US 3385563 A
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Description (OCR text may contain errors)
May 28, 1968 T. w. srmsom JR BLOCK FOR SUPPORTING AND GUIDING A LINE OR THE LIKE Filed Oct.' 1'7. 1966 2 Sheets-Sheet 1 i961 INVENTOR 77/00/45 M. 3776 6 0, J 1?,
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May 28, 1968 T. W. STINSON, JR
BLOCK FOR SUPPORTING AND GUIDING A LINE OR THE LIKE Filed Oct. 17, 1966 2 Sheets-Sheet 2 4 m s Z R'& w 00 N 2 T: i WW .L v 1 mi 2 W V w 2 M M We w a 4? M 4 L no. z 66 21 n 1 United States Patent Ofice Patented May 28, 1968 3,385,563 BLOCK FOR SUPPORTING AND GUIDENG A LINE OR THE LIKE Thomas W. Stinson, .l'rx, 5408 Dunstan Court, Charlotte, N.C. 28205 Filed Oct. 17, 1966, Ser. No. 587,206 7 Claims. (Cl. Z54195) ABSTRACT OF THE DISCLOSURE The present invention relates to a block for supporting and guiding a line or the like that is tensioned around the block in a non-vertical plane and wherein the block includes means mounted thereon for disposing the block inherently in alignment substantially with the plane of the tensioned line therein for proper handling of the line in its non-vertical plane, with the means for positioning the block being advantageously incorporated in the block in a simple and inexpensive construction.
In handling a line, rope, or other strand-like material in a hanging block of the type wherein the material is supported and guided in the groove of a sheave, a prob lem is encountered when the material is run through the block at an angle that disposes the material in a nonvertical plane as the weight of the block causes the block to assume a position in a plane that is inclined downwardly away from the plane of the material with the result that the material may run out of the sheave groove or ride on the rim of the sheave causing possible fouling of the material and damage to the sheave or other block structure. This problem is particularly significant when a block that is heavy enough to withstand a heavy and highly tensioned line must also be used to handle lighter and more lightly tensioned line, which results in a pronounced inclination of the heavy block with respect to the plane of the light line, as when a lead line is run through the block in advance of the main line.
By the present invention, the block is disposed so that the sheave will be positioned substantially in the nonvertical plane of the line so that the line will be maintained in the sheave groove for effective handling thereof without fouling or excessive wear and without regarding special or additional attachment of the block to the supporting structure.
Briefly described, the block of the present invention includes a frame, a sheave mounted on the frame, a link member pivotally attached to the frame, means for pivotally attaching the link member to a supporting structure for pivotal suspension of the frame and sheave, and means mounted on the block for disposing the sheave substantially in the non-vertical plane of a line tensioned in the block.
In the preferred embodiment of the present invention, the sheave disposing means includes a tension spring that is attached to and extends between the frame and the link member, to which it is attached at an arm that is rigidly fixed to the link member and extends upwardly therefrom when the line is tensioned in the sheave to dispose the tension spring above the sheave when the line is tensioned in the block so that the spring will pull the frame and sheave upwardly about the pivot connection with the link member into the plane of the line. This disposition of the tension spring also functions to position the link member and frame initially at opposite inclinations to a vertical hanging disposition so that the sheave will be initially inclined to facilitate engagement. of the line in the sheave during initial tensioning of the line.
The various features and advantages of the present invention are incorporated in the preferred embodiment that is described in detail hereinbelow and illustrated in the accompanying drawings, in which:
FIG. I is an elevational view of an electrical transmission line tower to which blocks according to the preferred embodiment of the present invention are attached for stringing of electrical conductors;
FIG. 2 is an elevational view of the block illustrating at the right in FIG. 1 and showing it in its initial position prior to the tensioning of a line therein;
FIG. 3 is an elevational view of the block illustrated at the left in FIG. 1 with a line tensioned therein;
FIG. 4 is an elevational view of the block of FIG. 2 with a line tensioned therein to a lesser tension than the line of FIG. 3; and
FIG. 5 is a side elevational view of the block of FIG. 2.
In the embodiment illustrated, blocks 10 of the present invention are mounted on an electrical transmission line tower T for supporting and guiding the stringing of electrical conductors C at a location where a change in direction is being made in the extent of the line to follow a particular right-of-way path with the result that the conductors C will be strung in non-vertical planes, such as the horizontal planes shown in the figures.
This stringing operation starts with the stringing under relatively light tension of light lead lines L through a sequence of blocks 10 at spaced towers T. The lead lines L are then used to draw heavier pulling lines P through the system of towers T, which pulling lines P are in turn used to pull the relatively heavy conductors C through the system under relatively heavy tension.
