US2738480A - Tap clamp connector - Google Patents

Description

March 13, 1956 Q HUBBARD TAP CLAMP CONNECTOR 2 Sheets-Sheet 1 Filed April 6, '1953 March 13, 1956 ac. HUBBARD 2,738,480

TAP CLAMP CONNECTOR Filed-April 6, 1955 2 Sheets-Sheet 2 IN V EN TOR.

David C Hubbard wi fluzr r415 army United States Patent TAP CLAMP CONNECTOR David C. Hubbard, Centralia, Mo., assignor to A. B. Chance Company, Centralia, Mo., a corporation of Missouri Application April 6, 1953, Serial No. 346,823

4 Claims. (Cl. 339-109) The present invention relates to tap clamps, and is particularly concerned with the provision of improved tap clamps which provide a better connection, that may be easily installed, and removed at any time.

The present application is a continuation-in-part of my prior application, Ser. No. 55,071, filed October 18, 1948, for Tap Clamps, and is substituted for said application.

One of the objects of the invention is the provision of an improved tap clamp adapted to be actuated by a threaded member in which the eye screw threads are enclosed in a threaded chamber containing a corrosion inhibiting compound, and in which the threads are protected from the weather and never exposed nor brought into the arc zone, where they can be damaged, so that their damage is practically eliminated; and the tap clamp may be properly tightened on the conductor at any time when service is renewed.

Another object of the invention is the provision of an improved tap clamp which is provided with a resilient locking means, which is disposed outside of the primary current path and is entirely enclosed in service, but may be exposed for inspection by opening the clamp; and the primary purpose of which is to compensate for conductor flow and for preventing line vibration from shaking the clamp loose.

Another object of the invention is the provision of an improved tap clamp which is substantially balanced rotatively and dynamically on the line, the jumper connector being disposed above the main line contact to ofiset the weight of the eye screw for reducing conductor fatigue and lengthening conductor life.

Another object of the invention is the provision of an improved tap clamp, the clamp jaws of which are adapted to reduce fatigue of the conductor by being provided with bell mouthed ends where the conductor emerges from the clamp to prevent the sharp bending of the conductor at one place.

Another object of theinvention is the provision of improved tap clamps, the jaws of which are adapted to hang on the conductor without turning when the clamp is tightened and to make a maximum contact with all of the outside strands of the conductor throughout the conductor range of the clamp, thus eliecting a greater conductivity between line and clamp, better current distribution, less heating, and ability to withstand heavy surges, and reducing radio and TV interference.

Other objects and advantages of the invention will be apparent from the following description and the accompanying drawings, in which similar characters of references indicate similar parts throughout the several views.

Referring to the two sheets of drawings accompanying this specification,

Fig. 1 is a front elevational view of a tap clamp embodying my invention applied to a multi-strand conductor, with the clamp in the open position;

Fig. 2 is a side elevational view, taken from the right side of Fig. 1, showing the parts in the same position in 2,738,480 Patented Mar. 13, 1956 full lines and the parts in the closed or clamping position in dotted lines;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 1, looking in the direction of the arrows;

Fig. 4 is a sectional view taken on the line 4-4 of Fig. 2, looking in the direction of the arrows;

Fig. 5 is a sectional view taken on the plane of the line 5-6 of Fig. l, with the parts shown in the clamping position in full lines and in the open position in dotted lines;

Fig. 6 is a fragmentary sectional view taken on the plane of the line 66 of Fig. 2, looking in the direction of the arrows;

Fig. 7 is a fragmentary sectional view taken on the plane of the line 7--7 of Fig. 2, looking in the direction of the arrows;

Fig. 8 is a fragmentary sectional view taken on the plane of the line 88 of Fig. 2, looking in the direction of the arrows.

Referring to Figs. 1, 2, and 5, the tap clamp is indicated in its entirety by the numeral 1% and its principal parts are the tap housing 11, movable jaw or gripper 12, and the eye screw assembly 13, and the tap wire connector assembly 14.

