Spade lug having scored surfaces

A connector for providing an electrical connection between an electrical conductor and an electrical terminal. The connector is formed by a body member having a crimpable sleeve for securing the electrical conductor. A slot is formed in the body member for extending around the post of the terminal, and at least one surface of that portion of the body member surrounding the slot is provided with a relatively high frictional surface for engagement with the terminal.

BACKGROUND OF THE INVENTION 
This invention relates to an electrical connector and, more particularly, 
to an electrical connector for providing a electrical connection between a 
electrical conductor and a electrical terminal. 
Many types of connectors have been provided for providing an electrical 
connection between an electrical conductor and a barrier strip, a terminal 
block or a single terminal. A spade lug is a popular type since it is 
easily connected to an electrical conductor, and is shaped so as to extend 
around a threaded binding post on the barrier strip or terminal so that it 
can be clamped around the binding post by a nut in threaded engagement 
with the post. In this manner, the connection can be quickly and easily 
made and disengaged. 
However, these types of connections suffer from the fact that the engaging 
surfaces of the spade lug, being of a relatively smooth material having a 
low coefficient of friction, such as gold, brass or brass-plated metal, 
easily become disengaged from the terminal, thus compromising or 
destroying the integrity of the electrical connection. 
SUMMARY OF THE INVENTION 
It is therefore an object of the present invention to provide an electrical 
connector for providing an improved electrical connection between an 
electrical conductor and an electrical terminal. 
It is a further object of the present invention to provide an electrical 
connector of the above type in which a relatively high frictional 
connection is made between the surfaces of the connector and the 
corresponding surfaces of the electrical terminal to improve the clamping 
action and integrity of the connection. 
Toward the fulfillment of these and other objects, the connector the 
present invention includes a plate member having means on one end for 
connection to an electrical conductor. A slot is formed in the other end 
portion of the body member for extending around the threaded post of an 
electrical terminal. At least one surface of that portion of the other end 
portion of the body member that surrounds the slot is treated to provide a 
relatively high frictional engagement with the corresponding surface of 
the terminal.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The connector of the present invention will be described, by example, in 
connection with an audio loudspeaker referred to, in general, by the 
reference numeral 10 in FIG. 1 of the drawings. The loudspeaker 10 
includes a cabinet, or housing, 12 having a back wall 12a on which a 
electrical terminal assembly 14 is provided. The electrical terminal 
assembly 14 is of a conventional design and includes a base member 15 and 
two threaded nuts 16a and 16b in threaded engagement with a pair of 
threaded posts, respectively extending from the base member. Normally, a 
pair of electrical conductors 18a and 18b are clamped between the nuts 16a 
and 16b, respectively, and the base member 15 for connecting an amplifier 
to the loudspeaker 10. 
A pair of washers 20a and 20b are usually provided between the nut 16a and 
the base member 15, and a pair of washers 22a and 22b are usually provided 
between the nut 16b and the base member 15. The washers 20a and 20b 
provide two spaced flat surfaces between which is clamped the conductor 
18a, and the washers 22a and 22b provide two spaced flat surfaces between 
which is clamped the conductor 18b. Normally the end portions of the 
conductors 18a and 18b are stripped of insulation and placed between the 
washers 20 and 20b and the washers 22a and 22b, respectively, to secure 
the connection. 
The electrical connector of the present invention is shown by the reference 
number 24 in FIGS. 2 and 3 and is designed to facilitate the connection 
between the conductors 18a and 18b and the terminal assembly 14. The 
connector 24 is formed by a body member 26 having a crimping sleeve 28 
formed integrally therewith by forming two tabs 28a and 28b which are bent 
inwardly toward each other. An end portion of the conductor 18a or 18b is 
stripped of insulation and placed in the sleeve 28 before the sleeve is 
crimped over the conductor 18a, to secure the connection between the 
conductor 18a and the connector 24 in the manner shown in FIG. 2. 
The end portion of the body member 26 opposite that of the sleeve 28 is 
enlarged to form a head portion 30. A slot 32 is formed in the head 
portion 30 and is of a size so as to receive either binding post of the 
terminal assembly 14 on which the nuts 16a or 16b are threadably engaged. 
According to a main feature of the present invention, the opposite surfaces 
of the head portion 30 are provided with a relative high-friction surface, 
as shown by the reference numbers 34a (FIG. 2) and 34b (FIG. 3). The 
expression "relatively high friction surface" is meant to encompass all 
surfaces that have a coefficient of friction that is greater than that 
normally provided by a copper, brass, gold or similar type metal surface. 
As an example, the body member can be fabricated of a metallic material 
such as copper, gold, brass, or the like, and the relatively high friction 
surface can be obtained by scoring, or scratching the surfaces 34a and 34b 
in a conventional manner. The surfaces 34a and 34b substantially 
correspond in size to the corresponding surfaces of the washers 20a, 20b, 
22a and 22b. 
In this manner, when the conductor 18a is attached to the connector 24 in 
the manner described above, and the head portion 30 is inserted between 
the nut 16a and the base member 15, and, more particularly, between the 
two washers 20a and 20b, the relatively high friction surfaces 34a and 34b 
are engaged by the washers 20a and 20b upon advancement of the nut 16a 
towards the base member 15, resulting in a very positive clamping of the 
connection 24 between the washers. Of course, another connector 24 would 
be connected to the conductor 18b and clamped by the nut 16b in the same 
manner. 
The relatively high friction surfaces 34a and 34b dramatically increase the 
frictional engagement of the connector 24 with the terminal assembly 14, 
and provide a superior connection that improves the current carrying 
capability of the connection while insuring that the connection will not 
deteriorate with age. 
It is understood that several variations may be made in the foregoing 
without departing from the scope of the invention. For example, the 
washers 20a and 20b and the washers 22a and 22b can be eliminated in which 
case the connector 24 of the present invention would extend directly 
between the nuts 16a and 16b and the corresponding surfaces of the base 
member 15. 
Other modifications, changes and substitutions are intended in the 
foregoing disclosure and, in some instances, some features of the 
invention can be employed without a corresponding use of other features. 
Accordingly, it is appropriate that the appended claims be construed 
broadly and in a manner consistent with the scope of the invention.