US2865600A

US2865600A - Tensioning device for cables

Info

Publication number: US2865600A
Application number: US526093A
Authority: US
Inventors: Robert C Roebling
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-08-03
Filing date: 1955-08-03
Publication date: 1958-12-23
Anticipated expiration: 1975-12-23

Description

Dec.23, i958 R. c. ROEBLING 2,865,600

E TENSIONING DEVICE FOR CABLES Filed Aug. 5, 1955 INVENTOR @kf/MEM] MEM ATTORNEYS United States Patent TENSIONING DEVICE FOR CABLES Robert C. Roebling, Skidaway Island, Ga.

Application August 3, 1955, Serial No. 526,093

4 Claims. (Cl. 254-67) This invention relates to a wire cable terminal fitting for attaching the cable to an object to which tension is to be applied through the cable.

One of the objects of the invention is to provide a fitting of the type described, in which the adjustment of the cable tension may be made without imparting torque to the cable.

Another object of the invention is the provision of an adjustable cable tensioning device, in which the point of attachment of the cable thereto is offset with respect to the line of thrust of the tension adjusting means, so that the fitting will not twist under the stress incident to adjustment, and therefore, no tool is required to hold the device while the tension adjustment is being made.

A more specic object of the invention is to provide a device, as described, fundamentally functioning as a turnbuckle, including a frame having a longitudinal guideway therein non-round in cross-section, and a sleeve reciprocably but non-rotatably guided therein, having an anchor cord fixed thereto and extending from one end of said frame, said sleeve having a threaded socket which cooperates with an adjusting screw non-reciprocably mounted in said frame coaxial with said socket and cooperating with said sleeve to adjust the longitudinal position of said sleeve with respect to said frame, the latter having anchorage means for a cable adjacent its opposite end, external to said guideway and offset from the axis of said adjusting screw.

Still another object of the invention is to provide locking means for said screw to prevent its rotaryV and reciprocable movement with respect to said frame.

Other objects of the invention will appear as the following description of a practical embodiment thereof proceeds.

In the drawing which accompanies and forms a part of the following specification, and throughout the figures of which the same reference characters have been used to designate identical parts:

Figure l is a perspective View of the fitting shown attached to the end of the cable to be tensioned;

Figure 2 is a plan View of the fitting shown in Figure 1; l

Figure 3 is a longitudinal section taken along the line 3-3 of Figure 2;

Figure 4 is a front elevation of the fitting;

Figure 5 is a cross-section taken along the line 5 5 of Figure 3.

Referring now in detail to the disclosure of the several figures, the numeral 1 represents as a whole the frame of the fitting which is formed with the longitudinal guideway 2. Said guideway in the illustrated embodiment of the` invention is a channel of` rectangular.cross-section, preferably square, with parallel sides 3' and 4 and an integral bottom 5, which is of less length than the sides, so as to provide adjacent one end an opening 6. In general, it is contemplated that the fitting will be used with the bottom 5 ofthe Channel uppermost, so that the openof the sleeve and the inserted screw 25. f e

ing 6 may be regarded as being in the top of the guideway.

The sides 3 and 4 are connected at their ends adjacent the opening 6 by a cross piece 7 formed with a notch 8 converging downward from the top, and communicating with the opening 6. The sides of said notch are convex, which sides merge into a bottom that is semicylindrical, the cross piece by virtue of the notch constituting a fairleader for the passage of an anchor cord, as will appear. A pair of spaced wings 9 and 10 extend upwardly from the outer face `of the bottom 5 in parallel planes perpendicular thereto. Said wings are provided near the end of the fitting opposite the cross piece 7 with aligned apertures 11 and 12 offset an appreciable distance from the guideway 2, in which the pin 13 is journaled, bridging the space between said wings, and forming an anchorage for the hook or eye at the end of the cable to be tensioned. In the drawing, the cable is designated at 14, and having the eye 15.

