Abstract
A sewing machine having a device for manually changing a feed dog (10), including the feed dog (10) and a feed-dog holder (30). The feed-dog holder (30) is disposed in an arm bed (103) that is associated with the sewing machine, and the feed dog (10) is receivable in a clearance (31, 81) of the feed-dog holder (30). The feed dog (10) that is located in the clearance (31, 81) has a support face (15) which may be disposed parallel with the surface of a sewn-product support which may contain a needle-hole plate (113) or be configured as a needle-hole plate (113), the sewn-product support and/or the needle-hole plate (113) may at least partially be formed by the surface of the arm bed (103), and the support face (15) may be received in an opening (140) of the needle-hole plate (113). The feed dog (10) is fastenable in the clearance by a fastening element (40, 82, 83) or of a setting element (50) such that the support face (15) is alignable so as to be substantially parallel with the surface of the sewn-product support or of the needle-hole plate (113). The fastening element (40, 82, 83) or the setting element (50) is releasably held in the feed-dog holder (30).
Claims
1. A sewing machine including a device for manually changing a feed dog, comprising the feed dog and a feed-dog holder, the feed-dog holder is disposed in an arm bed that is associated with the sewing machine, the feed-dog holder includes a clearance in which the feed dog is receivable, the feed dog that is located in the clearance has a support face which is disposed parallel with a surface of a sewn-product support which contains a needle-hole plate, the feed dog has a base face that is disposed so as to be opposite the support face, and in the assembled state the base face at least partially bears on a base area of the clearance, the needle-hole plate is at least partially formed by the surface of the arm bed, the support face is received in an opening of the needle-hole plate, and the feed dog is fastenable in the clearance by a fastening element or of a setting element such that the support face is alignable so as to be substantially parallel with the surface of the needle-hole plate, and the fastening element or the setting element is releasably held in the feed-dog holder.
2. The device as claimed in claim 1, wherein the opening has a greater length than the feed dog or than a web of the feed dog that is guided through the opening, such that a position of the feed dog in relation to the opening is variable.
3. The device as claimed in claim 1, wherein the opening has a greater width than the feed dog, such that a width of the feed dog is variable.
4. The device as claimed in claim 1, wherein the clearance has at least one lateral edge which delimits the base area at a periphery thereof, and the feed dog is at least partially received by the lateral edge of the clearance.
5. The device as claimed in claim 1, wherein the feed dog in the position thereof in relation to the clearance is settable or lockable by the setting element.
6. The device as claimed in claim 5, wherein the setting element comprises an eccentric feature, and the eccentric feature is guided on a pin.
7. The device as claimed in claim 5, wherein the setting element is configured as part of a pin that is held in a threaded bore in the feed-dog holder.
8. The device as claimed in claim 5, wherein the setting element comprises a locking element.
9. The device as claimed in claim 1, wherein the fastening element comprises an element from selected from the group including screws, nuts, threaded bolts, bolts, or guide rails.
10. The device as claimed in claim 1, wherein the fastening element is at least partially held in the clearance of the feed-dog holder.
11. The device as claimed in claim 1, wherein the fastening element is at least partially held in an insert element.
12. The device as claimed in claim 1, wherein the fastening element is captively held by a securing element.
13. The device as claimed in claim 1, wherein the feed dog is positionable in the clearance by a fixing element.
14. The device as claimed in claim 13, wherein the fixing element contains a magnet or a ferromagnetic region.
15. The device as claimed in claim 1, wherein the feed dog is positionable in the clearance by a locking element.
16. The device as claimed in claim 15, wherein the locking element is rotatably disposed in the feed-dog holder.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] The invention will be explained in more detail by means of illustrated exemplary embodiments. In the drawings:
[0051] FIG. 1 shows a perspective illustration of a first exemplary embodiment according to the invention, in an exploded illustration;
[0052] FIG. 2 shows a view of the screw-securing feature according to FIG. 1;
[0053] FIG. 3 shows a second view of the screw-securing feature according to FIG. 1 or FIG. 2;
[0054] FIG. 4 shows a perspective illustration of a second exemplary embodiment according to the invention, in an exploded illustration;
[0055] FIG. 5 shows a detail of a variant of a feed dog for employment in the exemplary embodiment according to FIG. 4;
[0056] FIG. 6 shows a section through the fastening element of the exemplary embodiment shown in FIG. 4, in the installed state;
[0057] FIG. 7 shows a section through the fastening element of the exemplary embodiment shown in FIG. 4, in the installed state;
[0058] FIG. 8 shows a perspective illustration of the second exemplary embodiment according to the invention, in an exploded illustration, having a variant of the holding element;
[0059] FIG. 9 shows a perspective illustration of the second exemplary embodiment according to the invention, in an exploded illustration, having a further variant of the holding element;
[0060] FIG. 10 shows a view of a third exemplary embodiment from above;
[0061] FIG. 11 shows a section through the feed dog and the associated linear guide;
[0062] FIG. 12 shows a view of a variant of the linear guide in the Y-Z plane;
[0063] FIG. 13 shows a side view of a variant of the linear guide in the X-Z plane;
[0064] FIG. 14 shows a perspective view of the rail according to FIG. 12;
[0065] FIG. 15 shows a schematic illustration of a sewing machine;
[0066] FIG. 16 shows a perspective illustration of a fourth exemplary embodiment according to the invention, in an exploded illustration;
[0067] FIG. 17 shows a further perspective illustration of a fourth exemplary embodiment according to the invention, in an exploded illustration according to FIG. 16;
[0068] FIG. 18 shows a view of the feed dog in FIG. 16, in the installed state;
[0069] FIG. 19 shows a section through the feed dog according to FIG. 16, in the installed state;
[0070] FIG. 20 shows a perspective illustration of a fifth exemplary embodiment according to the invention, in an exploded illustration; and
[0071] FIG. 21 shows a view of the fifth exemplary embodiment from above.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0072] A device for manually changing a feed dog 10 for a sewing machine, according to FIG. 1, comprises the feed dog 10 and a feed-dog holder 30. For the sake of improved clarity, the illustration of details of the sewing machine has been dispensed with in the figures, since said details are well known from the prior art, see CH707972 A1, for example, which is incorporated herein by reference. The feed dog 10 is receivable in a clearance 31 of the feed-dog holder 30. The feed-dog holder 30 is disposed in an arm bed 103 of the sewing machine 101, as is shown in FIG. 15. The feed dog 10 is fastenable in the clearance 31 by a fastening element 40, wherein the fastening element 40 is releasably held in the feed-dog holder 30. The fastening element 40 may comprise a screw 41, for example.
