Year: 1888

page_text: Date of Application, 30th Jan., 1888
Complete Specification Left, 18th May, 1888
Complete Specification Accepted, 3rd Aug., 1888
We, WILLIAM SMITH of 150 Mayall Road, Herne Hill in the County of Surrey,
Engineer and JoHN PATRICK O'DONNELL of Cambridge Villa, Cambridge Road, New
Malden in the County of Surrey, Signal Engineer, and Patent Agent do hereby
declare the nature of this invention to be as follows:-
:-
Our invention has reference to apparatus, for working, ground interlocking, and
mutual detecting of Railway points and Signals, and it comprises arrangements and
mechanism, whereby both the main and branch junction signals can be worked by one
lever, and the corresponding Distant Signals by another lever.
The arrangements for working both the Junction Signals by one lever, are such as
to constitute a point detector, which determines which signal (that is the main or the
Branch) shall be worked according to the position of the points, the conflicting
signals being locked and the working of the unlocked junction signal having the
effect of releasing the corresponding distant signal. We are thus enabled (just as
with Hill and O'Donnell's patent ground locking gear) to do with two levers what
has been hitherto usually done with five (or at least four) levers, that is to say where
there have been two levers for the two junction signals, two for the two distant signals,
and one for the facing point lock.
In the case of trailing points both the stop signals for coming off two lines on to
one line can be worked by one lever, the position of the trailing points determining
which signal shall be lowered to safety; when a signal is lowered, the points and
conflicting signals are locked and the corresponding distant signal released.
In an ordinary junction for example consisting of two sets of points, one point lock,
two down junction signals, two down distant signals, two up stop signals, and two up
distant signals, requiring in all eleven levers with the ordinary arrangements; according
to our present invention six levers would not only suffice but in many ways help the
attainment of increased safety.
Hill & O'Donnell's patent No. 6661 of A.D. 1886 (subsequently developed) fulfills
more or less similar purposes. Inasmuch as there exist parts of mechanism more or
less modified common to both inventions we will first trace the natural transition from

page_text: the claimed features of the former invention to the claimed features of the present
invention as the best possible illustration of their divergence to an extent constituting
them independent inventions.
Figures 1. 2. and 3 roughly illustrate an arrangement for a (horizontal) form of
Mossrs. Hill & O'Donnell's apparatus (verbally referred to in their specification amongst
other, modifications but without detailed illustration) figure 1 being a side view of a
drawbar B, figures 2 sectional views of the side uprights of the sliding frame with
their counterpart side uprights of the fixed frame shewing the bearings or mounting
of the three parallel bars in one plane (hence called horizontal form although the bars
exhibit more depth than breadth).
Figure 3 is a ground plan with the three bars in their normal position ready for a
signal to be lowered to safety by the drawing of the slide bar A through the action
of B where by also the points P¹ P² and the signal connected with C would be
locked.
In this arrangement it is the outer frame which is fixed and the inner frame which
slides across with the throw of the switch points P1, P2, and which carries the signal
slide bars A and C whose fixed horizontal arms a¹ and respectively engage with
the right and left double arms and of the selecting draw bar B one getting
into gear as the other gets out. H. and H are the detecting or locking pieces on the
parts of the sliding frame which represent or are the equivalent of a stretcher bar as
ordinarily used for detecting and plunging the switch points in position.
Now in our present invention there are to be noticed two independent features of
novelty, each a point of radical divergence from the claims of the prior patent. The
first is illustrated in the diagrams called figures 4 (plan) and 5 (elevation) wherein
A, B and C are supposed to be mounted as if to fulfill the same functions as in
figures 2 and 3. but the means of connection and communication of motion from B to
its selected parallel signal slide bar gives the radical divergence and real feature of
novelty being in this case a rocking lever arm 12 extending from (or beyond) A to
(or beyond) C through slots in A. B and C.
