US 3533048 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Oct. 6, 1970 W '1-;=-AGNO ETAL 3,533,048
ELECTRICAL CONNECTOR TAB RECEPTAGLES Filed May 2, 1968 2 Shets-Sheet 1 Mi fNVE/VTOES' wmommo TeAeNo LucmN OBERT O'ct. 6,1970 E NQ E15 m. 3,533,048
ELECTRICAL CONNECTOR TAB RECEPTACLES Filed May 2, 1968 2 Sheets-Sheet 3 JNVENTOQS LJLAmMmo 'Te-AGNo Lucmwo 05am E m-5 JQK-L United States Patent Int. Cl. H01r 7/28 US. Cl. 339-95 7 Claims ABSTRACT OF THE DISCLOSURE A tab receptacle comprises short turned in sides and a base provided with a central spring area having lateral outwardly-directed spring arms.
This invention relates to electrical connector tab receptacles.
Tab receptacles are well-known devices for making releasable connection to terminal tabs which are customarily provided on electrical components to facilitate electrical connection to the components. Terminal tabs generally comprise flat strips of metal of rectangular crosssection and with straight sides, the section having a major width substantially greater than a minor width to present opposite sides to the post of substantially greater width than the post thickness.
A successful form of tab receptacle based upon the disclosure of US. Pat. No. 2,774,951 comprises a receptacle portion of channel-shaped clip form, sides of the channel being rolled inwardly to present edges opposed to the channel base. The base has a central portion elevated to present a platform opposed to the edges and the platform is arcuately bowed transversely of the channel and towards the edges. The platform is laterally slotted. In operation, a tab is resiliently clamped between the edges of the platform, the platform being flattened to effect area contact with one side of the post. The elevation of the platform serves to avoid interference between edges of the post and the rolled sides of the clip at their junction with the base, and the arcuate form of the platform serves to extend the effective lengths of the springs defined by the side arms and also to provide for improved area con tact between the platform and the tab side.
In view of the spring action required it is necessary to utilize high quality spring metal and also carefully to control the treatment of the metal so that the spring action is maintained satisfactorily during extensive periods of service. Due to the rolled nature of the channel sides a substantial width of material is required for forming the receptacle, compared with the finished width of the re ceptacle.
Alternative receptacle forms have been proposed which avoid the rolled-in form of the arms. For example, US. Pat. No. 2,996,026 discloses a receptacle having a channel-shaped clip form of which the sides are merely folded over to clamp the tab between the folded over portions and the base of the channel. To provide for spring action the base is provided with a pair of parallel, longitudinal slots with the metal between the slots curved longitudinally of the receptacle in convex manner towards the folded over portions. In operation the curved portion is flattened against one side of the tab to exert a spring action clamping the other side of the tab against the folded over portions. The spring extends substantially throughout the length of the receptacle.
In an electrical connector tab receptacle according to te present invention, the receptacle portion is of generally channel form having sides turned in to present side parts ice opposed to the base of the channel for slidably receiving a tab between the channel base and the turned-in side parts, the base is slotted longitudinally beneath each of the turned-in parts to define a pair of generally parallel slots, lateral slots extend from each end of each of the longitudinal slots towards the middle part of the base to define base portions extending laterally outwards from the middle portion of the base, free ends of the base portions remote from the middle portion being turned up towards respective turned-in side portions.
The base portions serve as cantilever spring extending laterally of the receptacle from the middle portion of the base, the springs being relatively short in effective length compared with the length of the receptacle portion and for a given deflection of the free ends are capable of exerting a higher spring force than a similar spring of a longer effective length.
An object of the invention is to provide a tab receptacle having springs in the base of short length relative to the length of the receptacle section.
Another object of the invention is the provision of a tab receptacle provided with L-shaped cantilevered springs in a base thereof.
A further object of the invention is to provide a tab receptacle wherein axially-extending slots are formed in the sides of the receptacle section and inwardly-directed slots normal to the axially-extending slots are formed in a base of the receptacle section to provide L-shaped cantilevered springs thereby providing springs of increased effective length.
An additional object of the invention is the provision of a tab receptacle provided with laterally extending spring arms struck out from a base of a receptacle portion and a central embossment along the base to increase withdrawal forces and to augment the spring action of the lateral spring arms.
A still further object of the invention is to provide corrugations along lateral spring arms in the base of a tab receptacle thereby stiffening the spring arms.
Still a further object of the invention is the provision of corrugations along edges of L-shaped lateral spring arms in the base of a tab receptacle to improve contact cleaning action between the serrated edges and a tab mateable with the tab receptacle as well as to increase withdrawal forces therebetween.
