Improvements in Safety Bars for use in connection with Railway Signals and Switches.
Year: 1890

page_text: Date of Application, 24th Apr., 1890
Complete Specification Left, 23rd Jan., 1891-Accepted, 28th Feb., 1891
PROVISIONAL SPECIFICATION.
Improvements in Safety Bars for use in connection with Railway
Signals and Switches.
We, JOHN PATRICK O'DONNELL and ILLIUS AUGUSTUS TIMMIS, both of
2, Great George Street, Westminster, in the County of Middlesex, Civil Engineers,
and WILLIAM SMITH, of 8, Geneva Road, Brixton, in the County of Surrey,
Engineer, do hereby declare the nature of this invention to be follows:-
It is the usual practice to actuate safety bars (whether those fixed in conjunction
with the plunger or those used as rear bars or fouling bars or again those
used as treadles for electrical train signalling or interlocking) by means of
rockers or half cranks fixed in brackets clipped to the lower part of the rail.
It is well known that these bars work through an angle of 90 degrees that is
from the normal down position up to the top of the rail and then down to a corre-
sponding low position on the other side, and that it requires great power to work
them. With our invention we provide at suitable places along the bar (the bar
being made in the usual section) blocks which have fitted on their under side a
friction roller and on a safety bar chair which we prefer are bevel blocks or circular
blocks upon which the rollers fixed to the blocks on the bar work. The action is
as follows.
Normally the friction roller is approximately at the bottom of the bevel block or
circular block as the case may be on the chair and as the bar is actuated the roller
revolves on the block on the chair, the bar is moved upward and falls again on the
other side of the chair block.
The reverse action is similar to that previously described. Instead of arranging
and fixing special safety bar chairs we can fix brackets which clip the rail, pass
underneath and rise again the other side with suitable blocks for the bar blocks
and friction roller to work upon, to prevent the bar from rising too high or to
prevent it from being maliciously taken bodily away, we fix an L bracket of
metal to the bar projecting underneath the rail the distance normally between
the top of the bar and the stop on the bracket and the under side of the rail being
equal to the correct rise of the bar in working. It is obvious although not desirable
that instead of fixing the friction roller on to the blocks attached to the bar the
roller may be fixed in the block on the chair, in which latter case the blocks on the
bar would be bevel shaped.
Our invention may be made to work in accordance with the method set forth in
the Specification of O'Donnell & Timmis No. 12947 dated August 16th 1889, that
is to say, the bar would never go beyond the horizontal centre in working, but
would rise nearly to the top of the rail and fall again to the same position from
which it rose.
The friction roller hereinbefore described with reference to what we would call
the single action lock bar may also be applied in the case of the double action lock
bar where two blocks are fixed to the bar working from the normal position over a
block on the chair to the left and then back again which would complete one
motion of the bar to lock the points in one direction, and again where the bar
would move from the normal position to the right and back again which would
lock the points for the other position. The principle of this double action bar
is set forth in the Specification of O'Donnell, Smith & Timmis No. 18720 dated
22nd of November 1889.
Dated this 24th day of 1000
JOHN P. O'DONNELL,
Agent for the said Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in Safety Bars for use in connection with Railway
Signals and Switches.
We, JOHN PATRICK O'DONNELL, Civil Engineer, and ILLIUS AUGUSTUS
TIMMIS, Civil Engineer, both of 2, Great George Street, Westminster, in the
County of Middlesex, and WILLIAM SMITH, of 8, Geneva Road, Brixton, in the
County of Surrey, 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 :-
It is the usual practice to actuate safety bars whether those fixed at the facing
points in connection with the plungers or those used as rear bars, or fouling bars, or
again those used as treadles for electric train signalling or interlocking, by means
of rockers or half cranks. It is well known that as these bars work through an
angle of 90 degrees, that is from the normal down position up to the top of the
rail and then down to a corresponding low position, it requires great power to
operate them.
In the Specification of Letters Patent bearing date October 31st 1889,
numbered 17245, we describe and illustrate blocks which have a bevel projection
on the under side, attached to the bar.
Arranged on a special safety bar chair which we prefer are corresponding bevel
blocks upon the bevels of which the blocks fixed to the bar work. The actuating
connection may be fixed to any convenient portion of the bar.
Our present invention consists in providing where necessary, friction rollers at
the angles of the bevels to ease the travel of the bar.
We will now describe our invention reference being made for that purpose to
the accompanying drawing. The same letters refer to the same parts in the several
figures of the drawing :-
Figure 1 is a side elevation partly in section, of the bar, the connections for
working it and the blocks and rollers.
Figure 2 is a plan showing the facing points and the application of the bar.
Figure 3 illustrates a section of the chair block and bar block with the roller.
Figure 4 is an enlarged plan of the bar and the special chair.
Figure 5 illustrates a side view of the chair with the bar raised to its highest
position.
Figure 6 is a front view of the chair with the rail and bar in section.
Figure 7 is a view of the cast bracket for bull headed rails, in lieu of the chair,
the bar and rail being in section.
Figure 8 illustrates a form of bracket suitable for flat bottomed rails.
Figure 9 is an underneath view of the bar showing the block, roller, stop and
connecting piece for working the bar.
Figure 10 is a side view of Figure 9.
Figure 11 is a side view of the stop with the bar in section.
In all of these figures A is the bar, B the bevel block fixed to the bar, C is the
bevel block on the chair, D is the rod connecting the bar with the T crank.E, Fis
the rod connecting the other end of the T crank to the plunger K, G is the rod
from the signal box, through which the T crank is actuated, H is the stretcher
bar of the switch points which is locked by the plunger K, B' is the left hand bevel
of the block on the bar; B2 is the right hand bevel of the said block; B³ is the
friction roller; C is the right hand bevel of the chair block C; C2 is the left hand
bevel of the chair block C; C³ is the cast bracket suitable for flat bottomed rails;
C4 is the cast bracket suitable for bull headed rails (both of these brackets may be
made of wrought iron) upon which the bar is actuated L is the stud plate to
which the rod D is attached, M is the stop attached to the bar.
We wish it to be understood that we are aware that various forms of working facing
point lock bars have hitherto been used and we are also aware that a chain bar with

page_text: circular blocks or semi-circular blocks, has been used before. We wish it to be
understood that we desire to lay no claim to any of these arrangements.
Having now particularly described and ascertained the nature of our said inven-
tion, and the manner in which the same is to be performed, we declare that what we
claim is:-
For working safety bars in railway signalling apparatus, employing friction
rollers in bevel blocks attached to the bar, the said rollers working on a suitable
surface, such as bevel blocks on special chairs or bevel blocks in suitable brackets,
the whole operating substantially as described with reference to Figures 1 to 11 of
the drawing annexed.
Dated this 23rd day of
1801
JOHN P. O'DONNELL,
2, Great George Street, Westminster, London, S. W.,
Agent for the said Applicants.