IMPROVEMENTS IN RAILWAY BRAKES
Year: 1855

page_text: by the Act.)
PROVISIONAL SPECIFICATION left by John Henry Johnson at the Office
of the Commissioners of Patents, with his Petition, on the 19th April
1855.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of Glasgow, North Britain, Gentleman, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN RAILWAY BRAKES," a com-
munication from abroad, to be as follows:-
This Invention relates to an improved construction and arrangement of
railway brakes, whereby the whole of the wheels of the carriage are raised from
off the rail simultaneously when the brakes are brought into action. The first
and last axle of each carriage is acted upon by a pair of brakes, and these brakes
consist each of a cast-iron box fitted to slide along a rack, which is jointed at
its upper end to a fixed eye secured.to the cross beams of the carriage framing.
Inside each box is fitted a toothed pinion gearing with the racks; these pinions
serving to lengthen the brake, and so bring its foot in contact with the rail when
the carriage is to be stopped. The pinion is actuated by a second pinion fitted
on to the same spindle, which second pinion is placed outside the cast-iron
box, and is actuated by means of a segment wheel or pinion which gears into
it. On the axis of this segment wheel is fitted a lever arm, to the free end of
which is attached a cord or chain, which is connected to a pair of blocks or

page_text: hauling tackle, the cord of which after passing round suitable guide pulleys is
wound on to a drum on the top of the carriage. There will then be four cords
or chains, one to each brake, and these four cords or chains are wound on to
drums of their own. The drums are placed one above the other on two ver-
tical spindles, and these spindles are actuated simultaneously by an endless
chain and pinions worked by a winch handle. A projection or horn is formed
on the side of each box next the axles, and when the brakes are to be brought
into action, the feet of the brakes are brought in contact with the rails by
actuating the racks and pinions, and the projections are pushed under the axles
by the impulse of the carriage. This has the effect of raising the carriage
bodily from off the rails, and as the axles continue to revolve they wind them-
selves on to the projections before mentioned, which projections now bear the
entire weight of the carriage. To prevent the racks from running down by the
weight of the carriage, a ratchet wheel is fitted on to one end of the spindle,
which carries the rack-actuating pinion, and this wheel is held fixed by a seg-
mental toothed detent, which allows the rack to extend itself, but not to run in;
a cord or chain is attached to this detent, and connected with the blocks and
tackle, so that it is held firm during the elongation of the brake. When the
brake is to be released, the detent is thrown out of gear by a small arm on the
axes of the rack pinion, which pushes back a second detent or pall, kept pressed
against the first one by a suitable spring. All the carriages of a train may be
acted upon by one handle by connecting their drums by endless chains, but the
gearing should be so arranged that the brakes of the end carriages will be
brought into action rather sooner than those of the centre of the train, in order
to avoid the shocks which would otherwise occur from the end or back carriages
overrunning the front ones.