Improvements in and relating to Semaphore Signalling Apparatus for Railways.
Year: 1888

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Semaphore Signalling Apparatus
for Railways.
We FREDERICK STITZEL and CHARLES WEINEDEL both of Louisville, in the
County of Jefferson, State of Kentucky, United States of America, Engineers do
hereby declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement :-
13
Our invention relates to an improvement in semaphore signalling mechanism that
is particularly adapted to signal "danger or. indicate "safety" when the device is
employed in connection with the block system of railway services.
The object of our present invention is to perfect the working mechanism of a
semaphore signalling device so as to render each block a continuous magnetic circuit
when it is clear of cars or in a state of safety and cause the locomotive or cars that
enter the block, and while they occupy the same to cut off the battery current
from the electro magnets of the semaphore and return it to the battery by
establishing a continuous circuit through the wheels and axles of the locomotive
or cars.
A further object is to provide an improved means for utilizing the railway rails of a
block, between the terminals of said block as electrical conductors for battery current,
which is adapted to energize electro magnets employed to operate the semaphore
signalling device in conjunction with other forces so as to set and hold the visual blade
concealed and thus indicate a clear track or safety. The short circuiting of a current
by a locomotive or car entering the block forms an electrical connection between the
tracks causing the electro magnets of the semaphore to become dormant and allow the
force of gravity to operate upon the semaphore mechanism and carry the signal blade
to a position which will indicate danger.
A further object is to so construct a portion of the working mechanism of the sema-
phore apparatus as to release the visual blade or semaphore and allow it to fall to

page_text: danger by the gravity of the blade without the aid of the thermomotor hereinafter
shown when the electro magnets that hold the blade concealed to indicate safety are
demagnetized and their armatures released.
With these objects in view our invention consists in certain features of construction
and combinations of parts that will be hereinafter described and pointed out in the
claims.
Referring to the drawings making a part of this specification ;-
Fig. 1 is a front elevation of the signal apparatus complete with the front removed
to show interior mechanism the parts being set to indicate safety.
Fig. 2 is a side elevation of the working parts as viewed from the right side of the
semaphore, the casing being broken away or removed at that side.
Fig. is a front view of the machinery, showing the semaphore blade set for
danger, a portion of the frame being broken away to expose the parts bebind it.
Fig. 4 is a plan view of the operating mechanism taken on the line w w see Fig. 1
or above the armature bar.
Fig. 5 is an enlarged side elevation in section of the thermomotor taken on an axial
line through both chambers.
Fig. 6 is a side elevation of the mechanism as viewed from the left side this side of
the case being removed.
Fig. 7 is a rear elevation of the semaphore apparatus with the casing shown in
section to expose the interior.
Fig. 8 is a sectional elevation of the casing and interior parts taken on the line ax
or between the electro magnets, to show the standard and hook latch pivoted on it that
engages a locking bar by one end to hold it horizontal.
Fig. 9 is a plan view of the railway rails of a block, a battery and two electro
magnets showing the manner in which the rails are attached to the battery at one end
of the block and the electro magnets are electrically connected to said rails at the
other end of the block.
We provide a casing A which is made rectangular and preferably of metal but other
material may be used in its construction.
This casing is of such a relative size to the contained mechanism as to receive it and
give support thereto by suitable bracketed projections which are attached to the interior
surface of its vertical walls.
The depending bracket plate A¹ is attached to the upper surface of the casing and
hangs down a sufficient distance to engage with its lower end the horizontal
plate A².
Upon the upper surface of the casing A the shield B is erected, this consists of two
parallel plates a a¹ which are held spaced apart by a horizontal portion a² of the upper
ends of the plates, this latter named piece may be rivetted to the vertical plates to
connect them, or it may be an integral portion of these plates.
The shield B should be stiffened to secure it in place so that it may withstand wind
currents to which it is exposed, to effect this we provide a bracket A' which is seated
upon the top of the casing A has a bearing against the rear surface of the shield B and
is rigidly secured to both so as to form a knee braco to the shield B.
Upon the front side of the plate a of the shield B a white signal is displayed which
may be attached to the shield or the surface be painted to produce a safety emblem
thereon.
D
Within the shield B a visual blade C is pivoted near its centre of length and upon
the side edge of the blade above the point of pivotal support just mentioned, a weight (2
is affixed so as to overbalance the upper portion of the blade and cause it to fall into
a horizontal position when the attached mechanism, which will be hereinafter described
permits such an action of gravity.
