Year: 1898

page_text: I, EDWARD ETHEL GOLD, of Number 64, West Seventy-Seventh Street, Borough
of Manhattan, in the City of New York, United States of America, Manufacturer,
do hereby declare the nature of the said invention to be as follows:-
This invention relates to means for utilizing the heat generated by the passage
of a current cf electricity over a poor or resistant conductor, either as an electric
heater where the purpose is to generate heat, or as a rheostat where the purpose is
to impede the flow of electric current, and the heat necessarily thereby generated
represents such an amount of energy that it is necessary to thoroughly ventilate
the conductor in order to dissipate it.
1 employ for either purpose a resistant wire wound into a coil, which may
be a continuous helix or other equivalent arrangement, and preferably naked or
having only a thin and readily heat conducting covering, in order that the heat
generated in the wire may be readily given off to the air or other fluid surrounding
it.
a
In my Specification filed September 11, 1897, No. 20,923, I have described
various ways of supporting such a resistant coil or helix by supports external
to it, such as an open-work tube around which or within which it is coiled, or
by a support internal to it, such as an enamelled rod placed within it,
said coil or helix being in most instances coiled helically into a
larger or compound helix. My present invention provides other means
for supporting such resistant coil without necessarily coiling it into
compound helix or spiral, or other curved form, it being one of the objects of
my present invention to provide an efficient support for such a resistant coil
when extended in substantially straight direction. My invention also provides
means for supporting such resistant coil when curved or wound into other forms.
According to all the forms of my invention, I prefer to form the coil by winding
a resistant wire continuously around a cylindrical mandrel to form it into a helix
whose cross-section is circular; but this form may be variously departed from,
either by winding on mandrels of other shapes, or by winding first forwardly and
then backwardly, forming what may be termed a zigzag coil, whose
cross section may be circular
or
otherwise. In all cases this resistant
coil is formed of wire having sufficient stiffness or resilience so that the
coil when wound tends somewhat strongly to retain its original form, and resists
any effort to bend or distort it. The coil is also wound with its convolutions
open or spaced apart, preferably to the same extent that they are destined to be
in the complete heater, that is, sufficiently separated to prevent any accidental
deflection of them into contact, which would short-circuit the portion of wire
between the points of contact, and sufficiently separated to afford free spaces for
circulation of air between them to conduct away the heat and keep them cool.
It is a characteristic of all forms of my present invention, that the support
and coil are so relatively conformed that the coil by reason of its resilience shall
have its convolutions or loops of wire, or certain of them, so elastically pressed
against the support as to cause the coil to cling yieldingly upon the support.

page_text: The support may consist of one or more rods or strips arranged either inside
or outside of the coil and touching the same continuously or at certain intervals
only, in order to leave the greater portion of the resistant wire out of contact
with the support and surrounded by air or other fluid for conducting away the
heat.
In one form of my invention, I prefer to construct the support of a straight rod,
of a diameter considerably smaller than the interior of the coil, so that when
placed within the coil it may touch the same cnly tangentially, and elsewhere
than at such tangential points of contact it is out of contact with the wire of the
coil leaving a free intervening space for circulation of air within the coil. The
rod may be of glass or porcelain or other insulating material of sufficient strength,
but I prefer to make it of metal, as a suitably stiff wire, and to insulate it from
the resistant coil by coating it with insulating enamel. The supporting rod and
the coil are relatively conformed in such manner as to cause the convolutions of
the coil to press elastically into firm contact with the rod, the coil being thus
caused to cling thereupon. With a straight rod and straight coil or helix, this
may be done either (1) preferably by winding the coil of the degree of openness
desired, and after applying it on the rod twisting it so as to put it under tortional
.strain sufficient to cause it to tend to adopt a sinuous or helical form, whereby it
is deflected laterally and presses elastically against the rod, touching the latter
at points which rotate spirally around the rod, the ends of the coil
being secured to heads to hold it under tortional strain; or (2) by
compressing the coil endwise upon the rod, the coil being originally
wound more openly than desired in the heater, so that its convolutions
are forced together and held by being fixed to heads on opposite ends of the rod,
so that the coil seeks to escape laterally, and thereby presses itself yieldingly
against the rod so as to touch the latter at points which will usually progress
spirally around the rod; or (3) by deflecting the coil in any manner into sinuous
or helical form, and giving it a set in such form in any way, as by annealing
and tempering it, whereupon when relieved of restraint, it tends to retain its
distorted form, and hence when thrust upon the rod, seeks to resume such dis-
tortion, and hence presses laterally against the rod. Or (4) the coil may be bent
at intervals of a few convolutions, the successive sections thereof being thus thrown
sufficiently out of line with one another, so that when the straight rod is passed
within the thus distorted coil, the latter is forced partly back toward its original
shape, so that its convolutions press elastically and laterally against the rod.
Or (5) the coil may be similarly bent at intervals back and forth, and the rod
thrust within every alternate section but passing exteriorly to the intervening
sections, the deflection being sufficient to cause the latter to press radially against
one side of the rod, while the sections through which it passes press in the con-
trary direction against the opposite side of the rod, whereby the coil clings upon
the rod, the latter being partly interior and partly exterior.
Or the elastic clinging of the coil upon the rod may be effected by varying the
shape of the coil, as for example, (6) by giving the coil a cross-section other
than circular, for example a flattened cross-section, so that its opposite sides shall
press against opposite sides of the rod. Or (7) by distorting the coil from a
circular cross-section as by indenting it on diametrically opposite sides, causing
such opposite points to approach each other and eventually to pass each other, so
that the opposite semi-convolutions cross, and between them the rod is thrust,
so that their effort to return causes them to press yieldingly upon the rod. Or (8)
the coil may be contracted at intervals into close contact with the rod, embracing
it on opposite sides, and between such points of contact the coil may be expanded
to such diameter as to be out of contact with the rod.
Or according to another part of my invention, the relative conformation of the
rod and coil to each other by which the coil clings upon the rod, may be effected
by the distortion of the rod instead of by the distortion of the coil. Thus with
a straight coil, the rod may be (1) bent into a helix whose diameter may equal

