Improvements in or relating to Dynamos or Electric Motors, and in Apparatus for Driving Fans by Electricity
Year: 1897

page_text: Date of Application, 26th Mar., 1897
16:7
Complete Specification Left, 2nd Oct., 1897-Accepted, 18th Dec., 1897
14.
L
"Improvements in or relating to Dynamos or Electric Motors, and
in Apparatus for Driving Fans by Electricity:"
I; JOHN WALTER GIBBS of 72 to 76, Duke Street; in the City of Liverpool,
Ventilating Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention has for its principal object a method for ventilating dynamos of
electro-motors whereby a current of air shall be passed through the machine without
allowing dust or other dirt to enter. It also has reference to the form of the dynamo
whereby it shall interfere as little as possible with the effect of the fan.
74
$:
11
I place a fan on the axis of the dynamo and so arrange the casing that the fan
shall draw air froin the dynamo from the centre or as near the centre as possible.
Near the side of the dynamo in any convenient position I place one or more orifices
for the air to enter these orifices facing the fan and so arranged that a strong current
of air shall pass these orifices in its travel towards the fan. The result is air is
drawn out of the casing of the dynamo or motor producing a partial vacuum and
further air is drawn along past the air receiving orifices to the fan. Any dust or grit
contained in this air is carried on to the fan, but the suction caused from the partial
vacuum in the casing causes part of the current of air to turn round at an angle of
180 degrees or thereabouts and enter the orifices and so supply the hiatus caused
by the drawing out of the air. The dust cannot enter with its air, as the momentum
caused by its speed obliges it to travel forwards on the same principle as the
numerous dust extracting devices, such as Van Gelder's Tornado, and the, like.
Where the fan is wanted to be used also for ventilating purposes it is very desirable
that the motor shall be in as small a space as possible. I therefore prefer to form the
motor as a gramme ring with the magnet poles formed as circular curved blades
closely surrounding the gramme ring. The part of the magnets however on which
the coils are placed are bent inwards so that the coils themselves shall not project
beyond the circle formed by the poles and between the two coils I place the
armature. By this means a single cylindrical or nearly cylindrical casing with a
back in which the bearing and oiler is placed form the casing for the dynamo and
one or more little projecting hoods in the sides with the orifice in front for the
entrances of the ventilating device already mentioned. In the back plate the
bearing and terminal footstep or pivot and oiler are placed. The advantages of
this arrangement are that the ventilation passes from the outside among the field
megnet coils and through the gramme ring and thus the entire mechanism is
ventilated. Mica valves can if desirable be used to shut off the ventilating holes
when the machine is not at work so as to prevent dust settling therein.
Dated the 25th day of March 1807
$122

page_text: "Improvements in or relating to Dynamos or Electric Motors, and
in Apparatus for Driving Fans by Electricity."
I, JOHN WALTER GIBBS of 72 to 76 Duke Street in the City of Liverpool, Ventilating
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 is best described by aid of the accompanying drawings, in which,
Figure 1 is a longitudinal section,
Figure 2 a transverse section through Figure 1 at Z Z,
Figure 3 a section of a dynamo through Y Y,
Figure 4 a side view of the frame-work together with the fan, fan shaft, dynamo
and its appurtenances carried in bearings thereon.
In these, A is the armature, F field magnets, C commutator, G shaft, and B bearings
of shaft, P driving pulley, K rocking shaft or brush holder, R rails on which the
dynamo is fixed, brass supports of dynamo, W wire coil round armature, W1 wire
coil round field magnets, S spider carrying armature, K¹ key of same, H (Fig. 4)
hollow centre screws, and L lubricators, M dust-proof casing, N in dotted lines the
brushes. U (Fig. 4) fan, U¹ circular framing surrounding the fan and V¹ framing
attached thereto carrying the bearings of the dynamo. The fan U is placed on the
axis G of the dynamo and the casing can be so arranged as to draw air from the
dynamo from the centre or as near the centre as possible by arranging holes into
the dynamo close to the shaft and just behind the fan. In the drawing, which is a
small dynamo in actual operation, the openings into the centre of the dynamo are not
shown, as it was found that with these small dynamos they are not requisite. Near
the side of the dynamo in any convenient position, especially in large sized machines
I place one or more orifices at q Fig 4 as shown by arrows for the entrance of air,
preferably in front of the side window Q and facing the fan. These are so arranged
that a strong current of air shall pass these orifices q turn and go through into the
dynamo and then through the central orifices in front in its travel towards the fan.
Air is drawn out of the casing of the dynamo through the holes near the centre
nearest the fan producing a partial vacuum and air is drawn along past the air
receiving orifices q to the fan. The result is that any dust or grit contained in this
air is carried on to the fan, but the suction caused by the partial vacuum in the
casing causes part of the current of air passing the side window Q to turn round.
through an angle of 180 degrees or thereabouts and enter the orifices q in front of
window Qand so supply the hiatus caused by the drawing out of the air from the
central portion of the fan. The dust however cannot enter with the air as the
momentum caused by its speed in approaching the fan obliges it to travel forward on
the same principle as the numerous dust extracting devices, such as Van Gelder's
Tornado, and the like. When the fan is wanted to be used also for ventilating
purposes it is very desirable that the motor shall be in as small a space as possible.
I therefore prefer to form the motor as a gramme ring with the magnet poles formed
of circular curved blades closely surrounding the gramme ring and its appurtenances.
The part of the magnets however on which the coils are placed are bent inward or
reduced in circumference so that the coils themselves shall not project beyond the
circle formed by the poles and between the two coils I place the armature and its
appurtenances. By this means a single cylindrical or nearly cylindrical casing with
a back in which the bearing or oiler is placed forms the casing for the entire dynamo,
and one or more little projecting slots or windows Q in the sides with the orifice in
front form the entrances of the ventilating device already mentioned when ventilation

page_text: is required. They also serve to enable one to observe the armature and brushes
without having to open the casing. In the back plate the bearing and terminal foot-
step or pivot and oiler are placed. The advantages of this arrangement are that the
entire dynamo is enclosed in a single cylindrical casing, that the ventilation passes
from the outside among the field magnet coils and through the gramme ring and
thus the entire mechanism ventilated. Mica valve can, if desirable, be used to shut
off the ventilating holes when the machine is not at work so as to prevent dust
settling thereon and in cases of machines of small size the ventilation is found not
to be required.
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. The improvement in dynamos or electric motors, which consists in placing the
armature and its appurtenances inside the field magnets and arranging the latter so
that the entire dynamo is contained between the magnets and the back plate and
can be surrounded by a single casing substantially as described.
2. The improvement in apparatus for driving fans by electricity, which consists in
the combination of two or more magnets of substantially cylindrical, rectangular or
other substantially regular shape for casing in outside contour, but recessed for the
coils so that the coils shall stand about flush with them on the outside with armature
commutator and brushes enclosed in the field magnets and a smooth casing of
cylindrical rectangular or other regular shape corresponding with that of the magnets
enclosing the same substantially as described.
3. The arrangement for ventilating electric motors used for driving fans so as to
supply them with a continuous current without dust substantially as described.
4. The general arrangement and construction of apparatus for driving fans by
electricity substantially as described and illustrated in the accompanying drawings.
Dated the 30th day of September 1897
WM. P. THOMPSON & Co.
Patent Agents
Of Liverpool, Manchester, Birmingham and London.