Improvements in Trimming Attachments for Sewing Machines.
Year: 1887

page_text: Date of Application, 20th Apr., 1887
Complete Left, 19th Jan., 1888
Complete Accepted, 24th Feb., 1888
PROVISIONAL SPECIFICATION.
Improvements in Trimming Attachments for Sewing Machines.
I, ALEXANDER ANDERSON, Manager of The Singer Manufacturing Company's
Works, Kilbowie, Dumbartonshire, do hereby declare the nature of this invention (a
communication to me from abroad by The Singer Manufacturing Company, of New
York, in the United States of America, Sewing Machine Manufacturers) to be as
follows:.
My invention relates to that class of trimming attachments for sewing machines in
which the knife or cutter is carried by a bar, reciprocating vertically in bearings in
the head of the machine, the said knife or cutter working in a slot in the throat plate;
and the object of my invention is to provide a convenient device, of the class referred
to, in which the cutter-carrying bar may be readily thrown into or out of operation
when desired, and in which the knife may be adjusted on its carrying bar relative to
the needle or the line of stitches.
According to my invention the cutter carrying bar is reciprocated vertically in the
head of the machine by a sliding block embracing the needle-bar and operated from
the crank-disc or cylinder at the forward end of the driving shaft by a crank having
a lesser throw than the needle-bar operating crank. The said sliding block is slotted
to receive the pin or roller of its operating crank and is coupled with the cutter-
carrying bar by a spring-pin entering a notch or recess in said bar. When the cutter
bar is to be thrown out of operation the said pin is withdrawn from its notch or recess
and the said bar will then be lifted by a spring connected therewith so that the notch
will be beyond the range of the spring-pressed coupling-pin on the reciprocating
coupling block. The cutter-carrying bar is provided with a projecting handle by
which it may be depressed in opposition to the stress of its lifting spring to bring the
notch within the range of the coupling-pin when the cutter is to be thrown into
operation. The cutter is secured to a block adjustably attached to the lower end of
the cutter-bar so as to be adapted to be moved laterally towards or from the needle or
the line of stitches made thereby.
Rigidly secured to or formed integral with the crank-pin on the driving shaft which
gives motion to the needle bar is a crank arm having a pin or roller slightly eccentric
to the driving shaft so as to have, in practice, a throw of about one-quarter of an inch,
TD 077

page_text: .
the said pin or roller entering a slot in a coupling block, preferably surrounding the
needle-bar and recessed or slotted to embrace the cutter bar which has vertical
bearings in the arm or head of the machine between the said needle-bar and the
presser bar. The coupling block carries a coupling pin and has a recessed projection
extending outward through a slot in the face-plate and adapted to receive a light
spring which forces the said coupling pin into a notch in the cutter bar when the latter
is to be coupled with the reciprocating block.
When it is desired to run the machine without operating the cutter-bar and cutter
the spring-pressed pin is withdrawn from the notch in the said bar and the latter will
then be lifted by a spring attached to a stationary part of the arm or head and to a
handle secured to the cutter bar and projecting outward through a slot in the face
plate. When the cutter is thus lifted by the spring, the notch therein will be out of
range of the coupling pin carried by the reciprocating coupling block so that the
latter will move up and down idly without imparting movement to said bar.
When the cutter-bar is to be set in motion the operator presses down on a handle
to bring the notch into register with the pin and thus couple the said bar with the
block, a stop-pin which comes in contact with the block limiting the downward
movement of the cutter bar when the said notch is in register with the coupling pin.
The spring for the coupling pin is light, so that when the pin is out of the notch
the frictional contact between the said pin and the cutter bar will not be sufficient to
overcome the stress of the lifting spring, otherwise the said har might accidently be
thrown into operation, when not desired, by the friction of the said pin.
To provide for a lateral adjustment of the blade or cutter on the cutter bar towards
or from the needle-hole in the throat plate of the machine the said cutter is carried by
a block adjustably secured to the cutter-har by screws passing through slots in the
lower end of the said bar. The shank of the knife or cutter is also slotted to provide
for vertical adjustment thereof.
From the foregoing it will be apparent that the cutter-bar may be readily thrown
into or out of operation when desired and that the knife or cutter may be adjusted as
may he required. When the cutter-bar is thrown out of action, the finger at the
lower end of the cutter or knife will be lifted above the throat plate, but when the
said cutter is in operation its throw is so small that the said finger is not disengaged
from the throat-plate.
Dated this Nineteenth day of April 1887.
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.

