Improvements in Two-pole Single-limb Dynamo-electric Machines and Electro-motors having Vertical Magnets with the Poles Downwards.
Year: 1894

page_text: Date of Application, 12th Nov., 1894
Complete Specification Left, 12th Aug., 1895-Accepted. 14th Sept., 1895
PROVISIONAL SPECIFICATION.
Improvements in Two-pole Single-limb Dynamo-electric Machines
and Electro-motors having Vertical Magnets with the Poles
Downwards.
We, THOMAS PARKER LIMITED, of Wolverhampton in the County of Stafford,
Electrical Engineers, and THOMAS PARKER, Managing Director of the said
company, do hereby declare the nature of this invention to be as follows:-
This invention relates to two-pole single-limb dynamo-electric machines and
electro-motors which have vertical magnets with the armatures in position at the
lower ends of the magnets; and has for its object certain improvements in connection
with the construction and method of fixture of the pole pieces, for the purpose of
facilitating manufacture and improving the construction of parts of the machines
and motors, and of increasing the facility of inspecting and removing the armatures
thereof.
In such machines and motors, as usually or frequently heretofore constructed,
the metal of each pole piece is made continuous with the metal of the corresponding
magnet limb. The weight of the magnet systein complete is frequently supported
from brackets which overhang their own supports, and the bottoms or outer ends
of each pair of pole pieces are held together by a grid which is fixed thereto
by means of bolts screwed up endways into the pole pieces, and which do not
This method of
consequently tighten the pole pieces towards one another.
carrying the magnet system is not mechanically satisfactory, nor is the method
of connecting the lower ends of the pole pieces; and moreover, if the armature
is to be examined or removed, it is necessary to disconnect the lower ends of
the pole pieces from one another and to lift out one of the pole pieces entire
together with its corresponding limb of the magnet, and the limbs of the magnets
must also be disconnected at their upper ends; or else the armature must be
threaded out end ways which, of course, necessitates removing one of the bearings.
Now, according to this invention, each pole piece is divided into an upper and
lower portion, of which the upper portion is formed with its metal continuous
with the metal of the corresponding limb of the magnet, and may be lifted clear
away from the lower portion. The two lower portions of a pair of pole pieces
are fixed to brackets of brass, or other non-magnetic metal, which are adapted
for fixture to the bed, and the lower ends of the pole pieces are fixed together by
means of bolts of brass, or other non-magnetic metal, running through from one to
the other, such bolts being formed, conveniently, with a middle portion which acts
as a distance piece between the two pole pieces and with portions which pass through
holes formed in the pole pieces and are screwed for nuts on their ends. The two
lower portions of the pole pieces, the two brackets, and the bolts by which the pole
pieces are fixed together, form a rigid cradle or girder which may be lowered into
place and fixed between two sides of a hollow bed, or may be otherwise fixed to any
bed of suitable form, and in either case such cradle forms a permanent fixture of
the machine, and the portions of the pole pieces which form part thereof have their
faces which are adjacent to the armature rising only to or about the level of the
centre thereof so that the armature may readily be lifted out from between such
portions of the pole pieces. The bolts, aforesaid, may pass through portions of
the brackets, if desired, either in lieu of or in addition to passing through the ends

