SAFETY GEAR FOR STARTING LARGE FLY OR OTHER WHEELS
Year: 1884

page_text: We, CHARLES JOHN GALLOWAY and JOHN HENRY BECKWITH both of Knott Mill
Iron Works, Manchester in the County of Lancaster Engineers, do hereby declare
the nature of our Invention for SAFETY GEAR FOR STARTING LARGE FLY OR
OTHER WHEELS " to be as follows:-
"
Our Invention relates to gear for starting large wheels into motion, such as the
flywheels of large engines, when their cranks happen to be on dead centre, or the
wheels of other heavy machinery which require to have their motion begun or
assisted at first starting. For this purpose, we provide a shaft caused to revolve
by a small engine or other suitable motor, and on this shaft we fit a pinion
engaging with the gearing of the large wheel. The pinion is fitted on the shaft
with a helical or inclined feather or with several such feathers, or it may be fitted
When the shaft is
on a square or polygonal shaft made with a helical twist.
caused to revolve in the one, direction, the pinion being in gear with the large
wheel, it is caused by the helical strain to bear against a collar on the shaft and
is compelled to turn with the shaft, turning the large wheel. But when the large
wheel itself moves with such speed as to turn the pinion faster than the shaft on
which it is fitted, the pinion is, by the helical strain, caused to slide back out of
gear with the large wheel.
ABEL & IMRAY,
Agents for the Applicants,
28, Southampton Buildings, London, W.C:

page_text: We, CHARLES JOHN GALLOWAY and JOHN HENRY BECKWITH both of Knott Mill
Iron Works, Manchester-in the County of Lancaster, Engineers, do hereby declare
the nature of our Invention for "SAFETY GEAR FOR STARTING LARGE FLY OR
OTHER WHEELS" to be as follows:-
Our Invention relates to gear for starting large wheels into motion, such as the
flywheels of large engines, when their cranks happen to be on dead centre, or the
wheels of other heavy machinery which require to have their motion begun or
assisted at first starting. For this purpose, we provide a shaft caused to revolve by
a small engine or other suitable motor, and on this shaft we fit a pinion engaging
with the gearing of the large wheel. The pinion is fitted on the shaft with a
helical or inclined feather or with several such feathers, or it may be fitted on a
square or polygonal shaft made with a helical twist. When the shaft is caused to
revolve in the one direction, the pinion being in gear with the large wheel, it is
caused by the helical strain to bear against a collar on the shaft and is compelled
to turn with the shaft, turning the large wheel. But when the large wheel itself
moves with such speed as to turn the pinion faster than the shaft on which it is
fitted, the pinion is, by the helical strain, caused to slide back out of gear with the
large wheel. Fig. 1 of the accompanying Drawings shews a starting pinion arranged
as above described in gear with the internal teeth of a large fly wheel or driving
drum, Fig. 2 shews the pinion out of gear. A is the internally toothed rim of the
wheel or drum to which the starting gear is applied; B is a shaft caused to
revolve by a small engine or other suitable motor in the direction in which the
large wheel has to be driven. On this shaft, between its bearings C C are formed
helical grooves and ridges D), and the pinion E is internally rifled to fit them. The
wheel A being at rest, and the pinion E being put in gear with it, as shewn in
Fig. 1, on turning the shaft B in the direction of the arrow, the pinion, turning in
the same direction, causes the wheel to revolve. As long as force to turn the
pinion E is transmitted through the helical grooves and ridges the resultant of
this force strains the pinion against the collar F; but when the wheel A begins to
move faster than the pinion Ẹ can be turned by the shaft B, then the pinion is
turned as a nut on the helical shaft securing itself back out of gear with A as
indicated in Fig. 2, and in that condition of things, the wheel A is left free to
revolve independently of the shaft B.
Having now particularly described and ascertained the nature of our Invention
and in what manner the same is to be performed, we declare that what we
claim is :-
.
Safety gear for starting large fly or other wheels, consisting of a shaft having on
it a pinion gearing with the wheel and fitted to slide along a helical feather or its
equivalent so inclined that when the pinion is driven by the wheel, it is caused to
slide out of gear, substantially as described.
Dated this 20th day of June 1884