycles or bikes which has been specifically designed for replacing a series of different length pedal cranks.

As is known, the optimum length of a bicycle pedal crank, as measured from the pedal axis to that of the central driving assembly pivot pin, will depend on the physical characteristics of the cyclist, the bicycle type and the running path features. Actually, as the pedal crank length is increased, the lever arm will be in turn increased and accordingly the required force will decrease, with a corresponding decreasing of the maximum number of revolutions which can be obtained.

The professional use bicycles, or high quality bikes, are conventionally provided with pedal crank seals made of special materials, allowing to provide a suitable stiffness with a comparatively small weight. The mentioned seals, which are very expensive, must be replaced for any different required lengths of the pedal crank.

SUMMARY OF THE INVENTION

Accordingly, the main object of the present invention is to provide, by a single pedal crank, different equivalent lengths, so as to fit the pedal crank to cyclists having different physical characteristics (even with the lower limbs of asymmetrical configuration), as well as to fit it to racing or mountain bikes of different size or to the running path type.

For achieving the above mentioned object, as well as yet other objects, which will become more apparent hereinafter, the subject pedal crank comprises a recess for engaging therein a cam or the like element, in which a threaded attachment is formed for the pedal pivot pin, which, upon assembling, will lock the cam insert in the seat or recess therefor. By turning through 180 degrees said cam insert, or replacing it by other different eccentricity cam inserts, it will be possible to easily change the equivalent length of the pedal crank.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be disclosed in a more detailed manner hereinafter with reference to the accompanying drawings, which illustrate, by way of a not limitative example, a possible embodiment thereof and in which:

Figure 1 is a side view of the pedal crank according to the invention;

Figure 2 is a side view illustrating the cam or eccentric insert;

Figure 3 is a top plan view, as partially cross-sectioned, of the subject pedal crank, the cam insert and pedal pivot pin being shown in an assembling position; and Figure 4 illustrates an enlarged detail of the pedal crank end portion, as partially cross- sectioned, with the cam insert and pedal pivot pin being shown in an assembling position thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The reference number 1 of the above mentioned figures shows the pedal crank rod, whereas the reference number 2 shows a hole for assembling the pedal crank on a pivot pin of a central driving assembly. At the other end portion of the pedal crank a recess 3 having a shape corresponding to that of the cam insert 4 is provided.

More specifically, said cam insert is provided with a threaded hole 5 arranged at an eccentric position and being provided with an abutment

6, which, upon assembling, will be located on a corresponding abutment 7 of the recess 3.

The reference number 8 shows the pedal pivot pin, the threaded end portion 9 of which is threaded in the hole 5 of the eccentric or cam insert 4, which will be accordingly locked in its recess or seat 3. Between the treaded attachment 9 of said pivot pin 8 and the pedal crank, it is possible to engage, in a suitable engagement seat 10, a washer 11 having a configuration corresponding to that of the recess 3.

By turning through 180° the cam insert 4 to bring the threaded hole 5 to a position opposite to that shown in the figures, it is possible to obtain a different equivalent length of the pedal crank. By assembling cam insert of different eccentricity, it will be accordingly possible to provide other different equivalent lengths.

The cam insert could also be engaged at the central driving assembly pivot pin or on both ends of the pedal crank, in order to allow the equivalent length thereof to be adjusted in a broader range. Said cam insert, moreover, could be locked in its seat by using locking screws, or any other suitable known means .

The pedal crank, in particular, can be made starting from Ergal carbon fibers, titanium or other suitable materials. The subject pedal crank is very advantageous since it can be easily made while allowing a cyclist to buy at a comparatively small cost, a plurality of different eccentricity cam inserts, to choose therefrom the length best fitted to the bicycle running path.

Thus, it should be apparent that the main object of the present invention has been fully achieved. While the invention has been disclosed with reference to a preferred embodiment thereof, it should be apparent that the disclosed embodiment is susceptible to several modifications and variations, all of which will come within the scope of the appended claims.

Claims

1. A bicycle pedal crank, having a pedal- central driving assembly pivot pin interaxis which can be fitted to the characteristics of the cyclist, of the bicycle or of the path, characterized in that said pedal crank comprises a recess (3) for engaging therein an element ( 4) , provided with a threaded eccentric hole (5), operating as an attachment for an end portion of the pedal pivot pin, that said eccentric-hole cam insert can be assembled with two different assembling positions by turning it through 180┬░, or can be replaced by other cam inserts of different eccentricity, thereby providing different equivalent length of said pedal crank.

2. A pedal crank according to Claim 1, characterized in that said cam insert (4) can be locked in its engagement recess by the threaded attachment (9) of the pedal pivot pin or, alternatively, by locking screws or any other suitable locking means.

3. A pedal crank according to the preceding claims, characterized in that said cam insert is designed for engagement on the central driving assembly pivot pin, on the two end portions of the pedal crank, to allow the pedal crank equivalent length to be adjusted in a broad length adjustment range.

4. A pedal crank according to the preceding claims, characterized in that said pedal crank has one or more of the disclosed and/or illustrated features.