Improvements in Switches and Appurtenances Used in an Electric Circuit.
Year: 1888

page_text: Date of Application, 30th Nov., 1888
Complete Specification Left, 30th Aug., 1889-Accepted, 5th Oct., 1889
PROVISIONAL SPECIFICATION.
Improvements in Switches and Appurtenances Used in an Electric
Circuit.
FREDERICK BAUMGART NICHOLSON and EDWARD JENNINGS JENNINGS both of
7 Westminster Chambers Victoria Street S.W. Electric Light Engineers do hereby
declare the nature of this invention to be as follows:--
"
Our invention relates to that portion of Electric Apparatus by which the current
is turned off and on and those supplementary appliances which protect the circuit
from excess of current generally described as Switches" and "Fuses and in
carrying our invention into effect we construct the contact making portions of the
switch arms with divisions or saw-cuts all more or less horizontal and parallel but
running alternatively in opposite directions in such manner that these portions may
(upon entering suitably shaped contact pieces or blocks) be capable of a certain
amount of vertical movement and in such action admit of the bearing surfaces still
maintaining their faces horizontal.
Although we describe this form only with regard to the contact arms, it is obvious
that the contact blocks may be similarly treated; preferably however we use a
contact block somewhat like an inverted letter T (1) the inside flange forming
contact face and the outside admitting of connection to the " lead" but the vertical
portion we finish off by turning outwards and then back again in such manner
that its extremity is parallel to, and overhangs, the lower face and acts as an
upper one; between these two of course the contact arm passes.
To admit of com-
pensation for wear we use a screw or screws through the upper contact projection
immediately over and working into the upright or vertical portion above described.
In switches where there are many contacts arranged around the base it may be
undesirable to turn the handle completely round as may occur from want of space
on a switchboard for instance, we then attach the handle to the switch and use it
in a similar manner to a ratchet drill working either right or left handed-many
little variations unnecessary to describe here will at once suggest themselves and
we believe we are the first to propose this action on Switches. If there is space on
a board to admit of half a revolution we simply pivot the handle horizontally so
that it can be thrown over and worked the other half revolution.
In the fuses" which protect the circuit controlled by the Switches we fit an
indicating device which is held in a prearranged position when the circuit is
complete but when the fuse is melted changes its position by gravity or otherwise.
This change may be instantly perceived by using a glass front or where this is
inadmissable allowing an indicating device to project outside the case.
Dated this 30th day of November 1888.
FREDERICK BAUMGART, NICHOLSON.
EDWARD JENNINGS JENNINGS.
DECARL NICHOLSUN.
EDWARD JENNINGS JENNINGS.
COMPLETE SPECIFICATION.
Improvements in Switches and Appurtenances Used in an Electric
Circuit,
We, FREDERICK BAUMGART NICHOLSON and EDWARD JENNINGS JENNINGS both
of 7 Westminster Chambers Victoria Street Westminster Electric Light 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:-
Our invention relates to that portion of electrical apparatus by which the current
is turned off or on and those supplementary appliances which protect the circuit

page_text: "
66
"Switches and Fuses." The
from excess of current generally described as
better to explain our meaning reference is made to the accompanying Drawings.
In carrying our invention into effect we construct the contact making portions of
the switch arms with divisions or saw-cuts all more or less horizontal and parallel
but running alternately in opposite directions in such manner that these portions
(see A Fig. 1 and A Fig. 2) may (upon entering suitably shaped contact pieces or
blocks see Fig. 1 & 2) be capable of a certain amount of vertical movement and in
such action admit, of the bearing surfaces still maintaining their faces horizontal.
Although we describe this form only with regard to the contact arms, it is
obvious that the contact blocks may be similarly treated (see Figs. 3 and 4) pre-
ferably however we use a contact block somewhat like an inverted letter T (1),
see Fig. 5, the inside flange C forming a contact face and the outside I admitting
of connection to the "lead" by means of a terminal for instance. The vertical
portion G we finish off by turning outwards and then back again in such manner
that its extremity E is parallel to and overhangs the lower face C and acts as an
upper one; between these two of course the contact arm passes.
To admit of compensation for wear we use a screw or screws (F Fig. 5) through
the upper contact projection immediately over and working into the upright or
vertical portion G above described.
In switches where there are many contacts arranged around the base it may be
undesirable to turn the handle completely round (as may occur from want of space
on a switchboard for instance) we then attach the handle to the switch, and use it,
after the manner of a ratchet drill working either right or left handed see Figs. 6
and 7 in which H is the handle, I the pawl J the head of the switch cross bar or
contact arm which receives the motion of the handle through the pawl.
The spring K holds the pawl up to its work whether working right or left handed.
Many little variations unnecessary to describe here will at once suggest them-
selves and we believe we are the first to propose this action on Switches.
If there is space on a board to admit of half a revolution we simply pivot the
handle horizontally so that it can be thrown over and worked the other half revolu-
tion, see Fig. 8.
In the fuses" which protect the circuit controlled by the switches we fit an
indicating device which is held in a prearranged position when the circuit is com-
plete but when the fuse is melted changes its position by gravity or otherwise.
This change may be instantly perceived by using a glass front or where this is
inadmissable by allowing an indicating device to project outside the case. See
Fig. 9 where L is the lead" M the fuse N the disc of insulating material sup-
ported on the fuse by a small metal clip. By a glass front the fall of the disc is
readily seen.
5
Fig. 10 shows the alternative plan in which the melting of the fuse allows the
arm N (the equivalent of the disc) to fall and as it projects beyond the case its
change of position is readily noted.
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:
1st. The construction or arrangement and combination of the parts of Switches
and Fuses substantially as and for the advantages herein described in reference to
and shown in the accompanying Drawings.
2nd. The constructing of Switches having the parts of the contacts arms or
blocks so formed as to admit of the working faces retaining a horizontal position
when interlocked substantially as and for the advantages herein described in
reference to and shown in the accompanying Drawings.
3rd. The constructing of the contact block in switches with the divisions so
formed that the contact surfaces are always horizontal as shewn in figures on
drawing.
Dated this 30th day of August 1889
FREDERICK BAUMGART NICHOLSON.
EDWARD JENNINGS JENNINGS.