IMPROVEMENTS IN RAILWAY AND OTHER BRAKES
Year: 1877

page_text: LETTERS PATENT to Thomas Dobson, of Crewe, in the County of Chester, for
the Invention of "IMPROVEMENTS IN RAILWAY AND OTHER BRAKES."
Sealed the 29th January 1878 and dated the 3rd September 1877
PROVISIONAL SPECIFICATION left by the said Thomas Dobson at the Office
of the Commissioners of Patents on the 3rd September 1877.
THOMAS DOBSON, of Crewe, in the County of Chester.
RAILWAY AND OTHER BRAKES."
IMPROVEMENTS IN
By the use of this Invention I obtain a greater frictional surface to act upon,
whereby I am able to do away with double brake blocks and appliances now frequently
used on railways, and, as a consequence, I prevent the axle boxes from being forced
against the horn plates or axle guards, whereby great strain on the carriage and
heavy shocks are now produced; also, by my Invention the strain is all within
itself or only between the brake and the wheel.
According to this Invention I clip or grip the sides of the wheel rim by means of
clips, one on each side of the wheel, these clips being made to grip the wheel rim
between them. This may be done in a great variety of ways; thus, for example, I
may use wedge appliances for forcing the outer end of a pair of shear-shaped brake
clips apart, while the opposite end is made to grip the wheel rim; or the same
object may be attained by means of cam, eccentric, screw, or winding chain and
pulley appliances, or other mechanical equivalents...
According to one arrangement I make the clip in the form of two levers jointed
together at or near the wheel, their other or outer ends opening up towards the
back, and between these outer ends I fit a wedge block which can slide between
and hold them, and thereby, according to the direction in which the block moves,
open or close the clip in a way similar to a pair of shears. The clip appliances are
continued up to the hanger or bracket on the framing and suspended therefrom;
these continued parts or brake straps are, when the wedge appliance and clip are
pulled back and the wheel released from the grip, made to act against a wedge-
Din 71

page_text: shaped part, which ensures their being evenly withdrawn or opened on each side of
the wheel. The straps may be formed so as to cause a certain amount of friction
against the face or flange of the tyre, or both.
This Invention may be applied to continuous brakes or to rolling stock in general,
and to revolving parts of machinery, such as cranes, capstans, and winches.
The aforesaid clip appliances may be so arranged and applied to railway waggons
that the weight of the ordinary brake lover will suffice to skid or retard the
wheel.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Dobson in the Great Seal Patent Office on the 2nd March
1878.
THOMAS DOBSON, of Crewe, in the County of Chester.
RAILWAY AND OTHER BRAKES."
"IMPROVEMENTS IN
According to this Invention I clip or grip the sides of the wheel rim by means of
clips, one on each side of the wheel, these clips being made to grip the wheel rim
between them. This may be done in a great variety of ways; thus, for example, I
may use wedge appliances for forcing the outer end of a pair of shear-shaped brake
clips apart, while the opposite end is made to grip the wheel rim; or the same
object may be attained by means of cam, eccentric, screw, or winding chain and
pulley appliances, or other mechanical equivalents.
According to one arrangement I make the clip in the form of two levers jointed
together at or near the wheel, their other or outer ends opening up towards the
back, and between these outer ends I fit a wedge block, which can slide between
and hold them, and thereby, according to the direction in which the block moves,
open or close the clip in a way similar to a pair of shears. The clip appliances are
continued up to the hanger or bracket on the framing, and suspended therefrom;
these continued parts or brake straps or carrying links are, when the wedge
appliance and clips are pulled back and the wheel released from the grip, made to
act against a wedge-shaped part, which ensures their being evenly withdrawn or
opened on each side of the wheel. The straps may be formed so as to cause a
certain amount of friction against the face or flange of the tyre, or both.
And in order that this Invention may be more fully understood I will now
proceed to describe the same with reference to the accompanying Drawings, which
illustrate two modes of actuating the "clip brake," and three modes of clipping the
wheels.
Figure 1 is a side view, Figure 2 a plan, and Figure 3 an end view of a brake
made according to one mode of carrying out this Invention.
A is a railway carriage wheel; B, B, are two levers carrying brake blocks b, b,
which grip the sides of the wheel rim; the levers B are jointed together by the
fulcrum bolt C, and the other ends of these levers are held in a wedge appliance or
staple D consisting of two plates d, d, united by bolts d', d'; between the plates d, d,
there is a wedge piece d", which fits between the two levers B. The bolt C forming
the fulcrum of the levers B is fastened to the bracket e and the framing F of the

page_text: carriage. H, H, are links let into the brake blocks b, b, and fastened to them by
rivets;
these links are suspended from the bracket e. G is a lever connected to the
wedge appliance D, and jointed to rods g, g, which serve to operate the lever G and
wedge appliance by any convenient and well-known appliance, either by hand or
power. The lever G being operated in the direction of the arrow the clip will open
and the brake blocks b, b, be drawn away from the sides of the wheel rim.
lever G being moved in the opposite direction, the clip is closed, the brake blocks b
gripping the sides of the wheel rim.
The
Figure 4 is a side view, and Figure 5 a plan of a modified arrangement, the
difference from the arrangement described being that the levers B, B, in this case
cross each other like shears, so that the lever G, when operated in the direction of
the arrow, will cause the brake blocks b to grip the sides of the wheel rim, and
vice versa.
Figure 6 is a plan of an arrangement of clip brake, where the brake blocks b, b,
not only grip the sides of the wheel rim, but also the flange and part of the face.
By the use of this Invention I obtain a greater frictional surface to act upon,
whereby I am able to do away with double brake blocks and appliances now
frequently used on railways, and, as a consequence, I prevent the axle boxes from
being forced against the horn plates or axle guards, whereby great strain on the
carriage and heavy shocks are now produced; also, by my Invention the strain is
all within itself, or only between the brake and the wheel.
This Invention may be applied to continuous brakes or to rolling stock in general,
and to revolving parts of machinery, such as cranes, capstans, and winches.
The aforesaid clip appliances may be so arranged and applied to railway waggons
that the weight of the ordinary brake lever will suffice to skid or retard the
wheel, that is, if the clip levers be made long enough.
And having thus described the nature of this Invention, I declare that I claim,—
Firstly. The application of brake blocks laterally to grip or clip the wheel rim
between them, as set forth.
Secondly. The clip or grip brake appliances, as described and shewn.
In witness whereof, I, the said Thomas Dobson, have hereunto set my hand
and seal, this Twenty-seventh day of February, in the year of our Lord One
thousand eight hundred and seventy-eight.
TITAca
DODSON
THOMAS DOBSON. (LS.)