[0073] According to the embodiment in FIG. 1, various feed dogs 10 may be fastened to the feed-dog holder 40 by way of two screws 41.
[0074] A setting element 50, by way of which the feed dog 10 in the position thereof in relation to the clearance 31 is settable, is also illustrated in FIG. 1. The setting element 50 according to FIG. 1 is configured as a pin which has a head end 51 and a neck 52. The head end 51 has a larger diameter than the neck 52. The neck 52 may have an external thread. The neck 52 can at least be partially held in a bore 33 that is attached in the clearance 31. The bore 33 may be configured as a threaded bore. An eccentric disk 55 may be disposed on the neck 52. The eccentric disk 55 is received in a mounting 11 of the feed dog 10, if and when the feed dog 10 is placed into the clearance 31.
[0075] Instead of a separate eccentric disk 55, the head end 51 could also be configured as an eccentric feature, this not being illustrated in the drawings. The position of the feed dog 10 in the clearance 31 is thus establishable, depending on the position of the eccentric disk 55. The head end 51 may have a receptacle element for an activation key. According to a further exemplary embodiment, the head end 51 may have a rough profile or a fluted feature, enabling the head end 51 to be manually rotated so as to move the eccentric disk 55 to the desired position, on account of which a fine adjustment of the feed dog 10 may be performed. The feed dog 10 may thus be aligned depending on the contour that is located in the needle-hole plate 113 of the sewing machine 101. A needle-hole plate 113 of this type is shown in FIG. 9, for example.
[0076] If and when two fastening elements 40 are used, one of the fastening elements 40 may be received without play, that is to say by way of an interference fit, in the bore 12 of the feed dog 10, and the respective other fastening element 40 may be received without an interference fit, that is to say with play, in the associated bore 13 of the feed dog 10.
[0077] A fixing element 86 which may be configured as a magnetic element, in particular as a magnetic pin, for example, may be used for fixing the feed dog 10 in the correct position, prior to the blocking of the feed dog 10 being performed by the fastening element or elements 40.
[0078] FIG. 2 and FIG. 3 in an exemplary manner show the screw 41 of FIG. 1, and a screw-securing feature 42. The second screw of FIG. 1 may have a screw-securing feature of the same type. The screw-securing feature 42 according to this exemplary embodiment is configured as a thin-walled cylinder 43 having a planar cover face 44. The cover face 44 has a central opening 45 through which the screw head 46 protrudes. The screw head 46 has a receptacle 47 for an activation key. By way of the opening 45 in the cover face 44 of the thin-walled cylinder 43 it is guaranteed that the user may loosen or tighten the screw 41 at any time.
[0079] The thin-walled cylinder 43, at that end that is opposite the cover face 44, has a tab 48. The tab 48 in the assembled state encompasses the screw head 46.
[0080] As is illustrated in FIG. 1, the screw head 46, optionally together with the screw-securing feature 42, bears on a ledge of a respective bore in the feed dog. The screw-securing feature is not illustrated in FIG. 1. The thin-walled cylinder has a bore or a hole through which a rope or a cable, respectively, is guided, said rope or cable, respectively, being likewise fastened in the feed-dog holder or in the feed dog, in order for the screw to not be able to drop into the sewing machine.
[0081] The securing element herein is configured such that the rope may conjointly rotate and is not wound around the screw.
[0082] The screws 41 have a screw neck 49. The screw neck 49 in the assembled state protrudes through the bore in the feed dog 10, and is held in a threaded bore 32 that is disposed in the clearance 31. To this end, the screw neck 49 has an external thread (not illustrated in the drawings).
