Year: 1888

page_text: I, JOHN TWEEDDALE, of 20 Church Street, Johnstone, in the County of Renfrew,
North Britain, Engineer, do hereby declaro the nature of this Invention to be as
follows, that is to say :-
My said Invention has for its object to improve the construction of electro-magnetic
motors or the mode of combining or arranging their parts, with the view of obtaining
increased efficiency.
In carrying out my Invention I arrange two electrically excited magnets, or two
or more pairs or sets of such magnets, so that the effect of attraction or repulsion
between them will be to turn or otherwise move the magnets in a manner to bring
fresh parts successively opposite each other. The parts thus brought successively
opposite may be arranged to approach each other to a uniform distance of a sixteenth
of an inch or even less without touching or they may be arranged so that the
distances vary gradually but slightly.
In one simple arrangement designed for obtaining a to-and-fro' motion, or for
obtaining rotation of a shaft by means of a crank and connecting rod from a part
moving to-and-fro', two electro magnets or pairs or sets of such magnets are fixed on
shafts or spindles mounted in hearings, those of one spindle being stationary and those
of the other being movable rectilineally or otherwise in guides or upon lever carrying
arms. On the spindle in stationary bearings there is fixed a toothed sector gearing with
a toothed sector centered to act as a lever, and this lever is connected by a link to the
movable part carrying the other spindle. The movable spindle has also on it a
toothed sector and this sector gears with a fixed toothed sector. The electro magnets
are formed or provided with pole pieces having curved surfaces the parts of which
are at regularly varying radial distances from the axes of the spindles. When the
parts of the pole surfaces of shortest radius are opposite each other, the spindles are
at their shortest distance apart, and then the electric current is by a suitable com-
mutator made to produce attraction between the magnets. The magnets in acting
under the attractive force tend to move so that their spindles will. move apart but the

page_text: toothed sectors and connections cause the magnets to turn at the same time and
thereby to bring fresh surfaces opposite each other. When the movable spindle has
reached the furthest position from the stationary spindle the commutator alters the
electric currents in a manner to cause repulsion, which results in a return movement
of the parts. If rotation of a shaft is required the movable spindle or part carrying
it is connected by a connecting rod to a crank on the shaft. There may be two or
more pairs or sets of magnets acting in different directions on the same crank or on
separate cranks. Levers and connecting links may be substituted for the toothed
sectors.
By a modification a rotatory motion may be obtained directly by arranging two sets
of electro magnets on two rotating shafts, the magnets being disposed or having the
parts of their surfaces at varying radial distances, and the shafts being geared
together so that the parts of gradually increasing radii of one set will be brought
successively opposite to the parts of gradually diminishing radii of the other set,
and vice versu.
Permanent magnets may be used in place of some of the electro magnets.
Dated this Ninth day of March 1000

page_text: I, JOHN TWEEDDALE, of 20 Church Street, Johnstone, in the County of Renfrew,
North Britain, 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, that is to say:
My said Invention has for its object to improve the construction of electro-magnetic
motors or the mode of combining or arranging their parts with the view of obtaining
increased efficiency.
In carrying out my Invention I arrange two electrically excited magnets, or two or
more pairs or sets of such magnets, so that the effect of attraction or repulsion
between them will be to turn or otherwise move the magnets in a manner to bring
fresh parts successively opposite each other. The parts thus brought successively
opposite may be arranged to approach each other to a uniform distance of a sixteenth
of an inch or even less without touching; or they may be arranged so that the
distances vary gradually but slightly.
A simple arrangement of motor made according to my Invention is shown on two
accompanying sheets of explanatory drawings, figures, 1, and 2, on sheet, 1, being
a plan and elevation of the motor, and figures, 3, and 4, on sheet, 2, a plan and
sectional elevation of commutator details. Figures, 5, and 6, are an elevation and
an inverted pian of one of the electro magnets. In these drawings the same
reference letters and numerals are used to mark the same or like parts wherever they
are repeated.
In the motor shown in figures, 1, and 2, the framing consists of a bed plate, A,
having cast on it three raised frames, B, C, D, two, C, D, of which are fitted with
bearings, E, for a crank shaft, F, on one end of which there may be placed
a flywheel and a pulley or pinion for giving off the power developed by the
motor. The crank shaft, F, is provided with two diametrically opposite cranks or
crank pins, G 1, and G 2, which are respectively actuated by oppositely acting electro
magnets. One crank pin, G I, is connected by a rod, H I, to a lever frame consisting
of a pair of levers, J 1, fixed on a rocking shaft, K 1, centered at the lower part of
the framing. In bearings in the upper ends of the levers, J 1, there is carried by
means of journals formed on its ends a plate or magnet holder, L. 1, to which an
electro magnet, M I, is fixed. The form of the electro magnets will be best under-
stood from figures, 5 and 6. Each is made with two curved polo picces, N, S, with
shanks on which the exciting conducting wire is wound and which are connected by
a back part, made by preference in the same piece with the shanks and pole pieces.
On the outer journal of the magnet holder, L 1, there is fixed a toothed sector, P 1,
which gears with a toothed rack, Q 1, fixed on the frame, D, and when the levers, J 1,
move from or towards the crank shaft, F, the rack, Q 1, acting on the sector, P 1,

