SOME IMPROVEMENTS IN THE CONSTRUCTION OF CERTAIN. PARTS OF THE MECHANISM USED IN WATCHES AND CHRONOMETERS, WHICH IMPROVEMENTS.ARE ALSO APPLICABLE TO SOME KINDS OP CLOCKS
Year: 1842

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
HENRI PERRIN, of Neuchatel, in Switzerland, Watch Manufacturer, at present
residing in George Yard, Lombard Street, in the City of London, send
greeting.
WHEREAS I did by petition humbly represent unto Her present most
Excellent Majesty Queen Victoria that I had invented "SOME IMPROVEMENTS
IN THE CONSTRUCTION OF CERTAIN. PARTS OF THE MECHANISM USED IN WATCHES
AND CHRONOMETERS, WHICH IMPROVEMENTS.ARE ALSO APPLICABLE TO SOME KINDS
OP CLOCKS;" and Her said Majesty, being willing to give encouragement to all
arts and inventions which may be for the public good, was graciously pleased,
by Her Royal Letters Patent, under the Great Seal of the United Kingdom
of Great Britain and Ireland, bearing date at Westminster, the Eighth day
of August, One thousand eight hundred and forty-two, in the sixth year of
Her reign, for Herself, Her heirs and successors, to give and grant unto me,
the said Charles Henri Perrin, my executors, administrators, and assigns, Her
especial license, full power, sole privilege and authority, that I or they, by
myself or themselves, or by my or their deputies, servants or agents, or such
others as I or they shall agree with, and no others, during the term of fourteen
years from the date of the said Letters Patent, should and lawfully might
make, use, exercise, and vend my said Invention within that part of Iler said
Majesty's Dominions called England, Her Dominion of Wales, and Town of
Berwick-upon-Tweed, in such manner as to me, my executors, administrators,
and assigns, shall seem meet, and as that I or they shall enjoy the whole profit
and advantage arising by reason of the said Invention during the said term

page_text: of fourteen years, and for that end Her said Majesty requires and strictly
commands all Her subjects whatsoever, within England, Wales, and Berwick-
upon-Tweed aforesaid, that they shall not, neither directly nor indirectly,
make, use, or put in practice my said Invention, or any part thereof, nor in
anywise counterfeit, imitate, or resemble the same, nor make any addition
thereto or subtraction therefrom, whereby to pretend himself or themselves
to be the Inventor or Inventors, thereof; and whereas the said Letters Patent
contain a proviso, obliging me, the said Charles Henri Perrin, particularly to
describe and ascertain the nature of my said Invention, and in what manner
the same is to be performed, by an instrument in writing under my hand and
seal, and to cause the same to be inrolled in Her Majesty's Iligh Court of
Chancery within six calendar months next and immediately after the date of
the said Letters Patent, as in and by the same (reference being thereunto
had) will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Charles Henri Perrin, do hereby declare that my said Invention is described
and ascertained in manner following, and by the aid of the two Sheets of
Drawings hereunto annexed, that is to say:-
My improvements relate to those parts of the mechanism used in watches
and chronometers, (and in some kinds of clocks), whereby the operation or
manipulation of winding up the maintaining power is regulated, that is to say,
in watches and chronometers, and in some kinds of clocks, a spirally coiled
spring, called a mainspring, is used for the maintaining power, by which the
moving parts of the watch, chronometer, or clock are actuated and kept in
motion; such spring requires to be wound up from time to time by application
of a winding-up key, turned round by the hand, in manner well known, and
some contrivance is used to prevent overwinding, which contrivance offers no
impediment to the action of turning the key and winding up the mainspring
until that spring is become fully wound up (or as much as it is intended to be
wound up), and then the said contrivance wholly stops the further winding up
by the key, and prevents overwinding by totally stopping any further turning
motion by the key. One object of my improvements is to prevent (or rather
to avoid) overwinding, because when the mainspring is become fully wound'
up (or as much as it is intended to be wound up), then, by virtue of my
improvements, instead of the further motion of turning the key being wholly
stopped, as is usual, such further turning motion is freely permitted to take
place to any extent, but, nevertheless, such further turning motion of the key
will not produce any further effect of winding up beyond the proper extent of
winding up which is suitable for the mainspring.

page_text: And another object of my improvements is, to avoid any injury being don?
to the mechanism of the watches, chronometers, or spring clocks, wherein my
said improvements are applied, in consequence of the winding-up key being
inadvertently urged with a tendency to turn the same round in a contrary direc
tion to that direction which is proper for performing the winding up; because, by
virtue of my improvements, the turning motion of the winding-up key is freely
permitted to take place to any extent in a contrary direction to that direction
which is proper for winding up, but, nevertheless, such contrary turning motion
of the key will not exert any strain or produce any injurious effect on the
mechanisin of the watch, chronometer, or spring clock; wherefore, by virtue of
my improvements, no improper turning motion, nor force tending to produce
improper turning motion, can ever be communicated to the mechanism of the
watches, chronometers, or spring clocks to which my improvements are
applied, however carelessly or improperly the operation or manipulation of
winding up may be performed, because the turning motion of the winding-up!
key is permitted to take place under all circumstances, and the key is never
stopped from turning, but all the turning motion and force which may be given
to the key can never communicate to the mechanism of the watch, chro:
nometer, or spring clock any other motion or force than that which is intended
and which is proper for effecting the winding up of the mainspring to its
intended extent of winding up, but no further than that intended extent; that
is to say, in all cases if the winding-up key is turned round in a direction
contrary to that which is proper for winding up, such contrary motion of the
key can take place freely without producing any effect on the mechanism; or,
if the said key be turned round in the proper direction for winding up, then
(in case any winding up is at the time required) so much winding-up as is
required will be duly performed, but no more, for after the winding up has
proceeded to the full extent that is required, so that the mainspring is fully
wound up, then although the winding-up key may continue to be turned round
ever so much further, no motion or force will be thereby communicated to
the mechanism of the watch, chronometer, or spring clock.
The manner
of constructing those parts of the mechanism of watches, chronometers, and
spring clocks to which my improvements relate must be varied, to suit the
mode whereby the maintaining power of the mainspring is applied to or
connected with the wheelwork and mechanism of the watch, chronometer, or
spring clock.
Sheet I. contains representations of the manner of constructing my said
improvements in cases where the mainspring operates by means of a chain
or catgut and a fusee; part of the Figures in Sheet I. being suitable for

page_text: ordinary watches or spring clocks, and other part of those Figures for chro-
nometers or for watches of a superior class, or for spring clocks having what is
termed a going fusee, with an auxillary spring and a ratchet wheel and click
for keeping up the action of the maintaining power during the time that the
winding up is going on.
And Sheet II. contains representations of the manner of constructing my
said improvements in cases where the mainspring operates directly on the
wheelwork, without any fusee and chain.
DESCRIPTION OF THE DRAWINGS..
Sheet I., Figures 1 to 11, together with Figure 43, represent my improve-
ments when the same are applied to chronometers, or to watches of the very
best class, or to spring clocks having a going fusee, 'as before mentioned.
Figure 1 is a horizontal plan of the fusee A, and the circle B denotes the
spring barrel in their relative situations, the Figure shews the manner in which
the chain i winds around the spiral groove of the fusee A, and around the
cylindrical circumference of the spring barrel B, also shewing the main tootlied
wheel D, which is applied beneath the base or largest end of the fusee A, and
likewise the large ratchet wheel E of the going fusee, which ratchet wheel E
is interposed between the base of the fusee and the main wheel D. The
aforesaid parts (excepting the spring barrel) are represented separately in the
detached Figures, but all those parts, videlecet, those marked A, B, D, E, are
constructed in the usual manner, and require no alteration in consequence of
the application of my improvements, except that a circular recess is hollowed
out in the upper or small end of the fusee A, in order to receive a spring c,
a detent f, and a ratchet wheel or ratchet'g, as is seen in Figures 1, 2, and 3,
the ratchet g being formed on the arbor or axis of the fusee (see Figure 5),
and that axis (instead of being firmly fastened into the fusee, as is usual) is
fitted through the central hole of the fusee, so as to allow the axis to turn
round easily in that central hole without communicating any motion to the
fusee, except inasmuch as the teeth of the ratchet g of the axis may be caught
by the hooked end m of the detent f. That detent is mounted on a- centre
screw h, which screws into the solid of the fusee and serves as the centrè
of motion for the detent. f. The end of the spring c applies behind the
hooked end m of the detent to urge that hooked end towards the teeth of the
ratchet g, so that (when permitted) the hooked end m will take a secure hold
between the teeth of the ratchet g, in the manner shewn in Figure 2; and
tbe said teeth are formed suitably for being firmly held by the said hooked
end m, when the axis and its ratchet 9 are turned round (by the usual and

