US3435788A - Sewing machine - Google Patents

Description

April 1, 1969 M. FRESARD ET AL 3,435,788

SEWING MACHINE Filed Oct. 20, 1966 I Sheet of s INVENTORS Win/e451; Fess/1w 04/11/20 BmeuFF/I BY W ATTORNEY M. FRESARD ETAI- April 1, 1969 SEWING MACHINE Filed on. 20, 1966" Sheet 2 of 3 FIG. 2

flu eca F ees/mp BY @A-M/DO BA/8uFF4 ATTORNEY April 1, 1969 M. FRESARD ETYIAL SEWING MACHINE Sheet 5- of 5- Filed Oct. 20, l96

INVENTORS Mk 4 EL FIEZSAED 0L l/VD ATTORNEY United States Patent Office Patented Apr. 1, 1969 3,435,788 SEWING MACHINE Marcel Fresard, Petit-Lancy, and Olindo Barulfa, Chatelaine, Geneva, Switzerland, assignors to Mefina S.A., Fribourg, Switzerland, a company of Switzerland Filed Oct. 20, 1966, Ser. No. 588,016 Claims priority, application Switzerland, Nov. 8, 1965, 15,372/65 Int. Cl. Db 3/02 US. Cl. 112158 4 Claims ABSTRACT OF THE DISCLOSURE A sewing machine for making ornamental stitches. includes an amplitude adjustment lever which not only permits adjustment of the amplitude of a zigzag stitch by moving the lever angularly but also permits selection of a particular cam of a series of cams by rotating a shaft carried by the lever. Rotation of the shaft brings the selected cam opposite a cam follower, which through related connected means, transmits oscillatory motion to a cradle carrying the needle bar of the sewing machine. The movement of the series of cams is accomplished by providing a positioning cam on the shaft, which cam engages an offset portion of a pivoted lever whose arms are disposed beneath the lowermost of the series of cams.

The present invention has for its object a sewing machine capable of making ornamental stitches, comprising a series of control cams juxtaposed on a driving shaft, an oscillating follower capable of entering into contact with one or the the other of these cams under the control of a selection device. The follower is angularly integral with an oscillating slide and a dog bears against the slide to transmit the movements \of the slide to an oscillating cradle. A needle-bar is slidably disposed in the cradle and one end of an amplitude adjusting lever determines the position of the dog along the slide and at its other end carries a shaft and a driving knob.

The sewing machine according to the invention is characterized by the fact that the selection device comprises a mechanism which permits rno'vmg the series of control cams vertically along their driving shaft to bring one or the other of the cams. opposite the feeler, which mechanism is controlled by angular movement of a driving knob carried by a spindle which in turn is connected with the amplitude adjusting lever, actuating said mechanism.

The accompanying drawing shows, diagrammatically and by way of exarnlple, one embodiment of the sewing machine according to the invention.

FIG. 1 is a sectional view in elevation of the upper arm of an ornamental stitch sewing machine showing its control unit.

FIG. 2 is a plan view of this control unit.

FIG. 3 is a front view of the control unit with an end view of the control lever.

FIG. 4 shows a detail of a positioning cam.

The sewing machine shown in the accompanying drawing is a sewing machine capable of effecting ornamental stitches, such as zigzag stitches, serpentine stitching, etc. In such a sewing machine, the needle-bar 1 slides vertically in a cradle 2 capable of oscillating around a vertical spindle 3 under the control of a connecting rod 4 hinged at one of its ends 5 to the cradle 2, the other end 6 of this connecting rod ending in a dog bearing against the face or slide 7 of a lever '8 hinged at 9 to a supporting lever 10 (see FIG. 2). The length of the connecting rod 4 is adjustable due to an eccentric 11 and a locking screw 12 connecting the end dog 6 of the connecting rod 4 to the remainder 'of the latter.

As best shown in FIGURE 1, the upper arm or frame 13 of the sewing machine has disposed therein a horizontal shaft 14 adapted to drive, on the one hand, the needle-bar 1 and, on the other hand, by means of a tangent screw 15 and of a pinion 16, to drive a vertical spindle 17 supported by a bearing 18 situated in the upper part of the frame 13. The outer part 119 of the bearing 18 provides a pivoting axis for an amplitude adjustment lever 20. One of the arms 21 of the lever 20 carries a journal pin 22 engaging in a slot 23 made in the end dog 6 of the connecting rod 4. The journal pin 22 and the slot 23 are designed to guide the connecting rod 4 during its to and fro movements induced by the oscillation of the lever 8. These oscillations are in turn produced by a follower 24 of cam 25 forming part of a group [of cams 25, 26, 27 connected with the vertical spindle 17 by means of a pin 28 engaged transversely in the latter, one end 29 of the pin being situated in a corresponding axial groove 30 of the cam block 25, 26, 27. The follower 24 is carried by the lever 8 and thus transmits all the movements imparted thereto by the cam 25 tosaid lever and, thus, to the slide 7.