Pins restrain the said arm from being drawn out of gear and form the fulcrum as
required for the lever action of the arm. If A. B and Care flat bars b¹² may be an
arm of vertical section and slotted to hold A. B & C, or it may still be of a flat form
and held by strap pieces like the toothed wheel in figure 6 or otherwise. It would
equally suffice to have the arm 6' 62 pinned (a pivotted or hinged joint) at one point
through (no matter which) A. B or C. The draw bar B gives an increased draw to
the selected signal slide bar. Here another possibility of magnifying the uses of B
appears; by having the normal position of the lever arm 61 62 central and two signal
slide bars on each side, then openings to correspond in the fixed frame will easily
allow B to select and work one at a time out of four signal slide bars, two by pull and
two by thrust from its normal position at which alone the switch points can be changed
by the switch point lever.
The second radical point of divergence consists in ceasing to cause the slide bars A
and C to be carried by the sliding frame and on the contrary mounting them in the
fixed frame like B in figures 2 & 3 when like the latter they (A & C) must have their
own notches (h & h in Fig. 1 counterparts of H and H' in figures 2 & 3) which pass,
let
pass, or are locked by, or lock, as required, with block pieces in the sliding frame.
It is in this latter case that such gearing as "rack and pinion" (see figures 6 & 7) or
pulley and chain become available substitutes for the lever arm; in this case also it
becomes easy to carry out Hill & O'Donnell's specified proposition to replace the
sliding frame by a more ordinary form of stretcher bar solid or divided, such block
piece H and its counterpart notch h above referred to rather acquire the appearance
respectively Hof a notch in a stretcher bar and a gap between two solid additional
pieces laid upon a signal slide bar one of which solid additional pieces (at h)-pisses
through as required its counterpart notch Hor, on the contrary one or the other acts
as a stop against the solid parts adjacent to the notch H.
When the first or both of these two leading points of divergence are carried out,
various alternative arrangements, modifications. &c., such as those alluded to in

page_text: Messrs. Hill & O'Donnell's specification are more or less still applicable but in possible
variations the real contrast between the two inventions is proved by the fact of our
present gearing never allowing A or C to be beyond touch and influence of B. This
invention possesses certain other features of novelty that are not similarly recognisable
as diverging from or corresponding to anything in the specification of the above
mentioned prior invention.
:
One of these other features of novelty consists in arranging one or more of what
we call "secondary sets" of signal slide bars at right angles to a primary set" or its
connections. By a primary set we mean the bars A & C with their actuating
mechanism working as described at right angles to the stretcher bar (or its substitute)
for the switch points. Where the same locking is required but only one signal to be
shewn, of course either A or C (in a primary or a secondary set) can be a mere
detecting bolt and lock or a mere dummy as far as signal working purposes are
concerned. The bar B, through which A & C are actuated, may be relieved of locking
functions and work clear of the stretcher bar or of its substitute.
In figure 8 there is shewn in plan a "primary set," A & C (locking and crossing at
right angles the stretcher bar of the junction points) actuated by B through a pulley
and chain whilst A and C with their selecting draw bar 13¹ (carrying a lever arm for
the sake of variety of illustration) form what we have termed the "secondary set."
The drawing of A by B sets A free to be drawn in its turn by B₁ whilst A when
drawn locks the prior drawn A. All the bars in this except the stretcher bar (divided)
SS are laid flat so as to allow of the whole apparatus to assume a flat well boxed up
form suitable for placing on the ground between the switch points which will be
together with their corresponding two stop and two distant signals worked by three
cabin frame levers only. Similarly we propose to employ for detecting and interlocking
purposes ground gearing mechanism of the same kind of arrangements of "sets" of
bars working the same with four, or with five, or with six cabin frame levers, the said
bars having connections for performing any desired further movements.
In such a
double set as figure 8, A & C may be employed merely to lock and detect the points
whilst A & C are connected to the stop signals.