page_text: proper action of the winding-up key) in the proper direction for winding up
the chain i around the spiral groove of the fusee A, as is shewn in Figure 1.
And the said, usual and proper action of the winding-up key will be duly
transmitted by the teeth of the ratchet and by the detent which has hold of
those teeth to the fusee, so as to wind up the chain i around the fusee in the
same manner as would take place if the axis were firmly fastened to the fusee,
as usual; but nevertheless, if by inadvertence the winding-up key should be
turned round in a contrary, direction to that which is proper for winding up,
then the sloped sides of the teeth of the ratchet g will act against the corre-
sponding sloped part of the hooked end m of the detent f, and overcome the
force of its spring c, so as to remove the said hooked end m, and allow the
teeth of the ratchet to slip one after another past the said end m; thus
permitting the winding-up key, together with the axis and its ratchet g, to be
turned in the contrary direction to that which is proper for winding up without
causing any injurious effect, on the mechanism of the chronometer, or watch, or
spring clock; and when the manipulation of turning the winding-up key in the
proper direction for winding up has been continued until the chain i is become
wound up around all the extent of the spiral groove in the fusee, as is shewn in
Figure 1, then the said chain will come into contact with the prominence at the
tail end k of the detent f, so as to press that tail end k and gather the same
inwards towards the axis of the fusee, whereby the hooked end m of the said
detent will be removed from its previous contact with the teeth of the ratchet
g. (in opposition; to the force of its spring c), so as to permit the ratchet g to
turn round without any obstruction to its teeth, and consequently, however much
the axis of the..fusee may be turned round by the winding-up key, and in
whichever direction it may be so turned, no force or motion can be communi-
cated to the fusee, because the axis thereof is become detached so as to turn
round easily within, the central hole of the fusee without producing any sensible.
action thereon.. The difference (as to the action of winding up) between the
ordinary construction of mechanism for that purpose and my improvements is,
that in the ordinary construction the turning motion of the winding-up key
(together, with that of the axis of the fusee whereon that key is applied) is
resisted, stopped, and prevented by the mechanism in every case when it would
be improper that such turning motion should be transmitted to the fusee,
whereas by my improvements in all such cases the said turning motion of the
winding-up key and of the axis is permitted to take place freely, but without
producing any sensible effect on the fusee, that is to say, whenever it is
attempted to turn the winding-up key and the axis of the fusee in a contrary
direction to that direction which is proper for winding up, then the turning

page_text: 'motion of the key and of the axis is resisted so that they are prevented from
turning in the common construction; whereas by my improvements the said
key and axis are allowed to turn round freely, but such contrary turning
does not produce any sensible effect on the fusee; and also, whenever it is
'attempted to turn the said key and axis farther round than is proper for fully
winding up the whole of the intended extent of chain around the spiral groove
of the fusee, then such further motion of the key and axis is prevented from
taking place in the common construction, whereas by my improvements such
further motion of the key and of the axis is freely permitted to take place to
any extent, but without producing any sensible effect on the fusee. And in
consequence of the winding-up key being allowed to turn freely, in manner
aforesaid, no injury can be done to the mechanism by careless or improper
manipulation in winding up, whereas in the ordinary constructions the
mechanism may be (and frequently is) injured if undue force is applied to turn
the key when the motion thereof is resisted and stopped, and intended to be
prevented from turning by the mechanism. The circular recess or cavity
which, as already mentioned, is hollowed out in the upper or small end of the
fusee A is formed concentrically with the axis of the fusee, by turning out the
said hollow in a lathe or turn bench, so that the said cavity will be within the
uppermost and smallest coil of the spiral groove around the fusee, the size of
the said cavity being such as will leave a border edge b, b, of adequate strength
around it, for the purpose of separating the cavity from the said upper and
smallest coil of the spiral groove, which coil passes around the outside of the
said border edge; but nevertheless, the uppermost and innermost end of the
spiral groove, in consequence of its approach towards the centre of the fusee,
terminates by penetrating through the said border edge, so that the said upper-
most and innermost end of the spiral groove leads into the said circular recess
or cavity, in the manner of a notch, in one part of the circumference of the:
said border edge, which border edge may be considered to be deficient at
that part of its circumference where such notch is, and the prominence at
the tail end k of the detent passes through the said notch, so as to
protrude out from the cavity and into and across the spiral groove of the
fusee at the uppermost and innermost end of that groove, wherefore when
the chain i becomes fully wound up around the said spiral groove of the
fusee, and when, in consequence of being fully wound up, the chain comes to
occupy almost the said uppermost and innermost end of the spiral groove,
then the chain will come in contact (as appears in Figure 1) with the said.
prominence at the tail end of the detent (which prominence protruded into
and across the spiral groove), and the chain, by forcing the said prominence

page_text: inwards into the cavity from which it had previously protruded (as in Figure 2),
will move the whole detent f so far about its centre of motion h (in opposition
to the elastic force of its spring c) as will be sufficient for removing the hooked
end m of the same detent from its previous contact with the points of the teeth
of the ratchet g, in manner already explained. The spring c is fastened in.
place within the said cavity in the fusee by means of a screw at the fixed end
of the spring, as is shewn in Figures 1, 2, and 3; and in consequence of the
outer edge of that end of the spring applying closely to the interior circum-
ference of the cavity the spring is kept secure in place by means of the one
screw before-mentioned, but the spring may have a steady pin or stud in addi-
tion to the screw, if required. The elastic or acting portion of the spring C.
must be properly tapered in thickness and curved suitably for being contained
within the cavity in the fusee, and for acting by the extreme end of the said
elastic part of the spring behind the hooked end m of the detent f, so as to.
urge that end m with a moderate and elastic pressure towards the teeth of the
ratchet g, but so as that the said spring will yield easily whenever the detent f
is acted upon in opposition to the elastic force of the spring, whether the detent
is acted upon by the teeth of the ratchet g acting with their sloping sides.
against the corresponding sloped part of the hooked end m of the detent f, in
case of the axis and the ratchet 9 being turned round by the winding-up key,
in a contrary direction to that which is proper for winding up, or whether the
detent is acted upon by the chain i bearing against the tail end k of the.
detent, as is the case when the chain i becomes wholly wound up around the.
spiral groove of the fusee. The detent f must be fitted so as to play easily.
about its centre of motion h, but so as to be very firmly sustained by the screw.
which forms that centre, because the same has to sustain all the force requisite
for winding up. Figures 1 and 2 shew that the teeth of the ratchet g are.
formed so that their upright or acting sides radiate from the centre of the axis,
of the fusee, and the hook at the end m of the detent f being made conform-.
able to the teeth of the ratchet g, and the centre of motion h of the detent f
being situated at the place represented in Figures 1 and 2, in respect to the
said teeth, it follows that the hook m of the detent will take proper hold of.
the teeth of the ratchet for winding up without risk of slipping; but the hook m
of the detent f will nevertheless be easily disengaged and withdrawn from the.
teeth by action of the chain i against the tail end k of the detent when the,
said chain becomes wholly wound up around the spiral groove of the fusee, as,
in Figure 1. The tail end of the detent f, where the chain i acts thereon, is
farther from the centre of motion h than the hook m is distant from the said.
centre h, and consequently the action of the chain i against the tail end of the.

