IMPROVE- MENTS IN CONTINUOUS BRAKES FOR RAILWAY TRAINS, AND WHICH MAY BE APPLIED IN OTHER CASES WHERE BRAKES ARE USED." PROVISIONAL SPECIFICATION
Year: 1879

page_text: LETTERS PATENT to Alexander Cunningham Boothby, of Kirkcaldy, in the
County of Fife, North Britain, Civil Engineer, for the Invention of "IMPROVE-
MENTS IN CONTINUOUS BRAKES FOR RAILWAY TRAINS, AND WHICH MAY BE
APPLIED IN OTHER CASES WHERE BRAKES ARE USED."
PROVISIONAL SPECIFICATION left by the said Alexander Cunningham
Boothby at the Office of the Commissioners of Patents on the 23rd September
1879.
"
ALEXANDER CUNNINGHAM BOOTHBY, of Kirkcaldy, in the County of Fife, North
Britain, Civil Engineer. 'IMPROVEMENTS IN CONTINUOUS BRAKES FOR RAILWAY
TRAINS, AND WHICH MAY BE APPLIED IN OTHER CASES WHERE BRAKES ARE USED."
This Invention, which relates to continuous brakes for railway trains and other
purposes, is a further development of the Invention for which Letters Patent were
granted to the said Alexander Cunningham Boothby, dated the 12th day of April
1879, and Numbered 1447.
According to the present improvements in place of applying the electric current
directly to the brake blocks as under the Specification filed in pursuance of my
former Letters Patent, I suspend on that part of one axle of each railway carriage,
van, or other vehicle, a bracket carrying bobbins, to which bobbins the conductors
from the electric generator are connected. These brackets and bobbins are free to
move slightly end wise on the axle and independently of each other, that is to say,
to and from the inner sides of the wheels. The brackets carrying the bobbins are
of such a length, that the cores of the bobbins are situated immediately at the inner
side of the tyres of the wheels, so that when the electric current is sent through the
conductors, the cores being thereby converted into magnets, are attracted against
the inner side of the tyres, and thereby stop or retard the rotation of that pair of
wheels. The inner ends of the cores are shod with pieces of soft iron or steel which
are renewed from time to time as the wear.

page_text: (
The brackets which carry the bobbins are fitted each with a lever, which levers
are connected together by a cross-bar. This cross-bar is linked to another lever on
a cross shaft between each pair of wheels, which cross shaft is fitted with eccentrics
operating in opposite directions, these respectively being connected by eccentric rods
coupled to the brake blocks on the opposite sides of each pair of wheels, including
that pair to which the bobbins are applied.
In place of using eccentrics, as herein described, the levers on the cross shafts
between the pairs of wheels may be duplex, so as operate a pair of levers in opposite
directions, attached to other levers connected to each pair of brake blocks.
Under another modification in place of attaching the bobbins rigidly to the levers,
as is the case in the modification herein before described, and also in place of
allowing the said levers to have an endwise movement on the shaft of the pair of
wheels to which they are applied, the upper part of each lever has a piece hinged to
it to which the bobbins are attached, and to the front of the bobbins (is or) are fixed
a piece or pieces of iron or steel whose contour corresponds to that of the flange and
tread of the tyre, this portion or these portions constituting in fact a continuation
or continuations of the core of the bobbin. When the electric current is applied,
this portion (or portions) corresponding to the contour of the tyre become electro
magnetized, and therefore is (or are) instantly attracted towards the rotating wheels,
thereby stopping or retarding them, and applying the brakes in the manner herein-
before described, excepting that under this modification the portion or portions
of the cores bearing on the flanch and tread of the wheels act the part of brake
blocks, and therefore render the. ordinary brake blocks on this pair of wheels
unnecessary.
When the current of electricity is withdrawn, the weight of the bobbins on the
inner side of the hinge piece causes the brake pieces to be lifted off the tyres.
In the event of the fracture of a coupling or of a conducting wire or wires in a
train taking place, which would have (by virtue of the apparatus set forth in my
foriner Provisional Specification) the effect of applying the brakes throughout a
train, I apply under my present improvements a moveable stop-piece or catch, which
is pulled out of its position against the levers on the cross shafts or against other
suitable parts of the mechanism by the occurrence of the fracture, so that if the
conducting wires are broken and the electric current thereby destroyed, the said levers
or other suitable parts of the mechanism instantly come in contact with the stop
,piece or catch, and so prevent the brakes from coming off the wheels so that each
portion of the train is stopped.