Combined Electric Generator or Motor, and Steam, Air, or the like Engine or Compressor.
Year: 1898

page_text: Date of Application, 20th Sept., 1898-Accepted, 10th Dec., 1898
COMPLETE SPECIFICATION.
Combined Electric Generator or Motor, and Steam, Air, or the like
Engine or Compressor.
I, BENJAMIN JOSEPH BARNARD MILLS, of 23, Southampton Buildings, in the
County of London, Patent Agent, do hereby declare the nature of this invention
(a communication to me from Marcy Lelland Whitfield, of 1011, Monadnock
Block, Chicago, Cook County, Illinois, Electrician, and Charles Clifton Cowan,
of 316, Front Street, Memphis, Shelby County, Tennessee, Cotton Broker, both
in the United States of America), and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement: ―
The object of this invention is to devise a machine which will combine within
itself the mechanism for producing or consuming electrical energy, and for con-
suming or producing the expansive energy of steam, air, etc. The aim in other
words, is to produce an engine which will be adapted to utilize both electric and
expansive energy, both directly as a producer and indirectly as a consumer, and
in which either character of energy may be produced or consumed independently
of the other. When the improved engine is used to consume expansive energy
and produce electric energy, it takes the form of a combined engine and dynamo.
When used to consume electrical energy and produce expansive energy, it is
a combined electrical motor and pump or compressor. As, however, the im-
proved engine may be used to produce or consume electric energy independently
of its consumption or production of expansive energy, it finds its fitting designa-
tion in neither of the terms before mentioned. It may be properly called an
electric engine.
Economy of space and power are both obtained by the improved construction.
The improved electric engine is capable of use in many places where existing
power producers or users are either inadequate or impossible to employ.
In accomplishing the object of the present invention a dynamo electric engine
is constructed in which one or more of the field magnets are interiorly hollowed,
so as to form what may be termed piston chambers. Within the chambers thus
formed, reciprocate pistons, which may be, and preferably are, connected by
suitable mechanism to the armature of the dynamo electric machine, so that
movement of one will cause corresponding movement of the other.
There is a fundamental difference between the function of the said piston
chamber, and that of the piston chamber or cylinder used in steam engine con-
struction. In steam engine construction, the design of the cylinder is controlled
by the object to make it sufficiently strong to allow the production of the desired
aimount of expansive energy with the use of the least quantity of metal, and the
metal is solely and simply a confining agent for the expansive power.
In the construction herein described, the design of the field magnet is con-
trolled by the amount of electric energy which it is to produce or utilize, or the
number of magnetic lines which it is to contain, and the use of the field magnet
to enclose the hollowed out portion which forms the walls of the piston chamber

page_text: is incidental and subservient to its use as a magnetic agent. Arising from this
difference in the purpose and function of the metal forming the field magnet,
are the facts that the position of the piston chamber within the field magnet
need not be confined to the central portion illustrated in the drawing of this
specification, nor need the proportions of the piston chamber relative to the field
magnet be those commonly used in steam engine construction.
When steam is conveyed to the piston chamber through suitable valve con-
nections provided, and the expansive engine becomes a steam engine, reciproca-
tion of the piston results in a corresponding movement of the armature, and the
dynamo electric machine becomes a producer of electric energy. If, on the con-
trary the dynamo electric machine is supplied with electrical energy and used
as a motor, reciprocation of the piston follows corresponding rotation of the
armature, and the steam engine is converted into a pump or compressor. The
power produced by the reciprocation of the piston may also be added to that
produced by the action of the armature as a motor to effect concentration of power.
The invention is fully illustrated in the accompanying drawings, in which
the same reference letters refer to the same or corresponding parts, and in
which:-
Fig. 1 is a side elevation of an illustrative form of the electric machine.
Fig. 2 is a top plan view of the same.
Fig. 3 is a central vertical section on the line 3-3, Fig. 2.
Fig. 3 is a detail cross section of the yoke containing the steam passages, on
the line 3 3ª Fig. 3.
Fig. 4 is a view of a modified construction, and Fig. 5 is a view of another
modified form of constructon.
