Improvements in Bell Signalling Apparatus.
Year: 1897

page_text: Date of Application, 25th Mar., 1897-Accepted, 1st May, 1897
Improvements in Bell Signalling Apparatus.
I, MATTHEW BARR BAIRD, of 59 Waterloo Street, Glasgow, Engineer, 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 :-
This invention relates to bell signalling apparatus used for signalling in mines,
on railways, and in other places and it has for its object to improve the construction
of such apparatus.
.
And in order that my said invention may be properly understood I have hereunto
appended an explanatory sheet of drawings whereon :-
Fig. 1 is a plan view of the apparatus.
Fig. 2 is a view of the apparatus with the gong or bell and hammer removed.
Fig. 3 is a side view of the apparatus.
The apparatus consists of a gong or bell a which is mounted on a stud b attached
to a base plate c which latter is capable of being secured in any suitable position.
Fitted also upon the stud b is a disc or wheel à having a double tumbler catch e
secured in its jaws e' by means of a pin. A stop fis made on the lower side of the
wheel d and this stop works in a slot g in the base plate e thereby regulating the
movement of the wheel.
Mounted on a stud h attached to the base plate c is a collar i baving at its upper
end a flattened part to which the spring hammer ; is secured by means of the
screws. The lower end of the collar is provided with a catch k having a rearward
projection on it.
}
m is a stop cast in one with the base plate c and against which
the catch is normally held by means of a plate spring n secured to a stud o cast
on the projecting lug c of the plate c. p is a bolt for securing the spring n to the
stud o.
The wheel d is provided with radial arms q to which wires or rods from any
direction can be attached to operate the apparatus.
In my invention the use of coil springs is obviated and the apparatus is simplified.
In order to operate the apparatus all that is necessary is for the party signalling
to pull the attached wire or rod and move the wheel d whereupon the tumbler
catch e pushes back the catch k and hammer j. When the tumbler e overrides the
catch the latter is released and the spring n coming into action causes the
hammer ; to sharply strike the bell and give a signal.
The apparatus is secured in a vertical position so that the wheel which is heavier
on the side at which the catch e is situated returns automatically to its original
position after each signal.
Indicators may be provided in connection with the signalling apparatus.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
consider novel and desire to claim is :-
1. In combination, the base plate, the bell, the wheel, the tumbler e, the catch k,
the bammer and the plate spring n acting on the catch k, substantially as
herein before described and shown on the drawings annexed.
2. The combination of the catch k having a rearward projection on it and a

page_text: plate spring n secured to the base plate and acting on the projection 1, substantially
as herein before described with reference to the drawings annexed.
Dated this 24th day of March 1897.
H. D. FITZPATRICK,
70 Wellington Street, Glasgow, Agent.