IMPROVEMENTS IN INTER- CATO " PROVISIONAL
Year: 1874

page_text: LETTERS PATENT to John Saxby, of Canterbury Road, Kilburn, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN INTER-
CATO "
PROVISIONAL SPECIFICATION left by the said John Saxby at the Office
of the Commissioners of Patents, with his Petition, on the 23rd
January 1874.
I, JOHN SAXBY, of Canterbury Road, Kilburn, in the County of
Middlesex, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN INTERLOCKING APPARATUS FOR RAILWAY POINTS AND SIGNALS,"
to be as follows:-
My Invention relates to improvements in the construction and
arrangement of apparatus whereby when any one lever of a system of
levers employed for working the points and signals of railways is moved
or about to be moved some other levers of the system are prevented

page_text: from being moved, and when the said lever has been fully moved over
some other levers of the system are released so that they may be moved.
For this purpose I mount in front of each lever of the system which has
to be interlocked a vertical rocking shaft which I connect to the lever or
to its spring catch in such manner that when the said lever is moved or
when its spring catch is raised to permit it to be moved the rocking
shaft is caused to turn partly round on its axis, and when the lever is
pulled over or when its spring catch is let down to hold it in the position
to which it has been pulled, the said rocking shaft is turned farther
round. From each such rocking shaft projects an arm which engages
with a horizontal bar mounted so as to slide longitudinally along the
row of levers in face of the successive vertical rocking shafts thereof, so
that when the rocking shaft is partly turned the bar thus connected to
it is caused to slide. These sliding bars have projections or hollows in
their edges, and the vertical rocking shafts have hollows in their cir-
cumference, and these projections or hollows of the sliding bars are
arranged in such relation to the hollows of the several rocking shafts as
to effect the required interlocking in the following manner:-When the
vertical rocking shaft of any lever has no projection of any of the sliding
bars engaged in the hollow of its circumference, and when its own
sliding bar is free to move that rocking shaft is free to turn, and the
lever connected to it may be moved, or the spring catch of that lever
may be raised with a view to the movement of that lever. When the
movement of the lever is begun, or when its spring catch is raised
before beginning the movement of the lever, the vertical shaft being
thereby turned partly round withdraws the hollow of its circumference
from facing projections on some of the sliding bars and so presents an
obstacle to the movement of those bars. As those bars are respectively
connected, as above described, to the rocking shafts belonging to
other levers of the system, the levers so connected to them are thus
locked. When the movement of the lever is completed, or when its
spring catch is let down, its rocking shaft being farther turned still
presents the obstruction to the bars already obstructed by it, and so
maintains the locked condition of the levers connected to those bars, but
by its farther revolution presenting hollows in its circumference to the
projections of others of the sliding bars permits them to be moved, and
so releases the levers with which they are respectively connected.
Moreover when by the movement of any lever or of its spring catch a

page_text: projection on the bar connected therewith is brought into the hollow of
any of the vertical rocking shafts, those shafts being thereby prevented
from turning, the levers to which they are respectively connected are
thereby locked.
Any of the rocking shafts may be made to work several sliding bars,
and the projections and hollows on the bars can be arranged so as to effect
the interlocking, as above described, according to the requirements of
the particular system of points and signals to which the apparatus is
applied.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Saxby in the Great Seal Patent Office on
the 22nd July 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
SAXBY, of Canterbury Road, Kilburn, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of January, in the
year of our Lord One thousand eight hundred and seventy-four, in
the thirty-seventh year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said John Saxby, Her special
license that I, the said John Saxby, my executors, administrators, and
assigns, or such others as I, the said John Saxby, my executors, admini-
strators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN INTER-
LOCKING APPARATUS FOR RAILWAY POINTS AND SIGNALS," upon the condition
(amongst others) that I, the said John Saxby, my executors or admini-
strators, by an instrument in writing, under my, or their, or one of their
hands and seals, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent,

page_text: NOW KNOW YE, that I, the said John Saxby, do hereby declare the
nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the accompanying
Drawings, and to the figures and letters marked thereon, that is to
nature or me sard шусинов, аnd
performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the accompanying
Drawings, and to the figures and letters marked thereon, that is to
Bay:
My Invention relates to improvements in the construction and
arrangement of apparatus whereby when any one lever of a system of
levers employed for working the points and signals of railways is moved
or about to be moved some other levers of the system are prevented from
being moved, and when the said lever has been fully moved over some
other levers of the system are released so that they may be moved.
For this purpose I mount in front of each lever of the system which has
to be interlocked a vertical rocking shaft which I connect to the lever or
to its spring catch in such manner that when the said lever is moved, or
when its spring catch is raised to permit it to be moved, the rocking
shaft is caused to turn partly round on its axis, and when the lever is
pulled over, or when its spring catch is let down to hold it in the
position to which it has been pulled, the said rocking shaft is turned
farther round. From each such rocking shaft projects an arm which
engages with a horizontal bar mounted so as to slide longitudinally
along the row of levers in face of the successive vertical rocking shafts
thereof, so that when the rocking shaft is partly turned the bar thus
connected to it is caused to slide. These sliding bars have projections
or hollows in their edges, and the vertical rocking shafts have hollows in
their circumference, and these projections or hollows of the sliding bars
are arranged in such relation to the hollows of the several rocking shafts
When
as to effect the required interlocking in the following manner:-
the vertical rocking shaft of any lever has no projection of any of the
sliding bars engaged in the hollow of its circumference, and when its
own sliding bar is free to move that rocking shaft is free to turn and
the lever connected to it may be moved, or the spring catch of that
lever may be raised with a view to the movement of that lever. When
the movement of the lever is begun, or when its spring catch is raised
before beginning the movement of the lever, the vertical shaft being
thereby turned partly round withdraws the hollow of its circumference
from facing projections on some of the sliding bars and so presents an