page_text: or slightly exceed the internal diameter of the coil, or may be (2) bent into a
zigzag or sinuous form so as to form alternated projections at its opposite sides,
being thereby caused to project beyond the diameter of the straight coil, so that
when the coil is placed over it, the coil is distorted sufficiently to cause it to press
firmly against such salient or projecting portions. By this latter and preferred
construction, the coil is supported at intervals of several convolutions making
tangential contact with one or two convolutions at each salient point of support,
and between such points extending within the coil and wholly out of contact
with its convolutions, whereby the greatest practicable length of wire is supported
with the fewest possible points of contact with its support. The degree of distortion
of the coil that should be produced by the rod, will vary with the stiffness of the
wire in proportion to its weight, and should be sufficient to generate sufficient
tension, so that the weight of the wire which is suspended between two upper
salient contact points, shall not cause it to sag out of contact with the intervening
lower contact point, but on the contrary shall sufficiently exceed the weight of the
wire to maintain a firm upward pressure at the latter point. The degree of tension
necessary will also vary with the extent of vibration or jarring to which the coil
is to be subjected. Or by a modification of the last described construction the
supporting rod may be (3) formed with alternated projections on its opposite sides,
either by forming projections or lumps thereon, or by making short bends in the
rod to constitute such projections, which projections may be directed in two
directions or in four directions or otherwise, and being sufficient in extent to
distort the coil in the manner described. Or as a further modification the rod may
be (4) increased in diameter at intervals forming annular projections which make
a close fit within the coil for a distance of one or two convolutions thereof, with
which these annular projections upon the rod may be in continuous internal
contact, while the portions of coil intervening between each two successive pro-
jections are extended through the air out of contact with the support, in manner
equivalent in effect to alternately increasing and diminishing the diameter of the
coil itself, so that its portions of diminished diameter closely embrace the rod,
while those of increased diameter extend freely through the air out of contact
with it. Such annular projections instead of making continuous circumferential,
contact with one or more convolutions, may be reduced to radial arms at two or
more points, preferably four in each convolution.
According to another part of my invention, the coil by whatever construction
it may be given a disposition to cling upon and be thereby supported by the rod,
is so placed upon the rod that the only tension to which it is subjected is that in
lateral direction due to its distortion by the rod, or to its own distortion, by which
it is made to cling upon the rod. To accomplish this, the coil is wound originally
with the same degree of openness that it is destined to maintain in the finished heater,
so that the coil is wholly free from any tension tending to cause its convolutions
to mutually approach or recede. To prevent any crowding of the coil toward
either end of the rod due to repeated jarring, each end of the coil is fastened
in place, preferably to the rod itself, or to the opposite end heads of the heater.
To fasten it to the rod, I may form a groove, notch or depression in the rod, into
which the wire is caused to enter by pinching it thereinto, or by contracting one
convolution into close engagement with such indented portion of the rod. Or as
a modification thereof, the rod may have a non-conducting washer fixed firmly
on it near each end, and the wire be drawn into a notch in such washer, the rod
being preferably reduced and shouldered to prevent displacement of the washer.
With either of the constructions described, it is only necessary to suitably
support the ends of the supporting rod; and to connect the ends of the resistant
coil to the conductors of a suitable electric circuit, in order to complete the electric
heater. While thus a single coil and rod with suitable supports and connections
5 constitute a complete heater, yet ordinarily I prefer to assemble a plurality of
coils and rods to constitute a single heater, as three, six, nine, or other number,
as circumstances may dictate. I prefer to support the rods by placing them in

page_text: sockets in opposite heads, between which the rods extend in preferably horizontal
direction, and substantially parallel to one another, the heads being preferably of
cathenware, and having recesses in their outer sides within which the electrical
connections are made by binding posts passing through the heads connecting on
their inner sides with the resistant coils, and on their outer sides in said recesses
with the circuit wires. Said recesses are covered by cap plates on the outer
sides of the heads. Preferably the heads are held apart not only by said rods,
but also by a tubular perforated or open-work casing extending between them
and enclosing the rods and coils, while permitting free circulation of air through
the heater; but such casing may be omitted. The heads are drawn together
against the rods, or rods and casing, by a central tie bolt having threaded ends
on which screw nuts, with preferably spring washers between them and the heads;
and one of the rods may itself be utilized as such tie bolt. To prevent rattling
of the rods in their sockets, I may cushion them by wrapping asbestos around
them, or by filling plaster of Paris into the sockets around them, and I may seat
springs in the sockets to press against the rods to allow for varying expansion
and contraction. When it is desired to prevent any possible rotative displacement
of the rods, I prefer to flatten their ends and insert them in correspondingly
flattened sockets in the heads. For a panel heater, the casing consists preferably
of an upright front plate having a grating or air inlet openings along its lower
side, and similar air outlet openings along its upper side, the remainder of the
casing constituted by a hood fastened back of said base plate, porcelain heads being
placed within said hood near its opposite ends, between which heads the rods
extend, carrying the coils, the ends of the rods being socketed in the heads, and
the connections between the ends of the coils being made with binding posts in
the respective heads, from which posts the circuit wires lead out through holes in
said casing.
In a heater containing a plurality of coils, the coils may be connected together
in series, or in multiple or derivation, or in any desired combination of these
two systems. Where different degrees of heat are desired, I subdivide the coils
into groups each containing one, two or more coils, and each group constituting
a separate branch of the circuit, which branch is opened or closed by a switch,
preferably one switch being employed to control all the branches. Thus for two
degrees of heat the coils will be subdivided into two groups; for three degrees,
into three groups, etc. Where several heaters are provided in a single apartment,
or in a single vehicle, it is preferable to control them all alike by one switch, in
which case each branch of the circuit includes serially the coils or groups of
coils pertaining to it in all the successive heaters. To this end for providing
three degrees of heat, I provide only two circuit branches, of which the first includes
the coil or coils of one group in each heater, and the second includes those of
the second group and in derivation therewith those of the third group in each
heater, so that for the first degree of heat the current is turned through the first
branch, and hence traverses the coils of the first group; for the second degree of
heat it is turned only through the second branch, traversing both the second
and third groups; while for the third degree of heat the current is turned through
both branches traversing all three groups in each heater.
According to another part of my invention, I support the coil in a different
manner upon a longitudinal support extending either internally or externally
of the coil. It is characteristic of this support that it engages the coil at mutually
opposed points in the circumference or perimeter thereof, the free portions of
wire between the supporting points being curved through the air so that they
are able to freely expand and contract. The support makes frictional contact
with the coil at mutually opposed points by being so proportioned as to press
the coil out of its natural shape, thereby putting it under transverse tension, so
that its effort to resume its natural shape causes it to maintain a pressure against
the points of support. Preferably the support makes continuous contact with
the coil, although the support may be intermittent, leaving the intervening portions

