Abstract:
A method and apparatus for applying covers to seat cushions and the like includes means to maintain the cushioning material under compression within the cover as the cushioning material is moved into the cover.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method and apparatus for applying covers to cushions and, in particular, for applying covers to cushions wherein the cushioning material is maintained under compression within the cover, and the cover is maintained under tension by the cushioning material in the finished product. 
     2. Prior Art 
     It has been known to form mattresses and the like by compressing the inner cushioning material and covering the material with a ticking. The compressed material is usually inserted into the ticking by means of conveyor belts or plungers or the like. It is also known to place material in compressed form into containers for shipping or storage. Various apparatuses have been provided, including means placing covers or bags in position and forcing the bags or covers onto the compressible material, or forcing the material into the bags or covers in a compressed form. It is also known to provide seat cushions for motor vehicles and the like wherein the covering material and the resilient cushioning material are so intimately associated that the covering material is under tension and the inner cushioning material is usually under compression. The purpose of this is to ensure conformance of the covering material to the various contours of the cushion. Thus, the covering material and the cushion retain a desired shape or contour, and it is less likely that the covering material will slip over the cushioning material when in use. Chute-like arrangements have also been employed for stuffing cushions. In some instances, the covers or ticking to be stuffed with the cushioning material is placed over the chutes and the cushioning material is forced inwardly of the covering material by means of conveyors or hydraulic or pneumatic cylinders. Various means are provided for ensuring that the covering material is retained in position until the cushion is fully received therein. 
     SUMMARY OF THE INVENTION 
     The instant invention pertains to providing seat cushions and the like (arm rests, head rests, etc.) for automobiles or other uses wherein an inner cushion is highly contoured such as to form a &#34;bucket-like seat&#34;, and these cushions are covered by fabrics and the like stressed so as to conform to the contours and to adapt to the shape desired. The desired final enclosures are usually achieved by forcing fabric or leather, etc. envelopes over foam-like cushions. The covers are smaller in size than the cushions, so that the cushions will be compressed and the fabric will be tensioned, thus forming a neat seat part which will at all times retain the desired shape with the fabric &#34;following&#34; the cushion material. 
     Unlike some cushions, such as may be found in household furniture, where some looseness may be tolerated, the finished product must have a taut cover, or at least one that is so anchored to the inner cushion that it will not slip. In some instances, Velcro-like fasteners or hog-rings are used to facilitate maintaining the fabric cover in place with respect to the cushioning material. Whether such fasteners are used or not it is necessary for automotive purposes that means be found for rapidly applying covers, which also provides seats or the like wherein the fabric and cushioning material function are a single unit. There is also a need for a method and apparatus for assembling enclosures and covers without reliance on the brute force of individual operators, and with a minimum of steps. 
     The instant invention provides a method and apparatus which eliminates reliance on brute force by individual operators and provides a machine which is relatively simple in construction, yet functions in a reliable and efficient manner. Utilizing the concepts of the instant invention, it is possible to build relatively simple machinery and employ simple methods of assembling of cushions. 
     It has been customary in the automotive industry to simply force covers onto cushions manually. This is a tedious and tiring process. Each cushion must be picked up and the cushion cover must be forced over the cushion from one end to the other by means of tugging and squeezing until the cushion is finally within the cover. One undesirable result of this type of operation is the high instance of injuries, and particularly undesirable is the high instance of Carpal Tunnel Syndrome. This is a syndrome commonly associated with workers whose jobs require excessive use of the hands, fingers and wrists in pulling. The instant invention eliminates the cause of much of this serious injury. 
     According to the invention, there is provided a method of applying cushion covers wherein a straight line production operation can be realized. According to the invention, covers can be placed in the path of movable cushions in an unstressed state; thus, they can be easily placed in position by operators. Then the cushion can be advanced into the cover utilizing mechanical pressure and means for compressing the cushion so that it can enter the cover. According to the method, a cushion is advanced through a compression zone beyond which the cover is placed. The cushion is advanced through the compression zone into the cover. The cover, in the meantime, is expanded as the oz cushion advances within it, with the cushion eventually contacting a closed end of the cover at which time the cushion is fully within the cover. The cushion, however, does not come into full contact with the cover until after the cushion has moved into contact with the closed end of the cover, and there is further movement of the cushion. 
