US609828A - Velocipede - Google Patents

Description

Nd. 808,828. 8 Patented Aug. so, |898. 8. MIEHLE.

VELUCIPEDE.

(Application led Oct. 23, 1895.)

2` Sheets-Sheet I.

(No Model.)

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Patented Aug. 30, |898. R. MIEHLE.

VELOCIPEDE.

(Application Bled Oct. 23, 1895.)

2 'sheets-sheet 2.

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UNITED STATESPATENT OFFICE.

4 ROBERT MIEHL, OF CHICAGO, ILLINOIS.

SPECIFICATION forming part of Letters `Patent N o. 609,828, dated August 30, 1898. Application led October 23, 1895. Serial N0. 566 ,616. (No model.)

To all whom t may concern:

Be it known that I, ROBERT MIEHLE, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Velocipedes, of which the following is afull, clear, and exact specification.

My invention relates moreparticularly to the driving mechanism for velocipedes, and, infact, for any other form of machinery; and it has especial reference to that class of driving mechanism in which the crank is acted on through the intermediary of a lever hav-A ing a iioating or shifting fulcrum.

My invention has for one of its objects to cause the pressure exerted against such fulcrum to react directly in propelling the mal chine instead of being expended on a mere dead resistance, as heretofore.

Another object of myinvention is to cause the pressure which is ordinarily expended without effect against the dead-center of the crank to react on the crank in a different line of force from the line of the driving force and thus carry the crank past dead-center.

A furtherobject of my invention is to cause the leverage of the propelling-lever to automatically increase when going down or making its driving stroke and t-o decrease when going up or returning.

With these ends in view my invention consists in certain features of novelty by which the said objects and certain other objects, hereinafter described, -are attained, all as fully described with reference to the accompanyin g drawings, and more particularly pointed out in the claims.

In the said drawings, Figure 1 is a side elevation of a portion of a bicycle provided withv my improvements. Fig. 2 is a plan view thereof, certain parts of the frame being broken away. Fig. 3 is a detail view showing the .return movement of the'driving-lever and two of the cranks, as hereinafter described. Fig, L is a detail view of a modilied form of driving-lever, showing the cranks in dotted lines, hereinafter described; and Fig. 5 is a further modification illustrating diagrammatically a different form of shifting connection between the driving-lever and one of the cranks, as hereinafter described.

1 represents a bicycle-frame of ordinary construction; 2, the crank-hanger; 3, the sprocket-wheel, secured to the crank-shaft 4 and geared to the ground driving-wheel 5 by lneans of chains 6 in the ordinary manner, and 7 8 are cranks secured to the crank-shaft l at opposite ends thereof, as usual.

9 is an additional crank-hanger which is shown detachably secured to the frame 1 in front of the crank-hanger 2, but of course, if desired, may be formed as a part of the frame or of the regular crank-hanger. .Iournaled in this crank-hanger 9 is a second crank-shaft 10, whose opposite ends are provided with cranks 11 12, respectively. The crank-shaft 10 is geared with or to the crank-shaft 4: in any suitable manner, such as by a pair of cogwheels or pinions 13 14, the former being secured to the crank-shaft 10 and the latter to the shaft 4:, so that the two shafts 4f and 10 will be compelled to rotate in unison.

15 16 are the driving-levers, provided at their rear ends with pedals 17 18, respectively, and pivoted at an intermediate point to the cranks 7 8, respectively. This pivotal connection between the levers 15 16 and the cranks 7 8 may be conveniently eifected by providing the levers with laterally-elongated bearings 19, provided, if desired, with antifriction devices (not shown) which bear upon the wrist-pins 2O of the cranks, as will be understood. The opposite end of each of the levers 15 16-that is, the end opposite the pedal-has a shiftin g or sliding connection, or what might also be termed a movable connection,7 with one of the cranks 11 12, which latter acts as a fulcrum for the lever. This sliding connection may be conveniently effected by providing each of the levers 15 16 with a loop or slot 21 22, respectively, which slots receive the wrist-pins 23 24, respectively, of the cranks 11 12, such wrist-pins, if desired, being in the form of antit'riction-rollers provided themselves with suitable antifrictionbearings on the cranks 11 12, whereby their travel back and forth in the slots 2122 Awill produce but a minimum friction.