page_text: of coil freely suspended through the air, as in the construction before described.
In carrying out this part of my invention, I may make the support in various ways,
for example (1) as a strip of preferably insulating material inserted within the
coil and slightly wider than the internal diameter thereof so as to distort the
latter out of its natural or original shape. If the coil was wound as a helix on a
cylindrical mandrel, the strip distorts it slightly out of the true circle into an
ellipse. I prefer to make such strip of sheet metal having longitudinal corru-
gations, its edges being curved or beaded and coated with enamel to insulate the
strip from the coil. Or (2) if further strength is desired, the strip may be wired
at its edges. Or (3) instead of a strip two parallel wires or rods may be employed,
preferably of enamelled metal, extending within diametrically opposite portions
of the coil, and sufficiently separated to distort the same. In either case the coil
instead of being circular, may be flat or of other shapes, and instead of
being a continuous helix may be wound back and forth or otherwise,
so that the coil consists of loops or convolutions of wire which are sufficiently
separated. By a further modification of this construction the support instead of
being interior may be exterior, in which case (4) it may consist of parallel insulat-
ing rods, preferably enamelled wires, engaging diametrically opposite sides of
the coil, and arranged somewhat closer together than the natural diameter thereof,
so that the coil is distorted between them by compression. To prevent the coil
slipping out from between the supporting rods, it is preferably indented at
diametrically opposite sides, and the rods are seated in the indentations. The
coil may be of various shapes in cross-section. Instead of the support having
two parallel portions engaging the coil, it may (5) have three parallel portions
either exteriorly of the coil and engaging indentations therein, or interiorly of
the coil. Or (6) the support may consist of four parallel rods or strips engaging
the coil preferably exteriorly, in which case by arranging the supports in pairs
above and below, the indentation of the coil may be omitted. By a further
modification (7) the supports may be partly exterior and partly interior, as
for example by arranging two rods or strips along the top of the coil, suitably
separated, and one strip or rod within the coil between them, their relative
positioning being such as to distort the coil and thereby maintain firm frictional
engagement. In all the described modifications under this part of my invention,
the loops of wire between the supporting points are curved and free to expand
and contract. A further feature of this part of my invention resides in arranging
the support or supports in a vertical plane or planes, so that the upward circulation
of air through the heater will be to the least possible extent impeded.
An intermittent support according to this part of my invention may be made
by flattening at intervals a central supporting rod so that its flattened portions
constitute strips wide enough to make a tight fit within the coil. Or a com-
bination of supporting strip and central rod may be constructed by folding a
strip of metal against itself and around a rod so as to enclose the latter and form
radial wings extending between diametrically opposite points in the coil, and
making a tight fit therein. Or instead of folding such strip around the rod, its
central portion may be slitted and embossed to alternately opposite sides, so that
the rod may be threaded through such slitted portion, while the top and bottom
edges of the strip are bent and enamelled. This part of my invention enables
a coil of large diameter to be employed, thereby facilitating the construction of
a single-coil heater in which the coil may be concentrically mounted within an
open-work casing. If the central rod is used, it may be employed as the tie bolt
for uniting the opposite heads of the casing, and its projecting threaded end:
may also be utilized as binding posts for uniting the circuit wires to the terminals
of the coil, by suitably insulating the respective wires from the rod.
Where the heater according to this part of my invention is to be arranged
vertically and subjected to jarring such as might displace the coil longitudinally,
I prefer to indent the support where it touches the coil, so that the wire convolutions
will seat in such indentations.

page_text: This part of my invention lends itself readily to the modification of the coil
into a compound helix, in which case the internal supporting strip is itself bent
into a helix resembling the spiral blades of an Archimedes screw, as used for
example in screw conveyors. Or a heater may be built up of several straight
coils extended horizontally with their supports in vertical planes and mounted in
a casing adapted to admit of upward circulation of air through the coils. I
prefer to construct the casing with porcelain heads having upright sockets to
receive the opposite ends of the supporting strips. For a cylindrical heater, I
may arrange five or other number of such coils symmetrically around the center.
For uniting the heads I may connect them by a central tie rod. Such a heater
has preferably a tubular open-work casing to enclose the coils, supported at its
ends by said heads. For a panel heater, I may employ an upright front plate
having gratings or inlet openings at bottom and outlet openings at top, with a
curved back piece or hood forming an internal flue, within which flue three or
more coils may be arranged one above another, their supporting strips extending
horizontally from end to end of the casing.
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London,
Chartered Patent Agents.
I, EDWARD ETHEL GOLD, of Number 64, West Seventy-Seventh Street, Borough
of Manhattan, in the City of New York, United States of America, Manufacturer,
do hereby declare the nature of the said invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to electric heaters in which the heat is generated by the
passage of a current of electricity over a poor or resistant conductor. The heat
generated represents such an amount of energy that it is necessary to thoroughly
ventilate the conductor in order to dissipate it.
For the purpose of my invention I employ a resistant wire wound into a coil which
may be a continuous helix or other equivalent arrangement, and preferably naked or
having only a thin and readily heat conducting covering, in order that the heat
generated in the wire may be readily given off to the air or other fluid surrounding
it.
a
means
a
In my Specification filed September 11, 1897, No. 20,923, I have described
various ways of supporting such a resistant coil or helix by supports external
to it, such as an open-work tube around which or within which it is coiled, or
by a support internal to it, such as an enamelled rod placed within
it, said coil от helix being in most instances coiled helically into
larger or compound helix. My present invention provides other
for supporting such resistant coil without necessarily coiling it into
compound helix or spiral, or other curved form, it being one of the objects of
my present invention to provide an efficient support for such a resistant coil
when extended in substantially straight direction. My invention also provides
means for supporting such resistant coil when curved or wound into other forms.
According to all the forms of my invention, I prefer to form the coil by winding
a resistant wire continuously around a cylindrical mandrel to form it into a helix