[0083] A device for manually changing a feed dog 10 for a sewing machine 101, according to FIG. 4, comprises the feed dog 10 and a feed-dog holder 30. The feed dog 10 is receivable in a clearance 31 of the feed-dog holder 30. The feed-dog holder 30 is disposed in an arm bed 103 of the sewing machine 101, as is shown in FIG. 15. The feed dog 10 is fastenable in the clearance 31 by a fastening element 40, wherein the fastening element 40 is releasably held in the feed-dog holder 30. The fastening element 40 may comprise a threaded bolt 60 and an associated nut 61.
[0084] According to the embodiment as per FIG. 4, various feed dogs 10 may be fastened to the feed-dog holder 30 by way of two threaded bolts 60 and the associated nuts 61.
[0085] A setting element 50, by way of which the feed dog 10 in the position thereof in relation to the clearance 31 is settable, is also illustrated in FIG. 4. The setting element 50 according to FIG. 4 is configured as a set screw 65 which has a screw head 66 and a screw neck 67. The screw head 66 has a larger diameter than the screw neck 67. The screw neck 67 may have an external thread 68. The screw neck 67 may at least be partially held in a threaded bore 34 which is attached to a mounting 35 in the feed-dog holder 30. An eccentric disk 69 may be disposed on the screw neck 67. The eccentric disk 69 is received in the mounting 35 of the feed-dog holder 30 if and when the feed dog 10 is placed into the clearance 31 and bears on the feed dog 10. The feed dog 10 may be finely adjusted in the clearance 31 by way of the position of the eccentric feature of the eccentric disk.
[0086] Instead of a separate eccentric disk 69, the screw head 66 could also be configured as an eccentric feature, this not being illustrated in the drawings. The position of the feed dog 10 in the clearance 31 is therefore establishable depending on the position of the eccentric disk 69. The screw head 66 may have a receptacle element for an activation key. According to one further exemplary embodiment, the screw head 66 may have a rough profile or a fluted feature, enabling the screw head 66 to be manually rotated so as to move the eccentric disk 69 to the desired position, on account of which the fine adjustment of the feed dog 10 may be performed. The feed dog 10 may thus be aligned so as to correspond to the contour that is located in the needle-hole plate 113 of the sewing machine 101. A needle-hole plate 113 of this type is shown in FIG. 9, for example. The needle-hole plate shown in FIG. 9, by virtue of the large recess, may not be used for sewing but serves only as an alignment template.
[0087] If and when two fastening elements 40 are used, one of the fastening elements 40 may be received without play, that is to say by way of an interference fit, in the bore 12 of the feed dog 10, and the respective other fastening element 40 may be received without an interference fit, that is to say with play, in the associated bore 13 of the feed dog 10. Alternatively or additionally thereto, two bores 12 of the same type may be provided in the feed dog, and the first threaded bolt 60 may be embodied with an interference fit, and the second threaded bolt 62 may be embodied without an interference fit. Alternatively or additionally thereto, a holding plate 70 which has two bores 71 may be provided, the diameter of the latter corresponding substantially to the external diameter of the nuts. The holding plate may be configured as a sheet-metal holding plate, in particular.
[0088] FIG. 5 shows a feed dog 10 of another construction mode, which may be attached to the feed-dog holder 30 that is illustrated in FIG. 4. The feed dog 10 has a first external web 16 and a second external web 17. The first external web 16 and the second external web 17 have a constant web width, and have a substantially identical length. A central web 18 is disposed between the first external web 16 and the second external web 17. The central web 18 has a larger web width than the first 16 and the second external web 17. The central web 18 has a shorter length than the first 16 and the second external web 17. The first 16 and the second external web 17 and also the central web 18 define the support face 15 on which the sewn product bears. The first 16 and the second external web 17 and the central web 18 have a plurality of transverse flutes that improve the adhesion of the sewn product on the feed dog, enabling the sewn product to be acquired by the feed dog and to be moved in the indexing direction.
[0089] The feed dog in FIG. 4 differs from the feed dog illustrated in FIG. 5 in that the central web 18 has a web width that at least partially is smaller than the web width of the first 16 and the second external web 17. Furthermore, the first 16 and the second external web 17 have a web width that when viewed across the web length is variable.
[0090] The first 16 and the second external web 17 and the central web 18 may be interconnected. Since the central web 18 is shorter than the first 16 and the second external web 17, the first 16 and the second external web 17 form two arm elements that delimit a void. This void enables the sewing needle, upon having pierced the sewn product, to be able to be guided by the feed dog, such that the needle thread that is conjointly guided by the sewing needle may configure a loop that can be acquired below the feed dog by a hook of the gripper, and may be connected to the bobbin thread.
[0091] FIG. 6 shows a section through the fastening element 40 of the exemplary embodiment that is shown in FIG. 4, in the installed state. The fastening element 40 by way of which the feed dog 10 is fastenable in the clearance 31 is illustrated in a section. The fastening element 40 according to FIG. 6 is configured as a threaded bolt 62 which by a flange is held at a defined screw-in depth in the bore 32 of the feed-dog holder 30. A region having a larger external diameter than the external diameter of the thread that fits into the bore 32 extends above the flange. The region having the larger external diameter is designed so as to match the internal diameter of the bore 12 of the feed dog 10, such that the feed dog is fitted by way of an interference fit. An external thread which receives the internal thread of the nut 61 adjoins above the interference-fit region. The nut bears on a ledge that is located in the bore 12. The bore 12 is configured as a stepped bore. The lower part of the stepped bore has a smaller internal diameter that the upper part of the stepped bore. The upper part of the stepped bore thus receives the nut 61 that captively holds the feed dog on the feed-dog holder 30. A holding element 70 which is configured as a holding plate may be additionally provided.
