Improvements in Electrical Switches, Specially Applicable for Electric Vehicles Fitted with Two Motors.
Year: 1889

page_text: Date of Application, 4th Dec., 1889-Accepted, 11th Jan., 1890
Improvements in Electrical Switches, Specially Applicable for
Electric Vehicles Fitted with Two Motors.
I FREDERIK VILHELM ANDERSEN of 14 Westdown Road, Catford in the County.of
Kent, Electrical 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:-
My invention for improvements in electrical switches specially applicable for electric
vehicles relates to that class of switch employed for turning on the electric current to
two electric motors serving to propel a vehicle and has for its object to construct the
switch in such manner that the desirable combinations of the two motors can readily
be obtained to give suitable driving powers for varying loads and speeds.
In a switch constructed according to my invention the terminals are connected to
the generator of electricity and if the switch be at its zero position the current will be
cut off from the motors and by turning the handle of the switch in one direction to
successive positions, in the first position the current of electricity is passed through
a resistance and through the two motors in series; in the second position the
resistance is cut out of the circuit, the two motors being left in series; in the third
position one, say the left hand, motor is cut out of the circuit, the circuit passing
through the right hand motor only; and in the fourth position the current is passed
through the two motors in parallel, the motor or motors revolving in the forward
direction in all these positions of the switch. By turning the handle of the switch
in the opposite direction to similar positions, the same results are obtained except
that the current passes through the armature or the field magnets of the motor or
of each motor in the opposite direction to reverse the direction of rotation of the
motor or motors; and in the third position the current is passed through the left
hand motor only, instead of through the right.
In the accompanying three sheets of drawings
Figs. 1 and 2 are longitudinal sections on planes at right angles to one another of
switch constructed according to my invention and
Figs. 3 and 4 are transverse sections. and
Fig. 5 is a plan of the same..
..
Fig. 6 is a diagram shewing the manner in which the electrical connections with
the switch are made and a developement of the contact plates on the circumference
of the switch.
The switch is mounted on a base block 1 to which is secured a bracket 2 carrying
the top plate 3 of the apparatus. The switch is enclosed by means of the metal
cylinder 4 and cover 5. Mounted on a vertical shaft 6 capable of being rotated in bear-
ings in the base block 1 and top plate 3, is a wooden cylinder 7 serving to support the
contact plates 8, 9, 10, 11, 12 of the switch. Two sets of brushes 13, 14, 15, 16, 17;
18, 19, 20, 21, 22, 23, 24, 25, 26 and 27, 28, 29, 30, 31 are mounted on wooden
bars 32, 33 supported in the base block 1. and top plate 3. The brushes 13 to 26
bear on the contact plates on a single line parallel to the axis of the cylinder and
the brushes 27 to 31 bear on the contact plates in a parallel line, the lines sub-
tending an angle of 165 degrees at the centre of the shaft 6. On the shaft 6 is
arranged a wheel 34 provided with recesses into which takes a roller 35 secured
to the bracket 2, by the spring arm 36. The recesses in the wheel 34 are arranged
to stop the rotation of the shaft dead at certain definite points in this case at zero,
The shaft 6
and at angles of 30, 60, 90, and 165 degrees on either side of zero.
is rotated by means of the handle 37 which can be removed and replaced by a

page_text: cap 38. To the handle is attached a pointer 39 moving over a scale marked on
one side of the zero with the word "forward" and on the other side with the word
"backward" and on either side at angles of 30, 60, 90, and 165 degrees respectively
of the zero with the words "slow," " half," 86
normal," "full speed." The shaft is
prevented from rotating more than 165° on either side of zero by means of the
projection 40 which comes in contact with the bracket 2.
The electrical connections to the brushes are clearly indicated on the diagram Fig. 6
where 41 represents a battery or other source of electricity, 42 a resistance, 43 and 44
the field magnets and armature of one-the right hand motor-respectively, and 45
and 46 the armature and field magnets of the left hand motor.
When the pointer is at zero the current is completely shut off from the motors.
When the pointer is moved to 30 degrees forward of the zero, the current passes from
the battery 41 through the resistance 42, brush 24, contact plate 12, brush 23, field
magnets 43, brush 22, contact plate 11, brush 21, armature 44, brush 20, contact
plate 10, brush 19, armature 45, brush 17, contact plate 9, brush 16, field magnet 46,
brush 15, contact plate 8, brush 14, back to the battery 41. The current thus passes
through the resistance and motors in series, the motors rotating in the forward
direction.
When the pointer of the switch is moved to 60 degrees forward of zero, the
brush 25 bears on the contact plate 12, the resistance 42 being thus short circuited.
The current follows thence the same course as before.
If the pointer is at 90 degrees forward of zero, the current passes by the brush 25,
contact plate 12, brush 23, field magnet 43, brush 22, contact plate 11, brush 21,
armature 44, brush 20, contact plate 10, brush 18, back to battery 41, the left hand
motor being short circuited and consequently only the right hand motor is worked.
If the pointer is at 165 degrees forward of zero, the current passes by the brush 25,
contact plate 12, where it divides, one part passing by the brush 23, through the field
magnets 43, brush 22, contact plate 11, brush 21, armature 44, brush 20, contact
plate 10, brush 18, to battery 41, and the other through the brush 26, field magnets 46,
brush 16, contact plate 9, brush 17, armature 45, brush 19, contact plate 10, brush 18,
to battery. The whole current is thus passed through the two motors in parallel; the
motors rotating in the forward direction.
When the pointer is at 30 degrees backward of zero, the brushes 27, 28, 29, 30, 31
bear on the contact plates on the top interrupted line 165 degrees and the current
passes from the battery 41, through the resistance 42, brush 24, contact plate 12,
brush 23, field magnets 43, hrush 22, contact plate 11, brush 31, armature 44,
brush 29, contact plate 10, brush 28, armature 45. brush 27, contact plate 9, brush 16,
field magnets 46, brush 15, contact plate 8, brush 14, back to battery 41. The two
motors and the resistance are thus arranged in a series circuit and the direction of the
current through the motors is such that they run in the backward direction.
When the pointer is at 60 degrees backward of zero, the current follows the same
course except that the resistance is short circuited by the brush 25.
When the pointer is at 90 degrees backward, the brushes 27, 28, 29, 30, 31
bear on the contact plates on the dotted line 90 degrees and the current passes
from the battery by the brush 30, contact plate 10, brush 28, armature 45, brush 27,
contact plate 9, brush 16, field magnets 46, brush 15, contact plate S, brush 14, to the
battery 41. The left hand motor only is consequently operated and in the backward
direction.
When the pointer is at 165 degrees backward of zero, the current passes from
the battery 41, brush 30, contact plate 10, where it divides, a portion passing bv
the brush 29, armature 44. brush 31, contact plate 11, brush 22, field magnets 43.
brush 13, contact plate 8, brush 14, to battery 41, and the other portion passing by
the brush 28, armature 45, brush 27, contact plate 9, brush 16, field magnets 46.
brush 15, contact plate 8, brush 14, back to battery 41. The motors are thus arranged
in parallel and so as to rotate in the backward direction.

page_text: Having now particularly described and ascertained the nature of my said inven-
what manner the same is to be performed I declare that what I
tion and in
claim is:
The electrical switch specially applicable for electric vehicles arranged constructed
and operated substantially in the manner described with reference to the drawings.
Dated this 4th day of December 1889.
WHEATLEY & MACKENZIE,
40, Chancery Lane, W.C., Agents.