Field of Search:
174/4R,138R,154,155,156,164,168,169,172 254/134.3PA,19R,191-197 248/55,65,67.5 24/115E,132R,132CL,132LP,132HL,132AT 188/64
Claims:
I claim
1. A device for clamping a tensioned line comprising a body, a roller mounted in said body and over which the line is adapted to pass, a clamping cap carried by said body and provided with a clamping element engageable with both the line and said roller, and means for clamping said cap and clamping element in an operative position in tight engagement with both the line and said roller, said body being of upwardly opening U-shape, a shaft supported at its ends by the arms of said body and extended thereacross, said roller being mounted on said shaft said cap pivotally connected at one side with one of the arms of said U-shaped body, said means being connected between the other end of said cap and said body, said means being engaged at its upper end to said cap and provided with a handle at its lower end, the bottom surface of said body being provided with a recess adapted to receive a similarly shaped portion of said handle to clamp said cap in closed position.
2. A device according to claim 1 wherein said body is an insulator and said line is a cable extending across said roller and adapted to be pulled taut, said roller being provided with a dished surface over which said cable extends and having end annular flanges engageable by said clamping element when the latter engages said cable.
3. A device according to claim 2 wherein said means comprises a pair of endwise aligned rods having threaded adjacent ends, and a turnbuckle threaded on said adjacent ends.
4. A device according to claim 3 wherein said handle is a ring engageable by a tool to move it into and out of locking engagement with said recess.
5. A device according to claim 2 wherein said cap comprises a body and said clamping element is removably secured against the lower face thereof and has its bottom portion shaped to engage both said cable and end portions of said roller.
6. A device according to claim 2 wherein said means is an integral rodlike element the upper end of which is bent to extend over the top of said cap adjacent its free edge and is provided with a downturned extremity, said cap being provided with a recess receiving such extremity, the lower end of said means being bent to form a ring formed from said handle, the free end of which is straight and inclined downwardly and outwardly relative to said insulator body, said recess in the body being downwardly and outwardly inclined for receiving the corresponding inclined portion of said ring.
7. A device according to claim 1 wherein the arm of said U-shaped body adjacent said clamping device is provided with a second recess, said handle having a projection engageable in said second recess to support said cap in open inoperative position until said cable is tensioned.
8. A device for clamping a tensioned line comprising a body, a roller mounted in said body and over which the line is adapted to pass, a clamping cap carried by said body, a clamping element fixedly secured to the bottom surface of said clamping cap and engageable with both the line and said roller, and means for clamping said cap and clamping element in an operative position in tight engagement with both the line and said roller.
9. A device for clamping a tensioned line comprising a body, a roller mounted in said body and over which the line is adapted to pass, a clamping cap carried by said body, a clamping element fixedly secured to the bottom surface of said clamping cap and engageable with both the line and said roller, and means for clamping said cap and clamping element in an operative position in tight engagement with both the line and said roller, said body being of upwardly opening U-shape, a shaft supported at its ends by the arms of said body and extended thereacross, said roller being mounted on said shaft, said cap pivotally connected at one side with one of the arms of said U-shaped body, said means being connected between the other end of said cap and said body, said means including a handle pivotally secured at all times to the other side of said cap, one of said arms of said U-shaped body on the other side thereof having a recess in the outer surface thereof, and a projection extending at an angle from the end of said handle matable with said recess for fixedly spacing said clamping element above the line and said rollers thereby eliminating wear when the line is moved.
Description:
BACKGROUND OF THE INVENTION
In stringing high voltage lines, the lineman must handle a line with what is commonly known as a "hot stick" which is approximately 4 feet long and keeps the lineman out of danger while securing the line to the insulators. The line, of course, has been stretched as tight as practicable before being tied to the insulator, and tying of the cable is extremely time-consuming and quite tedious.
