Patent Document

BRIEF SUMMARY OF THE INVENTION 
       [0001]    The invention relates to a device for manufacturing latex mattresses, comprising a conveying system for mattress moulds, wherein each mattress mould is made up of an upper and a lower mould section, which are pivotally interconnected, and wherein the latex-filled mattress moulds can be subjected to one or more mattress-forming processing steps while being moved through the conveying system. 
         [0002]    With a device as referred to in the introduction, latex mattresses are formed in mattress moulds in a continuous process. Said mattress moulds are arranged one behind another, forming a “train”, in a conveying system, which system comprises a closed, circulating conveyor, for example, on which the mattress moulds are placed. During their movement over the conveyor, the mattress moulds are subjected to various mattress-forming processing steps, such as 1) filling the mattress mould with a predetermined amount of liquid latex, 2) vulcanising, 3) emptying the mattress mould at the end of the conveying path, i.e. removing the newly formed latex mattress from the mattress mould in order to carry out further processing steps, such as drying the mattress, etc, and 4) conditioning the emptied mattress mould so as to form a new latex mattress. 
         [0003]    At present the removal of a newly formed mattress from the mattress mould still takes place manually. At the end of the conveying path each mattress mould is opened (which may or may not take place in an automated manner) by causing the lower and the upper mould section to pivot away from each other. The newly formed latex mattress which has thus been made accessible must be manually removed from the lower mould section or the upper mould section. 
         [0004]    The operating conditions under which the manual removal of a newly formed latex mattress from a mattress mould takes place are less than optimal. Usually the newly formed latex mattress that is to be removed from the mould still has a fairly high temperature (on account of the manufacturing process), making it necessary for operators to wear protective clothing. Furthermore, the manual removal of the latex mattresses leads to unnecessary damage to the mattresses and consequently to a relatively high percentage of rejects. In addition to that, the manual operations are not very ergonomic, leading to injury and absence through illness of operators. 
         [0005]    The object of the invention is to overcome the aforesaid drawbacks, and according to the invention the device is provided with means for removing a latex mattress from a mattress mould. This obviates the need for operators to carry out manual operations, which on the one hand leads to improved ergonomic conditions but also to a reduced number of rejects and less damage to the mattresses. 
         [0006]    In a first embodiment, the removing means comprise at least one deforming element that can be placed into contact with the latex mattress, said removing means comprising first clamping means made up of at least a first and a second clamping element, which clamping elements are movable relative to each other, wherein either one of the first or the second clamping element can be moved between a circumferential edge of the lower or the upper mould section and the latex mattress that has been moved away from said circumferential edge by the deforming element. 
         [0007]    The latex mattress to be removed is first deformed by the deforming element in such a manner that the long side of the mattress is moved clear of the circumferential edge of the (lower or upper) mould section that contains the mattress. By inserting a clamping element, which mates with the other clamping element, into the space between the circumferential edge and the mattress that has thus been created it becomes possible to clamp down the latex mattress and automatically—i.e. without any manual operations being required—remove it from the mould section. Since the removing means are placed into contact with the mattress in a controlled manner, the risk of damage and rejects is minimal. 
         [0008]    An improved method of removing the latex mattress, which leads to an even further reduction of damage and rejects, is achieved in that in another embodiment the removing means further comprise second clamping means made up at least of a third clamping element that is movable with respect to the deforming element. 
         [0009]    More specifically, at least the deforming element, the first clamping element, the second clamping element and/or the third clamping element extend along substantially the entire length of the latex mattress, making it possible to realise an improved clamping down and thus prevent damage. 
         [0010]    A compact construction which is easy to control can be realised if, in a specific embodiment, the removing means are mounted on a yoke which is movable with respect to the conveying system. 
         [0011]    In the first embodiment, the yoke is mounted on a drivable arm of, for example, a robot. This enables a more flexible operation of the device according to the invention, wherein the newly formed mattress can be removed either from the lower mould section or from the upper mould section. 
         [0012]    In another embodiment, the yoke is movably arranged between two slightly spaced-apart parallel guides. The yoke is movably (in vertical direction) connected to a flexible connecting element that is wound on a rotary winding element. 