page_text: whose cross-section is circular; but this form may be variously departed from,
either by winding on mandrels of other shapes, or by winding first forwardly and
then backwardly, forming what may be termed a zigzag coil, whose
cross-section may be circular or otherwise. In all cases this resistant
coil is formed of wire having sufficient stiffness or resilience so that the
coil when wound tends somewhat strongly to retain its original form, and resists
any effort to bend or distort it. The coil is also wound with its convolutions
open or spaced apart, preferably to the same extent that they are destined to be
in the complete heater, that is, sufficiently separated to prevent any accidental
deflection of them into contact, which would short-circuit the portion of wire between
the points of contact, and sufficiently separated to afford free spaces for circulation
of air between them to conduct away the heat and keep them cool.
It is a characteristic of all forms of my present invention, that the support
and coil are so relatively conformed that the coil by reason of its resilience shall
have its convolutions or loops of wire, or certain of them, so elastically pressed
against the support as to cause the coil to cling yieldingly upon the support.
The support may consist of one or more rods or strips arranged usually inside of the.
coil (though in some instances outside thereof) and touching the same continuously
or at certain intervals only, in order to leave the greater portion of the resistant
wire out of contact with the support and surrounded by air or other fluid for con-
ducting away the heat.
In one form of my invention I prefer to construct the support of a straight rod,
of a diameter considerably smaller than the interior of the coil, so that when
placed within the coil it may touch the same only tangentially, and elsewhere
than at such tangential points of contact it is out of contact with the wire of the
coil leaving a free intervening space for circulation of air within the coil. The
rod may be of glass or porcelain or other insulating material of sufficient strength,
but I prefer to make it of metal, as a suitably stiff wire, and to insulate it from
the resistant coil by coating it with insulating enamel. The supporting rod and
the coil are relatively conformed in such manner as to cause the convolutions of
the coil to press elastically into firm contact with the rod, the coil being thus
caused to cling thereupon. The accompanying drawings, Sheets 1 and 2, show
how I may construct a heater according to this form of my invention. In these
drawings,
Fig. 1 is a side elevation of an elemental heater comprising a single helix and
its interior supporting rod, Fig. 2 being a transverse section thereof;
Fig. 3 includes three transverse sections of the rod, showing at a b and c the
position thereon of the convolution of the coil nearest to the lines 3-a, 3—b
and 3 respectively in Fig. 1.
Fig. 4 is a diagrammatic cross-section;
Fig. 5 is an elevation of one form of helix before placing it upon the rod.
Fig. 6 is an elevation of another form of helix.
Fig. 7 is a sectional elevation of a complete electric heater constructed accord-
ing to my invention; Fig. 8 is a transverse section thereof; Fig. 9 is a transverse
section of the coils and supports therefor showing the mode of connecting the
coils together serially.
Fig. 10 is a fragment of one of the supporting rods, on which are marked the
contact points at which the helical convolutions tangent the support.
Fig. 11 is an oblique elevation of a fragment of the helix showing the preferred
mode of applying stress thereto.
Fig. 12 is an end elevation of the helix after having been twisted in the
manner shown in Fig. 11.
Fig. 13 is an elevation of a modification, of which Fig. 14 is a cross-section.
Figs. 15 and 16 show a further modification.
Figs. 17, 18 and 19 are cross-sections of other modifications.
In all these views A designates the coil or helix of resistant wire, having
sufficient stiffness to retain its helical form; and B is the supporting rod, pre-

page_text: ferably round or cylindrical, though this shape may be departed from, and of
small diameter relatively to the coil, and preferably of a metal rod or wire, insulated
by a coating of enamel.
Preferably both the rod and coil are straight, and to cause the coil to press
against and cling upon the rod I may resort to either of the following means:-
(1) Preferably by winding the coil of the degree of openness desired, as shown
at A in Fig. 6, and after applying it on the rod, twisting it as shown in Fig. 11,
so as to put it under tortional strain sufficient to cause it to tend to adopt a
sinuous or helical form, whereby it is deflected laterally and presses elastically
against the rod, as shown in Figs. 1, 2 and 3, touching the latter at points which
progress spirally around the rod, as shown at in Fig. 10, the ends e of the coil
being secured to heads CC fastened by pins d d to hold it under tortional strain; or
(2) By compressing the coil endwise upon the rod, the coil being originally
wound more openly than desired in the heater, as shown at A¹ in Fig. 6, so that
its convolutions are forced together and held by being fixed to heads on opposite
ends of the rod, so that the coil seeks to escape laterally, and thereby presses
itself yieldingly against the rod so as to touch the latter at points which will
usually progress spirally around the rod; or
(3) By deflecting the coil in any manner into sinuous or helical form, such as
shown in Fig. 5, or in Fig. 12, and giving it a set in such form in any way, as
by annealing and tempering it, whereupon when relieved of restraint, it tends
to retain its distorted form, and hence when thrust upon the rod, seeks to resume
such distortion, and hence presses laterally against the rod; or
(4) The coil may be bent at intervals of a few. convolutions, the successive
sections thereof being thus thrown sufficiently out of line with one another, as
shown in Figs. 13 and 14, so that when the straight rod is passed within the thus
distorted coil, the latter is forced partly back toward its original shape, so that its
convolutions press elastically and laterally against the rod; or
(5) The coil may be similarly bent at intervals back and forth, and the rod
thrust within every alternate section but passing exteriorly to the intervening
sections, as shown in Figs. 15 and 16, the deflection being sufficient to cause the
latter sections to press radially against one side of the rod, while the sections
through which it passes press in the contrary direction against the opposite side
of the rod, whereby the coil clings upon the rod, the latter being partly interior
and partly exterior.
Or the elastic clinging of the coil upon the rod may be effected by varying the
shape of the coil, as for example, (6) by giving the coil a cross-section other than
circular, for example a flattened cross-section, as shown in Fig. 17, so that its
opposite sides shall press against opposite sides of the rod.
the coil from a circular cross-section as by indenting it on diametrically opposite
Or (7) by distorting
sides, causing such opposite points to approach each other and eventually to pass
each other, so that the opposite semi-convolutions cross, and then thrusting the
rod between them, as shown in Figs. 18 and 19, so that their effort to return
causes them to press yieldingly upon the rod. Or (8) the coil may be contracted
at intervals into close contact with the rod, embracing it on opposite sides, and
between such points of contact the coil may be expanded to such diameter as to
be out of contact with the rod, as shown in Fig. 24 of Sheet 5.
Or according to another part of my invention, the relative conformation of the
rod and coil to each other by which the coil clings upon the rod, may be effected
by the distortion of the rod instead of by the distortion of the coil. The application
of this feature of my invention is shown in Sheets 3, 4 and of the drawings, in
which,
Figs. 1 and 2 are elevations looking at right angles to each other illustrating
the preferred construction, both views being partly in mid-section;
Fig. 3 includes three transverse sections a, b and c, taken respectively on the
lines 3-a, 3-6 and 3 in Fig. 2;
Fig. 4 is a diagrammatic cross-section;

