Patent Publication Number: US-6983503-B2

Title: Apparatus for packing free terminal convolutions of spring assembly used in mattress

Description:
TECHNICAL FIELD 
     The present invention relates to an innerspring assembly used in a mattress for absorbing external loads, and more particularly, to an apparatus for packing free terminal convolutions of a spring assembly used in a mattress, by which terminal convolutions exposed from an upper surface and/or a lower surface of the spring assembly are packaged to interrupt interference between the convolutions and a padding member. 
     BACKGROUND ART 
     Generally, a spring assembly having free terminal convolutions (hereinafter, referred to as spring assembly) is an elastic body to provide a cushion and shock-absorbing function together with padding members each layered on an upper surface and a lower surface of the spring assembly. The spring assembly is composed of a plurality of coil springs arranged in a side-by-side arrangement, usually in parallel columns and parallel rows. 
     In the case where coil springs are regularly arranged in upper and lower directions of upper and lower border wires which form the upper and lower surfaces of the spring assembly, the terminal convolutions of the coil springs are exposed in a given height from an upper portion of the upper border wire and/or a lower portion of the lower border wire. 
     As shown in  FIG. 1 , the spring assembly, generally indicated at  100 , includes an array of springs  110  arranged in parallel columns C and parallel rows R, upper and lower border wires  120  and  120 ′ disposed on upper and lower portions of the array of springs  110  for supporting the outermost coil springs  115 , helical coils  130  engaged to the parallel row R of the array of springs  110  for fixing the terminal convolutions of the adjacent coil springs  115 . 
     The coil springs  115  are arranged in a vertical direction, where they are fixed in a space between the upper and lower border wires  120  and  120 ′ by means of sheet metal clips  140 . The coil springs  115  have free terminal convolutions  115   a  exposed outwardly from the upper and/or lower border wires  120  and  120 ′ at an upper end portion and/or a lower end portion of the body. 
     The coil springs  115  are fixed in the space between the upper and lower border wires  120  and  120 ′, and the helical coils  130  are engaged to the upper and lower portions of the spring array  110  in the row directions R, thereby forming the free terminal convolutions  115   a  on the upper portion of the upper border wire  120  and/or the lower portion of the lower border wire  120 ′. 
     In the case where the terminal convolutions  115   a  of the coil springs  115  are exposed outwardly from the upper and lower border wires  120  and  120 ′ on the basis of a transverse plane of the spring array  110 , when the padding members  150 , such as non-woven fabric or floss silk, are layered on the upper surface and the lower surface of the spring array  110  and are enclosed by a cover, as shown in  FIG. 2 , the padding member  150  and the terminal convolutions  115   a  are in contact with each other, thereby causing the padding member to be damaged. 
     In addition, if the terminal convolutions  115   a  are deflected to one direction by the external force applied to the mattress, the spring assembly  100  has a problem in that the resilient force of the coil spring  115  is deteriorated due to the load focused toward one point. The deflected terminal convolutions  115   a  are contacted with a periphery surface of the upper border wire  120  or the lower border wire  120 ′, thereby producing a frictional noise. 
     DISCLOSURE OF THE INVENTION 
     Therefore, an object of the present invention is to solve the problems involved in the prior art, and to provide an apparatus for packing free terminal convolutions of a spring assembly used in a mattress, by which terminal convolutions exposed from an upper surface and/or a lower surface of the spring assembly are packaged to interrupt interference between the convolutions and a padding member. 
     In order to achieve the above object, there is provided a spring assembly for a mattress, in which an outermost coil spring of a spring array is secured in a space between upper and lower border wires by pins, and helical coils are disposed in row directions on upper and lower portions of the spring array to knit an adjacent coil spring, such that each coil spring has a free terminal convolution protruded from an upper portion of the upper border wire and/or a lower portion of the lower border wire, the spring assembly includes an enclosure partially or fully provided in the row direction or a column direction on an upper end portion and/or a lower end portion of the coil spring to cover the terminal convolution, thereby interrupting interference between the terminal convolution and the upper and/or lower border wire and absorbing a lateral load applied to the terminal convolution. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above objects, other features and advantages of the present invention will become more apparent by describing the preferred embodiment thereof with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view illustrating a conventional spring assembly. 
         FIG. 2  is a schematic view illustrating an application of a conventional spring assembly. 
         FIGS. 3 through 8  are cross-sectional views illustrating a non-woven fabric covering a spring assembly according to a preferred embodiment of the present invention, respectively. 
