Signal Levers.
Year: 1887

page_text: Date of Application, 15th Sept., 1887
Specification Accepted, 18th Oct., 1887
Signal Levers.
We, JOHN SAXBY and JOHN STINSON FARMER both of Canterbury Road Kilburn
in the County of Middlesex Engineers 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:-
Our invention relates to locking apparatus for railway, points and signals which we
construct and arrange with a view to simplicity and compactness as we will describe
referring to the accompanying drawings.
Fig. I is a transverse section and Fig. 2 a part front elevation of a locking frame
according to our invention. Fig. 3 is a side view and Fig. 4 is a vertical section of one
of the rockers, these figures being to an enlarged scale. Fig. 5 is a plan and Fig. 6 a
transverse section of a set of the locking rods and bars, and Figs. 7, 8, 9 and 10
shew details of these as we will hereafter explain.
»
Each of the point or signal levers L which has to be interlocked with others of
the row has as usual its spring catch S to hold the lever at each end of its stroke by
catching against the shoulders at the ends of the quadrant Q. The spring catch rod S
has an extension S' below the quadrant, and the end of this extension is guided in
the hole of a bracket attached to the lever L. From the side of S¹ projects a stud s
into the hole of a block s' which is fitted to slide along a curved groove formed on one
side of the rocker R. This rocker is pivotted on a cross framing and its groove is
of such curvature that when the rocker is in its middle position, the sides of the
groove are circular arcs struck from the fulcrum of the lever L as a centre.
this curved groove is open at both ends it can be readily made truly, circular by
fixing the rocker or a number of them on the face plate of a lathe and turning their
grooves. From the bracket which is fixed on the lever L a stud 12 projects into
the groove of the rocker and travels along it when the lever is moved so as to keep
the rocker steady when the studs of the spring catch is at or near the middle of the
groove. An arm projecting from the rocker or two such arms, as shewn in the
drawings, have jointed to them sliding rods A which when the rocker R is moved
by the spring catch are made to slide across a number of sliding bars B above or
Urine 21
As

page_text: below them or both above and below and also across shorter bars or locks such as B¹
Fig. 5 on the same plane with them. The bars B have projecting from them locks
such as B in the plane of the rods A. The short bars B and locks B² are made with
bevilled ends to take into bevilled' notches in the edges of the rods A. In some cases
as at A Fig. 5, short locks are fitted to slide on the faces of the rods A so that when A
is in suitable position the movement of a lock B' on the one side of A¹ is trans-
ferred through A¹ to the lock on its other side. When any of the bars B carrying
locks B2 or any of the locks B' or B³ is engaged in a notch of a rod A and cannot
move out of the notch, then that rod A cannot be moved and consequently the
rocker R which works the rod A and the spring catch S which works that rocker cannot
be moved, and the lever L to which that spring catch belongs is therefore locked.
When however one of the bars B' or locks B2 or B³ finds facing it a notch on
some rod A into which notch it can be moved, then the rod A in the notch of which
the lock is engaged can be moved, but the act of moving it engages the lock in the
notch of the other rod A, and so locks the lever L that belongs to that rod. In
some cases it is desirable that a lever having once been moved over and back,
shall not be capable of being moved again until another lever has been moved
back. A provision for this is shewn in section by Fig. 7 and in the plan Fig. 5 by
the parts marked A3 A4 B³ and B. The rod having the notch A* being moved so as
to present A to the lock B³, then A³ can be moved in the direction of the arrow
thrusting B³ out of its notch into the notch A*. But before B³ begins to move the
edge of the notch a³ is just past the edge of a pawl B' pivotted on the bar to which B³
is fixed and this pawl does not obstruct the movement of A³ thrusting B³ out of its
notch. As B³ moves out of the notch moving B with it the sloping face of B¹
allows it to ride over the face of A³. But when A³ is pulled back the pawl B falls
into the notch a³ and prevents A³ from being again moved in the direction of the
arrow, until A shall have been moved thrusting B³ back to the position shewn in
Fig. 5 and thereby withdrawing the pawl B+ from the notch a³.
Obviously the numbers and positions of the cross bars B and the locks B1 B2 B3
and pawl B may be varied to suit the particular character of the interlocking
required for the set of levers to which the apparatus is applied.
We would have it understood that we make no general claim to actuation of the
interlocking gear by rockers worked by the spring catches of the point and signal
levers, nor do we claim generally the use of notched rods A in combination with
transversely sliding bars B or locks B1 B2 B3 for interlocking, but,
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, we declare that what we claim is :-
1. In interlocking apparatus for railway point and signal levers, the use of a
rocker R made with a curved groove open at the ends, in combination with the stud s
on the spring catch rod S and with the stud on the lever L, substantially as
described.
2. In combination with a rocker worked by the spring catch of a point or signal
lever the notched sliding rods A and cross sliding bars B with locks B¹ B or B³
substantially as described.
3. In combination with a pair of notched locking rods A³ A' and an inter-
vening cross lock B³ the pawl B* pivotted on B³ as and for the purpose set forth.
ABEL & IMRAY,
Agents for the.Applicants.