Improvements in Link Mechanisms for Transmitting Rotary Motion.
Year: 1897

page_text: Date of Application, 17th Sept., 1897-Accepted, 13th Nov., 1897
COMPLETE SPECIFICATION.
Improvements in Link Mechanisms for Transmitting Rotary Motion.
We HOSMER TUTtle, of 613 Fifth Street, in the City of Cedar Rapids, County
of Linn and State of Iowa, United States of America, Mechanical Engineer, and
SHELLEY TUTTLE, of 959 East Second South Street, Salt Lake City, in the County
of Salt Lake and State of Utah, United States of America, Gentleman, do hereby
declare the nature of this invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
In this improvement cranks and crank-pins or their equivalents are used on
the axle of the hind wheel, sprocket wheels on the axle of the pedal-shaft and
forked connecting rods to unite said axles, as described in the Specification of
British Patent No. 16,701, dated July 28th 1896. But in this improvement the
location of the hind cranks is different, the interlocking sprockets and the engaging
or hooked ends of the forked connecting rods are provided with anti-friction
rollers and special guides are provided for said connecting rods in place of sus-
pension links; the construction is shown in the accompanying drawings, in
which―
Figure 1 represents a side view of a bicycle provided with a mechanism con-
structed in accordance with this invention but showing only one of the forked
rods. Figure 2 represents on a larger scale a top view, partly in section, of the
mechanism. Figure 3 represents a side view of the same with the pedals and a
portion of the horizontal frame, and the upper frame removed. Figure 4 repre-
sents in top view and partly in section the rear wheel axle, its ball-bearings,
crank-shaft and connecting rods. Figure 5 is a side view of the rear portion of
one of the forked connecting rods, its crank-pin, ball-bearing cone, and locking
device for said cone. Figure 6 is a perspective view of the crank pin. Figure 7
is a transverse vertical section of one of the forked connecting rods and its
oscillatory and longitudinally reciprocating ball-bearing support. Figure 8 is
a side view of the same. Figure 9 is a longitudinal vertical section of the cross-
head guide. Figure 10 is a side view of a modified form of sprocket wheel for
engagement with the arms of the forked connecting rods. Figure 11 is an edge
view of said sprocket wheel. Figure 12 is a top view of one of the
branches of the forked connecting rod adapted for engagement with
said sprocket wheel. Figure 13 is a side view of the same. Figure 14
is a side view of another branch of the forked connecting rods provided with a
curved and divergent removable tin for engagement with sprocket wheels of larger.
diameter, for greater speed. Figure 15 represents a side view of the bicycle
showing, also for simplicity, only one of the forked rods with slightly modified
operating means connected with its rear end, and also modified means to support
its front end. Figure 16 represents on a larger scale a top view, partly in section
of the operating mechanism. Figure 17 represents a side view of the same with
the pedals and a portion of the horizontal frame, and the upper frame removed.
iigure 18 is a side view of one of the ring-bearings of the rear wheel having
therein a disc carrying an oscillatory crank pin, and the cam attached to said

