Improvements in Electrical Apparatus for Firing Fuzes for Mines and other purposes.
Year: 1895

page_text: [Communicated from abroad by SIEMENS & HALSKE, of Berlin, in the German
Empire,, Electrical Engineers.]
Improvements in Electrical Apparatus for Firing Fuzes for Mines
and other purposes.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate,
Westminster, in the County of Middlesex, Electrical Engineers, do hereby declare
the nature of this invention to be as follows:-
.
This invention relates to electrical apparatus for firing fazes for mines and other
purposes.
The invention consists mainly in an arrangement whereby an amount of energy
is in the first, instance stored up, and then, by the actuation, of an independent
detent lever such stored energy is made to actuate a dynamo the moving parts, of
which are in their turn made to actuate a contact device whereby a circuit in which
the fuze or fuzes is or are included, is connected with the dynamo circuit; there
are also provided appliances for simplifying the construction of the apparatus and
the mode of manipulating the same. For these purposes a dynamo actuated by p
coiled spring or other convenient motor has its armature winding connected with
the field magnet winding through a contact key or switch which is also so connected
with the circuit containing the fuze or fuzes, that if after the dynamo has been
driven for the requisite length of time for producing the necessary current, the key.
or switch is actuated, it is made to break the short circuiting connection between
the armature and field magnet windings, and cause the current to pass through the
fuze circuit so as to fire the latter. The apparatus can be variously, constructed
for this purpose. Thus, according to one arrangement, the armature shaft, of the
dynamo is geared by means of a pinion with a toothed wheel on a shaft to which is
attached the inner end of a spiral spring, the outer end of which is attached to a
barrel fixed to the framing. The said shaft carries.a crank handle by which it
can be rotated so as to wind up the spring, and the shaft is held in the wound
position by means of a ratchet wheel and pawl or other suitable catch, so that, on
releasing the latter, the wound. spring will effect the rotation of the shaft and
consequently also of the armature.
The said wheel on the driving shaft, according to one modification, carries a
stud which, when the armature has made the requisite number of revolutions to
produce the necessary current in the field magnet windings, comes in contact with
the before mentioned contact key or switch and moves.this so as to break the short
circuiting connection of the dynamo, and cause the current to pass through the
fuze circuit.
In cases where it requires a greater number of revolutions of the armature for
producing the necessary current than can be afforded by a single rotation of the
spur wheel on the driving shaft, the before mentioned stud for actuating the
contact key not fixed on the said spur wheel but on another spur wheel on a
separate axis that is driven by a pinion on the driving shaft.