page_text: obstacle to the movement of those bars. As those bars are respectively
connected, as above described, the rocking shafts belonging to other
levers of the system, the levers so connected to them are thus locked.
When the movement of the lever is completed, or when its spring catch
is let down, its rocking shaft being farther turned still presents the
obstruction to the bars already obstructed by it, and so maintains the
locked condition of the levers connected to those bars, but by its farther
revolution presenting hollows in its circumference to the projections of
others of the sliding bars permits thom to be moved, and so releases the
levers with which they are respectively connected. Morcover when by
the movement of any lever or of its spring catch a projection on the bar
connected therewith is brought into the hollow of any of the vertical
rocking shafts, those shafts being thereby prevented from turning, the
levers to which they are respectively connected are thereby locked.
Any of the rocking shafts may be made to work several sliding bars,
and the projections and hollows on the bars can be arranged so as to
effect the interlocking, as above described, according to the require-
ments of the particular system of points and signals to which the
apparatus is applied.
DESCRIPTION OF THE DRAWINGS.
Fig 1, Sheet I., represents a transverse section of a frame of point and
signal levers shewing one of the hand levers A connected by an obliquely
slotted bar B, a plan of which is shewn by Fig. 1ª to the pin of a crank C
on a vertical rocking shaft D. The bar B has a slot with oblique
terminations, such that at the first part of the stroke of the lever A the
crank C and rocking shaft D are turned partly round, and at the last part
of the stroke it is turned farther round in the same direction.
Fig. 2, Sheet I., represents a like arrangement, the rocking shaft D.
being in this case mounted horizontally, and its crank C worked by a
vertical rod E, the pin of which travels in the slot of B. Some of the
rocking shafts D, of which there is one to each hand lever, work sliding
bars F having on them projections which either obstruct or are obstructed
by others of the rocking shafts, as will be more fully explained here-
after.
Instead of working these rocking shafts by the movement of the hand
levers A, as shown in Figs. 1 and 2, they are preferably worked from

page_text: the movement of the spring catches of the levers, so that on closing the
spring catch handle before moving any lever the necessary locking of
some of the other levers is effected, and the unlocking of others of the
levers is not effected till after the lever has been moved fully over and
its spring catch let go. For this purpose the movement of the rocking
shafts is effected by connecting them to the rockers which are worked
by the movement of the spring catches, as described in the Specifications
of Patents granted to me on the 17th June 1871, No. 1601, and the 23rd
June 1871, No. 1655.
Fig. 3, Sheet II., represents a transverse section; Fig. 4, an elevation ;
and Fig. 5, a plan of a system of four levers having their interlocking
effected by the movement of vertical rocking sliafts worked in this
manner; and Fig. 8, Sheet III., represents a transverse section; Fig. 9,
an elevation; and Fig. 10, a plan of a like system of four levers having
horizontal rocking shafts worked in a similar manner.
Figs. 6 and 7 shew to an enlarged scale sectional plans of the vertical
rocking shafts in two of their attitudes; and Figs. 11 and 12 in like
manner shew to an enlarged scale longitudinal sections through the
horizontal rocking shafts in two attitudes.
I will first describe the mode of communicating motion from the
spring catches to the rocking shafts, whether they be mounted vertically
or horizontally, referring to Figs. 3, 4, 5, 8, 9, and 10, in which the
same letters are employed to mark corresponding parts. The sliding
rod K of the spring catch of each of the hand levers A has at its lower
end a stud which works in the slot of the rocker G, so that when the
rod K is raised by grasping the handle of the spring catch the rocker G
is caused to oscillate vertically, the front end being raised. The lever A
being then pulled over the stud k travels along the slot in G, and when
the lever has attained the end of its stroke the spring catch rod K being
allowed to descend, its stud / descending gives a farther oscillation to
the rocker G in the same direction as before, that is to say causes its
front end to rise farther. To prevent the shifting of the rocker G while
the stud is passing along its slot over or near its fulcrum, I attach to
the rocker a vertical rod L which passes through a slot in a horizontal
bar M connected to and moving with the hand lever A. A plan of this a
slotted bar M is shewn at Fig. 13, the slot is narrow along the greater

