Abstract:
A device for detachable fastening of an embroidery frame ( 27 ) with one or more embroidering fields on an embroidery frame support ( 25 ) of a program-controlled sewing or embroidering machine. On the embroidery frame ( 27 ), two sliding interlocks ( 61 ) are fastened which guarantee a play-free latching in the x and y direction and which, for sliding the embroidery frame ( 27 ) in relation to the embroidery frame support ( 25 ), move a latching element temporarily out of a latching slot ( 51 ). The latching element is configured as a pivotable lever with a downward-projecting detent.

Description:
BACKGROUND 
     The invention relates to a device for detachable fastening of an embroidery frame on an embroidery frame support, and more particularly to such devices for an embroidery module in a program-controlled sewing or embroidering machine. 
     The connection between an embroidery frame and its support which has the drive apparatus for the embroidery frame, must be separable in order on the one hand to have the possibility of being able to fasten embroidery frames of various size and shape on the embroidery frame support, and on the other hand, to be able to lay the material to be embroidered, for example a fabric, outside the sewing machine into the embroidery frame, and to fasten it there. 
     From DE-GM 29 614 512, such a device for detachable fastening of an embroidery frame on the embroidery frame support of a program-controlled sewing or embroidering machine is known. In the embroidery frame support which is arranged in household sewing machines alongside the lower arm and is connected with this through coupling and latching devices, the drive means for movement of the embroidery frame attachments in the x and y direction is arranged. On the embroidery frame support, a holding angle of steel with upward-projecting retaining studs is provided for connecting or coupling the embroidery frame. On the embroidery frame, a guidance channel open downward is fastened, into which the vertical section of the holding angle is latchable with the retaining studs insertable from below, and latchable through two opposing movable locking slides. The sliding interlocks are guided lengthwise in the guidance channel and connected with two holding plates. The holding plates project beyond the guidance channel such that they can be grasped with two fingers of a hand and can be pressed against each other. Between the two locking slides, a spring is inserted which presses these apart when the spring is released, and thus pushes the outwardly directed ends under the retaining studs in the guidance channel. This known device makes it possible, in a simple manner and with the use of only one hand, to fasten the embroidery frame on the embroidery frame support or to remove it therefrom. It has, however, the disadvantage that the embroidery frame, due to the vertically operating latching in the x and y direction, cannot be held sufficiently free of play and in this way, the reproducibility of the embroidered pattern cannot be guaranteed in every case. 
     From DE-GM 29612102, a device for the automatic identification of the size and construction of an embroidery frame on a sewing or an embroidering machine with program-controlled embroidering device is furthermore known. This device makes it possible for the control unit of the sewing machine to recognize the embroidery frame directly connected with the embroidery frame support and therewith to utilize completely the surface available for embroidering within the embroidery frame. As a means of identification, on the embroidery frame, in the region below the guidance channel, corresponding means of identification, for example, coding prongs, are provided. The identification means are joined fast with the coupling and latching apparatus in the known device, and for this reason only allow a recognition of the respective embroidery frame which is connected fast with the latching apparatus. If there is a possibility on the embroidery frame of connecting this at various points with the embroidery frame support, then in the known manner, no identification of the fastening point can take place on the corresponding embroidery frame. 
     SUMMARY 
     The object of the present invention is to create a device for detachable fastening of an embroidery frame which not only makes it possible to join the embroidery frame with the embroidery frame support, but to lock the embroidery frame in at different places with reference to the embroidery frame support in order to be able, by successively using correspondingly larger embroidery frames, to embroider basically larger embroidering fields. 
     A further object is to provide, after fastening the embroidery frame on the embroidery frame support, the possibility of making the place of attachment on the respective embroidery frame type determinable by the control unit or appropriate sensors. 
     This object is accomplished by a device in accordance with the invention by providing a drive connected to an embroidery frame support with an embroidery frame holding plate attached thereupon. A retaining and latching element is installed on the embroidery frame with two movable sliding interlocks with spring-loaded grips. The sliding interlocks each engage with one latching hook on correspondingly constructed latching surfaces in recesses located in plates on the embroidery frame holding plate. The retaining element is mounted movable along a guide rail on the embroidery frame, and code sections and latching slots are positioned on the guide rail or on the embroidery frame. 
