Improvements in Driving Mechanism for Velocipedes.
Year: 1895

page_text: Date of Application, 5th Nov., 1895
Complete Specification Left, 4th Aug., 1896-Accepted, 10th Oct., 1896
PROVISIONAL SPECIFICATION.
Improvements in Driving Mechanism for Velocipedes.
I, BIRGER LJUNGSTRÖM, of 44B Grefgatan, Stockholm, in the Kingdom of
Sweden, Mechanician, do hereby declare the nature of this invention to be 'as
follows:-
One of the most common forms of mechanism for driving velocipedes and similar
vehicles, consists of oscillating treadles or levers, connected by means of chains or
ropes with clutches on the driving wheel or its shaft. These clutches have pulleys
or drums, driven by means of the chains or ropes wound around them, extending
from the treadles. When the pulley is driven forwards, the clutch binds, and
operates the driving wheel, while it slips and runs loose during the return motion
of the pulley. The pulleys, which are arranged in duplicate in the usual manner,
have, in respect to each other, an alternate motion in the same order as the treadles
or levers. This invention relates to an improvement of the pulley, which is not,
as hitherto, made in one single piece, (a construction which, besides being heavy,
renders the fixing of the rope or chain to the same difficult), but is composed of a
number of parts, so that a light construction and a cheap make is obtained.
There is, besides, a peculiar arrangement, whereby the rope can be fastened and
disengaged by a single turn of the hand.
According to this invention, the clutch has, as usual, an outer shell or drum,
between which and the part to be driven, as, for instance, the shaft of the wheel, a
sleeve attached to the same, or the nave of the driving wheel, clutch balls or
rollers are placed, which oblige the said driven part to follow the shell or drum,
when turned in the one direction, but permit the said shell to turn loosely in the
other direction. The shell or drum is provided with a disc, to which are fixed the
two circular plates, one at either side, which plates form the sides of a pulley.
Between the plates, which, at the rim, are bent outwards from each other, is
attached an aluminium plate of the shape of a crescent. This plate, with part of
its inner edge, embraces closely the aforesaid disc, while its outer edge is curved
away, so as finally to reach almost the circumference of the circular plates, where
it meets the S-shaped curve of the inner edge, sprung from the point of contact
with the pulley disc. The crescent plate is fixed between the circular plates by
means of rivets, and the said plates are secured to the disc also by means of rivets.
These latter rivets are prolonged into pins, traversing and retaining another
pulley, mounted on the same shell or drum, a little distance from the described
pulley, and consisting likewise of two plates, between which is a disc. These
two pulleys are likewise retained together by means of a large joining pin, having
two slots or notches, one destined to receive the knotted end of the driving rope,
which extends from the treadle to the pulley, and the other the end of the returning
chain, which leads from one of a pair of spring or other returning pulleys. One of
the side plates of the driving pulley is provided with a slot, widened in the outer
end, and going close to the middle disc. When fixing the driving rope, the end of
the same is first inserted between the rims of the side plates, and introduced
through the slot at the extreme end of the latter, then pushed along the slot down
towards the disc, and placed into the slot of the joining pin before mentioned,
where a knot on the rope is lodged in the enlarged end of the said slot. The rope
then passes in a spiral between the plates, resting, counted from the centre, first on
the disc, and then on the rim of the crescent plate, until reaching the end thereof.

page_text: Immediately before the rope comes to the said point, it begins to widen, so that it,
after having passed the same point, can rest upon the rims of the side plates. The
winding off from the pulley may go on until the rope, forming a tangent to the
middle disc, encounters the end of the crescent plate. The shape of the pulley
with respect to the leverage of the rope on the shaft, is such, that the said
leverage diminishes towards both ends of the stroke of the chain, it being greatest
near the middle position. The rope consists of a number of fine steel wires,
twisted together into a wire rope, round which is wound a somewhat thicker wire
protecting the wire rope from wear, without impairing the flexibility. The above
mentioned widening of the driving rope, having the result that it can rest upon the
rims of the plates, has been effected by the progressive enlarging of the turns of
the wire. The retaining rope is fixed in the same way as the driving rope, passing
out through an opening in one of the side plates of its own pulley, the knotted end
being placed in the slot in the pin before mentioned.
