Improvements in Buttonhole Sewing Machines.
Year: 1887

page_text: Improvements in Buttonhole Sewing Machines.
1, WILLIAM NORRIS, of 3 Barron's Place, Waterloo Road, in the County of Surrey,
Engineer, 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 :-
This Invention relates more particularly to the apparatus in button hole sewing
machines for giving the "cross stitch" and "barring" motion to the table carrying
the work during the operation of making a button hole; the object being to greatly
simplify the construction, and to reduce the cost of machines so fitted, while ensuring
greater accuracy and preventing the breaking of needles, an evil in machines of this
description which has hitherto caused great loss of time and inconvenience.
In the accompanying drawing I have shewn my invention fitted to a button hole
sewing machine of existing type.
Fig. 1. is a back elevation of a button hole machine partly in section.
Fig. 2. a plan view and
Fig. 3. an end elevation of the same.
In these figures, A is the main driving shaft mounted in bearings in the frame B
of the machine and carrying the usual needle and shuttle cams.
A pinion secured to the shaft A gears with a toothed cam wheel D mounted on
a forked camfaced rock lever D' carried by the shaft A. This lever which is of
peculiar construction is formed with an upwardly projecting arm d which bears on
the underside of a concentric cam E formed in one with the screw feed cam F
secured to an intermediate shaft E¹ mounted in bearings in the frame B.
The outer end d of the lever D¹ is cam shaped in form and bears against a bowl g
carried by a double slide G on the upper part of which is mounted the work-table G¹

page_text: of the machine. A coiled spring g' is interposed between an abutment 6 on the frame B
and the rear end of the lower slide G. This spring has a tendency to keep the
bowl g against the cam face d¹.
Pivotted to the frame B of the machine and lying between the concentric cam E and
a cam D2 formed on the toothed cam wheel D, is a rock lever H fitted at its free end!
with a bowl (which bears upon the cam D) and a projection h¹ which strikes
either one or other of the faces of the cam E, as will be hereafter explained. This
lever is more clearly shewn in side and plau views at Fig. 4.
The feed motion is communicated to the table G¹ carrying the work by the arm e,
screw cam F, shaft E' and feed wheel E³, a tail lever e¹ on the feed wheel overlies a
cam a on the driving shaft A and is retained in position by a coiled spring in the
usual manner.
The action of the machine is as follows-
The work having been secured to the plate G¹ by the presser clamp G³, and rotary
motion being communicated to the shaft A and pinion C, the cam wheel D will
revolve on the pin d causing the cam D to raise the lever H until its
projection strikes the smaller periphery of the cam E thereby causing the
lever D¹ to descend, forcing back the slide G against the coiled spring g¹ and
advancing the work under the needle the exact distance required for a stitch on one
side of the button hole.
As the cam D in its rotation leaves the bowl h of the lever H, the coiled spring g'
will return the lever D¹ to its normal position (see Fig. 5) ready for another stitch
to be made the work being now advanced by the feed mechanism to the required
position.
The operation just described is repeated until the end of the button hole is reached
when the cam E in its rotation will bring one or other of the shoulders e in contact
with the arm d on the lever D¹ (see Fig. 6) and the projection on the lever H
being slightly wider at top than the arm d, it will engage with the larger periphery
of the cam E, thus locking the lever H while the cam D' in its rotation rocks the
lever D¹ and advances the work twice the distance, so giving the necessary stitch for
forming the "bar" of the button hole. This is effected by the cam E being half the
throw of the cam D³, and while the lever H is held rigidly between the two cams, the
lever D¹ is made to rock a distance equal to the full throw of the cam. D'.
The number of stitches necessary to form the "bar" of the buttonhole is determined
by the distance the projection h¹ is in advance of the arm d.
The bar of the buttonhole being completed, a further rotation of the cam E will
cause the projecting arm d of the lever D to pass the shoulder e* and engage with the
larger periphery of the said cam (see Fig. 7.) thus depressing the lever D¹and causing
the work to advance under the needle in order to form the other side of the button-
hole, when the operation described with reference to Fig. 5. will be repeated. The
feed cam now by reason of its construction feeding in an opposite direction.
It will be seen by reference to Figs. 5 and 7, that while the sides of the buttonhole
are being worked, the lever H has always an amount of play corresponding to
the throw of the cam E, so that by means of this lever the throw of the cam D is
halved.
It will be seen (referring to Fig. 6.) that the projection ¹ has taken its position
relative to the cam Ę for forming the opposite side of the buttonhole before the
projection d has passed on to the larger periphery of the said cam; consequently there
can be no sudden jerk on the mechanism which has hitherto been the case, thus
reducing to a minimum the chances of breaking a needle.
Fig. 8 shews a slightly modified form of the rock lever D' which I may fit with a
removable steel face. The dotted lines in this figure shew the method of setting out
the cam face.
Instead of the cam face I may if thought desirable form a cam groove in the rock
lever D' which will engage with a bowl such as g. In this case I may dispense with
the coiled spring g‘.

page_text: 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 button hole sewing machine the rock levers H, D³ constructed and operating
substantially in the manner above set forth.
2. In a button hole sewing machine the combination of the rock levers H and D',
cams D and E with the screw feed cam F for the purpose above set forth.
Dated this 13th day of September 1887.