[0092] FIG. 7 shows a section through the fastening element 40 of the exemplary embodiment that is shown in FIG. 4, in the installed state. The fastening element 40 by way of which the feed dog 10 is fastenable in the clearance 31 is illustrated in a section. The fastening element 40 according to FIG. 6 is configured as a threaded bolt 62 which by a flange is held at a defined screw-in depth in the bore 32 of the feed-dog holder 30. A region having the same external diameter as the external diameter of the thread that fits into the bore 32 extends above the flange. The region above the flange has a smaller diameter than the internal diameter of the bore 12 of the feed dog 10, such that the feed dog is fitted having play. An external thread that receives the internal thread of the nut 61 adjoins above the receptacle region for the feed dog 10. The nut bears on a ledge that is located in the bore 12. The bore 12 is configured as a stepped bore. The lower part of the stepped bore has a smaller internal diameter than the upper part of the stepped bore. The upper part of the stepped bore thus receives the nut 61 that captively holds the feed dog on the feed-dog holder 30. A holding element 70 which is configured as a holding plate may be additionally provided.
[0093] The setting element 50 by way of which the feed dog 10 in the position thereof in relation to the clearance 31 is settable is also illustrated in a section in FIG. 7. The setting element 50 according to FIG. 7 is configured as a set screw 65 which has a screw head 66 and a screw neck 67. The screw head 66 has a larger diameter than the screw neck 67. The screw neck 67 may have an external thread 68. The screw head 67 may at least partially be held in a threaded bore 34 that is attached in a mounting 35 in the feed-dog holder 30. An eccentric disk 69, which in this exemplary embodiment is configured so as to be integral with the set screw 65, may be disposed on the screw neck 67. The eccentric disk 69 is received in the mounting 35 of the feed-dog holder 30, if and when the feed dog 10 is placed into the clearance 31, and bears on the feed dog 10, that is to say in particular on the rear wall of the feed dog 10. The feed dog 10 in the clearance 31 may be finely adjusted by way of the position of the eccentric feature of the eccentric disk 69.
[0094] FIG. 8 shows a perspective illustration of the second exemplary embodiment according to the invention, in an exploded illustration, having a variant of the holding element. Reference is made to the description relating to FIG. 4 for those elements that have already been described in the context of FIG. 4. Said elements have the same reference signs as have been used in FIG. 4. The setting element 50 is configured as a template 72 which is a component part of the holding element 70. The template is configured as a web element which may equalize the width differential of the feed dog. The template bears on the second external web 18 of the feed dog 10. The template 72 is removed upon alignment of the feed dog, or prior to the commencement of sewing, and serves only for the alignment. The alignment is performed in that the rear face of the template 72 is positioned into a clearance of the feed-dog holder 30. Thereafter, the feed dog or the external web 18 is pushed against this lateral face of the template and by way of the two holes is screw-fitted to the feed-dog holder 30. Once the feed dog has been screw-fitted, the template 72 is removed and the matching needle-hole plate (not shown) is inserted.
[0095] FIG. 9 shows a perspective illustration of the second exemplary embodiment according to the invention, in an exploded illustration which shows a further variant of the holding element 70 which in this exemplary embodiment is formed by the needle-hole plate 113. The needle-hole plate has a clearance which is adapted to the contour of the feed dog 10, such that the feed dog is exactly positioned in the needle-hole plate 113. Here too, the needle-hole plate 113 serves only as a template for the alignment. The feed dog 10 is loosely screw-fitted. The needle-hole plate 113 is inserted and is positioned in the arm bed by way of the usual mounting. Thereafter, the feed dog 10 or the external web 17, respectively, is pressed onto one side and screwed tight. Thereafter, the needle-hole plate 113 is replaced by a needle-hole plate suitable for sewing.
[0096] FIG. 10 shows a view of a third exemplary embodiment from above, in which the feed dog 10 is held in the feed-dog holder 30 by way of a fastening element 40 which is configured as a guide rail. The feed dog is held in the position thereof by a holding element 70. The holding element 70 is configured by a snap-fit element 73. The snap-fit element 73 captively holds the feed dog on the guide rail. The snap-fit element 73 in this exemplary embodiment is configured as a gripper arm which in the locking position thereof is held by a spring element.
[0097] FIG. 11 shows a section through the feed dog and the associated guide rail 37 which is configured as a linear guide. The guide rail 37 contains a setting element 50. The setting element 50 may be configured as a set screw 56 which enables adjustment of the feed dog in the X-direction, that is to say in the direction transverse to the indexing direction.