The eye screw assembly 13 preferably includes the eye screw 15 and the spring 16. The eye screw 15 is provided with a circular head 17 having a circular eye opening 18, the head and eye being of such size that it may be received in the sockets or gripping jaws of standard clamp sticks. The eye head 18 is carried by a cylindrical shank 19, which is also of a suitable size to pass the aperture in the headof any standard clamp stick.

The eye screw 13 is provided above the shank 19 with a radially extending thrust flange 20, which may be circular in shape and is provided with an annular upper thrust surface 21 for engaging the spring 16. Above the thrust flange 20 the eye screw is provided with a cylindrical guide surface 22 for guiding the movable jaw or gripper 12, this cylindrical guide surface 22 terminating at an annular shoulder 23, where it is integrally joined to a cylindrical shank 24 of reduced size, which is small enough to pass into the threaded bore 25 of the upper housing 11 without interfering with the threads.

At its extreme upper end the eye screw is provided with the enlarged threaded end portion 26 for engaging the threads in the threaded bore 25 of the upper housing 11. The length of the threaded portion 26 is only a fraction of the length of the threaded bore 25 so that the threaded portion 26 is never disposed adjacent the clamped conductor 27 in the arc zone; and the threaded portion 26 is always disposed well up into the threaded bore 25, where it is protected from ice, moisture, and from the weather,

The reduced shank portion 24 is of such length that the eye screw-may be threaded fully into the threaded bore 25 to clamp very small conductors without having the shoulder 23 strike the threads 25.

The radial thrust flange 20 is small enough in diameter so that it may be received inside the partially cylindrical chamber 27 of the upper housing, as shown in Fig.

5, when the conductor 28 is clamped, so that only the lower cylindrical shank 19 of the eye screw projects outside of the upper housing 11.

The spring 16 preferably consists of a double coil spring lock washer; but various types of springs may be employed. .Thus the spring 16 has an upper turn 29,

which is substantially in the same plane, except that its end portion is turned upward at the sharp corner 39 to accomplish the lock washer function.

.In the same way the lower turn 31 of the spring-.16 is substantially in the same plane, except that the end portion32 is turned downward so that its sharppomelt ,33may dig into the annular surface 31,for its locking function.

The upper and lower turnsof the spring have their end portions :spacedv fromreach'other-toj providezroom for the; integral offset 34, which joins them; and theqspacingmf-r the-end;portions,:30:and 32 is such:that:-th'ezspringtmay be clamped with its coils solidly ,engagingeachother so.thatp theeyescrew clamps the conductor'solidly;'while having the spring present to-take up any'looseness, shouldnany occur.

The movable jaw'or gripper 12 comprises a cast metal member made of metal of high conductivity; such, as copper; and it is provided with a forwardly projecting jaw;

portion 35and a rearwardlyprojecting:;actuating body 36, The body 36 is rounded at 37 'onits rear side ,and pro,-, vided with a pair of diagonally extending walls 38, 39-

leading tothe;laterally projectingretaining ribs 40, 41, which have rounded surfaces at 42;

The body 26 has the substantially rectangular .grooves 43 andu44- between the body portion 36 and the jaw portion ,35 for receiving the inwardly extending- guide walls 45, 46 that are carried by the upper housing 11. In general, the upper housing 11 has its chamber 28 complementary in shape to the body 36 of thegripper 12 and of the same shape longitudinally throughout the length of the chamber 28 so that the gripper body 36 mayslide freely upward or downward in the chamber 28.

Thejjaw portion 35 of the gripper extendsforwardly outside the chamber 23 and is made of substantial length in a lateral direction so that the jaws :will engageall of the outside conductors of a stranded conductor 27 for:

effecting a better current distribution. and a better contact.

The-jaw 12 has an upper obtuse V shaped. clamping surface 47, which is located with its apex in alignment with the apex 48 of the upper clamping surface 49 of an upper jaw formation 50, which is of corresponding length, and which is in the shape of a part of a hexagon.

