IMPROVEMENTS IN ELECTRIC-SEMAPHORES FOR RAILWAY PURPOSES
Year: 1881

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention
of "IMPROVEMENTS IN ELECTRIC-SEMAPHORES FOR RAILWAY PURPOSES."
A communication from abroad by Frances Robert Fountaine Brown, of the
City of Montreal, in the Province of Quebec, in the Dominion of Canada,
Mechanical Engineer.
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 21st January 1881.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN ELECTRIC-SEMAPHORES
FOR RAILWAY PURPOSES." A communication from abroad by Francis Robert
Fountaine Brown, of the City of Montreal, in the Province of Quebec, in the
Dominion of Canada, Mechanical Engineer.
The object of this Invention is to provide simple and effective mechanism for
operating railway signals or semaphores; and it consists partly in a simple com-
bination of gearing operated by a weight, and so arranged that the strength of the
electro-magnet need not be in proportion to the said weight; and the Invention
further consists in a certain combination of mechanism hereinafter specified.
In the accompanying Drawing Figure 1 is a side elevation, and Figure 2 a cross
section.
A represents a box, which may be made of any material and design suitable for
containing the lamp B, and the mechanism hereinafter described; C is a metal
frame for supporting the said mechanism; D is an electro-magnet suitably fastened
to the frame C, and properly connected by wires to a battery and circuit-breaker
placed at a point from which the signal should be manipulated; E is a lever
pivoted to the frame C and provided with an armature e; f is a spring placed as
shown, to draw the armature e from contact with the electro-magnet whenever the
current is broken; F is an arm attached to or forming part of the tumbling
plate G, and whose end rests upon the lever E, when the armature e is not in contact
Price 1

page_text: with the electro-magnet D. The dog H is pivoted on the same pin as the plate G,
but moves independently. One wing of this dog H fits into the ratchet wheel I,
and its other wing between two blocks or their equivalent on the tumbling-plate G.
The ratchet wheel I is keyed to the same spindle I¹ as the spur pinion J, which
meshes into the spur wheel k. This latter wheel K is keyed to the same spindle as
the toothed wheel L, around which hangs the chain M, upon one end of which a
suitable weight is hung. So long as the dog H is in gear with the ratchet-
wheel I the full power and resistance produced by the weight on the end of the
chain M is sustained by the said dog, and the gearing consequently remains
stationary till the dog H is thrown clear of the ratchet when, when of course the
gearing revolves from the action of the said weight.
The tumbling plate G is so balanced on its spindle by a weight g or otherwise,
that unless supported it will fall in the direction indicated by the arrow, and being
placed in the relation to the dog H described, strikes it sufficiently hard to knock
it out of gear with the ratchet wheel I, which latter immediately revolves till one
of the pins k placed in its face comes in contact with the arm h on the tumbling
plate G, which action turns the plate G back into the position from which it has
just fallen, carrying with it the dog H again into gear with I, as will be understood
by reference to the Drawing.
The gearing just described is designed to operate the semaphore arm which is
keyed to the spindle N and geared, as shown with the spindle I' to which the
ratchet wheel I is also geared; and as this has only four teeth at equal distance
apart each movement of the wheel I gives the semaphore an eighth of a turn, the
gearing between the two spindles N and I' being as two is to one.
With the view of signalling at night, I key onto the spindle I' the spiders P
having four eyes, each of a different colored glass. These eyes are so placed that
at each stoppage of the wheel I, one of them remains opposite to a properly
protected hole in the box A immediately in front of the lamp B, thus indicating
by the color of the glass the signal which the position of the semaphore arm
represents.
As it sometimes happens that the arm will be opposite the hole above referred
to, corresponding holes are made in the arm O, so that the signal-light shall not
at any time be obscured.
At the commencement of the Specification I refer to an electro-inagnet D, suitably
located for the purpose of actuating a properly magnetized lever E, which lever is
so placed that when in a certain position it supports the arm F on the plate G,
holding the dog H in gear with the ratchet wheel, and thereby supporting the
weight N without sustaining any strain therefrom. From this description it will be
seen that a very weak electro-magnet will answer the purpose, while at the same
time as heavy a weight as the material of the gearing will sustain may be hung upon
the chain M. To attain this effect is really the essence of the Invention, as the
motion of the semaphore can thereby be depended upon, provided the weight is
wound up, to insure which I pivot to the lamp stand or any suitable place a lever Q,
one end of which is forked to allow the chain to pass freely through it, the other
end being crooked, so as to engage with the catch R secured to the door S, as shown.
When the door S is closed the crooked lever Q securely locks it, as the forked end
of the lever is heavier than the other.
By placing a pin T through the chain M. near the weight and having no other
obstruction on the chain M, the said chain will pass freely through the forked end, as
before referred to, except when the pin T comes in contact with it, consequently the
door remains locked, except when opened by the pin coming in contact with the
lever. By this arrangement it is absolutely necessary to wind up the weight before
the door S can be opened or the lamp B lighted.
I have not referred particulary to the battery and circuit-breaker for operating
the mechanism herein described, as any electrician will understand how to arrange
the same.
It is however important to mention that in order that the operator may
know in what position the semaphore stands, I arrange immediately over or near

page_text: the circuit breaker a dial with a needle to indicate the position of the said
semaphore, which needle is connected to the frame C by a properly charged wire U,
and otherwise arranged, so that when the current is broken in the said wire U the
needle moves a given distance on the dial and thus indicates as required.
With the view of securing the automatic action of the signal, I attach to the
binding post of the wire U a spring V of platinum or other suitable material, and
place four brass pins W in the ratchet wheel I, so that at each movement of the
said wheel one of the pins W comes in contact with the spring V, thereby con-
veying the desired signal.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,
In an electro-magnetic railway signalling apparatus, the frame C, lever E pivotted
thereto, and having the armature e and spring f, balanced tumbling plate G having
the arms F and h, ratchet wheel I provided with pins k and W, dog H resting
between blocks on the tumbling plate and engaging with the ratchet wheel I,
weighted chain M and gearing suitably mounted, combined with the electro-
magnet D, wire U and spring V, substantially as and for the purpose specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Twenty-first day of January, in the year of our Lord
One thousand eight hundred and eighty one.
W. KUB LAKE. (L.S.)