US3693563A

US3693563A - Ornamental cam selecting device for zig zag sewing machine

Info

Publication number: US3693563A
Application number: US100675A
Authority: US
Inventors: Noboru Kasuga
Original assignee: Janome Sewing Machine Co Ltd
Current assignee: Janome Corp
Priority date: 1969-12-26
Filing date: 1970-12-22
Publication date: 1972-09-26
Anticipated expiration: 1989-09-26
Also published as: DE2063561A1

Abstract

A cam selecting device comprising a plurality of ornament cams packed in a row, a cam follower provided opposite to the ornament cams and shiftable along the cams, a selecting cam for shifting the cam follower along the ornament cams, and a rack mechanism for releasably securing the cam follower in any predetermined positions along the ornament cams so that precise cam selecting relation of the constituent parts may be established to obtain correct ornamental zigzag stitches.

Description

United States Patent Kasuga [451 Sept. 26, 1972 ORNAMENTAL CAM SELECTING DEVICE FOR ZIG ZAG SEWING MACHINE [72] Inventor: Noboru Kasuga, Kamiichibun-Kata- Machi, Japan [73] Assignee: Janome Sewing Machine Co., Ltd.

[22] Filed: Dec. 22, 1970 [2]] Appl. No.:' 100,675

[30] Foreign Application Priority Data Dec. 26, 1970 Japan ..44/123000 Dec. 26, 1970 Japan "44/123001 [52] U.S.Cl. ..1l2/158A [51] Int. Cl. ..D05b 3/04 [58] Field ofSearch ..1l2/15,8 R, 158 A, 158D [5 6] References Cited UNITED STATES PATENTS 3,064,602 11/1962 Danno 142 1 5 3,435,788 4/1969 Fresgard etal. ..ll2/l58A Primary Examiner-Patrick D. Lawson Attorney-Michael S. Striker [5 7] ABSTRACT A cam selecting device comprising a plurality of ornament cams packed in a row, a cam follower provided opposite to the ornament cams and shiftable along the cams, a selecting cam for shifting the cam follower.

along the ornament cams, and a rack mechanism for releasably securing the cam follower in any predetermined positions along the ornament cams so that precise cam selecting relation of the constituent parts may be established to obtain correct ornamental zigzag stitches.

11 Claims, 11 Drawing Figures PATENTEDSEPZB m2 sum u or g 'mvsmgpa #060 AM 0514 ORNAMENTAL CAM SELECTING DEVICE FOR ZIG ZAG SEWING MACHINE BACKGROUND OF THE INVENTION The invention relates to general zigzag sewing machines, and more particularly to an ornament cam selecting device for a zigzag sewing machine, in which a cam follower connected to the stitching mechanism of sewing machine is operated by means of a selecting cam to establish a given relation with respect to a series of ornament cams respectively defining ornamental zigzag stitches, and such a relation is maintained and varied by means of the same selecting cam.

In a zigzag sewing machine, it is natural that omament cams are used to determine the respective ornamental zigzag stitches and a single cam follower or cam followers may be used for operation in engagement with the respective ornament cams. In such a sewing machine, since the numbers and kinds of ornamental stitches are determined by those ornamental cams to be mounted in the sewing machine, it will be quite natural that provision of as many ornament cams as possible may be desires. However the machine am is not so spacious as to accommodate so many numbers of ornament cams unless the ornament cams are each made thinner as much as possible. If the ornament cams are made thinner, the cam follower or cam followers will have to be accordingly made thinner because a cam follower which is thicker than the ornament cams or which is in an inexact position with respect to the selected cam will engage more than the selected cam, and accordingly the ornamental stitches to be obtained will be different and diverged from the predetermined ones. However, reduction in the thickness of the ornament cams and cam follower must be limited. On the other hand, if the ornament cam selecting device is made up more precise it will be natural that the cost will be higher. Especially if the cam follower is made up thinner below a certain limitation, wear at the cam follower will greatly increase and, in effect, endurance will be lowered due to its relative engagement with the ornament cams. Moreover the cam follower may be broked or bent during its operation.

The fundamental object of the present invention is to eliminate the abovementioned disadvantages. Namely the object of the invention is to provide an ornament cam selecting device in which a cam follower will select any desired ornament cams by means of a selecting device without any higher precision. According to the present invention the cam follower is operated in the successive steps to be positioned for engaging a selected ornament cam. In the first step the cam follower is subjected to substantially rough displacement and in the second step it is subjected to precise positioning. Accordingly the selecting cam for operating to displace the cam follower will not be required to have a high precision in its peripheral configuration, and a cam of lower precision will enough to operate the cam follower without any inconveniences. As for operating to precisely position the cam follower in the second step, a rack plate is used. The rack plate with its V shaped teeth will correctly secure the cam follower in a selected position.