The surface of the visual blade is painted red or any other preferred colour to
indicate an occupancy of the block which the semaphore is intended to make
known.
On the horizontal bracket plate A³, two electro magnets D D' are mounted and to the
left of these magnets a vertical post E is erected that extends vertically so as to engage

page_text: the top surface of the casing A. Another post E¹ is placed near the rear of the casing A
in line with the front post E and parallel to it.
Near the top of the posts E E¹ there are screw tupped holes made in axial line with
each other, into these holes the threaded bolts bb are inserted the inner ends of the
same being supped to receive the conical pointed ends of the squared shaft F and
thus provide antifriction supports for the shaft which permit it to rock freely
therein.
Upon the shaft F near the front post E, an arm G is located, its hub c having a
round hole made through it at right angles to the body of the arm to allow it to be placed
upon the shaft and swing freely thereon, the body of the shaft F being rounded at this
end to allow such a connection of parts.
The arm G has a lateral extension d made upon its body, which latter is lightened
by a removal of material as shown and at the projecting corner d' of the portion d a
sprocket chain e is connected which is carried up and over a sprocket wheelf that is
mounted on and affixed to the cross shaft on which the visual blade C is pivotally
supported to vibrate.
To the free end of the chain e a weight e' is attached, which hangs pendent and holds
the arm G, with its upper edge in the position shown in Fig. 3, or nearly horizontal.
When the arm G is adjusted as just stated, the weight e will have desconded far
enough to partially rotate, the sprocket wheel and carry the visual blade ▸ to a
position at right angles to the shield B or to indicate danger.
A counterbalance piece G¹ is made to project from the hub c of the arm G about
in line with the latter, the piece G₁ being of such relative weight as to poiso
the arm.
Between the post E and another shorter post E' that is erected from the bottom of
the casing A, the gravity bar 1 is pivotally supported to vibrate freely, this bar has an
armature bar J secured to its end that is nearest to the electro magnets D D¹, said
armature bar extends towards the magnets and is of such a length as to locate its free
end nearly over the pole piece of the nearest magnet D.
On the free end of the rigid armature bar J just mentioned, another bar Jhis loosely
supported, the connection of the two bars being effected by the insertion of a weighted
car g through a slot in the top bar J, the car having a rigid connection with the
lower jaw J, a cross pin being inserted in a hole in the ear to afford a rocking
bearing.
It is necessary that the portion h of the loose bar J' which is nearest the gravity
bar 1 should be slightly heavier than the outer portion ', so as to hold the latter part
raised off of the pole piece of the magnet D1, the fulcrum point of the lower bar on
which it has limited vibration is the one edge of the pole piece or core of the magnet D
that is nearest the gravity bar I.
In order to prevent the lower bar J¹ from having an improper vibratory movement
on its fulcrum point, an ear is loosely inserted through a slot made in the top
armature bar J and a pin is inserted through a hole in the projecting end of the ear i
to limit the vibratory movement of the lower bar J¹.
The car i is of a sufficient length to allow a proper vertical vibration of the lower
bar J so that its outer end may be drawn into close contact with the pole piece of the
outer magnet D¹ when said magnet is energized by completion of an electric circuit
through the pair of magnets.
The length and weight of the gravity bar I is such that it will nearly balance the
compound armature bar J J', the latter preponderating sufficiently over the gravity
bar to cause them to fall gently into place over the poles of the magnets when free
to do so.
A portion of the body of the gravity bar I is cut away to allow the latching dog k
to be pivoted between jaws formed on the bar, this dog lies in an inclined position with
its latching toe k projecting above the upper surface of the gravity bar, the weight of
its body below its pivotal point of support holding it in this position, free to yield when
it is pressed against on the outer inclined face k, but locked from yielding when

page_text: .
pressure is applied to its opposite inclined face k³ by the abutment of the finger k*
with the lower surface of the gravity bar I..
The end of the rocking arm G is extended so as to allow it to have contact with the
outer face k² of the toe of the latching dog ke so that when this bar is moved by means
that will be explained further on in this description, the latch will yield and pull back
to hold the arm G in a nearly upright position, provided the gravity bar is prevented
from vibration by the electrical force of the energized magnets D D₁, that will actuato
the compound armature J J and hold its loose piece Jin close contact with their
poles.
