Interlocking Levers for Railway Signalling.
Year: 1894

page_text: Date of Application, 17th Apr., 1894-Accepted, 19th May, 1894
COMPLETE SPECIFICATION.
Interlocking Levers for Railway Signalling.
I, SAMUEL TELFORD DUTTON of Marl Bank in the City and County of
Worcester, Railway Signal 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 has reference to improvements in interlocking pull-over levers, and
consists in a handy and convenient method of making one lever lock another. It is
understood of course that the interlocking may be either by one lever directly
locking a conflicting one, or by one lever releasing another one.
The way in which I carry out my invention is illustrated as follows:
Figure 1 is a side view partly in section of a pullover lever arranged for locking
only. In this figure the lever is in the normal position.
Figure 2 illustrates the lever pulled over and the locking effected.
Figure 3 is a front view shewing the interlocking tappets and locks and the
sheave of the pull-over lever.
Figure 4 illustrates the pull-over levers in the normal position. The lever seen
in this figure is for working points with a reduced stroke, and is arranged for
releasing as well as interlocking.
Figure 5 shews the interlocking tappet during the travel of the lever.
Figure 6 shews the interlocking tappet when the movement is completed and the
final movement given to the said tappet.
Figure 7 is a plan on the underside of the sheave of the pullover lever shewing
the arrangement of the interlocking tappets and locks. This figure also illustrates
the application of what is known as an "Annett's key" such as shewn and described
in the Specification of the Patent to James E. Annett No. 3,427, dated
October 2nd 1875.
An ordinary signal lever "a" (pivotted in a frame adjacent to other similar
levers) is provided with a sheave "" and the said sheave has at one part of its
periphery a curved rib or sector " C.
"
A tappet "d" having notches "d" in its sides is arranged in the same plane as
the rib C and is free to slide in the guide "g." The next adjacent lever is
provided with a similar tappet "f" shewn in Figure 3 having a notch "f1" A
lock "e" slides horizontally in the guide "g" between the two said tappets and
has bevelled corners so that the movement of one tappet can move the lock to the
right or left to cause it to engage with the notch in the other tappet, and prevent
the last said tappet from being moved by the lever to which it pertains. The
rib "c" has 2 lugs "" and ""at one end of it. These lugs engage with a
projection "p on the end of the tappet "d."
"
"
In the modification shewn in Figure 4 the rib C "is provided with two lugs at
each end, and the tappet has two projections, one for each pair of lugs on the
rib "c." This form of lever is better adapted for use in working points."
The working of my invention is as follows:-On moving over the lever
Figure 1 the lug "" of the rib "c" moves down the tappet "d" and the
necessary locking of conflicting levers is effected:-This will be seen on
reference to Figure 3 as assuming that the tappet "," Figure 3 is moved, the
notch "d" is moved beyond the lock " and also beyond the lock "e" so
that the tappet "f" connected to the next lever is locked in its normal position
thro' the notch "f1" in the tappet "f." The lever which is a signal lever, on
being pulled right over assumes the position in Figure 2. Upon the lever being
replaced to its normal position the lug ""cn the return movement of the

page_text: sheave or pulley "6" moves back the tappet "d" into the normal position, as
illustrated in Figure 1. In Figure 4, which illustrates both locking and
releasing in the single movement over of the lever "a1" the projection "3"
moves the tappet "j" to the left and effects the locking and on the completion
of the stroke of the lever, which is a point lever the projection ""completes
the movement of the tappet and effects the releasing of the adjacent lever
which was locked by the tappet "j" when first moved by the lever "a" while
the lever "a" is in its travel after the tappet is first moved, there is no
movement on the tappet as will be seen in Figure 5 but on the completion of
the movement of the lever, the tappet is given a final movement and the sheave
and tappet assume the position as shewn in Figure 6.
The releasing and interlocking of the tappets "j" attached to the various
levers is illustrated in Figure 7, in which the tappet "j" has to be moved
until the notch "3" is in front of the lock ""; the tappet "/" attached to
the next lever is then free to be moved and consequently the lever with which
it works is free.
The Annett's key "m" is shewn inserted in the lock "n" which is attached
to the frame. This key may be taken out of the lock and carried to an
outlying siding or elsewhere for the purpose of unlocking points or signals that
are not worked from the frame or are out of reach of ordinary rod or wire
connections. The key cannot be removed from the lock "n" without moving
the slide "o" which is connected to the slide "o" and lock "p." This move-
ment draws lock "p" into the notch "pl" thereby locking tappet "1" and the
lever attached to it. The slide "o" may be carried on through the frame
and lock other levers, or it may be released by other levers according to the
requirements of the case.
When the key is out this locking cannot be moved or the levers worked until
the key is again replaced and turned.
Having now particularly described and ascertained the nature of my said inven-
tion & in what manner the same is to be performed I declare that what I
claim is :-
1. The combination with a pivoted lever provided with a curved rib "c" having
two lugs at one end of it, of a sliding tappet provided with a projection at one end
and a notch in one side, a guide supporting the said tappet and a horizontally
arranged lock engaging with the said notch and sliding in the said guide when the
said lever is moved to operate the tappet whereby the next adjacent similar lever
is locked, substantially as set forth.
2. The combination with a pivoted lever provided with a curved rib "c" having
two lugs at each end of it, of a sliding tappet provided with a projection at each
end and a notch in one side, a guide supporting the said tappet and a horizontally
-arranged lock, engaging with the said notch, and sliding in the said guide when
the said lever is turned to operate the tappet, substantially as and for the purpose
:set forth.
Dated this 16th day of April 1894.