US2780789A

US2780789A - Electrical lead connector

Info

Publication number: US2780789A
Application number: US384751A
Authority: US
Inventors: Bader Hans
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-10-07
Filing date: 1953-10-07
Publication date: 1957-02-05
Anticipated expiration: 1974-02-05

Description

Feb. 5, 1957 H. BADER ELECTRICAL LEAD CONNECTOR 4 Sheets-Sheet 1 Filed Oct. '7, 1955 INVENTOR. Zia/Z5 Bade," I

ll li- MIR:

Feb. 5, 1957 H. BADER 2,780,789

ELECTRICAL LEAD CONNECTOR Filed Oct. 7, 1953 4 Sheets-Sheet 2 IN V EN TOR. Jimzs Bader Feb. 5, 1957 BADER 2,780,789

ELECTRICAL LEAD CONNECTOR Filed Oct. '7, 1955 4 Sheets-Sheet 5 8 F fwd? [may Feb. 5, 1957 H. BADER 2,780,789

ELECTRICAL LEAD CONNECTOR Filed Oct. 7, 1953 4 Sheets-Sheet 4 l INVENTOR.

Hans fielder I 4 24 84 Wag: q

th re f pp n pr u t maintaiw ntastl tween the terminal elementswithot "the u screws or bolts foreach pairof connected term United States Patent F ELECTRICAL LEAD CONNECTOR Hans Bader, Orland Park, Ill.

Application October 7, 1953, Serial No. 384,751 9 Claims. (Cl. 339..59)

This invention relates to lead connectors forelectrical apparatus, and more particularly to such deviceswhich afford separable connections for'the-lead wires of'electrical equipment having relatively high values of operatin current.

One of the general objects of my invention is to provide a lead connector embodying parts for making connections in a plurality of leads, and having separable housing elements which carry and normally enclose said parts.

As another object, the invention has withinitspurview the provision of a lead connector having terminalelenients for making connections in a plurality of"leads, an 'd in which device means is provided'fonsimultaneousblapplying contact pressure to the terminal element's."

My invention has for another object the provision of a lead connector unit having separable parts-whifoh-"each carry a'plurality of lead connecting elements; said separable parts, during -use, bei-ng' normallydamped-together, and having latch devices thereon which are adapted to ready engagement and disengagement to facilitate 'the assembly and disconnection of the 'parts. l

It is another object of this invention to provide a lead connector for making separable connections in a plurality of lead wires having relatively'hi-gh current carryiqg'eapaeity, and wherein separable terminal lernentsffbfithe lead wires are disposed; in parallel relationsliipwith ,in-

sulating blocks interposed between the terminal elements for adjacent leads, said terminal elements and insuiat g blocks being laterally aligned andhaving means coat: 3

ments.

My invention further comprehends theprovisiqn of a lead connector suitedto use on traction n otors an the 2,73%,189 Patented Feb. 5, 1957 E relieved from the terminal elements of the parts, and wherein the latching devices also serve to lock the pressure applying parts during use.

Other objects and advantages of the invention will be apparent from the followingdescription and the accompanying drawings in which similar characters of reference indicate similar parts throughout the several views.

Referring to the four sheets of drawings:

Fig. 1 is a side elevational and somewhat diagrammatic view depicting a typical manner of use and arrangement forthe-application of a preferred embodiment of my lead connector to the power leads of a traction motor of the type utilized on locomotives, street cars and the like;

Fig. 2 in an end sectional view drawn to a largerscale thanFig. 1 and wherein the structure of my lead connector is viewed substantially as indicated by a line 2--2 in Fig. 1 and the accompanying arrows;

"Fig. 3 is a bottornplan view of the lead connector shown"in'jFig-. 1, wherein the power leads areindicated ,f em t ly;

Fig. 4 is'a side elevational view of the lead connector shown in Figs. 1, 2 and 3, drawn to a larger scale than Fig. l, and wherein the power leads are fragmentarily illustrated;

Fig. 5 is an end sectional view of the lead connector,

: theparts is broken away and shown in section, as viewed at the position of a line 8--8 of Fig. 6;

Fig 9is an exploded side elevational view which depicts three separable parts of my lead connector in separated relationships with respect to one another; and

