IMPROVEMENTS IN THE CONSTRUCTION OF SCREW APPARATUS FOR CONVEYING CEMENT AND LIKE MATERIALS FROM PLACE TO PLACE."
Year: 1881

page_text: LETTERS PATENT to William Walter Hewitt, of Swanscombe, in the County
of Kent, for an Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF
SCREW APPARATUS FOR CONVEYING CEMENT AND LIKE MATERIALS FROM
PLACE TO PLACE."
PROVISIONAL SPECIFICATION left by the said William Walter Hewitt at
the Office of the Commissioners of Patents on the 4th July 1881.
WILLIAM WALTER HEWITT, of Swanscombe, in the County of Kent. 'IMPROVE-
MENTS IN THE CONSTRUCTION OF SCREW APPARATUS FOR CONVEYING CEMENT
AND LIKE MATERIALS FROM PLACE TO PLACE."
"
This Invention has for its object improvements in the construction of screw
apparatus for conveying cement, grain, sewage, shingle, ballast, brick bats, &c., and
other materials from place to place.
For this purpose I employ a metal trough of U form with an axis having one,
two, three, four, or more screw blades revolving in it. Screw conveyers of this
class are well known, but my Invention consists in the method of construction,
which is as follows:-The trough is cast in convenient lengths with flanges by
which the lengths are bolted together. Across each length at one end a bridge
piece is formed upon which there is a bearing for the axis.
The axis also is made in lengths, and is square in section except where it is
turned down to enter the bearings. The screw is cast in sections, each consisting
of a boss with a square opening for the axis and two or more blades on opposite
sides. Each blade is a quarter turn of the screw, so that one of these sections is
not unlike a propellor for a steam boat. These sections are threaded on the axis
so as to form a continuous two bladed screw passing along the trough from end to
end with only such breaks or intervals as are requisite to clear the bridges and
I Price G21

page_text: bearings upon which the axis is carried. The sections are fixed upon the axis by
pinching screws through the bosses.
Or in place of arranging the sections close together upon the axis so that the
screw threads are continuous, the sections may be set at short intervals apart.
The screw sections serve also to couple the several lengths of the axis. The two
lengths of the axis are arranged to meet and butt together within the boss of one
of the sections, and the bosses of the screw sections forming the coupling are made
A screw conveyer
with flanges, and these are fixed together by bolts and nuts.
of this construction thus consists of a few simple parts repeated until the conveyer
is built to the length required. The conveyer also can always when necessary be
shortened or lengthened in a very short time and without skilled labour.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Walter Hewitt in the Great Seal Patent Office on the
4th January 1882.
"
WILLIAM WALTER HEWITT, of Swanscombe, in the County of Kent.
'IMPROVE-
MENTS IN THE CONSTRUCTION OF SCREW APPARATUS FOR CONVEYING CEMENT
AND LIKE MATERIALS FROM PLACE TO PLACE."
This Invention has for its object improvements in the construction of screw
apparatus for conveying cement and other materials from place to place.
For this purpose I employ a metal trough of U form with an axis having one,
two, three, four, or more screw blades revolving in it. Screw conveyors of this
class are well known, but my Invention consists in the method of construction,
which is as follows:-The trough is cast or formed in convenient lengths with
flanges by which the lengths are bolted together. Across each length at one end a
bridge piece is formed upon which there is a bearing for the axis.
The axis also is made in lengths, and is square in section except where it is
turned down to enter the bearings. The screw is cast in sections, each consisting
of a boss with a square opening for the axis, and in the case of a double bladed
screw with two blades on opposite sides. Each blade is a quarter turn of the
screw, so that one of these sections is not unlike a propellor for a steam boat.
These sections are threaded on the axis so as to form a continuous two, bladed
screw passing along the trough from end to end with only such breaks or intervals
as are requisite to clear the bridges and bearings upon which the axis is carried.
The sections are fixed upon the axis by pinching screws through the bosses.
Or in place of arranging the sections close together upon the axis so that the
screw threads are continuous, the sections may be set at short intervals apart.
The screw sections serve also to couple the several lengths of the axis. The two
lengths of the axis are arranged to meet and butt together within the boss of one
of the sections, and the bosses of the screw sections forming the coupling are made
with flanges, and these are fixed together by bolts and nuts. A screw conveyor
of this construction thus consists of a few simple parts repeated until the conveyor
is built to the length required. The conveyor also can always when necessary be
shortened or lengthened in a very short time and without skilled labor.
In order that my Invention may be fully understood, I have shewn in the
Drawings hereunto annexed various views of apparatus constructed as above
described.
Figure 1 is a vertical section, and Figure 2 a plan of a portion of the metal
trough and screw mounted therein. Figure 3 is an end elevation of one of the
lengths of the trough, and Figure 4 a section taken on the line A, B, Figure 2.
Figure 5 is an elevation on a larger scale of one of the brackets that carry the
bearings for the axis of the screw blades. Figure 6 is a vertical section of the same
on the line C, D, Figure 5. Figures 7 and 8 show elevations of one of the sections
of the screw.
A are the sections or lengths of trough. They may either be cast or they may be
of steel or wrought iron; in the Drawing they are shown to be of wrought iron.
They are formed with flanges at their ends by which they are bolted one to
another, and are made strong so that they need only to rest upon supports at long
intervals apart. If the trough is of cast iron the bridge which carries the bearings
of the screw axis is cast in one piece with the trough, but if the trough is of
wrought metal the bridge piece is bolted on, as shewn, and forms a good tie or
strengthening piece to keep the trough in shape. The bridge piece is made narrow
and deep so as to give the necessary strength and yet leave as little space as

page_text: possible between the screw blades which come on either side of it, so that the screw
may be as nearly as practicable continuous, and thereby avoid any heaping up of
the material in the trough below the bearings of the screw axis. Each length of
the axis of the screw is preferably of the same length as the sections of the trough.
It is square except where it is to be supported in a bearing, here it is circular, and
it is also formed with flanges to come against the ends of the bearings, as shown, so
as to exclude dirt from entering.
The abutting ends of two lengths of the axis both enter the boss of one of the
sections of the screw, and this boss is coupled by a coupling to the boss of the
section of the screw next to it, as shewn by the Drawing. Outlets from the trough
can be formed in it at any convenient points, and they can be fitted with slides by
which they can be closed or left open, as desired.
The boss of each section of the screw has a square hole formed centrally through
it into which the square axis fits. The boss has two segments of a screw projecting
from opposite sides of it, each segment or blade being a quarter turn of the screw;
thus when threaded onto the axis, in the way shown in the Drawing, they form a
continuous double threaded screw. Or a single threaded screw or screw with a
greater number of threads might be built up in the same way.
In some cases the trough might be formed with an outer casing through which
hot or cold water, steam, or air may be passed, so that the materials fed along by
means of the screw may be at the same time heated or cooled. In this way grain
might be dried, or in the case of cement the cement might be cooled.
Apparatus constructed in the manner above described may be employed for
conveying a great variety of materials from one place to another, more especially
such substances as cement, grain, sewage, shingle, ballast, clinkers, coke, brickbats,
and granular substances, and from the nature of its construction it can be made of
great strength should the purpose for which it is to be used render strength
necessary.
Having thus described the nature of my Invention, and the manner of performing
the same, I would have it understood that I claim,-
The construction of screw apparatus for conveying materials from place to place,
substantially in the manner herein before described.
In witness whereof, I, the said William Walter Hewitt, have hereunto set
my band and seal, this Fourth day of January, in the year of our Lord One
thousand eight hundred and eighty two,
W. WALTER HEWITT. (L.S.)