Cable fuse identification system

A method and apparatus for detecting proper arrangements of fuses (10) in fuseblock (70). A scanner (80) detects a chemical material in fuse (10) and identifies the material and correlates the material to a proper amperage rating. The arrangements of different amperage rating fuses in the block is automatically compared to a standard by a microprocessor or computer to determine if fuse location is proper.

FIELD OF THE INVENTION 
The present invention relates to fuses in general and in particular to a 
fuse identification system. 
BACKGROUND OF THE INVENTION 
Current practice in the automobile industry is to protect electrical and 
electronic equipment installed in automobiles by means of fuses located in 
the fuse block in the glove compartment or under the dashboard of the 
automobile. These fuses are, for the most part, relatively low amperage 
and are designed to protect apparatus such as radios, lights, and turn 
signals. Also, these fuses operate in a temperature controlled environment 
since they are inside the passenger compartment of a car. 
Many of the major electrical loads in an automobile are found underneath 
the hood of a car, such as the starter, alternator, and the battery, to 
name several. These electrical apparatus draw relatively high currents 
compared to the typical fuse located under the dashboard. If these 
underhood electrical apparatus were to be protected by fuses mounted in 
the passenger compartment, the wiring connected to them would have to be 
routed through the firewall to the passenger compartment to the fuseblock 
and then back through the firewall to the component under the hood. This, 
of course, would add weight to the automobile, additional labor costs, and 
increase the cost of production. It is, therefore, desirable to locate 
some circuit protector under the hood of automobiles. 
It is preferred to group these large automotive fuses together in one 
location under the hood in a fuseblock. Since different components under 
the hood of an automobile have different operating and starting 
characteristics, it follows, naturally, that fuses of different amp 
ratings and characteristics will be inserted in the fuseblock. However, in 
order to standardize the shape of the fuseblock so that it can be used in 
different model automobiles requiring different combinations of fuse 
ratings, the large automotive fuses have been standardized as to size and 
shape. Therefore, potential problems exists in that an improper rated fuse 
may be inserted out of order and open at too low a current or a fuse with 
too high a rating may be inserted in the improper order and not protect 
downstream components. 
Manufacturers realizing that this is a problem have verified that fuses are 
inserted in the proper order by visually verifying location of fuses. 
However, this method is labor-intensive in that it requires an extra 
worker on the assembly line. 
SUMMARY OF THE INVENTION 
According to the present invention, a large automotive fuse is comprised of 
a metal element having a first and second terminal connected by a fusible 
element. The metal element of the automotive fuse is enclosed in 
aninsulating material made of transparent, high-temperature thermoplastic. 
The thermoplastic material is laser etched, to identify the amperage 
rating of the fuse, and incorporates trace elements of chemicals that are 
detectable by an automatic scanner. After the fuses have been 
automatically assembled in a fuseblock, the scanner automatically 
verifies, by detecting the trace elements in the thermoplastic material, 
that fuses of the proper rating are in the proper position in the 
fuseblock.

DETAILED DESCRIPTION OF THE DRAWING 
A large, automotive fuse, shown in FIG. 1 is designated generally by the 
numeral 10. Fuse 10 is comprised of a one-piece metal element, not shown, 
and an insulating housing 50. The metal element is comprised of a first 
terminal 20 and a second terminal 30, connected by fusible element. The 
fusible element and the upper portions of first terminal 20 and second 
terminal 30 are encased in an insulating material 50. 
Plastic casing 50 is made out of a transparent, high-temperature 
thermoplastic. The transparency allows visual faults in the elements to be 
readily detected. The high-temperature plastic will maintain structural 
integrity at elevated operating temperatures. Plastic casing 50 also 
incorporates chemical compounds which are added to the plastic during the 
molding process to identify the amperage rating of the fuse. The chemicals 
are identifiable by a scanner linked to a computer for identifying this 
certain combination of chemicals and, hence, the fuse amperage rating. In 
the preferred embodiment of the invention, proprietary chemicals available 
from Veritec, Inc., 23801 Calabasas Road, Suite 2039, Calabasas Park, 
Calif. 91302, were used. 
FIG. 2 shows fuses incorporated into a fuseblock. This drawing shows three 
fuses which is intended to be illustrative only since many more fuses may 
be incorporated into a fuseblock. Also, while these fuses are shown 
arranged in a front-to-back, single file sequence, other fuseblock 
arrangements are compatible with the present invention. 
In the FIG. 2 fuseblock, block 70 is comprised of end walls 74 and side 
walls 72 joined to form a hollow, rectangular open area 76. Into this open 
area, fuses 10 are inserted into receptacles not shown. The order the 
fuses are inserted into the fuseblock are important if a fuse of an 
improper rating is used in the wrong location. Important electrical 
equipment may not be protected from overcurrent damage. 
Since the fuses are inserted into a block mechanical, there is always the 
opportunity for error. Thus, the uses have to be checked in order to 
ensure the proper fuse is in the proper location. 
FIG. 3 shows fuseblocks 70 on a conveyor belt 82 which moves from left to 
right. Scanner 80 mounted over conveyor belt 82 projects a beam of 
radiation at the fused blocks 70. The reflected light will vary depending 
on the presence or absence of the proprietary chemicals discussed above. A 
computer or microprocessor, not shown, may be incorporated directly into 
scanner 80 or not separately to compare the reflected light patterns from 
the fuses and fuseblock arrangement 70 to determine proper arrangement as 
it is well known in the art. 
The fuses 10 are laser etched to provide identification of the amperage 
rating of the fuse on the top horizontal surface. The fuses may also be 
laser etched with the date or a code that can be used to determine the 
date of manufacture and, hence, provides a quality control on the 
manufacture of fuses and traceability for locating specific batches of 
fuses. Laser etching, rather than hot stamping or incorporating 
information in the mold, ensures a more durable marking system. Also using 
laser etching, the date inscribed on the fuse and other data may be 
changed on a routine basis, or even on a daily basis, which is not 
practical with hot stamping and other types of marking. 
Although specific embodiments of the invention have been described above, 
those skilled in the arts will appreciate that the invention may be 
practiced in other manners than those shown. For example, the automotive 
fuse, other than being a blade-type plug-in fuse, may be incorporated into 
the electrical system by bolting, soldering, clamping, or other means.