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Патент USA US3028542

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April 3, 1962
,
R. FAVRE
3,028,532
ARRANGEMENT FOR ELECT
RO-MAGNETICALLY SUSTAINI NG
Filed June 21, 1957
THE MOVEMENT OF‘ A SPIRAL BALANCE SPRING
2 Sheets-Sheet 2
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QMvznPor:
R0 48,!- FAVRE
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A-‘H‘ormty
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United f Statfis . Patent".
" ICC
magnet 11; said screen cuts out, on the one hand, the
disturbances produced in’ operation as a consequence of
the parasitic magnetic ?elds which may arise and, on
the other hand, it uniformizes, except for a well de?ned
area corresponding to the are 5, the magnetic poten
tial of the medium in which the magnet oscillates.
3 028,532
ARRANGEMENT FOEELECTRO-MAGNETICALLY
SUSTAINING THE MOVEMENT OF A SPIRAL
BALANCE SPRING
3,028,532
2
l
1
.
Patented Apr. 3, 1962
‘
_
Robert Favre, Lausanne, Switzerland, assignor to Fab
riques Movado, La Chaux-de-Fonds, Switzerland, a
Swiss ?rm
Filed June 21, 1957, Ser. No. 667,216
The embodiment illustrated in FIG. 2 is a modi?cation
of that illustrated in FIG. 1. According to this modi
_
Claims priority, application Switzerland June 22, 19:6
?cation, the magnet 11 is provided with four poles while
11 Claims. (Cl. 318—132)
10 the soft iron armature includes two symmetrical sec
tions 101 and 102 terminating each with two arcuate ex
tensions 121 and 122 or 123 and 12.; extending each over
'an angle equal substantially to one quarter of a cir
of a'spiral balance spring.
_
cumference. The two windings 14 and 15 surround
This arrangement is of the type constituted'by a mag
netic circuit including a section rigid with the balance 15 respectively the’outer central parts of the two arma
ture sections.
wheel and a stationary section and byan electric cir
This last arrangement shows the advantage of cutting
cuit designed so as to transmit in its turn through the
out a large fraction of the mutual inductance between
‘agency of the magnetic circuit the impulses which are
the windings and this advantage may in certain'case be
adapted to sustain the movement of the balance wheel.
Now according to the present invention, there is pro 20 quite important.
This mutual inductance is entirely eliminated in the
vided a magnetic screen protecting the oscillating section
case of the embodiment illustrated in FIG. 3 which forms
of the magnetic circuit with a view to removing the dis
a second modi?cation of the embodiment illustrated in
turbances arising during operation under the action of
FIG. 1. As a matter of fact, the windings 14 and 15
parasitic magnetic ?elds and to uniformizing the mag
are each subdivided in the ‘case of FIG. 3 into two half
netic potential of the medium inside which said section
windings these half-windings being ?tted respectively
oscillates seas to ensure the astatic equilibrium of the
over the outer parts of the four sections 101 . . . 104
balance wheel.
The present invention has for its object an arrange
ment for electro-magnetically sustaining the movement
The accompanying drawings illustrate‘ by way of ex
ample ?ve embodiments of the arrangement according
forming together the rigid armature 10 and inter
connected two by two by the arcuate extensions
to the invention together with various electric circuits 30
adapted to be associated with said embodiments. In
121 . l . 124.
said drawings:
The advantages of the arrangements described hitherto
are numerous and in particular there should be men
tioned:
'‘ The rapid reversal of the magnetic ?uxallows ob
35 taining an impulse the amplitude of which ‘is su?icient
embodiments.
for sustaining the movement of the balance wheel by
FIG. 5 is a cross-sectional view through line V»--V of
FIG. 1 is a plan view of a ?rst embodiment.
FIGS. 2, 3 and 4 are similar views of three further
means of a small number of convolutions and of a
FIG. 4.
magnetic ?eld of a reduced intensity.
FIG. 6 is a partial view of a detail modi?cation.
The balance wheel is astatically equilibrated by rea
FIGS. 7 to 11 are wiring diagrams adapted for use
40 son of the constancy of the magnetic potential through
with the arrangements according to FIGS. 1 to 6.
out the range of elongation.
The embodiment illustrated in FIG. 1 includes a mag
The magnetic losses are very small by reason of the
netic circuit constituted by a stationary section formed
small value of the magnetizing ?eld and of the absence
by a soft iron armature 10 and a section rigid with the
of any parasitic or stray magnetic ?eld.
