Improvements in Gear Wheels.
Year: 1898

page_text: Date of Application, 25th Oct., 1898-Accepted, 26th Nov., 1898
COMPLETE SPECIFICATION.
Improvements in Gear Wheels.
I, WILLIAM GLEASON, of 104, Platt Street, Rochester, Monroe County, New York,
United States of America, Manufacturer, 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:—
In using toothed metal gearing, more particularly of the heavier kind, especially
if run at high velocities, there is liable to occur objectionable rumbling and jarring,
and disagreeable noise, resulting from the rapid concussion of the teeth as they
encounter each other in passing. In attempting to avoid these difficulties and
objections one of a pair of coacting gears has sometimes been constructed with
wooden teeth to engage the metal teeth of the other gear; or, the teeth of one
gear have been capped or covered with a soft material, as leather, to prevent noise
and jar. But these devices have not proven satisfactory for the yielding covering of
the teeth has proved too frail to stand the stress and wear brought upon it, and the
wooden cogs are liable to swell out of shape during periods of wet weather or if
employed in damp wheel pits, or, on the other hand, will shrink and so get loose
and rattle during warm dry weather, or if used in shops or apartments heated by
artificial means.
To overcome these various difficulties and objections by producing an improved
tooth or cog for such gears, which shall be durable, and prevent noise and jar while
operating with other teeth, and also which shall run with the least friction, is
the object of my invention. To accomplish this I form grooves or cavities length-
wise in the working faces of the cogs of one of a pair of coacting gears and insert
therein bars or strips of a non-metallic substance, or of a metal different from that
of which the primary cogs are composed, having said strips or bars project
from the faces of the cogs to receive the impact and pressure of the opposing cogs
of the companion gear. I form these grooves or cavities dovetail in cross section
and slightly tapered in length. The bars or pieces inserted are formed of similar
cross section and taper, so they may be driven firmly into their seats in the cogs
and, ordinarily, hold to place by friction. These grooves or seats for the bars
are formed as wide as the size of the tooth or cog will permit, leaving sufficient
material between the groove and the point of the tooth for strength. The bars are
practically trapezoidal in cross section and formed so as not to cover any part of the
face of the cog on either side of the groove the latter being preferably about
midway of the width of the face of the tooth between its point and root. That
s to say, the groove is formed about equally on either side of the pitch circle of the
rear and so as to leave about an equal amount of the original face of the tooth on
ither side.
In addition to friction a suitable cement or other adhesive substance may be
mployed, in some cases, for holding the teeth to place in the gear. The teeth of
he gear designed to be provided with the bars are made thicker than those of the
ther gear of the pair.
This invention applies equally well to the teeth of either spur or conical gears,
ut in the latter case the taper in length of the groove is slightly sharper or more

page_text: marked. But one gear of a pair is usually provided with these anti-rattling and
anti-friction bars, and it may be either the driving or the driven gear as may be
convenient. In case of a pair differing in size it is usually the smaller gear that
is provided with the bars.
The teeth of gears provided with these anti-friction bars
are usually not cut or planed, save as to the grooves themselves, said teeth being
generally left in the rough casting. After the bars are put to place in the teeth
of a gear their projecting working faces are truly formed or curved so as to work
accurately with the cut faces of the teeth of the companion gear of the pair.
The teeth of bevel gears, particularly if mounted on vertical shafting, are
usually provided with a holder for each bar to bear against its large end to prevent
it becoming displaced or dropping out from the action of gravity. This holding
plate may be a simple flat piece of metal secured to the gear by means of a screw or
other simple fastener in position to cross the joint between the primary tooth and
its contained bar and bear upon the latter.
As stated, these bars may be made of any suitable material, including even
metal different from that of which the gear is composed. Bars of vulcanite or paper
fiber have been found very satisfactory for heavy gearing. Such fibrous bars
not being sonorous very much deaden the noise of the gears which results from the
cogs striking each other in a succession of heavy blows.
In order that my said invention may be more fully understood and readily carried
into effect I will proceed to describe the drawings hereto annexed.
Figure 1 is a cross section of some of the adjacent teeth of a pair of coacting
gears. Figure 2 is an elevation of the working face of a spur tooth seen as
indicated by arrow in Figure 1, a part being broken away and the adjacent part
of the gear sectioned on the dotted line at the point of the arrow. Figure 3 is
a similar elevation of the tooth of a bevel gear.
In the working faces, b, of the teeth, d, of the gear B, adapted to co-act with the
faces a of the teeth c of the gear A are formed grooves, e, in which are inserted the
bars C, truly formed. The grooves are planed or milled accurately with a machine
adapted to the purpose, so that the bars shall be alike as to size The dovetail
form and broad bearing of the bars in the teeth enable the former to hold firmly
to their seats when driven tightly to place. In case a pair of gears is calculated to
turn in either direction the teeth of one gear are provided with these bars on
both faces.
Figure 3 shows the method of employing the holding-pieces f. These pieces are
secured to the gear in convenient positions to bear upon the ends of the bars.
Instead of a separate holder for each bar a ring of metal, whole or in sections,
may be employed to bear upon all the bars.
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:
(1) A gear tooth having a bar or strip of metal or material different from that of
which the tooth is formed inserted in or on its engaging face or faces and project-
ing therefrom, the projecting face or faces of said bar or strip being curved or
formed to correspond to the working face of a gear tooth.
(2) A pair of coacting toothed gears the working faces of the teeth of one of which
being each provided with a separate bar or body of metal or material different from
that composing the tooth, as set forth.
(3) A gear having its teeth thickened and the working faces of the teeth each
provided with a groove with a separate bar or body of metal or material different
from that of the tooth with its acting face laterally curved to correspond to the
working face of a gear tooth and its inner face having an extended bearing on the
bottom wall of the groove in the body of the tooth, substantially as described.
(4) The combination with a gear tooth, of a bar independent therefrom and of a
different material than the body of the tooth, said bar being seated in a dovetail

page_text: groove in the tooth and covering the face of the tooth with the working face of the
bar projecting from the face of the tooth, substantially as shown and described.
(5) The combination with a gear having a tooth provided upon its face with a
groove dovetailed in cross section and tapered longitudinally, of a separate bar or
body of material different from that of the tooth and tapered with its sides beveled
to fit the beveled walls of the dovetail groove and held therein with its working
face projecting from the face of the tooth, all substantially as shown and described.
(6) The combination with a gear- having its teeth provided upon their faces
with dovetail grooves tapered longitudinally, of a separate bar or body of material
different from the body of the tooth tapered longitudinally and dovetail in cross
section held in each groove, and a plate secured to the side of the gear and over-
lapping the joint between the tooth and bar and bearing against the larger end of
the bar to prevent endwise displacement thereof, substantially as shown and
described.
.
(7) Teeth for gear wheels constructed, arranged, and adapted to operate sub-
stantially as herein before described and shown.
Dated this 25th day of October 1898.
ROBERT E. PHILLIPS, Assoc. M. Inst. C.E., M.I. Mech. E.,
Chartered Patent Agent,
70, Chancery Lane, London, W.C., Associate Agent.