MXPA01009345A - Method and apparatus for manufacturing innerspring assemblies - Google Patents

Abstract

A method for the manufacture of an innerspring assembly, suitable for a mattress, cushion or the like, comprises the steps of a) positioning a first string (6) of pocketed coil springs in juxtaposition with a plurality of adhesive applicators (12) disposed in mutually fixed relation on an axis parallel to a longitudinal axis of said first string (6), b) applying adhesive from said adhesive applicators (12) to said first string (6) of pocketed coil springs, and c) bringing said first string (6) into adhesive contact with a second string (6a) of pocketed coil springs. Apparatus for carrying out the method is also disclosed, as are innerspring assemblies produced by the method.

Description

METHOD AND APPARATUS FOR DEVELOPING ASSEMBLIES OF INTERNAL SPRINGS This invention relates to a method and apparatus for manufacturing assemblies with internal springs, in particular assemblies with internal springs for mattresses or the like, said assemblies of internal springs comprise strings of bagged springs arranged side by side and adhered to each other laterally by adhesive. The way to make assemblies for mattresses and the like starting from springs of bagged turns is already known. Typically, bagged spring chains are made by feeding springs directly from a coil spring forming machine in the space between two layers of a weldable fabric, the two layers subsequently sealing together to form a bag that encapsulates the spring. The fabric is then traversed forward, the next spring is encapsulated, and the procedure is continued in the same manner. In this way, long chains of bagged springs are constructed. Said chains of springs bagged herein are referred to as "chains" of springs. An assembly of internal springs of suitable dimensions for a mattress can be constructed by placing suitable lengths of strings of springs bagged side by side and adhering them together.

Automated methods for forming inner spring assemblies in this manner as well as the apparatus for carrying out such methods are already known. For example, European Patent No. 0154076 describes a method in which an adhesive applicator passes over a chain of bagged springs, the applicator being activated briefly as it passes over each spring, so that a line of adhesive is applied to the spring, parallel to the spring. the lines that define the transverse sides of the bags, and then causes the chain of springs to make contact with another similar spring chain. European Patent No. 0421495 describes another method wherein a chain of bagged springs passes longitudinally after a fixed adhesive applicator, such that said adhesive is applied to one side of the chain, which is then pressed into contact with the corresponding side of a second chain of springs. In both mentioned methods, the amount of adhesive applied to the various springs in each chain is substantially the same. This can be a drawback, since it results in an assembly of internal springs having a uniform degree of firmness of the assembly of internal springs over their entire length. Sometimes it is desirable that the firmness of the internal spring assembly has some variations in its length. For example, we know how to make a mattress with three areas of firmness, a central region, which carries most of the weight of a person lying on the mattress, being relatively rigid, while the parts of the head and feet of the mattress are less rigid for comfort. A more sophisticated arrangement is a 5-zone mattress where the central part is again the most rigid, but the ends are also somewhat more rigid than the intermediate regions. Said arrangements can not be easily produced using the known internal spring assembly apparatuses. Another drawback of the known systems is that the need to move the chain of springs after the fixed adhesive applicator, or to move an applicator on a chain of springs, can slow down the manufacturing process. A method and apparatus for the manufacture of internal spring assemblies has now been engineered, which alleviate or substantially mitigate the aforementioned and other drawbacks of the prior art. According to a first aspect of the invention, a method for the production of internal springs is provided, said method comprises the steps of: a) placing a first string of coiled springs in juxtaposition with a plurality of adhesive applicators placed in a fixed mutual relation on an axis parallel to a longitudinal axis of said first chain, b) applying adhesive from said adhesive applicators to said first chain of bagged coil springs, and c) placing said first chain in adhesive contact with a second chain of springs of coils bagged.

The method according to the invention has advantages mainly in that, because a plurality of adhesive applicators are used, the amount and / or distribution of the adhesive applied in each individual bag can vary, thus allowing the control of the firmness of the adhesive. the regions of the assembly of internal springs, and therefore of the finished mattress. Also, because the adhesive can be applied simultaneously from the adhesive applicators to all the bags of the first chain (instead of being applied in sequence to the bags), an increase in operating speed and production can be achieved. Also, where the adhesive applicators are activated simultaneously, the time between the supply of the adhesive and the contact of the first and second can be minimized, and it is also the same for all the parts of the chains, obtaining an improved adhesion and more consistent. The invention also provides an assembly of internal springs manufactured by the method of the first aspect of the invention. According to another aspect of the invention, there is provided an apparatus for use in the manufacture of an assembly of internal springs, said apparatus comprises a plurality of adhesive applicators, means for placing a first string of coil springs in juxtaposition with said plurality. of adhesive applicators, and means for bringing said first chain into an adhesive contact with a second chain of bagged coil springs, wherein said plurality of adhesive applicators is placed in a fixed relationship mutually on an axis parallel to a longitudinal axis of said first one. chain. For most applications, the adhesive is preferably supplied from the plurality of adhesive applicators simultaneously or substantially simultaneously. Preferably, the first chain of bagged coil springs is longitudinally fed to the apparatus of the invention and then transversally moved in juxtaposition with the adhesive applicators. Preferably, the adhesive applicators are arranged in a line and arranged on the path of transverse movement of the first chain. Each applicator will generally have an adhesive outlet directed downward (which is usually in the form of a liquid), usually in the form of a nozzle. For some applications, each applicator can have more than one outlet, for example a number of nozzles arranged in a row transverse or parallel to the longitudinal axis of the first chain, or a single nozzle with more than one hole arranged to supply adhesive in directions different The first chain may be manufactured by conventional techniques, for example by inserting springs in compressed condition between the layers of a folded sheet of a fabric that can be welded ultrasonically and forming closed compartments for each spring by making a series of welds.