         FIGS. 9 and 10  are cross-sectional views illustrating a non-woven fabric covering a spring assembly according to a preferred embodiment of the present invention, respectively. 
         FIGS. 11 through 14  are cross-sectional views illustrating a molding of polyurethane foam disposed to a spring assembly according to a preferred embodiment of the present invention, respectively. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Reference will now be made in detail to preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
       FIGS. 3 through 8  are cross-sectional views illustrating a non-woven fabric covering a spring assembly according to a preferred embodiment of the present invention, respectively.  FIGS. 9 and 10  are cross-sectional views illustrating the non-woven fabric covering the spring assembly according to a preferred embodiment of the present invention, respectively.  FIGS. 11 through 14  are cross-sectional views illustrating a molding of polyurethane foam disposed to a spring assembly according to a preferred embodiment of the present invention, respectively. An outermost coil spring  115  of a spring array  110  is secured in a space between upper and lower border wires  120  and  120 ′ by pins  140 , and helical coils  130  are disposed in row directions R on upper and lower portions of the spring array  110  to knit an adjacent coil spring  115 , such that each coil spring has a free terminal convolution  115   a  protruded from an upper portion of the upper border wire  120  and/or a lower portion of the lower border wire  120 ′. An enclosure  10  is partially or fully provided in the row direction R or a column direction L on an upper end portion and/or an lower end portion of the coil spring to cover the terminal convolution  115   a , thereby interrupting interference between the terminal convolution  115   a  and the upper and/or lower border wire  120  and  120 ′ and absorbing a lateral load applied to the terminal convolution. 
     In components of the spring assembly  100  according to the present invention, the spring array  110 , the upper and lower border wires  120  and  120 ′ and the helical coil  130  have the same functions as those of components of a spring assembly, the description of which will be omitted herein. It will be described a difference between the present invention and the conventional spring assembly, the terminal convolution is covered by the enclosure  10 . 
     The enclosure  10  is a member to cover the upper end portion or the lower end portion of the coil spring  115 . Preferably, the enclosure  10  has a volume sufficient to wholly cover the terminal convolution  115   a . In particular, the enclosure  10  may be any one of polyurethane foam and flexible non-woven fabric. 
     Although the embodiments are described with respect to the polyurethane foam and the non-woven fabric as the enclosure  10 , any material to wholly cover the terminal convolution  115   a  and thus interrupt the interference between the padding member and the border wires can be employed. 
     Meanwhile, in the process of covering the terminal convolution  115   a  using the non-woven fabric as the enclosure  10 , as shown in  FIGS. 3 through 10 , the non-woven fabric must be partially or fully provided in the row direction R or the column direction C on the upper end portion and/or the lower end portion of the coil spring for covering the terminal convolution  115   a  in the row direction R, and must be joined to an opposing side of the fabric. 
     Of course, when the non-woven fabric is enclosed around a circumference of the terminal convolution, one or more non-woven fabrics may be joined to each other to cover the terminal convolution  115   a , and it would be apparent that a method of covering the terminal convolution using a non-woven fabric is covered by the scope of the present invention. 
     For example, as shown in  FIG. 3 , an upper non-woven fabric may cover the upper portion of the spring array  110  to fully enclose an upper portion of the terminal convolution  115   a , and an end portion of the upper non-woven fabric may be tacked on or joined to a convolution of the terminal convolution  115   a . Alternatively, as shown in  FIGS. 9 and 10 , an upper non-woven fabric may fully cover the upper portion of the spring array  110 , and an end portion of the upper non-woven fabric may be tacked on or joined to the upper border wire  120  or the lower border wire  120 ′. 
     In addition, as shown in  FIGS. 4 and 5 , a lower non-woven fabric may be disposed in the row direction R under a lower portion of the terminal convolution  115   a , and an upper non-woven fabric may be disposed in the row direction R on an upper portion of the terminal convolution  115   a , such that the upper non-woven fabric may be tacked on or joined to the lower non-woven fabric. Alternatively, a lower non-woven fabric may be disposed in a column direction C under a lower portion of the terminal convolution  115   a , and an upper non-woven fabric may be disposed in the column direction C on an upper portion of the terminal convolution  115   a , such that the upper non-woven fabric may be tacked on or joined to the lower non-woven fabric. 
     At this time, as shown in  FIG. 4 , the upper non-woven fabric and the lower non-woven fabric may be cut by a piece, and enclose the terminal convolution  115   a  in the row direction R or column direction C. Alternatively, as shown in  FIG. 5 , the upper non-woven fabric and the lower non-woven fabric may enclose the terminal convolution  115   a  in the row direction R or column direction C, without cutting them. 
