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United States Patent  [li] Patent Number: 4,869,677
Johnson et al.  Date of Patent: * Sep. 26,1989
U.S. Patent Sep. 26,1989 Sheet 1 of 2 4,869,677
U.S. Patent Sep. 26,1989 Sheet 2 of 2 4,869,677
 BACKPLANE CONNECTOR
 Inventors: Lennart B. Johnson, Milford; William B. Walkup; Steven F. Laychak, both of Amherst, all of N.H.
 Assignee: Teradyne, Inc., Boston, Mass.
[ * ] Notice: The portion of the term of this patent subsequent to Apr. 7, 2006 has been disclaimed.
 Appl. No.: 201,082
 Filed: Jun. 1,1988
Related U.S. Application Data
 Division of Ser. No. 31,242, Mar. 26, 1987, which is a division of Ser. No. 828,160, Feb. 10, 1986, Pat. No. 4,655,518, which is a continuation of Ser. No. 641,915, Aug. 17, 1984, abandoned.
 Int. CI.* H01R 4/66; H01R 9/09
 U.S. Q 439/80; 439/108
 Field of Search 439/59-62,
439/64, 101, 108, 607-610, 629, 79, 80
 References Cited
U.S. PATENT DOCUMENTS
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3,530,422 9/1970 Goodman .
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4,042,289 8/1977 Heinonen et al. .
4,134,632 1/1979 Lindberg et al. .
4,392,705 7/1983 Andrews, Jr. et al. .
4,428,640 1/1984 Pittman .
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4,486,059 12/1984 Deyoung .
4,494,818 1/1985 Petersen et al. .
4,512,618 4/1985 Kumar .
4,521,062 6/1985 Kurbikoff et al. .
FOREIGN PATENT DOCUMENTS
2517482 6/1983 France .
Teradyne Information Sheets, KE II Printed Circuit Cardedge Backplanes.
Teradyne Information Sheets, Minimax Backplane Interconnection Systems, 1978.
Teradyne Information Sheets, Minimax/LSI Inverse DIN Backplane System, 1981.
Teradyne Information Sheet, Inverse DIN Daughter Board Stiffener, 1983.
Primary Examiner—Neil Abrams
A backplane/daughter board connector including a first connector element and a mating second connector element that fits between upwardly extending sidewalls of the first element, the first element being provided with an additional contact carried by one of its sidewalls, and the mating connector element being provided with a further contact carried by a facing outside wall, the sidewall contacts providing a short ground path.
17 Claims, 2 Drawing Sheets
This application is a division of application Ser. No. 031,242, filed Mar. 26,1987, of Lennart B. Johnson et al. 5 for "BACKPLANE CONNECTOR", which is a division of application Ser. No. 828,160, filed Feb. 10, 1986, of Lennart B. Johnson for "BACKPLANE CONNECTOR", now U.S. Pat. No. 4,655,518, which is a continuation of application Ser. No. 641,915, filed Aug. 17, 10 1984, now abandoned.
FIELD OF THE INVENTION
The invention relates to a connector for connecting a daughter printed circuit board (PCB) to a backplane. 15
BACKGROUND OF THE INVENTION
Backplanes are printed circuit boards or metal plates on the upper sides of which "daughter" PCB's are detachably mounted perpendicularly to the backplanes for 20 easy removal. One way of electrically connecting a daughter board to another daughter board, the backplane, and other circuitry is by a two-piece multiplecontact connector consisting of a first connector element that is attached to the backplane and a mating 25 second connector element that is attached to the daughter board and fits between upwardly extending sidewalls of the first element. When the two elements are joined, a plurality of rows of contact posts directed upwardly between the sidewalls of the first element are 30 connected to a plurality of corresponding downwardly directed forked contacts of the second element.
SUMMARY OF THE INVENTION
We have discovered that by providing a backplane/- 35 daughter board connector with an additional contact carried by a sidewall of one of the two connector elements and a further contact carried by a facing outside wall of the other connector element an additional connection for distributing current, e.g., for ground or 40 power, can be advantageously provided without increasing the overall size of the connector.