         [0013]    More specifically, the rotary winding element is mounted on a support that can be moved over said two guides. 
         [0014]    The invention also relates to removing means as described herein. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0015]    The invention will now be explained in more detail with reference to a drawing, in which: 
           [0016]      FIG. 1  is a schematic view of a device according to the prior art; 
           [0017]      FIG. 2   a  is a schematic view of an embodiment of the removing means according to the invention in a first operating condition thereof; 
           [0018]      FIG. 2   b  is a schematic view of the embodiment of the removing means of  FIG. 2   a  in a second operating condition thereof; 
           [0019]      FIG. 3  shows a first embodiment of a device according to the invention; 
           [0020]      FIG. 4  shows a second embodiment of a device according to the invention. 
       
    
    
       [0021]    For a better understanding of the invention, like parts will be indicated by the same reference numerals in the detailed description of the figures below. 
       DETAILED DESCRIPTION OF THE INVENTION  
       [0022]      FIG. 1  schematically shows an embodiment according to the prior art, in which latex mattresses are made. The device  1  is built up of a conveying system  2 , preferably a circulating conveying system. A number of mattress moulds  3  are transported over said circular conveying system  2  in succession, and a mattress is formed in each of the mattress moulds  3 . While the mattress moulds  3  are being moved over the conveying system  2 , the amount of latex contained in the mattress moulds  3  is subjected to a number of mattress-forming operations. 
         [0023]    In  FIG. 1  a number of such mattress-forming operations, indicated  4   a - 4   d , are shown merely to illustrate and explain the system, which is known per se. 
         [0024]    Numeral  4   a  indicates a filling station, from which each passing mattress mould  3  is filled with a predetermined amount of liquid latex. Numeral  4   b  indicates a heating or vulcanisation line, in which the amount of latex contained in each of the mattress moulds  3  is vulcanised so as to form the mattress. 
         [0025]    Numeral  4   c  indicates the location in the conveying system  2  where the latex mattresses that have been formed in each of the mattress moulds  3  are removed therefrom and carried to a discharge station  5 . Said discharge station is partially built up of a conveyor belt, on which each of the removed, newly formed mattresses is carried off for further processing. 
         [0026]    Subsequently, each mattress mould  3  from which the latex mattress has been removed is conditioned (prepared) at the location indicated by reference numeral  4   c  before being filled with an amount of liquid latex at the filling station  4   a , after which the entire manufacturing cycle is repeated. 
         [0027]      FIG. 2  is a detailed view of the discharge station  5 , i.e. the location in the conveying system  2  where the newly formed mattresses are removed from each of the mattress moulds. As  FIG. 2  shows, the conveying system  2  is built up of two drivable guideways  10   a - 10   b , over which the mattress mould  3  can be moved. The mattress mould  3  is built up of two shell members  3   a  and  3   b , which are interconnected by a hinge  13 . 
         [0028]    The shell members  3   a ,  3   b  comprise a lower mould section  14   a  and an upper mould section  14   b , respectively, which fit together exactly when the shell members  3   a  and  3   b  are moved together, thus creating a moulding cavity  17  into which latex (not shown) can be introduced so as to form the latex mattress. The lower mould section  14   a  is provided with an upright edge  15 , which may alternatively be present on the upper mould section  14   b , however. 
         [0029]    It should be noted that the manner in which the mattress mould  3  is filled with liquid latex is not relevant for a correct understanding of the invention. According to one manufacturing method, the mattress mould  3  is filled in open condition and the desired amount of liquid latex is introduced into the lower mould section  14   a . The upright edge  15  prevents undesirable leakage of liquid latex. According to another manufacturing method, the mattress mould  3  is filled in closed condition and the correct amount of liquid latex is injected into the moulding cavity  17  enclosed by the two closed mould sections  14   a - 14   b  through an opening formed in the upper mould section  14   b.    
         [0030]    A number of upright pins  16   a - 16   b  are provided in each of the lower and upper mould sections  14   a - 14   b , which pins extend into the latex mattress during the forming process of the latex mattress. Said upright pins function to transfer heat more efficiently into the core of the mattress to enable an improved control of or assist in the mattress forming process. 
