US2682039A - Terminal adapter clip for spark plugs - Google Patents

Description

June 1954 5. A. TINNERMAN 2,68

TERMINAL ADAPTER CLIP FOR SPARK PLUGS Filed Feb. 7, 1952 INVENTOR 650965 4. 71/4/5044 BY %M ATTORNEY Patented June 22, 1954 TERMINAL ADAPTER CLIP FOR SPARK PLUGS George A. Tinnerman, Cleveland, Ohio, assignor to Tinnerman Product a corporation of Ohio s, Inc., Cleveland, Ohio,

Application February 7, 1952, Serial No. 270,406

2 Claims. 1 This invention relates in general to electrical terminal connections and Ideals, more particularly, with an improved construction of a terminal connector or adapter for'sparkplugs, and the like, in theform of a sheet metal clip that is equally eiiective in use as the usual solid metal terminal connector, and which is preferable in many instances in that it is considerably cheaper in' cost of 'manufacture and otherwise adapted to :provide a locked terminal connection which is not subject'to'loosening or removal under the most severe conditions I of vibration.

A primary object of the invention'is to'provide a sheet metal terminal connector or adapter in the form of'asplit tubularishell or sleeve which is resilient initself and carries resilient tongues for" engaging the usual threaded electrode or binding post'in'a spark'plug or other electrical device in 'a pronounced 'locking'action' provided by the combined resiliency of saidsplit tubular shell and said resilienttongues.

A further object of "the'invention is to provide a sheet metal terminal connector orsadapter of this character in which the extremities of said resilient tongues are forme'd'on a helix corresponding to the helix of the'thread on'theelectrode or binding'post for. uniform threaded engagement therewith in a resilient thread locking action supplied. primarily byth-e resiliency of the splittubular shell or sleeve.

Another object of' the invention'is'to provide such a sheet metaliterminal .clip or adapter in the form-of split tubular shell or sleeve which is adapted to-be received in an associated socket type terminal in a manner whereby said'socket compresses and contracts the clip to cause the tongues thereon to engage the electrode in a pronounced clinching or gripping action by which the terminal connector is retained in operative positiononthe electrode under an added thread locking action over and beyond the normal gripping action of the tongues-of-the clip.

An additional object of the invention is to provide a sheetmetal terminal clipor adapter embodying the foregoing features-of construction'an'd' which is readily; attached to the electrode of a spark plug,- or thelike, by a simple, eXpeditiouspush-on type of connection, and which will thereafter be retained in satisfactory electrical connection, notwithstanding the fact that the'vehiclemight be-subjected to excessive vibration during use. Additionally, the

invention contemplates such a terminal clip or adapter by means ofwhich any conductor may be readily removed, or any spark plug: may be readily replaced, without disturbing the connections of any of the other associated spark plugs.

Further objects and advantages, and other new and useful features in the construction, arrangement'and general combination of elements of the invention will be'readily apparent as the following description proceeds with reference'to the accompanying drawings, for purposes of illustration but not of limitation, in which like reference characters designate throughout, and in which:

Fig. 1 is a perspective viewshowing a portion of a spark plug havingits threaded electrode flted'witha sheet metal clip or adapter in accordance with the invention, and with the socket type terminalof an associated conductor in position to be attached thereto;

Fig. 2 is a view similar to Fig. 1 showing the socket type terminal in broken lines as attached to the sheet metal clip or adapter;

Fig. 3 is a sectional view on line 33 of'Fig. 2, looking in the directionof the arrows; and,

Fig. 4 shows, on a greatly'enlargecl scale, the formation of the sheet metal blank for providing a terminal clip or adapter in accordance with the invention.

Referring now, more particularly, to the drawings, there is illustrated in Figs. 1 and 2 the upper portion of a sparkplug P having a connecting stud or electrode I in the form of a threaded stem or binding post. The high tension wire or conductor C which is to be detachably connected to the electrode I of the spark plug P is provided with a terininal'comprising a tubular sheet metal portion 5 defining'a substantially rigid socket.

To connect the terminal 5 of the high tension conductor C to the spark plug P, the present invention contemplates the use of a sheet metal like parts clip or fastening device 19 which serves as an adapter that can be quickly attached to the projecting stud'or electrode I of the spark plug P in a substantially lockedconnection that is adapted to withstand any degree of vibration to C which the enginemaybe subjected'during use.

The socket type'terminal 5 on the conductor C is adapted for snap fastening engagement with theclip or adapter It, thus provided, in a manner whereby the conductor C may be readily connected to'or disconnected from the spark plug, desired, and in a minimum of time and effort. While in the present embodiment, the conductor terminal 5 is provided in the form of a tubular socket, the clip or adapter ID of the *"present invention isusable with equal efiectiveness in connection with the well known spadetype of terminal having the same general application and use.

