Improvements in Operating Safety or Lock Bars for Railway Points.
Year: 1899

page_text: Improvements in Operating Safety or Lock Bars for Railway Points.
I, WILLIAM BUCK, of Carisbrooke, Battenhall, Worcester, Engineer, do hereby
declare the nature of this invention to be as follows:-
My invention relates to safety or lock bars for facing points on railways and
consists of apparatus for lessening the amount of work and strain hitherto involved
in the movement of a lock bar by leaving it at rest when its movement is unneces-
sary and by lessening the strain and exertion of the operation when its movement
is unavoidable. It is absolutely necessary to work the bar whenever the points
are being unbolted, but its movement may be dispensed with in many cases when
the points are being bolted. To effect this abatement I connect the rod for
working the bar to a set of knee joints or toggles one link of which has a fixed
pivot the other acts upon one arm of an ordinary crank whose other arm is con-
nected by a rod or pusher to a T crank. The long straight member of this
Tcrank is slotted from end to end, the short arm being connected in the ordinary
manner to the lock bar. The rod or pusher works the T crank by means of a pin
or stud fitting the slot. The rod for working the bar and plunger acting upon
the toggle links when they are standing in a straight line and at right angles to
the thrust lifts the bar with comparative ease.
.
One limb of the toggle is formed by an arm of a crank for working the plunger.
When the toggle links are pushed or pulled out of line the cranks are moved
and the rod to the T crank pushing at right angles in the slotted arm moves the
T crank and works the lock bar, the plunger being withdrawn at the same time.
The return stroke bolts the points but draws the pusher and its stud to the other
end of the inclined slot of the T crank without moving the lock bar. To ensure
the stud passing to the extreme end of the slot I generally employ a spring or
weight to press the pusher sideways in either direction.
In the event of the lock bar failing I stop the movement of the rod from the
cabin by means of a catch or trip lock pivotted to the same in such a position
that it cannot pass under a stop fixed to the lock bar unless the bar is properly
lifted.
In cases where it is necessary or desirable to work the bar whenever the plunger
is moved, either for bolting or unbolting the points the following modification
is necessary. The slotted T crank and other parts required for the intermittent
working of the bar are dispensed with and an ordinary straight lever used instead,
each end of which is connected to a set of toggles similar to those herein before
described with or without the crank arm. This lever takes the place of the
ordinary T crank being connected at one end to the plunger and at the other end
to the lock bar. According to the position of the said lever one of the toggles
has its links in a straight line while the other set is bent or forms an angle. The
middle joints of the toggles are coupled together by a link the centre of which is
jointed to the working rod.
One of the toggle arms in each set is slotted to allow for their differential action.
The working lever and rod acting on the toggles when they are straight require

page_text: but little effort at the commencement of the stroke to lift the bar gradually but
the movement is accelerated by the inclination of the toggle links towards the
end of the stroke when the bar is being lowered.
I, WILLIAM Buck, of Carisbrooke, Battenhall, Worcester, Engineer, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following state-
ment:-
My invention consists of apparatus for working an ordinary facing point locking
bolt and lock bar in such a manner that the movement of the bar can be dispensed
with when the points are being bolted, and its working facilitated when its move-
ment is required.
In the accompanying drawings, Fig. 1 shows the arrangement for working a
lock bar when the points are being unbolted, its movement being dispensed with
when the points are being bolted. Figs. 2, 3 and 5 are other views of the same
apparatus with corresponding letters for reference.
My invention is applicable to lock bars of all kinds, whether-mounted on rockers,
rollers or inclines.
The
In Fig. 1a is the rod for working the lock bar 6 and plunger c for bolting the
points. d and d form a set of knee joints or toggles, the end of the link d being
prolonged in a curve to counteract the radial movement of dupon its pivot
thereby causing the rod a to move in an approximately straight line. The link d
has an arme which works the plunger c for bolting the points. The link dis
connected by the crank f to a rod or pusher g which pushing at right angles works
the crank from i to j by means of a pin or stud fitting the slotted arm.
other arm of the T crank is connected to the lock bar b in the usual manner.
The well known action of the toggle joints d d when pulled out of a straight
line by the rod a renders the lifting of the bar an easy matter. When the
joints d d are pulled by the rod a into the position shown by the dotted lines in
Fig. 1 the cranks and lock bar are moved and the plunger withdrawn. The return
stroke of the rod a bolts the points but does not move the bar b because the stud
or pin of the rod g is drawn down the then inclined slot of the T crank from j to k
without moving the T crank. is a stop.
The pusher when at k is at right angles to the slot and the following stroke
moves the crank from k to 1 and works the bar b. The return stroke draws the
stud down the slot from 7 to i without moving the T crank.
To insure the stud of the pusher passing to the end of the slot I cause a spring m
to act upon the pusher when the crank f draws the stud to either end of the slot
at i ork. The spring m is pivotted at one end on a fixed stud n and is connected
in the middle by a slotted link o to the crank arm that moves the pusher. The
other end of the spring m is connected by an inclined link p to the pusher. The
spring is normally set or curved as shown by dotted lines at m¹ and is brought
into action by the link o. Its deflection gives a thrust on the link p thereby
causing the stud of the pusher to travel to the end of the slot at i or k.
An alternative arrangement of spring is shown in Fig. 4 having an adjustable
coil spring which presses the lever w upon a roller on the pusher g.
To prevent the stud from being drawn back along the slot before the com-