page_text: detent easily disengages the hook m.
ratchet g, may, if desired, be covered
Figure 11, whereof the central hole e fits the axis at the party, Figure 5, of
that axis, and the circumference of the plate, Figure 11, applies upon the
circular border edge b, b, which surrounds the circular cavity wherein the
detent f, the spring c, and the ratchet g are contained, so that the said cavity
will be completely covered over by the said plate of steel, and the same may
be held in place by two small screws which are inserted through the holes
marked d, d, Figure 11, and screwed into corresponding holes marked d, d,
Figures 1 and 2, at the bottom of the circular cavity aforesaid, but the
said plate of steel, Figure 11, is not in all cases necessary to the
action of my improvements, and may in some cases be omitted. Note.-
The spiral groove around the fusee is to be cut in the usual and
well-known manner by aid of a suitable machine, the only difference being
that whereas according to my improvements the axis of the fusee is not to be
fastened into it as usual, but is to be fitted to turn round easily in the fusee.
A temporary axis must be driven tight into the fusee, in order to be used for
the operation of turning the fusee and cutting the spiral groove around it;
and that groove should be completed before commencing to excavate the
circular cavity in the upper or small end of the fusee. The said cavity is to
be hollowed out (by turning) to such a diameter as will leave a sufficient
border edge b, b, around the cavity, except at that part of the circumference
of the said edge where the smallest and uppermost end of the spiral groove
terminates in and conjoins with the cavity at a notch in the said border edge;
and the said cavity is to be hollowed (by turning) to 'such a depth into the
fusee as that the flat bottom of the cavity will correspond to the said end of
the spiral groove at the said notch by which the groove conjoins with the
cavity; wherefore, when the detent f is applied in place on the flat bottom of
the cavity, the prominence of its tail k, which protrudes out from the cavity
through the said notch, will protrude into and across the spiral groove at the
innermost and uppermost end of the groove, so as that the chain i, when it is
wholly wound up, as in. Figure 1, cannot fail to come fairly in contact
edgeways with the edge of the said prominence k. The detent f is made of
steel, flat on both sides, and its thickness somewhat greater than that of the
chain ; and the edge of the prominence k must be suitably formed for the
chain to apply to that edge without risk of the chain slipping off the said edge.
The ratchet g may be made of the same piece of steel with the axis, as is
shewn at g, Figure 5, where n is the round part of the axis, which is fitted into
the central hole through the fusee, so as to be capable of turning round in
The detent f, and its spring c, with the
over by a flat circular plate of steel,

page_text: that hole with an easy motion; and s is a pin hole across the axis to receive a
cross pin for passing through and fastening the steel collet, Figure 9, which is
applied on the lower end of the part n of the axis, in order to retain the fusee
A, as well as the large ratchet wheel E of the going fusee, and also the main
toothed wheel D, in their proper intended situations, one in contact with the
other upon the axis, that is to say, the fusee A is mounted on the round part
n of the axis, Figure 5, the ratchet 9 of the axis applying with its flat surface
to the flat bottom of the circular cavity in the top of the fusee, and so as
that the axis will turn round easily within the fusee. The large steel ratchet
wheel E of the going fusee (shewn separately in Figure is applied beneath
the base x, x, of the fusee, and two spring clicks q, q, with springs for them,
are fitted on the large ratchet wheel E; those clicks act in the teeth of the
winding-up ratchet wheel p, p, Figure 4, of the fusee, when the parts are put
together. The ratchet wheel p, p, is contained in a hollow within the base of
the fusee, as shewn in Figure 4, leaving an angular space or vacant ring all
around the ratchet wheel p, p, for the reception of the clicks q, q, Figure 6, and
their springs, as well as a border or rim which projects up from the flat surface
of the large ratchet wheel E, Figure 6, so as to surround the said springs and
clicks q, q, and include the same within the border or rim. The large ratchet
wheel E, see Figure 6, has likewise a small circular border rim n, n, around the
central hole of the wheel E, which rim n, n, projects up from the flat surface of the
wheel E, in order to enter into a corresponding circular cavity at the centre of the
ratchet wheel p, p, Figure 4, of the fusee. The main toothed wheel D is applied
on the axis with its upper side, Figure 7, in contact with the under side of the
large ratchet wheel E; the centre hole of the main toothed wheel D fits on the
part n, Figure 5, of the axis, and a small border rim around that central hole
projects up from the flat surface of the main wheel D, so as to enter into and
occupy the central hole of the large ratchet wheel E, Figure 6. An annular
cavity or vacant ring is hollowed out in the flat surface of the main wheel
D, Figure 7, in order to receive the auxiliary spring t, t, of the going fusee;
the end u of that spring being fastened to the main wheel D by a screw u.
The head of that screw appears at u, Figures 8 and 10, which represent the
under side of the main wheel D. The end v, Figure 7, of the auxiliary spring
t, t, has a pin v projecting up from it, in order to enter into a hole v, Figure 6,
in the large ratchet E, so that the auxiliary spring t, t, bas one of its ends
fastened to the main wheel D by the screw u, and its other end is connected
with the large ratchet wheel E by the pin v; and the said spring t, t, forms the
only connection to transmit force from the large ratchet-wheel E to the main
wheel D for turning the same round, and therefore the said spring becomes

page_text: bended or wound up or charged in readiness for acting as an auxiliary force, in
order to keep up the motion of the main wheel D when the fusee is turned
round by the winding-up key during the action of winding up; and in conse-
quence of such auxiliary force, the going of the chronometer or watch or
spring clock will not be at all interrupted by the winding up. During that
winding up the large ratchet wheel E is prevented from turning backwards by
a spring click, not shewn in the Drawing. The steel collet, Figure 9, which,
as already mentioned, is applied and fastened by the cross pin s upon the lower
end of the part n, Figure 5, of the axis, is applied beneath the under side of
the main wheel D, and is lodged within a central hollow formed in that under
side, as shewn at r, r, Figures 8 and 10. The said steel collet, Figure 9, when
so applied and fastened on the axis, retains the several parts in due place.
thereon, videlecet, the fusee A, the large ratchet wheel E, and the main toothed
wheel D, but none of those parts are fastened upon the axis. It is unnecessary
to enter into further explanation of the going fusee, with its auxiliary spring
t, t, and large ratchet wheel E, or the action of those parts, the same being well.
known, without any difference being made in them in consequence of my.
improvements, except that the fusee is not fastened on the axis. In Figure 5,
,, are the pivots of the axis of the fusee whereon it revolves, those pivots
being sustained in holes through the frame plates or other suitable supports;
and wis the square to which the winding-up key is applied. For ordinary
watches and some kinds of spring clocks, that is to say, in cases where a going.
fusee with an auxiliary spring is not used, the parts corresponding to those
herein-before described may be also constructed as is represented by Figures
12 to 15 in Sheet I. All the parts at the uppermost and smallest end of the
fusee are to be the same as is represented in Figures 1, 2, and 3, and as
already described; but the axis of the fusee, Figures 16 and 19, is to be some-
what different. The ratchet, instead of being made of the same piece of steel
with the axis, is to be a small ratchet wheel, Figure 17, with a square hole
through its centre to fit upon the square part o of the axis, Figure 16; and a
steel collet, Figure 18, is applied upon the same square part o above the ratchet
wheel, so that the axis will be as shewn in Figure 19, when the said parts are
put together. The round part n, Figures 16 and 19, of the axis is fitted into
the central hole through the fusee, and the projecting rim h, which is formed of
the same piece of steel as the axis, is sunk within the central part of the base
of the fusee around its central hole, as is shewn in Figure 12; and the steel,
ratchet wheel a, Figure 14 of the fusee being firmly fastened to the base of the.
fusee, Figure 12, by three screws f. f. f, the said projecting rim of the axis,
becomes wholly included within the central part of the fusee, and the round part.

