US3048369A

US3048369A - Tagline fairlead construction

Info

Publication number: US3048369A
Application number: US835676A
Authority: US
Inventors: Leonard L Hanson
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-08-24
Filing date: 1959-08-24
Publication date: 1962-08-07
Anticipated expiration: 1979-08-07

Description

1962 IL. L. HANSON 3,048,369

TAGLINE FAIRLEAD CONSTRUCTION Filed Aug. 24, 1959 2 Sheets-Sheet 1 gg/ mm ATTORNEY 1962 1.. 1.. HANSON 3,048,369

TAGLINE FAIRLEAD CONSTRUCTION Filed Aug. 24, 1959 2 Sheets-Sheet 2 lNVENTO/R' ma m ZZZ/4%! h e A7 7 URNEVS.

3,048,369 Patented Aug. 7, 1952 3,048,369 TAGLHJE FAIRLEAD CONSTRUCTION Leonard L. Hanson, 14195 Thatcher Ave., River Forest, Ill. Filed Aug. 24, 195?, Ser. No. 835,676 6 Claims. (Cl. 254-139) This invention relates to taglines used for steadying material handling buckets or other devices suspended from the booms of cranes, and more specifically, to a fairlead structure adapted for use as part of such a tagline assembly.

As is well-known in the art, the term tagline commonly refers to an entire assembly used for steadying a bucket or grapple so that it will not twist during operation and so that it may be controlled more easily and accurately. Ordinarily, such an assembly includes a spring-operated reel mounted intermediate the upper and lower ends of a boom, the reel carrying a coil of cable connected at one end to the bucket or grapple suspended from the free end of the boom. During operation, the tagline cable winds upon and unwinds from the reel to apply a substantially uniform guiding force to the bucket and to prevent it from twisting about its suspension lines.

To guide the cable as it is wound or unwound from the reel, it is necessary to provide the tagl-ine assembly with a fairlead structure through which the cable passes. Such fairleads generally comprise a housing having two or more sheaves over or between which the tagline cables pass, the sheaves being provided for the purpose of reducing wear of the cable and fairlead assembly. However, in the operation of a crane equipped with a lifting device such as a clamshell bucket, the bucket will necessarily swing from side to side as the boom is brought about, thereby urging the cable with considerable force against the sides of the sheave housing. If at the same time the bucket is also raised or lowered, the cable will quickly cut into and saw through the sides of the housing, causing irreparable dam-age to both the housing and the cable itself. As a result, it is not uncommon for the housing of a new tagline fairlead to wear out and require replacement of the entire unit is less than one week of heavy service. Moreover, the problem has not been solved by providing a fairlead wit-h upstanding side sheaves in addition to its horizontal sheaves, since the cable will be forced by the swinging bucket into the corners between adjacent sheaves where it then saws quickly through the sheave mountings and the walls of the fairlead housing. Such dam-age prevents operation of the entire crane and results in expensive work interruptions for the replacement of worn parts.

Accordingly, it is an object of the present invention to provide a tagline assembly having a fairlead structure which is simple and durable in construction and which overcomes the aforementioned defects and disadvantages of present fairlead structures. Another object is to provide a fairlead structure which permits the mounting of a tagline assembly at right angles upon a boom, or at various angles upon the boom, without danger of causing excessive wear of either the cable or the fairlead structure. A still further object is to provide a fairlead which is self-adjusting for different boom angles so that the usual adjustments to a tagline assembly required where work is to be performed at various boom angles are entirely eliminated.

Other objects will appear from the specification and drawings in which:

FIGURE 1 is a broke-n perspective view of a tagline assembly mounted upon a boom and equipped with a fairlead structure embodying the present invention; FIG. 2 is an exploded perspective view illustrating the fairlead assembly; FIGURE 3 is a plan view of the fairlead structure, the mounting plate for that structure being shown in section; FIGURE 4 is a broken side elevation of the fairlead structure and mounting plate; FIGURE 5 is a broken elevational view showing another side of the fairlead structure; FIGURE 6 is a longitudinal sectional view of the fairlead taken along line 66 of FIG. 3; FIGURE 7 is another longitudinal sectional view taken along line 7-7 of FIGURE 4; FIGURE 8 is a broken perspective view illustrating a modification of the present invention; and FIGURE 9 is a top plan view of the modified structure of FIGURE 8.

