Improvements in Switches for Electric Circuits.
Year: 1898

page_text: Date of Application, 17th May, 1898
Complete Specification Loft 17th Fah 4000
Ancoated 15th low 1000
Improvements in Switches for Electric Circuits.
CECIL BURMAN CALLOW, of Newlands, St. Helens, Isle of Wight, and JUSTUS ECK,
of 5, Priory Road, Bedford Park, London, W., Electrical Engineers, do hereby
declare the nature of this invention to be as follows:-
In the switches, where the moving contact parts have to occupy two or more suc-
cessive positions of contact, it is often desirable that the movement should be
quick from one point to the other, and it is always desirable that the successive
positions should be such that the maximum surface contact is obtained, and that
the movement should be to the desired point and not beyond it.
In our device the moving contact part is connected to the handle by single
or double way springs according as the successive movements of the contact parts
are all in the same direction or not, acting in the case of the double way springs
through hinged pieces.
The object of the hinged pieces is to free the springs from distortion, or risk of
falling off or being forced off when compressed. This is accomplished by the
hinged part falling away from the contact part, as and when required.
The contact part is held by a detent from moving until the handle is moved
to a position which corresponds or nearly corresponds, with the next contact
point at which time there is considerable tension on the springs. The handle then
releases the detent which permits the contact part to spring forward, its movement
being stopped by another detent corresponding to the next contact point.
In the event of the tension of the springs being insufficient to release the contact
part from its position the handle communicates directly with it and forces it wholly,
or partially, out of contact.
By the means described above the contact parts of multiple way switches are
caused to jump with certainty successively from centre to centre of the contact
points in accordance with the movement of the handle.
Dated this 16th day of May 1898.
CECIL BURMAN CALLOW.
TIISTITS TOK
Improvements in Switches for Electric Circuits.
We, CECIL BURMAN CALLOW, of Newlands Villas, St. Helens, Isle of Wight,
and JUSTUS Ecк, of 5, Priory Road, Bedford Park, London, W., Electrical
Engineers, 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:-
In switches where the moving contact parts have to occupy two or more suc-
cessive positions of contact, it is generally desirable that the movement from one

page_text: position to the other should be quick, and it is always desirable that the successive
positions should be such that there should be maximum surface contact and also
that the movement should be to the desired position and no further.
In the accompanying drawing Figure 1 is a side sectional elevation on the
line YZ; Figure 2 an end elevation with the handle A removed and Figure 3
a sectional end elevation on the line W-X, of one form of our device.
The moving contact part in this case consists of a segmental part M, firmly
fixed to the shaft. E and revolving on its axis, carrying plates L on which are
mounted contact fingers K. To the same shaft is also rigidly connected another
segmental piece D.
The segmental piece D is connected to the lever B which itself is rigidly con-
nected to the handle represented at A, as of a wheel form, by one or two sets of
springs X according as the successive movements of the contact part are to be all
in one direction or sense, or otherwise. In the latter case where two sets of
springs are used they are attached to pieces O, hinged at P to the segmental part D.
The object of these hinged pieces is to free the springs from distortion or risk
of falling off or being forced off when in compression. This is accomplished by
the part falling away from the part D as and when required.
The segmental part is prevented from moving by the detent F until the lever B
which is connected rigidly to the handle A is moved round so as to release it by
pushing the detent back as shewn at F in Figure 1, as the lever reaches this posi-
tion one of the sets of springs is in considerable tension so that directly the detent
is depressed the moving contact part springs forward until its motion is stopped
by the next detent.
In the event of the tension of the springs being insufficient to release the contact
part from its existing position there is a projection C attached to B which comes
into mechanical contact with a projection R on D and thus directly forces the
moving contact part forward until the friction is sufficiently reduced to allow the
springs to act in the normal manner.
The number of detents coincides with the number of successive positions of the
switch, and in the drawing a five way switch is shewn in which the five detents are
mounted on a common support G and pressed forward by springs held in position
by a back plate I.
Limit stops N are fixed on the support G to prevent the segmental part D getting
out of range of the detents F.
In the figures are also shewn insulated contact forks J supported by a plate H
screwed to the common support G. There may be one or more sets of plates H
supporting contact forks. To the contact forks are connected the circuit conductors
and the contact fingers are connected to one another in such a way that the desired
connections are made between the different circuit conductors.
The number of plates L may or may not coincide with the number of detents
according to the use to which the switch is supplied.
It will be seen from the above that the position of the moving part is always
to a place defined by the position of the detents and these are so arranged that the
maximum surface contact is always obtained in the electrical contacts.
It will also be seen that the movement of the handle and the contact parts need
not be round a centre but may equally well be in a straight line in which case
the detents will be in a straight row and likewise the contact fingers and forks.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is :-
1. A means of securing in a multiple way switch quick movement to each of
the successive positions.
2. A means of securing quick movement either forward or backward in a
multiple way switch.
.1.'

page_text: 3. A means of securing quick movement in a switch independent of the rate of
movement of the handle.
4. A means of mechanically coupling the handle to the moving contact part in
a switch in the event of the springs being insufficiently strong to work it.
5. A switch in which the successive positions of the contact part are such as to
secure maximum surface contact.
6. A switch in which the handle is freed from the contact part in such a manner
that it cannot control the exact position of the contact part.
7. A switch which may be moved backwards and forwards without the spring
parts becoming distorted or damaged.
Dated this Fourteenth day of February 1899.
C. BURMAN CALLOW.
JUSTUS ECK.