Microminiature Printed Circuit Connector

Abstract

A connector comprising a connector block with contact elements mounted therein for contacting the leads of a printed-circuit card. The contact elements have tabs for positioning and locking the contact elements in the connector block. The connector block includes an aperture for receiving a printed-circuit card and apertures for receiving the contact elements.

Description

This invention relates to connectors for printed-circuit cards which are rugged, reliable, and effective in performance.

The present invention provides a connector block, having an internal chamber, with a longitudinal aperture or slot for receiving a printed-circuit card and apertures for receiving contact elements. Connector block internal surfaces enable the contact elements to self lock in the block when inserted into the contact receiving apertures. Special features of the connector block cooperate to retain the contact elements in position to contact the circuit leads on the printed-circuit card and to impart structural reinforcement to the contact elements.

An important feature of the present invention concerns the simple and inexpensive character of the contact elements.

Another feature of the present invention concerns the character of the connector block.

Another feature of the present invention resides in the provision of a commercially feasible organization of connector parts.

These and other features will become apparent to those of ordinary skill in the art upon reading the following detailed description in conjunction with the following drawings wherein;

FIG. 1 is a plan view of a segment of a sheet metal strip which has been piloted through a progressive die to stamp and form contact elements in accordance with the present invention.

FIG. 2 is a plan view of a contact development blank from which a contact element in accordance with the present invention is formed.

FIG. 3 is a transverse sectional view of a contact element taken along line 3-3 of FIG. 1.

FIG. 4 is a side view of a contact element in accordance with the present invention.

FIG. 5 is a partial plan view of a connector block in accordance with the present invention.

FIG. 6 is a partial sectional view of the connector block of FIG. 5, taken along broken line 6-6 of FIG. 5 and a portion of a printed-circuit card which is to be inserted into the connector block.

FIG. 7 is a transverse sectional view taken along line 7-7 of FIG. 5 showing opposed contact elements mounted in the connector block and depicting the use of a tool to release a contact element from the connector block.

FIG. 8 is a perspective view of a polarizing key which may be utilized to polarize the interconnection between the printed-circuit card and connector shown in FIG. 6.

Attention is now directed to FIG. 1 which depicts a sheet metal contact strip segment 10 comprising a pilot portion 12 with uniformly spaced circular pilot apertures 14 and contact elements 16 extending from one side of pilot portion 12. The sheet metal may comprise beryllium copper or other spring metal material which has been passed through a suitable progressive die to form the contact elements 16 of contact strip segment 10.

FIG. 2 shows a section of contact strip segment 10 including a contact development blank which has been stamped from a reel of sheet metal. The contact development blank comprises laterally adjacent contact sections 18 and 20 of unequal length. Rectangular band relief apertures 24 or 26 have been formed in the blank and adjacent areas of sections 18 and 20 have been separated by lancing the development blank along collinear lines which respectively terminate in apertures 24 and 26. Sections 18 and 20 are adjoined by a common section 28 as shown. Bend relief apertures 24 and 26 are provided to facilitate subsequent folding of shorter section 20 onto longer section 18. FIG. 3 shows the manner in which the contact section 18 is folded double onto contact section 20.

Referring now to FIG. 4, it can be seen that contact element 16 comprises elongated contact section 20, bent to one side at one end to form curved contact tab 30, and contact section 18, bent to the same side at one end to form locking tab 32.

FIGS. 5, 6, and 7 depict various significant features of the present invention. In FIGS. 5--7, connector block 40 comprises a generally rectangular member of molded electrically insulating material such as diallyl phthalate or glass filled epoxy. It is preferred to utilize diallyl phthalate as it possesses greater mechanical strength and rigidity. Apertured mounting tabs 42 (only one is shown), at opposite sides of the main body of block 40, permit the mounting of block 40 to support such as a mother board.

Elongated central aperture 44 is provided for receipt of printed circuit card 60 in connector block 40. A longitudinal row of laterally spaced apertures 46 are provided on opposite sides of a central longitudinal plane passing through the front and back of connector block 40, for receiving respective contact elements 16. Thin, internal, transverse divider walls 48, on each side of back wall ridge 50, separate longitudinally adjacent apertures 46 and extend to the front wall of connector block 40. Divider wall "crackout" is avoided since divider walls 48 are protected by the front wall and supported on three sides.

