IMPROVEMENTS IN TIMEKEEPERS
Year: 1859

page_text: LETTERS PATENT to James Ferguson Cole, of Devonshire Street, in the
County of Middlesex, Watchmaker, for the Invention of "IMPROVEMENTS
IN TIMEKEEPERS."
Sealed the 24th April 1860, and dated the 28th October 1859.
PROVISIONAL SPECIFICATION left by the said James Ferguson Cole
at the Office of the Commissioners of Patents, with his Petition on
the 28th October 1859.
I, JAMES FERGUSON COLE, of Devonshire Street, in the County of Middlesex,.
Watchmaker, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN TIMEKEEPERS," to be as follows:-
The distinguishing points or principle in this Invention consist in a reversion.
of the locking angles of the anchor pallets in lever escapements in time-
keepers, in such manner that the alternate pressure of the escape wheel teeth
on each locking will throw each pallet respectively out of locking, instead of draw-
ing each pallet respectively into the spaces of the wheel teeth, as is the case in.
the ordinary detached lever escapement. The first consequence of this difference.
of direction of the locking angle of each pallet is, that the wheel will have a con-
stant tendency to unlock itself without offering to the balance or balance spring
the slightest difference of resistance at the time of unlocking. In this repellent
lever escapement the power from the escape wheel is wholly transmitted to the

page_text: anchor pallets and lever, and from the lever wholly to the balance, with only
the smallest possible loss of power by drop of the wheel teeth, as these pallets
admit of very close scaping. On the balance axis is fixed a simple duplex ruby
roller, only in such a position on the staff as will agree with the plane of the
repellent lever arm, the acting end of which is made in the form of a thin
wedge, and of such length as to rest upon the ruby roller, the extreme end of
the arm being carefully shortened, so as to pass just freely through the roller
notch by intersection.
Having thus explained the form and adaptation of the lever arm in con-
nection with the roller and balance, I now proceed to describe the acting effect
of the anchor pallets on which the escape wheel pressure is constant, except at
the moment of escaping; the wheel tooth then drops on one of the lockings,
and by the small incline of the locking face the impulse end of the lever is
brought to rest on the outside of the roller with a very small amount of
pressure; in this condition of the lever arm one of the lockings will arrest a
tooth of the wheel by only a sufficiently sound engagement, and if the balance
and roller be moved in the direction of the lever, force, the wedge-formed point
of the lever will enter the roller notch without any drop; and give impulse to
the roller and balance with the fullest effect,, as, on the wheel tooth passing
over the locking edge of the pallet, impulse will be given by the wheel to the
pallets, either by using a star wheel with pointed teeth, with or without under-
cutting; such wheel, in this case, giving impulse on the long impulse plane of
each pallet respectively, in the manner of ordinary trade manufactured pallets
as regards the impulse planes only of such pallets; or, otherwise, the impulse
from the wheel to the pallets may be made by cutting the escape as an ordi-
nary club-toothed lever wheel, with the impulse planes partly on the wheel
teeth and also partly on the anchor pallets; but the mode or method I prefer
to adopt is, by forming the escape wheel with the impulse planes entirely ou
the wheel teeth instead of on the pallets; in this case the anchor is formed by.
setting pallets of ruby or other suitable stone into the anchor piece, in such
manner and at such an angle for locking as will effect the repellent action of
each pallet respectively, the said ruby pallets having the locking edges smoothly
finished for receiving impulse from the long incline formed upon each tooth of
this kind of escape wheel, the ruby pallet edges being set so as to represent
arms of equal radius, or nearly so.
The three modes of giving impulse to the pallets by a single incline either,
on the respective pallets or on the wheel teeth are the already adopted modes
of impulse in detached-lever escapements, and therefore the principle herein-
before described consists in the combination of two angles upon each pallet:

