US3787801A - Double thickness p.c.b. flag terminal - Google Patents

Abstract

A unitary electrical terminal made from sheet material for a printed circuit board edge connector, comprising a contact part including a base member of a channel section and double thickness, sides of the channel being extended at one end of the base member to define a pair of resilient, parallel spaced contact arms for receiving between an edge of a printed circuit board, each arm being of double thickness, the thickness of each contact arm being formed at the free end of the contact arm remote from the base member.

Description

United States Patent 1191 Teagno et al.

[ 1 DOUBLE THICKNESS P.C.B. FLAG TERMINAL [75] Inventors: Wladimiro Teagno; Franco Trevisiol, both of Turin, Italy [73] Assignee: AMP Incorporated, Harrisburg, Pa.

[22] Filed: Feb. 9, 1972 [21] Appl. No.: 224,832

[30] Foreign Application Priority Data Feb. 24, 1971 ltaly 20976 A/7l [52] US. Cl... 339/258 R, 339/125 R, 339/176 MP, 339/276 F [51] Int. Cl H05k-1/07,HOlr 11/22 [58] Field of Search... 339/17 F, 17 L, 17 LM, 125, 339/126 R,132, 119 R,'119 L, 176 MF,176

MP, 192 R, 217 S, 258 R, 25 8.P, 198 G, 198- [56] References Cited UNITED STATES PATENTS 3,316,526 4/1967 Obert et a1 339/176L 2,51 1,806 6/1950 Macy..... 339/276 T 2,813,258 11/1957 Klumpp 339/276 F 3,656,093 4/1972 Kinkaid 339/17 L X 3,467,944 9/1969 Hammell et al 339/192 R X [45] Jan. 22', 1974 1/1932 Jones 339/258 P x 3,200,360 8/1965 M61061... 339/176 MP x 3,289,148 11/1966 Antes. 339/176 MP 3,577,116 5/1971 Baumanis 339/125 1. 3,537,061 10/1970 Haag et a1. 339/31 M 3,086,096 4/1963 McGee 339/176 MP x FOREIGN PATENTS OR APPLICATIONS 1,498,649 9/1967 France 339/176 MP 572,018 9/1945 Great Britain. 339/258 P 1,276,672 10/1961 France 339/258 R Primary Examiner-Marvin A. Champion Assistant ExaminerLawrence J. Staab Attorney, Agent, or Firm-William J. Keating; Jay L.

Seitchik; Frederick W. Raring [5 7] ABSTRACT A unitary electrical terminal made from sheet material A for a printed circuit'board edge connector, comprising a contact part including a base member of a channel section and double thickness, sides of the channel being extended at one end of. the base member to define a pair of resilient, parallel'spaced contact arms for receiving between an edge of a printed circuit board,

each arm being of double thickness, the thickness of each contact arm being formed at the free end of the contact arm remote from the base member.

2 Claims, 5 Drawing Figures PATENTEB JAN 2 21974 SHEET 2 BF 2 DOUBLE THICKNESS P.C.B. FLAG TERMINAL The present invention relates to electrical terminals for printed circuit board edge connectors.

Known printed circuit board edge connector terminals have a contact part including a pair of resilient spaced arms for receiving an edge of a printed circuit board between them.

The thickness of a printed circuit board can vary between relatively wide manufacturing tolerances and it is desirable that the arms of the contact part of an electrical terminal exert a sufficiently high contact force on the printed circuit board to obtain a good electrical contact for the minimum of deflection, that is, when the thickness of the printed circuit board is at or near its lower limit of tolerance and yet are not strained beyond their elastic limit when receiving a printed circuit board having a thickness at or near the upper limit of the manufacturing tolerance.

The contact force exerted by an arm for a given deflection can be increased by increasing the thickness of the arm. However, when the terminal is formed from sheet material and where a connector part of the terminal is in the form of a ferrule intended for crimping to a conductor wire, the increased'thickness of the ferrule often produces difficulties when forming a satisfactory crimped connection.

