Patent Publication Number: US-6209285-B1

Title: Automatic device for collection and packing in a container, of the strip produced by a carding unit

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to carders, in which a thin layer of fibrous material is processed by a series of carding surfaces, which are provided with coverings with tips, and are set in motion relative to one another, in which the flock fibres are opened, in order to produce separated, stretched fibre strips. In this operation, the impurities and dirt are eliminated, the fibres are mixed with one another, and a fibre strip with a regular yarn count is obtained, which is collected in large containers, to be sent to the successive processing stages. 
     In particular, the subject of the present invention is the operation of packing in the collection container, the strip produced by a carding unit, or by a drawing frame. 
     In the known art, devices are described for collection of the strip produced by a carder, for example in the German patent in the name of Rieter, no. 1,510,339, and in the Italian patent application MI95A02123 in the name of the same applicant. In these devices, the exchange of the strip end, when the full container is replaced by an empty container, with corresponding gripping and cutting of the strip section to be joined, is complex and unreliable; inter alia it takes place with both containers at a standstill. 
     In order to make apparent the technical problems which are involved in this operation, and to eliminate them by means of the present invention, the assembly of the carding unit and the collection unit are described briefly with reference to the drawing in FIG.  1 . In the carding unit  1 , the fibres, which are separated and mixed in the carding operation, are matted into a web, which has a consistency which is sufficient to be drawn through a condenser by a calender unit  2 , which is also known as the drawing unit. This strip is supplied to the collection unit  3 , which draws it by means of two calenders (not shown in the figure), from the carding unit, and packs it in the containers  4 , by means of a rotary distributor plate, which places the strip in the container itself, in superimposed coils. This rotary distributor  5  is eccentric relative to the container  4  being filled, which is disposed beneath the collection unit  3 . 
     The distributor  5  consists of a horizontal plate, which is driven with rotary motion around its own centre, according to the arrow B, at a speed of approximately hundreds of revolutions per minute. 
     In turn, the underlying container  4 , which is being filled, has a cylindrical shape, and is disposed coaxially on a rotary platform  6 , which in turn is driven with rotary motion around its own vertical axis according to the arrow C, at a speed of approximately tens of revolutions per minute, thus distributing the strip in the container, according to coils, the centre of which is translated according to coaxial circles, relative to the platform  6  and the container  4  which is being filled, with an accumulation which increases progressively in thickness but not in level, owing to the effect of the progressive compression of the spring which is beneath the base of the container  4 . 
     The collection of the strip in containers, so that it can be sent to the subsequent processing operations, makes the carding operations independent from the subsequent operations. 
     At the output of the calenders  2  of the carder  1 , along the path of the strip  7  according to the arrow A, towards the collection unit  3 , and in particular at the guide pulleys  8   a,b,c  of the latter, according to the known art there is provided a thread-sensor device, which detects whether the strip is present or absent, i.e. whether it is continuous or broken, and in the latter case, the device stops the carder/collection assembly. 
     The strip which is produced during the carding has limited tensile strength, and must be suitably processed: for this purpose, packing the strip in a container, in superimposed coils, allows it to be extracted subsequently, without generating tensions which the limited strength of the strip cannot withstand. It is also known from the state of the art, for example from patent application MI95A02123 in the name of the same applicant, that for this reason the container for collection of the strip is provided with a mobile base  9 , which is thrust upwards by a spring  10 , or by an equivalent element, which allows the base  9  to descend as the depositing of the coils of strip onto its surface progresses; this depositing compresses the spring  10 , with a range which is limited by an upper end-of-travel projection for the plate  9 , and a lower support projection for the spring  10 . By this means, the free section of strip, from the distributor element, to the level at which it is deposited in the depositing operation, as well as from the collection element, to the level from which it is collected in the successive operation, in which the strip in the container is supplied to a successive processing operation, remains quite short, and an effect of undesirable drawing of the strip is substantially prevented. 
     The present invention relates more specifically to the operation of replacement of the containers, and to control and transfer of the end of the strip, from the full container to the empty container, which replaces it in sequence. 
