US1423007A - Intermittent-grip device - Google Patents

Description

s. s. MORTON.

INTERMITTENT GRIP DEVlCE.

APPLICATION FILED SEPT.Z5,1920.

Patented July 18, 1922.

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S S. MORTON.

INTERMITTENT GRIP DEVICE.

APPLICATION FILE D SEPT. 25, 1920.

1,423,007. Patented July 18, 1922.

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Zfi b/ .kE- 3 g stars rear INTERMITTE T-GRIP DEVICE.

Specification of Letters Patent. g mma; J l 18 1922 Application filed September 25, 1920. Serial No. 412,739.

following to be a full, clear, and exact de-,

scription of the invention, such as will on able others skilled in the art to which it appertains tomake and use the same.

My invention relates to improvements in intermittent grip devices for driving shafts and the like in a step by step manner, and the invention has more particular reference to a device of this character havingan oscillating motion.

This application forms a continuation in part of my United States application, Serial No. 323,709 filed Sept. 15, 1919.

One object of the invention is to provide an intermittent grip device which may be set quickly and easily for driving a shaft or the like in either direction, or set with equal facility in a neutral position at which no driving of the shaft will take place, even though the device continues to oscillate.

In carrying out the above, a flexible friction band surrounds the drum or shaft to be driven and an oscillating lever is connected to the ends of said band for alternately contracting and releasing the latter. Before the device will operate in .thismanner, however, the hand must be initially contracted by relatively canting the band and lever, and a further object is to provide: yielding means for effecting this canting, without interfering with pro-per release of the band on the idle strokes of the lever.

Astill further object is to provide a device of the class set forth in which the flexible band is contracted by cam action and in which the strengthwith which the shaft is gripped, is increased as thc resistance to turning increases, thereby posltlvely war-ding against any slippage of the band on the shaft or drum.

Yet another object is toprovide anintermittent grip device which will be. compara tively simple and inexpensive, yet absolutely positive in operation, and one in which little wear will occur.

With the foregoing and minor objects in view, the invention resides in the novel con struction and arrangement of parts hereinafter described and claimed, the descriptive with a matter being supplemented by the accompanying drawings. 7

Figure 1 is an elevation, partly in section, showing an intermittent grip device constructed in accordance with my invention.

Figure 2 is a horizontal sectional view out principally on line 22 of Fig. '1, parts however being broken away and in section below this line. i

F igure'3 is a vertical sectional view with parts in elevation, showing a different position of parts from that disclosed in Fig. '1.

F igurew3 is a detail horizontal sectional view taken on line Zi -3 of Fig.

Figure 4 is a vertical transverse section as viewed on line 4.4c of Fig. 1.

Figure 5 is a view in elevation showing.

metal links 5, 6 and 7, the link 7 being positioned between the inner ends of the links 5 and 6 and pivoted thereto at 8. The inner sidesof all ofthe links, are curved for tight contact with the drum 2 and I provide means for loosely connecting the free ends of the links 5 and 6 with each other and for fulcruming thelever 4; to the band. In the present showing, the link 5 is provided airof inwardly extending ears 9 and the ink 6 is'formed with a similar ear 10 loosely received'between said ears 9. All

of the ears 9 and 10 are slotted in a direction transverse to the axis of the drum 2 and for future reference I have given the slots of the ears 9 the reference numerals 9 while 10" refers to the slot of the ear 10. These slots loosely receive a fulcrum pinll by m'ean'sofwhich the oscillatory lever 4 is connected with the band 3. The inner end of this lever is provided with a T-head 12 whose center carries the fulcrum pin 11 and whose ends are provided withrollers 13 or other appropriate shoes which engage cam surfaces 14 on the outer terminals 15 of the links 5 and 6. 'The band is normally spread or opened to bring the shoes and cam surface into contact, by means of a coil spring or the like 16, the outer ends of the slots 9 and 10,thatis the ends adjacent the free ends of the ears 9 and 10, then receiving the fulcrum pin 11 as shown in Figs. 1 and 2. With the parts in this position, the lever 4 maybe oscillated without any turn ing effect whatever on the drum 2, since the band 3 is loose on the latter and will turn to and fro with said lever. By relatively canting the band and lever, however in either direction, said band is initially contracted or tightened upon the drum so that the frictional contact thus created, will cause the lever 4 to tilt on the fulcrum 11 during any subsequent movement. Nhen the lever tilts in one direction on the fulcruin 11, the band 3 is tightened and thereby rigidly grips and turns the drum 2, but

during the return motion of the lever, the band is loosened to some extent and turns freely on the drum. By forcing the inner end of the lever in one direction, transversely of the drum 2, the gripping device is set for rotating the drum clockwise, while forcing the end of the lever in the opposite direction will cause counter-clockwise rotation, and fOT'tllG purpose of effecting this shifting, I may provide any'appropriate means, two examples being given below.

