US 3487355 A
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Description (OCR text may contain errors)
Dec. 30, 1969 T. M. CAIRNS ELECTRICAL CONNECTOR Filed Dec. 22, 1967 THOMAS M C A/RNS INVENTOR mg 1%" ATTORNEYS United States Patent US. Cl. 339176 3 Claims ABSTRACT OF THE DISCLOSURE An electrical connector is formed by inserting a terminal of electrically conductive material into a terminal block of electrically nonconductive material. The terminal is cylindrical in form and has an annular recess about the circumference thereof. The terminal block has both an aperture therein for receiving the terminal and an opening therein which intersects a portion of the aperture. The cylindrical terminal is inserted in the aperture of the block until a portion of the annular recess thereof is aligned with the opening intersecting the aperture. A locking member is inserted in the opening and a portion thereof projects into the intersected part of the terminal receiving aperture to enter the annular recess of the terminal and thereby secure the terminal to the block.
BACKGROUND OF THE INVENTION Electrical connectors are formed by inserting a terminal or plurality of terminals of electrically conductive material into a terminal block of nonconductive material.
Many different types of connectors are available for utilization in constructing electrical circuit packages in which interconnection of various electrical components is necessary. Most of todays electrical connectors require that for assembly of the terminal and the terminal block, the terminal must be aligned in an exact position with respect to a terminal receiving aperture of the block. If the terminal is not accurately aligned with the aperture, the terminal, the block or either of them may be damaged or broken when the terminal is inserted. The pre-alignment of the terminal and its receiving aperture in the block is, of course, an expensive operation in that either sophisticated mechanical handling apparatus or human operators are necessary to align the terminal and aperture prior to terminal insertion.
Another problem encountered with the electrical connectors constructed in accordance with present day teachings is that the terminals, once inserted in a terminal block, tend to become dislodged. Thereafter, the connectors do not function properly when they are assembled with other connectors. The dislodgement of such terminals also causes malfunctions and shorting of the electrical equipment interconnected by the terminals.
The electrical connector of this invention is so designed that the insertion of the terminals into the terminal block can be accomplished without prior orientation of the terminals and the block. The connector of this invention has the terminals thereof secured to the terminal block in such a manner that they do not become dislodged after assembly. The electrical connector of this invention is, therefore, more economical to fabricate and more reliable in operation.
SUMMARY OF THE INVENTION This invention is directed to an electrical connector and, more particularly, the invention is directed to the construction of an electrical connector in which a terminal of electrically conductive material may be easily inserted into a terminal block of nonconductive material and subsequently secured thereto.
The connector of this invention is formed by inserting a terminal of electrically conductive material into a terminal receiving aperture formed in a terminal block of electrically nonconductive material. The terminal is formed so as to have at least a first cylindrical surface area of a first diameter and another cylindrical surface area concentric with the first surface area and of smaller diameter than the first diameter. The surface area of smaller diameter forms a depressed portion of the terminal having the shape of an annular recess about the circumference of the terminal.
The terminal block is formed so as to have both an aperture therein for receiving the cylindrical terminal and an opening therein, in part, intersecting the terminal receiving aperture along a portion of the length of the aperture. A locking member is receivable in the opening of the terminal block and the locking member has a portion thereof which projects within the terminal receiving aperture of the block at the area of intersection of the aperture and opening.
When a terminal is positioned within the terminal receiving aperture with a portion of the annular recess thereof aligned with the portion of the opening intersecting the aperture, the locking member may inserted in the opening. The portion of the locking member which pro? jects within the terminal receiving aperture enters the aligned annular recess of the terminal and locks the terminal to the block.
Since the depressed portion of the cylindrical terminal forms an annular recess about the entire circumference of the terminal, the terminal may be received in the terminal receiving aperture of the terminal block and a portion of the annular recess will always be aligned with the opening intersecting the aperture. The locking of the terminal to the block by the locking member which projects Within the annular recess insures that the terminal will not become dislodged with respect to the block during subsequent utilization or handling of the connector.
BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is an elevational view which shows an electrical connector constructed in accordance with the teachings of this invention. FIGURE 2 is a plan view taken along line 22 of FIGURE 1 which shows both the electrical connector of 'FIGURE 1 and, in shadow, a cooperating electrical connector also formed in accordance with the teachings of this invention. FIGURE 3 is an elevational View, in cross section, taken along line 33 of FIGURE 2 which shows the manner in which the terminals are secured to the terminal block by the locking member. FIGURE 4 is an isometric view which shows electrical terminals formed in accordance with the teachings of this invention. FIGURE 5 is a view similar to FIGURE 3 but which shows another embodiment of an electrical connector formed in accordance with the teachings of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT Construction In FIGURE 1 there is shown an electrical connector constructed in accordance with the teachings of this invention and generally identified by the numeral 10. As best seen in FIGURE 2, the connector 10 has a plurality of terminals, generally identified by the numeral 12, the terminals being formed of electrically conductive material such as beryllium copper. Each of the terminals 12 is received in a terminal receiving aperture 14 formed in a terminal block 16. The terminal block 16 is constructed from a nonconductive material, such as a plastic, and may be formed in a molding operation.
The electrical terminals 12 are best shown in FIGURE 4 wherein both a male terminal and a female terminal are shown. The terminals are formed so as to have a first cylindrical surface area 18 of a first diameter and a second cylindrical surface area 20 of a diameter approximating the diameter of the first cylindrical surface area. Intermediate and inteconnecting the first cylindrical surface area 18 and the second cylindrical surface area 20 is a portion of the terminal which defines an annular recess 22 about the circumference of the terminal 12. The depressed metal 23, forming the bottom of the annular recess 22, has a circular cross section of a diameter smaller than the diameter of the first cylindrical surface area 18.
The annular recess 22 of the terminal 12 may be formed by machining out the recess in an otherwise solid, cylindrical terminal. On the other hand, the recess 22 may be formed by rolling the recess into a thin wall tubular member so as to form the female terminal and by rolling in the recess 22 and a nose 24 to form the male terminal. The terminals 12 are connected by connector strips 26 to beaded strands of electrical conductors 28, best seen in FIGURE 2. The annular recess 22 may be formed in the terminals 12 by many other ways known to those skilled in the terminal forming art.
The terminal block 16, shown in elevational view in FIGURE 1, has a plurality of already described terminal receiving apertures 14 therein. The terminal receiving apertures, in the connector of the preferred embodiment, are of circular cross section with a diameter slightly larger than the diameter of the first and the second cylindrical surface areas 18 and 20' of the electrical terminal 12. As seen best in FIGURE 1, the plurality of terminal receiving apertures 14 are in a vertically stacked arrangement having two rows with equal spacing bet-ween the centers of each of the apertures in each of the two rows.
In the central portion of the terminal block 16, as viewed in the plan view of FIGURE 2, an opening 30 is provided along the full vertical dimension of the block. The opening 30 also has a guideway 32. As best seen in FIGURE 3, the opening 30- of the terminal block 16 intersects, in part, a portion of each of the terminal receiving apertures 14. More particularly, as viewed in FIGURE 3, the opening 30 intersects the right side of the apertures 14 in the left row and the left side of the apertures in the right row.
A locking member, generally designated by the numeral 34, is received in the opening 30. A guide 36 formed on the locking member 34 is received in the guideway 32 of the opening 30 so as to guide the locking member as it moves along the length of the opening after insertion therein. The locking member 34 has formed integrally therewith projecting portions 38, best seen in FIGURE 2, which extend into the various terminal receiving apertures 14 of the terminal block 16.
In its preferred embodiment, each of the plurality of terminal receiving apertures 14 formed in the terminal block 16 has an annular ridge 40 projecting into each of the apertures at the front thereof (FIGURE 1). The purpose of these ridges is to locate each of the terminals 12 within its particular terminal receiving aperture 14.
Assembly and operation The electrical connector 10, in accordance with the teachings of this invention, is assembled in the following manner. With reference to FIGURE 2, a terminal 12 is inserted in each of the terminal receiving apertures 14 of the terminal block 16. Since each of the terminals 12 are cylindrical and since each of the annular recesses 22 thereof or also cylindrical, each of the terminals 12 may be inserted in the terminal block without any prepositioning of the terminal at a prescribed angular attitude with respect to the block. It should be understood that the terminal receiving aperture 14 may be of anyearn figuration which permits the free insertion of the cylindrical terminals 12 without prepositioning of the terminals.
Each of the terminals 12 is inserted into its associated aperture 14 until the front of the terminal engages the annular ridge 40 of the receiving aperture. At this particular position, the terminal is at its fully inserted position and a portion of the annular recess 22 thereof is aligned with a portion of the opening 30 which intersects the specific terminal receiving aperture 14. Since the terminal has an annular recess about its entire circumference, the terminal may be in any position within the terminal receiving aperture and still have a portion of its recess aligned with the opening 30.
