US3401659A

US3401659A - Buttonhole stitching device

Info

Publication number: US3401659A
Application number: US537234A
Authority: US
Inventors: Kasuga Noboru
Original assignee: Janome Sewing Machine Co Ltd
Current assignee: Janome Corp
Priority date: 1966-03-24
Filing date: 1966-03-24
Publication date: 1968-09-17
Anticipated expiration: 1985-09-17

Description

Sept. 17, 1968 NoBoRu KASUGA 3,4L559 BUTTONHOLE STITCHING- DEVICE 5 Sheets-Sheet 1 Filed March 24, 1966 v INVENTOR. /l/ara. JQ/Risa Sept. 17, 1968 NOBORU KASUGA 3,401,559

BUTTONHOLE STITCHING DEVICE Filed March 24, 1966 5 Sheets-Sheet 2 Sept 17, 1968 NOBORU KASUGA 3,401,659

BUTTONHOLE STITCHING DEVICE Filed March 24, 1966 5 Sheets-Sheet 5 Sept- 17, 1968 NoBoRU KASUGA 3,401,659

BUTTONHOLE STITCHING DEVICE Filed March 24, 1966 5 Sheets-Sheet 4 Sept. 17, 1968 NoBoRU KASUGA BUTTONHOLE STITCHING DEVICE 5 Sheets-Sheet 5 Filed March 24, 1966 INVENTOR, /Varu /dammji United States Patent O 3,401,659 BUTTONHOLE STITCHING DEVICE Noboru Kasuga, Tokyo, Japan, assignor to Janome Sewing Machine Co., Ltd., Tokyo, Japan Filed Mar. 24, 1966, Ser. No. 537,234 16 Claims. (Cl. 112-1S8) The present invention relates to a buttonhole stitching device for a sewing machine, and more particularly to a buttonhole stitching device for making two parallel rows of small zig-zag stitches on opposite sides of a buttonhole, and longer bar tack stitches at the ends of the buttonhole.

Buttonhole stitching devices are known in which a cam follower is operated by a buttonhole cam to make large amplitude oscillations which are used for producing bar tack stitches. To make t-he shorter lateral stitches of the buttonhole, the cam follower is prevented from making the large amplitude stitches by stop means which block movement of the cam follower after a shorter oscillation so that the small stitches are made on one side of the buttonhole. The constructions according to the prior art have the disadvantage that the stopping of the oscillating cam follower produces a rattling noise.

It is one object of the invention to provide a buttonhole stitching device which operates very quietly.

It is another object of the invention to provide a buttonhole stitching device in which small amplitude stitches are not obtained by blocking movement of the cam follower, but by causing the cam follower to oscillate about a first axis when making large amplitude stitc-hes, and about a second axis when making small amplitude stitches.

Another object of the invention is to provide a buttonhole stitching device forming neat and precise stitches along a buttonhole, while the feeding mechanism of the sewing machine is automatically actuated to move in one direction while the stitches are made on one side of the buttonhole, and in the yreverse direction when the stitches are made on the other side of the buttonhole.

Another object of the invention is to use the manually operated knob by which a standard sewing machine is set to make straight stitches along a center line, or in two lateral field positions, for the purpose of controlling the buttonhole stitching device to make rows of small stitches on the sides of the buttonhole, and larger stitches at the ends of the buttonhole.

It is a related object of the invention to provide a buttonhole stitching device in a sewing machine without increasing the number of manually operated knobs or handles of the same.

It is another object of the present invention to provide a sewing machine with a buttonhole stitching device which can be easily operated by an unskilled and inexperienced person.

lt is another lobject of the invention to provide a but,- tonhole stitching device in which the amplitude of the small lateral stitches and of the bar tack stitches can be simultaneously adjusted.

lt is another object of the invention to provide a buttonhole stitching device in which the length of the rows of lateral stitches is determined by the operator by setting a control knob.

