IMPROVEMENTS IN THE CONSTRUCTION OF SEWING MACHINES
Year: 1879

page_text: LETTERS PATENT to Meshach Hopkins, of Walworth, in the County of Surrey,
Engineer, and John Hopkins, of Camberwell, in the said County, Physician,
for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF SEWING
MACHINES."
Sealed the 21st May 1880, and dated the 24th November 1879.
PROVISIONAL SPECIFICATION left by the said Meshach Hopkins and John
Hopkins at the Office of the Commissioners of Patents on the 24th November
1879.
MESHACH HOPKINS, of Walworth, in the County of Surrey, Engineer, and JOHN
HOPKINS, of Camberwell, in the said County, Physician.
"IMPROVEMENTS IN
THE CONSTRUCTION OF SEWING MACHINES."
This Invention consists in improvements in the construction of sewing machines
and relates, first, to the construction and arrangement of mechanism whereby the
tension on the thread is regulated and controlled by the action of certain parts of
the machine in a simple and efficacious manner, and, secondly, to improvements
which are capable of being applied to the ordinary feeding mechanism of sewing
machines for the purpose of obtaining a longer stitch, whilst at the same time such
improvements admit of the easy regulation of the length of stitch, as required.
On the
We will now proceed to describe the first part of our said Invention.
screw or spindle of the tension device, which is of the ordinary construction, is
mounted a pinion or cog-wheel into which gears a rack formed on or attached to
one end of a bar or rod, the other end of which is connected by means of a vibrating
link to a bell-crank or other suitably shaped oscillating lever pivoted to the frame
of the machine or to a bracket attached thereto; the opposite end of the said
oscillating lever has a groove or slot therein in which works a pin or stud attached
to the presser bar or any connection thereof which partakes of the same move-
ments. By these means the rack and pinion cause the tension screw or spindle to
revolve in accordance with the up or down movement of the said presser bar,
thereby varying the amount of pressure exercised by the spring on the tension
device, thus regulating the tension on the thread according to the thickness of the
material being acted upon.
Instead of connecting the mechanism above described to the presser bar, we in
some cases connect it in a similar manner to the stitch regulator, cam lever, or
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page_text: feed bar, or other suitable part of the feed mechanism, whereby the tension device
is actuated as above described, and the amount of tension on the thread is regulated
according to the length of stitch.
A modification of the above described arrangements consists in dispensing with
the said rack and pinion and forming the end of the bar or rod wedge-shaped; one
side of the said wedge shaped end works against a stud fixed to the frame of the
machine, and the other side against a pin attached to a sliding plate which has a
claw shaped projection attached thereto and situated in front of the tension
spring. On the said bar or rod being caused to advance through the medium of
the oscillating lever, as will be well understood, the inclined surface of the wedge-
shaped end of the bar or rod bearing on the stud of the sliding plate moves the
latter laterally and thereby frees the tension device from the action of the spring;
on the reverse action of the said bar or rod the spring carries the sliding plate back
to its normal position and again acts on the tension device. The above described
arrangement is actuated by any of the means hereinbefore described, or in some
cases the oscillating lever is connected in a similar manner with the needle bar or
any attachment thereof having a similar vibratory action, or the end of the bar or
rod opposite to that which is wedge-shaped is pivoted directly to the needle bar or
attachment thereof, thus dispensing with the necessity for the oscillating lever.
In some cases we construct the end of the bar or rod of a conical instead of a
wedge-shaped form, or we cause the end of the bar or rod to act upon a cone
arranged between the before mentioned fixed stud and the stud on the sliding
plate, or a projection with an inclined or bevilled edge is attached to the frame,
and the end of the bar or rod which is pointed works between the same and the
stud of the moveable plate. By any of the above described means the plate is
caused to slide laterally and thus to regulate the pressure of the before mentioned
spring on the tension device.
Instead of employing one bar or rod with a wedge-shaped or conical end, as
above described, two similar or rods are sometimes employed, in which case
one is attached to and actuated by the presser bar, and the other by the feeding
mechanism, or needle bar, or attachments thereof; or one is actuated by the latter
and the other by the feeding mechanism; or three bars or rods respectively connected
with and actuated by the above mentioned parts of the machine are employed,
substantially as above described. When this form of constructed is employed the
respective wedge-shaped or conical ends of the rods act in conjunction with each
other.
