US2644144A

US2644144A - Terminal for electric fixtures

Info

Publication number: US2644144A
Application number: US123767A
Authority: US
Inventors: Arthur A Richardson
Original assignee: GUY H BURT; HARRY M BURT
Current assignee: GUY H BURT; HARRY M BURT
Priority date: 1949-10-26
Filing date: 1949-10-26
Publication date: 1953-06-30
Anticipated expiration: 1970-06-30

Description

June 30, 1953 A. A. RICHARDSQN `2,644,144

TERMINAL FOR ELECTRIC FIXTURES 2 Sheets-Shea?l l Filed Oct. 26. 1949 lllll l/ll/ \\\\1\ A FIT/qll nllllmmnlllll 7'; @Wl lll lll 70 84 Y A from/Ey l @f1 -lllll l June 30, 1953 A. A. RicHARnsoN TERMINAL FOR ELECTRIC FIXTURES 2 Sheets-Sheet 2 Filed Oct. 26. 1949 :i lnino INVENTR. HRT/4W R/cdHRDSoN TTO/QNEY at a low cost, and

Patented June 30, 1953 TERMINAL FOR ELECTRIC FIXTURES Arthur A. Richardson, Edgewood, R. I., assignor to Harry M. Burt and Guy H. Burt, doing business as The Lloyd Products Company, Providence, R. I.

Application `October 26, 1949, Serial No. 123,767

This invention relates to terminals for electric xtures.

The actual terminals showny `and described in the instant application are specifically Vdesigned to be used in sockets for fluorescent electric lampV starters and sockets for the lamps themselves, but. it is to be understood that these particular embodiments of the invention are given by way of example only and are not to be interpreted as limitative. Y A A terminalof the type to `which the present invention relates in generalcomprises a body of electrically non-conductive material, having a wire passageway 'with' a laterally extending branch or notch. An electrically conductive member projects into the notch and `forces Wire 'into the same `causing thewire tojtake the shape of a U with the legs of the U on opposite sides of theconductive member. This arrangement is intended to lockthe wire in the body. Restraint I against displacement of the wire is exercised by resistance of the wire to iiow through the passagewaydened by the recess .and conductive member and frictional engagement between the rwire and the walls lof said passageway. However,

in practice, due to manufacturing tolerances and ,theuse of wires of silghtly varying diameters, Vthe trictional restraint usually is slight and, as a result, terminals of this type are not reliable and a terminal of the character described which comprises very few and simple parts, can be produced is ruggedy and efficient in opfelation. j 7 l Y It is another object of my invention to provide a terminal lof the 4character described which can be manipulated by hand alone, i. e. without the use ci` tools or wrenches'.

It is another object of my inventionfto provide .la terminal of the character `described which makes agood electric contact with va wire.

9 Claims. (Cl. 339-489) lil having terminals constructed in accordance with closure plate removed and` with It is another'object ,of` my invention to provide a terminal of the character described `in i lwhicli the operating element is so constructed andarranged thatit can be worked with ease.' -:,QOther objectsof my invention'will in part be obvious and in part will bepointe'd out hereinafter. A l

. My invention `accordingly consist-.sin the features lof construction, combinations of elements and arrangements of parts which will be exemplied in the -devices hereinafter described and of which the Ascope of application will be indicated in the appended claims. 1 l

'I'he present invention is a continuation-inpart of my copending application, Serial No. '711,245 for Electric Connectors led November 21, 1946, now abandoned.

In the accompanying drawings in which are shown various possible embodiments of my invention,

Fig. 1 is a front View of a starter for a fluorescent lamp, said starter 'being mounted in a socket having terminals constructed in accordance with Fig. 5 is a rear view 'of the socket with its clo- Y sure `plate removed and-with lead wires clamped in place;

Fig. 6 is a sectional View taken substantially along the line 6-6 of Fig. 5;

Fig. 7 is a view similar to Fig. 5 of the socket as it-appears after the lead wires have been inserted, but before they have been clamped;

Fig. 8 is a side view of a fluorescent lamp socket the present invention; Y

Fig. 9 vis a front view of the socket shownA in Fig. 10 is a top view of said socket; A Fig. 11 is a rear view of the socket with the lead wires clamped in place; 1 y

Figs. 12 and 13 are sectional views taken substantially along thelines I2-.I2 and l3-l3 of Fig. 11; and v Fig. 14 is a view 'similar to Fig. 11, showing` the Essentially the principal `objects of my invention are achieved by-making the conductive member; hereinabove referred to, both ilexible. and

resilient instead of comparatively stiff as hereto- Tore, although said member still must beresistant enough to bending to be able to force a wire into a U-sh-aped conguration inthe notch.

