Method and apparatus for mounting an electrical connector on a printed wiring board

Abstract: Disclosed is a method and apparatus for mounting an electrical connector on a printed wiring board. The printed wiring board is initially positioned on loca ting projections on a tooling plate. Eyelets are positioned in hold down apertures in the connector. The hold down apertures initially engage the locating projections to align the connector pins with pin receiving apertures on the printed wiring boar d. Engagement continues until the pins are positioned in the apertures and the lowe r end of the eyelet is deformed to engage the innerside of the down aperture and t he lower side of the printed wiring board.

Description: Background of Invention 1. Field of the Invention: The present invention relates to electrical connectors and more particularly to methods and apparatus for attaching electrical connectors to a substrate. 2. Brief Description of the Prior Developments: In the assembly of electronic devices it is frequently necessary to mount connectors having a plurality of signal pins or pin like elements on a printed wiring board or on other substrates. There will ordinarily be a plurality of pin receiving apertures on the surface of the printed wiring board and conventionally each of the pins on the connector will be aligned with one of the pin receiving apertures and the connector will then be engaged with the wiring board. The connector will also often be equipped with a pair of mounting brackets at its opposed ends. Each of these brackets will have a hold down aperture which is aligned with a hold down aperture on the printed wiring board. An eyelet, rivet or any other number of well known commercial fasteners may be inserted through these hold down apertures to fix the connector to the wiring board but only after the signal pins have first been aligned with them inserted into their respective pin receiving apertures. The method as described above for fixing a connector to a printed wiring board has several disadvantages. First, the alignment of the signal pins with the pin receiving apertures is a rather exacting procedure which must be accomplished within close tolerances. Further, the conventional method as described above involves two distinct procedures in that the eyelet is not attached to the connector and the wiring board until the signal pins have first been aligned with them and inserted into the pin receiving apertures. The carrying out of these two distinct procedures may result in a significant addition to the time and expense required for the overall assembly operation. US patent No. 4,884,336 discloses a method for mounting an electrical connector to a printed circuit board with a top actuated eyelet. The connector is mounted in a two-step process, whereby the actuating tool first grips and restrains the connector and thereafter the connector is positioned relative to a printed circuit board, and the tool is operated to actuate the eyelet to attach the connector to the board. The method permits the eyelet to be used to facilitate positioning of the connector on the printed circuit board. European patent application EP 0 598 492 A1 discloses a further method and apparatus for mounting connectors. According to this method, the circuit boards are aligned with the connectors by inserting string loaded pins through holes in the board. The connectors are then mounted by inserting pegs on the connector housing through the same holes which include the pins. The pins are displaced from the holes as the pegs are inserted therein while alignment is maintained. A need remains for a method and apparatus for mounting a connector on a printed wiring board or other substrates which can be performed quickly and effectively in essentially a single integral procedure. Summary of the Invention The present invention provides an assembly for mounting an electrical connector on a substrate wherein the connector comprises a plurality of pins and at least one fastening means; the substrate includes a plurality of pin receiving apertures for receiving the connector pins and at least one aperture for receiving said fastening means and the assembly includes a tooling plate for receiving the substrate, and a projection extending from said tooling plate or through said tooling plate and adapted to be received in the fastening means receiving aperture of the substrate characterized in that said connector further comprises at least one hold down means having an aperture in which said fastening means is disposed; said projection is adapted to be received in the aperture of the connector for locating the connector with respect to the substrate; and the projection and/or the tooling plate comprises deformation means for deforming the fastening means for causing the fastening means to secure the connector onto the substrate as the pins of the connector are inserted into the pin receiving apertures in the substrate. The present invention further provides a method of mounting an electrical connector on a substrate, said connector having a plurality of pins and at least one fastening means, comprising the steps of positioning a substrate having pin receiving means, comprising a plurality of pin receiving apertures, and at least one fastening means receiving aperture in the substrate, adjacent to a tooling plate, wherein a projection is extending from or through said tooling plate, such that the projection is aligned with the aperture on the substrate positioning the connector such that the fastening means is aligned with said projection; initially engaging the hold down means with the projection characterized