Improvements in and relating to Compensation Devices for Chronometer Watches.
Year: 1899

page_text: Date of Application,
18th Foh 1800
Complete Specification Left, 10th Oct.. 1899-Accepted, 18th Nov., 1899
Complete Specification Left, 10th Oct.. 1899-Accepted, 18th Nov., 1899
PROVISIONAL SPECIFICATION.
Improvements in and relating to Compensation Devices for
Chronometer Watches.
I, ANTOINE BOREL, of 1, Rue de la Poste, Geneva, Switzerland, Watchmaker,
do hereby declare the nature of this invention to be as follows:-
It is a well known fact that in any chronometer watches the escapement of
which is duly compensated for middle temperature differences, a retarding action
of some seconds is caused by the extreme temperatures to which the watch
may be accidentally exposed; this fact has already been observed by the well
known English watchmaker Dent in the year 1833 and the said difference bears
therefore the name of; "Dents anomaly."
The purpose of the present invention is to eliminate as far as possible the
said Dent's anomaly in chronometer watches and this is obtained by two distinct
means of compensation: the one acting upon the balance wheel of the watch
escapement, the other one upon the spiral spring.
In the annexed drawings
Figure 1 is a plan view and
Figure 2 a cross section of the first of these devices.
Figure 3 is a plan view of the second one.
In Figures 1 and 2, 1 is a compensated balance wheel the arms 2 of which
are provided with two movable weights 3. which are connected to the said arms
by means of suitable screws 4 passing through longitudinal slots made in the
said arms so as to allow the said weights to move radially to or from the axis
of the balance wheel.
In proximity to the said weights 3. the arms 2 are provided with suitable
lateral projections upon which are fixed two bimetallic blades 5 and 6, the free
ends of which are placed one over the other and in the path of the weight 3,
which is pressed against the said free ends of the bimetallic blades 5 and 6 by
means of a spring 7, fixed to the balance wheel arm 2. The bimetallic blades 5
and 6 are made to work in inverse sense upon the weights 3, that is to say: if
the blade 5 has for instance its steel portion placed inward and its brass portion
placed outward, the blade 6 will have its steel portion placed outward and its
brass portion placed inward.
Now if a very high temperature acts upon the watch, the blade 5 will be
bent inwardly towards the axis of the balance wheel and remove the weight 3
in the same direction which will cause a slight advance of the watch.
During this function the blade 6 will remain out of action.
If in the contrary the watch is submitted to a very low temperature, the
bimetallic blade 6 will be bent toward the axis of the balance wheel and remove
the weight 3 in the same direction, which will again cause a slight advance of
the watch.
The bimetallic blades
and 6 may be made of any other suitable combination
of metals whatever but such combination will always be made so as to have

page_text: the most dilatable of the two metals forming one of those blades placed inwardly
if the most dilatable of the two metals forming the other blade is placed out-
wardly.
The material of which the pieces 3 are made may vary according to the more
or less weight they will have in view of producing the best control of the watch.
In Figure 3 A is a paw having two bimetallic arms B and C which replace
the usual tail of the paw; these arms are for instance made each of an internal
portion of steel and of an external portion of brass. A spring E tends to main-
tain the paw constantly bearing either with its arm B against the eccentric D
or with its arm C against the screw F, which is screwed through a hole Y of
the piece G, fixed to the cock-bridge. The fixed piece G is furthermore pro-
vided with supplementary holes Y¹ and Y into which the said screw F may be
screwed with a view of altering the length of the acting portion of the bimetallic
arm C. There are further provided in the cock-bridge supplementary holes 7
and Z corresponding to the holes Y¹ and Y and in which the screw of the
eccentric D may be screwed with a view of altering the length of the acting
portion of the bimetallic arm C.
Supposing that, in a watch the escapement of which is preferably compensated
for the usual temperature-differences, the said watch shows a retard of several
seconds when exposed to very high or very low temperatures the above described
device will be able to prevent this by causing an advance of several seconds at
such very high or very low temperatures.
If, for instance, the temperature is very high, the bimetallic arm B will be
bent in the manner shown at an exaggerate rate by dotted lines in the drawing,
so as to cause the paw A to be rotated in the sense of the arrow 1, thereby
shortening the length of the spiral-spring and causing an advance of several
seconds of the watch.
During this operation the arm C remains quite inactive, being free to move
between the end of the screw F and the eccentric D.
If on the contrary, the watch is exposed to very low temperatures, the bi-
metallic arm C will be bent in the manner shown at an exaggerate rate by the
dotted lines in the drawing and the result will again be a rotation of the paw A
in the sense of the arrow 1 and a shortening of the spiral-spring, causing an
advance of several seconds of the watch.
The same result might be obtained either by interverting the arrangement of
the metals composing the bimetallic arms, that is to say in making the internal
portion of each arm B and C of brass and the external portion of steel, or by
using other suitable metals or combinations of metals, as for instance, palladium,
silver, gold, nickel, and the like.
Dated this 18th day of Rohman
1000
CARPMAEL & Co.,
Agents for the Applicant.
1 DIECIFICATION.
Improvements in and relating to Compensation Devices for
Chronometer Watches..
I, ANTOINE BOREL, of 1, Rue de la Poste, Geneva, Switzerland, Watchmaker,
do hereby declare the nature of this invention and in what manner 'the same
is to be performed to be particularly described and ascertained in and by the
following statement;
1
It is a well known fact that in any chronometer watches the escapement of

