A CERTAIN IMPROVE- MENT OR CERTAIN IMPROVEMENTS IN THE MECHANISH OF TIMEKEEPERS
Year: 1837

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
GOWLAND, of Leather Sellers Buildings, in the Parish of Allhallows-on-tlic-
Wall, within the City of London, Watch and Chronometer Maker, send
greeting.
WHEREAS by certain Letters Patent under the Great Seal of the United
Kingdom of Great Britain and Ireland, bearing date at Westminster, the
Second day of November now last past, especial licence, full power, sole
privilege and authority, were given and granted unto me, the said. James
Gowland, that I, the said James Gowland, my executors, administrators, and
assigns, or such others as I, the said James Gowland, my executors, adminis-
trators, or assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England, Wales,
and the Town of Berwick-upon-Tweed, my Invention of "A CERTAIN IMPROVE-
MENT OR CERTAIN IMPROVEMENTS IN THE MECHANISH OF TIMEKEEPERS;" in which
said Letters Patent there is contained a proviso obliging me, the said James
Gowland, by an instrument in writing under my hand and seul, particularly to
describe and ascertain the nature of my said Invention, and in what manner
the same is to be performed, and to cause the same to be inrolled in the
High Court of Chancery within six calendar months next and immediately
after the date of the said recited Letters Patent, as in and by the same,
reference being thereunto had, will more fully appear.
NOW KNOW YE, that in compliance with the said proviso, T, the said
James Gowland, do hereby declare the nature of my Invention of "A Certain

page_text: Improvement or Certain Improvements in the Mechanism of Timekeepers,"
and the manner in which the same is to be performed, is described and
ascertained (reference being had to the several Drawings hereunto annexed,
in all of which similar parts are marked with the same letters).
My Invention consists of an improvement or improvements in that part of
the mechanism of watches, chronometers, and other timekeepers usually
called the escapement, by communicating motion or impulses from any of the
usual trains of wheels (acted upon by a main spring or other moving power)
through the medium or by means of the balance spring to the balance. The
modes in which the motion or impulses may be communicated according to my
Invention are various; and for the purpose of more clearly exhibiting the
nature of my Invention, and how it is to be performed, I shall proceed (with
the aid of three Drawings) to describe some of its modifications.
The Drawing numbered 1 represents one of the modifications of my said
improvements, in which Drawing Figure 1 is intended to represent that part
of a watch, chronometer, or timekeeper which is called the escapement. In
this Figure the top or upper part of the cock marked A, A, in Figure 2, the
upper part of the balance (marked M, M, M, M, in Figure 2), and nearly
the whole of the balance spring (marked S, S, S, S, in Figure 2), are removed
to shew the various parts, leaving a portion of the balance spring marked S, S,
in Figure 1, and also a portion of the balance axis marked L in Figure 1,
to which is attached the unlocking pallet, marked K, and coloured red in both
Figures.
Figure 2 shews a vertical section of the same escapement (as if taken
through the dotted line Z, Z, in Figure 1). W, W, represents the watch
plate, with the part marked V, V, cut away, to which the whole escapement is
attached by means of the union screw U, U. The cock A, A, is screwed to
the potance C, C, by means of the screws, one of which is represented in this
Figure, and marked B. The counterpotance E, E, is attached to the potance
by the screw D and proper steady pins. The part marked F, F, is the escape
pinion, which works in jewelled sittings fixed in the potance C, C, and
counterpotance E, E, and works into the fourth wheel of the train in the
usual manner. On the upper part of the axis
fitted the revolving escapement bar G, G, G.
spring I, I, with its banking screw H, the
banking screw Y, and the balance spring stud P.
with its mean-time weights N, N, N, N, works with one end of its axis L in a
jewelled setting in the cock A, A, and the other end of the axis L, having a
jewelled setting inserted in it, works upon the top of the escape pinion F, F.
of the escape pinion is firmly
This bar carries the locking
unlocking spring J, with its
The balance M, M, M, M,