The anchor cord 16 extends from the end of the fitting 1, throughthe notch 8. It is of conveniently short length, and provided at its outer end with a suitable anchor 17, designed to be stationarily held by a fixed support. The end of the anchor cord within the fitting 1 is secured to a sleeve 18, which is reciprocable but nonrotatable within the guideway 2. The sleeve 18, as shown, is tubular, having a bore 19 at one end which fits the anchor cord, and through which the anchor cord is inserted. The opposite end of the sleeve is counterbored, the inner end of the counterbore forming a conical shoulder 20 adjacent its juncture with the bore 19. The outer end of the counterbore is threaded, forming a socket 21. The end of the anchor cord is fastened to the cable in some conventional manner, usually by a molten socketing metal. The sleeve may be of any suitable shape, but is here shown as being cylindrical, with the exception of a narrow intermediatevzone which is of a shape complementary to the cross-sectional shape of the guideway, that is, in the present instance, square, as indicated at 23, so that it slidably fits the surrounding structure of the guideway, but prevents any torsional stress being cornmunicated by the sleeve to the anchor cord. The opening 6 provides access of the sleeve to the guideway from the under side, the sleeve being presented to the guideway in an inclined manner.

The end of the guideway opposite the notch 8 is closed by a transverse wall 24 through the perforation of which an adjusting screw 25 is inserted, said screw being freely reciprocable in said aperture. The screw has an inner threaded portion 26, an intermediate thrust collar 27, and an outer cylindrical portion 23 having a kerf 29 in its outer end. The thrust collar rests against the end wall 24, and the threaded portion 26 interengages with the threaded socket 21, so that the action of the screw when tightened is to draw the sleeve 18 inwardly of the fitting 1 and thereby shorten the length of the anchor cord extending from the fitting, thus placing tension upon the cable anchored to the pin 13.

In the form of the invention shown, the open vside of the guideway is bridged intermediately by a plate 22, the purpose of which is to reduce friction caused by binding when the screw is hardto turn. Without this fourth side of the square, the binding forces are unbalanced and can build up without limit. The plate 22 is preferably located far enough from the cross piece 7 to allow for the aligning of the sleeve within the guideway after it has been inclinedly inserted through the opening 6. The plate is also preferably of sufficient lengthf as to underlie the guideway throughout the extent of travel of the square portion 23 of the sleeve. This provides underlying support for the reciprocatorylunit consisting Y 3 When the --cable 14 -is under tenson, the fitting 1 will position itself with the anchor cord and the cable 14 in rectilinear alignment, so that the direction of thrust of the adjusting screw will be offset atan acute angle from the direction ofy the cable. This relationship of parts prevents torque being transmitted to the cable when the screw 2S is` tightened, for in order for torque to be developed, the entire guideway would have to rotate about the axis of the cable at the point represented by the pin 13, which it obviously cannot do. Since the imposition of torque in either direction upon the cable either shortens it or lengthens it, a precise tension adjustment cannot be obtained if such torque is present. The absence of the developmentof torque in the cable incident to the l adjustment of the tension. in the present invention permits a precise adjustment to be made;

The screw is locked in any position ofadjustment by means of the loop clamp 30, which freely surrounds theI outer cylindrical portion 28 of the screw, and having perforated lugs 31 and 32 which rigidly lock the clamp when tightened by means of the screw 33, which passes freelyv through the perforation in the lug 31 and threads into the perforation of the lug 32. The plate 10 has a portion 34 extending forwardly therefrom to a position in which it lies laterally against the lug 31,

and having a perforation 3S registering axially with the perforations in the lugs 31 and 32, the screw 33 passing through the perforation 3S and fixing the locking clamp against the extended portion 34. Assuming, for example, that the cable terminal tting of the present invention were inter-calated in the line of tension of a guy cable supporting a stack which might be vaffected by wind pressure, in the absence of the rigid locking means afforded by the locking clamp 36, if the wind were to blow against the stack in such direction as to sway it slightly toward the cable, the thrust collar 27 would obviously move away from the end wall 24 a slight distance,

and when the wind pressure became relieved, the stack would sway back to vertical, bringing the thrust collar with heavy impact against the end wall 24. This would put a heavy strain upon both the cable and anchor cord, which is avoided by the locking means for the screw 25, as disclosed, since with the locking means rigidly clamped about the screw and immovably held by the extended portion of the plate 3l), it would be impossible for the thrust collar to come out of contact with the wall 24 so that the swaying of the stack would be taken up by the progressive straightening of the cable without any unpactive strain.

While I have in the above description disclosed what l believe to be a practical embodiment of the invention, it will be understood by those Skilled in the art that the specific details of construction and arrangement of parts, as shown, are by the way of example and not to be construed as limiting the scope of the invention.

