Abstract
Hook for lockstitch sewing machine, both of the rotary type and of the Central Bobbin type (CB-shuttle or CB-hook), which includes a bobbin case (508, 708, 808, 908, 1008, 1108, 1208) with an improved slide, composed of multiple components, including a slide body (515a, 615a, 715a, 815a, 915a, 1115a, 1215a) which performs entirely the functions of guiding the slide on the bobbin case and of creation of the leverage with the lever (16, 16b), and at least one secondary component (582, 782, 882, 982, 1182, 1286), fixed to the slide body and apt to perform the function of slide's claw or guide and/or protection of the thread.
Claims
1. A rotary or Central Bobbin (CB-shuttle) hook for a lockstitch sewing machine, the hook comprising: a bobbin case including a slide and a lever, said slide comprising multiple primary components including a slide body housed in a guide of the bobbin case, the lever moving in relation to the slide body to provide leverage for disengagement of the slide, and at least one secondary component connected to said slide body and separate from said slide body.
2. The hook according to claim 1, wherein said at least one secondary component is connected to the slide body by one or more of gluing, clinching, riveting, interlocking, and screwing using one or more screws.
3. The hook according to claim 1, wherein said at least one secondary component is mounted on the slide body before the insertion of the slide body into the guide on the bobbin case, by at least one interlock in a groove formed on the underside of the slide body.
4. The hook according to claim 1, wherein said at least one secondary component is mounted on the slide body after the insertion of the slide body into the guide on the bobbin case.
5. The hook according to claim 1, wherein said at least one secondary component connected to the slide body and separate from the slide body is a slide claw separate from the slide body.
6. The hook according to claim 5, wherein a front part of the slide body is longer than the maximum protrusion of said secondary component and overlaps an opening formed in a wall of the bobbin case for the passage of the slide claw, and cooperates with said bobbin case wall to create the continuity of the profile to support the passage of the needle thread.
7. The hook according to claim 1, wherein the continuity of the profile of the bobbin case to support the passage of the needle thread is realized by a bobbin case wall.
8. The hook according to claim 7, further comprising a recess formed in the inner diameter of the bobbin case wall, the recess being contained within the thickness of said wall, the recess configured to receive the slide claw in a forward position at rest of the slide.
9. The hook according to claim 1, wherein said at least one secondary component connected to the slide body and separate from the slide body is an element configured to guide and protect the bobbin thread.
10. A bobbin case of a rotary or Central Bobbin (CB-shuttle) hook for a lockstitch sewing machine, the bobbin case including a slide and a lever, said slide comprising: multiple primary components including a slide body housed in a guide of the bobbin case, the lever moving in relation to the slide body to provide leverage for disengagement of the slide, and at least one secondary component connected to said slide body and separate from said slide body.
11. The hook according to claim 5, wherein the slide claw separate from the slide body is made of a sheet bent into a C-shape, the sheet having a thickness less than the thickness of the slide body.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The invention will now be described with reference to exemplifying but non limiting embodiments, described in the appended figures, wherein:
(2) FIG. 1 shows an exploded view of a Central Bobbin hook (CB-shuttle) complete with bobbin case, known;
(3) FIG. 2 shows an exploded view of a complete rotary hook with bobbin case, known;
(4) FIG. 3 shows only the bobbin case, the bobbin and the basket of the rotary hook as FIG. 2, known, disassembled and sectioned with a plane passing through the axis of rotation of the hook;
(5) FIG. 4 shows another embodiment of the bobbin case, the bobbin and the basket of the rotary hook of FIG. 2 for coreless bobbins, known, disassembled and sectioned with a plane passing through the axis of rotation of hook;
(6) FIGS. 5a and 5b show an embodiment of the bobbin case according to the present invention respectively in perspective and exploded view;
(7) FIG. 5c shows the slide claw illustrated in FIG. 5b;
(8) FIG. 5d shows the slide body illustrated in FIG. 5b;
(9) FIG. 5e shows a top view of the bobbin case of FIG. 5b;
(10) FIG. 6d shows a modification of the slide body illustrated in FIG. 5d according to the present invention;
(11) FIG. 7 shows a perspective view of another embodiment of the bobbin case according to the present invention;
(12) FIGS. 8a, 8b, and 8e show another embodiment of the bobbin case according to the present invention, respectively in perspective, exploded, and top views;
(13) FIGS. 9a, 9b, and 9e show another embodiment of the bobbin case according to the invention, respectively in perspective, exploded, and top views;
(14) FIGS. 10a and 10e show another embodiment of the bobbin case according to the present invention, respectively in perspective and top views;
(15) FIGS. 11a and 11b show another embodiment of the bobbin case according to the present invention, respectively in perspective and top views;
(16) FIG. 11c shows the slide claw illustrated in FIG. 11b;
(17) FIG. 11d shows the slide body illustrated in FIG. 11b;
(18) FIGS. 12a and 12b show another embodiment of the bobbin case according to the present invention, respectively in perspective and top views;
(19) FIG. 12c shows the slide claw illustrated in FIG. 12b;
(20) FIG. 12d shows the slide body illustrated in FIG. 12b.
