IMPROVE- MENTS IN HYDRAULIC CAPSTANS AND IN VALVES FOR DISTRIBUTING THE FLUID PRESSURE TO THE ENGINES THEREOF
Year: 1878

page_text: LETTERS PATENT to Andrew Betts Brown, of Rose Bank Iron Works,
Edinburgh, in the County of Edinburgh, for the Invention of "IMPROVE-
MENTS IN HYDRAULIC CAPSTANS AND IN VALVES FOR DISTRIBUTING THE FLUID
PRESSURE TO THE ENGINES THEREOF."
Sealed the 19th July 1878, and dated the 3rd April 1878.
PROVISIONAL SPECIFICATION left by the said Andrew Betts Brown at the
Office of the Commissioners of Patents on the 3rd April 1878.
ANDREW BETTS BROWN, of Rose Bank Iron Works, Edinburgh, in the County
of Edinburgh. "IMPROVEMENTS IN HYDRAULIC CAPSTANS AND IN VALVES FOR
DISTRIBUTING THE FLUID PRESSURE TO THE ENGINES THEREOF."
My Invention has for its object improvements in hydraulic capstans of large
power, in which the machinery is contained in the capstan head. On the 16th
November 1877, Letters Patent were granted to me (No. 4288), in which I
described a capstan having four single-acting pendulous cylinders placed in the
capstan head, operating by rams and rollers upon a fixed excentric keyed to the
capstan post, through which the pressure water passed to a valve chest which
revolved with the capstan.
My improvements now relate,-
In the first place, to an arrangement of revolving excentric attached to the light-
powered capstan barrel in conjunction with levers and pawls, to enable me to
obtain very high and variable hauling powers on a larger capstan drum, running
on a turntable and encircling the upper capstan.
Secondly. To an improved valve for distributing the water or other pressure
fluid to the revolving cylinders in the upper or light-powered capstan. In such
large capstans I bed down a large circular plate, which is anchored by strong bolts
to a mass of concrete in the ground. In the centre of this plate I key fast a
hollow mast of steel or other suitable material. Round the outer edge of this bed plate
I arrange a series of teeth, into which work four or more pawls placed at equal
distances round the circle. These pawls are worked by short levers keyed to shafts,