Still an additional object of the invention is to provide a tab receptacle that requires less metal to make since the spring arms are shorter than normal, the metal can be cheaper due to shorter spring arms thereby allowing the use of a metal having a lower coemcient of elasticity and close tolerances are unnecessary as a result of the width of the blank is not critical to the function of the receptacle.
Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there are shown and described illustrative embodiments of the invention; it is to be understood, however, that these embodiments are not intended to be exhaustive nor limiting of the invention but are given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.
The invention will now be described by Way of example with reference to the accompanying partly diagrammatic drawings, in which:
FIG. 1 is a perspective view of a first embodiment to an enlarged scale;
FIG. 2 is a transverse cross section of the receptacle portion of the connector of FIG. 1 taken on the line 2-2 viewed in the direction of the arrows;
FIG. 3 is a longitudinal section of the connector of FIG. 1 taken on the line 33 viewed in the direction of the arrows;
FIG. 4 is a plan View of a partly formed metal blank for forming a strip of terminals according to the FIG. 1 embodiment with the relative size of a blank for terminals having rolled-in side portions shown in chain-dotted lines;
FIG. 5 is a perspective view of the second embodiment;
FIG. 6 is a plan view of the receptacle of FIG. 5;
FIG. 7 is a transverse section taken on the line 7-7 of FIG. 6;
FIG. 8 is a view similar to that of FIG. 7 but with a tab in position; and
FIG. 9 is a fragmentary perspective view of a modification of the embodiment of FIG. 5
The electrical connector tab receptacle of FIGS. 1 to 3 comprises a receptacle portion 1 integral at one end with a conductor crimping portion 2, the connector being formed by folding a flat blank of the form shown in FIG. 4 in a press die. The crimping portion 2 comprises an insulation support ferrule 3 and a wire crimp ferrule 4 of U-form for securing to the insulation and core of an insulated conductor in known manner. The receptacle portion 1 is adapted releasably to receive a tab 5, as shown in FIG. 3, and comprises a generally channelshaped section having a flat base 6 formed with turned-up sides 7. Upper edge parts 8 of the sides 7 are turned in to extend parallel to the base, as shown, or at a slight inclination towards the base 6. The turned-in parts 8, as seen in FIG. 2, are short relative to the width of the channel section and each extends through less than onethird of the width of the receptacle.
Rearwardly of'the turned-in parts 8, the sides 7 of the channel extend in convergent manner through a transition section 9 between the receptacle portion 1 and the crimping section 2, and merge with side arms of the wire crimp ferrule 4. The base 6, adjacent the turned-in parts 8 and next to the sides 7, is slotted longitudinally through a major length of the base to provide a pair of parallel slots 10. The slots 10 terminate short of the forward end of the receptacle and short lateral slots 11 extend inwards, at the forward and rear ends of slots 10, to define rectangular tongues 12 extending outwardly from a middle portion of the base 6. Of course, lateral slots 11 can be angled toward each other toward the center of the base, angled away from each other toward the center of the base or one lateral slot is angled toward the other slot which is normal to the respective slot 10. Outer free ends of the tongues 12 are turned up to present edges 13 opposed to respective turned-in parts 8 and thereby form L-shaped springs. The edges 13 form the free ends of the L-shaped springs cantilevered from the middle portion of the base 6 and having relatively short spring arms 14, as 4 seen in FIG. 2.
Rearwardly of the L-shaped springs the base 6 is formed centrally with a latching detent 15 for releasably securing the receptacle in a housing in known manner. The lead ing end or mouth of the receptacle is suitably flared, as seen at 16 in FIG. 3, to facilitate insertion of the tab 5, and to this end the leading corner portions 17 of the parts 8 are turned up at an inclination, and the leading edge 18 of the base is bent down. In addition the leading corners of the turned-up parts 13 of the L-shaped springs are suitably chamfered at 19.
In operation the tab 5 is pushed into the mouth of the receptacle 1 to engage the leading end of the tab with the leading ends of the Lshaped springs, further insertion causing the L-shaped springs to be deflected downwards to admit the tab between the edges 13 and the turned-in parts 8, as shown in FIG. 3. The edges 13 engage the underside of the tab and urge the tab 5 upwards against the underside of the turned-in parts 8. The short arms 14 of the springs are bowed downwards as seen in FIG. 2,
and overstressing of these arms is avoided by the portions of the base 6 around the springs which prevents deflection of the edges 13 below the upper surface of the floor 6.
Since the tab exerts an upward force on the turned-in parts 8, there may, where high spring forces are generated by deflection of arms 16, be a tendency for upward deflection of parts 8 by bending of the sides 7.