page_text: the first angle for the locking being the lesser angle, while the angle for im-
pulse is the greater angle in regard to the power given out by the pressure of
the escape wheel, as described in the three before-mentioned modes of the
wheel and pallet action.
The lever arm may be made of hard gold or other suitable material, or.a
simple pin inserted radially into any suitable part of the anchor will answer the
same purpose; the length of the lever arm being about equal to the radius of
the anchor pallet arms, any little deviation from such length will be of no
material consequence, provided the diameter of the ruby roller be so adapted
to the scaping are of motion of the anchor pallets as will produce about
30 degrees of motion as the scaping arc of the roller and balance; the balance
are may be more or less, at discretion, according to the proportions preferred for
all or any of the acting parts.
I do not confine myself to the employment of angular pallets only, as the
pallets can be made to act less perfectly by straight line single planes, or curved
surfaces for the impulse and lockings.
Another part of my Invention relates to an escapement of the chronometer
class, inasmuch as the teeth of the escape wheel are made to act directly upon
a roller, or in other words, a cylinder fixed upon the balance axis, or otherwise
the cylinder may be itself the axis. The roller I prefer to employ is a ruby roller
with a notch or slit on on on one side, in the manner of an ordinary duplex ruby
roller, and about the usual diameter; the diameter, however, is governed by
the size and number of teeth determined on for the escape wheel; the engage-
ment of the wheel teeth with the ruby roller being so pitched and proportioned
that any two teeth of the wheel shall comprehend or include an arc of the
roller circumference equal to about 36 degrees, more or less, at discretion,
such number of degrees being the scaping arc of motion at the roller and
balance; under these circumstances of the wheel and roller, any power applied
for driving the wheel so. as to give impulse by the wheel tooth acting on one side
of the roller notch, will also create or produce considerable friction on the cylin
drical circumference of the roller, and would materially impede or check the
momentum and motion of the balance; but as a remedy for this impediment to
motion of the balance I employ a short linear spring of tempered steel or hard
gold, and into that side of the spring intended to lie towards the wheel teeth,
I insert a small ruby, pallet; this pallet is set in. the spring in the manner of
ordinary chronometer locking or discharging stones; but in reference to this
part of my Invention, the pallet must be set at an angle of about 45 degrees
from the root line or bending direction of the said spring, which must be so
fixed on the watch movement plate as to allow the angle of the ruby pallet, to

page_text: press on one of the wheel teeth near to the ruby roller. The purpose intended
by me in my use of this spring is to reduce friction on the roller by holding
back the tooth in action by the diagonal pressure of the pallet on each tooth of
the wheel in succession; the spring is made to rest upon a banking pin fixed
in the frame plate, and is required to be raised by the wheel tooth only the
smallest effective quantity; when the roller notch advances the acting tooth on
the roller will enter the roller notch immediately clearing the spring pallet,
and in passing onward gives impulse to the balance by pressure on the side of
the roller notch, which action will be repeated at every impulse of the
balance.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Ferguson Cole in the Great Seal Patent Office on
the 28th April 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
FERGUSON COLE, of Devonshire Street, in the County of Middlesex, Watch-
maker, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of October, in the year of our
Lord One thousand eight hundred and fifty-nine, in the twenty-third year
of Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said James Ferguson Cole, Her special licence that I, the said
James Ferguson Cole, my executors, administrators, and assigns, or such
others, as I, the said James Ferguson 'Cole, my executors, administrators,
and assigns, 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 TIMEKEEPERS," upon the condition (amongst
others) that I, the said James Ferguson Cole, my executors 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 Inven-
tion, 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 James Ferguson Cole, do hereby
declare the nature of my said Invention, and in what manner the same