With these objects in view, the present invention relates to a buttonhole stitching device for a zig-zag sewing machine. One embodiment of the invention comprises a cam follower operated -by a drive cam and having an abutment; a carrier supporting the cam follower for oscillatory movement about a first axis; fulcrum means having a fulcrum cooperating with the abutment of the cam follower for supporting the same for oscillatory move- 3,401,659 Patented Sept. 17, 1968 ice ment about a second axis; mounting means, preferably a support shaft, for mounting the carrier for movement with the cam follower between a normal position and a displaced position, and for mounting the fulcrum means for movement between a first position in which the fulcrum is spaced fr-om the abutment in the normal position of the carrier and engages the same in said displaced position, and a second position in which the fulcrum engages the abutment in the normal position of the carrier; and control means, preferably a manually turned cam shaft with cams cooperatingV with the carrier and fulcrum means, and having three positions for setting the device to make small stitches on opposite sides of a buttonhole, respectively, or for `making bar tack stitches -at the ends of the buttonhole. The two control cams of the control means have a first position for simultaneously moving the carrier to the normal position and the fulcrum means to the first position so that the cam follower oscillates about a first axis. Motion transmitting means are actuated by a projecting portion -or pin of the cam follower means and are connected with the needle bar assembly for oscillating the needle under the control of the cam follower means. In the first position of the control cams, the cam follower oscillates about the first axis to perform a large oscillation corresponding to long bar tack stitches of the needle.

When the control cams are turned to a second position, the carrier is placed in its normal position and the fulcrum means is placed in the second position so that the cam follower oscillates about the fulcrum and second axis. Since the second axis is closer to the projection or pin of the cam follower which cooperates with the `motion transmitting means, the cam follower performs smaller oscillations resulting in short stitches on one side of t-he buttonholes.

When the control earns are turned to a third position, the carrier is moved to the displaced position and the fulcrum means to the first position so that the cam follower again oscillates about the fulcrum. Since the carrier is in a displaced position, small stitches are made on the other side of the buttonhole.

ln the preferred embodiment of the invention, the carrier and the fulcrum means are angular levers having apex portions mounted on a support shaft, and cam follower arms cooperating with the two control cams on the manually turned control cam shaft. The other arm of the carrier supports a pivot means on which the cam follower is mounted at one end, while the other end of the cam follower cooperates with the drive cam. The abutment is formed by a Vbent over projection which cooperates with a fulcrum pin on the other arm of the fulcrum lever. The cam follower has a projection or pin for actuating the motion transmitting means and thereby the needle, and this projection or pin is spaced a greater distance from the pivot means and first axis than from the fulcrum pin, abutment, and second axis so that the oscillations of the cam follower about the fulcrum pin are smaller than the oscillations about the pivot means, corresponding to t-he smaller amplitude of the lateral stitches as compared with the greater amplitude of the bar tack stitches;

Standard sewing machines have a control knob or handle for turning a control shaft on which a cam is mounted for setting the needle bar assembly between three positions in which the needle is in a central position, or in one of two lateral field positions. In accordance With the present invention, the same knob and control shaft are used for setting the buttonhole device, as explained above, and the standard control shaft carries the two control cams of the buttonhole stitching device. lndicia representing the three field positions of the needle,

and additional indicia representing the three positions of the buttonhole stitching device, are provided on the control knob.

The amplitude adjusting means of standard sewing machines are used in accordance with the present invention to vary the amplitude of the stitches produced by the motion transmitting means so that the amplitude of the lateral small stitches and of the bar tack stitches can be simultaneously adjusted.

The control cam shaft carries a third control cam by which the feeding means of the sewing machine are said to forward feed or reverse feed. The relative position of the third control cam to the rst and second control cams of the buttonhole stitching device is such that the material in which the buttonhole is to be made is fed forward while s mall stitches are made on one side of the buttonhole, is fed in the opposite direction when small stitches are made on the other side of the buttonhole, and is not fed at all when bar tack stitches are being made at the ends of the bu-ttonhole.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and i-ts method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. l is a front view illustrating a sewing machine provided with the buttonhole stitching device according to the invention;

FIG. 2 is a fragmentary perspective view illustrating a buttonhole stitching device according to one embodiment of the invention in conjunction with parts of a zigzag sewing machine;

FIG. 3 is a vertical sectional view illustrating a sewing machine provided with the buttonhole stitching device;

FIG. 4 is a horizontal sectional view of the sewing machine shown in FIG. 3;

FIG. 5a is a fragmentary elevation, partially in section, illustrating a tirs-t operational position in which the needle is on the right side of a small stitch on the left side of a buttonhole;

