US2900837A - Device for the adjustment of decorative stitch stencil in automatic zig-zag sewing machines - Google Patents

Description

Aug. 25, 1959 K. BRANDT 2,900,837,

DEVICE FOR THE ADJUSTMENT 0F DECORATIVE STITCH STENCIL IN AUTOMATIC ZIG-ZAG SEWING MACHINES Flled Jan 14, 1957 5 Sheets-Sheet 1 IN V EN TOR. KURT BRANDT A #0 meys Aug. 25, 1959 K. BRANDT 2,900,337

DEVICE FOR THE ADJUSTMENT OF DECORATIVE STITCH STENCIL IN AUTOMATIC ZIG-ZA Filed Jan. 14, 1957 G SEWING MACHINES 5 Sheets-Sheet 2 Fig. 2

INVEN TOR.

K UR T BRA ND 7' Ahorneys Aug. 25, 1959 K. BRANDT 2,900,837

- DEVICE FOR THE ADJUSTMENT OF DECORATIVE STITCH STENCIL IN AUTOMATIC ZIG-ZAG SEWING MACHINES Filed Jan. 14, 1957 5 Sheets-Sheet 3 Fig.6

INVENTOR. KURT BRANDT A flameys Aug. 25, 1959 K. BRANDT 2,90

DEVICE FOR THE ADJUSTMENT OE DECORATIVE STITCH STENCIL IN AUTOMATIC ZIG-ZAG SEWING MACHINES Filed Jan. 14, 1957 5 Sheets-Sheet 4 INVENTOR. I KURT BRANDT BY P t A Nor/keys Aug. 25, 1959 K. BRANDT 2,900,837 7 DEvTcEFoR THE ADJUSTMENT 0F DECORATIVE STITCH Y STENCIL IN AUTOMATIC ZIG-ZAG SEWING MACHINES Filed Jan. 14, 1957 5 Sheets-Sheet 5 IN V EN TOR.

KURT BRANDT BY r DEVICE FOR THE ADJUSTMENT OF DECORATIVE STITCH STENCIL 1N AUTOMATIC ZIG-ZAG SEWING MACHINES Kurt Brandt, Augsburg, Germanyv Application January 14, 1957, Serial No. 634,044 Claims priority, application Germany January 14, 1956 31 Claims. (Cl. 74--568) This invention relates to a device for rapidly setting adjustable cams and more particularly for setting the elements which control the formation of fancy stitches and fancy stitch combinations in automatic Zig-zag sewing machines.

When a zig-zag sewing machine equipped with noninterchangeable fashion stitch cams for producing automatic fancy stitches is required to form decorative stitch patterns which call for the automatic control of the stroke of the feed dog as well as of other elements, at least two cams are required for the formation of one particular pattern. One cam is needed to control the stroke of the feed dog and the other controls the position or width of the stitch. Assuming for instance that ten cams have been-built into a machine, then the number of automatic basic patterns would be restricted to five, if no allowance is made for the possibility of forming combinations of different cams.

The present invention contemplates the formation of any desired decorative pattern with the help of a single or a twin set of adjustable cams.

According to the invention one or several cam discs are each divided into several independent elements or segments which may be set by means of a setting member resembling a key. Each one of a plurality of different key members produces a different decorative pattern; the formation of any desired decorative pattern therefore merely requires the availability of a comparatively small and cheap item, namely amember resembling a key, whereas the costly set or sets of cams are required once only.

