A NEW OR IMPROVED SEWING MACHINE
Year: 1883

page_text: LETTERS PATENT to William Frederick Thomas of Holborn Viaduct in
the City of London for an Invention of "A NEW OR IMPROVED SEWING
MACHINE"
PROVISIONAL SPECIFICATION left by the said William Frederick Thomas at
the Office of the Commissioners of Patents on the 29th October 1883.
WILLIAM FREDERICK THOMAS of Holborn Viaduct in the City of London "A
NEW OR IMPROVED SEWING MACHINE
"
My invention relates to a construction and arrangement of sewing machine,
particularly adapted for heavy work, such as sewing leather. For this purpose, I
provide on the main shaft of the machine the following cams: one for working the
shuttle, one for the needle, one for the take up, two for moving a hook which holds a
loop of the needle thread to receive the shuttle, one for working a friction stop of
the presser foot, and two for working tho feed, all these cams giving movement to
levers which are connected to the several working parts. The shuttle is proferably
of the kind reciprocating in a circular path, movement being given to it by a rack
on a sliding rod worked by the first cam The needle is guided to move vertically
in the usual way. The take up is effected by a vertically reciprocating lover having
the needle thread passed over a pulley at its end. The hook, which takes hold of
the loop of the needle thread and holds it while the needle asconds until the point
of the shuttle enters it, has the following movements, one upwards to bring its point
to the proper level for entering the loop, a second forwards to seize the loop, a
period of rest while the needle ascends, and then a movement downwards and
forwards presenting the loop which it holds for the entrance of the shuttle.
presser foot has attached to it several loops fitted to slide between stationary plates.
These at one part of each revolution during the ascent of the needle through the
material, are pressed firmly together by the action of a spring so as to prevent the
presser foot from being raised. At other parts of the revolution the pressure, squeezing
the plates together, is relieved by the cam so that the presser foot is free to be raised.
By this arrangement of friction stop, the presser foot can always take a position
The

page_text: suited to the thickness of the material operated on. The feed is of the usual
four motion kind, with the usual adjustment for length of stitch. By the arrange-
ment of machine described, I am enabled to sew, without the aid of an awl; material
of considerable thickness and strength such as leather, and when waxed thread is
used, I apply under the table a small gas jet to keep the thread in a soft 5
condition. Sometimes, instead of the shuttle above described arranged to reciprocato
in a circular path. I employ a shuttle reciprocating rectilineally, this shuttle being
of a form modified to suit the use of a waxed thread by having the thread recl
mounted in it with its axis transversely to the line of the shuttle's movement, so as
to give more freedom for the thread to be drawn off tho reel.
1

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Frederick Thomas in the Patent Office on the 29th
April 1884.
WILLIAM FREDERICK THOMAS of Holborn Viaduct in the City of London “A
NEW OR IMPROVED SEWING MACHINE
"
My invention relates to a construction and arrangement of sewing machine,
particularly adapted for heavy work, such as sewing leather. For this purposo,
I provide on the main shaft of the machine the cams: one for working the shuttle,
one for the needle, one for the take up, two for moving a hook which holds a loop
of the needle thread to receive the shuttlo, one for working a friction stop of the
presser foot, and two for working the feed, all these cams giving movement to
levers which are connected to the several working parts. The shuttle is preferably
of the kind reciprocating in a circular path, movement being given to it by a rack
on a sliding rod worked by the first cam. The needle is guided to move vertically
in the usual way. The take up is effected by a vertically reciprocating lever having
the needle thread passed over a pulley at its end. The hook, which takes hold of
the loop of the needle thread and holds it while the needle ascends until the point
of the shuttle enters it, has the following movements: one upwards to bring its
point to the proper level for entering the loop, a second forwards to seize the loop,
a period of rest while the needle ascends, and then a movement downwards and
forwards presenting the loop which it holds for the entrance of the shuttle. The
presser foot has attached to it several plates fitted to slide between stationary
plates. These at one part of each revolution during the ascent of the needle
through the material, are pressed firmly together by the action of a spring so as to
prevent the presser foot from being raised. At other parts of the revolution the
pressure, squeezing the plates together; is relieved by a cam, so that the presser
foot is free to be raised. By this arrangement of friction stop, the presser foot can
always take a position suited to the thickness of the material operated on. The
feed is of the usual four-motion kind, with the usual adjustment for length of
stitch. By the arrangement of machine described, I am enabled to sew, without
the aid of an awl, material of considerable thickness and strength such as leather,
and when waxed thread is used, I apply under the table a small gas jet to keep the
thread in a soft condition. Sometimes, instead of the shuttle above described,
arranged to reciprocate in a circular path, I employ a shuttle reciprocating
rectilineally, this shuttle being of a form, modified to suit the use of a waxed
thread by having the thread recl mounted in it with its axis transversely to the
line of the shuttle's movement so as to give more freedom for the thread to be
drawn off the reel.
Fig. 1 of the accompanying drawings is a front view and Fig. 2 a back view of
a sewing machine arranged as above described, Fig. 3 is a plan of the whole
machine and Fig. 4 is a plan of the lower part sectional on the plane of the axis
of the driving shaft. Fig. 5 is a part longitudinal section, Fig. 6 a transverse
section and Fig. 7 a plan of the part where the needle, hook and shuttle act in
conjunction, these three figures being drawn to an enlarged scale. On the driving"
shaft A are fixed the several cams as follows. The cam B engages a roller on a
lever b which is connected by an adjustable link b¹ to a sliding rod b' having at its
side rack teeth that engage with a pinion 6³ mounted on a vertical axis. On this
'

