IMPROVED MECHANICAL ARRANGEMENTS FOR CONVERTING RECIPROCATING MOTION INTO ROTATORY MOTION
Year: 1871

page_text: LETTERS PATENT to Alfred Milnes Hobson, of Stockwell, in the
County of Surrey, for the Invention of "IMPROVED MECHANICAL
ARRANGEMENTS FOR CONVERTING RECIPROCATING MOTION INTO ROTATORY
MOTION."
Sealed the 7th May 1872, and dated the 9th November 1871.
PROVISIONAL SPECIFICATION left by the said Alfred Milnes Hobson
at the Office of the Commissioners of Patents, with his Petition,
on the 9th November 1871.
I, ALFRED MILNES HOBSON, of Stockwell, in the County of Surrey,
do hereby declare the nature of the said Invention for "IMPROVED
MECHANICAL ARRANGEMENTS FOR CONVERTING RECIPROCATING MOTION INTO
ROTATORY MOTION," to be as follows:-
This Invention is designed to dispense with the use of the crank in
machines in which cranks are employed to convert reciprocating motion
into rotatory motion, such as sewing machines, lathes, steam engines,

page_text: velocipedes, and numerous other machines worked either with cranks or
by any other known means for converting reciprocating into rotatory
motion.
:-
The means by which I propose to accomplish the above object are as
follows Take for example a sewing machine worked by two treddles.
Instead of connecting the said treddles by rods to a two-throw crank
shaft and an endless band as commonly practised I employ the follow-
ing improved mechanical arrangements:-On a cross spindle mounted
in bearings beneath the bed plate of the machine or in the stand thereof
I place loosely two grooved pullies, each in a vertical line with each of
the aforesaid treddles, and to the movable end of each of the said treddles
I fix one end of a piece of catgut, or other suitable flexible material.
This catgut I pass around one of the aforesaid grooved pullies, then over
guide rollers fixed to the under side of the framing of the machine, and
then around the other grooved pulley, and finally fix the other end of the
catgut to the other treddle. A lever arm or pin is fixed to the face or
flat side of each of the aforesaid grooved pullies, and upon each of the
said pins I mount loosely an excentric pawl, the edge whereof is formed
of a V or other shape in cross section, and one end of this V shaped
edge takes into a V or other shaped groove formed around the circum-
ference of a small pulley fixed on the before-mentioned cross spindle
opposite to each excentric pawl. I also employ a light spring to keep
one end of the said excentric pawls in the grooves of their respective
pullies.
The operations of the improved mechanical arrangements above
described are as follows:-Motion being imparted to the treddles of the
machine will lift up one pawl lever and pawl and lower the other lever
and pawl, the effect of which will be to cause the edge of the lifted pawl
to bite or press closely in the groove of its respective grooved pulley,
which being fixed on the cross spindle, as before stated, will impart
rotatory motion to the said spindle and sewing machine connected
therewith by any suitable means. A reverse movement of the treddles
will cause the opposite pawl to be lifted and continue the rotatory
motion, and so on in succession.
By the foregoing improved mechanical arrangements considerable
speed of the machine may be obtained with a comparatively slow move-
ment of the treddles and little exertion of the operator, and further by

page_text: this Invention the machine can never be turned backwards by reason of
the pawls only acting in one direction, as above described; and a most
important feature in this Invention consists in getting rid of any null
points or having to pass centres, as is now the case where cranks are
used.
It will appear obvious that the foregoing arrangements are equally
applicable to other machines than sewing machines; but for machines.
that require a reversing motion, such as marine and locomotive engines,
the same may be effected by having two sets of pawls and grooved
pullies, and by means of a sliding clutch to bring one or other of the
pawls into action so as to turn the machinery either backward or
forward as required.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alfred Milnes Hobson in the Great Seal Patent
Office on the 9th May 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
MILNES HOBSON, of Stockwell, in the County of Surrey, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of November, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alfred Milnes Hobson, Her special
licence that I, the said Alfred Milnes Hobson, my executors, adminis-
trators, and assigns, or such others as I, the said Alfred Milnes Hobson,
my executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVED
MECHANICAL ARRANGEMENTS FOR CONVERTING RECIPROCATING MOTION INTO
ROTATORY MOTION," upon the condition (amongst others) that I, the said
Alfred Milnes Hobson, my executors or administrators, by an instrument

