US3744012A

US3744012A - Teeter terminal clamp

Info

Publication number: US3744012A
Application number: US00241581A
Authority: US
Inventors: C Gutshall
Original assignee: Elco Industries Inc
Current assignee: Elco Industries Inc
Priority date: 1972-04-06
Filing date: 1972-04-06
Publication date: 1973-07-03
Anticipated expiration: 1990-07-03
Also published as: DE2313392A1; FR2179723A1; FR2179723B3; JPS4915978A; IT978846B

Abstract

The teeter terminal clamp for removably securing the terminal portion of a single conductor or two conductors of the same or different diameter comprises a threaded shank having a head for rotating the shank, the head having an underhead surface with at least one, integrally-formed, substantially-circular or oval protrusion surrounding the shank and intermediate the inner and outer extremity of the underhead surface; a clamping plate substantially centrally apertured and assembled loosely and tiltably on the shank adjacent the head, the plate having on the side adjacent the head at least one, substantially-circular or oval recess complementing the shape of the protrusion whereby the extremity of the protrusion registers with an intermediate portion of the inner wall of the recess when the protrusion and recess are in registration, the plate also having on the other side conductor-engaging, anti-pullout surface irregularities; and means for retaining the plate on the shank adjacent the head.

Description

United States Patent Gutshall July 3, 1973 TEETER TERMINAL CLAMP [57] ABSTRACT [75] Inventor; Ch -k E, G t h ll, S h b The teeter terminal clamp for removably securing the [1[ terminal portion of a single conductor or two conductors of the same or different diameter comprises a [73] Asslgnee: Elm Indusmes Rockford threaded shank having a head for rotating the shank,

22 Filed; Apt 1972 the head having an underhead surface with at least one,

integrally-formed, substantially-circular or oval protru- [Zll Appl' 241581 sion surrounding the shank and intermediate the inner and outer extremity of the underhead surface; a clamp- 52 us. Cl. 339/246, 339/95 R s Plate Substantially Centrally apertured and assem- 51 int. Cl non- 9/10 bled loosely and tiltably on the Shank adjacent the 581 Field of Search 339/95, 246, 263 head. the plate having on the side adjacent the head at least one, substantially-circular or oval recess comple- [56 Ref ren g Cited menting the shape of the protrusion whereby the ex- UNITED STATES PATENTS tremity of the protrusion registers with an intermediate portion of the inner wall of the recess when the protrusion and recess are in registration, the plate also having Primary ExaminerJoseph H. McGlynn Attorney-Albert H. Pendleton, William J. Birmingham on the other side conductor-engaging, anti-pullout surface irregularities; and means for retaining the plate on the shank adjacent the head.

13 Claims, 15 Drawing Figures PMENIEUJuL a ma FIG.I

FIG. 2

FIG. 5

FIG. 3

FIG. 4

memsum am 3.744.012

FIG. 6 4

1 TEETER TERMINAL CLAMP BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to terminal clamps of the threaded type which are employed to releasably secure the terminal portions of elongated members such as electrical conductors to a workpiece or to each other. More specifically, it relates to a threaded terminal clamp having a clamping plate which teeters or tilts in order to accommodate and securely clamp either a single wire or two wires of the same or different size and in the case of a pair of wires to apply approximately equal clamping loads to each wire.

While the present invention will be described with particular reference to threaded terminal clamps specifically designed to cope with the problem of clamping the terminal portions of two electrical conductors having different sizes or diameters, it should be understood that the invention is not necessarily limited thereto.

The inventive concepts set forth herein can be readily adapted to cope with equal-load clamping problems associated with elongated members in general, as those skilled in the art will recognize in the light of the present disclosure.