When the arin G is released from the latch dog k the chain and weight, together
with the overweight of the signal blade will cause the latter to fall to a horizontal
position, and the arm rest in the position shown in Fig. 3, and when this occurs, the
top edge of the arm G will abut against the stop or check lug 10 formed on the
adjacent front wall of the casing A so as to prevent the arm from a further vertical
movement.
Upon the square shaft F the thermo motor L is securely mounted.
S
The motor L is composed of two conical chambers ss held together by tubular
braces these latter also furnishing a means for the transferring of contained
liquid. from one chamber to the other.
.
At a point midway between the ends of the tubes s² 83, a transverse brace t is fixed
to the bodies of these tubes, and a squared perforation is made through the brace at a
central point between the tubes s² to allow the thermo-motor to be placed upon the
shaft F which is adapted to afford vibratory support to the motor.
It will be seen by inspection of Fig. 5 that the lower wall of the chamber s¹ which
is located on the side of the apparatus nearest, the electro magnets D D is in
line with the surface of the upper side of the other chambers as shown by dotted
lines rr Fig. 5.
.
The disposition of the two chambers as just explained will cause the chambers to
be in a proper position to receive liquid from the other chamber s' when they are
located with the line nearly horizontal.
The heads of the chambers s s¹ are given an inclination from a right angle with
regard to the axis of each chamber, and are slightly convexed or dished outwardly
and it will be noticed in Fig. 5 that the head of the chambers or the one that is
lowest when the motor is given a nearly upright position is made double walled
with a space intervening between these walls.
The space s that is made between the walls of the head in chamber's is preferably
filled with wire cloth or other cellular metallic fabric that will allow a proper amount
of the liquid that is introduced into this chamber to enter the space, and he quickly
heated by the large contact surface thus afforded, when the exterior face of the
head is exposed to beat rays from a lamp M or other heat developed that is placed
to project the heat it evolves upon it.
Two or more perforations are made through the inner wall of the head in
chamber to permit the flow of liquid from the interior of this chamber into the
space between the inner and outer head and a tube S is preferably made fast to the
inner head, so as to furnish a direct passage for vapour generated between the heads
to transfer it to the upper portion of the chamber where it escapes and by its
accumulation produces pressure upon the liquid in the chamber to drive it through
the tubular braces into the upper chamber s¹.
By this transposition of the liquid an over weight is produced in the upper
chamber that will cause the motor to vibrate sufficiently to remove the head of the
chambers from the lamp M and lie nearly horizontal or more properly speaking with
the line about in a horizontal plane.
When the motor L is in the position just described the lower projecting edge of
the chambers will lie on a projecting lug formed on the casing A so that it will be
prevented from falling lower than that point.
We prefer to employ chloroform as liquid to place in the thermo motor as it is

page_text: weighty is readily vaporized and quickly returns to liquid when removed from heat
influence.
Upon the shaft F between the motor L and arm G a quadrant N is placed, and
consists of two metal bars, that diverge from each other at about an angle of 90°,
their adjacent ends centering in a transverse hub n that has a squared hole made
centrally in it of a size to fit neatly upon the shaft F, a set screw y that is
inserted in the hub has contact with the shaft to hold the quadrant in position
firmly.
The outer ends of the bars 5, 6, of the quadrant N are made integral with an
arched metal rim N¹ and bound or limit the length of this arch.
To the hub n opposite the quadrant N a counterbalance N2 is secured or made
integral therewith; this is of such weight that it will poise the quadrant and attached
parts.
Between the post E' and another upright, bracket E³, a locking bar O is pivoted
near its centre of length, the end O' which extends to lie adjacent to and by the side
of the two magnets D 11 is of greater weight than the portion 02 that projects in
the opposite direction and a movable weight o is placed on the latter named part 02
that can be shifted to slightly overbalance the other end which is thus caused to
abut against the top of the slot in which the free end of the portion 02 vibrates.
The outer end of the portion O', of locking bar O is cut away on the edge to
permit it to enter a vertical elongated slot made in the upright standard P on which
a vibrating latch p is pivoted, so that the hook gl on the depending end 9 of the
latch p will rock below the edge of the end O' and hold this end of the locking bar O
from falling.
Q
It will be noticed that the latch p has an arm pl extended at right angles to the
body of the hook piece 9 so as to cross the path of the pivoted bar J¹ of the com-
pound armature J J which latter named piece is held slightly above the arm p
when the two electro magnets D D' are dormant or demagnetized.
