US 3097906 A
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Description (OCR text may contain errors)
July 16, 1963 s. G. SHANNON 3,097,906
ELECTRICAL CONNECTOR Filed May 26. 1960 INVENTOR. uel 6. Shannon United States Patent 3,097,906 ELECTRICAL CONNECTOR Suel G. Shannon, Harrisburg, Pa., assignor to Incorporated, Harrisburg, Pa. Filed May 26, 1960, Ser. No. 31,981 3 Claims. (Cl. 339253) In the art of making electrical connectors which may be disconnected and reconnected at will, it is highly desirable to maintain a high degree of interfacial contact between the current-carrying interfaces of the connectors. It is an object of this invention to provide such a connector whereby intimate face-to-face contact is achieved with a fairly low assembly force. This is especially valuable in multiple connectors wherein the assembly force of the units is a function of the number of connections.
It is also an object of this invention to provide such a disconnect" type electrical connection wherein the mating portions fit together in such a manner as to provide a large surface of contact area. It is also an object of this invention to provide such a connection wherein there is a high degree of residual pressure holding said elements together when the said connection is made. It is an object of this invention to provide such a connection whereby high tensile strength is achieved with a relatively low insertion force.
It is also an object of this invention to provide such a disconnect wherein the mating portions may be either aligned longitudinally of the conductors or at a right angle thereto so that it becomes a flag type connection without changing the structure of the connector.
It is a further object of this invention to provide a disconnect of the type described herein, whereby the receptacle may be formed of a piece of fiat stock wtih a portion folded over to form the. receptacle and a locking means between the folded-over portions and the opposed surface to restrict the opening between the surfaces.
Other objects and attainments of the present invention will become apparent'to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.
In the drawings:
FIGURE 1 illustrates a strip of flat metal stock, stamped to form a connector embodying the principles of this invention;
FIGURE 2 is a view similar to FIGURE 1 after the connector has been formed;
FIGURE 3 is a perspective view of the connector shown in FIGURE 2, and a partial fragmentary view of a tab adapted to be inserted therein;
FIGURE 4 is an enlarged cross-sectional view of the connector of FIGURE 3 interlocked and disposed in a housing;
FIGURES 5 and 6 are partially cut-away views showing two positions of the tab in relation to the receptacle; and
FIGURE 7 is another embodiment of a connector made according to this invention.
The connector comprises a tab T and a receptacle R (FIGURE 3). The receptacle, generally illustrated in the drawings, may be stamped from sheet metal (FIG- URE 1). A carrier strip 10 links a plurality of receptacle members together in strip form. The receptacle includes two pairs of ears 12 and 14. The ears 12 are adapted to receive the insulation on a conductor C to secure the receptacle to the insulation. The cars 14 are also formed in the shape of a U (FIGURE 2) and may be crimped to the uninsulated end of the connector C (FIGURE 3) to make an electrical cont-act therewith.
Again referring to FIGURE 1, the blade portions 16, 16 of the sheet-metal stamping has an opening 18 in the middle of the blade, which opening is generally shaped in the outline of a bow tie. This opening forms the axis of the fold in forming the receptacle. Another opening 20 is disposed in the blade near the fernule-gripping member 14. The free end of the blade has a projecting tab 22 which cooperates with the opening 20 when the blade is folded to form the receptacle. The tab locks the re ceptacle in folded position.
In forming the receptacle, the cars 12 and 14 are bent upwardly to form U-shaped members as previously described. The blade 16 is folded back on itself along the mid-section line of the opening 18. The tab 22 is bent down through the receptacle of the opening 20 and curled to form a locking member 19". This construction holds the upper part of the blade 16 with relationship to the lower part of the blade 16' so that the members cannot be opened more than a predetermined amount, governed by the thickness of the tab T. As shown in FIG- URE 4, any attempt to spring open the blades is resisted by the locking member 19.
The free ends of the blade 16' are formed into an inclined plane (FIGURE 3) so that a pair of prongs 24 and 26 are formed thereon. As shown in FIGURE 4, these cars permit the receptacle to be inserted into a block B. Because of the resilience of the upper blade portion 16, it tends to pivot about points 17, 17 which permits it to spring past a shoulder 30 in the block and prevents retraction of the receptacle from the block. With the tab in position between the blades, the receptacle is locked against extraction. The prongs 24, 26 are relatively short and stiff, and thus prevent release of the receptacle with the tab in place.
The blade portions 16 and 16' are slightly bowed so that they form large radii arcs in concave-concave relationship.
-As shown in FIGURES 5 and 6, a pair of dimples 32 and 34 may be indented into the receptacle so that they will locate the tab centrally of the receptacle and prevent relative lateral motion between the tab and receptacle after the connection is made. Also as shown in FIG- URES 5 and 6, the portions 15, 15' of the blades adjacent to the opening 18 are disposed at an angle to the longitudinal axis of the receptacle. This relationship not only provides a tapered lead-in for the path of the tab during insertion but also provides a strengthening of the receptacle so that it resists being accidentally deformed by careless usage. This protects the critical spacing of the blades by comprising a strengthening rib which resists pressure at right angles to the blades. The lips 38 and 40' adjacent the opening 18 are slightly bellmouthed to improve the ease of insertion of the tab into the receptacle. Also, these lips limit insertion of the receptacle into the block.
