Title:
ELECTRICAL CIRCUIT BOARD TERMINAL SPRINGCLIP
United States Patent 3848947


Abstract:
An electrical terminal for use with a circuit board. The terminal comprises a conductive rivet having a head and a shaft, the shaft being adapted to be disposed through a circuit board aperture, and a spring means disposed around at least a portion of said rivet.



Inventors:
JAMBOR D
Application Number:
05/251933
Publication Date:
11/19/1974
Filing Date:
06/16/1972
Assignee:
DOT CO INC,US
Primary Class:
Other Classes:
439/550, 439/817
International Classes:
H05K1/18; (IPC1-7): H05K1/04
Field of Search:
339/17,18,126,128,253,254,255,202,3
View Patent Images:
US Patent References:
3699495ELECTRICAL CONNECTOR FOR VEHICLE INSTRUMENTS1972-10-17Raynor
3441899ELECTRICAL CONNECTOR1969-04-29Gold
3104926Solderless terminal1963-09-24Scoville
2911615Connector for electric wires1959-11-03Popejoy et al.
2761115Binding post1956-08-28Visconti
2701871Quick-acting binding post1955-02-08Rauch
2040665Connecter for toy railroad tracks1936-05-12McKeige
0845268N/A1907-02-26



Foreign References:
FR957085A
FR1017239A
IT400025A
FR1081200A
Primary Examiner:
Frazier, Roy D.
Assistant Examiner:
Lewis, Terrell P.
Claims:
What is claimed as new is as follows

1. An electrical terminal comprising:

2. An electrical terminal as claimed in claim 1, wherein the coil spring extends along said shaft between said slot and the end of the shaft opposite the head.

3. An electrical terminal in combination with a circuit board comprising;

4. The combination as claimed in claim 3 wherein said portion of said shaft includes said bore.

5. The combination as claimed in claim 3 wherein said spring means comprises a resilient grommet.

6. The combination as claimed in claim 5 wherein the grommet is positioned on that side of the circuit board proximate the rivet head.

Description:
BACKGROUND OF THE INVENTION

The present invention relates to the electrical terminal art, and particularly to terminal structure mounted on a circuit board for removably securing one or more component conductor leads.

Various terminals have previously been suggested in this art, many of which retain component leads by means of solder or other similar fastening means. Such terminals are not practical in certain environments, as for example, where it is desired to repeatedly add or replace component leads while performing experimental work. Further, such terminals do not afford protection against possible damage to the component resulting from the excessive heat required to liquify the solder alloy to make the connection.

Consequently, solderless connections have been developed and have taken such forms as clips, crimps, spring fingers that grip the wire as it is inserted into a socket, and coil spring terminals which are designed to receive conductor leads between the confined convolutions of the coil spring. These terminals perform their intended functions satisfactorily but again they have limitations which may be undesirable. For example, in using such terminals the component leads after often subjected to such high stress the damage occurs to the leads which could prevent repeated use of the component. In those terminals where the force is not so great, there is the problem of lead retention by the terminal and the likelihood of producing undesirable resistive effects.

The present invention recognizes the various difficulties of prior solderless terminals and it is an object of the present invention to provide an improved solderless terminal which permits repeated fast and reliable electrical connections including a substantially lower contact resistance than the prior art terminals.

Another object of the invention is the provision of an improved solderless terminal which may be readily added to or removed from circuit boards and readily reused.

Still another object of the invention is to provide an improved solderless terminal which is relatively inexpensive and which is more reliable in operation than the previously suggested terminals.

These and other objects and advantages of the invention will become apparent from a study of the attached drawings and from a reading of the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of the terminal shown in FIG. 2.

FIG. 2 is a side view of the terminal connector of a preferred embodiment of the present invention.

FIG. 3 is a front view of the terminal shown in FIG. 2 without the attachment thereto of the coil spring.

FIG. 4 is a view of a second embodiment of the invention disclosed herein.

FIG. 5 is a view of a third embodiment of the invention herein disclosed.

FIGS. 1-3 show a first embodiment of the present invention which embodiment is comprised of two basic elements -- a spring member and a specially machined rivet. The spring 4 in FIG. 2 is a helical spring of conductive material, and has an end 12 which is straight and extends normally to the longitudinal axis of the helical configuration (See FIG. 1). The rivet 1 is machined to provide a hole 6 extending completely through and centered in the head and shank, and a bore 5 extending through the end of the shank farthest from the head, and substantially normal to the axis of hole 6. A pair of notches, 13 and 14, are formed in the shank proximate the rivet head, and a slot 18 is formed to extend through the rivet shank also proximate the rivet head.

In use, the rivet is inserted shank first into a hole in a printed circuit board, the rivet head being positioned on or adjacent the underside of the board as shown in FIG. 3. The spring 4 is then positioned on and affixed to the rivet shank extending from the board surface opposite the side of the board where the head is positioned so that the rivet shank is surrounded by the coils of the spring. The straight end 12 of spring 4 is positioned in slot 18 and its free end is bent to engage notch 14 (FIG. 2), thereby locking the spring to the rivet and the rivet to the board.

A second embodiment of the invention is disclosed in FIG. 4 of the drawings. Utilizing a slightly modified rivet, the coil spring is first positioned on and fastened to the rivet shank, one end of the spring positioned in notch 13 adjacent the rivet head. The shank is then inserted from the underside of the board through the board hole. In this embodiment, the shank has been further provided with a groove 15. As shown in FIG. 4 when the rivet is properly positioned in the hole, groove 15 is presented at the upper side of the board. By using a tool, such as a tweezers, or by using ones own fingers, the grooved shank is grasped and pulled upwardly against the spring action of the coil spring thereby moving hole 5 into useful position so that a component lead wire can be inserted therein. Additionally groove 15 can be used for a direct connection of wires including a solder connection. The clamping of the wire in hole 5 of the rivet shank provides sufficient means for holding the rivet and coil assembly in a state of attachment to the circuit board.

A third embodiment of the present invention is disclosed in FIG. 5. Grommet 2A replaces coil spring 2 and the grommet completely encloses that portion of the rivet located at either the bottom or the top of board 3. A groove 7 is located on the rivet shank between the head and groove 15, and a small split ring spring 11 with a bent segment 10 is disposed within groove 7. The grommet serves the purpose of electrically insulating the rivet where it is attached to the board. The grommet may be attached to the board with adhesive, and this fixing of position of the grommet allows its natural spring action to assist in accepting and holding a wire or component lead after compression (to expose hole 5), and release, of the grommet. The flange 16 creates a retention means, and hole 8 allows either servicing of hole 6, or the complete removal of rivet 1.

In any of the embodiments hole 6 has the additional purpose of providing means for connection to the terminal by acceptance of connectors of a male type, such as a banana plug, component lead, etc.

It is understood that various embodiments of the invention, other than those illustrated, may be apparent to those skilled in the art. Hence it is desired that the invention not be limited to the exact construction and operation shown and described herein and that all modifications and equivalents may be resorted to which fall within the scope of the invention as claimed.