Improvements in Windmills and Wind-motors.
Year: 1897

page_text: Date of Application, 9th Aug., 1897
1000
PROVISIONAL SPECIFICATION.
Improvements in Windmills and Wind-motors.
I, JAMES DUNDAS WHITE, of 3, Paper Buildings, Temple, in the County of
London, Barrister-at-Law, do hereby declare the nature of this invention to be as
follows:
A horizontally revolving windmill or wind-motor with sails hung vertically on
a framework fitted round the shaft, each sail being hung on pivots with the pivotal
axis sufficiently far from the centre of resistance that the sail, when swinging
freely, feathers to the wind with the larger side to leeward. Each sail feathers
thus during its passage up-wind, and on reaching the windward point the larger
side of it encounters a stop on the framework by which it is intercepted and the
sail is thus spread during its passage down-wind, till, on its passing the leeward
point, the wind, taking it aback, swings it to the feather again. The sail-carrying
framework is such as to reduce to a minimum the transverse strain on the shaft.
Each stop intercepts the larger side only of the sail and is connected with the frame-
work both above and below the sail so that it intercepts the sail right across; it
is so fitted that it has a parallel movement such that raising it draws it towards
the shaft and clear of the sail altogether, while releasing it lets it return to the effec-
tive position. A controlling line led through the shaft is connected to the stops
by a system of blocks and bridles such that drawing in the line raises those
stops which offer least resistance first, and that so doing when the windmill or
wind-motor is revolving thus raises the various stops as the sails are feathering
clear of them.
Improvements in Windmills and Wind-motors.
I, JAMES DUNDAS WHITE, of 3, Paper Buildings, Temple, in the County of
London, Barrister-at-Law, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
This invention relates to improvements in windmills and wind-motors of the
horizontal class. In the accompanying drawings Fig. 1, represents an elevation
and Fig. 2 a plan of a horizontal windmill, Fig. 3 represents a sail fitted for auto-
matic regulation, and Fig. 4 a combination of blocks and bridles alternative to
that shewn in Fig. 1.

page_text: A is the shaft, supported by the collar B which rests on supporting struts C C C C
On the shaft is fitted a sail-carrying framework D D D D constructed so to locate
the sails as to minimize the transverse strain on the shaft. The arms of the frame-
work are connected in horizontal series by braces not shewn in the drawings, and
the upper arms, which sustain the weight of the sails, are stayed to the head of
the shaft by the braces F F.
EEEE are the sails, each of which is hung vertically between the corresponding
arms of the framework by the pivots G G in such a way that in each sail the pivotal
axis is sufficiently far from the centre of resistance that the sail, when swinging
freely, feathers to the wind with the larger side to leeward. As regards balance,
each sail is in equilibrium about its pivotal axis.
HHHH are intercepting stops, each consisting of a vertical rod connected to
the framework by hinged cross-bars of equal length so that the vertical parallelism
of the rods is preserved and that raising them and letting them drop causes them
to move towards and from the shaft respectively; the proportions are such that
each stop, when in the dropped or effective position (as shewn in Fig. 1 by the
ordinary lines) prevents the larger side of the sail passing through between the
arms, and when in the raiséd or idle position (as shewn in Fig. 1 by the dotted
lines) is clear of it. Each stop is fitted so as to prevent its falling below the
effective position, or being raised in the idle position beyond that extreme from
which, when released, it will automatically fall back to the other. Each stop
is fitted so as to be interposed between the two sail-carrying arms on the one side
and the sail on the other. Buffers may be fitted to reduce the jar of the sail
striking the stop.
The stops are controlled by means of the line J which passes over a sheave
near the top of the shaft and is connected to the stops in either of the following
ways. To the end of the line J are attached as many blocks (K K' in Fig. 1) as
there are pairs of stops, and each opposite pair of stops are connected by a bridle
(L in Fig. 1) rove and running freely through one of these blocks. Or the line J
may be attached to a single block, through which is similarly rove a bridle, to
each end of which is attached another block, through each of which again is rove
a bridle, of which each end is attached to a stop; this alternative arrangement
of blocks and bridles is shewn in Fig. 4 and is applicable where the stops are four
in number. Both arrangements are such that drawing in the line J operates to
raise those stops which offer least resistance first, and that so doing when the
windmill is revolving raises the various stops when the sails are clear of them.
The controlling line J is led down through the shaft and connected to the
collar M, which is fitted on and revolves with the shaft but of which the vertical
height may be regulated by the apparatus N, moving on the vertical rod O and
fitted with the counterpoise P; the arrangement being such that normally the
stops outweigh and sustain the collar M and the counterpoise P keeps the ap-
paratus N clear of it, but that drawing down the apparatus makes the wheel Q
impinge upon and depress the collar M, so drawing in the line J.
The operation of the windmill is as follows; when the windmill is revolving,
as each sail reaches the windward point the larger side of it encounters the stop
and is by it kept spread till the sail reaches the leeward point when the wind,
taking the sail aback, swings the larger side round to leeward, and the sail is
carried up-wind on the other side, feathering on its pivots, till at the windward
point the larger side again encounters the ston.
The revolution is stopped by drawing all the stops to the idle position, thus
letting all the sails feather together. The revolution is started by letting the
stops resume the effective position and by turning the shaft sufficiently to make
the sails draw; this may be done by a lever so fitted as to be effective in one
direction only, and to become disconnected by the contrary strain.
The arrows W W indicate the direction of the wind.
Automatic regulation may be obtained by making part of each sail consist of
one or more hinged slats, as shewn in Fig. 3, so constructed that normally each

page_text: is in the same plane as the rest of the sail, but that excess of wind-pressure
makes it lift and so diminishes the efficiency of the sail.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a horizontal windmill or wind-motor the combination with the shaft of
a sail-carrying framework of the design shewn in the accompanying drawings,
substantially as herein described.
2. In a horizontal windmill or wind-motor intercepting stops connected with
the framework by hinged cross-bars and having a parallel movement, substantially
as herein described.