What I claim is:

l. Tensioning device for cables comprising a body member provided with a tubular guideway therethrough of non-ro-und cross-section having an end wall at one end with a hole therethrough and having a bridge piece at the other end formed with a divergent sided notch opening laterally with respect to said guideway, a bifurcated wing extending longitudinally outward from the side of said guideway toward which said notch lares, a pin supported by said wing bridging the space between the bifurcations, the bridging portion of said pin forming a connecting means for the attachment 4of a cable, an elongated slide nonrotatably reciprocable in said guideway having a portion thereof of complementary cross-sectional size and shape with respect to the crosssection ofsaid guideway, a screw extending freely through thehole in said wall having a shoulder at an intermediate point-,abutting Ysaid Awall,` said screw being threadedly coupled to `said slide for drawing it toward said connect- ,Y

ing means, one Side Quaid-ninaaggravarsi/seguid end wall, a clamp lock secured to the extending portion of said side and clampably engaging that part of said screw which extends outwardly beyond said shoulder, a exible member fixed to said slide extending from the end opposite said screw and through said notch for anchoring said tension device to an extraneous object, the side of said guideway toward which said notch llares being formed with an opening between said notch and wing for permitting the insertion of said slide, the opposite side of said guideway being formed with an opening extending from said bridge piece, of a length at least equal to that of said slide, to make room for the manipulation of said slide in inserting it, and aligning it in said guideway coaxially with said screw.

2. Tensioning device for cables comprising a body member provided with a tubular guideway therethrough of non-round cross-section having an end wall at one end with a hole therethrough and having a bridge piece at the other end formed with a divergent sided notch opening laterally with respect to said guideway, a bifur-` cated wing extending longitudinally outward from the side of said guideway toward which said notch flares, a pin supported by said wing bridging the space between the bifurcations, the bridging portion of said pin forming a connecting means for the attachment of a cable, an elongated slide nonrotatably reciprocable in said guideway having a portion thereof of complementary crosssectional size and shape with respect to the cross-section of said guideway, a screw extending freely through the holel in said end wall having a shoulder at an intermediate point abutting said wall, said screw being threadediy coupled to said slide for drawing it toward said connecting means, one side of said wing extending beyond said end wall, a clamp lock secured to the extending portion of said wing and clampably engaging that part of said screw which extends outwardly beyond said shoulder, and a exible member fixed to said slide extending from the end opposite said screw and through said notch for anchoring said tension device to an extraneous object.

3. Tensioning device for cables adapted to be intercalated between sections thereof, comprising a body member formed with a guideway of non-round crosssection having -an end wall, said body member having a wing outside said guideway extending longitudinally thereof and having a portion overhanging said guideway, a slide nonrotatablyv mounted in said guideway to which one cable section is adapted to be connected, a screw freely passing through a hole in said end wall having threaded connection with said slide, said screw having an elongated head abutting said end wall and under- Y lying the overhanging portion of said wing, and means at its outer end for turning it, said wing having a connection for the other section of the cable laterally offset from the axis of said screw, and a loop clamp having its bight embracing said elongated head, and its limbs positioned adjacent the overhanging portion of said wing, and a screw passing through registering holes in said wing and limbs for tightening said clamp and securing it to said wing. i

4. Tensioning device for cables comprising a body member providing a tubular guideway therethrough of y polygonal cross-section having an end wall at one end with a hole therethrough, a screw extending freely through said hole and an appreciable distance into said guideway,l said screw having a shoulder rotatably abutting the exteriorof said body member and means by which said screw may be turned, a slide reciprocable within saidA guideway of exterior shape and size to fit said guideway` nonrotatably, said screw being threadedly coupled to slide for reciprocating the latter, *an outwardlyextending 5 6 cable section carried by said slide, said body member References Cited in the tile of this patent p'rOVd'ed .a Sl-Ot beyond Bald guideway t0 P permit insertion of said slide with the correlated cable section into said guideway when assembling, and a bridge 469,889 Spad@ Mar- 1 1892 piece spanning said slot at the end of said body member 5 113311741 Qlllglla et al June 14 1921 on the side of the axis of said screw opposite said wing, 2,120,497 Helffl'lch June 14 1938 engaged by said correlated cable section for diverting 2471642 Nevllle July 11 1941 said correlated cable section toward coaxial relationship with the cable section anchored to said wing when said FOREIGN PATENTS cable sections are mutually tensioned by said screw. 10 444,207 France Aug. 1, 1912