Improvements in and connected with Safety Bars for Railway Signals and Switches.
Year: 1889

page_text: Date of Application, 31st Oct., 1889
Complete Specification Left, 28th July, 1890-Accepted, 6th Sept.. 1890
PROVISIONAL SPECIFICATION.
Improvements in and connected with Safety Bars for Railway
Signals and Switches.
We, JOHN PATRICK O'DONNELL of 2 Great George Street, Westminster, in the
County of Middlesex, Civil Engineer, and WILLIAM SMITH of 8 Geneva Road, Brixton
in the County of Surrey Engineer, and ILLIUS AUGUSTUS TIMMIS, 2 Great George
Street, Westminster in the County of Middlesex Civil Engineer do hereby declare
the nature of this invention to be as follows:-
It is the usual practice to actuate safety bars whether those fixed at the facing
points in conjunction with the plungers or those used as rear bars, fouling bars, or
again those used as treadles for electrical train signalling or interlocking; by means
of rockers or half cranks, fixed in brackets which clip the rail from the underside. It
is well known that, as these bars work an angle of 90° i.e. from a 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. With our invention we provide at suitable
spaces along the bar (the bar may be of any of the usual sections) blocks which have
a level V projection on the underside. Arranged on a special safety bar chair which
wo prefer, are corresponding bevel A 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.
The action consists, that normally the right hand bevel of the block fixed to the bar
rests upon the left hand bevel of the block on the special chair, and as the bar is
actuated, it simply slides upwards on the left hand bevel of the block in the special
chair, until it reaches the top of the latter bevel, when it falls, sliding downwards, on
the right hand bevel of the special chair block.
The return motion is similar, the left hand bevels of the blocks fixed to the bar
sliding upwards till the top of the bevels in the special chairs are reached, when the
bar falls to the normal position, the right hand bevels in the bar blocks sliding down-
wards on the left hand bevel of the special chair blocks.
Instead of arranging and using special safety bar chairs, we can fix brackets, which
clip the rail, pass underneath it, and rise again the other side, with bevel blocks for the
bar blocks to slide upon. To prevent the bar rising too high, or to prevent it from
being maliciously taken bodily away, we fix a bracket to the bar, projecting under-
neath the rail, the distance normally between the top part of the stop on the bracket
and the underside of the rail being equal to the correct rise of the bar in working.
1
1
1000
JOHN P. O'DONNELL,
2, Great George Street, Westminster, S.W., Agent for the said Applicants.
COMPLETE SPECIFICATION.
Improvements in and connected with Safety Bars for Railway
Signals and Switches.
We, JOHN PATRICK O'DONNELL of 2 Great George Street, Westminster in the
County of Middlesex Civil Engineer, WILLIAM SMITH of 8 Geneva Road Brixton in
the County of Surrey, Engineer, and ILLIUS AUGUSTUS TIMMIS of 2 Great George
Street Westminster in the County of Middlesex, Civil 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 in actuating safety bars whether those fixed at the facing
points in connection with the plungers or those used as rear bars, fouling bars or
دتة

page_text: again those used as treadles for electric train signalling or interlocking, by means of
rockers or half cranks fixed in brackets which clip the rail from the under side. It is
well known that as these bars work through an angle of approximately 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. With our
invention we provide at suitable spots along the bar (the bar may be of any of the.
usual sections) blocks which have a bevel-V projection on the under side. Arranged
on a special safety bar chair which we prefer are corresponding bevel V blocks upon
the bevels of which the blocks fixed to the bar work. The actuating connection may be
fixed at any convenient portion of the bar. The movement from the normal position may
be from left to right or right to left according as is desirable. In the drawing Figure 3
the movement is represented as from right to left so that the left hand bevel block
fixed to the bar rests upon the right hand bevel of the block on the special chair and
as the bar is actuated it simply slides upward on the right hand bevel of the block on
the special chair until it reaches the top of the latter when it falls sliding downwards
on the left hand bevel of the special chair block. The return motion is similar, the
right hand bevel of the block on the bar slides upwards on the left hand bevel of the
special chair block until the bar block reaches the top of the special chair block when
it fall downwards to the right. 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 bevel blocks for the bar blocks to slide upon. To prevent the bar rising
too high or to prevent it being maliciously taken bodily away, we fix a stop to the
bar projecting underneath the rail.
We will now describe our invention reference being made for that purpose to the
accompanying drawings. The same letters refer to the same parts in the several
figures in the drawings.
Figure 1, is a side elevation partly in section, of the bar the connections for
working it and the blocks. 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 the block
on the bar. In reference to this view although the two bevels on the block B
and c on the chair block C are shown touching yet in actual practice they would be
apart a distance varying from 1th to th of an inch. 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 in lieu of the chair the bar and
rail being in section. Figure 8 illustrates another form of chair which we propose to
fix alternately with the special block chair. If desirable the special block chairs may
be fixed at each end of the bar and every second chair in the middle (between the
outside chairs) might be of the alternate design as in Figure 8 and used simply as a
rest for the bar when normal and to prevent any buckling in the event of pressure
taking place between the two block chairs. Figure 9 is an underneath view of part of
the bar showing the block and the stop and the connecting piece for working the bar.
Figure 10 is a side view of Figure 9. Figure 11 is a side view of the stop M 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, F is 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 is the left
hand. bevel of the block, 62 is the right bevel of the block, c is the right hand bevel of
the chair block C, c is the left hand bevel of the chair block C, C³ is the special safety
bar chair, C is the cast bracket (if desirable this bracket may be made of wrought
iron) upon which the bar is actuated. is the straight edge of the alternate
chair Cupon which the bar A rests when normal or when 'worked. L is the stud
plate to which the rod D is attached, MI is the stop attached to the bar. It is obvious
that the bevels either on the bar or on the chair or both may be hollow in the centre
or otherwise arranged to ease them in working, it may also be considered desirable to
alter the arrangement of fixing the rail to the special chair, and the shape, of the fisù

page_text: plate forming the other surface and the special chair on which the bar works may
also be arranged to suit special circumstances. It would doubtless be found to ease
the working of the bar if the bevels were rounded at their ends.
We wish it to be understood that we are aware that various forms of working
facing point lock bar have been hitherto used and we are also aware that a chain bar
with 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.
Haying now particularly described and ascertained the nature of our said
invention 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 bevels or bevel
blocks attached to the bar for the purpose of working on corresponding bevels
formed on the chair or in brackets, the whole operating substantially as described in
reference to Figures 1 to 11 inclusive of the drawing annexed.
Dated this 28th day of Lu1 1900
JOHN P. O'DONNELL,
'Agent for the said Applicants.