IMPROVEMENTS IN WATERPROOF FELTS FABRICS AND SHEETS
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I ALEXANDER DAVIDSON of Addison Lodge Wimbledon in the County of
Surrey Paper Manufacturer do hereby declare the nature of my Invention for
"IMPROVEMENTS IN WATERPROOF FELTS FABRICS AND SHEETS" to be as
follows:-
This Invention has for its object improvements in waterproof felts fabrics and
sheets.
All felts fabrics and sheets which have been treated with pitch, tar, asphalte or
other resinous substances for the purpose of rendering them waterproof are dirty
to handle and liable to stick together when rolled up or laid on each other.
By this Invention I prevent this adhesion of waterproof felts fabrics and sheets
and render the same more cleanly to handle by covering their surfaces with a
coating of meal or flour ground from husks of oats, wheat barley, maize rice or
other grain.
Or in place of these materials a like meal or flour may be employed obtained by
grinding wood or sawdust between millstones or in a suitable mill.
The meal is applied to the waterproofed surfaces while the latter are hot and
adhesive and becomes more or less embedded in these surfaces, which are thereby
rendered dry cleanly and non-adhesive.

page_text: I ALEXANDER DAVIDSON of Addison Lodge, Wimbledon in the County of
Surrey, Paper Manufacturer, do hereby declare the nature of my Invention for
"IMPROVEMENTS IN WATERPROOF. FELTS FABRICS AND SHEETS" and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement:-
This Invention has for its object improvements in waterproof felts fabrics and
sheets.
All felts fabrics and sheets which have been treated with pitch, tar, asphalte or
other resinous substances for the purpose of rendering them waterproof are dirty to
handle and liable to stick together when rolled up or laid on each other.
By this Invention I prevent this adhesion of waterproofed felts fabrics and
sheets and render the same more cleanly to handle by covering their surfaces with
a coating of meal or flour ground from husks of oats, wheat, barley maize, rice or
other grain.
Or in place of these materials a like meal or flour may be employed obtained by 1
grinding wood or sawdust between millstones or in a suitable mill.
The meal is applied to the waterproofed surfaces while the latter are hot and
adhesive and becomes more or less embedded in these surfaces, which are thereby
rendered dry cleanly and non-adhesive.
In order that my said Invention may be most fully understood and readily
carried into effect I will proceed to describe more in detail the manner in which I
prefer to conduct the manufacture.
The felt or other fabric is passed through the waterproofing material, whilst this
is contained in a heated state, in a trough containing a roller, the fabric is led
down beneath this roller and thus is completely immersed. The fabric as it
emerges is conducted through rollers by which the surplus of the waterproofing
composition is squeezed out; or in some cases the squeezing rollers may be omitted,
where it is desired that the felt or fabric should carry with it as much of the
waterproofing material as it will contain.
This is the ordinary process for waterproofing felt for roofing and like uses.
The waterproofing material which I usually employ is pitch, sufficiently thinned
by the admixture of tar to give to the goods the flexibility desired; but any such
like material at present employed for waterproofing felt may le made use of.
After emerging from the pot containing the waterproofing material the fabric
with the material still hot upon it is led over rollers in a horizontal position, and
meal or flour is distributed uniformly over the upper surface. The meal or flour
descends from a hopper having a long slit in the bottom extending transversely
from side to side of the fabric and some distance above it. The slit is guarded by
a roller which as it slowly revolves carries down the moal or flour in a uniform
stream. Or in place of this arrangement any well known apparatus for insuring
the uniform distribution of the meal or flour upon the surface of the fabric may be
employed. The fabric is then squeezed between rollers to cause the meal or flour
to adhere firmly. From the pressing rollers the fabric is led back over guide
rollers, so as to bring the other surface to the upper side; and then in like manner
meal or flour is applied to this surface from a hopper or otherwise as already
described. The fabric is again passed between pressing rollers and is then
completed.
The meal or flour which I prefer to employ is prepared from the husks of oats.
These husks are easily obtained in the market, and I prepare them for use by
grinding them to a meal or flour by means of mill stones such as are employed in

page_text: grinding wheat. Or in place of husks of oats other materials may be employed in
the preparation of the meal or flour as stated above.
Having thus particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that I claim
as my improvements in waterproof felts fabrics and sheets the application thereto
and combination. therewith of meal or flour ground from husks of oats or from
other material, and which meal or flour forms a coating to the fabric adhering to
and covering the waterproofing composition substantially as described.
Dalth:. Ord J. 1001