NEW OR IMPROVED APPARATUS FOR EFFECTING COMMUNICATION THE PASSENGERS, GUARDS, AND ENGINE DRIVERS OF RAILWAY TRAINS. BY NIGHT OR BY DAY
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by John William Gray at the Office
of the Commissioners of Patents, with his Petition, on the 2nd
February 1865.
I, JOHN WILLIAM GRAY, of Eagle Cottage, Park Road, Peckham, in the
County of Surrey, Civil Engineer, do hereby declare the nature of the said
Invention for "NEW OR IMPROVED APPARATUS FOR EFFECTING COMMUNICATION
THE PASSENGERS, GUARDS, AND ENGINE DRIVERS OF RAILWAY TRAINS.
BY NIGHT OR BY DAY," to be as follows (that is to say):-
My Invention has reference to "an apparatus for effecting communication
between the passengers, guards, and engine drivers of railway trains by night
or by day," to be fixed on the top of each carriage, and worked from the
interior, so that when once the apparatus is set in motion it cannot be stopped
or righted from the inside, whereby passengers are ensured a speedy com-
munication with the guards and engine drivers in cases of molestation,
accident, or otherwise while travelling, and consists of an alarm caused by a
hammer striking on a gong or bell, the said hammer receiving motion
through the medium of an encased helical spring (mounted in suitable
hearings), which being wound up by tooth and pinion movement is suddenly
liberated by the omission of a few teeth on the pinion wheel taking into the
teeth on the case covering the aforesaid spring, at which liberation the tension
of the said spring throws the before-mentioned hammer (to which the said
spring case is attached) back on to the gong or bell. This stroke is repeated
by the revolution of the before-mentioned pinion wheel, which is double the

page_text: width of the teeth on the aforesaid spring case, which teeth take into one-
half of the width of the said pinion wheel, the teeth on the main helical
spring by which the said pinion wheel is driven taking into the other half,
the omission of the teeth, as before described, being on the half taken into
by the teeth on the spring case first alluded to.
The main spring is likewise encased and mounted in suitable bearings,
being wound up in the same manner as that in an ordinary clock, and retained
in its position by two palls, one acting in the usual manner on the spindle
to which the centre of the spring is attached, the other acting on the teeth on
the outside of the case. This last-mentioned pall extends outwards from its
centre forming a lever, which lever has attached to its extremity a cord or
chain passing into the interior of the carriage upon which the signal is
placed, the cord or chain being for the purpose of liberating the pall
through the medium of the person desiring communication with the guards
and engine driver. Directly the said pall is liberated the action of the main
spring commences, and causing the before-mentioned pinion wheel (into
which it takes) to revolve, motion is thereby communicated to the first-
mentioned spring, throug the medium of which the strokes on the gong or
bell causing the alarm are obtained. Simultaneously with the liberation of
the last-mentioned pall a semaphore arm is thrown from a perpendicular to a
horizontal position, taking with it the covering from a lamp which is fixed on
the same framing as the gong or bell.