Methods and apparatus for use in the manufacture of innerspring assemblies

Abstract

An apparatus is provided for applying adhesive to a string of pocketed coil springs during manufacture of an innerspring assembly, which apparatus comprises a plurality of independently actuatable adhesive applicators, each having a different transverse position relative to a longitudinal axis of the string of pocketed coil springs, and means for causing relative movement between the string of pocketed coil springs and the plurality of adhesive applicators, along a longitudinal axis of the string. The apparatus is adapted to apply adhesive to the string of pocketed coil springs, during relative movement between the first string of pocketed coil springs and the plurality of adhesive applicators, in a pattern that varies between at least some pockets of the string of pocketed coil springs.

1 . An apparatus for applying adhesive to a string of pocketed coil springs during manufacture of an innerspring assembly, which apparatus comprises:
 a plurality of independently actuatable adhesive applicators, each having a different transverse position relative to a longitudinal axis of the string of pocketed coil springs; and   means for causing relative movement between the string of pocketed coil springs and the plurality of adhesive applicators, along a longitudinal axis of the string, wherein the apparatus is adapted to apply adhesive to the string of pocketed coil springs, during relative movement between the first string of pocketed coil springs and the plurality of adhesive applicators, in a pattern that varies between at least some pockets of the string of pocketed coil springs.   
     
     
         2 . The apparatus as claimed in  claim 1 , wherein the adhesive applicators are disposed on a linear axis, which is aligned with an operable axis of the coil springs of the string. 
     
     
         3 . The apparatus as claimed in  claim 1 , wherein the apparatus is adapted to move the string of pocketed coil springs relative to the adhesive applicators, which are stationary relative to a remainder of the apparatus, during application of adhesive to the string. 
     
     
         4 . The apparatus as claimed in  claim 1 , wherein the apparatus is adapted to apply adhesive to the string of pocked coil springs in a pattern that has a plurality of zones, with a separation between the adhesive and weight-bearing faces of the resultant innerspring assembly being different between at least some of the zones. 
     
     
         5 . The apparatus as claimed in  claim 1 , wherein the adhesive applicators are arranged to apply adhesive to each pocketed coil spring in turn, with adhesive being applied to a particular pocketed coil spring before any adhesive is applied to a next pocked coil spring to which adhesive is to be applied. 
     
     
         6 . The apparatus as claimed in  claim 5 , wherein the adhesive applicators are arranged to apply adhesive to a single pocket at the same time. 
     
     
         7 . The apparatus as claimed in  claim 1 , wherein the relative movement between each string of pocketed coil springs and the plurality of adhesive applicators is continuous during application of adhesive to the string. 
     
     
         8 . The apparatus as claimed in  claim 1 , wherein the adhesive applicators are disposed in mutually fixed relation. 
     
     
         9 . The apparatus as claimed in  claim 1 , wherein the apparatus is adapted to move the adhesive applicators relative to the string of pocketed coil springs, which are stationary relative to a remainder of the apparatus, during application of adhesive to the string. 
     
     
         10 . The apparatus as claimed in  claim 1 , wherein the apparatus includes at least one adhesive applicator adapted to apply adhesive to a substantially central region of one or more of the pocketed coil springs, and at least one adhesive applicator adapted to apply adhesive to a region of the same pocketed coil springs that is closer to an end of the pocket, and hence closer to a weight-bearing surface of the resultant innerspring assembly, than the central region. 
     
     
         11 . The apparatus as claimed in  claim 10 , wherein the apparatus includes a further adhesive applicator adapted to apply adhesive to a region of the same pocketed coil springs that is closer to the other end of the pocket, and hence closer to the other weight-bearing surface of the innerspring assembly, than the central region. 
     
     
         12 . The apparatus as claimed in  claim 1 , wherein each adhesive applicator has more than one outlet nozzle. 
     
     
         13 . A method of applying adhesive to a string of pocketed coil springs during manufacture of an innerspring assembly, which method comprises the steps of
 (a) providing apparatus for applying adhesive to a string of pocketed coil springs during manufacture of an innerspring assembly, which apparatus comprises a plurality of independently actuatable adhesive applicators, each having a different transverse position relative to a longitudinal axis of the string of pocketed coil springs;   (b) causing relative movement between the string of pocketed coil springs and the plurality of adhesive applicators, along a longitudinal axis of the string; and   (c) applying adhesive to the string of pocketed coil springs, during relative movement between the first string of pocketed coil springs and the plurality of adhesive applicators, in a pattern that varies between at least some of the pockets of the string of pocketed coil springs.   
     
     
         14 . The method as claimed in  claim 13 , wherein the adhesive applicators are disposed on a linear axis, which is aligned with an operable axis, which is a normal compression axis, of the coil springs of the string to which adhesive is being applied. 
     
     
         15 . The method as claimed in  claim 13 , wherein the string of pocketed coil springs is moved relative to the adhesive applicators, which are stationary relative to a remainder of the apparatus during application of adhesive to the string. 
     
