US3132614A - Zig-zag sewing machines - Google Patents

Description

y 2, 1964 L. BQNQ 3,132,614

ZIG-ZAG SEWING MACHINES Filed 'Dec. 1. 1960 s Sheets-Sheet 1 gi B0710 4 225 1% may 0 A7757 nab May 12, 1964 L. BONO 3,132,614

ZIG-ZAG SEWING MACHINES 1 I IV WW WM WMIII y y 2, 1964 L. B NQ 3,132,614

ZIG-ZAG SEWING MACHINES Filed Dec. 1, 1960 5 Sheets-Sheet 3 United States Patent 3,132,614 ZIG-ZAG SEWING MACHINES Luigi Bono, Pavia, Italy, assignor to Necchi Societa per Azioni, Pavia, Italy Filed Dec. 1, 1960, Ser. No. 72,940 Claims priority, application Italy Feb. 4, 1960 2 Claims. (Cl. 112-158) The present invention relates to a sewing machine having a transversely movable needle bar and a control mechanism to vary the transverse movements of said needle bar.

In a machine of one type having cams and followers to control the lateral movements of the needle, the cams may be driven with a unidirectional step-by-step motion. The size of the steps may be adjusted so that the number of stitches in a given design are varied to make the design longer or shorter for a given length of stitch. Since it is not possible to assure that each complete cycle of the sewing design controlled by the cam will be made of a definite number of stitches, there will always be small irregularities in the design, but this deficiency is more than compensated for by the possibility of varying the lengths of theldesigns.

In a machine of another type having cams and followers to control transverse needle movements, the cams rotate continuously with a definite transmission ratio to the driving shaft. In these machines, there always are the same number of stitches for each rotation of the cams, so that there can be no variation in lengths of the design with stitches of equal length. But in this case the possibility that the needle will occupy the identical position with respect to the fabric in making the design compensates for the restriction on changing the lengths of the designs.

The object of the present invention. is to provide a machine in which either cams designed to rotate stepby-step or cams designed to rotate continuously may be mounted to cooperate with the cam followers and be driven automatically with motion of either form. This mechanism is simple and inexpensive and requires no special preparation by the operator, except the choice of cams.

The invention will be described by reference to the accompanying drawing which shows one embodiment by way of illustration.

FIG. 1 is a view of the sewing machine, partially in section;

FIG. 2 shows details of FIG. 1 on a larger scale;

FIG. 3 is a cross-section through the machine along the line IIIIII of FIG. 2;

FIG. 4 is a section through the machine along the line IVIV of FIG. 3;

FIGS. 5 and 6 show details of FIG. 3;

FIG. 7 is a view along the line VII--VII of FIG. 2;

FIGS. 8 and 9 are an elevation and a plan view respectively of a group of cams which can be applied to the machine; p

FIGS. 10 and 11 show in elevation and in plan view, respectively, another group of cams which can be applied to the machine;

FIG. 12 shows sewing designs which can be obtained with a group of cams such as that illustrated in FIGS. 8 and 9; i

FIG. 13 shows a sewing design which can be obtained with a group of cams, such as that shown in FIGS. 10 and .11. i

As shown in the drawings, the sewing machine comprises a frame 1 having a top cover 2 in which a door 3 is located. A driving shaft 4 within the frame 1 operates the usual mechanism to reciprocate the needle bar 5 "ice with the needle 5. The shaft 4 also carries gear 6 which engages gear 7 to rotate vertical shaft 8.

A cam 9 fixed to the lower end of shaft 8 engages the walls 10,11 of a channel in a lever 12 pivoted to oscillate about a pin 13 on another lever 14. The lever 14 is pivoted to the frame 1 by pin 16 and carries a pin 15 which is maintained in contact with a lever 17, also pivoted on pin 16, by a spring 19. A finger piece on the end of lever 17 extends through slot 18 to the exterior so that the lever 17 may be moved about pivot 16 to adjust lever 14 and shift the axis of oscillation of lever 12.