‘
balance wheel and formed by a magnetized bar 11 rock
The
balance
spring
has
a
very
stable
characteristic
45
ing inside the space de?ned by two arcuate extensions
guge since it is subjected to a very reduced magnetic
12 formed at the ends of the armature coaxially with
e
.
the balance wheel. Said armature in the shape of a
The terrestrial magnetic ?eld exerts no in?uence on the
U carries over its medial section a coil 13 formed by
arrangement by reason of the screening provided by the
two elementary windings 14 and 15 connected with a
'
transistor T and with a battery P, the connections being 50 ‘arcuate extensions.
’ The passage of the balance wheel through its medial
provided in the manner illustrated in any of FIGS. 7
to 11.
position generates a single impulse instead of a couple
'
of impulses of opposite directions as in the case for all
other prior methods and thereby the e?iciency of the
ing along the axis of the balance wheel sees the gaps
between the arcuate extensions 12, Le. across the poles 55 arrangement is. increased.
'In contradistinction with all prior methods and means,
of the magnet formed by lllare equal to only a‘few
the remanent magnetism of the armature does not lead
degrees, and at the utmost to about 20°
to any braking of the balance wheel after the sustaining
The operation of this arrangement is as follows:
impulse is produced. "
At the ‘moment at which the magnetized bar 11 passes
The angles a and 7 through which the observer stand
through its medial position illustrated in FIG. 1‘, the
magnetic ?ux passing through the coil 13 is suddenly
60
Experimentation has shown that the most favorable
angles [3 and 'y are comprised respectively between 1°
and 5° and between 3° and 20°.
: The arrangement illustrated in FIGS. 4 and 5 includes
an, armature 20 made of magnetic material showing no
reversed, this reversal produces in the winding 14 an
electric'impulse which starts a current in the circuit of
the transistor T which is normally locked and this pro
duces thus a secondary impulse in the winding 15. The 65 'remanence such as that sold under the name of “Ferrox
cube” or of a similar sintered metallic oxide having a high
latter impulse produces in its turn a modi?cation in the
magnetic ?eld passing through the armature 10 whereby
electrical resistivity, said armature forming the stationary
section of a magnetic circuit and between the aligned ends
the magnet‘ll is subjected to an impulse adapted to sus
of said armature is mounted a magnetized bar 21 form
tain the movement of the balance wheel.
It will also be remarked that the arcuate extensions 70 ing the oscillating section of said circuit.
Over the medial'part of the armature 20 is wound a
.1’! do not only lead to a reversal of the ?ux in the arma
‘double coil 22 the elementary windings of which are con
ture but that they also form a magnetic screen for the
3,028,532 ‘
3
> nected as ‘in the case 'of'the
4
,
winding 13 of FIGS. 1, 2 and
3 with a transistor Tand a battery P in any of the man-v
ners disclosed in FIGS. 7 to 11 for instance.
, The magnetic bar 21 is enclosed‘ inside a stationary
ingthe amplitude of the balance wheel as in the preced
‘ingly described embodiment.
'
-
,
I
yFIG. 6 illustrates a modi?cation of the magnet shown
in FIGS. 1 and 4. Said modi?ed magnet is in the shape
magnetic screen 23.’ ‘The latter includes‘a casing having
a cylindrical 'wall Z‘tboaxially surrounding the balance
terminal sections and it carries .along‘the surfaces limiting
wheel and the diameter of which is slightly larger than
that of the magnet, said'cylindrical wall being associated
with two circular plates v25 arranged at short distances
from the upper and lower surfaces of the magnet respec 10
laterally said central section two blades 27. The latter
extending at small distances from the lateral surfaces of
the terminal sections of a reduced breadth -.of the magnet
collect all the lines of force passing through the latter, ex- 7
tively.
of a bar of which the central section is broader than its
cept those which pass through its polar surfaces and which
_
'Said casing is provided with'lateral openings 26 located
serve for modifying the magnetic condition of the arma- ,
in registry with'the ends of the armature and the breadth
ture.
