US3246284A

US3246284A - Electrical connector

Info

Publication number: US3246284A
Application number: US269905A
Authority: US
Inventors: Glenn S Farison
Original assignee: Chrysler Corp
Current assignee: Old Carco LLC
Priority date: 1963-04-02
Filing date: 1963-04-02
Publication date: 1966-04-12
Anticipated expiration: 1983-04-12
Also published as: GB1024938A

Description

April 12, 1966 e. s. FARISON 3,246,284

ELECTRICAL CONNECTOR Filed April 2, 1963 2 Sheets-Sheet 1 INVENTOR. 51 7777 6 )Zrzxa 71.

A ril 12, 1966 s. s. FARISON 3, 8

ELECTRICAL CONNECTOR Filed April 2, 1963 2 Sheets-Sheet 2 INVENTOR. 6/9777? 6', i'krzzs'aw /W M11 HM United States Patent 3,246,284 ELECTRICAL CONNECTOR Glenn S. Farison, Southfield, Mich, assignor to Chrysler Corporation, Highland Park, Mich, a corporation of Delaware Filed Apr. 2, 1963, Ser. No. 269,905 4 Claims. (Cl. 339-223) This invention relates generally to detachable electrical connectors and more particularly to a detachable electrical terminal particularly suited for connecting an ignition cable to a spark plug of an internal combustion engine.

In the past, various designs of ignition cable terminals have been employed many of which were formed from flat metal blanks to provide, at one end thereof, a connecting portion of generally hollow cylindrical shape for circumferentially engaging the terminal of a spark plug. A generally axially extending slot, resulting from the forming operation of the connecting portion, provided a means whereby some resiliency could be experienced in the connecting portion for purposes of either connecting or disengaging the cable terminal from the spark plug terminal.

Such resilient connecting portions have not been entirely satisfactory because the tendency is to bend and permanently distort the connecting portion especially during disengagement of the cable terminal from the spark plug terminal.

Accordingly, it is an object of this invention to provide a detachable electrical terminal having a relatively resilient connecting portion and means for preventing the resilient connecting portion from becoming permanently distorted.

Another object of this invention is to provide, in a detach'able electrical terminal, a relatively resilient connecting portion formed to provide means for prevent-ing permanent distortion thereof and means for urging the connecting portion generally radially inwardly.

Other objects and advantages of this invention will become apparent when reference is made to the following description taken in conjunction with the drawings wherein:

FIGURE 1 is a plan view of a partially formed blank used in forming a detachable electrical connector according to the invention;

FIGURE 2 is a cross-sectional view taken substantially on the plane of line 2-2 of FIGURE 1 and looking in the direction of the arrows;

FIGURE 3 is a side elevational view of the detachable connector with portions thereof broken away and in cross-section showing a spark plug terminal received therein;

FIGURE 4 is an end view of the ignition cable-receiving portion of the connector shown in FIGURE 3;

FIGURE 5 is an end view of the connector taken substantially on the plane of line 5-5 of FIGURE 3, with the spark plug removed, and looking in the direction of the arrows;

FIGURE 6 is a side elevational view of a spring clip employed in conjunction with a modified form of the invention;

FIGURE 7 is a fragmentary end elevational view of the spring clip of FIGURE 6 taken generally in the direction of the arrow in FIGURE 6;

FIGURE 8 is a fragmentary cross-sectional view taken on the line 88 of FIGURE 5, looking in the direction of the arrows, illustrating the cooperative action between the spark plug terminal, detachable connector and the spring clip in the modified form of the invention; and

FIGURES 9, 10, 11 and 12 are views similar to FIG-

URES

1, 3, 5 and 8, respectively, illustrating another form of the invention.

Referring now in greater detail to the drawings, FIG- URE 1 illustrates a partially formed terminal or connector blank 10 which is subsequently formed to assume the configuration generally shown by FIGURES 3, 4 and 5.

The blank 10 is formed of generally

rectangular body portions

12 and 14 which are connected to each other by means of an integrally formed medial bridge or connecting portion 16 of relatively reduced width. Body portion 14 is preferably formed to have transversely directed corrugations or convolutions 18 which are provided with a plurality of indentations 20, two of which are shown in FIGURE 2. Preferably, the indentations are formed in a plurality of substantially aligned rows but in staggered relationship as between successive rows.

