Improvements relating to the Main Springs of Watches, Clocks, and the like.
Year: 1889

page_text: Date of Application, 12th Feb., 1889
Specification Accepted, 16th Mar., 1889
Improvements relating to the Main Springs of Watches, Clocks, and
the like.
I, ERNEST KARTHAUS, of Huntsville, in the County of Madison, and State of
Alabama, watch maker and jeweller, do hereby declare the nature of my invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
My invention relates to improvements in mainsprings for watches, clocks, and other
instruments employing going barrels, and to the method of inserting and removing
the same from the going-barrels of time pieces and other. instruments, that will be
hereinafter fully described and claimed.
This invention relates to an improvement in that class of mainsprings in which
the outer end thereof is connected with a coiled tension or friction spring which
encircles the inner periphery of the barrel, the object of this construction being
to prevent the over winding of the mainspring by causing the coiled tension or
friction spring to slip and relieve the mainspring when undue pressure is exerted
upon the latter and thereby guard against the breakage of the mainspring from over
winding, and also prevent injury to the watch-movement in the event of breakage of
the mainspring from a change in temperature or other causes.
The primary object of my invention is to provide a strong and durable tension or
friction device adapted for holding the end of either a strong or weak mainspring equally
as well and without the aid of cavities in the barrel or projections on the device, which
will not release the mainspring from the barrel except in the event of overwinding the
mainspring, and which will obviate the danger of breakage of the end fastenings and
the use of stop-guards of any character.
A further object of my invention is to facilitate the insertion and removal of main-
springs of watches and other instruments while they are in a coiled or wound up state
and to enable this result to be attained without the use of special instruments or coiling
and inserting such springs.
In the accompanying drawings:-
Figure 1 is a plan view showing the mainspring and tension or friction spring coiled
within the barrel.
Figure 2 is an enlarged view of the mainspring removed from the barrel, with its

page_text: coils open, and the coiled tension or friction spring attached to the outer end of the
mainspring.
Figure 3 is a plan view of the mainspring having a detachable encircling clasp or
ring for holding it in a coiled or wound up state in a condition ready for insertion
into a going barrel according to my method.
Figure 4 is a detached plan view of the clasp ring to receive the mainspring, and
Figure 5 illustrates my method of simultaneously inserting a coiled main-
spring at one end of a going barrel and removing another spring at the opposito
end thereof.
Like letters of reference denote corresponding parts in all the figures.
In the accompanying drawings, I have illustrated my invention in connection
with the going barrel of a watch, but I would have it understood that I do not confine
myself to the use of my invention in connection with this particular art as I am
aware that it can be used with good results in clocks and other instruments which
employ going barrels.
A is the going-barrel of a time keeper, and c is the winding arbor.
The interior wall or surface of the barrel is made perfectly smooth, and is devoid of
lugs or openings commonly resorted to in other devices. I employ a coiled tension
spring D which is of such diameter or size as to closely hug the interior wall of the
barrel, and the tension spring has the outer end or coil of the mainspring E secured
thereto in the manner presently described.
The coiled tension spring D is formed of a spring plate or strip of hard smooth
steel which is properly tempered, and to one end of this coiled tension spring is
permanently connected the free end of the outer coil of the mainspring, by means
of a rivet e which passes transversely through the meeting lapped ends of the main-
spring and coiled tension spring, as clearly shown in figure 2. This rivet is passed
through the mainspring and coiled tension spring at a suitable distance from the
ends thereof, to forin a fork or seat in front of the rivet; and this fork or seat
receives the free or unattached end of the tension spring that closely hugs the inner
periphery of the barrel and is held in place by frictional contact therewith. The rivet
is preferably provided on its inner end with a shoulder which imparts considerable
strength thereto and closely connects the ends of the tension spring and mainspring
together. The elasticity of the tension spring is sufficient to hold it in close contact
with the inner periphery of the barrel and prevent it from slipping until the full or
proper winding of the mainspring has been secured, thereby holding said tension
spring under the proper tension solely by frictional contact with the barrel.
however, undue tension or pressure is brought to bear upon the mainspring, by over
winding the same, changes in temperature, or other causes, it follows that the tension
spring is bowed inwardly or forced radially, which movement will reduce the degree
of pressure or force which said tension spring presses upon the inner wall of the
barrel and thereby permit said spring to turn or slip in the barrel and relieve any
undue pressure upon the mainspring. Furthermore, this slipping of the tension
spring will not cause a loosening or unwinding of the mainspring; on the contrary,
the latter is maintained in its fully wound up state.
When
This tension spring is constructed or contrived so that it will be impossible for either
of its ends to become displaced and slide upon the other and decrease the diameter of
said tension spring, and in this manner destroy the frictional contact between it and
the barrel.
It may also be stated that the free or unattached end of the tension spring is held
between the mainspring and the other end of the tension spring in such a perfect
manner that the greater the pull or draw exerted upon the mainspring, the
firmer will the free end of the tension spring be clamped in the seat or fork formed
by and between the mainspring and said tension spring. Should the tension spring
loose its required tension or force by reason of a careless insertion into or removal
from a barrel, the rivet can be tightened, when the two ends of the tension spring and
mainspring are brought closer together.
In figure 3 of the drawings, I have illustrated my improved method of holding