Another object of the present invention is to provide a ornament cam selecting device which may be easily manufactured. As aforementioned, the selecting cam,

which required little precision for displacing the cam follower, will be easily manufactured. Such a selecting cam may be pressed out of a metal plate or other material with a little machining added. The rack plate for finally securing the cam follower in a predetermined position is substantially rectangular in form with V shaped teeth formed therein will also be easily manufactured, for example, in the same manner as the selecting cam may be. It is apparent that the rack plate, with its V shaped teeth, will accurately secure the ,cam follower in a predetermined positionrwith the selecting cam and rack plate being employed as such, the cam selecting device of the present invention will be very easily manufactured. Moreover the cam selecting device requires little precision machining, it will be manufactured at the lowest cost.

Still another object of the present invention is to provide a cam selecting device which is much durable almost permanently. Generally with respect to such a kind of device, wear is inevitable on the relative engaging parts. It is apparent that precisely finished cam will generally be unable to maintain the precision for a long time. The fact that the selecting cam according to the present invention requires little precision shows at the same time that even if the cam has been considerably weared, is still operable and may be used almost permanently as a member for displacing the cam follower. On the other hand, since the rack plate of the invention operates merely to position the cam follower by means of the V shaped teeth, the teeth will have little wear and the durability will be almost permanent. Accordingly, the cam selecting device of the present invention will be durable for a long time, almost permanently.

The preferred embodiments of the present invention will be clearly understood from the following description in reference to the attached drawings, in which:

FIG. 1. is a front elevational view of the cam selecting device for a zigzag sewing machine according to the present invention.

FIG. 2. is a side elevational view of the cam selecting device partly sectioned and viewed from numeral II in FIG. 1.

FIG. 3 is a vertical elevational section of the cam selecting device in FIG. 1. and taken along line III-III in FIG. 2.

FIG. 4. is a horizontal elevational view of the cam selecting device taken along line IV--lV in FIG. 3.

FIG. 5. is a vertical elevational section of the cam selecting device in FIG. 1 partly eliminated and taken along the plane defining the side surface of the cam follower disengaging carn in the present invention.

FIG. 6. is a vertical elevational section of the cam selecting device in FIG. 1 partly eliminated and taken along the plane defining the side surface of the cam follower displacing cam in the present invention.

FIG. 7. is an exploded perspective view of the cam selecting device according to the present invention.

FIG. 8. is anotherembodiment of the present invention partly eliminated and corresponding to the embodiment in FIG. 2. I

FIG. 9. is another embodiment of cam follower according to the present invention.

FIG. 10. is still another embodiment of the present invention corresponding to the embodiment in FIG. 3.

FIG. 1 1. is a horizontal elevational section of another embodiment of the present invention corresponding to the embodiment in FIG. 4.

Detail explanation of the invention:

In reference to FIGS. 1, 7 and 8, numeral 1 represents aU-shaped base member which is fixedly mounted at a set position in the sewing machine arm 80 by means of a fastening screw 79. The U shaped base member 1 is formed with a mount seat 1a depending from the lower wall at the forward end thereof. The U shaped base member 1 isalso formed with a gear seat 50, which may be fixedly mounted by means of fastening screws 60 60 in the inner part of the lower wall of the base member 1 at the bottom side thereof. The gear seat 50 is, as shown in the drawings, depending from the bottom side of the lower wall of the U-shaped member 1 and horizontally and externally bent at its intermediate portion to secure a vertical gear shaft 2 on the horizontal portion thereof.

On the gear shaft 2 an elastic seat washer 47 is mounted and then a gear memberis rotatably mounted. The gearmember is composed of gears 4 5 which are integrally and coaxially made up and held on the gear shaft 2 by means of a fastening screw 61 threaded into the gear shaft 2 at the top thereof. The

gears

4 and 5 are respectively adapted to engage a worm 59 on the drive shaft of the sewing machine and an ornament cam driving gear 6. Thus the rotationof the driving shaft of the sewing machine is transmitted to the cam driving gear 6 through the

gears

4 and 5 in a reduced speed.

In the U-shaped base member 1 there is provided a vertical cam shaft 3 spaced from and in parallel with the gear shaft 2. On the cam shaft 3 the cam driving gear 6 and a plurality of ornamentcams 7 are rotatably mounted in a packed state with the cam driving gear 6 being at the bottom thereof. As is well known, the cam driving gear 6 and the ornament cams 7 are united by means of a vertical pin 6a provided on the cam driving gear 6 and extending through the ornament cams 7 in parallel with the cam shaft 3 so that the cam driving gear 6 and the ornament cams 7 may be rotated in unison. On the top of the ornament cams 7 on the cam shaft 3, a compression spring 68 is placed and then a holding disc plate69 is positioned, and finally an elastic ring 70 is fitted in a groove 3a around the cam shaft 3 at the upper part thereof to rotationally hold the ornament cams 7 and the cam driving gear 6 on the cam shaft 3. Accordingly any or all ornament cams 7 on the cam shaft 3 may be exchanged at will by removing the elastic ring 70 from the cam shaft 3.

