US567155A - Velocipede-gear - Google Patents

Description

O. S. MoINTIRE. VELOGIPEDE GEAR.

Patented Sept. 8, 1896.

5: a g u %ZMM Same/1m NITED STATES ATENT rrrcn.

CHARLES S. MCINTIRE, OF ALLEGHENY, PENNSYLVANIA, ASSIGNOR TO THE U. S. CYCLE IMPROVEMENT COMPANY, OF PITTSBURG, PENNSYLVANIA.

VELOCIPEDE-GEAR.

SPECIFICATION forming part of Letters Patent No. 567,155, dated September 8, 1896.

Application filed rarel 7, 1896. Serial No. 578,442. (No model.)

T0 aZZ whom it may concern:

Be it known that I, CHARLES S. MoINTIRE, a citizen of the United States, residing at Allegheny, in the county of Allegheny and State of Pennsylvania, have invented or discovered new and useful Improvements in Velocipede-Gear, of which the following is a specification.

In the accompanying drawings,which make part of this specification, Figure 1 is a side elevation of my improvement, and Fig. 2 is a plan with wheel in horizontal section.

My improvements, generally stated, relate to a compound drivingear for velocipedes, wherein power is transmitted from the pedalshaft to the shaft of the driving-wheel, pri marily, by sprocket and wheels and a short chain, and, secondarily, by crank-s and connecting-rods.

It is well known that various styles of driving-gear have been invented to span the distance between the pedal-shaft and the shaft of the driving-wheel.

From all the mechanism proposed the trade has almost universally adopted the sprocket wheels and chain, not because it is satisfactory, but the least objectionable. The ordinary length of this sprocket-chain is fifty-two inches, and among other defects may be enumerated its tendency to stretch, to bind against the points of the sprocket-teeth, and to slip. It also presents a large number of pockets well adapted to receive dust, oil, and mud, and the same fact is true of the sprocketwheel. Every wheelman knows the injury caused in this way by cutting the teeth of the wheel. There is always also some backlash. chain has not thus far been altogether satisfactory and apparently never will be owing to inherent difficulties, which will be ever present. One of these difficulties is backlash, since there are from three to nine gear-wheels used, and there must be sufficient space between each pair to permit the teeth to enter and clear themselves.

Another serious question in the ordinary cogged-gear-driven machine is that of alinement, for if the frame is warped or twisted the teeth will obviously not mesh, and to se- The attempt to substitute gears for the cure permanent rigidity of frame requires a comparatively heavy structure. For this reason it is neither mechanically nor practically feasible to use ball-bearin gs on the usual train of gear-wheels. The conditions, therefore, seem' to require a chain despiteits disadvantages.

In the construction set forth in this specification I use, it is true, a chain, but its length is only one-fourth that of the ordinary chain, as it only covers. a portion of the distance between the pedal-shaft and the shaft of the driving-wheel, and for this reason its stretch is reduced to one-fourth. The chain also is protected from dirt and mud and the sprocketwheels are set so close together that slipping is practically overcome.

The chain portion of the driving-gear covers only preferably about one-fifth of the distance between the pedal and driving-wheel shafts. The remaining four-fifths is covered by rigid connecting-rods, as will be more clearly seen in the detailed description. The result is that the chain is so short that the whole driving-gear is practically a rigid one and possesses all the desirable features of such a connection.

In the several views, 2 is a gear-case, of any appropriate form, preferably filled with lubricant and secured between the bottom tube A, upright tube B, and bottom stays of the frame.

In suitable bearings in the side walls turns pedal-shaft 3.

4 4 are the pedal-cranks.

5 is a sprocket-wheel keyed on shaft 3, but preferably only three inches in diameter.

6 is a second sprocket, preferably one and three-eighths inches in diameter and about three inches behind the first sprocket-wheel. It is secured to counter-shaft 7, which also has bearings in the side walls of the case 2.

8 is a sprocket-chain connecting the two wheels, and for the sizes just stated would be thirteen inches long. Upon the opposite ends of counter-shaft 7, which project through the case, are hung two cranks 9 9, connected to connecting-rods 1O 10, which at their rear ends are provided with cranks 11 11, fast upon the shaft 12 of the rear driving-wheel 13. The cranks 9 9 and 11 11 are desirably set at an angle of ninety degrees to their mates.

It will also be seen that when the pedalshaft is at the point where the rider can use the least muscular power the crank on the counter-shaft 6 is at its position for exerting the most power mechanically.

N o dead-centers are possible, for it is only once in nine revolutions that the angle of the pedal-cranks is the same as the angle with one of the cranks 9 9 on the counter-shaft, and then onlywith one, never with two simultaneously.

The proportions of the machine above given may be Varied, but I believe only to disadvantage. One important fact is that the only In velocipedes, the GOIIllJillHlllOllO'f afranic; a case secured to the lower ends of the bot tom tube and upright tube; a pedal-shaft journaled in the forward end of said case substantially at the point of intersection of the prolongation of the bottom and upright tubes; a sprocket-wheel upon said pedal-shaft; a countenshaft journaled in said case immediately in the rear of the pedal-shaft; a reduced sprocket -wheel upon said countershaft; a chain connecting the two sprocketwheels; cranks upon the ends of the countershaft; a rear driving-wheel; cranks upon the axle of said driving-wheel and parallel driving-rods connecting the pairs of cranks.

In testimony whereof I have hereunto set my hand this 1st day of February, A. D. 1896.

CHARLES S. MGINIIRE. Witnesses:

WM. L. PIERCE, L. D. IAMs.

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