2. Description of the Prior Art .The art relating to terminal clamps for electrical connectors is highly developed because of the long-existing need for improved means for releasably securing electrical leads, both solid and stranded, wires, cables and other connectors to one another and to terminal posts. This need is dictated in part by the cost, inconvenience and obvious hazards, including shock, electrocution, fire and other destructive consequences which can occur if a hot lead becomes unintentionally and unknowingly unfastened. This need is reflected in part in the establishment of various applicable performance standards by Underwriters Laboratories, lnc. It is reflected in part in the patent art in this field, typical of a some of the prior art being U.S. Pat. Nos. 2,151,674,

2,304,711, 2,946,039, 3,050,706 and 3,509,517.

The need and the problems associated therewith are even more acute in connection with clamps which must be readily releasable, yet highly secure when fastening either one or two wires, including pairs of wires of different diameters. Some of the prior art terminal clamps have been specifically designed to have the versatility of accommodating a plurality of electrical wires having different diameters but approximately equal clamping loads. Various approaches include, for example, clamping plates which teeter or rock relative to the shank axis. To permit such teetering the aperture in the plate may be oversized or, at least, elongated in a direction generally perpendicular to the axis of the wires being accommodated. Some of the prior art pa tents relating to terminal clamps for accommodatng wires of different size include, for example, U.S. Pat. Nos. 3,081,507, 3,177,456, 3,178,675, 3,191,140, 3,238,495 and 3,509,521.

Another problem which the piror art has attempted to solve is the inconvenience and cost of assembling the clamping devices on the threaded fasteners at the job site, particularly when the terminal clamps are very small in size and require a high degree of finger dexterity to install. A related problem arises when removing or unclampng the terminal clamp to temporarily release, remove or replace the wires. The clamping plate may fall off the shank or even stick or otherwise remain attached to the wires which were clamped thereby.

To cope with these problems, terminal clamps have been fabricated with retaining shoulders or rings integrally formed on the shank itself. These retain the clamping plates on the shank so that the electrician has a preassembled device available for use. lnaddition, the shoulder positively lifts the plates from the wires as the shank is unthreaded. Prior art devices employing shoulders on the threaded shanks, although not necessarily for retaining terminal clamps, include, for example, U.S. Pat. Nos. 2,192,322, 3,141,722, 3,205,473, 3,372,366 and 3,398,393.

Prior art teeter terminal clamps, however, have suffered from one or more shortcomings. For example, some have been unduly complex, comprise a number of parts, are difficult to assemble or use or are quite costly to manufacture. Some have to be assembled on the job or require a nimble-fingered person to apply. Some are structurally weakened by virtue of the particular configuration required for the clamping function.

Some are lacking in performance characteristics and versatility, particularly in their ability to handle pairs of wires of different diameters with approximately equal holding power. Some do not retain the clamping plate prior to use, or fail to positively lift the clamping plate from tee wires when the clamp is unscrewed from the wires.

Some, particularly the peaked or rooftop types, are not well adapted to cope with stranded wire and lend themselves to flattening and related overtightening problems. The captured peak-type terminal clamp, wherein the threads or retaining collar are rolled on or otherwise added to the shank after assembly of the plate'thereon, also have the additional disadvantage of an undesirably large space or gap along the shank between the undersurface of the head and the beginning of the threaded portion or collar.

It is to the solution of these and other problems to which the present invention is directed. This will be apparent from the following objects.

OBJECTS OF THE INVENTION It is therefore a general object of the present invention to provide an improved teeter terminal clamp overcoming many of the shortcomings and disadvantages of prior art types. It is another general object to provide a low-cost, simplified teeter terminal clamp which in certain embodiments comprises only two easy-to-manufacture components. It is another general object to provide a preassembled teeter terminal clamp which can be quickly and conveniently secured or released and does not require special skills to utilize.

It is a more specific object to provide an improved teeter terminal clamp which can be interchangeably employed to releasably secure the terminal portions of a single wire or a pair of wires. It is another specific object to provide a clamp which can releasably secure a pair of wires of different sizes to one another or to a terminal post with substantially equal holding forces. It is another specific object to provide a terminal clamp capable of meeting accepted standards for secureness, pullout load and minimum torque at failure.

