Year: 1887

page_text: Date of Application, 13th June, 1887
Complete Left, 13th Mar., 1888
Complete Accepted, 27th Apr., 1888
I, EDMUND GRACE WASTFIELD of 42 Marlboro Road Liverpool in the County of
Lancaster Mechanical Engineer do hereby declare the nature of this invention to be
as follows:
This Invention relates to low pressure or atmospheric Vacuum motors and has for
its chief objects economy in construction and efficiency in work.
In carrying out my Invention I prefer to construct the motor of the vertical
inverted type. The generator resembles in form an ordinary vertical high pressure
boiler and consists of an outer shell or casing and an internal fire box with the
usual chimney and furnace door. When lightness is important I prefer to construct
the outer shell and fire box of thin galvanized iron but in ordinary cases I use a thin
sheet iron shell in combination with a cast iron fire box and chimney base passing
through the water and steam space.
The motor is connected with the generator in any usual or convenient manner and
it is by preference similar to a vertical steam engine of the ordinary type. The
working cylinder is arranged so that the vapour produced in the generator circulates
freely around the working cylinder or cylinders thus keeping it or them at an
approximate temperature to the contents of the Generator. An arrangement herein-
after described is employed to return any condensed vapour to the water space of the
generator. The motor engine usually actuates the Crank and Fly Wheel as in a
high pressure steam Engine and connected with and worked from the engine in any
convenient way is a vacuum pump.
The efficiency of the motor engine depends upon the action of the vacuum pump
and to prevent leakage of air past the plunger or bucket of the pump the vacuum
pump is provided with a groove or depression in the Barrel just below the bottom of
the packing gland. The groove being connected in any convenient way with the
delivery side of the pump above the upper valve, should the pump ram from any
cause fit loosely in the gland or Barrel, any back leakage must necessarily be water
from the said groove instead of air which would, as it is well known, impair or destroy
the vacuum
A

page_text: This
In any convenient position but preferably vertical by the side of the Generator, is
a Cylinder containing a coil of tubing which forms a surface condenser.
condenser Coil prefer to construct of Tin lined Lead pipe as being found to be
practically unoxidizablə and unaffected by anything which may ordinarily be found
in the feed water.
The bottom of the Coil is brought to the suction inlet of the Vacuum Pump. The
delivery from the pump is carried upwards to a globular casting secured to the side of
the generator just below the working water level. The delivery pipe from the
Vacuum pump is brought into the globular casting sufficiently far to allow of a nozzle
being so fixed that an induced current is set up in the globular casting whereby any
water of condensation in the jacket of the Working Cylinder is by the induced action
of the jet withdrawn by means of a pipe affixed to the lowest portion of the jacket and
connected to the globular casting behind the jet before mentioned.
The Cylindrical Case containing the Condensor Coil is fitted with apertures; one
near the bottom, the other near..the top. Pipes lead from these apertures to a larger
cooling tank of any convenient form or construction and placed in any convenient
position, the water surrounding the condensor Coil naturally circulates to and from
the cooling tank owing to the heat imparted by the Condensation of the Vapour as
hereinafter explained.
In order that the water level in the Generator may be maintained at an uniform
levol and also that the water level may be readily seen under all conditions, I attach
to the side of the Generator a Chamber of any convenient form containing a float, and
attach the float to a Valve, the faces of which are struck to the radius of a circle.
Below the valve a pipe is connected to the Cylindrical Condenser Case. When the
float and with it the Valvo is depressed by the Water level in the Generator falling,
water passes the Valve into the Generator through one of the two tubular connections.
A similar connection at the upper part of the Feed Caso maintains an equilibrium in
the interior. A narrow strip of glass secured to the sides of the float Chamber
enables the attendant to observe the Water level.
For some purposes I prefer to use an Engine in which the Aqueous. Vapour and,
the Vacuum alike act on one side of the piston only. The crank and other moving
parts are contained in a Casting of suitable form. I prefer to run this form of
Engine at an increased speed-As the Vacuum pump would be rendered less
effective by such increase of speed, I prefer to use a pair of gear wheels inside the
said Casting so that the Vacuum pump is driven at a less speed than the crank shaft
of the Engine. The Vacuum pump in this modification I prefer to place horizontally
so that by filling the lower part of the casting with water with a small volume of
oil floating on the surface the Vacuum pump plunger being submerged any leakage
in of air is prevented and lubrication is assured.