page_text: ring bearing to guide the crank pin. Figure 19 is a central horizontal section
of the parts shown in Figure 18. Figure 20 is a perspective view of one of the
crank-pins and its supporting arm. Figure 21 is a side view of one of the cams
mounted upon the pedal shaft and, connecting rod used to elevate and depress
the front end of the forked connecting rods of the mechanism. Figure 22 is a
central horizontal section of Figure 21: Figure 23 is a perspective view of the
roller carrying arm and a portion of the vertical connecting rod.
In said drawings A represents the seat carrying standard of the frame, and A³
the braces between the crank shaft b carrying the pedals B and also the sprocket.
wheels C and C, and the crank axle for the hind wheel E, said axle d having
its ends received in ball-bearings a² (Figures 2, 3, 4) mounted in the rear ends of
the braces A and protected by caps a³ which also serve as a lock-nut for the
"ball-way.
Each end of the axle d has a crank arm d, and each end of the hub of the
wheel E has a similar crank arm e³, but the arms e² are set at an angle of 90°
to each other. The arms ², e of each crank are united together by a tubular
crank pin D having lugs projecting from its ends that are received in corre-
sponding cavities formed in the arms e³, and a bolt. D2 passing through said
arms and through the crank-pin D secures these parts together until it is desired
to remove the wheel E for repairs. The pin D is grooved circumferentially to
obtain a ball-way to receive the inner face of the balls of the ball-bearing around
it, and said balls are enclosed by the rear end of each forked connecting rod, being
adjustably retained in their seat by a balls-cone D³ having its periphery pro-
vided with serrations. To lock said cone, a dog d³ is secured with a screw to the
outer face of each connecting rod and has its acute end made to engage with some
one of the serrations on the periphery of the flange of the cone D³.
The sprocket wheel C has projecting from its periphery at equal distances apart
three teeth c, provided on their end with anti-friction rollers r to be received
alternately into sprocket receivers or pockets f placed on the front end of the
lower branch of a forked connecting rod F. A similar but inverted pocket f
is placed on the front end of the upper branch of the forked connecting rod F,
to interlock with one of the anti-friction rollers r. It is evident that the arrange-
ment of the interlocking parts can be inversed, and that the sprocket wheel can
be provided with pockets in its periphery, as shown in Figures 10 and 11, and
the outer end of each branch of the forked connecting rod be provided with an
anti-friction roller r, as shown in Figures 12, 13, 14, to interlock with said pocket,
without departing from the spirit of my invention.
i
The distance between the front ends of the branches of the forked rod Fis
slightly more, but about equal to the diameter of the wheel C with the addition
of one of its sprockets or anti-friction rollers. Said distance is maintained by a
vertical brace Fa uniting said branches, and divergent braces F uniting the
pocketed ends to said brace F³. The front portion of the connecting rod F may
be suspended from the standard A by means of a link F3, as shown by dotted
lines in Fig. 1, having its lower end pivoted to the vertical brace F and its
upper end pivoted upon a short shaft secured to the standard A, but other means
are shown in full lines in Figures 1, 2, 3, 7, 8, 9, and they are mounted upon
the side braces A2 of the frame.
Said means consist of a guide plate H brazed or otherwise secured along the
inner face of each brace A2, and a cross head I, centrally provided with a pin i,
having its periphery screw threaded and made to pass through the vertical brace F
of the forked rod. Ball-bearings are interposed between the pin i and the opening
in said brace F. Ball-bearings are also interposed between the cross-head Ï
and the guide plate H, the latter being provided with two ball-way pockets h,
in the top and also in the bottom, and preferably only one ball in each pocket.
The grooved cross-head I is also provided with grooved ball-ways adjustably re-
tained by screws passing through the top and bottom thereof, and have their ends
closed by small plates secured to the ends of said cross-head.

page_text: The above description relates to the left hand half of the driving mechanism,
but the mechanism on the right hand side is exactly similar and consists of the
forked connecting rod G having the brace G2 carried by cross-head and guide-
plate as above described. The lower branch of the connecting rod G has a
pocket 9, and the upper branch an inverted pocket 9. The sprocket wheel C³
is provided with three sprockets provided with anti-friction rollers and equally
spaced apart, but so timed relatively to the sprockets c of the wheel C as to be about
thirty degrees in the rear of each one of them.
The frame of the machine is provided with a forward brace A³, as usual.
In the operation of the mechanism, the rocking up and down of the rear end
of the connecting rod F or G causes an inverse motion of the front end of said
rod. In other words, when the left hand crank piu D on the rear end begins
to ascend and passes above a horizontal line passing through the centre of the rear
shaft, its front end descends, and its pocket f receives into engagement one of
the uppermost sprocket teeth, and said sprocket tooth in its revolution pulls upon
the rod F and continues to revolve the rear axle d. When the crank pin D
descends below the centre of the crank shaft d, the front end of the rod F ascends
and its pocket f receives into engagement the bottom sprocket-tooth of the wheel C
and said sprocket tooth pushes the connecting rod F rearwardly and continues
to revolve the rear axle d.
As there must necessarily be some moments in which the pockets of the rod F
are not in engagement with the anti-friction roller of either a top or a bottom
sprocket tooth, the duplication of the mechanism is required to actuate the rear
crank axle during these intermediate movements. The sprocket teeth are pre-
ferably made to project slightly on one side of the sprocket wheel, so that the
body of the latter will not be in the way of the hooked ends of the connecting
rods, and said teeth can be made shorter. As there is only one tooth, or at the
most a portion of two teeth in engagement with the connecting rods, and said
teeth are provided with anti-friction rollers, the friction is reduced to the minimum
possible.
The diameter of the sprocket wheels, and the number of teeth they are to carry
can be selected according to the speed of motion that may be desired.
In the modification shown in Figures 16, 17 there is keyed or otherwise secured
upon the hind axle da disc D, Figure 18, having its periphery provided with a
grooved ball-way. Said disc is received within the annular ball-bearing cones a
of a ring A into which they are screwed. The periphery of said ring is secured
to the inclined rear brace and to the side brace As of the frame. To the inner
face of the ring A is secured a cam K by means of side lugs k and screws passing
therethrough and entering the side of said ring. The groove in said cam is
elliptical, with its long axis vertical, to increase the leverage of the crank-pin
without increasing the diameter of the sprocket wheel, as the power of said pin
is exerted mainly when it reaches the top and bottom of its course.
To permit the crank-pin or its roller to follow the groove of the cam, said
pin is carried by one end of an arm 3, the opposite end of which is pivoted to
the face of the disc D. For the passage of the crank-pin, to reach the groove of
the cam, said disc has a substantially radial slot d', that permits it to swing in
and out while following the groove of the cam.
A simpler construction can be obtained by dispensing with the cam K and
the crank pin arm and having the crank-pin welded upon the face of the disc,
as in Patent No. 16,701, above mentioned.
As before stated, the front portion of the forked connecting rod may be sus-
pended from the standard A by means of a link F3 as shown by dotted lines in.
Figures 1 and 15, having its lower end pivoted to the vertical brace F, and its
upper end pivoted upon a short shaft secured to the standard A, but other means
are shown in Figures 15, 16, 17, 21, 22. They consist of a cam-way c attached
to, or preferably forming part of each sprocket wheel Caud C. Said cam-way