It is still another specific object to provide a teeter terminal clamp capable of coping with the problems peculiar to the clamping of stranded wire. It is still another specific object to cope with the problems peculiar to peaked or rooftop clamps. It is still another specific object to provide a teeter terminal clamp having a design which does not structurally weaken the components.

These and other objects will become apparent as the description thereof proceeds.

SUMMARY OF THE INVENTION These objects are achieved by a teeter terminal clamp comprising a threaded shank having a head configured to receive a tool for rotating the shank and an apertured clamping plate loosely and teeterably assembled and retained on the shank adjacent the head. The head has an underhead surface with at least one, integrally-formed, substantially-circular or oval protrusion, preferably generally V-shaped in cross sectional configuration, concentric with the shank axis and intermediate the inner and outer extremities of the underhead surface.

The clamping plate, which is preferably generally rectilinear, has on one side thereof at least one complementary substantially-circular or oval recess, also preferably V-shaped, but of larger diameter or larger major or minor axes. The sizes of the protrusion and recess are coordinated so that the extremity of the protrusion registers with the inner wall of the recess intermediate the outer and inner margins thereof. The clamping plate on the other side also has wire-engaging, anti-slip surface irregularities, such as grooves or embossmerits, portions of which are at least in part transverse to the axes of the wires being retained.

In a particular embodiment the clamping plate is retained on the threaded shank adjacent the head by an integrally-formed annular collar. The collar may be formed as disclosed, for example, in applicants copending application Ser. No. 222,532, filed Feb. I, 1972.

As will be apparent from the drawings, the present invention lends itself to a variety of embodiments. Some of these embodiments are specifically adapted to meet particular needs. As used hereinafter, the term substantially circular is intended to encompass elongated or oval configurations as well. The concept is manifestly applicable to such alternative configurations, as those skilled in the art will recognize in the light of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more clearly understood from the following detailed description of specific embodiments read in conjunction with the accompanying drawings, wherein:

FIG. I is a fragmentary elevation view, partly in section, showing on a magnified scale a preferred embodiment of the teeter terminal clamp of'the present invention prior to threading it into a workpiece for clamping purposes;

FIG. 2 is similar to FIG. 1 except that it shows the teeter terminal clamp after being threaded into a workpiece for clamping two conductors of different diameters;

FIG. 3 is an elevation view, on a slightly reduce scale as compared with FIGS. 1 and 2, of the headed blank prior to assembling the clamping plate and rolling the threads and retaining collar thereon;

FIG. 4 is a bottom plan view of the blank shown in FIG. 3;

FIG. 5 is a perspective view on an enlarged scale of the clamping plate of the embodiment of the present invention shown in FIG. 1;

FIG. 6 is an overhead plan view of the clamping plate of FIG. 5;

FIG. 7 is a sectional vie w along the line 77 of FIG.

FIG. 8 is a corner or diagonal view showng the side of the plate of FIG. 6 in the same general direction as in FIG. 7;

FIG. 9 is a front elevation view of the plate of FIG.

FIG. 10 is a sectional view along the line 10 10 of FIG. 6;

FIG. 11 is a bottom plan view of the plate of FIG. 6;

FIG. 12 is an elevation view, partly in section, showing on a magnified scale another embodiment prior to tightening the threaded shank in a workpiece;

FIG. 13 is similar to FIG. 12 and shows the disposition of the components after tightening of the threaded shank;

FIG. 14 is a sectional view along the line l4l4 of FIG. 12; and

FIG. 15 is a sectional view along the line 15-15 of FIG. 12.

It should be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.

DETAILED DESCRIPTION OF THE DRAWINGS, INCLUDING PREFERRED EMBODIMENTS Referring to FIG. 1, the teeter terminal clamp of the present invention comprises shank 10 having threads 12 along at least a portion of the length thereof and generally circular head 14 at the upper terminal end as viewed in FIG. 1. Head 14 is slotted, as indicated by slot 16, to receive the blade of the screwdriver for rotation of the shank whereby the clamp may be tightened or loosened. Clamping plate 18 is loosely and teeterably assembled on shank 10 adjacent the undersurface 20 of head 14 by means of retaining collar 22.