     Furthermore, as shown in  FIGS. 6 and 7 , a lower non-woven fabric may be disposed in the row direction R under a lower portion of the helical coil  130 , and an upper non-woven fabric may be disposed in the row direction R on an upper portion of the terminal convolution  115   a , such that the upper non-woven fabric may be tacked on or joined to the lower non-woven fabric. Alternatively, a lower non-woven fabric may be disposed in the column direction C under a lower portion of the helical coil  130 , and an upper non-woven fabric may be disposed in the column direction C on an upper portion of the terminal convolution  115   a , such that the upper non-woven fabric is tacked on or joined to the lower non-woven fabric. 
     At this time, the lower non-woven fabric is disposed at a position adjacent to the helical coil  130  or the spring array, and then the upper non-woven fabric is cut by a piece, as shown in  FIG. 6 , or the upper non-woven fabric is continuously used without cutting it, as shown in  FIG. 7 . 
     As shown in  FIG. 8 , an upper non-woven fabric may be faced to another non-woven fabric to cover an upper portion of the terminal convolution  115   a  along the row direction R, and a front end portion of the upper non-woven fabric may be wound around the terminal convolution to cover a lower portion of the terminal convolution  115   a , such that the upper non-woven fabric may be tacked on or joined to an adjoining surface of the upper non-woven fabric. Alternatively, an upper non-woven fabric may be faced to another non-woven fabric to cover an upper portion of the terminal convolution  115   a  along the column direction C, and a front end portion of the upper non-woven fabric may be wound around the terminal convolution to cover a lower portion of the terminal convolution  115   a , such that the upper non-woven fabric may be tacked on or joined to an adjoining surface of the upper non-woven fabric. 
     As shown in  FIGS. 11 through 14 , in the course of enclosing the terminal convolution  115   a  using the polyurethane foam as the enclosure  10 , a wanted portion of the spring assembly  100 , i.e., the terminal convolution  115   a  of the coil spring  115  is inserted into a mould (not shown) and is set at a given temperature during a predetermined time to partially or fully foam the terminal convolution  115   a  in the column direction C or row direction R. 
     In addition, in the course of enclosing the terminal convolution  115   a  of the coil spring  115  using the non-woven fabric shown in  FIGS. 3 through 10  or the polyurethane foam shown in  FIGS. 11 through 14 , the terminal convolution  115   a  of the upper portion of the spring array  110  is partially or fully enclosed in the row direction R or the column direction C, and then the terminal convolution  115   a  of the lower portion of the spring array  110  is partially or fully enclosed in the row direction R or the column direction C. 
     The operation of the present invention will now be described. 
     First, in the case where the terminal convolution  115   a  of the spring assembly  100  is enclosed by the upper and lower non-woven fabrics, the upper and lower non-woven fabrics enclose around the terminal convolution  115   a  at a start point and an end point, and then adjoining surfaces are tacked on or joined to the lower non-woven fabric. 
     As shown in  FIGS. 3 through 10 , in the case where the terminal convolution  115   a  of the coil spring  115  is enclosed by the polyurethane foam, the terminal convolution  115   a  of the coil spring  115  is inserted into a mould (not shown) and is set at a given temperature during a predetermined time. 
     As such, the enclosure  10 , such as non-woven fabric or polyurethane foam, is secured to any one of the upper and lower portions of the spring assembly  100 . Specifically, the enclosure  10  is partially or fully secured in the row direction R or column direction C to the terminal convolution  115   a  of the coil spring  115 . 
     Then, each padding member  150  is deposited on the upper and lower surfaces of the spring assembly  100 , and is enclosed by the upper and lower cover and is sewed, thereby completing the process of manufacturing the mattress. 
     While the present invention has been described and illustrated herein with reference to the preferred embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations can be made therein without departing from the spirit and scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention that come within the scope of the appended claims and their equivalents. 
     INDUSTRIAL APPLICABILITY 
     With the above description, the enclosure of the non-woven fabric or the polyurethane foam is secured to the upper portion of the spring assembly, thereby protecting the padding member directly contacted with the circumference of the enclosure. 
     As such, if a weight of user is applied to the spring assembly in use, the enclosure interrupts the contact between the terminal convolution and the padding member, and an inclination of the terminal convolution is minimized, thereby blocking the frictional noise. 
     In addition, the padding member layered on the spring assembly is in surface contact with the enclosure enclosing the circumference of the terminal convolution, the terminal convolution does not interfere with the padding member, thereby preventing the friction therebetween and thus prolong a life of the mattress.