IMPROVE- MENTS IN RAILWAY BRAKE APPARATUS
Year: 1861

page_text: PROVISIONAL SPECIFICATION left by William Leopard at the Office of
the Commissioners of Patents, with his Petition, on the 14th November
1861.
I, WILLIAM LEOPARD, of Hurstpierpoint, in the County of Sussex, Corn.
Merchant, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN RAILWAY BRAKE APPARATUS," to be as follows:-
My improvements in railway brake apparatus is based upon the principle,
which is in a certain degree self-acting, & as previously secured to me by a
Provisional Protection, under the Patent Law, accorded to me, No. 1450, &
dated June 7th 1861, in so far that the power applied to the brakes is derived
from the rotating motion of the wheels and axles of the carriage, the guard or
other attendant simply putting them in or out of gear, as may be required.
To effect communication between the guard and the several brakes of a
train I use a longitudinal shaft, in which my first improvement consists of a
peculiar coupling, by which the shaft of one carriage is attached to the shaft of
the adjoining carriage, each part of the coupling (one to each end of every
shaft), is formed of a central disc or block carrying joints, in which are fitted
two arms, which fold, and are acted on by springs in the manner of the blade
of a clasp knife; these can be disposed to assume a radial position from the
centre piece, or be folded down so as to project in the direction of the next
carriage; each of the centre pieces have two notches or recesses cut therein,
which receive the arms of the coupling opposed to it. After the carriages are
brought together the coupling arms are folded down so as to engage with
notches of the opposed coupling. On the longitudinal shaft fitted to each
carriage supplied with these brakes, I fix an eccentric or cam which supports
and controls the position of a bearing, carrying one end of a short shaft placed

page_text: a little above the carriage axles, & extending from one of the axles to about
the centre of the carriage. On this shaft I fix a screw wheel or pinion, which
takes into an endless screw fixed on the axle of the carriage above mentioned,
and close to which is the bearing of the short shaft, sustained by the cam on
the longitudinal shaft of communication. By the partial rotation of the shaft
of communication the screw wheel and shaft is lifted out or dropped into gear
with the endless screw on the carriage axle; a ratchet wheel on same shaft is
also released or left in gear with a pawl by same motion, according to its
greater or lesser extent, for purposes which will be herein-after explained.
The short shaft transmits the power to the brakes, for which purpose it is
furnished with a bevil pinion at the stationary end (that is, near the middle of
the area of the carriage); this pinion gears with a bevil wheel or segment of
teeth placed on a double elliptical cam; the two extreme parts of these cams
are diametrically opposite to each other; they act directly on the brakes and
force them against the wheels.
The brake framework I employ consists of tie rods stretched between the
axle guards and a cross stretcher supporting the double-brake cam last herein
mentioned. The brakes are fitted and sustained between the tie bars, being
mounted on sliding cross bars disposed across the breasts of each pair of
wheels, which bars advance or recede bodily therefrom. The brake blocks are
mounted on these cross bars, and have a strong spring or springs interposed
between them, and the cross sliding bars to cause the brake to offer a resilient
pressure to the wheels in the first instance, and up to a certain extent. The
cross sliding bars are connected with semicircular pieces, the ends of which
abut on the brake blocks, while the mid parts, which are disposed back to
back, and receive the force of the double-cam action before mentioned, &
transmit it to the brake blocks. To allow for the wear of the blocks screws
& nuts are disposed on these curved arms, which have the effect of lengthening
them at pleasure, and so making up for wear. The springs before mentioned,
as affording a capability of resiliency in the pressure by their ends taking into
the supporting tie bars, also serve to withdraw the brake blocks from the
wheels.
The framework and the arrangement of the parts and the brakes may of
course be varied according to circumstances. The action of the brakes is
this: Supposing the guard or attendant desires to apply the brakes, he rotates
the longitudinal connecting shaft, so as to lower all the screw wheels into their
endless screws on the axles, thus rotating the short shaft of each carriage, and
so transmitting a powerful rotating force to the double-brake cam, and thereby
forcing the brakes on the wheels. To prevent anything breaking (but which