page_text: In place of driving the dynamo armature by means of a coiled spring a descending
weight may be employed. In this case to avoid the necessity of using a separate
weight when the apparatus has to be transported from place to place the dynamo
may itself be made to act as such weight, for which purpose it is suspended from
a trestle frame by means of a pitch chain attached at one end to the frame and
passing firstly round a pitch wheel on the driving shaft of the dynamo, and then
round a pitch pinion on a shaft on the frame which shaft carries a crank handle,
so that by rotating this the pinion is made to raise the chain and thereby also the
suspended dynamo, this being retained in the raised position by a catch device on
the crank shaft.
When this catch device is released, the weight of the dynamo in pulling at the
pitch chain effects the rapid rotation of the crank shaft, and the motion of this
is transmitted to the armature of the dynamo by means of any suitable
transmission gear. The action on the contact key is the same
described.
RB before
For simplifying the manipulations of the above described apparatus the following
arrangements of the driving gear may be employed.
Assuming the use of a coiled spring as motor, the barrel to which the outer end
thereof is attached is mounted loose on the driving shaft, so that the barrel is rotated
on the shaft by hand for winding up the spring.
On the framing of the apparatus is provided a double ended catch lever, one end
of which has a catch adapted to gear with ratchet teeth on the spring barrel, while
the other end has a catch adapted to gear with a ratchet wheel fixed on the driving
shaft.
On rotating the barrel for winding up the spring, the first named end of the lever
is raised by the action of the ratchet teeth of the barrel; 'and' the catch of the other
end of the lever, being thereby moved downwards, is made to engage with the
ratchet wheel on the driving shaft which is thus held stationary during the winding.
When the apparatus is to be put in action, the first named end of the lever is
simply depressed, whereby its catch is caused to hold the barrel stationary, while
at the same time the other end of the lever is raised, thereby freeing the driving
shaft and allowing it to be rotated by the wound spring. By preference, the two
arms of the double catch lever are not connected rigidly together but through a
spring device so that their separate action is not impeded in the case of the catch
of the one coming in contact with the top of a ratchet tooth instead of entering a
space. When the above described device is applied to an arrangement in which
the spring barrel remains stationary, and the winding up of the spring is effected
by the rotation of the driving shaft, the before mentioned catch lever has only a
single catch adapted to engage with the teeth of a ratchet wheel fixed on the
driving shaft, so as to prevent this from being rotated by the spring when this is
being wound up.
The lever has two spring arms which are arranged to press with friction against
the sides of the ratchet wheel so that when the driving shaft and ratchet wheel are
being rotated for winding up the spring, the frictional contact of the spring arms
causes these and with them the catch lever to be moved into the position in which
the catch engages with the ratchet wheel as described. When it is required to
drive the dynamo by the spring, the outer end of the catch lever is depressed so as
to release the catch from the ratchet wheel, the lever is then held in this position
by the spring arms which are drawn in the reverse direction to that first described
by the revolving ratchet wheel.
The barrel is by preference not fixed rigidly to the framing of the machine but
by an elastic connection which will enable it to yield slightly to the impetus
acquired by the rotating parts at the end of the uncoiling motion of the spring, and
thus prevent injury to the latter.
For the same purpose also, instead of fixing the spur wheel that imparts motion
to the armature, rigidly to the driving shaft, it may be connected thereto by a
ratchet wheel and pawl connection that will allow of the wheel being rotated by

page_text: the momentum of the armature without continuing to rotate the driving shaft when
the spring is completely unwound.
Dated this 16th day of November 1805
ABEL & IMRAY,
Agents for the Applicants.
DE PONTUATION.
Improvements in Electrical Apparatus for Firing Fuzes for Mines
and other purposes.
We SIEMENS BROTHERS & Co. LIMITED of 12 Queen Anne's Gate,
Westminster, in the County of Middlesex, Electrical Engineers, do hereby
declare the nature of invention and in what manner the same is to be performed
to be particularly described and ascertained in and by the following statement :-
This invention relates to electrical apparatus for firing fuzes for mines and
other purposes.
The invention consists mainly in an arrangement whereby an amount of energy
is in the first instance stored up and then, by the actuation of an independent
detent lever, such stored energy is made to actuate a dynamo the moving parts of
which are in their turn made to actuate a contact device whereby a circuit in
which the fuze or fuzes ia or are included is connected with the dynamo circuit ;
there are also provided appliances for simplifying the construction of the apparatus
and the mode of manipulating the same.
For these purposes as shewn diagrammatically in Fig. 1 of the accompanying
drawings a dynamo A actuated by a coil spring or other convenient motor has its
armature winding connected in short circuit with the field magnet winding through
a contact key or switch k which is also so connected with the circuit containing
the fuze or fuzes Z that after the dynamo has been driven for sufficient time to
produce the necessary current, the key or switch being actuated breaks the short
circuiting connection between the armature and field magnet windings, and causes
the current to pass through the fuze circuit so as to fire the latter.
The apparatus can be variously constructed for this purpose. Thus according
to one arrangement as shewn in Figs. 2, 3 and 4 the shaft of the armature A. of
the dynamo is geared by means of a pinion r, with a toothed wheel rg on a shaft a
to which is attached the inner end of a spiral spring F the outer end of which is
attached to a barrel fixed to the framing.
The shaft a carries a crank handle K by which it can be rotated so as to wind
up the spring and the shaft is held in the wound position by means of a ratchet
wheel and pawl H, or other suitable catch, on releasing which the wound spring
effects rotation of the shaft a and consequently also of the armature A.
The wheel r, on the driving shaft a according to one modification carries a
stud n, which, when the armature has made the requisite number of revolutions to
produce the necessary current in the field magnet windings, comes in contact with
a stud ng on a contact spring f¹ and moves this so as to break the short circuiting
connection c₁ c, of the dynamo, and cause the current to pass through the fuze
circuit.
In cases where it requires a greater number of revolutions of the armature for
producing the necessary current than can be afforded by a single rotation of the
spur wheel, the stud for actuating the contact key is not fixed on this wheel but
a cam X on the shaft of another spur wheel driven by a pinion 4 on the shaft a
acts on a tooth ng on a spring so as to break the contacts cs c
In place of driving the dynamo armature by means of a coiled spring any other
suitable driving force may be employed thus a descending weight G may be
employed as shewn in Fig. 6.

