Year: 1885

page_text: I EDWARD JOHN COWLING WELCH of Palace Chambers, Saint Stephens in the
City of Westminster Civil Engineer do hereby declare the nature of this invention
to be as follows:-
This invention relates to improvements in brakes such as are described in the
specification of a former Patent granted to me and another No. 16599 in the
year 1884 and in which the brakes are applied by a weight controlled by pneumatic
apparatus and operating upon the brake blocks through a powerful toggle combi.
nation of levers; and in which also automatic take up gear is provided to compensate
for the wear of the brake blocks and prevent derangement of the toggle thereby.
By my present invention I have much simplified the construction of such brakes
and have rendered them more generally applicable. In the arrangement which
I now employ there is a plunger or ram mounted in a vertical position beneath the
platform of the carriage, and there is a cylinder also serving as the operative
weight which is moveable up and down upon the said ram.
Two passages are provided through the interior of the ram, one to be used when
working by vacuum and to be coupled with a continuous pipe passing along the
train; and the other passage to be similarly used when the brakes are controlled
by means of compressed air. The lower end of the ram is provided with a piston
packed either with a cupped leather metallic rings or otherwise by which a
tight joint is made against the walls of the cylinder and another cup leather or
other packing is provided at the upper end of the cylinder and this forms a tight
joint against the sides of the ram. The vacuum connection is with the interior of
the cylinder through the bottom of the ram; when air is exhausted from the
cylinder the atmospheric pressure forces it upwards. The compressed air con-
nection on the other hand is with the space between the two cupped leathers or
other packings and the air forcing its way into this space raises the cylinder-the
ram is enclosed in an outer casing to protect it from dust; and the cylinder passes
freely within this casing through the lower end. The casing carries the bearings
for an horizontal axis on which are levers forming part of the hand gear by which
the weight cylinder can be lifted when required when the vacuum or pressure
mechanism is out of use.

page_text: At the lower end of the weight cylinder is the automatic take up gear com-
pensating for the wear of the brake blocks-it consists of a cylindrical sleeve
having right and left hand screw threads cut within it. This sleeve is capable of
sliding freely in an horizontal direction within a corresponding guide passage
formed at the lower end of the weight cylinder. The right and left screw threads
receive corresponding screw stems terminating at their outer ends in eyes to which
are jointed the toggle levers serving to apply the brake blocks to the wheels.
When the cylindrical sleeve is turned the eyes at the outer ends of the stems are
moved further apart. The sleeve is turned automatically at the proper times in
the following manner.
There are ratchet teeth upon the exterior of the sleeve and extending from end
to end of it; with these teeth a ratchet or pawl carried by a lever engages. This
lever is received into a recess in the guide passage of the weight cylinder and is
able to turn freely about the sleeve.
The outer end of the lever is connected by a link with a fixed centre upon the
casing. So long as the movement of the weight cylinder is confined within its
ordinary limits the pawl does not travel far enough around the ratchet sleeve to
engage with a fresh tooth, but when in consequence of wear of the brake blocks
the weight cylinder descends further than usual then the pawl takes a tooth in the
ratchet sleeve which is thus turned when the weight next ascends.
In this way the distance between the eyes of the coupling is increased and the
requisite compensation of the wear of the brake blocks is effected.

page_text: Improvements in Brakes for Railway and other Vehicles.
This Invention relates to improvements in brakes such as are described in the
Specification of a former Patent No. 16599 in the year 1884 and in which the
brakes are applied by a weight controlled by pneumatic apparatus and operating
upon the brake blocks through a powerful toggle combination of levers; and in
which also automatic take up gear is provided to compensate for the wear of the
brake blocks and prevent derangement of the toggle thereby.
By the present invention the construction of such brakes is much simplified and
they are rendered more generally applicable. In the arrangement which is now
employed there is a plunger or ram mounted in a vertical position beneath the
platform of the carriage, and there is a cylinder also serving as the operative
weight which is moveable up and down upon the said ram.
Two passages are provided through the interior of the ram, one to be used when
working by vacuum and to be coupled with a continuous pipe passing along the
train; and the other passage to be similarly used when the brakes are controlled.
by means of compressed air. The lower end of the ram is provided with a piston
packed either with a cupped leather metallic rings or otherwise by which a tight
joint is made against the walls of the cylinder and another cup leather or other
packing is provided at the upper end of the cylinder and this forms a tight joint
against the sides of the ram. The vacuum connection is with the interior of the
cylinder through the bottom of the ram; when air is exhausted from the cylinder
the atmospheric pressure forces it upwards. The compressed air connection on the
other hand is with the space between the two cupped leathers or other packings
and the air forcing its way into this space raises the cylinder-the ram is enclosed
in an outer casing to protect it from dust; and the cylinder passes freely within
this casing through the lower end. The casing carries the bearings for an hori-
zontal axis on which are levers forming part of the hand gear by which the weight
cylinder can be lifted when required when the vacuum or pressure mechanism is
out of use.
At the lower end of the weight cylinder is the automatic take up gear com-
pensating for the wear of the brake blocks-it consists of a cylindrical sleeve
having right and left hand screw threads cut within it. This sleeve is capable of
sliding freely in an horizontal direction within a corresponding guide passage
formed at the lower end of the weight cylinder. The right and left screw threads
receive corresponding screw stems terminating at their outer ends in eyes to which
are jointed the toggle levers serving to apply the brake blocks to the wheel.
When the cylindrical sleeve is turned the eyes at the outer ends of the stems are
moved further apart. The sleeve is turned automatically at the proper times in
the following manner.
There are ratchet teeth upon the exterior of the sleeve and extending from end
to end of it; with these teeth a ratchet or pawl carried by a lever engages. This
lever is received into a recess in the guide passage of the weight cylinder and is
able to turn freely about the sleeve.
Or in place of forming the teeth upon the sleeve they may be upon a ring
through which the sleeve can slide with groove and feather.