Mechanism after the character of the secondary set A, B, and C will be found
employed for similar purposes and described (in an elementary and in an improved
form) in Hill, Smith & O'Donnell's specification of their invention for which letters
patent have been applied No. 13019, A.D. 1887. We now further claim that under
our improved form such imechanism can be made to answer even as a primary and as
a single independent set. However we do not claim the use of a swinging cross-
beam connected by links, to the ends (or other parts) of two signal pull rods whether
the said swinging cross-beam is pulled and released by chain or wire connections or
pulled and returned even by rod and crank motion but we claim as novel and more
effective than any other prior arrangement our employment of our rocking lever arm
(as 'one out of several alternative kinds of possible gearing) only in connection with the
selecting draw bar B (its carrier) mounted centrally in two fixed bearings for draft
parallel to A&C, which lever arm moreover actuates A & by a firm pull and return
thrust motion (with leverage and more or less sliding and inclined plain action)
without any connections of the nature of links whilst a simple hinged or pin joint
connecting the end of B with the end of a plain rod leading to an ordinary crank is
thus enabled to afford perfect rectilinear motion to B3 through rod and crank
connections all the way up to the lever in the signal cabin frame.
Respecting the two separate kinds of employment (namely Ist as a primary set, i.e.,
crosswise to a stretcher bar, or as a secondary set, i.e., crosswise to the bars or
connections of a primary set) of such (lever saving) apparatus as ours, it may be
observed that the minute exactitude and precision of mutual detecting and locking
action between the slide bars and the stretcher bar of a primary set are not called for
to anything like the same degree in the case of similar mechanism working as a
secondary sei. Hence an arrangement somewhat inefficient for use as a primary set
may be effectually employed as a secondary set.

page_text: In order to more fully secure safety at Junctions, we have provided as part of our
apparatus certain means whereby, if the rod to the Facing Points becomes severed,
and the points themselves lie for fouling the Trailing Line, then the Trailing Signal
cannot be given to the "safety attitude."
We effect this result by means of a blade from the Facing points working in
connection with; and interlocking a Blade in the wire working the Trailing
Signal.
This result may also be effected by interlocking the Facing and Trailing points on
the ground by a bar from each and a tappet lock or otherwise.
In all apparati, where reduction of levers is desired, especially where one lever is
working two Signals, it is an additional safeguard to connect an indicating Disc
to the point lever & place the said Disc immediately behind the one Signal
lever.
.
The words "Main " or Branch or other like words to be painted on the Disc to serve
as a reminder to the Signalman as to the position of the points & would therefore
guide him in signalling the Train.
13 1
IT
1000

page_text: COMPLETE SPECIFICATION.
Improvements in Railway Signalling Apparatus.
We, WILLIAM SMITH of 150 Mayall Road, Herne Hill in the County of Surrey,
Engineer and JOHN PATRICK O'DONNELL of Cambridge Road, New Malden in the
County of Surrey, Signal Engineer and Patent Agent 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 has reference to apparatus for, working ground interlocking, and
mutually detecting Railway points and signals. It thus effects similar purposes to
those for which Letters Patent were granted to Hill and O'Donnell No. 6661 of
A.D. 1886, but by somewhat different mechanical movements.
The development and further improvements made in the mechanism of Hill and
O'Donnell's above mentioned prior invention have greatly changed the prospective
value of much of the apparatus, and many of the features of novelty alluded to and
described in the provisional specification of the present invention.
Accordingly we now waive at least herein, several features of novelty including
these possible forms of our mechanism, wherein the pair of (right and left) signal
slide bars (A and C of a primary set) are carried sideways with the throw of the
switch points. Furthermore it may be found that our combined detecting, point
locking, and signalling slide bars (as applied crosswise to the stretcher bar S. §¹
of the switch points) may preferably be actuated without the intervention of our
selecting and lever saving gear, that is to say after the more ordinary double
plunger way.
However our employment in "secondary sets" of central selector bars (E in
Figures I. II. III.) as the actuating carriers, furnished with any of the three
illustrated kinds of gear, stands as our most special feature of useful novelty, whilst
the same kind of mechanism and gearing still remain as practicable apparatus for
primary sets, even though eclipsed in favour by other arrangements, and only remaining
or retained for similar, but subordinate uses.