page_text: m of the axis beneath; the rim h fits into the central hole of the steel ratchet
wheel a, which is fastened as aforesaid to the base of the fusee. The afore-
said mode of fitting the axis into the fusee leaves the same quite free to turn
round within the fusee, except inasmuch as it may be prevented from so
turning by the teeth of the ratchet wheel; Figure 17, on the axis being
caught by its detent (which is like f. Figure 1) during the manipulation of
winding up, in the manner already described. The circular plate of steel,
Figure 11, is to be applied on the upper end of the fusee, and fastened thereto.
by screws, to serve, not only as a cover over the ratchet and detent, Figure 1.
(as already described), but also to serve for retaining the ratchet, Figure 17,
and the collet, Figure 18, in place on the square of the axis. The plate,
Figure 11, fits with its central on the part r, Figures 18 and 19, of the steel,
collet, which is fitted on the axis, and the upper part 9 of that collet, together
with the lower end of the axis, from the pivots by which the axis is sustained.
in the pivot holes through the frame plates or other suitable supports. The.
square o, at the upper end of the axis, is to receive the winding-up key. The
main toothed wheel, Figures 13, 14, 15, is as usual, without any difference in
consequence of my improvements. Figure 15 is the upper side of the main
wheel, whereon the base of the fusee, Figure 12, applies. A circular
border i, i, Figure 15, projects up above the upper surface of the wheel
around its central hole d, and that border i, i, is received in the annular
hollow k, k, Figure 12, in the base of the fusee; the central hole d,
Figures 13 and 15, then fits around the central part e, Figure 12, at the base
of the fusee. Figures 13 and 14 represent the under side of the main wheel,
which has a circular hollow g, g, Figure 13, sunk in its under surface around.
its central hole d, to receive the clink c, and its spring b, and also to receive.
the steel ratchet wheel a (see Figure 14), which wheel, as already stated, is
firmly fastened to the base of the fusee by the three screws f. f. f, which are.
inserted through the wheel a, and which screw into the three holes f, f, f,:
Figure 12, in the base of the fusee. The foregoing description of the Figures
in Sheet I. explains the manner whereby my improvements are to be applied
to all such watches, chronometers, or spring clocks, as operate by means of a,
fusee. Several of the parts herein-before described are constructed in the
usual manner, without any departure from that common manner being.
required in consequence of my improvements, videlicet, all the parts which,
apply beneath the base of the fusee, and also the fusee itself, are as
usual, except as to the circular cavity, which is hollowed out in the
uppermost and smallest end of the fusee, and except that the fusee is not
made fast upon its axis, but is fitted freely into the central hole of the fusee..

page_text: And 'note.-The said parts beneath the base of the fusee may be constructed i
any other suitable manner than those herein-before described, and which latte
have been described by way of example of the application of my improvements
and to explain how they combine with the usual parts. Note.-The ratchet, 9
Figures 1, 2, 3, and 5, of the axis of the fusee is there represented with a
smaller number of teeth than the corresponding ratchet, Figures 17 and
19, but the number of teeth in the ratchets, such as Figures 1, 2, 3, 5, and
Figures 17, 19, is not material, and may be varied at pleasure. The square
whereon the winding-up key is to be applied may be at either end of the axis
of the fusee, Figure 5 or Figure 19, according as is required or preferred.
Sheet II. represents my improvements when the same are applied to the
spring barrels of such watches or spring clocks as operate without any fusee.
Figures 20 and 21 are plans of the mechanism at one of the ends of
the spring box or spring barrel; and of the main toothed wheel which is
formed around the circumference of the said box or barrel. Figure 20 shews
the relative positions of the parts of the said mechanism when the spring
is relaxed or is nearly as far down as it is intended to be relaxed, where-
fore the spring requires (or is about to require) winding up, and the hooked
end u of the detent i, e, u, having hold of. one of the teeth of the ratchet
f of a central axis which is within the axis of the spring barrel, the parts
are prepared for winding up the spring by applying the winding-up key
to the square on the end of the said central axis, and turning the same
round in the proper direction in the usual manner; but if the key should
by inadvertence be turned round in a contrary. direction, then the teeth of
the ratchet will slip passed the hooked end u of the detent, and allow such
contrary 'turning to take place freely without any risk of injury being done to
the mechanism of the watch or clock. Figure 21 shews the relative positions
that the several parts of the same mechanism will acquire when the spring is
almost wholly wound up as far as it is intended to be. The hooked end view
of the detent i, e, ut, is then become removed from its previous contact with the
teeth of the ratchet-f, so as to offer no impediment to the turning round
of the ratchet and the central axis by means of the key, and therefore such
turning can take place freely in either direction without any risk of doing
injury. Figure 22 shews the end of the spring barrel received in the same
direction as in Figures 20 and 21, but without the mechanism shown in those
Figures, the end of the barrel being prepared for the reception of the
mechanism. Note.-Figure 22 shews the cover of the spring barrel, being
that end of the barrel which is removable, in order to get the spring in or out
of the barrel; therefore Figure 22 shews how the mechanism can be applied to

page_text: that cover, whereas Figures 20 and 21 shew the solid end of the spring barrel
with the mechanism applied thereto. It is immaterial whether the mechanism
shewn in Figures 20 and 21 is applied to the solid end of the barrel or to the
cover thereof, provided that the said cover- is made secure in its place with a
steady pin to prevent the cover turning round in the barrel. Figure 23 repre-
sents the opposite end of the spring barrel from that end which is shewn in
Figures 20 and 21.. The bridge which sustains one of the ends of the axis of
the spring barrel is shewn in Figure 23, and also the winding-up ratchet
wheel r, with its spring click. The remaining Figures in Sheet II. represent
the parts of the mechanism detached, as will be explained. The construction
of the spring barrel, with its bridge, Figure 23, and winding-up ratchet wheel 1,
with the spring click for the same, are as usual in some kind of watches.which
have only one plate for the framework of their mechanism, except that the
round hole which is seen at the centre of the ratchet wheel r, Figure 23, is not
usual. Figure 24 is a flat plate which belongs to the bridge, Figure 23, and
which is applied thereto to cover up the ratchet wheel r, so as to retain that
wheel and tlie axis of the spring barrel securely in place; the said plate is
fastened in its place by three or four screws, which pass through the holes
8, 3, s, in Figure 24, and which screw into corresponding holes s, s, s, Figure 23,
all which is as usual. The axis of the winding-up ratchet wheel 7, although it
serves as usual for the axis of the spring barrel, is nevertheless distinct from
the central axis before mentioned, to which the winding-up key is applied; the
said central axis is fitted into a perforation through the centre of the axis of
the winding-up ratchet wheel r, Figure 23. It is the. perforated axis which
serves as the axis of the winding-up ratchet wheel r, and of the spring barrel,
as aforesaid; and the ratchet f is fastened on the said central axis whereon the
winding-up key is applied, but that central axis is at liberty to turn round
freely within the perforated axis of the spring barrel, except inasmuch as it
may be prevented from so turning by the teeth of the ratchet f being caught
by the hooked end u of the detent i, e, u. The detent i, e, u, as well as its
spring g, is applied on a circular steel plate b, Figures 20 and 21, which is
firmly fastened on the extreme end of the perforated axis of the spring barrel.
The said circular steel plate b is shewn separately: at Figure 28, and the
detent i, e, u, at Figure 31. The spring 9 for the same is shewn separate in
Figure 30, also the ratchet f at Figure 27.. The perforated axis of the
spring barrel is shewn separate at Figures 32 and 33. The ratchet wheel r
is made in the same piece of steel with the perforated axis. of the spring
barrel; and the circular plate b (Figure 28) has a square central hole = to
fasten upon a square z, Figures 32 and 33, at the extreme end of the per-

