IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES AND ELECTRIC MOTORS.
Year: 1882

page_text: LETTERS PATENT to John Imray, of No 28, Southampton Buildings, Chancery
Lane, in the county of Middlesex, for an Invention of IMPROVEMENTS
IN DYNAMO-ELECTRIC MACHINES AND ELECTRIC MOTORS. A communication
from abroad by James Joseph McTighe and Thomas Joseph McTighe, both of
Pittsburgh, United States of America.
COMPLETE SPECIFICATION filed by the said John Imray at the Office of
the Commissioners of Patents on the 10th June 1882.
JOHN IMRAY of No 28, Southampton Buildings Chancery Lane in the County
of Middlesex "IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES AND ELECTRIC
MOTORS A communication from abroad by James Joseph MoTighe and Thomas
Joseph McTighe, both of Pittsburgh, United States of America.
"
This invention relates to the construction of dynamo-electric machines and
electric motors, and is designed to improve the method of making and fitting the
parts. It consists in the hereinafter described and claimed improvements firstly
in the construction of the armature or ring; secondly in that of the commutator,
and finally in the construction and disposition of the field magnet.
The construction of the armature is intended to permit of the separate winding
of the coils on suitable forms and then placing them on the ring and in such
manner that there will be no weak spot in the ring or core to yield to the centri-
fugal force and no slippage of the coils on the core or the core on the shaft. The
construction of the commutator is designed to afford a simple effective and cheap
mode of making this part of the machine
The disposition of the field magnet is productive of great concentration of
magnetism at the locality most desirable, with an expenditure of wire as little as
possible.
In the drawings Fig 1 illustrates in perspective the armature rings ready to
receive the coils; Fig 2 is a partly sectional elevation of the armature rings (coils
represented by dotted lines) the diamagnetic heads and shaft; Fig 3 is a transverse
section of Fig 2, at line xx; Fig 4 is a longitudinal vertical section of the complete
machine; Fig 5 is an end elevation of the field magnet alone; Fig 6 is a longi-
tudinal section of the commutator; Fig 7 is a transverse section of the same on
D

page_text: line y y; Figs 8 and 9 are details. The armature core is composed of a number of
metallic rings a, preferably of soft iron each ring having an excision or slit b, wide
enough to admit a coil. The rings are placed together with all the slits b, in a
line (as in Fig 1) and the coils are inserted there at and slipped around upon the
core successively. When all the coils are on the core the rings a are worked
around till the slits b are all out of line, the balance being maintained by dis-
tributing the slits bat equal intervals circumferentially. The coils are now locked
securely. To secure the coils against circular motion the heads bare provided.
These are of brass or other diamagnetic material having the projections c on their
inner face, which enter between the coils until they meet the rings a, when they
are bolted together by the bolts e, which may pass through the rings a as shewn,
or along grooves cut in the rings. The position of the coils is shewn by dotted
lines in Fig 2 and by the section Fig 3. The heads B are then secured to the
shaft D by set screws or keys.
Thus constructed the armature is very strong and well balanced and easily taken
apart for repairs. A single coil may be removed, by taking out the bolts e
removing the heads B, and working the core rings a around to form a slit at the
desired coil, which can then be taken out. After replacing with a new coil the
parts may be restored to their normal positions in a few moments and made as
secure as before. The core rings, heads and bolts, can if desired, all be insulated
from each other. The rings a may be punched out of sheet metal, and the bolt
holes or grooves, and slits 6 similarly formed.
A modified form of the rings a is shewn by the section Fig 8 where the ring is
V shaped in cross section; this facilitates the sliding of the rings on one another,
as they become guides in this form. The slit b may be diagonal, as in Fig 9. The
commutator is made as follows; F is a solid block of hard rubber or other insulating
material of cylindrical form and fitted to the shaft D in any suitable manner.
GG are collars (Fig 4) one at each end of the body F and integral therewith.
The body F is perforated, either in moulding, or subsequently by drilling with a
number of holes lengthwise and arranged concentric with the axis. Wires bars or
rods are then driven into the perforations tightly fitting the same throughout.
The whole is then turned down in a lathe till the surface of the bars i is even and
smooth, after which if required by the brushes used, the hard rubber is removed
from between the bars i at their sides The wires or bars i may then be turned
outwardly, or so shaped beforehand, to form the extensions k, whose ends are
perforated. An insulating head or flange H is then fixed to the body F, clamping
the bars i against the latter; and the extension k secured by screws which also
serve to secure the coil terminals in junction. The holes in body F, and the
bars i may be any shape in cross section. Instead of proceeding as above, the rods
or bars i may be inserted in a plain cylindrical insulator F as shewn at Figs 6
and 7, and the cylinder cut down, as indicated by dotted lines till the bars i are
exposed, thus leaving the collars G G as before.
In the field magnet advantage is taken of the fact that in ordinary electro-
magnets, the inductive action of the current being exerted in all directions, is
wasted outwardly. This waste does not take place if the core is expanded so as
to envelope the coil, thus forming what may be termed a tubular electro-magnet
Such a magnet with a given number of convolutions of wire and a given current
will create a more intense field than an ordinary electro-magnet. This advantage
is applied to the dynamo-electric machine or motor in the following manner.
M is
the core having the curved pole piece N embracing partially the armature. The
core M is fitted to the cylinder O, having the bottom P. Before bolting the core M
to the bottom P. the coil Q is inserted, filling up the annular space between the
core M and the cylindrical wall O. The wall O which thus becomes an extension
of the lower end of the core M is continued upwardly at opposite sides to form
the cheeks R carrying the south polarity upwardly. To these is bolted the iron
cap T having the curved pole-piece S. The inductive effort of the current is thus
availed of inwardly and outwardly and the magnetic field thus created is

