Abstract:
The invention relates to a device for simultaneously conveying and regulating the temperature of shaped parts, comprising a conveying device, which is suited for advancing objects, and at least one blower by means of which the objects can be subjected to the action of an air flow while being advanced. The conveying device is characterized in that it is formed by a closed channel whose clearance height approximately corresponds to the height of an individual shaped part, whose clearance width at least along a portion of its length is greater by a multiple than the width of an individual shaped part, in whose base plate a multitude of air inlet openings are arranged with a blowing direction oriented in the longitudinal direction of the channel and diagonal to the surface, and in whose cover plate, which is situated opposite the base plate, a multitude of air inlet openings are placed. The air flow produced by the blower can be introduced into the channel via the air inlet openings.

Description:
This application is the US national phase of international application PCT/EP02/12653 in Deutsch on filed 13 Nov. 2002, which designated the US. PCT/EP02/12653 claims priority to DE Application No. 101 57 703.6 filed 24 Nov. 2001. The entire contents of these applications are incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   The invention concerns an apparatus for simultaneously conveying and regulating the temperature of shaped parts according to the preamble to claim  1 . Such apparatuses, which shall hereinafter be called temperature-regulating conveyors, are known and are particularly used to remove by conveying plastic shaped parts directly after production thereof in a press-stamping machine and simultaneously rapidly cool them down to a temperature at which their shape is stable. One example of a plastic shaped part in which this is required is a screw cap for a drinks bottle. Such caps, which may for example consist of polypropylene or polyethylene, are produced in great numbers by injection moulding and are then removed from the mould in the machine at a temperature of approximately 100° C., whereby their form is not yet stable. In order to be able to take them directly to further processing after their production, they must be cooled as quickly as possible down to the specified processing temperature. The throughput of the cooling apparatus must be thereby adapted to the high production rate of today&#39;s injection-moulding machines, which produce about 1200 caps per minute. 
   Prior-art temperature-regulating conveyors typically consist of a conveyor belt and of fans located thereabove that blow temperature-regulated air onto the conveyor belt. However, in order to achieve a high throughput with such an arrangement, a great length and/or width of conveying line and therefore a correspondingly great size of temperature-regulating conveyor is required. 
   A conventional apparatus for the conveying and simultaneous cooling of substrates for data-carrying discs such as CDs, DVDs or the like is known from DE 199 07 210 A1, wherein the substrates rest on carriers during conveying, which carriers slide on an air cushion. Conveying occurs by means of the air cushion along an open channel with a U-shaped section, in the base plate of which a plurality of diagonal air inlet openings are provided for the production of an air cushion with a horizontal stream component. In order to guide part of the cooling air flow onto the substrates, each of the carriers has a vertical and several substantially horizontal holes, which together form a distribution system, through which air in the carrier can flow out, first centrally upwards and then laterally via the substrate. This apparatus is specially designed for the requirements of DC and DVD production and is relatively expensive because of the carriers with an internal air-distribution system that are required. 
   U.S. Pat No. 4,418,482 discloses an apparatus for simultaneous conveying and cooling of plastic bottles after ejection from a injection-moulding machine. The bottles lie with their necks on two rollers that are parallel to one another and rotate in opposite directions to one another along a fissure between these rollers. The main part of each bottle protrudes thereby into a hollow space underneath this fissure, wherein an air stream is blown for cooling. The manner of operation of this apparatus is based on the shape of the plastic bottles and is suitable only for objects of such or of a similar shape. 
   DE 25 09 469 B2 relates to a pneumatic conveying system for conveying pieces of matter, whereby the conveying line is constituted by a vertically extending channel that is closed on all sides. An upwardly directed air stream is created in the channel by blowing in air via diagonal openings on one side of the channel, the open cross-section of which channel corresponding approximately to the cross-section of the conveyed matter, the conveyed matter in the channel being moved upwards by the dynamic pressure of the air stream. The apparatus serves exclusively for the conveying of the conveyed matter. Its temperature is of no interest. 
