US 1507712 A
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Sept. 9, 1 24. 1,507,712
C. s. PROUDFOOT CABLE EQUALIZEH Filed April 18 1922 lzarles 6i Prazuybat.
Aliarne Patented Sept. 9, 1924.
UNITED STATES PA NT- CHARLES s. rnounro'or; or WES'IMONT, PENNSYLVANIA;
CABLE neunrrzna. I
Application filed April s, 1 22. Serial No. 555,007.
To all whom it may concern Be it known that I, CHARLES S; PROUD FOOT, a citizen of the United States, and a resident of the borough of VVestm'ont, county of Cambria, and State of Pennsylvania, have invented vcertain new and useful Iniprovements in Cable Equalizers; and I which are wound on and unwound from a drum of a hoisting mechanism, or otherwise overhauled, in order that the tension in each part of the cable shall'be similar and the hoisting portion of the apparatus maintained in relative position. i,
cable equalizer operates automatically and is particularly adapted for usein connection with power cranes or other hoisting apparatus, and especially sofor handling heavy loads.
In hoisting apparatus of'this kind the cable may be wound on or unwound from a power-operated drum or spool preferably provided with spiral grooves in which wire cables are seated, and these cables arethen led downwardly and rove around a sheave or sheaves arranged in any of the wellknown manners, and prior to my invention the bights of anumber of cables were rove. over sheaves so mounted that they could be adjusted by means of adjusting screws and nuts.
Prior types of cable equalizers are'necessarily in most inaccessiblelocations between the upper part of the apparatus "and the ground, and'these arenot automatic, "so that their adjustments may be made at one time and they may be out of adjustment shortly thereafter, especially if heavy loads are lifted, causing one portionof the cable or one cable to stretch more than the other. As compared with these prior nOn autOmatic equalizers, my cableequalizer is automatic in operation and requires no attention and adjusts itself at all times.
In connection with a hoisting apparatus of the general character above described-the bights of intermediate or preferably cone tral portions of the hoisting cables are led over my apparatus partof which comprises two eccentrics or eccentric sheaves secured together or in a fixed relation to each other and arranged with their throws diametr 'cally 'opposite'or at an angle with each other.
Thel'throw of the eccentricis' the distance from-the shaft axis on which it'is mounted to the center of the eccentric. Theseeccentrics are provided with'grooved rims and one cable is rove-in the grooveof the mm of one eccentric and the other cable in the groove of the vrim of the other eccentric.
These eccentrics are preferably adjusted in the first instance with their axes of throw substantially horizontal and extending in opposite directions, thus being preferably at' anangleof180 degrees with each other they may be arranged'at a lesser angle if desired','-but' with'their throws non-cointo fully utilize their equalizing effect, but
c'ident, and if [one of the-ropes or cables stretches more than the other one, the eccentric aroundwhich it is rove will yield in one direction while the other eccentric will move oppositely, so that the tension will thereby be equalized and"so"maintained at all times. This williequire' no attentionwhatever until the axis of throw of,the eccentrics has I become substantially vertical, or nearly in'linewi'th' the cablesjand with the size of equalizerl have i'isedthis "will allow for a' differenceinf'stretch between the ropes of. one foot orjmo-re. If these eccentrics were made solid they would operate as above described, provided the hoisting' sheavesdo not "Swing so thatthe axis 'oflift is substantially vertical 'at all times,- but as, howevefiduring certain hoisting operations theload is apt'to swing a littleat times, I provide each of my 'eccen'sv trics with'a slip ring so mounted that the swinging motion, of th'e" cables will permit centrics to prevent chafing or rubbing the the slip 1 rings to' creep slightly on the ectrio sheaves which are preferably formed 7 integral andmounted rotatably' on a) shaft,
:I secure ,thein relatively by keying separate ,eccent'rics'on ashaft-and permit the shaft'to rotate in bearings, or I may use another form of equalizer in" which" the sheaves areeccentricallymounted on op- "po'sed crank arms, which crank arms form part of a shaft/adaptedt'o rotate in' bearings, inwhi'ch case the sheaves may alsorotate on the crank'pins, thereby obviating the I the eccentric sheave, may be arranged at any angle to each other, so long as these lines are not coincident, that is, in the same plane and extending in the same direction.
Having thus given a general description of my invention, I will now, in order to make the matter more clear, refer to the annexed sheet of drawings, which form part of this specification, and in which like characters refer to like parts v Figure 1 is a front elevation of my improved equalizer showing a portionof the framework upon which it is mounted, broken away to more clearly show the manner of construction and operation; Fig: ure 2 is an end elevation of the apparatus shown in Figure 1 with the framework broken away to show the shaft mounting; Figure 3 is a detail side elevation of the reccentrically mounted equalizing sheave, and Figure 4 is a vertical sectional elevation through the eccentrically mounted equalizing sheaves taken on the line 1V-IV of Figure 3.
Referring now to the characters of reference on the drawings 2-1 indicates the hoisting drum as a whole, carried by the shaft 2, which may be mounted in any suitable bearings, the right hand portion of the drum 3 being provided with left hand spiral grooves, while l is the left hand portion of the drum provided with a right hand series of spiral grooves and forming part of or attached to the drum is the gear wheel 5 adapted to mesh with a pinion to rotate it in either di- ,rection by any suitable source of power.
