US2652795A

US2652795A - Zigzag sewing machine

Info

Publication number: US2652795A
Application number: US84611A
Authority: US
Inventors: Robert Ramon Casas; Court Jean
Original assignee: Mefina SA
Current assignee: Mefina SA
Priority date: 1948-12-20
Filing date: 1949-03-31
Publication date: 1953-09-22
Anticipated expiration: 1970-09-22
Also published as: DE825333C; GB683379A; NL91135C; GB683293A; GB683380A; CH297807A; DE821458C; FR1000403A; GB683291A; CH279597A; US2682845A; FR1008799A; NL81093C; BE492433A; CH297806A; CH277952A; NL88362C

Description

R. cAsAs ROBERT r-:T AL 2,652,795

Sept. 22, 1953 z'IGzAG SEWING MACHINE Filed March ,5.1, 194e 4 Shets-Sheet l R. cAsAs ROBERT ET AL 2,652,795

sept. 22, 1953 ZIGZAG SEWING MACHINE Filed March 3l, 1949 u 4 Sheets-Sheet 2 l Sept 22, 1953 R. CASAS ROBERT ET Al. 2,652,795

` ZIGZAG SEWING MACHINE Filed March 5l, 1949 4Sheets-Sheet 3 R. CASAS ROBERT ET AL 2,652,795

zIGzAG SEWING MACHINE Filed March 3l. 1949 4 Sheets-Sheet 4 Patented Sept. 22, 1953 UN l TE star-s f 'if 'I YOFQFl-'C'E .2,652,795 ziozAG snWlNG MACHINE Ramon v4'Casas VRobert and Jean Court, Geneva,

Switzerland, :assgnors lto Mena "S. A., Binningen, Switzerland, a corporationo'f Switzervland Application March 31, 1949, Serial No.f84,'611 In Switzerland December "20, 51948 5 Claims.

l In the known sewing machines i'ittedwitha der`vice for forming aso-called fzig-.zagsstitch, not Aonly a verticalreciprocating movement, 'but-'also a lateral rocking movement are imparted tothe needle. The resultis that the needle, when going down, is situated infront of different points o'f the-rotary hook andthe loop seizing beak of the latter comes and catches the loop, formed 'by the upper thread at the beginningof the upiward stroke of the needle, either too early o1' too late, which causes the formation of irregular stitches or even misses, when the extent of the vrocking lateral movement of the needle-carrier ina to and `fro lateral movement synchronised. "-1

with its vertical reciprocating movement. This machine aims at remedying the mentioned drawbaci: by the fact that it includes a rotary hook, the rotation shaft of which is .inclined in relation to the axis of the Vertical .displacement of the needle-carrier.

The attached drawing shows diagrammatically andby way of vexample a form of executionof the sewing machine `in accordance with the invention.

Fig. 1 is a iront View of same, certain parts of `the casing being broken away.

Fig. 2 is a part cross-section view, illustrating the position of the rotary hook.

23 is a perspective View of the actuating mechanism for the feeding means and of lthe actuating mechanism for the retaining stops of the rotary hook. K

/iis a profile view of the actuating mechrn for the feeding means..

. 5 is a top View of the mechanisms housed in ne lower arm of the sev/ing machine.

Vmobile stops il and it. f y a 'lever having ytwo arms l5, t2, rigidly conmachine.

'locking movement in a vertical plane.

guides t, ihoused inthe arms of a. rocking support 3 having thegeneral shape'ofa U'and pivot- "ing on la verticalfaxle 9, parallel tothe needle- `carrier 5. 'This rocking element is actuated in a 1rocking 'tuating mechanism described in a co-pending movement around its axle by an acapplication, so that the needle-carrier 5 is actuated in a to land iro lateral movement synchronised 'with lits vertical reciprocating movement.

