THE CONSTRUCTION OF CLOCKS
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Jacob Merzbach at the Office of the
Commissioners of Patents on the 25th September 1880. A communication
from abroad by Erhardt Junghans and Arthur Junghans, both of Schramberg,
Germany.
"IMPROVEMENTS IN
JACOB MERZBACH, of Snow Hill, in the City of London.
THE CONSTRUCTION OF CLOCKS." A communication from abroad by Erhardt
Junghans and Arthur Junghans, both of Schramberg, Germany.
This Invention has for its object improvements in the construction of clocks.
According to one arrangement the mechanism consists of a drum containing the
spring which by its rotation imparts motion to three wheels. The said drum is
wound by means of the square axle. This axle has a pinion on it, which gears
with a wheel on the axle carrying the spring drum. The main frame has a second
Between this
plate connected to it at its upper part by distance pegs or screws.
plate and the main plate is another train of wheels. There is also a box coutaining
an ordinary spring (a watch spring, for example); on the back of the said box there
is a star wheel mounted concentrically on the axis of the said box. The star wheel
engages with a ratchet which impels the mechanism. The said ratchet rotates on its
axis, and at a point of its revolution comes in a tooth on the star wheel, which
opperation takes place, according to arrangement of mechanism, once every minute,
or it may be more or less as required, thus serving to quicken the speed of the
larger works or mechanism.
The rotation of the ratchet works a wheel having pegs on its face which actuates
a pawl. The rotation of this wheel serves to tighten up the spring in the aforesaid
drum. The turning of the axis on which is fastened the aforesaid pawl and a
wheel, which latter gears with another wheel which carries a trigger catch spring
on the same axle as the box. This catch spring engages with a stop wheel on the
axis.
The pawl for actuating the spring is rotated by suitable gearing, by which means
the lost or expended power of the spring is re-wound automatically. Where it is.
necessary to indicate the time in other parts of the building, besides that in which the
clock is situated, I connect wire and bell crank arrangement to the pawl, and the
striking is effected in a similar way. By this Invention a constant power is
obtained by two independant arrangements of mechanism. By the combined action
of the pawl and star wheel an accurate motion is imparted to the hands, and at the
same time the spring is kept constantly in tension by means of the aforesaid pinion

page_text: and wheel, which effects the regulation, say, every 15 minutes. The main spring
in the drum effects the winding up of the spring in the box, and the extra power
serves to rotate the hands. Thus, it will be seen that there is a continuous
automatic and regular power, as is the case with electric clocks. The following
is an arrangement of the principle driven by water power:-In a closed casing a
wheel or turbine rotates. This water wheel or turbine, has, for example, ten blades
or cups which are filled every fifteen minutes until there is sufficient power to
actuate the mechanism. This mechanism is composed of a wheel for indicating
seconds, a stop wheel, a wheel with pegs on its face, a box containing the spring, a
star wheel a pawl engaging therewith. By this means some of the mechanism as
before described (that is two pinions and two driving wheels) are dispensed with,
which are employed in the former example, to enable the clock to go for 36 hours;
besides these there is no other particular alteration of mechanism. The following
is another arrangement of striking clocks possessing the before named advantages:-
There is a drum having on it a toothed wheel, and mounted (in this case) on the
central shaft or axis, on which centre the indicating hands are also fixed. The two
arrangements of mechanism are mounted between plates, or in any suitable or
convenient manner for compactness, and the winding up of the main spring is
effected by the before named central axis, whereby the unsightly keyhole as is usual
in all clocks wound up from the face is dispensed with. In this case the toothed
wheel is of a much larger diameter, and, consequent on its size and the greater
number of teeth, it has more power and requires a weaker and shorter spring. The
action of the hands is effected in the following manner:-The movement of the
minute hand is effected by a wheel projecting through the plate gearing with the
_change_pinion. The bour_hand_is_also_on_a_separate tube, working around, but..
independent of the drum or central axis. The central shaft projects out or on a level
with the face of the minute hand, which latter must be large enough to admit of a
key. There is a projecting tube secured to one plate, and on it is fixed an arm.
The said tube forms a bearing for the axle of a running wheel. The said arm has
a projecting pin or peg at its outer end which carries an escapement wheel. The
formation of the teeth on the escapement wheel has been found easy to make, and
strong. The arm in pendulum clocks has five projections, and three in ships'
clocks, and may be of any convenient size. The effective power is 5°, whereby
20% is effective by the pendulum fork. The anchor is pivotted and has arms with
cut pegs which are equidistant from the centre. A continuation of the anchor
terminates in a fork, in which a tooth of the pendulum engages. The length of the
stroke of the anchor and pendulum is limited by stops. The latter is provided
with pegs to prevent the pendulum rod slipping off, but in heavy clocks may be
kept in position and in gear with the anchor by a spring, and in case of the swing
being too great, the aforesaid tooth would disengage itself with the fork, whereby
there would be a higher pressure of the arms of the anchor on the escapement
wheel, the teeth for actuating same being slightly bent for this purpose.
The next part of my Invention relates to mechanism for indicating when a clock
is wound up or run out, as the case may be; for this purposo a disc is fastened to
the drum, and a tooth on it engages with a wheel, which is loosely mounted on the
front plate. This wheel has on its axis an indicating hand projecting through the
face of the dial, by which means the state of the spring is indicated. A turn of the
disc with its tooth partially rotates said wheel and the hand; this is prevented from
turning back by the hump, a circumferential part of the disc locking the wheel
until by winding up the tooth again it comes into its corresponding recess in the
wheel, and so on.