page_text: is to be performed, to be particularly described and ascertained in and by
the following statement thereof, reference being had to the Drawings here-
imto annexed, that is to say:
The distinguishing points of principle in this Invention consist in a reversion
of the locking angles of the anchor pallets or locking faces of the escape
wheel:
teeth in lever escapements in timekeepers, in such manner that the alternate-
onward pressure of the escape wheel teeth on each pallet locking will throw
each pallet respectively out of locking, instead of the pressure drawing each
pallet respectively into the spaces of the wheel teeth, as is the case in ordinary
detached lever escapements. The first consequence of this difference of
direction of the locking angle of each pallet is that any tooth of the escape
wheel when resting on either pallet locking, will have a constant tendency to.
unlock. itself therefrom by the pressure reversing the ordinary motion or
tendency to motion of the pallets, thereby destroying the detachment without
offering to the balance or balance spring the slightest difference of resistance
at the time of unlocking, as compared with the resistance during the entire
arc of vibration of the balance. In this escapement, which I designate the
anti-detached or repellent lever escapement, the power from the escape wheel
is wholly transmitted to the anchor pallets and lever, and from the lever
wholly to the balance, with only the smallest loss of power by drop of the
wheel teeth on the lockings, as pallets and wheels of the several descriptions
herein given admit of very close scraping.
Figure 1 of the accompanying Drawings is a plan of an anti-detached or
repellent lever escapement constructed according to my Invention. A is the
circumference of the balance, on the axis of which an ordinary duplex ruby
roller B is fixed, or a roller of hard steel, gold, or other suitable material of
corresponding cylindrical form or nearly so may be employed. This roller B
or its substitute having a longitudinal narrow notch on the outer side, with
the acting edges of the notch smoothly finished in the manner of an ordinary
ruby roller. The roller, of whatever kind it may be, is fixed in such a position.
on the balance axis as will agree in elevation with the plane surface of the
repellent lever arm C. The acting end of the lever arm is made and finished
in the form of a single pointed thin leaf or wedge, the arm of either form
being made of such length as to rest upon the circumference of the said ruby
or other roller employed, and the extreme acting end of the arm carefully
shortened so as to pass just freely through the roller notch B by intersection.
Having thus far explained the forms and adaptation of the lever arm in
connexion with the roller, which roller operates in two ways, firstly, by
detaining the lever arm, and secondly, by receiving the lever impulse alter

page_text: nately on the sides or edges of the roller notch, or both, and thereby giving
motion to the balance; I proceed to describe the acting effect of the before--
mentioned anchor pallets and wheels, and also other modifications of pallets
and wheels constructed by me for the same purpose. On all or either of the
afore-mentioned pallets the escape wheel force is constant, except at the
moment of escaping; the wheel tooth in either case next in action then drops
on one of the pallet lockings, and by the slight incline of the locking faces of.
the pallets D, D, in this mode of action, as in Figure 1, the impulse end of
the lever arm is brought to rest upon the outer surface of the roller with a
very small amount of pressure, consequent to the little inclination of the
locking angles, as compared with the greater angles for the impulse or drive.
of the wheel teeth continuously in the assigned direction on pallets of this
description, or on pallets of other forms herein-after specified. In this con-
dition of the lever arm when resting on the circumference of the roller, one of
the pallet lockings as at D' will arrest a tooth of the escape wheel E by only
a sufficiently sound engagement; and if the balance and roller be moved in.
the direction of the lever force, as indicated by the arrow, the wedge formed
extremity of the lever will enter the roller notch without any drop, and give
impulse to the roller and balance with the fullest effect, as on the wheel tooth
passing over the locking edge of the pallet, impulse will be given by the wheel
to the pallets by using a wheel.with star-shaped pointed teeth, as in Figure 1,
such wheel in this case giving impulse on the long impulse plane of each
pallet respectively, in the manner of ordinary trade manufactured lever pallets
as regards the impulse planes only of such pallets. The escape wheel E
may be made with any other number of teeth than those shown.
I also produce the action and effects herein-before described by employing
an ordinary club-toothed lever wheel with the impulse planes partly on the
wheel teeth and partly on the anchor pallets; I otherwise form the escape.
wheel with the impulse planes entirely on the wheel teeth instead of on the.
pallets. The pallets may embrace three, four, or any number of the said
teeth.
•
The anchor is sometimes formed by setting pallets of ruby or other suitable
stone into the anchor piece, in such manner and at such an angle for locking
as will effect the repellent action of each pallet respectively, the said ruby
pallets having their acting edges and ends smoothly finished for receiving
impulse from the long incline formed upon each tooth of this kind of escape
wheel, whether made of steel, brass, gold, or other material, the ruby pallet
edges or acting ends of the stones being set in the anchor piece, so as to
represent arms of equal radius or nearly so.

