IMPROVEMENTS IN BRAKES FOR RAILWAY AND OTHER CARRIAGES AND WAGONS, ALSO APPLICABLE FOR OTHER PURPOSES
Year: 1876

page_text: LETTERS PATENT to William Davison, of Darlington, in the County of Durham,
Engineer, for the Invention of "IMPROVEMENTS IN BRAKES FOR RAILWAY AND
OTHER CARRIAGES AND WAGONS, ALSO APPLICABLE FOR OTHER PURPOSES."
Sealed the 13th March 1877, and dated the 4th December 1876.
*IM-
PROVISIONAL SPECIFICATION left by the said William Davison at the
Office of the Commissioners of Patents on the 4th December 1876.
WILLIAM DAVISON, of Darlington, in the County of Durham, Engineer.
PROVEMENTS IN BRAKES FOR RAILWAY AND OTHER CARRIAGES AND WAGONS, ALSO
APPLICABLE FOR OTHER PURPOSES."
In the ordinary arrangement of the brakes of railway carriages or wagons the
brake lever whereby the brake shoes are applied to the wheels is arranged in com-
bination with push rods, a spanner, a guard, and other well known parts in such a
manner that by pressing the said brake lever the brake shoes are forced upon the
wheels. As the said brake shoes become reduced or worn away it becomes necessary
to adjust the said apparatus to compensate for this reduction, and for this purpose
the length of the said push rods, that is to say, the distance between the brake
shoes and spanner is increased by changing the connecting pins from one to another
of the series of pin holes found in the ends of the said push rods, where they are
connected to the spanner. But according to my Invention I obviate the necessity
for adjustment of the said push rods. Instead of the ordinary connection of the
push rod to the spanner by loose pins passing through holes in the rods and in the
spanner I secure the said rods permanently to the ends of the spanner. I use a
ratchet wheel, which is placed between two hanger plates or bars suspended from
the sole bar or frame of the wagon or carriage, and is attached to the spanner or to
its shaft or journal. On or near the axis of this ratchet wheel the brake lever is
mounted. The said brake lever has pivoted on it a pawl which takes into the
teeth of the said ratchet wheel in such a manner that when the said brake lever is
raised in its guard the said pawl will ride over the ratchet teeth, and when the
said lever is depressed the said pawl will pull the ratchet wheel around on its axis
and thereby force the brake shoes upon the wheels. As the brake shoes are reduced
or worn away the said pawl takes up or advances over the teeth of the ratchet.
[ Paine G21

page_text: wheel and thereby effects, the required adjustment of the push rods to compensate
for such reduction.
By this Invention the brake apparatus is rendered automatic or self adjusting,
and will accomodate itself to the continual wearing or reduction of the brake shoes,
and the lever will always work in the same space and be in the most favorable
position for applying pressure to the brakes, that is to say, it will act on the brake
shoes at the commencement of its depression, thereby insuring the greatest effect of
the pressure or force available for putting on the brakes.
My improved apparatus is constructed and arranged in the same, or substantially
the same, manner when applied to other than railway purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Davison in the Great Seal Patent Office on the 2nd June
1877.
WILLIAM DAVISON, of Darlington, in the County of Durham, Engineer. "IM-
PROVEMENTS IN BRAKES FOR RAILWAY AND OTHER CARRIAGES AND WAGONS, ALSO
APPLICABLE FOR OTHER PURPOSES."
In the ordinary arrangement of the brakes of railway carriages or waggons the
brake lever whereby the brake blocks are applied to the wheels is arranged in
combination with push rods, a spanner, a guard, and other well known parts in
such a manner that by pressing the said brake lever the brake blocks are forced
upon the wheels. As the said brake blocks become reduced or worn away it
becomes necessary to adjust the said apparatus to compensate for this reduction,
and for this purpose the length of the said push rods, that is to say, the distance
between the brake blocks and spanner is increased by changing the connecting pins
from one to another of the series of pin holes formed in the ends of the said push
rods where they are connected to the spanner. But according to my Invention I
obviate the necessity for the adjustment of the said push rods. Instead of the
ordinary connection of the push rod to the spanner by loose pins passing through
holes in the rods and in the spanner I secure the said rods permanently to the ends
of the spanner. I use a ratchet wheel which is placed between two hanger plates
or bars suspended from the sole bar or frame of the wagon or carriage, and is
attached to the spanner or to its shaft or journal. On or near the axis of this
ratchet wheel the brake lever is mounted. The said brake lever has pivoted on it
a pawl which takes into the teeth of the said ratchet wheel in such a manner that
when the said brake lever is raised in its guard the said pawl will ride over its
ratchet teeth, and when the said lever is depressed the said pawl will pull the
ratchet wheel around on its axis and thereby force the brake blocks upon the
wheels. As the brake blocks are reduced or worn away the said pawl takes up or
advances over the teeth of the ratchet wheel and thereby effects the required
adjustment of the push rods to compensate for such reduction.
My Invention is illustrated in the accompanying Drawing, in which Figure 1 is
a side elevation showing a railway wagon provided with brakes according to my
said Invention; Figure 2 is a transverse section on the line x, x, Figure 1; Figure 3
shows a modified form of ratchet wheel detached. Like letters indicate the same
parts throughout the Drawing.
A is the sole bar or frame of the said wagon; B, B, are the wheels; C, C, are
the brake blocks; a, a, are hanger plates, one of which in Figure 1 is shown broken
to allow the mechanism to be seen; bis the spanner, to whose ends b¹ the rods o
are connected by pin joints, as shewn; d is the ratchet wheel fixed on the shaft or
axle of the said spanner, which shaft or axle turns freely in bearings formed in
the plates a. In Figure 1 the said ratchet wheel is shown without teeth on a
portion of its periphery, but if desired I may use a wheel with teeth all around it,

page_text: as shewn in Figure 3. e is the brake lever, and f the pawl, which is pivoted on
the same in a convenient position to engage with the teeth of the ratchet wheel d;
f1 is a stop to prevent the displacement of the said pawl; g. is the guard for the
said lever.
By this Invention the brake apparatus is rendered automatic or self adjusting,
and will accommodate itself to the continual wearing or reduction of the brake
blocks, and the lever will always work in the same space and be in the most
favorable position for applying pressure to the brakes, that is to say, it will act on
the brake blocks at the commencement of its depression, thereby ensuring the
greatest effect of the pressure or force available for putting on the brakes.
My improved apparatus is constructed and arranged in the same, or substantially
the same, manner when applied to other than railway purposes.
Having thus fully described my said Invention, and shown how the same may be
conveniently and advantageously carried into practise, I wish it understood that I
claim, the improved mechanism or apparatus comprising the ratchet wheel affixed
to a spanner or lever to which the push rods are permanently or undetachably con-
nected, and the brake lever provided with a pawl which engages with the said
ratchet wheel and actuates the same, and thereby sets or adjusts the brake blocks
with a capability of maintaining the said blocks in the required position relatively
to the wheels, as above set forth.
In witness whereof, I, the said William Davison, have hereunto set my hand
and seal, this Thirty-first day of May, in the year of our Lord One thousand
eight hundred and seventy-seven.
WILLIAM DAVISON. (L.S.)