The blocks 19 are necessarily heavy to withstand the substantial weight of the conductors C and the high tension used in stringing the conductors C. This substantial weight of the blocks is a disadvantage in stringing the light lead lines L and pulling lines P as the weight of the blocks will tend to displace the blocks at an inclination downwardly away from the plane of the lead lines L and pulling lines P unless compensation is made as provided by the present invention.
Each block 10 is formed with a composite frame 12 having one integral side 12a and an intermediately hinged side 1%. The sides 12a and 12]) are secured together in spaced relation by bolts 14 at their outer ends and by a retaining pin 16 at their inner ends, which retaining pin 16 is detachable to permit the hinged portion of the side 1212 to swing open for insertion of a line bet-ween the frame sides for seating in the groove 18 of a sheave 20 that is mounted in the frame 12 for free rotation on a shaft 22 extending between the frame sides 12a and 12b centrally thereof. The sheave 20 is provided with a groove liner 24 of resilient material, such as nylon, as a protection for the lines being run through the block and as a protection against wear of the sheave by the running lines and the swivel connections thereon. This frame 12, sheave 26, and liner 24 construction is conventional and does not form a part of the present invention except in combination with the other elements described hereinbelow.
In the illustrated embodiment, a mounting stud 26 is attached to the frame 12 by the aforementioned retaining pin 16 and extends therefrom for pivotal attachment on a pivot pin 28 carried at the outer end of a link member 30, which in turn is pivoted on a pin 32 at its inner end for pivotal attachment of the link member 30 to conventional means 34 for pivotally mounting the block 10 to a mounting flange F that depends from the arm A of the tower T so that the block hangs freely therefrom for swivel movement.
The link member 30 may be an integral member or may be compositely formed, as illustrated, of a pair of parallel portions that are attached in spaced relation by the pins 28 and 32 with the stud 26 and attaching means 34, respectively, disposed intermediately of the link member portions. The link member 30 is also formed with an arm 36 rigidly fixed thereto and extending transversely therefrom to provide a mounting for a spring attaching pin 38. This arm 36 also may be integrally formed or may be compositely formed, as illustrated, of a pair of spaced parallel portions extending from the respective portions of the link member 30 and with the spring attaching pin 38 extending between the portions at their outer ends. The particular form of the link member 39 and arm 36 may be varied as desired for convenience of manufacture.
The spring attaching pin 38 forms a component of means for disposing the sheave 20 substantially in the nonvertical plane of a line tensioned therein, which means also includes a tension spring 40 having one end attached to the spring attaching pin 38 and its other end attached to a bracket 42 mounted on one of the bolts 14 at the outer end of the frame 12 and extending between the bolt and the arm 36 above the frame 12 and sheave 20 when a line is tensioned in the block 10 to apply an upward force at the outer end of the frame 12 such as to raise the frame 12 and sheave 20 about the pivot connection to the link member 30 from a normal hanging position at a downward inclination with respect to the plane of the line into a generally planar alignment with the line so that the line will remain in the sheave groove 18 when the line is run through the block 10. The spring 40 is formed in two parts, 401: and
4011, joined by chain links 44 extending therebetween to provide means for adjusting the spring tension by changing the number of links in the chain 44.
FIGURE 4- illustrates a typical use of the block 10 with a light lead line L. In this condition, the weight of the block 10 in relation to the tension of the lead line L causes the frame 12 and sheave 20 to be disposed below the mounting flange F that depends from the tower arm A such that the link member 30 is inclined downwardly. In this condition, the tension spring 40 acts to raise the outer end of the frame 12 into the horizontal plane of the lead line L such that the sheave 20 is disposed substantially in the plane of the lead line L notwithstanding the inclination of the link member 30.
In FIGURE 3, the pulling line P is run through the block 10 at a higher tension than the lead line L of F IG- URE 4. This higher tension causes the weight of the block to be less effective such that the link member 30 is not inclined to the extent that it is in FIGURE 4, but the tension spring 40 serves to hold the frame 12 and sheave 20 in the general plane of the pulling line P in the same manner as in FIGURE 4.
Although the frame 12 and sheave 20 are shown in horizontal alignment with the plane of the line in both FIGURES 3 and 4, some slight misalignment may be tolerated as it is necessary that the alignment only be suflicient to retain the line in the sheave groove 18. Thus, the spring 40 is suitable, without adjustment, to position the sheave 20 effectively over a moderate range of line tensions that result in some variation in the angular disposition of the link member 30 with respect to the plane of the line. Where the tension of the line is substantially less and the weight of the block 10 causes the link member 30 to be substantially inclined to the plane of the line, the link member arm 36 will be inclined toward the desired sheave position such that the extent of the spring 40 will be reduced and adjustment of the spring tension by reducing the number of intermediate chain links 44 may be necessary to obtain satisfactory results.
