US3174726A - Fairlead - Google Patents

Description

March 1965 w. P. ATKINSON ETAL 3,17

FAIRLEAD Filed April 16, 1962 2 Sheets-Sheet 1 3Y0 JJ 2 30 r m w FIG. 1

INVENTORS: WILLIAM PATKINSON 4 BRUNO LLONNGREN ATTORNEY March 1965 w. P. ATKINSON EI'AL 3,174,726

FAIRLEAD 2 Sheets-Sheet 2 Filed April 16, 1962 FIG. 5

INVENTORSI WILLIAM PATKINSON BRUNO LLONNGREN ATTORNEY United States Patent 3,174,726 FAIRLEAD William P. Atkinson and Bruno L. Lonngren, both of South Milwaukee, Wis., assignors to Bucyrus-Erie Company, South Milwaukee, Win, a corporation of Delaware Filed Apr. 16, 1962, Ser. No. 187,483 4 Claims. (Cl. 254-196) This invention relates to an improved fairlead and more particularly to improved guide rollers for a fairlead carried in a fixed housing and having a frame rotatable about an axis substantially coincident with the center line of a cable as it is guided through the throat of the fairlead to a cable-winding device.

It is common practice to provide a fairlead in the association with cable-winding equipment on dragline excavators, for example. Such a fairlead usually comprises a housing in which a frame is rotatably supported for rotation about a first axis substantially coaxial with a cable directed therethrough. Mounted on the frame is a pair of deflection sheaves for directing the cable toward a cable-winding device. Any angular deflection of the cable with respect to the plane of rotation of the deflection sheaves is known as an off-lead condition and can be compensated by rotation of the frame and deflection sheaves until the cable lies in the plane of the deflection sheaves.

A guide means for the fairlead is ordinarily provided to rotate the frame until the cable is substantially coplanar with the deflection sheaves. Such guide means may comprise a pair of fixed guide plates spaced equidistantly from and parallel to the plane of rotation of the deflection sheaves. Cylindrical roller guide means have also been used to guide the cable toward the plane of rotation of the deflection sheaves.

Such guide means are attached to the fairlead frame and rotate therewith about the main axis. The rotation of the fairlead frame is occasioned by the action of the cable being drawn over the guide means at a portion of the guide means away from the main axis. The primary function of the guide means is to rotate the fairlead frame and deflection sheaves so that the cable is directed over one of the deflection sheaves. Deflection sheaves have a larger diameter than the cable and less wear occurs between the cable and sheave than would occur between the cable and the surface of the guide means. It is therefore an advantage to provide a guide means which rotates the frame quickly in response to an off-lead cable condition. After rotation, the cable no longer touches the guide means but is aligned in the plane of the deflection sheaves and is drawn over one of the sheaves by the cable-winding means.

Previous guide means have been subjected to extreme wear and consequent grooving at their central portions adjacent the main axis of rotation of the fairlead frame. Such wear can result in a single deep groove or a series of shallow grooves in the guide means and the effectiveness of the guide means is virtually eliminated as the cable tends to seek the worn groove or grooves in the guide means and with the cable acting in said worn portion there is not sufficient moment arm to rotate the frame.

The wear is most likely to occur when the cable is drawn in a lateral off-lead condition from the fairlead, with little or no deflection from the main axis of fairlead rotation. Such small or negligible deflection means that the moment arm of force acting on the guide means is insufficient to rotate the fairlead.

Further, as guide means must be replaced from time to time, it is advantageous to provide a guide means which is readily replaceable without occasioning lengthly downtime for the excavator, or the like.

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To avoid the problems of previous guide means for fairleads, the preferred embodiment of this invention discloses a pair of tapered guide rollers each rotatable on axes that are parallel to one another and spaced equidistantly from the main axis of rotation of the fairlead. The tapered guide rollers each have an enlarged central portion and the outer surface of the rollers taper inwardly toward the end portions thereof. The rollers are spaced from each other so that a cable drawn between them can contact only one of the rollers at a time. Upon contact with the tapered surface of a roller, the cable tends to slip along the rotating surface in a direction away from the enlarged central portion of the roller thereby increasing the moment of the cable acting on the roller to rotate the fairlead frame about its main axis. Thus, the tapered guide rollers, with the cable acting thereon, provide for a quick rotation of the fairlead frame so that the cable is guided over one of a pair of deflection sheaves, thereby reducing the Wear on the cable and on the guide rollers.

