IMPROVEMENTS IN REVERSING GEAR FOR STEAM AND OTHER ENGINES
Year: 1884

page_text: We, JAMES WHITEHEAD and JOHN POLLOCK, both of Limestone Road, Belfast,
in the County of Antrim, Ireland, Engineers, do hereby declare the nature of
our said Invention for IMPROVEMENTS IN REVERSING GEAR FOR STEAM AND
OTHER ENGINES," to be as follows:- .
This Invention relates to improvements in apparatus employed for actuating the
weigh shaft or other gear which acts on the valves and effects the reversing of
heavy marine engines and similar motive-power engines.
The improved apparatus comprises a steam or water cylinder or small steam
engine, provided with the usual ports and valve, and having a cross-head on the
piston rod connected by links or rods to a lever on the weigh shaft or other gear of
the main engines. The piston rod of the small engine is prolonged beyond the
crosshead, in the form of a quick threaded screw, corresponding in length to the
stroke of the piston. This screw spindle passes through the eye of a bevil wheel
or spur wheel which is screwed to fit it, and which is carried in a fixed framing,
so that it is free to rotate, but is kept from moving along the screw spindle by a
collar which holds it to the frame. This bevil wheel or spur wheel gears into a
pinion on a transverse axis, or on an axis parallel to the piston rod, and screw,
according as bevil or spur gearing is used; and the pinion is formed with a long
eye fitting over a hollow sleeve which is connected to it by a feather and groove,
so that it may slide freely through the eye, but must rotate with the pinion. Into
one end of the hollow sleeve is fitted a screw spindle which extends outwards
through a bearing bracket, and is fitted with a hand wheel. At the opposite end,
the hollow sleeve is connected to a rod acting through a bell crank or other lever
on the valve rod of the small engine. When the hand wheel is turned, the screw
spindle on which it is fitted acts on the hollow sleeve which it traverses outwards
or inwards according to the direction in which the screw turns, and the sleeve
acting through the levers on the engine valve opens it, and admits steam into the
end of the cylinder corresponding to the direction in which the valve is moved.
The piston is driven towards the end of the cylinder, and the screw at the end of
the piston rod is drawn or pushed through the screwed eye of the bevil wheel or
spur wheel. The wheel is thereby rotated, and in turn gives motion to the pinion
with which it gears, and the pinion in rotating turns with it the hollow sleeve. So
long as the hand wheel is turned the engine valve is acted upon and admits steam

page_text: to the cylinder, but when the hand wheel is stopped, the bollow sleeve while
continuing its rotation slides as a nut within the eye of the pinion and by its
traversing movement it acts through the levers on the valve which it moves into
such a position as to shut off the supply of steam to the cylinder. Should the
momentum of the piston and its connections have a tendency to produce further
movement after the steam is shut off, the cylinder would immediately get steam on
the opposite side of the piston to check its movement so long as the hand wheel is
at rest. To prevent the hand wheel being turned too far and causing the piston to
be driven through the end of the cylinder and to regulate the distance to which
the piston shall be acted upon to move the weigh shaft or other gear of the main
engines, a regulating nut is fitted on the screw spindle and the nut after a few
turns of the spindle in either direction comes against a stop. The nut can be set
to any position on the spindle according to the stroke of the piston required.
To admit of the apparatus being worked by hand at any time that may be
required, a large handing wheel is fixed on the eye of the bevil or spur pinion or
shaft connected to the pinion boss, so that by turning the handing wheel the pinion
may drive the screw wheel, and acting through the piston rod crosshead and rods
may actuate the lever of the weigh shaft or other valve gear, but while the
apparatus is being worked by the large handing wheel the screw spindle must be
turned or moved along with it. For this purpose a pin is fixed to the boss of the
pinion or eye of the handing wheel to engage with a projecting arm or to fit in a
circular slot in a disc or flange fixed on the screw spindle to be turned as far either
way as may be required to open the valve and admit steam to either side of the
piston before the projecting arm or the ends of the slot. would come against
the pin.
Instead of the screw described as acting to rotate the bevil wheel, a rack may be
formed on the end of the piston rod, and be arranged to actuate the small screw
spindle through a pinion.
Doted this Savantoonth day of March 1881

