US2063280A - Take-up mechanisms for sewing machines - Google Patents

Description

8, 1936. M. l.. WATERMAN 2,063,280

* TAKE-UP MECHANISMS FOR SEWING MACHINES Filed June 29, 1935 Patented Dec. 8, 1936 UNITED STATES PATENT OFFICE TAKE-UP MECHANISMS FOR SEWING MAC The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application June 29, 1935, Serial N0. 28,996

Claims.

This invention relates to improvements in thread take-up mechanisms for sewing machines and more particularly in needle-thread take-ups, the invention having for its object to provide for ready manufacture of a durable thread take-up mechanism capable of efliciently meeting high speed requirements of operation.

With the above and other objects in View, the invention comprises the devices, combinations and arrangements of parts hereinafter described in connection with the accompanying drawing which illustrates a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the accompanying drawing, Fig. 1 is a front end elevation of the bracket-arm head and bedplate of a sewing machine containing the improved needle-thread take-up mechanism. Fig. 2 represents a vertical section of the bracket-arm head of the machine. Fig. 3 represents an enlarged vertical section of the universal-joint connections between the take-up lever and its actuating crank-member. Fig. 4 represents a horizontal section of the connections illustrated in Fig. 3. Fig. 5 represents a perspective view of the pivot-block of the universal-joint connection.

Referring to the drawing, the sewing machine frame includes the usual bed-plate or worksupport I and a bracket-arm terminating at its free end in a head 2 which overhangs the worksupport.

Rotatably journaled in the bracket-arm I is a horizontally disposed actuating shaft 3 carrying a counterweighted crank-arm 4 provided with a crank-pin 5. Pivotally embracing the crank-pin 5 is the upper bearing-boss B of a needle-bar link I having its lower bearing-boss 3 pivotally embracing a stud-pin 9 extending from a split collar I0 which is clamped upon the upper end of a needle-bar II. The needle-bar II is journaled for vertical reciprocation in a bearing bushing I2 suitably secured in the bracket-arm head 2, the needle-bar carrying at its lower end a needle I3.

Cooperating with the needle I3, below the work-support I, is a loop-taker I4 which in the present instance is of the horizontal-axis rotary hook type adapted to cast loops of needle-thread about a mass of under thread contained in a bobbin-case I5.

The work is intermittently advanced by a dropfeed mechanism including a feed-dog I6 operating through the throat-plate I1 upon the worksupport. Yieldingly opposed to the feed-dog is a presser-foot I8 carried by the usual spring-aepressed presser-bar I9 vertically movable in the bracket-arm head 2.

The present invention resides more particularly in the needle-thread take-up mechanism and while, in its preferred embodiment, it is in the nature of an improvement on the take-up forming the subject of the U. S. patent to W. F. Dial et al., No. 695,915, Mar. 25, 1902, it is to be understood that the invention, as defined by the appended claims, is not restricted to the specific type of take-up herein described and illustrated in the accompanying drawing.

According to the present construction, the upper end of the needle-bar link 1 carries a bearing member in the form of an auxiliary bearing-boss adjacent and substantially parallel to the bearing-boss G of said link. Journaled in said bearing-boss 20, for pivotal and bodily endwise movements therein, is a stud-pin 2| having a circular head 22, providing a shoulder 23 which serves to limit inward movement of ther stud-pin 2|. Embracing the stud-pin head 22 is a collar 24 provided with diametrically alined apertures 25, said collar being xedly secured upon the head 22 by a screw 26.

The stud-pin head 22 is diametrically provided with a guide-slot presenting parallel side walls 21 confining therebetween a pivot-block 28 having spherically rounded upper and lower ends 28 in engagement with the collar 24. The pivot-block 28 is provided with a guide-aperture 29 terminating in the spherical ends of said block and slidably receiving a guide-rod 30 passing through the collar apertures 25, said apertures being slightly larger than the diameter of the guiderod to provide for and limit tilting movements of the pivot-block.

The guide-rod 30 constitutes the depending arm of a two-armed take-up lever, of which the other arm 3I extends forwardly through a suitable slot in the bracket-arm head2 and adjacent to the usual guard-flange 32, the arm 3| of said lever being provided with the usual threadeye 33. Intermediate the arms 3D and 3l thereof, the take-up lever has a bearing hub 34 pivotally journaled upon a headed fulcrum-pin 35 disposed substantially parallel to the rotation axis of the actuating shaft 3 and to the pivotal axes afforded by the crank-pin 5 and the stud-pin 2|. The fulcrum-pin 35 is suitably secured in an aperture in the frame head 2 by means of a set-screw 36. The take-up lever performs its usual function o1' controlling the needle-thread in the formation md `setting of stitches.