` For the foregoing purpose, in the terminals o1v "my, invention hereinafter described, the conduc- Vtive member is lfabricated from flat resilient elec- ,tricall'y conductive stock, such for instance as Phosphor-bronze strip, which is sufficiently thin to be llexible, and said member is prevented from becoming toov flexible by not making the strip overly thin and `by keeping short the length thereof which presses wire into the recess.

Certain ancillary features of vmy invention .are achieved byhaving. the conductive member biased to a position in which it leaves the wire passageway and recess clear and by employing a rotary cam for effecting movement of said member against thisebias, the cam having'a manipulatory tab so that operation of the terminal is a very simpleV matter.

Referring now in detail Ato ,the drawings ,and

more particularly Figs. 1 through 7, the reference numeral denotes a starter of a type conventionally employed to place a hot starting fluorescent lamp in operation. By way of example the starter comprises a cylindrical metal can 22, one

end. of which is closed by a disc 24 of electric I,insulating material through which a pairof ter- Aminal studs 2S, 2B extend. These studs are electrically connected to a conventional starting Sv'ritchlocated Within the can. l l

The starter is removably received in va socket whose purpose it is to connect said starter in the Ioperating circuit for a fluorescent lamp. To

this end,`said socket comprises a block 32 of elec- ,.trical insulating material from the upper surface of which an integral annular flange 34 extends to form a well 36 for receiving the end of the starter can from which the

studs

26, 28 project. ,The unders'urface of the block is. fashioned with 'two

recesses

38, 48 in which

blade contacts

42, 44

are disposed. This arrangement results in the ,formation :of arpartition 45 across the base o-f the well 36. Said partition has a pair of arcuate

concentric keyholetslots

48, 50, one running from .each of the

recesses

38, 40 to the well 36. Said slots are designed to accommodaterthe studs 2t. 28, thelarger portions of the slots being ladapted to pass the enlarged heads of the studs` and the smaller portions of the slots being adaptedto 4,accomrnodate, the reduced Shanks of thestuds.

The

blades

42, 44 include portions V52, 54 which ,are adapted to` engage the starter studs 25, 28,

these being inonepiece with reaches 53, 58 that 'are adapted 'to engage the

lead Wires

60, 52 for .placing the starter in a conventional fluorescent .lamp circuit. Thevportions 52, `54 are of any standard conguration, for example straight, as

shown. f

Said blades are formed from a length offlat resilient electrically conductive stock, suchforV Ainstance as a. Phosphor bronze strip. In one piece `with each stud engaging Vportion is ashank 64 which is` connected to its corresponding portion by areturn-band 66. Each shank is connected to y -its associated

reach

56, 58 by a right-anglebend Y Y 61. At the tip of each reach is a contact member :68' in the shape of a short toe disposed atan angle to the reach. This contactmember is the conductive memberV hereinabove mentioned.

The resiliency of the contact member support is for biasing the contact members away from vwire engaging position. The resiliency of the stud engagingv portions and/or their sup-ports is to enable the portions properly to engage the'studs of the starter cam. rlhe resiliency and flexibility of the contact members is to enable these latter to function in accordance with my invention as Will be described in detail hereinafter. It is within the scope of my invention to have the by channels 16 to the

recesses

38, 40 andthe right-'angle bends 61 are disposed in these channels. 64 are so shaped and are so heldin the block'32 by suitable shaping of the

recesses

38, 48 .and channels 16 that when the `'reaches are ,un-

stressed, each reach is biased to an idle position away from the inner wall 18 of its associated recess 14, as illustrated in Fig. 7.

Means also is provided forv forcing each reach toward its adjacent wall 18. InV the form ofthe invention shown herein saidv means comprises a rotary member such as a cam 80. Thefcanii's located at aside of the block in a shall-ow recess 82 that communicates with the recess f14., Said cam is made from an electrical insulating mate- -recess Y B2.

Y rial and is journalled on the rivet 1t.v A'radial l y tab 84 in o-ne piece with thev cam serves-'asa manipulatory handle therefore. Said cani. has'a flat lobe 86 which is the operative portion'of the l cam and is at the .portion of maximum radius. The remainderof the cam surface is of lesser radius. 1 p

It will be apparent that when vthe cam is in fthe position illustrated in Fig. 7 with its smallest Vradius facing the reach, said reach will be remote from the wall 18. `As the cam isturned approxifmately 150, in a clockwise direction as viewed in Fig, 7, to the position shown in Fig. 5, the flat `lobe will engage thereach and urge the Ysa'rnefto a positionadjacent the zwall 18. In such posi'- tion, the tab 84 is received within thekshallow The recess 14 has a laterally extending no 88 running in a direction generally at rightangles to the wall 18. The center ofV this notclfikisgapvproximately alignedY with the contactmember 68fwhen the cam is in its operative positionA shown in Fig. 5.

