Improvements in Appliances for Starting Gas and similar Engines.
Year: 1889

page_text: Date of Application, 10th Jan., 1889
Complete Specification Left, 4th Nov., 1889-Accepted, 7th Dec., 1889
PROVISIONAL SPECIFICATION.
Improvements in Appliances for Starting Gas and similar Engines.
I JOHN MCCLURE CALDWELL PATON of Bloomsgrove Works, Nottingham in the
county of Nottingham, engineer do hereby declare the nature of this invention to be
as follows:
My invention relates to appliances for starting gas and similar engines. For
starting said engines ordinarily the crankshaft is turned by hand and the strap
pulley fixed thereon and shafting or machine driven by the strap are rotated thereby.
For the larger sizes of engines this is inconvenient or impossible and in such cases
the belt has been thrown off to enable the engine to start, or claw or friction
clutches have been arranged on the shaft and the pulleys or other parts transmitting
the power placed loose upon the shaft and thrown into gear with the crank shaft
by means of said clutches operated by hand after the engine has been started by
turning the shaft and has attained its ordinary speed. My improvement consists
in the employment of self acting centrifugal friction clutches in place of clutches
operated by hand. These self-acting clutches may be of any ordinarily used or
known kind, consisting of arms or discs keyed upon the crankshaft to which
weights arranged to be rotated by said arms or discs and capable of moving outwards
under the influence of the centrifugal force are connected and directly, or indirectly
through lever and link connections, cams, screws, or their equivalents, press friction
blocks against the pulley or other part transmitting the power, these pulleys or
parts being placed loose upon the crankshaft, and the rotating weights being
returned to their positions nearer to the centre of the shaft by means of springs
when the rotation of the shaft is stopped and thereby disengaging the friction
blocks from the pulleys or other parts transmitting the power.
With this arrange-
ment the crankshaft is always disconnected from the pulley or other part transmitting
the power when the engine is standing, so that for starting the same the crankshaft
can be conveniently turned by hand by means of a handle or its equivalent. As
the speed increases, the friction blocks are gradually pressed with increasing force
against the pulley or other parts transmitting the power until the latter begin to
turn with the crankshaft, when the minimal ordinary speed has been attained, the
weights and power of the clutches being so proportioned as to assure this result,
and when the engine is stopped, the clutches selfactingly disengage themselves.
Dated this 8th day of January 1889
EMMOTT & Co.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Appliances for Starting Gas and similar Engines.
I, JOHN MCCLURE CALDWELL PATON, of Bloomsgrove Works, Nottingham in the
County of Nottingham, Engineer, do hereby declare the nature of this invention, and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :—
My invention relates to appliances for starting gas and similar engines. For
starting said engines ordinarily the crank shaft is turned by hand and the strap pulley
fixed thereon and shafting or machine driven by the strap are rotated thereby. For
the larger sizes of engines this is inconvenient or impossible and in such cases the bolt
has been thrown off to enable the engine to start, or claw or friction clutchies have
been arranged on the shaft and the pulley or other parts transmitting the power
placed loose upon the shaft and thrown into gear with the crank shaft by means of

