Improvements in Sewing Machines.
Year: 1898

page_text: Improvements in Sewing Machines.
I, WILLIAM HENRY DORMAN, of the Green Hall, Stafford, Engineer, do hereby
declare the nature of this invention to be as follows:-
These improvements are principally intended to be made use of in machines
for sewing boot uppers, harness, and other leather work, and the machine pro-
duces a lockstitch and uses two waxed threads.
The work is placed upon a flat table where it is held down by a spring presser
foot which is operated, so as to be raised at the proper times, by a cam, lever,
pawl and ratchet; the pawl on its descent being tripped from engagement with
the ratchet teeth by a stationary piece so as to release the presser foot to the
influence of the spring pressure. For the purpose of raising the foot to insert
the work a treadle, lever and connections are made use of.
The presser foot when down upon the work is locked by a spring, lever and
bar which are released by a cam at the proper times. The same are released by
a cam lever in connection with the aforesaid treadle when this latter is made
use of.
The needle is straight and is furnished with a hook. It is carried in a rack
bar and operated by a toothed segment and suitable cam and connections.
The shuttle carries a reel of thread through the loop drawn up by the needle.
It works to and fro in a curved race, being operated by a driver, toothed seg-
ments and suitable cam. It is provided with adjustable stops to limit its move-
ment as well as with an adjustment for varying its forward and backward
movement.
An arrangement is made use of for preventing the wearing or sawing of the
thread in the needle barb which consists of an arm suitably operated by a cam,
lever and gearing.
The feeding of the work is done by the awl by means of a cam, segment and
rack the amount of feed being regulated by a stop screw in conjunction with a
spring. Another screw is provided in the rack for the purpose of adjusting the
awl relatively to the needle.
The awl is straight and carried, like the needle, in a rack bar operated by a
segment lever, cam and connections.
%
The thread take up consists of fixed and moving trucks in connection with a
slide, lever and cam; the amount of the movement being capable of variation.
A tension truck and waxpot are provided suitably heated by steam or gas, as
are also other parts of the machine, so requiring.
The thread is locked fast at suitable times by a cam and lever, and released by
a spring.
Dated this 3rd day of December 1898.

page_text: I, WILLIAM HENRY DORMAN, of the Green Hall, Stafford, Engineer, 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:—
These improvements are principally intended to be made use of in machines
for sewing boot uppers, harness, and other leather work. The machine produces
a lock stitch and uses two waxed threads. It is illustrated in the accompanying
drawings in which: —
Fig. 1 is a front view of the machine.
Fig. 2 is an end view.
Fig. 3 is an enlarged view of the upper portion of the machine.
Fig. 4 is a plan of the same.
Fig. 5 is a vertical section shewing the needle bar, and the shuttle going
through the loop of thread.
Fig. 6 is a plan shewing the shuttle race and the driver.
Figs. 7, 8 and 9 are further enlarged views of the shuttle.
Fig. 10 shews the presser foot lift lever.
Fig. 11 is a plan shewing the thread hook..
Fig. 12 is a plan shewing the awl feed.
Fig. 13 is an elevation of the awl bar and slide.
Fig. 14 is a plan shewing the take up.
Fig. 15 is a plan shewing the thread lock.
Figs. 16 and 17 are enlarged views of the thread lock spring.
Figs. 3 to 6 and 10 to 15 are all to the same scale.
The frame a, which may stand on a suitable bench or table, supports the various
working parts of the machine. The pulley 6 receives motion from a suitable
driving belt and runs loose upon the driving shaft b¹. It is pressed into engage-
ment with the cone 6-fast upon the shaft 6-for the purpose of driving the
machine, by the wedge 63, connected to a suitable treadle. A spring separates
the cone and pulley when the wedge is released.
The upright shaft 6 is revolved through the pair of bevel wheels 65, 66 and
is supported in bearings 67 68. Upon this shaft are mounted the balance wheel 6"
and the various cams which give movement to the different parts of the machine.
The work to be sewn is placed upon the table c, which may be of convenient
size and shape for the purpose, and is held down thereon by the presser foot d,
the bar d✶ of which is free to slide vertically in the head a¹ of the machine. The
spring holds the presser foot down and the same is raised, prior to the feed
movement of the work, by the cam da which operates the lever . This lever
is mounted on the pivot and is provided with the cam roll and at its for-
ward end with the pawl the latter of which is adapted to engage the ratchet
teeth formed upon the presser foot bar *. When the pawl de rises it lifts
the bar d✶ and foot d and when the pawl descends it is tripped out of engage-
ment with the teeth by means of the stationary piece which is provided
for the purpose upon the frame a¹ and projects slightly beyond the teeth d.
The pawl d is made wider than the teeth so that its extra width engages the
piece. The presser foot is thus enabled to accomodate any variations in the
thickness of the work, being always raised a uniform height from the surface
thereof when the pawl rises and always set free to the influence of the down-
ward pressure of the spring d when the pawl descends.

