A NEW OR IMPROVED FLYING OR AERIAL TOY
Year: 1876

page_text: PROVISIONAL SPECIFICATION left by John Clayton Mewburn at the Office
of the Commissioners of Patents on the 28th July 1876. A communication
from abroad by La Société Dandrieux Gravier et Compagnie, of Paris, France.
JOHN CLAYTON MEWBURN, of 169, Fleet Street, in the City of London, Patent
Agent and Consulting Engineer. "A NEW OR IMPROVED FLYING OR AERIAL TOY."
.This Invention consists of a new or improved toy which the inventors call
"helicoptre." It is in the form of a bat, and is based on the principle of two
screws, the rotation of which in contrary directions, produced by the twisting of a
spring situated between them, raises the apparatus or toy into the air and maintains
it there until the complete exhaustion of the torsion of the spring.
The toy consists of a frame or central portion formed of two longitudinal rods of
reed the ends of which are embedded and fixed in two pieces of cork which keep
them in the same relative position. Between the two rods is a spring formed of
india-rubber threads stretched between two hooks which are fitted respectively to
the upper and lower corks. The upper hook is rigidly fixed to its cork, and the
lower hook passes through the lower cork, into and through a wooden sheath, and
is fixed to a third piece of cork under the lower of the two corks hefore mentioned.
For clearness of description, I will herein-after call the cork which is at the upper
end of the rods, the first cork, the cork at the lower end of the rods the second
cork; and the lowest cork to which the lower hook is fixed the third cork. The
second and third corks are separated by the sheath above mentioned, the exterior
of which is conical, and the conical part rests on a small plate of very thin metal
embedded in the third cork. This plate is perforated for the passage of the hook.
To opposite sides of the first cork are fixed two thin light rods of rattan, which
with sheets of goldbeaters' skin connecting these rods with the longitudinal rods,
form wings and constitute the principal screw of the toy. The second screw which
serves as a rudder is made like the first, that is to say, of rods of rattan and gold-
beaters' skin. This screw is fitted to the third cork, its two wings are movable and
can turn or pivot on their point of attachment to the cork, in order to allow as with
a rudder of giving any desired direction to the toy. The goldbeaters' skin portion
of the wings may be of various forms, and either narrow or very wide. Their free
edges may be straight or formed like the wings of a bat or otherwise.
To put the toy in action, the second cork is taken hold of by one hand, and the
third cork is rotated with the other hand from left to right, around the lower hook

page_text: which serves as the axis so as to twist the india-rubber threads of the spring. When
the spring has been sufficiently twisted the toy is held in a slightly elevated
position and released; it then shoots into the air like a bird, turns and flutters, and
if in its travel it strikes against an obstacle, the coiling for example, it retains its
position vertically while seeking to avoid such obstacle. This result is easily under-
stood seeing that the spring being strongly twisted will when the third cork is freed
begin to untwist owing to the elasticity of the india-rubber, and will consequently
cause the third cork to rotate rapidly in the contrary direction to that given to it
while twisting; the wings of the screw fixed to this cork will receive the same
rotation, but as the resistance of the air opposes this movement of the screw, the
body of the toy will be drawn or impelled by the elasticity of the india-rubber,
and will rotate in a reverse direction to that of the third cork, and the wings of the
upper screw will follow this reverse movement. The india-rubber in untwisting
will thus turn the two screws in opposite directions to each other, the result of this
double rotation being a movement of the whole apparatus or toy in the direction
of its axis.
The toy can be made in various forms especially as regards the screws, but for a
good arrangement it is necessary to observe the following conditions :-
The wings of the upper screw should be larger than those of the lower one, their
action on the air being thus more powerful. The total weight of the lower hook,
second and third corks, thin metal plate, and the wings of the lower screw should
be greater than that of the first cork, and the wings of the upper screw, in order
that the centre of gravity may be below the middle of the body of the apparatus,
so that it may always go in a vertical direction, the first cork being at the top.
All the parts should be made of very light materials. The first cork should project
above the top line of the wings to allow of their continuing to turn when the toy
incets the ceiling or any obstacle which prevents it rising..
.
In some cases the screw with narrow wings is placed at the top, and that with
broad wings at the bottom, the result being that the movements of the toy resemble
those of a grasshopper. And the movements and evolutions may be otherwise
varied by changing the direction in which the toy is let free or by modifying the
form and curve of the wings and screws.