Improvements in or relating to Sprocket Wheels.
Year: 1895

page_text: Date of Application, 1st Oct., 1895
Complete Specification Left, 26th June, 1896-Accepted, 8th Aug., 1896
PROVISIONAL SPECIFICATION.
Improvements in or relating to Sprocket Wheels.
We, FRANCIS GLEASON, Northwest Corner of American Street and
Susquehanna Avenue, Philadelphia, County of Philadelphia, State of Pennsyl-
vania, United States of America, and GEORGE YOUNG SHERMER of 20 Pastorius
Street, Germantown, County of Philadelphia, State of Pennsylvania, United
States of America, Manufacturers, do hereby declare the nature of this invention
to be as follows :—
This invention relates to certain new and useful improvements in sprocket wheels,
and it consists substantially in such features of construction and combinations of
parts as will hereinafter be more particularly described.
The invention has for its general object the variations of speed of driven parts, as
well as the compensation for wear and stretching of drive chains.
The invention has for its further object to obtain an equal driving power from a
less number of sprockets or teeth and at the same time to greatly reduce the friction
between the wheel and drive chain.
The invention has such other objects in view as will more fully hereinafter
appear.
As ordinarily constructed sprocket drive wheels are made up of different standard
sizes, each particular size embodying a particular multiple of sprockets or teeth,
those of the different sizes varying in numbers according to the variation of the size
or circumference of the wheel, and it is well known that with any particular sprocket
drive wheel there are in each revolution as many successive frictional touches or
engagements with the drive chain, as there are teeth or sprockets on the wheel,
and yet, owing to want of perfect relation between the drive chain and wheel,
at no one time during the revolution of the wheel is there more than a very
small fraction of the whole number of teeth or sprockets in actual working
bearing or engagement with the links of said drive chain. For instance with
an ordinary sprocket drive wheel with eighteen teeth in its circumference,
probably only two of such teeth would be in actual working engagement at any
one time.
We have found that practically all the driving effect required, may be secured by
the use of a wheel having only such a number of teeth equi-distantly arranged, as
will give the actual working effect of those of the ordinary wheel.
Our wheel embodies other features of improvement, and is so constructed as to
readily compensate for wear and stretching of the drive chain, as well as to vary
the speed.
Said wheel is provided with a central spider having three radial ribs or spokes
which ribs or spokes are equi-distant, and terminate at their ends or extremities, a
little short of the felloe portion of the wheel segments, hereinafter more specifically
referred to.
The shaft is of course concentric with the spider as well as with the rim or
wheel circle and the radial ribs or spokes of the spider are flat on one of their
faces, while their opposite faces are formed with longitudinal channels or grooves
which receive and guide the radially operating slides or expanders through
the medium of which the adjustments of the several segments of the wheel rim
or circle are effected. The said slides fit the grooves quite snugly, and are
flush with the surfaces of the ribs in which they work, and normally these slides
extend a little beyond the ends or extremities of the ribs or spokes of the spider.

page_text: In each of the radial ribs or spokes of the spider is formed a slot while in
each of the slides at a point corresponding to the inner extremity of said slot,
is a threaded hole or opening which receives a threaded screw which serves to
tighten the slide in its position after it has been moved, as hereinafter more fully
explained. It is evident that said slides will be securely held in their places
of adjustment since the bead of the screws rest or bear against the opposite sides
of the ribs when the screws are tightened up by means of a small wrench, or other
suitable device.
Preferably in order to avoid angles in the grooves or channels in which the
slides or expanders work, both the said slides and grooves are correspondingly
rounded at their inner ends or extremities; and the said slides or expanders
are provided on their outer surfaces, near their inner ends with projecting
ribs or blades, which do not quite reach to the shaft and the inner ends of
which are bevelled upwardly and outwardly. These blades or ribs co-operate with
the adjusting cone and nut, hereinafter described, in effecting the outward adjust-
ment of the slides, as well as the corresponding expansion of the segments of the
wheel rim or circle. .
.The said wheel rim or circle is constituted of three separate expansible segments
each of which is provided with side flanges so that when united in forming a
continuous wheel or circle, any slipping of the drive chain is obviated. It will be
understood, however, that said wheel rim or circle might be constructed of any
other suitable form transversely.