in that: Said connector further comprises hold down means with an aperture having said fastening means disposed therein, and said projection and or, said tooling plate comprises a means for deforming the fastening means, wherein said method further comprises engaging said fastening means with the projection until the connector pins engage the pin receiving means in the substrate; and causing said fastening means to secure the connector onto the substrate by engaging the fastening means by said deformation, as the pins of the connector are inserted into the pin-receiving apertures in the substrate. In the method and apparatus of the present invention the hold down apertures of the connectors are first superimposed and aligned with location projections which extend perpendicularly upwardly from a tooling plate. The connector is then lowered toward the tooling plate until the hold down apertures are initially engaged with the tooling projection. Downward motion of the connectors continues until the pins first engage then are seated in the pin receiving apertures in the printed wiring board and the hold down apertures are fully engaged with the locating projection. An axial force is then applied downwardly to the eyelet against a deformation means in the tooling plate to bend the eyelet to engage the printed wiring board within its thickness and on its lower side. The eyelet also engages the connector on its upper side so as to fix the connector to the printed wiring board. By the term "eyelet" what is meant is any type of tubular rivet or other fastener which can concentrically engage a projection that fits through an aperture. Brief description of the drawings The method and apparatus of the present invention is further described with reference to the accompanying drawings in which: Fig. 1 is a top plan view in fragment of a connector showing one hold down bracket; Fig. 2 is a vertical cross sectional view through line II-II in Fig. 1; Figs. 3a-3f are schematic illustrations of the connector, the printed wiring board and the connecting apparatus showing successive steps in the method of the present invention; Fig. 4 is a schematic illustration of the connector and printed wiring board showing the final connected assembly; Fig. 5 is a vertical cross sectional view of the locating projection element of the apparatus used in the method of the present invention; Fig. 6 is a schematic end view of an alternate embodiment of the apparatus of the present invention; and Fig. 7 is a schematic end view of another alternate embodiment of the apparatus of the present invention. Detailed Description of the Preferred Embodiments Referring to Figs. 1 and 2, a connector is shown generally at numeral 10. This connector includes a receptacle 12, a guide pin 14, a mounting bracket 16, a press block 18 and an end wall 20 positioned between the bracket and the press block. It will be understood that there is shown only one end of the connector and at the other end there will be a similarly positioned and essentially identical mounting bracket and guide pin. It will also be seen that the mounting bracket includes a hold down aperture 22 in which there is positioned an annular rivet which is also commonly referred to as an eyelet 24. Signal pins as at 26 and 28 extend downwardly from the press block. Referring to Figs. 3a - 3f, a preferred embodiment of the method of the present invention is illustrated in greater detail. Referring particularly to Fig. 3a, it will be seen that in the first step of this method a tooling plate 30 is provided which has an upwardly extending perpendicular locating projectile 32 along with deformation recesses as at 34 and 36. The functions of this projection and deformation recesses will be explained hereafter. A printed wiring board 38 having a pair of apertures as at 40 is positioned so that the apertures are engaged with the locating projections of the tooling plate and the printed wiring board abuts the tooling plate in side to side relation. Referring particularly to Fig. 3b, the connector is then superimposed over the printed wiring board and the tooling plate so that it's hold down apertures and the concentric eyelet are in vertical alignment with the locating projections at the tooling plate. In the next step of the method the eyelet is initially engaged with the locating projection as is shown in Fig. 3c. It will be noted from Fig. 3c that upon the initial engagement of the hold down aperture and the eyelet with the locating projection that the pins of the connectors are not yet engaged with a respective pin receiving aperture in the printed wiring board. Referring particularly to Fig. 3d, it will be seen that additional tooling is then provided by way of an eyelet support block 42 which is superimposed above the mounting bracket and in particular the hold down aperture and the eyelet. There is also a U-shaped channel 44 which is positioned above the eyelet support block and the connector. Above the U-shaped channel there is also a ram 46 which pushes downwardly on the connector. The action of this ram will result in the pins as at 26 and 28 engaging pin receiving apertures as at 48 and 50 in the printed wiring board. It will also be noted that there are pin receiving recesses as at 52 and 54 positioned immediately beneath each of the pin receiving apertures in the printed wiring board. At this stage of the method shown in Fig. 3d, however, the pins have not yet entered these pin receiving apertures. Referring particularly to Fig. 3e it will be seen that downward pressure by the ram continues in this method until the pins pass through the pin receiving apertures in the printed