The Valves of the Motor Cylinder I prefer to construct of the usual D shape or in
the case of the smaller engines or the high speed form before referred to, a simple
form of piston valve rendering a valve spindle gland unnecessary, as well as reducing
friction.
The Governor I prefer to employ is cheaply and readily constructed by using
instead of the usual rigid links, flat link Chains, a spiral spring placed on the governor
spindle giving the necessary resistance.
The Governor by a suitable and convenient arrangement operates a combined stop
and throttlo valve, so that the engine is practically started, and when running is
maintained, at a uniform speed by the governor actuating the stop and throttle valve
and controlling the admission of aqueous vapour to the Valve box.
In many cases I prefer to construct the Generator with sides or staves of wood
similar to a barrel or cask, the staves being held together by adjustable bands or
hoops. The fire box may be either of cast or wrought iron with a chimney of the
same material.
A valve made as high as practicable allows the excess of pressure inside the
generator to escape..
When Motors of large size are employed or when it is desired to use them for the.

page_text: propulsion of tramcars, Yachts, or Locomotives, it is most desirable that some
arrangement should be employed so that the motors be practically self-starting, as
well as capable of being started, stopped, or reversed as often or as quickly as may
be desired. To effect this 1 employ a separate Vacuum pump actuated by an over-
head Motor Cylinder. The piston rods of the Motor Cylinders and Vacuum pump
being in line and continuous. A piston Valve actuated by an auxiliary piston of
short stroke controls the admission of Vapour to and from the Motor Cylinder. The
centre portion of the piston rod is enlarged and fitted with a metal block sliding in a
slot forming a bearing for a lever connected with a hand lever, the opposite sli de
Valve controlling the auxilliary piston rendering the action certain and by the
adjustment of the tappets.on the Valve spindle so controlling the main piston that the
requisite cushioning is obtained, or the effective stroke reduced as desirable.
The action of the Motor is as follows:-
The Generator being filled with water to the working level and caused to boil, the
contained air is expelled through the escape Valve before mentioned-The combined
stop and throttle Valve being now opened and the fly wheel turned by hand the
Aqueous Vapour passes into the Condensor Coil and is condensed whereupon the
Motor starts. The condensed Vapour is returned to the Generator without contact
with air, by means of the Vacuum pump. A closed circuit is thus maintained.
When the engines are fitted with the separate independent Vacuum pump-before
mentioned, the conditions being as before, the attendant having opened the Vapour
supply pipe, and actuating the same by means of the hand lever, a vacuum is at once
established in the common condensor, so that by opening the starting Valve to the
main engines they at once start; or they may be stopped and reversed and again
started by link motion of the usual form, the independent Vacuum pump maintaining
a constant vacuum meanwhile in the Condensor into which its own exhaust vapour is
led and condensed..
The Motor being well adapted for driving Tram Cars, I use any convenient.
arrangement of Motor, Generator, and Condensor. But, for this purpose I employ
an arrangement whereby the power is transmitted through Clutches which throw in
or out of gear at will, either a fast or slow speed gear. The tractive power may be
transmitted to the axles of the Car by means of pitch chains. The Cooling Tank is.
fitted with a Valve of considerable area so that the whole of the cooling water may
promptly flow away, and on the Valve being re-closed a fresh supply, of cold water:
may be supplied from the nearest hydrant or available supply. To check the speed, a.
powerful brake arrangement, operated by a Vacuum Cylinder is employed at will,
placing one side of the brake piston in communication with the Condensor, the vapour
from the Generator being admitted to the other side of the piston to exert tho
necessary pressure. Suitable arrangements are provided so that to release the brake.
the connexion with the Condensor is closed, and the piston, being placed in equilibrium,
no longer applies the pressure.
L 11
ol 1
T
A D 1007
WILLIAM E. HEYS,
Agent for Applicant.

page_text: I, EDMUND GRACE WASTFIELD of the city of Liverpool in the county of Lancaster,
Mechanical 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 :-
The invention relates to low pressure or atmospheric vacuum motors and has for its
chief objects economy in construction and efficiency in work. The motor is worked
by steam at a pressure preferably not exceeding or but slightly exceeding that of the
atmosphere thereby minimising risk from explosion.