Referring to FIG. 2, the undersurface 20 of head 14 and the contacting upper surface of clamping plate 18 are complementarily designed, as described in detail hereinafter, so as to clamp terminal ends of conductors having different diameters, such as

electrical leads

24 and 26 which are being clamped to workpiece 28 in support structure 30. Despite the difference in diameters of

leads

24 and 26, the clamping loads on these leads are substantially identical.

Referring to FIGS. 3 and 4, underhead surface 20 has at least one, integrally-formed, substantially circular and generally V-shaped protrusion 32 concentric with the axis of shank l0 and intermediate the inner and outer extremities of underhead surface 20, that is, between the juncture of the shank with the underhead surface and the outer edge thereof. As is apparent in FIG. 1, this protrusion registers with a generally V- shaped, substantially circular recess in clamping plate 18 whereby the geometry is such that the clamping plate self-adjusts or tilts to accommodate a single conductor lead or conductor leads of'different diameters as protrayed in FIG. 2. Manifestly, the clamp also will accommodate two leads having the same diameter.

Referring to FIGS. 5-11, clamping plate 18 has a generally V-shaped, substantially circular recess 34 formed on the upper surface 36 thereof concentric with the aperture defined by wall 38, which is centrally located relative to

side walls

40, 41, 42 and 43. The aperture defined by wall 38 may be circular or oblong with major and minor axes. It is oversized relative to the shank so that plate 18 can teeter, rock or tilt relative to shank 10, and thus accommodate wires of different diameters. The minimum diameter or axis of aperture 38 is, however, less than the maximum diameter of collar 22 whereby plate 18 is retained on the shank adjacent the head 14 by collar 22. The distance between the undersurface 20 of head 14 and collar 22, relative to the height or thickness of plate 18 is coordinated with the other variables so as not to restrict the desired degree of tiltability of plate 18.

When the protrusion 32 and recess 34 are concentrically aligned with the axis of the shank and in contact, as portrayed in FIG. 1, the lower extremity of protrusion 32 registers with the inner wall of recess 34 between the upper and lower edges thereof. As shank is threaded into a workpiece so as to clamp conductor leads, the lower surface of the clamp contacts the leads and, if uneven, tilts in a fashion whereby protrusion 32 is caused to slip or slide down further into recess 34 on the high side and to ride upon the upper surface 36 of plate 18 on the low side. This action continues until the lower surfaces 52 of plate 18 (or embossments thereon) contact both leads. Further tightening applies approximately equal loads to the leads.

The lower surface 52 of clamping plate 18 has wireengaging, anti-slip surface irregularities or

embossments

44, 45, 46, 47, 48, 49, 50 and 51 thereon which frictionally grip or otherwise imbed themselves into the wires to be clamped, thereby preventing the wires from being pulled out or shaken loose accidentally. At the same time the clamping action does not injure or materially reduce the current-carrying capacity of the leads. These irregularites or embossments are formed by stamping or otherwise forming

complementary grooves

56, 58, 60, 62, 64, 66, 68 and 70 in the upper surface 36 of plate 18. At the same time, the

upper surface portions

72, 74, 76 and 78 adjacent the four corners of plate 18 are stamped or otherwise formed so as to direct the corners down-wardly, producing

downward extremities

80, 82, 84 and 86, respectively.

The lower surface 52 also has a generally circular protrusion 88 intersecting the embossments 44-51, which also assists in gripping the wires or leads to be clamped. Protrusion 88 is generally opposite recess 34 and is preferably formed from the metal displaced to form the latter. It should be noted that in all instances the wire-gripping protrusions or embossments 44-51 are disposed so that in the normal clamping operation, at least one and normally two, embossments are at right angles to the axes of the leads being clamped. This disposition maximizes the anti-pullout characteristic.