Embodiments of the invention are illustrated by the accompanying drawings in which Fig. 1 is a longitudinal section of a cam drum with one fixed and eight adjustable cam discs, the discs being 5 represented as having been set for a particular pattern:

Fig. 2 is a section taken in the plane of a cam disc II (Fig. 1):

Fig. 3 is a section taken in the plane of a cam disc IIII (Fig. 1):

Fig. 4 is a view of the setting member which resembles a key:

Fig. 5 shows four different cross sections of the setting member resembling a key: 1

Fig. 6 is a longitudinal section of a cam drum with four adjustable cam discs and a setting member adapted to be unlocked by being turned:

Fig. 7 is a section taken in the plane of cam disc VI I-VII:

Fig. 8 "is a longitudinal section of a cam drum with four adjustable cam discs and a setting member adapted to be unlocked by being turned:

Fig. 9 is a detail of a cam drum with a multi-part setting member:

Fig. 10 is a cross section of the setting member shown 70 i through 30. The cam body 44 of cam disc III-,-III

i F 09?? l r S le 4 United States Patent IC Patented Aug. 25, 1959 Fig. 11 is a longitudinal section of a cam drum with two adjustable cam discs; and

Fig. 12 is a section taken in the plane of cam disc IXIX.

Inside the body 1 of the sewing machine is a transverse shaft 4 mounted in bearings 2 and 3. The transverse shaft 4 is driven by the arm shaft through a worm 6 and a wormwheel 7. Secured to the transverse shaft 4 (Fig. 1) is one set of cams 8 for controlling the stroke of the feed dog, not shown in the drawing, one set of cams 9 for controlling the width or position of the stitch, and possibly one non-adjustable cam for controlling the zigzag stitch mechanism.

The cam assemblies 8 and 9 are adjustable and to this end consist of several members. Assuming, for instance that cam assembly 9 is required to control a stitch patoff surfaces.

tern comprising 24 stitches per pattern, in other words, that the needle which is likewise not shown is required to swing twelve times to the left and twelve times to the right, then the cam assembly 9 must have twelve projections 11 and twelve depressions 12 which in the illustrated example (Fig. 1) are distributed between the adjacent cam discs II, II-II, III-Ill, IV'-IV. The cam disc I-I consists of an annular body 13 provided with six slot-shaped recesses 14. Cam elements 15 are inserted into these slot-shaped recesses 14, the flanks 16 and 17 of the cam elements being held between the sides 18 and 19 of the slot-shaped recesses 14 in the annular body 13. p I

The transverse shaft 4 has a central bore 20 for the reception of the key- like setting members 21 and 22. Furthermore holes 23 are drilled radially into the transverse shaft 4, tappets 24 being slidably located inside the radial holes and adapted radially to displace the cam elements 15.

The key- like setting members 21 and 22 are likewise provided with elevations 25 and depressions 26 so that the variations in the distances 27 of the points of the contour from a central base cylinder, for instance in plane A-B (Figs. 4 and 5) the outside contour of cam disc I-1, will conformably represent the desired positions of the surfaces 28 and 29 of the cam elements comprised in the assembly.

The heads of the cam elements 15 are provided with sloping lead-in and run-off surfaces 30 and 31. Between the cam body 13 and the cam elements 15 are either springs 32 which bear, on the one hand, against a shoulder 33 in each recess of the cam body 13 and, on the other hand, at 34'against the cam element urging the latter inwards in the direction of the arrow towards the cam centre, or alternatively there are arranged between the cam body 13 and the cam elements 15, leaf springs 35 which bear, on the one hand, against shoulders 36 in each recess and, on the other hand, against the cam elements at 38 and likewise urge the latter in the direction of the arrow, i.e. inwards towards the cam centre. The means described therefore create a direct connection by contact between the surface 39 of the cam element 15 and the external contour 25 and 26 of the key-like setting member 21.

Displaced through an angle of 15 alongside cam disc II is the next cam disc II-II (Fig. 3), which is contrived substantially in the same way as cam disc I-l excepting that the outer contours 40 of its cam elements 41 are sections of are without inclined lead-in and run- The associated cam body 42 is coupled with cam body 13 of cam disc I-I by means of coupling pins 43.

Cam disc III-III is again constructed exactly like cam disc II but angularly displaced in relation to the latter is coupled with cam body 42 of cam disc IIII by means of coupling pins 45.

Finally, alongside cam disc IIIIII, is a further cam disc IV--IV which is displaced through a further angle of 15. Cam disc IV-IVis otherwise constructed exactly like cam disc HII.