         [0031]    At the end of the manufacturing process, the mattress mould  3  (which is closed at that stage) is conveyed in the direction of the removing station  4   d  (see  FIG. 1 ). The shell member  3   b  of the mattress mould  3  is pivoted upwards—in a manner which is not relevant for a correct understanding of the present invention—providing access to the two mould sections  14   a - 14   b . The mattress (not shown) that has been formed in said mattress mould  3  may have come loose from both mould sections  14   a - 14   b  as a result of the preparatory application of a so-called releasing agent, and consequently it is contained, being more or less freely accessible, in either the lower mould section  14   a  or the upper mould section  14   b.    
         [0032]    At present, as already described above, the mattress that is present in the open mattress mould  3  is manually removed from the respective lower or upper mould section  14   a - 14   b  at the location of the removing station  4   d.    
         [0033]    According to the invention, the device comprises removing means that remove the newly formed mattress from the lower or the upper mould section. Said removing means are indicated at  30 , and in this embodiment they are freely movable with respect to the mattress mould  3 . In this embodiment, the removing means  30  are movable in horizontal and in vertical direction in the device  1 . The removing means  30  are movable in vertical direction away from and towards the open mattress mould  3  by means of a flexible connecting element  24 . 
         [0034]    The connecting element  24  is connected to the removing means  30  with one end and passed over a pulley  23  towards a rotary winding element  22 , which can be driven by a driving motor  22   a . The flexible connecting element  24  is wound on the rotary winding element  22  in one or more windings, so that the removing means  30  can be moved in vertical direction by suitably winding or unwinding the connecting element on or from the winding element  22  by means of the driving motor  22   a.    
         [0035]    The winding element  22  as well as the driving motor  22   a  are mounted in a supporting construction  20 , which can be moved in horizontal direction over two slightly spaced-apart, parallel guides  21   a - 21   b . Said movement over the guides  21   a - 21   b  can be effected by means of suitable guide wheels  25   a - 25   b , for example. 
         [0036]    The operation of the removing means according to the invention will now be explained by means of an embodiment as shown in  FIGS. 3A and 3B . 
         [0037]    As is shown in  FIG. 3A , the removing means  30  comprise a deforming element  33 , which is placed on the newly formed latex mattress, directly along a long side of the mattress and the upright edge  15  of the lower or upper mould section. The position at which the deforming element  33  is placed on the latex mattress to be removed (which is present in the moulding cavity  17 ) is indicated at A in  FIG. 2 . The deforming element  33  extends along the entire length of the mattress to be removed, parallel to the upright edge  15 . 
         [0038]    The deforming element  33  forms part of a yoke  31 , which is coupled to the flexible connecting element  24  for realising the vertical movement with respect to the mattress that is to be removed. The yoke  31  has a considerable weight, which can be further increased by means of an auxiliary weight  31   a . As a result of the force of gravity and the considerable weight of the yoke  31  (and the auxiliary weight  31   a ), the deforming element  33  is moved down some distance into the supple, flexible latex mattress. As a result, the circumferential edge of the latex mattress, which abuts directly against the circumferential edge  15 , will be moved clear of the circumferential edge at that location. 
         [0039]    The removing means  30  are furthermore provided with first clamping means made up of first and second clamping elements  34 - 35 , which are movable relative to each other. In the embodiment as shown in  FIGS. 3A and 3B , the first clamping element  34  is fixedly connected to the yoke  31  at the location of the deforming element  33 . Upon deformation of the latex mattress to be removed by the deforming element  33 , the first clamping element  34 , too, will move down into the supple, flexible mattress material. 
         [0040]    The second clamping element  35  is pivotally connected to the yoke  31  via pivot point  36 . The second clamping element  35  is provided with a flange  35   a , which is pivotally connected, via pivot point  43   a , to a spindle shaft  42  that forms part of first moving means  40 . The spindle  42  is slidably accommodated in an extension cylinder  41 . The extension cylinder  41  is in turn connected to the upper side of the yoke  31  via pivot point  43   b.    
