IMPROVEMENTS IN HEMSTITCHING OR VEINING MACHINES."
Year: 1880

page_text: LETTERS PATENT to Duncan McGlashan, of Glasgow, in tho County of Lanark,
North Britain, for an Invention of "IMPROVEMENTS IN HEMSTITCHING OR
VEINING MACHINES."
PROVISIONAL SPECIFICATION left by the said Duncan McGlashan at the
Office of the Commissioners of Patents on the 17th July 1880.
DUNCAN MCGLASHAN, of Glasgow, in the County of Lanark, North Britain.
"IMPROVEMENTS IN HEMSTITCHING OR VEINING MACHINES."
This Invention relates to improvements in that class of sewing machines known
as hem-stitching or veining machines, and which are more especially used for
sewing down the hems of pocket handkerchiefs.
The improvements have for their object to spread out the openings in the cloth
by so acting on the needle whilst it is in the cloth, so as to ensure that all the
warp or weft threads will be enclosed or tied up with each stitch, in place of, as
sometimes happens with the hitherto used hem-stitching or veining machines, somo
of the said warp or weft threads being left loose.
Another object of this Invention is to do away with the necessity for "hand-
drawing" both the warp and weft threads as has hitherto been practised, this object
being attained by the packing or pressing of the warp and weft threads together
by the action of the needle upon them, as hereinafter described.
The means by which the foregoing objects are effected consists of a pair of wave
cams on the same shaft. One of these cams is conical, and is formed at one part
with a gradual rise, which continues over a sufficient portion of the surface of the
cam as to move the feed and the cloth forward whilst the noedle is in the cloth
at the part where the veining is to be introduced, thereby packing or pressing
the weft or warp threads in one direction, whilst the other cam is a cam which
operates directly upon the rocker or frame which carries the needle bar without the
intervention of links or connecting pieces causing the needle to pack or press the
weft or warp threads in a direction at right angles to the feed motion, and that
either in a right or left hand direction.
By means of the wave shaped cams hereinbefore described, the variability in
length of throw of the feed and needle bar frame or rocker is effected, the surface
of the cams being made broad enough for the purpose of a variable feed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Duncan McGlashan in the Great Seal Patent Office on the 15th
January 1881.
DUNCAN MCGLASHAN, of Glasgow, in the County of Lanark, North Britain.
"IMPROVEMENTS IN HEMSTITCHING OR VEINING MACHINES,"
My said Invention relates to improvements in that class of sewing machines
known as hemstitching or veining machines, which are more especially used for
sewing down the hems of pocket-handkerchiefs.
--The said improvements have for their principal object to so spread out the
openings in the cloth as to insure that all the warp or weft threads will be enclosed-
or tied up with each stitch, in place of, as sometimes happens with the hitherto
used hem-stitching or veining machine, some of the said warp or weft threads being
left loose.
And in order that my said Invention may be properly understood, I now proceed
more particularly to set forth the system, mode, or manner in or under which the
same is or may be used or practically carried into effect, reference being had to the
accompanying Drawings, and to the letters and figures marked thereon, that is to
say:-
Figure 1 of the accompanying Drawings represents an elevation as seen from one
sido of a hem-stitching or veining machine provided with the improvements
constituting my Invention; Figure 2 is an elevation as seen from the other side;
Figures 3 to 9 are details, as hereinafter described. The driving shaft A gives
rotation to the motion shaft B, by spur wheels in the usual manner. Upon the
shaft B are fixed two wave cams C and D. Tho cam C is of the general figure of
the frustum of a cone, and is provided with raised and depressed portions to give
the ordinary motions to the presser foot for presenting the cloth in the proper
position beneath the needle for the formation of the hem stitch.; but in addition
to these raised and depressed portions for giving the ordinary motions, the said cam
is provided with a raised portion at c, for moving the presser foot and feeding the
cloth forward whilst the needle is in the cloth at the part where the veining is to
be introduced, so as to cause a packing or pressing of the weft or warp threads in
one direction. The cam Cacts upon a runner e on an arm fattached to the rocking
bar F, turning on pivots at the said bar F being provided with an arm f³ extending
to and bearing upon the front of the presser-foot bar g, which is pressed forward
by the spring g, so that the runner e is always in contact with the surface of the
cam C; Figure 3 is an end elevation of a portion of the machine shewing the
conical form of the cam C more clearly. The rises and depressions in the said
cam Care shewn more clearly in Figures 4 and 5, which are respectively developements
of the surface of the cam at the part of largest diameter and at the part of least
diameter. The variability of the throw of the presser foot for a variable feed, in
accordance with the size of stitch to be made, is obtained by shifting the runner e
towards one or other edge of the cam C upon the arm f, and fixing it in position by
the pinching screw e, the rises and depressions in the said cam being graduated
so that they give the same relative amounts of motion in any circumferential line
of the surface of the said cam. The runner is preferably provided with an
antifriction roller ³ for bearing upon the cam C.
The cam D, for acting upon the needle bar to give the necessary throw to the
needle, is also a wave cam. It is shewn separately in Figures 6, 7, and 8, which
are respectively front and back elevations and a side elevation of the said cam.
The said cam D is formed with a depressed part d for throwing the needle bar in
one direction, and maintaining it therein during the two penetrations of the needle
on one side of the hem, and with a raised part & for throwing the needle bar in
the other direction, for the penetration at the other side of the hem. The motions