wiring board and enter the pin receiving recesses in the tooling plate. It will also be seen from Fig. 3e that the eyelet is pushed downwardly against deformation means at the base of the locating projection. This deformation means will preferably be an axially expanded lower section of the locating projection which will be disclosed hereafter in greater detail. Such downward axial pressure on the eyelet continues until the lower end of the eyelet will be crimped as at 55 as is shown in Fig. 3f. Upon the completion of this method, the tooling plate is removed to leave an assembly such as is shown in Fig. 4 wherein the eyelet engages the connector at its top and the printed wiring board at its bottom by means of crimp 55 to affix these elements together. Referring to Fig. 5, the engagement of the locating projection, eyelet support block, the eyelet and the printed wiring board is shown in further detail. It will be seen that the eyelet support block has a vertical bore 56 with a rivet receiving recess 58 on its lower side. The locating projection has an upper nipple 60 and a lower axially expanded deformation section 62. Outwardly from this deformation section there is an annular collar 64. Beneath the locating projection in the tooling plate there is also an axial bore 66 in which there is a plug 68 which is at the upper end of a spring 70 which is attached at its lower end to a projection spring base 72. The eyelet 24 is positioned over the nipple of the locating projection and is retained at its lower end between that nipple and the annular collar and at its upper end in the recess of the eyelet support block. As downward axial pressure is applied to the eyelet its lower section is deformed outwardly by the lower flared deformation section of the locating projection. That lower portion is received in the deformation recesses so that a crimp is formed as at shown at numeral 55 in Fig. 4. While such downward axial pressure is applied to the eyelet, spring 70 is compressed in the axial bore 66. After the lower end of the rivet has been crimped and the downward axial pressure is removed the spring expands to at least partially remove the printed wiring board from the locating projection. Referring to Fig. 6, a second preferred embodiment of the method and apparatus of the present invention is illustrated. In this embodiment a connector shown generally at numeral 110 and being essentially identical to those shown in Fig. 1 and 2 has been positioned with a eyelet 124 on an upper tooling plate 130 with a perpendicular locating projection as at 132 with deformation recesses 134 and 136. In a manner similar to that described in the first embodiment, a printed wiring board 138 is also engaged with the locating projections between the connector and the upper tooling plate in a manner similar to that described in connection with the first embodiment. The upper tooling plate 130 is itself superimposed over a base plate 176 which has a medial raised section 178 from which the projection extends. Interposed between the upper tooling plate and the base plate are vertical springs 180 and 182. In this apparatus the connector is engaged with the printed wiring board in a manner similar to that described above, as is the locating projection is inserted into the aperture 122. The springs 180 and 182 are in a generally expanded position until the eyelet is seated in the deformation recesses and deformed by a lower axially expanded section of the projection. As downward axial pressure is then applied to deform the lower end of the eyelet the springs yield to this pressure as the eyelet is crimped. After the eyelet is crimped and the downward axial pressure is removed from it the springs force the upper tooling plate upward to at least partially remove the rivet from the upward locating projection. Referring to Fig. 7, a third preferred embodiment of the method and apparatus of the present invention is illustrated. In this embodiment a connector which is shown generally at numeral 210 is essentially similar to the one described in conjunction with Figs. 1 and 2. This connector is mounted with eyelet 224 over tooling plate 230 which has a locating projection 232 which is positioned inside eyelet 224. In a manner similar to the embodiments described above, the apparatus of the embodiment includes an eyelet support block 242, a U-shaped channel 244 and a ram 246. In this embodiment the connector is fixed to the printed wiring board in a manner as was described in the first two embodiments. After the eyelet has been moved downwardly to the deformation recesses 234 and 236, a solenoid 280 is automatically activated to move the projection 236 upwardly. In this embodiment, an axially expanded section 282 of the locating projection deforms the eyelet during the upward motion of the projection. The upward motion of the projection also causes the wiring board to at least partially disengage from the eyelet 224. It will be appreciated that there has been described a method and apparatus for mounting a connector to a printed wiring board or other substrate which enables the eyelets or tubular rivets and the signal pins to be mounted in their respective apertures in one quick and efficient operation and which takes advantage of the need to mount those eyelets to easily align the signal pins with their pin receiving apertures. While the present invention has been described in connection with the preferred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiment for performing the same function of the present invention. Therefore, the present invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the appended claims.