In the U-shaped base member 1, a vertical support shaft 8 is secured at the upper and lower ends thereof by means of fastening screws 62 62 spaced from and in parallel with the cam shaft 3. On the support shaft 8, a U-shaped swing frame 9 is swingably mounted together with a washer 81 which is placed between the lower wall of the swing frame 9 and the lower wall of the U- shaped base member 1. On the support shaft 8 a cam follower 10 is at its intermediate portion pivotally mounted together with a compression spring 38 between the opposite walls of the U-shaped swing.

frame 9 with the compression spring 38 being placed between the cam follower 10 and the lower wall of the U-shaped swing frame 9.

The cam follower 10 is also slidable axially along the support shaft 8. The cam'follower 10 is at one end formed with a cam'engaging portion 1 1 and at the other end formed with a recessed portion 41. In the U-shaped swing frame 9, a vertical guide shaft 13 is secured spaced from and in parallel with the support shaft 8 by means of upper and lower. fasteningscrews 63 63. The guide shaft 13 is engaged by the recessed end 41 of the cam follower 10 to positively guide the cam follower when it axially slides on the support shaft 8. At the same time the guide shaft 13 is adapted to transmit the swinging movement of the cam follower 10 to the U- shaped swing frame 9 in accordance with the peripheral configuration of any selected one of the ornament cams 7 which is engaged by the cam engaging end 1 1 of the cam follower 10.

On the side wall of the U shaped swing frame 9, L-

shaped plate 75 and plate 76 are secured in a superposed state by meansof fastening screws 64 64. The L- shaped plate 75'has a depending cam engaging end 45 which .is adapted to engage a cam 14 as will be described hereinafter. The plate v76 has a vertical engaging edge 42 which is adapted to engage a roller 44 on a U-shaped swing body '12 as will be described hereinafter.

On the aforementioned depending mount seat la a pin 16 is mounted horizontally extending therefrom. On the pin '16 a bloc 15 is turnably mounted at the lower end thereof for changing a needle position. The bloc 15 is formed with a bore 15a spaced from the lower base portion thereof. a

The U-shaped swing body 12 is fitted over the bloc 15 and is swingably secured thereon by'means of a pivot pin 17 extending through the opposite walls of the U-shaped swing body 12 and also through the bore 15a of the bloc 15. The pivot pin 17 is fastened there and prevented from the axial movement by means of a fastening screw threaded into the bloc 15 at one side thereof. On the upper part of the bloc 15 a screw 55 having an engaging end 55a is threaded into from the opposite side thereof and is fastened there by means of a fastening screw 56 threaded into the bloc 15 at the top thereof. 7

In the U-shaped base member 1 a U-shaped support frame 48 is secured on the upper wall thereof spaced from the U-shaped swing frame 9 by means of fastening screws 66 66. On the opposite walls depending from the U-shaped support frame 48 a transverse shaft 26 is supported across the machine arm 80. A coil spring 57 is at one end hung to the neck of the fastening screw 56 on the top of the bloc l5 and the other end anchored to the transverse shaft 26 to urge the bloc 15 in the clockwise direction around the pin 16 so that the screw 55 having the engaging end 55a will always engage a needle position changing cam not shown with the engaging end thereof.

The U-shaped swing body 12 is formed with an extension on the front wall thereof, in which a vertical arcuate slot 18 is provided. As is well known, a pin 20 mounted on one end of a transmission rod 19 is engaged in the arcuate slot 18. The other end of the'transmission rod 19 is connected to the needle bar support not shown so that the swinging movement of the U- shaped swing body may be transmitted to the needle bar support.

On the upper part of the U-shaped swing body 12, a pin 43 is extended through the opposite side walls thereof to mount a roller 44 on the end protruded on the inner side wall of the U-shaped swing body 12. The roller 44 is heldthere and prevented from axial movement by means of a detaining washer 73 fitted to the groove provided around the protruded end of the pin 43. The pin 43 is prevented from axial movement by means of a fastening screw threaded into the top wall of the U-shaped swing body 12 and fastening the pin at as set position.

A coil spring 58 is at one end hung to a hole 12a provided in the upper part on the front wall of the U- shaped swing body 12 and at the other end anchored to the transverse shaft 26 to urge the U-shaped swing body 12 in the clockwise direction around the pivot pin 17 so that the roller 44 may contact the vertical engaging edge 42 of the plate 76 attached to the side wall of the U-shaped swing body 12 together with the L- shaped plate 75. The transverse shaft 26 is secured on the U-shaped support frame 48 by means of a fastening screw 67 threaded into the support frame 48 at the top thereof and engaging the recessed portion 26a of the transverse shaft 26 to fasten the same at a set position on the U-shaped support frame 48.