page_text: a mainspring in a coiled or wound up condition ready for insertion into a watch
barrel, and in figure 5, 1. have shown the method of simultaneously fitting a
new and removing an old spring from the barrel, which method I will presently
describe.
The common practice of placing mainsprings upon the market is to wind wire around
the same to prevent the uncoiling thereof, these wires being removed before the springs
are placed in the barrels.
It is apparent that special means must be resorted to for preventing the uncoiling.
of the springs after the wires are removed, and the appliances of a watch-maker
are required to fit the springs in place properly and make the required connection
with the barrels.
In order to facilitate the ready insertion and removal of springs, I resort to the use
of a ring-shaped clasp G, which is made of metal or other suitable material, and is
fitted closely around the mainspring and its tension spring prior to their insertion into
the going-barrel, (see figure 3).
The interior diameter of the clasp-ring is slightly smaller than the diameter of
the barrel which the main spring is to enter, so that the mainspring and its tension
spring are properly held to insure the ready insertion thereof into the barrol, which is
accomplished by adjusting the clasp-ring against one end of the barrel and forcing the
mainspring and tension spring into the barrel, the clasp-ring being slipped from the
mainspring and tension spring when they enter the barrel.
my
Having now particularly described and ascertained' the nature of said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
1. The combination with a going barrel and a mainspring of a watch or other time-
keeper, of a tension spring completely encircling the mainspring and having both
ends thereof connected to the outer coils of the mainspring and to one another in
such a manner as to prevent the ends of the tension spring from sliding past one
another, said tension spring being fitted tightly in the going barrel to be held by
frictional contact against the inner periphery of the barrel and capable of a radial
movement inwardly upon the mainspring by an excessive strain upon the latter,
substantially as described for the purpose set forth.
2. The combination with a going barrel and a mainspring, of a tension spring com-
pletely encircling the mainspring and having one end permanently united to the outer
coil of the mainspring, the unattached or free end of the tension spring being
detachably connected to the united ends of the tension spring and mainspring to
prevent the ends of said tension spring from sliding past one another, the tension
spring being capable of a radial movement inwardly upon the mainspring, substantially
as described, for the purpose set forth.
3. The combination with the going barrel and a mainspring of a tension spring
encircling the mainspring, said tension spring having one end thereof secured to the
outer coil of the mainspring by a transverse rivet which passes through the tension
spring and mainspring at a suitable distance from the ends of the same to form a seat
or fork, the unattached or free end of the said tension spring being fitted in the fork
or seat and thereby held against sliding past the same, substantially as described, for
the purpose set forth.
4. The herein described method of inserting mainsprings into the going barrels of
time-keepers and other instruments, which consists, first, in placing a non-expansible
clasp around the mainspring to be inserted, the interior diameter of said clasp being
of corresponding or slightly smaller diameter than the barrel into which the main-
spring is to be inserted, and then forcing the mainspring into the barrel and causing
the clasp to strike the end of the barrel, substantially as described, for the purpose
set forth.
5. The herein described method of inserting and removing mainsprings into and
from the going barrels of other time-keepers and other instruments, which consists,
first, in placing a non-expansible clasp-ring around the main-spring to be inserted,

page_text: the interior diameter of said clasp-ring being of corresponding or slightly smaller
diameter than the barrel into which the mainspring is to be inserted, then partially
forcing another mainspring already fitted in the barrel from the opposite end
thereof, and finally forcing the first mainspring completely into the barrel and
entirely expelling the second mainspring therefrom, as and for the purpose
described.
6. The herein described non-expansible clasp-ring adapted to be placed around a
inainspring and having its interior diameter corresponding to the interior diameter of
the going-barrel into which said mainspring is to be inserted.
Dated this 19th day of Fahruary 1880.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.