Improvements in Apparatus for Controlling the Action of Electrio Motors at a distance.
Year: 1897

page_text: Improvements in Apparatus for Controlling the Action of Electrio
Motors at a distance.
We, WILLIAM OLIVER SMITH and GEORGE KEITH BULLER ELPHINSTONE, both of
101, St. Martin's Lane, in the County of London, Electrical Engineers, do hereby
declare the nature of this invention to be as follows:-
This invention relates to an apparatus for causing an electric motor to perform
work at a distant point. The direction of rotation of the moving parts connected to
the work being performed or the fraction of a revolution or number of revolutions.
through which the electric motor is intended to move any suitable object being all
controlled from the transmitting end.
As an example we may instance the electric control by the above mentioned means
of electric light projectors, the training elevation or depression of guns, the opening
to any desired extent of any valve controlling other machinery or in the case of
steering apparatus the movement and control of the steam steering engine or of the
rudder itself.
The way in which we accomplish this object is as follows:-At the transmitting
station, a lever or other mechanism, either actuated directly by hand, or through the
agency of suitably toothed wheel work, is made to wind a spring; this spring being
connected to the lever or other mechanism; the other end is connected to an axle
capable of making any number of desired revolutions, but controlled by means of
an anchor escapement held in either of two limiting positions by means of two
electro-magnets and a jockey spring; the arrangement being such that, upon electrical.
impulses being received alternately, by either of the above electro-magnets, the.
moving system referred to is capable of rotating in either direction, and so releasing
the wound-up springs.
Connected to the lever carrying the end of the spring first referred to, are two.
cams, so arranged that any movement of the lever in either.direction causes one of
two small rollers to lift on the periphery of the cam, and by its movement to close
either of two electrical circuits; that is to say, when the lever is turned to the right,
one cam acts on one of the rollers, and closes one circuit; and when the lever is
moved to the left the other circuit is closed in the same manner.
The movement of these rollers and levers can, if desired, be made to break an
electric circuit instead of making it. These electric circuits are carried to two
magnetic clutches situated at the distant point where the motor is to be controlled
by suitably bevelled gearing, or right and left-handed worms; parts of these two
magnetic clutches can be kept in a state of constant rotation in opposite directions.
The other halves of these two clutches are connected together and rigidly joined to
the moving mechanism which it is desired to operate by means of the motor.

page_text: Connected also to this part of the moving mechanism, that is to say the part which
revolves when work is to be done, is a small commutator having one brush or fixed
contact joined to some source of electrical energy; and two other brushes, which by
means of the segments in the commutators are alternately placed in connection
with the source of supply. The disposition of these segments being such that, at
no time can the last named two brushes be both in contact. The contact being
broken from one at some small interval of time before it is made on the other. Wires
are led from these two contacts to the two electro-magnets above mentioned, which
govern the movement of the anchor escapement controlling the wheel system
which carries one end of the transmitting springs.
When the apparatus is connected up and ready for use, it will be seen that any
movement of the lever causes the spring to be constrained, and at the same time
energises one or other of the two magnetic clutches at the distant point. The motor
then driving round the mechanism through the agency of this clutch, sends alternate
impulses to the electro-magnets in the transmitting instruments, unlocking, as it
were, the transmitting mechanism' step by step, until no strain remains upon the
spring, when the roller will be free to drop into the space for the purpose at one
end of the cam, and so put out of action the magnetic clutch at the far end.
When it is desired, these magnetic clutches may be differentially wound, so that
at the transmitting end it is only necessary to open a circuit and not make one. A
pointer may be fixed upon the wheel which engages with the anchor escapement,
to afford an indication that the desired amount of work has been done at the distant
**point.
In the case of motors of large size where it is not desirable to allow the motor to
continue always running; this apparatus may be arranged to control a suitable
starting resistance for the motor.
DOLL
1007
WILLIAM O. SMITH.
G. K. B. ELPHINSTONE.
Improvements in Apparatus for Controlling the Action of Electric
Motors at a distance.
* We, William OLIVER SMITH and George KEITH BULLER ELPHINSTONE, both of
101, St. Martin's Lane, in the County of London, Electrical Engineers and Manu-
facturers, 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 a means of controlling the action of motors at a distance.
The direction of rotation of the moving parts connected to the work being performed
or the fraction of a revolution or number of revolutions which the motor is intended
to move any suitable object being all controlled from the transmitting end.