Transverse ends

22 and 24 of body 12 are formed, as by notches or cut-out portions 26, to provide laterally extending and oppositely directed

projections

28, 30 and 32, 34, respectively. Projections 28 and 33 are then bent slightly downwardly from the plane of the blank 10 while

projections

32 and 34 are bent slightly upwardly. It is not absolutely necessary that the various projections be bent in precisely the direction stated. In fact, the respective directions'rnay be reversed depending on the subsequent sequence of operations to be performed on the blank 10 as will be apparent from the following description thereof.

Metal blank 10 is subsequently curled, generally about its longitudinal axis 36, until body portion 14 assumes a generally U-shape as illustrated by the end view thereof in FIGURE 4. Body portion 14 being thusly formed is suited for the later reception therein of one end of an ignition cable 38 shown in phantom lines in FIGURE 3. The upper ends 39 and 41 of the U-shaped body portion 14 are later curled inwardly toward each other, as illustrated generally in phantom lines in FIGURE 4, in order to contain the ignition cable 38 therein and establish electrical contact, for example, by means of internally engaging an overcurled extension 37 of the electrical conductor or conductors contained therein. Cable 38 will, of course, as illustrated in FIGURE 3, generally assume the form of the convolutions or corrugations 18.

Simultaneously with the forming of body 14 into a U-shape, the medial connection portion 16 and body portion 12 are also curled. The medial portion 16 is formed to assume a generally arcuate cross-section approaching a semi-circular configuration. Body portion 12, however, is spirally curled so as to form a generally cylindrical barrel or connecting portion 40 which is closely received about a spark plug terminal 42.

It is necessary to establish a particular relationship during the formation of the barrel. That is, the

transverse end portions

22 and 24 must be curled in a manner which will result in having the projections first described as being bent upwardly assume an uppermost position relative to those projections first described as being bent downwardly. Accordingly, with reference to the blank 10 illustrated in FIGURE 1, body portion 12 would be curled into a generally cylindrical form so as to have

projections

32, 34 and end portion 24 disposed above or on the outer arcuate surface of end portion 22 as shown in FIGURE 5.

The tabs or projections 28, 3t), 32 and 34 may be originally bent to assume a relationship different from that described. For example, tabs 28, 3t) and

tabs

32, 34 could all be downwardly bent from the plane of the blank.

Body. portion 12 could then be curled so as to have end 22 pass under end 24 and when

tabs

32 and 34 reached a position of general juxtaposition with the slots 26 of end 22,

tabs

32 and 34 could be bent inwardly generally toward the center of the curled body portion 12. By having all the tabs originally bent in the same direction, prior to curling, the actual curling operation may be simplified by eliminating possible interference between the tabs during the curling operation. Y

The maximum size of aperture 44, as defined gene-rally by the barrel-shaped body portion 12, is determined by the coaction of bent projections or

tabs

32, 28 and 30, 34. That is, as the barrel 40 is urged radially outwardly,

end portions

22 and 24 are moved relative to each other until

tabs

28 and 32 as well as

tabs

30 and 34 abut against each other to prevent further relative movement of

end portions

22 and 24.

Barrel 40 may be formed so as to have the cooperating tabs, such as 32 and 28, spaced from each other when the barrel is in its free state. In such an arrangement, the tabs could move towards each other whenever a spark plug terminal is inserted within the aperture 44 urging the barrel radially outwardly.

It should be noted that slots or cut-outs 26 not only serve to form the respective tabs but also provide a space for the reception therein of the several bent tabs when body portion 12 is curled to assume a generally cylindrical form as shown by FIGURE 5.

In view of the above, it can be seen that the provision of interlocking abutment tabs or projections will prevent an undue distortion of the barrel or connecting portion 40 whenever the cable terminal is frictionally disengaged from the spark plug terminal. It should be noted that 'no amount of angular movement or twisting during the disengagement operation will cause the aperture 44 or barrel 40 to become permanently distorted as occasioned with the prior art.