   Lastly, JP 2000 280 265 A shows a cooling apparatus for objects made of plastic, wherein containers circulate in a chamber that is cooled by an air stream. The objects are continuously placed in the containers as they arrive and after one cycle in the chamber they are taken out of the containers again. 
   SUMMARY OF THE INVENTION 
   In view of this state of the art, the object of the invention is to create a temperature-regulating conveyor that is of compact size that is able to regulate with great uniformity the temperature of a high throughput of shaped parts. 
   This object is achieved according to the invention by an apparatus with the features of claim  1 . Advantageous embodiments are shown in the appended claims. 
   The special feature of the invention lies in the double function of the air stream provided to cool the shaped parts, which air stream by creating dynamic pressure also directly causes the advancing of the shaped parts. A separate conveying apparatus in the form of a belt or the like is thereby advantageously dispensed with. 
   Furthermore, the shaped parts, that serially come singly out of the mould-injection machine, are distributed diagonally to the conveying direction over a given width and are conveyed parallel next to one another, whereby the length of the conveying line can be kept relatively short. The shaped parts are then preferably grouped for direct further processing in a serial sequence and are released individually after one another. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     An example of an embodiment follows that is disclosed by drawings. In these drawings: 
       FIG. 1  shows a first perspective view of a temperature-regulating conveyor according to the invention with a view of the inlet for shaped parts with open cover plate; 
       FIG. 2  shows the view of a temperature-regulating conveyor according to the invention viewed from the same direction as in  FIG. 1 , but ready for operation with closed cover plate; 
       FIG. 3  shows an enlargement of a first detail of the view in  FIG. 1 ; 
       FIG. 4  shows an enlargement of a second detail of the view in  FIG. 1 ; 
       FIG. 5  shows a further enlargement of the second detail of  FIG. 1 , but viewed from another direction than in  FIG. 4 , namely with a view of the outlet for shaped parts. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   As  FIG. 1  shows, in the case of a temperature-regulating conveyor according to the invention the conveying device is assembled on the top side of a tub-shaped oblong housing  1 , which housing  1  together with the adjustable blowers  2 A to  2 C arranged underneath is mounted on a carrier frame  3  comprising rail sections that are bolted together. 
   The conveying device is an elongated straight channel  4  that is formed by a horizontal base plate  5 , a cover plate  6  and two side walls  7 A and  7 B, wherein both side walls  7 A and  7 B on the longitudinal edges of the cover plate  6  are firmly connected to said cover plate and the cover plate  6  is in turn connected on a longitudinal side with the base plate  5  by means of a hinge in such a way that the channel  4  can be opened through simple opening of the cover plate  6  for maintenance or repair work. During operation the cover plate  6  is parallel to the base plate  5 , so that the channel  4  is closed. This situation is shown in  FIG. 2 . Whereas the housing  1 , the base plate  5  and the side walls  7 A and  7 B may consist of different plastics or of metal, a transparent material, such as for example Plexiglas is preferred for the cover plate  6  in order that operation of the apparatus can be observed without difficulty and faults can be immediately recognised. 
   The channel  4  has a rectangular section that is constant over the greater part of its length. Whilst the clear height of the channel  4  is roughly the same as the height of the shaped parts  8  that are to be conveyed, the width of the channel  4  is many times wider than the width of such a shaped part  8 . It will be subsequently assumed that the shaped parts  8  are screw caps  8  for drinks bottles, some of which are illustrated in  FIG. 1  and  FIGS. 3 to 5 . As can be seen in these Figures, it is further assumed that these caps  8  are conveyed to the temperature-regulating conveyor from the injection-moulding machine with the open side uppermost. It is furthermore assumed that the caps  8  arrive individually serially, so that the main part of the inlet  9  is narrower and first widens out from the inlet  9  and then maintains a constant width. 