     According to the method, a compressible cushion having a preshaped form is placed into a cover which will complement the exterior appearance of the cushion because it is of a smaller size than the cushion and provides a tight fit. In order to unite the cushion and cover, it is o necessary to either expand the cushion cover or compress the cushion. According to the method of the instant invention, the need to manually expand the cover by an operator and place it in a holding chute or channel or the like while a cushion is inserted into it is eliminated. Instead of this, according to the invention, the method consists of placing the cover in an unexpanded state in the path of movement of the foam or the like cushion, which is compressible, holding the cover in position with an open end of the cover facing the oncoming cushion and expanding the cover as the cushion moves along while retaining the cover in position until the cushion reaches the outermost end of the cover. According to the invention, expansion of the cover occurs as the cushion moves into it. This is in contrast with concepts wherein covers are forced onto a preformed cushion without the cushion changing shape, and those concepts wherein the cover must be expanded before being placed in position. Further, neither the cushion nor the cover must be placed on or in means, for tensioning or compressing one or the other and thereafter repositioned before final assembly can be achieved. According to a method of the instant invention, the operator does not find it necessary to considerably stress the cover in placing it in position. Stressing of the cover occurs under the force of the moving cushion. 
     The invention further provides an apparatus including means for receiving and retaining a cushion cover of a size less than the exterior size of the cushion to which it is to be applied in the path of a moving cushion without stressing of the cushion cover to a larger than normal size throughout its length. The apparatus includes a means for forcing a cushion towards a cover positioned in a primarily unstressed condition in the path of movement of the cushion. The cushion is moved through a means for compressing the cushion, and then the cushion is moved forwardly into the cover without substantially contacting the cover until the cushion has moved to the closed end of the cover and engaged the latter end. The apparatus comprises means for gradually expanding the cover around the cushion as the cushion moves forward but without materially contacting the cushion until the cushion reaches the closed end of the cover. Thereafter, upon continued movement of the cushion, now carrying the cover with it, the cover is stripped off a portion of the machine and into intimate contact with the cushion. According to the invention, expansion of the cover is accomplished by movement of the cushion within the cover while the cover remains in a fixed position. The apparatus embodies means for transmitting the force of the cushion, which is compressed to the cover without contact between the cover and the cushion and while the cushion is moving within the cover and the cover is retained in a fixed position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a preferred form of the apparatus according to the invention; 
     FIG. 2 is a top plan view thereof; 
     FIG. 3 is a fragmentary sectional view thereof taken along line 3--3 of FIG. 2; 
     FIG. 4 is a perspective view from a side opposite that shown in FIG. 1; 
     FIG. 5 is a view showing a cover placed in position on the apparatus; and 
     FIG. 6 is a view showing a cushion inserted into the apparatus. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A stuffing machine according to the invention comprises a base 10 having an upper platform 12 comprising a forwardly extending portion 14. A pair of spaced side plates 18 and 20 extend upwardly from base 12 and form therewith a channel 22. Upstanding brackets 24 and 26 are attached to side plates 18 and 20 respectively and to base 10. The brackets comprise vertically extending legs 28 and 30, horizontal arms 32 and 34 and depending legs 36 and 38. Legs 36 and 38 and associated reinforcing brackets 40 and 42 fixedly support compression plate 44. Plate 44 is substantially a flat plate-like member and is supported at an acute angle with respect to the platform 12. Plate 44 forms with side plates 18 and 20 and base 12 a channel for receiving a cushion 45 (FIG. 6) which is to be placed within a cover. The plate 44 is angled so that the cushion 45 will be compressed as it moves across the platform 12 forwardly, from the left as viewed in FIG. 1, through the channel 22 and beneath the plate 44. Brackets 24 and 26 are provided with horizontal members 32 and 34 of sufficient length to space the plate 44 inwardly from the side plates 18 and 20 sufficiently to provide passageways 46 and 48, FIG. 2, between the plate 44 and the side plates 18 and 20. The passageways 46, 48 provide clearance for bracket structures and control arms and the like that are often attached to cushion frames or cushions which are used in forming seats in the automotive field as is well-known in the art. The horizontal legs 32 and 34 are positioned upwardly of this channel by means of the depending legs 36 and 38 to also facilitate movement of these attachments with a cushion which may be forced from the left side of the apparatus as shown in FIG. 1 towards the right side as will be described hereinafter. 
     An upper plate-like member 50 comprising substantially a flat plate is seen to have rear reinforcing members 52 and 54 which provide bosses for pivotally mounting plate-like member 50 upon pins 56 and 58 supported by the depending legs 36 and 38 of the brackets 24 and 26. 
     The plate 50 freely pivots about the pins 56 and 58 and normally plate 50 lies as shown in FIG. 1 with its rearward end 60 bearing on the mating rearward end 62 of the lower plate 14. In any event, plate 50 is substantially closer to plate 14 at its rearward end 60 than it is at the point of pivotal connection to the brackets 24 and 26. As illustrated in FIG. 4 the plate 50 can be pivoted so that its rearward end lies substantially above the rearward end 62 of the plate 14. Referring particularly to FIGS. 1 and 2, it will be seen there is a longitudinally extending slot 64 provided in the platform 12 which extends rearwardly from the extending portion of the platform 12 and adjacent the forward edges of the side plates 18 and 20. Post 66 extends vertically within slot 64 and on its lower end is attached to a piston rod 68 of hydraulic motor 70 (FIG. 3). It will be seen that post 66 can be moved within the slot 64 by the hydraulic cylinder 70. At its upper end the post 66 supports a pusher bar 72. Bar 72 will travel with the post 66 and is adapted to push a cushion such as in FIGS. 5-6 beneath plate 44 and into the space between the plate-like members 14 and 50. 
