Year: 1885

page_text: We, OTWAY EDWARD WOODHOUSE, and FREDERICK LAWRENCE RAWSON, of
No. 11 Queen Victoria Street, in the City of London, Electrical Engineers, and
WILLIAM WHITE of 15 St. Dunstan Road, West Kensington, in the County of
Middlesex, Instrument maker, do hereby declare the nature of this invention to
be as follows :—
Our invention relates to apparatus for completing and breaking electric circuits
in a simple and efficient manner, with which may be combined a safety fuze for
automatically breaking the circuit when the current is in excess of any desired
amount.
Our device consists of a single or double metallic tube, which may be circular,
square, or of other desired shape, called the sliding tube, split at one end, called
the contact end, which slides within another accurately fitting metallic tube or
tubes, called the guide tube. This guide tube is mounted on a metal standard
fixed to the base of the instrument, and which forms or is connected to one of the
terminals of the instrument. The sliding tube, when pushed through the guide
tube by means of a suitable handle, makes contact in one of the following ways;
by the contact-end sliding into or over a tube, or both into and over a tube fixed
on a standard of metal which is connected to or forms one of the terminals, and
thus connecting this terminal and the other terminal connected to or formed by the
standard to which the guide tube is fixed; or by the contact end sliding between or
over two segments of tube fixed to standards insulated from one another connected
to or forming the terminals of the instrument, both segments accurately fitting
part of either the inside or the outside of the sliding tube.
If the circuit is completed in the latter method we make two slots opposite to
one another in the contact end of the sliding tube, so as to divide it into two
segments similar and in corresponding positions to the segments of tubes between
which the contact end makes connection. This arrangement prevents the contacts
being connected by an are on drawing out the sliding tube, and gives a double
break greatly reducing the amount of motion of the tube required to break circuit.
The sliding tube may be prevented from turning by any suitable arrangement,
such as a pin fixed in the guide tube and sliding in a slot in the sliding tube.

page_text: Those portions of the various tubes where contact is made, may conveniently be
split so that a springy and more accurate contact is obtained; and we sometimes
arrange that either the contact end of the sliding tube is made of two tubes, one
of rather larger diameter than the other, and between which enter the tube, or
portions of tube on to which the contact tube is pushed, or vice versâ; by this
arrangement the sparking may be always made to take place on one of the tubes
which is fixed so as to be easily replaced when worn out.
.
Instead of making the spark at break of contact take place on the metallic
portions of the switch, we sometimes place in the sliding tube a carbon rod which
is pushed forward by a spring against another_carbon rod or block in the other
contact tube to such a distance that this carbon contact is not broken until after
the break between the metallic portions, and so all the arcing takes place on the
carbon, which is easily replaceable.
In some cases we place a spring inside or outside the sliding tube which forcibly
withdraws this tube from the contacts, when a catch is released, or the sliding
tube drawn back.
With the preceding device we may combine a flat plate of vulcanized fibre or
other suitable insulating material, to one side of which is fastened a plate of metal
of the same shape, preferably lead or tin, called the fuze. The plates are of
rectangular shape reduced in breadth midway between the ends and with two
transverse slots extending partly across near the ends. These slots are slightly
larger in breadth than the diameter of two screws with heads, whose under
shoulders are flat and of about the same diameter as the breadth of the fuze, and
which screw into two metallic plates raised above and fixed to the base of the
instrument, and which may form the connection between either of the standards
and its terminal in the before mentioned switch. The centres of the screw holes
are the same distance from one another as the centres of the transverse slots in the
fuze, and the fuze is clamped between the two screw heads and these two raised
metallic plates, the transverse slots enabling it to be withdrawn or replaced by
unscrewing the screws a short distance. The metal plate on the fuze is made of
such a thickness that it melts when the current reaches a pre-arranged amount,
thus automatically breaking the circuit as is well understood.
Dated th Jon of Desemba 1905

page_text: :
We, OTWAY EDWARD WOODHOUSE, and FREDERICK LAWRENCE RAWSON, of
No. 11 Queen Victoria Street, in the City of London, Electrical Engineers, and
WILLIAM WHITE, of 15 St. Dunstan Road, West Kensington, in the County of
Middlesex, Instrument Maker, 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 apparatus for completing and breaking electric circuits
in a simple and efficient manner, with which may be combined a Safety Fuze for
automatically breaking the Circuit when the current is in excess of any desired
amount.
Our device consists of a single or double metallic tube which may be circular,
square, or of other desired shape, called the sliding tube, split at one end called
the contact end, which slides within another accurately fitting metallic tube or
tubes, called the guide tube. This guide tube is mounted on a metal standard
fixed to the base of the instrument and which may form or may be connected to
one of the terminals of the Instrument. The sliding tube, when pushed through
the guide tube by means of a suitable handle makes contact in one of the following
ways, by the contact end, (when the sliding tube is single) sliding into or over a
metallic tube called a contact tube, or when the sliding tube is double, both into
and over a contact tube fixed on a standard of metal which is connected to or forms
one of the terminals and thus connecting this terminal and the other terminal
connected to or formed by the standard to which the guide tube is fixed or by the
contact end sliding between or over or both between and over, two segments of
metallic tube called contact tubes fixed to standards insulated from one another
connected to or forming the terminals of the instrument, both segments accurately
fitting part of either the inside or the outside of the sliding tube.
. If the circuit is completed in the latter method, we make two slots opposite to
one another in the contact end of the sliding tube so as to divide it into two
segments similar and in corresponding positions to the segments of tubes between
which the contact end makes connection. This arrangement prevents the contacts
being connected by an arc or drawing out the sliding tube and gives a double break
greatly reducing the amount of motion of the tube required to break circuit. The
sliding tube may be prevented from turning by any suitable arrangement, such as
a pin fixed in the guide tube and sliding in a slot in the sliding tube. Those
portions of the various tubes where contact is made may conveniently be split, so
that a springy and more accurate contact is obtained; and we sometimes arrange
that either the contact end of the sliding tube is made of two tubes, one of rather
larger diameter than the other, and between which enter the tube or portions of
tube on to which the contact tube is pushed, or vice versa; by this arrangement
the sparking may be always made to take place on one of the tubes which is fixed
so as to be easily replaced when worn out. Instead of making the spark at break
of contact take place on the metallic portions of the switch, we sometimes place

