US3633149A

US3633149A - Connector and assembly for baseless electric light bulbs

Info

Publication number: US3633149A
Application number: US864723A
Authority: US
Inventors: Frederick Jean Maltais
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1969-10-08
Filing date: 1969-10-08
Publication date: 1972-01-04
Anticipated expiration: 1989-01-04
Also published as: AT300114B; BE757058A; GB1272357A; NL7014082A; AU1941670A; DE2048112A1; FR2065092A5

Abstract

An electrical connector and a housing assembly therefor for mounting ''''baseless'''' electric light bulbs of the type having filament terminals formed of a simple loop of wire at each end. The connector has an upstanding spring contact portion which supports at its free end one of the loop terminals of the bulb and retains the loop terminal thereon against spring tension by a catch projection. In the assembly two such connectors are sprung towards one another to electrically engage and mechanically support the bulb suspended therebetween.

Description

United States Patent [72] Inventor Frederick Jean Maltais Camp Hill, Pa. [21] Appl. No. 864,723 [22] Filed Oct. 8, 1969 [45] Patented Jan. 4, 1972 [73] Assignee AMP Incorporated Harrisburg, Pa.

[54] CONNECTOR AND ASSEMBLY FOR BASELESS ELECTRIC LIGHT BULBS 17 Claims, 5 Drawing Figs.

[52] U.S. Cl 339/52 R, 339/176 L, 339/217 S, 339/256 R [51] Int. Cl ..H01r 33/08, HOlr 1 1/22 [50] Field of Search 339/50, 52, 144,147,176 L, 217 R, 217 S, 221, 252 R, 252 F, 252 T, 256 R, 256 C, 256 T, 258 F, 259 F; 313/318, 331

[56] References Cited UNITED STATES PATENTS 3,125,299 3/1964 Woofter et a1.. 339/188 3,265,923 8/1966 Preziosietal 313/318 3,422,302 l/1969 Carpenter et al. 313/318 FOREIGN PATENTS 32,308 11/1968 Germany 339/221 107,924 7/1917 Great Britain.....

Primary Examiner-Marvin A. Champion Assistant Examiner-Lawrence J. Staab AttorneysCurtis, Morris and Safford, William J. Keating,

Ronald D. Grefe, William Hintze, Adrian J. La Rue, Frederick W. Raring, Jay L. Seitchik and John P. Vandenburg PATENTEIJ JAN 4km v;- q 2 583' a 4% v 6,

244 INVENTOR 2a. FEEDER /c/ JEAN MAL 74/5 CONNECTOR AND ASSEMBLY FOR BASELESS ELECTRIC LIGHT BULBS This invention relates to electrical connectors and assemblies and more particularly to such devices for use with baseless" electric light bulbs of the type having filamentterminals formed of a simple loop of wire at each end, and with other similar devices. A particular such assembly might also be referred to as baseless cartridge lamp socket.

The type of bulb described herein typically finds use in lowvoltage applications, such as automobile service lights or highintensity reading lamps for home use. The bulbs, and the connectors and assemblies described and claimed, are capable of high-voltage uses.

Baseless bulbs have been developed because of the great expense in manufacture of the base portions of the more traditional types of bulbs (such as screw or bayonette bases) relative to the remainder of the bulbs. It is estimated that this single portion of the bulb can account for as much as 30 percent of the total cost of manufacture. Such savings in massproduced items such as automobiles can be significant. Unfortunately, under the current manufacturing tolerances the spacing between the terminal loops varies by more than an eighth of an inch.

Consequently, it is an object of the present invention to provide a simple, inexpensive connector for the baseless type bulb where substantial savings in this combination of bulb and connector can be realized over bulbs having integral bases (especially if the costs of the complimentary socket for such bases are considered).

It is a further object of the present invention to provide a connector capable of making effective and convenient connection with such baseless-type bulbs and also to provide assemblies incorporating such connectors for reliably and conveniently mounting such bulbs in spite of a loop spread variation of greater than an eighth of an inch.