FIG. 5b is an elevation corresponding to FIG. 5a, and illustrating a second operational position in which the needle is on the lef-t side of a small stitch on the left side of a buttonhole;

FIG. 6a is an elevation corresponding to FIG. 5a, and illustrating a third operational position in which the needle is on lthe right end of a small stitch on the right side of the buttonhole;

FIG. 6b is an elevation corresponding to FIG. 6a, and illustrating an operational position in which the needle is at the left end of a small amplitude stitch on the right side of the buttonhole;

FIG. 7 is a fragmentary exploded perspective View illustrating the buttonhole stitching device;

FIG. 8a is a schematic view illustrating the small stitches on the left side of the buttonhole produced in the operational positions of FIGS. 5a and 5b;

FIG. 8b is a schematic view illustrating bar tack stitches of larger amplitude at the forward end of the buttonhole;

FIG. 8c is a schematic View illustrating a row of small amplitude stitches on the right side of the buttonholes produced in the positions of FIGS. 6a and 6b; and

FIG. 8d is a schematic view illustrating large amplitude bar tack stitches at the rear end of the buttonhole.

Referring now to the drawings, and more particularly to FIG. 1, a knob 43 is provided for setting the machine to produce zig-zag stitches of dilferent amplitude. In the 0 position, a straight line of stitches will be made by the needle. A second control knob 33 has three

indicia

64, 65, 66 relating to the left, center and right eld positions of the needle, two

indicia

61 and 63 relating to two rows of small amplitude stitches on opposite sides of a buttonhole, and indicia 62 relating to bar tack stitches. A fixed mark 33 is provided on the casing of the machine for setting the indicia of control knob 33.

Referring now to FIGS. 2, 3, 4 and 7, a needle bar 41 supports a needle, not shown, and is mounted in a needle bar assembly including a support 35 with bearings 70 mounted for pivotal movement on an adjustable pivot 34 on which a spring 36 connected to support 35 is mounted so that the needle bar assembly is biased by spring 36 -to turn about pivot 34 to a normal position in which a pin 40, see FIG. 4, on one side of the end portion 39 of a connecting link 38 abuts a curved guide face 27 of an oscillatable member 26. As best seen in FIGS. 2 and 7, a member 30 is secured by screws 31 to oscillatable member 26 and has a projection 30 cooperating with a pin 16 on a cam follower 14.

Oscillatable member

26, 30 has a journal 26a projecting into a bearing sleeve 25 on a setting lever 23 which has a bore 23a receiving a stationary shaft 7 which is mounted on the casing 1 of the sewing machine. Another arm 24 of set-ting lever 23 cooperates with a setting cam 10 which turns with control cam shaft 32 when knob 33 is turned. When

indicia

64, 65, 66 are placed opposite the xed mark 33 on the casing 1 of the machine, cam 10 is turned between three positions in which setting lever is angularly displaced so that journal 26a of oscillatable member 26 is shifted between three field positions.

A main drive shaft 2 is rotated by a motor, not shown, and carries a fixed gear 3 meshing with a gear 4 which is xedly secured to a substantially triangular drive cam 5 and is mounted together with the same on a transverse stationary shaft 6 which is secured by a screw 1 to a projecting portion 1 of the machine frame, as shown in FIG. 4.

Cam follower 14 is mounted for oscillator-y movement on a pivot means 18, and has on one side the above mentioned projecting pin `16 which cooperates with the projecting portion 30 of the oscillatable

member

26, 30.

An amplitude adjusting knob 43 has a shaft 44 mounted in the machine casing and carrying an amplitude adjusting lever 44 having at the end a pin 45 projecting into a groove 39a in end portion 39 of link 38, as best seen in FIG. 4.

When amplitude adjusting knob 43 is operated, end portion 39 of link 38 is moved so that pin 40 slides along the guide face 27 of oscillatable member 26, varying the effective radius of the same between pin 40 and the rocking axis dened by journal 26a.

The above described structure is used for the usual sewing operations of the machine. During rotation of drive shaft 2, cam 5 rotates and oscillates cam follower 14 about shaft 18. Projecting pin 16 of cam follower 14 engages part 30 of

oscillatable member

26, 30 and oscillatesthe same about the axis provided by journal 26a. The oscillating motion of member 26 is transmitted by pin 40 to link 38, 39 so that the needle bar assembly 35 is oscillated while `the force of spring 36 is transmitted over link 38, pin 40,

oscillatable member

26, 30, and projecting pin 16 to cam follower 14 which is urged against cam 5.