The distance between longitudinally adjacent divider walls 48 is sufficient to accommodate the positioning therebetween of contact elements 16 for operative engagement with corresponding printed-circuit card leads such as lead 62 of printed-circuit card 60. The connector block 40 is internally curved as shown at 52 to conform to the curvature of contact tabs 30. The back wall between laterally spaced apertures 46 is aligned with card slot 44. The sides of backwall ridge 50 are shaped to define a series of recessed, rounded shoulders 56 between longitudinally adjacent divider walls 48.

Contact elements 16 are mounted in connector block 40 (as shown in FIG. 7) for resiliently contacting the leads of printed-circuit card 60. Each contact element 16 is readily mounted within connector block 40 by insertion into a corresponding contact receiving aperture 44. Inclined surfaces 58 facilitate contact element insertion. As each contact element passes through aperture 46, contact tabs 30 and 32 successively resiliently deform. Contact element insertion progresses until locking tab 32 abuts shoulder 56 to lock the contact element in position, with contact tab 30 seated against curved surface 52. Locking tab 32 resiliently urges the contact element into surface abutting engagement with the adjacent internal surface which provides structural reinforcement to the contact element.

A contact element 16 can be withdrawn from connector block 40 by aligning the working end 80 of a tool with the contact element to be removed so that tool leg 82 deflects tabs 30 and 32. The contact element can new be passed through aperture 46 as the contact element is pulled in the direction away from the back of block 40. The contact element on the right in FIG. 7 is shown with a double bend to illustrate the possibility of bending the part of the contact elements projecting out of the block 40 in any fashion desired.

FIG. 8 shows a polarizing key 90 which may be utilized to polarize the printed-circuit card 60 relative to connector block 40. Key 90 is of plastic material, such as nylon, having a thickness T, corresponding to the distance between adjacent divider walls 48, which is slightly less than the width of key slot 64 in printed-circuit card 60. The upper portion key 90 is of reduced width relative to the lower portion thereof to define lateral shoulders 92. Key 90 may be inserted into aperture 44 in position between longitudinally adjacent divider walls 48 with the lower portion resting upon ridge 50 and the shoulders 92 in locking engagement with the edges of aperture 44. Key aperture 94 allows the lower portion of key 90 to flex inward as it is pushed into aperture 44. The upper portion of key 90 will project above connector block 40 so that printed-circuit card 60 may be inserted into the connector block 40 only when key slot 64 is aligned with key 90.

The connector shown and described hereinabove includes two rows of opposing contact elements 16 in the connector block 40, but it should be understood that one of the rows may be eliminated if contact with only one side of a printed-circuit card is required. The strip segment 10 (FIG. 1) lends itself to rapid or automatic connector assemblage since contact elements 16 may be simultaneously inserted into the connector block while still attached to pilot portion 12 and subsequently severed therefrom. By assembling connector block 40 and the contact elements 16 in this manner appreciable time saving is effected compared to the time that would be required to insert individual contact elements into the connector block.

Claims

We claim:

1. In an electrical connector, the combination comprising:

a connector block having walls defining a chamber thereinside including a front wall which perpendicularly intersects with a sidewall to form an inside longitudinally extending frontward inside corner and a backwall which perpendicularly intersects with the sidewall to form an inside longitudinally extending rearward inside corner;

the front wall having a slot therein spaced laterally of the sidewall and extending longitudinally in a direction parallel to the frontmost corner, the sidewall having a longitudinal row of serially spaced laterally extending divider walls arranged inside the chamber to define a longitudinal row of serially spaced subchambers inside the connector block on the side of said slot in said front wall where said sidewall is located, the backwall having a longitudinal row of serially spaced row apertures therein with the apertures each being located in the backwall between adjacent divider walls and rearwardly of a respective subchamber defined by the adjacent divider walls;

a longitudinal row of serially spaced identical contact elements extending through the aperture row in the backwall into the subchambers inside the connector block, each contact element being mounted in a respective subchamber between the inside of the front, side, and backwalls;