In carrying out my invention I prefer to construct the motor of the vertical inverted
type with a generator resembling in form an ordinary vertical high pressure boiler
that is it consists of an outer shell or casing and an internal fire box with the usual
chimney and furnace door.
When lightness is important I construct the outer shell and fire box of thin
galvanized iron. But under my invention I construct a generator of a thin sheet
metal shell say iron steel or copper in combination with a cast iron fire box and
chimney base passing through the water and steam space.
;
The motor is connected with the generator in any usual or convenient manner and
it is by preference similar to a vertical steam engine of the ordinary type. The
working cylinder is arranged so that the vapour produced in the generator circulatos
freely round the working cylinder or cylinders thus keeping it or them at a temperature
approximate to that of the contents of the generator. An arrangement hereinafter
described is employed to return any condensed vapour to the water space of the
generator. The motor engine usually actuates the crank and fly wheel as in an high
pressure steam engine and connected with and worked from the engine in any
convenient way is a vacuum pump.
The efficiency of the motor engine depends on the action of the vacuum pump and
to prevent leakage of air past the plunger or bucket of the pump the vacuum pump is
provided with a groove or depression in the barrel just below the bottom of the
packing gland the groove being connected in any convenient way with the delivery
side of the pump above the upper valve or to any convenient part of the engine having
a head of water above the said groove or depression; should the pump ram from any
cause fit loosely in the gland or barrel any back leakage must necessarily be water
from the said groove instead of air which would it is well known impair or destroy the
vacuum.
In any convenient position but preferably vertical by the side of the generator is a
cylinder containing a coil of tubing which forms a surface condenser: this condenser
coil I prefer to construct of tin lined lead pipe as being found practically unoxidizable

page_text: and unaffected by anything which may ordinarily be found in the feed water but
such condensers may be made and located in any usual or suitable manner. Under
my invention the bottom of the coil or condenser is brought to the suction inlet of
the vacuum pump and the delivery from the said pump is carried upwards to a
spherical casting secured to the side of the generator just below the working water
level. The delivery pipe from the vacuum pump is brought into the globular casting
sufficiently far to allow of a nozzle being so fixed that an induced current is set up
the globular casting whereby any water of condensation in the jacket of the working
is by the induced action of the jet withdrawn by means of a pipe to the lowest portion
of the jacket and conducted to the globular casting behind the jet before mentioned.
Any other suitable jet may be connected to the delivery pipe of the pump to act in the
manner above specified.
in
The cylindrical case containing the condenser coil is fitted with apertures, one near
the bottom the other near the top. Pipes lead from these apertures to a larger cooling
tank of any suitable form or construction placed in any convenient position. The
water surrounding the condenser coil naturally circulates to and from the cooling tank
owing to the heat imparted by the condensation of the vapour as hereinafter
explained.
In order that the water level in the generator may be maintained at a uniform level
and also that the water level may be readily seen under all conditions I attach to the
side of the generator a chamber of any convenient form containing a float, and attach
the float to a valve the faces of which are struck to the radius of a circle. Below tho
valve a pipe is connected to the cylindrical condenser case. When the float and with
it the valve is depressed by the water level in the generator falling, water passes the
valve into the generator through one of the two tubular connections. A similar
connection at the upper part of the feed case maintains an equilibrium in the interior.
A narrow strip of glass secured to the side of the float chamber enables the attendant
to observe the water level.
For some purposes I use an engine in which the water vapour and the vacuum alike
act on one side of the piston only. The crank and other moving parts being contained
in a casting of suitable form. I prefer to run this form of engine at an increased
speed and as the vacuum pump would be rendered less effective by such increase of
speed I use a pair of gear wheels inside the said casting so that the vacuum pump
is driven at a less speed than the crank shaft of the engine. The vacuum pump in
this modification is placed preferably horizontally so that by filling the lower casting
with water having a small quantity of oil floating on the surface the vacuum pump
plunger is submerged and any leakage in of air is prevented and lubrication is
assured.
The valves of the motor cylinder I prefer to construct of the usual D shape or in
the case of the single acting or high speed engines before referred to of a simple
form of piston valve rendering a valve spindle gland unnecessary as well as reducing
friction. This is effected by making the valve piston or rod with grooves connected
by a slot or slots opening to an aperture or apertures leading through the cylinder
walls to the steam space; such construction is applicable to pistons or rods other than
valve pistons or rods. The engine is practically started and when running is
maintained at a uniform speed by the governor actuating a stop and throttle valvo and
controlling the admission of aqueous vapour to the valve box.
In many cases I construct the generator, with sides of staves of wood similar to a
barrel or cask. The staves being held together by adjustable bands or hoops. The
fire may be either of cast or wrought iron or of other suitable metal with a chimney
of the same material. A valve made as light as possible allows the excess of pressure
inside the generator to escapo.
When motors of large size are employed or when it is desired to use them for
the propulsion of tram cars, yachts, or locomotives it is most desirable that some
arrangement should be employed so that the motors are practically self starting as
well as being capable of being started stopped or reversed as often or as quickly as
may be desired. To effect this I employ a separate vacuum pump actuated by an

page_text: overhead motor cylinder. The piston rods of the motor cylinder and vacuum pump
being in line and continuous. A piston valve actuated by an auxiliary piston of short
stroke controls the admission of vapour to and from the motor cylinder. The centre
portion of the piston rod is enlarged and fitted with a metal block sliding in a slot
forming a bearing for one end of a lever connected with a hand lever. The opposite
end of the said lever having a forked extremity which operates a small D slide valve
controlling the auxiliary piston and rendering the action certain by the adjustment
of tappets on the valve spindle so controlling the main piston that the requisite
cushioning is obtained or the effective stroke reduced as desirable.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is an elevation of one form of the motor under my invention showing the
general arrangement, 1 being the generator, more particularly described in Fig. 2,
2 is the motor similar in construction to an ordinary steam engine and fitted with
any convenient form of governor. The cylinder is by preference so proportioned that
it has a larger piston area and shorter proportionate stroke than that of an ordinary
steam engine. The working cylinder and the slide valve being both carefully steam
jacketed as shown hereafter. 3 is a tube or column containing a coil of tin lined
lead piping or a coil or a surface condenser of any other convenient form or a jet
condenser may be used. The column 3 is filled with water which thus surrounds.
the condenser. As the contained water would necessarily become heated connections
are provided 4. and 5 whereby the warmed water is allowed to flow away and cold
water is admitted to take its place. 6 is the feed water regulator, 7 an escape valvo,
8 an arrangement termed an ejector, 9 the exhaust pipe from the motor engine to the
condenser, 1( a connection whereby any condensed water from the steam jacket is
returned to the water space of the generator 1. Fig. 2 is a section of a generator
constructed in accordance with my invention and consisting of an outer shell of sheet
iron 1 with a cast iron fire box and uptake 11. A battle plate of any convenient form
or material being shown at 12. A further improvement relative to the generator is
shown at Fig. 3 where the metal outer shell 1 is replaced by staves of wood 13
similar to a barrel or cask the staves being held together by adjustable bands or
hoops 14 the drawing shows a cast iron fire box and uptake 11. But in some
cases I prefer to use a thin galvanized iron firebox and uptake. Fig. 4 is an
elevation part being in section of a vacuum pump under my invention. 15 is the
groove or depression connected with the delivery side of the pump above the upper
valve as shown at 16 or in any convenient way in order that the chamber 15 being
maintained full of water any back leakage past the plunger 17 must necessarily be
water from said groove instead of air which would impair the vacuum. Fig. 5 is
an elevation and Fig. 6 a section of apparatus under my invention for keeping the
cylinder jackets of low pressure engines free from water, 18 is the delivery pipe from
the air pump, 19 nozzle causing an induced current thereby withdrawing any water of
condensation from the jacket of the working cylinder through the pipe 20 into the
suction chamber 21 and injecting the same into the generator.
Fig. 7 is a section of the feed regulator which by its action maintains the water.
in the generator at a constant level. 22 is the chamber of any convenient form in
which is a float 23 and attached thereto is a valve 24 the faces of which are preferably
struck to the radius of a circle. Below this valve a pipe 25 is connected to the
cylindrical condenser case (3 Fig. 1). When the float and with it. the valve is
depressed by the water level in the generator falling, water passes the valve into the
generator through one of the two tubular connections 26 and 27 the upper tubular
connection 26 maintains an equilibrium in the interior of the casing 22 so that the
water entering by 25 flows in by the action of gravity to the generator through 27.
narrow strip of glass 28 carried in a frame secured to the side of the float chamber 22
enables the attendant to observe the water level and that the float is duly acting.