It is another object of the present invention to provide an assembly for low-voltage applications where the baseless bulb may be readily hand-snap fit and removed from an insulated housing.

In this specification and the accompanying drawings I have shown and described several preferred embodiments of my invention and have suggested various alternatives and modifications thereof; but it is to be understood that these are not intended to be exhaustive and that many other changes and modifications can be made within the scope of the invention. These suggestions herein are selected and included for purposes of illustration in order that others skilled in the art will more fully understand the invention and the principles thereof and will thus be enabled to modify it and embody it in a variety of forms, each as may be best suited to the conditions of a particular use.

In the drawings:

FIG. 1 is an isometric view in partial section of a baseless cartridge lamp assembly illustrating a preferred embodiment of the present invention;

FIG. 2 is an isometric view of one of the connectors shown in FIG. 1;

FIG. 3 is a partial vertical cross section taken along plane 33 in FIG. 1; and

FIG. 4 is a side elevation of a modified embodiment of the present invention.

FIG. 5 is a side elevation of a further modified embodiment, particularly of the tongue portion of the present invention.

In the preferred embodiment illustrated in the drawings, the connector assembly is formed of two spaced connectors 12 mounted in a housing 14. Each connector 12 (see FIG. 2) is fixed in position on the housing 14 by a mounting means wherein the locking legs 16 fix the base 18 of the connector into position by snapping in behind the retaining lips 20 of the anchor legs 22. The terminating means 24 for the wire leads 26 are illustratedas an F-crimp type connector 24 joined to one end of the connector base 18 (see FIG. 2). FIG. 4 illustrates such a terminating means 24a crimped onto a wire lead 26a where the wire engaging legs 28a and the insulation support legs 30a are shown in their applied, i.e. crimped, configuration.

As the connector 12 is snapped into position on housing 14, the upstanding spring tab 32 passes through a slot 34 in the floor of the housing 14. This spring tab functions as a contact member 32 to engage and support one end of the baseless cartridge bulb 36 by the latters loop terminating wire 38.

In the embodiment illustrated in FIGS. 1 to 3 an identical connector 12 is similarly mounted in an opposing relation to the first connector 12 with the free end of each spring tab32 of the two respective connectors 12 being spaced by an amount greater than the largest normal spacing encountered between the loops 38 of this type of baseless cartridge bulb 36.

The bottom of the spring tab 32 is joined to the base of the connector 18 advantageously at an angle of about The free end of this spring tab 32 is formed into a tongue 40 having support shoulder 42 at the base of the tongue 40 and ears 44 formed from the sides of the tongue 40 which serve as catch projections for retaining the loop terminating wire 38 in position.

In the embodiment illustrated in FIGS. 1 to 3 the two opposing connectors 12 are each angled away from one another by about 5 from the vertical and have their catch projections 44 extending away from each other. These catch projections 44 are shaped to form a gradual lead-in angle vertically from above together with a more abrupt retaining angle thereunder. Consequently, a bulb 36 can be mounted in such 'an assembly 10 by placing one of the loop terminating wires 38 around the tongue 40 of one of the connectors 12 until the loop 38 rests upon the support shoulder 42. Then the bulb 36 is pulled longitudinally springing the first connector 12 toward the other connector 12 and the loop 38 at the other end of the bulb 36 is pushed along the lead-in portion of the catch projections 44 and rests upon the support shoulders 42 of the other connector 12.

To facilitate the mounting of the bulb 36, the catch projections 44 can have tongue extensions 43 (see FIG. 5) which permit the bulb 36 to be snapped down into position without having first to pull one of the tongues 40 towards the other in order to get the second loop terminal 38 over the second tongue 40.