In order to avoid frictional resistance that might retard the vibration of the
locking bar O there is a supplementary piece 03 pivoted by one of its ends upon
the lower surface of the end O¹ of the locking bar, the outer end of this piece 03.
being slightly wider than the end of the rocking bar is allowed to move sideways and
adjust itself without friction so that it may be engaged by the latching hook q
when the locking bar O is vibrated and its end 0₁ rises in the slotted standard P to
engage the hook and thus secure the bar in a horizontal position.
The locking bar O is slotted at the point where it is pivoted between its supports
and in this slot a weighted latching block R is loosely mounted on the same rod that
pivotally supports the locking bar and lies with its body projected vertically
downward, a pin 7 on the side of the locking bar preventing the body of the latching
block R from moving towards the weighted end of the locking bar while a free
movement in the opposite direction is afforded when the sloping side of the locking
toe 8 of the latching block. R is engaged by the quadrant N, or rather by a roller Ri
which is pivotally supported on the rear side of the quadrant at the end nearest the
magnet D D. The diametrical size of the roller R¹ and its position on the side of the
quadrant bar 6 is such in relation to the locking toe 8 of the locking block R that
the roller R will abut against the toe and remain in such contact when the quadrant N
is carried up by the motor L until said motor rests with its upper chamber s¹ in
contact with the stop or projection on the casing A as has been previously.
mentioned.
Upon the side of the quadrant N that is adjacent to the rocking arm G there is
a curved latch bar G* pivoted by its outer end 9 so as to have a vibratory motion on
this point of attachment. The other end of the curved latch bar G is secured to
have a limited vertical movement by the insertion of a set bolt 11 through a slotted
projecting flange 12 and into the side of the quadrant, the length of this slot
determining the movement of this curved latch bar.
Near the point of pivotal support of the gravity bar I on the edge that lies below
the curved latch bar G an anti friction roller T is secured to rotate freely on a stud,

page_text: the diameter and point of attachment of the roller T adapt it to have rolling contact
with the outer surface of the curved latch bar G of the rear face of the rocking
arm G, a pendent latch 13 will engage the offset shoulders 14, 15 formed near the
opposite ends of this curved bar upon its upper arched surface.
It will be noticed that the offset 14 which is nearest the point of pivotal attachment
of the bar G to the quadrant, is not as deep as the shoulder 15 made near the other
extremity of the bar, and that the curved surface of the latch bar G gradually rises
from the offset 14 to afford material for the production of the offset 15 which is formed
by the removal of material from the top surface of the curved bar between the bottom
edge of the offset 15 and the outer end of the bar G..
In Fig. 9 of the drawings, a plan view of the tracks of a block is shown and it
will be noticed that the battery 20 for, the production of electric current is located at
one end of the block with its positive and negative poles connected by conductor
wires 21, 22 to the track ends. At the other end of the block, the semaphore
signalling, device is placed with its electro magnets D D¹ attached to the rails
by proper conductors so as to complete the electrical circuit when the battery is
charged.
It is évident from the position of the compound armature bar J J upon the poles
of the magnet D and nearly in contact with the pole of the other magnet D', that if
the track is free as shown in Fig. 10, the current of electricity which energizes the
magnets will attract the loose lower bar J' with the full force of the maguet to hold
it in contact with the same.
If a locomotive, a car, or train of cars enters the block from either end of the
same, the axles and wheels of the car or locomotive will establish an electrical con-
nection between the tracks and "short circuit" the battery so as to cut out the
electro magnets D D¹ of the semaphore apparatus and render them inert thus releasing
the armature J, J.
In operation of the semaphore device it is understood that when the track of the
block is clear of cars or locomotive, the semaphore signal. blade C will be in an
upright position and be concealed in the shield B. It will also be noted that the
tendency of the weight C and overweight of the signal blade is to move the latter
into a horizontal position that indicates danger. When the blade is in the position
just mentioned the arm G is elevated as shown in Fig. 3.
The top side of the lower chambers of the thermo motor L is in the same plane
with the outer bar 6 of the quadrant N, hence when this chamber of the motor is
lowered to a position that will place its head over the flame of the lamp, the quadrant N
will be vibrated to assume the position shown in Fig. 1 with a shoulder or abutment 18
formed on the outer edge of its arched rim N¹ in contact with the pending latching
block R and the arm G which has been engaged by the offset shoulder 14 will
be carried down by the weight of the liquid in the motor, and after, tripping over
the latch dog that is pivoted in the gravity bar I be retained in such a position
by the contact of said latch dog k and the contact of the armature bar J, J¹ witlı
the poles of the magnets D D¹..