In order to overcome this disadvantage, it has been known to mill part of the sheet material from which the terminal is to be formed so that the sheet material has, in effect, two thicknesses the contact part being formed from the greater thickness and the connector part from the lesser thickness. This milling operation is expensive and wasteful of material.

Another known method by which this disadvantage has been overcome is by positioning the arms of .the contact part of a terminal between strengthening plates of a similar configuration to the arms.

However, this requires the careful forming of the strengthening plates with a consequent increase in the cost of manufacture of the electrical terminal.

According to the present invention, a unitary electrical terminal made from sheet material for a printed circuit board edge connector comprises a unitary electrical terminal made from sheet material for a printed circuit board edge connector, comprising a contact part including a base member of channel section and double thickness, sides of the channel being extended at one end of the base member axially of the base'member to define a pair of resilient, parallelspaced contact arms for receiving between them an edge of a printed circuit board, each contact arm being of double thickness, the thicknesses of each contact arm 'being integrally formed at the free end of the contact armv remote from the base member.

In a preferred embodiment, a transition part extends transversely from one'end of a connector part of the electrical terminal and interconnects the connector part to an edge of the base member of the contact part, to give the electrical terminal a generally flag configuration.

An embodiment of the invention will now be described by way of example, reference being made to the Figures of the accompanying drawings, in which:

FIG. 1 is a plan view of an electrical terminal crimped to one end of a conductor wire:

FIG. 2 is a cross-section on the line lI-II of FIG. 1:

FIG. 3 is a perspective view of a printed circuit board edge connector and a printed circuit board shown in ghosted lines assembled to the edge connector;

FIG. 4 is a view of the underside of the edge connector of FIG. 3 assembled to a support plate for the printed circuit board; and

FIG. 5 is a cross-section on the line VV of FIG. 3.

As shown in FIGS. 1 and 2, an electrical terminal 1 formed as a unitary structure from a single piece of electrically conductive sheet material, for example, brass, comprises aconnector part 3 for connection to aconductor wire 5 and a contact part 7.

Theconnector part 3 includes two pairs of arms 9, 1 1 which define, before crimping, two open U-sha'ped ferrules. As shown, the ferrules are crimped respectively to theconductive core 13 and outerinsulating sleeve 15 of thewire 5.

Atransition part 17 extends transversely from oneend 18 of theconnector part 3 and interconnects theconnector part 3 to oneedge 39 of abase member 25 of the contact part 7. v

The contact part 7 includes thebase member 25 which is of channel section and double thickness. Sides of the channel are extended at one end of thebase member 25 axially of the base member to define a pair of spaced, parallel,elongate contact arms 19, 21. Thearms 19, 21 are of double thickness and the thicknesses of each arm are interconnected at thefree end 10 of the arm remote from thebase member 25. The inner thickness of the double thickness of sheet material of eachcontact arm 19, 21 so formed, is separated from the corresponding outer thickness, adjacent thefree end 10 of the arm, to form aprotuberance 31, 33. The opposed faces of theprotuberances 31, 33 define contact surfaces for resiliently contacting the opposite surfaces of a printed circuit board when positioned between thearms 19, 21. The contact surfaces are embossed as indicated at 35.

Thetransition portion 17 is connected to theedge 39 of thebase member 25 and aresilient locking lance 32 extends from the opposite edge 41 of thebase member 25 and, as shown in FIG. 2, is folded over on itself to extend upwardly between thearms 19, 21 generally towards theconnector part 3 of the terminal 1.