It is usually preferable that the conductor terminal 5 be attachable to the clip or adapter H) in any position of application and otherwise capable of slight swiveling movement on the clip as connected to the spark plug P. To this end, the wall of the socket-type terminal 5 is provided with a depression 6 on its periphery which forms an annular detent within said terminal 5 adapted to snap onto the clip or adapter I!) in any position of application and in positive but removable engagement therewith.

The clip or adapter I is a highly simplified, relatively inexpensive form of sheet metal device which lends itself to economical quantity production in that it may be produced at relatively low cost from ordinary sheet metal strip stock with little loss or waste of material. Any suitable sheet metal strip material may be employed, preferably that of a spring metal nature such as spring steel which may be heat treated and tempered to provide the clips with the desired toughness and hardness.

The clip device I!) is provided in the general construction illustrated in Figs. 1 and 2 from a suitable sheet metal strip or blank, as shown on an enlarged scale in Fig. 4, which is adapted to be rolled into a split tubular shell or sleeve, or the like. The blank preferably is provided with a projection H on one lower corner which is adapted to lie in the area of a corresponding cutaway portion l2 on the other lower corner of the blank when rolled into a split tubular shell or sleeve in the completed form of the clip. The projection l2 serves to close the open end of the split 13 in the tubular shell in a manner to prevent nesting and tangling of the clips when shipped, stored or otherwise handled in quantities.

As best seen in Fig. 4, the lower portion of the blank is provided with a series of similar cutouts I5 defining a set of resilient tongues I6 which extend substantially in horizontal alignment and which are of gradually increasing height from left to right in Fig. 4. In the present example, the clip is provided with three equally spaced tongues I6 but the invention fully contemplates various similar clip constructions having any other suitable number of such tongues as may be necessary or desirable. The tongues l6 have their extremities curved to conform substantially to the root of the threaded stud or electrode l of the spark plug P and said curved extremities otherwise have a slight helical shape corresponding to the helix of the thread on said stud or electrode l. The extremities of the tongues l6, thus provided, are bent radially inwardly in position for threadedly engaging the threaded stud or electrode l in the manner of a nut, and inasmuch as said tongues are of progressively increasing height, said inwardly bent and curved extremities thereof are all disposed on a common helix corresponding to the helix of the thread on the threaded stud or electrode I for even and uniform threaded engagement therewith in the most efiective manner. The arrangement, otherwise, is such that the body of the clip Ill is supported by the tongues [6 on the threaded stud or electrode I of the spark plug P in a balanced construction and in uniformly spaced concentric relation to said threaded stud or electrode I.

The upper portion of the blank, Fig. 4, is suitably slotted to provide a series of similar spaced fingers l8 which are bent slightly outwardly to define shoulders l9 and then inwardly toward each other to form a generally ball-shaped head which is adapted to connect readily to either a spade type conductor terminal or a sleeve type conductor terminal 5 as shown in Fig. 1, for example. Preferably, the spring fingers l8 are provided as extensions of the imperforate areas between the cutouts l5 such that said fingers l8 are relatively rigidly supported at their junctions with the blank while otherwise extending free for maximum resiliency as necessary for an easy and quick snap fastening action with the conductor terminal 5 to be attached thereto. The arrangement, otherwise, is such that the sockettype conductor terminal 5 is adapted to slip over the ball-shaped head of the clip defined by the fingers l8 and to compress the split tubular body of the clip as said terminal 5 is advanced to fully connected position thereon where the annular detent 6 in said terminal 5 snaps into positive engagement with the shoulders IS on said fingers iii of the clip.

The completed clip or adapter H), thus provided, is easily and quickly applied to threaded engagement with the threaded stud or electrode l of the spark plug P to the fully assembled position shown in Fig. 1. This is accomplished either by rotating the clip such that the tongues l6 threadedly engage the threaded stud l in the manner of a nut, or, by pushing the clip onto said stud in a direct axial thrust in which the extremities of the tongues l6 ratchet over the thread convolutions on said stud l to the fully assembled position of the clip on said stud as seen in Fig. 1. In such fully assembled position, the extremities of said tongues 16, Fig. 3, seat in frictional and gripping relation with the thread convolution engaged thereby under continuously effective spring tension provided by the inherent resiliency of said tongue 16 and the resiliency provided by the split tubular body of the clip itself.

The resiliency in the body of the clip itself resides in the construction thereof in the form of a. split tubular shell or sleeve which is expansible and contractible. This is of special importance in that the body of the clip is thereby adapted to expand to permit the extremities of the tongues [6 to slip readily over the thread convolutions on the stud l to the fully assembled position of the clip on said stud I, as aforesaid. Thus, the major portion of the required yielding of said tongues It, as they ratchet over the thread convolutions on the stud I, takes place as a result of the expansion of the split body construction of the clip; and accordingly, by such split body construction of the clip, it is possible to provide said tongues H5 in a relatively stiff and exceptionally strong formation for engaging the stud l firmly and rigidly in the most effective manner.