         [0041]    The long side of the latex mattress, which has been moved clear of the circumferential edge  15  by the deforming element  33 , can be clamped down by the first clamping means  34 - 35  by suitably driving the first moving means  40 , so that the second clamping element  35  will pivot about the pivot point  36  in the direction of the first clamping element  34 , as is shown in  FIG. 3B . 
         [0042]    Now that the long side of the latex mattress, which has been moved clear of the circumferential edge  15  of the mattress mould  17 , is clamped down between the first and the second clamping element  34 - 35 , the mattress can be taken or pulled out of the lower mould section  14   a  by moving the removing means  30  in upward direction (by winding the flexible connecting element  24  on the winding element  22 ). 
         [0043]    To prevent the mattress being damaged or torn on account of its weight at the long side that is clamped down between the first and the second clamping element  34 - 35 , the removing means  30  are provided with second clamping means made up of a third clamping element  38 , which can be moved with respect to the deforming element  33  by second moving means  50 . Said third clamping element  38  is pivotally connected to the yoke  31  via pivot point  39 , and furthermore to the extension spindle  52  via point  53   a . The spindle  52  is movably accommodated in the extension cylinder  51 , which is connected to the yoke  31  at point  53   b . The third clamping element  38  has a clamping point  37 , which, when actuated, can be moved towards the deforming element  33 , as is shown in  FIG. 3B . 
         [0044]    The mattress, which may or may not have been partially removed from the mould section  14   a , can be fully clamped down by means of the third clamping element  38 , thus preventing damaging or tearing of the mattress. 
         [0045]    To obtain a good clamping action, in order to prevent the mattress from being damaged upon removal and movement thereof, both the deforming element  33  and the first, second and third clamping elements  34 - 35 - 38  (including the clamping point  37 ) extend along the full length of the mattress to be removed. As a result, a satisfactory clamping down of the mattress with a good pressure distribution is obtained. The occurrence of pressure points, which will inevitably lead to damage to the mattress to be removed, is prevented in this manner. 
         [0046]    Furthermore, the yoke  31  is provided with a bearing edge  32 , which will be supported on the upper edge of a circumferential edge  15  of the mould section  14   a . In this way a proper orientation of the deforming elements  33  and of the first, second and third clamping elements  34 - 35 - 38  with respect to the mattress to be removed is obtained. 
         [0047]      FIG. 4  schematically shows another embodiment of the device according to the invention. In this embodiment, the removing means  30 , which are schematically shown in  FIG. 4 , are mounted on a drivable arm  60 , which forms part of a driving unit  61 . The arm  60  is an articulated arm made up of, for example, two arm sections  62   a - 62   b , which are connected to the driving unit  61  by means of flexible couplings or hinges  63   a - 63   b . The driving unit  61  is mounted on a support that extends above the conveying system  2 . Both mattresses that are present in the lower mould section  14   a  and mattresses that are present in the upper mould section  14   b  can be removed by the removing means, using the robot arm  60 , and be discharged in the direction of the discharge station  5  ( FIG. 2 ) in a simple manner. 
         [0048]    Once the mattress has been fully removed from the mould section  14   a  by the removing means  30 , the mattress is vertically suspended between the third clamping element  38  and the deforming element  33 . By moving the supporting construction  22  back in the direction of the discharge station  5  (see  FIG. 2 ) over the guides  21   a - 21   b  by suitable driving means (not shown), the clamped-down mattress is positioned above a conveyor belt  5   a , which conveyor belt is configured as an endless carrier  11  that moves on drivable rollers  12   a - 12   b.    
         [0049]    The mattress is placed on the conveyor belt  11  at the location indicated at Q by moving the yoke  31  down via the flexible connecting element  24  (a cable, for example) by means of the winding element  22 . By subsequently moving the third clamping element back to the position that is shown in  FIG. 3A , the mattress is released and can be further discharged, for example to a drying device, for further processing via the conveyor belt section  5   a  and the next conveyor belt section  5   b.    
         [0050]    Having thus described exemplary embodiments of the present invention, it should be noted by those skilled in the art that the within disclosures are exemplary only and that various other alternatives, adaptations, and modifications may be made within the scope of the present invention. Accordingly, the present invention is not limited to the specific embodiments as illustrated herein, but is only limited by the following claims.

Technology Category: 7