DETAILED DESCRIPTION OF THE INVENTION
(21) Since, as mentioned, the changes of a complete hook according to the present invention compared to a known complete hook, affect only its bobbin case and the relative slide, in the following will be illustrated in the figures and descriptions, only the bobbin cases and the relative slides according some embodiments of the present invention, omitting, for simplicity, to represent every time the rest of the complete hook.
(22) FIGS. 5a-5e show an embodiment of the bobbin case comprising an improved slide, composed of multiple components, according to the invention, with the presence of a flat slide body and a slide's claw made separately with a “C-bent” thin metal sheet and fixed to the slide body by means of an interlock in a groove formed on the underside of the slide body. The secondary component is mounted in the interlock before the insertion of the slide body into the guide on the bobbin case and remains fixed there once the slide body is inserted into said guide.
(23) FIG. 6d shows a different embodiment of the slide body shown in the previous FIG. 5d, from which it differs only by the simplified shape of the groove formed on the underside of the slide body for the interlocking of the secondary component of the slide's claw. This groove is easier to implement because it is produced by a single straight groove on the underside of the slide body (while in the execution of the groove according to FIG. 5d, the groove had a “T” shape).
(24) FIG. 7 shows a different embodiment of the bobbin case according to the invention, similar to that shown in the preceding FIGS. 5a-5e, from which it differs only by the front of the slide body that is longer than the maximum protrusion of the component constituting the slide's claw and that in the forward position at rest of the slide overlaps the opening formed in the wall of the bobbin case for the passage of the slide's claw, and cooperates herewith with the bobbin case wall to create the continuity of the profile to support the passage of the needle thread, that the opening on the wall interrupted. The embodiment shown in this figure presents also a protuberance on the outer wall of the bobbin case in correspondence to the position of the slide's claw.
(25) FIGS. 8a, 8b, 8e show a different embodiment of the bobbin case according to the invention, comprising an improved slide, composed of multiple components, with the presence of a slide body and a slide's claw made separately with a thin “C-bent” sheet and fixed to the slide body by means of an interlock in a groove formed on the underside of the slide body. The secondary component is mounted into the interlock after the insertion of the slide body into the guide on the bobbin case in a retracted position of the slide body beyond its backwards working stroke's end point and remains fixed to the slide body once the translation of the slide body is limited to its working stroke by means of the assembly of the lever.
(26) The secondary component constituting the slide's claw, in this embodiment is mounted from inside the well of the bobbin case after the insertion of the slide body into the guide on the bobbin case, while the slide body is in a retracted position. This embodiment avoids to have the through opening in the wall of the bobbin case, as it is sufficient a recess formed in the thickness of said wall to house the slide's claw in the forward position at rest of the slide, thus being realized the continuity of the profile of the bobbin case wall to support the passage of the needle thread.
(27) FIGS. 9a, 9b, 9e show a different embodiment of the bobbin case according to the invention, similar to that shown in the preceding FIG. 8, from which it differs only by the way of fixing to the body slide the secondary component constituting the slide's claw, which in this embodiment takes place through a screw. Also in this embodiment, the secondary component is mounted from the inside of the well of the bobbin case after the insertion of the slide body into the guide on the bobbin case.
(28) FIGS. 10a, 10e show a different embodiment of the bobbin case according to the invention, similar to that shown in the preceding FIG. 9, from which it differs only by the presence of a protuberance on the outer wall of the bobbin case in correspondence to the position of the slide's claw and the relative recess on the inside of the bobbin case's wall, which can be deeper thanks to the increase of thickness of the bobbin case's wall in this area due to the protuberance.
(29) FIGS. 11a-11d show a different embodiment of the bobbin case according to the invention, similar to that shown in the preceding FIG. 10, from which it differs only by the assembling way of the secondary component constituting the slide's claw, that also in this embodiment is mounted after the insertion of the slide body into the guide on the bobbin case, but this time it is mounted from the outside of the bobbin case, i.e. from above the slide, instead from the inside of the well of the bobbin case.
