An Improved Method of Regulating the Current Developed by and the Power of Dynamos or Magneto Electric Machines Electric Motors.
Year: 1889

page_text: Date of Application, 28th Feb., 1889
Complete Specification Left, 6th Sept., 1889-Accepted, 2nd Nov.,
1889
PROVISIONAL SPECIFICATION.
An Improved Method of Regulating the Current Developed by
and the Power of
Dynamos or Magneto Electric Machines
Electric Motors.
We, OLIVER FIRTH, of Eagle Works, Lister Hills Road, Bradford, in the County
of York, Electrical Engineer, and EDWARD WRIGHT CRABTREE, of Stirling Street,
Bradford, aforesaid, Electrical Engineer, do hereby declare the nature of this
invention to be as follows:-
-
This invention relates to a new method of regulating the current developed by a
dynamo or magneto-electric machine, and regulating the power of electric motors,
and consists essentially in regulating the distance or space between the poles of the
field magnets and the armature, as the amount of work required from the machine
is varied, thus as less current is required the poles of the field magnets are moved
away from the armature, consequently fewer lines of force pass from the poles of
the field magnets through the armature coils, and thus not only is less current
produced, but as the resistance to the revolutions of the armature is decreased less
power is required to drive the machine.
We mount the field magnets on a foundation in a vertical position with their
poles above and below the armature, the poles of the field magnets being turned
concentric with the armature, and we do not connect the poles of the two field
magnets together as is the general practice, but have them entirely separated. The
foundation is made with a slide therein, and the field magnets are prepared to fit
into the same, while by means of a screw with a right and left handed thread, the
field magnets can be made to travel in the slide, either towards or away from the
armature, thus bringing their poles closer or further away from the armature.
The screw for actuating the field magnets can be revolved by hand as the current
required to be developed by the dynamo or magneto-electric machine varies, or the
screw can be revolved automatically, the same means being employed to vary the
power of an electric motor.
It will be easily understood that as the poles of the field magnets are moved away
from the armature, the lines of force passing from the former through the coils of the
latter will decrease, and thus less current will be produced, which enables us to regu-
late the machine to develope the exact amount of current required.
There are other methods of arranging the mechanism for varying the distance
between the poles of the field magnets and the armature, but we wish it to be under-
stood that our invention consists essentially in the method of regulating the current
developed by a dynamo or magneto-electric machine, or the power of an electric
motor, by varying the distance between the poles of the field magnets and the
armature.
Dated this 26th day of February 1889.
0 ADITOTT

page_text: drying cylinder is employed for drying the india rubber composition on the fabric
between the spreading roller and taking up roller the object of our invention being
to avoid the necessity of winding back the cloth after each traverse through the
machine.
In carrying out our improvements we may make the machine longer than now
customary and we mount the steam drying cylinder at or about the centre portion
of the machine frame and we mount the spreading roller in a frame or brackets
capable of being traversed from one end of the frame to the other after the fabric
has been treated. The roll of fabric to be treated is placed in bearings at one end
of the machine as usual with the spreading roller in position for acting upon it;
a certain length of plain cloth called the wrapper is attached to each end of the
fabric to be coated; this wrapper is first passed over the spreading roller to the
upper side of the drying cylinder and round about half its circumference then it
passes over a movable change roller to the taking up roller placed at the other end
of the machine. The fabric is then ready to receive the india rubber composition and
after the gauge on the spreading roller has been adjusted and the driving belt put on
from the drying cylinder, which is the prime mover, to the taking up roller, the
machine can be started and after the fabric has all passed through the machine, we,
in place of winding it back by hand or otherwise, remove the change roller thereby
slackening the wrapper and permitting the spreading roller and its framing to be
traversed to the other end of the machine the wrapper still lying over the drying
cylinder. The change roller is then placed in the same bearings as before or in other
bearings so that the wrapper lies in contact with about one half the circumference
of the drying cylinder, the change roller being in position to guide the fabric in the
reverse direction through the machine when the rotation of the drying cylinder is
reversed, the spreading operation being repeated as often as necessary the drying
cylinder giving motion to whichever roller is for the time being acting as the taking
up roller.
By the arrangement described the fabric can be traversed continuously through the
machine as often as required to complete the operation without winding it back by
hand.
And in order that our invention may be fully understood and readily carried into
effect we will describe the accompanying Drawing which represents a side elevation
of our improved spreading and drying machine.
The frame a of the machine has bearings 6 6 for the batch rollers c c which act
also alternately as taking up rollers. The batch or roll of fabric d to be coated is
shown in this instance in the bearings 6 from which the fabric is taken over a
spreading roller e which is supported in a movable frame e¹ and under the gauge
not shown by which the dough is spread in the usual manner; from the spreading
roller e the fabric passes over and partly round the drying cylinder f which is driven
in the direction indicated by the arrow by any suitable driving mechanism not
shown.
The fabric passes from the cylinder f by which it is dried round a guide roller g
from which it passes on to the revolving taking up roller c¹ supported in the
bearings 61, the roller c¹ being driven by a band h from a pulley keyed on the axle
of the drying cylinder f.
When the fabric d has all passed from the roller c and is wound upon the roller c¹
the guide roller 9 is removed thus slackening the wrapper and allowing the
frame e with the spreading roller e and gauge to be traversed or moved in any
convenient manner from one end of the machine frame a to the other, the band /
is now changed from the roller c¹ to the roller c the wrapper still lying over the
drying cylinder f.
The guide roller is then replaced so that the wrapper lies in contact with about one
half of the circumference of the cylinder, the roller 9 being in position to guide the
fabric d to the roller c. When the machine is re-started the drying cylinder fis
driven in the opposite direction and by the band h gives the desired motion in the
reverse direction to the roller c which now becomes the taking up roller on

page_text: which the fabric d is wound and the fabric as it passes over the spreading
roller e is spread with dough at that end of the machine where the batch roller c
is placed.
The motion of the machine can be reversed in this manner as often as necessary
to repeat and complete the spreading operation.
We have not described any means for traversing or changing the frame with
the Spreading roller and gauge from one end of the machine to the other as this
could be done in a variety of ways and we lay no claim to any special arrangement
for the purpose.
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 :-
In a spreading and drying machine the combination with a single drying cylinder,
of a single movable spreading apparatus the whole so arranged that the fabric can
be coated with india rubber composition when being traversed in either direction
through the machine substantially as and for the purposes herein set forth.
Dated this 23rd day of September 1880
H. B. BARLOW,
17, St. Ann's Square, Manchester, Agent for Applicants.