page_text: makes the magnet holder, L 1, with its magnet, M 1, turn through an angle corre-
sponding to the movement and proportions of the parts. A second electro magnet, M2,
is carried by a holder, L 2, which is made with journals to turn in fixed bearings, R 1;
and on one of the journals of this magnet holder, L 2, there is fixed a lever, S 1,
which is conected by a link, T 1, to the lever, J 1, of the opposite magnet, M 1.
This connection makes the second magnet, M 2, turn oppositely to the first, M 1.
The magnets, M 1, M 2, shown at the lower part of figure, 1, and as at the nearer
side of the motor in figure, 2, are in the position in which their carrying centres are
furthest apart and in which they begin to attract each other, the poles of one magnet
being opposite to or facing the contrary poles of the other magnet. The attraction
causes the magnets to move towards each other, but in doing so they are forced to
turn on their carrying centres, which action brings fresh parts of the poles to face
each other but owing to their curvature with little or no diminution in the
distance between the parts successively nearest to each other.
With this arrange-
ment a comparatively long movement or stroke is imparted to the carrying centre
of the magnet nearest the crank shaft, such stroke corresponding to double the
throw of the crank. G 1, and giving the crank shaft, F, half a turn. On the half
turn being accomplished the direction of the electric current in the exciting coil
of one of the magnets is reversed, and in consequence the magnets repel each other
and in doing so effect or assist in effecting the next half turn of the shaft. As I
prefer to have an attracting action for both half turns of the shaft, arrange a
second pair of electro magnets M 3, M 4, to act on the second crank pin, G 2, of
the shaft, F, these magnets being carried by and having in connection with them
parts, H 2, J 2, K 2, L3, L4, P2, Q 2, R2. S 2, and T2, like those for the other
pair of magnets, M 1, M 2. When either pair of magnets, M 1, M. 2. or M 3, M 4,
is acting by attraction the other pair is acting by repulsion in a manner to assist the
turning action on the shaft, F.
Any suitable known kind of commutator may be used for reversing the electric
currents, the kind shown in the drawings and separately in figures, 3, and 4, is one
with mercury contacts. A small box, U, of non conducting material is made with
four compartments in which mercury is put, and two diagonally opposite compartments
are put in connection by conductors (not shown) with the positive pole of a galvanic
battery or other source of the electric current, the other diagonally opposite compart-
ments being connected to the negative pole. Above the commutator box, U, there is
a rocking spindle, V, made to rock by a face-grooved cam, W, on the crank shaft, F,
the cam acting on a bellerank. X, connected by a rod, Y, to a lever, on the rocking
spindle, V. On the rocking spindle, V, there are fixed two levers, Z 1, % 2, which
are insulated from the spindle and from each other and are connected by insulated
wires to the exciting coils of the electro magnets, M 1, M 3. The exciting coils of
the other electro magnets, M 2, M 4, are permanently connected in the circuit of the
battery or source of the electric current. The commutator levers, Z1, Z2, have each
a contact piece at each end and which dips into the mercury as the levers oscillate.
The connecting wires are not shown, to avoid rendering the drawing indistinct; but
their disposition will be easily understood, the currents being caused to pass in such
directions through the exciting coils of the electro magnets, M 1, M 3, connected to
the cranks, G 1, G 2, as will make the poles, N, S, of those magnets contrary or
similar to the poles of the other magnets, M 2, M 4, accordingly as the action has to
be attractive or repulsive in each case.
Permanent magnets may be substituted for the electro magnets, M 2, M 4, the
polarity of which remains unchanged.
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 :-
In an electro magnetic motor arranging one or more electro magnets the exciting
electric currents of which are periodically changed by a commutator to operate in

page_text: connection with one or more permanent magnets or electro magnets the exciting
currents of which do not change, and by alternate attracting and repelling actions to
produce reciprocating movements and by means of one or more connecting rods and
cranks impart rotation to a shaft, the parts being constructed to give turning or
angular movements to the magnets and the pole pieces of the magnets being of curved
forms such that the turning movements bring successive parts of the pole pieces into
proximity, substantially as herein before described.
EDMUND HUNT,
Applicant's Agent.