Improvements in Electrical Switches, suitable for use in connection with Electric Launches and the like.
Year: 1892

page_text: Date of Application, 19th Feb., 1892
Complete Specification Left. 21st Nov., 1892-Accepted, 18th Feb., 1893
PROVISIONAL SPECIFICATION.
Improvements in Electrical Switches, suitable for use in connection
with Electric Launches and the like.
We, CHARLES SCOTT SNELL, of Culver Park Saltash, Cornwall Electrical
Engineer and WOODHOUSE AND RAWSON UNITED LIMITED of 88 Queen
Victoria Street London, E.C. Electrical Engineers and Contractors, do hereby
declare the nature of this invention to be as follows:-
The object of our invention is to produce a simple and reliable switch for use on
electric launches or in equivalent positions, in which the movement of a single
lever from a central or 66
off" position to either right or left causes the motor
circuit to be completed for rotation either to the right or left as may have been
arranged.
The apparatus is so arranged that during the time in which this action is being
carried into effect, it causes the accumulator connections to be suitably coupled for
putting on only one half or other portion of the full power before the full power is
reached, and similarly in returning from full power to the "off" position, the half
power position is first reached.
In carrying our invention into effect, we make use of a switch having four
radiating double brushes alternate sets being connected and suitable contact plates
are provided on the same face. On the other side of the base another single brush
is attached to the same spindle and two contact plates are provided.
The double brushes consist of two brushes of different radii, arranged one over
the other, capable therefore of making contact on two plates at different distances
from the centre, and the contact plates are so arranged and formed, and the
electrical connections so made, that in moving from the "off" position to either
the right or the left, the accumulator battery being made up say, in two divisions,
these divisions are first placed in parallel for half speed, before they are placed in
series for full speed, the single back brush making and breaking the central con-
nections between the two divisions, whilst the double brushes make and break the
parallel connections, as well as the main motor connections, and the whole system
also has the functions of a reversing switch.
It is obvious that by further subdividing the batteries and adding extra contacts,
quarter power may be first used, then half, and then full power.
The better to ensure quick make and break, the switch handle (or its accessories)
is provided with an intermittent brake device acting against any attempt to change
from certain prearranged positions, but when once this effect is overcome, giving
free movement until the next position is reached producing therefore a quick break
action without springs, these may however be provided if deemed necessary, and
the handle may also have a lever and notched plate as in a locomotive reversing
gear the better to define exact positions.
Dated this 18th day of February 1892

page_text: COMPLETE
SPECIFICATION.
Improvements in Electrical Switches, suitable for use in connection
with Electric Launches and the like.
We, CHARLES SCOTT SNELL, of Culver Park, Saltash, Cornwall Electrical
Engineer and WOODHOUSE AND RAWSON UNITED LIMITED of 88 Queen
Victoria Street, London, E.C., Electrical Engineers and Contractors, 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 :-
The object of our invention is to provide a suitable and reliable switch for use
on electric launches or in equivalent positions, in which the movement of a single
lever from a central or "off" position to either right or left causes the motor
circuit to be completed, for rotation either to the right or left as may have been
arranged.
The apparatus is so arranged that during the time in which this action is being
carried into effect it causes the accumulator connections to be suitably coupled for
putting on only one half or other portion of the full power before the full power is
reached, and similarly in returning from full power to the "off" position the half
power position is first reached.
The better to explain our meaning reference is made to the accompanying
drawings, in which
Fig. I is a section and Fig. II a plan of one face of the switch,
Figs. III and IV are details of small brush and Fig. V is a section of same,
Fig. VI is the plan of another face of the switch,
Figs. VII and VIII show details of the brake device,
Fig. IX is a diagram of the connections,
Figs. X and XI a "notched plate" device,
Figs. XII and XIII side elevation and plan of switch case and Fig. XIV shows
enlarged view of handle for same.
It will be seen by reference to Fig. I that the centre spindle is operated by a
handle outside the case, and when moved rotates the whole system of brushes
which on the upper side of the base Z are carried by two insulating discs A' A'
Fig. I. The contact plates A, B, C, D, E, F, G shown hatched in Fig. II are
connected mechanically and electrically with the corresponding ones on the other
side of the base Fig. VI, and similarly marked in the diagram Fig. IX; and the
brushes H, I, J, are all connected together also K and L are connected and M
insulated and this arrangement admits of making the various combinations necessary
for the different speeds and directions.
For instance in the position shown in Fig. II the brushes couple up the whole
system in the manner shown in full lines in the diagram Fig. IX; which, as the
batteries are then arranged in parallel may be called the half speed position of one
direction (either ahead or astern if on a boat) but if moved to position shown with
dots and dashes obviously the direction of motion of the boat would be reversed
although half speed is again attained.
In passing from one position to the other it is obvious that each brush has had
to leave its contact plate, and the whole circuit has therefore been broken. To
connect the battery in series and obtain full speed a further movement is necessary
which shall connect E and F together (see Figs. II and IX) and join A to C and
B to D or C to B and A to D according to the direction of movement necessary.
This is effected by the use of the brushes N, O shown in Fig. V (this is a con-
tinuation of the section in Fig. 1) and Fig. VI and which are attached to, but
insulated from the main spindle, the brushes N, O being connected by a circular
strip of metal O' Fig. VI. These brushes N, O never touch the contact plates E
and F until the extreme right or left hand position is reached, in which position the

