An Improved Method of and Apparatus for Controlling the Action of Electric Motors and other Prime Movers.
Year: 1894

page_text: Date of Application, 23rd May, 1894-Accepted, 30th June, 1894
VVI U
An Improved Method of and Apparatus for Controlling the Action of
Electric Motors and other Prime Movers.
We, Colonel JOHN BECHER ORMSBY, R.A., and GEORGE HENRY BANISTER,
Civil Engineer, both of The Royal Arsenal, Woolwich, in the County of Kent, 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 chiefly to a method of and apparatus for controlling and
regulating the action of electric motors. It comprises the utilization of the
principle of hydraulic resistance and provides for varying the resistance so as to
accelerate, diminish or stop the action of the motor as required. We are therefore
able to dispense with the devices for providing electrical resistance for regulating
the speed of the motor and thereby insure an increased torque or turning moment
of the motor in starting the same. The said invention comprises improved
apparatus and the combination of the said apparatus with a motor of any suitable
kind attached to or connected with a gun-mounting for elevating and training the
gun or performing other operations necessary in the working of the same.
The said apparatus is constructed with chambers in which pistons or plungers
work to and fro. These chambers are arranged on opposite sides of a central shaft
on which is fixed a crank or eccentric for operating the plungers. These chambers
extend beyond the parts in which the pistons work and are connected by a pipe or
passage in which is placed a valve whereby the communication between the
chambers can be regulated so that the fluid can flow more or less freely or can be
entirely stopped. The said valve may be provided with a screw spindle or other
convenient means for moving or adjusting it. The said apparatus is placed in a
tank which is charged with water, or other liquid, such as oil, diluted glycerine,
diluted methylated alcohol or the like, and we provide for the entrance of the
liquid from the tank into the said chambers to compensate for, or make good, any
deficiency that may exist therein.
Our invention is illustrated by the accompanying drawings in which
Figure 1 is a plan, and
Figure 2 is a vertical section of our apparatus constructed according to the said
invention.
Figure 3 shows a portion of the said apparatus hereinafter described.
Figure 4 is a side elevation showing a modified form of our said apparatus.
Figures 5 and 6 are sections on lines x, x and y, y respectively of Figure 4.
Figure 7 is a plan shewing the said apparatus arranged in combination with an
electric motor.
Like letters indicate the same parts throughout the drawings.
A is the tank formed of iron or other suitable material. B, B are the chambers;
6 is the connecting pipe or passage between them. C is the valve. D is the motor
shaft. D' is an eccentric. E, E are plungers attached to the metal strap E¹ which
is moved to and fro by the eccentric in a well known manner.
By the rotation of the shaft or spindle D and the eccentric D', a reciprocating
movement is imparted to the plungers E causing movement of the liquid in either
direction alternately along the pipe or passage b between the two chambers B the
speed of which movement is controlled by the valve C; that is to say, more or less
resistance is offered to the flow of the liquid in the pipe by the said valve according
to its position. We prefer to arrange the port or passage C³ of the said valve so

page_text: that when the valve is in its mid position the passage is closed, the movement of
the liquid and of the plungers is thereby stopped, and the motor consequently
ceases to work; if the valve spindle C2 is then turned in either direction, the valve
will be moved to open the port or passage; the liquid can then flow along the pipe
and will therefore permit the plungers to move in their chambers more or less
rapidly according to the extent of the opening of the valve C, the motor being
thus set free to commence or resume its action.
The valve port C₁ may be circular, or rectangular, but is preferably of the
shape shewn in Figure 3. This shape allows of a very fine adjustment of the area
of the port.
As the entire apparatus is enclosed in the tank it is not necessary to provide the
ends of the chambers B through. which the plungers E work with stuffing boxes
and glands. Another advantage arising from the arrangement of the apparatus
within the said tank is that it permits us to provide in a very simple manner for
preventing a deficiency of liquid in the plunger chambers. For this purpose we
make small holes B' through the sides of the chambers for the admission of liquid
from the tank to compensate for any loss or escape of the same from the said
chambers, these holes being formed in such a position that they are uncovered at
the extreme outstroke of the plungers.
.
Our improved apparatus serves very efficiently either as a speed regulator or as
a brake.
In the alternative arrangement or modification of our invention illustrated in
Figures 4, 5 and 6 the above described parts are duplicated i.e. there are two pairs
of chambers and plungers. The motor-shaft D is provided_with a crank or
cranks D (or eccentrics) arranged to actuate the plungers E, E* working in
chambers B, B* placed on axial lines at right angles to each other as clearly shewn
in Figure 4. The chambers B are connected by a pipe b, and the chambers B* by
a pipe 6*. A controlling valve C is provided in each of the connecting pipes or
passages b, b. These valves are preferably connected to a common spindle. The
parts of the said apparatus may also be triplicated if necessary or desirable.
In Fig. 7 we have illustrated the manner of using our apparatus in combination
with an electric motor. F is the motor which may be of any suitable construction.
The motor shaft is preferably coupled directly to the crank or eccentric shaft D.
We provide the motor with a reversing switch, the handle G of which is directly
connected to the spindle C¹ of the aforesaid controlling valve C. As above
described the valve is so arranged that when closed it is in a middle position in the
port. The said switch is so constructed and arranged that when the valve is
closed, a movement of its handle G in either direction switches on the current and
at the same time opens the valve thereby permitting the motor to act. By
reversing this movement and re-placing the handle in mid position the valve is
closed and the motor brought quickly to rest.
This arrangement of our improved apparatus will be very advantageous for
training or elevating heavy guns or for similar operations where it is desirable to
be able to start, reverse, or stop the motor quickly.
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. An electric motor provided with apparatus for controlling or regulating its
action by the resistance of a liquid through the medium of reciprocating plungers
or pistons which force the liquid to and fro through a passage between them, the
area of which passage is variable, for the purpose specified.
2. The above described apparatus enclosed in a tank and having provision for
the entrance of liquid from the said tank to the chambers, for the purpose
specified.
3. The combination of the said regulating. or controlling apparatus with a motor
on, or connected with, a gun-mounting, for the purposes specified.

page_text: 4. An electric motor having combined therewith a speed controlling or regulating
apparatus such as that above described, and a switch provided with a handle
arranged to simultaneously operate the switch and the valve of the controlling.
apparatus, for the purposes specified.
Dated this 23rd day of May 1894.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.