It is therefore an object of the invention to provide a guide roller means for a fairlead wherein the guide roller means provides for increasing the moment arm for rotating the fairlead when said cable is in an off-lead position.

It is another object of the invention to provide guide roller means for a fairlead wherein said guide roller means may be readily removed and replaced without adjustment.

It is another object of the invention to provide a guide means for a fairlead which reduces wear on the guide means and cable by facile rotation of said guide means to align said cable with a deflection sheave for guiding the cable to a cable-winding device.

It is another object of the invention to provide improved guide roller means for a fairlead wherein cable and guide roller wear is reduced.

These and other objects will be apparent from the following description and drawings of which:

FIGURE 1 is a side elevation view partially in section of the fairlead of the invention;

FIGURE 2 is a plan view of the fairlead of FIGURE 1;

FIGURE 3 is an enlarged end view in partial section taken at line 3-3 of FIGURE 2;

FIGURE 4 is another modification of a guide roller;

FIGURE 5 is a reduced schematic elevation of the fairlead of FIGURE 1 with the cable in an off-lead condition; and

FIGURE 6 is a schematic plan view taken at line 6-6 of FIGURE 5.

As shown in FIGURES 1 and 2, a fairlead 11 is provided with a fixed housing 12 which is normally mounted in a rigid manner on a machine, as, for example, a dragline excavator (not shown). A conventional cable-winding means 13 (FIGURE 5) is located adjacent to the fairlead. The fairlead 11 compensates for any olf-lead condition of the cable 22 prior to its being wound upon the cable-winding means.

The fairlead 11 includes a main frame 14 having a rearwardly extending tubular shank 15 supported in suitable bearings 16 carried in housing 12 to permit rotation of the main frame 14 in fixed housing 12 about a main axis A. Normally, fairleads for the cable-winding means of dragline excavators, logging equipment and the like, have a main axis A" which is substantially horizontal as shown in FIGURE 1.

The main frame 14- extends forwardly of the shank 15 where parallel side plates 17 integral therewith provide support for transverse shafts 18 and 19, which lie in the same vertical transverse plane and are spaced equidistantly from the main axis A of the fairlead 11.

Rotatably supported by shafts 18 and 19 in a coplanar relationship are deflection sheaves 2t and 21 which guide cable 22 toward a path substantially coincident with the main axis A of the fairlead toward cable-winding means 13. The cable 22, at its other end, is attached to a load (not shown) which may be disposed at various locations above, below and to either side of the main axis A. The cable 22 is drawn through the throat 23 of the fairlead 11 and tubular shank by the winding means 13.

The parallel side plates 17 project forwardly of the shafts 18 and 19 to include spaced yokes 24 and 25 which may be joined together by a bridge portion 26. A pair of guide rollers 27 and 28 are each rotatably supported on spaced parallel axes in the ' yokes 24 and 25 respectively.

Referring more particularly to FIGURE 3, each guide roller is rotatably supported by means of bearings 29 on each end of a central support sleeve 30. 30 is provided with a shoulder 31 adjacent each of its ends to limit inward axial movement of the inner bearing race 32. A bearing cap 33, at each end of the guide rollers, abuts the outer bearing race 34 and is demountably secured, for example, to the guide roller 27 by means of cap screws 35.

To support each guide roller assembly in the frame 14, a pair of terminal support pins 36 are provided for each roller and the pairs of pins are demountably secured through each yoke 24 and 25. By positioning the guide roller assembly-and inserting the terminal support pins 36 at each end of the roller within the bores 30a of central sleeve 30, the guide roller assembly may be installed. Transverse pins 37 are inserted in openings 37A of sleeve 30 wherein said pins engage longitudinally extending transverse slot 38 of each terminal support pin to prevent any relative rotational movement between the support pins 36 and the sleeve 30.