The lower side of lever 12 is formed with an arcuate channel between walls, 20, 21, in which slides sector 22 pivoted on an end of lever 23 by pin 24. This lever 23 has a roller 25 on its lower side mounted on pin 24 and is pivoted by a pin 26 to arm 27, which is pivoted on the frame by pin 28. The pin 26 also carries a block 29 connected to the rod 30 which controls the transverse displacements of support 31 of the needle bar 5. A channel portion 32 on the end of lever 33 (FIG. 6) receives the roller 25 on lever 23, for shifting the sector 22 in lever 12 relative to its axis 14. This lever 33 is pivoted on a pin 35 and may be adjusted by another lever 36 pivoted on said pin. The lever 36 carries an adjustable eccentric abutment 37 engaging lever 33 and has a handle 38 extending outwardly through slot 39. Adjustment of handle 38 to position sector 22in lever 12 relative to axis 13 thereby determines the movement of rod 30 and transverse movement of needle 5 resulting from oscillation of lever v12, which adjustment of lever 17 to shift the lever 14 and the axis of oscillation of lever 12 will determine the location of the median line of movement of the needle.

For automatic sewing, the levers 14 and 33 may be adjusted automatically in accordance with a program device operated by the machine, the pin 15 on lever 14 and pin 34 on lever 33 being engaged by the automatic mechanism provided for this operation. In the embodiment shown herein, a program device comprising a pair of cams such as 77 or 82 is driven from the driving shaft 4 through either of two mechanisms to engage sensing means such as followers to shift the lever 14 through engagement of pin 15 by the slot 41 in lever 43 and the lever 33 through engagement of pin 34 by the slot 42 in lever 44.

The lever 43 is fixed to shaft 45 which is rotated by a lever 47. Lever 44 is fixed on shaft 46 which is rotated by a lever 48. Shafts 45 and 46 have hearings in a plate 49 fastened to the frame 1 by screws 50 in slots 51. Lever 47 carries a stud 52 which is engaged by the edge 54 of follower 57 movable by one of the pair of cams. The lever 48 carries a stud 53 which is engaged by the edge 55 of the tail of follower 58 movable by the other cam. These followers are pivotally mounted on a pin 59, on which is also mounted a third follower 60. This last follower 60 may be connected to a stitch-regulating device by rod 61 to vary the fabric feed in a known manner.

One mechanism for rotating the cams comprises a gear 62 on shaft 8 driving gear 63, shaft 64, gear 65 and cam engaging gear 66. The gear 66 rotates on a sleeve 49 fixed to the plate 49. The other mechanism comprises a step-by-step intermittent mechanism 69 driving shaft 67. A mechanism of this type is shown in applicants Patent 2,764,895. The mechanism carries an arm 70 which is actuated by the cam 71 fixed to the driving shaft 4 and is adjustable to vary the length of step through rotation of cam 72 by means of knob 72. The cam 71 is so positioned on the driving shaft 4 that the step-by-step movements of shaft 67 occur when the needle 5 is in its upper position out of the fabric.

In assembly the two shafts 8 and 64 are journaled in a cylindrical member 73 seated in frame 1. The member 73 may be rotated in the frame to adjust the clearance between gears 6 and 7, a set screw 74 securing the member in its adjusted position. Next the plate 49 is fastened in place and gear 65 is fixed on shaft 64. The slots 51 allow adjustment of plate 49 for clearance between gears 65 and 66 before tightening screws Sti. The followers 57, 58 and 60 may then be mounted. A lever 75 movable by any appropriate means carries a bent end 76 which can engage the ends of the followers so that they can be moved out of position for positioning the set of cams on sleeve 49.

One set of cams 77 designed for step-by-step movement has a hub 79 formed with a rectangular opening 80 in its outer end to engage the rectangular lug 81 on the end of shaft 67 when the hub is mounted on sleeve 49'. The other set of cams has a disk member fixed to the lower end of its hub carrying a pin 83 which may engage in any one of the holes 84 in the disk portion of gear 66. A washer 68 on sleeve 49 provides a bearing between the disk portion and the cams.