In the form of construction shown in Figs. 1, 2 and 3, the T-head 12 is provided with a laterally extending arm 20 having a roller or other shoe 21 on its free end which is received in a curved guide 22 concentric with the drum 2, said guide being carried by the end of a spring arm 23 which is anchored at 24 to any suitable supporting structure 25. Between its ends, the spring arm 23 carries a stirrup 26 receiving a cam 27 on a rock shaft 28 which may be turned at will by a suitable lever or the like 29. l/Vhen the cam 27 is turned in one direction, the spring 23 and the guide 23 are moved in the same direction, thereby shifting the T-head 12 transversely of the drum 2. mien the cam is turned in the opposite direction, however, said T-head is moved reversely. It will thus be seen that by properly actuating the lever 29, the grip device may be set for driving the drum 2 in either direction or for idling upon said drum.

In the form of construction shown in Fig. 5, the arm 20 is dispensed with and a yielding lever 30 is fulcrumed near one end to the cross head 12 of the lever 4, preferably upon the fulcrum pin 11 above described. At its inner end, the lever 30 is provided with a fork or other appropriate bearing 31 which bears on the drum 2. Near the outer end of the lever 30, the lever 4 is provided with a series of, teeth 32 into engagement with which said lever 30 may be" sprung.

this lever is moved in one direction, the T- head 12 is shifted in the corresponding di rection, while reverse movement of the head may be effected by shifting the lever 30 in the opposite direction. This lever may be held in either of its extreme positions or at a neutral position by means of the teeth 32 and it will therefore be seen that by means of said lever, the device may be set for idling or for driving either forwardly or rearwardly. Due to the resilient nature of the lever 30 and the spring 23, slight movement of the inner end of the lever 4, trans versely of the drum 2, as said lever alternately contracts and releases the band 3, is permitted and it will also be seen that the lever 4 is in no manner seriously resisted in its tilting upon the fulcrum pin 11.

As clearly shown in the several views, the T-head 12 is preferablyconstructed of two metal plates secured to opposite sides of the lever 4 and the free ends of the links 5 and 6 are received between said plates for cooperation with the shoes 13. flowever, although this construction is preferred, it need not be followed in all instances.

Regardless of the exact details disclosed, the operation of the device is as follows: As long as the T-head 12 is held in a neutral position by means of the arm 20 and associated parts, or the lever 30, the band 3 is loose upon the drum 2 as shown in Figs. 1 and. 5- and hence said band will turn freely with any oscillation of the lever 4 and will produce no driving of the drum. The moment that the band 3 and lever 4 are relatively canted, however, in either direction, driving of the drum takes place. In Fig. 3, the cam 27 has been operated, to cause the spring 23 and guide 22 to shift the T-head 12 to the left. This movement pulls the fulcrum pin 11 into tight contact with the outer ends of the slots 9 as shown in the detail sectional view, designated Fig. 3*. At the same time, the left hand shoe 13 is brought into contact with the adjacent cam surface 14, crowding the link 6 inwardly and contracting the entire band 3 upon the drum 2. When the lever 4 now moves to the right, it will turn slightly upon the fulcrum pin 11 since the band 3 is now frictionally gripping the drum 2. The moment this turning of pin 1.1 takes place, the lefthand shoe 13 coacts with the cam surface 14 to crowd the link 6 into still tighter contact with the drum. During this action, the fulcrum pin 11 draws to the left on the free end of the link 5 and the latter is thus also tightly held against the drums The result is that no slippage whatever of the band 3 takes place and the drum 2 is positively turned in the direction of the arrow shown in Fig. 3. Whenthe lever 4 moves on its return or idle stroke, that is to the left, the left-hand shoe 13 rides down the cam surface 14- with which it was previously in contact, thereby releasing the grip of the band 3 on the drum 2, with the result that said band returns to its initial. position without moving the drum in a retrograde direction.