page_text: Fig. 5 is an elevation of a fragment of the wire coil or helix before being placed
upon the rod;
Figs. 6, 7 and 8 show a complete heater having three coils, Fig. 6 being a
plan the end portions of which are in horizontal mid-section, Fig. 7 being a vertical
transverse section, and Fig. 8 being an elevation of one of the end pieces or heads.
Fig. 9 is a diagrammatic transverse section of two similar heaters having six
coils and showing their electrical connections.
Figs. 10 to 13 show a panel heater adapted for electric cars, Fig. 10 being a
front elevation with the front plate partly removed, Fig. 11 a transverse section,
Fig. 12 a transverse section with the case removed, and Fig. 13 a fragmentary
horizontal mid-section. Fig. 14 is a diagram illustrating the circuit connections.
The remaining views illustrate modifications. Fig. 15 is a sectional side
elevation of a modification having a spiral or corkscrew-shaped supporting red,
Fig. 16 including four transverse sections thereof on the lines 16-a, 16-6, 16-
and 16- respectively.
Fig. 17 is a sectional elevation showing a modified shape of rod;
Fig. 18 is an elevation of a supporting rod showing a further modified shape,
of which Fig. 19 is a transverse section;
Fig. 20 is a similar transverse section showing the rod having bends or humps
extending in four different directions instead of two;
Fig. 21 is a sectional elevation, and Fig. 22 a transverse section of a further
modification;
Fig. 23 illustrates a modification of Fig. 22;
In carrying out this second part of my invention the coil A of resilient resistant
wire is preferably a straight helix (see Fig. 5). The rod B is the same as in the
first part of my invention, except that it is distorted, to effect the requisite clinging
of the coil upon it, which may be effected in several different ways, namely:
(1) It may be bent into an open helix whose diameter may equal or slightly
exceed the internal diameter of the coil, this modification being shown in Figs. 15
and 16 of Sheet 5.
(2) Or the rod may be bent into a zigzag or sinuous form so as to have alter-
nated projections at its opposite sides, as best shown in Fig. 2 of Sheet 3, where
its projecting or salient portions are lettered respectively dd etc. These salient
portions project beyond the diameter of the coil, as indicated by the dimension .
in Fig. 2, so that when the coil is placed over the rod, the coil is distorted
sufficiently to cause it to press firmly against such salient or projecting portions,
as clearly shown. This, the preferred construction of this part of my invention,
is shown in Figs. 1 to 10 inclusive. With this zigzag or sinuous rod the coil is
supported at intervals of several convolutions, the rod making tangential contact
with one or two convolutions at each salient point d or d, as shown at a and c
in Fig. 3, and between such points extending within the coil and wholly out of
contact with its convolutions, as shown at 6 in Fig. 3, which is a section on the
line 3-6 in Fig. 2. By this means the greatest practicable length of wire is
supported with the fewest possible points of contact with its support. The degree
of distortion of the coil that should be produced by the rod, will vary with the
stiffness of the wire in proportion to its weight, and should be sufficient to generate
sufficient tension so that the weight of the wire which is suspended between two
upper contact points d d shall not cause it to sag out of contact with the inter-
vening lower contact point, but on the contrary shall sufficiently exceed the
weight of the wire to mantain a firm upward pressure at the latter point. The
degree of tension necessary will also vary with the extent of vibration or jarring
to which the coil is to be subjected.
(3) Or by a modification of the last described construction the supporting rod
may be formed with alternated projections on its opposite sides, either by forming
projections or lumps d d thereon, as shown in Fig. 17 (Sheet 5); or by making
short bends in the rod to constitute such projections, as shown in Fig. 18, which

page_text: projections may be directed in two directions, as shown in Figs. 18 and 19, or in
four directions, as shown in Fig. 20, or otherwise, and being sufficient in extent
to distort the coil in the manner described.
(4) Or, as a further modification the rod may be increased in diameter at
intervals, as shown in Fig. 21, forming annular projections pp which make a
close fit within the coil for a distance of one or two convolutions thereof, with
which these annular projections upon the rod may be in continuous internal
contact, while the portions of coil intervening between each two successive pro-
jections are extended through the air out of contact with the support, (in manner
equivalent in effect to alternately increasing and diminishing the diameter of
the coil itself,. as shown in Fig. 24 already referred to, so that its portions of
diminished diameter closely embrace the rod, while those of increased diameter
extend freely through the air out of contact with it).
Such annular pro-
jections instead of making continuous circumferential contact with one or
more convolutions, may be reduced to radial arms at two or more points, pre-
ferably four in each convolution, as shown at pin Fig. 23.
According to another part of my invention, the coil by whatever construction
it may be given a disposition to cling upon and be thereby supported by the rod,
is so placed upon the rod that the only tension to which it is subjected is that in
lateral direction due to its distortion by the rod, or to its own distortion, by which
it is made to cling upon the rod. To accomplish this, the coil is wound originally
with the same degree of openness that it is destined to maintain in the finished heater,
(as already described with reference to coil A of Fig. 6, Sheet 1, and coil A of
Fig. 5 Sheet 3.) so that the coil is wholly free from any stress tending to cause its
convolutions to mutually approach or recede. To prevent any crowding of the coil
toward either end of the rod due to repeated jarring, each end of the coil is
fastened in place, preferably to the rod itself, or to the opposite end heads of the
heater. To fasten it to the rod, I may form a groove, notch or depression in
the rod. as shown at e in Sheet 3, into which groove the wire is caused to enter
by pinching it thereinto, or by contracting one convolution into close engagement
with such indented portion of the rod. Or as a modification thereof. the rod
may have a non-conducting washer fixed firmly on it near each end, and the wire
be drawn into a notch in such washer, the rod being preferably reduced and
shouldered to prevent displacement of the washer.
With either of the constructions described, it is only necessary to suitably
support the ends of the supporting rod, and to connect the ends of the resistant
coil to the conductors of a suitable electric circuit, in order to complete the electric
heater. While thus a single coil and rod with suitable supports and connections
constitute a complete heater, yet ordinarily I prefer to assemble a plurality of
coils and rods to constitute a single heater, as three, six, nine, or other number,
as circumstances may dictate. This is shown in Sheets 1, 3 and 4. I prefer
to support the rods by placing them in sockets f f in opposite heads CC, as
shown in Fig. 7 of Sheet 1 and in Fig. 6 of Sheet 3, between which heads the
rods extend in preferably horizontal direction, and substantially parallel to one
another, the heads being preferably of earthenware, and having recesses in
their outer sides within which the electrical connections are made by binding
posts EE passing through the heads, connecting on their inner sides with the
resistant coils, and on their outer sides in said recesses with the circuit wires ww.
Said recesses are covered by cap plates FF on the outer sides of the heads. Pre-
ferably the heads are held apart not only by said rods, but also by a tubular per-
forated or open-work casing I) extending between them and enclosing the rods
and coils, while permitting free circulation of air through the heater: but such
casing may be omitted. The heads C C are drawn together against the rods, or
rods and casing, by a central tie bolt B₁ having threaded ends on which screw
nuts, with preferably spring washers between them and the heads; and
one of the rods B may itself be utilized as such tic bolt. To prevent rattling of
the rods in their sockets, I may cushien them by wrapping asbestos around them,