Figure illustrates a primary set A and C actuated by gearing, through the
movements given to their selector bar B; in the same figure a secondary set D and F,
is shewn actuated by an alternative description of gearing through the movements
given to their selector bar E.
In Figures II. III (for the sake of greater clearness and example of variation)
gear for lever saving mechanism is only shewn applied (third description of gearing)
to a selector bar E, which respecting its situation (as in a secondary set D and F)
exhibits its most novel and probably it most advantageous employment. In Figure 1
wheel and chain gearing is shewn in one
and rack and pinion in the
other, but they are both interchangeable. In this Figure the rod and crank
connections K, K, K2 shewn in dotted lines, would give an extra element of safety,
would ensure the full return of A and C, and might be substituted for one of the pulley
wheels and chains b' b².
"set
Figure 1 shews the same mechanism as figure III, but the latter illustrates
the mechanism moved out of its normal position in the ordinary routine of
employment.

page_text: The gearing used with the selector bar E in figures II. III, is the rocking lever
arm, which has wider possibilities of employment than even the rack and pinion, or
the pulley and chain descriptions of gearing, inasmuch. as it appears- available to
those forms of primary sets (claims now waived) wherein a sideways carriage motion
is given to A and C, with the throw of the switch points whilst B is stationary, or
conversely B thus carried, whilst A and C remain stationary.
"
The rocking lever arm gearing is simply a cross bar pivotted in its centre upon a
carrying blade, it extends beyond the selected bars (A and C) and is either pivotted
likewise to them or works in strap pinces fixed upon them. The working of this
system of gearing is described hereafter. The rack and pinion gearing consists of
a toothed wheel centred upon a travelling blade. Parallel to the central
blade are two selected blades D and F (figure 1) each provided on their near
sides with teeth. The teeth of the middle wheel are always in gear with both blades.
According to whether A or C has been previously worked, so in working the
bar E forward the wheel revolves along the locked blade and works with itself
the unlocked one, thereby in that action locking the points and lowering the signal.
The pulley and chain system of gearing consists of a draught wheel 11 12
(figure 1) in a carriage B; parallel to B are A and C connected together round the
draught wheel. The second wheel at the other end is intended to assist the return
motion.
The signalman in working his stop signal lever, communicates action to the
carriage B, which draws the draught wheels forward and according to the position of
the points lowers a signal and locks them.
In all three descriptions of gearing the fulcrum changes according to the previous
movement.
The respective advantages, and disadvantages of the three descriptions of gearing
are as follows The employment of the rocking lever arm gearing renders it
necessary that the slide bars of its set be so far apart that we intend to employ it as
a selector only for secondary sets, and for subordinate accessory uses only in primary
sets; on the other hand the rack and pinion and the pulley and chain gearing allow
of the slide bars of their sets, being apart from each other only half the distance
desirable in the case of the lever arm gearing; though rack and pinion is not a
favourite gearing, where avoidable; it has the advantage of being very compact.
In Figure a single cabin frame lever through the selector bar B works either
A or C as required, whilst a second cabin frame lever through E similarly works
either D or F as required.
In Figures II. III whilst the selector bar E works either D or F, as in Figure 1
the bars A and C of the primary set are cach left to be worked directly by their
respective separate cabin frame levers, without the intervention of any joint selector
bar. The Bars D and F may when desirable be worked by separate cabin frame
levers as shewn in Figures VI and VII. Otherwise our point detecting, locking,
and mutual signal slide bar interlocking features of novelty are identical in the
three figures I. II. III, and hence the following description reads as applicable to
the three.
In the most ordinary case of employment the slide bar A would be connected to
wire, chain, or rod and cank connections working (say) the Main Line Stop Signal;
the slide bar () to connections working the Branch Line Stop Signal; then
the signal slide bar D of the secondary set to connections working the Main Line
Distant Signal; and similarly the slide bar F of the secondary set to connections
working the Branch Line Distant signal.
