IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR REGULATING THE FEED TO SEWING MACHINES WITH ONE OR MORE SHUTTLES
Year: 1876

page_text: LETTERS PATENT to Donald Mc Rae, of Leeds, in the County of York, Tailor
and Draper, for the Invention of "IMPROVEMENTS IN THE METHOD OF AND
APPARATUS FOR REGULATING THE FEED TO SEWING MACHINES WITH ONE OR
MORE SHUTTLES."
Sealed the 30th June 1876, and dated the 5th April 1876.
COMPLETE SPECIFICATION filed by the said Donald Mc Rac at the Office
of the Commissioners of Patents on the 5th April 1876.
66
DONALD MC RAE, of Leeds, in the County of York, Tailor and Draper.
IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR REGULATING THE
FEED TO SEWING MACHINES WITH ONE OR MORE SHUTTLES."
This Invention relates to certain improvements in the sewing machines described
in the Specification of Letters Patent dated October Twenty-ninth, One thousand
eight hundred and seventy-three, and number 3513, granted to Thomas William
Sidgreaves.
My present improvement relates to the mode of regulating the feed in such a
manner as to make the stitches of each needle of equal tension. In the improve-
ments above referred to great difficulty is experienced in accomplishing the equal
tension of the thread from both shuttles.
My improvements are accomplished in the following manner-
Firstly. To regulate the feed of the thread so that the tension of both shuttles
are equal I attach a catch lever which is centred at one end on a screw stud, and is
secured to the shuttle plate by the same; to the other end of this said catch lever I
secure a plate which is bent to the desired form and projects in a longitudinal
direction over part of the shuttle race; this plate is kept in position by means of a.
guide peg passing through a slot hole formed in the plate; the shuttle end of the
said plate has a projection on each side at right angles forming the letter Ț; when
the machine is in motion the shuttle carriage comes in contact with the catch lever
and partly revolves the same on the screw stud; when the upper portion of the
lever gives a latteral motion to the T formed plate, which is drawn and the bent
portion pressed against a spring which presses the T end of the plate on to the thread
from the shuttles to the required degree of tention, which is regulated by a screw for
elevating or depressing the aforesaid spring; on the return of the shuttle carriage
the catch is releived, when the T end of the plate rises and releases the shuttle thread.
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page_text: Like parts are indicated by like letters and figures.
Fig. 1 is a side elevation of a sewing machine with my improvements attached..
Fig. 2 is a front elevation; Fig. 3, is a plan; Fig. 4 is a detail of my improved
shuttle plate; Fig. 5 is a plan of the same.
Fig. 6 is an end view of catch and spring for causing either needle to miss stitch.
Fig. 7 is a plan. Fig. 8 is an elevation of distance piece with shuttle carriage
attached. Fig. 9 is a plan of the same.
A is an ordinary bed plate; B, the standard of a sewing machine; C, a fulcrum
attached to bed plate; D, a disc secured to shaft E to which a revolving motion is
imparted in the usual manner; F is a lever centred on fulcrum C and is attached to
dise D by connecting rod d and to shuttle carriage G by rod ; the shuttle plate H
is secured to bed plate in the ordinary way; J is a groove or slide formed in H for the
shuttle carriage G to slide in; K is a catch lever centred on stud K', and at the top
end of this said lever is secured plate L which is kept in position by guide pin passing
through slot hole L'; the ends L and L3 form part of plate L and project over the
shuttle carriages; M is a spring for regulating the amount of tention of the shuttle
threads and adjusted by means of screw N; the spring O is for the purpose of
forcing catch lever K into its position; when the catch is not in contact with the
carriage G the spiral spring Pis secured on 'bar P, and the end of spring P and
P3 are attached to the block Q, to which is centred catch Q1, which can be turned to
either side of block Q parallel to the axis of spring rod P', the distance piece R is
fitted with carriage G and can be secured to shuttle plate by means of screws when
a different pitch is required between the rows of stitches.
Action of Apparatus.-When the machine is in motion the inclined portion of
the shuttle carriage G at G¹ will come in contact with end of catch lever K at K
and partly revolve the same on stud K', so that the plate L will be drawn towards
spring M, which will press the ends L and L³ down on to the thread of the shuttles,
the degree of tention is regulated by means of screw N, when more tention is
required; by screwing N down the spring will be forced nearer to the 'plate L,

page_text: and more pressure will be brought to bear upon the shuttle threads; the spring O
is for the purpose of forcing back the catch lever into its proper position when
releived by carriage G.
When it is desired to cause one of the needles to miss stitch, turn catch Q to one
side so that the same will be parallel to the axis of the spring, when the end Q³
will pass between two standard thread guides S, S, shewn in Figs. 1, 2 and 3,
which have a groove cut through the top of each for carrying the thread, and by
the act of passing between them will press the thread down, by which means the
loose or slack thread that should form the loop will be drawn tight, so that the
shuttle will pass without forming a stitch.
In witness whereof, I, the said Donald Mc Rac, have hereunto set my hand
and seal this Thirtieth day of March, in the year of our Lord One
thousand eight hundred and seventy-six.
5 Witness,
JOHN WAUGH,
Engineer and Patent Agent,
Bradford.
DONALD MCRAE. (L.S.)