After the application of the adhesive to the first chain, the first chain preferably moves on a turning mechanism by which the first chain is inclined in a straight position so that the surface of the first chain, to which it has been applied the adhesive comes into contact with the surface of the second chain. The second string most commonly will be a string that has been processed immediately before the same way as the first string. Preferably, the turning mechanism comprises a plate placed parallel to the adhesive applicators. It is preferable that the plate has a width corresponding approximately to the width of the first chain and rotates on its main edge, which is remote from the adhesive applicators. When the first chain is moved over the plate, the plate can then rotate to tilt the first chain away from the adhesive applicators and into contact with the second chain. The turning mechanism is preferably provided with means for retaining the chain of springs in one position during the turning operation. Said means conveniently comprise one or more electromagnets that are activated when the spring chain has been placed on the turn plate and turn off once the first chain is pressed in contact with the second chain. The different moments of the first chain, that is, in alignment with the adhesive applicators, below transversely of the adhesive applicators, and on the turning plate, they are most conveniently approached through suitable mechanical means, for example using electrical, hydraulic or electrical power. pneumatics. Preferably, suitable sensors are provided to monitor and control the various moments, in a generally conventional manner. The adhesive applied on the first chain can be one of those adhesives that are conventionally used in the manufacture of internal spring assemblies. Hot melt adhesives are particularly suitable. In general, any conventional adhesives having the desired properties (e.g., strong adhesion, good flow properties, and no odor) can be used. Adhesive applicators with applicators in stationary, fixed positions relative to the spring chain will be supplied for many adhesive applications. However, in other cases the adhesive will be supplied while the controlled movement of the applicators relative to the spring chains is carried out. This may be necessary or desirable, for example to achieve a particular distribution (eg elongated) of adhesive on the surface of a part of the bags or all of them. Obviously, such an effect can be achieved, either by moving the applicators in relation to a stationary chain of springs, or (as would be more comfortable) by moving the chain of springs relative to the fixed applicators. It is also desirable that the separation of the adhesive applicators from the spring chain be adjustable, for example to vary the size of the area to which the adhesive will be applied. Such an arrangement also allows bags with springs of different diameters to be accommodated. As explained above, the present invention allows the manufacture of assemblies of internal springs that are divided "in zones", that is, they have different strength portions. Thus, in accordance with a further aspect of the invention, an assembly of internal springs comprising spring loaded loop chains is provided, said chains being joined by applied adhesive to splice the surfaces of the bags of adjacent chains, where the amount and / or distribution of the adhesive applied to the bags of the adjacent chains is not uniform. Such an assembly of internal springs may comprise at least a portion, wherein the adjacent chains are connected by relatively high amounts of adhesive applied to the bags of said chains, and at least a portion wherein the adjacent chains are connected by relatively large amounts. Low adhesive applied to the bags of said chains. It will be understood that, although reference is made primarily to internal spring assemblies for use in mattresses, the same methods and apparatus may be used in the manufacture of internal spring assemblies for cushions and the like. The invention will now be described in detail only by way of illustration with reference to the accompanying drawings, in which Figure 1 is a schematic plan view of the apparatus according to the invention.; Figure 2 is a view on the line ll-ll of Figure 1; Figure 3 is a fragmentary perspective schematic view illustrating the stages in the development of the invention; Figure 4 is a schematic view of a chain of bagged springs for use in the manufacture of a "3 zone" mattress; Figure 5 is a view similar to Figure 4, but with a chain of bagged springs for use in making a mattress having a "5-zone" construction; Figure 6 is a side view of the bagged springs showing a suitable manner of application as an adhesive for the assembly of a mattress having a spring configuration included; and Figure 7 is a plan view of an assembly of internal springs included. With reference to figures 1 and 2, the apparatus for the manufacture of an assembly of internal springs is generally referred to as number 1. The apparatus 1 is fed with a continuous chain 2 of coil springs, which can be elaborated by means of techniques conventional A chain 6 of bagged springs is cut to a suitable length with conventional cutting means (not shown) from the guide portion from the chain 2. The chain 6 is transported longitudinally on a bed 4 by a suitable conveying means (not shown either) ). In the example illustrated, the chain 6 has a length of 20 bagged springs. This length corresponds to the length of internal springs finished. Once the guide chain 6 has been deposited on the bed 4, the conveyor means is temporarily stopped. The chain 6 is then guided laterally through the bed 4 by means of a conveyor plate 8 wherein the illustrated embodiment is activated by a pair of pneumatic bars 10. To obtain an increased accuracy it may be preferable that the conveyor plate 