Improvements in or applicable to Electrical Switchboards and Switches.
Year: 1889

page_text: Improvements in or applicable to Electrical Switchboards and
Switches.
We FREDERICK LAWRENCE RAWSON of 11 Queen Victoria Street London E.C.
in the County of Middlesex Electrical Engineer & WILLIAM WHITE Electrical
Engineer of the same address do hereby declare the nature of this invention to be as
follows:
The present invention relates to improvements in or applicable to electrical
distributing switchboards & switches & its object is to simplify & cheapen the
production of the same.
We form in an electrical distributing switchboard the connections to the two poles
of the main circuit by means of two main bars of metal which may be castings
arranged so that the connections are all on the surface of the board, the two mains of
the dynamo being connected to these two bars at one end of each by means of suitable
cable connectors. One of the main bars is made with projections on one side which
projections are bevelled off to allow the brushes as they are turned round to rise to the
top of the bar & so make a good contact for one end of the switch brush. The other
contnets of the switch brushes which may also be castings are bevelled off where the
brushes rise on to them & are provided with projections to recoive the terminal
screws under which the ends of the fuses are clamped, the other ends of the fuses
being clamped under terminal screws on to suitable plates at the other end of which
plates cable connectors for the external circuits are clamped down with a nut.
Into the other main bar when only used with single pole switches we screw terminal
screws for the end of the fuses the other ends being clamped on to plates similar to
& with cable connectors similar to those employed with the other bar.
All the contact plates on the surface of the board are the same height and are all
flat on the top so that they can be all planted on the board & filed or planed over at
one operation thus making the production exceedingly cheap & simple. To prevent
the brush passing over the surface of the contact plates & falling off the same
we screw a flat piece of brass on to the same instead of having a ridge or projection
cut on the bar.
Wo form the brush in a special manner riz.: we make it of several strips of
sheet metal which are bent or curved round at suitable angles or curves to fit within
each other with a space between each. These strips are put together with a washer
between each one so that the brush is solid in the centre & yet each strip is quite free
& elastic there being a space between each strip except at the centre where the space
is filled by the washer thus each strip of brass in the brush is perfectly free so that it
makes a separate & independent contact. When the switch is arranged so that the
brush flies off quickly by means of a spring as in "quick break" switches, to prevent
the loose handle from stopping such quick break by the edge of the bearing surface of
the handle causing too much friction on the outer bearing surface of the top plate
of the brushes, we bevel off the one or both so that it bears only in the centre.
We sometimes make the switches double pole in which case both the main bars are
fitted with the projections as described above & with the contact plates at both poles:
the switches are materially the same as the one described above with the exception
that instead of having the handle on the same spindle as the brush,we put the handle
on a separate spindle in the space between the two main bars, the brushes are con-
neeted by a bar or bars having suitable projections thereon in which a part of the
handle fitting engages.
Dated 6th November 1889.
F. L. KAWSUN.
WM. WHITE.

page_text: COMPLETE SPECIFICATION.
Improvements in or applicable to Electrical Switchboards and
Switches.
We FREDERICK LAWRENCE Rawson, of SS, Queen Victoria Street, in the City of
London, Electrical Engineor, and WILLIAM WHITE of 58, Broad Street, in the City
of London, 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 present invention relates to improvements in or applicable to electrical
distributors switch boards and switches, and its object is to simplify and cheapen the
production of the same.
We form in an electrical distributing switch board the connections to the two
poles of the main circuit by means of two main bars of metal which may be
castings arranged so that the connections are all on the surface of the board the
two mains of the dynamo being connected to these two bars at one end of each
by means of suitable cable connectors. One of the main bars is made with pro-
jections on one side which projections are bevelled off to allow the brushes as they
are turned round to rise to the top of the bar to make a good contact for one
end of the switch brush. The other contacts of the switch brushes which may
also be castings are bevelled off where the brushes rise on fo them and are pro-
vided with projections to receive the terminal screws under which the end of the
fuses are clamped, the other ends of the fuses being clamped under terminal screws on
to suitable plates at the other end of which plates cable connectors for the external
circuits are clamped down with a nut.
Into the other main bar when only used with single pole switches we screw
terminal screws for the end of the fuses, the other ends being clamped on to
plates similar to and with cable connectors similar to those employed with the
other bar.
All the contact plates on the surface of the board are the same height and are all
flat on the top so that they can be all planted on the board and filed or planed over at
one operation thus making the production exceedingly cheap and simple. To prevent
the brush passing over the surface of the contact plates and falling off the same, we
scrow a flat piece of brass on to the same instead of having a ridge or projection cut
on the bar.
We form the brush in a special manner, viz. : we make it of several strips of sheet
metal which are bent or curved round at suitable angles or curves to fit within cach
other with a space between each. These strips are put together with a washer
between each one so that the brush is solid in the centre and yet each strip is
quite free and elastic, there being a space between each strip, except at the centre,
where the space is filled by the washer, thus each strip of brass in fhe brush is perfectly
free so that it makes a separate and independent contact. When the switch is
arranged so that the brush flies off quickly by means of a spring as in quick break
switches to prevent the loose handle from stopping such quick break by the edge of
the bearing surface of the handle causing too much friction on the outer bearing
surface of the top plate of the brushes we bevel off one or both so that it bears only in
the centre.
We sometimes make the switches double pole in which case both the main bars are
fitted with the projections as described above and with the contact plates at hoth poles.
The switches are materially the same as the one described above with the exception
that instead of having the handle on the same spindle as the brush we put the handle
on a separate spindle in the space between the two main bars. The brushes are con-
nected by a bar or bars having suitable projections thereon in which a part of the
handle fitting engages.
Reference being made to the annexed drawings Fig. 1 is a plan and Fig. 2a side
elevation of a single pole switch board constructed in accordance with this invention

page_text: in which A and B are the two bars of metal in connection with the two poles of
the dynamo by means of the cable connectors C. C. and of these bars one has projec-
tions bevelled as shown at D to enable the brushes to rise easily. The other
contacts as shown at E are also bevelled and have projections F to take the terminal
screws clamping the fuses G the other ends of the fuses being similarly attached
to plates H to which are affixed cable connectors as shown. In the other main bar B
when only single pole we screw terminal screws I for the ends of the fuses G the
other ends of the fuses being attached to plates with connectors as shown and
similar to those described above. Flat pieces of brass Jare screwed to act as stops.
The brush is shown in Fig. 3 having strips of metal K bent or curved with a space
between, and having therein washers L, so that each plate of the brush is separate and
independent in action. In Fig. 4 is shown as a separate detail the bevelled junction
between the head and the top plate of the brush for use in quick break switches. In
Figs. 5 & 6 is shown the double pole arrangement in which similar letters indicate
similar parts to those on the single pole board the additional parts also being shown
riz., the handle on a separate spindle M and the motion conveyed by the bars N
through projections on the handle fitting.
Having now particularly described the nature of our said invention and the manner
in which the same is to be performed we declare that what we claim is:-
--
1. In an electric switch board the use of a main bar so formed as to provide suitable
contact plates for two or more switches substantially as described.
2. In an electric switch board the use of two main bars similarly constructed to
that described in Claim 1, and in combination with two or more double pole switches
substantially as described.
8. The construction of the brush of an electric switch as described and set forth in
Fig. 3.
4. The construction of electric switch boards substantially as described and shown
in Figs. 1, 2, 5, and 6.
1
T
1000