page_text: axis is fixed a disc 6 having projecting up from it an elongated stud 6 that drives
the shuttle bo. The shuttlo is of cylindrical shape with a hollow at one side to
accommodate the driving stud 65. As the cam B revolves causing reciprocation of
the lever b, and of the sliding rack b³, the disc b and its stud 6 are caused to turn
partly round forwards and backwards thus giving reciprocating rotary movement
to the shuttle be within the circular cavity in which it is enclosed. Within the
shuttlo is mounted the reel of thread b' from which the thread is led off tangentially
passed partly round pins 68 to give frictional resistance and finally led up
through an eye in the centre of the shuttle to the underside of the fabric or
material sewn.
For facility of introducing or removing a reel the part of the cover of the
shuttle above the reel is made removeable, being in the form of a disc that can bo
screwed into its place. At one side of the hollow of the shuttle there is a
projecting nose 6º pointed to enter the loop of the needle thread, through which at
each forward stroke tho shuttlo is driven. The cam C engages a roller on the bent
lever which works the needle slide c¹ and needle cup and down in the usual way.
The cam D engages a roller on a lover d by which is raised and lowered a spindle d¹
at the end of the lever. On this spindle is an arm d' connected by a rod to tho
cam D¹. On the spindle d' is fixed the book d' which by means of the cams D
and D is made to have an upward movement to present its point to enter the
bulge of the needle thread, a forward movement entering the bulge and seizing a
loop of the needle thread, and a farther forward and downward movement presenting
the loop for the entrance of the nose 6º of the shuttle. When the loop is engaged
on the shuttle, the hook d' retreats.
At E thero is a cam under the edge of a long bent lever e, the one end of which
is strained down by a spring el. The lever e is pivotted at e and it has a short
arme which bears against a set of friction plates & placed behind the slide of the
presser foot e. While the spring e' strains downwards the lever e, the short arm
squeezes the plates e closely together. Some of these plates are attached to the
slide of the presser foot so that they have to move up or down with it. The others
of the plates, which alternate with those already mentioned, are attached to the
stationary head of the machine. When the plates aro squeezed together by the
action of the spring e¹ on the lever e, there is so much friction of the alternating
plates on one another that the presser foot is kept firmly down on the fabric or
material sewn notwithstanding the upward drag of the needle and thread. When,
however, the protruberanco of the cam E raises the lever e in opposition to the
spring e', then the arm e³ ceases to squeeze together the plates and the presser
foot e can yield a little upwards during the ascent of the feed plate. The effect of
the friction plates ein preventing the presser foot from rising is the same whatever
be the thickness of the fabric or material interposed between the presser foot and
the feed plate. At F there is a cam which gives reciprocation to the lever f by
which a block f¹ carrying the feed plate is raised and lowered. There is also at F¹¹
a cam which pushing down in opposition to a spring a vertical rod f³ gives rocking
motion to a spindle fa from which an arm f' projecting upwards gives the to and
fro motion to the feed plate fb. A cam G gives reciprocation to a bent lever
which carries at its end a pulley g'. The needle thread from the bobbin g² is
carried over and under guide pullics go and g, and over the pulley g' and thence
down to the needle c; the upward movement of the lever g draws up the needle
thread after the shuttle has passed through it.
When a rectilineally reciprocating shuttle is to be used instead of the rotary 5
reciprocating shuttle, I make it of the form shewn in elevation at Fig. 8 and in
plan at Fig. 9 with the reel placed in it on a horizontal axis. By substituting a
straight race for the circular race above described and for the rack slide b² a straight
shuttle driver, the operation with the rectilineally moving shuttle is similar to that
described with respect to the rotary shuttle.
5

page_text: Having thus described the nature of my invention and in what manner the same
is to be performed, I claim :-
The construction of sewing machine substantially as herein described with
reference to the accompanying drawings.
In Witness whereof I the said William Frederick Thomas have hereunto set
my hand and seal this twenty eighth day of April in the year of our Lord One
thousand eight hundred and eighty-four,
5
W. F. THOMAS. (L.D.)