Since the tab extends through substantially the entire width of the receptacle between the sides 7, bending moments tending to cause such deflection of the parts 8 tend to be small. The tendency may be guarded against by forming the turned-in parts 8 with an initial slight inclination downwards toward the base 6 so that, on insertion of the tab, the turned-in parts 8 are deflected to extend substantially parallel to the base 6.
As shown by full lines in FIG. 4, the receptacle of FIG. 1 is formed from a flat metal blank having a portion B of generally rectangular profile corresponding to a development of the receptacle portion 1. The corresponding blank form for an equivalent receptacle portion having rolled side springs is as shown in chain-dotted lines at A, and it is evident that the blank of the present invention involves substantial saving in metal. In addition, since the precise width of the blank portion B is not critical to the function of the receptacle according to the present invention, whereas in the rolled spring form of receptacle the width of the blank portion may be critical, the present invention requires less careful control of the width of the strip from which the blank is formed than is the case with the rolled spring type of receptacle. The provision of short spring arms 14 allows the use of metal having a lower coefficient of elasticity to obtain equivalent spring forces to those of longer springs, and it is thus possible to con struct a tab receptacle not only using less material but also using cheaper material, and a substantial economy of manufacture may be obtained.
In the modification of FIGS. 5 to 8, in which like reference numerals refer to similar parts to those shown in FIGS. 1 to 3, a middle portion of the receptacle base is formed with a longitudinal embossment 20 projecting convexly above the base 6. The slots 10 from which the springs are formed extend into the sides 7 of the channel section adjacent turned-in parts 8, to increase the effective length of the spring arms, and the springs are curved arcuately away from the central embossment 20, initially downwardly and outwardly below the general level of the base 6 to present an upper convex surface, and at their outer ends upwardly in reverse curvature to present upper concavities. The free edges 13 of the springs terminate at the level of the embossment 20 and are opposed to the turned-in parts 8. The springs are stiffened by corrugations 21 extending laterally of the receptacle from the central embossment 20. Such corrugations can be provided in the long legs of spring arms 12 of the embodiment of FIGS. l-3 to stiffen same.
In operation, as seen in FIG. 8, the curvature of the arcuate portions is reduced and the free edges 13 and the central embossment 20 are resiliently depressed. The central embossment 20 serves tto increase withdrawal forces and to augment the spring action of the lateral spring arms 14.
In the modification of FIG. 9, in which like reference numerals are used for similar parts to those shown in the embodiment of FIGS. 5 to 8, the edges 13 of the spring arms are serrated in saw-tooth fashion with leading edges of the serrations being inclined rearwardly and up wardly to facilitate insertion of a tab into the receptacle and to resist withdrawal of the tab. The serrations serve to improve contact cleaning action of the edges 13 as well as to increase withdrawal forces. Serrations may also be provided along edges 13 of the spring arms 12 of the embodiment of FIGS. 1-3 in order to improve contact cleaning action between the serrated edges and the tab and to increase withdrawal forces therebetween.
It will, therefore, be appreciated that the aforementioned and other desirable objects have been achieved; however, it should be emphasized that the particular embodiments of the invention, which are shown and described herein, are intended as merely illustrative and not as restrictive of the invention.
1. An electrical connector tab receptacle comprising a tab receptacle portion having a base and sides defining a generally channel form, said sides having turned-in parts to present side parts opposed to and substantially parallel with the base of the channel for slidably receiving a tab between the channel base and the turned-in side parts, the base having longitudinal slots to define a pair of generally parallel slots and lateral slots extending laterally from each end of the longitudinal slots towards a middle part of the base to define laterally-directed spring base portions, and free ends of the base portions underlying the turned-in side parts being turned up towards respective turned-in side parts to present free edges of said base portions at respective locations intermediate free edges portion of the base are curved laterally of the receptacle, initially downwardly and outwardly and then upwardly.
5. A receptacle as claimed in claim 1, in which the middle portion of the base is formed with a longitudinal embossment raising the middle portion above the general level of the base, the free edges of the turned-up portions of the base being disposed substantially level with the longitudinal embossment.
6. A receptacle as claimed in claim 1, in which the base portions extending laterally outwards from the middle portion are formed with corrugations extending laterally of the receptacle.
7. A receptacle as claimed in claim 1, in which said turned-in side parts are slightly directed toward said base.
References Cited UNITED STATES PATENTS 2,770,792 11/ 1956 Batcheller. 2,980,878 4/1961 Swengel. 3,152,856 10/1964 Batcheller.
FOREIGN PATENTS 1,353,853 1/1964 France.
MARVIN A. CHAMPION, Primary Examiner J. H. MCGLYNN, Assistant Examiner U.S. Cl. X.R. 33925 6