The arms contact 19, 21 taper from a wider end adjacent thebase member 25 to their narrower free ends Referring now to FIGS. 3, 4 and 5 a plurality of terminals 1 areassembled in aninsulated housing 51. Thehousing 51 is generally L-shaped in transversev crosssection. Each terminal 1 is received in apassageway 53 separated fromadjacentpassageways 53 byside walls 55. Eachpassageway 53 has afirst portion 57 in which the contact part 7 of the terminal 1 is received and asecond portion 59 in which theconnector part 3 is received. Theportion 59 has its lower (as seen in FIG. 5) side open in order that a terminal 1 can be assembled in itsrespective passageway 53. Thefirst portion 57 has apart 63 of reduced cross-section which engages the contact part 7 adjacent thebase member 25 to minimise movement of the terminal 1 in the passageway should a force be applied to awire 5 in the direction of arrow N, and apart 65 of greater cross-section adjacent thearms 19, 21 which permits flexure of the arms. Thearms 19, 21 extend on opposite sides of aslot 64 formed in theside walls 55 for receiving a printed circuit board.

On therear surface 50 of thehousing 51, adjacent each end, there is arranged a pair of spaced,parallel rails 81, 83 generally of a hook-shape in transverse cross-section. Intermediate therails 81, 83 is positioned aresilient arm 85 which is connected to thehousing 51 adjacent the upper side of the housing. Theresilient arm 85 depends downwardly from the upper side and carries aproturberance 87.

As shown in the FIGS. 4 and 5, a printedcircuit board 70 shown in ghosted lines, is mounted on asupport plate 71. Thesupport plate 71 is formed with are cess 73 having two spacedparallel hooks 75, 77 and anindentation 79 arranged centrally of thehooks 75, 77.

When the edge connector is assembled to thesupport plate 71, therails 81, 83 of thehousing 51 engage under thehooks 75, 77 in therecess 73 of thesupport plate 71 so that any pull on a wire in the direction of arrow P will be transmitted to thesupport plate 71 and will not be transmitted to the printedcircuit board 70. Further, theprotuberance 87 resiliently engages in theindentation 79 to lock thehousing 51 against vertical movement as seen in the Figures, relative to thesupport plate 71. An arcuate recess (not shown) is formed in thesupport plate 71 which permits the flexible arm to be depressed when it is required to remove thehousing 51 from thesupport plate 71.

We claim:

1. A unitary electrical terminal made fromsheet material for a printed circuit board edge connector, comprising a contact part including a base member of channel section and double thickness, each sideof the'channel being extended at one end of the base member-in a direction parallel to the line of intersection of the side with the bottom of the channel to define a pair of resilient parallel spaced contact arms for receiving between them an edge of a printed circuit board, each contact arm being of double thickness, the thickness of each contact arm being integrally formed at the free end of the contact arm remote from the base member and being in touching relation throughout the major portion of said contact arms, and an integral ferrule portion of single thickness and connected by a transition part to an edge of the base member and of the contact part.

2. An electrical terminal as claimed in claim 1 in which the inner thickness of the double thickness of sheet material of each contact arm is separated from the complementary outer thickness adjacent the free end only to form a protuberance, the inner surfaces of the protuberances defining contact surfaces for electrical engagement with conductors of a printed circuit board when placed between the contact arms.

Claims (2)

1. A unitary electrical terminal made from sheet material for a printed circuit board edge connector, comprising a contact part including a base member of channel section and double thickness, each side of the channel being extended at one end of the base member in a direction parallel to the line of intersection of the side with the bottom of the channel to define a pair of resilient parallel spaced contact arms for receiving between them an edge of a printed circuit board, each contact arm being of double thickness, the thickness of each contact arm being integrally formed at the free end of the contact arm remote from the base member and being in touching relation throughout the major portion of said contact arms, and an integral ferrule portion of single thickness and connected by a transition part to an edge of the base member and of the contact part.

2. An electrical terminal as claimed in claim 1 in which the inner thickness of the double thickness of sheet material of each contact arm is separated from the complementary outer thickness adjacent the free end only to form a protuberance, the inner surfaces of the protuberances defining contact surfaces for electrical engagement with conductors of a printed circuit board when placed between the contact arms.

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