page_text: part of its length but is widened out at the ends, and the rod L is made
with a thinned part presenting shoulders which can pass through the
wide parts of the slot in M, but cannot pass through the narrow part.
Thus when the front end of the rocker G is raised, as above described,
the upper shoulders of L are brought above the bar M through the
widened end of its slot, and the lever now being moved the narrow part
of the slot of M being thereby made to travel along the thinned part of L
so that there are shoulders above and below M the rod L cannot move
vertically, and consequently the rocker G is kept steady until the
terminal widened part of the slot in M is brought to face the rod L,
whereupon the lower shoulders can rise through the widened slot, per-
mitting the rocker to make its farther stroke on the descent of the catch
rod K. The rocker G is connected by a rod H to the crank C of the
rocking shaft D. In the case where the rocking shaft D is mounted
horizontally the connecting rod H¹ is jointed in two planes to allow for
the vertical and horizontal circular movements of the rocker G and
crank C respectively. The rocking shaft belonging to each lever being
thus partly turned round by the first part of the lever's movement when
it is worked from the lever, as in Figs. 1 and 2, or before the com-
mencement of the lever's movoment when it is worked from the rocker G,
as in Figs. 3, 4, 5, 8, 9, and 10, and being farther turned round in the
one case by the last part, or in the other case after the termination of
the lever's movement, the interlocking is effected by the agency of these
rocking shafts in a manner which will be understood in reference to
Figs. 6 and 7, and to Figs. 11 and 12. Two of the rocking shafts D³
and D' have arms d³ and d', which by means of studs entering gates on
sliding bars F³, F³, cause these bars to slide to and fro longitudinally
when the rocking shafts are turned on their axes. These bars have on
them projections f¹, f, fs, and the rocking shafts are made with hollowed
and flattened parts in their peripheries, in such manner that in some
cases the sliding bars are obstructed by the rocking shaft so that they
cannot slide, or that they obstruct the rocking shafts so that the latter
cannot turn. It will be seen for example that the bar F in Fig. 6 is
obstructed by its projections f¹ and f² bearing against the solid parts of
the shafts D and D³, and consequently the rocking shaft D' which
works the bar F cannot be turned, whereby the lever or spring catch
which should move D' is locked. Also the projection f³ on the rod F³
catching in a hollow of the shaft D³ prevents that shaft from turning

page_text: and consequently locks the lever or the spring catch which works D³.
When however by the movement of D³ which is free the projection f³ is
withdrawn from D³, as shewn in Fig. 7, and when D' and D³ are turned
partly round, as shewn in the same Figure, then the projections f¹,f³,
are free to be moved along the hollowed out parts of D¹ and D³, and if
they were so moved with the bar F by the partial turning of D' they
would in their turn obstruct the shafts D' and D³, and consequently lock
the levers or spring catches connected to thoso shafts. In like manner
on referring to Fig. 11, it will be seen that f¹, locks D¹, and that f*
and f³ are locked by Ds and D³ respectively; but that on D³ being
partly turned, as shewn in Fig. 12, on f¹ and f being moved with the
bar F3 by turning D³, and on f³ being moved with the bar F by partly
turning D', then D³ and D' become locked, and D¹ is free and may be
turned into the position indicated by the dotted lines, thus locking ƒ¹,
the bar F, and the shaft D³.
Although in the Figures I have shewn the interlocking of four levers
only, it is to be understood that by repetition of the sliding bars F with
stops or projections on them like those above described placed in suitable
positions any number of levers can be interlocked in a similar manner
according to the requirements of the system of points and signals which
those levers may have to work.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I hereby declare that I make no
claim generally to the interlocking of levers for working the points and
signals of railways, nor do I claim the utilisation of the movement of
the spring catches of the levers for effecting such interlocking, nor the
use of rockers whereby the movement of such spring catches is com-
municated to the locking gear, but I claim the use in the interlocking
gear of railway point and signal levers, of rocking shafts having hollows
or flattened parts in combination with sliding bars having projections,
each of the said rocking shafts being moved from one of the lovers or
from the rocker worked by the spring catch of one of the levers, and
each of the said sliding bars being moved by an arm on one of the said
rocking shafts, in such manner that the movement of a rocking shaft
shall cause it to present solid parts to obstruct, or hollow parts to leave
free the movement of one or more of the projections on the bars; and
the movement of a bar shall cause it to present projections to obstruct

page_text: or to remove projections so as to leave free the movement of onc or
more of the rocking shafts, substantially as herein described.
In witness whereof, I, the said John Saxby, have hereunto set
my hand and seal, this Twenty-first day of July, in the year of
our Lord One thousand eight hundred and seventy-four.