page_text: of the pole pieces. In lieu of using the bolts above described for fixing the outer
or lower ends of the pole pieces together, such portions of the pole pieces may be
fixed to a girder-piece of brass, or other non-magnetic metal, passing right across
under the armature, such girder-piece taking the place both of the brackets and of
the bolts above described. The upper portions of the pole pieces, that is to say,
the portions which are formed with the magnet limbs, may be lifted up vertically
together with the magnet limbs and thus leave the upper half of the armature
exposed, and such portions of the pole pieces are put in place, and held therein, by
simply passing them down between suitable guides projecting upwards from the
brackets aforesaid or from the lower portions of the pole pieces, and fixing by means
of bolts or set screws.
The employment of this invention permits of the two magnet limbs, together with
the upper portions of the pole pieces, and the yoke piece, being cast in one piece
of metal.
This invention is specially suitable for application to dynamo-electric machines
which are driven direct by high speed engines, such as engines of the Willan's or
Bellis's type, and to electro-motors used for launches and the like, where the
armature centre is required to be kept low down.
Dated this 10th day of November 1894.
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicants.
Improvements in Two-pole Single-limb Dynamo-electric Machines
and Electro-motors having Vertical Magnets with the Poles
Downwards.
We, THOMAS PARKER, LIMITED, of Wolverhampton in the County of Stafford,
Electrical Engineers, and THOMAS PARKER, Managing Director of the said
company, 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 :-
This invention relates to two-pole single-limb dynamo-electric machines and
electro-motors which have vertical magnets with the armatures in position at the
lower ends of the magnets; and has for its object certain improvements in
connection with the construction and method of fixture of the pole-pieces, for the
purpose of facilitating manufacture and improving the construction of parts of the
machines and motors, and of increasing the facility of inspecting and removing
the armatures thereof.
In such machines, and motors, as usually or frequently heretofore constructed,
the metal of each pole-piece is made continuous with the metal of the corresponding
magnet limb. The weight of the magnet system complete is frequently supported
from brackets which overhang their own supports, and the bottoms or outer ends of
each pair of pole-pieces are held together by a grid which is fixed thereto by means
of bolts screwed up endways into the pole-pieces, and which do not consequently
tighten the pole-pieces towards one another. This method of carrying the magnet
system is not mechanically satisfactory, nor is the method of connecting the lower
ends of the pole-pieces; and moreover, if the armature is to be examined or
removed, it is necessary to disconnect the lower ends of the pole-pieces from one
another and to lift out one of the pole-pieces entire together with its corresponding
limb of the magnet, and to enable this to be done the limbs of the magnets must
also be disconnected at their upper ends; or else the armature must be threaded
out end ways which, of course, uecessitates removing one of the bearings.

page_text: Now, according to this invention, each pole-piece is divided into an upper and
lower portion, of which the upper portion is formed with its metal continuous with
the metal of the corresponding limb of the magnet, and may he lifted clear away
from the lower portion. The two lower portions of a pair of pole-pieces are fixed
to brackets of brass, or other non-magnetic metal, which are adapted for fixture to
the bed, and the lower ends of the pole-pieces are fixed together by means of bolts
of brass, or other non-magnetic metal, running through from one to the other, such
bolts being formed, conveniently, with a middle portion which acts as a distance-
piece between the two pole-pieces and with portions which pass through holes
formed in the pole-pieces and are screwed for nuts on their ends. The two lower
portions of the pole-pieces, the two brackets, and the bolts by which the pole-
pieces are fixed together, form a rigid cradle or girder which may be lowered into
place and fixed between two sides of a hollow bed, or may be otherwise fixed to
any bed of suitable form, and in either case such cradle forms a permanent fixture
of the machine, and the portions of the pole-pieces which form part thereof have
their faces which are adjacent to the armature rising only to or about the level of
the centre thereof so that the armature may readily be lifted out from between
such portions of the pole-pieces. The bolts, aforesaid, may pass through portions
of the brackets, if desired, either in lieu of cr in addition to passing through the
ends of the pole-pieces. The upper portions of the pole-pieces, that is to say, the
portions which are formed with the magnet limbs, may be lifted up vertically
together with the magnet limbs and thus leave the upper half of the armature
exposed, and such portions of the pole-pieces are put in place, and held therein,
by passing them down between suitable guides projecting from the brackets
aforesaid or from the lower portions of the pole-pieces, and fixing by means of
bolts or set-screws.
An application of the invention is illustrated by the drawings on Sheet I herewith,
of which
Figure 1 is an elevation, partly in transverse section on line ac of Figure 2, and
partly an end elevation with the bearing for the armature spindle removed, of a
dynamo-electric machine or electro-motor.
Figure 2 is a side elevation of the middle portion of the machine, including the
magnet, with the nearer side of the bed or supporting frame removed so as to shew
in full lines the face of the bracket which is fixed against the inside of the bed;
aud Figure 3 is a corresponding view to Figure 2 with the bracket removed.
The armature is omitted from the views for simplicity of illustration.
Each pole-piece is divided into an upper portion A and a lower portion A', the
division line a between them being at the level of the horizontal axis of the
armature, or approximately so. The upper portion A of each pole-piece is formed,
as above described, with its metal continuous with the metal of the corresponding
limb B of the magnet, and the two limbs are permanently joined together by the
yoke-piece C. The lower portions A¹ of the pole-pieces are fixed, by means of set-
screws b, to brackets D of brass or other non-magnetic metal. The lower ends of
the portions A of the pole-pieces are formed with lugs d, and lugs e are formed
also with the brackets D. Bolts E, of brass or other non-magnetic metal, have
their middle portions formed to act as distance-pieces between the lugs d of the
respective portions A¹ of the pole-pieces, and the ends of such bolts pass through
the lugs d'and e, and nuts are screwed up on their outer ends to rigidly fix
together, at the proper distance apart, the portions A¹ of the pole-pieces, and at
the same time rigidly fix also the brackets D to the portions A¹ of the pole-pieces.
The portions A¹ of the pole-pieces thus form with the brackets D and bolts E a
rigid cradle or girder. This cradle or girder is fixed in place between the sides F
of the bed by means of bolts c which pass through portions of the brackets and
through the sides of the bed.
The portions A of the pole-pieces may be lifted up with the magnet limbs B,
and thus leave the upper half of the armature exposed; and the armature may
then be readily lifted out from between the lower portions of the pole-pieces. In

