Apparatus and method for making a resilient unit

Abstract

Apparatus for forming a resilient unit comprises a conveyor 210 and first and second spring supply stations 212 and 214 , arranged in use to deposit respectively first and second spring types 216 and 218 under compression onto the conveyor. The conveyor is arranged in use to convey a row of the springs 216, 218 in a direction shown by Arrows A 4 towards pocketing station 220 . At the pocketing station 220 the springs are urged from the conveyor into positions between upper and lower sheets 222 and 224 , by a plurality of inserter devices 226 that move together in a reciprocating fashion in the direction of arrow A 5 , before retracting to the position shown. After each row of springs is inserted between the sheets 222 , upper and lower computer-controlled welding tools (not shown) come together at positions P between the springs to join the sheets together, forming pockets in which the springs are encased. After each welding event the resilient unit is indexed forwards a distance equal to one pocket width in the direction of Arrows A 6 by computer-controlled drive means (not shown). The next row of springs is then conveyed into position ready for insertion between the sheets of material, and the process is repeated. The two spring supply stations are arranged to supply springs that differ from one another in at least one characteristic.

1 . Apparatus for making a resilient unit, the apparatus comprising at least first and second spring supply stations, a conveyor and a pocketing station, wherein the first and second spring supply stations are arranged to supply respectively at least first and second spring types to the pocketing station, which first and second types differ from one another in at least one characteristic, the pocketing station being arranged in use to insert the springs between superposed sheets of material, and to encapsulate the springs in pockets formed by joining the sheets at least at positions between the springs, wherein the first and second supply stations are arranged in use to deposit respectively springs of the first and second type under compression onto the conveyor and the conveyor is arranged in use to convey the springs under compression to the pocketing station. 
     
     
         2 . Apparatus according to  claim 1 , wherein the supply stations are arranged to supply the springs to the pocketing station in at least one row. 
     
     
         3 . Apparatus according to  claim 1 , wherein the springs are supplied to the pocketing station in a row in which the first and second types of spring are offset with respect to each other. 
     
     
         4 . Apparatus according to  claim 1 , wherein the conveyor comprises one or more belts, or a belt and a compression plate. 
     
     
         5 . Apparatus according to  claim 1 , wherein the spring types differ from one another according to at least one characteristic, of a list including but not limited to: material composition, stiffness or resilience, height, width, colour, and shape. 
     
     
         6 . Apparatus according to  claim 1 , wherein there are three or more spring supply stations, arranged in use to supply respectively three or more spring types, which may differ from one another according to one or more characteristic. 
     
     
         7 . Apparatus according to  claim 1 , wherein the springs are arranged to be supplied to the pocketing station in a row comprising a plurality of discrete spring locations. 
     
     
         8 . Apparatus according to  claim 7 , wherein the individual spring locations may be occupied by a spring of a first type, or a spring of a second, third or successive type, or may not be occupied by a spring at all. 
     
     
         9 . A method of making a resilient unit, the unit comprising an array of springs in pockets formed between superposed sheets of material, the apparatus comprising: supplying at least first and second spring types from at least first and second supply stations to a pocketing station via a conveyor, which first and second types differ from one another in at least one characteristic, and inserting the springs between superposed sheets of material at the pocketing station, to encapsulate the springs in pockets formed by joining the sheets at least at positions between the springs, wherein the method comprises depositing the springs of the first and second type under compression onto the conveyor and transporting the springs on the conveyor, under compression, to the pocketing station. 
     
     
         10 . A method according to  claim 9 , wherein the method comprises supplying the springs to the pocketing station in at least one row. 
     
     
         11 . A method according to  claim 9 , wherein the method comprises arranging springs in the resilient unit such that one or more zones are formed, in which the springs have different characteristics. 
     
     
         12 . A method according to  claim 9 , wherein the method includes arranging springs in the resilient unit such that a pattern is formed in the resilient unit, which pattern may provide a visual, aesthetic or structural effect. 
     
     
         13 . A computer programme product on a computer readable medium, comprising instructions that, when executed by a computer, cause the computer to perform a method of making a resilient unit according to  claim 9 . 
     
     
         14 . A program for causing a device to perform a method of making a resilient unit, the unit comprising an array of resilient elements in pockets formed between superposed sheets of material, the method being in accordance with  claim 9 .