IMPROVEMENTS IN THE STRIKING WORK FOR CLOCKS
Year: 1883

page_text: LETTERS PATENT to Andreas Gulbrandsen Hovde of the Town of Hönefos in
the Kingdom of Norway for an Invention of IMPROVEMENTS IN THE STRIKING
WORK FOR CLOCKS
PROVISIONAL SPECIFICATION left by the said Andreas Gulbrandsen Hovde
at the Office of the Commissioners of Patents on the 15th September 1883.
ANDREAS GULBRANDSEN HOVDE of the Town of Hönefos in the Kingdom of
Norway, "IMPROVEMENTS IN THE STRIKING WORK FOR CLOCKS,"
This invention relates to striking trains adaptable to all kinds of clocks and
which are of a simpler construction, than striking trains hitherto known owing to
their being continuously or at short intervals wound up by one of the wheels of
the dial train.
The improvements chiefly consist in the consecutive winding up of the spring or
weight driving the going wheel by means of a pinion mounted on the axle of the
minute wheel, or on the axle of the dial train connected with the same, whereby
the said spring is, continuously sufficiently stretched to cause the required number
of strokes at fixed intervals.
For this purpose the striking train is composed of three principal parts: The
winding up mechanism, the scapement regulating the strokes of the hammer and
the dial and going train, and it may be arranged in three different modifications.
The invention comprises a peculiar disengaging gear, the principal part of which
is a toothed pinion, one or more consecutive teeth of which are omitted (the
circumference of the pinion being for instance divided into 14 equal parts, but
having only 12 teeth.)
Also a train of tooth wheels calculated and divided in such a manner, that the
main-spring is only wound sufficiently to produce the required number of strokes,
and that the effort or work in winding up is almost equally distributed.
Also two peculiar devices or arrangements for preventing the main-spring from
being overwound by the improper or forced turning of the hands, one of the said
devices consisting chiefly in a special shape of some teeth of the great going wheel,
and a second device in allowing the spring to slide in the casing.

page_text: Also a special escapement the principal part of which consists either of a movable
gear wheel having one or two teeth, or a fixed gear wheel having one or two teeth,
and an escapement lever or arm provided with a tooth placed opposite a tooth of
the great going wheel.
Also a balanced hammer with free motion in the manner of an ordinary balance,
for facilitating the use of the new striking train in ordinary watches.
Also a snail having a double row of stops or gradations, whereby the size of the
disc may be reduced one half.
Also the combination of a heart wheel with a corresponding snail of the kind
described.
The device for regulating the strokes comprises a circular plate as already used
in some clocks, being mounted loose on the axle of the minute wheel and provided
with a toothed dividing ring having teeth of different thicknesses and with an
ordinary toothed ring into which gears the pinion mentioned above. The latch or
detent rests with a pin in a notch of the toothed ring and with a tooth in the notch
of a circular disc mounted on the hammer axle, whereby the hammer is secured in
the required position. The release is effected by a tooth on the minute axle, the
said tooth being adapted to lift the lower arm of an angle lever, thereby lifting also
the upper arm and causing a tooth of the latter to enter the notch of the circular
disc from below, so as to disengage the tooth of the said latch or detent.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Andreas Gulbrandsen Hovde in the Patent Office on the 15th March
1884.
ANDREAS GULBRANDSEN HOVDE of the Town of Hönefos in the Kingdom of
Norway, "IMPROVEMENTS IN THE STRIKING WORK FOR CLOCKS,"
This invention relates to striking trains adaptable to all kinds of clocks and
which as compared to the striking trains hitherto known are of a simpler construc-
tion, the striking mechanism being arranged in such a manner that it is either
continuously or at short intervals wound up by one of the wheels of the dial train
or going part so that the whole series of wheels bitherto employed for the striking
train can be dispensed with.
To reduce the loss of power thereby caused to the going part, to a minimum, I
have completely altered the part which operates the hammer, and arranged the
same in the manner of a scapement so as to require less power and to be of an easier
construction. For the same purpose the winding mechanism of the striking train
is arranged in such a manner, that the work performed by the same is equally
distributed over 12 hours. The winding mechanism is connected with a new
disengaging device and the regulating mechanism of the striking part has been
the subject of several improvements for the purpose of simplification and economy
of space.
