Rudders and other Apparatus.
Year: 1887

page_text: Date of Application, 26th Mar., 1887
Complete Left, 22nd Dec., 1887
Complete Accepted, 10th Feb., 1888
Rudders and other Apparatus.
We, DAVID DEHANE NAPIER, WILLIAM DIXON NAPIER, and ALEXANDER KELLY,
of the Windlass Engine Works, Hyde Park Street, Glasgow, in the County of
Lanark, North Britain, Engineers, do hereby declare the nature of this Invention to
be as follows, that is to say :-
Our said Invention has for its object to modify and arrange differential self-
tightening frictional brake apparatus so as to make an improved brake or holder
suitable for application to rudders or other apparatus in which rotation in either
direction has to be controlled or prevented.
In carrying out our Invention we apply to a pulley, drum, or cylindrical boss fixed
on a rudder post, or on a shaft, a frictional brake strap made in two or more
segments. One segment is connected by a link to one end of a short lever, and
another segment on the other side is connected by a link to the other end of the
same lever, whilst the other ends of the segments, or the ends of segments jointed to
them are formed with lugs through which a screw spindle works. The lever is
formed with two fulcrum projections on its inner side, and when the lever is in its
middle position these fulcrum projections fit in fulcrum seats in a stationary block
which is made with its inner side concave and in contact or nearly so with the
circumference of the pulley, drum, or boss to which the brake is applied.
When the brake is required to operate the screw spindle is by means of a hand
wheel turned so as to draw the segments of the strap together; and then any strain
tending to frictionally move round the brake strap will tend to tighten it by causing
the lever to make its effective fulcrum for the time being on one of its two fulcrum
projections and so that if it moves at all it will take more on one side than it gives on
the other and thus tighten the strap.
A hand lever or other convenient appliance may be used instead of the screw
spindle for tightening and loosening the brake strap.
1007
EDMUND HUNT,
Applicants' Agent.

page_text: Improvements in Frictional Brakes or Holders Applicable to
Rudders and other Apparatus.
We, DAVID DEHANE NAPIER, WILLIAM DIXON NAPIER, and ALEXANDER KELLY,
of the Windlass Engine Works, Hyde Park Street, Glasgow, in the County of
Lanark, North Britain, Engineers, 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, that is to say :-
Our said Invention has for its object to modify and arrange differential self-
tightening frictional brake apparatus so as to make an improved brake or holder
suitable for application to rudders or to other apparatus in which rotation in either
direction has to be controlled or prevented.
In carrying out our Invention we apply to a pulley, drum, or cylindrical boss fixed
on a rudder post, or on a shaft, a frictional brake sirap made in two or more
segments, which are connected to opposite ends of a lever piece formed with two
fulcrum projections adapted to fulcrum seats in a block in such a way that one
fulcrum or the other acts according to the direction in which the pulley, drum, or
boss tends to rotate. The lever piece is consequently differential when acting, and if
it moves at all will take more on one side than it gives on the other and thus tighten
the strap. The strap segments may be drawn together to act on the pulley, drum, or
boss, or they may be loosened by means of a screw spindle, or a hand lever or other
convenient appliance.
On an accompanying sheet we show an explanatory drawing which is a sectional
plan of our improved frictional brake or holder as applied to a rudder. The rudder
post, A, has fixed on it a crosshead, B, which has formed in one piece with it a
pulley rim, C. To this pulley rim, C, there is applied a brake strap consisting of
four segments, D, E, F, G, of which two segments, D, G, are connected by links, H, J,
to opposite ends of a lever piece, K. This lever piece, K, is made with two fulcrum
projections, L, M, which fit in fulcrum seats formed in a block, N, set upon a pillar
or standard, P, and made with a concave inner side or face which is in contact or nearly
so with the pulley rim, C. The pillar or standard, P, may conveniently be one of
four which support screw or other steering gear (not shown). Two of the brake-
strap segments, F, G, are formed with lugs, Q, R, through which a screw spindle, S,
works so as to tighten or loosen the strap as required. The screw spindle, S, is
connected by a universal joint, T, to one end of a light shaft, U, the other end of
which (shown as detached) is connected by a second universal joint, V, to a short
shaft, W, carried by a standard, X, and having fixed on it a handwheel, Y.
When the brake is required to operate the screw spindle, S, is turned so as to
draw the segments of the strap together, and then a strain tending to frictionally
move round the brake strap in the direction of the arrow will tend to tighten it by
causing the lever piece, K, to make its effective fulcrum for the time being, the

page_text: fulcrum projection, M, so that the lever arm acting on the link, J, will be longer than
that acting on the link, H. If the strain is in the opposite direction the projection, L,
will become the effective fulcrum, and the link, H, will be drawn over further than
the link, J, is allowed to go, and the strap will be similarly tightened.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed, we declare that what we
claim is :-
The improved frictional brake or holder consisting of a strap applied to a pulley,
drum, or boss, provided with means for tightening or loosening it, and connected to
opposite ends of a lever piece made with two fulcrum projections to fit into fulcrum
seats in a block; the parts being combined and operating substantially in the manner
herein before described.
Dated this Thanty first dose of Dasamb 1007
EDMUND HUNT,
Applicants' Agent.