In the construction of the improved electric engine, considerations of economy
in the production of power, of the utilization of the greatest possible proportion
of the power produced, and of the avoidance of unduly heating the coils used
for energizing the field magnets of the dynamo electric machine, have caused the
communicators to adopt several types, each being fitted for special conditions.
Of these I will describe three of the most prominent types of construction,
namely, a bipolar type of generator both fields of which are interiorly hollowed
so as to confine piston chambers, a bipolar type of generator only one field of
which is formed so as to constitute a piston chamber, and a multipolar type of
generator two fields of which are specially formed so as to enclose piston chambers.
Other types may be devised and successfully operated, but I will refer only to
the three mentioned, as they are fairly representative of all.
Referring to Figures 1, 2 and 3, A represents the pole pieces of the dynamo
electric machine, B the armature thereof, C the energizing coils, and D the
magnetic yoke connecting the two pole pieces. The cross section of the yoke I),
as well as of the poles A, is determined by the amount of electrical energy to be
utilized in any special machine, and should be amply sufficient to carry the lines
of force.
The special feature of the improved machine consists in the use which is made
of the field magnets or poles of the dynamo. These field magnets not only per-
form their ordinary function of producing a magnetic field, but are so formed as
to constitute the piston chambers within which reciprocate pistons, by the action
of which the power necesary to effect the revolution of the armature is generated.
For this purpose they are hollowed interiorly to form the cylinders E. For this
purpose also, valve chambers I are formed integrally, or otherwise closely con-
nected to the field magnets at the extreme rear end of the same, space being
afforded between such valve chambers and the pole pieces A for the magnet
coils C.
Within the valve chambers I are stationed the valves I¹ which alternately con-
nect the ends of the cylinder with the supply pipe H and exhaust pipe H
respectively. Both the supply and exhaust pipes are cast within a yoke H, which
connects the two pole pieces, and serves also in this type of the electric engine,

page_text: to carry a portion of the lines of force produced by the energizing coils. Within
the yoke H is also cast the main steam inlet port H³ and the main steam dis-
charge port. Great simplicity and strength of construction is hereby attained.
The throttle valve on the shaft j and shown on the section line 6-6 of Fig. 3,
is preferably controlled to regulate the steam admitted to the cylinders, by means
of a magnetic valve controller L, which consists of magnets M, mounted upon
a suitable base, and operating an armature M connected to a lever keyed to
the valve stem j, and normally held distant from the magnetic pole pieces by
the spiral springs m (see Figs. 4 and 5). The magnets M are in the main circuit.
The strength of the current energizing the governor is thus directly dependent
upon the speed of rotation of the armature, and effective control is provided over
the amount of steam admitted to the piston chambers.
An electric valve controller is preferably only used when the machine is used
as a combined steam engine and dynamo. When the engine is used as a motor
and pump or compressor, the electric governor is disconnected.
The power produced by the reciprocation of the piston F is conveyed to the
armature shaft by the driving rods O. The driving rods O are connected to the
piston rods by the wrist pins o, which slide in slots formed in the guides g, and
are connected to the armature shaft by the wrist pins formed on the discs P
which are keyed to the armature shaft. To the crank pins are also attached
valve rods K which extend across the dynamo towards the opposite piston
chamber. As the driving rods are quartered with respect to each other, proper
action of the valve is thus secured. Suitable reduction in the movement of the
valves relative to that of the crank discs P is effected by proportioning the lengths
of the levers K', by means of which the valve rods are connected to the stems I³
on which the valves are mounted.
The operation of the improved electric engine is as follows:-
When steam is used in the piston chambers of the engine and the engine is
used as a combined engine and dynamo, steam is admitted through the steam
inlet pipe H3, passes into the piston chambers causing reciprocation of the
pistons F, and is discharged through the discharge port.