In the embodiment of the invention illustrated in FIG- URES 1 through 7, the numeral 10 generally designates a tagline assembly mounted upon the boom 11 of a crane or other lifting device. The tagline assembly essentially comprises a flanged reel 12 carried by a shaft 13 which is rotatably mounted at one end of a spring-enclosing cas- .ing .14. A line or cable 1'5 is wound about the flanged reel and passes through a fairlead structure 16 supported by an arm or mounting plate 17 which may be fixed to the casing 14. The coil spring (not shown) housed within casing 14 is connected at one end to shaft 13 to rotate the reel and to maintain cable 15 in a constant state of tension. The cable is connected at its end to any suitable lifting device such as a clamshell bucket or grapple and prevents that device from turning or spinning in operation. Except for the fairlead structure of the present invention, the tagline assembly 10 is entirely conventional and is fully disclosed in Ruddock Patent 2,166,479, issued July 18, 1939. Therefore, it is believed that a more detailed description of the structure and operation of the tagline assembly as a whole is unnecessary herein for the purpose of disclosing the present invention.

In FIGURES 3-5 it will be seen that the guide block 16 of the fairlead assembly is hollow and has the general shape of a double bell. The curved inner surfaces of the block or member 16 define a reeveway 18 therethrough, the walls of the block being flared outwardly at opposite end thereof to define enlarged months 19. Thus the reeveway or passage 18 tapers inwardly from opposite ends of the guide block reaching its narrowest point intermediate the enlarged mouths 19.

It will be observed that at its intermediate point the reeveway 18 is of circular cross-section (FIGURE 3). While the entire reeveway may be of circular section, I prefer to form the block and it inner surfaces so that the reeveway is generally elliptical along any transverse section above or below its intermediate point. In other words, the convex longitudinal curvature of the guide blocks inner surfaces is substantially greater when viewed along a plane extending along the major axis of the block (FIGURE 6) than when viewed along the minor axis thereof (FIGURE 7).

The guide block or member 16 may be cast from any metal having the necessary qualities of strength and durability. Steel having a high manganese content has been found particularly suitable because the smooth curved inner surfaces of the block tend to become even smoother or polished by movement of the cable 15 therethrough during operation of the structure.

In the embodiment of the invention illustrated in FIG- URES 1 through 7, the guide block is supported at one end of the mounting plate or arm 17 by means of a universal mounting structure generally designated by the numeral 20. The mounting means comprises a -U-shaped yoke or bracket 21 having apertured side arms 22 which receive mounting bolts 23. In FIGURE 2 it will be seen that the ends of the mounting bolts are smooth and unthreaded so that they may be rotatably received within openings 24 of the guide blocks side flanges 25. Therefore, when the parts are assembled as shown in FIG- URI-IS 3-5, the guide block or member 16 is capable of limited rotation about a rotational axis disposed at right angles to reeveway 13 and along a plane through the major axis of that reeveway intermediate mouths 19.

The intermediate portion of the mounting yoke 21 is centrally apertured to receive a pin or bolt '26 equipped with an enlarged head and adapted to extend through both the yoke and an aperture 27 in support arm 17. A nut 23 is threaded upon the reduced end of bolt 26 so that the yoke is firmly locked upon the arm while at the same time is free to rotate about the axis of the bolt. Therefore, the guide block 16 is also free to rotate about a second rotational axis disposed at right angles to and in substantially the same plane as the first rotational axis. It will be noted from FIGURES 3 and that the rear surface of the support arm is equipped with a sleeve 29 and that a suitable washer 30 may be disposed between the front face of the arm and the yoke to permit free rotation of that yoke (and the guide block carried thereby) about the second rotational axis.