Additionally, the expansible and contractible nature of the clip provided by the split tubular formation thereof makes possible a tenacious spring loaded engagement of the tongues 15 with the stud or electrode I when the associated conductor terminal 5 is telescoped onto the clip In, as illustrated in Fig. 2, thereby providing for a constant and positive contact between said clip In and the spark plug electrode 1. Thus, it will be understood that in Fig. 1, the clip to is shown as initially assembled on the stud or electrode I in which relation the split tubular body of the clip is slightly expanded such that the split l3 therein is widened and the tongues I6 grip the stud or electrode only under the inherent resiliency of said tongues I6 and the tension produced by the expanded clip body attempting to assume its normal untensioned condition.

When the conductor terminal 5, illustrated in broken lines in Fig. 2, is snapped onto the clip S9 to provide a completed connection, said terminal 5 acts in the manner of a socket receiving the spring fingers I8 and compressing the split tubular body of the clip such that the tongues I6 are forced inwardly into positive and constant gripping engagement with the stud or electrode I. Under this compressive force of the terminal connector 5, the split I3 in the clip, Fig. 2, is narrowed as the body of the clip contracts concentrically around the stud I and the tongues I6 become spring loaded in an added positive thread lock with said stud I, Fig. 3, considerably over and above the gripping action of said tongues I6 when the clip is initially assembled on the stud or electrode I as explained with reference to Fig. 1. The body of the clip II], in the compressed condition shown in Fig. 2, is necessarily relatively rigid and presents a substantially solid plug onto which the conductor terminal 5 is adapted to snap and be firmly and rigidly retained in connected relation with the spark plug P with little danger of distortion or mutilation of the clip II].

The engagement of the tongues I6 of the clip with the threaded stud or electrode I is such that the conductor terminal 5 may be easily and quickly disconnected from the clip Ill without removing the clip from assembled position on said threaded stud or electrode I. If desired, however, the clip IIJ may be readily separated from the threaded stud or electrode I simply by turning the clip in a counterclockwise direction in the manner of a nut, as necessary to remove the tongues I E of the clip from threaded engagement with the thread on the stud or electrode I.

The clip or adapter I0 preferably is constructed of relatively thin sheet metal the thickness of which is selected according to service requirements and the predetermined size of the terminals to be connected thereby. The clip is most effective when provided of spring metal suitably tempered and otherwise treated to give the desired toughness and hardness. A relatively cheap construction of the clip in accordance with the invention may be provided from cold rolled metal such as cold rolled steel which is untempered but of a spring metal nature and capable of providing an effective and reliable clip device, as and for the purposes described.

While the invention has been described in detail with a specific example, such example is intended as an illustration only inasmuch as the invention fully contemplates various modifications which may be provided without departing from the spirit and scope of the invention.

What is claimed is:

1. A terminal adapter comprising a piece of sheet metal bent to define a split tubular body which is expansible and contractible, means defining a resilient head on one end of said split tubular body, spaced tongues carried by said split tubular body extending longitudinally of said split tubular body with the extremities of said tongues projecting inwardly within said split tubular body, said split tubular body being adapted to expand when telescoped over a threaded stud type of terminal with the extremities of said tongues engaging said threaded stud, said tongues being of progressively increasing height and having their extremities curved and shaped to lie on a helix corresponding to the helix of the thread on said threaded stud for uniform threaded engagement therewith, said split tubular body being adapted to contract when an associated terminal is connected to the exterior thereof such that the extremities of said tongues grip said stud under constant compressive force in a completed connection.

2. A terminal adapter comprising a piece of sheet metal bent to define a split tubular body which is expansible and contractible, yieldable fingers extending free from the upper portion of said split tubular body and bent to define a resilient head, spaced tongues stamped from the material of said split tubular body and extending longitudinally of said split tubular body with the extremities of said tongues projecting inwardly within said split tubular body, said split tubular body being adapted to expand when telescoped over a threaded stud type of terminal with the extremities of said tongues engaging said threaded stud, said tongues being of progressively increasing height and having their extremities curved and shaped to lie on a helix corresponding to the helix of the thread on said threaded stud for uniform threaded engagement therewith, said split tubular body being adapted to contract when an associated terminal is connected to the exterior thereof such that the extremities of said tongues grip said stud under constant compressive force in a completed connection.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,514,928 Rabezzana Nov. 11, 1924 1,663,264 Thompson Mar. 20, 1928 1,790,239 Lawson Jan. 27, 1931 2,124,616 Grant July 26, 1938 2,430,543 Tinnerman Nov. 11, 1947

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