_
of which is substantially equal to that of said ends of the
Said blades have for their chief advantage the fact that
latter and also ‘to that of the magnet 21. Said casing is 15 they ensure a clean and rapid modi?cation of the mag
made of non-remanent magnetic material similarly to the
netic'condition of the armature 10 or 20 as the case. may _
armature 12, but its reluctance with reference to the mag
be at the moment at which‘the magnet registers with the
netic flux of the magnet21 is less than that of the arma
ends of the latter.
‘
a
ture "29.
'
‘It is of advantage to use for the different sections :of
This screening provides for the'uniformity of the mag 20 the various magnetic circuits described ‘which are .to be
netic potential of the medium inside which the bar oscil
provided with a permanent magnetization the proprietary
lates except for the comparatively narrow angular per
product “Ferroxdure” or the like having a large-electrical
'fectly de?ned area which ‘registers with the openings 26.
resistivity above 0.1 ohm-‘cm.
'
i '
a
When the poles of the magnetic bar are shifted away
The release of the electric circuit may also be-obtained
from the ends of the arrnature’20, the lines of ‘force pass
through ‘the agency ‘of a ‘mechanical switch controlled by
ing through magnet 211 c'lose solely through the stationary
the balance wheel. In~this case, the permanentrmagnet
screen 23. In contradistinction, when the poles of the
ization of the movableor stationary section of the mag
magnetic ‘bar occupy ‘a position adjacent the openings '26,
' netic circuit ‘may be replaced by the magnetization‘pro
a fraction of the magnetic ?ux passes through the arma
'duced by 'a coil and ‘the duration of which is limited ‘to
ture 20. Since the reluctance of the latter is higher‘than 30 ‘that of the impulse, ‘wliic‘h‘arran'gement improves jthe
that of the screening casing, the magnet 21 is subjected
ei?ciency.
'
'
‘i
I
~
'
in this latter position to a force which urges. it away from
Whati'I ‘claim is:
the medial position illustrated in dot-and-dash lines in
1. An arrangement ‘for electroimechanically ‘maintain
a
ing‘the movement of a spiral balance wheel, comprising
These conditions are favorable because this repelling 35 at least one bar of magnetic material diametrically ‘rigid
action appearing during the oscillation, of the balance
with the balance wheel and oscillating therewith, ‘and in
FIG. 4.
v
'
'
‘
wheel as soon as the bar 2\1.is near the openings 26 is
speedily replaced by an attractive force produced by the
cluding lateral longitudinally extending projections ‘rigid
with the oscillating bars ‘and adapted to collect all the
passage of ,a current impulse through the coil 22 as a
lines of force passing out of the said bars, except‘those
consequence of the release of the electric circuit due to 40 ‘which pass through the polar ‘surfaces “of ‘the bars, a
the passage of a fraction of the magnetic ?ux fromi the
magnetic circuit including a stationary section, the sta
magnet 21 into the armature 20.
tionary section, “being-made of ‘a magnetic material-show
This attractive force should in principle disappear as
ing no remanence, and the oscillating bars being'made
soon as the bar passes through its medial position. At
of a permanent magnet material, a stationary cylindrical
this moment, it is again subjected to a repelling force
magnetically screening casing, ‘made 'ofa “magnetic ma
which continues the driving action of the attractive force.
terial showing'no substantial remanence, surrounding the
If the attractive force is not wiped out whenlthe magnet
path followed by the ends of the ‘bars at a small distance
“passes through its medial position, said magnet is braked;
beyond same and provided with a number of diametri~ ~
.thisbraking may be used for obtaining an automatic ad
‘cally opposed gaps equal to the number of bar ends, ‘the
justment of the amplitude of the movement of the balance
‘breadths of which are substantially equal vto-those or said
.Wheel since it appears as soon as the speed of the latter
oscillating bars, said ‘casing cooperating‘magnetically with
passes beyond a predetermined value.
a
The arrangement illustrated in FIGS. 4 and 5 may be
modi?ed to form, a ?fth embodiment when the armature
20 of magnetic material showing no remanence is replaced 55
the stationary section, the ends of which face outwardly
i ‘by a :slightly magnetized armature and the magnetized
‘bar 21 is replaced by a bar of magnetic material showing
no
remanence.
.