The cam body 46 of this latter cam disc IV--IV is coupled with the cam body 44 of cam disc 1I1III by means of a coupling pin 47 which is at the same time connected with an adjusting disc 49 adapted to be tightened on the transverse shaft 4 by means of a grub screw 48. The adjusting disc 49 is arranged to compress the entire cam assembly 9 by pushing it against the zigzag cam 10 which together with the wormwheel 7 is secured to the transverse shaft 4 by means of a common key 50.

The zig-zag cam 10 is axially supported by a sleeve 51, the wormwheel 7, the second sleeve 52, and a second cam assembly 8 which is retained by an adjusting disc 53 likewise adapted to be tightened on the transverse shaft 4. Cam assembly 8 is constructed in exactly the same way as cam assembly 9 and the relative configuration of its cam elements for the control of the varying stroke of the feed dog is likewise determined by the contour of a second key-like member 22.

It will be understood from what has been said that the adjusting disc 53, the cam assembly 8, the sleeve 52, the wormwheel 7, the sleeve 51, the zigzag cam 10, the cam assembly 9 and the adjusting disc 49, when pushed on to the transverse shaft 4, -'will combine to form a cam drum which is rigidly mounted on the transverse shaft 4, and which has a peripheral surface of adjustably variable contour, the entire assembly being mounted on the body 1 of the sewing machine in bearings 2 and 3 and capable of being rotated by the arm shaft through the worm 6.

The cam assembly 9 which can be pre-set by means of the key-like setting member 21 is explored by a rocker 54 and cam followers 55 to 59 are adapted to be brought into play as required. The movement thus imparted to the rocker 54 is transmitted to the needle bar, not shown in the drawing. On the other hand, cam assembly 8 which can be pre-set by means of the key-like setting member 22 is explored by a second rocker 60 and its associated cam followers 61 to 64, likewise capable of being brought into play as required, but the resultant movements impressed upon rocker 60 are transmitted to the feed dog actuating mechanism, likewise not shown.

The key- like setting members 21 and 22 carry fin-like propections 65 and 66 which engage slots 67 and 68 in the transverse shaft 4 so that the key-like members are forced to participate in the rotation of the transverse shaft 4. Moreover a click catch 69 and 70 on each of the key- like setting members 21 and 22 retains the latter axially in their required positions inside the transverse shaft 4.

The embodiment of a cam assembly as illustrated in Fig. 6 with four adjustable cam discs is contrived in the same way as the cam assemblies that have been already described. The key-like setting member 100 is so shaped that the distance 103' (shown in dotted lines) is the same along the length of the key-like member where the tappets 103 make contact therewith so that the key-like member will slip easily into the bore 101 of the transverse shaft 102 when it is inserted therein. A spring-loaded retaining ball 104 built into the transverse shaft 102 slides along a slot 105 in the key-like member 100 and guides it into the shaft. After having been pushed home the key-like member 100 can be turned through an angle .106 when the retaining ball 104 will axially lock it inside the shaft. As a result of the turn given to the keylike member the tappets 103 will be displaced by the external contour 107 of the'key-like member 100 into the positionsrequire'd to push the cam elements into the appropriate positions for producing the desired decorative pattern.

The form of construction shown in Fig. 8 of a cam drum with four adjustable cam discs is again constructed exactly like the preceding embodiment. However, the drawing shows the key-like setting member 108 out of proper engagement. Not until the setting member 108 has been pushed home in the direction of the arrow will the tappets slide up the contour 109 of the key-like member 108 and be displaced into the positions in which the cam elements will be set to produce the desired decorative stitch pattern. The key-like member is axially held by the engagement of the click stops with the notches 111 and 112.