/Vhenever it is necessary to reverse the direc tion in which the drum 2 is driven, the cam 27 is operated to throw the spring 23 to the right. The same operation as that above described then takes place, except that the right-hand shoe 13 and cam surface 14 come into play, and the fulcrum pin 11 pulls against the outer end of the slot 10 The device will therefore be operative when moving in the direction in which it was previously idle, and vice versa.

The operation of the form of construction shown in Fig. 5 is identical with that above set forth, the only difference between the two forms being in the manner of relatively canting the band 3 and the lever a.

From the foregoing, taken in connection with the accompanying drawings, it will be seen that I have devised a comparatively simple and inexpensive, yet a highly ellicient and in every way desirable, intermittent grip device. This device is usable wherever a ratchet motion is necessary, for instance on the drum of a wire stretcher, in which instance the form of construction as shown in 5 is preferably followed. Figs. 1, 2 and 3 illustrate the form of construction which is preferably followed when adapting the invention to a transmission mechanism, for instance on a tractor. In these views the numeral 25 represents a portion of a transmission casing in which all of the working parts may be located. lWhen the invention is used in this connection. the lever l is power driven, but this need not be entered into in detail in view of the fact that the present application is restricted to the intermittent grip device, regardless of its use.

Since numerous changes may be made without departing from the spirit of the invention, as claimed, it will of course be understood that the accompanying disclosure is for illustrative purposes only.

I claim:

1. In an intermittent grip device, a drum, a flexible band surrounding said drum, a band-contracting lever adapted to travel bodily along an arcuate path concentric with said drum, and means for positively canting said lever, and band relatively before any travel of said lever along said a-rcuate path, whereby to initially contract said band.

In an intermittent grip device, a drum, a flexible band surrounding said drum, a band-con'racting lever adapted to travel bodily along arcuate path concentric with said drum, and spring means acting on said lever for rocking the latter and positively contracting said band upon the drum besaid lever, and means on said lever engag= ing one of said ends and cooperable with the aforesaid fulcrum in contracting the band on the drum when the lever is'turned in one direction.

l. In an intermittent grip device, a drum,

a band surrounding said drum, a lever having one end positioned adjacent the ends of the band, means loosely connecting said ends with each other and forming a fulcrum for said. lever, one of said ends having a cam surface, and a shoe carriedby said lever at a point spaced from its fulcrum, said shoe engaging said cam surface to crowd said one end inwardly and thereby contract the band, when the lever is turned in one direction.

5. In an intermittent grip device, a drum, an oscillatory lever having a T-head at one end extending transversely of said shaft, a fulcrum pin at substantially the center of said T-head, shoes near theends of said T- head, a band surrounding the drum with its ends provided with openings loosely receiving said fulcrum pin, said ends having cams contacting with said shoes and acted on by the latter to contract the band for turning the drum in one direction or the other after said band has been initially contracted, and means for relatively canting said lever and said band to initially contract the latter for driving in either direction.

6. In a transmission, a drum, a contractable band surrounding said drum, means for turning said band alternately in opposite directions, for contracting said band around said drum when turning in one direction and for releasing said band when turning in the other direction, and means under the control of the operator for positively contracting said band initially and for releasing said band independently of the band operating means.

7. In a transmission, a drum, a friction band surrounding said drum, a floating lever to which the ends of said. band are connected, means for moving said'lever bodily in a to and fro manner, a shoe carried'by said lever and located at a point spaced laterally from its fulcrum, a curved track concentric with said drum and in contact with said shoe, and means for shifting said track toward and, from said drum.

8. In a transmission, a drum, a friction band surrounding said drum, a floating lever to which the ends of said band are connected, means for moving said lever bodily in a to and fro manner, a shoe carried by said lever and located at a point spaced laterally from its fulcrum, a curred track concentric with said drum and in contact with said shoe, a spring connected to said track, and means for moving said spring to shift said track toward and from the drum.

9. In a transmission, a drum, a friction hand surrounding said drum, a floating lever to which the ends of said band are eonneoted, means for moving said lever bodily in ato and fro manner, a shoe carried by said lever and located at a point spaced my hand.

SAMUEL STEPHEN MORTON.

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