As can be seen from FIG. 1 the loop 38 is formed generally in the shape of a triangle so that the outer most portion of the loop is substantially straight or only slightly bowed. This means that the ears 44 do not have to be cumbersomely large. Note also that the support shoulders 42 are wide enough with respect to the width of the loop 38 so that the loop cannot slip down beyond the shoulders 42.

In order to assure that the connectors 12 are securely positioned against longitudinal movement, as well as otherwise, and thereby achieve proper spacing of the respective spring tabs 32, each of the locking legs 16 is formed from the flat metal stock by being lanced out a width the same as the width of the anchor legs 22. Retaining

projections

46 and 48 are left which capture their respective anchor leg 22 therebetween when the connector 12 is in position on the housing 14 thereby preventing any longitudinal movement along the housing 14.

The housing 14 can take many different shapes depending upon the particular application for which a given installation is intended. In the embodiment illustrated in FIGS. 1 to 3 the housing 14 consists only of a platform having the anchor legs 22 depending from one side and U-shaped protective shielding 50 extending up around and above each of the connectors 12. Since the shielding 50 does not cover any of the main portion of the bulb 36 when the latter is snapped into position suspended between the two connectors 12, the bulb 36 gives relatively unobstructed light and can more readily dissipate heat by both radiation and convection.

Since it is important that the spring tabs 32 maintain their relative spacing within fairly close tolerances, several precautions have been taken to ensure that these spring tabs 32 not be flexed to a point such that they take a permanent set. As previously mentioned, in these preferred embodiments the spring tab 32 is formed at a 95 angle to the base 18. Consequently, the inner face 52 of the shielding 50 is angled at to the vertical to act as a backstop preventing overstress of the connector 12 mounted therein. The slot 34 through the connector 12 extends is formed at the base of this face 52. Note that the access holes 54 in the housing 14 serve merely to facilitate the formation of the retaining lips of the anchor legs 22 in the molding process. Thus, while it would be desirable to have a back up for the spring tab 32 on the bulb side of the tab 32, there is not much material between the access hole 54 and the slot 34 from which to construct and support such a back up, and such was not found to be necessary in an installation where it was anticipated that the bulb replacements during the life of the installation would be relatively few.

Referring to the embodiment illustrated in FIG. 4, one can see on the right-hand side the form which such an overstress preventative backstop 56 might take. It is entirely within the scope of this invention to have such overstress preventative backstops on either side of a given spring tab 32.

In certain special applications (e.g. where the connectors 12 can be larger or where the loop spread variation is considerably less than one-eighth of an inch) the spring tab 32 can be formed relative to the corresponding face 52 of the shielding 50 so as to be spring loaded thereagainst. The shielding 50 would then serve as a positioning guide such that the bulb 36 could be pushed directly onto the connectors 12 in a single motion. This is possible because in sliding the bulb 36 down parallelly to the base of the housing 14 and with one of the loops 38 moving along one of the faces 52 the lead-in portion of the catch projection 44 will be positioned to engage the other loop 38.

Several additional specific features of the present invention beyond the broad invention can be best appreciated by a comparison of FIG. 4 with the previous figures. If the connectors 12 are to be formed by die stamping from flat metal stock as is the case in the illustrative embodiments, then it is a limitation of manufacture that the spring tab 32 should be at an angle greater than 90 to the base 18 because to do otherwise would unduly complicate the stamping die and increase the cost of manufacture. In the embodiment illustrated in FIG. 1, the terminating means 24 extend toward each other underneath the housing 14 below the bulb 36 so that the wire leads 26 are very close to one another as are the terminating means 24 which in some installations could cause a problem. In FIG. 4 this has been resolved by mounting the right-hand connector 12a in the opposite direction from the left-hand connector 120 and nectors 12a are illustrated as being substantially longer than the connectors 12 shown in FIGS. 1 to 3. This is typically done in order to suspend the bulb 360 at a greater distance from the elements of the housing 140 where the bulb 36a is of a higher candle power and, therefore, generates a greater amount of heat. These ribs 60 are intended to stiffen the extended length of the spring tab 32a so that the flexibility of the spring tab 32a will be substantially the same as the flexibility of the spring tabs 32.