The second part of our Invention consists, as hereinbefore stated, in improve-
ments in the feeding mechanism, of which the following is a description:-On the
ordinary stitch cam, eccentric, or crank, which is generally mounted on the main or
driving shaft, is placed, in such a manner as to be free to oscillate, a lever, one end
of which bears against the feed bar in its forward or stitch forming movement, the
other end of the same bearing against a fixed stud or projection attached to the
frame, or stitch regulator, or other suitable part of the machine, or the stud or pin
may work in a slot formed in the end of the said lever. By altering the position
of the said stud the extent of oscillation of the said lever is varied and the length
of stitch regulated.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Meshach Hopkins and John Hopkins in the Great Seal Patent
Office on the 24th May 1880.
MESHACH HOPKINS, of Walworth, in the County of Surrey, Engineer, and JOHN
HOPKINS, of Camberwell, in the said County, Physician. "IMPROVEMENTS IN
THE CONSTRUCTION OF SEWING MACHINES."
Our said Invention consists in improvements in the construction of sewing
machines and relates, first, to the construction and arrangement of mechanism
whereby the tension on the thread is regulated and controlled in accordance with
the length of stitch and the thickness of the material being operated upon by the
action of certain parts of the machine in a simple and efficacious manner, and,
secondly, to improvements which are capable of being applied to the ordinary
feeding mechanism of sewing machines for the purpose of regulating the length of
the stitch as required, and whereby a longer stitch can be obtained than is possible
by many of the machines as ordinarily constructed.
We will now proceed to describe the first part of our said Invention. On the
screw or spindle of the tension device, which is of the ordinary construction, is
mounted a pinion or cog-wheel into which gears a rack formed on or attached to
one end of a bar or rod, the other end of which is connected either directly or by
means of a vibrating link to a bell crank or other suitably shaped oscillating lever
pivoted to the frame of the machine or to a bracket attached thereto; the opposite
end of the said oscillating lever has a groove or slot therein in which works a pin
or stud attached to the presser bar or any connection thereof which partakes of the
same movements, or to any contrivance which is actuated upon by the material
under treatment according to the thickness thereof. By these means the rack and
pinion cause the tension screw or spindle to revolve in accordance with the up or
down movement of the said presser bar or other contrivance, and the said spindle
screws more or less into or out of its bearings, thereby varying the amount of
pressure exercised by the same on the tension device, thus regulating the tension
on the thread according to the thickness of the material being acted upon.
When it is desired to regulate the amount of tension according to the length of
stitch, a bar or rod having a rack formed on or attached thereto at one end has the
opposite end connected to the stitch regulator, cam lever, or feed bar, or other suitable
part of the feed mechanism in a manner somewhat similar to that hereinbefore
described for connecting the bar or rod to the presser bar whereby the tension
device is acted upon.
In some cases instead of employing a rack and pinion the bar or rod is formed
with a conical, tapered, or wedge-shaped end. One side of the said end works
against a stud or projection fixed to or forming part of the tension bracket, and the
other side acts upon a pin or projection attached to or bearing against a sliding or
moveable plate or similar contrivance which has a claw or fork shaped projection
attached thereto, and which is arranged in such a position as to be capable of
acting upon the tension spring. A bar or rod constructed and arranged as
hereinbefore described is in some cases connected by means of an oscillating lever
with the needle bar or any attachment thereof having a similar vibratory action,
or the end of the bar or rod opposite to that which is wedge-shaped is pivoted
directly to the needle bar or attachment, in which latter case the oscillating lever
is dispensed with.
In some cases instead of constructing the end of the bar or rod of a conical,
tapered, or wedge-shaped form, the same may be of any suitable shape, as will be
well understood, and is caused to act upon a conical, tapered, or wedge-shaped
projection attached to the frame, or the stud on the sliding plate is constructed
with a bevelled edge for the end of the bar or.rod to work against.
Instead of employing one bar or rod, as above described, two similar bars or rods

page_text: are sometimes employed, in which case one is connected to and actuated by the
presser bar, and the other is connected to and actuated by the feeding mechanism
or needle bar or attachment thereof, or one is actuated by the latter and the other
by the feeding mechanism; or three bars or rods respectively connected with and
actuated by the needle bar, presser bar, and feeding mechanism are employed,
substantially as herein before described. When two or three bars or rods are
employed they act in conjunction with each other.