The crank l1 is a trifle shorter than the crank 7 and is so arranged and proportioned with reference to it that when the latter has reached the deadcenter, or that position where the pressure on the pedal ceases to be effective, the crank 11 will be substantially trans- IOO verse to the line of movement of the slotted end of the lever 15, and hence the pressure of such slotted end of the lever against the wrist-pin of the crank 11 will impart positive forward movement to the gear-wheel 13,which through the intermediary of the gear 14 will continue the rotation of the crankshaft 4, and consequently carry the crank 7 past deadcenter or beyond its inactive position. The same relative arrangement of the cranks 8 12 is carried out on the opposite side of the machine.

It is apparent that when the cranks 11 and 7 are in a horizontal line and the point 20 is on the left of the shaft 4 the points 2O 23 will be farther apart than when the cranks are in the opposite position on the other side--that is to say, when the cranks are horizontal, but With the point 20 on the right of the shaft 4. This difference is due to the difference in the lengthsof the cranks, and it brings about a shorter and a more direct movement of the pedal in descending than in ascending, in the manner which I will now describe.

It will be seen that while the cranks are in the position shown in Fig. 3 the main crank7 is just about to enter its downward or propelling stroke, and the leverage at this stage is shortest because the point of application of the Work, which is the point 20, and the fulcrum, which is the roller 23, are at their maximum distance apart. This distance between the work and the fulcrum, it will be seen, is graduallT decreased throughout the lirst quarter of the downward stroke, at the com pletion of which first quart-er the points 20 23 are at their minimum distance apart, and then the points 2O 23 begin to recede from each other and thus continue to increase the distance between the work and the fulcrum until the main crank has reached the limit of its downward stroke, whereupon the distance between the points 2O 23 begins to decrease; but during the iirst quarter-upstroke of the main crank this decrease occurs less rapidly per given travel of the crank than it does during the travel of the main crank from the position shown in Fig. 3 down to the completion' of the iirst quarter of the downward stroke, and consequently during the return or upstroke the leverage is decreased by reason of the fulcrum failing to approach the work as near as it did at the completion of the 'rst quarter of the downward stroke. From the point of completion of the irst quarter of the upward stroke the distance between the points 20 23 increases until the position of the crank shown in Fig. 3 is reached.

By this construction it will be seen that both the direct and indirect or reactionary pressures of the driving-lever act positively in propelling the machine, and neither of these forces is expended on a dead or inactive fulcrum, as heretofore.

The modification shown in Fig. 4 consists simply in providing the driving-lever with an extension 15a for the provision of an additional pedal 17, whereby the machine may be used as a tandem.

In Fig. 5 I have illustrated a different form of movable or shiftable connection between the lever 15 and the crank 11, it being ot` course understood that Fig. 5 is an illustration of but one side only. In this form instead of providing the lever 15 with a slotted end I employ a link 21, which is slightly longer than the crank 11 and which has its ends pivoted to the lever 15 and to the crank 11, respectively, so that the oscillation of the lever 15 will be imparted to the crank 11, and thereby cause the rotation of the crankshaft 10.

It will be observed that in both .forms of my invention the wrist-pin of the crank 11 constitutes the fulcrum for the end of the driving-lever which projects beyond the pivotal point of said lever, and in both instances this f ulcrum is what might be termed a shifting or floating fulcrumthat is to say, its position changes with reference to the length of the driving-lever, and the strain eX- erted by said driving-lever upon this fulcrum is transmitted to the main crank-shaft and assists the main crank in rotating said shaft.

Having thus described my invention, what I claim as new therein, and desire to secure by Letters Patent, is-

1. In a driving mechanism for the purpose described,the combination with a crank-shaft having a crank, of a lever pivoted to said crank, and a second crank-shaft geared to said irst crank-shaft and having a crank provided with movable connection with said lever, said crank-shafts being geared to rotate in opposite directions substantially as set forth.

2. A driving mechanism for the purpose described having in combination a crank-shaft provided with a crank, a lever pivoted to said crank and havinga'pedal located at one side of said pivot and a loop or slotJ at the other side thereof, a second crank-shaft having a crank and being geared with and rotating in the opposite direction from-said first crankshaft, said second crank having a stud running in said loop or slot, substantially as set forth.

3. A driving mechanism for the purpose described having in combination a crank-shaft provided with a crank, a second crank-shaft having a crank of less length than said first crank, Isaid crank-shafts being geared together, and a lever connected to said irst crank and having sliding connection with said second crank, substantially as set forth.

ROBERT MIEIILE.

Witnesses:

F. A. HOPKINS, `EDNA B. JOHNSON.

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