page_text: forated axis, so that the plate b, Fig. 28, as well as the ratchet wheel
becomes as it were part of the perforated axis of the spring barrel. The centre
of motion e of the detent, i, e, u, Figures 20 and 21, is a screw, which is
screwed fast into the hole e, Figure 28, in the said circular steel plate b. The
spring g, Figures 20 and 21, acts against the detent to urge its hooked end w
with a gentle elastic force towards the teeth of the ratchet f; the spring
g is fastened to the plate 6 by a screw 9, Figure 30, and a steady pin
which enter into holes at g, Figure 28, in the plate b. The above particulars
of the construction being understood, it is evident that whenever the hooked
end u of the detent is (by action of its spring g) engaged in the teeth of the
ratchet f, as in Figure 20, and the winding-up key is applied to the square on
the end of the central axis of the ratchet f, then, if by means of the winding-
up key, the central axis, with its ratchet f, is turned round in the proper direc
tion for winding up the spring, the detent will duly transmit that motion to the
perforated axis of the spring barrel, so as to wind up the spring in consequence
of the centre of motion e of the detent being fastened into the circular steel
plate 6, which latter is fastened on the perforated axis. The winding up of the
spring will therefore take place as usual, in the same manner as would be the
case if the central axis to which the key is applied, and the perforated axis into
which that central axis is fitted, were one solid axis. And it is equally evident
that if the winding-up key is inadvertenly turned in a contrary direction to that
which is proper for winding up, that then the detent will easily yield, by its
spring g, so as to allow the teeth of the ratchet f to pass by the hooked end u
of the detent, and therefore the central axis will turn round within the per
forated axis of the spring barrel without communicating any motion or sensible
force thereto. Also it is equally evident, that if the detent i, e, u, is moved
about its centre of motion e, so as that its hooked end u will be removed from
its previous contact with the teeth of the ratchet f, as in Figure 21, then the
winding-up key and the central axis may be turned round freely in either direction
without communicating any motion or sensible force to the perforated axis of
the spring barrel. And now it remains to show how the detent is removed
from its said previous contact with the teeth of the ratchet as soon as the
spring is become almost fully wound up, but not before. The circular
steel plate 6 has a tooth c, Figure 28 (also Figures 20 and 21), projecting out
from its circumference, in order to actuate a circular ring of steel d, j, t, t, 2, v, w,
Figures 20 and 21, which ring is shewn detached in Figure 25. The
said ring is let into a circular recess which is excavated excentrically in the
end of the spring barrel (or else in the cover of the barrel, as shewn
in Figure 22), so that the ring, when lodged in its recess, is in the same plane

page_text: , which is included within the ring; but in consequenc
the ring being excentric to the spring barrel, the circumference of the plat
approaches very near to the ring at one part of the interior thereof, but ot
parts of the said interior are distant from the circumference of the plate b,
5 that the tooth c thereof will not reach to the interior of the ring, exce
at some certain part of that interior.
places, so as to leave four internal projections or teeth j, t, t, z, Figure 25, f
The interior of the ring is cut away
the purpose of being actuated by the tooth c of the circular plate b, i
order to turn the ring round within the circular recess into which it is fitted
0 The ring is cut open at one part of its circumference, and is made so tha
it tends to expand outwards with a slight clastic force within the said recess
in order that the ring may not be loose or liable to move therein by accident,
although it can be turned round easily within the recess by action of the
tooth c of the plate b. The recess wherein the ring is lodged is somewhat
undercut; and the exterior circumference of the ring being conformable to the
undercutting, the ring will keep its place in the recess. The ring d. j, t, t, z, v, w,
being made according to the Drawing, will be adapted for a mainspring,
which is intended to be wound up about three and three-quarter revolutions,
but not much more from the state of relaxation in which the spring will be
when it is down (or unwound as far as it is intended to be relaxed, as in
Figure 20), until the spring is wholly wound up as far as it is intended to be
strained, as in Figure 21. But note.-If the spring is intended to wind up a
greater number of revolutions than three and three-quarters, then the ring
must be made with as many more teeth (such as t) than are represented in
he Drawings as the intended number of revolutions exceed three and three-
quarters; all which is well known, because a similar ring is in common use
a some kinds of watches, and is actuated in the same manner as represented
the Drawings, that is to say, when the spring is down or unwound, and the
arts are as shewn in Figure 20, then the spring is prevented from unwinding
rther, because the tooth c of the circular plate b is stopped by the end of that
oth coming in contact with the interior of the ring at d, where that ring is'
ft of its full breadth, and is therefore adapted for arresting any further motion'
the tooth c and plate 6 in the direction of unwinding the spring, as is
own in Figure 20.
When the winding-up key is applied to the square on
e end of the central axis, and that axis, with its ratchet f, is turned round by
e key in the proper direction for winding up the spring, then as the detent
shold of a tooth of the ratchet f, the detent will carry the plate 6 round,'
cause the centre screw e of the detent is screwed into the plate 6, and
sequently the perforated axis of the spring barrel is turned and begins to

page_text: gone
wind up the spring. By the time about seven-eights of a revolution has been
made, in so winding up, the tooth c of the plate 6 will have gone round (without
reaching the teeth t, t, of the ring) until the said tooth c has come in contact
with the projection j of the ring, and then the tooth c, as it goes farther round,
will begin to turn the ring round with it in the excentric recess wherein the
ring is lodged; and whilst the tooth c is making about one-eighth of a turn
after such contact with the projection j, it will continue to turn the ring.in
that manner, and will turn it just so far as will bring the first tooth t of the
ring into the position which the projection j had previously occupied; and then,
owing to the excentricity of the ring, the tooth c will quit contact with the
projection j, and leave the ring at rest in its recess until the tooth c has
round another turn, and thereby regained the proper position for beginning
to turn the ring a second time by coming in contact with and acting against
the first tooth t of the ring, in the same manner as it acted before against the
projection j thereof; and by such second action of turning the ring by the
tooth c and the first tooth t of the ring, the latter is again moved round in its
recess until the second tooth t of the ring is brought into the position that was
at first occupied by the projection of the ring in Figure 20; then at the
next turn which is made by the tooth c, it turns the ring a third time by acting
against its second tooth t, as before, so as to get the ring round into the posi
tion which the ring (but not the other parts) has in Figure 21, and then
(owing to the excentricity of the ring) the tooth c quitting contact with the
second tooth t of the ring, leaves the ring at rest in its recess, but the tooth c
continues until it gets about three-quarters of a turn further round into. the
position which that tooth c (as well as the ring) has in Figure 21, by which
time the plate b and the axis of the spring barrel will have mado about three
and three-quarter revolutions, and the spring being wound up (as far as it is
intended to be) must not be wound any farther. According to the usual
action of such a ring after having been turned in the manner above described,
it would then put a stop to any farther motion of the winding up by pre-
senting to the end of the tooth ca part of the ring, where, in consequence of
being left of its full breadth, the ring would be adapted for arresting any further
motion of the tooth c in the direction of winding up the spring; but that is not
the manner in which the ring operates in my improvements, for the interior of
the ring is cut away at the part v thereof which presents itself to the tooth c
when the spring is almost wholly wound up, as in Figure 21, and in consequence
of the ring not being of its full breadth at v, it does not stop the tooth c.
According to my improvements the ring operates to bring into action a curved
lever
k, n, m, so as thereby to cause the detenti, e, u, to be disengaged from

page_text: the teeth of the ratchet f, as is shewn in Figure 21, in order to permit the
central axis and its said ratchet f to be turned freely round by the winding-up key
without producing any effect on the plate 6 and on the axis of the spring barrel.
The said curved lever x, k, n, m, is shewn separately in Figure 26, and from its
form it may be called the sickle; it is mounted on a screw x, which serves as
a centre of motion for the sickle, the screw a being screwed fast into the end
(or into the cover) of the spring barrel at p, Figure 22, so that the sickle
applies with its flat surface against the flat surface of the said end (or cover);
a spring, shewn separately in Figure 29, is also fixed upon the same end (or
cover) by a screw and steady pin at q, Figure 22; the extremity of the spring
acts against the tail end of the sickle so as to give the part k of the sickle a
constant tendency to approach towards the centre of the spring barrel; but at
all times (except when the spring is almost within one turn of being wound up)
the sickle is retained in the position shewn in Figure 20 by means of a pin n,
which is fixed into the sickle so as to project downwards from the under side
thereof, and that pin n is received into a small recess m, Figure 22, which
conjoins with the large circular recess wherein the ring is lodged; the pin n
applies to the exterior circular edge of the ring, and thereby (notwithstanding
the effort of its spring 1) the sickle is retained in the position Figure 20, so
as to be kept wholly out of the reach of the tail end i of the detent i, e, u,
when that tail end is carried round along with the plate b; but when the spring
is almost within one turn of being wound up, and the ring has been brought
(by the action already explained) into the position Figure 21, then an inclined
part w, which is cut away at the exterior circumference of the ring, presents
itself to the pin n of the sickle, so as to allow the sickle to be moved about its
centre of motion x, by action of its spring 7, into the position Figure 21, where
it can be seen that the curved end m, n, k, of the sickle will intercept and act
against the tail end i of the detent as the latter is carried round with the plate b.
Note. The sickle and the detent are situated in the same plane as well as
the ratchet f and the springs g and I, all which parts are situated in a plane
immediately above the flat surface of the end (or of the cover) of the spring
barrel, hence the curved part m, n, k, of the sickle and the end i of the detent
will apply truly edge to edge when they come in contact, as in Figure 21; but
owing to the recess a being excavated in the end (or in the cover) of the barrel,
the circular plate 6 and the excentric ring are situated in another plane
beneath the detent and the sickle and the ratchet and the springs 9 and 7.
The action which takes place between the curved part m of the sickle and the
end i of the detent, when the latter is first brought round in contact with the
former, has some tendency to move the detent about its centre of motion,
R
g

