IMPROVEMENTS IN LININGS FOR VENT FLUES OR CHIMNEYS, AND IN APPARATUS TO BE USED IN THEIR CONSTRUCTION
Year: 1882

page_text: LETTERS PATENT to Thomas Fraser, of the City and County of Aberdeen,
North Britain, for an Invention of "IMPROVEMENTS IN LININGS FOR
VENT FLUES OR CHIMNEYS, AND IN APPARATUS TO BE USED IN THEIR
CONSTRUCTION."
PROVISIONAL SPECIFICATION left by the said Thomas Fraser at the Oflice
of the Commissioners of Patents on the 10th February 1882.
THOMAS FRASER, of the City and County of Abordeen, North-Britain.
"IMPROVEMENTS IN LININGS FOR VENT FLUES OR CHIMNEYS, AND IN APPARATUS
TO BE USED IN THEIR CONSTRUCTION."
This Invention relates to certain improvements in linings for vent flues or
chimneys designed to prevent or diminish the adhesion of soot thereto, and thereby
to save time, trouble, and annoyance in cleaning such flues or chimneys. Vont
linings as hitherto made are formed of ordinary red clay or fire-clay into short
tubes which are smooth on the internal and external surface, and with the use of
such linings it is found that soot firmly adheres to the inside; but by the present
improvements, the internal surface of such linings is serrated or formed with
annular corrugations or ridges and grooves, which are formed while the clay tubes
are soft by means of indented or saw-like boards or combs caused to revolvo
within the clay tubes, and thereby to scrape or form the internal surface with
serrations.
In a modification of apparatus suited for this purpose, the indented board is
carried on a crank which is by preference jointed so that vent linings of oval or
similar cross section as well as cylindrical tubes may be operated on. The centre
pin or stud on which the crank turns may be fitted in a table or board, on or
over which the vent tube is placed with the crank and comb board within it.
Rotatory motion may be imparted to the crank, or the board caused to revolve by
means of a handle on it operated by an attendant.
Other equivalent means may be employed to form the corrugated internal
surface on the vent linings, as for example, by causing the clay tubes to rotate
round a stationary indented board; or the tubes may be formed by pressing
out of a pipe machine on a collapsible core whose surface is formed with corrugations
or alternate ridges and hollows, somewhat like the threads of a screw.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Fraser in the Great Seal Patent Office on the 8th August
1882.
-
THOMAS FRASER, of the City and County of Aberdeen, North-Britain.
"IMPROVEMENTS IN LININGS FOR VENT FLUES OR CHIMNEYS, AND IN APPARATUS
TO BE USED IN THEIR CONSTRUCTION."
My said Invention relates to certain improvements in linings for vent flues or
chimney's, designed to prevent or diminish the adhesion of soot thereto, and thereby
to save time, trouble, and annoyance in cleaning such flues or chimneys. Vent
linings as hitherto made are formed of ordinary red-clay, or fire-clay into short
tubes which are smooth on the internal and external surface, and with the use of
such linings it is found that soot firmly adheres to the inside. But by the present
improvements of this Invention, the internal surface of such linings or vents, is
serrated or formed with annular corrugations, or ridges and grooves; which are or
may be formed while the clay tubes are soft, by means of indented or saw-like
boards or combs caused to rotate, and rub, work, or scrape within the clay tubes,
and thereby form serrations all round the interual circumference and surface.
And in order that the full nature and novelty of my said Invention, and the
mode and means of performing or putting the same into effect or practice may be
properly understood, I shall now proceed to describe the Figures on the Sheet of
Drawings which I have hereunto appended for that purpose, the same reference
letters indicating-the-same-or-like parts where they are shown.
Figure 1 shows a full size sectional elevation, and Figure 2 a corresponding plan
of a vent lining A as in the act of being made according to the improvements with
internal annular serrated or corrugated surfaces, of my said Invention, and one
arrangement of my improved mechanism or appliances for forming or making the
said internal annular serrated surfaces.
Referring to these Figures 1 and 2, A represents an oval shaped vent lining, as
being turned or run up vertically out of the soft plastic clay, upon the top of a
horizontal elliptical revolving potter's wheel W, so far much as is done in making
the ordinary cheapest red-clay linings for chimneys; but instead of making them
plain or smooth on the inside surface, the same as on the outer surface, I, by the
improvements of this Invention make them serrated annularly round the inner
surface, as shown at a, a', with sharp angled ridges a, and grooves or flutes a',
leaving the sharp edged ridges a between them. In this way of turning up the
vent linings A on a potters wheel W, and of various sizes, either oval or elliptical
as shown in sharp black lines in these Figures 1 and 2, or round, as shown dotted in
plan on the right hand side of Figure 2 at A. 1 form the new serrated or fluted
surface of the ridges and grooves a, a', by means of a new or improved construction
or combination of mould board, plate, or comb B, and compensating arrangement
of lever fittings C, D, E, F, shown also in these Figures. The mould board, plate,
or scraper B, is curved or rounded on the rubbing surface B', formed with trans-
verse shaped flutes b, b', corresponding to the ridges and grooves a, a', to be formed
on the inner surface of the vent linings A, and preferably of a length equal to the
depth of the lining. This mould plate B is mounted vertical, with its serrated
surface B' next the inside of the lining A, and with its lower end resting on the
upper surface of the moulding wheel, plate, or tahle W as a guide, and jointed at
the back by a hinge piece Cand intermediate link D on deep joint pins c, d, to
the lever E, revolving or rotating loose on a central spindle F, projecting up into
the inside of the vent lining being formed, and coinciding with the axis W₁ of the

