US2445228A

US2445228A - Pull cable control

Info

Publication number: US2445228A
Application number: US737053A
Authority: US
Inventors: Tourneau Robert G Le
Original assignee: LeTourneau Inc
Current assignee: Keppel LeTourneau USA Inc
Priority date: 1947-03-25
Filing date: 1947-03-25
Publication date: 1948-07-13
Anticipated expiration: 1965-07-13

Description

y 1948- R G. LE TOURNEAU 2,445,228

rum. cum: con-men Original Filed Nov. 25, 1943 Fig. 2

R. GLQYZ'DuTneaw Patented July 13, 1948 UNITED PULL CABLE CONTROL Robert G. Le Tourneau, Longview, Tex assignor to R. G. Le Tourneau, Inc., Stockton, Calii'., a

corporation of California Substituted for abandoned application Serial No.

511,498, November 23, 1943.

This application March 25, 1947, Serial No. 737,053

This invention relates in general to, and it is an object to provide, a pull cable control device adapted to be applied to a live cable in a power driven cable system; said cable control device being operative to limit the .pull or tension which may be applied to said live cable, whereby to prevent cable damage, breakage to the mechanism which the cable system actuates, and personnel injury which might result ,from cable breakage.

A further object of this invention'is to provide a pull cable control device which is arranged to deflect a portion of the live cableout of straight line relationship with the remainder of the cable; said device being responsive to the tendency of said portion of the cable to straighten out as the pull or tension of the cable increases, and upon a given maxim-um cable tension being reached functioning to shut off the power source creating said cable tension.

An additional object of the instant invention is to provide a pull cable control device, as in the preceding paragraph, which includes manually controlled regulating means to alfiust the device to shut off the power source at different cable tensions; and means including a foot pedal arranged to be operator actuated.

It is also an object of the invention to provide a pull cable control device for a cable actuated mechanism, comprising a pivotally supported frame, a pair of sheaves mounted on the frame in adjacent but spaced relation, means yieldably maintaining said frame in position so that when a live cable reach is threaded about said sheaves from opposite sides, the portion of the cable extending between said sheaves is out of straight line relation with the remainder of the cable, a relatively long control or trigger arm fixed on and-projecting from the frame at right angles to the axis of the sheaves, and means to shut oi! the power source upon predetermined swinging of the frame and arm under the influence of said cable portion tending to straighten out when increasing tension is applied to said cable.

A further object of the invention is to produce a simple and inexpensive device, and yet one which 4 Claims. (01. 254-173) 2 of the invention applied to a cable-actuated lever press.

Fig. 2 is an enlarged fragmentary sectional elevation of the cable actuated sheave frame of the pull cable control device.

Referring now more particularly to the characters of reference on the drawings, the pull cable control device is here shown as embodied in the actuating mechanism of a lever press which follows substantially the structure shown in my Patent No. 2,370,739, dated March 6, 1945. This lever press comprises generally an upstanding press body i which supports a walking beam 2 pivoted as at 3, and from which walking beam a plunger 4 depends through the body into a working chamber or opening 5. The walking beam 2 includes a counterweight 8 at one end,

- and is connected at the other end with a block and tackle type cable system, indicated generally at I, which includes a sheave 8 on the walking beam and another sheave l fixed in connection with the floor therebelow.

The .pull reach iii of the cable system 1 leads downward to a cable drum ii of a power winch I! which includes an electric drive motor I3 and a fiuid pressure actuated clutch it. The clutch is controlled through the medium of a conduit II, by means of a valve I8 mounted on the body I some distance above the floor, and said valve includes an outwardly projecting operating handle ii.

In the above described lever press, operation of the winch II to wind the pull cable iii onto drum il shortens the cable system 1, causing the walking beam to swing downward and advance the plunger 4. When the cable system I is released the counterweight 6 swings the walking beam in the other direction and raises the plunger,

The above forms no part of the present invention and is merely an example of one type of cable actuated mechanism upon which the pull cable control device may be employed, and which device comprises the following:

will be exceedingly effective for the purpose for A pair of sheaves II are journaled in relatively closely spaced relation, and with their axes parallel, in a sheave frame F which includes spaced side plates is secured in rigid connected relation by cross members 20.

A live pull reach Ii of the cable system I is threaded through this sheave frame with the cable passing about one side of one sheave it and about the other side of the other sheave II.

A relatively long trigger arm 22 is fixed in connection with the above described sheaveframe The relative tension of

springs

22 and 24 is such as to normally maintain the trigger arm 22 in a position so that the, sheaves ll deflect a portion 2' of cable 2| between sheaves ll out of straight line relation with the remainder 01' cable reach 2|.

claim as new and useful, and desire to secure by Letters Patent is:

In order to prevent the sheave frame F from traveling with reach 2| ,a pair of beams 29 project in rigid relation from post 26 to points on opposite sides of said sheave frame, the latter being pivotally connected intermediate the sheaves, as at 8|, to the outer ends of said beams whereby to allow of swinging movement of said frame in response to the tendency of cable portion 8 to straighten out relative to reach 2| upon increasing tension in the latter.