page_text: The presser foot d is locked when down upon the work by the sliding bar e,
the end e of which butts against the bar d*, and is pressed thereon by the
spring acting on the bell crank e3 which is mounted on the pivot and
jointed to the bar e by the pin e. The bar e is released at the proper times by
the came which acts upon the roll e and the power of the spring e³ may be
regulated by turning the hand nut es.
For the purpose of raising the foot d to insert the work a suitable treadle is
provided which pulls down the rod f and operates the lever f¹ which is mounted
on the shaft fs carried in the frame a. The lift lever f is also mounted on the
shaft and on being raised by the operation of the aforesaid treadle takes under
the peg f in the bar d* and raises it and the foot d. It is necessary, however,
to set free the bar d* from the lock e before the foot d can be lifted and this
is done by the cam shaped end f³ of the lever f' acting upon the bell crank e³
and withdrawing the bar e prior to the contact of the lift lever f³ with the
peg f.
The needle is straight and furnished with a hook. It is carried in the toothed
needle bar and operated by the toothed segment lever and cam 7³. The
segment is mounted on the pivot and is provided with the cam roll g³. The
bar g slides vertically in the head frame a
The shuttle h carries the reel ¹ containing the thread h² and passes through
the loop of thread go drawn up by the needle. It works to and fro on the curved
races which enter the curved slots h h provided in the sides of the
shuttle. The slot his formed in the upper part of the shuttle. In it the needle
dips to cast off the loop of thread as the shuttle passes through. The shuttle
driver is mounted on the pivot and operated through the teeth h h and
lever 2, by the cam 13. The lever 12 is mounted on the pivot 14 and provided
with the cam roll . The segment on which are formed the teeth h¹-
can be adjusted upon the cam lever by means of the cramp screws 17 h³8
and set screw h¹ for the purpose of setting the position of the shuttle relatively
to the needle. Adjustable stop screws 20 h21 are used for positively determining
the shuttle movement.
The hook draws a loop of the thread prior to the needle hook engaging the
same and pays it back again as the needle rises so that sawing of the thread in
the needle hook is prevented.
The hook is operated by the shaft, pinion, toothed lever ³, and cam 4.
The lever is mounted on the pivot and provided with the cam roll 6. The
spring piece pushes the thread into the needle hook as it passes horizontally by
the rising needle.
The awl is straight and carried in the toothed awl bar j. It is driven up
and down by the toothed segment lever and cam . The lever is mounted
on the pivot and is provided with the cam roll. The work is fed by the
awl which receives a to and fro movement from the cam which operates the
toothed lever and rack slide 8. The lever j is mounted on the pivot and
the cam rollo is held to the cam by the spring, its movement and conse-
quently that of the feed of the awl-being regulated by an adjustable stop
screw The horizontal cross slide is mounted in the frame and is pre-
ferably formed in one with the vertical slideway in which the awl bar j
rises and falls. The teeth are made wide enough to allow of the feed move-
ment of the awl taking place without their sliding out of gear. For setting the
awl with reference to the needle the screw 16 is provided, by turning which the
awl feeding slide 3 may be moved upon the rack 8 the screws 17 18 serve
to hold, and if necessary cramp, the rack to the slide j
The thread take up consists of the fixed thread trucks and the moving
ones which latter are carried on the slide. The slide is moved to
and fro in the frame a by the cam, bell crank lever and link the stroke
being adjustable by setting the joint pin in the slot ko. The bell crank k
is mounted on the pivot k and provided with the cam roll
¹³.

page_text: The cam and lever
lock fast the thread while the take up acts. The lever
is mounted on the pivot and is provided with the roll. It acts on the
thimble loosely carried on the set screw and bearing against the U spring
which is also carried on the same screw P. The thread passes between the
ends 718 of the spring which are closed upon it by the action of the cam and
lever. The set screw 15 determines the amount of grip the thread shall
receive.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. In a sewing machine having a straight needle: Raising the presser foot
by means of a pawl engaging with ratchet teeth and tripping the pawl out of
engagement with the teeth as the presser foot descends for the purpose of enabling
the presser foot to accomodatę variations in the thickness of the work, substan-
tially as described.
2. In a sewing machine:-Locking the presser foot by means of a spring
pressed sliding bar which is released by a cam and lever prior to the rising of
the presser foot, substantially as described.
3. In a sewing machine:The cam ended lever which when operated first
releases the presser foot lock and afterwards raises the foot for the insertion of
the work, substantially as described.
4. In a sewing machine:-Carrying the needle in a straight needle bar pro-
vided with teeth and operating the same by means of a toothed segment lever
and cam, substantially as described.
5. In a shuttle sewing machine having a straight needle: The combination
of the adjustable toothed segment and the adjustable stop screws for setting the
shuttle with reference to the needle and for positively determining its forward
and backward movement, substantially as described.
6. In a sewing machine:-Carrying the awl in a straight bar provided with
teeth and operating the same by means of a toothed segment and cam, substan-
tially as described.
7. In a sewing machine:-Carrying the awl bar in a slideway provided with
cross slide to which a work feeding movement is given, substantially as
described.
8
8. In a
sewing machine:-The combined awl movement consisting of a
toothed awl bar with a toothed segment lever and cam to give the piercing move-
ment to the awl, and a toothed slide at right angles thereto with a toothed seg-
ment lever and cam to give the feeding movement, substantially as described.
9. In a sewing machine:-The method of setting the awl relatively to the
needle by adjusting the awl feeding slide upon the rack to which the feeding
movement is given, substantially as described.
10. In a sewing machine:-The take up, consisting of the fixed and moving
thread trucks the latter carried upon a slide operated by a lever and cam with
an intervening link connection capable of adjustment for regulating the amount
of, the pull upon the thread, substantially as described.
Dated this 4th day of September 1899