An Improvement in the Art of Making Mortar.
Year: 1892

page_text: Date of Application, 26th Apr., 1892-Accepted, 28th May, 1892
COMPLETE SPECIFICATION.
An Improvement in the Art of Making Mortar.
We, EDWARD TATNALL WARNER, of 903 Delaware Avenue, in the City of
Wilmington, County of New Castle, State of Delaware, United States of America,
Manufacturer, and JOHN FRANKLIN CURRY, of 17 South Clayton Street, in the
City of Wilmington, County of New Castle, State of Delaware, United States of
America, Mechanic, 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 :-
Our invention is concerned with the production of common mortar in contra-
distinction to the manufacture of hydraulic mortars or cements.
It deals, moreover, with the manufacture of mortar upon a commercial scale and
in large quantities, by the aid of mechanical appliances, as opposed to the well
known manual manufacture in the street mortar bed, and to operations in no step
of which is machinery employed
In fact, our invention has for its object the commercial production of
mechanically-mixed mortar for building and kindred purposes, our improvements
comprehending a mode of producing a machine-mixed homogeneous mortar
possessing a maximum tensile strength and exceptional smoothness, in an operation
which preferably commences with the handling of the raw materials, and which is
practically continuous and preferably without manual intervention throughout, and
which is conducted by the aid either of such various mechanical appliances as are
hereinafter referred to, and which conveniently serve automatically and with
certainty and uniformity to produce the ultimate product, or of others mechanically
the equivalents thereof.
Broadly stated, our invention comprehends a method of making common mortar
in which lime and water in appropriate proportions are first thoroughly mixed by
mechanical means so as to form a lime paste,-in which the lime paste thereby
produced, preferably but not necessarily after having been screened or strained, is
stored in bulk in vats or kindred large receptacles and therein retained for a period
of time sufficient to insure its slow but thorough digestion, its becoming slowly but
finally cold and homogeneous, and its assuming a putty-like or plastic consistency,
and in which the lime paste so digested and cold is in appropriate proportions by
mechanical means mixed with sand.
We have discovered that, as a result of the foregoing operation, we obtain a very
perfect mortar possessing qualities of strength, smoothness, and homogeneousness,
which no other hand-made or machine-made mortar of which we have knowledge
has heretofore possessed.
In the conduct of the operation which our improvements comprehend, the lime
is very thoroughly slaked with the smallest proportion of water, all particles of
core or unslaked lime are preferably eliminated from the lime paste, and the lime
paste itself after it has been permitted in bulk to digest slowly and become cold, is
admixed with the sand in such proportions that each grain of the latter is nicely
coated with the paste, the interstices between the grains being adequately filled
and all surplus of lime in the ultimate admixture avoided. The sand and lime,
being effectually assimilated by the foregoing operation, forms silicate of lime
which possesses greater strength than has heretofore been possessed by any
mechanically or manually admixed product of lime and sand, and which sets more
quickly.
The exceptional strength of our ultimate admixture is, as we believe, due not
only to the thoroughness of the mixing operations, but also to the fact that the

page_text: lime paste, after having been permitted in bulk to slowly digest or season and
become cold, is mixed cold with the sand.
In the accompanying drawings we have represented an apparatus conveniently
adapted to carry our method into effect. It is, however, to be understood that the
form, the construction, and the local relationship, of the various elements of said
apparatus which in their assemblage co-operate for the production of the desired
result, may be varied at the will of the constructor, and that certain of said
elements may, as hereinafter mentioned, be dispensed with.
In the drawings,
Figure 1 represents in side elevation an apparatus which we find it convenient to
employ.
Figure 2 is a view in perspective of a mortar-mixer which we find well adapted
for its purpose.
Figure 3 is a plan view of the revoluble mixing trough of said mortar-mixer.
Figure 4 is a fragmentary, partly sectional, and partly elevational, detail of a
two-way chute of the character represented in Figure 1.
Figure 5 is a side sectional elevation of a sieve or straining chamber through
which the lime paste may, if desired, be caused to be passed prior to its deposition
in the receiving vat.
Similar letters of reference indicate corresponding parts in all the figures.
In the drawings, A represents the ground floor, A' the second floor, and A' the
third floor of any preferred structure in which our apparatus as an entirety may be
supposed erected.
a is a charging chamber, preferably located on the ground floor, into which
either sand a', or lime a², may at will be fed.
B is an endless chain or bucket conveyor conveniently operating to elevate
material charged into the charging chamber to above the level of the third floor
of the building, and to discharge it conveniently into a two-way receiving chute C
preferably located above the level of the upper floor.
This chute C which is made as a two-way device simply for convenience, and is
provided with a discharging spout C*, through which, when the two-way valve c is
in the position represented in Figure 4, the lime elevated by the conveyor will be
discharged into the slaking box or mixer D,-and also with a discharging mouth c²
through which, when the valve c is in the position represented by dotted lines in
Figure 4, sand elevated by the bucket conveyor will be discharged conveniently
into the casing C³ of a spiral conveyor or worm C³, the rotation of which will serve
to convey the sand throughout the length of the conveyor casing and to discharge
it at its distant end through a suitable delivering spout c³, preferably into a rotary
or shaking sieve E of cylindric or other preferred character, through which the
sand will be strained or sifted, and whence it will gravitate conveniently into a
sand bin F, the discharging mouth f of which is controlled by a suitable valve,
operative to deliver the sifted sand into the mortar-mixer G, whereof hereafter.
The slaking box D may be of any preferred form, being, however, conveniently
a revolving receiver of the general character of the mortar-mixer hereinaiter
described, but operative to good effect with but a single mixing arm or set of
mixing arms. Into this slaking box the water supply pipe H discharges, and a
cock upon said pipe conveniently serves to regulate the feed of the water into
the box.
Within the slaking box the lime and water, supplied in the desired proportions,
are, as stated, intimately admixed by the operation of any preferred stirring arm or
other device or devices,-and from out of the bottom of said box, conveniently
through a central aperture, the slaked lime or lime paste is discharged conveniently
through a discharging chute d, and preferably through a sieve, or into a straining
chamber in which is contained a sieve i, being a wire screen of fine mesh, upon
the face of which the slaked lime is discharged and over the face and through the
mesh of which it is preferably swept, conveniently by a revolving brush, the
function of which, in connection with the sieve, to prevent all particles of core or