8 is driven by a servo motor . A row of 20 adhesive application guns 12 are placed on the path of the chain 6 and are activated when the chain 6 passes below them, so that they deposit a quantity of hot melted adhesive on the surface that faces upwards. each bag in the chain 6. This can be achieved by brief activation of the adhesive application guns 12 while the chain 6 is moving below the guns 12. Alternatively, the movement of the chain 6 below the guns 12 it may stop temporarily while guns 12 are activated. It will be apparent that by proper control of the movement of the chain 6 and the activation of the guns 12 various different patterns of adhesive can be applied to the surface of the bags making the chain 6. For example, the adhesive can be applied as a spot 13. single, generally circular (as shown in Figure 3), or as a series of stitches placed longitudinally along the bag (or otherwise, as described below), or a continuous line of adhesive can be applied to along the bag. Similarly, it is possible for all the guns 12 to be activated so that the adhesive is applied to all the bags, or to activate only some of the guns 12. After the application of the adhesive, the chain 6 is further transported, in the same direction, by the transport plate 8, on a rotary table 14. The rotating table 14 rotates 90 °, thus tilting the chain 6 in a straight position and pressing the surface of the chain 6 to which the adhesive in contact with the corresponding surface of a previously processed chain 6a resting on the main bed 16. Electromagnets (not shown) fitted below the turntable 14 contain the chain 6 in place during the tilting operation. While the chain 6 is being turned, the pneumatic bars 10 remove the transport plates 8 to their starting position (as shown in figures 1 and 2) and the next chain is transported on the bed 4. The next chain is then processed in the same way as the previous chain 6. In this way, the completed internal spring construction is formed of successive chains 6, 6a, 6b, etc. The degree of adhesion between the adjacent bags in successive chains in the assembly of assembled internal springs determines the degree of firmness of said part of the assembly of internal springs, and therefore of said part of a mattress wherein the assembly of internal springs will use In this way, it is possible to control the firmness of the mattress by means of the appropriate application of the adhesive to the respective bags. Figure 4 shows a suitable pattern of the application of adhesive for a mattress known as "3 zones". In such construction, the head and foot parts of the mattress are relatively soft, while the central region of the mattress is relatively firm. To achieve such a result, adhesive is applied to a large area 21 of the bags in the central part b of each chain, as compared to the area 22 of the adhesive applied to the bags in the two end portions a, c of the chain. Figure 5 shows a pattern of some more complex maneara of the application of the adhesive, suitable for the formation of a mattress of "5 zones". In such a mattress, the region m is again the firmer (the adhesive being applied to the larger area 31), but in this case, the end portions of head and feet k, or have an intermediate firmness (adhesive area 32), being separated from the central region k by relatively soft regions /, m (minor adhesive regions 33). The patterns of the adhesive application shown in Figures 4 and 5 are suitable for assemblies of internal springs wherein the bags of springs are arranged with their centers in a square arrangement, ie, where the bags are arranged in rows longitudinal and transverse regular. Another arrangement that is sometimes used is the so-called provision of included, wherein the spring bags are arranged in a hexagonal configuration. In the formation of said configuration, because it is not the central part of each spring bag that is pressed against the bags of the previous chain, but with the surfaces of the bag that are outside the center of the center line, the Adhesive application pattern shown in figure 6 is the most suitable. This pattern consists of two circular areas of adhesive 41, 42 applied to each bag, the two areas 41, 42 being separated along and out of the center of the longitudinal axis of each bag. A pattern of this form can be created by applying adhesive first to the areas 41, with adhesive application guns 12 off the center of the center lines of the bags, and then moving the adhesive application guns 12 to a second position. , out of center in the other direction, and apply the adhesive then to the second areas 42. The separation of the two areas 41, 42 along the center lines of the bags is carried near the movement of the chain towards the table Rotating between the two adhesive applications. Clearly, to enable the two areas of adhesive to be applied on opposite sides of the center line of each bag, it is necessary to have means for moving the adhesive application guns 12 relative to the chain. Therefore, means may be provided for moving the guns 12 as a unit, or for moving the chain a short distance along its longitudinal axis relative to the fixed guns. In a further alternative, a pattern like the one shown in Figure 6 can be produced using two rows of adhesive application guns, both arranged on axes parallel to the longitudinal axis of the chain, but off center between each other, so that one-row guns deposit adhesive on one side of the center lines of the bag (read, the first areas 41) and the other row of guns deposit adhesive on the other side (that is, on the second areas), 42). It will be apparent that the adhesive patterns can also be produced by the method of the invention, wherein the adhesive is applied to 2 areas (or more) on the center line of some or each of the bags. Said areas of adhesive may be discontinuous, or may overlap or merge to form single, longer areas.

