US1021836A - Lever mechanism. - Google Patents

Description

OOLUMI A PLANOUIAPH 00., WASHINBTON, D. c.

A. JOHNSTON.

LEVER MECHANISM.

APPLICATION FILED AUG. 1,1910.

PafentedAilr. 2, 1912.

2 SHEETS-SHEET 1.

A TTORN E Y.

A. JOHNSTON.

LEVER MEOHANISM.

APPLICATION FILED AUG. 1, 1910.

1,021,836. Patented Apr. 2, 1912.

2 SHEETSSHEET 2.

WITNESSES: IN VENTOR.

A TTORNEY.

COLUMBIA PLANOGRAPH 4:0.- WASHINGTON, n. c, 1

UNITED sTATEs PATENT oE IoE.

ANDREW JOHNSTON, OF TORONTQ ONTARIO, CANADA, ASSIG-NOR- TO MASSEY -I-IARRIS CO., LIMITED, OF TORONTO, CANADA.

LEVER MECHANISM.

Specification of Letters Patent.

Patented Apr. 2, 1912.

Application filed August 1, 1910. Serial No. 574,899.

To all whom it may-concern:

Be it known that I, ANDREW JOHNSTON, of the city of Toronto, in the Province of Ontario, Canada, have invented certain new and useful Improvements in Lever Mechanism, of which the following is a specification. 1

This invention relates to harrows in which an adjustable spring pressure is to be applied to lever mechanism especially adapted for the inner ends of the gangs by means of crank arms pivoted on the tongue or other member of the frame of the barrow, actuated by a hand lever and held as adjusted by suitable retaining means and my object is to (l) devise simple means for giving the hand lever as much leverage as possible, (2) to render it impossible for the lever to fly back and strike the driver when the retaining means: are released to take the spring pressure off the gangs, (3) to provide combined means tending to maintain the retaining means in normal working position and the hand lever out of working position. I attain these objects by the constructions hereinafter described and illustrated in the accompanying drawings in which- Figure 1 is a side elevation of a portion of a disk harrow provided with my improved lever mechanism. Fig. 2 is an enlarged side elevation partly broken away of the pressure adjusting mechanism. Fig. 3 is a plan view of the same parts. Fig. 4 is a front elevation of the same parts. Fig. 5 is a side elevation of the adjusting quadrant. Fig. 6 is a detailed side elevation of the lower end of the adjusting lever showing in full and dotted lines respectively its in engagement and out of engagement positions.

In the drawings like letters of reference indicate corresponding parts in the different figures.

A is the rear end of the tongue of the disk harrow. B is the usual cross bar of the frame, C an inner bearing of one of the disk gangs, D one of the adjusting bars for varying the angle of the gang. E is the ad-. justing lever therefor, F a crank arm secured on the shaft G j ournaled transversely of the tongue A the said arm extending rearwardly over the cross bar B. This crank arm is preferably double, as shown particularly in Fig. 3, and is trunnioned on the collar a sliding onthe pressure rod H. Engaging this collar is the coil spring?) the lower end of which engages the collar 0 fast on the pressurerod. A suitable stop such as a nut d is secured to the upper end of the pressure rod H. These parts are all old in the art, and it results that by rock- To the shaft G is secured a ratchet toothed.

quadrant I. This lies within the casing J suitably bolted to the tongue. On this casing is pivoted the retaining dog K provided with the foot engageable part 6 whereby it maybe thrown out of engagement with, the toothed quadrant. For the purpose of actuating the quadrantI provide the lever M. As very considerable pressure must be applied to the gangs it is in practice found very diflicult to secure in a neat form eflicient leverage for actuating the crank arms F. I have overcome this difficulty by pivoting the lever M on the easing J between the shaft G and the notched periphery of the quadrant I. Much greater leverage with the same length of lever may thus be obtained than by directly connecting the lever with the shaft G.

The lever engages the notched quadrant through the medium of an engaging part or projection f. As this part, when the lever is rocked, must move in the same are as the teeth of the quadrant with which it is engaged I cannot provide a fixed fulcrum point for the lever M. To obtain the necessary shift-ing fulcrum I provide the casing J with a stud N engaging in a slot 9 arranged diagonally at the lower end of the lever M. This arrangement allows the lever to rise and fall to permit the engaging part, f thereon to follow the path of the teeth with which it is engaged. This slot also fills a second function which will shortly appear. The dog K has a forwardly extending tail it formed thereon. To this tail is pivoted one end of a toggle O, the other end of which is pivoted on the casing J.

This toggle is preferably normally somewhat bent as indicated. The coil spring P is secured at one end to the lever M and at the other to the toggle O. This spring tends to draw the lever forward to the po sition shown in the drawings and also tends to yieldingly maintain the dog K in engagement with the toothed quadrant I. The tendency of the spring is not only to draw forward the lever M but also draw it against the projection i to lift to and to retain it in a position with the stud N in the bottom of the slot 9 in which position the engagaing part f is clear of the teeth of the quadrant I. The projection 2' is formed on the casing J and it will be seen that it forms a fulcrum which is engaged by the engaging part f of the lever and on which the lever may rock to the position shown in Fig. 6 (see also Fig. 1.) The result of this arrangement of the spring and the method of pivoting the lever is that if the dog is kicked out of engagement with the quadrant I the sudden return of the latter to its normal position under the influence of the spring Z) does not set up a violent vibration of the hand lever which would be dangerous to the driver on the seat Q.

The action of the device in view of the above description will be readily understood. The notched quadrant may be adjusted a tooth at a time by the hand lever and held by the retaining dog, the hand lever every time it is released being automatically returned to the forward position where it is out of engagement with the notched quadrant.

It will be noted that the dog K always engages one tooth behind the lever consequently it is desirable that the lever shall not be allowed to engage with the last tooth on the quadrant as there would be no tooth then behind for the dog to engage. I therefore partly build up the last tooth I as indicated particularly in Fig. 5 leaving only sufficient for the retaining dog to engage. This arrangement is possible as the dog engages the quadrant in a plane behind the hand lever.

That I claim as my invention is 1. In lever mechanism the combination of a pivoted ratchet segment; a fulcrumed actuating lever for the said segment liftably mounted on its fulcrum and adapted to engage the teeth of the ratchet; a pivoted retaining dog for the ratchet segment; and a single spring connected with both the lever and the said dog tending to draw said lever back and out of engagement with said ratchet teeth and tending also to maintain the dog in its normal position.

2. In lever mechanism the combination of a pivoted ratchet segment; a suitably fulcrumed actuating lever for the said segment adapted to engage the teeth of the ratchet in one direction or to slip back over said teeth in the opposite direction; a pivoted retaining dog for the ratchet segment; a toggle lever pivot-ally connected with a stationary part and thesaid dog; and a spring engaging said lever and the said toggle and tending to draw back said lever and to maintain the dog in its normal position.

3. In lever mechanism the combination of a pivoted ratchet segment; an actuating lever having a fulcrum located between the crank arm pivot and the periphery of the ratchet segment, and independent thereof; a segment-engaging-part on said lever, the lever being adapted to rise and fall on its fulcrum to permit the segment-engaging part to follow the arc of travel of the notch with which it may be engaged; a spring tending to draw back said lever; and a stationary part above and adjacent the fulcrum against which the spring is adapted to draw the lever to lift it on its fulcrum and disengage it from the ratchet segment.

Signed in the presence of ALF. DAY, WVALTER SHORT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

- Washington, D. G.

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