No. 733,337. -
PATENT-ED JULY 14, 1903..
W. J. FORSTER.
DEMAGNETIZER.
APPLICATION FILED MAR. 15, 1902.
N0 MODEL.‘
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"53: nonms PETERS ca. PNGTOLITNO" wnsmuamn, u. c.
Patented July‘ 14, 1903.
No. ‘733,637.
UNITED STATES PATENT DFEICE.
XVILLIAM J. FORSTER, OF MILWAUKEE, WISCONSIN.
DEMAGNETIZER.
‘SIPEGIFICATION forming part of Letters PatentNo. ‘733,637, dated July 14, 1903.
Application ?led March 15, 1902. Serial No. 98,278. (No model.)
:
To (/l/ZZ whmn it near/y concern:
Be it known that 1, WILLIAM J . FORSTER, a
P, that may be closed on one or the other of
electric contact - points Q B, one of these
points being electrically connected to electro
citizen of the United States, and a resident of magnet M and the other in like connection 55
Milwaukee, in the county of Milwaukee and with electromagnet N. I-Ience either of these
State of Wisconsin, have invented certain new
and usefulImprovements in Demagnetizers; electromagnets can be readily put in circuit
the pole-changer.
and I do hereby declare that the following is a with
In practice the local circuit is closed with
- full, clear, and exact description thereof.
of the electric-service line or with
My invention has for its object to provide aconductors
generator
of suf?cient electric current, and
simple economical apparatus having utility
, with an electrical current of sufficient inten
sity as means for demagnctizing various de
vices, especially watches and tools, said in
vention consisting in what is hereinafter par
ticularly set forth with reference to the accom
one or the other hollow-core electromagnets
is put in the circuit by means of the switch,
the pole-changer being then actuated to cause
frequent reverses of the direction of current 65
that goes through said magnet. Each brush
L is alternately on contact - pins of both
panying drawing and subsequently claimed. K
wheels
E and a contact- pin of one of said
The drawing is a diagram in perspective,
Hence there is alternate shunting
illustrating electric-service conductors and wheels.
and
energization
of the magnet, the fre
apparatus in accordance with my invention quency of the alternations being in propor
for electrical connection with said conduc tion to the rotary speed of the pole-changer
tors.
and number of the contact-pins thereof, this
Referring by letter to the drawing, A indi-,, number
always preferably such as will
cates a spring-plug connecting positive and insure a being
cool pin of each wheel at each con 75
negative conductors of an electric-service tact with a brush. Shunting of the magnet
25 line, and B another such plug connecting throws pressure of the current into the lamp
local - circuit conductors having insulated
J or other resistance to prevent the damag
spring-brush terminals 0 D, the latter plug ing
sparking that would otherwise take place
being engageable with the one aforesaid to between
pole-changer pins and the brushes
energize the local circuit. The brushes 0 D
L, due to alternations of said current.
have contact with the hub portions of a pair K
Hence
durability of the pole-changer is
of wheels E, of conductor material, in rigid insured.the The
lamp J as a resistance being
insulated connection with a spindle F, pro always included in the circuit will have full
vided with a pinion G, that meshes with a power when the magnet is shunted, but less 85
spur-wheel II, that is turned by a crank I to power when said magnet is energized, the
impart
rapid rotation to the wheels, an in
35
being then divided in said lamp and
candescent lamp J or other resistance being current
magnet, there being constant ?ickering of the
put in the circuit. Each wheel E is provided
with an even-number series of inwardly-pro
jecting contact-pins at intervals of ‘a circle,
aforesaid lamp when the pole-changer is in
operation. A watch, tool, or other device
that
has become magnetized is placed in the
those of one wheel alternating with those of
core of the electromagnet that is for
the other.‘ Insulated spring-brushes K L hollow
the
time
circuit aforesaid and demag
have cam end opposition to the pins of the netized asinathe
result
the above-described op
wheels E, and the arrangement of these eration, there beingof continuous
actuation of 95
brushes is such that they are alternately in
the
pole-changer
while
the
device
under treat
45 contact with a pair of pins of each wheel ment is exposed in said clectromagnet. The
when both are in rotation, the function of
electromagnct M is designed for
the two pin-wheels on the same spindle being larger
watches and the one N for narrow tools; but
that of a pole-changer.
Brush K is elec
either one of said electromagnets may be
omitted
and the one remaining put in per
nets M N of diiferent uses, and the brush L manent electroconnection with the brushes
is electrically connected to an electric switch
trically connected to hollow-core electromag
738,633?
that oppose the pole-changer without depar
ture from what I seek to cover as my inven
tion.
in matter of size, a pair of conductor-wheels.
insulated on a common spindle and each pro
vided with inwardly~extending contact-pins
Having thus described myinvention, what at intervals of a circle, the pins of one wheel
I claim as new, and desire to secure by Letters alternating with those of the other, cam end
Patent, is—
spring-brushes each alternately in touch with
1. Ademagnetizercomprisingahollow-core the contact-pins of both wheels and a single
electromagnet, a pair of conductor-wheels in
pin of one wheel, a switch arranged to close
an electrical circuit including either of said
vided with inwardly-extending contact-pins magnets and said brushes, means for rotat
at intervals of a circle, the pins of one wheel ing said spindle, other brushes in contact
alternating with those of the other, cam end with said wheels, the latter brushes consti
spring-brushes each alternately in touch with tuting terminals of a circuit for electric cur
contact-pins of both wheels and a single pin rent of suitable intensity, and aresistance in
of one wheel, means for electrically connect the circuit.
ing said brushes and magnet, means for ro
In testimony that I claim the foregoing I
tating the spindle, other brushes in contact have hereunto set my hand, at Milwaukee, in
with said wheels, the latter brushes consti the county of Milwaukee and State of VVis—
tuting terminals of a circuit for electric cur consin, in the presence of two witnesses.
rent of suitable intensity, and a resistance in
W'ILLIAM J. FORSTER.
sulated on a common spindle and each pro
IO
20
the circuit.
‘
2. A demagnetizer apparatus comprising a
plurality of hollow elect-ro'magnets different ,
\Vitnesses:
H. G. UNDERVVOOD,
W; S. UNDERWOOD.