IMPROVEMENTS IN CHRONO- METERS, WATCHES, AND OTHER TIME-KEEPERS,
Year: 1859

page_text: LETTERS PATENT to Richard Baker, of Liverpool, in the County of
Lancaster, Watchmaker, for the Invention of "IMPROVEMENTS IN CHRONO-
METERS, WATCHES, AND OTHER TIME-KEEPERS,"
PROVISIONAL SPECIFICATION left by the said Richard Baker at the
Office of the Commissioners of Patents, with his Petition, on the 25th
March 1859.
I, RICHARD BAKER, of Liverpool, in the County of Lancaster, Watch-
maker, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN CHRONOMETERS, WATCHES, AND OTHER TIME-KEEPERS," to be as
follows:-
In the ordinary chronometer escapement the scape wheel is locked by a
pallet or detent mounted on a spring, which rests against a banking pin or
stop. This detent spring carries a thin weak spring, which projects a little
beyond its end, and is called the passing spring. The spindle of the balance
carries a pin, which comes in contact with the projecting part of the passing
spring. As the balance swings in one direction this pin pushes the passing
spring away from the detent spring, and passes by it, but when the balanco
swings back again, the pin pushes the passing spring against the detent spring,.
and moves them both together away from the banking pin, and thus releases
the scape wheel; one of the teeth of the scape wheel then strikes a pallet on

page_text: the spindle of the balance, and gives the impulse to it. Before this tooth
leaves the pallet the detent spring returns by its clasticity to its banking pin,
and presents the detent to stop the next tooth of the scape wheel. By the
present Invention the detent is carried by a balanced lever, which also carries
the passing spring; the end of this lever is prolonged in a curved or other
suitable form, and carries a pin which enters a circular groove in a block or
disc on the spindle of the balance; the groove is wider than the pin, which
does not touch it, but as long as the pin is in the groove the lever cannot be
moved to such an extent as to release the scape wheel; when, however, the
pin on the balance spindle begins to lift the passing spring, and with it the
detent lever, the pin on the end of the detent lever enters a notch or recess
in the side of the aforesaid groove, which thus allows the lever to move
sufficiently to release the tooth of the scape wheel, and the impulso is then
given by one of the teeth of the scape wheel acting on a pallet in the block or
disc on the balance spindle. As the balance continues its motion, the inclined.
side of the notch or recess pushes the pin on the detent lever back into the
circular groove, and thus brings the detent back in readiness to receive and
lock the tooth of the scape wheel, which draws the detent lever against its
banking pin. The form and arrangement of the parts admit of variation, but
the action is such that the safety of the timekeeper does not depend upon a
spring, for the detent is compelled to return to its place without a spring,
or without depending upon a spring. to effect its return. This escapement.
is applicable to chronometers and watches, and other moveable or fixed
time-keepers.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Baker in the Great Seal Patent Office on the
22nd September 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
BAKER, of Liverpool, in the County of Lancaster, Watchmaker, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fifth day of March, in the year of our
Lord One thousand eight hundred and fifty-nine, in the twenty-second year
of Her reign, did, for Hersolf, Her heirs and successors, give and grant
unto me, the said Richard Baker, Her special licence that I, the said
Richard Baker, my executors, administrators, and assigns, or such others
as I, the said Richard Baker, my executors, administrators, and assigns,

page_text: should at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and lawfully.
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN CHRONOMETERS, WATCHES, AND OTHER TIME-KEEPERS," upon
the condition (amongst others) that I, the said Richard Baker, my exe-
cutors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to
be performed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Richard Baker, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the fol-
lowing statement thereof, that is to say :-
In the ordinary chronometer escapement the scape wheel is locked by a
pallet or detent mounted on a spring, which rests against a banking pin or
stop. This detent spring carries a thin weak spring, which projects a little
beyond its end, and is called the passing spring. The spindle of the balance
carries a pin, which comes in contact with the projecting part of the passing
spring. As the balance swings in one direction, this pin pushes the passing
spring away from the detent spring, and passes by it; but when the balance
swings back again the pin pushes the passing spring against the detent spring,
and moves them both together away from the banking pin, and thus releases
the scape wheel; one of the teeth of the scape wheel then strikes a pallet on
the spindle of the balance, and gives the impulse to it. Before this tooth.
leaves the pallet the detent spring returns by its elasticity to its banking pin;
and presents the detent to stop the next tooth of the scape wheel. By the-
present Invention the detent is carried by a balanced lever, which also carries
the passing spring; the end of this lever is prolonged in a curved or other.
suitable form, and carries a piu, which enters a circular groove in a block or
disc on the spindle of the balance; the groove is wider than the pin, which
does not touch it, but as long as the pin is in the groove, the lever cannot be
moved to such an extent as to reloase the scape wheel; when, however, the
pin on the balance spindle begins to lift the passing spring, and with it the
detent lever, the pin on the end of the detent lever enters a notch or recess in
the side of the aforesaid groove, which thus allows the lever to move sufli-
ciently to release the tooth of the scape wheel; and the impulse is then given

