An Improved Facing Point Detector.
Year: 1894

page_text: Date of Application, 13th Mar., 1894
Complete Specification Left, 31st July, 1894-Accepted, 6th Oct., 1894
PROVISIONAL SPECIFICATION.
An Improved Facing Point Detector.
We, THOMAS SHEVELS, of Sleethurn, Durham, Engineer and ROBERT SIMMON
of Esh Winning, Durham, Railway Signalman, do hereby declare the nature of this
invention to be as follows:-
Our invention relates to an improved facing point detector, for use on railways,
and has for its object to ascertain and ensure, that facing points move with and
obey the lever in the signal cabin, thus ensuring that any train or vehicle proceeds in
the direction and on the line intended for it to run upon.
In carrying our invention into practice, we provide a metal box of suitable size
and shape, placed in a suitable position, in proximity to the said facing points.
Through this box we carry a slide or plunger with a catch. This slide or plunger
is worked by rods and cranks from the signal cabin, and is worked by the same lever
that works the wedges and safety bar if such are used. The slide or plunger on a
movement of the lever in signal cabin brings the catch under and engages with a
metal pawl in the box, the said pawl working on a pivot, and the lever is held fast,
and cannot be moved, until the facing points have been moved, the said movement
by means of a crossbar, connecting the points, acting on the pawl, depressing one
end and elevating the other end out of the catch, the end that is depressed being
held by two clutches of suitable shape, in the front end of the box, and which act
by gravity, till the slide or plunger is returned. The act of returning the plunger
opens the before-mentioned clutches, and allows the pawl to fall by gravity into its
normal position.
Dated this 19th day of Marab 1904
THOMAS SHEVELS,
ROBERT SIMMON.
COMPLETE SPECIFICATION.
An Improved Facing Point Detector.
THOMAS SHEVELS of Sleetburn, Durham, Engineer, and ROBERT SIMMON of
Esh Winning, Durham, Railway Signalman, 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 relates to an improved facing point detector for use on railways,
and has for its object to ascertain and ensure that facing points move with and obey
the lever in the signal cabin, thus ensuring that any train or vehicle proceeds in the
direction and on the line intended for it to run upon.
In carrying our invention into practice we provide a metal box of suitable size
and shape placed in a suitable position in proximity to the said facing points.
Through this box we carry a slide or plunger which is actuated by the saine lever
in the signal cabin that operates the ordinary wedges and safety or locking bar, (or
by other lever) rods and cranks, and which has on its upper side a raised catch which
is capable of being drawn under and engaging with a pawl of suitable size and shape,
when the slide or plunger is withdrawn and the points are unlocked for the purpose
of movement. The said pawl is worked on a pivot and drops behind the catch by
gravity and prevents the slide from being returned till the points have been moved,
until by reason of the connecting crossbar or stretcher bar, the pawl is depressed
into the clutches, at its smaller end, and the said clutches keep that end depressed
and the other end elevated till the slide or plunger with catch is returned, and this
Price 8d7

page_text: slide being slightly wedge-shaped, in returning between the lower part of the
clutches opens them and so allows the pawl to go back to its normal position
by gravity.
Whilst describing the action of the crossbar or stretcher bar on the pawl we do
not limit ourselves to one solid bar, but may carry it through the box in duplicate,
in which case we would lock the points and depress the pawl by separate portions of
the duplicate bar.
In the accompanying drawings Fig. 1 is a side sectional view of our improved
facing point detector through the line 1 and 2 (Fig. 2). Fig. 2 is a plan. Fig. 3
is an end view through the line 3 and 4 (Fig. 1), and Fig. 4 is an end view through
the line 5 and 6 (Fig. 1).
Like letters of reference are used for corresponding parts throughout the
figures.
Through the box A we carry a slide or plunger B and B has a top slide or locking
bar B', a catch H and a slightly wedge-shaped part G all being made in one piece.
We also provide a pawl E which by reason of its shape is capable of being depressed
into and held by clutches such as F F (Fig. 4). This pawl works on a pivot J
and the clutches work on pivots J¹. The crossbar or stretcher bar D, D is con-
nected to the points in any suitable manner, but D' is only connected to one tongue
of the points, and that tongue being at the off or further side from the connection
with the signal cabin, and as this section of the bar carries the wheel I or other
means of depressing the pawl out of the catch H, any breakage or failure of the
points or disconnection by which one tongue might still be working and the other
cut off would be detected, as the pawl in such case could not be depressed and
consequently the slide or plunger could not be returned.
The crossbar D, D¹ in its part D has a projecting part or locking bar C which
has exactly the same travel as the points, and acts as a lock when the points are in
either of their proper positions by reason of the locking bar B¹ when in its normal
position holding it between the side of the box and the said locking bar B¹. Also
when B is withdrawn into the position shown in Fig. 1 to allow the points to be
moved, any failure of the points to properly close would prevent the return of the
locking bar B¹ by reason of the locking bar C not having travelled fully over and
clear of B!.
Thus to operate or move the points the slide or plunger must be withdrawn into
the position shown in Fig. 1 and it cannot be returned again till the points have not
only moved but have properly closed, and when it is so returned the locking bars
hold and secure the points in proper position.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is :-
―:
1. An improved facing point detector as heretofore described, to indicate fully to
the man in charge any failure to properly act by reason of breakage or otherwise
of the said facing points or their connections.
2. A pawl which is capable of being depressed into and held by clutches.
3. Clutches of such shape and form as will hold and secure the pawl.
4. A wedge-shaped slide or plunger.
5. The method of locking bars inside the box or case.
6. The whole combination and arrangement of parts for the aforesaid purpose as
illustrated in Figs. 1, 2, 3 and 4 of the accompanying drawings.
Dated this 20th day of s
THOMAS SHEVELS.
ROBERT SIMMON.