FR2702189A1 - Pedal and crank mechanism with offset pedalling access - Google Patents

Abstract

Device for improving the efficiency of a pedal and crank assembly subjected to one and the same human effort. The invention consists in an increase in the efficient length of the pedal-support crank during the downward stroke of the pedal in question. It consists of two pedals (A), two cranks (B), a chainwheel (C) and an opposite chainwheel (C'), a crank guide (D) for circular adjustment of the pedals on a different centre from that of the chainwheel, a rigid pin (E) for joining the chainwheel and opposite chainwheel together, and connection members (F). When the user pedals, the pedals describe a circumference with a different centre from that of the chainwheel. The device according to the invention is more particularly intended for the cycle industry.

Description

 The present invention relates to a crankset with an ezo-centered pedaling axis intended to improve the efficiency of the work provided by the user of the cycle or of any other machine requiring the use of a crankset.

 The observation of pedaling shows that the force applied to the pedal is exerted in the downward phase, the upward phase being devoid of productive force. The work provided by a couple resulting from the product of the driving force by the length of the couple's arm (G = F x D), human strength and movement can not be significantly improved1 the idea of the invention -teur is to lengthen the arm of the couple in the productive phase, ie in the descending phase of the pedal.

 The solution provided by the invention is the eccentricity of the pedaling relative to the axis of the plate 1 as defined on the attached fi -gure I. The distance d between the axis of rotation of the plate K and the pedaling axis G of radius r gives an improvement in efficiency equal to the ratio d / r, for the same pedaling effort.

 This device devised to satisfy the idea of the inventor, includes: two pedals (I), two cranks (B), a plate (C) and a counter plate (C '), a k; uide-cranks (D) t a rigid connection axis of the plate and counter-plate (E) and the connecting members (F) of the various above elements, the assembly being fixed on the frame of the machine to be equipped by the middle of the crank guide (D).

The accompanying drawings illustrate the invention:
Figure I shows the elements of physical explanations
and mathematics of this description.

2 shows, in top view or in section according to the
parts of the crankset, the succession of assembly of said parts
-these.

 La-fisure 3 represents the front view of a crank (B).

FIG. 4 represents the front view of the plate (c).

Figure 5 shows the front view of the crank guide (D).

The crank guide (D) comprises, in addition to the organs of connection with its frame of the machine not described ioiX, a circular light (I2) in which the rigid connection axis of the chainring and counter-chainring ( E), and two guide grooves (3). These are intended to receive the guide (I) from each crank (B) in order to give an eccentric circular movement of the plate to each pedal (A). The formula representing the axis of these grooves is:

 The plate (C) comprises, in addition to the drive teeth of the chain which completes any cycle crankset and the like, a lu -mière (2) for passage and sliding of the guide (I) of the ma -nivelle (B) of which it is integral, a light (I3) rigid connection with the axis (E) and a reservation (9) intended to receive the connecting member (F.7) which must secure the crank (B) and the plate (G).

 The counter plate (C ') is identical to the plate (C), except for the exception of the drive teeth of the chain, here unnecessary.

 The crank (B) comprises the element for fixing the pedal (II) in accordance with what has been done so far, the guide (I) which passes through the lumen (2) of the plate (C) or of the counter plate. (C ') to slide in the guide groove (3) of the crank guide -the (D) and two sliding slots (8) and (5) which allow the connecting members (F.7) and ( F.4) to hold this crank (B) in a non-rigid manner against its plate (C) or its counter-plate (C ').

 The rigid connection axis of the plate and counter plate (E) comprises a central rotation me and two male ends of polygonal circular connection coming to be inserted in the slots (I3) of the plate (C) and against -plateau (O ') and receiving in their breasts (6) the connecting member (F.4) for holding the crank (B) against its plate or its counter-plate.

 The pedals (A) do not provide any comments, remaining within the dimensions, due to the efforts to which they are subjected -sesX which is currently presented on the market, and which are not the subject of the present invention.

 All the above elements can receive any improvement intended to reduce resistance to friction and reduce their weight, in order to increase the performance of the crankset with eccentric pedaling axis.

 The device according to the invention allows, while respecting the pro -portions of the figures which accompany this description, a theoretical improvement in the yield of more than 22%.

Claims (2)

CLAIMS I) Disposi-si? to improve the efficiency of the human work provided to a crankset by offsetting the axis of the chainring and that of the pedaling, characterized by the distance of the pedal from the axis of the chainring by sliding the crank (B ) against its plate (C) or its counter-plate (C ') in the descent phase of the rotation of said pedal (A).  2) Device according to claim (I) characterized by lté- equipment of the crank (B) of the guide (I) sliding in the guide groove (3) of the crank guide (D) after crossing the plate (C) or counter plate (c ') by the light (2).  4) Device according to claim (I) allowing the -ment of the pedal (A) located opposite the plate (C) relative to -port to the axis thereof by creation of the counter- tray (c ').