(30) FIGS. 12a-12d show a different embodiment of the bobbin case comprising an improved slide, composed of multiple components, according to the invention, with the presence of a slide body and a component, which performs the function of guide or protection of the thread that is fixed to the slide body by means of an interlock in a groove formed on the underside of the slide body. The secondary component is mounted in the interlock before the insertion of the slide body into the guide on the bobbin case and remains fixed there once the slide body is inserted into said guide. Said secondary component is fixed to the rear side of the slide (opposite to the slide's claw) and has the function to guide and to protect the bobbin thread in the rotary hooks designed for coreless bobbins and bobbin cases and baskets without central shaft, in which the bobbin thread exits from the center of the bobbin case and passes between the slide body and the lever.
(31) In the appended Figures, corresponding elements will be identified by the same numerical references.
(32) FIG. 1 shows schematically an exploded view of a Central Bobbin hook 11 with horizontal axis “α” of rotation, known, in which only the elements relevant to the present description have been identified by numerical references: a hook body 2, comprising a well 18 in which the bobbin case 8 complete with bobbin 4 is housed; bobbin case 8 housed in the well 18 of the hook body 2, free to rotate within the hook body 2 and complete with slide 15 for the axial restraint of the bobbin case 8 to the hook body 2 to prevent accidental disassembly during sewing, with lever 16 that with its leverage system created on the slide 15 allows the operator to disengage the slide 15, and herewith the bobbin case 8, from the axial constraint to the hook body 2 to allow the removal of the bobbin case 8, and with the tension spring 9 to give tension to the bobbin thread (of which the graphical representation is omitted) wound on the bobbin 4 housed inside the bobbin case 8; a bobbin 4, on which is wound the bobbin thread (not shown), is housed in the bobbin case 8 and is constrained within the hook body 2 by the mounting of the bobbin case 8 on the hook body 2.
(33) FIG. 2 shows schematically an exploded view of a rotary hook 12 with horizontal axis “α” of rotation, known, in which only the elements relevant to the present description have been identified by numerical references: a hook body 2; a basket 6, free to rotate inside of the hook body 2 comprising: a well 18 of the basket 6 in which is housed the bobbin case 8 complete with bobbin 4; a bobbin case 8 housed in the well 18 of the basket 6, complete with slide 15 for the axial constraint of the bobbin case 8 to the basket to prevent accidental disassembly during the sewing operation, and complete with lever 16 that with its leverage system created on slide 15 allows the operator to disengage the slide 15, and herewith the bobbin case 8, from the axial constraint to the basket 6 to allow the removal of the bobbin case, and complete with tension spring 9 to give tension to the bobbin thread (whose graphical representation is omitted) wound on the bobbin 4 housed inside the bobbin case 8; a bobbin 4, on which is wound the bobbin thread (not shown), is housed in the bobbin case 8 and is constrained within the basket 6 by the mounting of the bobbin case 8 on the basket 6.
(34) FIG. 3 shows the only sub-assemblies basket 6, bobbin 4 and bobbin case 8, of the rotary hook 12 of FIG. 2, known, sectioned on a plane passing through the axis of rotation “α”. There are visible: the basket 6 comprising a well 18 of the basket 6 apt to house the bobbin case 8 with inside the bobbin 4, an inner diameter 19 delimiting said well 18 of the basket 6 in which fits the outer diameter 20 of the bobbin case 8, a protrusion 21 on the inner diameter 19 of said well of the basket 6 that mating with the guide 22 on the outer diameter 20 of the bobbin case 8 allows the angular reference of the bobbin case 8 for the proper fitting of the bobbin case 8 on the basket 6, a shaft 23 on which the hole 24 of the shaft 25 of the bobbin case 8 is inserted, an undercut formed by a groove 80 on shaft 23 with which the slide 15 is constrained when the bobbin case 8 is mounted on the basket 6; a bobbin case 8, complete with slide 15 and lever 16 (shown in the forward position at rest, as when the bobbin case is mounted on the basket) and comprising an outer diameter 20, a guide 22 on the outer diameter 20 of the bobbin case 8 and parallel to axis “α”, which mating with the protrusion 21 on the inner diameter 19 of the well 18 of the basket 6 allows the angular reference for proper fitting of the bobbin case 8 on the basket 6, a shaft 25 with a coaxial hole 24, a slide's claw 82 on the front of the slide 15, an edge 81 of the central hole of the slide that cooperates with the undercut formed by the groove 80 on the shaft 23 of the basket 6 to constrain the slide 15 when the bobbin case 8 is mounted on the basket 6, a through opening 70 on the wall of the bobbin case and on the outer diameter 20 of the bobbin case to pass the slide's claw 82, a guide 71 for guiding the slide; a bobbin 4, on which is wound the bobbin thread 7, which must be housed in the bobbin case 8 and is then constraint inside the basket 6 when the bobbin case 8 is mounted on the basket 6.
