AN IMPROVED FRICTIONAL COUPLING WHICH MAY ALSO BE USED AS A BRAKE
Year: 1881

page_text: LETTERS PATENT to William John Fraser, of 121, Adelaide Road, Haverstock
Hill, in the County of Middlesex, Engineer, for an Invention of "AN
IMPROVED FRICTIONAL COUPLING WHICH MAY ALSO BE USED AS A BRAKE."
PROVISIONAL SPECIFICATION left by the said William John Fraser at the
Office of the Commissioners of Patents on the 12th November 1881.
WILLIAM JOHN FRASER, of 121, Adelaide Road, Haverstock Hill, in the County
of Middlesex, Engineer. "AN IMPROVED FRICTIONAL COUPLING WHICH MAY ALSO
BE USED AS A BRAKE,"
My Invention has reference to a frictional coupling for conveying power from a
prime mover to a driving shaft or a machine for giving motion to the same, and
also to a brake for retarding motion.
And my Invention consists in the combination of two wheels united in action
by means of an endless band with an intermediate friction wheel or wheels capable
of being adjusted by means of a screw or levers so as to regulate the pressure on
the two band wheels, and tighten or loosen the band thereon as required, thereby
affording a better means of conveying and controlling the power and reducing the
friction on the bearings existing in ordinary frictional gearing.
A steel or other band may be used for the purpose, or a wire rope (in which
latter case the two wheels may be grooved) or other flexible form of connection
for conveying the power, sufficient play being allowed in the bearings of the band
wheels to allow of the tightening of the said band or bands by the pressure of the
intermediate wheel or wheels.
The said coupling can be used for any purpose in which power is required to be
conveyed for giving motion, and also wherever brake power has to be applied.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William John Fraser in the Great Seal Patent Office on the
12th May 1882.
WILLIAM JOHN FRASER, of 121, Adelaide Road, Haverstock Hill, in the County
of Middlesx, Engineer. "AN IMPROVED FRICTIONAL COUPLING WHICH MAY ALSO
BE USED AS A BRAKE."
My Invention of "An Improved Frictional Coupling which may also be used
as a Brake" has reference to a frictional coupling for conveying power from a
prime mover to a driving shaft or a machine for giving motion to the same, and
also to a brake for retarding motion.
And my Invention consists in the combination of two wheels united in action
by means of an endless band with an intermediate friction wheel or wheels,
capable of being adjusted by means of a screw or levers, so as to regulate the
pressure on the two band wheels, and tighten or loosen the band thereon as
required, thereby affording a better means of conveying and controlling the power
and reducing the friction on the bearings existing in ordinary frictional gearing.
A steel or other band may be used for the purpose, or a wire rope (in which
latter case the wheels may be grooved) or other flexible form of connection for
conveying the power, sufficient play being allowed in the bearings of the band
wheels to allow of the tightening of the said band or bands by the pressure of the
intermediate wheel or wheels.
The said coupling can be used for any purpose in which power is required to be
conveyed for giving motion, and also wherever brake power has to be applied.
Having thus stated the nature of the said Invention I will proceed to describe
more particularly in what manner the same is to be performed by the aid of the
accompanying Drawings, in which are represented the parts constituting the
improved frictional coupling above referred to.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is an elevation, Fig. 2 a plan or horizontal view, and Fig. 3 a transverse
vertical section in the line A, B, of Fig. 1. In these several Figures the same
letters of reference indicate corresponding parts. a, a, are two wheels, one of
which is keyed to the driving shaft from the prime mover, and the other to the
driving shaft of the machine to which motion is to be imparted. These two
wheels are united in action by means of an endless band b and combined with an
intermediate friction wheel c, the pressure of which on the band wheels a, a, is
regulated by the screw d, so as to tighten or loosen the band b thereon as required,
the movement of the screw being communicated to the axis of the wheel c, by
means of the fork e, or by other suitable means. If preferred, levers may be
substituted for the screw d.
By adjusting the pressure of the friction wheel c on the band wheels a, a, power
can be conveyed from a prime mover to a driving shaft or a machine, and can
be controlled as required, and the friction on the bearings caused by the outward
thrust in the ordinary frictional gearing will be obviated. The combination above
described may also be used advantageously as a brake.
For reversing motion it is advisable to fix a friction wheel below as well as
above the line passing through the centres of the band wheels as shewn, and
this second friction wheel may be actuated or regulated in its pressure by means
of the same screw or lever as the one above described. And for certain applications

page_text: of the principle or combination of two band wheels and a friction wheel or wheels
(say where less rigidity is required in conveying the power to some machines or
vehicles) a spiral or other spring may be introduced to lessen the grip on the
wheels and give a compensating power to the machine or machines driven.
Having thus described the nature of the said Invention and in what manner
the same is to be performed, I hereby declare that what I claim as of my Invention
is,―
-
The combination of two band wheels and a friction wheel or wheels adjustable
as to pressure on the band wheels by means of a screw or screws or levers, thereby
constituting a frictional coupling for conveying and controlling power and reducing
friction on the bearings, or a means of applying brake power, as hereinbefore
described.
In witness whereof, I, the said William John Fraser, have hereunto set my
hand and seal, the Twelfth day of May, in the year of our Lord One
thousand eight hundred and eighty two.
Witness,
WILLIAM SPENCE,
8, Quality Court,
Chancery Lane.
W. J. FRASER. (L.S.)