page_text: The inner end of the balance spring S, S, S, S, which in this Drawing I have
represented of the spiral or flat kind (but may he in any of the usual forms),
is fixed upon the axis of the balance by its collet R, R, in the usual way; the
outer end of the balance spring S, S, S, is fixed to the revolving escapement
bar G, G, G, by the stud P; upon the lower end of the balance axis L, Figures
1 and 2, is fitted the unlocking pallet K. The part 0, 0, 0, 0, Figures 1
and 2, is a locking rim, which is screwed to the potance plate C, C, concen-
This locking rim is equally
tric with the axis of the escape pinion F, F.
divided by a number of spaces, according to the number or frequency of the
beats the watch, chronometer, or timekeeper is designed to have. Those
spaces or notches are each of the same width as the locking pallet f, Figures
1 and 8. The teeth thus formed between these spaces have their exterior
surfaces curved in such a manner as to bring the extremity of each tooth
marked a little nearer to the centre of the rim than the extremity
marked b.
Figure 3 is a side view of the locking spring I, I, with its ruby locking
pallet f, and an end view of the unlocking spring J, J, screwed upon it. The
action of this escapement is as follows:-In Figure 1 the direction of the
motion of the balance axis, with its unlocking pallet K, coloured red, is
indicated by the inner arrow c as moving from right to left, the escapement
bar G, G, G, by means of the locking spring I, I, and the locking pallet f,
being firmly locked in one of the spaces or notches of the locking rim. Tho
unlocking pallet K in its progress then comes into contact with the foot of
the unlocking spring J, J, and raises it into the position shewn by the dotted
lines, by which means the locking pallet is forced out of the space or notch
cut in the locking rim 0, 0, 0, 0, and thus the train, being allowed to act
upon the revolving escapement bar G, G, G, carries it partly round in the
direction indicated by the arrows d, d, until it comes against the face of the
next .tooth in the locking rim, the unlocking pallet K (colored red) at the
same time disengaging itself from the unlocking spring J, J, the locking
pallet is forced into the space or notch of the locking rim, and is again firmly
locked. During this progression of the revolving escapement bar G, G, G,
the stud p has been moved forward, drawing with it the outer end of the
balance spring S, S, S, S, whilst the balance is still proceeding to the extremity
of its motion, as indicated by the direction of the arrow c, when the balance
returns to the right, revolving in the contrary direction, with a momentum in
proportion to the force of the impulse received by the spring S, S; S,' S, being
drawn forward, as before mentioned. When the balance is revolving in this
direction the unlocking spring yields to the unlocking pallet K; colored red,

page_text: and permits it to pass without raising the locking pallet f. The balance then
progresses on until its momentum in this direction is expended, when it returns
and repeats the action. The revolving escapement bar G, G, G, when locked,
is prevented from being moved round in either direction by the locking pallet f
being, by the pressure of the locking spring I, I (properly adjusted by the
screws attaching it to the escapement bar G, G, G) firmly held in one of the
spaces or notches of the locking rim between the face a and the face 6 of two
of the teeth. The face 6 of each of the teeth of the locking rim is made to
project for the purpose of catching the locking pallet when it comes to the
space or notch into which it falls. The banking screw y is for the purpose of
preventing or diminishing the vibration of the unlocking spring J, J; but this
banking screw must be so regulated as to allow of the free passage of the
unlocking pallet when the balance is moving in the direction indicated by the
arrow d. The impulse received by the balance spring, as before mentioned,
is communicated to the balance, and the force of each impulse being chiefly
in proportion to the distance passed over by the stud p at each motion of
the revolving escapement bar G, G, G, the impulses are little if at all affected
by the inequalities of the train.
Another modification of my improvements in the mechanism of timekeepers
is shewn in the Drawing Number 2, in which the cock potance, revolving
escapement bar, and such of the other parts herein-before described as are
adopted in this modification of my Invention, have similar lotters for reference.
The Figures 4, 5, and 6 represent plans of the escapement in this modifi-
cation in different states of its action, the several parts of these Figures being
the same as in Drawing Number 1, with the exceptions herein-after mentioned.
In this modification of my Invention I do not employ an unlocking spring, as
represented by J, J, Figures 1, 2, and 3, in Drawing No. 1, or an unlocking
pallet on the balance axis, as represented by K (colored red), Figures 1 and 2,
in Drawing No. 1, but in place thereof I use an impulso spring e, g, h,
Figures 4, 5, and 6, Drawing No. 2, oue end of which e is attached to the
revolving escapement bar G, G, G, Figures 4, 5, and 6, by the screw i. This
spring must be carefully and accurately made, and adjusted so as to produce
the effects herein-after mentioned. The spring must be made so as to exert
its greatest power in a circular direction, and in the same direction as that
in which the revolving escapement bar G, G, G, moves, and also to exert a
smaller power towards the outside of the circumference of the locking rim
0, 0, 0, 0. The adjustment of the spring is effected by means of the two
conical-headed screws j, k (Figures 4, 5, and 6), a section of which is shown
separately at Figure 7. The flexible part 9 of the spring is banked by the