In describing this invention reference will be had to the accompanying drawings
which represent three different modifications of the improved striking train, and in
which the same or similar parts will be designated by the same letters.
The striking work or train substantially consists of three principal parts.
1. The winding mechanism.
2. The escapement or mechanism for producing the blows of the hammer.
3. The regulating mechanism, or mechanism for controlling the number of blows
to be struck by the hammer.
Fig. 1 represents the principal parts of the first modification of the striking
train, while Fig. 1b represents the scapement on a larger scale.
The striking train is wound up by means of the pinion 7 (Fig 1°) mounted on
the arbor of the centre wheel. The pinion gears into the teeth of the going
wheel and turns the same to the left in opposition to the effort of a helical spring
or of a weight connected with the going wheel r, but not represented in the
drawing.
Of 14 teeth of the pinion two are filed off so as to leave but 12 teeth, owing
to which arrangement the going wheel r is turned 13 teeth to the left at each
revolution of the pinion l.
When however, the recess in the pinion 7 faces the going wheel r, which is the
case at the end of each hour, the going wheel is disengaged from the pinion / so as
to enable the wheel r to be turned back towards the right in the direction
indicated by the arrow Fig 1, under the influence of the spring or weight men-
tioned above. During the latter motion the striking takes place as the scapement,
described below, not only regulates the turning of the going wheel, but also sets
the hammer in motion, under the control of the latter.
The hammer b mounted on the arbor a is balanced by a counter weight 6' and
drawn towards the right against the pin o by a weak spring (not shown in the
drawings). On the hammer arbor a is loosely mounted a pinion d (Fig. 1b) having
two inclined teeth and which is pushed round towards the left against the pin 8¹
of the disc s made fast on the arbor a,.
:

page_text: The arbor a is held between two branches h² and h³ of the lever h pivoted at
its lower end and provided with a rest h¹. The lever h will hereinafter be called
escapement lever owing to its functions. k is the bell
In the position represented by Fig. 1. the hammer has just struck, and the small
pin at the rear of the disc s has come in contact with the branch h³, whereby
the escapement lever h has been moved towards the left so as to disengage the
rest h¹ and consequently the going wheel r. The goingwheel now turning towards
the right, engages the first tooth of the pinion d, whereby the hammer arbor is
turned and the hammer thrown towards the left. If now the going wheel engages
the second tooth of the pinion, the pin &² presses against the branch h² of the scapement
lever, whereby the rest h' engages the tooth or leaf of the going wheel r, owing
to which the going wheel is arrested at such a point that both teeth of the pinion d
are permitted to pass between two teeth of the going wheel r. (This position is
represented by Fig 1b). Owing to the impulse imparted by the goingwheel, the
hammer is swung to the left, until the spring fixed to its arbor offers too much
resistance, or until the tooth s³ comes in contact with the end of the branch h³,
which causes the hammer to swing again to the right like a balance, to disengage
the scapement again by the pin 82 and strike the bell.
When the clock is wound up, the teeth of the going wheel r must be free to
pass the pinion d, for which purpose the pinion d is loosely mounted on the
hammer arbor. The pinion d consequently works similar to a ratchet, and may
be arranged in a similar manner, as will be hereinafter set forth. It will be
observed that in this movement one stroke on the bell corresponds to two teeth
of the going wheel.
The regulation of the striking train is arranged as follows:
In the drawing, Fig. 1 represents the position of the mechanism after the clock
has struck 12.
The bolt f (pivoted at one end) rests with the tooth f' on the highest point of
the heart wheel m mounted on the arbor of the hour wheel, and presses with the
tooth at its left extremity against the step XII of the snail n mounted on the
going wheel r, the snail n has six more steps XI to VI which are connected with
the heartwheel in such a manner that after 12 of a rotation of the heartwheel
(corresponding to one hour) the end f¹ of the bolt descends one step, (or during
the second half of the rotation ascends one step) on the snail n.
