Year: 1886

page_text: WILLIAM HENRY DINES BA FR Met. S Graduate of Cambridge University,
Woodside Hersham Walton on Thames do hereby declare the nature of this inven
tion to be as follows ---
This instrument consists of an axle driven by the action of the wind upon a pair
of small sails similar to those of a windmill. The pitch at which the sails are
inclined to the wind is altered automatically so that whatever the friction of the
instrument, the angular velocity of the axle will always bear the same ratio toʻ
the velocity of the wind. This is effected by fixing upon the same axle as the
sails, a thin piece of metal, beaten out into the shape known mathematically as a
helicoid, & called the regulator. Behind this, between it & the sails, a fan is
placed. This fan is free to rotate about the same axis as the sails & regulator, but
is entirely independent of them. If the instrument be rotating too slowly, the
wind is deflected in passing over the regulator, & turns the fan, which by its'
rotation, increases the pitch of the sails, & thereby quickens the rate of the
instrument. The reverse effect occurs if the rotation be too fast.

page_text: I, WILLIAM HENRY DINES, B.A. Graduate of Cambridge University of Woodside,
Hersham Walton on Thames do hereby declare the nature of my invention for
MEASURING THE VELOCITY OF A CURRENT OF AIR OR OTHER FLUID; and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
The instrument consists of an axle, driven by the action of the wind upon a
pair of small sails, their pitch being altered automatically, so that, whatever the
friction of the instrument, the angular velocity of the axle will always bear the
same ratio to the velocity of the wind.
I will now explain, with the aid of drawings, the manner in which this is
performed.
Drawing No I represents a vertical section in a plane parallel to the direction of
the wind; No II, a horizontal section; No III a vertical section in a plane at right
angles to the direction of the wind.
The steel rod A A is turned by the action of the wind or current of air, the
velocity of which is to be measured, upon the sails B. B. (These sails and the
fan N N are not shewn in Section III.)
The motion is communicated to the vertical rod C C, by means of the endless
screw D, two toothed wheels and a pinion. The sails are free to turn within
small limits upon the steel rod E E, so that the pitch at which they are inclined
to the wind, can be altered. The pitch is regulated by the position of the
cranks F&F, the pins of the cranks working into the slots G & G. The piece
of metal containing these slots turns with the rod A A, but is free to slide upon it
longitudinally, its position being determined by the position of the rod H H, which
has a tongue K keyed on it, which fits loosely into the circular groove L. The
front of the rod A. A carries a piece of thin metal M M, of a particular shape, which
I call the regulator. Behind this, a fan of four arms N N is placed.
The rod A A. turns in the hole drilled in the casting 00. The fan turns on
the tubular part of this casting, so that both turn about the same axis, but are
independent of each other.
The fan is kept in place by the casting, but the weight is taken chiefly by the
small friction wheel Q. This wheel has a series of grooves turned in it, the
grooves fitting into the threads of the screw R, which is cut upon the tube carrying
the arms of the fan. The rod S is inserted to take the weight of the friction wheel
and fan, and thereby lessen the friction between the rod HH and its guides.
The rod S is adjusted by the screw T and is kept in place by the guide V.
The whole instrument is pivoted upon the hollow spindle W W, and is kept
facing the wind by the vane X.
The registration is effected by counting the number of turns of the vertical
rod C C. This is done by means of any light counting machine, placed in any
convenient position below the instrument, the connection being made by a flexible
wire of the required length. It is convenient to make the rod C O turn ten times
to each mile.

page_text: The shape of the regulator M. M. is that known as a helicoid. It is such that
the tangent of the angle between any small portion of its surface, and the axis A A
is proportional to the distance of such small surface from the axis. The blades of
the fan N N must be parallel to the rod A A, so that if the helicoid M M were
removed, the wind would have no tendency to turn them. The instrument may
be made of any size, but since the pitch of the sails is automatically adjusted, so
that the driving power of the wind upon them is always such as causes that part-
of the helicoid which is inclined at an angle of 45 degrees to the axis, to move
with the same velocity as the wind, the parts must be arranged in accordance with
this fact to ensure correct measurement.
For instance, in the instrument shewn full size in the drawings, this part of
the helicoid is 84 inches from the axis;-the endless screw works into a wheel
of 24 teeth, and a pinion of 6 teeth connected with that, works into a wheel
of 30 teeth; hence to cause the rod C C which carries the wheel of 30 teeth,
to turn once, the part of the helicoid considered, must move through a distance
of 16-8 × × 24 x 5 inches, or 528 feet, which is the tenth part of a mile.
The automatic adjustment is as follows:
22
If the rod A A, with its accompanying sails and regulator, be turning too
slowly, the wind is deflected in passing over the helicoid surface of the regulator
and turns the fan in a direction contrary to that of the hands of a watch. The
friction wheel is then drawn backward by the action of the screw R, carrying
with it the rod H H and the tongue K, which by means of the groove Land the
slots G G, alters the pitch of the sails, so that the rate at which they turn is
increased. If the rod be turning too quickly, the reverse effect occurs.
The readings of the instrument are thus rendered independent of its friction, for
all but very light winds, as any alteration in the amount of friction alters the
pitch of the sails which drive it, but not the rate of rotation.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
'
"
1st. The use of the particular shape of curved surface, which is herein described
as the regulator of the instrument, and which is defined by mathematicians as
a helicoid, whether used by itself, or in the manner herein described, or in any
other manner, for the purpose of measuring the velocity of any current of air
or other fluid.
"
2nd. The principle by which the deflection of a current of air or other fluid,
passing over a moving surface of the form herein described, or of any other form
that may be found convenient, is used for the purpose of automatically altering
the rate at which such surface is moving.
Dated this 11th dox of Ontahan 1008 ·