(35) FIG. 4, like the previous FIG. 3, shows the only sub-assemblies basket 6b, bobbin 4b and bobbin case 8b, of the rotary hook 12 of FIG. 2, known, but this time in the execution, also known, for coreless bobbins 4b, sectioned on the same plane passing through the axis of rotation “a” as in FIG. 3. These known bobbins 4b are generally composed merely of pre-wound and compacted bobbin thread 7, so as not to need a metal or synthetic core. The exit of the bobbin thread 7 from the bobbin 4b, is generally axially rather than tangentially as for the traditional bobbins 4.
(36) In FIG. 4 are visible: the basket 6b comprising a well 18b of the basket 6b apt to house the bobbin case 8b complete with bobbin 4b, an inner diameter 19 delimiting said well 18b of the basket 6b in which fits the outer diameter 20 of the bobbin case 8b, a protrusion 21 on the inner diameter 19 of said well 18b of the basket 6b, which mating with the guide 22 on the outer diameter 20 of the bobbin case 8b allows the angular reference of the bobbin case 8b for the proper fitting of the bobbin case 8b on the basket 6b, an undercut formed by a groove 80b on the inside diameter 19 of the well 18b, with which the slide 15b is constrained when the bobbin case 8b is mounted on the basket 6b; a bobbin case 8b, complete with slide 15b and lever 16b and comprising an outer diameter 20 of the bobbin case wall, a guide 22 on the outer diameter 20 of the bobbin case 8b and parallel to the axis “α”, which mating with the protrusion 21 on the inner diameter 19 of the well 18b of the basket 6b allows the angular reference for the proper fitting of the bobbin case 8b on the basket 6b, a slide's claw 82 on the front of the slide 15b, an edge 81b formed on the front of the slide 15b that cooperates with the undercut formed by the groove 80b on the inner diameter 19 of the well 18b of the basket 6b to constrain the slide 15b when the bobbin case 8b is mounted on the basket 6b, a through opening 70 on the wall of the bobbin case and on the outer diameter 20 of the bobbin case to pass the slide's claw 82, a guide 71 for guiding the slide a bobbin 4b, consisting of pre-wound and compacted bobbin thread, so as not to need a metal or synthetic core, which must be housed in the bobbin case 8b and is then constraint inside the basket 6b when the bobbin case 8b is mounted on the basket 6b.
(37) FIGS. 5a-5e show an embodiment of the bobbin case 508 comprising an improved slide 515, composed of multiple components, according to the invention, with the presence of a flat slide body 515a and a slide's claw 582 made separately with a “C-bent” thin sheet and fixed to the slide body 515a by means of an interlock in a groove 583 formed on the underside of the slide body 515a. The secondary component 582 is mounted in the interlock 583 before the insertion of the slide body 515a into the guide 71 on the bobbin case and remains fixed there once the slide body is inserted into said guide. FIG. 5a shows the mounted bobbin case, FIG. 5b shows the same bobbin case with the components exploded, FIG. 5c shows only the slide's claw 582, FIG. 5d shows only the slide body 515a with the relative details and FIG. 5e shows only the body of the bobbin case 508a.
(38) FIG. 6d shows a different embodiment of the slide body 615a compared to the previous FIG. 5d: it varies from that one only for the simplified form of the groove 683 formed on the underside of the slide body 615a for the interlock of the secondary component of the slide's claw. This groove is easier to implement because it is made by a single straight groove on the underside of the slide body (while in the execution of the groove according to FIG. 5d, the groove had the shape of a “T”).
(39) FIG. 7 shows a different embodiment of the bobbin case 708 according to the invention, similar to that 508 of the preceding FIGS. 5a-5e and varies from that one only for the front part 784 of the slide body 715a that is longer than the maximum protrusion of the component 782 constituting the slide's claw and that in the forward position at rest of the slide overlaps the opening 770 formed in the wall of the bobbin case for the passage of the slide's claw 782, and cooperates herewith with the bobbin case wall to create the continuity of the profile, to support the passage of the needle thread, that the opening on the wall was interrupting. In the embodiment shown in these figures is present also a protuberance 785 on the outer wall of the bobbin case in correspondence to the position of the slide's claw 782.