A torsion spring 51 is provided around the threaded stem portion of the fastening screw 67 protruded below the top wall of the U-shaped support frame 48. The torsion spring 51 at one end engages the vertical guide shaft 13 and at the other end engages the inner face of the front wall of the U-shaped support frame 48 to turn the U-shaped swing frame 9 in the clockwise direction around the vertical support shaft 8. However it is to be noted that the aforementioned coil spring is of force stronger than the torsion spring 51 and accordingly the U-shaped swing frame 9 is actually turned in the counterclockwise direction, so that the cam follower 10 may with its engaging end 11 engage, any selected one of the ornament cams 7.

On the transverse shaft 26, arm 28 and arm 39 are at their intermediate portions turnably mounted in an adjacent relation, and are connected together by means of a screw 78 which is inserted into a vertical elongated slot 28a at one end of the arm 28 and threaded into a threaded hole at one end of the arm 39, so that the relative angular positions of the two arms may be adjusted when necessary. The arm 39 is formed with a boss 39a at the intermediate portion thereof. Around the base 39a is mounted a torsion spring 27 which is of force stronger than the compression spring 38 acting on the cam follower 10. The torsion spring 27 with one end engages the opposite end of the arm 39 and with the other end is anchored to the inner face of the upper wall of the U-shaped support frame 48 to turn the arms 28 39 in the counterclockwise direction around the transverse shaft 26.

The arms 28 39 are turnably held on the transverse shaft 26 by means of a pair of holding washers 71 71 attached on the transverse shaft 26 on both sides of the arms 28 39 with a washer 100 of greater diameter being placed between the spring 27 and one of the holding washers 71 71. The arm 28 with the engaging end 28b is adapted to engage a cam as will be described hereinafter for displacing the cam follower 10. The arm 39 is provided at its operating end with pins 40 40a, and

is with the pin 40 adapted to engage a rack plate 35 as will be described hereinafter, and with the pin 40a adapted to press the central portion of the cam follower 10 with a force stronger than the compression spring 38 due to the torsion spring 27 acting on the arms 28 39.

The rack plate 35 is substantially L-shaped in cross section as shown in'FIGS. 4 and 7. The rack plate 35 is provided with V-shaped rack teeth at the vertical edge 35a of one wall and also provided with a transverse engaging projection 36 at the lower part of the other wall, and then secured on the vertical side wall of U-shaped support frame 49. The U-shaped support frame 49 is swingably supported on a vertical shaft 34 which is fixedly mounted in the U-shaped base member 1 spaced from and in parallel with the vertical support shaft 8 by means of an upper fastening screw 99. The lower portion of the vertical shaft 34 downwardly extending out from the lower wall of the U-shaped base member 1 is fitted into a receiving bore formed in the boss of the machine arm 80 and fixed there by means of worm screw 340 as particularly shown in FIG. 2. A washer 82 is placed on the vertical shaft 34 between the lower wall of the U-shaped support frame 49 and the lower wall of the U-shaped base member 1. A washer 54 is placed on the vertical shaft 34 just on the under side of the lower wall of the U-shaped base member 1.

Side by side with the fastening screw 99, a thrust adjusting screw 53 is threaded into the U-shaped base member 1 at the top wall thereof, the lower end of the thrust adjusting screw 53 is adapted to engage the upper wall surface of the U-shaped support frame 49. The thrust adjusting screw 53 is adjusted by means of a nut 530 with respect to the upper wall of the U-shaped base member 1 to have a given axial set position for adjusting the axial position of the U-shaped support frame 49 and accordingly the rack plate 35 attached thereto.

In the manner of the lower wall of the U-shaped support frame 49, there is provided a hole 49a, and on the edge of the vertical wall of the U-shaped base member 1 there is provided a recess 1d. A coil spring 37 is, at one end hung to the recess 1d and at the other end anchored to the hole 49a so that the U-shaped support frame 49 maybe turned in the clockwise direction. Thus any one of the V-shaped teeth 35a of the rack plate 35 provided on the vertical edge of one wall thereof will contact and maintain the pin 40 on the arm 39 accurately in the predetermined position.

On the upper wall of the U-shaped base member 1, there is provided a thrust adjusting screw 52 just in the same manner as the thrust adjusting screw 53. The lower end of the thrust adjusting screw 52 is adapted to engage the upper wall of the U-shaped swing frame 9. By adjusting the axial position of the screw 52 with respect to the upper wall of the U-shaped base member 1 by means of a fastening nut 52a, the axial position of the U-shaped swing frame 9 on the support shaft 8 may A cam shaft 22 is rotatably mounted transversely in the machine arm 80 between the U-shaped swing frame 9 and the transverse shaft 26 in parallel with the transverse shaft 26. A dial 210 is fixed on one end portion of the cam shaft extended out of the. machine arm 80 on the frontside thereof. On the cam shaft 22 there are coaxially secured a rack plate displacing cam 25 as shown in FIG. 4, a cam follower displacing cam 25 -as shown in. FIGS. 4 and 6, and a cam follower disengagingcam 14 as shown in FIG. 5.