     With the device of the invention, a play-free latching of the embroidery frame on the embroidery frame support is possible, and at the same time, with one and the same latching and coupling device, the embroidery frame can not only be joined with the embroidery frame support, but also to move this without the prior detachment from the embroidery frame support, latching it again, and identifying the latching site through the control unit. By pressing together both holding buttons, the embroidery frame can consequently be lifted from the embroidery frame support again as previously, or it can be slid along a guide track fastened to the embroidery frame and fixed at a suitable position, and the fastening site on the embroidery frame can be recognized by the guide unit of the machine. Sliding the embroidery frame in relation to the embroidery frame support takes place through briefly pressing the holding buttons together and subsequent lateral sliding of the embroidery frame. The locking in into the adjacent operating position then takes place automatically. When locking in, additionally a play-free clamping of the embroidery frame with the embroidery frame support takes place without further interventions by the operator being necessary. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be explained in greater detail on the basis of a preferred embodiment. In the drawings: 
     FIG. 1 is a perspective view of a household sewing machine with an attached embroidering module and installed embroidery frame in accordance with the present invention, 
     FIG. 2 is a plan view on the embroidering module and the embroidery frame as well as on the front end of the lower arm of the sewing machine with the embroidery plate, 
     FIG. 3 is a perspective view of the latching and coupling apparatus without casing when releasing the latching on position “ 44 ,” 
     FIG. 4 is a perspective view of the latching and coupling apparatus without casing with a locked in jack on position “ 44 ,” 
     FIG. 5 is a perspective view of the latching and coupling apparatus with casing upon releasing the latching on position “ 44 .” 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The sewing machine in accordance with FIGS. 1 and 2 has the usual sewing components, operating elements and other outfitting parts (in part not indicated in greater detail). It basically includes the machine housing  1 , the free arm  3  and the base plate  5 . On the machine housing  1 , for example, a video screen  7 , a track ball  9  with dedicated activation key (OK)  11  and release key (CL)  13  and a row of keys (not indicated in greater detail) for the direct selection of special functions. The needle  17  is shown that acts through the tapping hole  15  with a not illustrated holding device, and the presser foot that operates on the (not illustrated) sewing material is designated with  19 . The basic unit  21  of a mechanical and electrical connecting device (not illustrated) with the embroidering module  23  joinable with the sewing machine  1  contains the program-controlled drive apparatus for the embroidery frame support  25  for moving the support  25  in the x direction. In the embroidery frame support  25 , further drive equipment is provided for moving the embroidery frame  27  in the y direction. The embroidery frame  27  is, as generally typical, constructed in two parts and includes a closed interior frame  27   a  and a divided outer frame  27   b . On the outer frame  27   b , a clamping device  29  for clamping the sewing material is arranged. The embroidery frame  27  is connectable with the embroidery frame support  25  by means of a fastening device generally designated with  31 . 
     In FIGS. 3 and 4, the embroidery frame holding plate  35  is visible in the foreground, from which only the two plates  37  with the hooks  39  extending therefrom project beyond the housing of the embroidery frame support  25  (the latter omitted in FIG.  3 ). In the background, a short segment of the embroidery frame  27  with the guide and coding rail  41  attached thereupon are visible. On guide rail  41 , for example, there are three coding segments  43 ,  44 ,  45 , the latter being partially visible and partly covered by the embroidery frame holding plate  35 . The coding segments  43 ,  44 ,  45  can be made of pronged edges. It is also possible to configure these as a bar code (not shown). On the guide rail  41 , for example, a retaining and latching element, in short called retaining element  49  which forms the fastening device, is mounted movable longitudinally in a guide groove  47 . The retaining element  49  can be fixed and locked in on latching and retaining slots  51  in the region of coding segments  43  to  45  on the guide rail  41 . The retaining element  49 , which is represented with cover  57  broken away in FIGS. 3 and 4, includes a supporting body  53  which partially encloses the guide rail  41 , or extends below on its two ends. The two ends of the supporting body  53  are advantageously configured as end plates  55 , which close the cover  57  on the end faces. Between the two end plates  55 , in the middle, a longitudinal guide  59  is constructed for two sliding interlocks  61  mounted movably there. On the sliding interlocks  61 , two upwardly projecting grip plates  63  are provided, which project upwardly beyond the covering  57 . The sliding interlocks  61  include outwardly directed wedges  65  which engage oblique surfaces  67  on the retaining element  49  that are arranged basically parallel to the first wedge surface. The second wedge surfaces of the wedges  65  lie on the plates  37 , and in this way brace the embroidery frame  27  free of play on the embroidery frame support  25 . Furthermore, the sliding interlocks  61  include an outwardly directed latching hook  68  with an upward-lying oriented surface, which latching hooks  68  extend on the underside of the corresponding hooks  39  on the plates  37  in arrangement. 