page_text: powerfully concentrated between the pole pieces N and S, and free magnetism
will not exist externally to any considerable extent.
Having thus described the nature of the said invention and in what manner
the same is to be performed as communicated to me by my foreign correspondents
I claim:-
First. In an annular armature a core composed of a number of slitted rings
each capable of independent adjustment around its axis, substantially as described.
Second. In an annular armature a core composed of a number of slitted rings
of soft iron each capable of independent adjustment around its axis, substantially
as described.
Third. In an annular armature a core composed of a number of incomplete rings,
each having a single dividing excision and being capable of independent adjust-
ment around its axis, in combination with a number of longitudinally arranged
rods or bars capable of locking the said rings against circumferential movement,
substantially as described.
Fourth. An annular armature composed of a number of slitted rings circum-
ferentially adjustable, a series of coils placed on said rings and two or more
longitudinal bars or rods binding said rings together, substantially as described,
whereby the slits may be brought in line, the coils inserted, the rings adjusted
circumferentially to throw the slits out of line, and then the rings locked by the
said bars or rods.
Fifth. In an annular armature, a core composed of a number of incomplete rings
each having a single slit and circumferentially adjustable on its axis, in combi-
nation with diamagnetic heads and longitudinal rods or bars connecting said rings
and heads together substantially as described.
Sixth. In an annular armature a core composed of a number of incomplete
rings each having a single slit and circumferentially adjustable on its axis, in
combination with longitudinal rods or bolts, and heads having inward projections
abutting against the rings and forming spacing blocks for the coils, substantially
as described
Seventh. A commutator composed of a single cylinder of insulating material
having one or more integral collars perforated longitudinally, with a circular series
of holes, in combination with a series of metal rods or bars placed in said
perforations and retained by the collar or collars, substantially as described
Eighth. A commutator composed of a single cylinder F of insulating material
having one or more integral collars G perforated longitudinally as shewn in
combination with a series of metal bars or rods i placed in said perforations and
having the extensions k, a head H of insulating material clamping the extensions k
against the cylinder F or collar G and the screws 1, substantially as described
Ninth. In a dynamo-electric machine or electric motor, a single energising helix
in combination with a core of iron one end of which is provided with a curved
pole-piece, and the other end of which is connected to an iron flange or head
forming the base of a cylinder of iron which embraces the helix and extends
upwardly from both sides to a junction and terminates in the other curved pole-
piece substantially as described.
In witness whereof I the said John Imray have hereunto set my hand and
seal this Tenth day of June in the year of our Lord One thousand eight
hundred and eighty-two
JOHN IMRAY. (LS.)