The free end of trigger arm 22 is disposed in position relative to valve handle |1 so that after predetermined downward movement of said trigger arm it will engage and move the valve handle I! downwardly. The valve II is arranged so that when handle I1 is swung downward, as by hand or by the trigger arm 22, the clutch It is disengaged and the drum ceases to rotate.

The operation of the above described pull cable control device is as follows:

The spring 21 is adjusted so that when the cable reach 2| is under initial and normal tension, the trigger arm 22 is held clear of the valve handle I'I. However, when the tension on the cable system 1 becomes relatively greater, as when the plunger 4 reaches the end of its stroke, such greater tension on the pull reach 2| tends to straighten out the deflected cable portion 28, which in turn causes a response in the trigger arm 22, i.'e., the sheave frame F swings about its axis I. in a direction to swing the trigger arm 22 downwardly where the latter contacts the handle With continued downward swinging movement of the trigger arm 22. as the tension on cable reach 2| increases, the valve handle I! is swung to an off position, whereupon the winch l2 becomes inoperative or idle, permitting the lever press to return to its initial or starting position.

If the operator desires to reduce the amount of cable tension necessary to operate the cable control device, as for example to effect release of the lever press more quickly than normal, the operator depresses pedal 21. This in turn increases the tension on spring 24 and results in downward swinging of the trigger arm 22 under lesser tension on reach 2| than otherwise.

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construct-ion of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from thespirit of the invention, as defined by the appended claims.

This application is a substitute for Serial No. 511,499, filed November 23, 1943, now abandoned.

1. A pull cable control device for a cable system which includes a live cable reach and a power unit to actuate said reach, the power unit having a movable control member; said device comprising a fixed support spaced from and extending generally lengthwise of the live cable reach, a rigid beam projecting from the support to a point adjacent said reach, a frame pivoted on said beam for swinging movement about an axis intersecting the longitudinal plane of said reach, a pair of. sheaves journaled on the frame in spaced, adjacent relation, said reach passing about said sheaves from opposite sides, the sheave and frame axes being parallel, a rigidly mounted trigger arm projecting from the frame toward the support, axially alined oppositely extending tension springs connected at adjacent ends with the arm adjacent its outer end, and means securing said springs at their outer ends; the springs normally maintaining said arm and frame in position so that the sheaves deflect a portion of said reach out of straight line relationship with the remainder of the reach, whereby the frame and trigger arm are responsive to the tendency of said cable reach portion to straighten out upon increased tension thereon, and the arm being in position to actuate said control member upon movement of the frame in response to such increased tension.

2. A device as in claim 1 in which the springs extend substantially vertically, and a foot lever, the lower spring being connected at its outer end with such foot lever.-

3. A pull cable control device for a cable system which includes a live cable reach and a power unit to actuate said reach, the power unit having a movable control member; said device comprising a pair of cable deflecting members disposed in spaced relation lengthwise of the cable reach and between which said cable reach passes, said members being so positioned as to normally contact and deflect a portion of said reach out of straight line relationship with the remainder of the reach, means mounting one member for movement in response to a tendency of said cable reach to straighten out under increased tension in said reach, such means including a pivoted frame in which such member is mounted, a trigger finger projecting from said frame, a pair of tension springs, one of said springs being fixed at its outer end and connected at its inner end to said trigger finger, a foot lever, the other spring being fixed at its outer end to the foot lever and at its inner end to said trigger finger, and means to actuate the control member of the power unit through movement of the trigger finger.

4. A pull cable control device for a cable system which includes a live cable reach and a power unit to actuate said reach, the power unit having a movable control member; said device comprising a frame, a pair of sheaves mounted on the and sheaves are positioned to deflect a portion of the cable reach out of straight line relationship with the remainder of said reach, the frame when so positioned being responsive to the tendency of said cable reach portion to straighten out under increased tension therein, and the trigger arm being in position to actuate the control member upon movement of the frame in response to such increased tension; said ,arm securing means comprising a tension spring fixed at one end and havingeits-other end connected withthe trigger arm, a second spring, and a foot lever, the second springbeing connected at one end to the foot lever and at its opposite endlto the trigger arm.

, ROBERT G. WURNEAU.

6. 7 REFERENCES OITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,434,539 Gusowski Nov. 7, 1922 1,703,743 Hair Feb. 26. 1939 1,779,656 Brauer Oct. 28, 1930 1,941,153 Bpinetta Dec. 28. 1933 FOREIGN PATENTS Number Country Date 10,381 Great Britain 1915 351,933 Great Britain June 18, 1931