page_text: and so as to begin to disengage the hooked end u of the detent from its
previous contact with the teeth of the ratchet f, and that tendency in-
creases as the detent is carried farther round with the end of the detent
in contact with the curved part m of the sickle, and by the time that the
parts have got into the position Figure 21 (or near to that position), then
the detent will become wholly disengaged from the teeth of the ratchet, as
is there shewn, the disengagement being effected gradually and without
sensible effort; but in case the complete disengagement is not effected by the
time the parts get to the position Figure 21, so that the end i of the detent is
carried farther round, then that end i will be intercepted by the projection k
of the sickle, and the complete disengagement of the detent cannot fail to be
accomplished. Note.-The proper and intended action of gradual disengage-
ment of the detent (in manner aforesaid), before its tail i gets round so far as
the projection k, depends upon the action of the spring 1 of the sickle, which
ought to act with sufficient force to enable the sickle to react so much against
the end i of the detent by the time that the position Figure 21 is reached as
will overcome the force of the spring g of the detent, together, with any such
resistance to the motion of the detent about its centre of motion e as may
result from the hold that is taken by the hooked end of the detent in the
teeth of the ratchet; and as to the amount of such resistance, it is obvious
that it will depend upon the form of the teeth and of the hooked end of the
detent, and the position of the centre of motion e of the detent in respect to
those teeth. If all the parts are formed as in the Drawings, then suitable
adjustment must be made of the strength of the spring g of the detent,
in order to cause the hooked end u of the detent to apply with a proper
elastic pressure against the teeth of the metal f to ensure taking hold, but no
more pressure than is requisite for the purpose, and also corresponding adjust-
ment being made of the strength of the spring of the sickle to enable the
curved end m of the sickle to react against the tail end i of the detent with
suitable force, then, under those conditions, the intended gradual disengagement
of the detent from the teeth of the ratchet may be duly effected by the time
the parts reach the position Figure 21. And note.-The effort of the spring l
of the sickle to enable the sickle to react sufficiently against the tail end i of
the detent for effecting the disengagement becomes more efficient as the
contact of the said end i approaches nearer towards the centre of motion a of
the sickle during the progress of the said contact along the curve m, and it
will depend chiefly upon the adjustment given to the two springs 9 and 1, one
in respect to the other, that the disengagement shall be duly performed, in
manner above described, by the time that the position Figure 21 is attained;

page_text: but if from any fault, or from the parts becoming clogged by dirt, the dis-
engagement is not then effected, the projection k will render the disengagement
certain, so that no injury can be done to the mechanism of the watch by the
winding up of the spring (by the key) being continued beyond the intended
extent, because the winding-up key and the central axis will be allowed to
turn round freely after such disengagement is effected. The perforated axis
of the spring barrel, Figures 32, 33, and its ratchet wheel r, being in the same
piece of steel with that axis, the part a of the axis is fitted into the central
hole of the bridge O, Figure 23, and the two flat surfaces of the ratchet
wheel are included with an easy fitting between corresponding surfaces of
the bridge O and of its plate, Figure 24. By that means the perforated axis,
although it has no pivot or other support, is retained securely in place in the
watch, with liberty to be turned round in one direction for winding up
the spring, but motion in a contrary direction is prevented by the spring click
hooking the teeth of the ratchet wheel r, as is shewn in Figure 23. The
round parts b and d, Figures 32, 33, fit the centro holes in the two ends of
the spring barrel. A screw thread is formed around the outside of the axis
at c, between the said parts b and d, in order to receive a ring, Figure 34,
which is tapped withinside, and being screwed firmly on the screwed part c of
the axis, forms a proper centre piece for the spring. The said ring, Figure 34,
has a projecting hook t, to catch into a hole in the interior coil of the spring,
and also two notches v, v, for taking hold at opposite sides of the ring with
plyers, in order to screw it fast on the axis. The end 2. of the perforated
axis, Figures 32, 33, is formed to a square, on which the circular plate b,
Figure 28, is fitted very firmly. The perforation through the axis is seen
at x, Figure 33; and Figure 35 is the central axis, whereof the round part o is
fitted into the perforation. The part k of that central axis, Figure 35, is the
square to which the winding-up key is applied; and there is also a square on
the other end y, which reaches through the perforated axis, Figure 33, and
Con that square y the ratchet f, Figure 27, is fitted very firmly so as to become
fastened on the central axis; and by insertion of a cross pin through a hole x,
Figure 35, across the end y of the central axis, all the parts are retained
in due place. Note.-In the construction above described there is no pivot
required for sustaining the axis, Figures 32, 33, of the spring barrel in its
place in the watch, but it is wholly sustained by the fitting of its circular part a
and the two flat surfaces of its ratchet wheel r in the bridge O, Figure 23, and
between that and the plate, Figure 24. But note.--If required, the end y of the
central axis, Figure 35, might be formed a pivot for assisting to sustain the
axis of the spring barrel. In other watches, or in spring clocks which have

page_text: two plates for the framework of their mechanism, the perforated axis of the
spring barrel will be somewhat different, see Figures 36 and 37, wherein the
large part c is that which forms the central piece for the spring, and has a
projecting hook to catch into a hole in the interior coil of the spring, so that
the part c answers to the ring, Figure 34 (already described), except as to
being formed of the same piece of steel with the axis in Figure 36. The round
parts b and d, Figure 36, fit the central holes in the two ends of the spring
barrel. The square part z is to receive the circular plate b, Figure 28, and the
winding-up ratchet wheel r (see also Figure 38) is fitted on a square at the
other end of the perforated axis. The round part e of that axis serves as one
of the pivots for sustaining the axis of the spring barrel in place on the watch
or clock, and that part e being fitted into a pivot hole through one of the
frame plates, the winding-up ratchet will be at the exterior of those plates,
the spring barrel being between the two. The central axis is shewn separately
in Figure 37. The part k is the square to which the winding-up key is applied;
the round part o is fitted easily into the central perforation through the axis,
Figure 36. The square y, Figure 37, is to receive the ratchet f, Figure 27,
which thereby becomes fastened on the central axis is as shewn in Figure 36.
The end x, Figure 37, of the round part o of the central axis protrudes quite
through the perforated axis, Figure 36, and a flat round plate or washer. of
steel is fitted on the protruding end x, so that the circumference thereof.may
apply to the central part of the flat surface of the winding-up ratchet wheel r,
and then by insertion of of a cross pin through a hole across the end x of the
central axis the several parts are kept together, as shewn in Figure 36.
The round part a of the central axis, Figures 36 and 37, serves as a pivot by
which (together with the round part e, Figure 36, already mentioned) the axis
of the spring barrel is sustained in place in the frame of the watch or clock.
The small prominent rim i on the central axis, Figure 37, serves as a shoulder
to the pivot a, and also as a shoulder against which the ratchet f applies.
Figures 39 and 39ª represent an arrangement of a perforated axis for the
spring barrel, having a central axis within the perforation similar to Figures 36,
37 (already described), except as to being adapted for applying the winding-up
key at the other end of the axis, so that if a watch or clock having the arrange-
ment, Figures 36, 37, winds up from the back of the watch or clock case, then if
the arrangement Figures 39, 39, were to be used instead, the winding up would
take place in front or through the dial plate. In Figure 39, c forms the centre
piece for the spring b; and d, the round parts which fit the central holes in the
two ends of the spring barrel; e, one of the pivots for sustaining the axis in place;
r, the winding-up ratchet wheel, fitted firmly on a square at one end of the per-