A
Fig. 8 is a vertical section and 9 an elevation part being in section of a motor .in
which the aqeouus vapour and the vacuum alike act on one side of the piston. only;

page_text: 29 is the working cylinder surrounded by the stean jacket 30. 31 the piston to which
the connecting rod is secured. 32 crank shaft. 33 air pump with the inlet 34 and
outlet 35. The air pump as the engine is intended to run at an increased speed is
placed horizontally and is driven by a pin projecting from the face of
gear wheel 36
which in turn is actuated by a wheel of smaller diameter 37 secured to the motor
crank shaft. By this this arrangement the vacuum pump is driven at a less speed
than the crank of the engine. The main casing of the engine is filled with water
having a small quantity of oil floating on the surface I prefer to construct this type of
engine with the piston slide valve shown at 38 fig. 9 and 39 fig. 10.
For small powers and for domestic and other purposes I modify single acting
engines by placing the cylinder or cylinders in the steam space of the generator as
shown in fig. 10. 29 is the working cylinder 39 is the piston valve, 9 the exhaust
way leading to the condenser, 40 is a piston or equilibrium throttle valve actuated in
any convenient or suitable way by a governor actuated by the engine shaft, 41 is the
fire box with a chimney 42 passing through the steam and water space at the back of
the working cylinder, 43 is the vacuum pump driven by an excentric on the crank
shaft of the motor. In order to prevent leakage of air to the condensor past the
piston 31 and its valve 39 I construct the piston 31 with projections 44 as shown.
These projections have grooves or depressions on the surface next the walls of the
working cylinder 29. By means of aperturos 45 fig. 11 the steam in the generator
finds its way into the grooves in 44 and thence downwards to the groove 46. When
I use a double acting cylinder I use a modified arrangement to prevent leakage shown
at fig. 12, where 47 is a chamber or groove formed beyond the packing gland, steam
being introduced to fill this chamber or groove by means of the passage 48 which
communicates with the steam jacket or the generator in any convenient way.
The generator is arranged to actuate by any suitable and convenient arrangement a
combined stop and throttle valve fig. 13, the valve fitting has a passage 49 that com-
municates with the steam jacket, 50 is a valve secured to the spindle 51, the lower end
of which is screwed and passes downward inside the sleeve on the hand wheel 52, at
53 is a plain piston valve having a passage or way formed through in permitting
steam having passed the valve 50 to pass through it from the upper to the lower side,
54 is a port way leading to the valve box of the motor. The governor by a suitable
device takes hold of the wheel and sleeve 52 at 55. When it is desired to start the
motor the hand wheel 52 is turned thus lowering the valve 50 off its seat, steam then
passes through the passage ways in 53 and passing away through 51 actuates tho
motor, when the speed of the motor exceeds the required number of revolutions per
minute the governor by its connection at 55 depresses further the wheel 52, spindle 51
and with it the valves 50 and 53, thereby controlling the admission of aqueous vapour
or steam to the valve box and thus maintaining a uniform speed of the motor.
Fig. 14 is a section of the escape valve (7 fig. 1) being a valve made as light as
practicable which allows the excess of pressure inside the generator to escape, but
prevents any inrush of air into the steam space of the generator.
In order that the intensity of combustion may be as nearly as possible equal to the
work done by the motor and the consequent demand for steam the arrangement shewn
at fig. 15 may be employed 56 being a tube extending downwards into the water
space of the generator into which it dips. 57 is a float connected with the beam and
links 58 to the throttle valvo 59. At 60 is a woight adjustable on the horizontal lever
by which an exact equipoise can be obtained. Any rise of pressure in the generator
therefore tends to raise the float 57 merely closing more or less the throttle 59 which
controls the air supply to the ashpit of the generator.
The action of the motor is as follows:-The generator being filled with water to the
working level and caused to boil the contained air is expelled through the escape valve
before mentioned, the combined stop and throttle valve being now opened and the fly
wheel being turned by hand the aqueous vapour passes into the condenser coil and is
condensed thereupon the motor starts. The condensed vapour is returned to the
generator without contact with air by the vacuum pump. A closed circuit is thus
maintained.