When the parts are in the relative positions just mentioned the track will be
clear, and the armatures J J' will be attracted to hold them to show safety on the
shield B by concealing the signal blade C within said shield.
It will be evident from the foregoing description of the mechanism that operates
the semaphore blade, that when the quadrant N is carried up by the motor as the
latter is vibrated by transposition of the liquid from the lower chamber s, to the
upper chambers the roller R¹ that is on the rim of the quadrant will have contact
with the pivoted latch of the locking bar O and the locking bar will have its end 0¹
engaged on the top side of the bar by the upper edge of the slot in the standard P
and the hook q' of the latch p will lie immediately below the pivoted supplementary
piece 02 on end O¹ of the locking bar O.
The bar will thus be held horizontal or prevented from vibration in the manner
just explained when the block is occupied by cars or locomotive.
The arm G is released to move up and have its latch nearly in contact with the offset

page_text: shoulder 14 that is on the arched latch bar G' by the upward movement of the armature
bar J, J thus allowing the visual signal blade to fall to a position of danger by
its own gravity and the auxiliary action of the sprocket chain and attached weight.
It is one of the important features of our present invention that the action of the
motor and its position relative to the rocking arm G will in no case prevent the
latter from moving upward when the block is entered and the armature bar J J¹
released.
As if the magnets D D are rendered inert, the overweight of the blade on
one side added to the suspended weight C will instantly cause the blade C to
fall to danger.
When a block has been occupied by cars or locomotive and these leave the block to
enter an adjacent one, the electro magnets D D₁ will instantly draw down their
armature J J and it by contact with the arm p' of the latch p will trip the latter and
release the locking bar O which will thus be allowed to vibrate downwardly and
permit the quadrant to fall and carry the arm G downward so as to vibrate the signal
blade upwardly and thus conceal it behind its shield.
If the tracks of a block are occupied, and the thermomotor L has by overweight
of contained liquid in its lower chamber vibrated so as to carry the quadrant N.and
rocking arm G down thereby moving the signal blade so as to conceal it and indicate
safety, the quadrant and arm G engaged by it will be locked in the position just
mentioned by the simultaneous engagement of the roller on the quadrant with the
latch toe of the pendant latch dog that is pivoted on the locking bar O and the
lower end of the rocking arm G with the latch block that is pivoted in the gravity
bar I which is a part of the compound armature bar J J¹.
This locked engagement of parts will not be broken until the armature bar is free
to vibrate and release the arm G which can only occur when the tracks of a block are
connected by the wheels and axle of a car so as to short circuit the electrical current
and render the magnets dormant as has been explained.
It will be apparent from the foregoing description of our improved semaphore
signalling apparatus that the relative action of the motor L, quadrant N and rocking
bar G is such with regard to the compound armature bar JJ, magnets D D¹ and
rocking bar O that they will cooperate to reliably indicate danger, or track occupied,
by an automatic release of the visual signal blade C thus allowing it to move by
gravity to a position which will expose its entire surface. And when danger is
removed from the block or the track is entirely clear, the conjunctive action of
the motor rocking arm, locking bar, armature and electro magnets and closed battery
circuit will automatically effect the return of the visual signal blade to its shield and
thus conceal the danger signal from view. Many slight changes might be made in the
parts and combinations of parts of this invention without departing from the spirit or
exceeding its scope, hence we do not desire to be restricted to the exact forms of
construction herein shown but:-
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is
1. In a semaphore signalling device, the. combination with a closed circuit made
through the track rails of a railway block and a pair of electro magnets D D' of
a compound armature bar J J¹ pivoted to have contact with the poles of the
magnets, a visual signal blade pivoted to fall by gravity to indicate danger, a motor
adapted to engage the armature bar, and a chain or its equivalent connecting the motor
and visual signal substantially as set forth.
2. In a semaphore signalling device, the combination with a thermo-motor L, a
shaft F a quadrant N and supports E E¹ of a pivoted locking bar O and a pivotally
supported swinging hook p substantially as set forth.
3. In a semaphore signalling device, the combination with a thermo motor L, a
heating device M, a quadrant N a shaft F and supports E E' for the shaft, of a
pivotal locking bar O, a shoulder or stop R' on the quadrant, an adjustable weight o

page_text: on the locking bar and a pivoted hook p supported near the end of the rocking bar
substantially as set forth.
