IMPROVEMENTS IN AND RELATING TO TRIMMING OR CUTTING MECHANISM FOR SEWING MACHINES to be as follows:
Year: 1884

page_text: J, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake & Co, Patent Agents;
Southampton Buildings, London in the County of Middlesex, do hereby declare the
nature of said invention for "IMPROVEMENTS IN AND RELATING TO TRIMMING OR
CUTTING MECHANISM FOR SEWING MACHINES to be as follows:-
"
This invention relates to trimming mechanism for sewing machines which
mechanism is composed of a blade or cutting edge affixed to the bed of the
machine, and a cooperating moving blade operated by the power of the machine,
the said blades trimming the material being stitched in a line parallel with the line
of stitches.
The said invention has for its objects to enable a blade of this class, while
rotating on an arbor journalled in fixed bearings, to operate intermittently; to
provide an improved fixed blade, and means for securing the same whereby the
blade may be adjusted to compensate for wear of its cutting edge, and its usefulness
preserved much longer than heretofore; and to provide means for preventing the
scraps and lint formed by the cutting action from finding their way below the
throat-plate or bed of the machine, and obstructing or impeding the action of the
stitch-forming mechanism below said throat-plate or bed.
To these ends the invention consists partly in arranging an elongated fixed.
blade to present one of its ends as a cutting surface, and in providing supporting
and holding devices for the said blade whereby it is adapted to be moved end wise
to compensate for wear, and is positively held at any position to which it may be
adjusted. It also partly consists in the provision of a depression in the throat-
plate or bed of the machine arranged to receive the scraps and lint formed by the
action of the cutters, and prevent them in a great measure from being forced by
the moving blade downwardly through the slot in the throat-plate beside the fixed;
blade, all of which are hereinafter described.

page_text: In carrying the said invention into practice I provide a slot in the throat-plate
of the machine, and a fixed shear blade secured to a fixed part of the machine and
forming a part of one side of the said slot. A rotary blade is affixed to an arbor,
which is journalled in fixed bearings and has at is rear end a pinion engaging with
a pinion on the driving shaft of the machine. The rotary blade is substantially
disc shaped with an offset at one side. One edge of the said offset is sharpened,
and forms a cutting edge which extends outside of the periphery of the body of
the blade and is formed to assume substantially the same relation to the fixed
blade in passing the latter that the edge of an ordinary vertically reciprocating
trimming knife assumes to the fixed blade with which it cooperates. The cutting
edge of the rotary blade therefore cooperates with the fixed blade and cuts the
material interposed between the said blades intermittently, or once during each
rotation of the blade.
A portion of the periphery of the rotary blade constantly projects sufficiently
into the slot to prevent the material being trimmed from passing under the blade
beyond the point where it is cut by the co-operating cutting edges.
The described devices constitute a cheap and efficient trimmer easily applied, and
entirely independent of the head or arm of the machine. Heretofore a rotary disc
trimmer has been made having a cutting edge extending continuously around its
perimeter and journalled in fixed bearings, the said cutter being always in contact
with the work, partially obstructing the feed movements of the same. A disc
trimmer has also been intermittently operated by alternately raising and lowering
it while in operation, but such intermittent operation involves complication of
mechanism and expense which are avoided by the present improvements.
The tixed blade elongated and arranged diagonally, its upper end projecting
through a slot in the bed or throat plate of the machine, and constituting the
cutting edge.
The fixed blade is detachably clamped or secured to a suitable seat or bearing,
so that it can be moved endwise and readily removed to be sharpened or
renewed. The seat or bearing is sometimes formed on a block attached to the
supporting base below the bed plate and provided with diagonally arranged guides
between which the fixed blade is adapted to slide end wise when released. The
blade is clamped against its seat by a clamping bar secured by screws to the block
and adapted to be pressed at one end against the blade by said screws, and thus
secure the blade rigidly to the block When the screws are loosened the blade is
released and may be removed or adjusted.
It will be observed that the elongated blade having its cutting edge at its end,
and adapted to have endwise adjustment to compensate for wear of said edge,
enables the blade to be used until its length is so reduced that the clamp can no
longer hold it, the usefulness of the blade being thus indefinitely prolonged, while
the provision of the seat and guides for the blade and the detachable clamping
device enable the blade to be very readily and conveniently adjusted or removed.
The facility with which the fixed blade may be removed and applied enables the
distance between the line of stitches and the trimmed edge to be varied by using
a thicker or a thinner blade, the said distance being increased by using a thicker
blade, and vice verea. The diagonal arrangement of the fixed blade enables it to
avoid the loop-forming hook and gives it a longer cutting edge than if it were
vertically arranged.
At one side of the slot into which the fixed blade projects is a depression in the
bed plate, extending from the fixed blade a suitable distance toward the inner or
right hand edge of the bed plate, and forming a receptacle for lint scraps and other
debris created by the action of the trimming blades, and allowing the said matter
to work away from the blades and from the narrow slot through which the fixed
blade extends so that the lint or the like is not so liable to remain near said slot
and work down through the same onto the mechanism below, as when the bed
plate is level at the point where I form the depression. When the bed plate has
.

