Abstract:
A device for mounting any type of seat covers ( 10 ) on foam cushion parts ( 12 ) of a seat, more particularly a vehicle seat, uses gripping elements ( 14 ) which form actuation groups ( 16, 18, 20, 22, 24 ) receiving the profiled strips ( 26, 28, 30, 32, 34 ) arranged on the seat cover ( 10 ). The gripping elements pull the profiled strips ( 16, 18, 20, 22, 24 ) into channel-like recesses ( 44, 46, 48, 50, 52 ) in the foam cushion part ( 12 ) by a positioning device ( 42 ). The positioning device allows a relative movement between the foam cushion part ( 12 ) and the corresponding gripping element ( 14 ) to fix the seat cover ( 10 ) to the foam cushion part ( 12 ).

Description:
FIELD OF THE INVENTION 
   The present invention relates to a device for mounting seat covers of any type on foam cushion components of a seat, a vehicle seat in particular. 
   BACKGROUND OF THE INVENTION 
   In making vehicle seats, including aircraft passenger seats with the more recent seat technology generation, the previously customary wire insertion and tensioning systems have been replaced by a section fastening system (see, for example, DE 198 08 995 C1). In this new generation of section fastening systems, individual section strips of cloth, leather, plastic materials, or the like are mounted so as to be joined to the seat cover by sew-on narrowing strips. The respective section strips are oriented along the sew-on narrowing strips of the seat covers with respect to their extent and their length. The associated foam upholstery components of a particular seat, which are to be covered, are formed of a conventional flexible foam material, such as polyurethane foam. The seat component, together with its foam cushion, has on its side facing the seat cover channel-like recesses into which the respective section strip may be introduced, by hand, for example, for a process of fastening the seat cover on the foam cushion component. 
   The section introduced in this manner has flank elements on the side edge. The flank elements extend under the end sides of the foam cushion component delimiting a channel-like central recess by which the section component may be introduced into the respective foam channel. One significant advantage of this section fastening systems is that in the case of worn out seat covers or foam cushion components, such components may be replaced by disengaging the section component mounted on the seat cover from the channel introduced into the foam cushion component. The section inserted may be produced cost effectively as an extruded section, so that the fastening solution may be applied cost effectively despite the manual assembly required. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to provide a device for mounting seat covers where the assembly steps can be performed at least in part automatically to obtain additional time and cost advantages. 
   The object is basically attained by a device having gripping elements clustered in actuation groups which serve to receive section strips mounted on the seat cover. The gripping elements pull the section strips into channel-like recesses in a foam cushion component by a positioning mechanism. The positioning mechanism permits relative movement between foam cushion component and the respective gripping element for the purpose of fastening the seat cover on the foam cushion component. The device permits essentially automatic operation of applying the respective section strip to the seat cover. The section strips, which are sewn on the lower side of the seat cover are accordingly introduced manually or automatically into the recesses in the gripping elements and fastened there. The gripping elements extend, in the fastening situation described, through recesses in the foam cushion component, which extend transversely relative to the respective channel-like guides for the section strip. As a result of relative movement of section strip and seat cover with respect to the channel-like recesses in the foam cushion component, the section strips are then fastened in the foam cushion component, the fastening process involved being fully automatic. As soon as a particular section strip has been introduced into the associated foam channel in the foam cushion component, positioning of the seat cover on the foam cushion component to define the edges may then be carried out manually or, optionally, fastening on the foam cushion component may be performed by other operating equipment. The covered foam cushion component thereby obtained is then released as a seat component from the device for subsequent use. 
   The device of the present invention may be specially adapted for special components of the seat involved, for example, for the headrest area, the backrest, the seat component itself, and, optionally, in the case of aircraft passenger seats, in the form of leg, foot, or calf rests. 
   Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Referring to the drawings which form a part of this disclosure: 
       FIG. 1  is a diagrammatic, not-to-scale, perspective view of the device, according to one embodiment of the present invention in the initial state; 
       FIG. 2  is a perspective view of a process of introducing the section strip of a seat cover into the associated openings for the gripping elements of  FIG. 1 ; 
       FIG. 3  is a perspective view of a removal position for a finished covered seat component of the device of  FIG. 1 ; 
       FIG. 4  is a perspective view of the device of  FIG. 1  in the removal position of  FIG. 3 , with the covered seat component not shown; 
       FIG. 5  is a perspective top view of a basic diagram illustrating a foam cushion component as seat component, together with the gripping elements of the device of  FIG. 1  extending through the seat component; and 
       FIG. 6  is a bottom plan view of a seat cover with section strips extending longitudinally and transversely joined to the cover material by sew-on narrowing strips, according to one embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The device, according to an exemplary embodiment of the present invention, is shown in  FIG. 1  in its initial state. The device is used for mounting seat covers of any type. A bottom view of a seat cover is shown in  FIG. 6 , as an example. Such seat covers  10 , which may be of a cloth or leather material, or optionally of plastic, are to be fastened on foam cushion components  12  (see  FIG. 5 , for example) to obtain a seat component for a vehicle passenger seat or aircraft passenger seat. Seat components such as these may also be employed as treatment chairs, for example, in an operating area or the like. 
   The exemplary embodiment illustrated relates directly to the seat component of a motor vehicle seat. Other seat components may be comparably covered, for example, ones such as headrests, backrests, leg rests, etc. The device of the present invention has a plurality of gripping elements  14 , twelve gripping elements  14  being used in the present case for covering a seat component. The twelve gripping elements  14  are clustered in five actuation groups  16 ,  18 ,  20 ,  22 , and  24 , and accordingly integrated. The respective gripping elements  14  are designed to receive section strips  26 ,  28 ,  30 ,  32 , and  34 , which are positioned on the seat cover ( FIG. 6 ), it being possible to associate these section strips in the order indicated with the respective actuation groups of gripping elements  14 . The section strips in question may be rigidly connected by sew-on narrowing strips  38  of conventional design to the lower side of the seat cover  10 , and form in their longitudinal and transverse directions the corresponding seams  39 ,  40 , on the upper side of the seat component (see  FIG. 3 ). 
   The device also has a positioning mechanism  42 , which, as is shown by comparison of  FIGS. 1 and 4 , permits relative movement between foam cushion component  12  and the gripping elements  14 . The purpose of the automated device is to pull the individual section strips  26 ,  28 ,  30 ,  30 ,  34 , into the associated channel-like recesses  44 ,  46 ,  48 ,  50 , and  52  in the foam cushion component  12 . In this way, the seat cover  10  may be reversibly or releasably fastened to the foam cushion component  12 , that is, may be detached from the foam cushion component, as is to be discussed in greater detail in the following. 
   As shown in particular by the diagram in  FIG. 5 , each gripping element  14  includes a gripping tong, with each gripping tong having two tong components  54  moveably relative to each other. The respective tong components  54  are formed by a longitudinal slot extending along the longitudinal axis of the rod-shaped gripping element  14 . Gripping movement, that is a gripping process in which the gripping components are moved toward and detachably away from each other, is generated by a linear drive (not shown). The linear drive can be in the form of a pneumatic servomotor or a linear unit, for example, which makes the respective engagement movement possible. By preference, the linear drive grips the base component  56  (see  FIG. 5 ) of each gripping element  14 . A single drive is associated with each actuation group  16 ,  18 ,  20 ,  22 ,  24 , so that the gripping or separation movement for the particular actuatable gripping element  14  is effected by only one drive for one actuation group collectively. Consequently, chronologically sequential actuation of the individual actuation groups may be performed by the respective, preferably pneumatic, drives (not shown). 
   As is also shown in  FIGS. 1 and 3 , all gripping elements  14  are mounted within a common frame component  58 , which is vertically positionable by a first linear drive  60 . The first linear drive has four operating cylinders  62  which, as is indicated in the figures, are mounted on the corners of the device, and accordingly enclose the gripping elements  14  together with the frame component  58  on the external circumference side. The frame component  58  encloses the gripping elements  14  on the external circumference side, and may be moved to a position relative to the vertically stationary gripping elements  14  by the first linear drive  60 . It would also be possible to have embodiments in which the gripping elements  14  could be vertically adjusted in relation to the base of frame component  58  by a drive (not shown). In the present embodiment, however, the gripping elements  14  are mounted so as to be vertically stationary and permit the gripping movement only in a plane extending transversely to the vertical. 