the inside of the front wall between the divider walls being of concavely arcuate curvature and merging smoothly with the frontmost corner inside the connector block between the front and sidewalls, the frontmost corner being concavely rounded;

each contact element having first and second sheet metal strips with the first strip being longer than the second strip, the strips each being formed from different segments of a common sheet metal member, the strips being integrally adjoined to each other along a longitudinal line in the contact element shorter than the second strip extending from adjacent a rear end of the second strip located frontwardly of a rear end of the first strip partway toward a front end of the second strip located rearwardly of a front end of the first strip whereby a frontward portion of said second strip is separate from and not integrally adjoined to a frontward portion of said first strip;

the second strip being folded double onto the first strip about the longitudinal line whereby the frontward portion of each strip projects frontwardly from the portions of the strips which have been folded double in the aforesaid manner, the frontward portion of the first strip being curved into an arcuate contact tab strip portion curving to the side of the first strip having the second strip folded double thereon and the frontward portion of the second strip being curved into a locking tab strip portion also curving to the side of the first strip having the second strip folded double thereon, the contact tab strip portion ending at the front end of the first strip and the locking tab strip portion ending at the front end of the second strip, the respective tab strip portions being spaced apart, the contact tab strip portion and locking tab strip portion each being curved so that the front end of the first strip is located generally frontwardly of a frontmost extending portion of the locking tab strip portion located intermediate the front end of the second strip and the portion of the second strip which has been folded double onto the first strip and so that the front end of the second strip is located further rearwardly of the contact tab strip portion than is the frontmost extending portion of the locking tab strip portion;

each contact element being inserted into a respective row aperture into a subchamber inside the connector block so that the first strip touches a side of the respective row aperture close to the sidewall and extending frontwardly therefrom touching the inside of the sidewall, the inside frontward corner, and the inside of the front wall between the slot in the front wall and the inside frontward corner so that the contact tab strip portion thereof is fitted against the inside frontward corner and the inside of the front wall and then curves laterally beyond an edge of the slot in the front wall to terminate at a point inside the chamber located rearwardly of the slot in the front wall, the second strip being on the side of the first strip which is opposite to the side of the first strip which touches the inside of the front and sidewalls as aforesaid with the locking tab strip portion projecting away from the inside of the sidewall laterally and rearwardly toward the inside of the backwall so that the front end of the second strip abuts the inside of the backwall at a surface area thereof at the side of the associated row aperture furthest from the sidewall to resiliently lock the contact element into place.

2. The electrical connector set forth in claim 1 wherein the inside of the backwall includes a longitudinal row of serially spaced recessed shoulder surfaces each of which is immediately adjacent a respective row aperture of the side thereof furthest from the sidewall to provide the surface areas abutted by the front ends of the second strips of each of the contact elements.

3. A sheet metal contact element comprising:

first and second sheet metal strips made from laterally adjacent segments of a sheet metal member;

the first strip being longer than the second strip;

the segments being laterally integrally adjoined along a longitudinal line shorter than the second strip and being otherwise separate and nonadjoined;

the second strip being folded double onto the first strip about the line, the line extending from adjacent a rear end of the second strip partway toward a front end of the second strip;

the first strip having a front end projecting frontwardly of the front end of the second strip and having a back end projecting rearwardly of the rear end of the second strip;

a frontmost portion of the first strip being formed into an arcuate contact tab terminating at the front end of the first strip, a frontmost portion of the second strip being formed into an arcuate locking tab terminating at the front end of the second strip;

the frontmost portions of each strip each projecting sidewardly as well as frontwardly of the balance of each strip away from the side of the first strip onto which the second strip has been folded double;

the tabs being longitudinally spaced apart with the front end of the first strip being located frontwardly of the front end of the second strip;

the front end of the first strip pointing generally toward the locking tab;

the front end of the locking tab pointing generally away from the contact tab;

the contact tab being curved so that the front end of the first strip is closer to the locking tab than is the balance of the first strip defining the contact tab;

the locking tab being curved so that the front end of the second strip is further from the contact tab than is the balance of the second strip defining the locking tab.