page_text: parallel connections F to G (made by brush M see Figs. II and III) and C to E
made by brush I, are broken.
To ensure that the switch shall not remain in intermediate positions, we make use
of a device shown in Figs. VII and VIII. The bar Q is insulated and rigidly
fixed to the spindle through the hole Q', upon the bar Q the clip P slides carrying
a star wheel free to rotate, the arms of which fit into the notches of the bridge R
Fig. II against which they are forced by the springs Figs. VII and VIII. The
point S Fig. II represents the centre of the star wheel and the dotted lines the
arms. The springs cause the switch to take up a definite position, in such a way
that on turning the handle one arm leaves its notch and as the handle continues to
be turned the other arm comes to a dead point and directly it passes this the
switch is forced forward by means of the springs until another arm enters the next
notch, or if the force tending to turn the handle is removed before the dead point
is reached it returns to its original position.
It is obvious that by further subdividing the batteries and adding extra contacts,
quarter power may be first obtained then half and then full power.
In Figs. X and XI is shown a notched plate T in which a pin U engages, this
being released and the lever moved by first pressing down the half round guard
piece V, which is provided with a leg to which the pin is attached as seen in
Fig. X. The spring between the guard piece and handle tends to lock the lever
when at rest in any of the definite positions of off or full speed or half speed, at the
same time switching from any one position to an adjacent one can be rapidly done,
but a pause is necessary after reaching any position for the unlocking action to be
made, thus preventing the risk of damage to the motor by the too rapid action in
changing the connections.
The lever W can be withdrawn from the socket of the main lever when it is in
the centre or off position only, and in the case of the star wheel system before
mentioned this is effected by the metal casing X having a long slot with a central
enlargement through which the button Y on the handle (see Fig. XIV) will pass,
but it will not pass when the lever is at any other position.
It will be seen that the brushes are different lengths on the switch, but are
arranged side by side or at the same level, it is however obvious that they might if
desirable be superimposed so as to constitute double brushes working on contact
plates of different radii.
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 motor controlling switch, the combination of parts whereby the
direction of rotation and the power to be applied are controlled by the movement
of a single lever, substantially as described.
2. In an electric motor controlling switch, the combination with the actuating
lever of a quick make and break device, substantially as described and for the.
purpose set forth.
3. In an electric motor controlling switch, the combination with the actuating
lever of the notched plate device, substantially as described and for the purposes
set forth.
4. The construction or combination of the parts of a motor controlling switch,
substantially as described in reference to and shown in the accompanying drawings.
Dated this 18th day of Navamber 1040
C. SCOTT SNELL,
WOODHOUSE & RAWSON UNITED, LIMITED,
A. L. Foley, Secretary.