In operation, the mechanism disclosed will control both the transverse movements of the needle to vary the length of the steps of transverse movement and the mean position of the needle. The mean position is determined by the position of the pivot 13 of lever 12 which is ad justed by angular movement of lever 14, either manually by lever 17 or automatically by the upper cam of 77 or '78. This cam causes follower 57 to move lever 47 and lever 43, which shifts lever 14 through pin 15. The length of the lateral movements of the needle are dependent on positioning lever 33 to locate the sector 22 so that oscillation of lever 12 moves the needle according to the distance of sector 22 from pin 13. The lower cam also may adjust lever 33 by shifting follower 58 which rotates lever 48 and lever 4a to shift lever 33 through pin 34.

When the operator selects a design to be sewn, one of the cams such as 77 is positioned on the sleeve 49' to be driven step-by-step by the mechanisms 69. The knob 72 may then be adjusted to control the size of the steps without varying the length of the stitch. Different adjustments of the steps for equal size stitches form designs as shown in FIG. 12. The other cam 78 may be mounted with its hub 82 on sleeve 49' and pin 33 engaged in a hole 84 in the disk portion of gear 66 so that the cams will be driven continuously. By choice of cams and simultaneous control of feed of the fabric, various designs may be obtained such as shown in FIG. 13.

I claim:

1. A sewing machine comprising a drive mechanism, a needle, means driven by said drive mechanism for reciprocating said needle, other means driven by said mechanism for effecting lateral movement of said needle, and control means connected to said other means for controlling said other means, said control means including cam followers adapted to engage a plurality of replaceable cam units, two separate cam unit drive members, means driven by said drive mechanism for continuously rotating one of said cam unit drive members and simultaneously, intermittently step-by-step rotating the other of said cam unit drive members, said cam unit drive members being relatively movable and in the form of coaxial rotating members, one of said rotating members having a disk and the other a shaft projecting axially through said disk, separate and different cam engaging means on said disk and said shaft, said continuously rotating cam unit drive member engaging means being adapted to engage only a replaceable cam unit having complementary engaging means, said intermittently stepby-step rotating cam unit driving member engaging means being adapted to engage only a replaceable cam unit having complementary engaging means.

2. The sewing machine of claim 1 wherein said cam units are in the form of stacked sets of cams.

Fischer Jan. 3, 1961 Casas-Robert et al. Apr. 11, 1961

Claims (1)

1. A SEWING MACHINE COMPRISING A DRIVE MECHANISM, A NEEDLE, MEANS DRIVEN BY SAID DRIVE MECHANISM FOR RECIPROCATING SAID NEEDLE, OTHER MEANS DRIVEN BY SAID MECHANISM FOR EFFECTING LATERAL MOVEMENT OF SAID NEEDLE, AND CONTROL MEANS CONNECTED TO SAID OTHER MEANS FOR CONTROLLING SAID OTHER MEANS, SAID CONTROL MEANS INCLUDING CAM FOLLOWERS ADAPTED TO ENGAGE A PLURALITY OF REPLACEABLE CAM UNITS, TWO SEPARATE CAM UNIT DRIVE MEMBERS, MEANS DRIVEN BY SAID DRIVE MECHANISM FOR CONTINUOUSLY ROTATING ONE OF SAID CAM UNIT DRIVE MEMBERS AND SIMULTANEOUSLY, INTERMITTENTLY STEP-BY-STEP ROTATING THE OTHER OF SAID CAM UNIT DRIVE MEMBERS, SAID CAM UNIT DRIVE MEMBERS BEING RELATIVELY MOVABLE AND IN THE FORM OF COAXIAL ROTATING MEMBERS, ONE OF SAID ROTATING MEMBERS HAVING A DISK AND THE OTHER A SHAFT PROJECTING AXIALLY THROUGH SAID DISK, SEPARATE AND DIFFERENT CAM ENGAGING MEANS ON SAID DISK AND SAID SHAFT, SAID CONTINUOUSLY ROTATING CAM UNIT DRIVE MEMBER ENGAGING MEANS BEING ADAPTED TO ENGAGE ONLY A REPLACEABLE CAM UNIT HAVING COMPLEMENTARY ENGAGING MEANS, SAID INTERMITTENTLY STEPBY-STEP ROTATING CAM UNIT DRIVING MEMBER ENGAGING MEANS BEING ADAPTED TO ENGAGE ONLY A REPLACEABLE CAM UNIT HAVING COMPLEMENTARY ENGAGING MEANS.

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