Improvements in Trimming Attachments for Sewing Machines.
Year: 1897

page_text: Date of Application, 30th Mar., 1897-Accepted, 5th June, 1897
[Cominunicated from abroad by THE SINGER MANUFACTURING COMPANY, of New
York, United States of America, Sewing Machine Manufacturers.]
Improvements in Trimming Attachments for Sewing Machines.
I, WILLIAM HARVEY INSLEE, Manager of The Singer Manufacturing Company,
Kilbowie, Dumbartonshire, do hereby declare the nature of this invention and in
what manner the same is to be performed as communicated to me, to be
particularly described and ascertained in and by the following statement :-
My invention relates to that class of sewing machine trimmers by means of which
the surplus material extending beyond the seam is removed simultaneously with the
Bowing operation. In this invention the upper and lower blades or knives constituting
the shear trimming device are loosely mounted so that they may be simultaneously
adjusted laterally to vary the distance between the line of trimming and the line of
stitching, and I provido an adjusting device (preferably a screw) which is connected.
with the adjustable shear trimmer in such a manner that by moving said adjusting
dovico the attendant may vary the lateral position of the trimming blades, as may be
desired, and this may be effected whether the machine be in operation or at rest. To
prevent accidental displacement of the trimmer from the jarring of the machine when
in operation I provide means for retaining the adjusting device, (and consequently
the shear trimmer with which said adjusting device is connected) in any position to
which it may be removed by the attendant.
In the use of shear trimming devices considerable annoyance is occasioned by lint
and dust, resulting from the cutting, which works down into and clogs the mechanism
below the cloth-plate. This difficulty is, of course, greater where the trimmer is
laterally adjustable and where a slot of considerable width has to be made in the cloth-
plate to permit of the Interal adjustment of the trimmer. To obviate this difficulty I
provide, in connection with my laterally adjustable trimmer, an adjustable lint or
dust guard consisting preferably of a sliding plate one end of which extends closely
adjacent to the blades of the trimmer and which lint guard is connected with said
adjusting device so as to move laterally therewith, and consequently with the trimmer,
when the latter is adjusted to vary the line of trimming. The lint or dust guard thus
always preserves its close relation to the trimmer without any special care on the part.
of the attendant, and thus the slot in the cloth-plato required for the action of the
trimmer will always be kept as nearly closed as possible, so that in my improved
machine very little lint or dust works down beneath the cloth-plate.
In the accompanying drawings
Fig. 1 is a partial plan view of the lower part of a "Singer" single thread chain-
stitch machine embodying my invention, the cloth-plate being removed.
Fig. 2 is a partial rear side sectional view of the same.
Fig. 3 is a partial front end view of the machine, with the lower end cover-
plate removed.
Fig. 4 is a plan view of the cloth-plate, showing the adjustable lint guard and
other parts.
Figs. 5 and 6 are detail views of the trimming knives or blades, and
Fig. 7 is a detail view of the device for preventing rotation of the trimmer
adjusting screw.
A denotes a part of the frame of the machine, and B the lower rotating driving
shaft carrying the single thread chain-stitch looper b, the feed eccentrics b' and 6' and