The underface or bottom of plate 18 adjacent the aperture may optionally be debossed to produce the frustoconical configuration illustrated by the dashed lines 53 in FIG. 10. This aids in the feeding of the plate prior to assembly thereof under certain circumstances.

Referring to the alternative embodiment of FIGS. 12-15, the teeter terminal clamp comprises shank having threads 102 along at least a portion of the length thereof and generally circular head 104 having a slot 106 therein to receive the blade of a screwdriver. U- shaped clamping plate 107 is loosely and teeterably assembled on shank 100 adjacent the undersurface of head 104. It has depending

walls

108 and 109 and intermediate portion 110 with a centrally located aperture defined by wall 111.

As in the case of the embodiment of FIGS. 1-l1, the

undersurface of head 104 and the contacting upper surface of U-shaped clamping plate 107 are complementarily designed to achieve the desired equal clamping characteristics. Thus, regardless of any difference in diameter of conductor leads 112 and 114, they are clamped against threaded plate or nut 116 with substantially equal force.

The primary differences between this alternative embodiment and that of FIGS. 1-11 lie in the fact that the undersurface of head 104 has a double set of V-shaped substantially

circular protrusions

118 and 120 and clamping plate 107 has a complementary set of

recesses

122 and 124. The relationship of the protrusions and recesses are the same as in the embodiment of FIGS. l-11 whereby equal clamping action is achieved on leads of different sizes, as depicted in FIG. 13. Thus, as

protrusions

118 and 120 slide into the

recesses

122 and 124 on the left side of FIG. 13, the protrusions on the right side are disposed radially inwardly from the recesses. Thus, inner protrusion 120 on the right side bears directly on the upper or major surface 110 of clamping plate 107.

The matching of protrusions and recesses in FIG. 13 is thus self-leveling. Inasmuch as the concentric head and clamping plate have abutted each other with unyielding surfaces, the clamping forces on wire leads 112 and 114 are substantially equal.

As in the embodiment of FIGS. 1-11, the undersurface of clamping plate 107 has surface irregularities, e.g., protrusions with intermediate recesses, as best viewed in FIG. 15, which are designed to aid in the coining or forming of the clamping plate and also impart anti-skid or anti-slip features to retain wire leads 112 and 114. They thus prevent the wire leads from being pulled out or shaken out accidentally without materially reducing the current-carrying capacity thereof.

In FIG. 15, it should be noted that the outer of

surface protrusions

126 and 128 has

terminal portions

130, 132, 134 and 136 which are disposed at right angles to the normal disposition of the axes of the leads being clamped, thus maximizing anti-pullout characteristics. The embossed recesses, ridges, coinings, and/or formed members have the additional advantage of adding beam strength to the clamp so that more screw tension is permissible than would be the case if the structure were not subjected to such metal forming operations.

EXAMPLE A teeter terminal clamp was fabricated substantially in accordance with the embodiment of FIGS. 1-11 from heat-treatable zinc or cadmium-coated steel, the screw size being No. 6 with 32 threads per inch and a shank length of five-sixteenths inch. The resulting clamp was tested for torque, secureness and pullout characteristics, using both solid and stranded copper wire of various sizes, alone and in combination, in accordance with the requirements of Underwriters Laboratories Standard 486. The torque tests were made 2. The clamp of claim 1 wherein said means for retaining said plate comprises an integrally formed annular collar spaced from said head sufficiently to accommodate said clamping plate in loose relationship prior using a special fixture adapted for same and stock PT to tightening.

terminals. The secureness and pullout tests were made 3. The clamp of claim 1 wherein said means for rewith a machine and fixture similar to that shown in FIG. taining said plate comprises a nut threaded on said 1 of Underwriters Laboratories Standard 486, again shank.

using stock PT terminals. The results are set forth in the 4. The clamp of claim 3 wherein said plate has at following table: 10 least two opposed appendages extending from margins Torque tests Wire under pressure Torque at plate (Awg.) failure Mode of failure secureness load Pullout load #12 solid 22 in. lbs Screw fractured at top of neck... 5 lbs. for 2 hrs... 70 lbs. for 1 minute.