[0098] Therefore, the feed dog 10, according to this first embodiment of the fastening element 40, is guided in a guide rail 37 which is configured as a settable linear guide. Herein, the feed dog 10 is configured as a slide, and the feed-dog holder 30 is configured as a lower or guide part, respectively, and is set by way of a setting element 50 between the slide and the guide part. In this way, the individual feed dogs 10 may be set ex-works during assembly to the respective sewing machine 101, so as to ensure that said feed dogs 10 meet the requirements set for the material feed. The guide rail 37 may contain an element from the group of dovetail guides, or of the encompassing linear guides.
[0099] FIG. 12 shows a view of a guide element 20 for a feed dog 10. The feed dog 10 contains the guide element 20, or may be fastened to the guide element 20. The guide element 20 has a main body which contains a guide slide such that a linear guide is configured. The guide slide contains a first clamping element 22 which enables fixing of the feed dog 10 in the Z-direction, and a second clamping element 23 which allows fixing of the feed dog 10 in the Y-direction and the Z-direction.
[0100] Two clamping elements may be provided in particular, wherein one of the clamping elements enables the adjustment in the X-direction, and the respective other clamping element enables the adjustment in the X-direction and the Z-direction. Thus, that clamping element that performs the adjustment in the X-direction is employed as a floating support, and that clamping element that performs the adjustment in the X-direction and the Z-direction is employed as a fixed support. The feed dog, by way of the clamping element 22, 23, is not ultimately secured in the operating position in the sense of being held therein, but is merely braced, and is finally held or secured, respectively, in the operating position by a securing element (not illustrated).
[0101] The guide element 20 has an arm element 24, disposed on the left side in FIG. 12, and an arm element 25, disposed on the right side. Each of the arm elements 24, 25 supports a support element 21 which is C-shaped in the cross section and in each of which one clamping element 22, 23 may be received. According to one exemplary embodiment (not illustrated) the clamping element 22, 23 may be integrated in the main body 5 or in the guide slide 7.
[0102] FIG. 13 shows a side view of the guide element 20 of the feed dog 10 in the X-Z plane. In the present exemplary embodiment, the support element 21 contains a groove in which one of the clamping elements 22, 23 is received. The illustrated clamping element 23 is an elastic element that is biased in the support element 21, configured as a groove, in such a manner that said clamping element 23 has a curvature. This curvature bears on the wall of the feed-dog holder 30 (not illustrated here) such that the spacing of the feed dog 10 from the feed-dog holder 30 is establishable by way of the curvature radius of the clamping element 23.
[0103] FIG. 14 shows a view of the feed-dog holder 30 that is associated with the exemplary embodiment according to FIG. 13. The feed-dog holder 30 has a C-shaped cross section. In the present exemplary embodiment, one groove is configured by each of the legs of the “C”, a support element 21, as is shown in FIG. 12 or FIG. 13, being received in said groove. Each of the clamping elements 22, 23 is an elastic element which in the clearance is biased in such a manner that said elastic element has a curvature. An arc that bears on the wall of the feed-dog holder 30 is configured by this curvature, such that the feed dog 1 is establishable in the feed-dog holder 30 by way of the contact pressure of the clamping element 22, 23.
[0104] FIG. 15 shows a view of a sewing machine 101. The sewing machine 101 has a machine head 107 having a sewing device. The machine head 107 is disposed at the end of an upper arm 105. An upright element 102 adjoins the other end of the upper arm 105. A so-called arm bed 103 is disposed below the upper arm 105, so as to run substantially parallel with the upper arm 105. The arm bed 103 at one end is connected to the upright element 102. The arm bed 103 serves as a support for the sewn product 115. The machine head 107 contains a needle 111 which is moved up and down and periodically comes into contact with the sewn product 115. A needle thread 120 is guided in the sewing needle 111. The sewing needle 111 pierces the sewn product 115, the needle thread 120 herein being connected to a bobbin thread 116 that is located below the sewn product 115, on account of which a seam or a pattern is generated. The sewing needle 111 is releasably connected to a needle holder which is disposed at a lower end of a needle bar 109. The needle bar 109 is moved up and down by a needle-bar drive. The needle bar 109 is thus movable up and down in the direction of the needle-bar axis A, in order to carry out sewing stitches, this being symbolized by the double arrow A′. In order for zigzag stitches to be carried out, the needle bar 109 is mounted in the machine head 107 so as to be additionally pivotable about a pivot axis B, in a manner transverse to the sewing direction N, or in the longitudinal direction of the upper arm 105, respectively, this potentially being symbolized by the double arrow B′. The machine head 107 furthermore contains a presser-foot bar which has a conically or truncated-conically running lower end for coupling and fastening various presser feet. The presser-foot bar is not shown in the present illustration. Dissimilar presser feet are employed, depending on the type of sewing jobs to be carried out. At the commencement of the job, the presser-foot bar together with the presser foot is lowered such that the sole of the presser foot bears on the sewn product 115. In this position, the sewn product 115 is located on the needle-hole plate 113 between the feed dog 10 and the sole of the presser foot such that the location at which a needle stitch is to take place is precisely defined. The sewn product 115, prior to the next stitch being performed, may be displaced to the correct position by the feed dog 10 such that a continuous seam or a continuous needle pattern may be generated in this way. The feed dog 10 thus serves for ensuring that the sewn product 115 is indexed. Alternatively, the sewn product 115 may be clamped in an embroidery frame. The embroidery frame may be moved in the X-direction or the Y-direction, respectively, in a plane that contains the sewn product 115, such that the next piercing location of the sewn product 115 comes to lie below the sewing needle 111. The embroidery frame may be moved by a control element which may be a component part of the sewing machine or may be coupled to an external computer. Of course, the sewn product 115 may also be manually displaced across the support plane that is configured by the needle-hole plate and the surface of the arm bed 103 that adjoins said needle-hole plate. This operating mode is employed for darning or quilting, for example.