When it is desired to make an electrical connection, the cars 14 are crimped onto the wire and the cars 12 are crimped onto the insulation covering the connector. The receptacle R is insereted into the block B and the resilience of the upper blade 16 permits the receptacle to slide past the shoulder 30 in the block. The blade 16' then expands to cause the prongs 24, 26 to spring outwardly to lock the receptacle against retraction. A standard tab 40 with a locking detent 42 is inserted in the opposed block B. When it is desired to connect the male tab to the female receptacle, the blocks are brought together so that the tab 40 is guided into the double bell-mouthed opening 18 by the lips 38- and 40 in one direction and the ribs 15, 15' in the other direction. Also, the angle of the sides of the opening form a bell-mouth in the opposite direction so that the tab is more easily inserted. The tab is thus inserted between the blades 16 and 16', causing the tab 22 and the wings 24 and 26 to be spread and securely locking the receptacle in the housing against the shoulders. The locking member 22 acts as a stop so that the tab 40 can only be inserted at its proper distance into the receptacle. A large area of the faces of the tab makes face-to-face contact with the blades of the stamped pieces 16 and 16', thus providing excellent electrical contact with maximum contact surface area. Because of the resilience achieved by a large radius of curvature of the arcuate blades 16 and 16', a high connection strength between the tab and receptacle is achieved while reducing the force required to insert the tab into the receptacle. This greater resilience is caused by the use of the gently curved plates forming the arcuate section. The resultant is a smooth action insertion with no sliding edges or small pressure areas between the contact members.
As shown in FIGURE 5, the addition of the dimples 32 and 34 align the tab 40 centrally of the receptacle so that it is held at four points, each of the dimples, as well as the bent-up sides of the opening 18. FIGURE 6 illustrates how the same receptacle may be used as a flag type which will accommodate a tab coming in from the side without changing the construction of the receptacle. Again the dimples 32 and 34 align the tab 40 by cooperation with the sides of the opening 18 so that it is supported at four points.
The embodiment shown in FIGURE 7 is similar to the embodiment illustrated in FIGURE 3. The prongs 24, 26 are omitted and the blades 16, 16' are bellmouthed at 60, 60' to guide the tab into the receptacle when the connection is made from the side. The opposite edges could, of course, also form a bell-mouth to accommodate a tab from the opposite direction.
Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by Way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.
1. An electrical spring clip connector including a tabreceiving receptacle portion and a wire-attaching portion, said receptacle portion comprising an elongated strip of sheet metal folded back upon itself to define a bight and a pair of spring plates extending therefrom, said plates being smoothly curved over substantially their full length about axes of curvature parallel to the longitudinal axis of said bight, to present opposed convex contact surfaces, normally spaced near the mid-point of said length less than the thickness of a mating contact tab, and an integral locking member extending from the distal end of one plate and engaging the other plate to cooperate with said bight to restrain movement of the ends of said plates on insertion of the mating contact tab, the plates at said distal end being spatially disposed prior to insertion of the mating tab which, upon insertion, tends to flatten said plates against the resistance to separate of the ends thereof.
2. An electrical spring clip connector including a tabreceiving receptacle portion and a wire-attaching portion, said receptacle portion comprising an elongated strip of sheet metal folded back upon itself to define a bight and a pair of spring plates extending therefrom, said plates being smoothly curved over substantially their full length about axes of curvature parallel to the longitudinal axis of said bight to present opposed convex contact surfaces normally spaced near the mid-point of said length less than the thickness of a mating contact tab, a longitudinal slot in said bight for admitting and guiding the tab between said plates, the bight portions at the ends of said slot being deformed angularly inwardly of the bight to stiffen the bight and to present cam surfaces for guiding insertion of the tab, and an integral locking member extending from the distal end of one plate and engaging the other plate to cooperate with said bight to restrain movement of the ends of said plates on insertion of the mating contact tab.
3. An electrical connector according to claim 2 wherein said locking member comprises a tab traversing the plates centrally of the longitudinal axis of the receptacle portion in alignment with said slot to present a stop for the contact tab.
References Cited in the file of this patent UNITED STATES PATENTS 1,200,825 Fenety Oct. 10, 1916 1,496,759 Rohde June 3, 1924 1,635,256 Carter July 12, 19 27 2,024,814 Bell Dec. 17, 1935 2,617,847 C-ole Nov. 11, 1952 2,669,702 Klostermann Feb. 16, 1954 2,691,147 Sutton et a1. Oct. 5, 1954 2,938,190 Krehbiel May 24, 1960 FOREIGN PATENTS 508,679 Germany Sept. 30, 1930 402,474 Great Britain Dec. 7, 1933 640,432 Great Britain July 19, 1950 776,698 Great Britain June 12, 1957