Improvements in Interlocking Apparatus for Railway Point and Signal Levers.
Year: 1891

page_text: Date of Application, 9th May, 1891-Accepted, 20th June, 1891
Improvements in Interlocking Apparatus for Railway Point and
Signal Levers.
I, JOHN SAXBY of North Court Hassock in the County of Sussex, 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:-
My invention relates to a compact construction and arrangement of the inter-
locking gear for the levers employed to work the points and signals of railways, the
chief objects which I have in view being to ensure safety and to give ready access
to all parts of the apparatus for alteration or repair.
Fig. 1 of the accompanying drawings is a transverse section of a lever frame
shewing one of the point or signal levers and its connections to the interlocking
gear. Fig. 2 shews details hereinafter referred to.
On the spring catch rod R of each lever L I mount a pair of rollers, the one A'
above, the other A below a rocker B which is made in the form of a circular arc
and is pivotted at B¹ near its middle. From this rocker B projects vertically an
arm C which is linked by a horizontal rod D to the vertical arm E of a three
armed lever, the other two arms E' E2 of which are horizontal. To each of these
arms E E2 is jointed a vertically sliding bar P1 P2 which operates on bars T fitted
to slide across it horizontally at its side or it might be at both its sides as in the
known plunger and tappet interlocking gear. The plungers P of this gear have
notches as shewn in Fig. 2 in which engage the tappets T¹ that are fixed where
required on the bars T. When the spring catch rod R is raised in order that its
lever L may be moved, the rocker B is moved by it on its pivot B' in one direction
and thus the pair of plungers P' P2 connected to it are moved, the one up the other
down, acting on the tappet bars T so as to lock all levers that should be locked
before moving the lever L, but not yet unlocking any other lever. When the
lever L is brought over, the rollers A¹ A² running along the rocker B, and when
the spring catch rod R is lowered, the rocker B is moved in the same direction as
before and moves the pair of plungers P1 P2 farther. As by the first part of their
movement they effected locking by pushing some of the tappets T¹ out of their
notches, their farther movement maintains this locking and by presenting notches
for the reception of other tappets it unlocks such of the levers that may now be
safely moved.
It will be seen that any of the bars T can be readily removed to have locks such
as T' fixed upon them where required. Also, although I have shewn a set of tappet
bars T only on the one side of each set of the plungers P1 and P2, there might be
a set on each side, and thus a very large number of interlocking bars may be
accommodated within moderate space.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I claim :-
In combination with the spring catch rod of a point or signal lever and a pair of
rollers mounted thereon, a curved rocker linked to a three armed lever and a pair
of vertically sliding plungers crossed by tappet bars substantially as described.
Dated this 9th day of May 1891.
ABEL & IMRAY,
Agents for the Applicant