In previous fairleads having guide plates or cylindrical rollers for guide means, the cable must be displaced along the axis of the guide members a sufficient distance from the main axis A of the fairlead so that the force exerted by the cable and acting upon the guide member creates a suflicient moment to effect rotation of the fairlead to cause the desired alignment of the cable with the deflection sheaves. In the event that the cable is disposed at an angle to the plane of the deflection sheaves but is not displaced along the axis of a guide member a suflicient distance to insure rotation of the fairlead to align the deflection sheaves with the cable, the cable tends to wear a groove at that portion of the guide member. Continued use of the fairlead with the cable in an off-lead position results in continued wear of the guide member and increased wear on the cable as the cable is not properly aligned with the deflection sheaves.

To overcome this shortcoming of previous guide members, the guide rollers 27 and 28 have a large diameter central portion. The surface of each of the guide rollers is tapered from the central portion toward the end portions thereof. Accordingly, when the cable 22 contacts the tapered surface of one of the guide rollers 27 and 28 as the cable is drawn in a lateral off-lead position at a slight angle from the plane of rotation of the deflection sheaves 20 and 21, and, at a slight angle upwardly or downwardly from main axis A, the action of the cable against the tapered surface guide rollers 27 or 28 causes the cable 22 to move further along the tapered surface from the main aXis A. With the cable 22 acting on the tapered surface of the guide roller the fairlead frame 14 is rotated until the cable again lies in the plane of rotation of the deflection sheaves. When this occurs, the guide roller is no longer in contact with the cable and the deflection sheaves 20 and 21 are aligned to I The sleeve d a deflection sheave is considerably less than the wear occasiond between a guide roller and the cable, therefore, the quicker the fairlead frame rotates in response to the off-lead condition, the more the Wear is reduced.

Such tapered guide rollers 27 and 23 provide for the facile rotation of the fairlead for the rapid alignment of the cable with the deflection sheaves and thereby cable and guide roller wear is reduced.

Another guide roller it) is shown in FIGURE 4 wherein the roller 4% is provided with a central portion 40a having a larger diameter than the end portions thereof. In a fairlead frame, a pair of rollers 40 perform similarly to the tapered rollers 27 and 28 in that the larger diameter central portion tends to position the cable away from the central portion 46a to provide a greater moment arm along the axis B, so that the force of the cable against the guide roller rotates the fairlead about the main axis A to place the plane of rotation of the deflection sheaves and the cable in alignment. The wear between the cable and guide roller is reduced for the same reasons as set out above.

During operation of equipment using both a cablewinding drum and a fairlead, for example a dragline excavator (not shown), the object to be pulled by the cable attached to the cable-winding drum may be disposed at various positions in relation to the fairlead resulting in an off-lead condition of the cable. With the cable disposed at an angle to the plane of rotation of the deflection sheaves as shown in FIGURE 6, the fairlead 11 is rotated about the main axis A by the cable acting on the tapered surface of guide roller 28 until the deflection sheave 20 or 21 receives the cable drawn therethrough in the same plane as the plane of rotation of the deflection sheaves.

In this manner, cable contact is quickly transferred from one of the guide rollers to one of the deflection sheaves, thereby reducing the wear on the cable and on the guide roller.

When replacement of guide rollers 27 and 28 is needed, it is only necessary to remove capscrews 41 for detaching caps 42 from each end of rollers 27 and 28 so that the terminal pins 36 may be removed from each end. Replacement guide rollers similar to rollers 27 and 28 already assembled and adjusted are then placed in frame 14. The pins 36 are reinserted at each end of the rollers and the caps 42 are replaced. Thus the changing of the guide rollers is accomplished quickly and simply.