In preferred embodiments, there are grooves in the sidewall of the connector element toward the backplane and a plurality of resilient contact portions extending 45 from the grooves; the contact portions have laterally extending tabs at their upper movable ends to prevent the contact portions from extending too far into the region between the sidewalls to prevent jamming; there are further recesses in the sidewall near the tops of the 50 grooves to receive the movable ends of the contact portions when they are deflected; a single contact in the connector element toward the backplane has a plurality of contact portions located in the grooves; and the contacts on the other connector element are large 55 enough to contact a plurality of contact portions of a contact of the first connector element.
DESCRIPTION OF THE PREFERRED
The structure and operation of the presently preferred embodiment of the invention will now be described after first briefly describing the drawings.
FIG. 1 is a perspective view of a connector for connecting a daughter printed circuit board to a backplane 65 according to the invention.
FIG. 2 is a vertical sectional view, taken at 2—2 of FIG. 1, of the FIG. 1 connector.
FIG. 3 is an exploded diagrammatic perspective view showing a contact of a daughter board connector element of the FIG. 1 connector and the portion of the daughter board connector element on which the contact is carried.
FIG. 4 is an exploded perspective view showing a contact of a backplane connector element of the FIG. 1 connector prior to placement in grooves of sidewalls of a backplane connector element of the FIG. 1 connector.
FIG. 5 is a vertical sectional view, taken at 5—5 of FIG. 1, showing mating of contacts of the FIG. 1 connector in use.
Referring to FIG. 1, there is shown two-piece connector 10 for electrically connecting daughter printed circuit board 12 (shown diagrammatically without any electronic components) to backplane 14. Connector 10 includes lower backplane connector element 16 connected to backplane 14 and upper daughter board connector element 20 connected to daughter board 12. Secured to backplane 14 and passing upwardly through backplane connector element 16 are four rows of signal contact pins 18 for mating with a corresponding plurality of forked signal contacts 22 mounted in housing 24 (FIG. 2).
Referring to FIGS. 2, 3 and 5, signal contacts 22 of daughter board connector element 20 are forked at lower ends 26 in boxes 28 of plastic housing 24 and extend upwardly and are bent horizontally. The other ends 23 of contacts 22 pass through plastic guide board 30 and holes in daughter board 12, where they are soldered (FIG. 5). Aluminum stiffener 32 is connected between guide board 30 and housing 24 to cover exposed portions of contacts 22 and provide structure to daughter board connector element 20. On an outer face of side wall 34 of housing 24 are ground contacts 36, shown isolated from housing 24 and in more detail in FIG. 3. Contacts 36 are secured to wall 34 of housing 24 via vertical tabs 37, secured in place during molding of housing 24, and horizontal tabs 39, bent upward after molding. The lower ends of contacts 36 are inclined to provide guide surfaces 40. Laternally extending prongs 38 of contacts 36 pass through holes in daughter board 12, where they are soldered (FIG. 5). Contacts 36 are approximately 0.008 inch thick and are made of phosphor bronze with 100 microinches of nickel covered by 20 microinches of plated gold.
Referring to FIGS. 2, 4 and 5, it is seen that signal contact pins 18 of backplane connector element 16 are press fit in backplane 14, and that backplane connector element 16 has sidewall contacts 42 provided in grooves 44 of right-hand sidewall 46 extending upward from base 47. Each contact 42 has three contact portions 50 that extend upward from connecting portion 53 through holes 51 to grooves 44. Adjacent to the top of base 47, contact portions 50 bend away from contact region or cavity 54 between sidewalls 46, 56 to fulcrum portion 52. From there they bend back toward and into contact region 54, and at contact points 48 they begin to bend back away from region 54. At the upper movable end of each contact portion 50 is tab 58, which extends laterally behind overhanging portion 60 of sidewall 46. Recess 45 extends further into sidewall 46 at the top of groove 44. Contacts 42 are made of a copper alloy (C72500) and have a welded inlay at contact areas 48 (FIG. 4) of 100 microinches of nickel covered by 100 microinches of gold.