In another form of construction (Fig. 9) the setting member is embodied in a sleeve 113 with a hollow interior 114 which serves for the reception of the key proper 115. The key 115 has a shank 116, 117 which exactly fits into the bore 114 of the sleeve 113. Holes 118 are drilled transversely into the sleeve 113 and these contain tappets 119. Springs 120 urge the tappets 119 inwards in the direction of the arrow. When the setting member 113 is pushed into the bore 121 of the transverse shaft 122 for setting the cams, the key 115 must oc-= cupy the off position shown in Fig. 9, and the retaining spring 123 must be in engagement with the notch 124 in the key 115. In this position the contour 125 of the key 115 will displace the tappets 119 into such a position that their ends are flush with the outer surface 126 of the sleeve 113. When the setting member has been pushed into the bore 121 in the transverse shaft 122 far enough to permit the retaining spn'ng 127 to click into notch 128 and the blade 129 on the sleeve 113 to be in engagement with the groove 130 in the transverse shaft 122, the setting member 113 will be in such a position that the tappets 119 in the sleeve axially align with the tappets 131 in the transverse shaft 122.

The cam discs which are not specially shown in the drawing will now be set by pushing the key 115 home,

in the direction of the arrow into the in position, marked in dotted outlines, when the retaining spring 123 will engage notch 132. The contour 125 machined into the shank of the key will now displace the tappets 119 outwards into their effective positions and by acting on the tappets 131 move the cam elements which are not specially shown into the positions required [for the production of the corresponding decorative stitch pat-' tern.

In another form of construction (Fig. 11) a set of cams comprises two adjustable cam discs. Again the cam assembly is constructed as has been described. The tappets 133 associated with cam disc XX are offset in such a manner that their ends are closely adjacent the tappets 134 associated with cam disc IX-IX. Consequently, that part of the setting member 135 which carries the tappet displacing contour 136 may be of particularly simple design.

I claim:

1. In a sewing machine having a zig-Zag stitch mechanism, a combination variable-contour cam assembly for controlling the zig-zag stitch mechanism and setting means for rapidly setting the contour of the cam assembly, said combination cam assembly and setting means therefor comprising a cam assembly incorporating several cam discs each disc being subdivided into several elements each of which is capable of independent limited movement; and setting means carried by said cam assembly for setting each of said elements into any position within its range of limited movement, whereby said cam assembly may be given any one of an infinite number of contours.

2. In a sewing machine, a combination variablebeing subdivided into several segments each of which is capable of independent limited movement; two setting means carried by said cam assemblies, respectively, for setting each of the respective segments thereof; and driving means common to both of said assemblies for driving the same.

3. A device according to cilaim 1 wherein said elements of the cam assembly are of similar shape.

4. A device according to claim 2 wherein the segments of each cam assembly are of similar shape.

5. In a sewing machine having a zig-zag stitch mechanism, a combination variable-contour cam assembly for controlling the zigzag stitch mechanism and setting means for rapidly setting the contour of the cam assembly, said combination cam assembly and setting means therefor comprising a cam assembly incorporating several cam discs each disc subdivided into several segments each of which is capable of independent limited movement; and setting means associated with said cam assembly for setting each of said segments into any position within its range of limited movement, said setting means comprising a setting member which is common to said segments and which is in the form of a key adapted to be inserted and withdrawn to effect displacement of said independently moving segments, whereby depending upon the shape of the key, said cam assembly may be given any one of an infinite number of contours.

6. In a sewing machine, a combination multiple variable-contour cam assembly and setting means for rapidly setting the contour thereof, comprising two cam assemblies each consisting of several cam discs each disc being subdivided into several segments each of which is capable of independent limited movement; a keydike setting member for each cam assembly, and driving means common to both of said assemblies for driving the same.

7. A device according to claim 5, in which the keylike setting member in its eifective region has a circumferential conformation of which surface portions of said member which are contacted by said segments are located at different distances from the centre axis of the key-like setting member.

8. A device according to claim 6 in which each keylike member in its effective region has a circumferential conformation of which surface portions of said member which are contacted by said segments are located at different distances from the centre axis of the key-like setting member.