page_text: replacing the magnet limbs and portions A of the pole-pieces, the latter are passed
down between guides h projecting above the tops of the brackets D and over
studs i which stand forwards from the inner faces of such projections, open-ended
slots being formed in the portions A of the pole-pieces to fit down over the studs i.
The portions A of the pole-pieces are thus guided truly into place. The portions A
of the pole-pieces, and consequently the magnet limbs also, are securely held in
place by means of set-screws which pass through the projections and are screwed
into the portions A of the pole-pieces.
In
A further application of the invention is illustrated by the drawings on Sheet 2
herewith, of which Figure 4 is an end elevation, with the bearing for the armature
spindle removed, of a dynamo-electric machine, or electro-motor; and Figure 5 a
side elevation of the middle portion of the machine including the maguet.
these figures also the armature is omitted for simplicity of illustration. This
application corresponds with that described with reference to the drawings on
Sheet 1 herewith, except that the brackets D are fixed on the top of a bed F, and
the brackets are modified in shape accordingly, as shewn.
In lieu of using the bolts above described for fixing the lower ends of the pole-
pieces together, such portions of the pole-pieces may be fixed to a girder-piece of
brass, or other non-magnetic metal, passing right across under the armature, such
girder-piece taking the place both of the brackets and of the bolts. This girder-
piece should be formed with bearing faces corresponding to the inner bearing faces
of the brackets, against which the portions A¹ of the pole-pieces may be bedded,
and with guides between which the portions A of the pole-pieces are passed down
into place.
The employment of this invention permits of the two magnet limbs, together
with the upper portions of the pole-pieres, and the yoke-piece, being cast in one
piece of metal.
This invention is specially suitable for application to dynamo-electric machines
which are driven direct by high speed engines, such as engines of the Willan's or
Bellis type, and to electro-motors used for launches and the like, where the
armature centre is required to be kept low down.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. In a two-pole dynamo-electric machine or electro-motor which has a vertical
magnet with the armature in position at the lower end of the magnet, the pole-
pieces formed each of an upper and lower portion divided at or about the level of
the transverse axis of the armature, substantially as described for the purpose set
forth.
2. In a two-pole dynamo-electric machine or electro-motor which has a vertical
magnet with the armature in position at the lower end of the magnet, the pole-
pieces formed each of an upper and lower portion divided at or about the level of
the transverse axis of the armature, and the upper portions formed continuous with
the magnet limbs, so that they may be lifted out together therewith to expose the
upper side of the armature and allow of the same being readily lifted out from
between the lower portions of the pole-pieces, substantially as described.
3. In a two-pole dynamo-electric machine or electro-motor which has a vertical
magnet with the armature in position at the lower end of the magnet, the pole-
pieces formed each of an upper and lower portion divided at or about the level of
the transverse axis of the armature, and the lower portions formed with another
part or parts into a rigid cradle or structure which is fixed to the bed and may be
removed therefrom as a single rigid structure, substantially as described.
4. In a two-pole dynamo-electric machine or electro-motor which has a vertical
magnet with the armature in position at the lower end of the magnet, the pole
pieces forined each of an upper and lower portion divided at or about the level of
the transverse axis of the armature, and the lower portions rigidly connected with

page_text: one another at their lower ends by means of distance bolts, and rigidly connected
also with brackets with which and with the distance bolts they form a rigid cradle
or structure which is fixed to the bed and may be removed therefrom as a single
rigid structure, substantially as described and shewn by the drawings herewith.
Dated this 10th day of August 1895.
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicants.