Connecting terminal

A connecting terminal of electrically conductive material is in the form of a flat plate having first and second tabs which are stamped from the plate and bent upwardly from the same surface of the plate. The first tab is reversely bent to overlie the plate in spaced substantially parallel relation thereto for receiving an insulated wire and the second tab is disposed at an acute angle to the plate and is directed opposite to the first tab for anchoring the free end of the wire to the terminal. The first tab is provided with an elongated slot in the bent portion thereof so that on subsequent clamping of the wire by the application of pressure by opposed electrodes and the passage of current through the electrodes, the insulation will be burned off the wire under the first tab. The elongated slot allows for the escape of gasses and burned insulation material so as to insure a good electrical connection between the conductive core of the wire and the terminal.

BACKGROUND OF THE INVENTION 
The present invention is directed to a connecting terminal of the type 
having a reversely bent tab stamped therefrom for engaging a wire having 
an insulating cover whereby upon application of heat and pressure the 
insulating cover is burned off and the wire is welded to the terminal to 
electrically connect the wire to the terminal. 
In the prior art method shown in FIGS. 1-4, the connecting terminal 1 is 
obtained by blanking an electrically conductive metal plate such as a 
copper or copper alloy plate, to obtain a tab 2 which is reversely bent 
into spaced parallel relation with the plate thereby defining a hook-like 
portion as best seen in FIGS. 2a and 2b. 
An insulated wire 3 connected to an electrical apparatus 5 such as the 
starter of an electric motor, is connected to the terminal 1 by placing 
the wire in the bight 2a of the hook-like member 2 with the insulating 
cover 3a of the wire in firm, intimate contact with the bent portion 2b of 
the hook-like member as best seen in FIG. 3. With the wire 3 held in this 
position, the hook-like member 2 is pressed downwardly into engagement 
with the terminal plate 1 by means of opposed electrode bars 4. A current 
is then applied to the electrode bars 4 whereupon heat is generated due to 
the resistance of the terminal plate to burn through the insulating cover 
3a and bring the core 3b of the wire into intimate electrical contact with 
the terminal plate 1 and the reversely bent hook-like member 2 as best 
seen in FIG. 4. However, in such an operation, foreign material 6 such as 
unburned parts, oxides or carbides of the insulating cover 3a, may be 
trapped between the conductive core 3b of the wire and the reversely bent 
hook-like member 2 as shown in FIG. 4. Since the foreign material 6 acts 
an electrical insulater or semi-conductor, the foreign material may 
obstruct a satisfactory electrical connection between the conductive core 
3b and the connecting terminal 1. Furthermore, it is difficult to hold the 
insulated wire in the proper position relative to the reversely bent 
hook-like member 2 in order to obtain the best possible electrical 
connection upon application of current and pressure by means of the 
electrodes 4. Generally, the insulated wire is held by hand which presents 
a safety problem as well as being disadvantageous from the efficiency 
point of view. 
SUMMARY OF THE INVENTION 
Accordingly, an object of the present invention is to provide a connecting 
terminal having a suitable wire clamping element for engaging the 
insulated wire at a suitable position relative to the reversely bent 
hook-like member so that the insulated wire will be properly positioned 
and securely held in the proper position for the subsequent operation of 
the electrodes. In accordance with the present invention, it is only 
necessary to lay the insulated wire into the bight of the reversely bent 
hook-like member and bend the free end of the wire into engagement with 
the clamping piece. Thus it will no longer be necessary to manually hold 
the wire in proper position relative to the reversely bent hook-like 
member. 
A further object of the present invention is to provide a connecting 
terminal having an elongated hole punched in the reversely bent hook-like 
member so that upon passage of current through the clamping electrodes the 
residue resulting from the burning of the insulation can pass outwardly 
through the hole so as not to interfere with the obtaining of a good 
electrical contact between the conductive core of the wire and the 
reversely bent hook-like member on the terminal. 
The foregoing and other objects, features, and advantages of the present 
invention will be apparent from the following more particular description 
of preferred embodiments of the invention as illustrated in the 
accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION 
In the embodiment of the invention shown in FIGS. 5 and 6 the connecting 
terminal 11 is similar to the connecting terminal shown in FIG. 1 inasmuch 
as it is provided with a stamped tab 12 which is reversely bent into 
engagement with the terminal plate 11 for the purpose of electrically 
connecting the wire 13 to the terminal plate 11 by means of the electrodes 
14. Additionally, the terminal plate 11 is provided with a clamping piece 
16 which is stamped from the terminal plate 11 and bent upwardly to form 
an acute angle with the terminal plate 11. 