The opposite end of the mounting arm 17 is provided with an enlarged opening 31 for receiving the portion of shaft 13 disposed between reel 12 and casing 14 and with smaller openings 32 for the bolting or otherwise securing of the arm to the casing Therefore, when the parts are assembled as shown in FIGURE 1, the support arm 17 is rigidly fixed to the casing 14 and supports the guide element 16 for rotation about a first axis lying along the plane of the reel 12 and about a second axis substantially parallel with the rotational axis of that reel.

During operation of the structure, the guide block 16 is free to rotate about either or both of its rotational axes to provide a path of least resistance for the cable extending therethrough depending, of course, upon the elevation of the bucket or other lifting device and the inclination of the boom of the crane. The tagline cable slides easily along the smooth surfaces of the reeveway and, as pointed out above, tends to polish those surfaces during use so that they become almost mirrorlike in appearance. Frictional resistance to cable movement, as well as wear upon the cable itself are negligible and it has been found that the wear upon the fairlead unit itself is so slight that it will provide trouble-free operation for a period many times the life of an ordinary sheave-equipped fairlead.

Furthermore, it has been found that the structure of the present invention eliminates two time-consuming adjustments which are ordinarily required in connection with tagline assemblies. Since the reel of a tagline is disposed at the side of a boom and since the bucket or other lifting device is suspended along a vertical plane running down the booms center line, it has been necessary in the past to mount the cylindrical casing of a tagline assembly at an angle greater (or less) than 90 degrees with reference to the boom in order to reduce the likelihood of unequal wear upon the sheaves and premature breakdown of the tagline unit. In addition, changes in the angular position of the support arm with reference to the casing were required whenever a substantial change in the operating angle of the boom was made. Because of the double bell shape of guide element 16 and because of the free mounting of that element for rotation about two axes, such adjustments are unnecessary in a tagline assembly having the fairlead construction of the present invention, thereby avoiding much of the labor and expense ordinarily involved with tagline assemblies.

The fairlead structure illustrated in FIGURES 8 and 9 is similar to the embodiment already described except that the guide element 16' is rigidly secured to the support arm 17 by a pair of bolts 33 extending through aligned apertures in the arm and in flanges In FIG- URE 9 it will be observed that the flanges or side portions of the guide block 16 extend rearwardly to provide a flat rear face for engagement with the surface of the support arm.

The modified construction is of more limited use than the first embodiment because changes in the angle of support arm 17' may become necessary where the angle of the boom or the elevation of the work area varies considerably from one operation to another. However, like the first form shown in FIGURES 1 through 7, the structure of FIGURES 8 and 9 permits the mounting of a fairlead casing at right angles to a boom without the compensatory adjustments ordinarily required because of the lateral position of the reel with reference to the bucket and its supporting cables. As shown in FIGURE 8, the support arm 17' is preferably provided with an offset or angled portion 34 so that the passage or reeveway defined by the guide element will extend along substantially the same vertical plane as the cable-supporting reel.

While in the foregoing I have disclosed two embodiments of the present invention in considerable detail for purposes of illustration, it will be understood by those skilled in the art that many of these details may be varied Without departing from the spirit and scope of the invention.

I claim:

1. A tagline assembly for a crane consisting essentially of a vertical reel mounted upon the boom of a crane, a support arm extending along a substantially vertical plane adjacent said reel, a tagline extending between said reel and a lifting device suspended from said boom, and a fairlead structure comprising a guide member providing a passage extending therethrough, said member having a smooth, curved and uninterrupted passage-defining inner surface slidably engaging said tagline and flaring outwardly at opposite ends of said member to provide enlarged mouths, the curvature of said passage-defining inner surface being gradual throughout the entire extent of said passage, said guide member being secured to the free end of said support arm with the passage extending along the vertical plane of said reel of guiding the winding and unwinding of said tagline extending from said reel to a lifting device.

2.. A tagline assembly for a crane consisting essentially of a vertical reel mounted upon the boom of a crane, a support arm extending along a substantially vertical plane adjacent said reel, a tagline extending between said reel and a lifting device suspended from said boom, and a tagline fairlead structure comprising a guide member providing a passage extending therethrough, said member having a smooth, curved and uninterrupted inner surface slidably engaging said tagline and flaring outwardly at opposite ends of the member to provide enlarged months, the curvature of said passage-defining inner surface being gradual throughout the entire extent of said passage, a yoke mounted upon said support arm adjacent the free end thereof for movement about an axis substantially parallel with the rotational axis of said reel, said guide member being pivotally carried by said yoke for relative movement about an axis lying along the vertical plane of said reel.