A spring 31 acting on the cradle 2 causes the cradle to exert a constant force on the connecting rod 4 to maintain the dog 6, forming one of its ends, in contact with the slide 7 of the lever 8. The amplitude of the oscillation movements transmitted to the needle-bar 1 from the cam 25 by means of the follower 24, the lever 8, the connecting rod 4 and the oscillating cradle 2, may be adjusted by angularly moving the lever 20, so as to bring the dog 6 into different positions along the slide 7. This angular adjustment of the lever 20 is effected by acting on the arm 32 of said lever 20. The anrn 32 has an axial bore 33 in which is engaged a shaft or spindle 34 which provides an extension of the arm 32 of the lever 20 outside the frame 13. The free end of the spindle 34 carries a driving knob 35 rigidly mounted on the spindle 34. The spindle 34 passes through a slot 36 made in the frame 13, and surnoun'ding the slot 36 on the outer surface of the frame are marked reference marks 0, 1, 2, 3, 4, not shown in the drawing. By bringing the driving knob 35 to a position opposite one of these reference marks, there is produced an amplitude of the oscillation movements of the needle-bar 1 which amplitude is greater the higher the numerical order of the reference 'rnark olpposite it.

A brake, not shown, acts on the lever 20 to avoid untimely angular movements of the latter.

Independently of the brake, the lever 20 may be fixed in position opposite each of the reference marks 0, 1, 2, 3, 4 by means of notches 37 provided on a plate 38 mounted to oscillate about a spindle 39 fixed to the frame 13 of the sewing machine. A spring 40, hooked at one of its ends to a pin 41 carried by the frame 13 and by its other end to a hole 42 pierced in the plate 38, tends to cause the said plate to pivot in a clockwise direction looking at FIG. 2. A pin 43 engaged transversely in the spindle 34 is adapted to cooperate with the notches 37 to fix the positions 0, 1, 2, 3, 4 of the amplitude adjustment of the zigzag. The spindle 34 carrying the driving knob 35 is able to occupy four angular positions in the arm 32 of the lever 20. Indeed, and as is shown in FIG. 3, the front face 44 of the arm 32 has two cross-shaped grooves 45 and 46 in which the pin 43 may engage after rotation of the spindle 34. In order to do this, the spindle 34 may slide axially in the bore 33 against the action of a spring 47 slipped on said spindle and tending to maintain the spindle inside the arm 32. A clip 48 engaged in a groove 49 of the spindle 34 constitutes an axial stop for the latter preventing any possibility of rotation of the spindle 34 so long as the lever 20 has not been brought to the position corresponding to zero zigzag amplitude. In fact, the distance provided between the clip 48 and the inner face 50 of the frame 13 is not sufficient to permit the movement of the pin 43 out of the groove 45, to permit engagement in the other groove 46 of the arm 32. On the other hand, at the point of the O amplitude position, the inner face 50 of the frame 13 is provided with a recess 51 permitting sufiicient axial movement of the spindle 34 outwardly to permit the passage of the pin 43 from the groove 45 to the other cross-shaped groove 46.

The first use of the possible rotational movement of the spindle 34 controlled by the driving knob 35 is employed to eliminate the influence of the notches 37 on the adjustment of the amplitude. In fact, after having rotated the knob 35 and spindle 34 by a quarter of a turn the pin 43 in engaging itself in the groove 46, escapes from the notches 37 and the amplitude adjustment may be effected in a continuous manner from zero amplitude to maximum amplitude.

Another function of the driving knob 35 is that which permits the selection of one of the cams 25, 26 and 27. In fact, this group of cams 25, 26 and 27 may slide vertically along the spindle 17 against the action of a spring 52 engaged around the upper part of the spindle 17 and hearing against a stop 53 carried by the latter. The arm 32 of the lever has a lug 54 carrying an axle 55 for a forkedshaped hinged arm 56 (see FIGS. 1 and 2). The ends 57 of the arm 56 bear against a supporting washer 58 on which rests the last cam 27 of the series of cams 25, 26, 27 The angular position of the arm 56 relative to the lever arm 32 and, thus, the position of the cams 25, 26 and 27 along their driving shaft 17, is a function of the angular position of a positioning cam 59 integral with the spindle 34 extending the amplitude adjustment lever 20. The positioning cam 59 is made integral with the spindle 34 by a pin 60 (see FIGS. 1 and 4). The cam 59 is in contact with an intermediate part 61 of the arm 56 forming a boss. As will be seen upon examining FIG. 4, the cam 59 has four bearing surfaces 62, 63, 64, 65 for the boss 61. The two first bearing faces 62 and 63 are at a same radial distance from the spindle 34 and correspond to the selection position of the upper cam of the series of cams 25, 26 and 27. Upon selection of this cam 25, the first position 62 corresponds to the operation of the driving knob with action of the notches 37 on the pin 43, whereas in the second position 63 the operation of the knob 35 is effected independently of the notches 37. The third position of the knob 35 corresponding to the coming into action of the face 64 of the cam 59 produces a movement of the arm 56 bringing the cam 26 to the level of the follower 24. The bringing into the fourth position of the driving knob 35 causes the face 65 of the cam 59 to act on the arm 56 and brings the cam 27 to the level of the follower 24.