The second part of our said Invention consists, as herein before stated, in
improvements in the feeding mechanism, of which the following is a description :-
On the ordinary stitch cam, eccentric, or crank, which is generally mounted on the
main or driving shaft, is placed in such a manner as to be free to oscillate a lever,
one end of which bears against the feed bar in its forward or stitch forming
movement, the other end of the same bearing against a fixed stud or projection
attached to the frame or stitch regulator or other suitable part of the machine, or
the stud or pin passes through a slot formed in the end of the said lever. By
altering the position of the said stud the extent of oscillation of the said lever is
varied, and the length of stitch regulated.
We will now proceed to refer to the accompanying Drawings, from which the
nature of our said Invention will be more clearly understood. The same letters of
reference indicate similar or analogous parts in the several Figures. Figures 1 to
23 shew the apparatus and various parts thereof as constructed and arranged when
our said Invention is applied to machines constructed in accordance with which is
generally known as a chain stitch machine. Figure 1 is a side view of the
machine; Figure 2 is a section of the same taken through the line A, A ; and
Figure 3, a section taken through the line B, B; Figure 4 is an enlarged view of a
portion of the last named Figure; Figure 5 is a top view of Figure 1; Figure 6 is
a view of the feeding mechanism shewn at Al, in Figure 1; Figure 9 is an
enlarged view of a portion of Figure 2. In these Figures the apparatus for
regulating the tension consists of three bars or rods with tapered or wedge shaped
ends actuated respectively by the needle bar, presser bar, and feeding mechanism.
The bar or rod C actuated by the presser bar is shewn at Figures 19 and 20; c is
the tapered or wedge-shaped end thereof, the opposite end c is connected to the
Oscillating lever D, Figures 17 and 18; at the point d the said lever is pivoted at
the point d' to a bracket, Figures 26, 27, and 28, which is attached to the frame;
the opposite end d³ of the lever D is provided with an elongated hole or slot,
through which passes a stud d³ connected to the presser bar K. It will readily be
understood that when the presser bar K is acted upon by any variation in the
thickness of the material being worked upon the stud will actuate the oscillating
lever D, which, moving round its pivot, gives motion to the bar or rod C, which
receives a to and fro movement, whereby the tapered or conical end c is caused to
act upon the tension device as hereinafter described. The sliding or moveable
plate E is shewn at Figures 24 and 25; the end e of the said plate is formed at
right angles, or nearly so, to the remainder thereof, and is provided with a slot e¹,
through which the tension screw F passes, as shewn in Figure 4. The upper
portion of the plate E is slotted at e'. The said plate is mounted on and connected
to the part of the frame forming the tension bracket or box by means of the screw e³
and stud e in such a manner that it is free to slide in a direction parallel to the
tension spindle F; e is an adjustable block or pin secured to the plate E, the
position of the same in the slot es can be adjusted according to the amount of
tension required, or to the number of bars or rods employed; G is the stud or
projection attached to the tension bracket or frame of the machine, and g is a groove
or recess formed in the tension bracket for the block e to move in, and also
for the reception of the tapered or wedge-shaped ends of the before-mentioned
bars or rods. The tension spring f is firmly compressed by the plate E within
the recess f¹. The tension spindle or screw F passes through a pair of
tension discs h, h, and through a alot in the tapered or wedge-shaped end of the
bar I, and then through the end e of the plate E, and through the centre of the

page_text: tension spring f. The said spring is not brought "to block" by the plate E, there
being a space left between the bracket and the end e, which allows of the latter to
compress the spring sufficiently to permit the tension discs to open, and the thread
to run freely through the same, such action being effected by the sliding of the
plate E caused by the action of the tapered or wedge shaped ends of the bars or
rods between the fixed stud G and the adjustable block e. Figures 15 and 16 are
detached views of the bar or rod I, the tapered or wedge shaped end i of which
has an elongated hole or slot, and is inserted between the tension discs and the end e
of the plate, the tension screw passing through the slot in the end i; the opposite
end ¹ is connected to the end of the oscillating lever L, which latter is shewn
detached in Figures 29, 30, and 31; the other end of the said lever is turned
sideways at right angles, and then edge ways in an oblique direction, as shewn ;
through the slot or jaw is passed a stud, as shewn in Figure 6. The said lever L
is pivoted at 13; is the stitch regulating lever. It will be seen from the above
description that when the stitch regulating lever * is moved it actuates the
oscillating lever L, which alters the position of the tapered or wedge shaped end of
the bar or rod I, which acts on the tension device in a manner similar to that of
the end c of the rod C; M is a bar or rod pivoted to the needle arm Y with a
tapered or wedge shaped end m, and is shewn detached at Figures 21 and 22.