Mounted on the framework and forming part ofthat on which the drum is also mounted is a shaft 8 carried in bearings on a downward extension of the framework 10 and stiffening angles 9, and on this shaft the cable sheaves 6 and, 7 are mounted as illustrated. Other sheaves 11, 12, 13 and 14 areprovided and may be mounted in a lifting beam or cradle, not shown, or these may be provided with hooks or any other apparatus to carry the loads to be lifted, and these sheaves are mounted upon the shaft 15. The cables, which are preferably of wire, are 16, and in order to follow their arrangement'they may be said-,tobegin at the left hand side, which shows a double cable adapted to be wound or unwound in the spiral grooves of the drum portion 4:,
thence passing downwardly, around the sheave 11, thence upwardly around the sheave 7, thence downwardl sheave passes upwardly with its bight around. the eccentrically mounted equalizing sheave 17, while the bight of theother cable passes around the other eccentrically mounted equalizing sheave 18, each of these sheaves beingmounted upon the shaft 19 with their axes of throw fixed oppositely or at an angle of about 180 degrees or substantially in the same line. The two cables after passing around the equalizing sheaves 17 and 18, respectively, thence lead downwardly around the lower sheave 13, thence u wardly and around the upper sheave 6, tiencedownwardly and around the lowersheave 1 1, and thence upwardly and into the spiral grooves" of the right hand portion 3 of the drum, all ends of the cables being secured to the drum in any customary manner. The equalizing sheaves 17 and 18 are preferablyformed integral and rotatably mounted on the fixed shaft 19, or they maybe separate and keyed to the shaft, which in that case would be adapted to rotate in the bearings.- 'The shaft 19 is mounted in the. framework; 10 and firmly securedtherein by. keys as i1: lustrated, or otherwise, and each of these eccentric equalizing sheaves 17 and 18 may bemade integral and provided with a groove inits circumference, or each sheave around the 12 and thence one of these cables may have a center portion provided with a separate grooved slip ring 20 mounted thereon with oil holes 21 for lubricating the bearing surfaces, and after these rings are in place they may be secured by the washers 22, and in order to avoid the useuof loose parts the washers may be electrically welded to the eccentric sheave centers 17 or 18, or
they maybe secured thereto in any desired:
During the operation of the crane or lift;
around one eccentric sheave, such as 17, and,-
the other around the other eccentric sheave 18, their own tensions will automatically adjust the position on the sheaves, and 'ifone rope is longer, or has less tension thanthe other, its sheave will rise a little and the other sheave will correspondingly lower, so i that the tensions and lengths of the two ropes are adjusted automatically. The
equalizing sheavesare preferably locatedto receive intermediate or central bights of the cables. the shaft 15 and attachments should swing slightly during the lifting or lowering op- If the lifting sheaves mounted on a eration, the cables 16 would swing slightly and have a tendency to rub or chafe on the sheaves 17 and 18, but this is obviated by the use of the slip rings 20, which allow a slight creeping of these rings due to the swinging action, so that the cables will not be chafed at any time.
Although I have shown and described in detail a pair of sheaves with their throw arms relatively fixed opposite, or at an angle with each other, adapted to equalize one pair of cables or I may use a plurality of these adapted to separately equalize any number of pairs of cables desired.
Although I have shown and described my invention in considerable detail, I do not wish to be limited to the exact and specific details thereof, as shown and described, but may usesuch modifications in, substitutions for, or equivalents thereof as are embraced within the scope of my invention or as pointed out in the claims.
Having thus described my invention, what I claim and desire to secure by Letters Patent is 1. A cable equalizer comprising a pair of sheaves eccentrically mounted on a shaft which extends through them and within their peripheries with their throw arms relatively angularly disposed.
2. A cable equalizer comprising a pair of sheaves directly and eccentrically mounted on the same shaft which extends through them and within their peripheries, with their throw arms extending oppositely. I
3. A cable equalizer comprising a pair of sheaves directly and eccentrically mounted on the same shaft which extends through them and within their peripheries, with their throw arms relatively angularly disposed. 4. A cable equalizer comprising a pair of sheaves directly and eccentrically mounted on the same relatively fixed shaft which extends through them and within their peripheries, with their throw arms oppositely arranged. j
5. A cable equalizer comprising a shaft and a pair of integral sheaves rotatably and eccentricaly mounted thereon, with their throw arms oppositely fixed.
6. A cable equalizer comprising a pair of sheaves rotatably and eccentrically mounted on the same fixed shaft and secured together with their throw arms oppositely arranged.
7. A cable equalizer comprising a pair of sheaves rotatably and eccentrically mounted and secured together with their throw arms oppositely disposed, and a slip ring rotatably mounted on each sheave.
v 8. A cable equalizer'comprising a pair of eccentric sheaves integrally formed with their throw arms oppositely disposed, a
grooved slip ring mounted on each sheave and means for rotatably securing said slip rings in position thereon.
9. A cable equalizer comprisinga plurality of sheaves eccentrically mounted on a common shaft with their throwarms relativelyangularly fixed, and a grooved slip ring mounted on each sheave;
10. In a hoisting apparatus, a rotatable drum. power cables rove thereon, hoisting and leading sheaves around which said cables are rove, an equalizing device comprising a pair of sheaves directly and eccentrically mounted on the same'shaft which extends through them and ":within their peripheries, with their throw arms oppositely fixed and over which the bights of the sheaves around which said cables are rove,
an equalizer mounted on the framework comprising a common shaft, a pair of eccentrio-ally mounted sheaves on said common shaft which extends therethrough, the throw arms of said sheaves being oppositely fixedt oHARL 's's, PROUDFOOT.