Improvements in or Applicable to Fluid Pressure Motors.
Year: 1897

page_text: Date of Application, 18th Aug.. 1897
Complete Specification Left, 15th June. 1898-Accepted. 16th July, 1898
Improvements in or Applicable to Fluid Pressure Motors.
I, CARL JOST, of 13, Hornby Row, Bombay, India, Engineer, do hereby declare
the nature of this invention to be as follows:-
My said invention relates to means for automatically driving punkahs, sewing
machines and the like by means of steam water compressed air or other fluid
pressure.
As applied for example to driving a punkah the invention consists of a single-
acting cylinder and piston by means of which the punka' is pulled in one direction
and the weight of the pankah produces the return motion and lifts the piston (in
other cases a fly-wheel may be provided).
Above the top side of the piston when in its topmost position is an annular feed
pipe for the admission of steam, water compressed air or other fluid.
In the same
cylinder is a piston formed of a hollow ring and wings so that the fluid can pass
through. This piston is connected by a rod passing through a fluid-tight collar
into another cylinder in which works another piston. The two small pistons and
the rod connecting them are in equilibrium and act as a controlling valve. When
the controlling valve is in its topmost position the feed pipe is open and the
exhaust closed, when in its lowermost position the exhaust is open and the feed
pipe closed.
The method of working is as follows:-The fluid is admitted by the feed pipe to
the top of the piston, the exhaust being closed. The piston descends and when it
has reached the bottom of its stroke there is above the top of the piston an orifice
which communicates by means of a pipe with the top of the controlling valve. The
fluid coming in contact with the controlling valve forces it down since the surface
of the piston exposed to pressure is greater than that of the rod in connection with
the lower piston. When the controlling valve is pushed down the exhaust ports
are opened and the feed ports closed. The fluid escaping from the cylinder reduces
the pressure and enables the punkah in its return stroke to lift the piston. When
the piston comes in contact with the piston of the controlling valve it pushes the
controlling valve up, and closes the exhaust ports and opens the feed.
At the end of the piston rod is a pin which takes between two vertical guide bars
and into one of the lower joints of the combination of levers known as lazy tongs.
The top joint of the lazy tongs is connected by suitable means to the punkah,
which thus receives a much longer movement than that of the piston which drives it.
If the punkah when in motion is arrested by the hand, the motor is stopped and
a slight pull of the punkah will set the motor in motion again without the necessity
of shutting or opening the feed cock.

page_text: I, CARL JOST, of 13, Hornby Row, Bombay, India, Eugineer, 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:-
My said invention relates to means for automatically driving punkalis sewing
machines and other appliances and machinery by means of steam water compressed
air or other fluid pressure.
As applied for example to driving a punkah the invention consists of a single
acting cylinder and piston and appropriate connections for pulling or raising the
puukah in one direction. In this case the weight of the punkah serves as a recoi!
counterpoise or return force for again bringing the moving parts into their initial
position for a fresh impulse. In other cases where from the nature of the work
to be done there is no such recoil or return force the reversal of the parts may be
effected by a fly wheel or by means of an attached counterpoise or resistance.
The objects of my said invention are, first, to substitute a simple and conveniently
sized machine for human labour adapted for pulling and moving punkahs (i.c.
suspended swinging fans used for cooling purposes in hot climates), sewing
machines, lathes, smiths' bellows, bell pulling and other work of the like nature
where a constantly repeated pull or application of force is required; second, to
provide a machine which will produce automatically a force creating as nearly
as possible the effect produced by the human hand and arm when working on an
object such as a beli rope, or smith's bellows or by the human leg and foot
when working on a sewing machine or lathe, the principle being that by the
human agent more force is naturally exerted at the coinmencement of the muscular
strain being applied than afterwards; and, third, to provide a special valve at the
one end of an ordinary cylinder which will move in the cylinder itself, the opening
of the valve being caused by contact with a piston working in such cylinder and
closing of such valve being caused by the fluid pressure which is exerted on the
piston.
I attain these objects by the mechanism illustrated in the accompanying drawings
to which reference is hereinafter made.
Figure 1 is a vertical section on a plane A-B of Fig. 6;
Fig. 2, is a vertical section on a plane C-D of Fig. 5;
Fig. 3, is a horizontal section of the inlet pipe chamber on a plane E-F looking
from bottom to top of Fig. 1;
Fig. 4, is the plan of the exhaust pipe chamber on a plane G-H of Fig. 2;
Fig. 5, is a front elevation of the entire motor or machine showing base plate,
standards, cylinder, guide, and an arrangement of levers on the lazy tongs'
principle in mid position ;
**
33
Fig. 6, is a side elevation of what is shown in Fig. 5;
Figs. 7, and 7 shew the complete motor as applied to pulling a punkah (i.e.
suspended swinging fan);
Figs. 8, 9, and 10, shew a modification of the "
levers in various positions.
">
lazy tongs arrangement of
The words "top" and "bottom" " upwards" and "downwards" as used herein
refer to the attached drawings and do not imply that the motor must necessarily
occupy a vertical position.
Similar letters refer to similar parts of the machine throughout the several views.