' Fig. IQ is a top plan view of one of the parts of my lead l n'theacco npanying drawings, I have illustrated an exemplary ernb'odimentof my invention for illustrative .fplll'jpo s es. Although not limited to use on traction motors, as may be readily understood, such adaptation, as lldepicted in Fig. 1, is representative of a typical installa- ;tion for showing one use for my lead connector and its adant t sn her neotor 1 2 i s secured to and supported by an underframe structure l3 of a locomotive or the like, and is there As depicted in Fig. 1, my lead, conliz ed to provide a separable connection between portilqns 14dl1d150f power leads by which both the field eu s to naryghe traction motor of a locomotive or the like is supported relative to a driven axle 17 on one 'of'the locomotive trucks, and is connected to that axle for driving'purposes through gears such as 18 and 19. It becomes-necessary with relative frequency to disconnect traction motors and to remove them from a locomotive tr uck for repair or replacement. provide separable connections in the power leads for the "motor which are not only adapted to ease of separation and connection, but which are also suited to the maintenanoeoi-firm and low resistance connections duringthe .rogul-ar use; to which equipment of this type is subjected.

Thus, it is desirable to Having reference to the other views of the drawings,

3 as well as to Fig. 1, my disclosed lead connector 12 embodies two terminal and lead supporting

parts

20 and 22 which together constitute a housing of hollow and substantially boxlike structure. The housing part 20, as illustrated, includes a top wall 23 and an end wall 24 disposed in substantially right-angular relationship to one another; these walls preferably being made integrally of a single sheet of metal having portions 25 and 26 angularly disposed with respect to one another and coated exteriorly on all surfaces with a relatively heavy covering 27 of insulating material, such as rubber. Insulating

grommets

28 and 29, of a material such as rubber, are

firmly and tightly fitted into openings in the end wall 24 to provide seals and supports for insulated power leads such as 14a, 14b, 14c and 14d. Although the

grommets

28 and 29 in the illustrated structure each carry two of the lead wires, it may be understood that individual grommets for each lead, or other combinations of such grommets, may be utilized.

The other terminal and lead supporting part 22 of the illustrated structure includes a bottom wall 30, an end wall 32 in substantially right-angular relationship to the bottom wall 30 and disposed for mounting in opposed relationship to the end wall 24 of the terminal and lead supporting part 20, as well as opposed

side walls

33 and 34, all of which walls are made from a formed piece of sheet metal covered internally and externally by layers of insulating material 35. The end wall 32 has openings therein, through which grommets 36, 37 and 38 of an insulating material, such as rubber, are tightly fitted to carry lead wires a, 15b, 15c and 15d in separated and insulated relationship, as shown in Fig. 3. Also, the side walls 33 and. 34 have openings 39 and 40 therein, as shown in Fig. 5, which openings are substantially at the mid-portions of the respective side walls and are in opposed and substantially aligned relationship relative to one another.

The

side walls

33 and 34 and the end wall 32 of the terminal and lead supporting part 22 are of substantially the same height relative to the bottom wall 30 of that part and, in the disclosed structure, they have inwardly extending

flanges

42, 43 and 44 respectively thereon which are adapted to seat against the inner surface of the top wall 23 of the terminal and lead supporting part 20. Also, the top wall 23 of the terminal and lead supporting part has

marginal flanges

45, 46 and 47 thereon which overlie the outer margins of the

side walls

33 and 34 and the end wall 32 respectively of the terminal and" lead supporting part 22, when the two parts are in their assembled relationship. Furthermore, the bottom wall 30 of the terminal and lead supporting part 22 has a shoulder 48 thereon which engages the inner surface of and 14d respectively.

terminal elements

58, 59, and 62 have substantially

fiat contacting surfaces

63, 64, and 66 respectively and are mounted in spaced relationship with their contacting surfaces substantially parallel to one another.

terminal elements have their contacting surfaces 63 and 64 facing outwardly with respect to the insulating. block 67. In like manner, a block of insulating mater-ial fiilj is mounted between adjacent surfaces of the

terminal elements

60 and 62 and the contacting surfaces 65 and 66 of those terminal elements face outwardly with respect to the insulating block 68. Each of the insulating blocks- 67 and 68 is removably held in place between its adjacentterminal elements by means such as a wire bracket 69. In'th'e disclosed structure, each of the wire brackets 69 has a ringlike end portion 70 mounted on a stud 72 which is secured to the inner surface of the top wall 23 of the terminal and lead supporting part 20. Each such bracket also has a relatively straight portion 73 which extends through the mid-portion of one of the insulating blocks, through a spacing collar 74 at the end of the block remote from the stud 72 and into the mid-portion of one of the

grommets

28 and 29.