     
         16 . The method as claimed in  claim 13 , wherein the apparatus for applying adhesive to a string of pocketed coil springs during manufacture of an innerspring assembly is the apparatus claimed in  claim 1 . 
     
     
         17 . The method as claimed in  claim 13 , wherein the adhesive is applied to the string of pocked coil springs in a pattern that has a plurality of zones, with the separation between the adhesive and weight-bearing faces of the innerspring assembly being different between at least some of the zones. 
     
     
         18 . The method as claimed in  claim 13 , wherein adhesive is applied to each pocketed coil spring in turn, with adhesive being applied to a particular pocketed coil spring before any adhesive is applied to the next pocked coil spring to which adhesive is to be applied. 
     
     
         19 . The method as claimed in  claim 13 , wherein a relative movement between the string of pocketed coil springs and the plurality of adhesive applicators is continuous during application of adhesive to the string. 
     
     
         20 . The method as claimed in  claim 13 , wherein the adhesive from each adhesive applicator is applied as a continuous line of adhesive that extends over a plurality of pocketed coil springs. 
     
     
         21 . The method as claimed in  claim 13 , wherein the adhesive applicators are moved relative to the string of pocketed coil springs, which are stationary relative to the remainder of the apparatus, during application of adhesive to the string. 
     
     
         22 . An apparatus for manufacturing an innerspring assembly, which apparatus comprises the apparatus as claimed in  claim 1  for applying adhesive to a string of pocketed coil springs. 
     
     
         23 . The apparatus as claimed in  claim 22 , wherein the apparatus includes means for bringing a second string of pocketed coil springs into contact with a first string of pocketed coil springs, with adhesive having been applied to the second string of pocketed coil springs before it is brought into contact with the first string of pocketed coil springs. 
     
     
         24 . The apparatus as claimed in  claim 23 , wherein the apparatus includes means for successively bringing a string to which adhesive has been applied into contact with the preceding string to which adhesive has been applied, in order to form an innerspring assembly comprising strings of pocketed coil springs arranged side-by-side, with adhesive acting between abutting surfaces of adjacent strings of pocketed coil springs. 
     
     
         25 . A method for manufacturing an innerspring assembly, which method comprises the method as claimed in  claim 13  for applying adhesive to a string of pocketed coil springs. 
     
     
         26 . The method as claimed in  claim 25 , further comprising:
 (d) bringing a second string of pocketed coil springs into contact with a first string of pocketed coil springs, with adhesive having already been applied to the second string of pocketed coil springs before it is brought into contact with the first string of pocketed coil springs.   
     
     
         27 . The method as claimed in  claim 26 , wherein the steps (b), (c) and (d) are repeated for further strings of pocketed coil springs, so as to form an innerspring assembly comprising strings of pocketed coil springs arranged side-by-side, with adhesive acting between abutting surfaces of adjacent strings of pocketed coil springs. 
     
     
         28 . The method as claimed in  claim 25 , wherein the innerspring assembly is formed with strings of pocketed coil springs that are adhered together, side-by-side, with adhesive that is disposed in a pattern that has a plurality of zones, with the separation between the adhesive and weight-bearing faces of the innerspring assembly being different between at least some of the zones. 
     
     
         29 . The method as claimed in  claim 28 , wherein the strings of pocketed coil springs are arranged longitudinally of the innerspring assembly, such that the firmness of the weight-bearing faces varies longitudinally of the innerspring assembly. 
     
     
         30 . The method as claimed in  claim 29 , wherein a variation in firmness across the width of the innerspring assembly is provided by different forms of springs being present in different strings of pocketed coil springs that form the innerspring assembly. 
     
     
         31 . The method as claimed in  claim 30 , wherein a different form of spring is present in the strings of pocketed coil springs on one side of the innerspring assembly, relative to the form of spring present in the strings of pocketed coil springs on the other side of the innerspring assembly. 
     
     
         32 . An innerspring assembly manufactured by the method as claimed in  claim 25 , or using the apparatus as claimed in  claim 22 . 
     
     
         33 . The innerspring assembly as claimed in  claim 32 , wherein the innerspring assembly comprises strings of pocketed coil springs that are adhered together, side-by-side, with adhesive that is disposed in a pattern that has a plurality of zones, with the separation between the adhesive and the weight-bearing faces of the innerspring assembly being different between at least some of the zones. 
     
     
         34 . The innerspring assembly as claimed in  claim 33 , wherein the strings of pocketed coil springs are arranged longitudinally of the innerspring assembly, such that the firmness of the weight-bearing faces varies longitudinally of the innerspring assembly. 
     
     
         35 . The innerspring assembly as claimed in  claim 34 , wherein a variation in firmness across the width of the innerspring assembly is provided by different forms of springs being present in different strings of pocketed coil springs that form the innerspring assembly. 
     
     
         36 . The innerspring assembly as claimed in  claim 35 , wherein a different form of spring is present in the strings of pocketed coil springs on one side of the innerspring assembly, relative to the form of spring present in the strings of pocketed coil springs on the other side of the innerspring assembly.