Improvements in or relating to the Manufacture of Burial Caskets or Coffins.
Year: 1894

page_text: Date of Application, 1st June, 1894-Accepted, 7th July, 1894
COMPLETE
SPECIFICATION.
Improvements in or relating to the Manufacture of Burial Caskets
or Coffins.
I. GEORGE EDWIN SHAW, Engraver, of No. 5 West 4th Street, Cincinnati,
Ohio, United States of America, 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 :-
My invention relates to the manufacture of burial caskets; and is intended to
produce an article of manufacture, sale and use, possessing qualities not possible
to be attained by either wood or metal, and certain other qualities especially
desirable for this purpose not attainable within the same reasonable limits of
cost in any other material.
To these ends, my invention consists in the manufacture of burial caskets from
so-called " paper-pulp" material; preference being given to pulp made of straw
(which is generally regarded as a refuse product of slight market value), or of
wood or of any other pulp material of a fibrous character.
The casket when made of this material, with or without the admixture of
other ingredients, as and in the manner hereinafter set forth, may be "finished "
by treatment with oil, varnish, paint, etc.; or covered and ornamented in any
suitable manner or with any suitable material. The main body or foundation,
however, of the ornamental treatment, is produced in and during the process of
manufacture, by designs formed upon or recessed into the faces of compression
dies or plungers, employed in the manufacture; whereby the counterpart of such
designs is produced in or upon the surface of the casket and forms an integral
part of the body of the structure.
In order that my invention may be clearly differentiated from the manufacture
of other articles produced from paper-pulp material, I may state, that, owing to
the peculiar nature of pulp-material, the methods at present in vogue in the art
are limited to the production of comparatively small articles, of symmetrical
proportions; such, for example, as water-pails, washing-tubs, and the like; and
flat "boards," or blocks intended to be united with other materials into a composite
structure, such as car-wheels. The manufacture of box-shaped articles or those
having angular corners, so far as I am aware has not been hitherto successfully
accomplished, on account of the tendency of the material, as ordinarily
manufactured, to warp, shrink, and crack; and, although burial caskets of papier-
mache and of pulp have been suggested, no practicable burial casket has ever
to my knowledge been made of pulp material; certainly not a commercially
acceptable article, or one fulfilling the essential conditions of a casket for burial
purposes, before my invention thereof.
The casket of my invention is, however, light in weight, of extraordinary
toughness and resisting strength, is impervious to air or moisture, and is of
exceedingly ornamental appearance both by reason of the ornamental form given
to it in the process of manufacture, without additional cost over those of perfectly
plain or unornamented contour; and of its perfect adaptability to receive further
ornamentation as desired; may be produced in any color; and is more durable
than either wood or metal, yet possessing, for the purposes in view, the good
qualities of both.
Considered with reference to its inherent structure, it differs from ordinary pulp
structure, in two important particulars, growing out of the peculiar process of
manufacture and the construction of the mechanism, pointed out and claimed

page_text: Enroughout compressed together
in the interlocking relations naturally assumed by them, and' without being torn
apart, and also, that the product is desiccated by artificial heat applied during
compression of the material in such manner that compression follows up the
expulsion of moisture and natural shrinkage; whereby the material is more
condensed in structure, and thereby rendered more impervious and durable.
In the preferred process of manufacture, the pores of the structure are filled
with self-hardening adhesive material which is caused by heat and moisture to
flow into the interstices and permeate the material throughout.
The nature of the invention will be more fully understood from the subjoined
description, in connection with the accompanying drawings, in which:
Figure 1, is a side elevation of a specimen of my improved burial casket.
Figure 2, an end elevation of the same.
Figure 3, a cross section of the same.
Figures 4 and 5, are a diagram plan-section and a vertical cross-section of
a compression machine, illustrating certain essential principles of the manufacture,
and
Figures 6, 7. 8 and 9 enlarged details illustrating constructive features.
Taking into consideration economy of cost and the character of its fibre, I
prefer "straw" pulp, as a material for the manufacture of my improved casket.
The pulp is made in the usual manner, in suitable "pulp-mills," and consists of
the disintegrated fibrous constituents of the material mechanically suspended in
water. A predetermined quantity of this pulp is fed into the chambers of a
compression machine consisting, essentially, of a series of chambers, a, provided
with reciprocating plungers, b, arranged about a suitable core or "former," c, and
by a simultaneous compressive movement of the plungers, the material is compressed
to form about the core, and the water excluded by pressure and heat, forming the
casket A illustrated in Figures 1, 2, and 3.
For the purposes of the present application, Figures 4, 5, 6, 7, 8 and 9 will
sufficiently illustrate the essential characteristics of the compression apparatus
employed in carrying out my invention; which apparatus, inasmuch as it differs
from compression apparatus in common use only in certain features herein specified,
is illustrated only in respect to said features.
As one of the fundamental features of the process, affecting the nature of the
ultimate product, is simultaneous compression of the material about the core in
directions substantially in the projected axes of the plane sides and bottom of the
casket, four of the compression chambers a (each having a cross-area corresponding
in form and dimensions with the side in whose axis it is projected) are arranged
in a common horizontal plane (Figure 4) about the central core c (corresponding in
form and dimensions with the hollow interior of the casket body). The plungers b
fitting the several chambers are provided with suitable means, (such for example
as cylinders with pistons operated therein by liquid or other pressure,) adapted to
move the plungers inward simultaneously to a given limit, allowing proper
thickness for the shell of the compressed casket body A, so that the edges of the
plungers meet and define the side corners of the casket.
A vertical compression chamber, a, with plunger, b, is also arranged above the
core c, (Figure 5) to form the bottom of the casket body A, and said plunger
meets edge to edge with the other plungers at the ultimate limit of movement
defining the bottom corners of the casket.
In the plunger machines of this type heretofore suggested the walls of adjacent
plunger-chambers meet at a sharp edge coincident with the external corner edges
of the ultimate product as illustrated in Figure 6, in which e, e¹, designate the
meeting walls of adjacent chambers, and f, their meeting edge and also the corner
of the compressed casket body A. Now, in the compressive movement of the
plungers, b, from the positions shown to their limit of movement, (the outer face
of the casket body A) it will be seen that the action tends to produce. in the
compressed product a line of division between the compacted fibres extending

