AN IMPROVED CONSTRUCTION OF DRIVING BELT
Year: 1861

page_text: LETTERS PATENT to William Clissold, of Dudbridge, in the County of
Gloucester, Engineer, for the Invention of "AN IMPROVED CONSTRUCTION
OF DRIVING BELT."
Sealed the 31st October 1861, and dated the 2nd May 1861.
PROVISIONAL SPECIFICATION left by the said William Clissold at the
Office of the Commissioners of Patents, with his Petition, on the
2nd May 1861.
I, WILLIAM CLISSOLD, of Dudbridge, in the County of Gloucester, Engineer,
do hereby declare the nature of the said Invention for "AN IMPROVED CON-
STRUCTION OF DRIVING BELT," to be as follows:-
This Invention relates to a novel mode of constructing driving belts,
whereby any required strength of belt may be imparted thereto. In a Patent
already obtained by me, and bearing date May 22nd, 1860, I have described a
construction of driving belt, which, when tightened on its pullies, relies upon
its lateral pressure on the pullies for taking a firm hold and preventing the
slip to which driving pullies are in general very liable. The belt is, according
to this Invention, bevilled at its edges, to fit into V-grooves on the periphery
of the driving pullies, and it is composed of layers of leather or other material
connected together by pins, or otherwise. In practice I have found that the
beneficial thickness of which these belts may be made is limited, by reason of

page_text: the unequal strain upon the outer and inner layers of material, and, con-
sequently, that their strength cannot with advantage be indefinitely increased.
I therefore propose, instead of making bevilled edged belts, as heretofore,
with one continuous length of bevilled edge, to form them (when great strength
is required) of links, which (while presenting good contact surfaces to the
V-grooves of the pullies, against which they will press laterally without touching
the bottom of the grooves) will so divide the unequal strain as to render it
nugatory. The friction or wedge-shaped links I propose to make of strips of
leather or other flexible material coiled up or moulded to the ordinary figure
of a link, and these links I propose to connect together by link plates carrying
a stud at either end, which studs will enter the space in two adjacent flexible
links and hold them together, forming, in fact, fulcrum pins for these links to
turn on as they pass around the driving pullies; this arrangement permits of
any strength of link being used according to the work to which the belt is to
be applied. Belts constructed on this principle may be made wholly of metal,
in which case I prefer to line the grooves of the pullies with wood, to prevent
the grinding of metal against metal.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clissold in the Great Seal Patent Office on the
2nd November 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLISSOLD, of Dudbridge, in the County of Gloucester, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of May, in the year of our Lord One
thousand eight hundred and sixty-one, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Clissold, Her special license that I, the said William Clissold,
my executors, administrators, and assigns, or such others as I, the said
William Clissold, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times thereafter.
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "AN IMPROVED
CONSTRUCTION OF DRIVING BELT," upon the condition (amongst others) that I,
the said William Clissold, by an instrument in writing under my hand and

page_text: seal, should particularly describe and ascertain the nature of the said Inven-
tion, and in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Clissold, do hereby declare
the nature of my said Invention, and in what manner the same is to be.
performed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawing hereunto annexed, and to the
letters and figures marked thereon (that is to say):
This Invention relates to a novel mode of constructing that class of
driving belts which bind by lateral pressure on their pullies, and thereby take
so firm a hold as to remove the liability to slip, which is a disadvantage
common to ordinary driving belts. This improved class of belts (which already
forms the subject of Letters Patent granted to me, and bearing date the
Twenty-second day of May One thousand eight hundred and sixty, No. 1266,)
may be described as an endless band bevilled at its edges to fit into V-grooves
formed in the periphery of the driving pullies, such band being composed of
layers of leather or other material connected together by pins, or otherwise.
In practice it has been found that the beneficial thickness of which these belts
may be made is limited, by reason of the unequal strain upon the outer and
inner. layers, or parts of the material composing the belt, and, consequently,
that the strength of such belts cannot with advantage be indefinitely increased.
From this cause it was deemed necessary to limit the application of belts con-
structed of a wedge or taper form in cross section to uses where no great
strain was likely to be experienced.
:
Now the object of the present Invention is to increase the strength of belts
of this class as to render them equal to the heaviest work to which it has
hitherto been or may hereafter be found desirable to apply driving belts or
bands. To this end, instead of making bevilled edged belts, as heretofore, with
one continuous length of bevilled edge, I form them of links, which, while
presenting good contact surfaces to the V-grooves of the pullies (against which
they will press laterally without touching the bottom of the grooves), will so
divide the unequal strain upon the inner and outer surfaces of the belt hitherto
found so destructive to the wedge form of belt as to render the strain nugatory.
The friction or wedge-shaped links may be made of strips of leather or other
flexible material coiled up to the ordinary figure of a link, or they may be
made of moulded rubber or other suitable plastic material. These links I
connect together by link plates carrying a stud at either end, which studs
will enter the space in two adjacent flexible links and hold them together,

page_text: forming, in fact, fulcrum pins for these links to turn on as they pass around the
driving pullies.
In the accompanying Drawing I have shewn my improved construction of
link driving belt in several views, the friction links being in this example
composed of coils of leather. Fig. 1 represents the outer face, and Fig. 2 a
side elevation, of a portion of the belt drawn to full size; Fig. 3 is a view of
the inner face of the belt, and Fig. 4 is a cross section shewing the application
of the belt to a grooved pulley.
The wedge-shaped links a, a, fit into the groove of the pulley, but not so
as to bed therein, the object being to allow of the belt tightening on the
pulley by sinking deeper into the groove as the breadth of the links decreases
by wear. These links a are each made by preference of two parts to facilitate
the forming of sockets for the reception of the link plates b, b, and the parts
a, a, are coupled together in the middle by filling pieces a cemented thereto,
or otherwise attached to the parts a. I prefer to give to these filling picces
the form shewn at Fig. 5, as they then serve to keep the link plates (one of
which is shewn detached at Fig. 6) in position when the belt is slack, but
other means of effecting the object of the filling pieces may be adopted;
c, c, are the studs of the link plates, which may either be made of cast or
wrought metal, as thought most desirable. When making the flexible links a
of leather, I propose to form them with square sides, as shewn at Fig. 7, and
then to divide them lengthwise by a diagonal cut, as indicated by the red
line d, d. By bringing together the square sides of the severed link the
wedge shape will be obtained without waste of material. When the flexible
links are made of plastic material, they may be moulded at once into the
proper form for half links, and then cemented together preparatory to being
submitted to the curing operation.
"
Figures 8 and 9 shew, in side and plan views, a leather link strengthened by
a metal strap and suitable for driving belts of the heaviest class. The metal
strap e embraces the parts a, a, and its ends are secured by rivets. Slots
are cut in the strap for the insertion of the link plates, and the solid metal
between the slots will serve the same purpose as the filling piece a before
spoken of.
From the above explanation it will be understood that this mode of making
driving belts permits of any strength of link being used according to the work
to which the belt is to be applied. I would also remark that belts constructed
on this principle may be made wholly of metal, in which case I prefer to line
the V-grooves of the pullies with wood to prevent the grinding of metal against
metal.

page_text: Having now described the nature of my Invention and explained the
manner of carrying the same into effect, I wish it to be understood that, under
the above in part recited Letters Patent, I claim constructing wedge-shaped
driving belts suitable for working in conjunction with V-grooved pullies of
links, substantially in the manner and for the purpose above set forth.
In witness whereof, I, the said William Clissold, have hereunto set my
hand and seal, the Thirtieth day of October, in the year of our Lord
One thousand eight hundred and sixty-one.
WILLIAM CLISSOLD. (L.S.)