[0105] The needle-hole plate 113 comprises an elongate hole 114 through which the lower portion of the sewing needle 111, having pierced the sewn product 115 that is located on the needle-hole plate 113, may be guided into the forward region of the lower arm 103 during sewing. This means that the lower portion of the sewing needle at times protrudes into the interior of the arm bed 103, therefore being located below the needle-hole plate 113. In this position, the bobbin thread 116 may be encompassed by the sewing needle 111 and be linked to the needle thread 120 that is guided by the eyelet 129 of the sewing needle 111 in such a manner that a seam may be configured on the sewn product 115.
[0106] FIG. 16 shows a perspective illustration of a fourth exemplary embodiment according to the invention, in an exploded illustration. The device for manually changing a feed dog 10 for a sewing machine, according to FIG. 16, comprises the feed dog 10 and a feed-dog holder 30. The feed dog 10 is receivable in a clearance 31 of the feed-dog holder 30. The feed-dog holder 30 is disposed in an arm bed 103 of the sewing machine 101, as is shown in FIG. 15. The feed dog 10 is fastenable in a clearance 81 of an insert element 80 by a fastening element 40, wherein the fastening element 40 is releasably held in the insert element 80. The fastening element 40 may be configured as a bolt, for example. According to the embodiment in FIG. 16, various feed dogs 10 may be fastened in the insert element 80 by way of two fastening elements 40. The insert element 80 is received in the feed-dog holder 30. The insert element 80 is received in a clearance 31 of the feed-dog holder 30. The insert element 80 is held in the feed-dog holder 30 by one or a plurality of fastening elements 82, 83.
[0107] A setting element 50 by way of which the feed dog 10 in the position thereof in relation to the clearance 31 and/or to the insert element 80 is settable is also illustrated in FIG. 16. The setting element 50 according to FIG. 16 is configured as a pin which has a head end 51 and a neck 52. The head end 51 has a larger diameter than the neck 52. The neck 52 may have an external thread. The neck 52 may at least partially be held in a bore 33 that is attached in the clearance 31 or the clearance 81. The bore 33 may be configured as a threaded bore. The setting element 50 may contain a locking element 53. The locking element 53 serves for locking in relation to the needle-hole plate 113 which is not shown in FIG. 16. The locking element 53 according to the present exemplary embodiment is configured as an L-shaped tab. The lower leg of the “L” in the installed state is in particular vertically aligned and protrudes into a respective clearance of the needle-hole plate 113, as is shown in FIG. 19. The insert element 80 serves for the alignment of the feed dog. The insert element 80 ex-works is loosely screw-fitted, the feed dog 10 is inserted and is merely held by the setting element 50 which is configured as a locking element or a holding element, for example. Once the feed dog 10 has been aligned by way of the insert element 80, the latter is tightly screwed to the feed-dog holder 30.
[0108] The neck 52 may also be configured without an interference fit, that is to say with play, or may be held in the threaded bore 33 by a shaft lock-down device, for example a Benz pin (not shown), wherein a plain bore instead of a threaded bore may be provided. The alignment is not performed by way of an eccentric feature. Both fastening elements 40 are preferably embodied as interference-fit bolts, this is to say without play.
[0109] As is the case in FIG. 1, the setting element 50 may contain an eccentric disk, or the head end 51 may be configured as an eccentric feature, this being illustrated in the embodiment according to FIG. 20, for example. The head end 51 may have a receptacle element for an activation key. According to one further exemplary embodiment, the head end 51 may have a rough profile or a fluted feature, enabling the head end 51 to be manually rotated so as to move the locking element 53 to the desired position, on account of which establishing the feed dog 10 in relation to the needle-hole plate 113 may be performed. The tab may also serve as a handle or a lever element for moving the setting element to the desired position. The feed dog 10 may thus be aligned so as to correspond to the contour that is located in the needle-hole plate 113 of the sewing machine 101. A needle-hole plate 113 of this type is shown in a partially fragmented view in FIG. 19, for example.
[0110] If and when two fastening elements 40 are used, one of the fastening elements 40 may be received without play, that is to say by way of an interference fit, in the bore 12 of the feed dog 10, and the respective other fastening element 40 may be received without an interference fit, that is to say with play, in the associated bore 13 of the feed dog 10.
[0111] A fixing element which may be configured as a magnetic element, in particular as a magnetic pin, for example, may be used for fixing the feed dog 10 and/or the insert element 80 in the correct position, prior to the blocking of the feed dog 10 being performed by the fastening element or elements 40, or prior to the blocking of the insert element 80 being performed by the fastening elements 82, 83.