   In the base plate  5  a plurality of air inlet openings  10  ( FIG. 3 ) are arranged in a regular matrix-shaped arrangement, namely with a blowing direction in the longitudinal direction of the channel  4  and at an angle of approximately 45° to the surface of the base plate  5 . The shape of the air inlet openings  10  is comparable with the shape of the rear of the cutting tools of a commercially available cheese scraper, i.e. it consists of ellipsoid vaulting of the base plate  5  downwards, the depth of the base plate  5  exceeding the thickness of the base plate  5 , the vaulting ending abruptly in a straight cut in the base plate  5  that extends diagonally to the base plate  5 , so that at this cut a vertical opening exists. The air inlet openings  10  lead to an externally insulated cavity inside the housing  1 , which cavity is connected by pipes to the blowers  2 A to  2 C in such a way that during operation of the blowers  2 A to  2 C the air blown into the housing  1  by the latter flows out of the air inlet openings  10  diagonally upwards into the channel  4 . 
   The adjustable blowers  2 A to  2 C are preferably equipped individually or jointly with at least one filter and optionally also with heating and thus provide an adjustable throughput of purified air at a pre-settable temperature. Cleaning the air flow by filters may for example be necessary when there are particular hygienic requirements of the caps  8  the temperature of which is to be regulated in view of their later use for packaging foodstuffs or medicines. 
   Heating of the air stream may be of interest in the event of major fluctuations in ambient temperature. 
   In the cover plate  6  there are also a plurality of slit-shaped air inlet openings  11  with a regular matrix-shaped arrangement, so that during operation of the apparatus inside the channel  4  there is a virtually homogenous air stream that moves diagonally upwards. Obviously, hot caps  8  inserted into the channel  4  at the inlet are through the effect of this air stream conveyed along the length of the channel  4  and are simultaneously cooled by convection. The caps  8  slide as a result of the vertical component of the air stream with their bottoms virtually free of friction on an air cushion over the surface of the base plate  5  and are moved forwards along the length of the channel  4  by the dynamic pressure that the horizontal component of the air stream builds up on them. The opposite cover plate  6  prevents uncontrolled vertical movements, such as may for example occur through collisions between caps and ensures through the fixing of channel height at a value that is only just above the height of the caps that no cap can be overturned and thereby cause a blockage to material flow. 
   Through the widening of the width of the channel  4  to many times the diameter of a cap  8  it is ensured that even with a comparatively slow advancing of the caps  8  in the channel  4  a sufficiently high throughput can be reached by the caps arriving rapidly individually at the input  9  being able to be distributed over the entire width of the channel  4 , as shown in  FIG. 1  in the form of three rows of caps  8 . 
   If the caps need to be placed in containers for the purposes of storage or shipment after cooling, a kind of funnel would suffice as an outlet of the temperature-regulating conveyor wherein the caps  8  could be conveyed by the air stream. But if the caps have to be immediately conveyed to further processing, they must be again grouped in the serial sequence in which they arrive at the inlet  9 . This task is performed by further sections of the preferred embodiment of the invention that are connected to the section disclosed above. These further sections are explained below by means of  FIGS. 3  to  5 , wherein a small general overview of the temperature conveyer and alongside it an enlarged section that is indicated in the general overview by a frame are illustrated. 
   As  FIG. 3  shows, the channel  4  branches off first into a series of partial channels  13  that extend parallel to one another and are separated from one another by thin dividing walls  12 , the clear width of which partial channels  13  corresponds approximately to the diameter of a cap  8 . The air inlet openings  11  in the base plate  5  are continued in the partial channels  13 , like the air intake openings  11  in the cover plate  6  above the partial channels  13 . Advancing of the caps  8  therefore occurs inside the partial channels  13  just as before in the common channel  4 , but is now no longer distributed at random over the width of the device but in several straight columns. 
