IMPROVEMENTS IN THE CONSTRUCTION OF LOCOMOTIVE TRACTION ENGINES
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by Robert Edwards at the Office of
the Commissioners of Patents, with his Petition, on the 28th August
1867.
I, ROBERT EDWARDS, of Ashford, in the County of Kent, Engineer, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF LOCOMOTIVE TRACTION ENGINES," to be as follows:
This: Invention' relates, firstly, to a means of avoiding the difficulty hitherto
experinced in the boilers of locomotive and traction engines when travelling.
up and down inclines: In constructing such boilers I propose to divide them
transversely into two or more compartments, and to connect the steam spaces.
of each. division by pipes or otherwise.. The water spaces I also connect:
together, but I place valves in the connections so as to be able to open or
close communication between the divisions. I also in some cases connect; the
delivery pipe of the feed pump with the several divisions of .the water' space,.
using suitable valves for.:regulating the admission of the feed thereto.. The:
object to be obtained in the above arrangement is to be able to alter the level.
of the boiler without affecting the water level to the same extent as if the:
water space of the boiler were in one. By closing the communication.
between the divisions of the water space it will be obvious that the water will
be prevented from running from the elevated to the lower end of the boiler,
and-thereby-leaving-the-upper ends of the tubes exposed. If the boiler is
required-for-such purposes-as-necessitate-it-being-kept_long_in_an_inclined
position I then connect each water space with the feed. pump so as to be able

page_text: to pump water into either compartment. In ordinary cases the above arrange-
ment of pump is not required. In applying this improvement to ordinary
locomotive boilers I make the fire-box (external and internal) entirely
separate from the barrel, a hole being left for the products of combustion to
pass through to the tubes of the barrel, the barrel being divided into com-
partments if required, and the water and steam spaces, of the fire-box and
barrel connected as aforesaid.
The Invention relates, secondly, to the construction of gear used in
conveying motion (in locomotive engines especially) from the crank or other
shaft to the driving shaft wheels or other shafts; 1 construct it so as to be
capable of giving two speeds (without altering the speed of the engine) as
follows The cog wheel that gears with the driving shaft pinion is made up
of two sets of cogs on one wheel concentric and in the same plane, one set of
cogs forming an internal cog wheel, and the other set of cogs forming an
external cog wheel interior. to and smaller, than the former: This wheel is
mounted loosely on an excentric boss, which is carried by and is adjustable
axially on a fixed spindle. This arrangement enables the attendant to throw
either the external or internal cogs into gear with the driving pinion which is
placed between them, and a difference of speed will be the result. The
between the internal and external cogs is made wide enough, if required to be
able to put the cog wheel so as neither, set. of cogs gear with, the driving.
pinion so as to run the engine. by itself if .required.. As an improvement in,
the pitch chains used in traction engines for conveying motion from one shaft
to the other I make the pins which join the links together, so that the part of.
the pin in one link is excentric to the part. in the link which it joins, and one,
part is made square, hexagon, octagon, or. other suitable shape so as to prevent
them turning round when in their place, but they can be taken out, turned.
round or partially, round, and afterwards replaced, thereby lengthening or.
shortening the chain, as the case may be.
space
The last improvement consists in mounting the axle of the driving wheels
(in locomotive engines that are driven by a pitch chain geared to the driving
axle) in slots or in links, and by means of screws or keys shifting the axle in
a line with the centres of the pitch chain wheels for the purpose of taking up
any slack chain.