-Preferably the Atoe forms an acute angle with thema-ch, that ,is to say, an angle less than 90. A. toe atan angle ofl '15 functions satisfactorily.

y It may be mentioned here that it is convenient from a manufacturing. standpointnto make the lstud engaging portions, Shanks, reaches and conf tact members all in one piece. lrangement is employed, all these parts are flexi- .ble and resilient inasmuchas resiliency and flexi- `bility are necessaryin the stud engaging portionsAand/or' their lsupportsQi'n'the contact' mem- When such arbers and in the supports for the contact members.

The block includes a bore orv wirel passageway whichextends fromv an outerside `thereoft'o- `Ward :and into communication with the -recess1ll. Said bore meets the cavity at the monthl'of "the notch 88, being oriented transversely "of the noltch` `so that, if a lead wire is introducedintoythe bore Slt when the Vcarn'isin itsidlef position shown in Fig. '1the end of the Wire will'extend across `the mouth of the notch. `The inner endfofthe bore adjacent the recess 14 is constricted asindicated at 92, there 'beinga gradual narrowing f the bore into said constricted portion. l y l In the operation of the device the cam is'moved The reaches 58, bends B6, 31 and Shanks titsfidle. .(Fig117). position.' The vend of a,- lead wire is stripped of its insulating sheath; andis introduced, into the, bore 90. Insertion of the wire will. be limited by crowding ofthe sheath in the gradually constricting end of said bore. The length of bare stripped Wire is such that when insertion of the wire is limited in the foregoing fashion, the barelpart extends through the constricted `opening 92..,across the mouth of the recess 88 and a short distance ,along thewall 18. It will be observed that when the conductor `wire islinserted the reach 58 is awayfrom the wall 18 so as not to interferewith proper placement of the wire. 'Next the tab 84 4is `manipulated to rotate ,the cam 80, thus forcing the contact mem-v ber l6|! into the recess 88 `and nesting the tab in the recess 82. Aspthis occursthe contact member bends the bare wire beneath it into the shape `Of'a U. l ,i v f l. This bending action by itselfqis the same as the bending fto which wire is subjected in prior art terminals of the same general type. However, the locking actions differ because` of the flexibilityV of the `contact member 68., When the `wire is pulled, said contact member flexes toward .the wall A of the notch adjacent the bore and insodoing presses the wire against thiswall and exerts such a strong clamping action that the wirewill break before it will pull out.

order for the contact member to flex in the foregoing fashion, thin stock should be1 employed for its fabrication. I hav-e secured excellent results when said stock constitutes a flat Phosphor bronze strip having a, thickness of 0.015 inch, the terminal being used to secure in place a CF No. 18 wire such as conventionally is used with fluorescent fixtures.A A satisfactory length for a contact member of such thickness is 1/8 of an s inch. l

`The depth of the notch should exceed the diameter ofthe wirel held by the terminal; and I have v"observed that, where this depth is at least '1.5 times the diameter of the'wire, best results are securedsince this makes it certain that when the wire is pulled the tip of the contact member will force the wire against the wall A of the notch 88.*` By the same token the length of the contact member-preferably is such that its tip extends into the notch a distance at least onehaif the diameter of the wireto be used; A greater length of contact member anda correspondingly greater depth of notch does not affect the operation of my invention, providing that the contact member is not made so long that, due to a. tendency to buckle or bend, it is unable to forcewire into the notch. If desired, the notch can be deeper than the distance the wire is forced into the same.

The width of the notch should be at least sumcient to permit the contact member to push the wire therein in the shape of a U with the contact member between the legs of the same. Inasmuch as untinned stranded wire flattens when pressed, `a satisfactory width of notch for the accommodation of such wire is 1.5 times the diameter of the wire. However, my invention functions just as well where the notch is Wider, for example twice or 2.5 times the diameter of the wire. A notch of such greaterwidth is desirable since it permits the terminal to be used with stranded wire which is tinned and does not flatten.

An even greater width of notch is permissible i provided that the contact member is maintained A distance between said member and the wallA up to about 11/2 times the diameter of the wire will enable the terminal to operate in a satis-A factory manner. The spacing between said member and the wall A can be controlled through the |length of the shank, the position of the wall A and the position 0f a stop 84 against which the bend 61 abuts. f In Figs. 8 lthrough 14 I have shown a socket |00 embodying a modified form of my invention and designed to .physically support and supply electric energy to one end of a hot starting fluorescent lamp |02. `The socket construction is of the well-known twist type anddiifers from a conventional twist type socket only in its terminals. s

