US927201A - Foot-power driving mechanism. - Google Patents

Description

J. F. WILKINSON.

FOOT PGWER DRIVING MEOHANISM. A

APPLICATION FILED AUG, B.,A 190C.

' PaentedJuly 6, 1909.

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J. F. WILKINSON.

FOOT POWER DRIVING MEOHANIBM. A ArPLIcATroN FILED AUG. a, 190e.

927,201. Patented July 6,1909.

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FOOT POWER DRIVING MEGHANISM.

APPLIGATION HLBDAUG. s, 190e.

CP )f @MC JOHN FRANKLIN WILKINSON, OF GLOUCESTER, MASSACHUSETTS.

FOOT-POWER DRIVING MEGHANISM.

Specification of Letters Patent.

Patented July 6, 1909.

Application led August 8, 1906. Serial No. 329,706.

To all 'whom it may concern:

Be it known that I, JOI-IN FRANKLIN VIL- irlNsoN, of Gloucester, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Foot-Power Driving Mechanism, of which the following is a: specification.

This invention relates to a footpower mechanism or motor employing a treadle for rotating a crank-shaft, and a clutch for preventing backward rotation of the crankshaft and driving-wheel when the treadle is operated.

In Letters Patent No. 592,577, granted to me October 26, 1897, I have set forth a footpower driving mechanism comprising a treadle connected by a pitman with the crank-shaft, and a supplemental treadle con nected with a clutch on the crankshaft, the construction being such that the crank-shaft is rotated freely in one direction by a movement of the treadle, the clutch locking it against rotation in the opposite direction. The depression of the supplement-al. treadle causes the clutch to impart a partial rotation to the crank-shaft, suiicient to move the shaft from a dead-center position. In the construction of the said former patent, the operators foot is required to coperate with two treadles or treadle portions, namely, the usual main treadle connected by a pitman with the crank-shaft, and a supplemental treadle connected with the clutch, the supplemental treadl-e being normally yieldingly supported by the main treadle and capable of being depressed by the operators foot to the level of the adjacent portion of the main treadle. The said twoepart treadle construction is somewhat complicated, and leaves something to be desired .in the way of simplicity, ease, and efliciency of operation.

The present invention has for its objectto provide a simplified and improved construction of that portion of a foot-power mechanism of the character described, which includes the treadle or part on which the operators foot bears.

The invention consists in the improvements which I will now proceed to describe and claim.

Of the accompanying drawings, forming a part ofy this specificationff-Figure 1 `represents a front el-evation of a foot-power mechanism embodying my invention, applied to the supporting frame of a sewing-machine. Fig. 2 represents a section on line 2 2 of Fig. 1, and an elevation of the mechanism at the right of said line. Fig. 3 represents a perspective view of the rocking base which supports the treadle. Fig. L1 represents an enlargement of a portion of Fig. 2.

The same reference characters indicate the same parts in all the figures.

In the drawings,12 represents a crankshaft ournaled in suitable bearings.

13 represents a driving-wheel fixed to the crankshaft, the hub of the driving-wheel having a circular cavity, the inner wall 14 of which constitutes a clutch member adapted to coperate with a clutch-dog or member 15 mounted to oscillate on a plate 16 which is fitted in the cavity of the hub of the driving-wheel and is adapted to rotate independently of the crank-shaft and drivingwheel. The clutch member 15 is adapted to slip loosely on the friction surface of the driving-wheel when the latter is rotating in a forward direction, and to engage said friction surface and prevent backward rotation of the crank-shaftand driving-wheel, the operation in this respect being the same as that described in my former patent. For convenience, I will hereinafter refer to the member 15 and the part which carries it as the clutch.

To thc lower portion of the supporting frame is fulcrumed a part which I term a rocking base. This part, in the construction here shown, comprises a body portion which includes two side arms 17 and 18, and a connecting cross-bar 19. The body portion is fulcrumed to the supporting frame by means of pivots 2O 2O afliXed to the frame and engaging sockets 20 in the arms 17 and 1S and located at points near their inner ends. The body portion of the rockingbase is provided with an extension 30, projecting from l one side of the axial line of the pivots and forming the longer arm of a lever, the shorter arm of which is formed by the body portion of the rocking base. The extension 30 is preferably formed on the arm 18 of the body portion.