SUMMARY OF THE INVENTION
An insulating body, preferably of heavy U-shape, is provided with a roller therein mounted on a shaft projecting through the two arms of the insulator. Above the insulator is mounted a movable clamping cap, normally released from the roller and cable so that the cable with conventional stretching means may be pulled as tightly as possible over the top of the roller. The roller, of course, is adapted to roll freely during the tensioning operation. The cable is held in taut condition, whereupon the clamping cap is moved downwardly into engagement with the cable and roller. Of course, the cap need not be elevated and may be permitted to rest loosely in position while the cable is stretched. A clamping device is then brought into operation to clamp the cap downwardly into clamping position.
The clamping cap is provided with a central portion engageable against the cable and side portions engageable with the flanges of the roller, and the clamping portion of the cap is formed of hard rubber or other suitable material possessing a degree of resiliency only to a sufficient extent to permit a firm clamping of the device against both the cable and roller so that neither of these elements is able to move.
The clamping is effected by a clamping arm, the top of which is engageable with the clamping cap and the bottom of which is engageable beneath the insulator, the lower surface of the insulator being provided with an indentation to engage a similarly shaped portion of the clamping unit. This unit may be made of separate end-to-end bars connected by a turn buckle to adjust the length of the clamping unit so that a proper clamping action is obtained when the parts are in operative positions.
The element which engages the cable and roller may be of a separate piece from the clamping cap so that it is interchangeable with other clamping elements according to the thickness of the cable. Where many operations are to be performed on cables of the same size, the separable clamping element need not be employed, but may be formed integral with the cap. Moreover, the clamping unit extending between the cap and the bottom of the insulator need not be made of end-to-end connected bars, but may be made unitary, if desired, in accordance with one form of the invention shown and described.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a power pole showing the device in position on the top thereof;
FIG. 2 is an enlarged section on line 2--2 of FIG. 1, the pole and associated elements being eliminated;
FIG. 3 is a plan view of the device as suggested by the line 3--3 in FIG. 2;
FIG. 4 is a section on line 4--4 of FIG. 2;
FIG. 5 is a similar view on line 5--5 of FIG. 2;
FIG. 6 is a fragmentary section similar to FIG. 2 showing a modified form of clamping cap;
FIG. 7 is a section similar to FIG. 2 showing another modification of the invention; and
FIG. 8 is an edge elevation of the same as suggested by the line 8--8 in FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 to 5, inclusive, the numeral 10 designates a power pole shown as having a cross arm 12 at its upper end on which is mounted an insulator indicated as a whole by the numeral 14 having a dependent threading stem 16 adapted to be extended through an opening in the cross arm 12 and secured in position with respect thereto by a suitable washer and nut. Insulator 14 is shown as being relatively heavy and of generally U-shape comprising spaced arms 18 and a base 20, these elements defining a space or chamber 22 therein.
In the space 22 is mounted an insulating roller 24 having a dished surface terminating at the ends of the insulator in flanges 26, and the roller is mounted on a shaft 28' projecting through the arms 18 to be supported thereby.
Above the insulator is arranged a clamping cap indicated as a whole by the numeral 28 comprising a body member 30 hinged at one side as at 32 to the upper end of one of the arms 18. The body 30 is provided with a recess 34 adapted to receive the upwardly projecting portion of a clamping element 36 secured to the body 30 by screws or other fastening elements 38. The clamping element 36 is provided with side flanges 40 respectively engaging the roller flanges 26, while the central portion of the clamping element is provided with a downward projection 42 adapted to engage a cable 44 extending across the roller 24.
A clamping device indicated as a whole by the numeral 46 is adapted to clamp the cap 28 in operative position. This device comprises upper and lower end-to-end bars 48 and 50 having threaded adjacent ends 52 connected by a turnbuckle 54. The upper bar 48 is provided with a lateral extension 56 extending into a recess 58 in the adjacent edge of the cap 28 and pivoted thereto as at 60. The bar 50 is provided at its lower end with a handle 62 having an opening 64 therethrough. The handle is preferably curved as shown and the top thereof is adapted to snap into a recess 66 formed in the bottom surface of the insulator 14. The handle 62 may be provided with a projection 68 engageable in a recess 70 in the adjacent insulator arm 18 to support the cap 28 in open position during the cable tensioning operation, if desired, as further referred to below.