page_text: screw, and passes round the balance axis L. The moveable end h of this
spring is furnished with a ruby pin m and a clamp n, to which the outer end of
the balance spring S, S, S, S, is attached. The upper end of the locking
spring I, I, has a bridle o, p, through which the ruby pin m passes.
Figure 8 is a side view of the locking spring I, I, with its locking pallet f,
and the bridle o, p, shewing the manner in which the ruby locking pin m
passes through the bridle o, p, and projects below it, and also the manner in
which the balance spring S, S, S, S, is clamped and fixed to the end of the
impulse spring at h. The action of this escapement is as follows:-Figure 4
shews the escapement, with the ruby locking pin m locked in a space or
notch of the locking rim 0, 0, 0, 0, and the impulse spring e, g, h, wound
up in the manner herein-after described, the balance having just expended its
momentum in moving round to the right (in the direction indicated by the
arrow d), and being about to return to the left in the direction shewn by the
arrow c. The balance then returns to the left, as indicated by the arrow c,
and the balance spring S, S, S, S, is thus wound up, causing the clamped end
n, and along with it the ruby locking pin m, to be brought nearer to the
axis L, as shewn in Figure 5, where the ruby pin m is shewn lodged in the
inner angle at the end of the bridle o, p. The balance having now expended
its motion to the left (in the direction indicated by the arrow c), begins to
return in the contrary direction, as shewn by the arrow d in Figure 5, and
commences unwinding the balance spring S, S, S, S, until its power is
reduced, so that the impulse spring e, h, g (having been previously wound up, as
before mentioned), and having its power or pressure towards the circumference
of the locking rim counteracted by the power of the balance spring drawing tho
clamp n of the locking spring towards the centre of the locking rim, is able to
exert its power or pressure in a circular direction, as before mentioned, when
the impulse spring pulls forward the end of the balance spring S, S, in the clamp
n, with the ruby locking pin m (without the locking pin n touching or rubbing
against either the inner surface of the locking rim 0, 0, 0, 0, or the bridle o, p)
into the opposite angle p of the bridle, as shewn by the dotted lines in. Figure 5:
The balance spring thus receives an impulse by the motion of the impulse
spring e, g, h, along the length of the bridle, which impulse is commu-
nicated to the balance. The balance then, moving further round to the
right (in the direction indicated by the arrow d), relieves the clamp n from
the pressure towards the centre of the locking rim, and the impulse spring is
thus at liberty to exert its power or pressuro towards the circumference of the
locking rim, when, the ruby pin m being in a line with the axis L, the space
in the locking rim O, and the pallet f, the impulse spring forces its ruby pin m

page_text: outwards, and into the space in the locking rim O, where it is locked; and at
the same time pushes out the locking spring pallet f, and thereby allows the
train to act upon the revolving escapement bar G, G, G, so as to carry it
onwards in the direction indicated by the arrows d, d, until it falls against the
face of the next tooth in the locking rim, and becomes locked, as herein-before
mentioned. This motion of the escapement bar winds up the impulse spring,
as shewn in Figure 6, when the escapement comes into the first position
shewn in Figure 4, and is ready to repeat its action.
Another modification of my Invention is shewn by the Drawing Number 3,
in which the revolving escapement bar, and such of the other parts herein-
before described as are adopted in this modification of my Invention, have
similar letters of reference. The Figures 9, 10, and 11 represent plans of the
escapement in this modification in different states of action, the several parts of
these Figures being the same as in the Drawings Numbers 1 and 2, with the
exception herein-after mentioned. In this modification of my Invention I do
not employ an unlocking spring (as represented by J, J, Figures 1, 2, and 3,
in Drawing Number 1), or an unlocking pallet on the balance axis (as repre-
sented by K, colored red, Figures 1 and 2, in Drawing Number 1), or an
impulse spring (as represented by e, g, h, Figures 4 and 5 and 6, in Drawing
Number 2); but a similar effect is produced by the balance spring S, S, S, S,
in each of the Figures 9, 10, and 11, being attached to the locking spring
I, I, by the clamp n. This locking spring is made to press outwardly, or from
the axis of the revolving escapement bar G, G, G, with a force properly regu-
lated so as to produce the action herein-after described. This locking spring
I, I, is also furnished with two ruby pallets and s, as shewn in each of the
Figures 9, 10, and 11. The outer ruby pallet f is intended to pass over the
outside of the teeth of the locking rim, and to lock in the spaces or notches of
that rim. The other or inside ruby pallet S is intended to pass along inside of
the teeth of the locking rim 0, 0, 0, 0, and also to lock against the anterior
face of each of the teeth of that rim. Both of those pallets are banked by the
banking cock t, u, which is attached to the revolving escapement bar G, G, G,
by means of the screw v. Each tooth in the locking rim 0, 0, 0, 0, in this
modification of my Invention is made with a small projection on the exterior
surface at the anterior extremity of the tooth, the remainder of the outer part
of the tooth being a segment of a circle which is concentric with the axis of
the revolving escapement bar G, G, G. The projection on the outside of each
tooth is intended to catch the outer locking pallet when it has passed over
the outside of the last tooth, and thus enable the outer locking pallet f to lock
in the space or notch of the locking rim. The posterior part of the inside of