It is seen from the preceding description that a same control knob, in the present case the driving knob 35, is used for three separate functions:

Its first function consists in permitting amplitude adjustment of the zigzag by moving the lever 20 laterally along the slot 36 of the frame 13 opposite the reference marks 0, 1, 2, 3, 4 marked along the latter.

The second function of the knob 35 is to permit this amplitude adjustment with or without the notches 37 imposing a fixed position of the lever 20 opposite each of the reference marks 0, l, 2, 3 ,4.

The third function of this knob 35 is to permit the selection of one or the other of the control cams 25, 26, 27 by rotation of said knob 35 to bring it into the required angular position.

It is to be noted that the rotation of the knob 35 to permit the selection of one of the cams 25, 26 and 27 is only possible when the lever 20 is brought into the position 0 of zero amplitude. In this position, the follower 24 is automatically at a distance from the profile of the cams 25, 26 and 27 due to the fact that the dog 6 of the connecting rod 4 exerts pressure against the slide 7 beyond the pivoting point 9 of the lever 8. Thus, the follower 24 cannot in any way hinder the axial movement of the cams 25, 26 and 27.

Numerous modified embodiments of the sewing machine described above could be imagined. Thus, the number of cams of the control point instead of three cams could comprise more than three cams. All these cams may, of course, be replaced by another group in case another choice of decorative ornaments is to be made. It would even be possible to replace only the upper cam of the group of cams 25, 26 and 27.

As regards the selection device itself, it could of course be replaced by a pinion and rack device acting on the arm 56 or on a socket capable of being moved axially along the shaft 17 to drive with it the block of cams 25, 26 and 27.

We claim.

1. In a sewing machine for making ornamental stitches including a frame, a rotatable spindle, a series of control cams juxtaposed on and connected with said spindle for rotation therewith and being slidable axially thereof, a rotatably mounted amplitude adjustment lever including a first arm and a second arm, an oscillating slide, a cam follower integral with said slide, a dog connected with the first arm of said lever and bearing against said slide, an oscillating cradle, a needle-bar slidable in said cradle, said dog connected with said cradle and transmitting movement of said slide to said cradle, a selection device including a shaft rotatably mounted in said second arm. of the amplitude adjustment lever, said shaft extending through a slot in said casing, a knob on the extended end of said shaft, the angular movement of said shaft causing rotation of said amplitude adjustment lever to move said cam follower into and out of contact with a selected one of said cams, means for bringing one or the other of said cams opposite said cam follower, said means comprising a member hinged at one of its ends to the second arm of said amplitude adjusting lever, its opposite free end disposed against the bottom cam of said series of cams, spring means bearing on the top cam of said series of cams and urging said cams toward said member, a positioning cam fixed to said shaft and in contact with an intermediate part of said member, whereby upon rotation of said shaft said positioning cam urges said member and said series of cams upwardly against the tension of said spring to place a selected cam into the desired position opposite said cam follower.

2. A sewing machine according to claim 1, wherein said shaft is axially slidable in said second arm, spring means normally opposing the axial movement of said shaft, locking means preventing rotation of said shaft without simultaneous axial movement thereof, a stop carried by said shaft and cooperating with the inner wall of said frame to further prevent rotation of said shaft unless said amplitude adjustment lever is brought to zero amplitude position.

3. A sewing machine according to claim 2, including a transverse pin in said spindle, means carried by said frame and cooperating with said transverse pin to fix said amplitude adjustment lever in a selected angular position, the front face of the second arm of said amplitude adjustment lever having a plurality of grooves therein, said pin engageable with said selected one of said grooves upon rotation of said shaft of said amplitude adjustment lever to fix said shaft in position relative to the particular selected control cam.

4. A sewing machine according to claim 3 wherein said means carried by said frame includes a plate hinged to the frame, said plate having a plurality of notches therein for receiving said transverse pin, and spring means urging said plate against said pin.

References Cited UNITED STATES PATENTS 3/1966 Fresard 112-158 1/ 19 61 Eriksson 112--158 RICHARD J. SCANLAN, JR., Primary Examiner.

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