     Between the two sliding interlocks  61 , two helical springs  69  are held in a pre-loaded condition. The outside ends of the springs  69  are held by pegs  71  formed on the sliding interlocks. The spring ends lying opposite one another lie on a spring housing  73  which accommodates a locating spring  75  which lies on a plane perpendicular to the axes of the helical springs  69  and perpendicular to the embroidery frame holding plate  35 . The locating spring  75  is braced above on the spring housing  73  and is held by a lug  77  on a one arm stop lever  79 . The stop lever  79  is pivoted with its one end on the retaining element  49 . The free end is configured as a downwardly directed hook  81 . Its geometrical shape is constructed such that the hook  81  can engage basically free of play in one of the retaining slots  51  on the guide rail  41 . The two helical springs  69  can moreover be braced in shell-like supports  83  on the upper side of the longitudinal guide  59 . The longitudinal guide  59  moreover takes over the lateral guide of the stop lever  79  and also supports the pivot bolt  85 . On one of the two sliding interlocks  61 , a lifting component is mounted in the form of a contact surface  70  which, when the sliding interlocks  61  are pressed together with the holding plate  63  reaches underneath the free end of the stop lever  79  and lifts the locating hook  81  out of slot  51 . 
     In FIG. 4, on the left side of the image, a portion of the cover  57  with one of the fastening screws  87  is represented. Furthermore, on the cover  57 , a downwardly open recess  89  is visible into which a guide cam  91  on the plate  37  of the embroidery frame holding plate  35  engages, and establishes its height position with respect to the retaining element  49 . 
     The function of latching and sliding the embroidery frame  27  will be explained below. An embroidery frame  27  with one, two, three or more embroidery surface sections and correspondingly many retaining slots  51  and coding sections  43  to  45  is pushed, after pressing together the two grip plates  63 , vertically from above on the two plates  37  on the embroidery frame holding plate  35  until the two guide cams  91  are completely inserted into the recesses  89 . Now the pressure exerted on the holding plates  63  by the fingers of the one hand can be diminished to the extent that on the one hand, the hook  81  of the lever  79  is sprung against the surface of the guide rail  41 . On the other, however, the wedges  65  do not yet lie snugly on the inclined surfaces  67 , and consequently a movement of the embroidery frame  17  in the guide groove  47  is possible. When the holding plates  63  are further released, the latching hooks  68  slide under the matching hooks  39  on plates  37 . In this way, the embroidery frame  27  is held vertically on the support  25 . 
     As soon as, with lateral sliding, the hook  81  reaches the region of a slot  51  on the guide rail  41 , the lever  79  pivots downwardly due to the force of the locating spring  75  and latches the embroidery frame  27  on the embroidery frame support  25 , for example, in the region of code section  44  (FIGS.  3 / 4 ). When no forces are operating on the grip plates  63  any more, the two helical springs  69  press the wedges  65  on the inclined surfaces  67 . Through the play of the retaining element  59  in the guide groove  47 , the supporting body  59  is pressed onto the two plates  37 . There is now present in the x and y direction a completely play-free connection between embroidery frame  27  and support  25 . Due to the engagement of the hook  81  in the slot  51  on coding site  44 , the coding resources, here prongs, come before a sensor element (not represented) on the support  25  which first of all, on the basis of the prongs, recognizes the size and construction of the embroidery frame  27  and moreover also the site at which the embroidery frame  27  is joined with the support  25 . The data gathered from the coding by the sensor element is communicated to the machine control unit. Subsequently, the embroidering of the of the embroidering field within embroidery frame  27  allocated to code segment  44  can take place. In order also to be able to process the adjacent embroidery field, the grip plates  63  are pressed together with two fingers of one hand until the hook  81  and the wedge  65  have left the snug arrangement and a lateral sliding of the embroidery frame  27  on the embroidery frame support  25  is possible. As soon as the hook  81  is latched on the adjacent slot  51 , the not represented sensor unit, on the basis of the structure of coding section  43 , ascertains the new position of the embroidery frame  27  and signals the control unit of the sewing machine  1 . This can now forward the stored sewing or embroidery pattern in the new embroidering field at the proper site.