During the first hour the going wheel is turned 13 teeth by the pinion 7,
mounted on the arbor of the center wheel, at the same time the tooth f of the
bolt f descends so much that f¹ occupies the same height as step XI; and as the
distance from step XII to XI corresponds to 11 teeth of the going wheel r it will
be clearly seen that the going wheel when thus disengaged, is permitted to turn
to the right for two teeth only, in consequence of which the clock strikes 1.
As the distances between the next steps of the snail n correspond to 9, 7, 5, 3
and 1 teeth of the going wheel, it will be seen that the clock strikes 2, 3, 4, 5
and 6 respectively at each subsequent disengagement of the striking train. The
pin or tooth f now rests on the lowest point of the heartwheel, and f¹ presses
against the step VI of the snail n. At 7 o'clock the goingwheel is turned again
13 teeth towards the left, the extremity f¹ is caused to ascend one step on the
snail by the heartwheel and tooth f which permits the going wheel to turn
14 teeth towards the right, in consequence of which the clock strikes 7. The
above clearly shows how the clock strikes 8, 9, 10 to 12 respectively after each
subsequent hour; the steps of the snail being so arranged that the going wheel r
is permitted to turn two additional teeth after every full hour.
6 times 13 ==
From the above it will be seen that from twelve to six the going wheel turns
78 teeth while the striking train during this time only requires
2 + 4 + 6 +8 + 10 + 12 = 42 teeth, and that therefore the goingwheel has
been turned (7842) = 36 teeth in excess. This excess, however, is again
-

page_text: compensated between 6 and 12 o'clock, for to strike these hours 14 + 16 + 18 +
20+22+24= 114 teeth are required while during this time the going wheel is
turned 78 teeth only, consequently (11478) = 36 too little.
The number of teeth of the going wheel is of no importance as regards the
striking of the hours, but for the sake of details of construction as regards the
arrangement of the steps of the snail n it is desirable that the wheel should at
least have 36 teeth (that is to say (11+ 9 + 7 + 5 + 3 + 1).
For the purpose of preventing an excessive tension of the spring of the going
wheel when the hands are turned forcibly, it is advisable to limit the amount to
which the spring may be wound up, which is carried out by diminishing the
thickness of two of the teeth of the going wheel by filing them or by bending them
out of the plane of the wheel in such manner that while still capable of lifting
the hammer, they no longer engage in the teeth of the pinion l. In this case,
however, the going wheel must have at least 51 teeth; the wheel being turned
36 teeth to the left at six o'clock, 13 teeth more at seven o'clock (together 49 teeth),
in addition to two teeth which are filed down for the purpose mentioned above.
In the arrangement herein described the amount of work required for winding
up is to a certain extent equally distributed because the spring of the going wheel
is wound up every hour to an amount corresponding to the turning of the wheel
for 13 teeth, while the tension of the spring somewhat increases between 12 and 6
and decreases to the same extent between 6 and 12.
Instead of two teeth, as is the case in the arrangement herein described, the
pinion d may have but one tooth, if the pinion is provided with 7 teeth. In this
arrangement one stroke of the striking train corresponds to 1 tooth of the
going wheel, but for the purpose of compensating the winding up, the going
wheel must turn too much (to the right) every second hour, which is not to be
recommended.
The striking train illustrated in Fig. 2 is in many respects so similar to that
herein before described, that a full description of the details will not be required.
The differences of the two arrangements are the following:
The going wheel r (in this case only a toothed sector) turns for each stroke one
the toothed
tooth to the right, owing to which the pinion d has but one tooth;
sector is continually turned back into the same position (to the left) by means of
the pinion of the center-wheel arbor, whether one or more teeth have been used
for the preceding stroke.
Consequently, if the sector is to be turned a less number of teeth than the
number of teeth of the pinion 1, the sector remains in its position after having
been turned to the left, because, when the last right hand tooth slides away from a
tooth of the pinion, the sector falls back one tooth, as can easily be seen, until the
disengaging device, namely the toothless part of the pinion comes into action, as
already described, and the striking begins.
The escapement lever h is arranged horizontally, and generally rests owing to its
gravity on the pin h. The lever h has but one branch h³, against which presses
the tooth & in order to disengage the going wheel immediately before the hainier
begins to strike; in this action the tooth ¹ again serves as a stop.