page_text: each tooth is cut away, as shown at æ, by a circular file or other proper
means for that purpose, in order to allow the inner pallets to be moved
towards the circumference of the locking rim, and to catch and lock against
the anterior face of the next tooth. The pallets f and s must be so placed
that the pallet shall precede the pallets in their motion round the circum-
ference of the locking rim, to allow the pallet f to pass the outer projection of
the tooth, and to be free of it by the time when the inner pallet s locks
against the anterior face of the tooth. And those pallets must also be so
placed as barely to allow the outer pallet f to pass over the outer projection of
the tooth whilst the inner pallet & is against the posterior part of the inside of
the preceding tooth, which is cut away as before mentioned. And these
pallets must also be so placed that when the outer pallet f has passed the outer
projection of a tooth, the inner pallet s will barely be able to unlock, and pass
along inside of the tooth. The action of this escapement is as follows:―
Figure 9 shews it and the balance spring in the position it is in when, the
balance having just expended its momentum from right to left in the direction
shewn by the dotted arrow c, the ruby pallet of the locking spring I, I, is
firmly locked within the space w by the force of the balance spring, the
balance having wound up the balance spring, and causing it to overcome the
force of the locking spring I, I, and draw the clamp n, to which the outer pallet
fis attached, towards the axis of the balance. The ruby pallet s is free, and
the point of the locking spring I, I, is banked against the inner side of the
banking cock at u. The balance spring S, S, S, S, in this position is at its
greatest tension to the left, and consequently the outer end of the balance
spring, with its clamp a, is drawn inwards. The balance now returns to the
right, as shewn by the arrow c, at Figure 10, unwinding the balance spring
S, S, S, S, and allowing the locking spring I, I, to move its clamped extre-
mity with the locking pallets fands outwards, when the pallet is unlocked,
and the pallets is pressed towards the posterior part of the inside of the
preceding tooth in the locking rim 0, 0, 0, 0, and banked against the
banking screw at t. The force of the train then draws the revolving bar
G, G, G, with its locking spring I, I, a little forward to the right, just
sufficient to free the locking pallet f from the small projection on the outside of
the tooth, when the pallet s locks against the anterior face of the tooth. The
balance still proceeds, onwards in the direction of the arrow C, Figure 10,
until its inomentum is expended, when it returns again to the left (by the
power of the balance spring S, S, S, S), as shewn in Figure 11 by the arrow c.
When the balance has passed the centre of motion, and wound up the balance
spring S, S, S, S, until its momentum causes the balance spring to draw the

page_text: clamp n, with the locking pallets fands at the end of the locking spring I, I,
towards the axis of the balance, with a force superior to the pressure of the
spring I, I, in the contrary direction, but inferior to the pull of the train
forwards, the pallets is drawn inwards, and is thus unlocked from the tooth of
the rim 0, 0, 0, O; and the train carries the revolving escapement bar
G, G, G, forward until the pallet f is caught and locked in the next space,
marked w, in Figure 11, when it will come into a similar position to Figure 9,
and be ready to repeat its action. In this modification of my Invention
there are two motions of the revolving escapement bar during each vibration of
the balance, the one short and just sufficient to free the small projection on
the outside of the teeth, and the other much longer, giving the principal
impulse to the balance.
I do not mean or intend to claim as my Invention any of the parts herein-
before described which are known and in use, nor do I limit or confine myself to
the particular modifications of the escapements or the forms of the various parts
thereof hercin-before shewn and described. But I claim as my Invention,―
Firstly, the communication of motion or impulses to the balance directly
through the medium or by means of the balance spring, whether according to
any of the modifications herein-before shown and described, or by an alter-
nating lever, or in any other fit and proper manner.
And, secondly, a revolving escapement bar, and a locking rim, either in the
form shewn in the before-mentioned Drawings, or any other shapes, for the
purposes herein-before described.
In witness whereof, I, the said James Gowland, have hereunto set my
hand and seal, this First day of May, in the year of our Lord One
thousand eight hundred and thirty-eight