Referring to Fig. 8, this figure shows the upper and lower clamping surfaces 49 and 48, engaging the stranded conductor 27 over a substantial portion of its length so that every strand of the conductor engages some part of the clamping jaws.

Ateachendthe upper jaw clamping surfaces. 49, are, belled out at 51; and the lower clamping surface 48 is,

belled out at 52 upon a radius which provides a relatively long and gradually tapering funnel at each end of the jaws. This prevents any sharp bending of theconductorat the point where the gripping pressure is applied tothe conductor; but the bending takes place over a substantial portion of the conductor. 7

The taper of these bell-mouthedsurfaces is preferably less than the natural bending radius of the conductor, so

that as the conductor bends the point of contact between the conductor and the clamping jaws at. each end of the jaws shifts outwardly as'th'e conductor is bent more sharply. Thus the points of engagement between the jaws and the conductor at the ends of the jaws are shifted-as the conductor vibrates; and the clamping-surfaces tend toffer support against sharp bending through a-wide rangeof amplitudes.

As the conductor vibrates and flexes back=andforth at theends of the clamping surfaces, this fiexureis not con: 1 centrated at a single point; and there is no sharp-corner at:

the end of the clamp around which the conductor bends; and therefore there is less chance of fatigue failurerof-the conductor outside of the clamp; and a longerconductor life results.

The gripper 12 is provided on its front sidewitha depending skirt portion 53, which closes the front of'thetab. 154,; also serves to withdraw: the.agrippervllgfrom;,enrt

gagemcnt with the conductor; and this of particular imtending projections 59, 60, Fig. 6, which are locatedto. engage the inwardly extending bottom walls ,6l1and,,62,of

the upper housing which terminate the grooves 63, 64,.Fig. 3, at the bottom.

The gripper is inserted inthe bodyaby-tiltingthe, gripper until the projections59 and 60 clear the outer wall at the space between the ribs 45, 46, and the gripper is then straightened out inside the chamber 28.

When the eye screw 13 is installed by passing it through the gripper and threading it intothe ;bore- 25,' this :holds the gripper in proper alignment so that it is guided bythe: cylindrical surface 22 and locks the :grippen-withinithm body housing.

The upper housing 11 of the tap clamp is, provided with the threaded bore 25, which is closed at; its,. ,upp er;endv

where it has a counterbore 65 of smaller size which is unthreaded and which is preferablyprovided with a corrosion inhibiting compound adapted to lubricate the threads The compound also extends into the threadedbore .25

and;lubric,ate s the threads, andany' leakage. of the-.comv.

pound past the'threads covers threads below the threaded portion of the part 26 of the eye screw.

Thehousing 11 preferably has .an:external cylindrical, formation66 surrounding the bores 25 and 65,.andbelow. the bore 25 housingll isv provided with the-;depending; walls 67 on the rear side and 68, 69 onthe lateral sides for.

housing and guiding the lower gripper. 12.

The depending rear wall 67 is integrally joined to the cylindrical upper portion-66, and .both, arejoined ,by a longitudinally extending reinforcing rib 70, Fig. 2.

The external shape of the walls- 67, 68, 69may be varied, but to save material these walls arepreferably of substantially uniform thickness so that thelower housing,

has the flat diagonal surfaces 71, 72 joined byarounded portion 73,. and the flat lateral surfaces 74, 75,v Fig. 3, extending forwardly.

The upper cylindrical portion 66 of ,the .housingsup ports an integral, forwardly extending andlongitudinally extending fiange 76, Fig. 1, Fig. 5,whic,h ca.rries theupper; jaw flange 50, extending transversely to the front.flange76..

Theupperjaw flange 50 is elongated .in a lateral direction, as shown inFig. 1, andmay be of substantially the.

same lengthrrelative to the conductor 27 as the-lowerjaw,

35., The upperiaw formation 51Lpreferablytakes-v the.

shape of a half hexagon,,havingtwofullside flanges 77,

78 joined at the apex 48 and forming the uppermost part,

of the jaw formation50, and having two depending parallel flanges 79, 80, equivalent, to ,one,half, the side.ofthe same hexagonand bordering the jaw. formationjfljnfront andin back.