page_text: pletion of the stroke suitable projections or guards are formed on the bed plate
at r and s which keep the stud close to either end of the slot during the stroke.
In the event of the lock bar b failing to work, the movement of the rod a is
stopped by the catch or trip lock shown at t in Fig. 5. This lock is pivotted to
the rod a in such a position that it cannot pass under the stop u fixed to the lock
bar unless the bar is properly lifted. On the return stroke, when the bar is not
lifted, the lock can pass because its inclined end is pressed down by the stop u.
It is raised again when clear by the weight of its tail .
The toggle gear may be dispensed with and the lock bar and plunger worked
by the cranks and connections shown by dotted lines at y y in Fig. 1, the working
rod being attached at z, but the lock bar would not be lifted as easily as by the
toggle arrangement.
Figs. 6, 7 and 8 show a modification of the toggle or knee joint gear, by which
the lock bar is worked whenever the plunger is moved either for bolting or un-
bolting the points. In Fig. 6, a is the rod for working the lock bar 6 and
plunger for bolting the points. is a lever which takes the place of the ordinary
Tcrank, being connected at one end to the plunger and at the other end to the
lock bar. At equal distances from the fulcrum of this lever are connected the
toggles e eland eel with fixed pivots at g g¹. At the commencement of the stroke
of the rod a in either direction, one pair of the toggle links is in a straight line
as shown at e el, while the other pair is bent or forms an angle as at c c¹. The
toggles are coupled together by the bar f, to the centre of which is jointed the
working rod a. One of the toggle links in each set is slotted to allow for their
differential action. The parts f and e are double as shown in Fig. 8. Stops are
formed upon the bed plate at h h to prevent the toggle links being drawn or pushed
beyond a straight line. The link ey have an arm as shown by dotted lines
at for working the plunger, if such an arrangement is more convenient.
The toggle gear may be placed outside the rails as shown in Fig. 9, and con-
nected to existing cranks and rods & that work an inside bar and plunger, or may
work an outside bar as shown by the dotted lines at 7, also in Fig. 9. Either of
the arrangements shown in Figs. 1 or 6 may be used for facilitating the working
of a bar only, such as a platform or clearance bar, without a bolt or plunger.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, declare that what
I claim is:-
1. In combination with a bolt or plunger for railway points, the apparatus for
facilitating the movement of a safety or lock bar that is worked when the points
are being unbolted by the operating lever, and for leaving it unmoved when the
points are being bolted, substantially as described and shown in Fig. 1.
2. In combination with a bolt or plunger for railway points, the apparatus for
facilitating the movement of a safety or lock bar that is worked when the points
are being bolted as well as when they are being unbolted, substantially as described
and shown in Fig. 6.
3. The apparatus included in Claims 1 and 2 for working a similar bar, but
without a bolt or plunger.
4. The slotted Tee crank shown in Fig. 1 for working a lock bar in the manner
described, with or without the toggle gear.