page_text: The modes herein-before mentioned for giving impulse to the pallets by a.
single incline, either on the respective pallets or on the wheel teeth, or
dividedly on both, are the usually adopted modes of impulse action in ordinary.
detached lever escapements as regards the impulse planes only in such escape-
ments.
The improved principle of my repellent lever escapement, as herein-before
described, consists in the combination of two angles upon each pallet respec-
tively, the first angle for the locking being the lesser angle, while the angle
for impulse is the greater angle as regards the power given out by the pressure
of the escape wheel teeth in the three before-mentioned modes of the wheel
and pallet action. The disparity or difference in either case between each,
pair of angles is intended and adopted as a means of producing alternate
differential force from the lever to the roller, while moving in the same one or
other direction of the impulse for the express purpose of relieving the pressure
of the lever on the roller, and also for diminishing the friction arising there:
from during the vibratory motion of the balance, the motion being kept up
without any other means of impulse in this escapement than by the lever point:
acting on the sides and edges of the roller notch.
In Figure 1 the driving faces of the escape wheel teeth are made and
intended by me to agree with the locking faces of the respective pallets as
regards the line of direction of the acting faces of such or other forms of.
teeth. I thereby establish a double mode of action, the repellent effect upon.
the lever being mutually produced by the pallet angles, and also by the angles
formed upon the faces of the wheel teeth, which are intended to act with;
similar effect independently of the locking angles on the pallets, or otherwise.
in conjunction with the locking angles on the pallets; and I use those angles
in either or both ways for the same purpose at discretion, the object in both.
cases being to give to the escape wheel a power to unlock itself without impe-
diment to the motion of the balance, and thereby to remedy the defect of;
mechanical locking resistance as regards the adjustments of timekeepers.
In this escapement, when a ruby roller is employed, the lever arm may be.
made of hard gold or other suitable material, or for the same purpose a simple
wedge-formed pin inserted radially into any suitable part of the anchor piece.
will answer equally well, and may be made of like material; but when a hard.
steel roller is employed, the lever arm terminates in a wedge-formed ruby
pallet inserted or set therein, the lever arm in either case being in length
about equal to the radius of the anchor pallet arms. Any little deviation from
such length will be of no great consequence, provided the diameter of the,
impulse roller be so adapted to the scaping are of motion of the anchor.

page_text: pallets as will produce about thirty-six or forty degrees of motion as the scaping
arc of the roller and balance; the balance are may be more or less at discretion
according to the proportions preferred for all or any of the acting parts, and
the amount of motive power applied.
I do not confine myself to the employment of pairs of double plane angular
pallets only, as the pallets can be made to act by single planes, or by curved
surfaces for the lockings and impulse; and as a modification of the repellent
locking principle of this escapement, I also employ pallets such as are com
monly manufactured for the ordinary detached lever escapement. In this
mode of making the escapement I produce the repellent action of the pallets
and lever not by the pallet angles, but by the escape-wheel teeth, sloped as
before described, so as to correspond with the repellent locking faces of the
first kind of pallets in Figure 1, the differential angle in this case being
transferred to the escape-wheel teeth, which are cut suitably for repelling
the pallets independently of the first-mentioned locking angles on the pallets.
I otherwise employ the common ratchet-toothed wheel, fixing such wheel on
its pinion in a reverse direction to that necessary in ordinary detached lever
escapements, the teeth of such wheels being previously bent more upright in
a small machine tool at an angle only sufficient to repel the respective ordinary
lever pallets with proper effect. I also employ such ratchet-toothed wheels in
the usual manufactured condition without bending the teeth, but in such case
with less mechanical advantage.
In another modification I produce the repellent action of the lever by
employing the ordinary ratchet-toothed undercut wheel as usually applied in
ordinary detached lever escapements, and using the ordinary pallets with draw
lockings, not for detachment of the lever, as in this mode of producing the
repellent action the unlocking is effected by a slight banking spring fixed on
the frame in a line with the lever centre of motion, and acting as a check
spring in a notch cut in the lever or pallets, or on a pin, or between two pins
inserted in the lever or pallet piece in any manner suitable for unlocking the
escapement, thereby irrespectively of the first-mentioned locking angles in
Figure 1 or the repellent angles on the wheel teeth. This banking or dis-
charging spring I make of such strength as is only sufficient for unlocking the
wheel by an equally small are of bending, the lever or pallet immediately after
the unlocking quits the spring, and is free during the whole are of impulse in
either direction. Similar effects will be produced by fixing the check spring
to the lever, or by reducing the lever tail as a spring, and in both these modes
either spring employed must act upon a pin, or between two pins fixed in the
manner of ordinary lever banking pins; but in all the former modes of my