page_text: I think unlikely) a segment of teeth was mentioned as being used to transmit
the power which would limit the extent of motion transmitted by it to the
double cam, the driving pinion having reached its limit would carry it no
further. It was before mentioned that a ratchet wheel is also fixed on the
short shaft; this is toward the stationary end, and is in fact a double ratchet
wheel, having two sets of teeth set in opposite directions. A spring pawl
takes into one or other of these ratchets, according to the direction in which
the shaft is rotated (this, for the purposes of the brake, is immaterial).
Supposing the brakes have been pressed slightly up to the wheels the guard
can now, although raising the screw wheel out of gear, still leave the brakes
on by reason of the ratchet and pawl before mentioned preventing the short
shaft running back; a further upward motion of the screw wheel and its shaft
withdraws the ratchet from the pawl, the ratchet being released the shaft now
runs back, and the brakes recede from the wheels.
In order to provide for the transmission of a resilient force from the guard
to the shaft of communication, I arrange the screw hand wheel shaft to be
held abreast of the screw on the shaft of communication by the force of a
spring, which may be overcome by any superior force, and thus ease the gear.
Another arrangement of apparatus is as follows:-The sliding bars carrying
the brake blocks are mounted as before, but instead of being acted on by the
double cam, through the intervention of the segmental or other formed
thrusting pieces, I transmit the power by means of a double-armed lever
mounted on a cross shaft, such shaft having a screw, arc, or quadrant fixed
thereon; this segment gears with an endless screw on a short shaft disposed
somewhat as the short screw-wheel shaft before mentioned. This short shaft
having at the opposite end a wheel or pinion taking into the screw wheel on
the carriage axle as before, from which it is capable of being withdrawn or
put into gear, if desired, as before. When in gear the motion is transmitted
to the screw arm or segment, which rotates the cross shaft, & forces the
brakes on by means of the double-armed lever & rods extending therefrom
to the brake blocks or to the bars by which they are carried, these connecting
rods being double to each lever, it is immaterial in which direction the cross
shaft is oscillated; to facilitate this, and to offer a resilient force to the brake
blocks, I make these connecting rods elongating with strong springs, which
are compressed in traversmitting the thrust; this arrangement of rods also.
permits the free action of the double set of connecting rods to each arm and
brake.
In the above I have supposed the use of one double-armed lever taking
effect on the sliding bars carrying the brake blocks, but these bars may be

page_text: dispensed with, the brake blocks being mounted somewhat in the ordinary
way, and having two double-armed levers & four connecting rods to each lever
(two at each brake block); the double-armed levers are in this arrangement
disposed near each end of the cross shaft on which the actuating screw
quadrant before mentioned is fixed. I have also another arrangement for
throwing the pinion or wheel out of gear with the axle of the carriage; for
this purpose I mount the movable bearing of its shaft on an inclined arm
extended from a rocking shaft; another arm from same shaft is in connection
with a crank whose shaft receives rotary motion from a screw wheel fixed
thereon, which gears into an endless screw fixed on the longitudinal shaft of
communication. By rotating this crank to a certain position the screw wheel
and endless screw of the carriage axle are put in gear or withdrawn more or
less from contact with each other. A double ratchet wheel is also fixed on
this short power transmitting shaft into which a pawl takes; this pawl is
controlled by a crank or eccentric pin on the crank shaft last above mentioned,
which ensures the pawl being in gear at a certain point, in order to hold the
brakes against the wheels after the screw wheel has been withdrawn from the
endless screw of the axle by preventing the shaft retrograding, as before
mentioned. The apparatus also acts in whichever direction the longitudinal
shaft of connection is turned.
I will now describe a modification of the last arrangement, which is much
simplified. Instead of disposing the double-armed lever with the spring
connecting rods to the brakes on a horizontal cross shaft or axis, I mount it on
an axis disposed vertically, and strongly supported in position; on same axis I
fix an arm which terminates immediately over one of the carriage axles; on
this arm I form a segment of teeth, which takes into the endless screw fixed
on the carriage axle as before; when so geared a motion is communicated to
the vertical axis of the double-armed brake lever, which applies the brakes as
required; I apply means to raise or lower the lever & segment of teeth into
or out of gear with the endless screw by the motion of the longitudinal shaft
of communication, as before explained, and further means may be readily
applied to the toothed lever to retain it laterally in position, and so keeping
on the brake power after it has been withdrawn from contact with the endless
screw on the carriage axle.