The position of the striking train illustrated in Fig. 2 is the following:
The clock has just struck 2, and the sector fixed on the arbor of the going wheel,
rests with its right extremity against the pin II of the snail n mounted on the
axle of the goingwheel, which snail is similar in principle to those hitherto used.
In order to gain space the steps of the snail n are arranged in two rows or
groups; one group consists of the pins I to VI and the second of the steps
VII to XII The first row corresponding to the hours 1 to 6, comes in contact with
the end of the sector 73, and the second row comes in contact with the nose to
formed at the rear side of the sector r³, as soon as the required number of strokes
(indicating the hour) has been struck.
From the above it may easily be understood in what manner the steps and pins
of the oneil mnet ha arranged.

page_text: +
In the striking train illustrated by Figs. 2 and 2 an equal distribution of the
work of winding up (as in the arrangement first described) is not obtained; the
second arrangement is however simpler, cheaper, and servicable for many kinds of
clocks.
Both arrangements (Figs. 1 and 2) present the advantage, that the
striking train is not disarranged, even if the hands are forcibly turned, that is to
say the striking train remains in accordance with the dialtrain.
The striking train illustrated in Figs. 3ª, 3b, 3° consists in the following
arrangement:
The drawing represents a rear view of the clock with the striking train.
The striking train is wound up by means of the arbor of the wheel in gear with
the centerwheel, which wheel is for this purpose preferably provided with twice as
many teeth as the center wheel.
On the rear end of the shaft p of this wheel are loosely mounted the going wheel ?,
which always turns in the same direction and the pinion I fixed to r; both wheels
are connected with the shaft p by means of a helical spring.
The axle p makes 6 revolutions every 12 hours; but if the goingwheel has_
13 teeth and the striking train is arranged to strike one blow for each tooth, the
going wheel must equally make 6 revolutions every 12 hours in order to strike
78 blows (6 times 13 = 78). Consequently, the spring of the going wheel receives
a tension sufficient to produce the necessary number of strokes, but not more, and
in-this-case similar to the arrangement shown in Fig. 1 an equal-distribution-of
the work of winding up is obtained.
To prevent an overwinding of the spring (by forcibly turning the hands), it may
be recommended, to fix the outer end of the spring in the spring casing by friction
only instead of adopting a rigid attachment.
The movement of this striking train is substantially the same as that shown in
Fig. 2, with such modifications, however, as are required in consequence of the
vertical position of the hammer arbor."
For the same reason the teeth of the going wheel have the shape shown in the
drawing; the scapement lever h rests with its weight on the fixed pin h* and stops
in this position the going wheel, by pressing with its end against that tooth of the
goingwheel which is just on the point to lift (or turn to the right) the hammer on
the hammer arbor by means of the tooth d of the pinion d (mounted on the
hammer arbor a) for the purpose of striking the next stroke.
In the position represented in the drawing the hammer has just struck, and the
scapement lever has been disengaged by the tooth d¹ in the same manner as in the
movements above described.
The going wheel now turns the hammer to the right, and when the latter is
again pressed to the left by the force of the hammer spring, the scapement lever is
again disengaged and another blow struck on the bell, whereupon the movement
resumes the same position as represented in the drawing.
In this arrangement the strokes are regulated by means of the well-known
locking-plate i which here turns on the same arbor as the center wheel but on a
loose sleeve mounted on the said arbor.
The locking plate is, as usual, provided with a division rim having teeth of
different breadth and intervals and provided with a rim having 78 teeth into which
gears the pinion having 13 teeth.
The bolt rests with the pin v' in a notch of the division rim and with the
tooth in the recess of the disc u on the hammer arbor a Fig. 3°, whereby the
hammer is retained in the position represented in the drawing.
The disengement is effected by means of the tooth t of the centerwheel arbor,
which tooth lifts the levers c and c¹ firmly connected together and pivoted at c³,
whereby the triangular tooth c³ of the lever o¹ enters the recess of the disc u from
below, thereby removing the tooth v² of the bolt v from the said recess, whereby
the locking plate is disengaged.