page_text: centre of the moulding wheel or table W. The mould plate B is also provided
with a handle B2 secured to it, by which the moulder or potter can hold and guide
it, so as to press gradually into the clay at an angle, to form the ridges and
grooves a, a, to the full depth of the grooves and ridges, to form these all over
the inner surface as the clay recedes from the mould plate in turning round; or it
might be the mould plate B receding from the clay when this plate is turned
within the clay, as in the case of making the vent linings on a stationary plate or
table (instead of on a revolving potters table W) either with or without a stationary
outer mould for supporting the clay while forming the inner serrated or fluted
surface. The oscillating, lengthening, and jointed links C, D, E, allow the mould
plate or comb B, to move out and in from the centre spindle F, of the mould table
to suit the various radial distances of the inner surface a, a', of the oval vent
lining A while being formed, or it may be the different sizes of cylindrical or
conical vent linings or chimney cans, as indicated in dotted lines, as being formed
at A¹ in Figure 2, showing the links D, E, stretched further out than on the left
hand side of the same Figure.
Figures 3 and 4 show a sectional elevation and a plan respectively, of a single
piece or short length of oval vent lining A with the new or improved serrated or
fluted inner surface a, a³, as described in reference to Figures 1 and 2, in accordance
with my Invention. Figures 5 and 6 show a sectional elevation and a plan
respectively, of a round or cylindrical form of vent lining, with the new ridges a,
and bottom of the grooves a¹ of the inner serrated surface slightly rounded, instead
of sharp, as shown in the former Figures 1 to 4. Figures 7 and 8 show a sectional
elevation and a half plan respectively of a tapered or conical chimney can A
as formed with my new or improved inner serrated or ridged and grooved
surface a, a'.
In vent linings formed with these new or improved serrated inner surfaces, it
is found that the smoke passes freely out, and that they do not collect soot to
anything like the same extent as is the case with ordinary smooth surface linings,
and that any soot which does collect is far easier cleaned off than from the smooth
surfaced vents.
In using the improved mould plate or comb B, and compensating lever arrange-
ment C, D, E, either the wheel or table W and clay form on it, may revolve, as
described and indicated by the arrows in Figure 2, or they may be made to revolve
by hand or by motive power, when the table and mould is stationary.
Other equivalent means and appliances may be employed to form the corrugated
internal surface on the vent linings, as by causing the clay tubes to rotate round a
stationary indented mould board or plate B. Or otherwise the tubes or rough
blocks, may be first formed by pressing them out of a pipe machine, and cutting
them off and placing them on to a stationary mould table, with a collapsible core
piece or bar, whose surface would be formed with corrugations or alternate ridges
and grooves either annular or like the threads of a screw. And although these new
ridges or grooves a, a¹ have been described, as shown in the Drawings, as formed
annularly round the inner surfaces, they might be formed helically like screw
threads, either by turning the comb B while the pipes were being moved longi-
tudinally, as while being pressed out of the pipe making machine, or by causing
the comb B to move longitudinally while the pipes were being rotated on the
moulding wheel or table.
Having thus described the nature of my said Invention, and the manner of
performing the same, I have to state that I do not confine myself to the precise
details herein described or delineated, but what I consider novel and original,
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is,-
First. The forming of linings for chimneys, vents, flues, or chimney cans, with a
serrated or ridged and grooved surface round the inside, substantially as herein
described, and shown in the accompanying Drawings.
Second. The construction, or combination and arrangement, of mould or comb

page_text: plate, and its compensating levers B, C, D, E, for forming the serrated ridge and
groove surfaces on the inside of the linings for chimneys, vents, flues, or chimney
cans, substantially as herein described, in reference to and shown in Figures 1 and 2
of the accompanying Drawings.
In witness whereof, I the said Thomas Fraser, have hereunto set my hand
and seal, this Seventh day of August, in the year of our Lord One thousand
eight hundred and eighty two.
Witness.
W. R. M. THOMSON.
Patent Agent.
Glasgow
W.
THOMAS FRASER. (L.S.)