page_text: repellent lever action no banking pins or spring is required, as the lever
banking is effected by the repose of the lever point upon the roller, and the
spring in this case intended to keep the lever arm, or its wedge-formed ruby
pallet, against the respective roller, with only a nominal amount of pressure
during the vibrations of the balance, and thereby destroying the detachment,
which effect is produced by the repellent action of the spring independently of
the repellent angles on the pallets, as firstly described in Figure 1.
With regard to the lever arm, I make the wedge-formed extremity of the
arm to act on the roller and roller notch between the centres of motion of the
lever and balance, as in Figure 1, or by prolonging the lever arm in a curved
or other form. I reverse the extreme acting end so as to repose on the roller
on the opposite side of the axis beyond the balance centre of motion, the
position of the roller notch in this mode of action being opposite to the
former position when the balance spring and balance are at rest; but for
simplicity and greater soundness of intersection, I prefer to adopt the before-
mentioned shorter arm acting on the roller between the centres of motion of
the lever and balance, as in Figure 1. The roller B, first described and shown
at Figure 1 as being fixed upon the balance axis, may in the case of a steel
roller be made solid with the axis; but this mode of making the axis and
roller in one piece I do not prefer to adopt, and is only mentioned here to
show that this method has not been overlooked.
Another part of my Invention relates to an escapement of the chronometer
class, a view in plan of which is given at Figure 2, inasmuch as the teeth of
the escape wheel are made to act directly upon a roller, or in other words, a
cylinder fixed upon the balance axis or otherwise; the cylinder may be itself
the axis, as in the former named case; but the roller I prefer to employ in
this escapement is a ruby roller, with a notch or slit on one side in the manner
of an ordinary duplex ruby roller, and about the usual diameter; the diameter,
however, is governed by the size and number of teeth determined on for the
escape wheel, the engagement of the wheel teeth with the ruby roller being so
pitched and proportioned, as that any two teeth of the wheel shall comprehend
or include an arc of the roller circumference equal to about thirty-six to forty
degrees, more or less at discretion, such number of degrees being the scaping
arc of motion at the roller and balance. Under these circumstances of the
wheel and roller, any power applied for driving the wheel so as to give impulse
by the wheel tooth acting on one side of the roller notch, as indicated by the
arrow in Figure 2, will also create or produce considerable friction on the
cylindrical surface of the roller, and would materially impede or check the
momentum and motion of the balance, but as a remedy for this impediment to