page_text: which pass upwards in strong bearings into the large drum of the capstan. At the
top of this drum and close to the upper capstan other levers are keyed fast, which
are made longer than the lower levers to obtain greater power. To the end of these
long levers are attached connecting rods, the other ends of which have each two
roller wheels placed at their extremity. These wheels bear upon an excentric
which is keyed fast (when two powers only are required) to the under side of the
upper capstan. The four sets of connecting rods with their wheels are embraced
together by a ring free to revolve, which prevents them from straying from their
position on the excentric. Just inside the toothed rack is a roller path, upon which
runs a series of live rollers with their fraines to keep them in position. The large
capstan drum has a similar path turned upon it which rests on the upper part of
the rollers, and it has also a bearing at the centre which runs on the post or mast.
Higher up on this post a collar is placed, upon which rests the revolving excentric
which works the pawls.
The upper capstan, which is fully described in the aforesaid Patent, No. 4288,
has four pendulous cylinders, which receive the necessary distribution of water from
a valve, which forms the second part of my improvements. This valve is of the
circular flat description, having a face containing four ports leading to each of the
cylinders. Upon this face is fitted a casing attached by four or more bolts; on the
under side of the valve a bearing is arranged to work on the point of the steel post,
having a stuffing box to prevent the leakage of the return water. In continuance
with this bearing the hole in connection with the post passes to the inside or
exhaust space of the valve. The pressure water is brought through the centre of
the post by a strong wrought-iron pipe, which terminates in an excentric into
which it is made water-tight; on the upper portion of this excentric four holes
communicate with the centre of the said pipe and pass into the valve casing. Tho
excentric is prolonged through the top of the casing into the atmosphere through
a stuffing box to prevent escape of pressure water. Round the lower excentric a
ring is placed bearing on the valve face and forming a valve which is thus placed
partially in equilibrium, and into which is inserted a cup leather or other suitable
packing to prevent the pressure water passing into the exhaust. The excentric
and centre pressure pipe are made fast to the post while the valve face and casing
revolve with the capstan, the effect of which is that the valve ring receives a
species of planetary motion, and so keeps the valve and face always true and in
good order. As the valve face revolves the ports leading to their respective
cylinders are alternately exposed to pressure, and exhaust the waste water returning
through the annular space of the post.
A capstan constructed on the before-mentioned system will have two powers,
viz., that appertaining to the upper barrel (which makes as many revolutions as
there are teeth in the lower bed plate for one revolution of the lower barrel), and
to the lower barrel which moves so much slower with a correspondingly augmented
power.
When it is desirable to obtain a greater number of powers this may be effected
by making the revolving excentric to slide in grooves on the under side of the
quick speed capstan so as to give it more or less of excentricity, such sliding move-
ment being actuated by a rod and bevil wheels and screw, the said rod passing up
through the top of the quick speed capstan so as to be accessible froin without.
When such an arrangement is adopted it is necessary to multiply the number of
pawls in proportion to the number of different speeds and powers required from
the lower drum.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Andrew Betts Brown in the Great Seal Patent Office on the 1st
October 1878.
ANDREW BETTS BROWN, of Rose Bank Iron Works, Edinburgh, in the County
of Edinburgh. "IMPROVEMENTS IN HYDRAULIC CAPSTANS AND IN VALVES FOR
DISTRIBUTING THE FLUID PRESSURE TO THE ENGINES THEREOF."
My Invention has for its object improvements in hydraulic capstans of large
power, in which the machinery is contained in the capstan head. On the Sixteenth
November, One thousand eight hundred and seventy-seven, Letters Patent were
granted me (No. 4288) in which I described a capstan having four single-acting
pendulous cylinders placed in the capstan head operating by rams and rollers upon
a fixed excentric keyed to the capstan post, through which the pressure water passed
to a valve chost which revolved with the capstan.
My improvements now relate,-
In the first place, to an arrangement of revolving excentric attached to the
light-powered capstan barrel, in conjunction with levers and pawls to enable me
to obtain very high and variable hauling powers on a larger capstan drum
running on a turntable and encircling the upper capstan.
Secondly, to an improved valve for distributing the water or other pressure fluid
to the revolving cylinders in the upper or light-powered capstan.
In such large
capstans I bed down a large circular plate, which is anchored by strong bolts to a
mass of concrete in the ground. In the centre of this plate I key fast a hollow
mast of steel or other suitable material. Round the outer edge of this bed plate I
arrange a series of teeth, into which work four or more pawls placed at equal dis-
tances round the circle. These pawls are worked by short levers keyed to shafts,
which pass upwards in strong bearings into the large drum of the capstan. At the
top of this drum and close to the upper capstan other levers are keyed fast, which
are made longer than the lower levers to obtain greater power. To the end of these
long levers are attached connecting rods, the other ends of which have each two
roller wheels placed at their extremity. These wheels bear upon an excentric which
is keyed fast (when two powers only are required) to the under side of the upper
capstan. The four sets of connecting rods with their wheels are embraced together
by a ring free to revolve, which prevents them from straying from their position on
the excentric. Just inside the toothed rack is a roller path, upon which runs a
series of live rollers, with their frames to keep them in position. The large capstan
drum has a similar path turned upon it which rests on the upper part of the
rollers, and it has also a bearing at the centre which runs on the post or mast.
Higher up on this post a collar is placed, upon which rests the revolving excentric
which works the pawls.
The upper capstan, which is fully described in the aforesaid Patent, No. 4288,
has four pendulous cylinders, which receive the necessary distribution of water
from a valve, which forms the second part of my improvements. This valve is of
the circular flat description, having a face containing four ports leading to each of
the cylinders. Upon this face is fitted a casing attached by four or more bolts. On
the under side of the valve a bearing is arranged to work on the point of the steel
In con-
post, having a stuffing box to prevent the leakage of the return water.
tinuance with this bearing the hole in connection with the post passes to the inside
or exhaust space of the valve. The pressure water is brought through the centre of
the post by a strong wrought-iron pipe, which terminates in an excentric, into
which it is made water-tight. On the upper portion of this excentric four holes
communicate with the centre of the said pipe and pass into the valve casing. The
excentric is prolonged through the top of the casing into the atmosphere through a

page_text: stuffing box, to prevent escape of pressure water. Round the lower excentric a ring is
placed bearing on the valve face and forming a valve, which is thus placed partially in
equilibrium, and into which is inserted a cup, leather, or other suitable packing to
prevent the pressure water passing into the exhaust. The excentric and centre pressure
pipe are made fast to the post, while the valve face and casing revolve with the cap-
stan, the effect of which is that the valve ring receives a species of planetary motion,
and so keeps the valve and face always true and in good order. As the valve face
revolves the ports leading to their respective cylinders are alternately exposed to
pressure, and exhaust the waste water returning through the annular space of the
post.
A capstan constructed on the before-mentioned system will have two powers,
namely, that appertaining to the upper barrel (which makes as many revolutions as
there are teeth in the lower bed plate for one revolution of the lower barrel) and to
the lower barrel, which moves so much slower with a correspondingly augmented
power.
When it is desirable to obtain a greater number of powers this may be effected
by making the revolving excentric to slide in grooves on the under side of the quick
speed capstan so as to give it more or less of excentricity, such sliding movement
being actuated by a rod and bevil wheels and screw, the said rod passing up through
the top of the quick speed capstan so as to be accessible from without. When such
an arrangement is adopted it is necessary to multiply the number of pawls in
proportion to the number of different speeds and powers required from the lower
drum.
These are shewn in the accompanying Sheet, in which,—
Figure 1 represents a vertical section of my improved capstan.
Figure 2 is a partial section taken in plan on line A, B, the other and lower half
of the section on line.C, D.
Figure 3 shews a vertical section of my improved valve, and Figure 4 is a plan
of the same.
Figure 5 shews alternative arrangement of lever and connecting rod.
In Figure 1 A is the revolving light-powered capstan, as described in Letters
Patent, No. 4288, 1877. This capstan revolves upon the post B, which is hollow,
and at the top carries the improved valve C. On the top of this capstan a cover
for hand spokes is arranged at D; on the under side of this light-powered capstan
a square boss is formed, E, upon which an eccentric sheave F slides, being pulled
out, and in in its eccentricity by a screw G, shewn in dot lining. This is actuated
by bevel gear H and a rod I, passing up through the top of the capstan, and termi-
nating in a hand wheel J at the top.
It will be seen that by this arrangement the degree of eccentricity of the sheave F
can be altered until the sheave becomes concentric. Working round the periphery
of this eccentric sheave are four wheels K, K, &c.; these wheels have their axles
attached to corresponding long levers L, L, &c., which levers are in turn keyed fast
to shafts M, M, M; these shafts are carried in bearings N, N, N, N, formed in the
lower capstan drum O. On the under side of these shafts is formed a box or short
lever, in which work four or more pawls P, P, P, P, &c., which engage in a toothed
rack Q; this is formed in one with the lower bed plate R, which serves as a foundation
to the whole machine. Outside this plate is turned a bevel roller path S, S, having
a series of rollers T, T, with frame similar to that of a railway turntable. The
upper portion of the capstan O is turned with a similar bevil, and rests upon these
live rollers. The pawls P are forced outwards by india-rubber or other springs U,
each pawl acting independently of the others.
From this arrangement it will be seen that on the upper capstan A revolving,