[0112] FIG. 17 shows a further perspective illustration of a fourth exemplary embodiment according to the invention, in an exploded illustration, according to FIG. 16. The insert element 80 which has a first ledge 84 and a second ledge 85 is shown in FIG. 17. The bores 32 for the fastening elements 82, 83 are provided in the ledges 84, 85. The lateral flanks of the feed dog 10 bear on the internal edges of the ledges 84, 45. One ledge 87, 88 each may likewise be disposed in the clearance 31 of the feed-dog holder 30. The external edges of the ledges 84, 85 bear on the ledges 87, 88 of the feed-dog holder 30, if and when the insert element 80 is fastened to the feed-dog holder 30.
[0113] FIG. 18 shows a view of the feed dog 10 in FIG. 16, in the installed state, with the needle-hole plate 113 removed. The feed dog 10 is inserted into the insert element 80 which in turn is inserted into the feed-dog holder 30. The insert element 80 is connected to the feed-dog holder 30 by the fastening elements 82, 83. It is shown in FIG. 18 that the spacing between the ledges 84, 85 of the insert element 80 corresponds exactly to the width of the feed dog 10, such that the feed dog 10 may be precisely held in the clearance 81. Two fastening elements 40 of identical type extend from the internal base of the insert element 80 through the respective bores 12, 13 of the feed dog 10. Due to this, the position of the feed dog 10 in the X-direction may be fixed. The position of the insert element in the X-direction and in the Y-direction is established by the fastening elements 82, 83. If and when the lateral flanks of the feed dog 10 are fitted accurately between the internal flanks of the ledges 84, 85, the position of the feed dog 10 in the X-direction is also established. If and when at least one of the bores 12, 13 is configured as bore with play, the position of the feed dog 10 in the Y-direction may still be variable. Therefore, the position of the feed dog 10 in the Y-direction may be established by the setting element 50. To this end, the locking element 53 may be located in the locking position that is shown in FIG. 18. The locking element 53 may be configured so as to be integral with the head end 51 and/or the neck 52; said locking element 53 may however also be disposed so as to be rotatable about a locationally fixed neck. The feed dog 10 may have a respective clearance 90 which is specified for engaging the locking element 53. An unlocking clearance 75 for receiving the locking element 53 in the unlocked position thereof, for example, if and when the feed dog 10 is being replaced by another feed dog, may be provided in the feed-dog holder 30.
[0114] FIG. 19 shows a section through the feed dog 10 according to FIG. 16, in the installed state, in a perspective illustration. The feed dog 10 bears on the support face that is formed by the clearance 81 of the insert element 80. The insert element 80 bears on the clearance 31 that is formed by the feed-dog holder 30. Only part of the locking element 53, specifically part of the tab which protrudes through a respective opening in the needle-hole plate 113, is visible of the setting element 50. FIG. 19 also shows an opening in the needle-hole plate for one of the feed-dog arms, specifically for the external web 16. The second feed-dog arm, that is to say the external web 17 according to FIG. 5, is not visible in the present illustration, since said external web 17 lies in front of the sectional plane. The locking element 53 is configured in combination with the needle-hole plate 113 such that the locking element 53 engages in the clearance of the needle-hole plate 113 only once the locking action has been completely activated, such that it is guaranteed that the needle-hole plate 113 cannot be fitted in the case of an incomplete locking action.
[0115] FIG. 20 shows a perspective illustration of a fifth exemplary embodiment according to the invention, in an exploded illustration. The device for manually changing a feed dog 10 for a sewing machine, according to FIG. 20, comprises the feed dog 10 and a feed-dog holder 30. The feed dog 10 is receivable in a clearance 31 of the feed-dog holder 30. The feed-dog holder 30 is disposed in an arm bed 103 of the sewing machine 101, as is shown in FIG. 15. The feed dog 10 is fastenable in a clearance 81 of an insert element 80 by a fastening element 40, wherein the fastening element 40 may be releasably held in the insert element 80. The fastening element 40 may be configured as a dovetail groove, for example. One lateral flank of the feed dog 10 may be push-fitted in each case into this dovetail groove. The width of the feed dog 10 in the region of the lateral flanks may increase from the upper side, that is to say that side that during operation comes into contact with the sewn product, toward the opposite side, that is to say the lower side in the drawing. Due to this, the feed dog 10 is captively held in the insert element. According to the embodiment in FIG. 20, various feed dogs 10 may be fastened in the insert element 80 by way of two fastening elements 40. The dovetail groove may have flanks that form part of a cone, the tip of the latter pointing in the direction of the webs 16, 17, 18 of the feed dog 10. The feed dog 10 may be centered in the dovetail groove by way of a conical embodiment of the dovetail groove.
[0116] The insert element 80 is received in the feed-dog holder 30. The insert element 80 is received in a clearance 31 of the feed-dog holder 30, in particular. The insert element 80 is held in the feed-dog holder 30 by one or a plurality of fastening elements 82, 83. The alignment of the feed dog is performed ex-works by way of the insert element 80. The setting element 50 serves only as a locking feature. The setting element 50 may also in the case of this embodiment be held in the bore by way of a fit with play, or by way of a securing bolt.