'the casing gaps, said casing separating ‘the bars from the
stationary section and its gaps registering with the ends
of the bars each time ‘the balance wheel is in its medial
position of unstable equilibrium, the lines of force pro
‘duced by the permanent magnets constituted by the‘bars
and which pass through its polar surfaces closing solely
‘through ‘the casing when the balance wheel is away‘from
its medial ‘position and both through the casing and the
stationary section when the balance‘wheel is approxi
In this latter case, the ,?ux generated by the armature
20 is closed over the screening casing whenever ‘the bar
21 is shifted away from its medial position while it passes
through the bar when the latter is near registry with the
mately in said medial position, ‘and an electric circuit
wound over the stationary ‘section ‘of the magneticlcircuit
openings 26.
‘and subjected to the magnetic pulses produced by the
.
Consequently, when the balance wheel oscillates, the
movement of the bars in front of the gaps to produce :in
.reluctance of the magnetic circuit decreases as soon as 65 its turn modi?cations in the flux in the magnetic circuit
.the bar 11 reaches a position near the poles of the arma
and to sustain thereby the oscillations of the oscillating
This modi?es the magnetic conditions in said arma
bars.
2. An arrangement ‘for electromechanically maintainy
ture. The release ‘of the electric circuit thus obtained
vproduces a current impulse in the winding 22 which im 70 ing the movement of a spiral balance wheel, comprising
a bar of magnetic material diametrically rigid with the
pulsemakes an attractive force act on the bar 21.
balance wheel and oscillating exclusively therewith, a
As in the reverse arrangement, said attractive force
jcure.
should disappear at the moment of the passage of the
magnetic circuit including a stationary section and a. sta
:bar through its medial position, failing which the latter
tionary magnetic screen coaxially surrounding the path
istbraked. ' This leads to the same possibility of adjust 75 followed by the ends of said bar, extending at a short
»
3,028,532
distance outside and throughout'the length of. said path.
with the exception of two diametrically opposed narrow
gaps magnetically cooperating with the stationary section
andseparating, the latter completely from the bar, the
bar registering through its ends with the diametrically
over the stationary section of the magnetic circuit, en
tirely separated by the screen from the bar, and subjected
to the short magnetic pulses produced by the movement
1 of the bar in front of the gaps to produce thereby short
modi?cations in the ?ux in the magnetic circuit to sustain
the oscillations of the oscillating bar and balance wheel.
opposed gaps each time the balance wheel is in its medial
6. An arrangement for electromechanically maintain
position of unstable equilibrium, and an electric circuit
ing the movement of a spiral balance wheel, comprising
wound over the stationary section of the magnetic circuit,
a bar of permanent magnetic material diametrically rigid
entirely separated by the screen from the bar, and sub
je'cted to the short magnetic pulses produced by the move 10 with the balance wheel and oscillating exclusively there
with, a magnetic circuit including a stationary section of
ment of the bar in front of the gaps to produce thereby
a magnetic material showing no remanence, and a station
short modi?cations in the flux in the magnetic circuit to
ary magnetic screen coaxially surrounding the path fol
sustain the oscillations of the oscillating bar andbalance
lowed by the ends of said bar, extending at a short
wheel.
3. An arrangement for electromechanically maintain 15' distance outside and throughout the length of said path
with the exception of two diametrically opposed narrow
ing the movement of a spiral balance wheel, comprising
gaps, the ‘angular breadth of each of which is substan
a bar of permanent magnetic material diametrically rigid
tially equal to that of the bar, magnetically cooperating
with the balance wheel and oscillating exclusively there
with the stationary section and separating the latter com
with, a magnetic circuit of magnetic material showing no
substantial remanence, including a stationary section and 20 pletely from the bar, the bar registering through its ends
a stationary magnetic screen coaxially surrounding the
with‘ the diametrically opposed gaps each time the bal
ance wheel is in its medial position of unstable equilib~
path followed by the ends of said‘bar, extending at a
short distance outside and throughout the length of said
rium, the lines of force produced by the permanent
pathiwith the exception of two diametrically opposed
narrow-gaps, magnetically cooperating with the stationary
section and'separating the latter, completely from the bar,
the bar registering through its ends with the diametrically
opposed gapsv each time the balance wheel is‘ in its medial
magnets constituted by the bar closing solely through
the screen when the balance wheel is away from its
medial position and both through the screen and the
stationary, section when the balance wheel is approxi
mately in said medial position, and an electric circuit
positionof unstable equilibrium, and an electric circuit
- wound over the stationary section of the magnetic circuit
wound over the stationary section of the magnetic circuit, 30 entirely separated by the screen from the bar, and sub
entirely separated by the screen from the bar, and sub
j‘ected to the short magnetic pulses produced by the
jected to the short magnetic pulses produce-d by the move
movement of the bar in front of the gap to produce
ment of the bar in front of the gaps to produce thereby
thereby short modi?cations in the flux of the magnetic
short modi?cations in the ?ux in the magnetic circuit to
circuit to sustain the oscillations of the oscillating bar
sustain the oscillations of the oscillating bar and balance 35 and balance wheel.
wheel.