The'rack plate displacing cam 25 has a central boss .74 and peripheral recesses and projections formed on the cam 25 and accordingly the cam shaft 22. from rotating from a set position. 7 v The cam follower displacing cam 25 has a peripheral cam face'which is to be engaged by the cam engaging end 28b .of the arm 28. The cam follower disengaging,

cam 14 has a peripheral camface-which is to be en- I gaged by the depending cam engaging free end 45 of the L-shaped arm 75.

As shown in FIGS. 3, 4, and 7,, a feed adjusting cam 24 issecured on the cam shaft 22 at the inner end thereof between the rack plate displacing cam and side wall through a roller 86 and a washer 87. The other end of the lever 32 is bent to provide a horizontal seat 89 which isconnected to a connection rod connected to the feed regulator not shown by means of a threaded rod 31 with a compression spring 91, a ball headed nut 90 and a washer 92 being inserted therebetween. A considerably elongated vertical slot 29 is provided in the side wall of the U-shaped base member 1 for inspecting the engaging relation between the cam engaging end 11 of the cam follower 10 and the ornament cams 7.

Operation of the invention:

When the drive shaft of sewing machine is driven, the ornament cams 7 will be rotated in a reduced speed around the cam shaft 3 through the

gearing

59, 4,5, 6. As the ornament cams 7 are rotated, the cam follower 10, with its engaging end 1 l engaging any selected one of the ornament cams 7, will swing around the vertical support shaft 8. The swinging movement of the cam follower 10 will swing the U-shaped swing frame 9 due to the engagement between the opposite recessed end 41 of the cam follower and the vertical guide shaft 13on the U-shaped swing frame 9. The swinging movement of the U-shaped swing frame 9 is transmitted to the U- shaped swing body 12 due to the engagement between the roller 40 on the U-shaped swing body 12 and the vertical engaging edge 42 of the plate 76 attached to the U-shaped swing frame 9 together with the L' shaped plate 75. The swinging movement of the U-shaped swing body 12 around the pivot pin 17 is in turn transmitted through the. transmission rod 19 to the needle bar support not shown to swing the needle bar transversely across the feeding direction of the feed device not shown The swinging amplitude may be varied as well known by means of the amplitude regulating device not shown handling of which will shift the pin 20 shown in FIG. 1 attached to one end of the transmission rod 19 along the vertical arcuate slot 18 of the U-shaped swing body 12 in which the pin is engaged. The pin 20 may be shifted'toward and away from the pivot pin 17 to vary the swinging amplitude of the needle bar.

The needle position may be varied as well known by means of a needle position regulating device not shown handling of which will vary the angular positions of the bloc 15 around the horizontal pivot pin 16 with the aforementioned transverse screw 55 being at its engaging end 55a engaged with the'needle position changing cam not shown).

When the specific one of ornamental cams'is to be selected, the dial 21a is rotated. With rotation of the dial 21a, the cam 14 displaces the L-shaped plate 75 to turn the U-shaped swing frame 9 around the vertical shaft 8 against the coil spring 58 in the clockwise direction. Accordingly the cam follower 10 is turned in the same direction together with the U-shaped frame 9 and the cam'engaging end 11 of the cam follower 10 is disengaged from the ornament cam with which it has been in engagement. FIG. 5

At the same time, the rack plate displacing cam 25, with one of its projections, turns the rack plate around the vertical shaft 34 against the coil spring 37 in the counterclockwise direction to disengage the V- shaped tooth of the rack plate 35 from the pin 40 at the end of the arm 39, (FIG. 4). Subsequently the cam follower displacing cam 23 turns the engaging arm 28 7 around the transverse shaft 26 against the spring 27in the clockwise direction. Thus the arm 39 is together with the arm 28 turned in the same direction, and substantially up and down movement of the pin 40 along the vertical rach teeth 35a is obtained depending upon the peripheral configuration of the cam 23.

With the subsequent engagement of the aforementioned transverse engaging projection 36 of the rack plate 35 with one of therecesses of the cam 25, the rack plate 35 returns to engage the pin 40 through the force of the coil spring 37, and then the pin 40 is fitted into one of the vertical V-shaped rach teeth 35a at its V-shaped opposite slopes thereof and finally the position of the pin 40 is accurately determined at the bottom part of the V-shaped slopes of the rack tooth 35a.

When the pin 40 on the arm 39 is to be displaced in f the upward direction along the vertical rack teeth 35a, the cam follower 10 is displaced upwardly on the vertical support shaft 8 by means of the upward force of the compression spring 38 coaxially mounted on the shaft 8 between the underside of the cam follower 10 and the lower wall of the U-shaped swing frame 9, and then the position of the cam follower 10 with respect to any one of the ornament cams 7 is determined by the position of the pin 40.