The front flange 76 also supports a pointed, beakl 81, which tapers from the full width of the jaw 50 10a rounded apex 82, and which comprises a flange '83 that extends forwardly and downwardly, serving as a hook and a guide for guiding the tap clamp over thetop of the conductor 27, and for guiding the conductor intothe upper jaw 50, where it is retained by the parallel flanges 79 and 80, and by the V-formation of the flanges 77 and 78.

The upper apex 48 of the jaw formation 50 is preferably in alignment with the lower apex -47 of the gripper jaw.

The front flange 76 preferably supports an integral" socket formation 84, which is a partof the-tap wire connector assembly,- and bulges outward toward the left' of for.;passing :the connector pressureiscrewu86, forming an.-

other part of the tap wire connector. Pressure screw 86 has a threaded shank 87 which is provided with a single turn lock washer 88 and with a nut 89.

Socket formation 84, Fig. 7, terminates in a plane thrust surface 90, surrounding the through bore 85, this thrust surface being engaged by the lock washer 88, which inturn is engaged by the nut 89. l v

The pressure screw 86 terminates in a circular head 91 which may have a through bore 92, Fig. 7, and fiat lateral sides 93, 94. Externally the head 91 of the pressure.

screw may have rounded surfaces, and at its upper end it is provided with a jaw formation 95, which is elongated in both directions to the left and right, Fig. 4, of the pressure screw bore 92.

On its lower side the jaw 95 of the pressure screw may have a partially cylindrical groove 96, which may be belled upward in both directions from the midpoint 97, and which is adapted to receive the tap wire 98 and to clamp it against the housing 11.

The forward flange 76 of housing 11 is thickened and provided with the V-shaped groove formations 99, 100, in alignment with each other and on opposite sides of the bore 85 for receiving the tap wire 98 and providing clamping surfaces opposite the jaw 95.

On its outside the jaw formation 95 of the pressure screw may be provided with a reinforcing rib 101 which tapers toward each end and thus presents a rounded surface 101 from end to end of the jaw formation 95, as shown in Fig. 4.

The socket formation 84 may be substantially ball shape externally where it projects from the flange 76, except on the flat side 102 which is located forwardly an upwardly on the socket formation 84.

Internally the socket formation has a socket 103 with a flat side 104 toward the groove 99, and the side 105 toward the groove 100 may be partially cylindrical, but the socket 103 is tapered inwardly on all sides for formation by a suitable core.

The other two sides 106 and 107 of the socket 103 are partially circular since they are intended to receive the lower part of the circular head 91 of the pressure screw 86.

Thus the tap wire 98 may have its end inserted through the bore 92, and when the nut 89 is drawn up the ring prevent it from turning so that the tap wire is guidedinto the grooves with which it is clamped, and the pressure screw does not have to be held against turning when the nut 89 is driven home.

It will thus be observed that I have invented an improved tap clamp which has complete thread protection against corrosion and weather, easy installation and removal and weather protection for the spring which compensates for conductor flow.

The present tap clamp is balanced to protect the conductor by reducing conductor fatigue and effects a better and more complete contact with all of the strands of a conductor for better current distribution, higher conductivity and reduction of heating.

While I have illustrated a preferred embodiment of my invention, many modifications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a tap clamp, the combination of an upper housing member provided with an elongated threaded bore, forming a chamber for an anti-corrosion compound, the said housing having an. upper jaw formation and having a lower downwardly and forwardly open chamber for slidably receiving a lowerjaw member, a lower jaw member slidably mounted in said chamber, and a clamping screw having a thrust shoulder for engaging said lower jaw member and driving it toward said upper jaw member, said screw having an elongated shank of reduced size adjacent said upper jaw and lower jaw member in the arc zone, and having a relatively short threaded end portion which is located upwardly in said threaded bore, away from the arc zone, and housed against exposure to rain and ice, the said thrust flange and lower jaw member having their sliding parts. housedand protected against ice and rain in the lower downwardly open and forwardly open chamber of said housing.