In order to electrically connect an insulated wire to the connecting 
terminal 11, the insulated wire 13 which extends from an electrical device 
15 is passed beneath the reversely bent tab or hook-like member 12 similar 
to the manner shown in FIG. 3. The free end of the wire 13 is then passed 
under the clamping piece 16 such that the wire 13 will be wedged between 
the upper surface of the terminal plate 11 and the under surface 16a of 
the clamping piece 6. With the wire securely clamped by means of the 
clamping piece 16 it is no longer necessary to hold the wire in the 
opening 12a against the surface 12b of the hook-like member 12. Upon 
application of pressure on the hook-like member 12 and the connecting 
terminal 11 by means of the electrodes 14 the wire 13 will be captured and 
upon passage of current through the electrodes 14 the insulation on the 
wire 13 will be burned off in the vicinity of the hook-like member 12 so 
that the conductive core of the wire will be electrically connected to the 
connecting terminal 11. Thus, the safety factor and operating efficiency 
are both increased during the welding operation of the wire to the 
connecting terminal. 
In another embodiment of the present invention shown in FIGS. 7 and 8 the 
connecting terminal 27 is similar to the prior art connecting terminal and 
the manner in which the insulated wire 23 is connected to the connecting 
terminal 27 by means of a reversely bent hook-like member 28 is 
substantially the same. However, the tab which is stamped from the 
connecting terminal 27 to form the reversely bent hook-like member 28 is 
provided with an elongated hole 29. In order to provide adequate surface 
contact of the insulated wire 27 with the reversely bent hook-like member 
28 at 28b the over-all width E of the hook-like member 28 is greater than 
the width B of the hook-like member 12 in the previous embodiment in order 
to compensate for the presence of the hole 29. It is preferable that the 
width (C+D) of the portions 28b of the hook-like member 28 is equal to the 
width B of the hook-like member 12 as shown in FIG. 6a. Therefore, during 
the application of pressure and current by means of the electrodes 24, 24, 
the heat generation and the mechanical strength of the ultimate connection 
are not lowered. The provision of the hole 29 allows the escape of burning 
gasses and burned particles of the insulation to facilitate a better 
electrical connection between the hook-like member 28 and the conductive 
core of the wire 23. The method of connecting the wire 23 to the terminal 
27 is substantially the same as that indicated in the previous embodiment. 
The insulated wire 23 is placed at 28a under the hook-like member in 
contact with the surfaces 28b. Upon movement of the electrodes 24 towards 
each other the hook-like member 28 will be pressed into engagement with 
the upper surface of the terminal 27 thereby clamping the wire. Upon 
passage of current between the electrodes 24 the insulation on the wire 
will be burned off. As the remnants of the insulating material are 
scattered upon being burned and gasified, some of the scattered particles 
can pass through the hole 29 so as to substantially eliminate foreign 
material along that length of the wire 23 under the hook-like member 28. 
Thus, the bare conductive core of the wire 23 can be readily and 
efficiently welded to the connecting terminal. 
In the embodiment of FIG. 9, the connecting terminal 37 is substantially 
identical to the connecting terminal 27 with the exception of the hole 
through the hook-like member 38. The hole 40 is considerably longer than 
the hole 29 in the previous embodiment so that upon reversely bending the 
hook-like member 38 the ends of the rectilinear hole 40 will be 
substantially aligned with each other perpendicular to the upper surface 
of the terminal 37. The greater length of the hole 40 provides for a 
better dissipation of the burned foreign material and gasses during the 
passage of current from one electrode to the other. 
It is obvious that the connecting terminals 27 and 37 in the embodiments of 
FIGS. 7-9, could be provided with a clamping piece similar to the clamping 
piece 16 in the embodiment of FIGS. 5 and 6. Likewise, the hook-like 
member 12 in the embodiment of FIGS. 5 and 6 could be provided with an 
elongated hole similar to either of the holes disclosed in FIGS. 7-9. 
While the invention has been particularly shown and described with 
reference with preferred embodiments thereof, it will be understood by 
those in the art that various changes in form and details may be made 
therein without departing from the spirit and scope of the invention.