Also in the disclosed structure, the mid-portions of opposite end surfaces of the insulating blocks 67 and 68 have slots 75 and 76 therein which extend across the insulating blocks in directions substantially parallel to the contacting surfaces of the adjacent terminal elements.

Resilient clips

77 and 78, which are preferably made of wire coated with a highly effective insulating material, are engaged in slots 75 and 76 of each insulating block and have portions engaged in

grooves

79 and 80 which extend along opposite side surfaces of the terminal elements adjacent 'the opposite faces of each insulating block. These clips serve to aid in holding the adjacent insulating blocks and terminal elements in aligned relationship laterally of the contacting surfaces of the terminal elements.

In the terminal and lead supporting part 22,

terminal elements

82, 83, 84 and 85 are secured and electrically connected to

lead wires

15a, 15b, 15c and 15d respectively and they have substantially flat contacting surfaces 86, 87, 88 and 89 disposed in spaced and substantially parallel relationship relative to one another. The

terminal elements

82 and 85 are near the

side walls

33 and 34 of the terminal and lead supporting part 22, while the

terminal elements

83 and 84 are in spaced relationship at i the mid-portion of that terminal and lead supporting part.

the end wall 24, as well as an outwardly extending flange 49 extending from the shoulder 48 and disposed for mounting in overlapping relationship with respect to an outwardly extending flange 50 on the lower edge of the end wall 24 of the terminal and lead supporting part 20.

The contacting surfaces of the respective terminal elements are also in substantial alignment in a direction lateral to those surfaces.

Aninsulating block 90 is mounted between the

terminal elements

83 and 84 with its opposed side surfaces engag- Thus, the terminal and lead supporting parts of the disclosed structure have overlapping and angularly disposed surfaces along their adjoining edges which serve to provide a tightly sealed enclosure of boxlike structure when the parts are assembled together.

Metal strips

52 and 53 are secured to the outer edges of the top wall 23 of the terminal and lead supporting part 20 by removable fastening means, such as cap screws 54, threaded into

lugs

55 and 56 secured to opposite end portions of that top wall structure. In use, the

strips

52 and 53 are secured to a support, such as the underframe structure 13, as by welding at 57 (Figs. 4 and 9) thereby to provide a relatively permanent support for the terminal and lead supporting part 20 on a structure, such as a'locomotive. The other terminal and lead supporting part 22 is adapted to be removably supported relative to the terminal and lead supporting part 20 by a struc- -ture which will be more fully described,

' ing the surfaces of the terminal elements which are oppo'site their contacting surfaces.

As in the instance of the insulating blocks 67 and 68 which are utilized between terminal elements in the terminal and lead supporting part 20, the insulating block 90 is held in place by a wire bracket 69 having a ringlike end portion 70 secured to the bottom wall 30 of the terminal and lead supporting part 22'by a stud 72, as well as a substantially straight portion .73 which extends through the insulating block, through a spacing collar 74 and into the grommet 37. Also like the insulating blocks in the other terminal and lead supporting part, the insulating block 90 has slots 75 and 76 in the mid-portions of its opposite ends, which slots extend in substantially parallel relationship to the contacting surfaces of the

terminal elements

83 and 84 andcarry insulated and resilient wire clips 77 and 78 which have

portions engaging grooves

79 and 80 in the opposite edges'of the adjacent terminal elements 83 and A block of insulating material 67 is mounted'between adjacent surfaces of the

terminal elements

58 and 59, which I hdhfi t t t r pp rt n Pa -t. 2

en em W h-t e. sqh qti a surfaces 86 an vof 3 t e sr i hlsm h ms and; 8 .,i het tth a and lea su p rt n Part 2 w hthe rm n l and e d, suprtih ar s e e; br u h to e he i th ir a sem l r onsh Wh th s as mbled, n a s w in Figs. 5 and 7, the engaged teiminalelements and the arbor-a9 At the opposite sides ofthertermiml and lead support- -ing part 22, pressureplates 92 andr93 arev mounted for tlinear movement:v in the openings 39and 40 respectively inthe side walls. 33 and .34. ribs 94 and .95 .are securediin spaced relationship to the, outer surfaces'of the

pressure plates

92 and 93 respec- Insthev disclosed structure,

tively and project toutwardlyfrom those pressure plates,

.so that their end surfaces are exposed exteriorly ofv the .opposite side walls of theterminal and lead supporting part .22. Insulatingblocks ,96- andv97. are mounted betweenythe terminal elements 82.-and and the adjacent .xpressure.