page_text: The operations of the improved mechanical arrangements above
described are as follows:-Motion being imparted to the treadles of the
machine will lift up one pawl lever and pawl and lower the other lever
and pawl, the effect of which will be to cause the edge of the lifted
pawl to bite or press closely in the groove of its respective grooved
pulley, which being fixed on the cross spindle, as before stated, will
impart rotatory motion to the said spindle and sewing machine con-
nected therewith by any suitable means. A reverse movement of the
treadles will cause the opposite pawl to be lifted and continue the
rotatory motion, and so on in succession.
By the foregoing improved mechanical arrangements considerable
speed of the machine may be obtained with a comparatively slow move-
ment of the treadles and little exertion of the operator; and further by
this Invention the machine can never be turned backward by reason of
the pawls only acting in one direction, as above described; and a most
important feature in this Invention consists in getting rid of any null
points or having to pass centres, as is now the case where cranks are
used.
It will appear obvious that the foregoing arrangements are equally
applicable to other machines than sewing machines; but for machines
that require a reversing motion, such as marine and locomotive engines,
the same may be effected by having two sets of pawls and grooved
pullies, and by means of a sliding clutch to bring one or other of the
pawls into action so as to turn the machinery either backward or
forward as required, or I employ other suitable mechanical arrangements
for effecting such reversing movement.
And in order to explain my said Invention more fully I now proceed
to describe the means by which it may be carried into practical effect,
reference being had to the illustrative Sheet of Drawings accompanying
these presents, and to the numeral figures and letters of referenco
marked thereon as follows:-

page_text: respectively represent side and edge views (drawn full size) of parts
herein-after particularly described and referred to. At each of the
foregoing Figures I employ similar letters of reference to denote
corresponding parts.
A, B, respectively mark. the standards and table of a treadle sewing
machine; C is the driving axle, capable of revolving by its ends in
suitable bearings; D is a rod for carrying the treadle, which for the
purpose of explaining my Invention I have shewn as as a compound
rocking treadle; E is a bar fixed by its ends to the standards A; and G
is a lever bar connected to the bar E by a pin at a, which is the fulcrum
of the said bar; H is a rod connected by its lower end to the treadle I
and by its upper end to the lever G, as shewn; K, K, are rollers placed
loosely on the axle C; and L, L, are grooved pullies fixed on the axle C;
M is a plate fixed on each of the pullies; K and M' are excentric pawls
placed on pins 6 fixed in each of the aforesaid plates M, shewn more
clearly at Figures 3 and 4; N is a cord fixed by its ends to each end of
the lever bar G. The cord N is passed around each of the loose rollers
K, K, and over grooved guide rollers c, the aforesaid loose rollers and
excentric pawls being so placed as that when one pawl is over the centre
of the axle C the other pawl is under the centre of the said axle, so that
when one pawl is in action the other pawl is out of action, as follows:-
Suppose the several parts to be in the position represented by the
Drawing at Figure 1, upon pressure being exerted upon the treadle I the
raised end of the lever bar G will pull down this end of the cord N, and
by so doing will cause the excentric pawl M¹ to move in the direction
denoted by the arrow's flight at Figure 4 and cause the said pawl to grip
tightly the grooved part of the roller L, and thereby impart rotatory
motion to the axle C and transmit such motion to a sewing machine by
means of a pulley and endless band as commonly practised in driving
sewing machines. During the movement of this pawl the other pawl is
passing loosely over the groove of the other grooved pulley ready to act
to grip the grooved part of the pulley when the lever bar G is moved in
an opposite direction by the rocking movement of the treadle, as before
described, and in this manner and by these means the alternate action of
the pawls M¹ produces continuous rotatory motion of the axle C and
sewing machine connected therewith in one direction.
Having now fully described and set forth the nature and obiect of my

page_text: said Invention for "Improved Mechanical Arrangements for Converting
Reciprocating Motion into Rotatory Motion," together with the means
by which it can be accomplished, I would remark in conclusion that I
do not claim the exclusive use of any of the separate parts above
mentioned and referred to except when the same are employed in com-
bination and for the purposes of my said Invention as above described
ith
to