The'lcwer arm "2 contains a rotary hook fixed von ii, which'asshown is inclined at an angle substantially vless than 90 land mechanicaily connected by transmission mechanisms to the'main shaft'Pof the sewing machine. This rotary hook includes-a revolving cup Iii, iitted with a loop seizing beal: I2, intended for snapping the upper thread loop which is `formed on the side of the needle A at vthe beginning of the upward stroke o' the latter, This cup contains a bobbin te (lig, 3i kept fixed ina support i3. The latter includes two 'slightly inclined radial arms i5 and it which Aact alternately in conjunction with two These stops are carried nectedtoget'her by la linking element Eil, elastica'lly articulated, Vby means of a blade spring r, on e. part il rigidly fixed to the 'frame of the 'This part 2l is fixed by screws o to a bridge p which is itself rigidly fixed by screws V tothe lateral walls of the lower arm 2. The lever E 32 is actuated in a regular rocking movement by a cam c, rigidly fixed on a driving shaft 22, meol'iainically connected tothe main shaft P 'o the sewing machine.

The arm 2 further 'contains an actuating mechanism for the feeding means 23, including a support connected to an actuating cam 25 by means or two levers, of which one, 25, is rigid and has a rocking movement in a horizontal pla-ne, whilst the other, 2d, is elastic and has a The rigid lever iii pivots on va vertical fixed shaft while the velastic lever is carried by?. shaft 29 'revolving in a 'bearing arranged in a support s rigidly fixed to the lower arm by fastening elements o. These two levers 255, 'are arranged parallelle' one to the other. This actuating mechanism for Vthe conveyer being described in (zo-pending vap- 'is as follows:

The machine being in action, a regular vertical reciprocating movement is imparted to the needle by a connecting rod 30 articulated on a crank pin 3l fastened to the main shaft of the sewing machine.

In addition, the rocking support 8 is driven in a rocking movement around its axle 9. These: two movements of the needle-carrier are synchronised so that the lateral displacements of the needle take place during periods when the needle clears the cloth, as described in the mentioned co-pending applications.

The cup I of the rotary hook is actuated in a regular revolving movement, whilst the support I3 is kept immobile by the stops I'I and I8, alternately acting in conjunction with the armsy I5 and I6. The upper thread f passes between the arm I5 and the stop II, when the finger 32 acts in conjunction with the part b of the profile of the cam c and when the support I3 of the bobbin I4 is held against an angular displacement by the stop I8 acting in conjunction with the arm I6. On the contrary, the upper thread f can pass freely between the stop I8 and the arm I6, when the lever I 9 is in the position shown on Fig. 3 and when the support I3 of the bobbin I4 is held against an angular displacement by the stop Il, acting in conjunction with the arm By examining Fig. 2, in which the needle A is shown in its middle position, the position which it would normally occupy for a straight seam, one: notes that, the more it is displaced towards the right in relation to this middle position by the action of the device for forming the zig-zag stitch, the sooner the beak I2 of the cup Iii, revolving in a clockwise direction, engages itself quickly in the loop formed by the upper thread on the side of the needle at the beginning of its upward stroke, and, on the contrary, that the more this needle is displaced towards the left in relation to its middle position, the later is the: beak I2 in entering the loop formed by the upper thread. Now, when the revolving shaft of the rotary hook is situated in a plane containing the needle situated in its middle position, as is the case in the known sewing machines, and that, owing to this fact, the path followed by the beak I2 of the rotary hook is perpendicular to the displacements of the needle situated in its middle lateral position, and symmetric in relation to the plane containing the needle and the revolving shaft of the rotary hook, it may happen that, when the needle is displaced laterally from its middle position, the beak I2 passes too close to the hole of the needle, that is to say, when the needle has already gone back too high, it is no longer capable of engaging itself in the loop formed by the upper thread f. On the contrary, with the machine shown on the drawing, the shaft II of the rotary hook is not only situated rin a vertical plane parallel with the needle-carrier and perpendicular to the advancement displacement of the feeding means, as is the case with certain known machines, but is in addition inclined in relation to the axis of the needlecarrier. lThe result is that the beak I2 is situated, when it passes in front 'of the needle A, at a greater distance from the resting surface for the cloth 34, when this needle is displaced towards the right in relation to its middle position, than when the needle is displaced towards the left in relation to this middle position. In consequence, this beak I2 is always capable of catching correctly the loop formed by the upper thread,

v,the inclination of the shaft of the cup cornpensatngf at least partly, the differences be- '4 tween the ascending strokes performed by the needle before the passage of the beak I2, which occur when the needle is in its extreme left or right position.