page_text: which is duly compensated for middle temperature differences, a retarding action
of some seconds is caused by the extreme temperatures to which the watch
may be accidentally exposed; this fact has already been observed by the well
known English watchmaker Dent in the year 1833 and the said difference bears
therefore the name of; "Dent's anomaly.' "
The purpose of the present invention is to eliminate as far as possible the
said Dent's anomaly in chronometer watches and this is obtained by two distinct
means of compensation: the one acting upon the balance wheel of the watch
escapement, the other one upon the spiral spring.
In the drawings left with the Provisional Specification.
Figure 1 is a plan view and
Figure 2 a cross section of the first of these devices.
Figure 3 is a plan view of the second one.
In Figures 1 and 2, 1 is a compensated balance wheel the arms 2 of which
are provided with two movable weights 3, which are connected to the said arms
by means of suitable screws 4 passing through longitudinal slots made in the
said arms so as to allow the said weights to move radially to or from the axis
of the balance wheel.
In proximity to the said weights 3, the arms 2 are provided with suitable
lateral projections upon which are fixed two bimetallic blades 5 and 6, the free
ends of which are placed one over the other and in the path of the weight 3,
which is pressed against the said free ends of the bimetallic blades 5 and 6 bv
means of a spring 7, fixed to the balance wheel arm 2. The bimetallic blades
and 6 are made to work in inverse sense upon the weights 3, that is to say: if
the blade 5 has for instance .its steel portion placed inward and its brass portion
placed outward, the blade 6 will have its steel portion placed outward and its
brass portion placed inward.
Now if a very high temperature acts upon the watch, the blade 5 will be
bent inwardly toward the axis of the balance wheel and remove the weight 3
in the same direction which will cause a slight advance of the watch.
During this function the blade 6 will remain out of action.
If on the contrary the watch is submitted to a very low temperature, the
bimetallic blade 6 will be bent toward the axis of the balance wheel and remove
the weight 3 in the same direction, which will again cause a slight advance of
the watch.
.The bimetallic blades 5 and 6 may be made of any other suitable combination
of metals whatever but such combination will always be made so as to have
the most dilatable of the two metals forming one of those blades placed inwardly
if the most dilatable of the two metals forming the other blade is placed out-
wardly.
The material of which the pieces 3 are made may vary according to the more
or less weight they will have in view of producing the best control of the watch.
In Figure 3 A is a paw having two bimetallic arms B and C which replac
the usual tail of the paw; these arms are for instance made each of an internal
portion of steel and of an external portion of brass. A spring E tends to main-
tain the paw constantly bearing either with its arm B against the eccentric ])
or with its arm C against the screw F, which is screwed through a hole Y of
the piece G, fixed to the cock-bridge. The fixed piece G is furthermore pro-
vided with supplementary holes Y₁ and Y into which the said screw F may be
screwed with a view of altering the length of the acting portion of the bimetalli
arm C. There are further provided in the cock-bridge supplementary holes 71
and Z corresponding to the holes Y¹ and Y and in which the screw of the
eccentric D may be screwed with a view of altering the length of the acting
portion of the bimetallic arm C.
Supposing that in a watch the escapement of which is perfectly compensated
for the usual temperature-differences, the said watch shows a retard of several
seconds when exposed to very high or very low temperatures the above described

page_text: device will be able to prevent this by causing an advance of several seconds at
such very high or very low temperatures.
If, for instance, the temperature is very high, the bimetallic arm B will be
bent in the manner shown at an exaggerate rate by dotted lines in the drawing,
so as to cause the paw A to be rotated in the sense of the arrow 1, thereby
shortening the length of the spiral-spring and causing an advance of several
seconds of the watch.
During this operation the arm C remains quite inactive, being free to move
between the end of the screw F and the eccentric D.
If on the contrary, the watch is exposed to very low temperatures, the bi-
metallic arm C will be bent in the manner shown at an exaggerate rate by the
dotted lines in the drawing and the result will again be a rotation of the paw A
in the sense of the arrow 1 and a shortening of the spiral-spring, causing an
advance of several seconds of the watch.
The same result might be obtained either by interverting the arrangement of
the metals composing the bimetallic arms, that is to say in making the internal
portion of each arm B and C of brass and the external portion of steel, or by
using other suitable metals or combinations of metals as for instance, palladium,
silver, gold, nickel, and the like.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what
I claim is
1. In watches the combination with a compensated balance wheel of any
well known construction whatever, with radially movable weights and with
pairs of bimetallic blades, each of the said weights being pressed by a suitable
spring against the free end of one pair of such bimetallic blades and the metals
forming those bimetallic blades being disposed in inverse sense in each pair of
such blades so as to have the temperature acting upon the balance wheel dis-
placing the centre of gravity of the said weights by means of causing either
the one or the other of the blades of each pair of bimetallic blades to act upon
the movable weight bearing against it.
2. In watches the combination with a compensated balance wheel of the con-
struction claimed in Claim 1, with a paw having a tail formed of two bimetallic
blades the free end of each of which is pressed by means of a suitable spring
against an adjustable bearing so as to have the bending of any of the said bi-
metallic blades causing the rotation of the paw in one and the same sense of
rotation.
Dated this 10th day of October 1899.