page_text: motion of the balance I employ a short linear spring of tempered steel or
hard gold, and into that side of the spring intended to lie towards the wheel
teeth, I insert an angular ruby pallet, as at F, Figure 2. This pallet is set
in the spring in the manner of ordinary chronometer locking or discharging
stones; but in reference to this part of my Invention, the pallet must be set
at an angle of about forty-five degrees from the root line or bending direction
of the said spring, which must be so fixed on the movement frame plate as to
allow the angular face of the ruby pallet to press on the extreme point of one
of the wheel teeth near to the ruby roller, and also to press on all the other
teeth in like manner in due succession. The purpose intended in my use of
this spring in this escapement is to reduce friction on the roller by holding
back the tooth or teeth in action on the spring, and on the roller by the
diagonal pressure of the spring pallet on each tooth of the wheel in succession;
and further, the spring or pallet is made to rest upon a check or counter pin
or other banking piece fixed to the frame plate during only the moment of
-escapement impulse, and at all other times while the power of the train and
mainspring is on, the tension or force of the pallet spring is on the one tooth
engaged by the pallet, and also on the other teeth in the course of the wheel
revolutions. The teeth I prefer to make inclining backward, as represented in
Figure 2. This spring I call the retention spring, which I also employ in
other escapements, and which, when out of action is required to be raised from
its banking or check pin by pressure of the wheel teeth in action with the
pallet, and raised only the smallest effective quantity, as when the roller notch
advances the acting tooth on the roller will enter the roller notch, immediately
clearing the spring pallet, which then drops on its banking, and the wheel tooth
engaged with the roller passing onward gives impulse to the balance by pres-
sure on the side or edge of the roller notch, which action will be repeated at
every impulse, or two vibrations of the balance. The retention spring ruby
pallet, or pallet of other material is formed with a second angle resembling two
· sides of a prism, and set into the spring so as to allow the back of either tooth
of the wheel to pass backwardly or in the contrary direction of the impulse;
this second angle on the pallet is necessary as a preventive of impediment to
the return of the wheel tooth in case of a backward check of the balance before
the impulse is completed. By the use of this, which I designate the anti-
detached chronometer escapement, I am enabled to make the impulse on the
roller and balance, by fixing a suitably high numbered escape wheel direct
upon the pinion which carries the ordinary seconds hand, thereby greatly sim-
plifying the construction of timekeepers, and economizing various parts of the
work, and, consequently the manufacturing expense; some of these and other

page_text: advantages apply also in reference to my repellent lever escapement, described
in the first part of this Specification.
Having now described the nature of my said Invention, and in what manner
the same is to be performed, I declare that I claim,―
First, the method of making the locking angles on the pallets of lever
escapements with angles lying outwardly from the dead rest circle, as in a line
or plane of action projected from the locking corner of each pallet respectively
at such an inclination as will cause the pressure of the escape wheel teeth to
produce a contrary or reverse action of the pallets and lever, as compared with
the action produced on ordinary detached lever escapement pallets by the pres-
sure of the wheel teeth in such escapements, as berein-before described and
partially illustrated at Figure 1 of the accompanying Drawings.
Second, the producing the said contrary or reverse action of such lever
pallets by angular faces on the wheel teeth, either by round, half-round, or
flatted cylindrical pins, or by movable rollers for the wheel teeth to act upon,
as on the anchor pallets, for giving motion to the lever, and for communicating
the impulse power of the escape wheel for producing motion in the balance by
a wedge-formed single pointed extremity as the acting end of the lever, and
for making such lever to act in a hollow recess or notch, cut, or slit, made in
the side of a stone or other cylindrical roller (technically so called), the said
lever point acting in the roller notch, being the only means of giving impulse
or motion to the balance, the surface of the roller being the banking for the
repose action of the lever, as herein-before described and illustrated at Figure 1
of the accompanying Drawings.
And, third, the employment in escapements of the chronometer class of a
linear steel or gold spring, which acts on the teeth of the escape wheel in order
to prevent in this and other escapements a part of the force or friction on what
is technically called a ruby roller in ordinary duplex escapements, the said
spring acting in the manner essentially as herein-before described and illus-
trated at Figure 2 of the accompanying Drawings.
In witness whereof, I, the said James Ferguson Cole, have hereunto set
my hand and seal, this Twenty-eighth day of April, One thousand
eight hundred and sixty.
JAMES FERGUSON COLE. (L.S.)