Another form of the invention contemplates the provision of an externally positioned arcuate spring member generally engaging the outer peripheral surface of barrel 40. In the modified form of the invention, body portion 12 of blank is provided with an aperture 46 for receiving therethrough the depression 48 of the spring clip 50 as illustrated in FIGURE 6 and fragmentarily in FIG URE 7.

FIGURE 5, having a fragmentary portion of the barrel 40 broken away, illustrates the manner of assembling the spring clip 50 to the barrel by means of causing projection or nib 48 to extend inwardly through the aperture 46.

FIGURE 8 illustrates in greater detail the engagement obtained as between the barrel 40, spring clip 50, projection or detent 48 and the spark plug terminal 42. Preferably, the detent 48 is of a width and depth sufficient to engage tapered surface 52 (which in cooperation with shoulder 56 generally defines an annular recess) of termi nal 42 in order-to firmly and yet resiliently engage the terminal and urge the barrel 40 toward the shoulder 54 of the spark plug. In order to affect disengagement, the cable terminal need only be pulled so as to cause the detent 48 to be urged radially outwardly over the extreme diameter of the spark plug terminal. Aperture 46 is of a width which closely receives the detent 48 so as to substantially minimize any axial movement of the detent 48 and clip 50 relative to the aperture 46 and barrel 40.

The embodiment as shown in FIGURE 8, of course, retains all the advantages of the cable terminal of FIGURE 4 without the provision of an external spring clip 50. However, the structure of FIGURE 8 contains additional advantages as, for example, being able to provide a member (spring clip 50) for creating a strong locking force between the barrel 40 and the spark plug terminal and yet preventing the application of excessive forces thereto during disengagement because of the confining effect of the barrel 40 and interlocking projections or

tabs

32, 28 and 30, 34.

FIGURES 9 through 12 illustrate still another form of i the invention. All elements which are like or similar to those of FIGURES 1-8 are identified with like reference numerals.

Body portion 12 of blank 58 is provided with preferably two dimple-

like portions

60 and 62 raised from the surface thereof. Blank 58 and

tabs

28, 30, 32 and 34 are bent and formed similarly to blank 10 in order to assume spark 4 plug electrode-receiving barrel 40 as fragmentarily illustrated in FIGURE 10.

FIGURE 11, an end view of the barrel 40, illustrates the inwardly directed dimples or

detents

60 and 62 as being located generally on opposite sides of a vertical plane passing through the longitudinal axis of the barrel 49. The relationship of the various elements shown in FIGURE 11 is substantially that achieved when barrel 40 is properly engaged or seated onto terminal 42 of the spark plug. At this time, the cooperating tabs, such as 28 and 32, are spaced from each other a distance X, which allows for radial expansion of the aperture 44 and relative movement of

end portions

22 and 24, as caused by

detents

60 and 62 engaging the enlarged diameter of the spark plug terminal, during the process of engaging or disengaging the detachable connector from the spark plug. The cooperating tabs do, however, abut against each other in order to permit only that expansion of barrel 40 necessary for engagement or disengagement and to prevent undue forces on the barrel which might cause permanent distortion thereof.

FIGURE 12, a fragmentary cross-sectional view taken on line 1212 of FIGURE 11, better illustrates the interlocking relationship of the

detents

60 and 62 with the annular recess 64 of spark plug terminal 42.

Although but threeforms of the invention have been disclosed and described, it is apparent that other embodiments and modifications of the invention are possible within the scope of the appended claims.

I claim:

1. A detachable electrical connector for forming an electrical connection between an ignition cable and a spark plug terminal, comprising a generally U-shaped body portion adapted to be formed about said ignition cable in order to securely engage said cable, a spirally curled body portion having overlapping ends forming a terminal-receiving opening, a connecting portion of arouate cross-section joining said curled body portion to said U-shaped body portion, a plurality of cut-out portions formed on said curled body portion near said ends, and a plurality of tabs formed on said curled body portion near said ends, said tabs formed on the radially outermost overlapping end being bent through certain of said cut-out openings in a direction generally toward said terminal receiving opening, said tabs formed on the radially innermost overlapping end being bent through other of said cut-out openings in a direction generally away from said terminal-receiving opening.