2#l2 solid... 35in. d 5 b .f0r2 hrs... Do.

#14 solid- 28 in. d for 2 hrs..- 60 lbs. for 1 minute.

2-#l4 solid. 36 in. for 2 hrs..- Do

l#12 solid. 35 in.

#16 solid 28 in. lbs ..do 2 lbs. #16 stranded.. 30 in.

#18 stranded.. 36 in. lbs do 2 lbs.

. for 2 hrs... 70 and (i0 lbs. for 1 minute.

for 1 hr...- 45 lbs. for 1 minute. for 1 hr...- Do.

for 1 hr...- 35 lbs. for 1 minute.

in all tests the teeter terminal clamps met the torque requirements of Underwriters Laboratories Standard 486, which is a minimum torque of 20 inch pounds. The secureness and pullout tests were also successfully completed.

From the above description it is apparent that the objects of the present invention have been achieved. While only certain embodiments have been set forth, alternative embodiments and various modifications will be apparent from the above description to those skilled in the art. For example, the complementary protrusions and recesses on the head surface and clamping plate upper surface, respectively, could under certain circumstances be reversed. These and other alternatives are considered equivalents and within the spirit and scope of the present invention.

Having described the invention, what is claimed is:

l. A teeter terminal clamp for removably securing the terminal portion of at least one conductor comprising in combination:

a. a threaded shank having a head at one extremity and an entering end portion at the other extremity, said head being configured to cooperate with a tool whereby the shank may be rotated into or out of a threaded aperture, said head having an underhead surface having at least one, integral, substantially V-shaped, substantially-circular protrusion concentric with the shank axis and inter-mediate the inner and outer extremities of the underhead surface;

b. a clamping plate substantially centrally apertured to loosely and teeterably receive said shank, said plate having on one side thereof at least one substantially V-shaped, substantially circular recess complementing said V-shaped protrusion but having a larger diameter whereby the extremity of said V-shaped protrusion registers with the inner wall of said recess intermediate the two extremities thereof when said protrusion and said recess are concentrically aligned, said plate having wireengaging, anti-slip surface irregularities on the opposite side thereof; and

c. means for retaining said plate on said shank spacedly adjacent said head.

thereof away from said head and substantially aligned with the axis of the shank.

5. The clamp of claim 1 wherein said wire-engaging, anti-slip surface irregularities comprise grooves having at least portions disposed to intersect the wire being clamped substantially transversely.

6. The clamp of claim 1 wherein said wire-engaging, anti-slip surface irregularities comprise embossments disposed to intersect at least a portion of the wire being clamped substantially transversely.

7. The clamp of claim 1 wherein said clamping plate is substantially rectilinear.

8. The clamp of claim 7 wherein said wire-engaging, anti-slip surface irregularities comprise intersecting embossments spacedly adjacent each of the four corners of the clamping plate substantially perpendicular to the sides thereof.

9. The clamp of claim 8 wherein outer corner portions intermediate said embossments are inclined away from said head.

10. The clamp of claim 1 including a plurality of said protrusions on the underhead surface in spaced concentric relationship and a plurality of complementary recesses in spaced concentric relationship on said plate.

11. The clamp of claim 1 wherein the aperture of said clamping plate has a major and a minor axis.

12. The clamp of claim 1 wherein at least a portion of the clamping plate adjacent the aperture and internal radially of said surface irregularities is debossed and the opposed surface adjacent the head is complementarily upraised.

13. A terminal clamp for removably securing and providing substantially identical loads to wires of the same or differing diameters in the secured position, said clamp comprising in combination:

a. a threaded shank having a head at one extremity and an entering end portion at the other extremity, said head being configured to accommodate a tool for rotation of the threaded shank, said head having an underhead surface having at least one integral, substantially-circular protrusion surrounding said shank intermediate the inner and outer extremity, said shank having an annular collar adjacent but spaced from said underhead surface; and

b. a substantially rectilinear clamping plate having a substantially centrally-disposed aperture, said clamping plate being loosely and tiltably assembled on said shank between said head and said annular collar, said plate having on the surface adjacent said head at least one substantially circular recess complementing in cross section the configuration -of said protrusion but having a larger diameter whereby the extremity of .said protrusion registers being inclined away from said head.