page_text: unslaked lime or foreign particles from entering the vat J, in which the lime paste
is stored and permitted to remain in bulk for a period of time sufficient to cause it
to digest slowly, the lime settling to the bottom and leaving the water on top to be
pumped off, in order that there may remain only a very fine putty-like paste of
suitable character for ultimate admixture with the sand.
The period within which the mass of lime paste will digest, assume this putty-
like consistency, and become, as hereinbefore set forth, cold, varies somewhat with
the vat capacity, under conditions with which practical men soon become familiar ;
but the minimum period within which we, in the use of large vats, have found the
paste in proper condition for admixture with sand, has been a week or ten days, and
we have even retained it for two or three weeks, and by so doing we have found
that the long retention of the heat in, and the gradual cooling of, the mass, ensures
its thorough digestion and tempering, with the result that the mass when finally
cold is both homogeneous and plastic. The vats which we in practice employ are
of large size, and each capable of holding a large quantity mass or bulk of the
lime paste.
We represent but a single vat in the drawing, but in large plants the vat
capacity must be proportionately great.
It is proper to explain that while we have particularized a screening or straining
chamber, we do not confine ourselves to any form or application of screen, nor
indeed to the use of any screen, as the slaked lime may in many cases be deposited
directly and without the intervention of any screening operation, in the vat.
The lime-straining chamber shown in Figure 5 conveniently discharges through
an orifice into the vat J, and from the vat J, as shown in Figure 1, is a
discharge opening j, controlled by any suitable valve, through which said vat con-
veniently discharges into a conveyor chamber K, in which is a bucket conveyor k,
conveniently vertically erected, by the aid of which the digested lime paste is
elevated and discharges into a delivering chute k*, provided for the purpose with a
suitable discharge valve k², and discharging into the mortar-mixer G.
It is not of the essence of the foregoing apparatus that any special machinery
should be employed to occasion the operation of the various moving parts :-thus,
for instance, the movement of the bucket conveyor B for elevating the raw material,
the revolution of the slaking box D in which the lime is mixed with the water and
slaked, the movement, when employed, of the sieve E through which the sand is
preferably screened, the movement of a brush upon a sieve to strain any foreign
particles from the slaked lime when straining is resorted to, the operation of the
bucket conveyork for the discharge of the lime paste into the mortar-mixer, and
the revolution of the mortar-mixer itself,-may all be occasioned by any preferred
motive power and through any preferred connective mechanism.
13
Simply to indicate a possible and inexpensive way of imparting to these moving
elements the desired movement, we have represented a prime motor L, being a
steam, hot air, electric, or other preferred, actuating device, and a series of belts m
to m³, operating a series of pulleys n to n¹³-in certain instances geared through a
countershaft and bevel gears o,-which it is unnecessary to describe in detail, as
they speak for themselves upon Figure 1 of the drawings, and as their relative
arrangement may be indefinitely varied, or other connective or driving devices
substituted in their stead, or, in fact, separate motors employed to actuate separately
- or in preferred combination the various moving parts.
G is the mortar-mixer, which, as shown in Figure 1, is conveniently provided
with a central downwardly discharging spout G* conveniently terminating in a bag
funnel G¹, controlled by a suitable valve, through which delivery of the ultimate
admixture, the mortar which is the commercial product of the apparatus, can be
made into, for instance, a delivering box G' conveniently mounted upon a truck (³
running, if desired, upon a track upon the ground floor.
Many forms of mortar-mixing devices may, if desired, be employed, but we find
it convenient to employ such a mixing-machine as is that represented in Figure 2 of
.the drawings.

