Improvements in Interlocking Apparatus for Railway Signalling.
Year: 1889

page_text: Date of Application, 23rd July, 1889
Complete Specification Left, 22nd Apr., 1890-Accepted, 19th July. 1890
PROVISIONAL SPECIFICATION.
Improvements in Interlocking Apparatus for Railway Signalling.
I, SAMUEL TELFORD DUTTON, of Marl Bank in the City and County of
Worcester, Civil Engineer, do hereby declare the nature of this invention to be
as follows:-
My Invention has reference to improvements in actuating the interlocking
mechanism of railway point and signal lever apparatus of the kind known as the
tappet or plunger system.
As known in the art, there are three principles upon which this class of locking
is actuated
There is (1stly) that principle called the lever locking, where the tappets are
connected directly to and actuated by the lever.
(Secondly) That principle by which the tappets are connected to and actuated
Ly the catch rod of the handle or a prolongation thereof, and thirdly that system
which is a combination of principles 1 and 2 above referred to, by which a split
tappet is moved by the conjoint action of the lever and the catch handle.
My Invention consists firstly in improvements in actuating the interlocking
tappets by means of my improved handle.
Secondly. In my improved handle, by which 1 abolish the catch now in ordinary
use, and thirdly, in combining these improvements with my design of lever set
forth in the Specification of Letters Patent granted to me bearing date 28th April 1888
and numbered 6351.
With the catch rod interlocking of the tappet kind now generally in use, the
tappet moves with the lever and performs a stroke according to the vertical distance
it is fixed from the fulcrum of the said lever. It will easily be seen that the tappet
has so great a distance to travel through the lock bars that if more than one notch
is required on the same side of a tappet, the said notches will require to be so far
apart (to prevent one notch freeing a conflicting lock) as to necessitate a very wide
and expensive lock bar or series of channels. I obviate this unnecessary width of
lock bar by arranging that the interlocking tappet does not move while the
actuating lever is performing its travel.
My improved handle has two motions in the same direction for the forward
movement of the lever, and the like for the return motion of the lever.
1st. From the back position to a middle position, by which motion the tappet is
moved approximately half of its stroke, sufficient to effect all the locking, and
when the lever has completed its forward movement, the handle is again moved
from the middle to a forward position by which action the tappet performs the
second part of its motion, thereby completing the necessary releasing. The motion
of the handle and releasing tappet is therefore continuous, no back motion being
made.
I carry out my Invention in the following manner :-
The handle is jointed to the top of the lever and has two short arms coupled to
rods, one carried down the front, and the other behind the lever. One of these rods
passes through a double acting spiral spring, arranged in a clip attached to the lever.
The spring acting upon collars on this rod, tends, in the normal position of the lever,
to keep the handle in the back position.
The other rod, which I term the handle rod, is coupled near the foot-plate to one
end of a cross-bar, pivotted to the lever. The other end of the cross-bar carries
a friction roller, working in guides, or in a groove fixed to the frame.
This groove may be straight or curved, but its length corresponds to the stroke of
the lever, and so long as the roller is in the groove, the handle is kept in an
approximately vertical position.

page_text: The ends of the groove form shoulders or stops, to hold the lever in its normal or
worked position when the roller is raised or lowered by the handle.
Instead of the roller, a stud or die may be used, and instead of the spring acting
upon a separate rod, it may be applied to the handle rod.
The handle rod is carried down continuously, or as
a separate rod from the
cross-bar to a point near the fulcrum of the main lever, and there coupled directly,
or by a suitable crank to an interlocking tappet, having either square or bevelled
notches in its sides.
The tappet may be arranged to work horizontally, vertically, or at an angle to the
lever when normal.
I do not bind myself to the arrangement of the locks, and, connecting slides, as
it is obvious various arrangements may be made to suit special circumstances.
Dated this 23rd day of Inly 1880
JOHN P. O'DONNELL,
Agent for the said Applicant.
COMPLETE SPECIFICATION.
Improvements in Interlocking Apparatus for Railway Signalling.
I SAMUEL TELFORD DUTTON of Marl Bank in the City and County of Worcester,
Civil 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 actuating the interlocking
mechanism of railway point and signal lever apparatus, and consists, Firstly of
improvements in actuating the interlocking gear, Secondly of an improved handle by
which I abolish the spring catch handle now in ordinary use and Thirdly a com-
bination of these improvements with the form of lever set forth in the specification
of letters patent granted to me bearing date the 28th day of April 1888 and
numbered 6351.
In ordinary tappet interlocking now in use the tappet moves with the lever and
performs a stroke according to the distance it is fixed from the fulcrum of the said
lever. It will be readily seen that the tappet has so great a distance to travel through
the lock-plate that if more than one notch is required on the same side of the tappet
the said notches will require to be so far apart (to prevent one notch freeing another
or conflicting lock) as to necessitate a very wide and expensive lock plate or series of
channels. I obviate this unnecessary width of lock plate by arranging that the
interlocking tappet does not move while the actuating lever is performing its travel.
My improved handle has two motions in the same direction for the forward movement
of the lever and in like manner has two motions for the return movement of the lever
in which former case my handle is moved from the back position to a middle position
by which motion the tappet is moved approximately half of its stroke sufficient to
effect all the locking, and when the lever has completed its forward movement the
handle is again moved from the middle position to a forward position by which action
the tappet performs the second part of its action thereby completing the necessary
releasing, the motion of the handle and releasing tappet is therefore continuous no
back motion being made. The handle is jointed to the top of the lever and has
a short arm coupled to a rod, which latter is carried down the front side of the
lever. In cases where it is desirable to place the spring on the opposite side of the
lever the handle has two arms and two rods. For the purpose of explanation 1 will
only describe my improved handle with one arm connected to one downright rod in
front of the lever, this rod works in connection with a spiral spring arranged in the
clip or box attached to the lever, the spring acting upon projections upon the said
rod tends in the normal position of the lever to keep the handle in a back position.
The said downright rod is coupled below the foot plate to one end of the cross
bar pivoted to the lever the other end of the cross bar carries a friction roller working
in guides or in a groove plate fixed to the frame, this groove plate may be straight or