page_text: in the sliding tube a carbon rod which is pushed forward by a spring against
another carbon rod or block in the other contact tube to such a distance that this
carbon contact is not broken till after the break between the metallic portions, and
so all the arcing takes place on the carbon which is easily replaceable. In some
cases we place a spring inside or outside the sliding tube which forcibly withdraws
this tube from the contacts when a catch is released or the sliding tube drawn
back.
With the preceding device we may combine a flat plate of vulcanized fibre or
other suitable insulating material to one side of which is fastened a plate of metal
of the same shape, preferably lead or tin called the fuze. The plates are of
rectangular shape, reduced in breadth midway between the ends, and with two
transverse slots extending partly across near the ends. These slots are slightly
larger in breadth than the diameter of two screws with heads or nuts whose under
shoulders are flat and of about the same diameter as the breadth of the fuze and
which screw into two metallic pieces of any shape, flattened on top and raised above
and fixed to the base of the instrument and which may form the connection
between either of the Standards and its terminal in the before mentioned switch.
The centres of the screw holes are the sanie distance from one another as the
centres of the transverse slots in the fuze, and the fuze is clamped between the
two screw heads and these two raised metallic plates, the transverse slots enabling
it to be withdrawn or replaced by unscrewing the screws a short distance. The
metal plate on the fuze is made of such a thickness that it melts when the current
arranges a prearranged amount, thus automatically breaking the circuit as is well
understood.
And in order that our invention may be the better understood, we now proceed
to describe the same in relation to the drawings hereunto annexed, reference being
had to the letters and figures marked thereon. Like letters refer to similar parts
throughout the drawings.
Figure 1 is a sectional elevation, and Figure 2 is a plan of one form of our tube
switch.
Figure 3 is a sectional elevation of a modified form.
Figure 4 is a sectional elevation, and Figure 5 is a plan of a further modified
form.
'
Figures 6 and 7 are an elevation and plan respectively of the Automatic Circuit
breaking device.
In Figures 1 and 2, the terminals are connected to the guide tube, and contact
tube combined with our automatic circuit breaking device. a. is. the contact end
of the sliding tube which is double and slides within the guide tube b, which is
fixed in the standard c. This standard is connected by the metallic plate, d to the
terminal g¹; e is the contact tube fixed in the metallic standard f; g is a terminal
which is connected to f. by our automatic circuit breaking device, the outline of
which is shown at h in figure 2 by dotted lines, and in figure 3, g and fare
flattened above to receive the automatic circuit breaking device which is screwed
under the shoulders of the nuts i and k. The whole is planted on the insulating
base, is a handle to the push tube for convenience.
Figure 3 shows our tube switch and automatic circuit breaking device combined
with a carbon break as described, m is a piece of carbon fixed in the tube e, n is a
piece of carbon fixed in metallic piece o, and pushed forward by a spring p. The
carbons thus make first and last contact before and after the contact of the metallic
tubes, and thus receive what sparking may occur.
In figures 4 and 5 w is á pin, sliding in the slot c, the spring p'in addition to
pushing the sliding tube up, tends to twist the sliding tube into a position other
than that shown, so that when pushed home it rotates and the pin w holes it fast
6. el are the two contact tubes which are connected by the sliding tube, y is a slot
in the contact end of the sliding tube corresponding in size and position with the
separation space between e. and es is the wooden cover which supports a collar
or guide b:
L

page_text: In figures 6 and 7 a is a sheet of. vulcanized fibre or other suitable insulator
which is narrowed at d. d; b is a sheet of tin or other metal of the same shape,
completely covering the underside of the fibre and held by its ends being turned
up over the upper side; ell el are slots to receive the screws, the heads or nuts of
which clamp the device in position.
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:-
1st. The construction of a switch or electrical contact breaker consisting of a
push tube sliding in a guide tube and making contact by a single or double split
orifice with another fixed tube fitting accurately into, or both into and over, the
said sliding tube, as and for the purposes substantially as described.
2nd. The combination of a sliding tube contact breaker with a spring pressed
carbon projecting block in or on the sliding tube and a similar projecting metal or
carbon block on the fixed contact, to determine the last and first contacts on the
said carbon blocks, substantially as and for the purposes described.
3rd. The modified construction of switch or electrical contact breaker consisting
of a sliding push tube, accurately fitting over or into two fixed segments of tube
insulated from one another, the slot in the sliding tube coinciding at make and
break of contact with the spaces between the fixed segments, as and for the
purposes substantially as described.
4th. The combination of the switches as claimed in claims 1,
recoil spring automatically breaking contact when the sliding tube is
any suitable catch.
and 3 with a
released from
and 4 of an
5th. The combination with a switch as claimed in claims 1, 2,
automatic circuit breaking device consisting of a piece of insulating material
covered with a thin coating of metallic material, such as tin foil, and placed in any
convenient part of the circuit, so that it will break circuit automatically on the
current reaching any desired limit, substantially as described.
2
1000
FELL & WILDING,
1, Queen Victoria Street, London, E.C.,
Agents for the Applicants.