When the pin 40 on the arm 39 is displaced in the downward direction along the vertical rack teeth 35a depending upon the peripheral configuration of the cam 25, the pin 40 is so displaced by means of the torsion spring 27 which as aforementioned always applies a force stronger than the compression spring 38 to the arm 39 on the near part of the pin 40. Accordingly the cam follower is displaced in the same direction against the force of the compression spring 38 on the vertical shaft 8 along the ornament cams 7, since the pin 40a opposite to the pin 40 on the arm 39 is contacted on the upper central portion of the cam follower 10 by means of the torsion spring 27 as aforementioned. Thus the downward position of the cam follower 10 with respect to each of the ornament cams 7 is determined by the position of the pin 40 fitted into one of the rack teeth 35a of the rack plate 35.

Thus in the present invention, positioning of the cam follower is substantially accomplished merely by setting the pin 40 to a predetermined position. Accordingly it is clear that the cam follower displacing cam will require little precision when it is produced, however,

that it will accomplish an accurate positioning of the cam follower together with use of the rack plate which is also easy in production and precise in holding the pin in a set position.

Further, even if the cam 23 has got wear, will give no substantial influence on setting the cam follower. On the other hand, the V-shaped rack teeth of the rack plate will get little wear in view of the function it performs heretofore described. Thus the cam selecting device of the present invention will be of lower cost and also of almost permanent use. 7

Another embodiment of the present invention is shown in FIGS. 8 and 9, in which a part of the cam follower displacing structure is a little different from the first embodiment as shown in FIGS. 1 to 7. Namely the cam follower 10 is at its central portion formed with a pair of opposite flanges 72 72 to provide a groove therearound between the flanges. As shown in FIG. 8, the pin 40 which has been described in reference to FIGS. 1 to 7 is fitted into the groove between the flanges 72 72 to displace the cam follower 10 along the vertical shaft 8 substantially in the same manner as has been described in reference to FIGS. 1 to 7. However in this embodiment, it is apparent that the compression spring 38 may be eliminated since the cam follower 10 is directly displaced by the pin 40.

Still another embodiment of the present invention is shown in FIGS. 10 an 11, in which instead of the cam 14 for disengaging the cam follower 10 from one of the ornament cams 7, a disk 94 is provided on the transverse cam shaft 22. On the lower wall of the U-shaped base member 1 a lever 93 is at its intermediate portion pivotally mounted on a pivot pin 96 between the U- shaped swing frame 9 and the disk 94. One arm 95 of the lever 94 engages a pin depending from the lower wall of the U-shaped swing frame 9 due to the coil spring 58 and is usually turned in the clockwise direction and the other arm 92 is contacted to one side face of the disk 94. Further instead of the rack plate displacing cam 25, a disk 98 is provided on the transverse cam shaft 22. The disk 98 is with its one side face adapted to engage the aforementioned transverse engaging projection 36 of the rack plate 35. In this embodiment, the transverse cam shaft 22 is rotatable and axially displacable. A compression spring 97 is mounted around the cam shaft 22 on the end portion extended out of the front wall of the machine arm 80 between the front wall and the dial 21a. The compression spring 97 usually urges the cam shaft 22 in the direction forwardly of wall of the machine arm 80.

\ OPERATION OF THE EMBODIMENT When the dial 21a is pushed inward in the direction as indicated by the arrow, and then rotated, the disk 94 turns the lever 93 around the pin 96 against the coil spring 58 in the counterclockwise direction thereby to turn the U-shaped swing frame 9 in the clockwise direction, so that the engaging end 11 of the cam follower 10 may be disengaged from one of the ornament cams 7. At the same time, the disk 98 pushes the transverse engaging projection 36 of the rack plate 35 to turn the rack plate 35 against the coil spring 37 in the counterclockwise direction around the vertical support shaft 34, so that one of the V-shaped rack teeth 35a of the rack plate 35 may be disengaged from the pin 40 on the arm 39.

In this state, the dial 21a is rotated as abovementioned, the cam follower displacing cam 23 on the transverse cam shaft 22 will turn the arm 28 together with the connected arm 39 against the torsion spring 27 in the clockwise direction, in effect to displace the pin 40 on the arm 39 along the vertical V-shaped rack teeth 35a of the rack plate 35 in the same manner as described hereinbefore in reference to the first embodiment in FIGS. 1 l to 7. After that the dial 210 is released, the rack plate 35 returns to engage the pin 40 with one of the V-shaped rack teeth 35a to accordingly position the same in a predetermined position in the same manner as described hereinbefore.