     According to the known art, this operation is commonly carried out manually by the operators, who, when the pre-determined length required for filling of the container  4  has been reached, replace the full container by the new container, beneath the rotary distribution unit, and cut off the strip deposited in the full container, placing the end on the base of the new container. The mobile base  9  of the container is usually provided with needles or projections to engage and hold the end, and thus to start the new depositing of coils in the new container. 
     In the aforementioned patent application in the name of the same applicant, there is described a recent automatic container-changing device, in which, however, changing the container makes it necessary to change the speed of the machine, and to slow down or stop production of the machine for the change, with two transitory speeds at the beginning and end of the operation. 
     These methods for changing and moving the container are not altogether satisfactory, particularly in high-productivity carding units, which process 200 to 400 m of strip per minute. 
     SUMMARY OF THE INVENTION 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of showing the carding unit and other collection unit; 
     FIG. 2 is a plan view of the service structure; 
     FIG. 3 is a top view of the service structure; 
     FIG. 4 is a side view of the service structure; and 
     FIG. 5 is a series of top views showing the change and movement of containers. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In order to illustrate more clearly its characteristics and advantages, the present invention is described by way of non-limiting example, with reference to a typical embodiment illustrated in FIGS. 1 to  5 . 
     The plate  6 , which is disposed beneath the container  4  during the filling stage, is mounted on a service path platform  20 , which is slightly raised from the ground, and contains both an empty container  4 ′ which is waiting, and a full container  4 ″ which is being unloaded. On the other hand the eccentric distributor  5  is mounted on a support and service structure, which consists of pedestals  21  and an upper platform  22 , the service units of which are illustrated in greater detail in FIGS. 2 and 3. 
     The containers are mounted on pivoting wheels  24 , in order to facilitate their movement. The three containers are shown respectively with the base level  9 ′ corresponding to the maximum level for  4 ′, i.e. an empty container which is waiting; at the intermediate level  9 , i.e. a container  4  which is being filled; and finally at the minimum level  9 ″, i.e. a container  4 ″ which is completely full, to be unloaded and sent to the successive processing operation. 
     In the available thickness of the eccentric distributor  5  and of the platform  22  on which it is mounted, there are contained the control mechanisms, which, according to systems known in the art, make it possible to obtain high speeds of rotation of the eccentric distributor  5 , and a high linear speed of strip deposited in coils in the container. According to these known systems, the strip  7  which is obtained from the pulleys  8  penetrates in the eccentric distributor  5  via a funnel, and from there it is retrieved by a pair of small calenders, from which it emerges rotating, through a hole which is free from roughness, into the top of the container  4  which is being filled. The lower surface of the structure  22  which is presented to the container  4  is substantially flat and smooth; it acts as a top or ceiling for winding of the coils as they are being deposited by means of the distributor  5 , since the propensity of the coils to inflate tends to raise them upwards, and to bring them into contact with the said top. 
     The structure  21 / 22  is provided with movement units, which thrust the containers between the positions previously described, as well as with precision positioning units, which are illustrated schematically in FIGS. 2 to  5 . 
     The movement units consist substantially of an arm  26 , which thrusts the container which is waiting, which in turn thrusts the full container into the successive positions, when the container is changed. 
     This arm  26  projects from a guide with longitudinal protection  27 , is controlled in a known manner, for example by means of a double-effect pneumatic cylinder which is not shown in the figure for the sake of simplicity, with to-and-fro motion, is provided with a container support block  29 , and is supported by a support roller  30  on the platform  20 . 
     On the side opposite the longitudinal guide  27 , along the path of the containers  4 , there is provided a guide bar  33  for the container, with an intake stress raiser. In the platform  20 , which constitutes the path of the containers  4 , there is provided a circular cavity, in the filling position of the container. In this cavity there is positioned the rotary platform  6 , which must accommodate the container  4  which is being filled, which, during the operation of depositing of the strip in coils, must have its axis corresponding exactly with the centre  40  of rotation of the platform  6 . 
     The rotation of the platform is controlled by known means, for example by means of an electric motor and a belt drive, at a speed which is controlled by the machine control unit, and is kept compatible with that of the eccentric distributor  5 , such as to deposit, at each rotation of the container  4 , a constant number of coils of strip  7  via the distributor  5 , and a constant, controlled number of metres of strip. 