page_text: forated axis; z is a square on the opposite end for receiving the circular plate b,
Figure 28. The central axis is shown separately in Figure 39. The round part
o is fitted easily into the perforation through the perforated axis, a round steel
washer being applied on the part o against the shoulder i, and that washer
applies to the flat surface of the ratchet wheel r. The part k is the square to
which the winding-up key is to be applied. The part y, which protrudes through
the perforated axis, is a square whereon the ratchet f, Figure 27, is applied,
and by insertion of a cross pin through the hole x, all the parts are retained
together, as in Figure 39. The extreme end of the central axis, Figure 39*,
is formed into a pivot, which (together with the pivot e, Figure 39, on the
perforated axis, as before mentioned) sustains the axis in place in the watch
or spring clock. Note.-When the mainspring unwinds and gradually relaxes
itself during its ordinary action of impelling the wheelwork of the watch or
spring clock, it turns the spring barrel and the main toothed wheel round; but
at the same time the axis of the spring barrel and the plate b, with the detent
i, e, u, and its spring 9, will stand still, in consequence, the tooth c of the
plate 6 will react against the internal projection z, and the teeth t, t, of the
excentric ring, so as to turn that ring round within its recess at intervals, in
the same manner (during the unwinding of the spring) as took place during the
winding-up of the spring (as herein-before described), except that the turning
of the ring will be in a contrary direction; and by such contrary turning of the
ring, and by the gradual turning motion of the spring barrel in the act of impel-
ling the wheelwork of the watch or spring clock during the unwinding of the
mainspring, the several parts will be carried backwards from the situation which
they occupy (one in respect to another), as represented in Figure 21, until
they all regain the position represented in Figure 20, by the time that the
mainspring is got down, or is relaxed as far as it intended to go. The parts
represented in Figures 20, 21, may be constructed somewhat differently, as is
shewn in Figures 40, 41, and 42. Figure 40 represents the parts as they
will be when the mainspring is down, and answers to Figure 20. Figure 41
represents the same parts when the mainspring is wound up, and answers to
Figure 21. The chief difference is that the curved lever herein-before
described as the sickle is omitted, and a curved spring 1, Figures 40, 41, 42,
is substituted, for the purpose of acting against the tail end i of the detent
i, e, u; that spring is affixed to the excentric ring d, j, t, t, z, v, so as to be
carried round therewith when that ring is turned round (within the circular
recess at the end or cover of the spring barrel), by action of the tooth c of the
circular plate b, which action takes place as herein-before described; and owing
to the excentricity of the ring, the curved spring 1, Figure 41, will be carried

page_text: The
round with the ring from the position shewn in Figure 40 (when the main
spring is down), until, by the manipulation of winding up, the spring with the
ring is brought into the position shewn in Figure 41; by the time the main
spring is within about one turn of being wound up, and when it is in that
position, the spring is qualified, by its curvature and its elastic strength, for
operating or reaching against the tail end i of the detent when the same is carried
in contact with the curve of the spring 7, in the same manner as herein-before
described respecting the contact of the said end i with the curved part of the
sickle, and for the same purpose, viz, for effecting a gradual disengagement of
the hooked end u of the detent from the teeth of the ratchet f. The excentric
ring d, j, t, t, z, v, (see also Figure 42), is nearly the same as already described,
and as represented in Figure 25, except that it is not cut away at the exterior
to form any inclined part w, that inclined part being unnecessary.
curved spring is firmly fastened to the ring by a screw and a steady
pin, so that the curve of the spring will assume the position represented
in Figure 42, which is a curve somewhat excentric to the ring, and also
excentric to the spring barrel in a greater degree than the ring is excentric
thereto, wherefore the curved part of the spring will be qualified for reacting
against the end i of the detent when that end is carried round with the said
curved part, and the reaction will cause so much tendency to move the detent
about its centre of motion e as will begin to disengage the hooked end u of
the detent from its previous contact with the teeth of the ratchet f very soon
after the said tail end i of the detent is brought round into its first contact
with the curved part of the spring 1, and the said tendency will increase as the
detent is carried further round with its end i, in contact with the curved part
of the spring, so as most probably to cause the detent to become wholly
disengaged by an easy and gradual action by the time that the parts bave got
round into the position represented in Figure 41; but in case the complete
disengagement is not effected until the parts get round beyond the position
Figure 41, then the tail end i of the detent will be intercepted by a prominent
piece of steel which is fastened upon the ring by a screw with a steady pin,
and thereby the complete disengagement cannot fail to be accomplished; the
gradual disengagement and the certainty of complete disengagement being
attained in the same manner as would be done by means of the curved part
m of the sickle and of its projection k, Figure 21, as already explained. And
note. The said prominent piece of steel k, Figure 41, will be intercepted by
a piece x, which is firmly fixed by a screw and one or two steady pins to the
end (or to the cover) of the spring barrel, and which piece a reaches over the
ring, in order by so intercepting the piece to serve as a stop for preventing the

page_text: b
ring from being turned round in its recess by the aforesaid action of the end i of
the detent against the curved spring 7. The ring is prevented by such stop from
going materially beyond the position which the position which the ring is
represented to have in its said recess in Figure 41. The stoppage, which is
formed as aforesaid by the piece a intercepting the piece k, is only by way of
precaution for preventing the ring from being turned further round in its
recess than it ought to be turned in case that the action of the end i of the
detent against the curved spring should be able to give any motion to the
ring in its recess; but such motion it is not intended to give. And note.-
The picce x is so fixed in respect to the piece k as that the said pieces will
not come actually in contact one with the other, when the ring has been
turned in its recess by action of the tooth c of the plate as far round as it is
intended to be turned by the said tooth, but a very small interval should
remain between the said pieces, as is represented in Figure 41, in order to
avoid any risk of impediment to the action, whereby the tooth is to turn the
ring round in its recess to that position; the form of the teeth of the ratchet
f, as well as that of the hooked end u of the detent which catches in those
teeth, is different in Figures 40 and 41 from what is represented in Figures
20 and 21, but such difference is not a necessary consequence of the sickle
being used in Figures 20 and 21, and the curved spring 7 being used in lieu
thereof in Figures 40 and 41, for a ratchet f, and a detent i, e, u of the form
shewn in Figures 40 and 41, might be used in Figures 20 and 21; or, vice
versa, a ratchet f and detent i, e, u, of the form shewn in Figures 20, 21,
might be used in Figure 40 and 41. The teeth of the ratchet f in Figure 41
are sixteen in number, and the two sides of every fourth of those teeth conform
to the angles of a square, which is represented by dotted lines in Figure 41.
The hooked end u of the detent is made conformable to those teeth, and the
centre of motion e of the detent is situated in the line of one of the sides of the
said square prolonged. The result is that the action whereby the hooked end u
of the detent holds in the teeth of the ratchet f will have no tendency to move
the detent about its centre e, either to take deeper hold of the teeth of the
ratchet or to unhook from those teeth; and although the holding will be rendered
quite secure by the elastic force of the spring g of the detent, nevertheless the
required disengagement of the hooked end u, from the teeth of the ratchet f
will be easily performed, whether it is by means of the sickle, as in Figure 20
and 21, or by means of the curved spring 1, as in Figures 40 and 41.
Figure 43, Sheet I., shews how the ratchet g and hooked end m of the detent,
Figures 1, 2, and 3, Sheet I., for the axis of a fusee, or of the spring barrel of
a watch or spring clock, may be formed with eight teeth, whereof the two sides

