Improvements in Reversing Gear for Steam Engines.
Year: 1891

page_text: Date of Application, 27th Jan., 1891-Accepted, 28th Feb., 1891
COMPLETE SPECIFICATION.
Improvements in Reversing Gear for Steam Engines.
We, DANIEL AVERY FRAZER, of Michigan Street, Machinist, and JOHN
WESLEY COSFORD, of Cosford's Block, Physician, both of Mancelona, in the
County of Antrim, State of Michigan, United States of America, do hereby
declare the nature of our invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement and accompanying drawings:
Our invention relates to improvements in the reversing gear of steam engines,
and consists essentially of the arrangement of ports or passages and a rotary valve
between the steam chest and cylinder whereby the engine may be checked down,
stopped, air vented, and reversed by a continuous forward movement of a single
lever.
In the accompanying drawing,
Fig. 1. is a longitudinal vertical section of a device embodying my invention;
Fig. 2. a horizontal section of the same on the plans of line 3-3 of Figures 3
and 4;
Fig. 3. a transverse vertical section of the same on the line 2 of Figs. 1 and 2;
Fig. 4. the same on the line 1 of the same and
Fig. 5. a detail of the plug valve G.
Like letters refer to like parts in all the figures.
A. is the cylinder, B. the piston, C. the steam chest, D. the valve, E. E. the
live steam ports, and E' the exhaust port of a double acting steam engine; directly
beneath the steam chest is located a rotary valve G., having an annular exhaust
passage H. beneath and connecting the exhaust port É' with the exhaust pipe Eu
and also openings H' and H" which serve to connect the live steam ports E. E.
with ports II at each side of said passages which open into the chambers 1. I.
which chambers are extended in opposite directions as shown at F. F' and connect
with the respective ends of the cylinder A.
The opening H' is cut across the upper side of the valve G. to receive the steam
from E. and opens the side ports I' by uncovering them from above downward, the
integral part G" covering both ports I and the space between them; the
opening H is also cut across the top of the valve to receive the steam from E. and
is also cut down through the bottom into two parts G" G" and opens, the corre-
sponding ports I' by uncovering them from below upward.
J. J. are air vents consisting of channels across the bridge between the live
steam and exhaust ports, these channels are cut part way in the valve chamber and
the remainder in the valve and are connected and open when in line which occurs
when all ports 1. are cut off by bringing the valve in the centre, as shown in the
drawings.
The operation of our device is as follows:
The valve D. admits live steam alternately to the ports E. E. and exhaust the
same through E' in the usual manner. If, now, the upper side of the valve G. is
turned to the right, steam passing into H' will pass into the right hand chamber I.
and thence into the forward end of the cylinder A., and steam passing into H" will
pass through the opening in the bottom of the same into the left hand chamber I.
and thence into the rear of the cylinder A. and the engine will run in one direction.
If, however, the upper side of the valve G. be turned to the left, the steam will now
pass in the opposite direction, the steam from H' passing into the left hand
chamber I. and to the rear end of the cylinder A. and the steam from H" into the
right hand chamber I. and into the forward end of the cylinder A., thus causing
the engine to run in the opposite direction; by turning the valve G. toward the
[Prins d

page_text: middle position, the engine may be throttled down, and by bringing it to said
middle position, steam is cut off entirely, and the air vents opened and then by
further turning of said valve, the motion of the engine will be reversed.
Thus steam may be gradually cut off, the engine stopped air vented, reversed
and steam gradually let on by a continuous forward movement of a single valve.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is
1. In a steam engine having a double acting cylinder, a D. valve and ports from
said valve to the respective ends of saidcy linder, a rotary valve, as G., having
passages adapted to direct the steam alternately to either end of said cylinder
substantially as described.
2. In a steam engine having a D. valve, live steam ports and an exhaust port
under said valve, a rotary valve having an annular opening opposite the exhaust
port and openings opposite the live steam ports, chambers at each side of said
rotary valve and connected with the respective ends of the cylinder, ports, con-
necting said chambers with the openings in said rotary valve, said openings
alternately connecting with the opposite chambers I. as said valve is rotated,
substantially as described.
3. In a steam engine, a double acting cylinder, a D. valve, live steam and exhaust
ports, a rotary valve having an annular chamber H., openings H₁ and H",
chambers I at each side of said valve, each having an opening into one end of the
cylinder and ports from the openings H. H. to said chambers I. I. and the air
vent J substantially as described.
Dated this 17th day of November A.D. 1890.