In the accompanying drawings
:-
Fig. 1 is a sectional elevation of the transmitter mechanism.
Fig. 2 is a plan of the transmitter mechanism with the covering case removed.
Fig. 3 is an elevation of the switch levers.
Fig. 4 is a plan and elevation of the spring barrel.
Fig. 5 is an elevation of part of receiver mechanism.

page_text: Fig. 6 is a plan of receiver mechanism.
Figs. 7 & 8 show the dial of the transmitter with pointers.
Figs. 9 & 10 show the checking action on the transmitter.
Figs. 11 & 12 show the lower cam.
Figs. 13 & 14 show the stopping gear of the receiver.
Fig. 15 is a diagram of the connections of the apparatus.
The way in which we accomplish the object is as follows:
At the transmitting station we have a hand wheel A (Fig. 1) to the shaft of which
is rigidly fixed a worin B (Fig. 1), which gears into a worm wheel C (Fig. 1).
Rigidly fixed to the shaft D (Fig. 1) of the worm wheel C is a bevel wheel E (Fig. 1)
which gears into a bevel wheel F (Fig. 1). The wheel F is loose on its spindle which
is rigidly fixed to a casting H (Fig. 1). The casting H is free to rotate on the
shaft D, which passes up through the centre of casting H. Gearing into F is a
third bevel wheel G (Fig. 1) (having the same pitch diameter and number of
If the hand
teeth as wheel E), which is also loose and free to rotate on shaft D.
wheel A be turned, the shaft D and with it the wheel E can be caused to rotate
through any angle, and it is obvious that if the wheel G be held and kept from
rotating, the wheel F, and with it the casting H will be dragged round the shaft D
through half the angle through which the wheel E was turned no matter what the
ratio of the number of teeth of the wheel E, or wheel G is to the number of teeth
on wheel F.
Rigidly attached to casting H are two cams K & L (Figs. 1-2-11 & 12). At a
point M (Fig. 12) on the periphery of the cam L, the cam increases suddenly in
diameter by a small amount. If the casting H were turned to the right a roller
pressing on the smaller diameter of the cam L. close to M would be caused to
lift up on to the larger diameter. The cam K is similar but fixed on the
casting H, so that if the casting H be turned to the left another roller pressing
on the periphery of K would be lifted up on to the larger diameter in the same
manner. The cam L has screwed into it a pin N (Figs. 1-11 & 12) which presses
against one or other of the projections O or P (Fig. 4), according as the cam L is
rotated to the right or to the left. The projection is rigidly fixed to the top
end of the spring S (Fig. 1) and the projection P to the bottom end of S. If the
cam L is turned to the right it presses against O and carries it with it while P
remains pressing against the pin Q (Fig. 1). The pin Q is screwed to the base. X
(Fig. 1) of the transmitter. If the cam L is turned to the left the pin N presses
against P, and O remains pressing against pin Q. Thus whichever way the cam L
is turned it winds up the spring S and causes S to exert a force on pin N,
tending to bring the cams back to the position of rest that is with the pin N
opposite pin Q as shewn in Fig. 1.
In Figs. 2 & 3 are shown two levers T & U which are pivotted on the pin V.
Pin is rigidly fixed to the base X of the transmitter.
At one end of the
levers T & U are two springs Y and Y¹, which keep two small rollers R & R¹
(Fig. 3) pressed one against the periphery of cam K and the other against that of
cam L. Fixed to the levers T & U, but insulated from them are switch knives
W&W (Figs. 3 & 15) which can drop into the switch tongues 1, 2, 3 & 4 (Figs.
2 & 15).
The switch tongues 1, 2, 3 & 4 are so arranged that if knife W is used
1, 2 & 3 are connected together and if knife W₁ is used 1, 2 & 4 are connected
together. The motion of the bevel wheel G is controlled by means of an escape
wheel 5, (Figs. 1 & 2) and anchor escapement 6 (Figs. 1 & 2). Wheel 5 is
rigidly fixed to wheel G and locked by the iron anchor 6 which is pivoted
ata and a (Figs. 1 & 2) and held in one of two positions by one or other of the
electro-magnets m & m₁ (Figs. 1 & 2) and the jockey spring J (Figs. 1 & 2).