page_text: The motor is represented (Fig. 1) in the position of starting with the piston at
the beginning of its stroke, and the Huid entering the cylinder through a chamber
formed in this instance as an annular fluid supply pipe (shown in plan, Fig. 3).
b is the cylinder, c the piston, d the pin on the end of the piston rod from which the
pressure is transmitted. The controlling valve e is in its top position closing the
exhaust orifices h h. The controlling valve e is a cylindrical ring carried on a
spindle by means of arms, as shewn, so that the fluid traverses it and reaches the
end of the cylinder. The valve is in equilibrium and the end of the spindle alone
takes pressure which suffices to hold the valve up during the downstroke of the
piston. The upper piston g is in communication through the pipe ml (Fig. 2), with
the lower end of the cylinder. When the downstroke is complete, the upper side
of the piston c has descended below the opening of the pipe m and pressure is
communicated through this pipe to the upper piston which descends by reason of
the area of the piston being greater than that of the spindle thus forcing down
the controlling valve e and closing the inlet pipe a and opening the exhaust
passages h h. The return motion of the object worked on by the machine which in
the accompanying drawings is by way of example shown to be a punkah y (Fig. 7),
pults the piston up and the contents of the cylinder pass through the controlling
valve e and escape by the exhaust passages h h and ii into the chamberjj and
from thence through the outlet & to the exhaust pipe. When the piston approaching
its top position comes in contact with the controlling valve e it moves the valve e
upwards admitting the fluid pressure through the pipe a so as to raise the valve e to
its highest position, at the same time forcing the piston c downwards and so on.
Figs. 11, 12, 13, 14 and 15 illustrate a modified construction of the cylinder piston
and valves. In these figures, Fig. 11 is a vertical section, Fig. 12 is an elevation
partly in section at right angles to Fig. 11, Fig. 13 is a plan of the top cover,
Fig. 14 is a plan with the top cover removed, Fig. 15 is a plan of the lower part.
In this construction the exhaust pipe is fitted above and on opposite side to the
supply pipe a which in this case communicates with the lower chamber n n of a box
or casing surrounding the upper end of the cylinder. The upper part h¹ h¹ of this
box is separated from the lower part by a diaphragmn and forms the exhaust
chamber whence the exhaust passes to the exhaust pipe le¹.
The inlets from the supply chamber n n to the cylinder are placed at equal
distances round the cylinder thus exercizing a uniform pressure upon the piston and
the distributing valve while approaching or closing the supply apertures.
The piston c is formed as a hollow cylinder open at its lower end and provided
with a cup like projection at the top to receive suitable material to form a buffer so
that the contact between the piston and the distributing valve may be noiseless.
The piston rod p which is also hollow is hinged to the piston inside and has for
a short distance a number of small holes drilled through to permit air to enter the
cylinder when the piston is rising and to permit the escape of air when the piston
is being forced down by the fluid pressure. The fluid in the cylinder above the
upper piston g and in the pipe m l descends into the lower box by means of the
pipe m l.
Any fluid leaking past the piston c will also pass into the lower box
and escape through the pipe ji.
At the bottom of the cylinder a simple cup guide is provided fixed to the
cylinder by means of a bayonet joint. The upper surface z of this guide is sloped
so as to direct any water which may accumulate in the bottom of the cylinder into
the lower chamber j.
The punkah y (Figs. 7 and 7A) or other object worked on, acting as a counter-
poise brings back the piston c by means of the connectiou x with the arrangement
of levers connected together on the principle of "lazy tongs" ttt to the position
where pressure is re-applied so that on any arresting or stoppage of the movement
of the punkah y or object worked on at any portion of the return stroke the
working of the machine will be stopped and the supply of the pressure fluid to the
cylinder will be shut off thus preventing waste.

