Improvements in Trimmer Mechanism for Sewing Machinery.
Year: 1895

page_text: Date of Application, 11th June. 1895-Accepted, 20th July, 1395.
COMPLETE SPECIFICATION.
Improvements in Trimmer Mechanism for Sewing Machinery.
A communication from abroad by SAMUEL HICKOX WHEELER, of Fairfield,
County of Fairfield, State of Connecticut, United States of America,
Manufacturer..
ALFRED GEORGE BROOKES of 55 and 56 Chancery Lane, in the County of
London, Chartered Patent Agent, 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 to mechanism for trimming the work adjacent to the
seam in a sewing machine by means of a reciprocating or vibrating cutter, motion
being imparted thereto by connections between and some moving part of the
machine.
"
In machines of the class described, so far as my correspondent is aware, it is
very difficult, or altogether impossible, to throw the cutter into or out of operation
without first slowing down or stopping the sewing machine, resulting in loss of
time to the operator and necessitating the use of both hands to control the
operation of the trimmer mechanism.
The invention has for its object the production of a compact, simple and.
durable trimmer mechanism controllable at all times, whether the machine is
running at high or low speed, and within easy reach of the operator, who can
guide the work with one hand and with the other quickly throw the cutter into
or out of operation.
In accordance therewith the invention consists in the use in a sewing machine,
of a cutter-carrier provided with a cutter and reciprocated by a rocking lever,
and connections between the lever and a rotating cam, to rock the lever, the
connections being moveable into or out of operative contact with the cam. to
actuate or stop the cutter-carrier during the operation of the machine, substantially
as will be described.
Other features of the invention will be hereinafter described and particularly
pointed out in the claims.
Fig. 1 in end elevation and partly broken out, represents a sufficient portion of
the outer end of the overhanging arm of a sewing machine to be understood, with
the invention applied thereto.
Fig. 2 is a side elevation thereof partly broken out.
Fig. 3 is a vertical transverse section taken on the line a, a, Fig. H.
Fig. 4 is a top view of a portion of the mechanism shown in Fig. 2; and
Fig. 5 represents the surface of the actuating cam developed.
Referring to the drawings, the arm A, needle and presser-bars A' and A*
respectively, and the needle-bar actuating-shaft A, are and may be of usual
construction and operation, the same forming no part of the invention.
The trimming blade or cutter a is secured in usual manner to a reciprocating
cutter-carrier al mounted in suitable bearings in the head A* of the arm A, said
cutter-carrier being slotted at its upper end to receive a slide-block a connected
by a species of ball and socket joint to one arm b of a rocking lever, shown in
Fig. 3, as screwed upon the threaded and reduced end of a hollow sleeve b*
mounted. to rock in the bearing in a stand B, secured to the overhanging arın, in
suitable manner us by screws s.
.
:

page_text: The sleeve is shouldered internally at 6 and has an annular flange 6' at one end
to rest against the bearing 6, the attached portion of the rocking lever resting
against the other end of said bearing and thereby preventing longitudinal
movement of the sleeve therein.
A shouldered shaft e provided with a suitable thumb-nut c and threaded at its
extremity, as at c, is passed through the sleeve 62 and through an arm d held on
and to be moved by the shaft by a suitable nut c*.
A spring within the sleeve surrounds the reduced portion of the shaft o
between the shoulder of the sleeve and the larger part of the shaft, so that the
spring normally tends to keep the parts in the position shown in Fig. 3.
A stud d secured to the arm d and projecting from its inner side, enters a
suitable hole in the arm of the rocking lever, so that movement of the arm b
about its pivotal support will also swing the rocking lever and its attached sleeve,
as shown in full and dotted lines Fig. 2, or vice versa.
By moving the shaft c in the direction of the arrow Fig. 3, the arm will be
moved into dotted line position, but without withdrawing the stud d' from engage-
ment with the arm b', said stud having a depression d* in its inner end, see dotted
lines Figs. 3 and 4.
A suitable pin or post d² on the swinging arm, extends from its inner face and
has thereon a roll d to enter the groove e of an actuating cam E, fast on the
needle-bar actuating shaft A³.
The shape of the groove e in the cam, shown developed in Fig. 5, is such that
when the roll is in engagement therewith, rotation of the cam will swing the
arm d, and by means of its connection with the lever b, b¹, the cutter-carrier a¹ will
be reciprocated.
The rear wall of the cam groove e is of greater diameter than the front wall, as
shown in Figs. 2 and 5, so that when the roll d³ is in dotted liue position, Fig. 3, it
can be swung to the right, viewing Fig. 2, to clear the front wall of the groove e,
and thereby move the cutter mechanism into inoperative position; but the higher
rear wall will act as a barrier against movement of the roll d³ to the left, and
consequently prevents throwing down of the cutter into the path of the hook.
When it is desired to throw the cutter out of operation, the operator grasps the
thumb-nut cand pushes it in the direction of the arrow Fig. 3, thereby moving the
swinging arm d bodily away from the side of the arm A and withdrawing the roll
from the cam groove e.
1
A partial turu of the thumb-nut in the direction of the arrow Fig. 2, then swings
the arm d and carries the roll to one side of the cam; the stud d' is thereby
brought into position to permit the pointed end of a screw 10 to enter the
depression d, to positively hold or lock the mechanism out of operation, the
adjacent portion of the arm A being cut away to permit the swinging movement of
the stud d¹.
'
The rotative movement of the thumb-nut and shaft c also turns the lever b, b',
by means of the connecting stud d¹ into the dotted line position shown in Figs. I
and 2, to lift the cutter carrier and maintain it in inoperative position, with the
cutter lifted away from the work.
:
An adjustable stop pin c*, shown as a screw extended through. the thumb-nut c',
limits the movement of the shaft c in the direction of the arrow Fig. 3, so that it
may not be pushed out to an unnecessary. extent.
The spring s keeps the roll d³ in engagement with the cam when the cutter-
carrier is reciprocated, or holds the stud up against the bottom of the cut away
or recessed part of the overhanging arm when the cutter-carrier is inoperative.
The cutter may be thrown into and out of operation, during the operation of the
machine, by a slight movement of one of the operator's hands, and the whole
mechanism is mounted within convenient reach of the operator seated before the
usual work-table D.
As herein shown, the mechanism for actuating and controlling the cutter-carrier
is very simple, strong and compact, and not liable to get out of order.

