Improvements in Electric Switches.
Year: 1887

page_text: Date of Application, 14th Nov., 1887
Complete Left, 28th Mar., 1888
Complete Accepted, 4th May, 1888
PROVISIONAL SPECIFICATION.
Improvements in Electric Switches.
I, ROBERT WILLIAM PAUL, of 10, Ravensdale Road, Stamford Hill, London,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
The object of my invention is the improvement of electrical switches in such a way
as to secure an instantaneous making and breaking of a circuit or circuits, which
instantaneous making or breaking is not directly affected by the motion of the handle
of the switch except at a certain portion of that motion, and at the same time to secure
the automatic locking of the movable contact piece or pieces, either in the 'on' or
'off' position, by other means than friction, which is apt to be uncertain.
To effect this object I attach to the handle of the switch one or more springs, which
may be flat, straight, and free from tension, except when the circuit is in the act of
being made or broken. To the other end of the spring (or springs) is fastened a
movable contact piece; or two contact pieces may be used, one at each end of such
spring (or springs), in which case the handle may be attached to the spring (or
springs), at or near their centres. The length of the spring (or springs) is such that,
except when the circuit is being made or broken, its (or their) ends are prevented
from moving, with the movable contact piece (or pieces) attached, on to, or off from,
(as the case may be) the fixed contact (or contacts) by means of a fixed or movable
catch, for example a projection from a rocking lever, and it (or they) and the movable
contact piece are therefore locked. On turning the handle the spring (or springs) is
bent aside until its (or their) ends, with the movable contact piece (or pieces)
attached are, by the alteration in form of the spring (or springs), and not by its (or

page_text: their) increased tension overcoming a resistance, freed from the catch aforementioned,
when they are thereby released and the spring (or springs) tending to assume again
their normal or unstrained condition, cause its (or their) ends, with the movable
contact piece (or pieces) attached, to fly over, past another catch on the opposite side,
off from, or on to, (as the case may be) the fixed contact or contacts, where they are
locked by this catch, until the spring (or springs) are again bent aside by the
application of sufficient force to the handle. The releasing and locking mechanism
is positive, that is does not depend on friction for its action. The proportions of the
parts may be so arranged that, once the bending aside of the spring (or springs) has
freed the movable contact piece (or pieces) from the catch, no holding of the handle
will prevent the movable contact (or contacts) from flying off from, or on to the
fixed contact (or contacts) as the case may be.

page_text: Improvements in Electric Switches.
I, ROBERT WILLIAM PAUL, of 10, Ravensdale Road, Stamford Hill, London, N.
in the county of Middlesex, 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 :-
The object of my invention is the improvement of electric switches so as to secure
instantaneous making and breaking of an electric circuit, which instantaneous making
and breaking shall not be affected by the motion or want of motion of the handle
during the time when the movable contact piece is in motion to perform the making
or breaking; also to secure the automatic locking of the movable contact piece or
pieces either in the " on or "off" position by positive or non-frictional means, and
to prevent the movable contact piece or pieces resting in any intermediate position.
One of the methods by which I accomplish these ends will be understood from the
accompanying drawings and the following description of them.
b
Fig. 1 represents in plan, and Fig. 2 in end elevation one form of a double break
switch constructed according to my invention. To the base of non-conducting
material A are affixed the poles or fixed contacts B and C each of which consists of
a terminal and of a contact b or c, the plate 6 being under e but raised above the base
for increased insulation. To complete the circuit the movable contact D which is
shown in the drawings in the "off" position (connected to neither pole) is moved
between the contacts b and c. Now D is connected to a block of metal F, which is
firmly fastened to the handle H and freely pivotted at G, solely by means of the two
springs E E side by side, which springs are rivetted at their ends to D and are
fastened firmly to Fat their middles. On moving H therefore E and D move with
it as one piece. A casting J K L is firmly fixed to the base A by means of the part
marked J. At La triangular recess is formed to contain the rocking lever M and a
small spring N kept in place by the screw O so as to tend to keep the rocking lever M
in the position shown in the drawings. M is pivotted at P and its motion round this
point is limited by the sides of the recess L. When the movable contact I) is in the
"off" position as shown it is locked by one end of the rocking lever and by the
projecting armi K which also serves the purpose of a brake or buffer to gradually
destroy the momentum of D in flying from the
on " to the "off" position because
D then rubs along the side of K.
66
Suppose now the switch to be locked "off" as shown in the drawings, and the
handle H to be turned from right to left. The end of D catches the projection from
the rocking lever which locks it, and draws it down till the opposite end is stopped
by the side of the recess L. The springs E E are now altering their shape and
becoming bowed or bent with their convex sides towards the right, and this alteration
in form draws off D from the projection of the rocking lever M and thus unlocks it.
But the springs E E are now in such tension as to cause D to fly instantaneously on
to the fixed contacts b and c, previously passing under and lifting freely the opposite

page_text: end of the rocking lever M against the force of the spring N, which end on returning
to the normal position shown in the drawings locks the movable contact D in the
position between the contacts b and c. To break the circuit the operation is
reversed that is H is turned from left to right.
"
on
"
Now it is evident that if the position of H when D is just leaving the locking point
and the springs E are strained is the same as it would be if D were locked by the
opposite point and the springs were unstrained, it will not be possible to prevent
the instantaneous making and breaking by retaining the handle H after D has left
the locking point
The springs E E may be replaced by a single flat spring, or by a spiral spring, or
by a spring partly spiral and partly straight. The rocking lever M may be replaced
by any other form of catch such as a fixed pin stud or roller which may or may not
form part of the fixed contact, or by a suitably formed plunger acted on by a spring,
or by a catch and spring formed in one so that the movable contact may pass it freely
in one direction by lifting it, but be locked by it in the other direction. The movable
contact D may be made to fly in one direction only in which case only one catch
need be used. A single break switch may be made in which the current passes
through the spring to the movable contact, and only one fixed contact is used.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, what I claim is:
1. The construction of an electric switch in which a movable contact piece is carried
by a spring or other equivalent device the spring being in turn attached to a pivotted
handle or to some other actuating mechanisin.
2. The combination in an electric switch of a movable contact piece carried by a
spring or other equivalent device the spring being in turn attached to a pivotted
handle or to some other actuating mechanism, with suitable fixed or movable catches
so arranged as to cause the movable contact piece to fly on to or off from the fixed
contact or contacts.
3. The combination in an electric switch of a movable contact piece carried by a
spring or other equivalent device the spring being in turn attached to a pivotted
handle or to some other actuating mechanism, with suitable fixed or movable catches
so arranged as to cause the movable contact piece to fly on to or off from the fixed
contact or contacts independently of the motion of the handle while it is flying
on or off.
4. The use of movable catches for the purpose of locking electric switches
substantially in the manner described.
5. The use of movable catches for the purpose of imparting an impulse to the
movable contacts of electric switches by the action of a spring against such
inovable catches.
6. The use of movable catches whose motion is restricted by stops for the purpose
of imparting an impulse to the movable contacts of electric switches by the action of
a spring against such movable catches.
7. The switch substantially as described.