(40) FIGS. 8a, 8b, 8e show a different embodiment of the bobbin case 808 according to the invention, comprising an improved slide, composed of multiple components, with the presence of a flat slide body 815a and a slide's claw 882 made separately with a “C-bent” thin metal sheet and fixed to the slide body by means of an interlock in a groove 883 formed on the underside of the slide body 815a. The secondary component 882 is mounted in the interlock 883 after the insertion of the slide body 815a into the guide 71 on the bobbin case 808a in a retracted position of the slide body beyond its backwards working stroke's end point and remains fixed to the slide body 815a once the translation of the slide body 815a is limited to its working stroke by means of the assembly of the lever 16. Appropriate openings 872 are present on the inside bottom of the bobbin case body 808a, only for the purpose to mount the secondary component 882 in the retracted position of the slide beyond its backwards working stroke's end point. As can be seen from FIG. 8e of the bobbin case body 808a, this embodiment avoids to have the through opening in the wall of the bobbin case and is sufficient to have a recess 873 formed in the thickness of said wall to house the slide's claw 882 in the forward position at rest of the slide, thus being realized the continuity of the profile on the bobbin case wall to support the passage of the needle thread. Note that in this representation the wall thickness of the bobbin was not increased in correspondence to the recess 873.
(41) FIGS. 9a, 9b, 9e show a different embodiment of the bobbin case 908 according to the invention, similar to that 808 of the preceding FIGS. 8a, 8b, 8e and that varies from these only for the fixing method of the secondary component constituent the slide's claw 982 to the slide body 915a, which in this embodiment is realized by means of a screw 984 that is screwed into a threaded hole 987 realized on the slide body 915a on which, on the opposite, is absent the groove for the interlocking. Also in this embodiment the secondary component 982 and the screw 984 are mounted from the inside of the well of the bobbin case after the insertion of the slide body 915a into the guide 71 on the bobbin case. The appropriate openings 972 on the inner bottom of the bobbin case body 908a are simplified compared to those of the bobbin case 808 previously described. As can be noticed from FIG. 9e of the bobbin case body 908a, also in this embodiment the through opening in the wall of the bobbin case has been avoided and the recess 973 formed in the thickness of said wall is sufficient to house the slide's claw 982 in the forward position at rest of the slide. Note that also in this representation the wall thickness of the bobbin case was not increased in correspondence to the recess 973.
(42) FIGS. 10a, 10e show a different embodiment of the bobbin case 1008 according to the invention, similar to that shown in the preceding FIGS. 9a, 9b, 9e, from which it differs only by the presence of a protrusion 1085 on the outer diameter 20 of the wall of the bobbin case body 1008a in correspondence to the recess 1073 to house the slide's claw 982 and by its recess 1073 on the inside of the wall of the bobbin case body, which can thus also be deeper, without the risk of making the bobbin case wall too thin at that point, with embrittlement of the same.
(43) FIGS. 11a-11d show a different embodiment of the bobbin case 1108 according to the invention, similar to that shown in the preceding FIGS. 10a, 10e, from which it differs only by the slide body 1115a, the slide's claw 1182 and the assembling way of the secondary component constituting the slide's claw 1182, that also in this embodiment is mounted after the insertion of the slide body 1115a into the guide 71 on the bobbin case body 1008a, but this time it is mounted from the outside of the bobbin case, i. e. from above the slide, instead from inside the well of the bobbin case. In the implementation shown, the secondary component 1182 is mounted on the slide body 1115a by means of both an interlock in a groove 1183 formed in the upper side of the slide body, and a screw 1184 that is screwed into a threaded hole 1187 realized on the slide body 1115a. In the implementation shown, the bobbin case body 1008a is the same of the previous FIG. 10e, but in this case the through opening on the inner bottom of the well of the bobbin case, serves to pass only the part of the slide's claw that must interact with the bobbin and not the whole secondary component for its mounting on the slide body.
(44) FIGS. 12a-12d show a different embodiment of the bobbin case 1208 comprising an improved slide, composed of multiple components, according to the invention, with the presence of a slide body 1215a and a component 1286 that performs the function of guide and protection of the bobbin thread and that is fixed to the slide body by means of an interlock in a groove 1283 formed on the underside of the slide body 1215a. The secondary component 1286 is mounted into the interlock before the insertion of the slide body 1215a into the guide 71 on the bobbin body 1208a and remains fixed there once the slide body is inserted into said guide. Said secondary component is fixed to the rear part of the slide (opposite to the slide's claw) and performs the function to guide and to protect the bobbin thread in the rotary hooks designed for coreless bobbins and bobbin cases and baskets without shaft, where the bobbin thread exits from the center of the bobbin case and passes between slide body and lever.
(45) Naturally, the invention is not limited to the particular embodiments previously described and illustrated in the appended Figures, but it can be subject to numerous modifications of detail within the reach of a person skilled in the art, without departing from the scope of the invention itself, as defined in the appended claims.