page_text: curved but its length corresponds to the stroke of the lever and so long as the roller
is in the groove the handle is kept in an approximately vertical position. The ends of
the groove form shoulders or strips to hold the lever in its normal or worked position.
Instead of the roller a stud or die may be used, and in addition a quadrant plate with
notches for the down rod may be used if desired. In order that my invention may be
better understood and more readily carried into effect, I will describe the drawings
hereunto annexed. The same letters refer to the same parts in the several figures of
the drawings.
Fig. 1 is a side view of the lever showing my improved handle and the means by
which the tappet is actuated. In this Fig. A is the lever for actuating the points,
signals or other apparatus, B is my improved handle centred at B2 on the lever A,
C is the downright rod connecting the small arm of the handle B to the cross bar D,
D is the cross bar pivotted on the lever at d' having at one end the roller E; the
connecting links G connecting the other end of the cross-bar D at d² to the tappet H,
F is the fixed groove plate, the groove F being arranged for the travel of the
roller E. It will be observed that the projection F2 is the downward projection of the
groove plate F, F3 is a slight upward projection on the groove plate F, the former
acting as a stop for the roller in the normal position of the lever; the latter acting as a
stop for the roller E in the worked position of the lever. In my apparatus it will be
seen that I have abolished the usual drop weight or spring catch by which the lever
is held in its worked or normal positions. The roller E acting on the rib F2 of the
groove-plate F forms the means by which the lever is held in the normal position and
the roller E acting on the rib F³ of the groove-plate F is the means by which the
lever is held in its worked position. A³ is the fulcrum of the lever, at a are the rod
and wire connections for the purposes of working the apparatus outside the cabin.
The small block a riveted to the lever comes against the stop F' so as to prevent
damage to the downright rod C in pulling over the lever.
Fig. 2 is an enlarged view of the box containing the spring for forcing the handle
back to its normal position on the lever being replaced. O is the spring held by
tbe clips O O and pressing alternately against the square lugs on rod C.
Fig. 3 is a horizontal section of Fig. 2.
Fig. 4 is a view illustrating the lock-plate and the tappets H passing across the
plate with notches for actuating the locks. The tappets, locks and lock-plate may be
of the usual kind and are worked in the manner weil known in the art.
This figure
shows the method of coupling the connecting links G to the tappets H. I do not
however confine myself to the use of tappet locking as it is obvious other types of
interlocking may be actuated by my lever handle.
Fig. 5 is an enlarged diagramatic view of part of the lever A, cross bar D and
roller E. The end is connected to the downright rod C and upon this downright
rod being worked by the handle B Fig. 1, the cross bar and roller assume the
dotted position in Fig. 5, when the lever is now worked the whole will assume the
position shown in Fig. 6, the cross bar and roller meanwhile remain in the dotted
position, when the lever handle is pulled further over the cross bar and roller assume
the full line position; in these figures 5 & 6 the circle G represents the position of
the tappet pin in the normal position, G2 represents the said pin when the lever bandle
has been moved and G³ represents the said pin when the lever has been worked
and the lever handle pulled further forward, the latter movement completing all the
necessary releasing.
Fig. 7 is a horizontal view partly in section showing the cross bar D rollers E and
the manner in which they work in their grooves on the groove-plate F.
The action of my apparatus is as follows:-
Upon the signal man working his lever handle into the dotted position Fig. 1, the
downright rod C is pressed downwards, this action moving the connecting links G and
tappet H thus effecting all the necessary locking, meanwhile the roller E is moved
into the groove F of the groove plate F, upon the signal man now working his lever
the roller E works in the groove F of the groove plate F, no motion however being
communicated to the tappet, and the handle B is thus (while the roller E is in the

page_text: groove F) (practically locked). Upon the completion of the movement of the lever,
the signal man moves his handle B further forward from the dotted position B' to the
dotted position B2, this action further depressing the downright rod C the connecting
links G and the tappet H this movement completing the necessary releasing. The
roller E on the cross bar D is also moved into the dotted position against the rib F³ of
the groove plate F thus forming the means by which the lever is held in the worked
position. The reverse action of the lever consists in the signal nan pushing the handle
hack from the position B2 to B₁ thus moving upward the downright rod C links G and
tappet H, the roller E is then moved into the groove F1, the lever is now moved over
no motion being communicated during this action to the tappet H, but when the lever
is quite over and the lever handle is pressed further backward, the downright rod C
connecting links G and tappet H are inoved further upward into their normal position,
the rollers E meanwhile assuming the normal position against the rib F of the groove
plate F. I do not bind myself to the precise arrangements of locks and connecting
slides as shown, as it is obvious other descriptions of locking gear may be actuated by
the connecting links G.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is-
1st. In interlocking apparatus for railway point and signal levers the actuation of
locking gear by means of a jointed lever handle, whose movement is controlled by an
anti-friction roller working between suitable fixed guides, substantially as described
and illustrated in the accompanying drawings.
2nd. In combination with the handle B and the groove plate F; the cross bar D,
roller E, connecting links G and tappet H, the whole arranged and operating sub-
stantially as described and as illustrated in the accompanying drawings.
Dad thin 92nd day of April 1890
JOHN P. O'DONNELL,
2, Great George Street, Westminster, London, S.W.,
Agent for the said Applicant.
JOHN P. O'DONNELL,
2, Great George Street, Westminster, London, S.W.,
Agent for the said Applicant.