page_text: For simplifying the manipulations of the above described apparatus the
following arrangements of the driving gear may be employed.
The working of the apparatus may in practice be considerably simplified by the
employment of the special arrangements shewn in Figs. 5 and 7 by means of
which the act of winding up the spring automatically brings the lever H, or H,
into the position for releasing the mechanisin.
In the modification shewn in Fig. 5 the spring barrel is loose on the axle.
The movements of the two levers H, and S, depend on each other. The
lever H, rotates frictionally tight on the pivot a, while the lever S, urged by
the spring f, which is fixed to the lever H₁. causes the pin e to press on
the projection of the lever H₂.
Both these levers are within reach of two ratchet wheels re r7, re being rigidly
connected with the spring barrel T and r with the shaft a. When the barrel is
wound up, the lever H, is lifted by the action of a tooth of the ratchet wheel ra
sliding past a bevilled projection b₁ on H, as soon as H, is lifted, the pin e being
'free to descend, the lever S, which is shaped as a pawl urged by the spring f
engages with the ratchet wheel r, this prevents the shaft as from rotating and the
spring can be wound quite up. A second pawl S₁ holds the spring barrel. At
the moment when the mine is to be fired, it is therefore only necessary to press
down the lever H2, by doing which its arm b, raises the pine and lifts the pawl S
out of engagement with the ratchet wheel r7. The shaft being no longer held
fast, can be caused to revolve by the spring F. When the lever He is depressed
the apparatus is in the condition shewn in Fig. 5, so that the barrel can be again
wound up and the operation may be repeated.
The two levers H, and S, may be rigidly connected together if the position of
the wheel, is always the same after it has completed its course.
The spring connection may then be omitted, since there is no danger of the
pawl S, striking against a point of a tooth on the wheel'r, and holding it.
Fig. 7 shews a modification in which the spring barrel is fixed.
The two levers H, and S, are freo to rotate about the pivot a,, and their
movements.depend on each other as described with reference to Fig. 5.
Two friction springs frigidly connected to the lever H3 press against the sides
of the ratchet wheel r, thus tending to move with it. If the handle g be turned
clockwise, the spring F is wound up, and the shalt a is rotated; the ratchet
wheel which is rigidly fixed on tlie shaft carries the friction springs with it,
and brings the lever H, into the position shewn in Figure 7. The pawl lever S
urged by the spring fattached to the lever H, engages the ratchet wheel, and
locks the shaft a. On depressing the lever H, the projecting tooth b₂ lifts the
pine, and the pawl lever S, out of engagement with the ratchet wheel, the
shaft a is then caused to rotate by the spring F, and the mine is fired.
The barrel T which is free on the shaft a has a projection p pressed by the
lever hand spring against a stop e, and thus held. If the spring F should act
too forcibly on the spring barrel it can slightly yield. When there is high
terminal velocity a ratchet coupling consisting of a ratchet wheel r₁ and pawls
is interposed between the shaft and the driving wheel re so that after completing
their course the driving wheel and armature can continue to revolve in virtue of
their momentum without fear of the spring F being damaged.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what.
we claim is :-
1. Electrical fuze firing apparatus comprising a dynamo machine having its
field magnets wound in series with the armature, which is driven by a weight or
spring and gearing which is held by a catch, on the release of which the gearing
after a certain number of revolutions of the armature operates contacts whereby
an electrical current is transmitted to the fuze, substantially as described with
reference to the accompanying drawings.

page_text: 2. The construction of fuze firing apparatus such as is above referred to,
substantially as described with reference to the Figs. 2, 3 and 4.
modified construction, substantially as described
3. The
to Fig. 5.
4. The
to Fig. 7.
with reference
modified construction, substantially as described with reference
ABEL & IMRAY,
Agents for the Applicants.