Improved Instantaneous Brake for Stopping Machinery, and for Automatically Preventing Overwinding from Mine Shafts.
Year: 1896

page_text: Date of Application, 8th July, 1896-Accepted, 29th Aug., 1896
COMPLETE SPECIFICATION.
Improved Instantaneous Brake for Stopping Machinery, and for
Automatically Preventing Overwinding from Mine Shafts.
We, WILLIAM BARNES, Foreman Fitter, and THOMAS EDEN, Engineer, both
residing at The New Spes Bona Gold Mining Co. near Johannesburg, South
African Republic, do hereby declare the nature of our invention and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement and accompanying drawings, that is to say :-
This invention relates to the construction, adaptation and application of an
improved, more simple, and effective mechanical appliance, or
means, for
expeditiously arresting the motion of steam and other engines, or motors having
fly wheels, or any other wheel in motion, and in order that the carrying out of
our invention in practice may be fully understood, we have illustrated it on the
accompanying 2 sheets of explanatory drawings and have marked the same with
letters of reference corresponding with those in the following description of our
invention.
Figure 1 is a side view, and Figures 2 and 3 end views.
In carrying out our invention we use a tightening rod (A) having a right and
left hand screw cut respectively on its ends, by means of which the upright brake
blocks (B. B) may be moved to or from the wheel they are to control. These
brake blocks are hinged to the floor of the engine room, or to the bed of the engine,
in any convenient manner. The ends of the tightening rod pass through nuts,
working on loose joints in the forked ends of the two levers or arms (C. C) placed
respectively on either side of the wheel to which the brake power is to be applied.
The opposite ends of the these levers are hinged to fixed standards (D. D¹) or
other suitable contrivances whereby they may have a lateral motion from the
standards as a centre. These levers or arms are attached, by means of suitable
hinges or joints (a. a'), to the centre of the brake blocks (B. B), so that when the
tightening rod (A) is caused to revolve a short distance by pressing down the hand
lever (E), which is fixed at any convenient point of the rod, the action of the
right and left hand screws on its ends, acting on the nuts in the levers or
arms (C. C), draws them inwards towards the periphery of the wheel (F) partly
embraced by the brake blocks (B. B') which are carried forward on to the wheel
and by the enormous pressure they exert almost instantaneously arrest its motion,
and stop the whole of the machinery driven or worked by the engine. The pitch
of the screws may vary according to the speed of the travel required.
Our invention can also be adapted and applied to overhead winding in such
manner as to prevent overwinding, the skip, when reaching a certain fixed height
beyond which there is danger, causing the brake to be automatically applied and
the engine stopped. In carrying out this portion of our invention, we use a
counterpoised lever rod (G) fixed in a pit or cavity under the flooring (H) of the
engine room and which is connected by a hinged joint at the end furthest from the
bead gear, to an inverted standard (1) bolted to the underneath side of the flooring.
The lever rod (G) is loosely jointed to a connecting rod (K), which passes
vertically through the floor, from the hand lever (E), by means of a hole at a
right angle to its length, through which the end of the connecting rod passes, a
nut (L) screwed on to extremity of the latter, serves as a stop to prevent the
lever arm falling below the required distance. To prevent the nut moving from
its position, a check nut or split pin may be used underneath it. The counter-
poised lever passes through a hanging or other conveniently fixed guide and is
supported at its outer extremity on the catch (M) forming the lower end of a

page_text: vertical lever (N), made to swing backwards and forwards on a pin which passes
through it at the floor level. The underside of the catch (M) is bevelled off to
admit of the lever, on being raised, to automatically relock itself in position, a
short lever arm and weight (M2) attached to the rear of the lower end of the
vertical lever (N) serves to thrust the catch forward under the end of the counter-
poised lever. The nut or stop (L) is set and fixed in such position, that when the
forward end of the counterpoised lever is resting on the catch, the engine driver is
free to use the hand lever (E) for the purpose of applying the brake to his engine
without interfering with, or altering the position of, or releasing the counterpoised
lever. An eye bolt (0) is forged on the lever (N) just above the catch (M) and
to which one end of a light strong rope or wire is attached, the bight of the rope
is then carried over a pulley on the floor, or to the foot of the head gear, to the
height at which it is desired that the brake shall be automatically applied, when
its other end is attached to a lever, fixed at a right angle to the spindle with which
it is connected in the head gear, and which is so fitted that when the cage, truck,
or skip, or other load being raised, touches or comes in contact with the head gear
lever, to which the end of the rope or wire is attached, it causes such lever to be
raised to such an extent that the strain on the rope or wire releases the catch (M),
and causes the counterpoised lever (G) to fall from its horizontal position and to
bring down the connecting rod (K), which in turn pulls forward the lever (E), and
causing the rod (A) to revolve and draw the brake blocks (B. B') together, and to
almost instantaneously stop the engine and arrest the upward motion of the load at
any desired point; by these means the danger of overwinding is, in so far as it can
be controlled by human foresight, absolutely prevented. In order to set the
counterpoised lever for repeated action, it is but necessary to raise it to a horizontal
position by means of the lever (K), and to thrust forward the lever (N), the
catch (M) on the end of which, then passes under and supports the end of the
counterpoised lever, or, by the contrivance previously described (M²) the latter
may be made to automatically set or lock itself.
We do not limit ourselves to the precise details of our invention, as hereinbefore
specified and as illustrated on the accompanying drawings, because equivalent
modifications or variations can be made in such details and quite consistent with
the principles or characteristic features of our invention; but,
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. In an improved engine brake, the general construction, adaptation or
application, and the combination and use of the several parts, in the whole, con-
stituting an improved more simple and efficient means for applying brake power to
engines or other motors or wheels in motion, substantially as herein before set forth
and as illustrated on the accompanying drawings.
2. In an improved engine brake, the general construction adaptation or application
of the several parts, constituting in the whole, an improved more complete and
efficient means for applying brake power to engines and other motora or to wheels
in motion, in connection and in combination with the counterpoised lever (G) the
connecting rod (K) the inverted standard (1) the catch (M) the lever (N) the eye
bolt (O) the line (P) and the levers (Q) in the head gear. The whole combination
forming an improved more complete efficient and automatic means for preventing
overwinding from mines and shafts, by almost instantaneously stopping the engine
after the load has passed the height of the landing stage, substantially as
hereinbefore set forth and as illustrated on the accompanying drawings.
Dated this 8th day of July 1896
EDWARDS & Co.,
65 and 66, Chancery Lane, London, Agents for the Applicants.