Note that it is also within the scope of the present invention to rotate the left-hand connector 12a 180 and make that lefthand connector identical to the configuration of the righthand connector and similarly accommodate the anchoring legs 22a and the backstop 56.

In some installations a protective covering completely separate from the housing 14 is provided over the whole assembly 10 so that protective shielding of the type illustrated in FIG. 1 is not necessary. In such a case, the shielding function is dispensed with and the size greatly reduced so that it becomes (as illustrated in FIG. 4) a backstop 50a preventing overstressing and also serving as a further spring stifi'ener for the contact numbers 32a (by preventing flexing in the lower portions of the spring tab 32a beyond the backstop position). By comparing the outboard backstop 50a with the inboard backstop 56, one will note that the latter is considerably shorter than the former. This is necessary because of the presence of the bulb above the inboard position. The lower backstop 50a has an additional advantage that it permits engagement of the respective tongues 40a between one 5 thumb and forefinger to spring them toward one another and thus more readily release the bulb 36a.

In a typical installation, these assemblies 20 might accommodate a bulb 36 approximately Ila-inch long and having from 4 to 12 candle power. Each connector might be approximately three-quarters of an inch long and have an upstanding portion of one-half to three-quarters of an inch high.

A configuration for the tongue 40 and the catch projections 44 of the spring tabs 32 which have been found to be effective have the free end of the tongue 40 trimmed at the comers at a 45 angle, have the upper lead-in 61 of the catch projections 44 angled at 15 to the vertical and have the retaining cutback 63 thereunder angled at 45". These angles have been specifically illustrated in the catch projection 44b of FIG. 5. These catch projections 44 are bent to extend outwardly at right angles to the face of the tab 32. Advantageously, the cutback angle can be extended beyond the catch projections 44 and into the tongue 40 where it is radiused at a point 65 where it relocating the right hand anchoring legs 22a beyond the end of 50 joins the top of the Support Shoulders 42 and by an amount the bulb position. Since the right-hand connector has been rotated 180 the catch projections 440 are bent in the opposite direction from the catch projections 440 on the left-hand connector. This latter change can be accomplished with a relatively minor die change. Note therefore that in this case the two connectors 12a are no longer of identical configuration. An alternative method of accomplishing the same result while retaining the identical configuration of the two connectors would be to use a flag-type" crimp terminating means oriented to extend from the side of the connector 12, or alternatively to form the F-crimp-type terminating means reoriented 180 from the configuration shown so that the insulation support legs 30 (rather than the wire-engaging legs 28) are directly attached to the base 18.

Another feature of this invention which has been incorporated into the illustrated

connectors

12 and 12a is a stiffening rib 58. This serves to strengthen the base 18, but more particularly to stiffen the hinge between the base 18 and the spring tab 32 and thereby transfer the bulk of the spring action up away from the hinge portion and into the body of the spring tab 32. This reduces the likelihood of the spring tab 32 taking a set and thereby impairing its proper function.

The connectors 12a illustrated in FIG. 4 have an additional stiffening rib just below the catch projections 44a. The consimilar to the radius of the loop-terminating wire 38 of the bulb 36. For example, in one installation the diameter of the loop 38 is about 0.022 inches and the radiused portion of the tongue 40 is about 0.013 inches. It has been found that the bulb 36 can be readily removed from the connectors 12 merely be pulling upwardly. The 45 angle of the cutback of the projections 44 grip the bulb 36 securely, but still permit removal when sufficient pull is exerted.