In order to give an easy access to the bobbin, a tipping-over cover is provided for. This cover includes two flaps 36 pivoting on pins 31 rigidly fastened to the frame. In addition, always with a view of facilitating access to the bobbin I4, said bobbin is arranged eccentrically in the cup Il).

One embodiment of the machine has been described here with reference to the attached drawing, given as an example, but it is obvious that many modified forms can be achieved. In particular, the actuating mechanisms for the needlecarrier, the feeding elements and the rotary hook can be of any other known types than those shown and described in the related patent applications.

We claim:

1. A sewing machine comprising a frame, a work feeder, a vertically reciprocable and laterally vibratable needle for the formation of a so-called zig-zag stitch and including a needle-carrier, an actuating mechanism imparting to said needlecarrier a vertical reciprocable movement and a lateral vibratory movement synchronized with its vertical reciprocable movement, a. rotary hook mounted with its peripheral portion in close proximity to the path of travel of said needle, means rotating said rotary hook and a thread seizing beak on the peripheral portion of the rotary hook, the axis of the rotary hook being inclined at an angle substantially less than relative to the axis of the vertical reciprocations of the needle carrier and the rotary hook being rotated in a direction that the beak will move upwardly in its thread seizing path of travel between the extreme positions of lateral vibratory movement of the needle.

2. A sewing machine as claimed in claim l in which the axis of the rotary hook is situated in a plane parallel to said needle carrier and perpendicular to the advancement displacements of the work feeder of the machine.

3. A sewing machine comprising a frame, a work feeder, a vertically reciprocable and laterally vibratable needle for the formation of a socalled zig-zag stitch and including a needle carrier, an actuating mechanism imparting to said needle carrier a vertical reciprocable movement and a lateral vibratory movement synchronized with its vertical reciprocable movement, a rotary hook including a revolving cup mounted with its peripheral portion in close proximity to the path of travel of the needle, means rotating said revolving cup, a thread seizing beak carried by said cup, the axis of the revolving cup being inclined at an angle substantially less than 90 relative to the axis of the vertical reciprocations of the needle `carrier and the revolving cup being rotated in a direction that the beak will move upwardly in its thread seizing path of travel between the extreme positions of lateral vibratory movement of the needle, the axis of the revolving cup lying in a plane parallel to said needle carrier and perpendicular to the direction of feed of the work feeder, and a bobbin support eccentrically positioned in said cup.

4. A sewing machine comprising a frame, a work feeder, a vertically reciprocable and laterally vibratable needle for the formation of a socalled zig-zag stitch and including a needle carrier, an actuating mechanism imparting to said needle carrier a vertical reciprocable movement and a lateral vibratory movement synchronized With its vertical reciprocable movement, a rotary hook including a. revolving cup mounted with its peripheral portion in close proximity to the path of travel of the needle, means rotating said revolving cup, a thread seizing beak carried by said cup, the axis of the revolving cup being inclined at an angle substantially less than 90 relative to the axis of the vertical reciprocations of the needle carrier and the revolving cup being rotated in a direction that the beak will move upwardly in its thread seizing path of travel between the extreme positions of lateral vibratory movement of the needle, the axis of the revolving cup lying in a plane parallel to said needlel carrier and perpendicular to the direction of feed of the Work feeder, and a bobbin support eccentrically positioned in said cup, tWo arms extending radially from the bobbin support, a rocking lever mounted on said frame, two mobile stops carried by said lever for alternately cooperating with said arms to keep the support in a nonrotary position While permitting the thread of the needle loop to pass between said arms and stops.

5. A sewing machine as claimed in claim 3 and comprising a tipping-over cover pivotally mounted on the frame and covering said rotary hook.

RAMON CASAS ROBERT. JEAN COURT.

No references cited.