Improvements in and relating to the Manufacture of Coffins.
Year: 1891

page_text: Date of Application, 22nd June, 1891-Accepted, 5th Sept., 1891
COMPLETE SPECIFICATION.
Improvements in and relating to the Manufacture of Coffins.
We, LUDWIG OTTO MUELLER of Arcostrasse .3-IV Architect and LAMBERT
STADER, of Zweigstrasse 7-III Sculptor both of Münich in the Empire of
Germany 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 :-
This invention relates to that class of coffins in which a trellis or frame-work of
wooden laths is covered by and serves as a support for a covering or casing of a
suitable plaster, and it relates more especially to the coffins the manufacture of
which is described in the Specification or Specifications accompanying our
application for Letters Patent No. 14522, filed the 15th day of September 1890.
The object of the present invention is to improve the manufacture of these coffins
and the like in the manner hereinafter described.
The said coffins consist of a framework of wood over which is laid a cement or
mass consisting of gypsum, dextrine and silicate which when dried or set becomes
impermeable in the atmosphere, but becomes quickly disintegrated and decomposed
when acted upon by the damp of the soil.
In order to prevent the dry laths or staves of wood of which the framework is
made from becoming damp when the wet cement or mass is laid on them and
consequently tending to warp and dislodge the cement when dry or drying the laths
of wood are covered with a substance such as heavy oils containing carbolic acid
known as carbolineum, asphalt, varnish, or the like impervious to moisture, either
before or after the laths are made up into a frame.
To secure also a firm union of the framework and the cement and also to preserve
the wood, the former may be soaked after making up or before use in a solution of
a metallic salt such as sulphate of copper, or cupric oxyde of ammonia.
To the materials above said of which the cement covering is made there may be
added carbonate of soda, or carbonate salts in general, also washed or precipitated
chalk and sulphur.
Thus by the addition of chalk the strength of the cement covering may be
increased, the proportion in which it is added may be about 2 lbs. of chalk to every
100 lbs. of gypsum used. The chalk acts not only as a binding material but also
renders the mass smooth and workable and lessens its specific weight.
The dextrine may be replaced by any other mucilaginous matter or binding
material which fills the pores in the cement until the coffin is laid in the earth.
When the coffin is for use in very porous ground such as gravel or rubble it is
not necessary to add sulphur to the ingredients of the cement as there is sufficient
change of water and air in the soil to effect the quick decomposing of the cement;
in close or firm ground such as loam or clay sulphur should be added as its action
is to decompose the cement and render the same porous, the amount of sulphur
added may be small the exact proportion being quite immaterial.
In regard to the addition of carbonate salts it may be remarked that when the
coffin is interred, the dextrine is first dissolved out and as the water soaks deeper
into the casing of the coffin it sets up a chemical action by which an almost insoluble
salt is produced with one which is readily soluble. Thus, from sulphate of lime and
silicate of soda, silicate of lime and sulphate of soda are produced, the last
mentioned salt being soluble so that it is dissolved out and leaves a mass the
porosity of which allows unhindered passage to the air and water. The porosity
depends upon the amount of carbonate, preferably soda or potash corbonate, added,
a limit being set to the addition of dextrine and silicate. The quantity of carbonate

page_text: may be increased until for instance a fully washed out sample of the hardened
cement is found when broken to be permeated by small channels.
A convenient quantity is, with a proportion of 1 lbs. of dextrine to the relative
amount of gypsum, to lbs. of the carbonate..
To allow the casing of the coffin to be made reasonably thin and yet of sufficient
strength any suitable fabric such as linen or jute is used as a body or backing for
the cement covering, as follows;
A. suitable mould being chosen for the cement casing the cement is made by
mixing in 1 gallon of hot water (or in a larger quantity in the same relative
proportions, 1 lbs. of dextrine, and adding to the solution 3rds of a lb. of silicate
(soluble glass) and (one-tenth of a lb. of carbonate of soda, these two being
previously dissolved in sufficient water. Sufficient gypsum is then stirred into this
solution to make a stiff paste which is afterwards spread in the mould and a piece
of fabric well pressed down on the inner side, the trellis or frame of wood previously
made to shape is then placed over the cement and covered in with more of the
cement; if desired the single laths may be covered in by strips of fabric cemented
down by the second application of cement.
The coffin so made soon becomes set and hard and in the atmosphere is impervious
but when interred is gradually but quickly rendered porous for passage of air and
water.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
In the manufacture of coffins composed of wooden open frames covered with a
cement like mass, the method of uniting the cement and the wood consisting in the
use of fabric, the covering of the wood with material impervious to water and the
steeping of the wood in a preserving liquid as set forth.
(2) In the manufacture of coffins covered with a cement-like casing adapted to be
rendered porous by damp of the earth, the combination with gypsum, silicate, and
dextrine or equivalent binding material, of a carbonate salt or salts, chalk and
sulphur or of one or more of these materials in the manner and for the purpose or
purposes herein described.
Dated this 22nd day of June 1891
HERBERT & Co.,
18, Buckingham Street, Strand, W.C., London, Agents to Applicants.