21 represents a treadle, which is connected by a rod 22 to the arms 17 1S of the rocking base, the rod entei'ing sockets 2i" in said arms and constituting a pivotal connection between the said treadle and arms, said connection being preferably near the outer ends of the arms and one edge of the treadle. The treadle projects from its pivotal connection with the arms across the body portion of the rocking base and beside the lever eX- tension 30.

Q3 23 represent springs which are interposed between the treadle 2l and the crossbar 19 of the rocking base. The said springs are adapted to be compressed by a downward moven'ient of the treadle and to impart such movement yieldingly to the rocking base. rIhe extension 30 of the rocking base is connected by a pitman 25 with the crank shaft l2, and the treadle 2l is connected by a rod 26 with an ear T affixed to the clutch plate 1G. rThe oscillation of the treadle therefore oscillates the clutch, and imparts motion yieldingly through the springs 23 to the rocking base, which, in turn, imparts a rotary motion to the crank shaft through the pitman 25.

It will be seen that the treadle which is adapted to move independently of the rocking base, when depressed causes a compression of the springs 23, so that not only is motion tansmitted from the treadle to the rocking base through said springs, but power is also stored in the springs by the downward movement of the operators foot on the treadle, this power being imparted to the crank shaft, through the arm 30 and rod 25 to compensate for temporary increase of resistance to the running of the machine, whether by the addition of more work or from other causes. The upward movement of the treadle is assisted by the springs, but does not depend wholly upon them, but in part upon the pressure exerted by the operators heel upon the forward portion of the treadle at the outer side of the springs. It will also be seen that the freedom of independent niovement of the treadle and the yielding connection between it and the rocking base, enables the amplitude of the vibrations of the treadle to be reduced to the minimum. llhile the rocking base must necessarily oscillate in a path or fixed extent or amplitude, the treadle, which is directly connected only with the clutch, can move in a path of varying and lesser amplitude, hence the toe portion of the operators foot is not required to rise and fall to the extent that would be required if direct contact between the foot and the rocking base were required. I have found in practice that by giving the treadle a direct connection only with the clutch, and providing the rocking base yieldingly connected with the treadle as the means for imparting motion from the treadle to the crank shaft, the operation of the machine is materially simplified, the

operator having but one treadle part to manage, instead of having two treadle parts as heretofore. I have also found that the operation is attended with less jar or jerk-. ing motion and vibration than in my former constructions.

I prefer to make the springs Q3 of helical form, and so proportion them that their convolutions will close and act as a stop to limit the independent downward movement of the treadle, so that the treadle cannot strike the rocking base, the noise and ar which would attend direct contact between the treadle and the base, being avoided. The arms 17 1S of the body portion of the rocking base are preferably provided with stop ears 2S, which project under the forward portion of the treadle.

It will be seen that the treadle presents a heel bearing directly over the pivotal connection of the treadle to the base, and at one side of the fulcrum of the base, and a toe bearing at the opposite side of said fulcrum. A downward movement of the operators heel is therefore imparted directly to the rocking base through the pivot connecting the treadle to the base, while a downward movement of the toe causes the treadle to swing downwardly on its pivot and impart a corresponding movement to the rocking base.

I claim:

l. The combination with a crank shaft and a clutch thereon, of a support, a rocking base fulcrumed on the support, and formed as a lever, a connect-ion between said lever and the crank shaft, a treadle pivoted to the said base and adapted to oscillate independently thereof, a connection between said treadle and the clutch, and a powerstoring and delivering connection between the treadle and the base. Y

2. rlhe combination with a crank shaft and a clutch thereon, of a support, a rocking base fulcrumed on the support, and formed as a lever, a treadle pivoted to thet base and adapted to oscillate independently thereof, connections between said base and treadle to the crank shaft and clutch respectively, and a spring engaged with the treadle and base and adapted to yieldingly transmit motion from one of said parts to the other.

3. In a driving mechanism of the character stated, a support, a rocking base constituting a two-armed lever, and comprising a body portion fulcrumed on said support, and forming the shorter lever arm, and an eXtension forming the longer lever arm, a treadle pivoted to the shorter arm of the body portion, and Vextending across the fulcrum of the lever, and springs interposed between the treadle and the body portion, and adapted to yieldingly transmit motion from the treadle to the rocking base.

4. In a foot power driving mechanism, a

and a toe-bearing et the opposite side of said fulcrum.

In testimony whereof I have affixed my signature, in presence of tWo Witnesses.

JOHN FRANKLIN WLKINSON.

Witnesses:

C. F. BROWN, E. BATGHELDER.

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