IMPROVED SAFETY GEAR FOR STARTING ENGINES
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
We JOHN MUSGRAVE Engineer and ARTHUR WALSH, Draughtsman both of the
Globe Iron Works, Bolton in the County of Lancaster do hereby declare the nature
of said Invention for IMPROVED SAFETY GEAR FOR STARTING ENGINES, to be as
follows:-
Our Invention relates to safety gear for starting large engines and the object of
our Invention is to prevent accidents arising through the starting gear being left
in gear with the large engine.
In performing our Invention we employ a pinion gearing into the teeth of the
driving or fly-wheel of the large engine: this pinion has a radial slot by means of
which it is mounted loosely on a shaft from which it receives motion by means of
one or more catches or teeth fixed in the shaft: this shaft is driven by a worm
and worm wheel or other gear actuated either by a small starting engine or by
hand,
To start the large engine the pinion is raised by a lever into gear with the fly-
wheel and on setting the starting engine into motion the main engine is turned:
as soon as the main engine begins to drive instead of being driven the radial slot
in the pinion allows it to drop and the pinion is guided out of gear by a stud
secured to the frame work and projecting into a groove or slot in the pinion: by
this means the pinion hangs on the stud and is always clear of the driving wheel
when thrown out of gear either by hand or by the large engine and it cannot get
into gear unless raised by the lever. In place of the stud an incline could be
arranged below for the pinion to slide upon when out of gear.

page_text: We JOHN MUSGRAVE, Engineer, and ARTHUR WALSH, Draughtsman, both of the
Globe Iron Works, Bolton, in the County of Lancaster, do hereby declare the
nature of said Invention for IMPROVED SAFETY GEAR FOR STARTING ENGINES, and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
Our Invention relates to safety gear for starting large engines, and the object of
our Invention is to provide simple and efficient mechanism for starting large engines
whereby we prevent accidents arising through the starting gear being left in gear
with the large engine.
1
In performing our Invention we employ a pinion or starting wheel which may be
thrown into gear with the teeth of the driving or fly wheel of the large engine by
a lever and thrown out of gear by the driving or fly wheel when it becomes the
driver, or by hand when the engines are stopped: this pinion has a radial alot by
means of which it is mounted loosely on a shaft from which it receives motion by
means of one or more catches or teeth fixed in the shaft which bears against, a
projection on the pinion: this shaft is driven by a worm and worm wheel or other
gear actuated either by a small starting engine or by hand."
To start the large engine the pinion is raised by a lever into gear with the
Aly
wheel and on setting the starting engine into motion the main engine is turned:
as soon as the main engine begins to drive, instead of being driven, the radial slot
in the pinion allows it to drop or move out of gear or ungear and the pinion is
guided out of gear by a stud secured to the framework and projecting into a groove
or slot in the pinion: by this means the pinion is partly supported on the stud and
partly on the shaft and is always clear of the driving wheel when thrown out of
gear either by hand or by the large engine and it cannot get into gear unless raised
by the lever. It is obvious that the stud may be fixed in any convenient position
so as to cause the pinion to move horizontally or otherwise.
In place of the stud an incline may be used below for the pinion to slide upon
when out of gear. This incline may be a tapered block fixed below the pipion
which would move along the inclined surface of the block when thrown out of
gear, the highest part of the block being near where the pinion gears into the fly
wheel.
And in order that our Invention may be fully understood and readily carried
into effect we will proceed to describe the accompanying Sheet of Drawings,
reference being had to the Figures and letters marked thereon.
Fig. 1 is an elevation and Fig. 2 a plan showing our improved safety starting
gear applied to an internally toothed fly wheel of a large engine. Fig. 3 shows
part of the same applied to an externally toothed driving wheel. Fig. 4 is an
elevation of the starting pinion and Fig. 5 is a section (on the line XY) of the
same.
d
a is the fly, wheel :. b is the pinion or starting wheel in which is a slot o through
which the shaft & passes; in this shaft is fixed the catch e that bears against a
projection on the side of the pinion when the shaft forms the axis of the pinion:
when the fly wheel becomes the driver the slot allows the pinion to travel out of
gear into the position shown in dotted lines on Fig. 1 and the projection fis moved
away from the catch e so that the shaft d can rotate without communicating motion
to the pinion: g is the stud which supports the pinion in the desired position when
it is not in gear with the fly wheel: h is the lever by which the pinion is moved
into gear with the fly wheel when it is necessary to start the large engine. On the

page_text: shaft d is a worm wheel i that receives motion from a worm ; driven by the
starting engine: collars k k are secured on the shaft d to keep the pinion 6 from
moving laterally: is the cylinder of the starting engine.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed we would have it
understood that we do not limit ourselves to the details herein described and shown
as they may be varied or modified without departing from the nature of our
Invention. It is obvious that a slot of a modified form and placed in a different.
position may be used in place of the slot hereinbefore described so long as it enables
a motion such as is provided for in our arrangement to be given to the pinion so as
to enable it to move or be moved out of gear in the manner we describe or in an
equivalent manner; again the pinion may be driven by hand or by power in any
convenient manner and
We declare that what we claim is
1.-The use of a slot which admits of the pinion of a starting engine being moved
and thrown out of gear by the wheel of the large engine when the latter becomes
the driver, substantially as herein set forth.
2. The combination of parts such as are hereinbefore referred to and constituting
our improved starting gear, substantially as herein described and illustrated in the
Drawings annexed.
3. In a starting engine, the employment of a pinion or starting wheel so mounted
or supported that the pinion is kept engaged with the wheel of a large engine while
driving it and is allowed by means of a slot to move so as to be disengaged and
thrown out of gear by the action of the started wheel when it becomes the driver
and remain disengaged even though the starting engine be in motion, substantially
as herein specified.