page_text: inward diagonally from the corner of and the greater proportion of the fibres at the
end of the mass in one compression chamber are by the conditions of structure
held apart from those of the adjacent compression chamber and, excepting those of
the inner layer of the casket, they are given no opportunity to coalesce or interlock,
but are simply brought together as compression proceeds, with less and less
force to the extreme outer layer in which the ultimate movement of the
plungers simply brings the fibres to the point of contact without any compression
together.
As a result of this inherent structural defect in this general type of machines
compressing by means of plungers, in the manner described, about a core, a product
of no practical value is produced because the subsequent shrinkage of the material
opens the corners or places in the periphery when the described action took
place and, as a result, machines of this class have commonly been regarded as
failures.
I have discovered a complete practical remedy for this defect, and illustrate
the same in Figure 7, that is to say: I chamfer away the meeting edge or corner
formed by the walls of adjacent plunger chambers to a line xy, thus forming a
triangular space a yf extending the entire length of the meeting walls, and outside
the limits of the plunger action.
As the plungers 6 move inward, the pulp in this space becomes so far compacted
with the main body of pulp in the chambers, that as the plungers reach the
points ay and move toward their meeting point f, the pulp of the triangular space
is carried forward and forced diagonally inward into the body of pulp on either
side, and bent to form the corner: and in so doing, its fibres are forced into
interlocking relations with those on either side. By this means, and by the
additional material thus forced into the mass, the corner of the casket is rendered
fully as dense and perfect as the rest of the casket body, and there is no break
in the interlocking continuity of the fibres.
Suitable provision for drainage is also made, so that the water contained in the
pulp may readily escape, as is necessary in the manufacture of pulp articles. This
is effected, preferably in the following manner ;-For the convenient application of
heat presently to be explained herein, I prefer to employ imperforate plungers b
and core c; and in order to effect the desired drainage at both sides of the mass
under compression, I employ external minutely perforated plates p (Figs. 8 and 9)
channelled at the under-side; as facings for both the plungers and the core. The
water expressed from the pulp material at the core-side, passes through the
perforations of the facing plates to the channels adjacent to the imperforate
surface of the core, and escapes below. That passing through the facing plates of
the side plungers, drains out below in like manner. The ultimate drainage of the
plunger-side of the bottom of the casket is provided for by a series of minute
perforations o through the shell of the upper plunger chamber above the line of
contact of the edges of the chamber with those of the side chambers.
A further fundamental feature of the manufacture, is the direct application of
heat in and during the compression, at both sides of the casket shell; so that
continued compression follows up the exclusion of moisture and natural shrinkage,
so as to compact the fibres more perfectly and render the product as dense and
non-porous as possible, in order to prevent subsequent warping and cracking.
In the manufacture of articles from pulp, it has been common to employ heat,
but only at one side of the shell produced. This method of heat application
desiccates one side of the structure, producing an unequal texture, causing it to
warp. In small articles, such as have heretofore been produced from pulp, and
especially by reason of their symmetrical form (such as pails etc.) this difficulty
has been sufficiently overcome by the subsequent oil-soaking and baking process,
termed "indurating," but such is not practicable with burial caskets.
I find however that the application of heat in the manner herein described, in
connection with the other features of the process affords a perfect remedy for this
difficulty and at far less cost than "indúrating."

