IMPROVEMENTS IN HYDRAULIC CAPSTANS
Year: 1877

page_text: LETTERS PATENT to Andrew Betts Brown, of Rosebank Iron Works, Edin-
burgh, in the County of Edinburgh, for the Invention of "IMPROVEMENTS IN
HYDRAULIC CAPSTANS."
Sealed the 1st February 1878, and dated the 16th November 187
PROVISIONAL SPECIFICATION left by the said Andrew Betts Brown
at the Office of the Commissioners of Patents on the 16th November
1877.
ANDREW BETTS BROWN, of Rosebank Iron Works, Edinburgh, in the County of
Edinburgh. IMPROVEMENTS IN HYDRAULIC CAPSTANS."
"
My Invention has for its object improvements in hydraulic capstans for pulling
trucks or warping ships.
Hitherto these capstans have been made with their hydraulic engines attached to
a bed plate, the capstan head being connected to the crank shaft which works in
bearings provided in the bed plate. Such an arrangement necessitates a pit of
sufficient size to enable the engines to be examined for repairs and oiling.
My improvements consist in placing the hydraulic engines in the revolving capstan
head, the post or shaft round which the capstan revolves being stationary and
held in the bed plate. For this purpose I construct a cruciform casting, which forms
the base plate, and is held down by four bolts embedded in a mass of concrete.
Into this casting I key fast a hollow post. Upon this post runs the capstan, having
its bearing close to the cruciform base plate, and also at the point of the post.
Above the bearing and keyed fast to the post I place an excentric having double
flanges. At equal distances on the periphery of the capstan head I arrange four
pendulous hydraulic cylinders, having their strokes to suit the throw of the excen-
tric. Into these cylinders work rams, provided with the usual cup leathers. These
rams are provided at their outer extremity with double jaws, in which run two
chilled cast-iron wheels, bearing on the excentric.

page_text: On the top of the post a cylindrical hydraulic valve is attached, round which is
fitted a corresponding casing, this casing being attached to the capstan head. From
four branches of this casing, pipes proceed to the four pendulous cylinders, such
pipes being made spiral in form, to permit the slight movement of the cylinders
without stuffing boxes. This cylindrical valve has pressure and exhaust ports.
The pressure port is connected with a centre pipe passing through the hollow post,
and the exhaust port connected with the annular space in the post. Cup leathers
are introduced in the usual manner at top and bottom of this cylindrical valve
casing to prevent leakage of water.
The lower portion of the capstan head, containing the cylinders, is of much
larger diameter than the upper or capstan head proper, thereby enabling a second
power to be obtained.
The upper portion of the capstan, being merely a hollow shell or barrel, is
attached to the lower portion by a hinge on one side, and a locking bolt on the
other, so that it may be inoved by up-ending on the hinge, and so exposing to sight
the hydraulic engines.
In place of the cylindrical valve herein-before described, four slide valves of
ordinary description can be arranged at equal angles, all of which may be worked by
one excentric attached to the top of the post:
The pressure water is led in at the centre pipe, while the exhaust returns by a
pipe led into the side of the post and communicating with the annular space. When
the pressure water is admitted to the capstan, the cylinders revolve with the capstan
head, the excentric remaining stationary.

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
13th May 1878.
ANDREW BETTS BROWN, of Rosebank Iron Works, Edinburgh, in the County of
Edinburgh. "IMPROVEMENTS IN HYDRAULIC CAPSTANS."
My Invention has for its object improvements in hydraulic capstans for pulling
trucks or warping ships.
Hitherto these capstans have been made with their hydraulic engines attached to
a bed plate, the capstan head being connected to the crank shaft which
works in bearings provided in the bed plate. Such an arrangement necessitates
a pit of sufficient size to enable the engines to be examined for repairs and
oiling.
My improvements consist in placing the hydraulic engines in the revolving
capstan head, the post or shaft round which the capstan revolves being stationary
and held in the bed plate. For this purpose I construct a cruciform casting, which
forms the base plate, and is held down by four bolts embedded in a mass of concrete.
Into this casting I key fast a hollow post. Upon this post runs the capstan,
having its bearings close to the cruciform base plate, and also at the point of the
post. Above the bearings and keyed fast to the post I place an excentric having
double flanges. At equal distances on the periphery of the capstan head I arrange
four pendulous hydraulic cylinders, having their strokes to suit the throw of the
excentric. Into these cylinders work rams, provided with the usual cup leathers.
These rams are provided at their outer extremity with double jaws, in which run
two chilled cast-iron wheels bearing on the excentric.
On the top of the post a cylindrical hydraulic valve is attached, round which is
fitted a corresponding casing, this casing being attached to the capstan head. From
four branches of this casing, pipes proceed to the four pendulous cylinders, such
pipes being made spiral in form to permit the slight movement of the cylinders
without stuffing boxes. This cylindrical valve has pressure and exhaust ports. The
pressure port is connected with a centre pipe passing through the hollow post and
the exhaust port connected with the annular space in the post. Cup leathers are
introduced in the usual manner at top and bottom of this cylindrical valve casing
to prevent leakage of water.
The lower portion of the capstan head, containing the cylinders, is of much larger
diameter than the upper or capstan head proper, thereby enabling a second power to
be obtained.
The upper portion of the capstan, being merely a hollow shell or barrel, is
attached to the lower portion by a hinge on one side, and a locking bolt on the
other, so that it may be moved by up-ending on the hinge, and so exposing to sight
the hydraulic engines.
In place of the cylindrical valve herein-before described, four slide valves of
ordinary description can be arranged at equal angles, all of which may be worked
by one excentric attached to the top of the post.
The pressure water is led in at the centre pipe, while the exhaust returns by a
pipe led into the side of the post and communicating with the annular space.
When the pressure water is admitted to the capstan, the cylinders revolve with the
capstan head, the excentric remaining stationary.
In order that my said Invention may be most fully understood and readily
carried into effect, I will proceed to describe the Drawings hereunto annexed.