The invention may be modified in such a way that the excentric disc and crescent
plate are in one piece, to which the side plates are secured, and the pulley thus
formed may be fixed to the side of a flange on the shell. In the same way, also,
the return pulley may be secured to a special flange on the shell. As to the ropes,
they may, for a part of their length, consist of a chain, & for another part,
preferably the part wound upon the pulley, of such a rope as described.
Dated this 5th day of November 1895.
NEWTON & SON,
Agents for the Applicant.
improvements in Driving Mechanism for Velocipedes.
I, BIRGER LJUNGSTRÖM, of 44B Grefgatan, Stockholm, in the Kingdom of
Sweden, Mechanician, 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 :-
One of the common forms of mechanism for driving velocipedes and similar
vehicles, consists of oscillating treadles or levers, connected by means of chains or
ropes, with clutches on the driving wheel or its shaft. These clutches have pulleys
or drums, driven by means of the chains or ropes wound around them, extending
from the treadles. When the pulley is driven forwards the clutch binds, and
operates the driving wheel, while it slips and runs loose during the returu motion
of the pulley. The pulleys, which are arranged in duplicate in the usual manner,
have, in respect of each other, an alternate motion in the same order as the
treadles or levers. This invention relates to an improvement of the pulley, which
is not, as hitherto, made in one single piece, (a construction which, besides being
heavy, renders the fixing of the rope or chain to the same difficult), but is composed
of a number of parts, so that a light construction and a cheap make is obtained.
There is besides, a peculiar arrangement, whereby the rope can be fastened and
disengaged by a single turn of the hand.
I will describe my invention having reference to the accompanying drawings in
which
Fig. 1 is an end elevation of pulleys constructed according to my invention.
Fig. 2 is an elevation partly in section, taken about the line X Y of Fig. 1, and
looking towards the right hand.
Fig. 3 is a sectional elevation taken upon the line X' Y' of Fig. 1, looking
towards the right.
Fig. 4 is an elevation partly in section of Fig. 1, taken about the line xy looking
towards the left.

page_text: Fig. 5 is a sectional elevation taken upon the line ≈¹ y¹ looking towards the left.
Fig. 6 illustrates a detail of the construction.
Fig. 7 illustrates a clutch suitable to be employed in such driving mechanism
and
Fig. 8 shews in elevation so much of a bicycle having such driving mechanism
fitted thereto as is necessary to shew the application of my invention.
This
According to this invention the clutch has, as usual, an outer shell or drum A
see Fig. 7, between which and the part a to be driven, (as, for instance, the shaft
of a wheel, a sleeve attached to same, or the nave of the driving wheel), clutch
balls or rollers are placed, which oblige the said driven part a to follow the shell
or drum A, when turned in one direction, but permit the said shell A to turn
loosely in the other direction. The shell or drum A provided with a disc B
securely fixed thereto or made therewith in a piece and best seen at Figs. 1 and 2
to which are fixed two circular plates C C¹, one at either side, which plates form
the sides of a pulley; at Fig. 2 the circular plate C has been removed. Between
the plates CC, which, at the rim are bent outwards from each other, is attached
an aluminium or other plate D, of the shape approximately of a crescent.