4. In a semaphore signalling device, the combination with a thermo-motor L, heating
device M, a quadrant Na rocking arm G and a shaft F secured to the quadrant and
motor, a curved latch bar G4 pivoted by one end to the arched rim of the quadrant N
and a pivoted gravity bar I to which is attached a compound armature bar J J¹
a swinging latch block 8 supported on the rocking bar and a. pair of electro
magnets D D located to have their poles engaged by the compound armature bar J J¹
when the magnets are energized substantially as set forth.
5. In a semaphore signalling device, used in connection with a railway block
system, the combination with two electro magnets D D', that are included in a
circuit of which the parallel rails of the block are electrical conductors, the parallel
railway rails of a block, and an electrical generator or battery, of a compound
armature bar J J' supported to vibrate and assume a position in contact with the poles
of one magnet, and near the pole of the other magnet when the magnets are
rendered dormant by reason of a short circuit of the electrical current through the
axles and wheels of a car or locomotive on the block, and be attracted to have close
contact with both magnets, and be thus forcibly held, when these magnets are
electrically energized by reason of the removal of the short circuit from the main
conductors or railway tracks of the block substantially as set forth.
6. In a semaphore signalling device, used in combination with a railway block
system the combination with a pair of electro magnets D D¹ included in an electrical
circuit of which the railway rails are conductors, the railway rails of a block, a
compound armature bar J J', supported and pivoted to engage the poles of these
magnets, and a pivoted latch hook p supported, near the end of the armature bar,
of a locking bar pivotally sustained in a plane parallel to the armature bar, by an
engagement with the pivoted latch hook p when the armature bar is electrically held
in contact with the magnets and released from the latch hook p to vibrate from a
horizontal plane when the magnets are demagnetized by a short circuit formed on the
block substantially as set forth.
7. In a semaphore signalling device, a compound armature bar J J adapted to
have contact with the pole or core of one magnet of a pair of electro magnets
set in line with the bar, when these magnets are dormant or demagnetized and to be
attracted and yield so as to have contact with the poles of both magnets when said
magnets are rendered electrically active or are in a closed electrical circuit sub-
stantially as set forth.
8. In a semaphore signalling device used with a railway block system, the com-
bination with a casing A a shield B and a visual signal blade C pivoted in the shield,
of a thermo-motor L supported on the same shaft with a balanced quadrant M, a
quadrant N moved by the thermo motor and a rocking arm G substantially as
set forth.
9. In a semaphore signalling device used with a railway block system the combination
with a closed electrical circuit including a battery, two parallel railway tracks, the
length of the block and two electro magnets D D₁ of a compound armature J J¹
substantially as set forth.
10. In a semaphore signalling device, the combination with a horizontal shaft F
pivoted to rock on its centres, of a thermo motor L and a quadrant N secured
on and to this shaft to rock with it, and a rocking arm G loosely mounted on
the shaft that gives support to the motor and.quadrant substantially as set forth.
11. In a semaphore signalling device, the combination with a shaft F sup
ported to rock, a thermo motor L and a quadrant N mounted. on the shaft
and secured to rock with it, of a curved latch bar G pivoted to one arm of
the curved rim of the quadrant and secured so as to have a limited vibratory
movement, and a rocking arm G which is supported loosely on the shaft on which
the motor and quadrant are placed so that a latch 13 pivoted in the side of this
rocking arm G will engage offset shoulders 14 on the quadrant and thus adapt the
quadrant to rock the arms downwardly substantially as set forth.

page_text: 12. In a semaphore signalling device used in connection with a railway block
system, the combination with a visual signal blade C, a thermo-motor L, a quadrant N
fastened to the same shaft that pivotally supports the motor L, a rocking arm G loosely
mounted on the same shaft with the motor La flexible weighted connection e e¹ between
the signal blade and rocking arm, and quadrant N of a closed electrical circuit that
extends through the parallel rails as conductors, a pair of electro magnets D D' in-
cluded. in this circuit, and an armature bar JJ adapted to hold the rocking arın G
and the connected signal blade C to indicate safety when the track of the block is
clear, and release these parts to fall and indicate danger when the block is entered
by a car or locomotive substantially set forth.
Dated this 4th day of December 1888.
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C.,
Agents to Applicants.
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C.,
Agents to Applicants.