Year: 1887

page_text: Date of Application, 2nd May, 1887.
Specification Accepted, 3rd June, 1887.
I, BRUNO RUDOLPH of 34 Haide Strasse Berlin, German Empire Manufacturer 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:
This invention relates to machines for sewing knitted fabrics by what is known as
"overhead" sewing. In the Specification to Abels Patent No. 5330 of 1884 (being a
communication to him from me), I described the construction of such a machine
having two horizontal serrated feed discs between which the fabric was passed, in place
of the usual feed mechanism, which is inapplicable with elastic knitted goods. These
discs in the arrangement described in the said Specification were driven by a pin wheel
and star wheel motion, which parts were subject to rapid wear, and did not allow of
adjustment of stitch, and left the feed discs momentarily uncontrolled, so that the
elastic fabric which was under a certain tension, could recede somewhat, thus
rendering the sewing unequal.
My present invention relates to improvements in the machine described in the
Specification to the aforesaid Patent which have partly for their object to obviate the
above mentioned difficulties in connection with the feed discs, so that the fabric is never
left free by these, and an adjustment of the stitch is rendered possible. I will proceed
to describe the improvements for this purpose with reference to the accompanying
drawings, observing that the machine there shewn is mainly similar in construction to
that described in the said previous patent, and only those parts thereof will therefore
be described that relate to my present improvements.
The serrated feed discs a bare driven by the bevil wheels c. d. of which the wheel c
can be shifted up or down on the hollow spindle of a and is secured by screws e
Figs. 1 and 3 to the hollow boss fof the spur wheel g which is fixed on the spindle
of a and transmits its motion to the spindle of 6 through the spur wheel h. Thus the
wheel c can be shifted upward whenever the bevil gear gets worn, so as to avoid
looseness in working. The boss of c has threaded holes formed in it, into which screw
screws e passing through slotted holes in the boss f of g, so as to hold c tightly in the
position into which it is adjusted.

page_text: The way shaft is driven through worm wheel I and multiple-threaded worm.m, the
latter being rotated with a step-by-step movement by means of ratchet wheel n pawl o
(Figs. 1, 2 and 4) on disc o¹, rod o², double ended lever p. pl, and cam g on driving
shaft i. The disc o¹ thus has reciprocating motion imparted to it, being loose on the
axis of the worm wheel, n is fixed thereon, and the extent of motion imparted to n
and consequently to the discs a bat each stroke of the lever ppl can be varied so as to
vary the length of stitch by shifting the end of the rod o' in the slot of the lever, in
which it is held by a setting screw.
By this means any uncontrolled part of the cam motion is avoided, such as occurs
in other machines when stitches of the greatest length are not made.
The ratchet wheel n is provided with a counter pawl r so as to prevent any backward
motion of the discs a b when the disc o' is moved backward.
The worm m is carried in a frames that can turn on a pin s¹ and that is always
pressed upward by a spring t, so that the worm is always kept closely in gear with
the worm wheel l. The screw Figs. 1 and 4 regulates the position of the frame s
so as to accurately adjust the position of in relatively to l.
The feed discs a. b are consequently kept continuously in position until they receive
the forward motion for the feed, so that no slipping or backward motion of the fabric
is possible; the mechanism is very durable and allows of easy adjustment of the length
of stitch without any uncontrolled motion.
The device for guiding in the fabric described with reference to Figs. 8 to 8* of
Specification No. 5330 of 1884 is also improved to correspond with the improved
action of the feed discs, such improved construction being shewn at Figs. 5 to 21 of
the drawings, while the mechanism shewn at Figs. 22 to 24 which is fixed upon the
fixed central pillars of the feed discs a b, serves to insure that the fabric fed in between
these discs shall remain exactly at the same height during its passage through the
same which was not possible with the arrangements heretofore employed. Figs. 5
to 21 shew for the sake of clearness the whole of the separate parts of the guiding-in
mechanism, of which only those parts will be described that relate to the present
improvements.
The rear guiding cap C, which is fixed on the middle piece A serves to hold the
edges of the fabric which tend to roll up, accurately at the required height; it is shewn
in detail at Fig. 7b and consists of a piece C of triangular section with side cheeks that
embrace the middle plate A, being formed with a slit c³ into which fits the free upper
part of the tongue a¹ of A, C being fixed in this position by means of a screw c².
The lower part of has on each side of a a hollow or recess c³ ³, whereby, on the
one hand, a sure guide is provided for the fabric as it rolls up, and on the other hand
the correct height is insured for the part of the fabric that has not rolled up, so that
a nipping of the fabric in the apparatus is avoided. By means of this guiding cap C
the fabric to be sewn is accurately and smoothly guided at the required height before
it begins to roll up until it enters the slits of the front cap, in which it is further
guided until it enters the feed discs, such guiding being independent of the operator.
Figs. 5. 8 to 8 and 19. 19ª shown in natural size and Figs. 20, 21" in double
natural size the front cap E, F which serves for turning over regular shaped fabrics to
the outside to the extent of one mesh during the sewing, so as to be sewn at the half
second mesh. It consists of the cap E secured by screws ee to the middle piece A,
and a cap F secured to E by a screw f° as shewn at Figs. 5 and 19.
The cap E is formed forked at the lower part e² e and is divided by the tongue e¹
into the slits e³ e³.
The tops of these slits are somewhat lower than those of the other parts of the
apparatus, to the extent to which the fabric is to be turned over, that is to say, in
the present case, the height of one mesh.
The tops of the slits are formed concave, as shewn at Figs. 7 and 20°, whereby
the turning over of the edge is facilitated. The cap E serves at the same time for
guiding in the fabric at the determined height, and also to maintain it at that height
as it passes into the feed discs,