Each corresponding slide and wheel segment is made integral or in one
piece, and the point of intersection or union thereof is nearer to one end of
the segment than the other, the purpose of this being to lend additional
strength to those parts of the wheel rim or circle which necessarily are
rendered weaker, due to the severance thereof at equal points in the diameter of
said rim.
The wheel portion of our expansible sprocket wheel or pulley is composed of
two parts, that is to say, the rim portion, and the felloe portion, and the several
segments are so formed that at one end of each segment the felloe portion projects
beyond the end of the rim portion, while at the other end thereof the rim portion
projects beyond the felloe portion. Thus the projecting ends of the felloe portions
serve to receive and support the projecting ends of the rim portions in such
manner as to provide a very strong rim as a whole. The projecting portions
of the rim referred to are formed or provided with slots which receive small lugs
or projections on the corresponding projecting portions of the wheel felloe, which
construction is resorted to for the purpose of obtaining a perfect movable connection
between the segments. The extent of expansibility of the wheel rim or circle is
necessarily limited by the length of the slots referred to, but it is evident that in
wheels of large diameter these slots may be made as long as desired, and thus give
quite a range of expansibility in wheels of this class.
In some instances, we propose to dispense with the slots and lugs at the ends of
the segments, and in lieu thereof simply construct the rim portions at one end to be
lapped by the felloe portion of the contiguous end of the adjacent segment, or
vice versa; and in this way substantially the same form of movable connection is
had between the ends of the several segments of the wheel.
The projecting ends of the felloe portions of the segments are brought beneath
the overlapping portions of the rim, which, in the disposition of the radial ribs and
slides is such as to be close to the movable joints and serve to make the wheel quite
strong and capable of sustaining all the uses required of it.
It will be understood that instead of making the corresponding segments and
slides integral or in one piece with each other, they may be constructed separately
and then joined together in any suitable or secure manner, but preferably the
construction described is that which is employed practically.
In line with the radial spokes or ribs of the spider, and equidistant from each
cther, we employ three sprockets, or teeth which, as hereinbefore stated, furnish

page_text: substantially the same driving power or working capacity as a wheel of the same
size, embodying a greater number of teeth. Two out of three of these teeth or
sprockets are always in actual working bearing or engagement with links of the
drive chain while the third tooth serves to instantly take up such engagement or
bearing immediately as or before the tooth preceding it is released from the chain.
Thus the sprockets or teeth are practically isolated from each other in that all of
the intermediate teeth as ordinarily employed in sprocket drive wheels, are
dispensed with; and there is not that frictional and useless engagement of the
links of the chain with teeth which are inactive or passive, while the actually
working teeth are in effective engagement. The said sprockets or teeth, as is
evident, could be formed at the ends of the slides and be made to extend through
openings in the rim segments, but preferably the said slides, together with the teeth
and segments are all made in one piece or integral.
Referring back to the shaft of the wheel the same is screw-threated at a part
adjacent to the wheel boss while fitting and working upon the screw-threaded
portion is a combined cone and nut which constitutes the device by which the
expansion or adjustment of the wheel segments are effected by means of a suitable
wrench or other device for turning the same. This combine cone and nut is of
such shape and dimensions, as to enter between the bevelled edges of the projecting
ribs or blades. before referred to, and the shaft so that as the cone is screwed
up, it will act as a wedge and serve to move the slide outwardly and radially, and
thus expand the wheel segments. The said cone is preferably formed or provided
with a notched or milled edge which facilitates the unscrewing of the saine from
the shaft after it has been once loosened by means of a wrench or other suitable
device.
Normally the position of the segments of the rim of the wheel is such that the said
segments will be closely joined and then whenever it is desirable to expand the
segments, whether due to stretching or wear of the drive chain, it is simply necessary
to screw the cone up on the shaft when the effect will be as hereinbefore described
to separate the segments, and to take up any slack in the drive chain. By giving to
the segments a very large or unlimited degree of expansibility, it will of course be
understood that considerable variation in speed in the parts driven by the wheel
could be effected.
The screws are of course loosened prior to the adjustment of the cone and then
after the adjustments have been effected the said screws of course are again tightened
up and in this way the wheel segments are made firmly set to any position to which
they may be adjustable.
From the foregoing description it will be seen that our improved sprocket drive
wheel embodies very simple, yet effective devices in its construction, and it will
further be seen that the adjustment of its several parts can be very quickly made
and with very little difficulty and labour.