page_text: In Fig. 1 A is the cruciform casting, which is shewn in section with the bolt
holes B, B; two similar arms with bolt holes being formed at right angles,
but not shewn on the Drawing. Through these holes pass holding-down bolts,
which are anchored in a suitable mass of concrete.
A steel post C is keyed fast into this casting. This post is hollow, and has fitted
through its hollow centre a pressure pipe D, the flange E of which closes the lower
end tight. An exhaust branch F passes through the cruciform casting, and is
screwed into the side of the post communicating with the annular space which
exists between the outside of the pressure pipe D and the inside of the hole
through the post. The area of this annular space is made somewhat larger
than the area of the pressure pipe D, to give a free exhaust for the waste
water.
On the top of the post is fixed the cylindrical valve G, which is shewn to a larger
scale in Figures 3 and 4, as well as another alternative valve, Fig. 5 and 6, which
will be described further on.
The revolving capstan head is shewn at H, and it runs upon the steel post on its
bearings I and K.
At the centre of the bearing I at L a recess is formed which is filled with hemp
packing to render the revolving capstan head water-tight. Above the bearing I is
an eccentric M, having double flanges, which is keyed fast to the post. Between the
flanges (and bearing upon the excentric)run four pairs of rollers N, N, N, &c. These
rollers have their bearings in four hydraulic rams 0, 0, 0, 0, which have jaws formed
to receive the wheels, as shewn. These rams work in four corresponding pendulous
cylinders P, P, P, P, which have their oscillating bearings formed at equal distances
round the periphery of the revolving drum at Q, Q, Q, Q.
From the side of each of these cylinders branches off a spiral coil pipe R, R,
shewn in the section, Figure 1, of steel, which leads up to the valve G, which is
provided with four branches. The object of these flexible pipes is to permit the
cylinders to oscillate without the use of stuffing boxes.
To prevent the cylinders and rams with rollers from straying away from the
excentric a ring S embraces the whole of the upper portion of the roller pins upon
which are fitted bearing blocks T, T, T, T.
On the top of the revolving "capstan H is fitted the winding drum casting U,
which is hinged at V. This is made of two diameters suitable for giving two vary-
ing powers. It is arranged when closed to make contact with the top bearing
casting K at W, so as to take the strain directly upon the post. The lower part
unites with the capstan H, by means of a male and female groove X, and a locking
bolt arranged opposite the hinge V.
The valve G is shewn in large section in Fig. 3 and 4, in which the pressure pipe
D is connected tightly to the fixed cylindrical valve A, which has a pressure port B,
and an exhaust port C, which communicates with the annular space in the post E.
Round this cylindrical valve A is fitted the valve casing F, which has cup leathers
arranged above and below the ports at G and H. This casing revolves with the
capstan and has four branches, as already described, I, I, I, I, which lead through
the spiral pipes to the pendulous cylinders. When pressure water is admitted
through the pipe D, the capstan revolves, and with it the casing F, each cylinder
receiving pressure water and exhausting accordingly, as the valve casing F exposes
its ports to the pressure port B and the exhaust port C, the waste water
returning through the annular space to the pumping engines by the branch pipe F,
Fig. 1.
Fig. 5 and 6 shew in section and plan an alternative valve, which possesses
advantages of greater durability. In this valve four parts I, I, lead by the spiral
pipes to the pendulous cylinders. These terminate in four ports A, A, on the valve
face. Nearer the centre of the face are four exhaust ports B, B, all of which com-
municate with the annular space of the post at E. Four slide valves F, F, of the
ordinary single-acting description work in guides G, G, G, &c. On the back of
these valves is fitted an excentric strap H, which works in a groove in swivel

page_text: bushes J, J, J. This strap works upon the excentric K, which is fixed to the hollow
post C. This valve face is covered over by a valve chest L, which, together with
the face, moves round with the capstan. The pressure water passes through the
pipe D into the interior of this valve chest, and presses on the back of the slide
valves. As the capstan and valve chest revolve round the fixed excentric K, the
slide valves admit water to the pendulous cylinders and exhaust alternately, as
they move round.
Having thus described the nature of my said Invention, I would have it under-
stood that I do not confine myself to the exact details, but what I claim is,―
1st. Arranging the hydraulic engines in the revolving drum of the capstan, the
rams acting by friction rollers upon a fixed excentric or its equivalent, substantially
as herein-before described.
2nd. Conveying the pressure water or other fluid by a pipe leading through a
hollow capstan post, and returning the waste fluid by the annular space, sub-
stantially as herein-before described.
3rd. The arrangement of cylindrical or slide valves in which the valve face is
driven round by the capstan, while the valve remains stationary, in combination
with water passages in the hollow post, substantially as herein-before described.
4th. The construction of capstans, substantially as herein-before described.
In witness whereof, J, the said Andrew Betts Brown, have hereunto set my
hand and seal, this Eleventh day of May, in the year of our Lord One
thousand eight hundred and seventy-eight.
ANDREW RETT'S BROWN