page_text: of the cam D are conveyed to the needle bar H by a runner i similar to the
runner e. The said runner i is mounted upon a pin j, fixed to the arın , which is
fastened to the rocker or frame J, which carries the needle bar H and the needle
groove in the shuttle race, the said needle bar, needle groove, and frame all turning
upon the centre at h, the said frame J being guided by pins, as at ³, passing
through slotted holes in the said frame. Thus the cam D is caused to operato
directly upon the rocker or frame J without the intervention of links or connecting
pieces. The surface of the cam D is made of some considerable width, as shewn,
and the rise and depression are graduated in the direction of its width, decreasing
gradually to one side, so that by moving the runner i in one or other direction
along the pin j, and fixing it in position by the pinching screw ³, a variable
throw of the needle rocker is obtained in accordance with the size of stitch
to be made. To lessen the angle of inclination of the surface of the cain D, I prefer
to incline the cam in one direction on the one part d, and in the other direction on
the other part d², as will be scen clearly on reference to Figure 8. The antifriction
roller of the runner i is kept constantly in contact with the surface of the.cam D
by the spring k.
When the machine is in operation the needle makes three penetrations in forming
cach stitch corresponding to the three ponetrations of the ordinary hem stitching or
veining machine, one penetration on the one side, or folded part of the hem, and the
other two penetrations on the other side of the hem whereat the veining is effected.
In Figure 9 I have shewn a diagram of the penetration of the needle for four
stitches, in which Figure I have marked the respective penetrations for each
stitch 1, 2, and 3, in accordance with the times at which they are made. At tho
second penetration, however, and whilst the needle is in the cloth, the rise o on
the cam C causes the presser foot to be moved forwards to a slight extent to feod
forward the cloth to a similar extent, whereby the threads are packed or forced
back (by coming against the needle) into a position similar to that indicated in
Figure 9. The position of the needle at this time being indicated by the dotted
circle 2. When the needle leaves the hole of its second penetration, the cloth is
moved by the presser foot back for the third penetration, and this movement of the
cloth I prefer to be rather more than the distance between each hole 1, 1, or 2, 2,
so that the needle makes its third penetration not exactly into the hole 2, which it
made at the second penetration in the previous stitch, but slightly in advance of
that hole, as shewn at 3, 3, Figure 9, so as to ensure that no threads are left untied
up by the stitches. This movement of the feed is obtained from the part of the.
cam C, which is made slightly lower than the part at c³, sufficient to give this extra
degree of movement.
Having now described and particularly ascertained the nature of my said
Invention, and the system, mode, or manner in or under which the same is or
may be used or practically carried into effect, I would observe, in conclusion, that
what I consider to be novel and original, and thereforo claim as the Invention
secured to me by the hereinbefore in part recited Letters Patent is,―
First. The combination with or use in hem stitching or veining machines of
means for giving the presser foot or feed a movement whilst the needle is in the
cloth at the part where the veining is to be introduced, so as to move or feed the
cloth, and to cause the warp or the weft threads thereof to be packed or pressed in
one direction, essentially as and for the purpose hereinbefore described with reference
to the accompanying Drawings.
Second. The means for effecting the adjustment of the throw of the presser foot
or feed in hem stitching or veining machines, that is to say, a conical cam (C)
provided with the necessary rises and depressions upon its conical surface for
giving the desired movements to the feed, the said rises and depressions being
graduated from one side of the cam to the other, so that they bear the same relative
proportion on any circumferential line of the said cam, whereby the requisito
variability of feed is obtained from the said cam by moving the part which bears

page_text: upon the said cam to receive its motion towards one or other side of the said
cam, essentially as hereinbefore described with reference to the accompanying
Drawings.
Third. The general arrangement or combination of the wave cam D with the
frame or rocker which carries the needle bar and needle groove in the shuttle race,
whereby the ordinary intervening links or connecting pieces are dispensed with, as
herein before described and illustrated in the accompanying Drawings.
In witness whereof, I, the said Duncan McGlashan, have hereunto set my
hand and seal, this Tenth day of January, in the year of our Lord One
thousand eight hundred and eighty one.