‘
4. An arrangement for electromechanically maintain
ing the movement of a spiral balance wheel, comprising
a bar of permanent magnetic material diametrically rigid
with‘ the balance wheel and oscillating exclusively there
with, ama'gnetic circuit of magnetic material showing no
substantial remanence, including a stationary section and
a stationary magnetic screen coaxially surrounding the
path followed by the ends of said bar, extending at a
short distance outside'and throughout the length of said
7. An arrangement for electro~mechanically maintain
ingthe movement of a spiral balance wheel, comprising
a bar of magnetic material showing no remanence, dia
metrically rigid with the balance wheel and oscillating
exclusively therewith, a magnetic circuit including a sta
tionary section of permanently magnetized material and
a stationary magnetic screen of magnetic material show
ing no substantial remanence, coaxially surrounding the
path followed by the ends of said bar, extending at a
short distance outside and throughout the length of said
path‘ withthe exception of two diametrically opposed 45 path with the exception of two diametrically opposed
narrow gaps, the angular, breadth of the ends of which
narrow gaps, magnetically cooperating with the station
are at, the utmost equal .to about 20°, magnetically co
ary section and separating the latter completely from the
operating with thestationary section and separating the - bar,‘ the bar registering through its ends with the dia
latter completely from the bar, the bar registering through
metrically opposed gaps each time the balance wheel is
its ends with the diametrically opposed gaps each time 50 in its medial position of unstable equilibrium, the lines
the balance wheel is in its medial position of unstable
of force produced by the permanent magnet constituted
equilibrium, and an electric circuit wound over the sta
tionary section of the magnetic circuit, entirely separated
by the screen from the bar, and subjected to the short
by the stationary section closing solely through the screen
when the balance wheel is away from its medial position
and both through the screen and at least partly through
magnetic pulses produced by the movement of the bar in 55 the oscillating bar when the balance wheel is in a posi
front of the gaps to produce thereby short modi?cations
tlon approximating said medial position, and an electric
in the flux in the magnetic circuit to sustain the oscilla
circuit wound over the stationary section of the magnetic
tions of the oscillating bar and balance wheel.
circuit, entirely separated by the screen from the bar,
5. An arrangement for electromechanically maintain
and subjected to the short magnetic pulses produced by
ing the movement of a spiral balance wheel, comprising 60 the movement of the bar in front of the gaps to produce
a bar of magnetic material diametrically rigid with the j thereby short modi?cations in the flux in the magnetic
balance wheel and oscillating exclusively therewith, a
circuit to sustain the oscillations of the oscillating bar
magnetic circuit including a stationary section and a sta
and balance wheel.
tionary magnetic screen constituted by a cylindrical cas
8. An arrangement for electro-mechanically maintain
ing of a magnetic material showing no substantial rema 65
ing the movement of a spiral balance wheel, comprising
nence, coaxially surrounding the path followed by ‘the
a bar of magnetic material diametrically rigid with the
ends of said bar, extending at a short distance outside
balance
wheel and oscillating exclusively therewith, a
and throughout the length of said path with the exception
magnetic circuit including a stationary section and a
of two diametrically opposed narrow gaps, the breadth
of which is substantially equal to that of the bar, mag 70 stationary magnetic screen made of a magnetic material
showing no substantial remanence, coaxially surrounding
netically cooperating with the stationary section and sepa
rating the latter completely from the bar, the bar regis
tering through its ends with the diametrically opposed
the path followed by the ends of said bar, extending at
a short distance outside and throughout the length of said
path with the exception of two diametrically opposed
gaps each time the balance wheel is in its medial position
of unstable equilibrium, and an electric circuit wound 75 narrow gaps, the angular breadth of which is substantially
3,028,532,
8
equal to that of the bar, magnetically cooperatingvwith
the stationary section and separating the latter completely
from the bar, the bar registering through its ends with
the diametrically opposed gaps each time the balance
the bar registering with the diametrically opposed gaps,
through its ends, each time the balance Wheel is in its
medial position of unstable equilibrium, two windings
surrounding different portions of the stationary section“
wheel is in its medial position of unstable equilibrium,
and the mutual coef?cient of inductance of which is
and an electric circuit’ wound over the stationary section
extremely small, means for feeding said windings with
of the magnetic circuit, entirely separated by the screen
from the bar, and subjected to the short magnetic pulses
electric current, the modi?cations in the magnetic ?ux
produced by the movement of the bar infront of the
produced by the movement of the bar in front of the
gaps acting on the current in the windings to produce
gaps to produce thereby short modi?cations in the flux 10 in its turn modifications in the magnetic ?ux and thereby
in the magnetic circuit to substain the oscillations of the
sustain the oscillations of the bar.
