US 3013244 A
Description (OCR text may contain errors)
Dec. 12, 1961 M. F. RUDY 3,013,244
CLAMP CONNECTION AND SPACER FOR ELECTRICAL TRANSMISSION LINES Filed May 1. 1957 2 Sheets-Sheet 1 INVENTOR. Mai/0N F; 21/0) Dec. 12, 1961 M. F. RUDY 3,013,244
CLAMP CONNECTION AND SPA FOR ELECTRICAL TRANSMISSION NES Filed May 1. 195'? 2 Sheets-Sheet 2 ./G mun 42 IN VENTOR.
BY aw F176. 5. M
47708/VEY5 United States Patent Qfifice 3,013,244 Patented Dec. 12, 19%1 3,013,244 CLAMP CONNECTION AND SPACER FUR ELECTRICAL TRANSMISSION LINES Marion F. Rudy, Northridge, Calirl, assignor to Verdugo Products Company, Van Nuys, Calif., a corporation of California Filed May 1, 1957, Ser. No. 656,250
1 Claim. (Cl. 339245) This invention relates to electrical power transmission systems and is particularly directed to improvements in clamp connection and spacer assemblies for electrical transmission lines employing bundle conductors. This invention finds particular usefulness in connection with the twin conductors separated by a conducting spacer assembly, but this is by way of illustration and not of limitation.
A general object of this invention is to provide an improved clamp connection and spacer for electrical trans mission lines and particularly transmission lines of the type employing bundle conductors. Another object is to provide an improved self-aligning spacer assembly having excellent electrical characteristics and low corona loss. Another object is to provide an improved clamp assembly including cooperating releasable clamping parts together with improved means for-preventing accidental disassembly of the parts in released position. Another object is to provide an improved ball' and socket connection between the clamp assembly and another member such as a spacer member.
Another object is to provide an improved form of dust guard for the ball and socket connection. A more detailed object is to provide an improved form of resilient mounting for the dust guard, including one or more clamp washers constructed and arranged to be subjected to bending stresses. Other related objects and advantages will appear hereinafter.
In the drawings:
FIGURE 1 is a bottom plan view showing a preferred embodiment of my invention.
FIGURE 2 is a top plan view partly in section and partly broken away.
FIGURE 3 is a sectional elevation taken substantially on the lines 33 as shown in FIGURE 2.
FIGURE 4 is a view similar to FIGURE 3 showing the clamping jaw in released position.
FIGURE 5 is a sectional detail taken substantially on the lines 55 as shown in FIGURE 4.
FIGURE 6 is a fragmentary view partly in longitudinal section, showing details of the ball and socket c0nnection.
FIGURE 7 is a fragmentary sectional view showing the cooperating fin and groove which permit installation of the ball within the socket by relative turning movement of the parts.
As shown in the drawings, the spacer member generally designated 10, is connected at its opposed ends to clamp assemblies 11 which engage parallel electrical transmission cables 12 and 13. These cables comprise twin conductors. The cables operate at the same electrical potential and without phase difference, and the spacer member and clamp assemblies 11 are formed of electrically conducting materials.
The clarnp assemblies 11 are substantial duplicates and hence, only one need be described. The body or hook member 14 cooperates with a movable jaw 15 to define a recess 16 to receive the electrical transmission cable 12. The hook 14 is provided with a threaded opening 17 to receive the clamping bolt 18 and this bolt extends through an inclined aperture 19 provided on the jaw 15. A lock washer 20 is engaged by the bolt head 21 and contacts the jaw 15. In this position of the parts the abutment surface 22 on the hook is engaged by a portion of the jaw 15.
The jaw 15 may be released to permit lateral insertion or withdrawal of the cable 12 relative to the recess 16. This is accomplished by turning of the bolt 18 to bring it to the position shown in FIGURE 4. In this open or released position the jaw 15 no longer contacts the abutment 22 and the inclination of the aperture 19 allows it to assume an angular position with respect to the bolt 18, thereby producing the desired clearance opening with respect to the hook 14.
It is highly desirable to prevent accidental disassembly of the parts of the clamp, since application of the clamp to the transmission line may be accomplished by a workman perched precariously on a tower and wearing gloves on his hands. If the parts should become disassembled during the process of installation they may fall to the ground and cause considerable inconvenience and delay.
In accordance with my invention, means are provided to prevent complete separation of the bolt 18 from the threaded opening 17. As shown in the drawings this means includes a slot 23 at one end of the bolt 18 extend ing axially thereof. A spring finger 24 is mounted in a recess 25 in the hook 14 adjacent the abutment 22. This spring finger has a projecting end which enters the slot 23 in the bolt 18 when the bolt has moved axially out of the threaded opening 17 to a predetermined position. A pin 26 holds the spring finger in position within the recess 25.