page_text: no depression, a slot must be provided through the plate, of sufficient width to
receive the moving blade, but as the depression is entirely below the said blade it
can be brought so close to the fixed blade as to leave only sufficient space to
permit the insertion of the thickest fixed blade that is likely to be employed, the
said space being entirely filled when the thickest blade is employed, and being so
narrow, when the thinnest blade is employed, that it will not permit the passage of
any considerable amount of lint or the like. It is obvious that the described
improvements may be employed with a reciprocating, instead of a rotary, blade.,
Dated this 17th day of March 1884

page_text: I, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, & Co, Patent
Agents Southampton Buildings, in the County of Middlesex do hereby declare
the nature of my invention, for "IMPROVEMENTS IN AND RELATING TO TRIMMING
OR CUTTING MECHANISM FOR SEWING MACHINES" 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 trimming mechanism for sewing machines which
mechanism is composed of a blade or cutting edge affixed to the bed of the machine,
and a cooperating moving blade operated by the power of the machine, the said
blades trimming the material being stitched, in a line parallel with the line of
stitches.
The said invention has for its objects to enable a blade of this class, while rotating
on an arbor journalled in fixed bearings, to operate intermittently; to provide an
improved fixed blade, and means for securing the same whereby the blade may be
adjusted to compensate for wear of its cutting edge, and its usefulness preserved
much longer than heretofore; and to provide means for preventing the scraps and
lint formed by the cutting action from finding their way below the throat-plate or
bed of the machine, and obstructing or impeding the action of the stitch-forming
mechanism below said throat-plate or bed.
To these ends the invention consists partly in arranging an elongated fixed blade
to present one of its ends as a cutting surface, and in providing supporting and
holding devices for the said blade, whereby it is adapted to be moved end wise to
compensate for wear and is positively held at any position to which it may be
adjusted. It also partly consists in the provision of a depression in the throat-plate
or bed of the machine arranged to receive the scraps and lint formed by the action
of the cutters, and prevent them in a great measure from being forced by the
moving blade downwardly through the slot in the throat-plate beside the fixed
blade, all of which are hereinafter described.
In the accompanying drawing
Figure 1 is an end elevation of a sewing machine provided with my improve-
ments.
Figure 2 is a front elevation of the same, and
Figure 3 is a section on the line x x Figure 1.
Similar letters of reference indicate corresponding parts in the several figures.
a represents a slot in the throat-plate of the machine, and b a fixed shear blade
secured to a fixed part of the machine and forming a part of one side of the said
alot.
c represents a rotary blade affixed to an arbor d, which is journalled in fixed
bearings e, and has, at its rear end, a pinion f engaging with a pinion g on the
driving shaft g¹ of the machine. The rotary blade c is substantially disc shaped
with an offset c¹ at one side. One edge of the said offset is sharpened, and forms a
cutting edge which extends outside of the periphery of the body of the blade, and
is formed to assume substantially the same relation to the fixed blade 6 in passing
the latter that the edge of an ordinary vertically reciprocating trimming knife
assumes to the fixed blade with which it co-operates. It will be seen therefore that
the cutting edge of the rotary blade co-operates with the fixed blade and cuts the
material interposed between the said blades intermittently, or once during each
rotation of the blade.