When the knob 43 is rotated, pin 45 in groove 39a displaces pin 40 on portion 39 along guide face 27 so that

link

39, 38 causes the needle bar assembly and needle to perform greater oscillations when pin 40 is farther spaced from journal 26a than when pin 40 is closely located to journal 26a. When the axis of pin 40 coincides with the axis of journal 26a, no oscillations are performed by the needle bar assembly, and a straight line of stitches lis made. By turning control knob 33 between three positions in which

indicia

64, 65, 66 are respectively located opposite the mark 33', setting cam 10 is turned to positions displacing setting lever 23 angularly about shaft 7 whereby the position of journal 26a is varied together with the position lof oscillatable

member

26, 30, pin 40,

and link 38, 39 whereby the field position of the needle bar assembly and needle can be selected. A stop screw 29 limits movement of setting lever 23.

When a buttonhole is to be stitched by the buttonhole device of the present invention, which will now be described, control knob 33 is turned to a position in which one of the

indicia

61, 62, 63 is located opposite the fixed mark 33. Consequently, control shaft 32 is turned to an angular position which it does not assume during normal sewing operations.

In addition to setting cam 10, two

control cams

8 and 9 are mounted on shaft 32. As best seen in FIGS. 2 and 7,

cams

8, 9 and 10 are located adjacent each other on shaft 32, and are secured to each other by a screw 61 passing through corresponding bores in

cams

8, 9 and 10 and being screwed into a holding ring 60 which is secured by screws 59 to shaft 32 so that

cams

8, 9 and 10 are fixed on shaft 32, but may be exchanged for other cams.

Control cams

8 and 9 have substantially circular peripheries of different diameters. As best seen in FIG. 5a, control cam 8 has a recess 8', and a control cam 9 has a projection 9 having the same radius as the circular periphery of cam 8.

Support shaft 7 supports not only setting lever 23, as described above, but also an angular cartier lever 11, and an angular fulcrum lever 19. The apex portions of carrier lever and fulcrum lever 419 have bores through which shaft 7 passes. Spacing rings 58 and 57 are located between

levers

11, and 19, and levers 19 and 23. Axial movement of

levers

11, 19 and 23 is prevented by end rings 53 and 54 secured lby screws 55 and S6 to stationary support shaft 7, but levers 11, 19 and 23 are mounted on shaft 7 for angular movement.

Carrier lever 11 has a cam follower arm .12 cooperating with control cam 8, and fulcrum lever 19 has a cam follower arm 22 cooperating with control cam 9. The other arm 13 of carrier lever 11 has a bore supporting pivot pin 18 on which cam follower 14 is mounted for oscillatory movement, as explained above. Pivot means 18 defines a first axis about which cam follower 14 oscillates, and it will be understood that the position of pivot pin 18 depends on the position of carrier 11 which is dilferent when follower arm 12 engages recess 8' or the circular periphery of cam 8.

Fulcrum lever 19 has an arm 21 with a fulcrum pin 20 cooperating with an abutment fon cam follower 14 formed by a bent over rectangular projection 17. FIG. 5a, for example, shows the abutment projection 17 in broken lines in a position abutting fulcrum pin 20 on fulcrum lever 19. FIG. 5a also shows projecting pin 16 constituting a motion transmitting element by which the oscillatory movement of cam follower 14 is transmitted to oscillatable member 26, of the motion transmitting means by which cam follower 14 is connected with the needle bar assembly and needle. It will be seen that projecting pin 16 is spaced a shorter distance from fulcrum pin 20 than from pivot pin 18.

Fulcrum lever 19 has a projection provided with a hole 22 into which a coil spring 52 is hooked. The other end of the coil spring is secured to the casing of the machine, as `best seen in FIG. 3, so that fulcrum lever 19 is urged to a position in which cam follower arm 22 abuts control cam 9. As explained above, spring 36 biases the needle bar assembly, and a motion transmitting means connecting the same with cam follower 14 so that pressure is exerted by part 30 of

oscillatable member

26, 30 on pin 16 to urge pin 15 against drive cam S, while pivot means 18 is urged to turn carrier lever 11 in clockwise direction to a position in which cam follower arm 12 abuts the periphery of control cam 8.

