CONNECTOR WITH COMPLIANT RETAINER

Abstract: A cross-shaped retainer post (14) for fixing a connector (10) to a printed wiring board (18), the post having an oval longitudinal bore (20) which causes the post to break along the juncture (22, 24) of the ribs (15, 15a, 15b, 15c) nearest the major axis (21) of the bore (20) when the ribs (15, 15a, 15b, 15c) of the cross are stressed upon insertion into a locating hole (16).

Description: This invention relates to connectors for printed wiring boards and more particularly it relates to means for locating and holding the connector to the wiring board until soldered. The mechanics of holding a card connector housing to a printed wiring board (PWB) until it is soldered, as known in the prior art, involves either mechanical fasteners (screws, rivets, etc.), weighted plates placed on top of components and removed after soldering, or posts integral with the housing. Molded posts which are part of the housing are particularly suited for surface mount connectors. Such connectors are known from e.g. US-A-4435031. The posts provide a means for accurately locating the connector legs to the PWB solder pad and holding the connector in place during the soldering process by engaging holes located in the PWB. There is an interference fit between the posts and the holes. With known post designs of various shapes the interference fit results in material being scraped from the post as it is inserted into the locating hole. These scrapings present assembly problems by preventing contact between the connector and PWB. According to the invention there is provided means for locating and holding a connector housing to a printed wiring board having locating holes therein, said means comprising: a post extending from said housing for engaging said holes with an interference fit to locate the housing with respect to said printed wiring board characterised by said post having a plurality of ribs extending outwardly from the post at locations around the post and an elongated longitudinal bore, the transversal crossection of which having a major axis aligned with diagonally opposed junctures of adjoining ribs and sized to provide a frangible juncture which separates when said post is inserted in a locating hole. When inserted the post forms two separated legs from the integral post allowing the ribs to flex to conform easily to the hole size or location without scraping material from the post and to reduce insertion forces. An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. 1 is a front elevation view showing a connector housing with locating posts extending downwardly from the housing through locating holes in a PWB. Fig. 2 is an enlarged cross-sectional view of a post of Fig. 1 taken along the line 2-2 before insertion into a location hole of a PWB. Fig. 3 is a plan view of a post inserted into a locating hole of a PWB with an interference fit. Referring to the drawing, the embodiment chosen for purposes of illustration includes a connector housing 10 having terminals 12 and locating posts 14 fastened to and extending downwardly from the housing. The posts 14 are shown inserted through locating holes 16 of PWB 18. The posts 14 are sized for an interference fit with holes 16 and are preferably molded as an integral part of the housing 10. Referring particularly to Fig. 2 each post 14 is seen to have a plurality of ribs numbered 15, 15 a , 15 b and 15 c located around the post at an angle 17 of about ninety degrees to each other. There is an elongate longitudinal bore 20 extending through post 14. The bore 20 is shown with a crossection in the shape of an oval with its major axis 21 aligned with directly opposed junctures 22, 24 of adjoining ribs 15, 15 a , 15 b and 15 c . The bore is sized to provide frangible walls at junctures 22, 24 which separate when the post 14 is inserted in hole 16 of PWB 18 as best shown in Fig. 3. The bore 20 breaks through the junctures of ribs 15, 15 a and 15 b , 15 c allowing the ribs to flex. The cross configuration shown provides four narrow surfaces which easily conform to hole size or location without scraping the post or ribs as the case may be.

Claims: Means for locating and holding a connector housing (10) to a printed wiring board (18) having locating holes (16) therein, said means comprising: a post (14) extending from said housing (10) for engaging said holes (16) with an interference fit to locate the housing (10) with respect to said printed wiring board (18) characterised by said post (14) having a plurality of ribs (15, 15 a , 15 b , 15 c ) extending outwardly from the post (14) at locations around the post and an elongate longitudinal bore (20), the transversal crossection of which having a major axis (21) aligned with diagonally opposed junctures (22, 24) of adjoining ribs (15, 15 c and 15 a , 15 b ) and sized to provide a frangible juncture which separates when said post (14) is inserted in a locating hole (16). The means as claimed in claim 1 wherein said post (14) has four ribs (15, 15a, 15b, 15c) located at ninety degrees to each other, and said elongate longitudinal bore (20) has an oval crossection having its major axis in alignment with diagonally opposed junctures of adjoining ribs.

Inventors: HAHN, MARLYN EUGENE
Applicants: E.I. DU PONT DE NEMOURS AND COMPANY
Application year: 1987
Main classification: H01R9
IPC codes: H05K3, H01R12, H05K1, H01R43, H05K5