[0117] A setting element 50, by way of which the feed dog 10 in the position thereof in relation to the clearance 31 and/or to the insert element 80 is settable, is also illustrated in FIG. 20. The setting element 50 according to FIG. 20 is configured as a lever element which has a head end 51 and a neck 52. The head end 51 has a larger diameter than the neck 52. The neck 52 may have an external thread. The neck 52 can at least be partially held in a bore 33 that is attached in the clearance 31 or the clearance 81. The bore 33 may be configured as a threaded bore. The setting element 50 may contain a locking element 53. The locking element 53 serves for locking in relation to the needle-hole plate 113 that is not shown in FIG. 20. The locking element 53 according to the present exemplary embodiment is composed of the head end 51 which is in contact with a spring element that is attached to the feed dog 10, if and when the feed dog 10 is located in the installed position thereof.
[0118] The feed dog is locked in the installed position in that the lever element of the setting element 50 is moved to a position in which the head end 51 presses onto the spring element 19 that is shown in FIG. 21, biasing the latter. The setting element 50 contains a detent 57 that in the installed state is in particular vertically aligned and protrudes into a respective opening 140 of the needle-hole plate 113, as is shown in a similar manner in FIG. 19 for the tab of the locking element 53.
[0119] The spring element 19 may be inserted into the feed dog 10, that is to say be configured as an inlay element, or said spring element 19 may be configured as a component part of the feed dog 10. In particular, the spring element may be manufactured from the base material by way of a locally acting material-treatment method, for example by hardening, zone-melting, tempering, radiation, or other methods that are known to a person skilled in the art for modifying the microstructure of the material of the feed dog in a localized manner.
[0120] As in FIG. 1, the setting element 50 may contain an eccentric disk, or the head end 51 could be configured as an eccentric feature, as is illustrated in FIG. 20 or FIG. 21. The head end 51 may have a receptacle element for an activation key. According to one further exemplary embodiment, the head end 51 may have a rough profile or a fluted feature, enabling the head end 51 to be manually rotated so as to move the locking element 53 to the desired position, on account of which establishing the feed dog 10 in relation to the needle-hole plate 113 may be performed. The tab or detent 57 may also serve as a handle or gripping element for a tool for moving the setting element 53 to the desired position.
[0121] The feed dog 10 may thus be aligned depending on the contour that is located in the needle-hole plate 113 of the sewing machine 101. A needle-hole plate 113 of this type is shown in a partially sectional view in FIG. 19, for example. In particular, it may be avoided by way of this fine adjustment that the feed dog 10 during operation comes into contact with an edge of the needle-hole plate 113, and that the feed dog 10 or the needle-hole plate 113 may be damaged. In particular, the needle-hole plate may have an opening 140 that is generated by a milling method, for example. The needle-hole plate 113 may only be fitted upon complete locking of the feed dog, since the detent 57 only fits into the opening 140 in this instance.
[0122] If and when two fastening elements 40 are used, the feed dog may be received in one of the fastening elements 40 without play, that is to say by way of an interference fit, and may be received in the respective other fastening element 40 without an interference fit, that is to say with play. In particular in the case of the configuration of the fastening element as a dovetail groove, a movement of the feed dog in the X-direction and in the Z-direction may be prevented. The movement in the Y-direction, according to the exemplary embodiment that is illustrated in FIGS. 20, 21, may be prevented by bracing the spring element 19 by the setting element 50.
[0123] A fixing element which may be configured as a magnetic element for example, in particular as a magnetic pin, may be used for fixing the feed dog 10 and/or the insert element 80 in the correct position before blocking of the feed dog 10 is performed by the fastening element or elements 40, or before blocking of the insert element 80 by the fastening elements 82, 83 is performed, respectively.
[0124] One advantage of this exemplary embodiment lies in that a precise alignment of the feed dog is enabled both in the X-direction as well as in the Y-direction by fastening elements which are configured as form-fitting guide elements for the feed dog, such as a dovetail groove for a respective flank of the feed dog, for example. In particular, the web elements 16, 17, 18 of the feed dog are aligned so as to be parallel with the Y-axis, that is to say that said web elements are aligned exactly in the indexing direction of the sewn product. The alignment in the X-direction, that is to say in the longitudinal direction of the arm bed 103, is performed exactly in relation to the respective clearance or the respective clearances in the needle-hole plate 113.
[0125] It is obvious to a person skilled in the art that many further modifications are possible in addition to the exemplary embodiments described, without departing from the inventive concept. The subject matter of the invention is thus not limited by the preceding description and is defined by the scope of protection that is established by the claims. The widest possible reading is relevant to the interpretation of the claims or of the description. In particular, the terms “contain” or “include” are to be interpreted in such a manner that they refer to the meaning of elements, components, or steps in a non-exclusive manner, on account of which it is to be indicated that the elements, components, or steps may be present or used such that they may be combined with other elements, components, or steps that are not explicitly mentioned. If and when the claims refer to an element or to a component from one group that may be comprised of A, B, C . . . N elements or components, this wording is to be interpreted in such a manner that only one single element of this group is required and this does not require a combination of A and N, B and N, or any other combination of two or more elements or components of this group.