Now when the points have been set right for the Main Line as (say) in figure III
an attempt to draw A so as to work-the Main Line Stop Signal will detect the perfect
closing of the switch tongue to its rail at S, because if the switch points have not
travelled their full throw, the projecting rib a on the upper face of A, will not be
ble to pass through its counterpart notch or gap a¹ on the lower face of the stretcher
bar S. St. As the efficient draft of A works the Main Stop Signal, the points
become bolt locked and will be only released on the complete return of A to its

page_text: normal position. Again the effectual draft of A carries its rib piece a³ on its
underside clear of obstructing the path of the rib piece on the upper face of D and
thus after the Main Stop Signal has been lowered to safety, the Main Distant Signal
can be similarly lowered.
Furthermore A cannot be returned to its normal position until after D has been returned.
Similarly, after the switch tongue had been closed to its rail at S¹ ( could be
drawn to fulfill its detecting, locking, and signal working functions, whilst F would
repeat towards C, the rôle of D towards A. Thus the five pull and return motions,
1st. the switch points, (2) primary slide bar A (3) primary slide bar C
(4) secondary slide bar and (5) secondary slide bar F can be each worked efficiently
in their correct rotation only; which rotation is automatically determined by the
position of the switch points.
For doubly ensuring the safe interlocking of the four signal slide bars, there may
be extra locking ribs on the bars whereby A and F interlock with each other and
likewise C and D.
A distinctive feature in this invention (similar in this respect to Hill and
O'Donnell's prior inventions) is that the point locking bolts or signal slide bars A
and C, themselves are the medium through which their respective signals are
worked, and that therefore should any of the connections between the Signal Cabin
and the said locking bolts A and C (or their equivalents, plungers, as hitherto used)
become severed the Signals cannot be lowered to the safety attitude.
Figure IV shews the selector bar B employed additionally as a point lock, and as
a detector, act only by reason of the rib piece on its upper face; but also the rib
piece 63 on its lower face interlocking with e on the upper face of E; the same
figure also illustrates B, worked by the same rod and crank connections as a facing
point treadle or safety bar, but the connections and working of B may be managed
in many other ways.
The above use of the bar B suggests an immense variety of possible arrangements
of our invention by more or less employing and incorporating into the same the
leading features of novelty patented as No. 16435 of the 29th November 1887
namely the bar called the. "normal" locking bar and which was found to be a very
suitable means of connection to the treadle or facing point safety bar. These ideas
are illustrated in Figures V. VI. and VII.
In Figure IV three cabin frame levers are arranged to work all the points and
signal movements but in Figure VII, the signal slide bars of both primary and
secondary sets are worked direct without the intervention of joint selector bars,
and hence six cabin frame levers are required.
*
The chief feature to be noted in Figure VII is that the slide bar K intermediate
and parallel to A and C is not a selector bar like B in figure IV, but practically the
normal locking bolt of Patent No. 16,435 above mentioned. It should be here
particularly observed that. K by reason of k¹ in its normal position can lock the points,
that its crossbar H (may be a fixture or a rocking lever arin) necessitates that K must
be moved from its unlocking position into its normal locking position prior to,
or simultaneously with the movement of either A or C, but that the return of either
A or C to their normal positions leaves K unaffected although the movement of K. from
its normal position to its unlocking position would ensure the full return of A or C to
their normal positions; in fact K (otherwise than with a selector bar) has its normal
position in the opposite direction to the normal positions of the right and left hand
signalling slide bars.
Figures II. III shew how a cross bar H, might be the medium for connecting the
primary set A and C jointly to a facing point safety bar, without H being mounted
on either a selector bar, like B or a normal locking bar like K, for the safe acting of
which the steadiest movement parallel to A and C is most desirable. Of course where
no safety bar is provided for the points, the cross bar I will be omitted.
Figure VI represents a modification of Figure II inasmuch as the signal slide
bars D and F of the secondary set are herein worked directly without the intervention
of a point selector bar E.

page_text: Five Cabin frame levers here suffice and the simplification of the mechanism
enables the action of H to be studied more clearly than elsewhere. However the
utility of this arrangement appears to be less than that of any of the other figures,
since a lever saving selector bar may be most confidently applied to secondary
however much doubts may prevail (prior to extensive trial) as to their use in the
more delicate situation of primary sets.