page_text: as shown at f Fig. 6 Sheet 3, or by filling plaster of Paris into the sockets around
them, as at f Fig. 6 Sheet 3, and I may seat springs in the sockets to press
against the rods to allow for varying expansion and contraction, as shown at i,
Fig. 7 Sheet 1. When it is desired to prevent any possible rotative displacement
of the rods, I prefer to flatten their ends and insert them in correspondingly
flattened sockets in the heads, as shown in Sheet 3.
For a panel heater, I prefer to employ the construction shown in Figs. 10 to 13,
Sheet 4, where the casing consists preferably of an upright front plate G having
a grating or air inlet openings n along its lower side, and similar air outlet open-
ings n along its upper side, the remainder of the casing being constituted by a
hood G fastened back of said front plate, porcelain heads C₁ C being placed
within said hood near its opposite ends, between which heads the rods B B extend,
carrying the coils, the ends of the rods being socketed in the heads, and the con-
nections between the ends of the coils being made with binding posts r r in the
respective heads, from which posts the circuit wires lead out through holes m m
in said casing.
In a heater containing a plurality of coils, the coils may be connected together
in series, or in multiple or derivation or in any desired combination of these
two systems. Where different degrees of at are desired, I subdivide the coils
into groups each containing one, two or more coils, and each group constituting
a separate branch of the circuit, which branch is opened or closed by a switch,
preferably one switch being employed to control all the branches. Thus for two
degrees of heat the coils will be subdivided into two groups; for three degrees,
into three groups, etc. Fig. 9, Sheet 4, shows in cross-section two heaters having
cach six coils, divided into two groups of three coils each in two branch circuits c¹
Where several heaters are provided in a single apartment, or in a single vehicle,
it is preferable to control them all alike by one switch e, in which case each branch w
2 of the circuit includes serially the coils or groups of coils pertaining to it in
all the successive heaters. To this end for providing three degrees of heat, I
provide, as shown in Fig. 14 Sheet 4, (which is a diagram of the circuit con-
nections of Figs. 10 to 13) only two circuit branches, of which the first w includes
the coil or coils (1, 2, 3) of one group in each heater, and the second includes
those (4, 5, 6) of the second group and in derivation therewith those (7, 8, 9) of the
third group in each heater, so that for the first degree of heat the current is turned
by switch through the first branch c¹, and hence traverses the coils of the first
group for the second degree of heat it is turned only through the second branch w³,
traversing both the second and third groups; while for the third degree of heat
the current is turned through both branches w¹ and w² traversing all three groups
in each heater.
According to another part of my invention, I support the coil in a different
manner upon a longitudinal support extending either internally or externally
of the coil. It is characteristic of this support that it engages the coil at mutually
opposed points in the circumference or perimeter thereof, the free portions of
wire between the supporting points being curved through the air so that they
are able to freely expand and contract. The support makes frictional contact
with the coil at mutually opposed points by being so proportioned as to bear firmly
against the coil so that it tends to or may press the coil out of its natural shape,
thereby putting it under transverse tension, so that its effort to resume its natural
shape causes it to maintain a pressure against the points of support. Preferably
the support makes continuous contact with the coil, although the support may be
intermittent, leaving the intervening portions of coil freely suspended through
the air, as in the construction before described.
Several applications of this part of my invention are shown in Sheets 6, 7, 8
and 9 of the accompanying drawings, wherein,
Fig. 1 is a cross-section of the resistant coil and its support;
Fig. 2 is a side elevation of Fig. 1, partly in section;
Fig. 3 is a transverse section showing the preferred construction;