Provision for spring tension adjustment is not always necessary, as where the range of use is predictably small, and various other means of adjusting spring tension may be used.
In the accompanying illustrations the block 10 is shown in use with a line tensioned in a generally horizontal plane. The present invention is, however, applicable as well to situations where the line is tensioned in a plane that is neither vertical nor horizontal, in which case the link member 30 will be inclined with the result that the link member arm 36 will also be inclined and the sheave supporting extent of the spring 40 therefrom will dispose the sheave 20 at an inclination generally aligned with the plane of the line.
Not only is the sheave 20 properly positioned when a line is tensioned in the block 10, but it is advantageously disposed at a slight initial inclination when the block is hanging without a line therein so that the line will be initially received in the sheave groove 18 and will be retained therein as the line is drawn in its non-vertical plane to its fully tensioned disposition. This initial block position is seen in FIG. 2, in which it is seen that the spring 40 pulls the end of the frame 12 upwardly so that the frame and link member 30 are oppositely inclined such that the sheave 20 is inclined initially in the direction of subsequent line tensioning. As the line is being drawn to its running tension, it will pull the frame 12 and sheave 20 outwardly, causing pivoting of the link member 30, with the transverse extension of the arm 36 disposing the spring 40 above the frame and sheave to maintain an upward spring tension thereon that raises the sheave 20 into general planar alignment with the line when the line reaches its running tension.
As the arm 36 extends transversely from the link member 30, it is necessary to provide clearance with the tower arm A when the block is being tensioned inwardly with respect to the tower T. This is provided, as seen in FIGURE 3, by a bracket B that extends outwardly and downwardly from the tower arm A and to the lower end of which is attached the attaching means 34 of the block 10 such that the link member arm 36 will not contact the tower arm A when the block 10 is swung to a generally horizontal position.
vFrom the above, it is apparent that the present invention provides a simple arrangement for maintaining proper sheave position with respect to a line in a simple mechanism that can be readily adapted to an existing block by attaching a stud 26, link member 30, and spring 40 unit thereto or can be inexpensively incorporated in the original manufacture of a block, and that requires no additional attachment to a supporting structure.
The present invention is applicable to various types of blocks and is not intended to be limited to a single sheave block as the invention is especially applicable to heavy blocks of the type that have a plurality of sheaves in each block structure. Also, the invention is not restricted to the field of electrical transmission line stringing as it has application as well to various other fields, such as shipping and hauling.
It is to be understood that the preceding detailed description has been provided as an example of the present invention and is not intended to limit the scope thereof, which scope is not intended to be limited except as defined in the appended claims.
1. A block for supporting and guiding a line or the like that is tensioned around said block in a non-vertical plane, said block comprising a frame, a sheave mounted on said frame, a link member pivotally attached to said frame, means for pivotally attaching said link member to a supporting structure for pivotal suspension of said frame and sheave from said supporting structure, and biasing means interconnecting said frame and said link member for pivoting said frame with respect to said link member to dispose said sheave substantially in the non-vertical plane of the tensioned line.
2. A block for supporting and guiding a line or the like according to claim 1 and characterized further in that said sheave disposing means is disposed above said sheave when the line is tensioned therein.
3. A block for supporting and guiding a line or the like according to claim 1 and characterized further in that said sheave disposing means is a tension spring attached to and extending between said link member and said frame and spaced from the pivotal connection of the link member and frame.
4. A block for supporting and guiding a line or the like according to claim 3 and characterized further in that said link member has an arm rigidly fixed thereto for extension above said link mem er when said line is tensioned in said sheave, and said tension spring is attached to said arm.
5. A block for supporting and guiding a line or the like according to claim 4 and characterized further in that when the line is not tensioned the tension spring disposes said link member and frame at opposite inclinations to a vertical hanging disposition to position the sheave at an inclination that facilitates engagement of the line in the sheave during initial tensioning of the line.
6. A block for supporting and gniding a line or the like according to claim 1 and characterized further in that said sheave disposing means disposes said sheave at an inclination to a vertical hanging position prior to tensioning of the line therein to facilitate engagement of the line in the sheave during initial tensioning of the line.
7. A block for supporting and guiding a line or the like that is tensioned around said block in a non-vertical plane, said block comprising a frame, a sheave mounted on said frame, a link member pivotally attached to said frame, means for pivotally suspending said link member from a supporting structure for pivotal suspension of said frame and sheave therefrom, and biasing means connected to said frame for pivoting said frame with respect to said link member to dispose said sheave substantially in the non-vertical plane of the tensioned line.
References Cited UNITED STATES PATENTS 1,431,788 10/1922 Hale 254- EVON C. BLUNK, Primary Examiner.
H. C. HORNSBY, Assistant Examiner.