Improvements in Driving Gear for Driving Screw Propellers and for other Purposes.
Year: 1888

page_text: PROVISIONAL CRITIC
Improvements in Driving Gear for Driving Screw Propellers and for
other Purposes.
I, PETER WILLIAM WILLANS of Ferry Works, Thames Ditton, in the County of
Surrey, Engineer, do hereby declare the nature of this invention to bo as follows:-
The object of my invention is mainly to enable engines which can only run in one
direction to be used for driving screw propollors and for such like purposes and yet
admit of the propeller or other shaft being driven in either one or other direction as
may be desired.
I effect this by setting the screw or other shaft to be driven in a line with the engine
shaft and in the case of a screw propeller shaft causing the thrust upon the propeller
shaft when the shaft is revolved in one direction to keep it clutched to the engine shaft
so that it revolves with and at the samo speed as this shaft-or when revolved in the
opposite direction causing the pull upon the shaft to disengage it from the engine
shaft and then cause motion to be transmitted to the screw shaft through toothed
pinions which gear both with a toothed wheel on the engine shaft and with another
wheel on the screw shaft and which are carried by stud axes which at this time aro
held at rest. The screw shaft will then be driven in the opposite direction.
One way in which I effect this as follows:-
:-
At the end of the engine shaft I fix a wheel carrying an internal ring of teeth. On
the end of the screw shaft is keyed a toothed wheel of smaller diameter. Gearing into
both of them are pinions on stud axes carried by a disc which is loose on the screw
shaft. Around the circumference of the disc is a cone friction socket into which a
corresponding cone keyed on the screw shaft can be made to engage.
When the screw shaft is turned in one direction tho screw shaft (to which a slight
endway movement is permitted) is drawn in a direction to disengage the friction cone
on the shaft from the disc. If then the disc is prevented from revolving either by a
friction band around its circumference or in other suitable ways the internal toothed
wheel on the engine shaft will drive the pinions and cause them to drive the toothed
wheel on the screw in the opposite direction to that in which it was before revolving.
In this way the reversing of the movement of the screw can be effected simply by
applying the break to the disc.
A lover may be used if required for disengaging the clutch in case of sticking or
otherwise.

page_text: COMPLETE SPECIFICATION.
Improvements in Driving Gear for Driving Screw Propellers and for
other Purposes.
I, PETER WILLIAM WILLANS of Ferry Works Thames Ditton in the County of
Surrey 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 :-
The object of my invention is mainly to enable engines which can only run in one
direction to be used for driving screw propellers and for such like purposes and yet
admit of the propeller or other shaft being driven in either one or other direction as
may be desired.
I effect this by setting the screw or other shaft to be driven in a lino with the
engino shaft and in the case of a screw propeller shaft causing the thrust upon the
propeller shaft when the shaft is revolved in one direction to keep it clutched to the
engine shaft so that it revolves with and at the same speed as this shaft or when
revolved in the opposite direction causing the pull upon the shaft to disengage it from
the engine shaft and then cause motion to be transmitted to the screw shaft through
toothed pinions which gear both with a toothed wheel on the engine shaft and with
another wheel on the screw shaft and which are carried by stud axes which at this
time are held at rest. The screw shaft will then be driven in the opposite direction.
One way in which I effect this is as follows:-
At the end of the engine shaft I fix a wheel carrying an internal ring of teeth-On
the end of the screw shaft is keyed a toothed wheel of smaller diameter-Gearing into
both of them are pinions on stud axes carried by a disc concentric with and running
loose on the screw shaft. The circumference of the disc is formed with a cone friction
socket into which a corresponding cone keyed on the screw shaft can be made to
engage.
When the screw shaft is turned in one direction the screw shaft (to which a slight
endway movement is permitted) is drawn by the action of the screw in the water in a
direction to disengage the friction cone on the shaft from the disc. If then the disc
is prevented from revolving either by a friction band around its circumference or in
other suitable ways the internal toothed wheel on the engine shaft will drive the
pinions and cause them to drive the toothed wheel on the screw in the opposite
direction to that in which it was before revolving. In this way the reversing of the
movement of the screw can be effected simply by applying the brake to the disc.
The effect of such application being to reduce the speed of the whole system
including both engine and propeller, until the propeller, ceasing to travel as fast as the
vessel is pulled backwards by the pressure of the water against the forward side of its
blades, with the effect of withdrawing the cono from the socket and so leaving the
pinions free to rotate.
A lever may be used if required for disengaging the clutch in case of sticking or
otherwise.
In order that my said invention may be fully understood and readily carried into
effect I will proceed to describe the drawings hereunto annexed.

page_text: ".
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a longitudinal section of reversible driving gear constructed in accordance
with my invention. Figure 2 shows separately the toothed ring, the inner toothed
wheel and the pinions.
a is the engine shaft, b is a wheel keyed upon it, c is a ring of internal teeth fixed
into the wheel b. d is the screw shaft, which is so carried in its bearings that it can
move longitudinally a short distance. e is a toothed wheel keyed upon the screw shaft.
fis another wheel loose on the shaft d, it is formed with a conical socket f¹ into which
the cone g keyed on the screw shaft fits. When the screw is revolving forward the.
thrust drives the cone into the socket and so locks the parts ƒ and g together. The
wheel also carries studs upon which pinions hh are mounted to turn freely.
The teeth of the pinions engage both with the toothed ring c and with the wheel e and
when the wheel is locked fast with the screw shaft the pinions h cannot rotate on the
studs and as the pinions engage with both c and e they then lock these parts together
and make the screw shaft fast with the engine shaft. A brako strap not shown in the
drawing is provided; it can be tightened around the periphery of the wheelf so as to
hold this wheel and prevent it turning. There is also a lever i by means of which
when the engine is at rest the screw shaft can be drawn back so that the cone g may
not be jammed into the socket f. Then on the engine being started whilst the wheel f
is held fast the pinions h rotate on the studs and rotate the wheel e and so turn the
screw shaft in the reverse direction to that in which the engine is running. The
thrust of the screw will then hold the cone g back out of contact with the socket f'.
This reversible driving gear may be used otherwise than for driving a screw
propeller in such cases the necessary slight endwise movement of the shaft d is by'
mechanism provided for the purpose.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. Driving gear substantially as described.
2. The combination of mechanism for transmitting motion from a driving shaft to
a driven shaft consisting of a toothed wheel on the ono within a toothed ring on the
other and pinions engaging with both; such pinions being carried by a wheel which
is loose in one of the shafts and can at will either be held fast and prevented from
turning or clutched fast with the shaft on which it is mounted substantially as
described.
3. The application of such gear to driving the propellers of steam vessels by means
of a non-reversible engine.