page_text: a third or trimmer-operating eccentric 6. Mounted in a bearing portion of the
horizontally reciprocating and vortically vibrating feed-bar C is a small rock-shaft D
having a depending arm d to which is attached the shank of the upper shear blade e,
said rock-shaft passing through a hole ein said blade and said shaft having a
horizontal arm d¹ forked to embrace the eccentric b². The arm has a
sleeve d' rigidly attached to said shaft, and said sleeve is provided with a depending
log d'.
The lower shear blade e' is placed loosely on the rock-shaft D, said blade having a
hole through which said shaft passes. Said blade is also provided with a notch e
to embrace a lng e' on the feed-bar C so that while said blade is thus held rigid with
said feed-har it is freo to be adjusted laterally relative thereto. A coil springƒ
interposed between the blade and an adjusting-nnt d' on the shaft D holds the
said blude closely against the blade e, a lock-nnt d'securing said adjusting-nut in
place..
G is an adjusting screw tapped in a portion of the frame A and provided with
flanges between which is an annular groove g' into which extends the lug of the
sleeve, so that by turning said screw by its milled hend g the rock-shaft D and
the shear blades e and e' mounted thereon may be moved laterally towards or from
the needle or tho line of stitching, according to the direction in which said screw may
be turned. To prevent accidental displacement of the adjusting screw the latter is
provided with a toothed wheel or flangos g to be engaged by a lug or tooth 4 of a
holding spring I.
1 is a lint or dust guard made in the form of a sliding plate adjustably mounted on
the cloth-plate J, the outer end of said plate or lint guard I fitting closely adjacent to
the shear blades e and e¹, but not being in actual contact therewith so as to interfere
with the free action thereof. The plate or lint guard I is provided with a slot at i up
through which extends the upper end of a plate or shoe k placed loosely in an annular
groove between the flanges of the toothed wheel 9' where it is retained by an
overhanging part of the spring . As the said plate or lint guard I mounted in said
groove will be moved laterally by the screw G when the latter is turned to adjust the
shear blades of the trimmer it will be apparent that the said plate or guard will always
preserve its close relation to the shear blados, so that there will be no opening formed
on the cutting sides of said blades, when the trimmer is adjusted laterally, and thus
lint or dust will largely be prevented from working downward through the cloth-
plate. In this connection it may be observed that the trimmer and the lint guard
have a common adjusting device, to wit, the screw G, so that they will have co-incident
lateral movements during adjustment.
In the operation of my inproved trimmer the lower blado e' rises and falls with the
feed bar while the upper blude e is vibrated so that it descends to close the shears
when the blade e' rises, the shears opening when the feed bar is performing its idle or
return movement and closing when the feed is moving forward to advance the work.
When it is desired to adjust the trimmer laterally the attendant simply lifts the
holding spring H frem ils engagement with the toothed wheel and then turns
the adjusting screw G by its milled head to effect the desired adjustment of the
trimmer towards or from the nocdlo of the machine, and this adjustinent may be
effected whether the machine be running or not.
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. The combination with the stitch-forming mechanism of a sewing machine, of
a shear trimming device, comprising upper and lower knives or blades, loosely
mounted for Interal adjustment, an adjusting device connected with said blades
and by means of which adjusting device the lateral position of the said
blades may be varied either when the machine is in operation or at rest, and means
for holding the said adjusting device stationary in any position to which it may havo
been moved.

page_text: 2. The combination with the stitch-forming mechanism of a sewing machine, of
a shear trimming device, comprising upper and lower knives or blades, loosely.
mounted for lateral adjustment, an adjusting device connected with said blades
and by means of which adjusting device the lateral position of the said
blades may be varied either when the machine is in operation or at rest, means
for holding tho said adjusting device stationary in any position to which it may
have been moved, a laterally movable lint guard extending closely adjacent
to said shear blades, and means whereby said lint guard may be moved laterally
with said blades when the lateral positions of the latter are changed by said
adjusting device.
3. The combination with the stitch-forming mechanism of a sewing machine, of
a feed-bar, a laterally adjustable shear trimmer mounted on said feed-bar and an.
adjusting device whereby the said trimmer may be moved laterally relative to said
stitch-forming mechanism.
4. The combination with the stitch-forming mechanism of a sowing machine, of
a feed-bar, a laterally adjustable shear trimmor mounted on said feed bar and a
laterally adjustable lint guard co-incidently movable with said shear trimmer.
5. The combination with the stitch-forming mechanism of a sewing machine, of
n feed bar, a rock-shaft mounted in said feed bar and laterally adjustable relativo
thereto, an upper shear blade vibrated by said rock-shaft, a lower shear blade movable.
with but stationary relative to said feed bar, and a spring for holding said blades in
cutting contact with cach other.
6. The combination with the stitch-forming mochanism of a sowing machine, of
a feed bar, a rock-shaft mounted in said feed bar and laterally adjustable relative
thereto, an upper shear blade vibrated by said rock-shaft, a lower shear blade movable
with but stationary relative to said feed bar, a spring for holding said blados in.
cutting contact with each other, and a laterally adjustable lint guard.
7. The combination with the stitch-forming mechanisin of a sowing machine, of a
shear trimmer comprising upper and lower blades both of which are laterally adjust-
ablo relative to the needle of the machine, and an adjusting screw connected with
said blades and by turning which thoir lateral adjustment may be effected.
8. The combination with the stitch-forming mechanism of a sewing machine, of
a shear trimmer comprising upper and lower blades both of which are laterally
adjustable relative to the needle of the machine, an adjusting scrow connected with
said blades and by turning which their lateral adjustment may be offected and means
for retaining said screw in any desired position of adjustinent.
9. The combination with the stitch-forming mechanism of a sowing machine, of
a shear trimmer comprising upper and lower blades both of which are laterally
adjustable relative to the needle of the machine, an adjusting scrow connected
with said blades and by turning which their lateral adjustment may be effected, means
for retaining said screw in any desired position of adjustment, and a laterally
adjustable lint guard connected with said screw to be adjusted by the latter-
co-incidently with said shear blades.
ليوم
1
Ch 1907