page_text: To this end, the movable plungers and also the core, are formed as hollow
imperforate chambers and connected by flexible steam hose s, into which steam,
either superheated or under pressure, so as to maintain a given temperature, or hot
air, is introduced after compression has proceeded to the proper stage, and the
remaining vestiges of moisture are vaporized and driven off, by heat communicated
by direct contact of the plungers and core; and the material is at the same time
further compacted by pressure, as natural shrinkage proceeds.
In proceeding to form a casket, the successive steps of the process are as
follows; The pulp material contained in sufficient water to enable the fibres to
assume natural positions, is introduced around the core, in the chambers a in front
of the now-withdrawn plungers 6 so as to completely fill all the space to the
exclusion of air.
Power is then simultaneously applied to the lateral and vertical plungers and the
liquid material subjected to pressure, which gradually forces out the contained
water at the screen-faces of the core and plungers, and the fibres gradually settle
and become compacted in the relations naturally assumed, inasmuch as the pressure
is at all times perpendicular to the plane of the layer produced. (In this case,
is desirable to give a slight "flare to the sides of the casket and therefore the
faces of the lateral plungers are correspondingly inclined; but the angle is so
slight as not to affect the general principle.)
it
After the water has been substantially expressed, and the compression has
proceeded to a point approximating the limit of movement of the plungers, steam
is admitted to the plungers and core, simultaneously; and sufficient heat is thus
directly communicated to the compressed layer to vaporize the remaining moisture
while the compression proceeds to its full limit; thus following up the natural
shrinkage and more thoroughly compacting the material.
The manufacture as thus described produces a perfect casket, practicable and
useful in all respects, and ready, when treated with oil, varnish or other "finish,"
for the market. But, a further improvement in the product may be produced by
first mixing with the pulp used, a suitable quantity of starch or other leguminous
substance, finely pulverized and mixed with cool water, and thoroughly disseminated
through the pulp. The process proceeds in all respects, as herein before described:
but in the final part of the process, a further action takes place, namely, the moist
starch or leguminous substance, contained in the liquid material is by heat applied
as described, "cooked" and caused to swell and burst its cell structure; and, by
such swelling, produce an internal pressure, causing the resulting pasty mass to
permeate and fill the minute interstices of the casket body; and, by its adhesive
quality, when subsequently dried and hardened, cement the whole together.
The introduction of these or like substances in the manner described, are
refinements of the process not absolutely essential; but produce a somewhat
improved article over that produced from pulp alone.
When the compression is fully completed, and a limited time allowed for drying,
the casket is removed from the apparatus and treated with oil, varnish or paint, or
otherwise, to give the desired "finish." This ornamental finish, as to form is
however already produced in the material by the recessed dies, as before indicated;
and an external appearance of great elegance is thus cheaply produced.
The casket thus produced, differs from ordinary articles produced from pulp
material in being much stronger and more durable by reason of the perfect inter-
locking of the fibres throughout, and especially at the angles and corners, and is
more durable, in respect to atmospheric and other influences, by reason of its more
dense and compact structure resulting from the simultaneous action of heat and
pressure; whereby its porosity being practically eliminated, it has no tendency to
warp or shrink.
Finally the burial casket embodying these desirable qualities, and in an
ornamental form, realizing the highest attainment of artistic design, is produced
A complete at the minimum of cost, and in practically unlimited quantities, as an
article of manufacture within the reach of all.

page_text: Having now particularly described and ascertained the nature of the said inven--
tion and in what manner the same is to be performed, I declare that what I
claim is ;-
1.
1. A burial casket composed of fibrous pulp-material produced by pressure.
applied to all outer surfaces and heat applied to both inner and outer surfaces-
both heat and pressure being applied simultaneously until the casket is completed-
and having thereby a uniformly and compacted extremely dense structure.
2. A burial casket produced from fibrous pulp-material by simultaneous
external pressure compacting the fibres in the positions naturally assumed, without
displacement and thereby having the fibres uniformly interlocked and compacted
without strain or rupture at any points in the structure as herein set forth.
3. A burial casket produced by compression from fibrous "pulp" material having
a leguminous substance disseminated throughout the mass, and, by moisture and
heat caused to permeate the interstices of the finished product and become adhesive
by drying as set forth.
4. A burial casket or similar article produced from fibrous pulp-material having
its corner angles or weak places or points of greatest strain strengthened by
additional material forced into it during compression and the fibres of such
additional material interlocked and compacted with those of the shell by pressure
substantially as set forth.
5. A burial casket or similar article produced from fibrous pulp-material.
rendered dense and practically non-porous by compacting pressure and by heat
applied during pressure to both sides of the layer under compression.
6. A burial casket or other box shaped article produced by compression from
fibrous pulp-material having the junctions of sides ends and bottom strengthened
by additional material forced into the mass during compression at and constituting
the outer angles substantially as set forth.
Dated this 1st day of June 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.