Iclaim:

1. An ornament cam selecting device for a zigzag sewing machine having a machine arm, a drive shaft longitudinally journalled in said machine arm, and a needle bar support, comprising: a cam shaft, a plurality of ornament cams rotationally mounted on said cam shaft and rotated from said drive shaft, a support shaft in parallel with said carn shaft, a cam follower pivotally mounted on said support shaftand axially displacable to selectively engage said ornament cams, a transmission rod for transmitting the swinging movement of said cam follower to said needle bar support in accordance with the peripheral configuration of a given ornament cam, means for disengaging said cam follower from any of said ornament cams, a cam for axially displacing said cam follower on said support shaft, an actuating arm member turnably mounted in said machine arm and adapted to be turned off by said cam, said actuating arm member and said cam follower being connected to move in unison with each other, a pin secured on one end of said actuating arm member, a rack plate turnably mounted in said machine arm and having V- shaped teeth formed thereon for releasably holding said pin, means for turning said rack plate, said first and second means being secured on an operating shaft having an operating knob so that with manual operation of said knob, said first means may disengage said cam follower from any of said ornament cams and simultaneously said second means may turn said rack plate to release said pin on said actuating arm member whereby said cam may operate said actuating arm member to turn the same for positioning said pin, and finally said second means may operate said rack plate to hold said pin with one of said V-shaped teeth in a predetermined position together with said cam follower which is displaceable in unison with said actuating arm member.

' 2. 'An ornament cam selecting device for a zigzag sewing machine according to claim 1, comprising; a swing frame having said support shaft and a guide'shaft mounted thereon in parallel with each other, said cam follower being pivotally mounted on said support shaft, said cam follower engaging any of said ornament cams with one end thereof and engaging said guide shaft with the opposite end thereof to transmit to said swing frame the swinging movement of said cam follower in accordance with the peripheral configuration of a' given ornament cam, a compression spring mounted on said support shaft for elastically displacing said cam follower in the axial directionof said support shaft, said pin on said actuating arm member being in engagement with said cam follower, said pinbeing releasably held by one of said V-shaped teeth of said rack plate so that said cam follower may be held in a predetermined position in accordance with the positionin which said pin is held, and said cam follower being elastically displaced by said compression spring in the axial direction of said support shaft in accordance with the set position of said pin. I

3.. An ornament cam selecting device for a zigzag sewing machine according to claim 1 wherein said cam follower is at one end formed with a cam engaging portion for engaging one of said ornament cams and at the opposite end formed with a recess for engaging said guide shaft to transmit to said swing frame the swinging movement of said cam follower in accordance with the peripheral configuration of any of said ornament cams, said cam follower being at its central portion formed with a pair of flanges to provide a groove therebetween, wherein said pin onisaid actuating arm member being in engagement with said groove, and wherein said cam engaging said actuating arm member for axially displacing said cam follower on said support shaft.

4. An ornament cam selecting device for a zigzag sewing machine according to claim 1 whereinia cam may be employed forsaid means for disengaging said cam follower from any of said ornament cams.

5. An ornament cam selecting device for a zigzag sewing machine according to claim 1 wherein a disc may be employedfor said means for disengaging said cam follower from any of said ornament cams.

6. An ornament cam selecting device for a zig-zag sewing machine according to claim 1 wherein a cam justably connected to said actuating arm member in a may be employed for said means for turning said rack plate.

7; An ornament cam selecting'device for a zigzag sewing machine according to claim 1 wherein a disc may be employed for said means for turning said rack plate. 7 a

8. An ornament cam selecting device for a zigzag sewing machine according to claim 1 comprising another arm member having an engaging end and adsuperposed state, said arm member engaging said cam with said engaging end thereof so thatthe movement of said arm member caused by said cam may be trans initted to said actuating arm member.

9. An ornament cam selecting device for a zigza sewing machine according to claim 1 wherein said rack plai is mounted on a U-shaped swingable support, said rac plate having atransverse engaging pro ection formed thereon for engaging said means for turning said rack plate.

10. An ornament cam selecting device for a zigzag sewing machine according to claim 1 said supporting shaft and said guiding shaft are mounted on a swing frame, wherein said cam follower is pivotally mounted on said support shaft .and is slidable in the axial direction on said support shaft, said cam follower having'a cam' engaging portion formed at one end thereof for engaging any of said ornament cam and havinga recess formed at the other end thereof for engaging said guide shaft, said swing frame being U-shaped and having a L-shaped plate and an elongated plate attached thereto in a superposed state, said L-shaped plate having a depending engaging end for engaging swing frame, said swing body and said rack plate being each disposed in said U-shaped base member, said gearing means transmitting the rotation of said drive shaft to said ornament cams in a reduced speed.