page_text: said clutches operated by hand after the engine has been started by turning the shaft
and has attained its ordinary speed. My improvement consists in the employment of
self-acting centrifugal friction clutches in place of clutches operated by hand. These
self-acting clutclies may be of any ordinarily useil or known kind, consisting of arms
or discs keyed upon the crank-shaft to which weights arranged to be rotated by said
arms or discs and capable' of 'moving outwards under the influence of the centrifugal
force are connected and directly, or indirectly through lever and link connections,
cams, screws or their. 'equivalents, press friction blocks against the pulley or other
part transmitting the power, these pulleys or parts being placed loose upon the
crank-shaft, and the rotating weights being returned to their position nearer to the
centre of the shaft by means of springs when the rotation of the shaft is stopped
and thereby disengaging the friction blocks from the pulleys or other parts trans-
mitting the power. With this arrangement the crank-shaft is always disconnected
from the pulley ar other part transmitting the power when the engine is standing,
so that for starting the same the crank-shaft can be conveniently turned by hand
by means of a handle or its equivalent. As the speed increases, the friction blocks
are gradually pressed with increasing force against the pulley or other parts trans-
mitting the power, until the latter begin to turn with the crankshaft when the
minimal ordinary speed has been attained, the weights and power of the clutches
being so proportioned as to assure this result, and when the engine is stopped, the
clutches self-actingly disengage themselves.
In order to render more clear the nature of my invention, I have shown one
arrangement for carrying it into effect on the drawings appended hereunto which
represent my improvement applied to the crank shaft of a gas-engine.
By fig. 1. my improved appliance is represented in transverse sectional elevation,
and by fig. 2. in side elevation partly in section.
In these drawings A represents the crank shaft of the engine; B is a fly wheel or
driving pulley provided with the bush B' and is loose upon the crank-shaft; C is a
boss keyed fast to the crankshaft A and revolving with it, provided with arms (". In
the drawings these arms C¹ are represented as two in number, though more may be
used if necessary, and they are shewn securely screwed into the boss. Upon these
arms the weights (2 are arranged so that they can freely slide up or down upon the
arms C. To the weights C friction blocks C covered with leather are fixed as
shewn.
When the crankshaft is at rest, and consequently the boss C is not revolving, the
springs (placed as shewn, between heads C, the arms and the weights C², or in
any other position to produce the same result) push these weights towards the crank
shaft, at the same time withdrawing the friction blocks from the pulley or fly
wheel B.
When the engine has been started and is obtaining its proper supply of gas and air
and is approaching its normal speed, the centrifugal force imparted by the motion to
the weights, is sufficient to overcome the resistance of the springs C³ ³, and to cause
the weights to press upwards until the friction blocks C Care in close contact
with the fly. wheel or driving pulley B, and as the speed of the engine further
increases the pressure, of these friction blocks against the fly wheel, due to the
centrifugal action of the weights CC increases until this pressure is sufficient to
convey the whole power of the engine to the fly wheel or driving pulley B, and thus
to permit the power of the engine to be transmitted through this flywheel or driving
pulley.
.
When the engine is stopped, the pressure of the friction blocks (becomes reduced
as the speed decreases, and the springs C³ force them out of contact with the
pulley B, so that the crankshaft is disconnected again and ready for re-starting the
engine by turning the crankshaft.
The arrangement of centrifugal clutch is also useful in case the engine is getting
overloaded while running. If too much work is put upon a gas or similar engine
it slows down and occasionally stops. It does not struggle to keep turning like a
steam engine does, because there is not a constant pressure behind its piston as

page_text: with steam, but when a gas engine runs very slow it at times fails to get an
explosion and the engine stops, as there is no pressure behind the piston, and men
have to be called in to help, turning the flywheel and starting the engine again.
With my improved, clutch, when the engine slows to any great extent, the friction
blocks are drawn back, the work is thus taken off the engine and it can at once
commence to resume its speed. In this way, although by overloading the shafting
the speed of the flywheel or pulley may be reduced, or the latter even completely
stopped, the engine continues running and as soon as the excess of work is taken
off the flywheel or pulley, the driving re-commences in its normal manner.
not confine myself to the special construction of centrifugal friction clutch described
with reference to the drawings, but any other arrangement of centrifugal friction
clutch may be used for the purpose hereinbefore set forth.
I do
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, declare that what I
claim is
The application upon the crank-shaft of a gas or similar engine of a centrifugal
clutch so arranged that it disconnects the crankshaft and driving pulley when the
engine is stopped and automatically connects them when the engine is nearing its
normal rate of speed and automatically disconnects them again when the engine
slows speed, substantially as herein before described and for the purpose set forth.
Dated this 1st day of November 1889
EMMOTT & Co.,
Agents for the Applicant.