As shown in FIGS. 2 and 4, shaft 32 carries a feed control cam 46 which has a hub portion secured by a screw to control shaft 32. A feed control lever 47 is mounted on shaft 7 for turning movement and is held in position by a resilient split ring 47. Feed control lever Cil 47 has a cam follower projection 48 cooperating with feed contnol cam 46, and an end portion connected by a link 50 to feed adjusting and reversing means 49 pivotally mounted on a pivot 51 carried by a frame portion 73 of the machine casing 1.

Feed control cam 46 has three cam portions for turning the lfeed adjusting means 49 to a first position in which the material is forward fed, a second position in which the material is fed in the reverse direction, and a third position in which the material is not fed. Feed control cam 46 is mounted on shaft 32 in a predetermined angular relation to control

cams

8 and 9 and to

indicia

61, 62, 63 on control knob 33.

Operation Vhen the operator sets knob 33 to a position in which indicia 61 referring to the stitches on the left side of the buttonhole is placed opposite mark 33', control cam 8 is placed in the position shown in FIG. 5a in which recess 8' is located opposite cam follower a-rm 12 of carrier means 11 which is located in recess 8 of cam 8. Cam follower arm 22 of fulcrum means 19 is located on the circular periphery of cam 9 spaced from projection 9'. As long as cam follower arm 12 is located on the circular periphery of control cam 8, as shown in FIG. 6a, carrier means 11 is in a normal position in which the axis of pivot means 18 is in the position N. IHowever, since in the position of FIG.5a, cam lfollower arm 12 is located in recess 8', the axis of pivot means 18 is shifted to the position L so that cam follower means 14 is correspondingly displaced. When drive cam S is in the position of FIG. 5a, the needle is at the point 5c in FIG. Sa.

Due to the fact that cam follower means 14 with abutment 17 is displaced to the left as viewed in FIG. 5, while fulcrum means 19 with fulcrum pin 20 remains in the same position, abutment 17 is in contact with fulcrum pin 20' so that cam lfollower ymeans 14 does not oscillate about pivot means 18 but oscillates about the fulcrum provided by pin 20 and abutment 17. Since pin 16 is spaced a small `distance from the axis M provided by fulcrum pin 20, it moves a small distance, corresponding to small stitches on the left side of the buttonhole as shown in FIG. 8a. During such oscillation, pivot means 18 is oscillated together with carrier means 11 whose cam follower arm 12 rises from control cam 8 in the position in which the lowest portion of drive cam 5 is effective, and this raised position is shown in FIG. 5b. The small oscillating motion of pin 16 is transmitted by motion transmitting means to the needle bar assembly and needle, as described above.

At the same time, feed control cam 46 is placed in a position in which the feed adjusting lmeans 49 are set to forward -feed so that a row of small stitches on the left side of the buttonhole is made, as shown in FIG. 8.

When the row of stitches has reached the end of the buttonhole, the operator turns control knob 3-3 to a position in which indicia 62 representing bar tack stitches is located opposite mark 33'. Control cam 8 is turned to a position in which cam follower arm 12 of carrier means 11 is located on the circular periphery of control cam 8 as shown in FIG. 6a. However, control cam 9 is not yet in the position of FIG. 6a, but still in the position shown in FIG. 5a and 5b so that cam follower arm 22 of fulcrum means 19 rests on the circular portion of cont-rol cam 9.

In this position, carrier means 11 is turned counterclockwise so that pivot means 18 is moved to the right and its axis assumes the position N, while the abutment 17 is spaced from fulcrum -pin 20. Consequently, cam follower means 14 does not oscillate about fulcrum pin 20, but oscillates about pivot means 18. Since pin 16 is spaced a greater distance from pivot means 18 than from fulcrum pin 20, it moves in an oscillatory movement of greater amplitude, displacing the motion transmitting ymeans and the needle bar assembly with the needle correspondingly so that larger amplitude bar tack stitches are made from the point d to the point 5e in FIG. 8b. The starting point 5d is identical with the end point of the smaller stitches assumed by the needle in the position of FIG. 5b since the depth of recess 8 corresponds to the distance between the bottom of the recess and cam follower arm 12 in the position of FIG. 5b.