By this operation the striking train receives a start (through the spring of the
going wheel) whereby the tooth v³ is placed on the disc u, while the hammer is

page_text: still retained by the tooth c³ and becomes only disengaged when the tooth ₺ passes
the lever c'and the angular lever c c¹ descends.
At this moment the striking begins and keeps on until the tooth of the bolt
again falls into one of the recesses of the division rim (of the locking plate) and
the tooth falls into the recess of the disc u.
The going wheel may be mounted loosely on the arbor of the center-wheel and
turned by the same by means of a spring, in which case the locking plate is
mounted on a separate arbor. The pinion may then have 6 teeth and the toothed
rim of the locking plate 72 teeth, whereby the same result is obtained, if each
stroke corresponds to two teeth of the going wheel as in the arrangement illustrated
by Fig. 1a
From the above, it will be seen that by various combinations of the details above
described, various other arrangements of striking trains may be constructed.
In the arrangements shown by Figs 1 and 2, the hammer arbor may for
instance be arranged; in a vertical position, while in the arrangement shown in
Figure 3 a horizontal hammer arbor may be employed without requiring important
modifications of the construction.
The mechanism of the movement may be arranged with various other combinations
without departing from the principle of my invention.
The winding up mechanism may be set in motion by a ratchet wheel and pawl,
the pawl lever being raised and lowered by means of an excentric mounted on the
arbor of the centerwheel.
The helical spring of the hammer arbor has the strength of a balance spring of
an ordinary watch. It is sufficient if the spring of the going wheel has a rigidity
equal to that of 2 or 3 such balance springs, and it is clear that the power required
for the tension of the same, especially if the work of winding up is equally
distributed, is so insignificant that the loss of power of the dial-spring used for
this purpose has no influence on the movement of the clock.
.
The resistance caused by the striking train is indeed so small, that even watches
may be provided with this arrangment
to
In this case, however, springs of corresponding strength are used in all instances
produce the effects obtained by means of gravity in the above described
In striking mechanism for clocks, the continuous or successive winding up or
restoration of the motor which drives the going wheel (such as a spring or
weight) either directly from the arbor of the minute wheel or the wheel of the
dial train gearing into the minute wheel, or indirectly from a wheel mounted
on the arbor of one of these wheels.
In striking mechanism of the class designated by the preceding claim, the use
of a disengaging device, illustrated by Figs. 1 and 2, and consisting in the
omission of one or more teeth from the pinion h
In such striking mechanism, the proportion and division of wheels described
with reference to Figs 1 and 3, for the purpose of giving to the main-spring
the exact tension necessary to produce the required number of blows, and for
equally distributing the work in winding up.
In such striking mechanism, the two devices described with reference to Figs. 1ª
and 3, whereby the main spring of the striking work is prevented from being
overwound by the forcible turning of the hands, one of the said devices
consisting chiefly in filing off or bending sidewards some teeth of the going
wheel, while the other device consists in allowing the said spring to slide in
the casing.

page_text: In striking mechanism for clocks, the use of the escapement described with
reference to Figs 1, 2 and 3, the said escapement consisting chiefly of the
movable wheel d, having one or two teeth, Figs 1 and 2, or of the fixed
wheel d, Fig. 3, also with one or two teeth, and of the escapement lever h
with its modifications.
.
In' striking mechanism for clocks, the use of a balanced hammer having a motion
similar to that of an ordinary balance spring, whereby the application of the
striking mechanism to ordinary watches is facilitated.
In striking mechanism for clocks, the use of a snail n, Fig. 2ª, having a double
row of stops for the purpose of reducing its size.
In striking mechanism for clocks, the use of a heart wheel m, Fig 1*, in combi-
nation with the corresponding snail n divided and calculated substantially as
described.
In striking mechanism for clocks provided with locking plate and bolt, the use
of the regulation described with reference to Figs 3*, 3b, 3° by means of the
disc u with corresponding tooth and bolt v, also the described disengagement
by means of the lever co³, tooth cs and tooth t.
The whole substantially as described.
In witness whereof I, the said Andreas Gulbrandsen Hovde, have hereunto set
y hand and seal this 9th day of March A.D. 1884.
a HAVD