page_text: of every other tooth conform to the angles of a square, which is represented by
dotted lines in Figure 43. The hooked end m of the detent m, h, f, k, is
conformable with those teeth, and the centre of motion h of the detent is
situated in the line of one of the sides of such square prolonged; the result of
which will be the same as already stated respecting the ratchet and detent in
Figure 41.
And note. In either Figure 41 or Figure 43, the form of the
teeth of the ratchet is suitable for acting backwards against the end of the
detent, so as to cause the teeth to slip easily past that end in case of the
winding-up key being, by inadvertence, turned round in a contrary direction to
that which is proper for winding up. And note. Respecting the disengage-
ment of the hooked end of the detent from the teeth of the ratchet in any of
the cases herein-before described, (Figures 1, or 21, or 41, or 43,) which
disengagement is to take place, as herein-before described, when the spring is
wound up as much as it is intended to be wound up, that disengagement should
in all cases be rendered quite complete, so that there will be no risk of the
detent continuing to slightly touch the ends of the teeth of the ratchet, when
the same may be turned round after the disengagement has been effected. In
order to render the said disengagement quite complete, the action (or the re-
action) whereby it is effected should in all cases be derived from some part
which operates with a yielding or elastic force in the act of effecting the dis-
engagement. For instance, in case of the fusee, Figures 1, 2, 3, it is the
chain i which effects the disengagement, by pressing against the prominence at
the tail end of the detent; but as the chain exerts that pressure by virtue of
its tension and consequent tendency to assume a straight line, the chain can
yield by deflection from that straight line, and it does yield, in a very slight
degree, in the act of pressing against the said prominence with sufficient force
for overcoming the adhesion between the hook of the detent and the teeth of
the ratchet, as well as for overcoming the elastic force of the spring of the
detent, so as to effect the disengagement; but when that is effected, less
pressure by the chain i is then required for keeping the detent disengaged than
was required for its disengagement; wherefore the chain i, on being less
pressed, will somewhat recover from its deflection by virtue of its tension, and
in so recovering it will move the detent a very little farther than the place of
disengagement, so as to remove the hook of the detent clear away from the
And in like manner, in Figure 21, the re-
points of the teeth of the ratchet.
action which the curved part m of the sickle exerts against the tail end i of
the detent is exerted with an elastic force for effecting the disengagement.
And the same may be said of the reaction exerted by the curved spring 1,
Figure 41. The result in each case is that the detent will be removed some-

page_text: what further than the place of disengagement, and its hooked end will be
wholly removed from any risk of contact with the teeth of the ratchet. Note.-
In either of the new arrangements herein-before described for effecting my
improvements, whether Figures 1, 2, 3, or Figures 20, 21, or Figures 40, 41,
or Figure 43, the manipulation of winding-up the mainspring may be performed
without any necessity for turning the winding-up key round and round in the
proper direction for winding up, as must be done in the usual constructions of
watches, chronometers, and spring clocks; but according to my improvements
the winding up may be performed by turning the winding-up key (that key
being of the ordinary kind) in the proper direction for winding up a little way
round, or as far round as may be convenient, and then turning the key back-
wards, which it will do easily, and then turning forwards again in the said
proper direction, then turning backwards, and then forwards again, and so on,
until the winding up is effected, after which the key will turn round freely
without producing any further effect; this results from the action (herein-
before described) of the detent in the teeth of the ratchet on the central axis
to which the winding-up key is applied, for that action permits the backward
motion of the winding-up key and central axis to take place freely, and the
said action also ensures that all forward motion of the said key and axis will
occasion an equivalent extent of winding up of the mainspring until the same
is become wound up to the full extent that it is intended to be wound up, and
after that the action of the new arrangements also ensures that no further
winding up (which would be overwinding) can take place. The parts of the
mechanism which are colored blue in the Drawings should be made of steel
for strength and durability, and should be hardened and tempered and
polished, as is usually done for steel work in watches, chronometers, and spring
clocks. Note. The mechanism herein-before described may be greatly
varied in the form and arrangement of its various parts without departing
from the mode of action by which my improvements are effected. In applying.
and adapting my improvements to watches, chronometers, and spring clocks of
different constructions as to the mechanism of their mainsprings, and the acces-
saries thereto, and as to the parts concerned in the manipulation of winding
up, variations will be necessarily required in the parts by which my improve-
ments are to be carried into effect, in order to adapt those parts to the
mechanism of the watch, chronometer, or spring clock to which my improve-
ments are to be applied and adapted. I have herein-before described, by way
of example, such constructions of the parts by which my improvements are to
be carried into effect as are suitable for the application of the said improve-

page_text: ments to those constructions of watches, chronometers, or spring clocks which
are in most common use.
In the foregoing description, and in the Drawings hereunto annexed, some
parts have necessarily been described and represented which are commonly
used, and do not form part of my Invention. For instance, in Sheet I., the
spring barrel B, the main toothed wheel D, the winding-up ratchet wheel p
Figure 4, or a, Figure 14, with the spring clicks or click thereto belonging;
the auxiliary ratchet wheel, Figure 6, and spring t, u, v, Figure 7; the collet,
Figure 9; the fusee A itself, with its spiral groove, except inasmuch as that
the fusee is not fastened upon its axis, and inasmuch as it is excavated at its
upper part; also, the central axis of the fusee, with its square, to which the
winding-up key is to be applied, except inasmuch as that the said axis is not
fastened into the fusee, and inasmuch as it has a ratchet formed on or fastened
upon it; and in Sheet II., the spring barrel, with its cover, and the toothe
wheel formed around that spring barrel; also, the bridge O, Figure 23; the
winding up ratchet wheel r, Figures 23, 28, and the spring click thereto
belonging; the axis of the spring barrel, Figures 32 to 40, except inasmuch as
such axis is perforated through its centre, and inasmuch as that the central
axis, with the square to which the winding-up key is applied, is distinct from
the said axis of the spring barrel, and is fitted into the perforation through
the centre thereof; also, the ring, Figures 25 and 42, except as to the inclined
part w of the ring, Figure 25, or the stop pieces x, k, and the curved
spring of the ring, Figure 42. In most cases my improvements may be
applied to old watches, chronometers, or spring clocks by suitable alterations of
the existing mechanism, or renewals of part thereof; so as to adapt the same
for receiving and acting in concert with the parts by which my improvements
are to be carried into effect.
Having now described my said improvements, I, the said Charles Henri
Perrin, do hereby declare that the new Invention, whereof the exclusive use is
granted to me by the Letters Patent herein-before recited, consists in the
improved construction, herein-before described, of certain parts of the
mechanism of watches and chronometers, and of such kinds of clocks as are
actuated by a mainspring for maintaining power, and which are therefore
called spring clocks; those said parts being' such of the parts herein-before
described, and represented in the Drawings hereunto annexed, as have relation
to the operation or manipulation of winding up the mainspring, which serves
for the maintaining power of the watch, chronometer, or spring clock.
The essential character of the Invention being that the central axis to which

page_text: the winding-up key is applied is not (as heretofore) fastened into the fusce or
into the axis of the spring barrel, but is fitted into the fusee or into a
central perforation through the axis of the spring barrel, with liberty to turn
freely round in the fusee or in that perforated axis, except inasmuch as may be
prevented by a toothed ratchet which is formed on or fastened on the said
central axis to which the winding-up key is applied, and also by a detent
adapted to act in the teeth of the said ratchet, the centre of motion of
which detent is borne by the fusee or by a piece affixed to the perforated axis
of the spring barrel, and which detent, by action of a suitable spring, will catch
and hold in the teeth of the ratchet when the winding-up key is turned in the
proper direction for winding up; but the same detent will not hold the said
tecth, but will allow them to slip easily if the said key is turned in a contrary
direction. And also the said detent will (by action of some of the new
arrangements herein-before described) become wholly and completely disen-
gaged from the teeth of the ratchet when the spring is wound up as far as it is
intended to be wound up, and in consequence the winding-up key, and the
central axis to which the same is applied, will be set at liberty to be turned
freely round as soon as the winding up is effected without being able to com-
municate any further force to the mechanisin of the watch, chronometer, or
spring clock.
In witness whereof, I, the said Charles Henri Perrin, have hereunto set
my hand and seal, this Twelfth day of November, One thousand eight
1
.