     When the container  4  has been correctly positioned, it is rotated by the platform  6 , which rotates constantly in the direction of the arrow C, with the assistance of the radial projections  41 , which however do not constitute an obstacle to the movement of the container  4  for translation on its wheels  24 , by means of the arm  26 , in the operation for the change of containers. 
     The units for positioning of the container  4  during filling consist of two pairs of centring rollers which can be opened and closed. 
     The pair of centring rollers  50   a,b , which are disposed at the intake of the filling position, are supported by the structure  21 / 22 , by means of the adjustable supports  51   a,b , which support two mobile levers  52   a,b , which are hinged at  53   a,b , according to the detail in FIG.  4 . 
     At the fixed pin  53 , there is disposed a pre-loaded coiled spring  54 , which is secured at one end to a plate  55 , which is integral with the pin  53 , and is secured at the other end to the lever  52 , which rotates relative to the fixed pin  53  by means of interposition of the bearings  56 . The pre-loading of the two springs  54  tends to rotate the levers  52   a,b  towards their aperture through the path of the platform  20 , until the levers are supported on a stop  57   a,b , which acts as an end-of-travel stop. The rollers  50   a,b  are mounted on bearings, such that they do not oppose substantial friction to the rotary motion of the container  4  which is being filled. During movement of the containers, the levers  52   a,b  can be thrust forwards and towards the exterior, according to the arrow D, and as far as the position shown in a broken line, in order to let the new container  4 ′ enter, to replace the full container  4 . When this thrust ceases, and the levers are released, the action of the coiled springs  54  prevails, and returns the two levers and their rollers  50   a,b  to the position shown as an unbroken line. 
     The pairs of centring rollers  60   a,b , which are disposed at the output of the filling position, are also supported by the structure  21 / 22 , with the supports  61   a,b , which support two mobile levers  62   a,b , which are hinged at  63   a,b . Similarly to the rollers  50   a,b , the rollers  60   a,b  are also mounted on bearings, in order to limit the friction in the rotary motion of the container  4 . 
     The two levers  62   a,b  can move according to the arrow E, between two positions, which are delimited by end-of-travel stops, which are not shown in the figure, between a closed position which is shown as an unbroken line, and an open position which is shown as a broken line. The movement is carried out by known control means, for movement of extension and retraction between the said positions. For example, the control is provided by two pneumatic, double-effect cylinders  64   a,b , which are mounted on cross-members of the structure  21 / 22 . These cylinders can have their slider  65   a,b  extended into the position shown as an unbroken line, in order to intercept the path of the container  4 , or they can have their slider  65   a,b  retracted into the position shown as a broken line, in order to release the path of the container  4 . 
     In FIG. 3, the container  4  is shown in the correct filling position, with its axis  66  corresponding to the centre  40  of the platform beneath, owing to the action of the rollers  50  and  60  in contact with its outer surface, which keep it centred in position during the rotation. 
     In order better to explain the movement during the change of containers, the salient steps of the movement are described with reference to FIG.  5 . The change of containers can take place with the carder  1  and the collection device  3  functioning at full speed. For the sake of greater clarity, the full container  4  is shown crossed by two diameters. 
     In position indicated as step I, the container  4  is in the filling position, centred on the rotary platform  6 , and rotating together with the latter. The position of the rotary platform is indicated by the area delimited by broken lines. The rotary container  4  receives the strip  7  wound into coils, from the eccentric distributor  5 . The centring rollers  50   a,b  and  60   a,b  are adjacent to the cylindrical surface of the container, in order to keep the latter in position. The empty container  4 ′, which is waiting, is in the parked position, spaced from the container which is being filled. When the container  4  is completely full, the container is changed, by unloading the full container  4 , and replacing it by the empty container  4 ′ which is waiting. The change of container is normally associated with a system for controlling the length in metres, i.e. the linear quantity of strip deposited. This control can be carried out by means of adding revolution counters, which are disposed on the calenders of the carder unit, or on those which are associated with the distributor  5 . These revolution counters are connected to the control unit of the collection unit, in order to determine when the required length in metres has been obtained, for each change of container. 