When

cams

8 and 9 are turned to the position for making bar tack stitches, feed control cam 46 is turned to a position for setting the feed adjusting means 49 in such a manner that the material is not fed so that the -bar tack stitches are superimposed.

The operator now turns control knob 33 to a position in which indicia 62 is located opposite mark 33 so that

control cams

8 and 9 yare turned to the position shown in FIG. 6a. Control cam 9 holds carrier means 11 in the normal position in which the axis of pivot means 1S is in the normal position N. However, since projection 9' of control cam 9 raises cam follower arm 22 of fulcrum means 19, fulcrum pin 20' is moved to the right into engagement with abutment 17, `and supports cam follower means 14 for oscillatory movement about the axis provided by the fulcrum 20. Consequently, projecting pin 16 oscillates over smaller amplitudes, and such movements are transmitted -by the -motion transmitting means to the needle bar assembly and needle to produce small amplitude stitches on the right side of the buttonhole, as shown in FIG. 8c.

At the same time, lfeed control cam 46 is placed in a position for setting the feeding means 49 to reverse feed so that the stitches are made in direction of the arrow in FIG. 8c.

When the operator places a control knob 33 again in the position in which indicia 62 indicates bar tack stitches, cam 8 is turned to a position in which its circular periphery is effective, and cam 9 is turned to a position in which its circular periphery is effective, las ldescribed above with reference to FIG. 8b, so that cam follower means 14 oscillates about pivot means 18 and pin 16 moves greater distances to cause the needle to move in large amplitude bar tack stitches closing the upper end of the buttonhole.

It is assumed that during these buttonhole stitching operations, amplitude adjusting knob 43 is in a selected position in which arm 44 with pin 45 in groove 39m has turned in portion 39 of link 38 to a position in which pin 40 on end portion 39 is located on guide surface 27 a selected distance from the pivot axis defined by journal 26a. If stitch amplitude adjustment knob 43 is turned to another position, the amplitude of both the lateral small stitches and the bar tack stitches is simultaneously adjusted. Setting cam is inoperative as long as knob 33 is turned to one of the positions represented by indicia 61, v62, 63, and setting lever 23 may assume a position resting on stop screw 29 shown in FIG. 7.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of zig-Zag sewing machines differing from the types described above.

While the invention has been illustrated and described as embodied in a buttonhole stitching device in which a cam follower oscillates about a first axis to make large amplitude bar tack stitches, and about a displaceable fulcrum for making small lateral stitches on the sides of a buttonhole, it is not intended to be limited to the details shown, since various ymodifications and structural changes may be made Without `departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various `applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalance of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. In a sewing machine, in combination, a buttonhole stitching device, comprising a drive cam; cam follower means cooperating with said drive cam and having an abutment; motion transmitting means actuated by said cam follower means and adapted to be connected with a needle for oscillating the same under the control of said cam follower means; carrier means supporting said cam follower means for oscillatory movement about a first axis spaced from said abutment; fulcrum means having a fulcrum cooperating with said abutment for supporting said cam follower means for oscillatory movement about a second axis; mounting means for mounting said carrier means for movement with said cam follower means between a normal position and a displaced position, and for mounting said fulcrum means for movement between a first position in which said fulcrum is spaced from said labutment in said normal position of said carrier means and engages the same in said displaced position, and a second position in which said fulcrum engages said abutment in said normal position of said carrier means; and control means having three positions for simultaneously moving said carrier means to said normal position and said fulcrum means to said first position so that said cam lfollower means oscillates about said first axis and the nedle makes long bar tack stitches, or said carrier means to said normal position and said fulcrum means to said second position so that said cam follower means oscillates about said fulcrum and the needle makes short stitches on one side of a buttonhole, or said carrier means to said displaced position and said fulcrum means to said first position so that said cam follower means oscillates about said fulcrum and the needle makes short stitches on the other side of the buttonhole.

2. A buttonhole stitching device according to claim 1, wherein said mounting means includes a support shaft supporting said fulcrum means and said carrier means for angular movement.

3. A buttonhole stitching device according to claim 1, wherein said carrier means has a first cam follower and said fulcrum means has a second cam follower; and wherein said control means include a manually turned cam shaft having first and second cams cooperating with said first and second cam followers for simultaneously moving said carrier means and said fulcrum means.

