Improvements in Worm Gearing.
Year: 1895

page_text: Date of Application, 18th Oct., 1895
Complete Specification Left, 20th July, 1896-Accepted, 17th Oct., 1896
Improvements in Worm Gearing.
We, ERNEST JOHN CLUBBE and ALFRED WILLIAM SOUTHEY, both of
18, Elm Street, Gray's Inn Road, in the County of Middlesex, Electrical
Engineers, and COLIN CAMPBELL MURRAY GIBSON, of 6, Gaisford Street,
Kentish Town, in the County of Middlesex, Engineer, do hereby declare the
nature of this invention to be as follows:—
This invention relates to an improved form of construction for the teeth of what
are known as worm or screw wheels, that is to say geared wheels which are
adapted to be rotated by the action of a worin or screw.
The principal object of the invention is to reduce the excessive friction which,
with worm wheels constructed in the usual manner, is as is well known set up
between the teeth of the wheel and the threads of the worm, and thus to economize
the power required for actuating mechanism through this form of gearing.
Heretofore the teeth of worm wheels have usually been formed so as to extend
obliquely across the width of the face or periphery of the wheel, and have been
cast or otherwise formed in one with the framework of the wheel or have been
rigidly attached thereto. Now, by our invention, we employ, in place of such
rigid teeth, rollers mounted to rotate upon stu: pins fixed to the wheel so as to
substitute rolling for rubbing contact between the teeth and the threads of the
worm, these rollers being preferably furnished with ball bearings at each end so
as to still further reduce the friction.
In the case of small wheels, or those intended to transmit but little power,
each tooth might consist of a single roller but in larger wheels, or those requiring
greater strength, two or more rollers would be employed in the place of each tooth,
the stud pins carrying such rollers being so set as to suit the obliquity of the
threads of the worm with which the wheel is designed to gear.
The diameter of the rollers would, in general, be made substantially equal to
the thickness of teeth constructed in the ordinary manner, and their surfaces would
preferably be so shaped as to present in profile the proper oycloidal or other
flank curves.of geared wheel teeth.
Dated this 18th day of October 1895.
COMPLETE SPECIFICATION.
Improvements in Worm Gearing.
We ERNEST JOHN CLUBBE and ALFRED WILLIAM SOUTHEY, both of
16 Elm Street, Gray's Inn Road in the County of Middlesex, Electrical
Engineers and COLIN CAMPBELL MURRAY GIBSON formerly of 6 and now of
73 Gaisford Street, Kentish Town in the County of Middlesex, Engineer do
hereby declare the nature of this invention and in what manner the same is to
Improvements in Worm Gearing.
We ERNEST JOHN CLUBBE and ALFRED WILLIAM SOUTHEY, both of
16 Elm Street, Gray's Inn Road in the County of Middlesex, Electrical
Engineers and COLIN CAMPBELL MURRAY GIBSON formerly of 6 and now of
73 Gaisford Street, Kentish Town in the County of Middlesex, Engineer do
hereby declare the nature of this invention and in what manner the same is to

page_text: be performed, to be particularly described and ascertained in and by the following
statement:
This invention relates to the construction of the teeth of worm wheels, that
is to say wheels which are geared with a worm or screw for the transmission of
rotary motion.
The object of the invention is to reduce the friction generated and economize
the power consumed in the transmission of motion between the worm and worm
wheel and it consists in a construction of worm wheel whereby a rolling is
substituted for a rubbing contact between the worm and wheel.
The invention will be described with reference to the accompanying drawings
forming part of this specification wherein Figure 1 is a faco view of the worm
wheel with one roller tooth in section, the worm being also shewn in section, and
Figure 2 is an edge view of part of the wheel.
According to our invention we employ, in place of the ordinary worm wheel
teeth, roller teeth A mounted to rotate upon stud pins B fixed to the rim of the
worm wheel C these rollers being preferably furnished with ball bearings b b at
each end between them and the stud B.
In the case of small wheels, or those intended to transmit but little power, a
single roller A would suffice for each tooth of the worn wheel but in the case
of larger wheels, or those requiring greater strength, two or more rollers A would
be employed side by side across the worm wheol, as shewn in Figure 2, and
would together take the place of a tooth the stud pins B carrying such rollera being
set to suit the pitch and obliquity of the worm threads D with which the wheel is
designed to gear.
The rollers would preferably be so shaped as to present in profile the proper
oycloidal or other flank curves as shewn in the drawings.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
In worm gear for the transmission of motion, constructing the teeth of the
worm wheel of rollers running on studs fixed to the wheel rim substantially as
specified.
Dated this 20th day of Inle 1898.