Improvements in Actuating Devices for Railway Signals.
Year: 1890

page_text: Date of Application, 21st Oct., 1890-Accepted. 20th Dec., 1890
COMPLETE SPECIFICATION.
[Communicated from abroad by THE FONTAINE SAFETY SIGNAL COMPANY, of
Detroit, in the County of Wayne and State of Michigan, United States of
America.]
Improvements in Actuating Devices for Railway Signals.
I, HENRY HARRIS LAKE, of the firm of Haseltine Lake & Co. Patent Agents,
45 Southampton Buildings in the County of Middlesex, do hereby declare the nature
of this invention and in what inanner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
My invention relates to devices for actuating signals, either visual or audible,
through the wheel of a passing engine.
In attempting to transmit the blow of a locomotive wheel to a signal, two serious
difficulties are encountered. If the part struck by the wheel is suffered to rise freely
after being depressed by each wheel (so that it is struck by all or nearly all the
wheels of one side of the train), the excessive jar destroys the device in a short time.
On the other hand, if the device is connected with mechanism to prevent its rising
quickly after being depressed (such as a dash pot or other equivalent device) the
inertia of the moving parts, and their resistance to rapid motion, is so great, that
while the machine will operate regularly and easily in the case of a slowly moving
train, the shock from a train running at high speed, say sixty miles an hour, is so
instantaneous that the device fails to operate and is soon destroyed. Even the
inertia of the moving parts of a very light signal apparatus is sufficient to destroy the
actuating mechanism in a short time under the impulse of fast, running trains, if a
rigid connection is made.
"I have succeeded by the device illustrated in the accompanying drawings in obviating
both these difficulties, and in providing a signal which will be struck by very few
wheels of any train, and is very durable and reliable.
Figure 1 is a central, vertical section of my device and Figure 2 is a plan view
thereof.
any
A represents one of the rails of a track. B is a housing supported in suitable
manner in proximity to the rail, and may be firmly secured thereto by means of
clamping bolts C, engaging the foot of the rail, or in any other suitable manner.
F represents a lever fulcrumed on a pin D, which is carried in the housing B, and
the long arm of said lever is connected by a link with the piston rod of a piston J in
the dash-pot K.
F represents a lever whose short arm f is in close proximity to the rail A, and
extends normally slightly above said rail, while its long arm P acts as a spring for a
portion of its length, and is connected with a chain or cord, or cable, R, which leads
around the pulley S, and is connected with the signal mechanism, of any desired
kind. The chain R may be connected with lever F¹ if desired. A spindle G
surrounded by a spring H is connected to the lever F and the said spindle passes
through a fixed bracket so that when the lever F is raised the spring will be compressed
and will then react to bring said lever back to its original position as shown in
Fig. 1.
The lever F is connected with the lever F¹ by a bolt c which passes through the
short arm of lever F1, and loosely through the short arm of lever F, and is encircled
by a coiled spring d, one end of which bears on the underside of lever F, while the
other end bears on the collar held by the jam nuts e on bolt c, so that the levers F
and F¹ are at this point held together only by the elastic force of the spring d.

page_text: a represents a cushion of rubber or resilient material, interposed between the
levers. F and F¹.
b represents a bolt which passes loosely through the levers F and F' on the long
arm side of the fulcrum of said levers, for the purpose of holding said levers together,
yet permitting the lever F under certain circumstances, to play slightly on bolt b.
A circulating pipe L connects a port ġ at or near the bottom of the cylinder with
the port at or near the top of the cylinder, and this circulating pipe is provided
with a check valve M. A supply pipe N connects the circulating pipe with a
reservoir O, placed in any convenient position within the housing. Two minor
ports i and jare formed at or near the bottom and top of the cylinder respectively,
and these are connected by a circulating passage or pipe k, which is controlled by an
adjustable valve 1, the handle m of which is in accessible location for being con-
veniently adjusted. A cover S¹ is hinged at n to the housing and secured by a
lock o.
