AN IMPROVED CONSTRUCTION OF CLUTCH FOR DRIVING MACHINERY
Year: 1866

page_text: LETTERS PATENT to William Clissold, of Dudbridge Works, near Stroud,
in the County of Gloucester, Engineer, for the Invention of "AN IMPROVED
CONSTRUCTION OF CLUTCH FOR DRIVING MACHINERY."
Sealed the 27th July 1866, and dated the 9th February 1866.
PROVISIONAL SPECIFICATION left by the said William Clissold at
the Office of the Commissioners of Patents, with his Petition, on the
9th February 1866.
I, WILLIAM CLISSOLD, of Dudbridge Works, near Stroud, in the County of
Gloucester, Engineer, do hereby declare the nature of the said Invention for
"AN IMPROVED CONSTRUCTION OF CLUTCH FOR DRIVING MACHINERY," to be as
follows:-
This Invention relates to a novel construction of clutch for driving
machinery, in which the disadvantages attendant on the friction clutch are
removed, by combining in one clutch the principle of action of both kinds of
clutch.
The Invention is designed chiefly for use with my V belts, which press laterally
against the inclined sides of the grooved driving pulley, but it may be applied to
driving pulleys of the ordinary construction, whether flat or grooved, or to cogged
gearing. Upon the shaft or axle to be driven I key the fixed half of an ordinary
clutch, and mount loosely on the same shaft or axle the driving pulley which I
provide at one side with clutch teeth to fit into the teeth of the fixed clutch, and

page_text: at the other side with a hollow cone. I also key upon the shaft or axle a
solid cone to fit into this hollow cone, and I leave a sufficient space between the
cone or friction clutch and the fixed tooth clutch to allow of the pulley being
slidden into a position where it will be free of both. I give an endway motion
to the pulley by a hand lever, which embraces the boss and serves to shift it to
the right or left, and secure it in position in the manner well understood.
The action of this improved clutch is as follows:-In starting the machinery
which is to be driven by the pulley I throw the pulley into gear with the
fixed cone, and hold it in contact until the required speed is attained. I then
in order to maintain that speed and prevent the slip to which friction gearing
is very liable, throw the pulley suddenly back into gear with the toothed
clutch and fix it in that position. As the toothed clutch is at the time of the
pulley engaging with it running at the like speed, no shock or tendency to
strip the teeth will be produced. This clutch may be modified, but with no
no great advantage, by making the tooth clutch which has been described as
fixed to slide on a feather on the shaft or axle and approach the pulley when
it is in gear with the friction cone. For this purpose a second hand lever
will be required to operate the tooth clutch and hold it up to its work.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clissold in the Great Seal Patent Office on the
9th August 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLISSOLD, of Dudbridge Works, near Stroud, in the County of Gloucester,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of February, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Clissold, Her special licence 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 CLUTCH FOR DRIVING MACHINERY,". upon the condition (amongst

page_text: others) that I, the said William Clissold, my executors or administrators, by
an instrument in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Invention,
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 construction of clutch for driving
machinery, by the use of which the disadvantages attendant on the ordinary
friction clutch and the toothed clutch are removed.
The improvement consists in combining in one clutch the principle of action
of both kinds of clutch. This improved clutch is designed chiefly for use with
my V belts, which press laterally against the inclined sides of the grooved
driving pulley, but it may be applied to driving pulleys of the ordinary con-
struction, whether flat or grooved, or to cogged gearing.
In the accompanying Drawing, Fig. 1 shews in plan view my improved
compound clutch applied to the driving shaft of a machine intended to be
operated by steam power.
A is the shaft or axle to be driven, and upon it is keyed the fixed half B
of an ordinary toothed clutch. Mounted loosely on the same shaft or axle is
the driving pulley C, which I provide at one side with clutch teeth B¹ to fit
into the teeth of the fixed clutch B. The other side of the pulley I hollow
out into a conical form, and in front of this hollow cone I mount and key to
the shaft or axle a solid cone D, which is intended to fit into the hollow cone,
and form with it a friction clutch. In mounting the solid cone D on its shaft
I leave a sufficient space between it and the fixed tooth clutch to allow of
the pulley being slidden into an intermediate position, where it will be free of
both the solid cone and the clutch teeth, and I give an endway motion to the
pulley C by means of a hand lever E, which rocks on a fixed fulcrum and
embraces the boss of the pulley. The attendant by rocking this lever is
enabled to shift the pulley to the right or left and secure it in position by
fixing the lever in the manner well understood and shewn in the Drawing.
The action of this improved clutch is as follows:-In starting the machinery
which is to be driven by the pulley C, I first throw the pulley into gear with
the fixed cone and hold it in contact by hand until the required speed is

page_text: attained; I then in order to maintain that speed and prevent the slip to which
friction gearing is very liable, throw the pulley suddenly back into gear with
the toothed clutch, as shewn by red lines in Fig. 1, and fix it in that position.
As the toothed clutch B is at the time of the clutch teeth of the pulley
engaging with it running at the same speed as the friction clutch, no shock or
tendency to strip the teeth will be produced in effecting the engagement of the
clutch teeth, but they will be about as free to interlock as if both divisions of
the clutch were at the time quiescent. This clutch may, if thought desirable,
be modified, but in my opinion with no great practical advantage, by making
the tooth clutch B which has been described as fixed to slide on a feather on
the shaft or axle A, and approach the pulley C when it is in gear and rotating
with the friction cone. For this purpose a second hand lever will be required
to operate the tooth clutch and hold it up to its work. This arrangement I
have shewn in plan at Fig. 2 in combination with a flat band driving pulley.
Having now set forth the nature of my Invention of an improved con-
struction of clutch for driving machinery, 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, the construction of compound driving
clutch as above described.
In witness whereof, I, the said William Clissold, have hereunto set my
hand and seal, the Sixth day of August, in the year of our Lord One
thousand eight hundred and sixty-six.
Witness,
ALFRED SMITH.
WILLIAM CLISSOLD. (L.S.)