Thus, improved guide rollers for a fairlead have been described wherein a cable in an off-lead condition acts on the tapered surface of a guide roller at a portion of the roller surface spaced from an enlarged central portion of the roller to facilitate the rotation of a fairlead to position a pair of deflection sheaves to receive the cable drawn therethrough to reduce wear on the cable and the guide rollers. The guide rollers also rotate around their longitudinal axes by the action of the cable drawn over their tapered surfaces. The tapered surface aids the cable in seeking a position on the roller surface away from an enlarged central portion of the roller to occasion the cable to act on the guide roller at an increased moment arm to quickly rotate the fairlead in the manner hereinabove described.

Having now described and illustrated two forms of the invention, it is to be understood that this invention is a .sa d f am and spaced equidistantly from said main axis and adapted to be contacted by said cable when said cable is in an oil-lead condition; mounting mean for each said roller comprising a central support sleeve received with each said roller; demountable bearing means at each end of said sleeve for rotatably supporting a roller; a pair of terminal support pins carried in said frame and insertable one in each end of said sleeve; and a detachable connection between each of the terminal support pins and said central support sleeve.

2. The structure according to claim 1 in which said detachable connection includes means to permit relative longitudinal movement between one of said terminal pins and said central support sleeve and means to prevent relative angular movement between said support pins and said sleeve.

3. In a fairlead having a frame, a pair of cable guiding sheaves mounted on the frame which are substantially co-planar and have a point on each of their periphery adjacent one another, said frame extending beyond said sheaves to terminate in spaced mounting yokes, the combination therewith of: a pair of cable guide roller assemblies each having a central support sleeve with hollow ends, bearings on the sleeve, a roller supported by the bearings and encircling the sleeve for rotation with respect thereto which roller has an outer surface of maximum diameter at its mid-point and a diminished diameter toward its ends; each roller assembly being positioned between spaced mounting yokes with its axis paralleling the plane of the sheaves and in parallel alignment with the other roller assembly; and support pins carried in said yokes which are inserted into the ends of said support sleeves to retain the roller assemblies in place.

4. An assembly as in claim 3 in which the outer surface of each roller is a smooth taper of maximum diameter at substantially the mid-point of the length of the roller.

References Cited by the Examiner UNITED STATES PATENTS 1,419,049 6/22 Harsel et al. 226-192 XR 3,006,608 10/61 Cirnino 254-490 3,063,680 11/62 Helsel 254-190 FOREIGN PATENTS 556,728 10/43 Great Britain. 1,110,217 10/55 France.

ERNEST A. FALLER, Primary Examiner.

SAMUEL F. COLEMAN, JOSEPH P. STRIZAK,

Examiners.

Claims (1)

1. 3. IN A FAIRLEAD HAVING A FRAME, A PAIR OF CABLE GUIDING SHEAVES MOUNTED ON THE FRAME WHICH ARE SUBSTANTIALLY CO-PLANAR AND HAVE A POINT ON EACH OF THEIR PERIPHERY ADJACENT ONE ANOTHER, SAID FRAME EXTENDING BEYOND SAID SHEAVES TO TERMINATE IN SPACED MOUNTING YOKES, THE COMBINATION THEREWITH OF: A PAIR OF ABLE GUIDE ROLLER ASSEMBLIES EACH HAVING A CENTRAL SUPPORT SLEEVE WITH HOLLOW ENDS, BEARINGS ON THE SLEEVE, A ROLLER SUPPORTED BY THE BEARINGS AND ENCIRCLING THE SLEEVE FOR ROTATION WITH RESPECT THERETO WHICH ROLLER HAS AN OUTER SURFACE OF MAXIMUM DIAMETER AT ITS MID-POINT AND A DIMINISHED DIAMETER TOWARD ITS ENDS; EACH ROLLER ASSEMBLY BEING POSITIONED BETWEEN SPACED MOUNTING YOKES WITH ITS AXIS PARALLELING THE PLANE OF THE SHEAVES AND IN PARALLEL ALIGNMENT WITH THE OTHER ROLLER ASSEMBLY; AND SUPPORT PINS CARRIED IN SAID YOKES WHICH ARE INSERTED INTO THE ENDS OF SAID SUPPORT SLEEVES TO RETAIN THE ROLLER ASSEMBLIES IN PLACE.

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