As the steam inlet and discharge conduits between the inlet port H³ and dis-
charge port are formed within the engine itself, leakage of steam is avoided, and
a very strong construction secured. The reciprocations of the pistons F produce
by reason of the connecting mchanism, rotation of the armature B, and conse-
quent generation of current." The speed of rotation of the armature is determined
by the amount of steam admitted to the steam chests or valve chambers I, and
this in turn is governed by the position of the throttling valve, which is governed
as to its position by the action of the magnets M through which the main current
passes, so that a close regulation in the speed of rotation of the armatur is
secured.
When the electric engine is used as a combined motor and pump, the operation
above stated is reversed.
The reciprocation of the pistons is in this case the result and not the cause
of the rotation of the armature, but otherwise the action of the engine is sub-
stantially the same.
In Figures 4 and 5 are shown views of two modified forms of construction.
In Fig. a bipolar type of generator is shown, with only one field magnet
hollowed to constitute a piston chamber. In this case, the energizing coil ('is
wound upon the yoke connecting the pole pieces for the double reason of securing
economy in copper on account of the increased size of the pole piece necessary
because of the hollowing of its interior, and of avoiding undue heating of the
coil. It is necessary in this instance to magnetically insulate the yoke H in
which are formed the steam inlet and discharge conduits.
In Fig. 5, a multipolar type of generator is shown with only two of the pole
pieces hollowed to constitute piston chambers. The pole pieces thus hollowed

page_text: are oppositely situated, and the engine corresponds to the type of engine shown
in Fig. 1, with the exception that two additional pole pieces are employed.
In all instances it is preferred to make the pole piece or pieces of a relatively
large mass with respect to the piston chamber formed therein, particularly when
the device is used as an electric generator operated by steam, in order that the
heat may be properly radiated without affecting the insulated wire of the field
magnets.
Other types of construction may be employed than those shown, and other forms
of valves, valve fittings, etc. The invention is not confined to the details of the
constructions shown, as these are unessential and do not affect the real character
of the invention.
Having now particularly described and ascertained the nature of the said in-
vention and in what manner the same is to be performed I declare that what I
claim is
1. A field magnet or pole piece of a dynamo or motor, said field magnet or
pole piece having its interior hollowed so as to constitute a piston chamber, and
having valve passages formed within said field magnet or pole piece, in combina-
tion with a piston and suitable valve mechanism, substantially as described.
2. A field magnet or pole piece of a dynamo, said field magnet or pole piece
being of relatively large mass and having its interior hollowed so as to constitute
a relatively small piston chamber, whereby the heat produced by steam within
said chamber will be radiated by said pole piece, and an armature rotatable with
respect to said pole piece, in combination with a piston, suitable valve mechanism,
and connections between said piston and armature, substantially as described.
3. The combination with an armature, of field magnets hollowed so as to con-
stitute piston chambers, having valve passages also formed within the same, a
yoke holding said field magnets in line with each other on opposite sides of said
armature and also completing the magnetic circuit through said field magnets,
pistons within said piston chambers, valve mechanism for controlling ingress to
and egress from said piston chambers, and mechanism for connecting said pistons
to said armature and thereby rotating said armature, substantially as described.
4. The combination with an armature, an armature shaft, discs on both ends
thereof, and field magnets hollowed so as to constitute piston chambers, having
valve passages also formed within the same, of a frame adapted to hold said
field magnets in line with each other on opposite sides of said armature and also
to complete the magnetic circuit through Said field magnets, pistons within said
piston chambers having valve passages also formed within the same,
mechanism for controlling ingress to and egress from said piston chambers, and
driving rods connecting said pistons and said dises, said driving rods being on
opposite sides of said field magnets and being quartered with relation to each
other, substantially as described.
valve
5. The combination with an armature, of field magnets hollowed so as to con-
stitute piston chambers, having valve passages also formed within the same, a
frame holding said field magnets in line with each other on opposite sides of said
armature and also completing the magnetic circuit through said field magnets,
pistons within said piston chambers, valve mechanisms for controlling ingress
to and egress from said piston chambers, mechanism for connecting said pistons
to said armature and thereby rotating said armature, and means operated by
each piston chamber for operating the valve mechanism of the opposite piston
chamber, substantially as described.
1000
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.