page_text: I, ALEXANDER ANDERSON, Manager of the Singer Manufacturing Company's
Works Kilbowie, Dumbartonshire, 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 :-
My Invention relates to that class of trimming attachments for sewing machines in
which the knife or cutter is carried by a bar reciprocating vertically in bearings in
the head of the machine, the said knife or cutter working in a slot in the throat
plate; and the object of my invention is to provide a convenient device of the
class referred to, in which the cutter-carrying bar may be readily thrown into or
out of operation. when desired, and in which the knife may be adjusted on its carrying-
bar relative to the needle or the line of stitches.
According to my invention, the cutter-carrying bar is reciprocated vertically in the
head of the machine by a sliding block embracing the needle bar and operated from
the crank disc or cylinder at the forward end of the driving shaft by a crank having
a lesser throw than the needle-bar-operating crank. The said sliding block is slotted
to recive the pin or roller of its operating-crank, and is coupled with the cutter-
carrying bar by a spring pin entering a notch or recess in said bar. When the cutter-
bar is to be thrown out of operation, the said pin is withdrawn from its notch or
recess, and the said bar will then be lifted by a spring connected therewith, so that
the notch will be beyond the range of the spring-pressed coupling-pin on the
reciprocating coupling block. The cutter-carrying bar is provided with a projecting
handle by which it may be depressed in opposition to the stress of its lifting-spring to
bring the notch within the range of the coupling-pin when the cutter is to be thrown
into operation. The cutter is secured to a block adjustably attached to the lower end
of the cutter bar so as to be adapted to be moved laterally toward or from the needle
or the line of stitches made thereby.
In the accompanying drawings Figure 1 is a partial front end view of a sewing-
machine embodying my invention, with the face plate removed. Figure 2 is a
sectional view of the same. Figure 3 is a sectional view similar to figure 2 with the
parts in different positions, and with some parts omitted. Figure 4 is a detail plan
view with the needle and cutter bars in horizontal section. Figure 5 is a detail
view of the sliding coupling-block, to show the crank-pin slot. Figure 6 is a detail
section of the cutter-bar and knife-carrying block on line x-----x Figure 2; and
Figures 7 and 8 are sectional and plan views, respectively, of the throat-plate.
Å denotes the head or the forward part of the arm of a sewing-machine and A' the
face-plate, the latter having openings or slots a and a'.
B is the driving-shaft, and B' the cam-cylinder secured thereto and having a crank-
pin, b, connected by a link, C, with the needle-bar D, in the usual manner. Rigidly
secured to or formed integral with the crank-pin b is a crank-arm b¹, having a pin or
roller, 62, slightly eccentric to the driving-shaft, so as to have in practice a throw of
about one-quarter of an inch, the said pin or roller entering a slot, e, in a coupling-
block E preferably surrounding the needle-bar D and recessed or slotted to embrace
the cutter-bar F, which has vertical bearings in the arm or head A between the said
needle-bar and the presser-bar G. The coupling block E carries a coupling-pin e¹,
having a head e² the said block having a recessed projection e³, extending outward
through the slot a in the face-plate and adapted to receive a light spring, e*, which
forces the said pin into a notch f, in the cutter bar when the latter is to be coupled
with the reciprocating block E.

page_text: When it is desired to run the machine without operating the cutter-bar and cutter,
the spring-pressed pin et is withdrawn from the notch f in the said bar, and the latter
will then be lifted by the spring a², attached to a stationary part of the arm or head,
and to a handle f, secured to the cutter-bar and projecting outward through the
slot a¹ in the face-plate A¹. When the cutter is thus lifted by the spring a², (see
Figure 2) the notch f therein will be out of range of the pin el, carried by the
reciprocating coupling-block, so that the latter will move up and down idly without
imparting movement to said bar. When the cutter bar is to he set in motion, the
operator presses down on the handle f* to bring the notch into register with the
pin e, and thus couple the said bar with the block E, as shown in figure 3, a stop
pin which comes into contact with the block E, limiting the downward movement
of the cutter-bar when the said notch is in register with the coupling-pin.
The spring e¹ is light, so that when the pin e¹ is out of the notch the frictional
contact between the said pin and the cutter-bar will not be sufficient to overcome the
stress of the lifting spring a² otherwise the said bar might accidently be thrown in
operation when not desired by the friction of the said pin.
To provide for a lateral adjustment of the blade or cutter f¹ toward or from the
needle-hole h in the throat-plate H, the said cutter is carried by a block, F¹ adjustably
secured to the cutter bar by the screws f2 passing through slots in the lower end of
the said bar. The shank of the knife or cutter f is also slotted (see dotted lines in
Figure 1) to provide for vertical adjustment thereof.
From the foregoing it will be apparent that the cutter-bar may be readily thrown
into or out of operation when desired, and that the knife or cutter may be adjusted as
may be required. When the cutter bar is thrown out of action, as in Figures 1 and 2,
the finger at the lower end of the cutter or knife will be lifted above the throat-plate;
but when the said cutter is in operation its throw is so small that the said finger is not
disengaged from the throat plate.
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 trimming attachment, the combination, with a notched or
recessed cutter bar, of a reciprocating coupling block and a spring-pressed pin carried
by the latter and adapted to engage the notch or recess in the said bar.
2. In a sewing machine trimming attachment, the combination with a notched or
recessed cutter bar and a lifting spring for the latter of a reciprocating coupling block
and a spring pressed pin carried by the latter.
3. In a sewing machine trimming attachment, the combination, with the cutter bar
having the notch fand the outwardly projecting handle f*, of the lifting spring a² and
the reciprocating coupling block E having the spring pressed pin e'.
4. The combination, with the driving-shaft B and a crank cylinder or disc thereon,
of the needle-bar-operating crank-pin 6 having a rigid arm carrying a crank pin or
roller, the slotted coupling-block E the spring pressed pin e¹ carried thereby, and the
notched or recessed cutter bar.
5. In a trimming attachment for sewing machines, the combination with the
vertically movable cutter bar F of the laterally adjustable knife carrying block F¹,
secured to the said bar, and the knife adjustably secured to the said block.
Dated this Eighteenth day of January 1888.
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.