page_text: is in the form of an equilateral triangle, the three sides corresponding with
the three sprocket-teeth of the wheel. The portion of the frame constituting the
journal box A5 for the pedal-axle is provided with radial lugs a5 adjacent to the
sprocket wheels. To cach lug is pivoted one end of a lever m carrying on its
opposite end a connecting rod M, the upper end of which is pivoted to the upper
branch of the forked lever and controls the up and down motion of the forward
end of the latter. Intermediate of the two ends of the lever m there is mounted
thereon a roller m³ that follows the cam-way c*.
The above description relates to the left hand half of the driving mechanism,
but the mechanism on the right hand side is exactly similar and consists of the
forked connecting rod G having the brace G2 carried by a similar lever and con-
necting rod, but the three sprocket teeth and the three sides of the cam are so
timed relatively to the cam and sprocket teeth of the wheel C as to be about
thirty degrees in the rear of each of them.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. A mechanical movement consisting of an axle carrying two crank pins, a
forked connecting rod mounted at one end upon each crank-pin and having at
the opposite end two oppositely disposed sprocket receivers, sprocket wheels for
engagement with said sprocket receivers, and anti-friction rollers between the
sprocket wheels and the forked connecting rod, substantially as described.
2. In a mechanical movement for bicycles, the combination of the axle of one
of the carrying wheels, two crank pins carried by said axle, two branched con-
necting rods having at one end two oppositely disposed sprocket receivers, sprocket
wheels having teeth for engagement with the branched connecting rods, a brace
uniting the branches of said rods, a guide-plate, and a cross-head embracing said
plate and having a pin revolubly connected with the branched connecting rod,
substantially as described.
3. In a bicycle, the combination of a sprocket wheel on the pedal-shaft, a
forked lever having one end adapted to engage with said sprocket wheel and its
opposite end provided with a journal-bearing, the hub of the bearing wheel pro-
vided with a crank-arm having cavities in its face, a second crank arm provided
with a screw-threaded pin, a tubular crank-pin having lugs in its end, and a bolt
passing through the crank pin and through the crank arms, substantially as a
described.
4. In a bicycle, the combination of a sprocket wheel on the pedal shaft, a
forked lever having one end adapted to engage with said sprocket wheel, and
its opposite end provided with a journal bearing to receive a crank-pin, the axle
of the rear wheel, a disc mounted thereon, the frame of the machine carrying a
ring receiving said disc and interposed ball-bearings, a cam secured to said ring
and having an elliptical guide way, a crank-pin carrying-arm pivoted to the disc
and a crank-pin passing through a slot in said disc and into the guide-way,
substantially as described.
5. In a bicycle, the combination of a sprocket wheel on the pedal shaft, a
forked lever having one end adapted to engage with said sprocket wheel and
its opposite end provided with a journal-bearing to receive a crank-pin, the axle
of the rear wheel, a disc mounted thereon and carrying a crank-pin, the horizontal
braces of the machine carrying a ring in the same plane as said disc and receiving
the latter, substantially as described.
6. In a bicycle, the combination of the axle of the rear wheel carrying a crank-
pin, a forked lever having one end receiving said crank-pin and the opposite end
provided with means to engage with a sprocket wheel, said sprocket wheel on
the pedals axle, a cam secured to the sprocket wheel, the journal bearing of the
pedal-axle provided with external lugs, a lever pivoted to one of said lugs and

page_text: carrying a roller for engagement with the cam, and a rod connecting said lever.
wit the forked lever, substantially as described.
Dated this 17th day of September 1897.
JENSEN & SON,
77 Chancery Lane, London, W.C., Patent Agents.