In the particular adjustment or expansibility of our improved wheel, herein before
set forth, as the adjustments are effected both the pitch line of the teeth as well as
the pitch of the wheel circle or band will be simultaneously and correspondingly
altered or changed.
It will be understood of course that in the details of construction of the several
parts, a great many immaterial changes could be adopted, and hence we do not wish
to be understood as limiting ourselves to the precise details of construction and
arrangements of parts described.
It will be seen that a sprocket wheel as above described is practically a
wheel having the distance from centre to centre on the pitch line of the
teeth several times greater than the pitch of the chain that is intended to run
thereon.
Dated this 30th day of September 1893.
BOULT & WADE,
Agents for the Applicants.

page_text: Improvements in or relating to Sprocket Wheels.
We FRANCIS GLEASON, Northwest Corner of American Street, and Susque-
hanna Avenue, Philadelphia, County of Philadelphia, State of Pennsylvania,
United States of America, and GEORGE YOUNG SHERMER of 20 Pastorius
Street, Germantown, County of Philadelphia, State of Pennsylvania, United
States of America, Manufacturers, 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 relates to certain new and useful improvements in sprocket
wheels, and it consists substantially in such features of construction and com-
binations of parts as will hereinafter be more particularly described.
The invention has for its general object the variations of speed of driven parts,
as well as the compensation for wear and stretching of drive chains.
The invention has for its further object to obtain an equal driving power from
a less number of sprockets or teeth and at the same time to greatly reduce the
friction between the wheel and drive chain.
The invention has such other objects in view as will more fully hereinafter
appear when taken in connection with the accompanying drawing, in which:
:-
Fig. 1 is a perspective view of a sprocket wheel embodying my several
improvements.
Fig. 2 is a view of the wheel looking at one face thereof the shaft being shown
in section, and the several segments of the wheel band or circle being in non-
expanded relation to each other.
Fig. 3 is a similar view to Fig. 2, looking at the opposite face of the wheel, and
showing more clearly the relative arrangement of the movable slides and their
operating cone and nut.
Fig. 4 is a transverse sectional view taken through one of the spider ribs and
its slide, said view also indicating the construction or transverse section of the
wheel rim or circle.
Fig. 5 is a detail view representing the movable connection between the several
expansible wheel segments; and
Fig. 6 is a detail view indicating more clearly the construction of the adjusting
cone or nut.
As ordinarily constructed sprocket drive wheels are made up of different
standard sizes, each particular size embodying a particular multiple of sprockets
or teeth, those of the different sizes varying in numbers according to the variation
of the size or circumference of the wheel, and it is well known that with any
particular sprocket drive wheel there are in each revolution as many successive
frictional touches or engagements with the drive chain, as there are teeth or
sprockets on the wheel, and yet, owing to want of perfect relation between the
drive chain and wheel, at no one time during the revolution of the wheel is there
more than a very small fraction of the whole number of teeth or sprockets in
actual working bearing or engagement with the links of said drive chain. For
instance, with an ordinary sprocket drive wheel with eighteen teeth in its
circumference probably only two of such teeth would be in actual working
engagement at any one time.
We have found that practically all the driving effect required, may be secured
by the use of a wheel having only such number of teeth equi-distantly arranged,
as will give the actual working effect of those of the ordinary wheel.

page_text: Our wheel embodies other reatures of improvement, and is 80 constructed as
readily compensate for wear and stretching of the drive chain, as well as to vary
the speed.
Referring to the drawings A, represents our improved sprocket wheel as a whole,
and 2, indicates the shaft to which said wheel is connected or otherwise secured.
Said wheel is provided with a central spider 3, having three radial ribs or spokes
indicated at 4, which ribs or spokes are equidistant and terminate at their ends or
extremities, a little short of the felly portion of the wheel segments, hereinafter
more specifically referred to.
The shaft 2 is of course concentric with the spider as well as with the rim or
wheel circle 5, and the radial ribs or spokes 4, of the spider are flat on one of their
faces, as shown at 6, while their opposite faces are formed with longitudinal
channels or grooves 7, which receive and guide the radially operating slides or
expanders 8, through the medium of which the adjustments of the several segments
of the wheel rim or circle are effected. The said slides 8 fit the groove 7, quite
snugly, and are flush with surfaces of the ribs in which they work, and normally
these slides extend a little beyond the ends or extremities of the ribs or spokes of
the spider, as indicated at 9.