Said socket includes a body |04 of insulating material whose rear face is provided with a. pair ofrecesses |06, |08 covered by a closure plate l I0. These recesses are mirror images of one another so only one will be described in detail. Each recess contains a blade I2 of thin Phosphor bronze strip stock, a portion i4 of which is fashioned in a conventional shape which is designed to engage a lamp pin that extends through an opening ||6 Extending away from said anchoring portion is the terminal part |22 of the blade. Said part,

includes a reach |24 and a toe |26, the latter constituting a wire engaging or contact member. The terminal part |22 of the blade is disposed in a cavity |28 into which a wire passageway |30 runs, the cavity including a laterally extending notch i32. The reach |24 is of such shape that, when unstressed, it maintains the contact member away from the notch |32. However, upon flexing of the reach outwardly toward the side of the body, the contact member will enter said notch. A portion of the wire passageway |30 immediately adjacent the notch |32 is constricted as indicated at |34. When a lead wire is clamped l, in the terminal, a pull thereon causes the contact member to flex towards the wall A' of the notch |34 and press the wire against this wall.

The cam is located between the reaches |24 of the two blades so that but a single cam is necessary to flex both reaches. The cam accordingly is provided with two lobes |42 and two low points |44. The latter engage the reaches when the contact members are backed out of the notches and the former `engage said reaches when the contact members are wit-hin the notches.

With a single cam operating both blades, the manipulatory handle tends to block one or the other Wire passageways (see Figs. 11 and 14). This is avoided by having the thickness of the cam less than the widthof the blades and thus providing between the cam and the lamp side of the body a space to accommo` date the wire passageways. In order Vbetter to define the wire passageways |30 and thus prevent the lead wires introduced into said passageways from being improperly positioned with respect` to the terminals, and more particularly to insure that the lead wires are kept level with the the reaches of notches so that they can 'be properly clamped, I provide a partition '|46 between the cam and wire passageways. Said partition is held in place Vvices which achieve all the objects of my invenminal comprising an electrically n'onconductive` body having a wire passageway extending inwardly from the outer' surface thereof and including a lateral notch, a flexible, resilient, elongated, blunt, electrically conductive terminal element in said vpassageway adjacent said notch, means to mount said'element 'for movement into Y andout of said notch in the direction of its iengtn whereby when lthe element is Ymoved into the notch Vwith a wire in the passageway extending across the notch,-said element will force the wire Vinto the notch in the shape of a U, said mounting -means being disposed to locate said element close to that wall of the notch which is nearer the end of the passageway through which the wire enters, whereby when-a wire forced into the notch bythe element is pulled the element will flex toward said wall and clamp the wire thereagainst,'and means mounted on and movable relative to saidbody to lforce Vsaid elementinto said notch, said forcing vmeans being disposed to act adjacent the end of saidelement remote from the notch.

' 2. A terminal as set forth in claim 1 wherein the mounting means is resilient and biases the element away from the notch.

, 3. A mounting means as set forth in claim 1 wherein the flexible element is short so that it will not 'buckle or bend 'when 'forcing 'thewl-re into the notch. l i i 4. A terminal as set forth in claim 1 wherein the 4distance from the element to the mentioned wall of the notch does not exceed 1.5 times the diameter of the wire ito be engaged by the terminal.

5. A terminal as set forthvin claim 1 wherein the width of thenotch does not exceed 2.5 times the diameter o'fA Wire to be engaged by the ter'- 'minaL 6. A terminal as set forth in claim 1 wherein the distance from the element to thementioned wall of the notch does not exceed 1.5 times the diameter of wire to be engaged by the` terminal, and wherein the depth of the notch is'at'leastl times the diameter of said wire.

7. A terminal 'as Yset forth in claim 1 wherein the distance from the element to the mentioned wall of the notch does not exceed 1.5 times the diameter of wire to be engaged by the terminal, wherein the depth of the notch is at least 1.5 times the diameter of said Wire, and wherein the tipl of the element extends into the Anotch atleast one-half the 'diameter of said wire.

8. A'terminal `as -set forth in claim 1 wherein the mounting 'means constitutes a flexible, resilient, elongated electrically conductive strip and wherein the flexible element'constitutes an elongated toe angularly extending away from an end ofthe strip. f Y,

9. `A termina-l `as set forth in claim 1 wherein the means mounted on'and movable relative to the body for forcing the'element into the `notch constitutes a cam rotatably mounted within the body.

ARTHUR A. rRICHARDSON.

References cited in the nie of this patent UNITED STATES PATENTS l Number Name I Date 1,605,033 Jensen Nov. 2, 1926 1,645,650 K irkman Oct. 18, 1927 1,953,966 yLynch .f Apr. 10, 1934 '1,960,191 Staub et al. -V May 2.2, 1934 2,097,603V Ruth -rrNov. 2, 1,937 2,154,247 Muldoon et al Apr. 11, 1939 2,309,311 Grohsgal Y fl r- Jan. 26,1943 COOk Apr. 2,518,489

Orlando ...;'..f Aug. 15,