Claims (25)

NOVELTY OF THE INVENTION CLAIMS

1. - A method for the production of an assembly of internal springs, said method comprises the steps a) placing a first chain of coil springs in juxtaposition with a plurality of adhesive applicators placed in a fixed mutual relation on an axis parallel to a longitudinal axis of said first chain, b) applying adhesive from said adhesive applicators to said first chain of bagged coil springs, and c) bringing said first chain to an adhesive contact with a second chain of bagged coil springs.

2. The method according to claim 1, further characterized in that the adhesive is applied from said plurality of adhesive applicators simultaneously or substantially simultaneously.

3. The method according to claim 1 or 2, further characterized in that the first chain of springs of bagged turns is placed being fed longitudinally, and then moving it transversely in juxtaposition with the adhesive applicators.

4. The method according to any of the preceding claims, further characterized in that after the application of adhesive to the first chain, the first chain is inclined in a straight position, so that the surface of the first chain, to the which adhesive has been applied, comes into contact with the surface of the second chain.

5. The method according to any of the preceding claims, further characterized in that the second chain has been processed in advance and immediately in the same way as the first chain.

6. The method according to any of the preceding claims, further characterized in that the movements of the first chain are made through suitable mechanical means, using electric, hydraulic or pneumatic energy.

7. The method according to any of the preceding claims, further characterized in that the adhesive that is applied to the first chain is a hot melt adhesive.

8. The method according to any of the preceding claims, further characterized in that the adhesive is supplied from the applicators of adhesive with said apiicadores in fixed positions, stationary in relation to the first chain.

9. The method according to any of claims 1 to 7, further characterized in that the adhesive is supplied from the adhesive applicators while the movement of the applicators in relation to the first chain is carried out.

10. - The method according to claim 9, further characterized in that the first chain is stationary and the applicators move.

11. The method according to claim 9, further characterized in that the apiicadores are fixed and the first chain moves.

12. An apparatus for use in the manufacture of an assembly of internal springs, said apparatus comprises a plurality of adhesive applicators, means for placing a first chain of bagged coil springs in juxtaposition with said plurality of adhesive applicators, and means for causing said first chain to be in contact with a second chain of bagged coil springs, wherein said plurality of adhesive applicators is placed in a fixed mutual relationship on an axis parallel to a longitudinal axis of said first chain.

13. The apparatus according to claim 12, further characterized in that the adhesive applicators are arranged in a line.

14. The apparatus according to claim 12 or 13, further characterized in that each applicator has a downwardly directed outlet for the adhesive.

15. The apparatus according to any of claims 12 to 14, further characterized in that each of the applicators has an outlet for the adhesive.

16. - The apparatus according to any of claims 12 to 14, which comprises a turning mechanism by means of which the first chain is inclined to a straight position so that the surface of the first chain, to which the adhesive has been applied, comes into contact with the surface of the second chain.

17. The apparatus according to claim 16, further characterized in that the turning mechanism comprises a plate placed in parallel of the adhesive applicators.

18. The apparatus according to claim 7, further characterized in that the plate has a width corresponding approximately to the width of the first chain and rotates on its main axis that is away from the adhesive applicators.

19. The apparatus according to any of claims 12 to 18, further characterized in that it comprises mechanical means for realizing the movement of the first chain.

20. The apparatus according to claim 19, further characterized in that the mechanical means work with electrical, hydraulic or pneumatic energy.

21. The apparatus according to any of claims 12 to 20, further characterized in that it comprises sensors to monitor and control the movements of the first chain.

22. - An assembly of internal springs made in accordance with the method of any of claims 1 to 11.

23. The assembly of internal springs according to claim 22, which is used for a mattress.

24. An assembly of internal springs comprising spring chains of bagged turns, said chains being joined by an adhesive applied to the surfaces that are connected to the bags of the adjacent chains, wherein the quantity and / or distribution of the adhesive applied to the bags for joining the chains is not uniform 25.- The assembly of internal springs according to claim 24, comprising at least a portion in which the adjacent chains are connected by relatively high amounts of adhesive applied to the bags of said chains, and at least a portion in which the adjacent chains are connected by relatively low amounts of adhesive applied to the bags of said chains.