     In step II, the centring rollers  60   a,b  on the output side are opened, thus releasing the output path of the platform  20 . The arm  26  supports its block  29  on the empty container  4 ′, thrusts the latter against the full container  4 , and continues its path forwards. Translation of both containers thus takes place; the empty container  4 ′ is translated but not rotated, whereas the full container  4  is translated and rotated whilst it still receives the strip, until the empty container replaces it beneath the distributor  5 . 
     In step III, the empty container continues to be thrust by the arm  26 , and arrives beneath the distributor  5 . Whilst the container is in transit, its walls open forwards the levers  52   a,b  of the centring rollers  50   a,b  on the intake side, thus loading the corresponding springs. In this step, depositing of the strip is already beginning into the empty container  4 ′, whilst it is in transit. In general, during the displacement step, the container continues to be translated, but it is not rotated, i.e. it is not yet rotated significantly. In fact, it must be taken into consideration that the pivoting wheels  24  of the replacement container  4 ′, which have already risen onto the rotary platform  6 , are already receiving a specific rotational thrust, but both the inertia of the container, and its support on the concave block  29  are braking significantly the rotation which is induced on the replacement container  4 ′, which thus requires a specific amount of time before it rotates synchronously with the platform  6 . 
     In step IV, the empty container  4 ′ continues to be thrust by the arm  26  beyond the filling position, thus reaching the configuration in step V, and therefore releasing the levers  52   a,b  of the centring rollers  50   a,b  on the intake side, which, owing to the effect of the loaded springs  54 , return rearwards to the position of interception of the container, and are supported on their end-of-travel stop  55   a,b . In this position, the constraint by the rollers  50   a,b  prevents the container from reversing beyond the position which is centred relative to the rotary platform  6 . 
     During this travel, the container  4 ′ enters the area which is delimited by the broken lines, which delimit the radius of action of the cutters, which will be described hereinafter. In this step, depositing of the strip continues in the empty container  4 ′, for a total of a few metres, onto the container base  9 ′, which is in the highest raised position. This initial depositing on the base of the container  4 ′ allows the strip to become attached to the base, and to keep satisfactorily taut the section of strip which is in common between the full container  4  to be unloaded, and the empty container  4 ′which is to replace it. 
     The arm  26  has now reached its end of travel, and withdraws rearwards, thus releasing the container  4 ′. In step V, the container  4 ′ is reversed into the filling position. For this purpose, the sliders of the pneumatic cylinders  65   a,b  are extended; the levers  62   a,b  close, thus intercepting once more the output path of the platform  20 . The centring rollers  60   a,b  on the output side are supported on the container  4 ′, and thrust it rearwards until it comes into contact with the centring rollers  50   a,b , in a centred position, in order to make the axis of the container correspond to the centre of rotation of the platform  6 . 
     This final position is shown as step VI, in which the empty container  4 ′ is centred in position on the platform  6 . The full container  4  is in the advanced position, and is well spaced. The container  41  is freely rotated by the platform  6 , and the normal collection of the strip in the new container  4 ′ continues. The strip  7  is still joining the containers  4  and  41 , through the area  70  delimited by the broken lines, which delimit the radius of action of the cutters, which are disposed beneath the platform  22 . 
     The collection unit  3  is provided with a system for controlled cutting of the strip which is common to the two containers  4  and  4 ′, on completion of replacement of the containers, and for control of the resulting end. This is altogether similar to the cutter described in the aforementioned patent application MI95A02123, in the name of the same applicant, and to which reference should be made. 
     The device according to the invention ensures that the strip  7  which reaches the two containers  4  and  4 ′, and which must be cut, is taut and in a specific position, such that this operation takes place automatically, and more reliably than in the devices according to the known art, in particular without affecting the speed of the carding machine and the collection unit. 
     When the change of container has been completed, the operators unload the full container  4 , and position a new container  4 ′, waiting, to the left of the collection unit  4 , thus, if possible, concentrating intervention in the carding section, on movement of full containers  4  and empty containers  4 ′.