Claims

1. An ornament cam selecting device for a zigzag sewing machine having a machine arm, a drive shaft longitudinally journalled in said machine arm, and a needle bar support, comprising: a cam shaft, a plurality of ornament cams rotationally mounted on said cam shaft and rotated from said drive shaft, a support shaft in parallel with said cam shaft, a cam follower pivotally mounted on said support shaft and axially displacable to selectively engage said ornament cams, a transmission rod for transmitting the swinging movement of said cam follower to said needle bar support in accordance with the peripheral configuration of a given ornament cam, means for disengaging said cam follower from any of said ornament cams, a cam for axially displacing said cam follower on said support shaft, an actuating arm member turnably mounted in said machine arm and adapted to be turned off by said cam, said actuating arm member and said cam follower being connected to move in unison with each other, a pin secured on one end of said actuating arm member, a rack plate turnably mounted in said machine arm and having V-shaped teeth formed thereon for releasably holding said pin, means for turning said rack plate, said first and second means being secured on an operating shaft having an operating knob so that with manual operation of said knob, said first means may disengage said cam follower from any of said ornament cams and simultaneously said second means may turn said rack plate to release said pin on said actuating arm member whereby said cam may operate said actuating arm member to turn the same for positioning said pin, and finally said second means may operate said rack plate to hold said pin with one of said V-shaped teeth in a predetermined position together with said cam follower which is displaceable in unison with said actuating arm member.

2. An ornament cam selecting device for a zigzag sewing machine according to claim 1, comprising ; a swing frame having said support shaft and a guide shaft mounted thereon in parallel with each other, said cam follower being pivotally mounted on said support shaft, said cam follower engaging any of said ornament cams with one end thereof and engaging said guide shaft with the opposite end thereof to transmit to said swing frame the swinging movement of said cam follower in accordance with the peripheral configuration of a given ornament cam, a compression spring mounted on said support shaft for elastically displacing said cam follower in the axial direction of said support shaft, said pin on said actuating arm member being in engagement with said cam follower, said pin being releasably held by one of said V-shaped teeth of said rack plate so that said cam follower may be held in a predetermined position in accordance with the position in which said pin is held, and said cam follower being elastically displaced by said compression spring in the axial direction of said support shaft in accordance with the set position of said pin.

3. An oRnament cam selecting device for a zigzag sewing machine according to claim 1 wherein said cam follower is at one end formed with a cam engaging portion for engaging one of said ornament cams and at the opposite end formed with a recess for engaging said guide shaft to transmit to said swing frame the swinging movement of said cam follower in accordance with the peripheral configuration of any of said ornament cams, said cam follower being at its central portion formed with a pair of flanges to provide a groove therebetween, wherein said pin on said actuating arm member being in engagement with said groove, and wherein said cam engaging said actuating arm member for axially displacing said cam follower on said support shaft.

4. An ornament cam selecting device for a zigzag sewing machine according to claim 1 wherein a cam may be employed for said means for disengaging said cam follower from any of said ornament cams.

5. An ornament cam selecting device for a zigzag sewing machine according to claim 1 wherein a disc may be employed for said means for disengaging said cam follower from any of said ornament cams.

6. An ornament cam selecting device for a zig-zag sewing machine according to claim 1 wherein a cam may be employed for said means for turning said rack plate.

7. An ornament cam selecting device for a zigzag sewing machine according to claim 1 wherein a disc may be employed for said means for turning said rack plate.

8. An ornament cam selecting device for a zigzag sewing machine according to claim 1 comprising another arm member having an engaging end and adjustably connected to said actuating arm member in a superposed state, said arm member engaging said cam with said engaging end thereof so that the movement of said arm member caused by said cam may be transmitted to said actuating arm member.

9. An ornament cam selecting device for a zigzag sewing machine according to claim 1 wherein said rack plate is mounted on a U-shaped swingable support, said rack plate having a transverse engaging projection formed thereon for engaging said means for turning said rack plate.

10. An ornament cam selecting device for a zigzag sewing machine according to claim 1 said supporting shaft and said guiding shaft are mounted on a swing frame, wherein said cam follower is pivotally mounted on said support shaft and is slidable in the axial direction on said support shaft, said cam follower having a cam engaging portion formed at one end thereof for engaging any of said ornament cam and having a recess formed at the other end thereof for engaging said guide shaft, said swing frame being U-shaped and having a L-shaped plate and an elongated plate attached thereto in a superposed state, said L-shaped plate having a depending engaging end for engaging said cam follower disengaging means and said elongated plate having a vertical engaging edge for engaging a roller provided on a swing body which is adapted to receive the swinging movement of said cam follower through said swing frame.

11. An ornament cam selecting device for a zigzag sewing machine according to claim 1 further comprising a U-shaped base member secured in said machine arm and gearing means provided in said machine arm between said drive shaft and said ornament cams, wherein said ornament cams, said cam follower, said swing frame, said swing body and said rack plate being each disposed in said U-shaped base member, said gearing means transmitting the rotation of said drive shaft to said ornament cams in a reduced speed.