Improvements in or relating to Toothed Gearing.
Year: 1899

page_text: Date of Application, 5th Sept., 1899-Accepted, 4th Nov., 1899
Improvements in or relating to Toothed Gearing.
A communication by CHARLES L. TRAVIS, of Minneapolis, in the State of
Minnesota, United States of America.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester,
both in the County of Lancaster, 118, New Street, Birmingham, in the County
of Warwick, and 322, High Holborn, in the County of Middlesex, Civil Engineer,
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:
-
This invention pertains to gearing, and particularly to such as employs anti-
friction rollers to constitute the engaging or intermeshing members, or to take
the place of the ordinary rigid teeth."
The invention may be embodied in bevel gearing, in spur gearing-which term
is meant to include both internal and external gears-or in racks and pinions, as
occasion may require. Its details may vary somewhat without departing from
the spirit or scope of the invention, the primary purpose of which is to sub-
stitute rolling for sliding or rubbing friction, and at the same time to produce a
strong and durable gearing.
In the drawings,
Figure 1 is a face elevation of a bevel gear or pinion embodying the invention;
Figure 2 a sectional view showing two such wheels in operative relation or
engagement;
Figure 3 an enlarged view showing the construction and mode of mounting
the rollers, portions being broken away to better show the arrangement and
construction of parts;
Figure 4 a sectional view illustrating the invention as applied to a spur
wheel and rack;
Figure 5 a similar view showing the rack with rigid teeth instead of rollers;
Figure 6 a sectional view, similar to Figure 2, but showing one of the bevel
wheels with rigid teeth;
Figures 7 and 8 sectional views showing pinions mounted upon axles made
integral with the wheel body or disc.
Referring now to the drawings, and first to Figures 1, 2 and 3 thereof, A
indicates the body or disc and hub portion of a wheel having a peripheral flange a
which is of a scalloped form, or is provided with alternate projections or cars b
and depressions or recesses c, the latter advisably of greater width than the
intervening projections or ears. In the case of spur wheels, or a wheel designed
to co-act with another wheel or rack moving in the same, or in a parallel plane,
the flange will be in the same plane with the disc or body portion on which
it is formed. In other words, the scalloped edge or alternate projections and
depressions may be simply the outer edge or periphery of the disc in the case of

page_text: spur gearing, but for bevel gears or wheels designed to impart motion to another
member moving in an intersecting plane, the flange a will be set at an appro-
priate angle to the body or disc A, as shown in Figures 2 and 3. The angle at
which the flange stands relatively to the body or disc portion will of course vary
according to the relative diameters of the two co-acting wheels. In Figure 2,
two such wheels are shown of equal diameter, and their flanges a are accordingly
set at an angle of 45° relatively to the body or disc portions.
The ears or projections 6 are designed to carry the supporting axles of a series
of rollers, which rollers will in the case of spur gearing and racks be of cylindrical
form, but in the case of bevel gearing will be conical or tapering, the taper
being such that straight lines contacting with their surfaces and running in the
general direction of their axes will all meet in the point of intersection of the
axes of two co-operating wheels.
BB indicate the rollers, which are made each in two sections, one on each
side of the flange a or the ear thereof. The axles of the rollers B may be
formed by short tubes or bushings C similarly made in two sections and placed
on opposite sides of the supporting or carrying ears b, as shown in Figures 2, 3,
4, 5 and 6. To firmly secure these bushings or bearing sleeves in their proper
positions, and to guard against any shifting or movement thereof either laterally
or longitudinally, the ears are drilled or bored to receive a fastening device,
rivet, or bolt D, and both faces of said ears are counterbored concentrically with
the bolt or rivet hole to receive the inner ends of the sleeves or bushings C, as
best shown, in Figure 3, though also seen in Figures 2 and 6. The sleeves or
bushings C are made of a length sufficient to enter counterbored seats or
sockets d, and to project from the faces of the ears or projections b a distance
slightly greater than the axial measurement of the rollers B. The sleeves or
bushings being placed in position, and the rollers B being mounted thereon, the
several parts are firmly and accurately secured and retained in place by means
of a rivet D or its equivalent, a bolt or like fastening, which is passed through
the sleeves and the intervening ear b, and properly secured in place. In practice
it is found convenient and expedient to employ rivets, preferably of steel, having
at one end a reasonably large and well formed head e, and of such length as to
permit the application of a washer f to its protruding end, and to leave metal
sufficient for the formation above or outside of said washer of a second head g.
The rollers and the sleeves or bushings are by preference made of hardened or
tempered steel, while the rivet is made of mild steel or other metal, or of an
alloy capable of being properly headed down as explained. By the construction
just described, the sleeves f are held very firmly in place, and are absolutely
precluded from shifting or tipping in any direction; hence if once properly set,
they will accurately locate and maintain in position the rollers B.
It will be observed by reference to the several figures, that the rollers B pro-
ject beyond the edges or periphery of their supporting or carrying ears b, and it
will also be noted that the spaces e between said ears are of greater width than
are the ears themselves measured in the planes of the axes of the rollers. The
purpose of this relatively greater width of space is to preclude contact of the ears
or rollers of one wheel with the ears of the other wheel, or in the case of a
rack and pinion, to prevent contact with the cars of the rack or the pinion, so
long as the rollers remain in place, the ears serving, however, to engage directly
and to impart motion from one disc to the other in case a roller be lost or broken.
The employment of the sleeves or bushings with their fastening devices pre-
sents many advantages from the manufacturing standpoint, permitting as it does
the more ready and perfect tempering of the sleeves, and the ready and perfect
seating or placing thereof. It also affords great facility of repair in the event
of an axle being broken or displaced.
While for many purposes the separate bushing or axle is preferred, a peculiarly
strong and durable gear or pinion may be produced by forming the axles integral
with the web or flange a. Such construction is illustrated in Figures 7 and 8,

