Improvements in Interlocking Switon mecanism.
Year: 1895

page_text: Date of Application (in United Kingdom), 25th Sept., 1895
Complete Specification Left, 25th Sept., 1895-Accepted, 15th Feb., 1896
Improvements in Interlocking Switon mecanism.
1, JOHN DIEFENBACH, of Springfield, Clark County, Ohio, U.S.A.,
Interlocking Switch Inspector, do hereby declare the nature of this invention
and in what manuer the same is to be performed, to be particularly described and
ascertained in and by the following statement :--
This invention relates to certain new and useful improvements in interlocking
switch mechanism for railways.
My improvements have reference to means for adopting the apparatus for switch
rails pointing in either direction without changing the location of the apparatus;
have reference to a construction by which the switch bar or pitman is locked when
the locking bar or pitman is locked, so that both become locked and unlocked at
the same time, and so that if either breaks the other will hold the switch; have
reference to an organization by which when the signal is set for a clear track the
switch bar or pitman and the locking bar or pitman are both locked by the signal
bar and the position of the switch can not be changed except the signal be first
set to indicate danger, and have reference to other features and to certain details
of construction.
The organization, construction, and operation by which I carry out these objects
in practice will more fully and at large appear in the description following and will
be particularly pointed out in the claims.
In the accompanying drawings on which like reference letters indicate
corresponding parts:
Fig. 1, is a plan view of a portion of the main line and switch rails of a railway
with my improvements applied thereto;
Fig. 2, is a transverse sectional view of one of the rails, the detector bar, its
supporting link and bracket ;
Fig. 3, is an enlarged plan view of my improved apparatus;
Fig. 4, is a longitudinal vertical sectional view on the line of Fig. 3; and
Fig. 5, is a transverse vertical sectional view on the line of Fig. 3.
My apparatus consists essentially of two parts (1) the signal lock and (2) the
switch-lock. The cross ties upon which this apparatus is placed are lengthened
and tied together at one end by an iron bar 3, bolted or spiked at 4, and at the
other by a platform of boards 5, bolted or spiked at 6. A metallic plate 7 is
placed upon one of the cross-ties and secured by the spikes 8 which hold the rail
chairs 9, and secured to the platform by bolts 10 and by being fitted to a channel 11
therein. The ties 2 are cut away at the top where the platform is located to place
the apparatus at the proper height. The plate 7 has stops 12 abutting against the
chairs to assist in holding them. The object in lengthening these ties and providing
with plate 7 is to positively fix the apparatus with respect to the rails so that there

page_text: can be no independent lateral movement which would prevent the switch rails from
maintaining the proper contact with the rails when once adjusted.
The rails of the main line are shown at 13 and the switch rails are shown at 14
and 15. A section 16 of one main rail deflects from the point 17 so as to form, in
connection with the switch rail 14 the junction or side track.
The switch rails 14 and 15 are laterally moveable as usual and are interconnected
by lugs 18 and bars 19. Extensions 20 and 21 from the lugs 18 pivotally connect
with the switch bar or pitman 22 and the locking bar or pitman 23, the former
having a section 24 pivoted thereto at 25, and having a bracket 26 where pivotal
connection is made with a T-lever presently to be described.
A stout metal plate 27 forms the base of a switch lock and is secured by bolts 28
to the platform 5. This base plate has blocks 29 and 30 each transversely slotted
to receive the pitmen 22 and 23 and each longitudinally slotted to receive the lock-
bar proper 31. These blocks have caps 32 fitted over studs 33 extending from the
blocks and held by cotter pins or other means 34. These plates keep the locking
bar 31 in place. This bar in turn keeps the pitmen from raising out of the slots.
Each pitman 22, 23 has transverse notches 35 and 26 a distance apart equal to
the movement to be given the switch rails 14, 15. The locking bar 31 has three
keys 37, 38 and 39 which fit at one time in the slots 35 and at another in the
slots 36. Open spaces 40 and 41 are left respectively between the keys 37 and 38,
and 38 and 39 to permit the pitmen to be reciprocated in the act of adjusting the
switch rails from one position to the other.