2. A detachable electrical connector for forming an electrical connection between an ignition cable and a spark plug terminal, comprising a first body portion adapted to be formed about said ignition cable so as to be securely engaged thereto, a second body portion curled so as to have overlapping ends forming a terminal-receiving opening, a connecting portion joining said body portions to each other, and a plurality of tabs formed on said second body portion near said ends, said tabs formed on the radially outermost overlapping end being bent in a direction generally toward the center of said terminal- -receiving opening, said tabs formed on the radially innermost overlapping end being bent in a direction generally away from said terminal-receiving opening, said tabs by virtue of their respective directions of bend being in position to abut against each other.

3. A detachable electrical connector for forming an electrical connection between an ignition cable and a spark plug terminal, comprising a first body portion adapted to be formed about said ignition cable in order to securely engage said cable, a spirally curled body portion having overlapping ends forming a terminal-receiving opening, a connecting portion joining said curled body portion to said first body portion, a plurality of cut-out portions formed on said curled body portion near said ends, and a plurality of tabs formed on said curled body portion near said ends, said tabs formed on the radially outermost overlapping end being bent through certain of said cut-out portions in a direction generally toward said terminal-receiving opening, said tabs formed on the radially innermost overlapping end being bent through other of said cut-out portions in a direction generally away from said terminal-receiving opening.

4. A detachable electrical connector for forming an electrical connection between an electrically conductive cable and a terminal of an electrode, comprising a first body portion adapted to be formed about said cable in order to be securely engaged thereto, a second body portion spaced from and connected to said first body portion, said second body portion having oppositely disposed end portions curled in order to form a generally cylindrical barrel with a terminal-receiving opening therein adapted for detachable connection to said electrode terminal, each of said end portions having first and second axial ends, and positive abutment means formed integrally with each of said axial ends, said abutment means comprising a generally axially extending tab member formed on each axial end of each end portion, at least 20 two of said tab members being bent so as to be generally inclined with respect to the axis of said terminalreceiving opening in order to respectively abut against the other of said tab members thereby preventing an undue enlargement of the di-ametrical size of said terminalreceiving opening whenever said cylindrical barrel is either being connected to or disconnected from said terminal.

References Cited by the Examiner UNITED STATES PATENTS 906,806 12/1908 Kortick et al. 1,566,465 12/1925 Champion 339-223 2,711,524 6/1955 Beaver 339256 2,715,215 8/1955 Flora 339258 X 3,141,724 7/1964 Raymond 339 256 FOREIGN PATENTS 604,880 7/1948 Great Britain.

JOSEPH D. SEERS, Primary Examiner.

PATRICK A. CLIFFORD, Examiner.

Claims

1. A DETACHABLE ELECTRICAL CONNECTOR FOR FORMING AN ELECTRICAL CONNECTION BETWEEN AN IGNITION CABLE AND A SPARK PLUG TERMINAL, COMPRISING A GENERALLY U-SHAPED BODY PORTION ADAPTED TO BE FORMED ABOUT SAID IGNITION CABLE IN ORDER TO SECURELY ENGAGE SAID CABLE, A SPIRALLY CURLED BODY PORTION HAVING OVERLAPPING ENDS FORMING A TERMINAL-RECEIVING OPENING, A CONNECTING PORTION OF ARCUATE CROSS-SECTION JOINING SAID CURLED BODY PORTION TO SAID U-SHAPED BODY PORTION, A PLURALITY OF CUT-OUT PORTIONS FORMED ON SAID CURLED BODY PORTION NEAR SAID ENDS, AND A PLURALITY OF TABS FORMED ON SAID CURLED BODY PORTION NEAR SAID ENDS, SAID TABS FORMED ON THE RADIALLY OUTERMOST OVERLAPPING END BEING BENT THROUGH CERTAIN OF SAID CUT-OUT OPENINGS IN A DIRECTION GENERALLY TOWARD SAID TERMINALRECEIVING OPENING, SAID TABS FORMED ON THE RADIALLY INNERMOST OVERLAPPING END BEING BENT THROUGH OTHER OF SAID CUT-OUT OPENINGS IN A DIRECTION GENERALLY AWAY FROM SAID TERMINAL-RECEIVING OPENING.