page_text: where the axles are indicated by the letter d', the two-part rollers being designated
by the letter B as before.
In Figure 7, the axle portions d' are axially bored and the rollers are retained
in place by rivets or bolts passing through the bored opening and provided at
one end with an enlarged head e and at the opposite end with a washer f held
in place by heading down the rivet D upon the washer as shown in Figure 7.
Instead of boring or drilling the axle portions d' as in Figure 7, they may be
made solid as in Figure 8, but with reduced projections to pass through and to
be headed down upon washers f as shown in said Figure S. The construction
shown in Figure 7 is, however, preferred, for the reason that it permits the body
or wearing portion of the axle to be tempered as desired, while permitting the
use of a rivet capable of being readily headed and thus made to retain the rollers
properly in place, whereas it is difficult to thus temper the solid axle portions d¹,
and to leave soft enough for heading, the protruding rivet portions under the con-
struction shown in Figure 8.
The invention, however, is directed broadly to the employment of the anti-
friction rollers on opposite sides of the web or disc of the wheel, whereby pressure
upon one roller section is caused to counterbalance pressure upon the other
section, and thus to maintain proper contact of the rollers of one wheel with
those of another. The matter of making the axles integral or making them
separate is therefore a secondary consideration.
As above explained, and as is indicated in Figures 2, 3, 7 and 8, the rollers BB
are of tapering form when used in bevel gearing, and the taper is such that
lines drawn from the point of intersection of the axes of the co-acting wheels,
will lie parallel or in contact with the surfaces of the rollers in the direction of
their length. The rollers of the two wheels will therefore come together in the
same way substantially as do the rigid teeth of ordinary bevel gears, except that
by reason of their ability to turn about their axes, the rollers will substitute
rolling for sliding friction, and thus greatly reduce the frictional resistance to
rotation of the wheels.
By the construction just explained roller teeth or co-acting rollers can be
employed in lieu of rigid teeth in two bevel wheels or wheels arranged to rotate
in intersecting planes, but it is essential to this result that spaces such as the
depressions or spaces c be left between the ears or supports by which the rollers
are carried, as otherwise the flange a of one wheel would preclude its inter-
meshing with the other wheel. The construction also affords means of imparting
motion from one to another wheel temporarily, in the event that a roller be
lost or broken.
In Figure 4, are represented the ears or projections 6 as extending outward
in the same plane with the body or disc A, the rollers and their bushings and
fastenings being shown in section, as otherwise the bushings would be hidden
by the heads of the fastenings. It will be seen upon reference to this figure, that
except for the inclination or annular arrangement of the flange, or the scalloped
periphery of the wheel, it is the same in this as in preceding figures, and so too
of the rack E, with which said wheel is shown co-acting.
Figure 5 is the same as Figure 4, except that the rack E' is represented as
having rigid teeth instead of rollers. The teeth in such case should be rather
longer and more slender than are the teeth of racks designed for use with ordinary
toothed gears.
Figure 6 represents the roller bevel pinion co-acting with a rigid toothed
bevel pinion, the teeth being spaced somewhat wider and made longer and more
slender than the teeth of ordinary bevel gears, to adapt them the better to co-
operate with the roller gear or pinion.
It will be observed that under the several embodiments of the invention here
represented, all tendency of the axles to twist, cant, or tip in any direction is
counteracted, first by the seating of the ends of the sleeves in the counterbored
faces of the supporting or carrying cars and the clamping of them in such position