9. A device according to claim 5 in which snap retention means are provided for retaining the key-like setting member in the required position.

10. A device according to claim 6 in which snap retention means are provided for each key-like setting member so as to retain the same in its required position.

11, A device according to claim 5 in which the keylike member, when inserted, is turned through a certain angle and is then secured against withdrawal by retention means.

12. A device according to claim 6 in which each keylike member, when inserted, is turned through a certain angle and is then secured against withdrawal by retention means.

13. In a sewing machine having a zig-zag stitch mechanism, a combination variable-contour cam assembly for controlling the zigzag stitch mechanism and setting means for rapidly setting the contour of the cam assembly, said combination cam assembly and setting means therefor comprising a shaft; a cam assembly incorporating several cam discs carried upon said shaft, each disc being subdivided into several segments each of which is capable of independent limited movemovement, said shaft being formed with radial guide Ways within which said segments, respectively, are arranged for sliding movement and with an axial bore communicating with said guide ways so that an actuation portion of each of said segments may project into said axial bore; spring means associated with said segments for continuously urging the same inwardly so that actuating portions of said segments are constantly urged into said axial bore; and a setting member in the form of a key and common to said segments, said setting member being adapted to be inserted into and withdrawn from said axial bore to engage said actuating portions ofsaid segments so as to effect displacement thereof against the force of said spring means so as to set each segment into any position within its range of limited movement, whereby with diiferent keys any one of an infinite number of different cam contours of said cam assembly may be obtained.

14. In a sewing machine, a combination variablecontour cam assembly and setting means for rapidly setting the contours thereof, comprising a shaft; two cam,

assemblies each consisting of several cam discs carried upon said shaft, each disc being subdivided into several segments each of which is capable of independent limited movement, said shaft being formed with radial guide ways within which said segments are arranged for sliding movement and with an 'axial bore communicating with said guide ways so that an actuating portion of each of said segments may project into said axial bore; spring means associated with said segments for continuously urging the same inwardly so thatsaid actuating portions thereof are constantly urged into said axial bore; two setting keys associated with said assemblies, respectively, each key being adapted to be inserted into and withdrawn from said axial bore to engage the actuating portions of those segments which are part of the respective assembly with which each key is associated to effect displacement of such segments against the force of said spring means, whereby with different keys different cam contours of each cam assembly may be obtained, and driving means for driving said shaft.

15. A device according to claim 5 including tappets provided in appropriate holes drilled into a transverse shaft which accommodates the key, said tappets being interposed between the several segments of the cams and said key so as to constitute thrust transmitting connection means for transmitting pressure from the key to said segments.

16. A device according to claim 6 including tappets provided in appropriate holes drilled into a transverse shaft which accommodates the key, said tappets being interposed between the several segments of the cams and the respective key-like setting member so as to constitute thrust transmitting connection means for transmitting pressure from the respective keys to said segments.

17. A device according to claim 5 including tappets provided in appropriate holes drilled into a transverse shaft which accommodates the key, said tappets being adjacent the key, are spheroid, conical, or similarly taper ing, so as to establish point-contact between the key and said segments.

18. A device according to claim 1 in which said setting means are in the form of a key which may be insorted and withdrawn, and the cross-section of the key, in the region of each cam disc or the segments thereof, has a contour the points of which vary in distance from the centre axis of the key member.

19. A device according to claim 2 in which each setting means is in the form of a key which may be inserted and withdrawn and the cross-section of each key, in the region of each cam disc or the segments thereof, has a contour the points of which vary in. distance from the centre axis of the key member.

20. A device as claimed in claim 1 in which said setting means comprise several optionally insertable key like members with differently shaped cross-sections or circumferential conformations are provided each adapted to effect displacement of the independently movable elements.

21. A device according to claim 2 in which each setting means comprises several optionally insertable keylike members with diflerently shaped cross-sections :or circumferential conformations are provided each adapted to effect displacement of the independently movable segments.