2. In a tap clamp connector, the combination of a fixed jaw member, a movable jaw member, and a clamping screw having a head adapted to be engaged, supported, and released by a clamp stick, said fixed jaw member having an elongated threaded bore closed at its upper end for receiving a corrosion inhibitive compound, and open at its lower end to receive said clamping screw, said clamping screw having a relatively short threaded end portion for engaging the threads in said bore, and having a shank of reduced size for clearance with the threads in said bore to locate the threaded part of the clamping screw in the bore out of the arcing range, which is at the open end of said bore, said screw passing through a bore in said movable jaw, and having a radial thrust flange below said movable jaw for urging the jaws together into clamping position.

3. In a tap clamp connector, the combination of a fixed jaw member, a movable jaw member, and a clamping screw having a head adapted to be engaged, supported, and released by a clamp stick, said fixed jaw member having an elongated threaded bore closed at its upper end for receiving a corrosion inhibitive compound, and open at its lower end to receive said clamping screw, said clamping screw having a relatively short threaded end portion for engaging the threads in said bore, and having a shank of reduced size for clearance with the threads in said bore to locate the threaded part of the clamping screw in the bore out of the arcing range, which is at the open end of said bore, said screw passing through a bore in said movable jaw, and having a radial thrust flange below said movable jaw for urging the jaws together into clamping position, said fixed jaw member and said movable jaw member each having a concave gripping surface for engaging a cable conductor with helical components, and said jaw members being widened longitudinally of said conductor gripping surface sufliciently to engage the outer surface of every helical component of said cable, for uniform current distribution and minimum total contact resistance, said fixed jaw having a depending skirt housing on three sides about said shank and movable jaw member, and said movable jaw member projecting laterally from said housing, and being grooved parallel to said screw on both sides to receive inwardly extending enclosing flanges, which tend to exclude ice.

4. In a tap clamp connector, the combination of a fixed jaw member, a movable jaw member, and a clamping screw having a head adapted to be engaged, supported, and released by a clamp stick, said fixed jaw member having an elongated threaded bore closed at its upper end for receiving a corrosion inhibitive compound, and open at its lower end to receive said clamping screw, said clamping screw having a relatively short threaded end portion for engaging the threads in said bore, and having a shank of reduced size for clearance with the threads in said bore to locate the threaded part of the clamping screw in the bore out of the arcing range, which is at the open end of said bore, said screw passing through a bore in said movable jaw, and having a radial thrust flange below said movable jaw for urging the jaws together into clamping position, said fixed jaw member and said movable iawmemb'er;each:'having a concave ?g1 ipping;surface for engaging a cable conductor with helical "comppnents,. and 'said' jawmembers being widenedldngiludi'nally of said-,conductorg ipping surface sufiiciently tqengage. the. outer, surface .of [every helical component of said cable, for. uniform. current distribution.andnninimurn. total contact resistance, ,said fixed-ujawhaving a depending skirt- .l10us 1 ing on three sides..-about ..said shank. and. movable, jaw member, and saidmovableiawmemberprojecting, latev ally fromi, saidqrhousingg. and; being-.grooved :parallel.;; to said fscrcw on'botbsideszto rcceivejnwardly extending en-u closing. fianges,: which tend-to exclude-ice,- said: skirt als'oextending downward far enough tohouse saidthrust flange, and a springcarried above-the thrust flange Orr-saidscrew.

References Citedintliefile of this patent UNITED STATES PATENTS.

Chandler.- Aug;: 3, 1926. Bodendieck .July .9, 1929.. Bowers .July;2, 1935. Mack- Oct: 8;;- 1935 He'itman Aug; 4, 1936. Beck'er- Feb. 10, 1942' Donoghue Dec. 15, 1942' Bodcndieck May .23, 1950. Hendley Nov. 14," 1950 Clapp Nov.- 13,1951' Moore Nov. 13; 1951 FOREIGN PATENTS Canada June 8,.1954-

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