Improvements in High-speed Gearing.
Year: 1888

page_text: PROVISIONAL SPECIFICATION.
Improvements in High-speed Gearing.
I, JAMES GIBSON, Engineer, of Cartha Works, Paisloy, in the County of Renfrew,
Scotland, do hereby declare the nature of this Invention to be as follows, that is
to say :-
My Invention consists in combining toothed and frictional gear for high-speed
purposes; my object being to obtain the comparative noiselessness of a frictional drive,
with the absolute certainty or absence of slip of toothed gearing. My Invention is
specially advantageous when the gearing is arranged for considerably reducing or
increasing rotatory speed. In carrying out my Invention, I fix on the driving shaft
one or more grooved or other frictional driving wheels and also one or more toothed
wheels both frictional and toothed wheels having the same effective diameters or pitch
circles. And on the driven shaft I fix frictional and toothed wheels to gear with
those on the driving shaft. The toothed wheels may in general be considerably
narrower than the frictional wheels. The frictional and toothed wheels on each shaft
may be made in the same piece of metal or in separate pieces of the same or different
metals; I however prefer to make the toothed wheels or at least their teeth of vulcanised
fibro, wood, compressed paper, or similar material possessing toughness without
metallic hardness.
EDMUND HUNT,
Applicant's Agent.

page_text: I, JAMES GIBSON, Engineer, of Cartha Works, Paisley, in the County of Renfrew,
Scotland, 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, that is to say :-
My Invention consists in combined toothed and frictional wheel gearing for high-
speed purposes; my object being to obtain the comparative noislessness of a frictional
drive, with the absolute certainty or absence of slip of toothed gearing. My Invention
is specially advantageous when the gearing is arranged for considerably reducing
or increasing rotatory speed. In carrying out my Invention I fix on the driving
shaft one or more grooved or other frictional driving wheels and also one or more
toothed wheels both frictional and toothed wheels having the same effective diameters
or pitch circles. And on the. driven shaft I fix frictional and toothed wheels to
gear with those on the driving shaft. The toothed wheels may in general be
considerably narrower than the frictional wheels. The frictional and toothed wheels
on each shaft may be made in the same piece of metal or in separate pieces of the
same or different metals; I however prefer to make the toothed wheels or at least their
teeth of vulcanised fibre, wood, compressed paper, or similar material possessing
toughness without metallic hardness.
On an accompanying sheet an explanatory drawing shows one convenient modi-
fication of my improved gearing, this drawing comprising a compound pinion,
or small wheel, A, B, C, fast on a driving shaft, D, and one half in section,
together with part of large wheel, E, with which the pinion is in gear and which
is shown in section.
The shaft, D, may be the armature shaft or first-motion shaft of an electro-motor
rotating at a high-speed which speed requires to be reduced when applying the power
to various purposes.
The frictional surfaces which I prefer to employ and which are adopted in the
example delineated are what are known as grooved frictional surfaces. The larger
wheel, E, which is represented as made all in one casting is constructed with two
outer parts, F, G, grooved and with a middle part, H, having ordinary spur teeth.
The pinion is made in three pieces, one, A, of metal being formed with a grooved
external surface and with an elongated central tube, J, on which is keyed a middlo.
piece, B, formed with spur teeth, and made of vulcanised fibre, wood, or other suitable
tough material. There is also keyed on the tube, J, a metal piece, C, formed with a
grooved external surface. The grooved surfaces of the outer pinion parts, A, and C,
gear or work in contact with the outer grooved parts, F, G, of the large wheel, E;
and the spur-toothed part, B, of the pinion gears with the spur-toothed part, H, of
the large wheel, E.

page_text: In general I prefer to make the frictionally acting parts broader than the spur-
toothed parts, and so that the power is mainly transmitted frictionally; but tho
arrangement of the several parts may be varied in different cases.
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 :-
The combining together of toothed and frictional wheel gearing for high speeds
substantially in the manner and for the purposes hereinbefore described.
Dated this Fifth day of January 1889
EDMUND HUNT,
Applicant's Agent.