4. A buttonhole stitching device according to claim l, wherein said carrier means has a first cam follower and said fulcrum means has a second cam follower; wherein said mounting means includes a support shaft supporting said fulcrum means and said carrier means for angular movement; and wherein said control means include a manually turned cam shaft having first and second cams cooperating with said first and second cam followers for simultaneously moving said carrier means and said fulcrum means.

5. A buttonhole stitching device according to claim 1, wherein said motion transmitting means include an oscillatable member, and a projection on said cam follower means cooperating with said oscillatable member, said projection being spaced a greater distance from said first axis than from said abutment and said second axis.

6. A buttonhole stitching device according to claim 1, including a pivot means on said carrier means supporting said cam follower means for pivotal movement about said first axis.

7. A buttonhole stitching device according to claim 1, wherein said motion transmitting means include an oscillatable member, and a projection on said cam follower means cooperating with said oscillatable member, said projection being spaced a greater distance from said first axis than from said abutment and said second axis; wherein said carrier means has a first cam follower and said fulcrum means has a second cam follower; wherein said control means include a manually turned cam shaft having a first and second cams cooperating with said first and second cams followers for simultaneously moving said carrier means and said fulcrum means; and including a pivot means on said carrier means supporting said cam follower means for pivotal movement about said first axis.

8. A buttonhole stitching device according to claim 1, wherein said cam follower means is a cam follower lever mounted at one end for pivotal movement on said carrier means, having at the other end a cam engaging portion, having on one side a projecting pin cooperating with said motion transmitting means and on the other side a projecting portion forming said abutment, said projecting portion being closer to said one end, and said pin being closer to said other end.

9. A buttonhole stitching device according to claim 8, wherein said fulcrum means is a fulcrum lever located adjacent said cam follower lever on said other side of the same and having a fulcrum pin cooperating with said projecting portion of said cam follower lever to support the latter for rocking movement about said second axis.

10. A buttonhole stitching device according to claim 9, wherein said carrier means is a carrier lever; and including pivot means connecting one end of said carrier lever with said one end of said cam follower lever; and wherein said mounting means include a support shaft supporting said carrier lever and said fulcrum lever.

11. In a sewing machine, in combination, a buttonhole stitching device comprising a rotary drive cam; cam follower means having one end portion cooperating with said drive cam, another end portion having a bore, an abutment intermediate said end portions, and a motion transmitting element intermediate said abutment and said one end portion; motion transmitting means actuated by said motion transmitting element of said cam follower means and adapted to be connected with a needle for oscillating the same under the control of said cam follower means; an angular carrier lever having an apex portion turnably supported on said support shaft, a first arm having a pivot means located in said bore of said cam follower means and supporting the same for oscillatory movement about a first axis, and a cam follower arm; an angular fulcrum lever having an apex portion supported on said support shaft for turning movement, a first arm having a fulcrum pin cooperating with said abutment for supporting said cam follower means for oscillatory movement about a second axis, and having a second cam follower arm, said carrier lever being supported on said support shaft for angular movement with said cam follower means between a normal position and a displaced position in which said pivot means and first axis are displaced, and said fulcrum lever being supported on said support shaft for angular movement between a first position in which said fulcrum pin is spaced from said abutment in said normal position of said carrier lever and engages the same in said displaced position, and a second position in which the fulcrum pin engages said abutment in said normal position of said carrier lever; and control means including a manually turnable shaft having three angular positions, and two control cams fixed thereon and respectively co operating with said cam follower arms of said carrier lever and of said fulcrum lever for simultaneously moving said carrier lever to said normal position and said fulcrum lever to said first position so that said cam follower means oscillate about said first axis and the needle makes long bar tack stitches, or said carrier lever to said normal position and said fulcrum lever to said second position so that said cam follower means oscillates about said fulcrum pin and the needle makes short stitches on one side of a buttonhole, or said carrier lever to said displaced position and said fulcrum lever to said first position so that said cam follower means oscillates about said fulcrum pin and the needle makes short stitches on the other side of the buttonhole.