oscillating bar and balance wheel, the magnetic material
11. An arrangement for electromechanically maintain
forming at least one of the following parts: the stationary
ing the movement of a spiral balance wheel, comprising
section, the oscillating bar and the casing, being selected
a‘ bar of magnetic material diametrically rigid with the
from sintered magnetic oxides having a resistivity above 15 balance wheel and oscillating exclusively therewith, a
0.1 ohm-cm.
,
V
magnetic circuit including a stationary section and a
9. An arrangement for electromechanically maintain
stationary magnetic screen coaxially surrounding the path
ing the movement of a spiral balance wheel, comprising
followed by the ends of said bar, extending at a short
a bar of magnetic material diametrically rigid with the
distance outside and throughout the length of said path
balance wheel and oscillating exclusively therewith, a 20 with the exception of two diametrically opposed narrow
magnetic circuit including a stationary section and a
gaps, magnetically cooperating with the stationary section
stationary magnetic screen coaxially surrounding the path
and separating the latter completely from the bar, the
followed by the ends of said bar, extending at a short
bar registering through its ends with the diametrically
distance outside and throughout the length of said path
opposed gaps each time the’ balance wheel is in its medial
with the exception of two diametrically opposed narrow 25 position of unstable equilibrium, two windings separated
gaps, magnetically cooperating with the stationary section
and separating the latter completely from the bar, the
bar registering with the diametrically opposed gaps,
through its ends, each time the balance wheel is in its
from the bar by the screen, surrounding different por
tions of the stationary section and the mutual coefficient
of inductance of which is extremely small, each winding‘
being constituted by two interconnectedv half-windings‘,
medial position of unstable equilibrium, and an electric 30 the mutual coe?icient of inductance of which is substan~
circuit wound over the stationary section of the magnetic
tially equal to zero, means for feeding said windings
circuit, entirely separated by the screen from the‘ bar,
with electric current, the short magnetic pulses produced
and subjected to the short magnetic pulses produced by
by the movement of the bar in front of the gaps acting
the movement of the bar in front of the gaps to produce
on the current in the windings to produce in its’t'urn
thereby short modi?cations in the ?ux in the magnetic 35 short modi?cations in the magnetic ?ux and thereby sus
tain the oscillations of the bar.
circuit to sustain the oscillations of the oscillating bar
and balance wheel, and means locking the electric circuit
against operation in the absence of said magnetic im
References Cited in the ?le of this patent
pulses.
UNITED'STATES PATENTS
40
10. An arrangement for electromechanically maintain
ing the movement of a spiral balance Wheel, comprising
2,704,334
Brailsford ____________ __ Mar. 15", 1955
a bar of magnetic material diametrically rigid with the
2,719,944
Brailsford _>__'.-. _________ __ Oct. 4, 1955
balance wheel and oscillating exclusively therewith, a
2,769,946
Brailsford ____' ______ _.,.__ Nov. 6, 1956
magnetic circuit including a stationary section and a
stationary magnetic screen coaxially surrounding the path 45
followed by the ends of said bar, extending at a short
distance outside and throughout the length of said path
with the’ exception of two diametrically opposed narrow
gaps, magnetically cooperating with the stationary sec
tion and separating the latter completely from the bar, 50
FOREIGN PATENTS
“
198,725
Great Britain __________ _._ June 4, 1923‘
907,199
France‘ .a _____________ __ June 18, 1945
910,563
Germany _____ __- ______ __ May3, 1954
1,092,411
France _r__-____.._- _____ __ Nov. 10, 19574
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