page_text: We, JAMES WHITEHEAD and John Pollock, both of Limestone Road, Belfast,
in the county of Antrim, Ireland, Engineers, do hereby declare the nature of
our said Invention for "IMPROVEMENTS IN REVERSING GEAR FOR STEAM AND
OTHER ENGINES," and in what manner the same is to be performed, to be par-
ticularly described and ascertained in and by the following statement:―
This invention relates to improvements in apparatus employed for actuating the
weigh shaft, or other gear which acts on the valves and effects the reversing of
heavy marine engines and similar motive power engines.
In the accompanying Drawings Figure 1 is a front elevation, Figure 2 is a
vertical section, Figure an elevation at right angles to Figure 1, and Figure 4 is
a back elevation of one modification of our improved reversing gear. Figures 5, 6,
and 7 are sectional elevations of modified arrangements..
The improved apparatus comprises a steam or water cylinder or small steam
engine: A, provided with the usual ports a and valve B, and having a crosshead C
on the piston-rod D connected by links or rods E to a lever F on the weigh shaft F'
or other gear of the main engines. The piston-rod D of the small engine is
prolonged beyond the crosshead C in the form of a quick threaded screw D'
corresponding in length to the stroke of the piston. This screw spindle D' passes
through the eye of a bevil wheel or spur wheel G. (either as shown in Figure. 2. or
in Figures 5 and 6) which is screwed to fit it, and which is carried in, a fixed
framing H, so that it is free to rotate, but is kept from moving along the screw
spindle by a collar g, which holds it, to the frame. The bevil wheel or spur wheel G
gears into a pinion I on a transverse axis J or on an axis parallel to the piston
rod D. and screw D¹, according as bevil or spur gearing is used; and the pinion is
formed with a long eye fitting over, a hollow sleeve K,, which is connected to it by
a feather and groove, so that it may slide freely through the eye, but must rotate
with the pinion I. Into one end of the hollow sleeve is fitted a screw spindle
which extends outwards through a bearing bracket M, and is fitted with a hand
wheel L. At the opposite end the hollow sleeve K is connected to a rod N acting
through a bell crank N¹ or other lever on the valve rod b of the small engine A.
When the hand wheel L is turned, the screw spindle on which it is fitted acts on
the hollow sleeve K which it traverses outwards or inwards according to the
direction in which the screw turns, and the sleeve acting through the rod and
lever N, N¹, on the engine valve B opens it, and admits steam into the end of the
cylinder corresponding to the direction in which the valve is moved. The piston
is driven towards the end of the cylinder, and the screw D¹ at the end of the
piston rod D is drawn or pushed through the screwed eye of the bevel wheel or
spur wheel G. The wheel is thereby rotated, and in turn gives motion to the
pinion I with which it gears, and the pinion in rotating turns with it the hollow
sleeve K. So long as the land wheel L is turned the engine valve B is acted upon
and admits the steam to the cylinder, but when the hand wheel is stopped, the
hollow sleeve K while continuing its rotation slides as a nut within the eye of the
pinion I, and by its traversing movement it acts through the levers N N¹ on the
valve which it moves into such a position as to shut off the supply of steam to the
cylinder. Should the momentum of the piston and its connections have a tendency
to produce further movement after the steam is shut off, the cylinder would
immediately get steam on the opposite side of the piston to check its movement so
long as the hand wheel is at rest.

page_text: To prevent the hand wheel L being turned too far and causing the-piston. to be
driven through the end of the cylinder, and to regulate the distance to which the
piston shall be acted upon to move the weigh shaft Fi or other gear of the main
engines, a regulating nut O is fitted on the screw spindle 1, and the nut after a
few turns of the spindle in either direction comes against a stop formed by the
bracket M. The nut O can be set to any position on the spindle according to the
stroke of the piston required.
To admit of the apparatus being worked by hand at any time that may be
required, a large handing wheel P is fixed on the eye of the bevil or spur pinion I
or shaft connected to the pinion boss, so that by turning the handing wheel the
pinion I may drive the screw wheel G, and acting through the piston-rod D
crosshead C and rods Ę may actuate the lever F of the weigh shaft F¹ or other
valve gear, but while the apparatus is being worked by the large handing wheel P
the screw spindle 7 must be turned or moved along with it. For this purpose a
pin p is fixed to the boss of the pinion I or eye of the handing wheel P to engage
with a projecting arm q or to fit in a circular slot in a disc or flange fixed on the
screw spindle to be turned as far as may be required to open the valve and admit
steam to either side of the piston before the projecting arm q, or the ends of the
slot would come against the pin p.
Instead of the screw D¹ described as acting to rotate the bevil wheel, a rack may
be formed in the end of the piston rod, and be arranged to actuate the small screw
spindle through a pinion.
In the arrangement shown in figure 5, a hand lever L¹ is used in substitution
for the hand wheel L to act through the spindle and rod and lever N N¹ on the
valve B, and in the modification illustrated in figures 6 and 7 the hand lever L' is
fitted to act directly on the valve rod b.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed we declare that what
we claim is,-
1. The combination of parts forming the improved reversing gear for motive
power engines, substantially as herein described and illustrated.
2. The arrangement of the screwed piston-rod extension D' operating the
gearing G, I, in combination with the screw spindle operated by a hand wheel or
hand lever to act on the valve of the engine A substantially as herein described
and illustrated.
Dated this Seventeenth day of December 1884.
J. WHITEHEAD.
J. POLLOCK..