page_text: by one of the teeth of the scape wheel acting on a pallet in the block or disc
on the balance spindle. As the balance continues its motion, the inclined side.
of the notch or recess pushes the pin on the detent lever back into the circular
groove, and thus brings the detent back in readiness to receive and lock the
tooth of the scape wheel, which draws the detent lever against its banking pin.
The form and arrangement of the parts admit of variation, but the action is
such that the safety of the timekeeper does not depend upon a spring, for the
detent is compelled to return to its place without a spring or without depending
upon a spring to effect its return.. This escapement is applicable to chro
nométers and watches, and other: moveable or fixed time-keepers.
C
Figure 1 of the accompanying Drawing is an elevation of an escapement.
constructed according to my Invention; Figure 2 is a plan of the detent
lever; Figure 3 is a separate elevation of the circular block E; Figure 4 is a
section of the same. The same letters refer to similar parts in each Figure.
A is the scape wheel of the ordinary form; B is the detent lever, turning on a
pin or pivots at 6, and balanced by the part B¹. The extent of motion of this
lever is regulated by two banking pins a, c.
is the detent, fixed on tho
lever B, and locking the tooth 1 of the scape wheel A, when the lever B is
against the stop or banking pin a. D is a portion of the arbor or spindle of
the balance; E is a circular block of metal, fixed to the arbor D, and carrying
a pin e, which passes close to the end of the lever B without touching it; F is
the passing spring, fixed at f to the lever B, and projecting a little beyond the
end of the lever B, so as to come within reach of the pin e, in the ordinary
manner. The end of the lever B carries or is made with a bent part h,
in which is fixed a pin i, which enters a groove g in the block E. When the
lever B is lying against the banking pin a, the pin i lies in the groove g,
but does not touch it, and therefore does not interfere with the free action of
the balance. As long, however, as the pin i is in the groove g, the lever B
cannot be raised sufficiently to unlock the tooth of the scape wheel. The face
of the detent C is inclined a little, so that the pressure of the tooth upon
it has a tendency to keep the lever in contact with the banking pin a. In
order to allow the detent lever to be raised at the proper time by the pin e a
notch or recess or cavity is made at n to allow the pin i to rise. The sides of
this recess are inclined, so as to push down the pin i as soon as the tooth 1 is
released, and thus prevent the escape of more than one tooth. As the tooth 1
is released, the tooth 3 drops against a pallet m in the block E, and gives the
impulse to the balance. When the balance swings in the opposite direction
to the arrow, the pin e pushes the passing spring F away from the lever B, and
passes by; the spring F then returns to its place. As the balance, swings

page_text: back in the direction of the arrow, the pin e lifts the passing spring F, and
with it the detent lever B and detent C. The tooth 1 being thus released the
tooth 3 moves forward and strikes the pallet m, and gives the impulse to the
balance. While the tooth 3 is still engaged with the pallet m, the inclined
side of the recess n pushes down the pin i and lever B, and thus places the
detent C in its proper position for stopping the tooth 2, which comes in
contact with it, and draws the lever B against the banking pin a. There is
thus no necessity for applying a spring to bring back the detent lever B to the
banking pin a. A spring may be applied for this purpose, if desired, but if
this spring were to break, the action of the escapement would continue,
whereas if the detent spring of an ordinary chronometer escapement breaks,
the action ceases, and there is danger of great damage to the whole apparatus,
owing to the train being released from the detent.
My improvements are applicable to chronometers, watches, and other time-
keepers. The form of the locking parts admits of some variation. Thus the
block E or the balance arbor may carry a pin, which may move in a circular
groove in an annular block or ring attached to the end of the lever B, and
provided with a notch or recess at one part to allow of the motion of the detent
lever at the proper time.
Having now described the nature of my Invention, and in what manner the
same is to be performed, I wish it to be understood that what I claim is, con-
structing the escapements of chronometers, watches, and other timekeepers
with a balanced detent lever, carrying a pin or projection which enters a
groove on a piece or block carried by the balance, or is otherwise locked by
the balance, except at the point where the impulse is to be given, as herein-
beforo described.
In witness whereof, I, the said Richard Baker, have hereunto set my
hand and seal, this Twentieth day of September, in the year of our
Lord One thousand eight hundred and fifty-nine.
KICH. BAKER.
(L.S.)