page_text: by the rivets or fastenings D, or by making them integral with the ears; and
second by the equal pressure applied to the rollers on opposite sides of each
ear or carrying projection b.
The construction above set forth is simple, light and cheap, and affords great
facility for drilling and assembling the parts, and for adjusting them in the
ovent that any ear be thrown slightly out of position, or any hole be bored in
the least degree out of proper inclination. The hub may be tapped or threaded
or otherwise adapted to be secured upon an axle shaft or other member.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated
to me by my foreign correspondent, I declare that what I claim is:-
1. A gear wheel consisting of a disc or body, a series of stationary axles carried
at or near the periphery thereof, and rollers carried by said axles in pairs, one
roller of each pair on one side of the disc or body and the other roller on the
other side thereof.
2. In a gear wheel, the combination of a disc or body; a series of axles pro-
jecting from opposite faces thereof at or near its periphery; and straight-faced
rollers applied to said axles on opposite sides of the disc or body.
3. In a gear wheel, the combination of a body having its periphery provided
with alternate cars or projections and recesses or depressions adapted to receive
corresponding ears or projections; and a series of rollers carried in pairs by
the cars or projections, the rollers of each pair being on opposite sides of the
carrying ear or projection.
4. The herein described gear wheel, comprising a body A; a series of pro-
jections or cars b; a series of depressions c alternating and corresponding in
form with the ears 6; axles supported by the ears 6 and projecting on opposite
sides thereof; and rollers B applied to said axles.
5. In a gear wheel, the combination of a body or disc provided with peripheral
cars or projections b; rivets or fastenings D passing through the ears and
projecting on opposite sides thereof; bushings encircling said fastenings and
secured thereby to the cars 6; and rollers encircling the bushings substantially
as and for the purpose set forth.
6. In combination with disc or body A having counterbored ears or pro-
jections ; sleeves or bushings having their inner ends seated in the counter-
hores of the ears; rollers encircling said sleeves; and fastenings passing through
the sleeves and serving to retain said sleeves and the rollers in position.
7. The combination substantially as herein set forth, of two co-acting gear
members, each provided with projecting ears and intervening recesses, said ears
being provided on both outer faces with rollers, substantially as shown and
described.
"
"
8. A bevel gear consisting of a body or disc A having a peripheral flange at
an angle to the plane of rotation, and provided with alternate projections and
depressions and sectional conical rollers carried by and upon opposite sides of
said projections and having their axes and their longitudinal surfaces radial to a
common point or centre in the axial line of the wheel.
9. The combination of two bevel gear wheels each comprising a disc or body
having a peripheral flange at an angle to said body, formed with alternate pro-
jections and depressions, each wheel provided with a series of rollers arranged in
pairs, the rollers of the respective pairs being carried upon opposite sides or
faces of the respective peripheral projections, and having a common centre
from which their axes radiate, substantially as set forth.
10. In a gear wheel, the combination of a main body or discs provided on
opposite faces with short axles, each consisting of a tubular sleeve, each sleeve
on one side being in alignment with another on the opposite side; and a faston-
ing passing through the bushings and the web or body of the wheel, and bearing
upon the ends of the bushings.

page_text: 11. The combination of two co-acting wheels, each provided with peripheral
ears or projections, and with lateral rollers on both outside faces of said ears,
whereby pressure brought by one wheel upon the other tends to force or to hold
the rollers of the co-acting wheels in engagement throughout their length.
Dated this 4th day of September 1899.
WM. P. THOMPSON & Co.,
Agents.