When the end m makes its forward stroke and touches the stud G it forces the
bar or rod C and the adjustable block e laterally, and with them the plate E,
thereby compressing the spring f and freeing from pressure the rod I and tension
discs h, h, the thread then being free to be drawn out for the next stitch. The
oscillating needle arm Y is pivoted to the frame at y, and is connected by the rod y',
which works upon an eccentric or crank on the main shaft X or on a supplementary
rocking shaft or lever. By the action of the arm Y a to and fro movement is
given to the rod or bar M, and an intermittent action is given to the plate E.
the backward movement of the rod or bar M the spring f is released and extends
to its normal position, thereby pressing the tension discs h, h, firmly together,
and causing them to clamp the thread during the formation and tightening of the
stitch.
On
Figures 34 to 40 are various views of the above described apparatus as modified
in order to admit of its application in the manner shewn to a spool machine, or a
machine constructed in accordance with the Wheeler and Wilson system, or other
machine of similar construction. Figures 35 and 36 are end views in section taken
respectively through the lines A, A, and B, B, Figure 34. Figure 37 is an end
view of the sliding plate E, the construction of which is modified in order to suit
this particular application.
Figures 38, 39, and 40 are views of the oscillating lever D also modified in form,
which is connected at one end with the presser bar, as described, but the opposite
end instead of being connected to the bar C is itself tapered, and has an inclined
enlargement on the side thereof. In this case the tension device is carried by the
needle arm or lever Y.
Figures 41 to 44 shew the apparatus constituting this Invention in a modified
form, and applied to a machine constructed in accordance with what is known as
the Singer system, or machines of similar construction, in which the tension device
is attached to the head thereof.
the feeding
are views of
1 end T of
ever R acts
That part of our Invention which refers to improvements in
mechanism is shewn in the following Figures:-Figures 10 and 11
the oscillating lever R, which is placed upon the stitch eccentric or
the main shaft X, as shewn at Figure 6. The upper end of the s
at on the ordinary feed bar, and the opposite end r³ rests against the stud S fixed
in a suitable position in the frame of the machine, or as hereinbefore described, the
result of such arrangement of mechanism being that when the stitch cam T makes
its forward or stitch forming movement it will be seen that the end of the lever R
is carried forward and the length of stitch increased, as shewn by the dotted lines
in Figure 10. Upon the return of the stitch cam T the end of the lever R is

page_text: carried back by the force of the spring acting upon the ordinary feed bar. The
regulation of the length of the stitch is effected in the ordinary way by means of
the regulating lever .
Having thus described and ascertained the nature of our said Invention, and the
manner in which the same is to be performed, we would observe in conclusion that
what we consider novel and original, and therefore claim as constituting the
Invention secured to us by the said hereinbefore in part recited Letters Patent
are,-
First. A lever so arranged as to be actuated by the presser bar or material
worked upon, such action being transmitted to the tension device by means of a
bar or rod having a conical, tapered, or wedge shaped end or rack acting on a
pinion, substantially as and for the purposes herein before described and set forth.
Secondly. A lever or bar or rod so arranged as to be actuated by the stitch bar
or stitch regulator, or any connection thereof, such action being transmitted to the
tension device by means of a bar or rod having a conical, tapered, or wedge shaped
end or rack acting on a pinion, substantially as and for the purposes herein before
described and set forth.
Thirdly. A lever or bar or rod so arranged as to be actuated by the needle bar,
needle arm, or any connection thereof, such action being transmitted to the tension
device, substantially as and for the purposes herein before described and set forth.
Fourthly. A double ended lever mounted upon the ordinary stitch crank or
eccentric, and one end of which bears against a fixed stud or pin, by which means
a great length of action is given to the other end, substantially as and for the
purposes hereinbefore described and set forth.
And, Lastly. The combinations and arrangements of mechanism, substantially as
and for the purposes herein before described and set forth.
In witness whereof, we, the said Meshach Hopkins and John Hopkins, have
hereunto set our hands and seals, this Twenty fourth day of May, in the
year of our Lord One thousand eight bundred and eighty.