Improvements in Fluid Pressure Engines.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Fluid Pressure Engines.
I, FREDERICK WILLIAM LANCHESTER, of Ladywood Road, Birmingham, Engineer,
do hereby declare the nature of this invention to be as follows;-
-
This invention relates to improvements in motive power and other fluid pressure
engines and refers more particularly to balanced motors of the type described
in the Specification of Letters Patent already granted to the present applicant
and numbered 13960 of the year 1896.
The principal object of my present invention is to provide a straight-line motion
for the piston or crosshead pin and thereby relieve the piston and cylinder (or
crosshead guide) from wear and also as far as possible to prevent the connecting
rod linkwork being subjected to the stresses incidental to the transmission of
power.
In one mode of carrying my present invention into effect I construct a motor
substantially in accordance with Figs. 4 and 5 of the Specification hereinbefore
referred to and I arrange spur gearing acting between the reverse rotating shafts
so as to ensure their relative rotation irrespectively of the connecting rod link-
work. By this means the linkwork is relieved of its power transmitting function
and the combined mechanism imparts a straight line motion to the piston pins
of the motor.
Where the design of the engine embodies a cross head there is no longer need
for the customary guides the motion of the joint pin being quite determined.
In trunk cylinder engines the bearing portion of the trunk may be largely
cut away and the piston may be considerably lightened and its construction
modified it being no longer necessary to provide against transverse stresses on
the piston pin.
Part of my present invention relates to an improved construction of piston
whereby great lightness is secured. In carrying this portion of my invention
into effect I construct the piston of two parts the piston body and the pin bracket,
the piston body consists of a ring stock and concave back plate in one piece and
the pin bracket is preferably a casting screwed on to a ring shaped projection
from the back plate this ring shaped projection being about two thirds the
diameter of the piston, the bracket is so designed as to carry the direct thrust
from the back plate to the piston pin and it will be seen that by adopting this
method of construction the back plate and other parts of the piston may be made
considerably lighter than would otherwise be practicable.

page_text: Improvements in Fluid Pressure Engines.
I, FREDERICK WILLIAM LANCHESTER, of Ladywood Road, Birmingham, 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:-
This invention relates to fluid pressure engines and is more particularly
applicable to balanced motors of the type described in the Specification to Letters
Patent No. 13,960 of 1896 already granted to me.
The principal object of the present invention is to relieve the piston and
cylinder or crosshead guide from wear and to prevent the connecting rod link
work being subjected to unequal stresses; while a further object of the invention
is to provide a piston that shall be of relatively great lightness while also having
the necessary strength.
The invention consists in gearing the respective crank shafts of the motor
so as to rotate in positive relation one with the other and irrespective of the con-
necting rod link work so that thereby the piston or piston's have a perfectly
straight line motion and the motive force is distributed equally through the con-
necting rod link work. The invention further consists in the form and construc-
tion of piston as hereafter specified.
In one mode of carrying my present invention into effect I construct a motor
substantially in accordance with Figures 4 and 5 of the specification to the
Letters Patent herein before referred to and I provide spur gearing upon and
acting between the reversely rotating shafts so as to positively ensure their
relative rotation irrespective of the connecting rod link work so that the link
work is partially relieved of its power transmitting function and the piston has
a straight line motion.
Where the design of the engine embodies a crosshead there would be no need
for the customary guides seeing that the straight motion of the joint pin would
be determined.
In trunk cylinder engines the bearing part of the trunk may be largely cut
away and the piston may be considerably lightened and its construction modified
having regard to the fact that no provision would be necessary for the transverse
stresses on the piston pin.
In order to further provide for a light piston I may construct the piston in
two parts, a piston body and a pin bracket. The piston body is formed with the
ring stock and concave back plate in one piece and the pin bracket is preferably
a casting screwed onto a ring shaped or flange projection from the back plate
which is preferably about two-thirds the diameter of the piston. The pin
bracket and piston body are so designed as to carry the direct thrust from the
back plate to the piston pin and it will be seen that by adopting such a design
the back plate and other parts of the piston may be considerably lighter than
would otherwise be practicable.
The invention as herein before described is illustrated in the accompanying sheet
of drawings, in which,
Figure 1 shows a longitudinal section of a motor constructed in accordance with
the Specification to the Letters Patent No. 13960 of 1896 and embodies the
present invention.
Figure 2 shows in detail the crank shafts and gearing employed according to
the construction of Figure 1.
Figure 3 is a detail plan view of one of the pistons shown in section in
Figure 1.
From the drawings it will be seen that the spur wheels AA are keyed to crank

page_text: shafts BB and gear with each other so that the respective crank pins CC occupy
positions always equidistant from the centre line of the motor. The crank
pins CC are coupled to piston pins DD by the connecting links D'D' which are
of equal length. The gear wheels AA are preferably of helical form so that
their running may be as silent as possible. The double helical form may be
employed or the special form shown in Figure 2 of the drawings in which a plain
pair of helical wheels are shown which combine with a groove and tongue thrust
arrangement a a' as illustrated. The piston pins DD are carried by brackets G
screwed or otherwise secured to the internal ring or flange projection F of the
piston. The back of the piston E is of concave form.
The tongues H integral with the pistons are not absolutely necessary but serve
to steady the piston in event of undue friction on the pin bearing and also serve
to hold and retain the lubricant and cause it to be more evenly distributed over
the interior of the cylinder. By the construction of a piston as herein before
described it will be understood that the metal is effectively disposed to resist the
stresses imposed upon it in working and that considerable saving in weight may
be thereby effected.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. In fluid pressure engines as herein before described means for effecting a
straight line motion of the piston consisting of reversely rotating crank
shafts, spur wheels mounted thereupon and in gear one with the other, and pairs
of connecting rods, for the purposes and substantially as described.
2. A balanced motor constructed as herein before described having rotating
shafts geared together and operating for the purposes and substantially as
described.
3. A piston of the form and construction herein before described.
4. A fluid pressure engine constructed and operating for the purposes and
substantially as described and illustrated.
Daven
VILIS The tray
OL Ecotuary 1099.
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and
25, Cross Street, Manchester, Agents.