page_text: The cap F has at its lower part rectangular hook shaped forks f³ ³ and a small
tongue f¹ Fig. 21. The rectangular hooks f³ of the forks f' serve to accurately
gauge the height of the seam having a width of a certain number of meshes, cor-
responding to the extent to which the fabric is to be turned over, this being then
sewn together at the next half mesh. This cap can also be used for turning over
cut knitted goods, the hook shaped forks ff being in that case made of a corre-
sponding increased length, because with cut fabrics several meshes must be turned over
in order to avoid fraying. For insuring a perfectly regular seam it is also requisite
that the edges of the fabric should be advanced by the feed discs, irrespective of
its thickness in such manner that on the one hand the needle shall pass accurately
through at the half mesh, and on the other hand that the edges of the fabric should
have a certain rigidity afforded them for the passage of the needle.
For this purpose the cap K K' Figs. 22 to 24 formed of two parts, situated on
the feed discs, is employed. This cap, the part K of which is fixed to the central
pillar of the back disc and K¹ to the pillar of the front disc are of a Z shaped section,
each part being formed of one piece. These are fixed by their lower horizontal limbs
kok, to the stationary pillars S² S³, on which the hollow spindles of the discs ab
revolve, by means of screws 80 s any shifting being prevented by pins 1° 1° 11 11.
The upper horizontal limb m° of the back part K passes, partly over the limb m¹
of the front part K¹, and these limbs m° m' are situated immediately above the smooth
edges of the rims of the discs a, b, which are not notched as described in patent
No. 533084.
The construction of the cap K (Figs. 23 to 23º), the limb mº of which in all its
details is of importance, is as follows.
The limb m° rests with the surface of the under projecting part n° (which extends
over the whole width of m°) upon the upper edge of the feed disc.
This part no has a thickened part 0° on the side on which the fabric is fed in, which
part is stepped off towards the needle in such manner that the under edge of 0°
stands slightly higher than the upper edge of the part n°(Figs. 23ª 23b) mo has a groove po
in line with the needle (Figs. 23 cd) which groove is cut to such a depth in n° that
the fabric, while bearing with its upper edge against the underside of the part 0°
stands accurately at the height of the first half mesh in front of the needle groove po,
so that the needle must always pass through it at the height of the half mesh.
The upper limb m¹ of the front cap K² rests with its undersurface upon the edge
of the front feed disc b, while the upper surface of m¹ bears against the undersurface
of the part 0°, so as to slide against this when the discs a bare moved apart by
drawing away the back one as described in the previous patent. By this means an
expansible slot N closed at the upper end, is formed between the discs, allowing for
varying thickness of fabric and yet always maintaining the upper edge thereof at a
definite height.
By means of this divided cap K K' therefore, the maintenance of the upper edge
of the fabric at a uniform height is insured, as any upward motion is prevented by
the part 0 of K while any downward slip is not possible because the guiding-in
mechanism has the tendency to move the fabric upwards; on the other hand the
width of the space is rendered automatically adjustable for varying thicknesses of
fabric as described.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is :-
1. In feed mechanism for sewing elastic goods, actuating the feed discs from a
cam on the driving shaft by a lever P, ratchet wheel n, and worm and worm wheel l m,
so that the feed discs are only moved when the fabric has to be fed forward, and are
held rigidly still at other times, so that no intermediate movement of the fabric is
possible, the length of stitch being varied without causing uncontrolled motion, by
varying the action of the lever p, substantially as herein described.
2. In combination with the construction of guiding-in mechanism herein described

page_text: with reference to Figs. 5 to 21ª of the drawings, the back guiding cap c and the front
cap E F, constructed and operating as and for the purposes set forth.
3. The construction of the divided cap K K fixed on the stationary supporting
pillars of the feed mechanism, wherein the parts m° n° and 0° and needle groove p
of cap K in combination with the part m¹ with needle groove p¹ of cap K¹, effect the 5
guiding of the edge of the fabric accurately at the required height during its passage
Between the feed discs, so that the needle passes through at the height of the half
mesh, while at the same time the slot N formed by the parts mº m² of the caps K K¹
is automatically adjusted in width according to the thickness of the fabric operated
upon substantially as herein described with reference to Figs. 22, to 24 of the 1
drawings.