page_text: Fig. 16 shows so much of a large sized self-starting reversing engine as is needful
to explain this part of my invention. 61 overhead main steam cylinder. At 62 the
rod is continued downwards as may be needed to an air pump which may be either
single or double acting. 63 is a piston valve actuated by an auxiliary steam piston.
64, being in turn controlled by its own slide valve as shown. The rod of this slide
valve is carried downwards and on it are two adjustable stops 65, 66. The centre
portion of the piston rod is enlarged as shown at 67 and is fitted with a metal block
sliding in a slot forming a bearing for a lever 68. Connected with this lever 68 is a
hand lever as shown which provides a means of working both air pump and valves to
produce an initial vacuum at starting. The end of 68 is caused to actuate by means
of 65, 66 the slide valve 69 of the auxiliary piston 64 thus rendering the action
certain as well that by adjustment of the tappets 65, 66 on the valve spindle. The
main piston is so controlled that the requisite cushioning is obtained or the effective
stroke reduced if desired.
When engines are fitted with the separate independent vacuum pump before
mentioned the attendant having opened the vapour supply pipe and actuated the said
pump by means of the hand lever a vacuum is at once established in the common
condenser (the exhaust both of the auxiliary and main pistons of the pump being led
thereto in any convenient way). On opening the starting valve to the main engines
they at once start owing to the existing vacuum in the condenser, they may
consequently be again stopped, reversed and again started by link motion of the usual
form or by other suitable device-the independent vacuum pump maintaining a
constant vacuum meanwhile in the condenser into which its own exhaust is led and
condensed.
For the propulsion of tram cars I may employ any suitable arrangement of parts
one such arrangement is shown at figs. 17 & 18. The same letters refer to similar
parts in both figures. 70 is the generator of any suitable form or construction 71 the
engine 72 is a tank containing a surface condensor said tank being filled with water
which therefore surrounds the tubes at 73 is a valve of large proportionate area by
lifting which when desired the warm water in 72 is allowed to rapidly rush out and
cold water admitted to replace it through the man hole 74. I prefer to so arrange
the under gear that two of the wheels of the Loco car are allowed to run loose on the
crank shaft 75 which is carried through into the axle boxes.
Both outside and inside bearing may for this purpose be used. 76 ure pitch chain
wheels so arranged with clutches that either a fast or slow speed can be maintained as
also that by suitably connected and arranged levers the action of moving the main
starting valve handle throws both of the said clutches out of gear. A powerful brake
actuated by the cylinder 77 by means of the vacuum maintained in the worm
condensor affords ample means of bringing the Engine Car to a standstill. In some
cases I prefer to use an arrangement of air condensor suitable arranged in the place of
or stead of the surface condensor shown at 72.
By an arrangement omitted for clearness in the drawing I connect the axle of said
engine car to a suitable form of governor so arranged that on a predetermined speed
being exceeded the governor operates a valve bringing into action the vacuum brake 77
and thus preventing the possibility of excessive speed being attained.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what I
claim is
First. For low pressure or vaccum motors steam generators having sheet metal
shells combined with cast iron fireboxes and uptakes substantially as set forth.
Second. For low pressure or vacuum motors steam generators having wood shells
combined with metal fireboxes and uptakes substantially as set forth.
Third. For low pressure or vacuum motors vacuum pumps having a groove or
depression connected to a head of water substantially as set forth.
Fourth. A low pressure or vacuum motor having the cylinder jacket and vaccum
pump delivery pipe connected to injector appliances substantially as set forth.

page_text: Fifth. Single acting low pressure or vacuum motors with submerged vacuum pumps
substantially as set forth.
Sixth. Low pressure or vacuum motors with steam packed pistons and rods sub-
stantially as set forth.
Seventh. The combination with a low pressure or vacuum motor of an auxiliary
vacuum pump with the main vacuum pump and a condensor common to both
substantially in the manner and for the purpose set forth.
Eighth. The combination of a low pressure or vacuum motor under my invention
with a tram car a road vehicle substantially as set forth.
Ninth. Low pressure or vacuum motors constructed and operating substantially as
set forth in figs. 1, 8, 9, 10, 16, 17 and 18.