12. A buttonhole stitching device according to claim 11, including a setting lever connected with said motion transmitting means for setting the needle bar assembly between three field positions; and a setting cam mounted on said control shaft and cooperating with said setting lever in angular positions of said control shaft in which said two control cams are not effective.

13. A buttonhole stitching device according to claim 12, and including a manually operated knob on said control shaft having three indicia associated with three field positions of the needle, and three indicia associated with lateral and bar tack stitches of a buttonhole.

14. A buttonhole stitching device according to claim 11 wherein said control cam cooperating with said carrier lever has a peripheral recess for placing said carrier lever in said displaced position; and wherein said control cam which cooperates with said fulcrum lever has a projection for placing said fulcrum lever in a position for making short stitches on the right side of a buttonhole.

15. A buttonhole stitching device according to claim 11 wherein said motion transmitting means include means for adjusting the stitching amplitude, and including manually operated means for adjusting said means to vary the stitch amplitude ofthe buttonhole stitches made under control of said cam follower means.

16. A buttonhole stitching device according to claim 11 wherein said motion transmitting means include an oscillatable lever having a projection; and wherein said motion transmitting element of said cam follower means is a projection cooperating with said projection of said oscillatable lever.

References Cited UNITED STATES PATENTS 3,247,817 4/1966 Eguchi 112-158 RICHARD I. SCANLAN, IR., Primary Examiner.

Claims

1. IN A SEWING MACHINE, IN COMBINATION, A BUTTONHOLE STITCHING DEVICE, DEVICE, COMPRISING A DRIVE CAM; CAM FOLLOWER MEANS COOPERATING WITH SAID DRIVE CAM AND HAVING AN ABUTMENT; MOTION TRANSMITTING MEANS ACTUATED BY SAID CAM FOLLOWER MEANS AND ADAPTED TO BE CONNECTED WITH A NEEDLE FOR OSCILLATING THE SAME UNDER THE CONTROL OF SAID CAM FOLLOWER MEANS; CARRIER MEANS SUPPORTING SAID CAM FOLLOWER MEANS FOR OSCILLATORY MOVEMENT ABOUT A FIRST AXIS SPACED FROM SAID ABUTMENT; FULCRUM MEANS HAVING A FULCRUM COOPERATING WITH SAID ABUTMENT FOR SUPPORTING SAID CAM FOLLOWER MEANS FOR OSCILLATORY MOVEMENT ABOUT A SECOND AXIS; MOUNTING MEANS FOR MOUNTING SAID CARRIER MEANS FOR MOVEMENT WITH SAID CAM FOLLOWER MEANS BETWEEN A NORMAL POSITION AND A DISPLACED POSITION, AND FOR MOUNTING SAID FULCRUM MEANS FOR MOVEMENT BETWEEN A FIRST POSITION IN WHICH SAID FULCRUM IS SPACED FROM SAID ABUTMENT IN SAID NORMAL POSITION OF SAID CARRIER MEANS AND ENGAGES THE SAME IN SAID DISPLACED POSITION, AND A SECOND POSITION IN WHICH SAID FULCRUM ENGAGES SAID ABUTMENT IN SAID NORMAL POSITION OF SAID CARRIER MEANS; AND CONTROL MEANS HAVING THREE POSITIONS FOR SIMULTANEOUSLY MOVING SAID CARRIER MEANS TO SAID NORMAL POSITION AND SAID FULCRUM MEANS TO SAID FIRST POSITION SO THAT SAID CAM FOLLOWER MEANS OSCILLATES ABOUT SAID FIRST AXIS AND THE NEDLE MAKES LONG BAR TACK STITCHES, OR SAID CARRIER MEANS TO SAID NORMAL POSITION AND SAID FULCRUM MEANS TO SAID SECOND POSITION SO THAT SAID CAM FOLLOWER MEANS OSCILLATES ABOUT SAID FULCRUM AND THE NEEDLE MAKES SHORT STITCHES ON ONE SIDE OF A BUTTONHOLE, OR SAID CARRIER MEANS TO SAID DISPLACED POSITION AND SAID FULCRUM MEANS TO SAID FIRST POSITION SO THAT SAID CAM FOLLOWER MEANS OSCILLATES ABOUT SAID FULCRUM AND THE NEEDLE MAKES SHORT STITCHES ON THE OTHER SIDE OF THE BUTTONHOLE.