On a stout trunnion 42 rising from the base plate 27 I pivot a T-lever having
arms 43, 44 and 45. A cottar pin or other device 46 prevents the T-lever from
slipping off of the trunnion 42. The arm 45 is slotted at 47 to receive the locking
bar 31 and has pintles 48 on which are mounted rollers 49. The locking bar 31 is
cit away where it passes through the slot 47 of the arm 45 to form shoulders 50
adapted to come in contact with the rollers 49, so as to swing the arm 45 and thus
operate or vibrate the T-lever when the locking bar is reciprocated.
The blocks 29, 30 preferably have lugs 51 and 52 overlapping the pitmen 22
and 23 to assist in holding them down in the slots of the blocks, in which they
travel. The locking bar 31 is operated by a rod 53, sometimes made in the form
of a pipe. This rod runs to the signal tower where it is operated by means of
a lever in the usual way. I have so far described my switch lock.
will next
refer to the usual detector bar and its connection with my said lock. This
detector bar is shown at 54 where it is supported near the rail on hangers 55,
pivoted to brackets 56, secured to the rail. A connecting bar 57 connects the
detector bar with a T-lever 58 pivoted to the platform 5 and connected by a
connecting bar 59 with the locking bar 31. Thus the detector bar is adapted to
perform its usual function of preventing any shifting of position of the switch rails
as the train approaches and goes over the switch joint. A rod 60 connects with
the T-lever 58 and runs to the tower lever, should the tower house be so located
with respect to the switch lock as to require this arrangement instead of rod 53.
and m.
I shall now describe my sigual lock and its connection with my switch lock. It
consists of a base plate a fastened by bolts b to the platform 5 and has brackets c
and d having slots g for the locking bolts h. These blocks c have caps i held by
screws or other fastenings j. The locking bolts h are pivoted to the pitmen 22 and 23
respectively, as shown at k. These locking bolts are also notched as shown at l
The signal barf has keys o and p on the lower side with a space q beyond
the key o and a space between the keys o and P. It also has a stops on the upper
side to limit its movement by coming in contact with the cap plate i. The keys o
and p are adapted to fit in the slots and m while the spaces q and r, when opposite
the locking bolts permit the latter to be reciprocated, while when the locking bolts h
occupy the spaces q and r they lock the signal bar against longitudinal movement.
The signal bar is attached to a signal wire t, und an operating wire & which runs
to the tower house lever, either direct or around a pulley and as shown by dotted
lines at which is the case when-the rod 60 is used.

page_text: Having now described the construction of my apparatus I will describe its
operation: In Fig. 1 the switch is set to maintain the main line and is locked in
that position by the presence of the keys 38 and 39 in the slots 35 of the
pitmen 22 and 23. The locking bolts are also now engaged by the keys o, p,
occupying their notches 1. Thus the switch lock is locked, (1) by the keys 38
and 39 engaging with the pitmen 22 and 23, and (2) by the keys o and p
engaging with the locking bolt h. Should therefore the locking bar 31 be moved
lengthwise until the spaces 40 and 41 come opposite the pitmen 22 and 23 with
the intention of changing the switch to run the train off on a siding or junction,
which might be done by a mistake or other carelessness or forgetfulness, the
switch could not be so changed because the locking boits would still be locked
by the signal bar f. Hence while the signal still indicates that the right of way
for the main line is open, the switch cannot be changed to carry the train to a
siding or junction. The signal must first be operated to the position to indicate
that the switch adjusted to turn the train to one side on the siding or junction,
before it is possible to so adjust the switch rails. On the other hand, it is clear
that a tower operator has it in his power to operate the signal bar and signal
without regard to a previous change of the switch rails. This signal bar is free
to reciprocate in the blocks c with its keys passing through the notches 1 while
the switch locking mechanism remains locked.
Now let it be supposed that it is desired to run a train off on the side track or
junction. The tower operator first changes his signal to a position to indicate that.
In doing this he permits the signal barf to move in the direction of the dotted
arrow by the gravitating action of the semaphore arm drawing on the signal wire t.
This will move the signal bar f until the spaces q, r, are opposite the locking
bolts. Then these bolts are free to be moved by the pitmen 22 and 23. Now
the operator turns his attention to the lever that operates the rod 53, and pushing
the locking bar 31 in the direction of the dotted arrow, he brings the spaces 40
and 41 opposite to these pitmen, and during this movement presses one of the
shoulders 50 against the roller 49 and thereby shifts the T-lever and draws upon
the pitman 22 and hence changes the switch rails to the new position. In doing
this the pitmen 22 and 23, with the locking bolt h slide outward in their respective
blocks. This movement brings the notches 36 of the pitmen and the notches M of
the locking bolts in line with the keys on the locking bar and signal bar respectively.