   In addition to the frame component  58 , the positioning mechanism  42  has a support component  64  for supporting the foam cushion component  12  along or on its lower side. The support component  64  has openings through which the gripping elements  14  extend when the support component  64  is in a lowered position (see  FIG. 1 , for example). In addition, the gripping elements  14  are clear of these openings when such openings are in a raised position (see  FIG. 4 ). Another or second linear drive  66  with four operating cylinders  68 , preferably powered by pneumatic means, performs the function of placing the support component  64  in the form of a planiform or plate-like support element in individual positions. The four operating cylinders  68  are mounted, grouped in pairs, facing each other on a U-shaped frame piece  70 . The free ends of each U-shaped frame piece  70  are connected to the upper side of the four operating cylinders  62  of first linear drive  60 , and are raised together with the four operating cylinders  68  of second linear drive  66  during their extension movement. This arrangement results in movement superimposed by first linear drive  60  on that of the second linear drive  66 . 
   For a better understanding, an operating process, that is, seat covering or an assembly process with the device of the present invention is described. 
   The device of the present invention is initially in its base position as illustrated in  FIG. 1 . In this position, all gripping elements  14  are closed, that is, the gripping components  54  of each gripping element  14  are essentially adjacent to each other, and the head components  72  on the upper free ends of the gripping elements  14  also are not separated. In the base or initial position, the foam cushion component  12  in the form of a conventional seat component, which forms a sort of bucket seat, is positioned on the gripping elements  14 . These gripping elements extend through channel-like recesses in the foam cushion component  12 , which is oriented vertically, transversely to the channel-like recesses  44 ,  46 ,  48 ,  50 , and  52 , in the foam cushion component  12 . The lower side of the foam cushion component  12  is positioned on the upper side of the planiform support component  64 . By the pneumatic control unit, the gripping elements  14  are then actuated, for example, by a foot-hand switch or the like such that the tong components  54  of each gripping element  14  move apart for the head component  72  to reach a mounting position for each opened gripping element  14 . 
   As is shown in  FIG. 2 , the first longitudinal section strip  26  may be introduced into the first actuation group  16  of gripping elements  14 , either manually or by a handling system. The respective gripping elements  14  of the first actuation group  16  may then be closed. In a similar manner the other section strips  28 ,  30 ,  32 ,  34 , are then introduced into the respective associated actuation groups  18 ,  20 ,  22 , or  24 , and the head components  72  move vertically to a corresponding axial distance from the associated channel-like recesses  44 ,  46 ,  48 ,  50 ,  52 , in the foam cushion component  12 . By preference, the process of introduction of the section strips takes place in the sequence  34 ,  32 ,  30 ,  26 ,  28 . After the respective procedure of introduction has been completed, and provided that all gripping elements  14  are closed and enclose the respective section strips, the frame component  58  is raised together with the support component  64  by the first linear drive  60  with its four operating cylinders  62 , as is shown in  FIG. 3 . The gripping elements  14 , mounted to be stationary in the vertical direction, then pull the respective section strips  26 ,  28 ,  30 ,  32 ,  34 , in the associated upward movement into the associated channels  44 ,  46 ,  48 ,  50 ,  52 , in the foam cushion component  12 . The section strips are then engaged in the associated channels. 
   In the respective installation situation, the edge components of the seat cover  10  are then pulled in over the associated cushion elements which surround the foam cushion component  12  on the edge. The covering process involved is completed as shown in  FIG. 3 . The gripping elements are then opened and, as is illustrated in  FIG. 4 , the second linear drive  66  is activated and the four other operating cylinders  68 , acting on the U-shaped frame piece  70 , move upward and in the process take at least the support component  64  upward with them. In the respective lifting movement, the covered seat component is moved farther upward. The head components  72  of the gripping elements  14  in the meantime have been moved to the release position, and are disengaged from the associated channels in the foam cushion component  12 . The foam cushion component, supplemented by the support component  64 , may be then removed by hand or by a handling unit. All gripping elements  14  are then closed again and the two linear drives  60 ,  66 , are then brought in, so that the device moves to its initial position as shown in  FIG. 1  for a new covering process. A repeated covering process may now begin. 
   While one embodiment has been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.