Figure Vis the most complicated and is intended to shew both primary and
secondary sets arranged to work each with their own selector bar, whilst a normal
locking bolt M with cross bar H is included in the same apparatus. As shewn some
substitute has to be contrived to give M. and B, the parallel and steady movements
which are afforded to B or K in other figures, by their double (front and back)
bearings on the framing of the apparatus. A normal locking bolt M and selector
bar B can be contrived one on a higher and one on a lower plane, both parallel
to A and C, and both possessed of double bearings, but the figure as drawn affords an
easier view or plan. As in Hill and O'Donnell's patent No. 6661 of A.D. 1886,
a sliding frame might be substituted for the stretcher bar S. S¹, whilst a fixed bed
plate and frame, would take the place of the boxlike case, which in the present
illustrations, furnishes the necessary stationary bearings of the sliding bars.
In order to more fully secure safety at Junctions, more especially where lever
saving gear is applied we have provided as part of our invention certain means,
whereby if the rod working the facing points becomes severed and the points lie for
fouling the trailing line, then the trailing signal cannot be given to the safety
attitude. We effect this result in the following manner--a sliding bolt attached
to the facing points, and another sliding bolt attached to the trailing points pass
and work through a small box or locking case. The ends or those portions working
through the box are notched to receive when desired a lock. The result effected may
be either locking or releasing, that is to say, the trailing may release the facing points,
or they may lock each other through this apparatus, according to the normal positions
of the points. When the facing points are moved over making the road. right for the
Branch its sliding bar shoots the lock into the notch in the sliding bar of the trailing
points, and prevents their being moved, so that if the rod working the facing points
becomes severed, leaving the points right for the Branch, the trailing signal cannot be
given, so the trailing points must first be set right, which latter cannot be effected,
since they are locked as previously described by the movement of the facing points.
To ease the travel of these sliding bars they may be arranged to slide on friction
rollers, or on ball bearings or the tappet action may be similarly assisted on either
inclined plane surface.
Another method of effecting this is to run the connections to the main trailing
signal, through the stretcher-bar of the facing points, or a prolongation thereof, and
by means of corresponding notches, prevent the said signal from being lowered, if the
facing points, lic for the Branch or fouling line.
Or again rod connections from the facing and trailing points, may so meet, that an
attempt to move one set of points into the position of one line fouling the other,
would simultaneously tend to fall or push the latter set of points out of the fouling
position.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed we wish it to be distinctly
understood, that we do not claim as novel, the mere rocking lever arm, or pulley and
chain, or rack and pinion mechanism, for actuating signal slide bars, which cross the
stretcher bar (or a prolongation of the same) but only our special or improved manner
of employing such mechanism-mounted-on-a.carrying bar, and most particularly, when
applied in the absolutely novel position of a "secondary set."
Accordingly we hereby claim
1stly. The apparatus for the working, detecting and ground interlocking of Railway
mints and signal in the

page_text: the former (primary) set of signal slide bars at right angles, all four bars being
provided with locking ribs, the one, or the other or both sets being optionally
actuated through our lever saving gear.
2ndly. The employment for lever saving purposes of our selector bars (B 112
or Eee²) held in two fixed bearings, midway between the signal slide bars of their
respective sets, which selector bars move parallel to the said signal sliding bars, and
actuate the latter by means of any of our three illustrated descriptions of gearing.
3rdly. The employment of the above last mentioned gearing with a bar, more or
less resembling a selector bar with connections for any of the illustrated subsidiary
purposes described, or describable as modifications of, or developments of the selector
bar with lever saving gear.
4thly. The described methods of ground interlocking, facing, with trailings points
and signals, complementary to the system of ground gearing of claims one, two and
three or substitutes therefor.
Dated this 18th day of May 1888.
JOHN P. O'DONNELL, C.E., M.I.M.E., &c.,
Agent for the Applicants.