An Improved Rotary Tubular Tooth, and its Attachment for Gear and Sprocket Wheels.
Year: 1896

page_text: Date of Application, 28th Sept., 1896-Accepted, 16th Jan., 1897
COMPLETE SPECIFICATION.
An Improved Rotary Tubular Tooth, and its Attachment for Gear
and Sprocket Wheels.
I, CHRISTIANA TAGELL of Berwick Street, North Brighton, in the Colony of
Victoria, Gentlewoman, 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 :-
.
The object of my invention is to provide a tooth for gear and sprocket wheels
by which the friction shall be reduced to a minimum. Hitherto it has been the
practice to attach the teeth to tooth wheels or the sprockets to sprocket wheels in
such a way that the rubbing faces of the said teeth or sprockets were immovable.
But with my invention the rubbing portion of each tooth or sprocket rotates upon
a pin or axle so that the friction generated by the pressure between two unyielding
surfaces is prevented. In the case of the sprocket wheel as used with the bicycle
the chain instead of bearing against a stationary sprocket glides over a rotary tooth
which rotates with the slightest pressure.
My invention consists of a wheel (either sprocket or. tooth): which has on its
circumference two flanges or shrouds with lugs or teeth thereon. These flanges
extend around the whole of the periphery of the wheel and may be integral with
or attached thereto. They are. situated one on each face of the said wheel.
Between each lug or tooth may be bays or indentations in which the corre-
sponding flange and roller of the other wheel or the block of the chain finds
clearance. In the space existing between each lug or tooth is placed a rotary
tubular tooth or roller which rotates upon a pin passing through and connected to
the two lugs or teeth aforesaid. Each rotary tubular tooth or roller on that portion
of its face nearest the wheel beds into a back bearing or recess which is formed
upon the wheel. The object of this bearing being to remove from the pin some of
the strain which would otherwise be wholly thrown upon it.
But in order that my invention may be better understood I will now refer to the
accompanying sheet of drawings which are to be taken as part of this specification
and read herewith.
Figure 1 represents a view partly in section and partly in elevation and on an
enlarged scale of a rotary tubular tooth or roller between two flanges. The pin is
in place and is shewn in elevation the dotted lines in its centre representing the
means of lubrication.
Figure 2 represents a sectional plan through X X in Figure 1 shewing the
roller protruding beyond the flange the pin with its lubricating hole and the back
bearing against which the rotary tubular tooth or roller bears.
Figure 3 represents a front elevation of a wheel and pinion provided with the
rotary tubular tooth or roller which I have applied to a bicycle for a multiplying
gear.
Figure 4 represents a side elevation of Figure 3 and as can be well understood
if both the wheel and pinion are constructed similarly to the pinion (as shewn on
the left hand) they need not gear one with the other but a sprocket chain can
be equally as effectually employed for transferring power between the one and the
other.
On reference to Figure 1 it will be seen that A is the wheel on, which are the
flanges B which as before said may either be integral with the said wheel or

page_text: attachable thereto. Between these two flanges is the rotary tubular tooth or
roller C rotating around a pin D having a central hole E for lubrication. The
pin D may either be taper as shewn or it may be parallel but in the former case
it possesses: the-advantage of adjustment since a new pin can always be inserted,
thereby taking up any slack that may be caused by undue wear. The pin may
also instead of being rivetted over at each end as-shewn have a shoulder at one end
and a nut at the other.
On reference to Figure 2 is more clearly seen the back bearing F. As before
said the object of this is to remove some of the strain off the pin the life of which
is considerably lengthened thereby.
The width of the tubular roller may vary according to circumstances as also may
its diameter but in all cases it revolves upon a pin as shewn.
The method of oiling the pin and the back bearing depends very greatly upon
which plane the wheels are working.in.
:
If in the horizontal plane the oil for the pin can be fed down the lubricating
hole E as shewn and the back bearing can be lubricated by the application of oil
to the front of the roller by which means on rotation it is carried round to their
back. Whereas if the wheels are working in the vertical plane one or more channels
may be cut in the two ends of the roller extending from the circumference to the
hole in the same whereby the oil will find it's way not only to the-back bearing
but also to the pin itself.
If one of the wheels is an internally toothed one and is applied to a bicycle' or
for other purposes the lubrication of the same is effected as before described.
Having now particularly described and. ascertained- the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1st. An improved rotary tubular tooth and its attachment for gear and sprocket
wheels and in combination a. rotary tubular roller as C rotating around a pin
as D as and for the purposes herein before described and as illustrated in the
drawings.
2nd. An improved rotary tubular tooth and its attachment for gear and
sprocket wheels and in combination 'a rotary tubular roller as C rotating around
a pin as D against a back bearing as Fas and for the purposes herein before
described and as illustrated in the drawings.
3rd. In an improved rotary tubular tooth and its attachment for gear and
sprocket-wheels a wheel such as A with integral or attachable flanges as B
between which rotate tubular rotary rollers as C against back bearings as F
as and for the purposes herein before described and as illustrated in the
drawings.
4th. In an improved rotary tubular tooth and its attachment for gear and
sprocket wheels'a pin as D either taper or parallel with central lubricating hole
as E as and for the purposes hereinbefore described and as illustrated in the
drawings.
5th. An improved rotary tubular tooth and its attachment for gear and sprocket
wheels consisting of the combination of a wheel as A with integral or attachable
flanges as B between which rotate around taper or parallel pins as D and against
back bearings as F the tubular rotary rollers as C as and for the purposes herein-
before described and as illustrated in the drawings.
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.