plates

92, and 93, respectively, and are secured ..-in placeby projectingstabs; 98..and 99 on -t herespec-tive pressure plates, and insulating spacers 100-pandv 102 interposed between-the tabs and-the opposite ends of the respectiveiusulating blocks and preferably having por- .-.-t ion s extending into recessesin the opposite ends of the vvinsulating blocks. ,iAlso screws'103 and 104, desirably of the .socketrhead type,.--extend thro he-pressure plate ,9;2-and 93.1:espectively andhaveyshoulders 105 and 106 engaging the exteriortsurfacesgof the pressure plates.

As inthe instance of the othenadjacentterminal elements ,and'insulating blocks, resilient and insulatedwire clips -77 and 78 extend through end slots 75 and 76 -in-the

insulating blocks

96 and 97 andphflve POItiOnSengaging grooves 79 in opposite edges of theterminal elements 82 and .85.

myd c o e struc u h tas i s su es a d 6 of t t r in -e em nt t 60 n th te mih and lead supporting part; 20 are'spaced to re ceive thereb t a d age the .wnta theshrfa ss 7. an 8 of t er na s sl h ht :8 and .8 int I? .I i!. 1 n le Y su ppu h Pa t 22 wh n th s termin a dle sup or .rihs P m a I br u weath r, in thsi tasse h ed e sh to on m th -1 Also h wh s hsshrt a el men s in th ermin l a e 'd gs a d a ned .fh w a fi contacting terminal elements in firm; engagement during e ut hi h l h ld h te i al vand ad surro ing. parts intheir assembled relationship andembcdies a releasable latch structure.forholdingthe parts in their assembled relationship, during the tightening or loosening of thepressure onthe, terminal elements for purposes of assembly and disassembly of the parts. Although the assembly and disassembly of the separable parts of my lead connector can be readily and quickly accomplished with my disclosed clamping. structure, the necessity of manually holding the parts together while the cont-act pressure is applied. or relieved is avoided.

In my disclosed clamping structure, an adjustable clamping element, such as. a bolt107 carrying a-nut 108 is supported for'rotation relative to the terminal and lead supporting part 2.2 by spaced

ribs

109 and 110 secured to the outer surface of the bottom wall 30v of the terminal and leadsupporting part 22 and adjacent substantially U- shaped parts 112 and 113 -WlllCll are also secured to the outer surfaceof the bottom wall 39. At opposite ends of the bolt 107 and outside of the terminal ,andtleacl suppor n a t 2.2 ver and 1. e, m u d o that the levers extend laterally across the exteriors of the

side walls

33 and 34 and acrosst-he mid-portions of'the pres- 11511161 13163 .92 and-93, with the bolt 107 extending through ,opposedeend portions=.of;-the levers. :-In. my preferred structure the levers 114aand1 15 are madeof formed metal strip material and are hollow,.with-'the;-.edges.of

. the strip material serving as the force transmitting portions thereof. At themid-portions of the inner-surfaces of the

levers

114 and 115, fulcrum plates 116 and .117

are secured thereto for engagement With-the exposed outer edges of the

ribs

94 and 95 on the pressure plates. The ends of the levers opposite those through which the bolt 1.07 extends project somewhat beyond the adjacent e c lg es of the side walls 33 and 34of the terminal and -;l e ad supporting, part 22 to serve as guides for the assembly ofthe; separable-parts of the lead connector by engagement with substantially U-shaped portions;118 and 119 of the metal strips '52 and 53. It may be noted-that the substantially U-shaped portions 118' and 119 of the metal strips 52 and -53 on the terminal and lead'supporting part-20 serve .as, fixed anchors for the .ends ofthe levers 114 and; opposite the pressure applying bolt 107. Thus, with the ends of the

levers

114 and 115 en- ,gaged; in the Ll-shaped

portions

118 and 119, the tightening of the nut 108 on the bolt 107 applies pressure to the engaged contacting surfaces of the terminal elements 'throughthe pressure plates and the aligned terminal elemerits. and insulating blocks.