In each of the radial ribs or spokes of the spider is formed a slot 10 while in
each of the slides 8, at a point corresponding to the inner extremity of said slot, is
a threaded bole or opening 11, which receives a threaded screw 12, which serves to
tighten the slide in its position after it has been moved, as hereinafter more fully
explained. It is evident that said slides will be securely held in their places of
adjustment since the heads of the screws rest or bear against the opposite sides of
the ribs when the screws are tightened up by means of a small wrench, or other
suitable device.
Preferably in order to avoid angles in the grooves or channels in which the
slides or expanders work, both the said slides and grooves are correspondingly
rounded at their inner ends or extremities (see 13); and the said slides or
expanders 8 are provided on their outer surfaces, near their inner ends with
projecting ribs or blades 14, which do not quite reach to the shaft 2, and the inner
ends of which are beveled upwardly and outwardly as indicated at 15. These
blades or ribs co-operate with the adjusting cone and nut, hereinafter described; in
effecting the outward adjustment of the slides, as well as the corresponding
expansion of the segments of the wheel rim or circle.
The said wheel rim or circle, as shown, is constituted of three separate expansible
segments 16, each of which is provided with slide flanges 17, so that when united
in forming a continuous wheel or circle, any slipping of the drive chain is obviated.
It will be understood, however, that said wheel rim or circle might be constructed
of any other suitable form transversely.
As shown in the drawings, each corresponding slide and wheel segment is made
integral or in one piece, and that the point of intersection or union thereof is
nearer to one end of the segment than the other, the purpose of this being to lend
additional strength to those parts of the wheel rim or circle which necessarily are
rendered wenker due to the severance thereof at equal points in the diameter of
said rim.
The wheel portion of our expansible sprocket wheel or pulley is composed of
two parts, that is to say, the rim portion 16, and the felly portion 19, and the
several segments are so formed that at one end of each segment the felly portion
projects beyond the end of the rim portion at 21, while at the other end thereof
the rim portion projects heyond the felly portion at 22. Thus the projecting
ends of the felly portions serve to receive and support the projecting ends of the
rim portions in such manner as to provide a very strong rim as a whole. The
projecting portions of the rim referred to, it will be observed are formed or
provided with slots 20" which receive small lugs or projections 21% on the corre-
sponding projecting, portions of the wheel felly, which construction is resorted to
for the purpose of obtaining a perfect movable connection between the segments.

page_text: From the construction shown it will be seen that the extent of expansibility of the
wheel rim or circle is necessarily limited by the length of the slots referred to, but
it is evident that in wheels of large diameter these slots may be made as long as
desired, and thus give quite a range of expansibility in wheels of this class.
In some instances, we propose to dispense with the slots and lugs at the ends of
the segments, and in lien thereof simply construct the rim portions at one end to
be lapped by the felly portion of the contiguous end of the adjacent segment or
vice rersa; and in this way substantially the same form of movable connection is
had between the ends of the several segments of the wheel.
From the construction shown and described, it will be seen that the projecting
ends of the felly portions of the segments are brought beneath the overlapping
portions of the rim, which, in the disposition of the radial ribs and slides is such as
to be close to the movable joints and serve to make the wheel quite strong and
capable of sustaining all the uses required of it.
It will be understood that instead of making the corresponding segments and
slides integral or in one piece with each other, they may be constructed separately
and then joined together in any suitable or secure manner, but preferably the
constructions shown is that which is employed practically.
It will be observed also that in line with the radial spokes or ribs of the spider,
and equidistant from each other, we employ three sprockets or teeth 22" which, as
herein before stated, furnish substantially the same driving power or working
capacity as a wheel of the same size embodying a greater number of teeth. As
will be observed by reference to the perspective views in the drawing, two out of
three of these teeth or sprockets 22ª are always in actual working bearing or
engagement with links of the drive chain 23, while the third tooth serves to
instantly take up such engagement or bearing immediately as or before the tooth
preceding it is released from the chain. Thus the sprockets or teeth are practically
isolated from each other in that all of the intermediate teeth, as ordinarily employed
in sprocket drive wheels, are dispensed with; and there is not that frictional and
useless engagement of the links of the chain with teeth which are inactive or
passive, while the actually working teeth are in effective engagement. The said
sprockets or teeth, as is evident could be formed at the ends of the slides and be
made to extend through openings in the rim segments, but preferably the said
slides, together with the teeth and segments are all made in one piece or integral,
as shown.