   As  FIG. 3  shows, the total of ten partial channels  13  in the example do not fill the entire width of the channel  4 , the partial channels  13  are rather organised into two symmetrical groups of five, between which an intermediate space  14  that is not used for partial channels  13  exists. At the front of this intermediate space  14  to the channel  4  there is a wedge-shaped deflector  15 , which distributes the caps arriving from the channel  4  as equally and free of congestion as possible between both groups of partial channels  13 . For this purpose the deflector  15  is movably placed in the base plate  5  and is made to periodically oscillate during operation of the apparatus through a drive under the base plate  5 . 
   On the front sides of the dividing walls  12  smaller, equally wedge-shaped but more acute deflectors  16  are provided that are intended to cause uniform filling of the individual partial channels  13  of each group and prevent blockages at the entrances to the partial channels  13 , for which reason the deflectors are rotationally positioned around a vertical axis and are driven during operation of the device to an oscillating movement like that of a ship&#39;s rudder. The rotation axis is always near the front surface of the dividing wall  12 , so that the point of a deflector  16  protruding into the channel  4  has maximum deflection. 
   In order to bring the different columns of caps  8  in the individual partial channels  13  together to form a single column, the outlets of each of both symmetrical groups of partial channels  13  first enter a collection channel  17 A or  17 B, as can be seen in  FIG. 4 . The clear width of the collection channels  17 A and  17 B corresponds roughly to the diameter of a cap  8 , and the advancing of the shaped parts in the collection channels  17 A and  17 B and in the end channel  18  occurs as previously in the channel  4  and in the partial channels  13  through an air stream directed diagonally upwards, which originates in air intake openings  10  of the type disclosed previously in the base plate  5 . 
   As the collection channels  17 A and  17 B extend transversely to the partial channels  13 , it is necessary to intervene in a deterministic manner between these two types of channels in the material flow in order to avoid a blockage in this place. For this purpose, at the outlets of the partial channels  13  a discharge device  19  is provided that can either block the outlet of the partial channel  13  or release a single cap  8  from the partial channel  13 . For this purpose, the discharge device  19  is shaped as a star-shaped wheel  19  that is fitted to a shaft  20  that extends transversely to the partial channels  13  and above them, which shaft  20  is under the control of a control device (not shown in the Figures) that can be locked or rotated around a preset angle by a drive. Driving and locking occur respectively in the zone of one or several of the bearings  21 A,  21 B and  21 C of the shaft  20 . 
   The shape of the wheel  19  is adapted to the shape of the caps  8  in such a way that if a cap  8  is under the wheel one of the teeth  22  thereof grips the cap  8  and holds it when the wheel  19  comes to a halt. At one rotation of the wheel  19  around a given angle exactly one cap  8  is conveyed out of the outlet of the partial channel  13  into the respectively assigned collection channel  17 A or  17 B. The star wheels  19  of the partial channels  13  of each of both symmetrical groups are oriented on the shaft  20  aligned with respect to one another and rigidly coupled so that blocking or releasing of caps  8  occurs simultaneously in all partial channels  13  of a group. 
   On the other hand, the wheels  19  of the left-hand group of partial channels  13  entering the collection channel  17 A opposite the wheels  19  of the right-hand group entering the collection channel  17 B are fitted staggered on the shaft  20  around half an angle between two teeth  22 . In this way with a rotation of the shaft  20  around the angle between two teeth  22  only on one of the two sides will the front row of caps be conveyed to the respectively assigned collection channel  17 A or  17 B, so that in a sequence of several such rotations of the shaft  20  around the angle the caps will be removed and further conveyed alternately from the two groups of partial channels  13 . A condition for this is that apart from the disclosed arrangement of the star wheels  19  on the shaft  20  there is also a suitable dimensioning of the length of the teeth  22  in relation to the dimensions of the caps  8  and their number per wheel  19 . 