* IF I,

UNITED STATES PATENT OFFICE v CERTIFICATE OF CORRECTION Patent No. 3 744 012 Dated July 3 1973 Inventofls) Charles E. Gutshall It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 27, change "tee" to -the;

Column 4, line 10, after "FIG. 7" insert -as indicated by the line 8-8 of FIG. 6--';

Column 4 line 44 change "the" Second Occurrence to Column 5 line 31, change "upon" to --up on I Column 5 line 50 change "down-ward1y"- to downwardly--;

Column 7, line 35, change "surface".to -undersurface--;

- Column 7, line 51, change "inter-mediate" to -in'termediate;

Column 10, line 3, change "registratin" toregistration-.

Signed and sealed this 8th day of January 197A.

(SEAL) Attest: EDWARD M.FLETCHER,JR. RENE D. TEGTMEYER Attesting Officer I Acting Commissioner of Patents T. ARM P6 105 (10-69) USCOMWDC and, I

I 9 U GOVlIIillIT PRINTING OFIICI: "6 O-JG-ill

Claims

1. A teeter terminal clamp for removably securing the terminal portion of at least one conductor comprising in combination: a. a threaded shank having a head at one extremity and an entering end portion at the other extremity, said head being configured to cooperate with a tool whereby the shank may be rotated into or out of a threaded aperture, said head having an underhead surface having at least one, integral, substantially V-shaped, substantially-circular protrusion concentric with the shank axis and inter-mediate the inner and outer extremities of the underhead surface; b. a clamping plate substantially centrally apertured to loosely and teeterably receive said shank, said plate having on one side thereof at least one substantially V-shaped, substantially circular recess complementing said V-shaped protrusion but having a larger diameter whereby the extremity of said V-shaped protrusion registers with the inner wall of said recess intermediate the two extremities thereof when said protrusion and said recess are concentrically aligned, sAid plate having wire-engaging, anti-slip surface irregularities on the opposite side thereof; and c. means for retaining said plate on said shank spacedly adjacent said head.

2. The clamp of claim 1 wherein said means for retaining said plate comprises an integrally-formed annular collar spaced from said head sufficiently to accommodate said clamping plate in loose relationship prior to tightening.

3. The clamp of claim 1 wherein said means for retaining said plate comprises a nut threaded on said shank.

4. The clamp of claim 3 wherein said plate has at least two opposed appendages extending from margins thereof away from said head and substantially aligned with the axis of the shank.

13. A terminal clamp for removably securing and providing substantially identical loads to wires of the same or differing diameters in the secured position, said clamp comprising in combination: a. a threaded shank having a head at one extremity and an entering end portion at the other extremity, said head being configured to accommodate a tool for rotation of the threaded shank, said head having an underhead surface having at least one integral, substantially-circular protrusion surrounding said shank intermediate the inner and outer extremity, said shank having an annular collar adjacent but spaced from said underhead surface; and b. a substantially rectilinear clamping plate having a substantially centrally-disposed aperture, said clamping plate being loosely and tiltably assembled on said shank between said head and said annular collar, said plate having on the surface adjacent said head at least one substantially circular recess complementing in cross section the configuration of said protrusion but having a larger diameter whereby the extremity of said protrusion registers with the inner wall of said recess intermediate the two extremities thereof when said protrusion and said recess are in registratin, said plate having on the opposite side thereof wire-engaging, anti-slip embossments disposed to intersect the wire being clamped substantially transversely, said embossments being spacedly adjacent each of the four corners and perpendicular to the sides thereof, outer corner portions intermediate said embossments being inclined away from said head.