page_text: As the lever arm b rocks with the rotation of the cam, the ball and socket
connection with the slide-block a' gives a positive yet easy connection with the
cutter-carrier a¹.
While I have shown a roll d mounted on the pin d to enter the cam groove,
it is obvious that any other suitable stud might be used, and while it is preferable
to bring the end of the stud d' into positive engagement with the screw 10, to lock
the cutter-carrier in inoperative position, it will be obvious that the cutter-
carrier could be held inoperative by moving the cam roll or stud d' onto the
smaller cylindrical portion ex of the cam, if desired, or against a part of the
arm A, with the same results.
The invention is not restricted in its application to the precise form of sewing
machines partly illustrated herein, as it is adapted to be used with any class of
machine having a conveniently located rotating shaft to which the actuating cam
may be secured.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:
1. The use, in a sewing machine, of a cutter-carrier provided with a cutter and
reciprocated by a rocking lever, and connections between the lever and a rotating
cam, to rock the lever, the connections being movable into or out of operative
contact with the cam to actuate or stop the cutter-carrier during the operation of
the machine, substantially as described.
2. The use, in a sewing machine, of a cutter-carrier provided with a cutter and
reciprocated by a rocking lever, and an arm laterally movable with relation to
and connected to rock the lever, and having a stud to operatively contact with a
rotating cam, movement of the arm laterally disengaging it from the cam and
stopping the reciprocation of the cutter-carrier during the operation of the machine,
substantially as described.
3. The use, in a sewing machine, of a cutter-carrier provided with a cutter, a
rocking sleeve having a rigidly connected lever to reciprocate the cutter-carrier,
a spring-controlled shaft longitudinally movable and rotatable in the sleeve, and
an arm on said shaft connected to the rocking lever and having a stud to operatively
contact with a rotating cam, whereby the operator may give the shaft a longitudinal
and rotative movement to disengage the stud and cam and lift the cutter-carrier,
substantially as described.
4. The use, in a sewing machine, of a cutter-carrier provided with a cutter and
reciprocated by a rocking lever, connections between the lever and a rotating
cam, to rock the lever, means to move the connections into and out of operative
contact with the cam, to actuate or stop the cutter-carrier during the operation of
the machine, and a locking device to positively hold the cutter-carrier in inoperative
position, substantially as described.
5. The use, in a sewing machine, of a cutter-carrier provided with a cutter and
reciprocated by a rocking lever, connections between the cutter-carrier and a
rotating cam and including a laterally movable arm having a stud, and means to
move the arm laterally and to rotate it in one direction to thereby withdraw the
stud from the cam to stop the reciprocation of the cutter-carrier during the
operation of the machine, the cam having a barrier wall to limit the rotative
movement of the arm and stud in the opposite direction and serving as a guide for
the entrance of the stud into the channel of the cam, substantially as described.
Dated the 8th day of June 1895.
WM. BROOKES & SON,
55 & 56 Chancery Lane, London, Agents for the Applicant.