page_text: The outer end of the lever is connected by a link with a fixed centre upon the
casing. So long as the movement of the weight cylinder is confined within its
ordinary limits the pawl does not travel far enough around the ratchet sleeve to
engage with a fresh tooth, but when in consequence of wear of the brake blocks
the weight cylinder descends further than usual then the pawl takes a tooth in the
ratchet sleeve which is thus turned when the weight next ascends.
In this way the distance between the eyes of the coupling is increased and the
requisite compensation of the wear of the brake blocks is effected.
requisite compensation of the wear of the brake blocks is effected.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a side elevation of a railway vehicle provided with brakes in
accordance with the invention-The parts are here shown in the position they
occupy when the brakes are on.
Figure 2 is an end elevation of the vehicle.
Figure 3 is a plan of the same with the upper parts removed to expose the
brake mechanism.
Figure 4 is a side elevation of a portion of the vehicle, the parts being in the
position they occupy when the brakes are off.
Figure 5 is an end elevation of the pneumatic apparatus beneath the platform
of the vehicle.
Figure 6 is a vertical section on the line 1, 1, in Figure 5.
Figure 7 is an underside view of the same apparatus.
Figure 8 is a side elevation of part of the brake mechanism showing especially
the arrangement of the mechanism for taking off the brake when the pneumatic
apparatus is not at work.
A is the plunger or ram fixed in a vertical position beneath the platform of the
carriage and B is a massive iron cylinder capable of movement up and down upon
the ram.
The ram at its lower end is here shown provided with a cup packing A'
forming an air tight joint and preventing the entrance of air into the cylinder past the
end of the ram. B' is another cup leather packing making an air tight joint between
the upper end of the cylinder and the sides of the ram. C is a pipe passing through
the ram A and this when in use is connected with an apparatus by which air can
be exhausted or withdrawn from the interior of the cylinder B. When this is
done the pressure of the external air raises the cylinder B. D is another pipe
passing down through the interior of the ram A, it is closed at its lower end and
connected with the lateral aperture D¹. When the pipe D is in use it is connected
with apparatus by which air can be forced into it. This compressed air issuing
from the pipe D enters the space between the two packings A' and B¹ and the
pressure which it exerts serves to raise the cylinder B. The pipes C and D are
not employed simultaneously but one or other is made use of according as the
vehicle forms part of a train in which the brakes are worked by vacuum, or one
in which air under pressure is employed. E is a casing also fixed beneath the
platform of the carriage, and the cylinder B when it is lifted enters within this
casing. The casing serves to protect from dust the packing at the upper end of
the cylinder and also the surface of the plunger or ram A; it also serves to support
some of the parts of mechanism.
E¹, E, are horns at the lower end of the casing E; these horns have guide slots
in them through which a spindle F inserted through the ram B passes. From
the ends of this spindle links G pass up to arms H¹ H' fixed upon an axis H
which also is carried in bearings formed upon the casing E. The axis H has upon
it another arın H' to which a rod I is connected. These parts form a portion of
apparatus hereinafter described for lifting the cylinder B when the pneumatic
apparatus is out of use.
B is a passage formed through the ram at its lower end; it receives into it the
blocks I, I, to which the thrust rods K' K' are jointed. The blocks I', I', are able
to slide along the passage B' but the form of the parts is such that they cannot