Electrical impulses received alternately by the electro-magnets m & my cause the
iron anchor to rock and alternately lock and unlock the wheel 5. Rigidly fixed to
wheel G is another toothed wheel 7 (Figs. 1 & 2) which gears into toothed wheel 8
(Figs. 1, 2 &8) fixed to the spindle of which is a pointer Z (Figs. 1 & 8) which

page_text: 1
moves over a dial d (Figs. 1-7 & 8). (Dial d is not shown in Fig. 2). Pointer Z
therefore shows on dial d the angle through which G has moved.
Rigidly fixed to shaft D is a toothed wheel 10 (Fig. 1) which gears into an idle
toothed wheel 11 (Fig. 2) which again gears into a toothed wheel 9 (Figs. 2 & 8).
The spindle of wheel 9 is a hollow sleeve which rotates loosely on the spindle of
wheel 8, and is carried by the bridge 12 (Fig. 2) (not shown in Fig. 8).
To the other end of the hollow spindle of 9 (Fig. 8) is fixed a pointer Z₁, which
is immediately helow and concentric with pointer Z. Pointer 7, therefore shows on
the same dial d the angle through which the shaft D and therefore the wheel E
(Fig. 1) has moved. The idle wheel 11 (Fig. 2) merely ensures that both pointers
shall turn in the same direction.
At the receiving station we have two electro magnetic clutches of any suitable
form, such as shown at 61 & 2, 63 & b± (Figs. 5, 6 & 15) the shafts of which v',
v2, v3 and 4 (Figs. 5 & 6) revolve in suitable bearings (not shown).
A spindle 20 (Figs. 5 & 6)-having two worms 21 & 22 (Figs. 5 & 6) cut on it, one
right and one left handed-is kept continuously revolving by means of an electric
motor or other source of power. These worms gear into worm wheels 23 & 24 (Fig. 6)
which are rigidly fixed through shafts v1, v2 to parts of the magnetic clutches 162.
These parts are therefore kept continuously revolving in opposite directions. The
other parts 3 & 6 of the clutches are fixed through shafts v³ & v to the spur
wheels & respectively. These two wheels h¹ and h² both gear into a spur
wheel h³ (Fig. 6) which is fixed to a centre shaft vs. It is obvious that if current
be sent into the clutch part 68 say so as to cause it to grip the part b' the wheel h³
and shaft v5 will be caused to revolve in a certain direction by the wheel h¹. The
wheel h² and clutch part 64 will run round idly. If current be sent to 64 so as to
cause it to grip b² the wheel h³ and shaft v5 will run round in an opposite direction
and hand b³ will run round idly.
On the shaft is a commutator n (Fig. 5 & 6) consisting of a drum of vulcanite
or other dielectric material. with a metal contact ring (Figs. 5, 6 & 15) toothed as
shown. The commutator ring n² has three brushes 13, 14, 15 (Figs. 5 & 6) on it
brush 15 making continuous contact with ring n², the other two brushes being in
contact with the toothed projections of n² alternately. The projections are so
arranged that the two brushes cannot be in contact with the ring n² both at the
same time.
The two magnets m and m₁ (Figs. 1-2 & 15) are connected as shown in Fig. 15
to the two brushes 13 & 14 (Figs. 5 & 6); therefore, if the shaft revolves
connection is made to the magnets m & m, alternately and the number of contacts
made depends on the number of revolutions or fractions of a revolution the shaft v
has made.
From the foregoing description it will be seen that when the apparatus is connected
up ready for use as shown in Fig. 15, any movement of the hand wheel A (Fig. 1)
will cause shaft D and wheel E to move through a certain angle, which angle is
indicated by the pointer Z₁. (Figs. 1 & 8). Wheel F and casting H with the two
cams K & L will be dragged round after wheel E constraining the spring S through
pin N (wheel G being held by the escape wheel 5 and anchor 6). One or other of
the switch rollers R or R₁ (Fig. 3) will be caused to ride up on its cam and will
cause its switch lever to make contact with switch tongues 1, 2 & 3 or 1, 2 & 4
according to whether the cams were rotated to right or left, thus allowing the battery
(or other source of electric current) to send current to one or other of the clutches
6 or 62 at the distant receiving station. The motor will then drive round the
mechanism in a certain direction through the agency of this clutch, and by rotating
the commutator n (Figs. 5 & 6) will allow the battery to send alternate impulses to
the electro-magnets m & m, (Fig. 2), these operating on the anchor 6 will unlock
the wheel 5 step by step and allow the wheel G to be driven round by the tension of
spring S till the cams have come back to their position of rest, when the roller which
was lifted will be free to fall back down the cam causing its switch lever to break
contact and so put out of action the magnetic clutch at the receiving station,

page_text: stopping the rotation of shaft v5. The rotation of the wheel G will be indicated by
the other pointer Z thus affording an indication that the work at the receiving end
has been done.