plate D with part of its inner edge, embraces closely the aforesaid disc B, while its
outer edge is curved away, so as finally to reach almost the circumference of the
circular plates C C¹. The crescent plate D is fixed between the circular plates C C¹
by means of rivets E, and the said plates are secured to the disc B, also by means
of rivets F. These latter rivets F are prolonged into pins traversing and retain
another pulley, see Figs. 1, 4 and 5 mounted on the same shell or drum A a little
distance from the described pulley, and consisting likewise of two plates H H¹,
between which is a disc J; at Fig. 4 the plate H¹ has been removed. The disc .J
has a spiral periphery to allow a cord R to be wound around same, and at the same
time to ensure evenness of winding. These two pulleys are likewise retained
together by means of a large joining pin K shewn detached at Fig. 6 of the
drawings having two slots or notches L L¹. The slot L' is to receive the knotted
or equivalent end S¹ hereafter called a knot of a driving rope S, which extends
from the treadle to the pulley, and the slot L receives one end of the returning
rope or chain R, which rope R leads either from one of a pair of spring or other
returning pulleys, or passes round a loose pulley P Fig. 8. The plate C of the
driving pulley is provided with a slot M see Fig. 3 widened in the outer end, and
extending towards the middle disc B. When fixing the driving rope, the end of
the same is first inserted between the rims of the side plates C C¹, and introduced
through the slot at the extreme outer end of the latter, then pushed along the
slot M down towards the disc B, and placed into the slot L' of the joining pin K
before mentioned, where a knot on the rope is lodged in the enlarged end of the
said slot. The rope S then passes in a spiral between the plates, resting, (counted
from the centre see Fig. 2,) first on the disc B, and then on the rim of the crescent
plate D, until reaching the end thereof. Immediately before the rope comes to
the said point, that is near the termination of the crescent plate D as at Fig. 2, the
said rope begins to increase in diameter so that after having passed such point; it
can rest upon the curved edges of the side plate C C¹. The rope may be unwound
from the pulley Fig. 2 until it forms a tangent to the middle disc B and encounters
the end of the crescent plate D. The shape of the pulley Fig. 2 with respect to
the leverage of the rope on the shaft, is such, that the said leverage diminishes
towards both ends of the stroke of the rope, it being greatest near the middle
position. The rope may consist of a number of fine steel wires, twisted together
into a wire rope, round which is wound a somewhat thicker wire protecting the
wire rope from wear, without impairing its flexibility. The above-mentioned
widening of the driving rope, having the result that it can rest upon the rim of the
plates, is or may be effected by the progressive enlarging of the turns of the
protecting wire and as described and claimed in and by the Specification of my
Patent application No. 20913/95 of even date herewith. The return rope is fixed
in the same way as the driving rope, passing out through an opening N Fig. 5 in

page_text: the side plate H¹ of its own pulley, the knotted end being placed in the slot L in
the pin K before mentioned.
The invention may be modified in such a way that the excentric disc B and
crescent plate D are in one piece, to which the side plates C C' are secured, and
the pulley thus formed may be fixed to the side a flange on the shell. In the
same way also, the return pulley may be secured, to a special flange on the shell.A.
As to the ropes, they may, for a part of their length, consist of a chain, and
for another part preferably the part wound upon the pulley of such a rope as
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 :-
1. In driving mechanism for velocipedes, a'driving pulley composed of two side
plates, having outwardly curved edges, and held excentrically upon a drum
connected by clutch mechanism to the axle to be driven, a plate and disc or plate
located between the two side plates to form a peripheral and somewhat spiral path,
for the rope or chain, from near the drum towards the outer periphery of 'the side
'plates, bolts or rivets extending transversely through the plates to secure same
laterally, and means for securing the end of the driving rope or chain to the pulley,
substantially as set forth.
2. In driving mechanism for velocipedes, a driving pulley composed of two side
plates having outwardly curved edges, and hele excentrically upon a drum,
connected by clutch mechanism to the axle to be driven, a plate and disc, or plate
only, located between the two side plates, to form alperipheral somewhat spiral
path from near the drum to the outer periphery of the side plates; in combination
with a return pulley, composed of two side plates fixed concentrically upon the
drum, a disc, having a cam shaped periphery, located between the side,plates to
permit of an even winding of the return rope thereon, bolts or rivets extending
through the plates of the driving and return pulleys to secure and connect same
together laterally, and means for securing the ends of the ropes to the pulleys
substantially as described.
3. The combination with the pulleys as previously claimed, by Claims 1 and 2
of the slots in the side plates and the exterior notched projecting bolt or part by
which the knotted or enlarged ends of the ropes' or chains are fixed and secured
substantially as and for the purposes described.
4. The general construction and arrangement of pulleys and parts composing an
essential feature of my improvements in driving mechanism for velocipedes all
combined and acting substantially as and for the purposes described and illustrated
with reference to the accompanying drawings.
Dated this 4th day of August 1806
0
BREWER & SON,
London and Leeds, Agents for the Applicant.