After the terminal has been properly positioned, other terminals may be inserted in selected apertures of the terminal block so as to complete the assembly of the connector. Once the desired number of terminals 12 or inserted in the block 16, the locking member 34- is placed in the opening 30 of the terminal block 16 with a guide 36 thereof entering the guideway 32 so as to locate the locking member in its travel along the opening 30. As the locking member is inserted and moved along the opening 30, the projecting portions 38 on each side of the looking member associated with the two rows of terminals, enter the associated terminal receiving apertures and the annular recesses 22 of the terminals located in the block. When the locking member is moved to its fully inserted position, the projecting portions 38 thereof secure all of the inserted terminals 12 to the block because the various portions of the projecting portions are received in respective ones of the annular recesses 22 between two areas 18 and 20 of greater diameter. Thus, the terminal is locked in the block from lateral movement although the terminal may be freely rotated if that is desired. Such a mounting of the terminal substantially reduces the possibility of dislodging the terminal during use or handling of the connector.
While the specific description above was addressed to an electrical connector wherein a plurality of female terminals were arranged in a vertically stacked array, it
should also be obvious that a plurality of male terminals,
such as shown in FIGURE 2, may also likewise be locked in a male terminal block 42. The terminal block 42 is made so that the terminal receiving apertures 44 thereof are of a size sufficient to confine the male terminals 12 received therein.
Alternate form In FIGURE 5 an alternate form of an electrical connector formed in accordance with the teachings of this invention is shown. In this particular form of the electrical connector 110, a pair of locking members 134 and 136 are utilized to lock a plurality of terminals 112 in three vertical rows. The locking member 134 is received in an opening and the locking member 136 is received in an opening 132. The locking member 134 is sufiiciently large such as described for the first form of the connector to lock two vertical rows of terminals 112 in position within the terminal block 116. However, the locking member 136 is smaller than the member 134 and is designed to lock only one row of electrical terminals 112 in position.
There has been described herein an electrical connector in which a terminal of electrically conductive material is inserted within a nonconductive terminal block and secured thereto without the necessity of orienting the terminal with respect to the terminal block before insertion. Once inserted, the terminal is secured to the block easily and quickly and the terminal is precisely located with respect to the block.
Many modifications of the electrical connector of this invention will be apparent to one skilled in the art in view of the teachings of this specification. It is intended that all modifications which fall within the true spirit and scope of this invention be included within the terms of the appended claims.
What is claimed is:
1. An electrical connector which comprises:
a plurality of cylindrical, electrical terminals, each of said terminals being formed both so as to be of generally fixed diameter and so as to have an annular recess therein about the circumference of said terminal, said annular recess being located intermediate areas of said terminal of fixed diameter;
a terminal block of electrically nonconductive material formed so as to have a plurality of circular, terminal receiving apertures aligned in two rows with a uniform distance between said rows, each of said apertures for receiving an individual one of said plurality of cylindrical terminals;
an opening in said terminal block along the length of adjacent sides of said two rows of terminal receiving apertures, said opening in part, intersecting a portion of each of said plurality of terminal receiving apertures at a location which is adjacent said annular recess of said terminal when said terminal is inserted in each of said apertures; and
a locking member movable along said opening of said terminal block, said locking member having project ing portions thereon for locking said terminals to said block, said projecting portions being located on opposite sides of said locking member associated with said rows of said terminal receiving apertures.
2. An electrical connector as defined in claim 1 wherein a plurality of terminal receiving apertures are aligned in a plurality of rows; wherein a plurality of openings are provided in said terminal block rather than said single opening; wherein said plurality of openings intersecting, at least in part, portions of different ones of said plurality of terminal receiving apertures at locations which are adjacent said annular recesses of said terminals when said terminals are inserted in each of said apertures; and wherein a plurality of locking members are provided, each of said locking members being formed so as to be receivable in an associated one of said openings, each of said locking members also being formed with projecting portions thereonwhich enter the-terminal receiving apertures associated with an individual one of said openings to secure said terminals inserted in said apertures to said block.
3. The electrical connector as defined in claim 1 fur ther comprising:
means for locating said plurality of electrical terminals within individual ones of said plurality of terminal receiving apertures in such relative positions that said annular recess of each of said terminals is aligned with that portion of said opening from which said projecting portion of said locking member will extend into said terminal receiving aperture to lock said terminal to said block.
References Cited UNITED STATES PATENTS 25 2,964,725 12/1960 Lehr et al.
FOREIGN PATENTS 2/ 1941 Great Britain. 7/1963 Great Britain.
KENNETH DOWNEY, Primary Examiner