page_text: A portion of the periphery of the rotary blade c constantly projects sufficiently
into the slot, to prevent the material being trimmed from passing under the blade
beyond the point where it is cut by the co-operating cutting edges. The described
devices constitute a cheap and efficient trimmer easily applied to a machine of the
kind shown, and entirely independent of the head or arm of the machine. Hereto-
fore a rotary disc-trimmer has been made, having a cutting edge extending
continuously around its perimeter and journalled in fixed bearings, the said cutter
being always in contact with the work partially obstructing the feed movements
of the same.
A disc-trimmer has also been intermittently operated by alternately
raising and lowering it while in operation, but such intermittent operation involves
complication of mechanism, and expense, which are avoided by the present
improvement. The fixed blade b is elongated and arranged diagonally as shown in
Figure 1, its upper end projecting through a slot in the bed or throat-plate of the
machine, and constituting the cutting edge. The fixed blade b is detachably,
clamped or secured to a suitable seat or bearing so that it can be moved endwise
and readily removed to be sharpened or renewed. In the present instance the seat
or bearing is formed on a block attached to the supporting base below the bed
plate and provided with diagonally arranged guides i between which the fixed
blade bis adapted to slide end wise when released.
The blade is clamped against its seat by a clamping bar j, secured by screws 1º
to the block 1, and adapted to be pressed at one end against the blade by said
screws, and thus secure the blade rigidly to the block. When the screw 12 is
loosened the blade is released and may be removed or adjusted.
It will be observed that the elongated blade b having its cutting edge at its end,
and being adapted to have end wise adjustment to compensate for wear of said edge,
enables the blade to be used until its length is so reduced that the clamp j can no
longer hold it. The usefulness of the blade is thus indefinitely prolonged, whilo
the provision of the seat and guides for the blade and the detachable clamping
device, enables the blade to be very readily and conveniently adjusted or removed.
The facility with which the fixed blade b may be removed and applied enables
the distance between the line of stitches and the trimmed edge to be varied by
using a thicker or a thinner blade b, the said distance being increased by using a
thicker blade, and vice versa. The diagonal arrangement of the fixed blade b
enables it to avoid the loop-forming hook m and gives it a longer cutting edge than
if it were vertically arranged.
In the bed-plate at one side of the slot a into which the fixed blade projects is a
depression a¹, extending from the fixed blade a suitable distance toward the inner
or right hand edge of the bed plate, and forming a receptacle for lint scraps and
other debris created by the action of the trimming blades, and allowing the said
matter to work away from the blades and from the narrow slot through which the
fixed blade b extends, so that the lint or the like is not so liable to remain near said
slot and work down through the same onto the mechanism below, as when the bed-
plate is level at the point where I form the depression. When the bed-plate has
no depression, a slot must be provided through the plate, of sufficient width to
receive the moving blade a, but as the depression is entirely below the said blade
it can be brought so close to the fixed blade b as to leave only sufficient space to
permit the insertion of the thickest fixed blade that is likely to be employed, the
said space being entirely filled when the thickest blade is employed, and being so
narrow when the thinnest blade is employed that it will not permit the passage
of any considerable amount of lint or the like. It is obvious that the described
improvements may be employed with a reciprocating instead of a rotary blade.
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
First. In a sewing machine, the combination of the throat plate having a slot
and a fixed blade at one side thereof, a shaft or arbor rotated in fixed bearings
'

page_text: above the bed of the machine, a rotary blade affixed to said arbor and projecting
continually into said slot, and an offset cutting edge forming a part of said blade
and co-operating once during each rotation of the shaft with said fixed blade, as
set forth.
Second. In a sewing machine, the combination with stitch-forming mechanism
and a bed, of a moving blade, an elongated blade co-operating with the moving
blade, a guide or support on which said elongated blade is longitudinally adjustable,
and means for detachably securing said blade to its support, as set forth.
Third. The combination with the moving blade, of the diagonal blade, a guide
and support therefor, and means for detachably clamping the diagonal blade to its
support, as set forth.
Fourth. In a sewing machine, the combination with the fixed and moving blades,
of the bed having a depression beside the fixed blade, and under the moving blade,
as set forth.
Dated this 7th of Dreamho 1001
HASELTINE, LAKE & Co.,
For the Applicant.