Claims: An assembly for mounting an electrical connector (10; 110; 210) on a substrate (38; 138; 238), wherein the connector (10; 110; 210) comprises a plurality of pins (26, 28) and at least one hold down means having an aperture (22; 122; 222) in which at least one fastening means (24; 124; 224) is disposed; the substrate (38; 138; 238) includes a plurality of pin receiving apertures (52, 54) for receiving the connector pins (26, 28) and at least one aperture (40) for receiving said fastening means (24; 124; 224); and a) the assembly includes a tooling plate (30; 130; 230) for receiving the substrate (38; 138; 238), and a projection (32; 132; 232) extending from said tooling plate or through said tooling plate (30; 130; 230) and adapted to be received in the fastening means receiving aperture (40) of the substrate (38; 138; 238) characterized in that b) said projection is adapted to be received in the aperture (22; 122; 222) of the connector (10; 110; 210) for locating the connector (10; 110; 210) with respect to the substrate (38; 138; 238); and c) the projection (32; 132; 232) and/or the tooling plate (30; 130; 230) comprises deformation means (34, 36; 62; 134, 136; 234, 236) for deforming the fastening means (24; 124; 224) for causing the fastening means (24; 124; 224) to secure the connector (10; 110; 210) onto the substrate (38; 138; 238) as the pins (26, 28) of the connector (10; 110; 210) are inserted into the pin receiving apertures (52, 54) in the substrate (38; 138; 238). The assembly of claim 1, wherein said fastening means (24; 124; 224) is an eyelet. The assembly of claim 2, wherein an eyelet support block (42; 142; 242) and a ram (46; 146; 246) is provided for applying an axial force on said eyelet in the direction of the substrate (38; 138; 238). The assembly of any of claims 1 to 3, wherein at least one spring or a solenoid (70; 180, 182; 280) is provided for applying axial force on the projection (32; 132; 232) in the direction of the connector (10; 110; 210). The assembly of claim 4, wherein the projection (32) has an upper engagement nipple (60), and wherein beneath the projection (32) in the tooling plate there is an axial bore having an axial spring (70) and said axial spring (70) is the means for applying an axial force on the locating projection (32) in the direction of the connector (10). The assembly of any of claims 1 to 3, wherein the tooling plate (130) is superimposed over a base plate (176), said projection (132) extending from said base plate (176) and at least one spring (180, 182) is interposed between said tooling plate (130) and said base plate (176). A method of mounting an electrical connector (10; 110; 210) on a substrate (38; 138; 238), said connector (10; 110; 210) having a plurality of pins (26, 28) and at least one fastening means (24; 124; 224), comprising the steps of: a) positioning a substrate (38; 138; 238) having pin receiving means, comprising a plurality of pin receiving apertures (52; 54), and at least one fastening means receiving aperture (40) in the substrate, adjacent to a tooling plate (30; 130; 230), wherein a projection (32; 132; 232) is extending from or through said tooling plate (30; 130; 230), such that the projection (32; 132; 232) is aligned with the aperture (40) on the substrate (38; 138; 238); b) positioning the connector (10; 110; 210) such that the fastening means (24; 124; 224)is aligned with said projection (32; 132; 232); characterized in that: c) said connector (10; 110; 210) further comprises hold down means with an aperture (22; 122; 222) having said fastening means (24; 124; 224) disposed therein, and said projection (32; 132; 232) and or, said tooling plate (30; 130; 230) comprises a means (34, 36; 62; 134, 136; 234, 236), for deforming the fastening means (24; 124; 224), wherein said method further comprises d) further engaging said fastening means (24; 124; 224) with the projection (32; 132; 232) until the connector pins (26, 28) engage the pin receiving means in the substrate; and e) causing said fastening means (24; 124; 224) to secure the connector (10; 110; 210) onto the substrate (38; 138; 238) by engaging the fastening means (24; 124; 224) by said deformation, as the pins (26; 28) of the connector (10; 110; 210) are inserted into the pin-receiving apertures (53; 54) in the substrate (38; 138; 238). The method of claim 7, wherein the fastening means (24; 124; 224) is an eyelet. The method of claim 8, wherein said deformation means comprising a radially expanded section of the projection (32; 132; 232), and wherein in step e) an axial force is applied to the eyelet against said radially expanded section of the projection (32; 132; 232). The method of claim 9, wherein in step b) the substrate aperture (40) for receiving said fastening means and the concentric eyelet are aligned in axial relation with the projection (32; 132; 232). The method of any of claims 9 to 10, wherein in step d) said eyelet is deformed outwardly to engage the substrate (38; 138; 238). The method of any of claims 7 to 11, wherein the substrate has two opposed ends and there is a substrate aperture position towards each of said ends. The method of any of claims 7 to 12, wherein the eyelet circumferentially abuts said fastening means receiving aperture (40). The method of any of claims 7 to 13, wherein the locating projection (32) has an upper engagement nipple (60), and wherein beneath the projection (32) in the tooling plate there is an axial bore having an axial spring (70) and said axial spring (70) is the means for applying an axial force on the locating projection (32) in the direction of the connector (10), and the axial force applied to the locating projection results from an expansion of said axial spring after the completion of step c). The method of any of claims 7 to 13, wherein the tooling plate (130) is superimposed over a base plate (176), said projection (132) extending from said base plate (176), and at least one spring (180; 182) is interposed between said tooling plate (130) and said base plate (176) and said spring is compressed during step c), and the axial force applied to the tooling plate results from the expansion of said spring (180, 182).

Inventors: CLARK STEPHEN L, HORCHLER DAVID C, NAILOR III WILLIAM K, PONTIUS GLENN J, STONER STUART C, CLARK, STEPHEN L., HORCHLER, DAVID C., NAILOR III, WILLIAM K., PONTIUS, GLENN J., STONER, STUART C.
Applicants: BERG ELECTRONICS MFG, BERG ELECTRONICS MANUFACTURING B.V.
Application year: 1996
Main classification: H01R12
IPC codes: H01R12, H05K3, H01R43