page_text: Afterwards the machine can again be set in motion by hand or by any means
which raises the "lazy tongs" arrangement of levers to its highest position. This
in the case of the example given in the accompanying drawings would be done in
the simplest way by giving the punkah y a swing when the machine would once
more proceed to work automatically until again stopped as before or until the fluid
pressure is shut off.
One construction and arrangement of the lazy tongs is shown in one position in
Fig. 5. The pin d which is mounted in a crosshead in the piston rod and works in
guide bars forms one of the hinge pins of the lazy tongs. In the construction
shown in Fig. 5 the ends of the bottom links of the lazy tongs are connected
to the lower ends of radius rods ww which have fixed fulcrums or centres of
oscillation so that as the piston ascends or descends the lazy tongs are extended or
contracted. As the piston approaches its highest point under the recoil of the load
the lazy tongs are extended to their greatest, length in which state they are in a
position to transmit the full force of the piston and thus the maximum force of the
piston is effective at the commencement of the pull imitating in this respect the
motion of the human hand as used in pulling punkahs so as to give the best effect.
A modification of the lazy tongs arrangement is shown in Figs. 8, 9, and 10. In
this construction additional links s s are interposed between the ends of the radius
rods w and the ends of the bottom links of the lazy tongs. Stops o o are in this
While the radius
case provided to restrict the swing of the radius rods w w.
rods ww are swinging between the stops oo the radius rods w w and the links 8 8
form idle links and have no effect in opening the lazy tongs. When however the
radius rods ww come in contact with the stops which limit their free range a
resistance is obtained and the lazy tongs are opened. These stops may be put in
different positions (two such are shown in Figs. 8 and 9) so as to cause the lazy
tongs to travel bodily for such distance as may be desired without opening out
at all.
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. A single acting fluid pressure motor combined with lazy tongs so as to
transmit the maximum pressure ou the piston at the commencement of each
effective stroke substantially as and for the purpose set forth and described with
reference to the accompanying drawings.
2. The combination with a set of lazy tongs of a single acting piston c working
in a cylinder b operated by fluid pressure controlled by an annular equilibrium
valve e which is operated so as to close the inlet by a separate valve piston g in line
with the main pistou receiving the fluid pressure when the piston c is about com-
pleting its stroke and reversed by the recoil of the load, for producing an
intermittent lift or pull with a strong initial impulse substantially as and for the
purpose set forth and shown.
3. The combination in a single acting fluid motor of the main cylinder the
piston c with its rod the supply chamber a (intermittently communicating through
ports with the interior of the cylinder b) the annular balanced controlling valve e
(operated by the independent valve piston g working in a separate cylinder
in line with the piston c for the purpose of closing the inlet ports and operated
by the piston c for opening or partly opening the inlet ports when the piston
completes its return stroke under the recoil of its load) the conduit m l making
communication between the interior of the lower part of the main cylinder and the
upper part of the cylinder of the valve piston y and the exhaust chamber h
communicating by ports (intermittently closed and opened by the valve e) with the
upper part of the cylinder b substantially as and for the purpose set forth and
shown.
4. In combination with a single acting fluid motor and lazy tongs such as

page_text: described the links ss and the stops o for determining the point of the stroke at
which the lazy tongs shall open substantially as set forth and described with particular
reference to Figs. 3, 9, and 10 of the accompanying drawings.
Dated this 21st day of May 1898.
E. T. WHITELOW, A.M. Inst., C.E.,
70, Deansgate, Manchester, Agent for the Applicant.