Improvements in and connected with Conveyor Belts.
Year: 1899

page_text: Date of Application, 11th Sept., 1899-Accepted, 25th Nov., 1899
COMPLETE SPECIFICATION.
Improvements in and connected with Conveyor Belts.
I, ALBERT THEODOR OTTO, of 32, Broadway, in the City County and State of
New York, United States of America, Machine Maker, 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:-
Conveyors for coal, ore, mineral or other substances have been made of a
belt and in most instances the edges of the belt have been bent upwards so as to
give the belt approximately a trough shape, and in other instances rubber tubes
have been fastened to the surface of the belt closely adjacent to the edges; and
in still other cases rims of rubber have been placed on each edge of the belt; in
all cases with the object of preventing the material from dropping off.
Belts of this character are exposed to very severe wear by the constant chang-
ing of the belt from the flat to the troughing shape as it passes over the carrying
pulleys, thereby disintegrating the belt and breaking the bond between the plies
at the line of fold and this is augmented by flattening the rim of the belt when
passing around the end pulleys and where the belt is long, the pull upon the
belt in moving it from one position to another is also very severe.
In my present improvement, the fabric of which the belt is composed is folded
so that the edges of the fabric are brought together near the middle of the belt,
while the edges of the belt itself are hollow, so that such edges can be inflated
and when passed over substantially cylindrical rollers, the hollow edges of the
belt stand up sufficiently high to give to the belt a trough-shape for receiving
coal, ore, ashes, flour, meal, or other material, and these hollow edges of the
belt are also adapted to receive ropes by which the tension for drawing the belt
along and the material upon it, is taken principally upon the ropes and the belt
itself largely relieved from the tension necessary in giving motion thereto, and
the end pulleys or rollers around which the belt passes in changing its direction
are to be made to conform to the belt, that is to say, the ends of such rollers are
advantageously conical so that the two surfaces of the belt are approximately the
same shape and undue strain or distension of the hollow portions near the edges
of the belt, is avoided, and where the edges of the belt fabric come together
they are advantageously lapped so as to break joints.
In the drawing,
Figure 1 is a diagrammatic illustration of the endless belt around its respective
rollers;
Figure 2 is a cross section in larger size illustrative of the manner in which
the layers of fabric are put together in making up the belt;
Figure 3 is a cross section showing the trough-shaped belt upon its cylindrical
roller:
Figure 4 is a cross section illustrating the belt where it passes around one of
the end drums or rollers in changing directions; and
Figure 5 shows parts of an end pulley for the belt represented in Figure 3.
The belt is preferably made of closely woven canvas in two, three or more
ayers or thicknesses cemented together by rubber or similar material. I have
hown three thicknesses of fabric abc and in laying up the thicknesses and construct-
[Price 8d.]

page_text: ing the endless belt, it is advantageous to employ canvas twice the width of the
complete belt, so that the layers of fabric can be folded around from the top
to the bottom portion and doubled at each edge, bringing the edges 22 of the
fabric closely together near the centre of the trough-shaped part; and it is also
advantageous that the edges should not all be upon one line, but should be in a
position to break joints as indicated in Figure 2, and after the belt has been
properly laid up with indiarubber or other adhesive material, it may be cured as
usual, and in folding over the fabric of the belt, the edge portions are to be left
hollow to any desired extent, and the opening is preferably uniform or nearly
so throughout each side of the endless, belt, and, after completion, the hollow
edges of the belt may be more or less inflated so as to have the desired pressure
within such hollow edges.
I prefer and use ropes de of manilla or similar material introduced into the
hollow edges of the belt and connected up with tension couplings as is done in
single rope drives, and of such length that the strain comes upon the ropes and
the belt is relieved to the desired extent.
...
The rollers for pulleys around which the endless belt passes from one position
to another, are to be cylindrical where the central portion of the belt passes, and
the end portions 3 are of reduced diameter to correspond to the normal con-
dition of the belt as manufactured, that is to say, that the hollow edges extend
equally above and below a central plane passing through the fabrics of the belt,
so that undue strain upon the hollow edge portions of the belt in passing around
the end rollers or pulleys is avoided, and it is also advantageous to terminate the
conical ends of the end rollers as grooves adapted to fit the exterior surface of the
belt when it contains the ropes, so that the motion may be given to the endless
belt through the action of the ropes without undue strain upon any part of the
belt;
but where the belt is employed to receive any material to be conveyed
from one place to another, such belt is to be made to assume a maximum trough
shape, and with this object in view, the straight cylindrical rollers are employed
at intervals and hence the bottom surface of the conveyor belt will be flat and
the hollow edges of the belt will be raised up and the upper surface of the belt
will hence assume the proper trough shape (see Figure 3) to receive the material
to be transported.
The delivery of the material to the belt can be made at any desired point. In
some instances, it will be at the end roller where the belt passes down and around
such roller, the material sliding off the belt into any suitable hopper or receptacle,
illustrated at o.
In many instances, belts of this character are arranged to receive material
and convey the same in one direction and deliver the same at any intermediate
point or at the end pulley or roller and then to receive other material upon the
under or return portion of the belt to convey the same in an opposite direction
and to deliver such material at any point before the belt reaches the distant pulley
around which the same returns; and in carrying out this feature of the invention,
rollers h h may be provided for the belt to pass over in an S-shape, so that the
delivery may be into a trough or receptacle p passing off laterally.
It is to be understood that I do not limit myself to any particular arrangement
of supply hopper or chute or delivery hopper or chute, or to any particular
direction in which the belt may be caused to travel between the reception of
the material and its delivery.
The material may be allowed to slip off the edges of the belt laterally if the
belt is raised up by a pulley that acts below the centre of the belt longitudinally.
The ropes de may be held in the edges of the belt fabric in any desired manner.
When the ropes de are not used, the pulleys f h and h¹ may be made with
conical ends as illustrated in Figure 5. When the belt is used for handling
roasted ores or other material in a hot condition, I apply a sheet of asbestos to
the surface of the belt, as shown at m, the same being rivetted or otherwise
attached, and of sufficient thickness to prevent the heat injuring the belt.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is: :-
1. The conveyor belt composed of a fabric that is double thickness in the
middle portion from side to side and single thickness at the tubular edges, the
single fabric at the edges being folded around from the top to the bottom portion,
the said middle portion being of a double thickness where strength is required,
substantially as set forth.
2. A conveyor belt having tubular edges formed by folding over the fabric
and securing the flat middle portions together and ropes within such tubular
edges, the belt and ropes being endless, substantially as set forth.
3. A conveyor belt having tubular edges and ropes within such edges, the belt
and the ropes being endless, in combination with pulleys that are cylindrical in
the middle portion and reduced in diameter towards the ends in line with the
ropes in the belt, substantially as set forth.
4. The endless conveyor belt composed of a fabric folded over upon the edges
and secured together at the flat middle trough-shaped portion so that the edges are.
tubular, in combination with pulleys by which a motion is given to the endless
belt and intermediate rollers that are cylindrical and support the belt and cause
the tubular edges to form the edges of the trough-shaped conveyor, the bottom
of such belt being substantially flat, substantially as set forth.
5. The endless conveyor belt composed of a fabric folded over at the edges and
secured together at the middle trough-shaped portion, so that the edges are
tubular, in combination with pulleys that are cylindrical to support the flat portion
of the belt, and the end portions of the pulleys are of reduced diameter for receiv-
ing the tubular edges, substantially as set forth.
Dated this 9th day of September 1899
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.