3. A tagline assembly for a crane consisting essentially of a vertical reel adapted to be mounted upon the boom of a crane, a support arm extending along a substantially vertical plane adjacent said reel, a tagline extending between said reel and a lifting device suspended from said F boom, and a tagline fairlead structure comprising a hollow member of double-bell shape having a smooth, curved and uninterrupted inner surface defining a reeveway therethrough and providing enlarged months at opposite ends of said reeveway, said member being mounted upon said support arm adjacent said reel for guiding the winding and unwinding of said tagline, said inner surface of said member slidably engaging said tagline and having a gradual and smooth curvature throughout the entire longitudinal and transverse extent of said reeveway.

4. A tagline assembly for a crane consisting essentially of a vertical reel mounted upon the boom of a crane, a tagline extending between said reel and a lifting device suspended from said boom, a fairlead structure comprising a tagline guide block having a passage extending therethrough and receiving said tagline, said block having a smooth uninterrupted passage-defining inner surface having a convex curvature in longitudinal section and an arcuate curvature in transverse section, said surface being slidably engageable with said tagline as the same moves longitudinally through said passage and defining open mouths at opposite ends of said passage of greater diameter than the portions of the passage disposed therebetween, each of said curvatures of said surface being smooth and gradual throughout the entire longitudinal and transverse extent of said passage, and means for mounting said tagline guide block upon said boom and adjacent said reel for guiding the winding and unwinding of said tagline.

5. A tagline assembly for a crane consisting essentially of a vertical reel mounted upon the boom of a crane, a support arm extending along a substantially vertical plane adjacent said reel, a tagline extending between said reel and a lifting device suspended from said boom, and a fairlead structure comprising a guide member providing a passage extending therethrough, said member having a smooth, curved and uninterrupted passage-defining inner surface slidably engaging said tagline and flaring outwardly at opposite ends of said member to provide enlarged mouths, the curvature of said passage-defining inner surface being gradual throughout the entire extent of said passage, said guide member being secured to the free end of said support arm with the passage extending along the vertical plane of said reel for guiding the winding and unwinding of said tagline extending from said reel to a lifting device, said guide member being mounted for pivotal movement about an axis extending along the vertical plane of said reel and for pivotal movement about a second axis parallel with the rotational axis of a d r el Y 6. A tagline assembly for a crane consisting essentially of a vertical reel mounted upon the boom of a crane, a support arm extending along a substantially vertical plane adjacent said reel, a tagline extending between said reel and a lifting device suspended from said boom, and a tagline fairlead structure comprising a guide member providing a passage extending therethrough, said member having a smooth, curved and uninterrupted inner surface slidably engaging said tagline and flaring outwardly at opposite ends of the member to provide enlarged mouths, the curvature of said passage-defining inner surface being gradual throughout the entire extent of said passage, a yoke mounted upon said support arm adjacent the free end thereof for movement about an axis substantially parallel with the rotational axis of said reel, said guide member being pivotally carried by said yoke for relative movement about an aXis lying along the vertical plane of said reel, said yoke being generally U-shaped and being provided with spaced parallel arms, and means mounted upon said arms of said yoke for pivotally supporting said guide member therebetween.

References Cited in the file of this patent UNITED STATES PATENTS 765,933 Nowland July 26, 1904 797,904 Meyer Aug. 22, 1905 1,778,086 Palm et a1 Oct. 14, 1930 2,304,534 Burns Dec. 8, 1942 2,367,836 Brown Jan. 23, 1945 2,413,786 Ruddock Jan. 7, 1947 2,458,573 Donahue Jan. 11, 1949 2,744,788 Grise May 8, 1956 2,766,966 Roessler Oct. 16, 1956 2,858,106 Anton et al Oct. 28, 1958 FOREIGN PATENTS 335,382 Great Britain Sept. 25, 193Q