One of the outstanding problems in the sewing machine art has been the provision of an efcient take-up mechanism capable of withstanding the wear incidental to operation of a. sewing machine at a speed at least equal to 4000 stitches per minute. The crank-and-link type of takeup presents lubrication diiii'culties, because of the bodily travel of the actuating connections for the take-up lever and the fact that an excess of lubricant may lead to soiling of the thread or the work. The present invention minimizes excessive lubrication requirementsbythe elimination of undesirable cramped conditions infthe actuating connections for the take-up lever, which cramped conditions mayarise fromV slightvariations from true parallel relationshipofl the - axes 3, 5, 2| and 35, and from any departures from the correct angular relationship "between the axis 2| and the guide-rod 30. I Y

According to the present invention, the tiltable l.pivot-.block..28 and the pivotal connection between ...the bearing-bossi() 4and the stud-pin 2|, comprise universal-joint connections with the ltake-up` lever-which eliminate the extreme precision require- :ments-diflicult tofmaintain under mass produc- .tion. As the `axis 35 of the take-up lever is fixed, intherpresent arrangement, the take-up lever 30, v.3|.fvibrates in` asingle plane. VShould the axis of thetakc-up lever-L30, 3| benot in perfect parallelism withY the axis of.` its .actuating crank-mem- ,.ber, the, planeV4 of vibration of the take-up lever ,will be slightly inclined to the-horizontal axis of the shaft 3. To accommodate .this condition, the stud-pinZl isf-ree tomove endwise inthe crank nbearing-boss `20. Thus, the take-up lever acituating vconnections automatically assume free .t driving relations and. therefore may operate with fa minimum offrictionv and consequent minimum heating yand wear at high speed operation.

,Having thusfset. forth the nature of the invenition,Y what Ifclaimherein is:-

i ,1. Thread take-up mechanism for sewing ma- ..chines comprising, .a pivotally mounted take-up `lever,..and supporting and actuating means for said leverincluding acrank-member, a connection-element freely movable in a direction subestantially ,parallel `to the turning axis of said crank-.memberr and a universal-joint connection incorporated in said means.

`2. Thread takeup mechanism for sewing machinescomprising, a take-up lever, andsupportingand, actuating means for said take-up lever including av crank-member, and relatively trans- .versely pivoted connections incorporated-in said Ymeans.

I3. Thread take-.up mechanism for sewing kmachinescomprising, a `take-uplevenrand support- Ving and actuating means forsaid take-.up lever including a v.connection-.element freelyA movable endwise, and relatively transversely pivoted connectionsV incorporated in said means.

.4. Threadtake-up mechanism forsewing machines comprising, avpivotally mounted take-up lever provided with a thread-eye, a rotary crankmember, a pivot-block in sliding engagement with said take-up lever, and relatively transversely pivoted connections between said crank-member and pivot-block.

5. Thread take-up mechanism for sewing machines comprising, a pivotally mounted take-up lever provided with a thread-eye and having a guide-rod, a. rotary crank including a pivotal and endwise movable connection-element and a pivot-block in sliding engagement with said guiderod and fulcrumed upon said connection-element for.. pivotal movement about an axis transverse to the pivotal axis of the connection-element.

6. Thread take-up mechanism for sewing machines comprising, a pivotally mounted take-up lever, a connection-element provided with a guide-slot, a pivot-block tiltably disposed in said guide-slot and slidably engaging said take-up lever, and a bodily rotatable support for said connection-element providing for pivotal and bodily endwise movements thereof.

7. Thread take-up mechanism for sewing machines comprising, a rotary crank-pin, a bearing member pivotally carried by said crank-pin, a

-stud-pin-supported by said bearing member for pivotal and bodily endwise movements, a pivotblock fulcrumed upon said stud-pin for pivotal movement about an axis transverse to the pivotal axis of the stud-pin, a take-up lever provided withr a thread-eye and having an arm slidably engaged by said pivot-block, and a pivotal support for-said take-up lever.

8. Thread take-up mechanism for sewing machines comprising, a rotary crank-pin, a bearingmember pivotally carried by said crank-pin, la stud-pin supported by said bearing-member-for pivotal and bodily endwise movements, said studpin havinga head provided with a guide-slot, an

apertured pivot-block` tiltably disposed in the guide-slot of the stud-pin head and fulcrumed upon said head for pivotal movement about an axis transverse to the pivotal axis of said studpin, a take-up leverprovided with a thread-eye and having an arm slidably embraced by said pivot-block, a pivotal support for said take-up lever, and means carried by said stud-pin head for limiting tilting movement of said pivot-block.

9. Thread take-up mechanism for sewing machines, comprising a pivotally mounted take-up lever having a guide-rod arm, a guide member slidably-embracing said arm, a crank member, and universally jointed connections between said `crank and guide members.

10. Thread take-up mechanism for sewing machines,.comprising a pivotally mounted take-up `lever having a guide-rod arm, a guide member slidably embracing said arm, a crank member having a turning axis substantially parallel to the pivotal axis ofthe take-up lever, and universally jointed connections between said crank and guide members.

MAX L. WATERMAN.

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