Although the connector 12 has been described and illustrated as having been made from flat metal stock, it is within the scope of the present invention to manufacture it by other methods and in other functionally equivalent configurations. For example, the connector I2 could be made from several separate elements joined together. The tongue 40 need only have one catch projection and the support shoulders could be replaced by some other equivalent stop projection, or projections, which could be molded or lanced out into appropriate position. Similarly, other terminating means and mounting means appropriate to a given installation might be substituted for those illustrated. Furthermore, it might be appropriate for a given installation to have the base 18 and the terminating means 24 substantially in line with the spring tab 32 rather than at the abrupt angle illustrated.

Iclaim:

1. An electrical connector formed of flat conductive metal stock comprising a base, a crimp-type wire-terminating portion formed at one end of said base, an upstanding contact member formed at the opposite end of said base, locking legs formed out of each side of said base in a downwardly and slightly outwardly direction relative to said contact member, a tongue formed out of the free end of said contact member which free end is opposite from the end adjoining said base, said tongue being narrowed and centered relative to the remainder of said contact member, said tongue being slightly undercut creating abrupt shoulders which serve as stops on said contact member spaced immediately below said tongue, the sides of said tongue being bent to form ears which ears extend slightly out from one face of said contact member and are shaped to form small angled catch projections each with a gradual lead-in angled from said free end the contact member and with a more abrupt catch angle from the direction opposite said free end. I

2. A connector as claimed in claim 1 wherein said terminating portion, said base, and said contact member are in line and further the latter is set at slightly more than a right angle to the two former.

3. A connector as claimed in claim 2 wherein said base and said contact member have a continuous strengthening and stiffening rib each, and the corners of the free end of said tongue are beveled.

4. A connector as claimed in claim 1 wherein said gradual lead-in is angled approximately and said catch angle is approximately 45.

5. A connector as claimed in claim 4 wherein said shoulders are formed at substantially right angles to the upstanding length of said contact member and the undercut portion of said tongue is radiused to approximate the average radius of the wire to be contacted.

6. An electrical connector assembly comprising a housing, two electrical connectors as claimed in claim 1, said housing having a platform with two spaced parallel slots with the upstanding contact members of each connector extending through a respective slot and oriented therein so that said ears of each of said contact members face away from the ears of the other contact member and said respective bases lie flat against said platform, two pairs of L-shaped anchor legs on said housing with each pair being proportioned, spaced, and positioned to grip securely within the L-shape a respective connector by its locking legs thereby to hold each of said connectors in place.

7. An assembly as claimed in claim 6 wherein said contact members are positioned slightly angled away from one another and further comprising a stress stop on said housing adjacent a long side of each slot extending up directly beside each contact member and angled to permit movement of said contact member toward said stop and also prevent movement to an overstressed position.

8. An assembly as claimed in claim 7 wherein said stress stop extends higher than its respective tongue and further comprise sidewalls to afford mechanical and electrical protection to said contact members, and wherein said locking legs in being lanced out from the sides of said base leave retaining projections on either side of each locking leg which projections together grasp their respective L-shaped anchoring leg thus preventing said connectors from shifting position between pairs of said anchoring legs.

9. An assembly as claimed in claim 8 further comprising a baseless light bulb having loop terminals at either end being mounted with each loop making spring contact around a respective tongue of a connector and captured between said ears and said stop of the contact member, said bulb being suspended between said tongues above said platform.

l0. An assembly as claimed in claim 8 for baseless light bulbs having loop terminals at either end wherein said connectors further comprise lead-in tongue extensions shaped with free ends of the tongues extending back towards one another toagracing sli htl less than the spacing between the loop termm s of said ul s while maintalmng the natural spacing of the respective bases of said tongues at a spacing slightly greater than the spacing between said loop terminals.

1111. An electrical connector assembly for an electrical component having wire loop terminals at opposing ends comprising a housing; two electrical connectors, each comprising means on said connector for positioning the connector, terminating means on said connector for affixing a wire lead to the connector, a spring tab on said connector having an externally directed catch projection flaired outwardly from the direction of the free end of said tab to form a lead-in and ending with an angled cutback of said projection and further having a stop projection adjacent the cutback of said catch projection, said catch projection and its cutback being shaped relative to said stop projection to retain a respective wire loop terminal therebetween; said spring tabs being oriented substantially parallel with each other, and said catch projections of the respective tabs extending away from each other.