page_text: Fig. 4 is a diagrammatic transverse section;
Figs. 5, 6 and 7 are transverse sections illustrating variations of the construction
shown in Fig. 3, Fig. 8 being a side view of Fig. 7;
Fig. 9 is a sectional elevation of a complete electric heater embodying my
invention, its end portions being shown in vertical mid-section;
Fig. 10 is a transverse section thereof:
Fig. 11 is a fragmentary horizontal section on the line 11-11 in Fig. 10;
Fig. 12 is a transverse section of an upright type of heater embodying my
invention;
Fig. 13 is a vertical mid-section showing my invention as applied in the con-
struction of a heater having a compound helix of resistant wire;
Fig. 14 is a diagram answering to Fig. 4 but showing a modified construction;
Figs. 15 to 22 inclusive are transverse sections showing constructions embodying
the principle illustrated in Fig. 14;
Figs. 23 and 24 are transverse sections of further modifications, and Fig. 25 is
a side elevation of Fig. 24;
Eig. 26 is a sectional side view of another modification, of which Figs. 27
and 28 are transverse sections cut on the dotted lines 27 and 28 respectively;
Fig. 29 is a fragmentary side elevation of another modified construction, of
which Fig. 30 is a transverse section;
Fig. 31 is a transverse section of a single coil heater and its casing;
Fig. 32 being a longitudinal mid-section of one end portion thereof.
In carrying out this part of my invention, I may make the support B for the
coil A in various ways, of which I will proceed to describe the examples shown:-
(1) The support may be a strip of preferably insulating material inserted
within the coil and which should be slightly wider than the internal diameter
thereof so as to distort the latter out of its natural or original shape. Such strip B
is shown in Figs. 1 and 2. If the coil A was wound as a helix on a cylindrical
mandrel, the strip may distort it slightly out of the true circle into an ellipse.
This is shown diagrammatically in Fig. 4, which also shows in dotted lines how
the expansion of the wire when heated is taken up within each semi-convolution
by the swelling of the loop of wire into a larger curve.
I prefer to make the strip B as shown in Fig. 3, of sheet metal having longi-
tudinal corrugations a, its edges being curved or beaded and coated with
enamel to insulate the strip from the coil. A similar construction is shown in
Fig. 5.
Or (2) if further strength is desired, the strip may be wired at its edges, as
shown in Fig. 6, where c c are the wires.
Or (3) instead of a strip two parallel wires or rods may be employed,, as shown
in Figs. 7 and 8, where ce are the rods, preferably of enamelled metal, extending
within diametrically opposite portions of the coil, and sufficiently separated to
distort the same. This differs from Fig. 12 of Sheet 4 of my said Specification
No. 20,923 of 1897, in that the support distorts the coil, so that the latter clings
on the supporting rods, which is not the case in said Fig. 12.
The coil A instead of being circular, may be flat (as shown in Fig. 23) or of
ether shapes, and instead of being a continuous helix may be wound back and
forth as shown in Figs. 24 and 25, or otherwise, so that the coil consists of loops
or convolutions of wire which are sufficiently separated.
By a further modification of this construction the support instead of being
interior may be exterior, in which case (4) it may consist of parallel insulating
rods, preferably enamelled wires c c, as shown in Fig. 15, engaging diametrically
opposite sides of the coil, and arranged somewhat closer together than the natural
diameter thereof, so that the coil is distorted between them by compression, as
shown in the diagram Fig. 14. To prevent the coil slipping out from between
the supporting reds, it is preferably indented at qq on diametrically opposite sides.
and the rods are seated in the indentations. The coil may be of various shapes in
cross-section, examples of which are shown in Figs. 16 and 17. Instead of the

page_text: support having two parallel portions engaging the coil, it may (5) have three
parallel portions, e.ther exteriorly of the coil and engaging indentations therein,
is shown in Fig. 20, or interiorly of the coil. Fig. 20 differs from the construction
shown in Fig. 18 of Sheet 5 of my said Specification No. 20,923 of 1897, in that
the coil in the latter was simply confined within three rods, whereas in my present
Fig. 20 the coil is compressed against the rods, so that it presses outwardly against
them, and hence clings to them, and also in that the coil is indented to receive
the rods.
Or (6) the support may consist of four parallel rods or strips engaging the col
preferably exteriorly, as shown with reds in Fig. 18 or with strips in Fig. 19, in
which case by arranging the supports in pairs above and below, the indentation
of the coil may be omitted. By a further modification (7) the supports may be
partly exterior and partly interior, as for example by arranging two rods or
strips along the top of the coil, suitably separated, and one strip or rod s
within the coil between them, as shown in Fig. 21, their relative positioning being
preferably such as to slightly distort the coil and thereby maintain firm frictional
engagement.
In all the described modifications under this part of my invention, the loops of
wire between the supporting points are curved and free to expand and contract.
A further feature of this part of my invention resides in arranging the support or
supports in a vertical plane or planes, as shown in Figs. 1 to 8, 19, 21 and 24, so
that the upward circulation of air through the heater will be to the least possible
extent impeded.
An intermittent support according to this part of my invention may be made
by flattening at intervals a central supporting rod so that its flattened portions
constitute strips wide enough to make a tight fit within the coil, as shown in
Figs. 26 to 28. Or a combination of supporting strip and central rod may be
constructed by folding a strip of metal against itself and around a rod t so as
to enclose the latter and form radial wings extending between diametrically
opposite points in the coil, and making a tight fit therein, as shown in Figs. 29
and 30. Or instead of folding such strip around the rod, its central portion may
be slitted and embossed to alternately opposite sides, so that the rod may be
threaded through such slitted portion, as shown in Figs. 31 and 32, while the
top and bottom edges of the strip are bent and enamelled. This part of my
invention enables a coil of large diameter to be employed, thereby facilitating the
construction of a single-coil heater in which the coil may be concentrically mounted
within an open-work casing, as shown in Figs. 31 and 32. If the central rod
is used, it may be employed as the tie bolt for uniting the opposite heads C of
the casing, and its projecting threaded ends may also be utilized as binding posts
for uniting the circuit wires to the terminals of the coil, by suitably insulating the
respective wires from the rod, as shown at u, Fig. 32.
Where the heater according to this part of my invention is to be arranged
vertically and subjected to jarring such as might displace the coil longitudinally,
I prefer to indent the support where it touches the coil, so that the wire convolutions
will seat in such indentations, as shown at the right-hand portion of Fig. 2.
This part of my invention lends itself readily to the modification of the coil
into a compound helix, in which case the internal supporting strip is itself bent
into a helix resembling the spiral blades of an Archimedes screw, as used for
example in screw conveyers, this being shown in Fig. 13. Or a heater may be
built up of several straight, coils extended horizontally with their supports in
vertical planes and mounted in a casing adapted to admit of upward circulation
of air through the coils, as shown in Figs. 9 to 12. I prefer to construct the
casin with porcelain heads CC having upright sockets to receive the opposite
ends of the supporting strips B B. For a cylindrical heater, I may arrange five or
other number of such coils symmetrically around the center, as shown in Figs. 9, 10
and 11. For uniting the heads I may connect them by a central tie rod 9. Such a
heater has preferably a tubular openwork casing 1) to enclose the coils,"
supported