page_text: turn within it. The blocks I³, 1', are provided with stems I, I³, upon which right
and left hand screws are cut, as is clearly seen in Figure 6. The two blocks are
coupled by means of a corresponding sleeve L screwed on to the stems I', I'; this
sleeve is cylindrical and is able to turn in the passage B'. B³ is a recess in the
lower part of the ram B, it constitutes a central enlargement of the passage B³.
M is a ring fitted into the recess B³, it surrounds the sleeve L fitting it accurately,
and a projection or feather within the ring enters a corresponding longitudinal
groove in the exterior of the sleeve L, so that the sleeve L cannot rotate
independently of the ring M and vice versa. Into the same recess B³ and
surrounding the ring M the boss N₁ of the lever N is fitted so that the lever may
turn freely about the ring. The outer end of the lever N is connected by a link Ŏ
to the lower end of one of the horns E¹ of the casing E. The lever N carries a spring
tooth or radial pawl N2 which is adapted to engage with ratchet teeth formed on
the ring M at the bottom of the groove M' therein. There are other teeth M³
formed around the periphery of the ring M and with these a spring pawl P fixed
upon the cylinder B engages. The pawl has a globular head which suffices to
prevent the ring turning in consequence of the oscillation of the vehicle in
travelling but yields and allows the ring to turn when force is applied to it.
The connecting rod 1 seen in Figure 8 is connected with an arm Q¹ upon an
axis Q, upon which also is the band lever Q. This hand lever plays up and down
as the cylinder B is raised and lowered in the ordinary working of the brake
apparatus. It can also when desired, be lifted by hand into a higher position
indicated by dotted lines in Figure 8 and marked Q. When it is so raised the
cylinder B is lifted and supported in an elevated position, the thrust of the
connecting rod I then being supported by the stop R₁ upon the bearing R which
carries the axis Q. So long as the bandle remains in the elevated position Q³ the
brakes are held off and do not operate; they are rendered operative however
either by drawing down the handle Q by hand or by again lifting the cylinder B
to its highest position by means of the pneumatic apparatus. By lifting the
cylinder B by vacuum or pressure the handle Q is released and it falls by its own
weight. When the pneumatic apparatus no longer sustains the cylinder B it
operates by its weight to put on the brake.
.
The connection between the cylinder B and the brake blocks is preferably such
as is shown by the Figures 1, 2, 3 and 4; the thrust rod K' is jointed to the
banger S and this, by means of rods T, T, is connected with the hangers U. U. on
which are brake blocks. These hangers are connected by a cross bar V and by
connecting rods W the bar V is connected with another bar X suspended by
hangers Y, Y, on which also are brake blocks to be applied to the second pair of
wheels. In like manner the thrust rod K³ is connected with a hanger S¹ which
by rods T¹ is connected with a bar V' suspended by hangers U₁ which also carry
brake blocks. The bar V¹ is coupled by rods W' with the bar X' suspended by
the hangers Y', Y¹, on which also there are brake blocks.
This is an arrangement applicable to four wheeled vehicles for applying brake
blocks to the wheels on both sides; in other cases other arrangements of leverage
may be adopted as is described in the specification of the former patent No. 16599
in the year 1884.
The action of the apparatus may be shortly described as follows :—
So long as the brakes are not to be applied the cylinder B is sustained by air
pressure, either that of the external air if there be vacuum within the cylinder B
or of the compressed air when the same is admitted to the space between the
packings A and B'. When the brakes are to be applied the vacuum is destroyed
or the compressed air is allowed to escape; the cylinder B then descends by its
own weight and it acts through the thrust rods K' K' and the system of leverage
represented by the drawings to press the brake blocks against the peripheries of
the wheels.
As the brake blocks become worn by use the cylinder B descends lower than it
did when the apparatns was first put to work and when the wear has gone on to a

page_text: certain extent the cylinder B descends sufficiently to allow the spring tooth or
pawl N to drop over the end of one of the teeth of the ratchet M¹.
In Figure 5 the parts are shown in this position; the cylinder has descended
sufficiently low to enable the tooth N' to engage. When next the cylinder rises
the ring M will be turned partly round in consequence of the connection of the
lever Ñ by the link O with the horn of the stationary casing E. In this way
the ring will be turned until the retaining pawl P drops into another notch of the
ratchet Mand retains the ring in its new position. In this movement of the ring M
it carries the sleeve L around with it and the screw 'stems I, I, travel a distance
out of the sleeve. This is equivalent to a lengthening of the thrust bars K¹, K³,
and the amount is sufficient to compensate for the wear which had previously
taken place in the brake blocks. When the cylinder B next comes down it does
not again descend so far as before being stopped by the brake blocks resting on
the peripheries of the wheels; and consequently the spring tooth N2 does not take
another tooth of the ratchet M' until after further wear has taken place.
CLAIMS :-
1.―The combination consisting of the ram fixed vertically beneath the platform
of the carriage and the cylinder moveable thereon and serving as the operative
weight to apply the brake blocks with which it is connected by levers substantially
as described. .
2.-The combination consisting of the said ram and cylinder and gear mounted
upon the cylinder compensating the wear of the brake blocks substantially as
described.
3. The combination consisting of the said ram and cylinder and the double
packing and connections admitting of either vacuum or pressure being employed
substantially as described.
4. The automatic compensating gear substantially as described.
5. The improved brakes substantially as herein described and shown.