12. A connector as claimed in claim 11, further comprising a tongue formed out of the free end of said spring tab, said tongue being narrowed to create shoulders at the base thereof where it joins the remainder of said spring tab, said shoulders being said stop projection, the sides of said tongue being bent to form cars which ears extend slightly out from one face of said spring tab and each ear being shaped to form an aforementioned catch projection.

13. An assembly as claimed in claim 12, wherein said spring tabs are positioned slightly angled away from one another and further comprising a stress stop on said housing adjacent a long side of each slot extending up directly beside each spring tab and angled to permit movement of said spring tab toward said stop and also prevent movement to an overstressed position.

14. A connector as claimed in claim 12, wherein said spring tab has a strengthening and stiffening rib in its portion opposite the free end of said tab.

15. A connector as claimed in claim 12, wherein the catch projection flares outwardly at an angle of approximately 15 and cut backs at an angle of approximately 45.

16. A connector as claimed in claim 15, wherein said shoulders are formed at substantially right angles to the length of said spring tab and further comprising an undercut portion where said tongue joins said shoulders which undercut is radiused to approximate the average radius of the wire to be contacted.

17. An assembly as claimed in claim 13, wherein said stress stop extends higher than its respective tongue and further comprises sidewalls to afford mechanical and electrical protection to each respective spring tab.

Claims

1. An electrical connector formed of flat conductive metal stock comprising a base, a crimp-type wire-terminating portion formed at one end of said base, an upstanding contact member formed at the opposite end of said base, locking legs formed out of each side of said base in a downwardly and slightly outwardly direction relative to said contact member, a tongue formed out of the free end of said contact member which free end is opposite from the end adjoining said base, said tongue being narrowed and centered relative to the remainder of said contact member, said tongue being slightly undercut creating abrupt shoulders which serve as stops on said contact member spaced immediately below said tongue, the sides of said tongue being bent to form ears which ears extend slightly out from one face of said contact member and are shaped to form small angled catch projections each with a gradual lead-in angled from said free end of the contact member and with a more abrupt catch angle from the direction opposite said free end.

4. A connector as claimed in claim 1 wherein said gradual lead-in is angled approximately 15* and said catch angle is approximately 45*.

10. An assembly as claimed in claim 8 for baseless light bulbs having loop terminals at either end wherein said connectors further comprise lead-in tongue extensions shaped with the free ends of the tongues extending back towards one another to a spacing slightly less than the spacing between the loop terminals of said bulbs while maintaining the natural spacing of the respective bases of said tongues at a spacing slightly greater than the spacing between said loop terminals.

11. An electrical connector assembly for an electrical component having wire loop terminals at opposing ends comprising a housing; two electrical connectors, each comprising means on said connector for positioning the connector, terminating means on said connector for affixing a wire lead to the connector, a spring tab on said connector having an externally directed catch projection flaired outwardly from the direction of the free end of said tab to form a lead-in and ending with an angled cutback of said projection and further having a stop projection adjacent the cutback of said catch projection, said catch projection and its cutback being shaped relative to said stop projection to retain a respective wire loop terminal therebetween; said spring tabs being oriented substantially parallel with each other, and said catch projections of the respective tabs extending away from each other.

12. A connector as claimed in claim 11, further comprising a tongue formed out of the free end of said spring tab, said tongue being narrowed to create shoulders at the base thereof where it joins the remainder of said spring tab, said shoulders being said stop projection, the sides of said tongue being bent to form ears which ears extend slightly out from one face of said spring tab and each ear being shaped to form an aforementioned catch projection.

15. A connector as claimed in claim 12, wherein the catch projection flares outwardly at an angle of approximately 15* and cuts back at an angle of approximately 45*.