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Патент USA US3088095

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April 30, 1963
B. soLow
3,088,085
ELECTRICAL RESISTOR
Filed Nov. 2'7, 1959
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BENJAMIN;
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United States Patent 0 i ice
3,088,085
Patented Apr. 30, 1963
2
F1
1
is not limited to the precise arrangements and instrumen
talities shown.
3,088,085
FIGURE 1 is a top elevational view of a base for the
ELECTRICAL RESISTOR
Benjamin Solow, North Hollywood, Calif., assiguor to
International Resistance Company, Philadelphia, Pa.
resistor of the present invention.
FIGURE 2 is a side elevational view of the base of the
resistor of the present invention with the terminals at
tached thereto.
view taken along line 3-3 of
Filed Nov. 27, 1959, Scr. No. 855,804
5 Claims- (Cl. 338-283)
‘FIGURE 3 is a sectional
The present invention relates to an electrical resistor,
FIGURE 2.
FIGURE 4 is a view similar to FIGURE 3 with the
and more particularly to a miniaturized, ?lm type elec 10
resistance
material coated on the base.
trical resistor.
FIGURE 5 is a view similar to FIGURE 4 showing the
The present trend in the electrical industry is toward
manner of varying the resistance value of the resistor.
miniaturized electrical components. Another trend in the
FIGURE 6 is a sectional view similar to FIGURE 5
electrical industry is to the use of printed circuit boards
on which the electrical components are mounted. For
showing the completed resistor.
FIGURE 7 is a bottom elevational view of the com
use on the printed circuit boards, the electrical compo
pleted resistor of the present invention.
nents should be as small as possible to take up as little
FIGURE 8 is a top elevational view of a modi?cation
room as possible on the board, and the terminals of the
components should be arranged for ease of mounting the
of the resistor of the present invention.
components on the board.
FIGURE 9 is a side elevational view of the modi?cation
of the resistor of the present invention.
Referring initially to FIGURES l-7, the resistor of
coated on an insulating base is to achieve a desired re
the present invention is generally designated as 10.
Resistor 10 comprises a substantially rectangular base
A problem in the manufacture of electrical resistors
of the type comprising a ?lm of a resistance material
sistance value, and particularly high resistance values.
The resistance value of a ?lm of resistance material can 25 12 of a hard, electrical insulating material, such as a
ceramic or glass. The top surface of the base 12 is pro
be varied by varying the composition of the resistance ma
terial, the thickness of the ?lm, and/or the length of the
?lm. Decreasing the thickness and/ or increasing the
length of the ?lm increases the resistance value. Varying
the composition of the resistance ?lm is impractical since
there are not many materials which have stable electrical
resistance characteristics. Varying the thickness of the
?lm is not satisfactory alone since the thickness is dif
?cult to control to achieve a desired value. Therefore,
it has been found preferable to combine varying the length
of the ?lm along with a variation of thickness to achieve
vided with a V-shaped groove 14 which extends back and
forth from end-to-end of the base 12 in a continuous,
sinuous path. The ends 14a and 14b of the groove 14
are adjacent opposite sides of the base 12 (see FIGURE
1). Each straight section of the groove 14 is spaced
from the adjacent straight sections of the groove 114 by a
ridge 16. The base 12 is provided with a pair of spaced,
blind holes 18 in the bottom surface of the base 12.
A separate terminating stripe 20 is coated on the outer
35
side of each of the ridge portions 161: and 16b just beyond
the ends 14a and 14b of the groove 14. Each of the ter
various resistance values.
minating stripes 20 extends downwardly along the adjacent
Most ?lm type electrical resistors use a cylindrical in
side of the base 12, along the bottom surface of the base
sulating base on which the resistance material is coated.
The length of the resistance material is varied by cutting 40 12 to an adjacent blind hole 18, and then upwardly along
a portion of the hole 18 (see FIGURE 3). The terminat
a spiral groove through the resistance layer to achieve a
ing stripes 20 are layers of an electrically conductive ma—
resistance path which extends helically around the base.
terial, such as gold or silver, which is painted, sprayed
By varying the pitch of the spiral groove, the length of the
helical resistance path is varied. This also varies the
or otherwise applied to the base 12.