22. A device according to claim 5 in which said setting means also include several optionally insertable keylike members with differently shaped cross-sections or circumferential conformations are provided each adapted to effect displacement of the independently movable segments.

23. A device according to claim 6 in which said setting means also include several optionally insertable keylike members with differently shaped cross-sections or circumferential conformations are provided each adapted to effect displacement of the independently movable segments.

24. In a sewing machine having a zig-zag stitch mechanism, a combination variable-contour cam assembly for controlling the zigzag stitch mechanism and setting means for rapidly setting the contour of the cam assembly, said combination cam assembly and setting means therefor comprising a cam assembly incorporating several cam discs each disc being subdivided into several elements each of which is capable of independent limited movement, said elements being mounted for sliding movement in radial direction; spring means for continuously urging said elements inwardly and therefore against the action of centrifugal force; and setting means associated with said cam assembly for setting each of said elements against the action of said spring means into any position within its range of limited movement, whereby said cam assembly may be given any one of an infinite number of contours.

25. In a sewing machine having a zig-zag stitch mechanism, a combination variable-contour cam assembly for controlling the Zig-zag stitch mechanism and setting means for rapidly setting the contour of the cam assembly, said combination cam assembly and setting means therefor comprising a cam assembly incorporating several cam discs each disc being subdivided into several segments each of which is capable of independent limited movement; a common setting member in the form of a key which is adapted to be inserted and withdrawn to effect displacement of eadh of said segments into any position within its range of limited movement; and compression spring means arranged located in chamber-like recesses cut into said elements and the surfaces of said cam discs and bearing against said segments as well as against said surfaces of said cam discs for continuously bringingsaid elements into contact with said setting member, whereby depending upon the shape of the key, said cam assembly may be given any one of an infinite number of contours.

26. A device according to claim 6 including com-' pression springs bearing against the movable segments and acting centripetally thereon, and against the surfaces of thecam discs, said springs being located in chamber like recesses cut into the segments and the surfaces of the cam discs.

27. A device according to claim 6 including leaf springs bearing against the movable segments and acting :centripetally thereon, and against the surfaces of the cam discs, said springs being located in chamber like recesses cut into the segments and the surfaces of the cam discs.

28. ,A device according to claim 5 in which there is provided for the reception of an inserted key-like member a cylindrical sleeve which possesses means .for creating an indirect positive connection between the segments and the circumferential surface of the inserted key-like member, the sleeve being insertable into a corresponding bore in a transverse shaft carrying said cam assembly and being adapted to be secured by catch means against displacement.

.29. A device according to claim 6 in which thereis provided forthe reception of an inserted key-like member a cylindrical sleeve which possesses means for creating an indirect positive connection between the segments and the circumferential surface of the inserted key-like member, the sleeve being insertable into a corresponding bore in a transverse shaft carrying said cam assembly and being adapted tobe secured by catch means against displacement.

.30. A device according to claim 13 in which there is provided for the reception of an inserted key-like mem-- bera cylindrical sleeve which possesses means for creating an indirect positive connection between the segments and the circumferential surface of the inserted key-like member, the sleeve being insertable into a corresponding borein said shaft and being adapted to be secured by catch means against displacement.

31. A device according to claim 1 having two adjustable cam discs with associated tappets arranged closely adjacent each other, whereas the associated elements of the cams are spaced further apart, and :aPPropriate transmission members interposed between the tappets and the associated elements.

References Cited in the file of this patent UNITED STATES PATENTS 484,005 Gleason Oct. 11, .1892

703,028 Wildman -2 June 24, 1902 1,896,635 Lombardi Feb. 7, 1933 1,904,068 Meacock Apr. 18, 1933 2,025,463 Lombardi Dec. 24, 1935 2,100,876 Schneider Nov. 30, 1937 2,207,463 Lawson et a1. July 9, 1940 2,803,121 Ferraguti Aug. 20, 1957 FOREIGN PATENTS 108,606 Sweden Sept. 28, 1943

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