page_text: and carrying with it the eccentric sheave F, set to its maximum eccentricity, every
revolution of the said capstan will cause the levers to make a complete stroke, and
so advance the lower capstan O through one of the toothed racks in the foundation
ring Q. There being four such levers and sets of pawls, the motion is nearly con-
tinuous. By altering the eccentricity of the sheave F to one-half its maximum
stroke each revolution of the upper capstan A will advance the lower capstan drum
O through one-half of one of the toothed racks. In like manner by further dimi-
nution of eccentricity one-fourth of a toothed rack may be taken, thus varying the
power and speed of the lower capstan drum O.
To prevent the rollers K straying from the eccentric sheave a ring is made to
embrace their axles with block working inside the ring, as shewn.
The pressure water or other fluid is introduced through a hollow in the post B
by a pressure pipe A, which terminates in the valve chest (Figures 3 & 4), the
water passing into the casing by holes B, B. This pipe serves also to hold the
eccentric C, into which it is made water-tight. The eccentric is prolonged con-
centrically through the top of the casing 1 through the stuffing box E into the
atmosphere for the purpose of balancing its lower portion, which is open to the
exhaust passage at F; this passage is in communication with the annular space
between the pipe A and the hole in the post G. Round this eccentric a ring H is
fitted, having a cup, leather, or other packing I to prevent the passage of pressure
water through to the exhaust, this ring being free to revolve upon the eccentric.
The ring rests on the valve face J in such a way as to embrace the annular space
through the post, and also the ports K, K, K, K, as they revolve; these ports com-
municate by suitable branches and pipes with the pendulous cylinders in the light-
powered capstan. The pipe A is inade fast to the lower end of the post at W
(Figure I.), and the annular space communicates with the return water pipo
at X.
The effect of this arrangement is that the valve face J and casing D being attached
to the upper capstan revolve with it, while the eccentric C is stationary, thus
bringing the different ports leading to the cylinders alternately within and without
the valve ring H, exposing them alternately to pressure and exhaust. While this
motion takes place the ring H revolves upon its own axis, effectually neutralizing
the tendency of the valve face J to wear unevenly. The ring H is also partially
in equilibrium, and it is free to slide down as any wear upon the face takes place.
The casing D is held down by four bolts in the usual manner, while the eccentric
casting C is attached to the tube A by a clutch L, which permits the direction
of the capstan to be reversed if necessary. The whole valve casing runs on the
point of the post, being provided with a stuffing box at M to prevent the escape of
exhaust water.
Figure 5 shews the arrangement of connecting rod A with double wheels B, B,
attached to the lever L, as herein-before described.
The valve, as herein-before described, may of course be used in the case of a
three or four cylinder engine, wherein the cylinders are stationary, as well as the
valve face, while the eccentric C rotates, in which case the fluid would be admitted
to the casing D by a branch.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that I do not confine myself to
the exact details herein-before mentioned, but what I claim is,-
1st. Constructing large-powered capstans by an arrangement of quick-running
light-powered capstan built on the top of a druin, in which is arranged a series of
levers and pawls actuated by an excentric or its equivalent, substantially as herein-
before described.
Second. Arranging capstans of high power, so that the upper portion may be
disengaged and thrown out of gear by bringing the excentric or its equivalent into
concentricity.
Third. Constructing flat-faced rotary slide valves in such manner that the valve

page_text: proper embraces the exhaust and admission ports, and at the same time rotates on
its axis, which is excentric to the valve face centre, substantially as herein-before
described.
In witness whereof, I, the said Andrew Betts Brown, have hereunto set my
hand and seal, this Thirtieth day of September, in the year of our Lord
One thousand eight hundred and seventy-eight.
ANDREW BETTS BROWN. (L.S.)