In FIG. 6 of the drawings, a modified type of the device is shown wherein an integral cap 72 is substituted for the cap 28. This type of cap may be used where no adjustment is to be made for cables of different diameters, in which case the clamping element may be integral with the cap. This element is likewise provided with a central projection 74 engageable with the cable 44, and with side flanges 76 adapted to engage the flanges 26 of the roller 24.
In this case, the extension 56 of the clamping device is eliminated. The cap 72 may be radially extended as at 78 and slotted as at 80 to receive a head 82 formed on the upper end of a clamping device indicated as a whole by the numeral 84 and again comprising upper and lower rods 86 and 88 threaded as at 90 into a turnbuckle 92. The head 82 of the clamping device is pivoted to the cap 72 by a transverse pin 94.
A further modification of the device is shown in FIGS. 7 and 8 wherein the cap 96 is provided with an integral cable clamping element 98 to engage, in this case, a thinner cable 100 and engaging also the flanges 26 of the roller 24. The contour of the bottom of the projection 98 may be of any shape according to the thickness of the cable, as will be apparent. In this case, an integral clamping element 102 is employed formed of rigid rod material provided at its upper end with a lateral projection 104 engageable in recess 106 in the top surface of the cap 96. The bottom of the clamping device is shaped to form a handle ring 106, and the free end of this ring is bent and flattened as at 108 to engage in an inclined notch 110 formed in the bottom surface of the insulator.
OPERATION
The handle 62 (FIG. 2) is arranged free of the notch 66 and the cap 28 may occupy the position shown in FIG. 2, loosely engaging the flanges of the roller 24, and the cable 44 is inserted over the top of the roller and tensioned in the usual manner. The pulling of the cable rotates the roller, and if the cap is left in closed position in the manner described, the bottom surfaces of the flanges 40 and projection 42 may be excessively abraided. To avoid this, the cap 28 may be supported in an elevated position by engaging the projection 68 in the recess 70.
While the cable is held under tension, the cap 28 will be closed by removing the projection 68 from the recess 70, unless the parts already occupy such position. With his "hot stick" the lineman will then move the handle 62 inwardly by engaging the stick in the opening 64, to snap the handle into the recess 66. The slight flexibility of the parts including the slight resiliency of the clamping element 36 will allow this operation to take place. Both the cable 44 and roller 24 will then be held clamped against any movement. It is desirable to clamp both the roller and the cable since, when pressure is exerted only on the cable, the latter might have a tendency to pull, roll or sway back and forth so as to possibly chafe through or be otherwise harmed. All of the parts will be rigidly fixed against any movement. If the clamping device 46 is slightly too long to provide the necessary clamping force, or if it is too short, suitable adjustment may be readily carried out by rotating the turnbuckle 54.
The operation of the form of the device shown in FIG. 6 is identical with that previously described. A direct force will be transmitted from the rod 86 to the free edge of the cap 72 instead of exerting such force through the extension 56. The clamping operation will be the same as before, and the integral form of the cap may be employed where all, or substantially all, operations are being carried out on cables of the same size.
The same operation takes place in FIG. 7. In this case the parts will be so designed that an integral clamping device 102 may be employed, there being no provision or necessity for adjusting the length of the clamping device.
The clamping element may be made of any suitable material such as hard rubber, Bakelite, Teflon, etc. It also will be noted that the device has many other applications for tightening and securing wires or other lines. For example, the device may be used for clamping in taut condition a clothes line stretched between cross arms or standards or uprights. Likewise, the clamping operation may be performed on the horizontal elements of heavy wire fences or other similar structures.
From the foregoing it will now be seen that there is herein provided an improved locking insulator which accomplishes all of the objects of this invention and others, including many advantages of great practical utility and commercial importance.
As various embodiments may be made of this inventive concept, and as many modifications may be made in the embodiments hereinbefore shown and described, it is to be understood that all matter herein is to be interpreted merely as illustrative, and not in a limiting sense.