Improvements in Rim-brakes for Cycles and other Road-vehicles.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Rim-brakes for Cycles and other Road-vehicles.
We, CLARK BROTHERS CYCLE COMPANY, LIMITED, of Essex Cycle Works, 24,
Dames Road, Forest Gate, in the County of Essex, Cycle Manufacturers, and
LEONARD DAVID KING, of the same address, Foreman in the employ of the said
Company, do hereby declare the nature of this invention to be as follows:-
66
This invention relates to what are known as rim-brakes" for cycles and other
road-vehicles; that is to say, brakes wherein the retarding influence is applied
to the rim of one of the road-wheels,. as distinguished from the tyre or the hub
thereof.
A rim-brake constructed according to our improved method, and applied, by
way of example, to the front wheel of an ordinary "safety " bicycle, comprises
a pair of double armed levers, mounted upon pins carried by the respective legs
of the front fork; the lower arm of each lever being furnished with leather or
other suitable rubbing material and projecting inwards towards the wheel-rim.
The upper arms of the levers also extend inwards, and cross one another, so that
each arrives on the opposite side of the vertical centre-line of the fork. The
outer extremities of these arms are, by means of a connector approximately in
the form of the letter Y inverted, connected with a tension-rod which takes
the place of the ordinary "plunger "-rod. This connector may be constructed
from a single piece of wire or rod bent into the required form. The Y-connector
and its rod are or may be maintained in tension by making the connector of spring
steel, or equivalent resilient material, and "setting" the two arms of the Y in
such a manner that their extremities have a tendency to diverge, thus carrying
the outer extremities of the levers apart and removing the brake-pads out of
contact with the wheel-rim. A spiral spring in compression may however be
substituted, if preferred; same being interposed between the outwardly projecting
extremities of the lever-arms. The brake-lever is preferably constructed in two
parts hinged together, each part being pivotted at a point intermediate of its
length. By this means, the direction of movement of the outer extremity of the
entire lever is reversed, thereby enabling the motion to be communicated to the
brake-blocks through a system of connections, which is in tension instead of in
compression.
On pressing the free end of the brake-lever towards the handle bar, in the
usual manner for the purpose of applying the brake, the opposite extremity
of the lever (where a compound lever is used) is moved in the same direction, the
tension rod and Y-connector are raised, the outer extremities of the crossed
arms are caused to approach one another whilst the arms of the Y-connector
converge, and the brake-pads carried by the lower arms of the levers are brought
into contact with the wheel-rim. Upon the handle heing released, the reverse

page_text: action takes place under the influence resulting from the tendency of the arms
of the Y-connector to open out.
Dated 10th
of Novemba 1900
Improvements in fim-orakes for Cycles and other noaÃ°ves
We, CLARK BROTHERS CYCLE COMPANY, LIMITED, of Essex Cycle Works, 24,
Dames Road, Forest Gate, in the County of Essex, Cycle Manufacturers, and
LEONARD DAVID KING, of the same address, Foreman in the employ of the said
Company, do hereby declare the nature of this invention and in what manner the
same is to be performed to be particularly described and ascertained in and by
the following statement:-
"
This invention relates to what are known as rim-brakes" for cycles and other
road-vehicles; that is to say, brakes wherein the retarding influence is applied
to the rim of one of the road-wheels, as distinguished from the tyre or the hub
thereof.
رو
A rim-brake, constructed according to our improved method, and applied, by
way of example, to the front wheel of an ordinary "safety bicycle, is illus-
trated in the accompanying drawings, whereof Fig. 1 is a front elevation and
Fig. 2 a side elevation. Fig. 3 is a detached view of the spring employed for
maintaining the brake "off."
According to the method of construction illustrated, the rim-brake comprises
a pair of double armed levers A A, mounted upon pins carried by the respec-
tive legs of the front fork B; the lower arm a of each lever being furnished with
leather or other suitable rubbing material a° and projecting inwards towards the
wheel-rim C. The upper arms a¹ of the levers A also extend inwards and cross
one another, so that each arrives on the opposite side of the vertical centre-line
of the fork. The outer extremities of the arms a¹ a¹ are, by means of a con-
nector, D, approximately in the form of the letter Y inverted, attached to the
brake lever E. In the design illustrated in the accompanying drawing, this con-
nector consists of two links d d hinged at d to the rod D; the latter being formed
in two parts and furnished with a set-screw ³, so as to be capable of adjustment
for length. A spring d², carried by the hinge pin d¹, engages by its
extremities d¹ d with the studs dd; the tendency of the extremities d'd to
diverge ensuring the arms a¹ a¹ of the levers A A being held, normally, in the
position in which the brake is "off." The two arms of the spring d² may, how-
ever, be utilised for connecting the pin with the outer extremities of the
arms a a¹, the links d d being dispensed with. Instead of a spring such as d²,
a spiral spring in compression may be applied between the outer extremities of
the said lever arms a¹ a¹.
Upon applying upward pressure to the free end of the brake-lever E, in the
usual manner, the hinge pin d' is drawn up with the effect that the lower ends
of the links d d are caused to converge, carrying with them the outer extremities
of the arms a¹ a¹. At the same time the arms a a of the levers A A are caused
to approach towards each other and thus to grip the wheel-rim C and to retard
the rotation of the wheel. Upon the release of the brake-lever, the brake-pads

page_text: immediately diverge from the wheel-rim while the arms a¹ a¹ of the levers A A
are also forced asunder by the extremities d d of the spring d².
The brake-lever may, however, if preferred, be constructed in two parts hinged
together, each part being pivoted at a point intermediate of its length. By this
means, the direction of movement of the outer extremity of the entire lever
is reversed thereby enabling the motion to be communicated to the brake-pads
through a system of connections which is in tension instead of in compression
as in the case with the ordinary plunger brake. Under these circumstances, upon
pressing the free end of the brake-lever towards the handle-bar, the opposite
extremity of the lever is moved in the same direction, the tension-rod and Y-con-
nector are raised, the extremities of the arms a a are caused to approach one
another and the brake-pads a° a° are brought into contact with the wheel-rim C.
Upon the brake-lever being released, the reverse action takes place and the brake-
pads are moved out of contact with the wheel-rim.
Having now particularly described and ascertained the nature of our said in-
vention and in what manner the same is to be performed, we claim :-
1. A rim-brake for cycles and other road-vehicles arranged and operating sub-
stantially as herein described and comprising a pair of double-armed and separately
pivotted levers, one arm of each lever being furnished with a pad while the other
arm crosses the corresponding arm of the fellow lever, these arms being con-
Dected with a tension-rod by means of links formed as or furnished with a spring
adapted to hold the brake-pads out of contact with the wheel-rim; the tension-
rod being in turn connected with the brake-lever.
2. A rim-brake for cycles and other road-vehicles, comprising a brake-lever
and a pair of double armed levers, such as A A, respectively pivotted upon the
legs of the fork B of the machine and connected by means of links, such as d d,
or by a spring such as d², with the brake-lever tension-rod D, substantially as
herein described.
3. In a rim-brake, wherein the motion of the brake-lever is communicated to
the brake-pads through a system of connections in tension, the combination with
the tension-rod D, of the links d, d, spring d² and separately pivotted levers A A
each having arms a¹, a¹ crossing one another, substantially as and for the purpose
specified.