Then a slightly further movement of the locking bar 31 will bring the keys 37
and 38 respectively into the notches 36 and lock the pitmen. The gravitating
movement of the signal just referred to having been somewhat further than
necessary for the position to be assumed, the operator now draws the signal
bar back a little, bringing the signal to the true resting point and placing the
keys o and across the notches m in the locking bolts h. Thus as in the first
case, the switch is doubly locked, being locked by the locking-bar and by the
switch bar in connection with their respective adjuncts. Therefore any future
adjustment or shifting of the switch rails must be preceded by first adjusting the
signal and the signal bar f. Hence in either position of the switch rails they are
5 doubly locked.
In adjusting the switch rails to the position last described it will, of course, be
understood that the detector bar 54 was shifted on its hinges 55, as usual with
such bare.
This
It will also be observed that the T-lever on the stud 42 has an arm 44.
0 arm is normally disengaged but is provided for the purpose of attaching the
pitman 22 at that side of the lever by transferring it to the place of the pitman 23
and putting the latter in the place of the pitman 22. This shifting is done to
accommodate the device to switch rails whose ends terminate in the opposite
direction from those shown. Thus the pitman 23 is never attached to the T-lever
5 and its function, together with the locking bolt h attached to it is that of providing
an additional locking means in case pitman 22 and the locking bolt h attached to it
should become broken. Also under these conditions the operator would be unable

page_text: to move the switch, as the T-lever would simply play idly back and forth in the
.locking bar 21 without moving the pitman 23, even though the signal bar f had
been adjusted to permit the locking bolt h attached to the pitman 23 to move.
This safeguard is valuable in practice as also this transferring of the pitmen
according to the direction in which the switch rails point.
It is important that an apparatus of this kind be so constructed that it cannot
be readily taken apart, or portions removed, and the switch unlocked. This is
particularly so in times of strikes. It will be observed that with my switch lock it
can not be taken to pieces while the bars 31 and f are locked by the tower lever.
To atttempt this in the first place the fastening devices over the plates 32 would
have to be removed; then the fastening device on the stud 42, but even then the
T-lever could not be raised out of place because the arm 43 fits snugly under the
bracket 26 and is held by a bolt. Then if it is attempted to vibrate the arm this
bolt will prevent it through the pitman 22 and the keys on the bar 31 and bar f
and bolt . Then if the pivot bolt be removed from the bracket 26 the T-lever
still cannot be vibrated far enough. to get the arm 43 from under the bracket 26
because the roller 48 will bind on the locking bar 31, and until the arm 43 is
withdrawn from under the bracket 26 the T-lever cannot be raised high enough to
raise the locking bar up high enough to clear the keys above the pitmen. Thus
the device is practically inseparable to the extent of unlocking the switch while the
locking bars 31 and the signal bar fare held by the tower lever and intermediate
connections.
In some cases the switch rails 14 and 15 lead off to what is called a derailing
branch or switch from which a train can be run off on to the ground. In using my
apparatus in connection with such switch rails the notches m in the locking bolt h
are omitted for the purpose of preventing any change of position of the signal
after the rails are adjusted. For instance, the signal bar is permitted to move
in the direction of the arrow and unlock the locking bolts h. The spaces q, r now
stand across the said bolts. Then the switch lock is operated as above described
and these bolts h move until their potch passes beyond the bar f, and the solid
part of the bolt stands in the spaces and 1. Thus the signal bar, with its
signal, is locked in the position the signal should be in when the switch is turned to
derail.
l
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :
1st. In an interlocking switch apparatus, the combination with notched pitmen
and connected notched locking bolts, of a keyed locking bar and a keyed signal
bar adapted, respectively to intersect the pitmen and locking bolts to lock said
pitmen and said bolts, and also adapted to reciprocate to unlock the same, and a
lever connected to one of the said pitmen and operated by the locking bar.