Referring back to the shaft 2 of the wheel, it will be observed that the same is
screw-tbreaded at that part indicated by the numeral 24, while fitting and working
upon the screw-threaded portion is a combined cone and nut 25, which constitutes
the device by which the expansion or adjustment of the wheel segments are effected
by means of a suitable wrench or other device for turning the same. This combined
cone and nut 25, it will be seen, is of such shape and dimensions, as to enter between
the bevelled edges of the projecting ribs or blades 14, and the shaft 2, so that as
the cone is screwed up, it will act as a wedge and serve to move the slide outwardly
and radially, and thus expand the wheel segments. It will be observed that the
said cone 25, is formed or provided with a notched or milled edge 26, which'
facilitates the unscrewing of the same from the shaft after it has been once
loosened by means of a wrench or other suitable device.
Normally the position of the segments of the rim of the wheel is such that the
said segments will be closely joined and then whenever it is desirable to expand
the segments, whether due to stretching or wear of the drive chain, it is simply
necessary to screw the cone up on the shaft 2, when the effect will be as hereinbefore-
described to separate the segments, and to take up any slack in the drive chain.
By giving to the segments a very large or unlimited degree of expansibility, it
will of course be understood the considerable variation in speed in the parts driven
by the wheel could be effected.
The screws 12, are of course loosened prior to the adjustment of the cone 25,
and then after the adjustments have been effected the said screws of course are

page_text: again tightened up and in this way the wheel segments are made firmly set in any
position to which they may be adjusted.
From the foregoing description it will be seen that our improved sprocket drive
wheel embodies very simple, yet effective devices in its construction, and it will
further be seen that the adjustment of its several parts can be very quickly made
and with very little difficulty and labor.
In the particular adjustment or expansibility of our improved wheel, hereinbefore
set forth, it will be observed that as the adjustments are effected both the pitch
line of the teeth as well as the pitch of the wheel circle or band will be
simultaneously and correspondingly altered or changed.
It will be understood of course that in the details of construction of the several
parts, a great many immaterial changes could be adopted, and hence we do not.
wish to be understood as limiting ourselves to the precise details of construction
and arrangements of parts shown and described.
It will be seen that a sprocket wheel as above described is practically a wheel
having the distance from centre to centre on the pitch line of the teeth several
times greater than the pitch of the chain that is intended to run thereon.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is
1. A sprocket wheel comprising a rim and felly divided into a number of
segments with the felly portions projecting at one end beyond the rim portions,.
and the rim portions projecting at the other end beyond the felly portions, sprocket
teeth on the rim arranged equi-distant at such points that two or more links will
lie between the teeth when they are engaged by the chain, and means for expanding
the segments, substantially as described.
2. A sprocket wheel comprising a rim and felly divided into a number of
expansible segments with the felly portions projecting at one end beyond the rim
portions and provided with lugs, and the rim portions projecting at the other end
beyond the felly portions and slotted to receive the lugs, sprocket teeth arranged
upon the rim equi-distant at such points that there are two or more links between.
the teeth when engaged by the chain, and means for expanding the segments.
substantially as described.
3. A sprocket wheel comprising a rim and felly divided into a number of
segments with the felly portions projecting at one end beyond the rim portions,.
and the rim portions projecting at the other end beyond the felly portions, teeth
upon the rim, slides joined to the segments and provided with the ribs or blades.
bevelled on their inner ends, and an adjusting cone working against said bevelled.
ends, substantially as shown and for the purpose described.
4. A sprocket wheel comprising a rim and felly divided into a number of
segments with the felly portions projecting at one end beyond the rim portions,.
and the rim portions projecting at the other end beyond the felly portions, teeth
upon the rim, the spider having radially disposed ribs provided with channels,.
slides working in said channels and joining or connecting with their respective
segments nearer to one end thereof than the other, and an adjusting cone or nut,.
all substantially as shown and described.
Dated this 26th day of June 1896.
BOULT & WADE,
Agents for the Applicants.