page_text: In that machine the letter G designates a revoluble cylindrical tank, suitably
mounted for revolution in any preferred manner, but conveniently provided with a
peripheral rack with which engages a pinion g¹ on a pinion shaft g* actuated by a
chain wheel y, driven by a chain g³ from a chain pinion g', on a driving shaft
actuated from any preferred motor by means of a pulley 9. It is obvious that the
rotation of the driving shaft through the pulley will occasion a revolution of the
mixing tank G.
Upon the inner end of the driving shaft g' which is suitably supported in any
preferred manner, is a bevelled pinion g' in engagement with a bevelled spur
wheel 98 keyed upon a stirring shaft g, housed in bearings 9" 9", upon the lower
extremity of which shaft is affixed a frame g¹, which carries a series, conveniently
three, of stirring arms g¹³.
It is obvious that the rotation of the driving shaft will through the bevel
gear gg occasion the rotation of the stirring shaft and frame and the consequent
revolution of the stirring arms at a speed proportionate to the speed of the driving
shaft and the proportion of the bevel gear.
P is a second driving shaft, preferably the counterpart of the driving shaft gr
and similarly supported and equipped with pulleys, which shaft through a bevel
pinion p and bevelled spur wheels p¹ conveniently occasions the revolution of the
second stirring shaft p³, which also is conveniently equipped with a frame p³,
carrying stirr ng arms p', the operation of which is identical with that of the stirring
arms g¹³ first described.
Qis a counterbalanced valve which conveniently closes the discharging orifice q,
Figure 3, in the bottom of the mixing tank.
This valve, which is conveniently in the nature of a puppet valve, has a vertically-
moving valve-stem y¹ housed in a slide bearing g, and its upper extremity is con-
nected with a balance chain q³ working over a chain wheel q, upon a balance
shaft g, suitably housed in the framework and equipped with a hand wheel gⓇ to
occasion any desired oscillation of the chain wheel. The extremity of the balance
chain not connected with the valve stem, is conveniently connected with a curved
scraper q', which serves as a counterbalance of the valve, and which, when the
valve is seated, is suspended clear of the floor of the mixing tank, but which, when
the valve is unscated, descends into contact with said floor, and serves in the
further rotation of the tank to direct its contents into the discharging orifice of
the tank.
The scraper itself is conveniently connected with a carrying yoke device q³,
housed in slide bearings 9' conveniently supported from or formed as a part of the
framework.
The details of the construction of this mortar-mixer are not of the essence of the
apparatus as an entirety, as it is obvious that so far as the mortar-mixer is con-
cerned, all that is required is that it should be a suitable mechanically-operated
mixing device by the aid of which the digested lime paste and the sand may be
thoroughly and intimately admixed, to the end that each grain of sand may become
thoroughly coated with the paste and all the interstices between the grains be filled
with it.
As already stated, the slaking machine or box D may be a counterpart of the
foregoing mortar-mixing machine, or it may be any other form of mixing device in
which lime and water are stirred up together automatically as contradistinguished
from manually, and from which the lime thereby slaked is caused to pass to a vat.
It will now be apparent that the slaking machine, the settling vat, and the
mortar-mixing machine, are the only indispensable elements of the apparatus as an
entirety.
Having now described an apparatus through the instrumentality of which the
operation of mechanically-mixing mortar can be automatically, that is to say with-
out the necessity of manual interference, performed,-we desire once again to
emphasize the fact that the special relative arrangement and the special construc-
tion of the various elements shown in the accompanying drawings and hereinbefore

page_text: particularly described, are not of the essence of said apparatus or of the
invention.
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 :
1. The improvement in the art of making mortar, which consists :-first, in
mechanically mixing lime and water to produce slaked lime;-second, in retaining
in bulk the lime paste thus produced for a time sufficient to insure its slow but
thorough digestion, its becoming slowly but finally cold and homogeneous, and its
assuming a putty-like or plastic consistency;-and, third, in mechanically mixing the
digested lime paste with sand;-substantially as set forth.
2. The improvement in the art of making mortar, which consists :-first, in
mechanically mixing lime and water to produce slaked lime; second, in straining
or screening the slaked lime to free it from core and foreign particles ;-third, in
retaining in bulk the lime paste thus produced for a time sufficient to insure its
slow but thorough digestion, its becoming slowly but finally cold and homogeneous,
and its assuming a putty-like or plastic consistency; and, fourth, in mechanically
mixing the digested lime paste with sand ;-substantially as set forth.
Dated this Fifth day of April A.D. 1892.
EDWARD TATNALL WARNER.
JOHN FRANKLIN CURRY.