2nd. In an interlocking switch apparatus, the combination with a notched pitman
and a connected notched locking bolt, of a keyed locking bar and a keyed signal
bar, adapted respectively to intersect said pitman and bolt to unlock the same and
also adapted to reciprocate and unlock them, and a lever connected to said pitman
and operated by the locking bar.
3rd. In an interlocking switch apparatus, the combination with a double notched
pitman and a double notched connecting bolt, of a keyed locking bar, and a keyed
signal bar, adapted respectively to intersect with and lock said pitman and bolt and
to reciprocate to unlock the same, and a lever connected to the pitman and operated
by the locking bar, a movement of the latter being adapted to move said pitman
and bolt a distance equal to that between the two notches in each.
4th. In an interlocking switch apparatus, the combination with a base plate having
a block slotted in two directions, a notched pitman fitted to one slot and a keyed
locking bar fitted to the other, a lever pivoted on the said plate connected to said
pitman, and operated by said bar, of another plate, a block thereon slotted in two

page_text: directions, a notched locking bolt fitted to one of the slots and connected to said
pitman, and a keyed signal bar fitted to the other slot, the said bars intersecting
and locking the pitman and bolt and adapted to reciprocate to unlock the pitman
and bolt respectively.
5th. In an interlocking switch apparatus, the combination with a plate having
blocks each slotted in two directions, a notched pitman in each block in one of the
slots, a keyed locking bar in the blocks and fitted to the other slots, a lever pivoted
to the plate and to one of the pitmen, and operated by the locking bar, of another
plate with blocks each having two slots, notched locking bolts connected to said
pitmen and one in a slot of each block, and a keyed signal bar in the other slots of
the block; said bars acting to lock said bolts and pitmen respectively and arranged
so that by adjusting the signal bar the bolts are unlocked and then by adjusting
the locking bar the pitmen are unlocked and the lever is vibrated to move one of
the pitmen.
6th. In an interlocking switch apparatus, the combination with two switch rails,
two double notched pitmen connected thereto and a double notched locking bolt
connected to each pitman, of a keyed locking bar adapted to reciprocate to lock.
and unlock the pitmen, a lever pivoted to the plate and connected to one pitman
and operated by said locking bar, and a keyed signal bar adapted to reciprocate to
lock and unlock the locking bolt, the arrangement being such that the unlocking
of said bolts must precede the movement of the pitmen and bolts by said lever and
locking bar.
7th. In an interlocking switch apparatus, the combination with a plate having
blocks slotted in different directions, a double notched pitman fitted to each block
in one of its slots, a keyed locking bar fitted to the other slot of each block and
arranged so that when its keys are in the notches the pitmen are locked and when
the pitmen are in spaces between its keys said bar is unlocked, and the lever
carried by the plate connected to one pitman and operated by the said bar.
8th. In an interlocking switch apparatus, the combination with a plate having
a block with slots in two directions, a notched pitman fitted in one of said slots,
and a keyed locking bar in the other, a lever pivoted to the plate and to the pitmen,
rollers carried by the lever and forming shoulders, and shoulders on said bar to
operate against said rollers to vibrate the lever, the arrangement being such that
when the keys are in the notches the pitman is unlocked, and when the pitman is
in the between the keys said bar is unlocked.
pace
9th. In an interlocking switch apparatus, the combination with a plate having
blocks each with two slots, a notched pitman in one slot of each block, the pitman
being transferable from one block to the other, a T-lever carried by the plate and
adapted to connect with one pitman when in either block, and a keyed locking
bar fitted to the other slots in the blocks and arranged to operate said lever.
10th. In an interlocking switch apparatus, the combination with a plate having
blocks with slots in different directions, and caps, notched pitmen fitted to a slot in
each block, one pitman having a bracket, a T-lever pivoted to the plate and fitted
under said bracket and pivoted to said pitman, and having a slot in its operating
arm, a keyed locking bar fitted to the other slots in the blocks and passing through
the slot in the lever, one arm of the lever also extending over the other pitman,
whereby when the bar is locked the parts are inseparable or nondetachable and
the pitmen rendered unlockable while the bar remains locked.
Dated this 25th day of Santember 1805
JOHN DIEFENBACH,
By Herbert Haddan & Co.,
18 Buckingham Street, Strand, London, W.C., Agents to Applicant.