The cylinder and circulating passage connected therewith are filled with glycerine
oil, or other suitable fluid not liable to freeze, a suitable supply of it being maintained
in the reservoir O, from which it freely communicates into and through the circulating
pipes and passages into the cylinder. The valve controlling the circulation between
the ports i and jis then slightly opened more or less as will be found necessary for
the proper operation of the parts.
The operation of my invention is as follows: If the short arm f of lever F be
compressed comparatively slowly, so that the inertia of the moving parts becomes
unimportant, and so that the liquid in the dash-pot will transfer from the upper to
the lower side of piston J, during the time in which the short arm of lever F is
descending, the two levers F and F¹ swing on the fulcrum D, as if they were a
single lever, and the long arm P of the lever F operates the signal mechanism, the
resilient character of said arm preventing undue shock.
When the long arm of lever F¹ is raised, the check valve M closes and holds the
piston J of the dash-pot K in an elevated position, thus holding down the short arm f
of lever F, and permitting said short arm f to rise only as fast as the liquid below
the piston J will run through the passage k, and this of course can be governed by the
valve l, which can be adjusted by the valve stem m to any desired degree of opening.
The spring H now draws the long arm of lever F downward, thus causing the
piston J to gradually descend and carrying downward the long arm of the levers F
and F¹.
C
But if the short arm of lever F be struck by the wheel of a train running at a high
rate of speed, and depressed very suddenly, the operation of the device is modified as
follows: The spring a yields to the force of the blow, thus converting this spring and
its sustaining bolt c into a fulcrum for the lever F, but as this is a yielding fulcrum,
the long arm P of lever F is not moved upwards in proportion to the relative lengths
of the two arms of said lever, and the shock of moving the signal is thus, lightened.
At the same time the bolt c draws downwards on the short arm of lever F¹, and the
long arm of lever F presses upwards on the cushion a thus raising the long arm of
lever F and the piston J of the dash-pot K, but to a less extent and more slowly than
would be the case if the levers F and F were rigidly connected together or were one
lever.
As the wheel passes beyond the short arm f of lever F, the reaction of spring d
forces said short arm upwards until it comes in contact with the cushion a, when
its upward course is checked because the dash-pot K is now holding the long arm of
lever F¹ in a raised position. If this permits the short arm of lever F to rise above
rail A, the next wheel again depresses said short arm, but with much less violence,
owing to its lowered position and the foregoing operation is repeated until the long
arms of both levers F and F¹ are raised to their highest working elevation by a series
of comparatively easy impulses instead of by a sudden and violent shock, and both
levers are then returned to their normal positions by the above described action of
spring H and dash-pot K.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondents, I declare that what I claim is :
1. An actuating device for a railway signal consisting of a lever having one end in
position to be struck by a passing train, and elastically connected with its fulcrum,
substantially as and for the purpose set forth.
2. An actuating device for a railway signal consisting of a lever having one end in
position to be moved by a passing train and having a shifting fulcrum, substantially
as and for the purpose set forth.
3. An actuating device for a railway signal consisting of a lever having one end
normally in position to be struck by a passing train, a main fulcrum on which said
lever vibrates and a yielding fulcrum indirectly connected with the main fulcrum,
substantially as and for the purposes set forth.
4. In a device for actuating a railway signal a pivoted lever and a lever having one
end normally in position to be struck by a passing train, and secured to said pivoted
lever by an elastic connection, substantially as and for the purposes set forth.
5. The combination of a pivoted lever F, a dash-pot K and a lever F having one
end in position to be moved by a passing train, and secured to lever F1 by a spring
connection c d and an interposed cushion a, substantially as and for the purposes set
forth.
.
6. In a device for actuating a railway signal, a lever having an elastic connection
with its fulcrum and with the signal mechanism, substantially as and for the purposes
set forth.
7. In a device for actuating a railway signal, a double lever, one part of which is
pivoted on a fulcrum and connected with a dash-pot or its equivalent, the other part
being elastically connected therewith and extending into position to be struck by a
passing train, and a connection from one of said levers to the signal mechanism,
substantially as and for the purposes described.
Dated this 21st day of October 1800
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.