,Inaddition to utilizing the levers 114. and 115v for efifecting; alignment of the separable parts of the lead connector; during assembly and for effecting the application of holding force against the contacting surfaces of the terminal elements, I also have leaf springs 120' and 122 mountedinternally. .of the

hollow levers

114 and, 115 and eXl nding longitudinally thereofithe leafsprings' .120 and 122' being supported by the screws 103 and 104.between

spacing collars

123 and 124 and .clampinganuts 125 and126 onthe screws.

Both

leaf springs

120 and 122 extend longitudinally of, the levers 114 and 115- on both sides of the

screws

103 and 104. v The ends of: the

- springs adjacent the bolt 107 are curved outwardly away from the levers and so that those end surfaces are normally aligned for engagement with the flat sides of the bolt head andnut to serveas locks to prevent the bolt and nut from turning; the locking actions of the. springs being released by inward pressure of the springs longitudinally of the bolt, sothat those springs are held out of alignment with thebolt head or nut, or both. The other ends of. the

springs

120 and 122 are bent inwardly of the levers 114 and 115and have latch elements 127 .and 128 secured thereto with latching

shoulder surfaces

129 and 130 normally projecting beyond the outer lever :surfaces for engagement with holding

surfaces

132 and 133 in

recesses

134 and 135 respectively, which recesses are provided on the inner surfaces of the. substantially U-shaped portions 118. and 119 of the strips 52v and 53.

-With this arrangement ofparts, the engagement of the latching. surfaces, holdsthe. separable terminal and ..lead

supporting parts of the lead connector in assembledrela- .tionship during eithertightening or loosening of thepressure on theterminal elements by turning either the bolt 107 or thenut: 103. Release of the latches is effected by. the. application of manual force against the end portions of thesprings from the outsides of the levers and toward the terminal and lead supporting. parts.

From the foregoing description and reference to the accompanying drawings, it may be readily understood that I have provided a lead connector embodying: separable unitary parts, which parts not only co-act to afiord a tight closure for the terminal elements, but which are subject to ready assembly and disassembly with latches for holding the parts together in aligned relationship during the tightening and loosening of a clamp structure which holds the contacting surfaces of the terminal elements tightly togethcrd uring use.

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, 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:

l. A lead connector for electrical apparatus comprising two housing parts which fit together to provide a hollow box-type enclosure, said housing parts each having base and end walls adjoined together at adjacent ends and extending in angular relationship to one another from the adjoined ends, said base and end walls of each part also having end portions opposite the adjoined ends which interfit respectively with end portions of the end and base walls of the other part in the assembly of the parts, said base walls and said end walls of the two parts respectively being in spaced and opposed relationship to one another when the parts are assembled, the end walls of the parts each having an opening therein for the passage of lead wires therethrough, terminal elements mounted in spaced and substantially parallel relationship to one another in each of the housing parts in the angle formed between the base and end walls, said terminal elements each having substantially parallel flat faces on opposite sides thereof disposed in substantially normal relationship to the base and end walls of the part in which they are mounted, insulating blocks interposed between the flat faces of alternate pairs of adjacent terminal elements in the housing parts and at the outer flat faces of the terminal elements in one housing part, said terminal elements and insulating blocks being in staggered relationship relative to one another in the two housing parts to provide a series of contacting terminal elements and insulating blocks when the housing parts are assembled in aligned relationship to one another in'a direction transverse to the fiat faces, and clamping means on the housing parts for applying pressure to said series of contacting terminal elements and insulating blocks when the housing parts are fitted together.

2. A lead connector for electrical apparatus as defined in claim 1, and further characterized by engageable latch elements on the two housing parts including arms extending laterally of the mid-portions of opposite edges of the base walls at positions spaced from the end walls for holding the parts together while the clamping means is tightened and loosened in the assembly and separation of the housing parts.