A layer 22 of an electrical resistance material is coated
width of the path which also changes the resistance value. 45
over the entire top surface of the base 12 (see FIGURE
Thus, by cutting a groove of a proper length, a resistance
4). The layer 22 may be of any of the well known type
path of a desired resistance value can be accurately ob
resistance materials, such as carbon or metal particles
tained.
mixed with a plastic binder, pure carbon, carbon mixed
With the trend to miniaturized components, the use of
spiraling to vary the resistance value of a ?lm type re
sistor has become less satisfactory. The smaller the size
of the resistor, the more dif?cult it is to cut a ?ne enough
with a metal, or a pure metal or metal alloy. The re
sistance layer 22 may be applied to the base 12 by either
painting, spraying paralytic deposition ?rom a gas or
vapor, or by deposition from an evaporated vapor in a
vacuum. The resistance layer 22 extends across the por
have their terminals extending longitudinally from the ends 55 tions of both of the terminating strips 20 which are on
the ridge portions 16a and 16b. Thus, the resistance layer
of the base. In order for such resistors to be mounted
'22 is electrically connected to the terminating strips 20.
on a printed circuit board, the terminals must be bent
A separate terminal wire 24 of an electrical conductive
and shaped to be inserted into holes in the board.
metal is inserted in each of the blind holes 18 in the base
It is an object of the present invention to provide a
60 12. The terminal wires 24 are each secured in the holes
novel electrical resistor.
18 by a layer of an electrically conductive cement 26
It is another object of the present invention to provide
spiral groove to achieve any major change in the resist
ance value. Also, the resistors using cylindrical bases
a novel miniaturized electrical resistor.
It is still another object of the present invention to
provide a miniaturized electrical resistor the resistance
which surrounds the end portion of the terminal wires 24
which are within the holes 18. The conductive cement
26 may be a plastic cement having metallic particles
value of which can be easily varied and adjusted to a 65 therein, or may be a solder. The conductive cement
26 not only physically secures the teminal wires 24 in
predetermined close percentage tolerance.
the holes 18, but also electrically connects the terminal
wires 24 to the terminating strips 20. Thus, the terminal
wires 24 are each electrically connected to the resistance
layer 22 through the conductive cement 26, and the ter
Other objects will appear hereinafter.
70
minating strip 20. The terminal wires 24 may be se
For the purpose of illustrating the invention there is
cured to the base 12 either before or after the resistance
shown in the drawings forms which are presently pre
It is a further object of the present invention to provide
a miniaturized electrical resistor which can be easily
mounted on a printed circuit board.
ferred; it being understood, however,
that this invention
3,088,085
layer 22 is applied to the base 12 according to the manner
that the resistance layer 22 is applied to the base 12.
After the resistance layer 22 is applied to the top
surface of the base 12, and the terminal wires 24 are
secured within the holes 18, the base 12 is placed with
its top surface against a lapping or grinding belt or Wheel
to grind away the tips of the ridges 16 (see FIGURE 5).
The grinding away of the tips of the ridges 16 also re
15
I claim:
1. An electrical resistor comprising a substantially rec
angular base of an electrical insulating material, said
base having a sinuous groove in its upper surface, said
groove extending from side-to-side of said base with one
25
30
easily adjusted to obtain a desired resistance value.
After the resistance value of the resistance layer 22 is
adjusted to the desired value, a protective jacket 28 of an
electrical insulating material can be provided around the
base 12, as shown in FIGURE 6. The protective jacket
28 may be coated, molded, or cast around the base 35
12 and across the resistance layer 22, leaving the terminal
from the base 12, and are parallel, the resistor 10 of
2. An electrical resistor in accordance with claim 1
the present invention can be easily mounted on a printed 40 in which the groove in the top surface of the base is
circuit board by inserting the terminals 24 through holes
V-shaped in transverse cross~section.
in the board.
Referring to FIGURES 8 and 9, a modi?cation of the
resistor of the present invention is generally designated
as 30.
3. An electrical resistor in accordance with iclaim 2
45
andgroove.
the resistance material is coated on only the sides of
the
Resistor 30 comprises a substantially rectangular base
32 of a hard, electrical insulating material, such .as a
4. An electrical resistor
in accordance
with claim 3 in
ceramic or glass. The top surface of the base 32 is pro
which t
'
‘
vided with a V-shaped groove 34 which extends from
side-to-side of the base 32 in a continuous, sinuous pat 50
55
pair of spaced blind holes in its bottom surface, said
60
groove being V-shape in transverse cross-section and ex
tending back and forth across the top surface of the base
65
The terminal wires 40 which are electrically connected
75 to the conductive stripes so as to electrically connect each
3,088,085
of the terminal wires to a separate end of the resistance
path.
References Cited in the ?le of this patent
UNITED STATES PATENTS
1,767,715
Stoekle ______________ __ June 24, 1930
2,711,463
2,711,464
2,742,551
2,775,673
2,777,039
2,818,354
6
Goeppinger et a1 _______ _- June 21, 1955
Anderson et a1. _______ __ June 211, 1955
Kohring _____________ __ Apr. 17, 1956
Johnson _____________ __ Dec. 25, 1956
Thias ________________ __ Jan. 8, 1957
Pritikin et a1 __________ __ Dec. 31, 1957
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