page_text: at its ends by said heads CC. For a panel heater, I may employ an upright front
plate F, Fig. 12, having gratings or inlet openings m, at bottom, and outlet open-
ings n at top, with a curved back piece or hood p forming an internal flue, within
which flue three or more coils may be arranged one above another, their supporting
strips being in vertical planes and extending horizontally from end to end of the
casing.
Having now particularly described and ascertained the nature of my said inver-
tion, and in what manner the same is to be performed, I declare that what I claim
is:―
1. The described electric heater comprising an open resilient coil of resistant
wire, and a support therefor extending longitudinally thereof, and adapted to
permit free circulation of air through the coil, the coil and support being relatively
conformed and proportioned so that the coil is subjected to stress causing its
loops or convolutions to press laterally against the support, whereby the coil clings
yieldingly upon the support independently of the direction in which the com-
bined coil and support extend, whereby the construction is applicable to a sub-
stantially straight coil which shall be free from vibration or displacement, in
essentially the manner set forth.
2. The described electric heater wherein the resilient resistant coil is put under
stress and caused to cling on the longitudinal support by being distorted by the
support out of its natural shape, in essentially the manner set forth.
3. The described electric heater comprising an open resilient coil of resistant
wire, and a support therefor consisting of a stiff rod passing through loops of the
coil, the combined rod and coil extended in substantially straight direction, and
the wire of the coil touching the rod at intervals, looped through the air out of
contact with the rod between its touch points, and pressing elastically against
different sides of the rod, so as to cling thereon, in essentially the manner set
forth.
4. The described electric heater wherein the resilient resistant coil is put under
stress and caused to cling on its supporting rod, by imparting distortion to the coil,
whereby a straight rod may be used, substantially as described with reference for
example to Figs. 1 to 19 of Sheets 1 and 2.
5. The described electric heater wherein the resilient resistant coil is put
under stress and caused to cling on its supporting rod, by twisting the coil to give
it torsional stress, substantially as described with reference for example to Figs. 1
to 12 of Sheets 1 and 2.
6. The described electric heater wherein the resilient resistant coil is put under
stress and caused to cling on its supporting rod, by distorting said rod sufficiently
to distort the coil, substantially as described with reference for example to Figs. 1
to 5 of Sheet 3 and Figs. 15 to 20 of Sheet 5.
7. The described electric heater wherein the resilient resistant coil is put under
stress and caused to cling on its supporting rod, by forming the rod of zigzag or
sinuous form, or with alternated projections on opposite sides, substantially as
described with reference for example to Figs. 1 to 5 of Sheet 3, and Figs. 17 to 20
of Sheet 5.
8. The described electric heater comprising a coil of resilient resistant wire
combined with a supporting rod extended within said coil, said coil and rod
relatively conformed to make contact only at intervals longitudinally of the coil,
the convolutions of the latter between the contact points being extended through
the air out of contact with the rod, substantially as described with reference for
example to Figs. 1 to 5 of Sheet 3, and Figs. 17 to 24 of Sheet 5.
9. An electric heater comprising a coil of resilient resistant wire combined
with a supporting rod extended within said coil, the coil wound with its con-
volutions of the degree of openness required in the heater, and applied upon the
rod without longitudinal stress so that its convolutions are free from any tendency
to vary their relative spacing, to the effect set forth.

page_text: 10. The described electric heater comprising a coil of resilient resistant wire
combined with a supporting rod extended within it, said coil and rod relatively
conformed to cause the coil to cling upon the rod, and the wire at the opposite
ends of the coil fastened upon the rod to prevent longitudinal displacement, sub-
stantially as set forth.
11. The described electric heater wherein the resilient resistant coil has a longi-
tudinal internal support, and its individual convolutions are distorted to exert
pressure against opposite sides of such support, in substantially the manner de-
scribed with reference for example to Figs. 17 to 19 of Sheet 2, or Figs.
of Sheet 6, or 23 to 32 of Sheets 8 and 9.
to S
12. The utilization as such internal support of Claim 11, of a strip wide enough
to cross the coil and afford frictional engagement with it, and arranged preferably
in a vertical plane substantially as described with reference for example to Figs. 1
to 6 of Sheet 6.
13. The supporting strip of Claim 12 formed of sheet metal, longitudinally
corrugated to stiffen it, having convex edges, and enamelled to insulate it from
the resistant wire, substantially as described with reference for example to Figs.
and 5 of Sheet 6, and Figs. 29 to 32 of Sheet 9.
14. The internal support of Claim 11 having depressions on its opposite sides
or edges to receive the successive convolutions of the coil, substantially as described
with reference for example to Fig. 2 of Sheet 6.
15. The described electric heater wherein the resilient resistant coil is supported
by two or more longitudinal rods, by which the individual convolutions are
sufficiently distorted to cause them to press frictionally against such rods, whether
the rods are internal, as shown for example in Figs. 7 and 8 of Sheets 6. or external
as shown for example in Figs. 14 to 20 of Sheet S, or partly internal and partly
external, as shown in Fig. 21 of Sheet S.
16. In an electric heater, the provision of any of the forms of coil and support
herein described with a casing comprising end heads upholding the longitudinal
support or supports, substantially as described.
17. In an electric heater, the combination of a plurality of longitudinal parallel
supports, resistant coils caused to cling thereon as described, and opposite end
heads having recesses receiving the ends of said supports, with means for holding
said heads in firm engagement with the supports, substantially as described with
reference for example to Figs. 7 and 8 of Sheet 1, Figs. 6 to 13 of Sheets 3 and 4,
and Figs. 9 to 12 of Sheet 7.
18. In an electric heater. the combination of a plurality of longitudinal parallel
supports, resistant coils caused to cling thereon as described, and opposite end heads
having recesses receiving the ends of said supports, with an openwork casing
extending between the heads and enclosing the supports and coils, and means,
such as a tie-rod or bolt, for drawing the heads together to hold them in firm
engagement with the casing and supports, substantially as described with reference
for example to Figs. 7 and 8 of Sheet 1, Figs. 6 and 7 of Sheet 3, and Figs. 9.
and 10 of Sheet 7.
19. A panel electric heater comprising the combination of a plurality of longi-
tudinal parallel supports, resistant coils caused to cling thereon as described, and
opposite end heads having recesses receiving the ends of said supports, with a
casing having a front plate with air inlet openings below and outlet openings
above, and a curved back plate or hood, adapted to permit an upward circulation
of air across the supports and through the coils, substantially as described with
reference for example to Figs. 10 to 13 of Sheet 4 and Fig. 12 of Sheet 7.
20. The described mode of connecting a plurality of coils in a single heater
casing for giving one, two or three degrees of heat, controllable by a single
switch, which may control likewise a series of heaters having their coils so con-
nected, substantially as described with reference for example to Fig. 14 of Sheet 4.
21. An electric heater comprising a single straight coil, a longitudinal support
within it, and a tubular openwork casing enclosing said coil, with end heads

page_text: drawn against said casing and held to said support, substantially as described with
reference for example to Figs. 31 and 32 of Sheet 9.
1
Ու 18 til 10900
J. C. MEWBURN & ELLIS,
55, and 56, Chancery Lane, London,
Chartered Patent Agents.