     FIG. 6 shows a cushion 45 positioned within the channel 22 and engaged by the pusher bar 72 as well as a cover 86 positioned over the plates 50 and 14. In FIG. 5 the cover 86 is seen to have been simply loosely fitted over the two plates 50 and 14. 
     As is shown in FIG. 6, when the cushion 45 is moved to the right, the cushion 45 moves beneath the compression plate 44 and between the plate-like members 14 and 50. As it moves forwardly beneath the plate-like member 50 under the influence of the pusher bar 72, the plate 50 starts to pivot about the pins 58 and 56 and move away from the plate-like member 14. This movement continues as the cushion 45 moves towards the end of the plates 14 and 50. In so doing, the cover 86 comes under tension from the force applied by the compressed cushion and expands to a size such that the cushion can move within it. At the same time, however, a substantial portion of the cushion 45 is not in contact with the cover 86 until the cushion reaches the edge 60 and 62. At this point, the cushion 45 comes in contact with the closed end of the cover 86. Thereafter, as the cushion 45 continues to move forwardly the cover 86 starts to slide off of the plate 14 and 50 and comes into contact with the cushion 45 which is constantly expanding as it moves outwardly of the ends 60 and 62 of the two plate-like members 14 and 50. The plate-like member 50 has pivoted to such extent by the time the cushion 45 reaches the edges 60 and 62 that the cover 86 is frictionally now engaged by the plates 14, 50. Upon continued movement, the cover 86 will simply slide off of the plate-like members 14, 50 under urging of the cushion 45 and surround the cushion 45 as it does so. 
     From the above it is seen that there is provided a method and means for applying a cushion cover to a cushion to form a unit in which the cover is so intimately in contact with the cushion that it will conform to the shape of the cushion and will tend to remain in the relatively fixed position with respect to the internally positioned cushion. This is accomplished by providing a cushion cover which is of a smaller size internally than the cushion which it is to cover. According to the invention, however, a cover can be placed in position to receive the larger cushion through an open end of the cover while the cover is in an untensioned stated. Thus the cover can be positioned relatively easily by a worker. Thereafter the cushion can be compressed and forced inwardly of the cover until it is fully within the cover while the cover remains in a fixed position. While forcing the cushion within the cover, the cover is expanded as the cushion moves within it. This expansion occurs without the cushion coming in substantial contact with the cover so only a modest force is needed to retain the cover in position while the cushion moves inwardly of it. The major force which must be exerted upon the cushion cover is that required to expand it so that the cover can receive the cushion but this is supplied without requiring a more substantial force to hold the cushion in position. Only when the cushion is substantially entirely within the cover is the cover contacted by the cushion and the cover and cushion moves off the work station as a single unit. It will be also seen that the force for expanding the cushion cover is actually supplied by the cushion itself. According to the invention an untensioned cover is positioned in the path of movement of a compressed cushion, the cushion is moved inwardly of the cover and the cover expanded as the cushion moves within it without coming in contact with the cushion along substantially a major portion of its surface and thus the tension and loading upon the cushion cover is controlled in such a manner that the major force required is for expanding the cushion to an open size to receive the cushion. As a result, it is extremely easy to position the cover in place and the forces needed to compress and move the cushion within the cover can be supplied by the machine and not by the operator. Further it is easy to hold the cover in position while the cushion is being forced within it. Although the cushion may come in contact with the sides of the cover, a major portion of the cover is not contacted and thus the cushion is relatively free to move within the cover. The expansion of the cover herein occurs after the cover is placed in position to receive the cushion and the cover need not be moved thereafter by the operator The cover does not have to be rotated from an upper to a lower position or vice versa in order to first be placed upon a chamber-like holder which expands the cover to a fully opened position and thereafter be provided with the cushion. The cover and the cushion are simply placed in order for insertion of the cover into the cushion without any further movement being required to align either element with means for pressing one within the other. Further, the placing of the cushion and the cover is relatively easily performed. Relatively modest effort is required to place the cover over the two plate-like members 14 and 50 and position the cushion within the chamber 22 prior to its being pressed rearwardly by the cylinder 70 and the pusher bar 72, as compared to what is required with previously known methods. The force for compressing the cushion expanding the cover and applying the cover to the cushion is supplied by the apparatus and not by the operator. The operator simply has to energize the apparatus to force the cushion from the left as viewed in FIG. 1 towards the right inwardly of the cushion cover in order to obtain the finished product. 
     Having thus described my invention, many modifications thereto will become apparent to those skilled in the art to which it pertains without deviation from the spirit of the invention as defined by the scope of the appended claims.