3. A lead connector for electrical apparatus as defined in claim 1, and wherein said clamping means comprises levers at opposite sides of the base wall of one of the housing parts and extending laterally of the latter men tioned base wall in spaced relationship to the end wall of said one of the housing parts, said levers having fulcrum surfaces aligned with the insulating blocks and terminal elements, an adjustable clamping member connecting the levers at one side of the fulcrum surfaces, and fixed holding elements on the other housing part for engagement with the levers at the sides of the fulcrum surfaces opposite the adjustable clamping member.

4. A lead connector for electrical apparatus as defined in claim 3, and further characterized by engageable latch elements on the levers and the fixed holding elements for releasably holding the housing parts together while the adjustable clamping elements are tightened or loosened.

5. A lead connector for electrical apparatus comprising two housing parts which fit together to provide a hollow box-type enclosure, said housing parts each having base and end walls adjoined together at adjacent ends and extending in angular relationship to one another from the adjoined ends, each housing part being open opposite said base and end walls, said base and end walls of each part also having end portions opposite the adjoined ends which interfit respectively with end porell) tions of the end and base walls of the'other pa'rtin the through, terminal elements mounted in spaced relationship to one another in each of the housing parts in the angle formed between the base and end walls, said terminal elements each having a substantially flat contacting face thereon, said contacting faces of the terminal elements being spaced from one another and disposed in substantially normal relationship to the base and end walls of the part in which they are mounted, insulating blocks mounted adjacent the terminal elements on the sides thereof opposite the contacting faces, said terminal elements and insulating blocks being grouped in staggered relationship in the two housing parts to provide a series of contacting terminal elements and insulating blocks with the contacting faces of the terminal elements engaged when the housing parts are assembled in aligned relationship to one another longitudinally of said series, and clamping means secured to one of the housing parts and engageable with portions of the other housing part for holding the parts together when the housing parts and terminal elements are fitted together.

6. A lead connector as defined in claim 5, and wherein said clamping means includes adjustable parts for applying pressure through said series of contacting terminal elements and insulating blocks.

7. A lead connector for electrical apparatus comprising two housing parts which fit together to provide a hollow box-type enclosure, said housing parts each having two walls adjoined together at adjacent ends and extending in angular relationship to one another from the adjoined ends to provide substantially L-shaped structures of corresponding sizes which fit together in inverted and opposed relationship to one another to define a substantially rectangular interior space therebetween, one of said walls of each of the parts having an opening therein for the passage of lead wires therethrough, terminal elements mounted in spaced and substantially parallel relationship to one another in each of the housing parts in the angle formed between the said two walls thereof, said terminal elements each having substantially parallel fiat faces on opposite sides thereof disposed in substantially normal relationship to said two walls of the part in which they are mounted, insulating blocks interposed between the flat faces of alternate pairs of adjacent terminal elements in the housing parts and at the outer flat faces of the terminal elements in one housing part, said terminal elements and insulating blocks being in staggered relationship relative to one another in the two housing parts to provide a series of contacting terminal elements and insulating blocks when the housing parts are assembled with the L-shaped structures in laterally aligned relationship to one another, and releasable latch means on the housing parts for holding the parts together.

8. A lead connector for electrical apparatus as defined in claim 7, and wherein said releasable latch means includes adjustable clamping structure for applying pressure through said series of contacting terminal elements and insulating blocks while the latch means is engaged.

9. In a lead connector for electrical apparatus, the combination comprising two separable parts, each of said parts including terminal elements having contacting surfaces thereon and located entirely within the outer surface limits of the parts, the contacting surfaces on the terminal elements of each of the two parts being in substantially parallel relationship to one another and aligned for engagement with the contacting surfaces of the terminal elements of the other part when the parts are aligned and engaged with one another, insulating spacers engaged with the terminal elements on the sides 10 thereof opposite the contacting surfaces of each part References Cited in the file of this patent which estahlishes a series of engaging terminal elements UNITED STATES PATENTS and insulating spacers extend ing laterally of the contacting surfaces when the parts are engaged, means exterior 31 1887 to opposite sides of the parts for gripping and applying 5 1158708 Mumgan 1915 pressure to said series of terminal elements and insulat- 1917009 Betts et July 1933 ing spacers for holding the contacting surfaces of the 2094329 Mascuch Sept 1937 engaged parts in firm contact with one another, and clip 2'217496 Rfley 1940 elements for holding the insulating spacers and terminal 2510344 Auerbach June 1950 elements of each part in aligned relationship when the 10 pressure of the gripping means is relieved.