Improvements in Armatures of Dynamo-electric Machines and Electric Motors.
Year: 1891

page_text: Date of Application, 29th June, 1891
Complete Specification Left, 28th Mar. 1892-Accepted, 30th Apr., 1892
PROVISIONAL SPECIFICATION.
Improvements in Armatures of Dynamo-electric Machines and
Electric Motors.
1, HUGH LONG BOURNE CALLENDAR, of 2 Princes' Mansions, Victoria Street,
in the City of Westminster, S. W., Fellow of Trinity College, Cambridge, do hereby,
declare the nature of this invention to be as follows:-
I make my armature of spirally laminated discs constructed of flat bars or strips,
A number of radial bars or strips are
preferably of iron, in the following manner.
firmly attached to a suitable hub which may also serve as a commutator. The
strips are insulated from each other throughout their length and are all bent round
in the same direction so as to lie close together forming a nearly solid and rigid
disc. Each strip will then approximately take the form of a part of the sprial
known as the involute of a circle, which is the curve described by the end of a
thread when it is unwrapped from a cylinder. The advantages of this method of
construction are that the strips are packed into the least possible space, that such a
disc, if suitably bound, possesses great mechanical strength and is comparatively
easy to make, and that the strips or bars form at once the core and framework and
also the winding and connectors of the armature.
Two or more such discs are fixed side by side on the same axis with their spirals
in opposite directions. The spiral laminae of opposite discs are connected in series,
alternately at the edge and at the hub, and to a commutator of the ordinary pattern
closed-coil armature."
in such a way as to form what is known as a
The following is a description of a simple two-pole machine of this type. Each
section of the hub or commutator is connected to two strips or laminae, preferably
of iron, of the same thickness as a section of the hub. The two strips are bent
round in opposite directions, each making nearly half a turn of the spiral. All the
strips are insulated from each other, & packed firmly together, so as to form two
spirally laminated discs fixed side by side on the same axis with their spirals in
opposite directions. That spiral of one disc which is connected to the first section of
the hub is connected by a cross piece at the edge of the disc to that spiral of the
other disc which goes to the second section of the hub, and so on in series all round
the discs. The discs are made to rotate between the poles of two field magnets
fixed on opposite sides of the axis, and the current is drawn off in the usual way by
means of two brushes pressing on opposite sections of the hub or commutator.
Two or more spiral laminae of each disc may be connected either in series or in
parallel to each section of the commutator. Three or more spiral discs may also
be mounted side by side, the laminae being suitably connected at the hub & at the
edge. Machines of this type may also be constructed with four or more sets of
poles, arranged at equal intervals round the disc; the amount of turn of each spiral
must be suitably proportioned & the laminae of opposite discs connected to
correspond.
ليمن
,
C
1201
HUGH L. CALLENDAK.

page_text: COMPLETE SPECIFICATION.
Improvements in Armatures of Dynamo-electric Machines and
Electric Motors.
I, HUGH LONG BOURNE CALLENDAR, of 2 Prince's Mansions, Victoria Street,
in the City of Westminster, S. W., Fellow of Trinty College, Cambridge, 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
I make my armature of spirally laminated discs constructed of flat bars or strips,
preferably of iron, in the following manner. A number of radial bars or strips are
firmly attached to a suitable hub which may also serve as a commutator.
strips are insulated from each other throughout their length and are all bent round
in the same direction so as to lie close together forming a nearly solid and rigid disc.
Each strip will then approximately take the form of a part of the spiral known as
the involute of a circle, which is the curve described by the end of a thread when
it is unwrapped from a cylinder. The advantages of this method of construction
are that the strips are packed into the least possible space, that such a disc, if
suitably bound, possesses great mechanical strength and is comparatively easy to
make, and that the strips or bars form at once the core and framework and also the
winding and connectors of the armature.
Two or more such discs are fixed side by side on the same axis with their spirals
in opposite directions. The spiral laminae of opposite discs are connected in series,
alternately at the edge and at the hub, and to a commutator of the ordinary pattern
in such a way as to form what is known as a < closed-coil armature."
The following is a description of a simple, two-pole machine of this type. Each
section of the hub or commutator is connected to two strips or laminae, preferably
of iron, of the same thickness as a section of the hub. The two strips are bent
round in opposite directions, each making nearly half a turn of the spiral. All the
strips are insulated from each other, and packed firmly together, so as to form two
spirally laminated discs fixed side by side on the same axis with their spirals in
opposite directions. That spiral of one disc which is connected to the first section
of the hub is connected by a cross piece at the edge of the disc to that spiral of the
other disc which goes to the second section of the hub, and so on in series all round
the discs. The discs are made to rotate between the poles of two field magnets
fixed on opposite sides of the axis, and the current is drawn off in the usual way by
means of two brushes pressing on opposite sections of the hub or commutator.
Two or more spiral laminae of each disc may be connected either in series or in
parallel to each section of the commutator. Three or more spiral discs may also
be mounted side by side, the laminae being suitably connected at the hub and at
the edge. Machines of this type may also be constructed with four or more sets of
poles, arranged at equal intervals round the disc; the amount of turn of each
spiral must be suitably proportioned and the laminae of opposite discs connected to
correspond.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a transverse section and Figure 2 an edge elevation partly in section of
an armature constructed according to this invention.
A is a central shaft and B is a layer of insulating material upon it. A', A³
are a number of strips fixed to the hub, they are section lined in Figure 1 whilst the
block shaded strips between them are insulating material. Only some of these
strips are shown but it will be understood that they occupy the whole of the space
between B and the dotted line concentric with it. B1, B2,
and C1, C2,
two sets of spiral strips curved in opposite directions. In Figure 1, only the strips 133
to B and C are shown but it will be understood that these strips with the insulating
are

page_text: material (shown in block shading) between them, occupy the whole space between
the dotted line and the outer band C which secures them. One end of the
strips A'A'.
are prolonged beyond the discs to form a commutator as shown in
Figure 2. The inner ends of the strips B and C are both connected to or made in
one piece with the strip A' whilst B and C are connected to or made in one piece
with A and so on.
The way in which the strips diverge from each other is shown
in Figures 3 which are three views at right angles to each other. The outer ends
of the strips B and C are connected together by a strip D'; B2 and C³ by a
strip D2 and so on.
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. An armature made up of spiral strips insulated from one another and having
their ends connected together substantially as described.
2. Armatures substantially as described and shown in the drawings.
Dated this 26th day of March 1892.
HUGH L. CALLENDAR.