When the end of the spring finger 24 engages the axial slot 23 and is moved into contact with the wall 25a of the recess 25, further turning movement of the bolt 18 in an unthreading direction is prevented. Tightening movement of the bolt 18 in the direction indicated by the arrow 27 in FIGURE 5 is permitted, however, since the spring finger simply moves out of the way and rides in one of the thread grooves on the bolt 18.
An improved form of ball and socket connection is provided between the clamp assembly 11 and the spacer member 10. A shank 30 on the hook 14 is internally threaded to receive a clamping bolt 31 which serves to clamp a ball element 32 to the end of the shank. The outer surface of the ball element is spherical and it has surface contact with the internal spherical surface 33 on the socket generally designated 34. One of these sockets 34 is provided at each end of the spacer member 10. Means of the general type shown in the Reese Patents 2,531,892 and 2,654,643 are provided for permitting installation of the ball into the socket. The form of helical thread is improved over that shown and described in the Reese patents, however, and in the improved form the thread on the ball 32 takes the form of a continuous helical groove 35 on an equatorial portion of the ball 32 and extending at an angle to the axis of the shank 30. The groove 35 is engaged by a helical fin 36 provided at the open end of the socket 34, so that by turning the spacer member 10 relative to the clamp assembly 11 the ball 32 can be inserted into the socket 34. The sides of the groove 35 are substantially parallel and the sides of the helical fin also are substantially parallel. This construction provides a minimum of interruption of the spherical surface on the ball 32. In the normal operating position of the spacer 10 and clamp assembly 11, the helical fins 36 and groove 35 are misaligned to such an extent that disassembly of the ball from the socket is substantially impossible. When the ball and socket parts are in the position shown in FIGURES 3 and 4, the clamp assernblies 11 have limited universal movement with respect to the spacer 10.
In accordance with my invention, I provide a dust guard to exclude foreign matter from the ball and socket connection, and I provide a novel form of spring to maintain the dust guard in position. As shown in the drawings, this dust guard comprises a shield member 40 having an internal spherical surface 41 adapted to engage the corresponding external spherical surface 42 adjacent the end of the spacer member 10. A central opening 43 in the shield loosely receives the outer cylindrical surface of the shank 30 and the inner edge of this shield adjacent the opening 43 bears against a flat spring washer 44 adjacent its inner diameter. Although I have shown two separate spring washers 44 loosely encircling the cylindrical shank 30, it will be understood that a greater or lesser number may be used depending on the stiffness desired. A cupped annular ring 45 loosely encircles the cylindrical shank 30 and its inner diameter engages the shank abutment 46. The outer diameter of the cupped annular ring 45 engages the outer portion of one of the fiat resilient washers 44. The washers 44 are subjected to bending stresses because the axial forces which are applied to them are exerted on the outer diameter on one side and on the inner diameter on the other. The washers 44 act resiliently to maintain the shield 49 in contact with the spherical surface 42.
The washers 44 need not be of the same thickness; it may be desirable to employ one or more thin washers with one or more thick washers to achieve the stilfness desired. It is also possible to use three or more washers of increasing thicknesses.
Having fully described my invention, it is to be understood that I do not wish to be limited to the details herein set forth, but my invention is of the full scope of the appended claim.
In a cable clamp device, the combination of: a hook and a jaw having parts cooperable to encircle and grip a cable therebetween, the hook having an integral shank projecting therefrom, a ball element at the projecting end of the shank, the hook having an abutment engaged by a portion of the jaw and having a blind threaded opening extending through the abutment, Walls on the book including laterally spaced diverging fins extending from the shank and cooperating with the abutment to define a pocket, the jaw having an aperture, a bolt extending through the jaw aperture and threadedly engaging the hook opening, the bolt having a head acting to clamp the jaw against said abutment, a major portion of the bolt head being received within said pocket, the jaw aperture having greater transverse dimensions than the crosssection of said bolt, turning movement of the bolt in the threaded opening serving to permit tilting of the jaw within said pocket and thereby to permit lateral withdrawal of the cable from the hook.
References Cited in the file of this patent UNITED STATES PATENTS 1,421,127 Chism June 27, 1922 1,702,124 Matthes Feb, 12, 1929 1,794,179 Keen Feb. 24, 1931 1,809,774 Coates June 9, 1931 1,925,064 Wahlers Aug. 29, 1933 2,159,154 Hixon May 23, 1939 2,346,181 Overend Apr. 11, 1944 2,380,240 Hufi'erd July 10, 1945 2,396,151 Brenner et a1 Mar. 5, 1946 2,456,546 Venditty Dec. 14, 1948 2,531,892 Reese Nov. 28, 1950 2,654,643 Reese Oct. 6, 1953 FOREIGN PATENTS 167,392 Austria Dec. 27, 1950