In order to insure that the shaft vs shall not overshoot after current has been
broken on the clutch, we provide a toothed wheel 30 (Figs. 6 & 13) fixed to
shaft, and a lever 31 (Figs. 6 & 13) with a projection 32 (Fig. 13) which
can fall between the teeth and so limit the rotation of the shaft v5. The lever 31 is
pivoted at 33 (Fig. 13) and has an iron armature 34 (Figs. 13 & 14) attached to its
end. The armature 34 is attracted by an electro-magnet 35 (Figs. 13, 14 & 15)
which is connected in the circuit of both of the clutches, so that when current is on
either of the clutches the lever 31 is held off and the shaft v free to rotate till the
circuit is broken at the transmitting end when the lever 31 falls in & locks the shaft v³.
Another safety device to ensure against the circuit of either of the clutches being
broken at the transmitting ends at a time when the shaft v5 was not in the right
position for the break to occur is provided in the transmitter. Two holes are drilled
in the base X of the transmitter, one of these holes is shown at 41 (Fig. 9).
In each of these holes is a pin, one of which is shown at 40 (Figs. 1 & 9)
which projects above the base X. A pin N¹ (Figs. 9, 11 & 12) is provided which is
screwed into the cam L (Figs. 11 & 12). In the position of rest, of the cams, the
pin N is exactly between the holes 40 & 41 in the base X-but as the cams are
moved to the right or to the left one or other of the pins in 40 & 41 is pressed down
by the pin N, and depresses one of two pivoted levers 42 or 45 (Figs. 9 & 10). At
the ends of each of these levers are spring pawls which in the position of rest of the
cams stand clear of two ratchet wheels, 46 & 47 (Figs. 1-9 & 10), which are fixed
to shaft of wheel A. The pawls are held off by two springs 44 & 49 (Fig. 9) which.
keep the levers 42 & 45 pressed against the pins in 40 & 41. While the lever which.
is depressed kept so the pawl flicks over the teeth of the ratchet wheel if the hand.
wheel A is kept rotating in the same direction, but if the hand wheel A is turned
back it will be locked by the pawl until the escape wheel has been allowed by the
magnets operating the anchor to bring the cams back to the rest position, when the-
ratchet wheel will be unlocked and the hand wheel A free to move in any direction...
One of the wheels 46 & 47 acts for right handed rotation of the hand wheel A, the
other for left handed rotation. We may employ instead of the foregoing device..
electro-magnets connected in the circuits of the clutches to operate levers 42 & 45.
The dial d is shown graduated as it might be if the apparatus were used for
controlling the valve of a steam steering engine or for moving the rudder directly
by the motor itself, but it is obvious that the graduations on the dial may be made
to represent the movement of an electric light projector gear for training or
depressing a gun or of any object geared to the shaft.
The magnetic clutches inay be differentially wound, so that it is only necessary to .
open a circuit at the receiving end instead of making one.
In place of the electro-magnet clutch, as described, we may cause the switch knives.
to make or break or reverse the current through an electric motor at the receiving
end, or to control a starting resistance for the same.
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 an electric control apparatus the method of controlling the action of electric
or other motors at a distance substantially as described and illustrated.
2. In an electric control apparatus the method of controlling the number of
revolutions or fractions of a revolution, or the distance through which an electric or
other motor is intended to nove any suitable object substantially as described and
illustrated.
3. In an electric control apparatus the method of indicating back to the
transmitting end the work done at the receiving end substantially as described and
illustrated.

page_text: 14: In an electric control apparatus the combination of electro. magnetic clutches
operating contacts for breaking their own circuits with receiving and transmitting
apparatus substantially as described and illustrated.
5. The electric control apparatus substantially as described and illustrated.
Dated this 22nd day of December 1897.
WILLIAM O. SMITH.
G. K. B. ELPHINSTONE.