   The two collection channels  17 A and  17 B oriented towards one another at the front are divided in the middle by a deviating piece  23  in the form of a wedge that is concavely rounded on both sides and deviates again by 90° the movement of the caps  8  arriving from the collection channels  17 A and  17 B so that the advancing direction of the caps again corresponds to the advancing direction of the caps in the partial channels  13 . After deviation on the deviating piece  23  the movement is taken sideways by guide rails  24 , which in the zone of the deviating piece  23  first delimit an end channel  26  that leads to the outlet  27  of the apparatus and the clear width of which corresponds approximately to the diameter of a cap  8 . 
   Advancing of the caps  8  in the collection channels  17 A and  17 B and in the passage  25  and in the end channel  26  occurs as in the channels  4  and  13  disclosed above through an air stream blown diagonally downwards, however with the difference that the slit cover plate  6  no longer reaches these zones. The collection channels  17 A and  17 B are also covered by a removable hood  28  just like the end sections of the partial channels  13 , the shape of which hood  28  is determined by the space requirements of the star wheels  19 , whilst the passage  25  and the end channel  26  are closed by an openable lid  30  at the top that is supported by two lateral supports  29 A and  29 B. In  FIG. 4  this lid  30  is shown in its open state. 
   Owing to the alternating provision of the collection channels  17 A and  17 B with groups of five caps  8  by the star wheels  19  on the deviation piece  23  a extending together of these groups in the manner of a zip fastening is achieved, if the rotation speed of the shaft  20  is adapted to the conveying time of the caps  8  in the collection channels  17 A and  17 B. In this way a possible jamming in the funnel-shaped passage  25  between the deviation piece  23  and the end channel  26  is avoided. At the outlet  27  a serial sequence of individual caps  8  appears as it is taken to the apparatus at its input  9  ( FIGS. 1 and 2 ). 
   In  FIG. 5 , which shows the same part of the apparatus as in  FIG. 4  from another viewpoint, certain further details of the pneumatic control of the advancing of the caps  8  are recognizable. In order to better check the movement of the caps at the passage from the partial channels  13  into the collection channels  17 A and  17 B and in particular to avoid collisions of the caps  8  with the front surfaces  31  of the dividing walls  12  pointing to the collection channels  17 A and  17 B, small air inlet nozzles  32  are diagonally arranged in these front surfaces  31 , wherefrom during operation an additional air stream is blown diagonally into the collection channels  17 A and  17 B, which promotes the movement of the caps  8  onto the deviation piece  23 . 
   In the deviation piece  23  two further air inlet nozzles  33  are furthermore also provided, one of which only is partially visible in  FIG. 5 . During operation of the apparatus a further additional air stream blows out of these nozzles  33  in the direction of the end channel  26  and thereby promotes the deflection of the caps  8  on the deviation piece  23 . The two valves  34  visible in  FIGS. 4 and 5  and the hoses extending therefrom in the direction of the deviation piece serve to supply the nozzles  33  with air. 
   Owing to the even arrangement of the air inlet openings  10  in the base plate  5  and of the air outlet openings  11  in the cover plate  6  with a suitable setting of the air throughput on the blowers  2 A to  2 C and of the distribution of the flow in the housing  1  by means of control lids and the like that may be provided there it can be guaranteed that inside the channels  4 ,  13 ,  17 A,  17 B and  26  a given minimum excess pressure dominates with respect to the environment. This prevents dust particles or unhealthy bacteria reaching the caps  8  that are to be conveyed via the inlet  9 , the outlet  27 , or the air inlet openings  11 . Through the deliberate addition of a bactericide gas, e.g. ozone, to the air blown into the housing  1  it is even possible to sterilise the caps  8  during conveying. 
   Although shaped parts have been discussed above and the preferred embodiment refers specially to caps for drinks bottles, it is obvious that the invention can be used for the simultaneous conveying and temperature regulating of any type of object that has an essentially beaker or bowl shape and which by weight and surface features is suitable for sliding on an air cushion.