Abstract:
A procedure for the manufacture of paint rollers comprised of a polyolefin core covered with a pile fabric consisting of tubular bodies similar in length made of polyolefins which are held in place by supports in the form of cylindrical bodies which may or may not be hollow. A mechanism at one end of the machine generates a lengthwise shifting and spiral rotational movement. A heat source softens the surface of the tubular body and incorporates a mechanism which generates the spiral rolling of a fabric cover on the tubular body softened on the outside.

Description:
OBJECT OF THE INVENTION  
         [0001]    The present descriptive account is related to a procedure for the manufacture of paint rollers comprised of a polyolefin core covered in a pile fabric, the end purpose of which lies in the fact that the tube, during the application of heat at a high temperature for a short time to cause the melting of the outer surface of the tube and during the winding of the fabric, is not threaded on a metal mandrel as previously, therefore being configured as a totally continuous manufacturing procedure and the covering being provided continuously with the tube crossing over the point generating heat and the station or fabric placement part on the extended tube.  
           [0002]    The tube is threaded on the machine from one side to the other at an appropriate distance so that the fabric is extended covering the tube without any break in the winding.  
           [0003]    In short, this invention is based on the fact that the tube per se, during the heat application stage and during the fabric winding stage, is not threaded directly on a metal mandrel, as is the case previously, but is rather a matter of a continuous procedure which makes it possible to thread the tubes through the heat and the station or stage where the fabric is placed on the tube proper made of plastic material, allowing the tubes to move one after the other at an appropriate distance so that the band of fabric can go from one tube to the other without there being any halt in the fabric winding or covering stage.  
           [0004]    The invention entails the fact of propelling the tubes on which the fabric covering is being joined in a traveling and, at the same time, a rotating movement for the purpose of achieving a spiral movement of the tube along its center line.  
           [0005]    The present invention is equipped with a device that can cut the fabric covering applied onto the body made of plastic material once the dimensions thereof have exceeded the cutting area. The cutting device cuts the fabric wound around the tubes in a gap between two advancing tubes. Then, the tube that is wound with the fabric is taken out of the machine manually or automatically. The following tube, which is in the process of being wound with fabric, continues in its lengthwise traveling movement and, at the same time, rotates with respect to the center line of the tube up to the cutting moment, thereby resulting in a spiral movement, which facilitates the application of the fabric covering.  
         FIELD OF THE INVENTION  
         [0006]    This invention is applicable within the industry dealing in the manufacture of paint rollers.  
         BACKGROUND OF THE INVENTION  
         [0007]    The applicant has no knowledge as to the current existence of any invention which is of the characteristics described in this descriptive account.  
           [0008]    The applicant is aware of the existence of some Patents or Utility Models for which application has been filed under the name of Biancamaria, Alvarez-Garcia, Newell, and Sekart.  
           [0009]    The Patents for which application has been filed under the name of Newell and under the name of Sekart are quite similar, given that they employ strips of polypropylene for manufacturing the tube, its process being continuous.  
           [0010]    The Patent for which application has been filed under the name of Biancamaria employs the tube fabricated in line by means of an extruder with rotating drawplate, and the tube turns on its center line as it is extruded, consequently moving along with a spiral movement, being a continuous process.  
           [0011]    The Patent for which application has been filed under the name of Alvarez-Garcia employs a pre-extruded tube and is not configured as a continuous process.  
           [0012]    It would be desirable to avail of a Patent such as that which is described in the present descriptive account, characterized due to the fact that, although pre-extruded tubes are employed, the process is continuous, which is possible thanks to the fact that the tubes are not threaded on a mandrel, contrary to the case of the aforementioned Patents which employ polypropylene strips, such as is the case of the aforesaid Newell and Sekart Patents, in which the mandrel serves as a “mold” in order to be able to appropriately shape the strips which are progressively rolled and as cooling.  
           [0013]    In the Patent for which application has been made under the name of Alvarez-Garcia, the mandrel serves to support the tube and is responsible for the rotating movement of the tube, also effecting the fact that the tube, during the heat-application phase, instead of losing its shape, remains rigid thanks to the action of the cooling device inside the mandrel, although no mention is made thereof in the aforesaid Patent.  
           [0014]    In the Patent for which application has been filed under the name of Biancamaria, the mandrel serves to support the tube, being responsible for the circular component of the spiral movement, and serves the purpose of cooling or rather solidifying the tube.  
           [0015]    The Patent for which application has been filed under the name of Biancamaria is currently in the public domain and employs heat to join the fabric, just the same as that of Newell patent and that of Alvarez-Garcia, whilst the Patent for which application has been filed under the name of Sekart employs fused polypropylene.  
           [0016]    It would be desirable, precisely as has previously been stated, to avail of a Patent such as that which is described in this descriptive account, which employs heat, a characteristic currently in the public domain, and which, nevertheless, does not employ any type of mandrel, this characteristic of not employing any type of mandrel being the innovative element, given that it affords the possibility of converting the process into a continuous process, increasing the manufacturing capacity.  
           [0017]    The fact of not employing any type of mandrel is possible due to the heat being applied more violently in this process, in other words, it is applied directly onto the body of the cylinder which is going to receive on the tube surface the body of the fabric material, achieving that the tube surface liquefies or melts or at least dissolves partially without the inside, in other words, the area comprising the cylinder, located on the interior, losing its consistency or rigidity, which leads to no need for any type of cooling means whatsoever being involved.  
           [0018]    Therefore, the invention described in this descriptive account is, in terms of the fact that all is a consequence of a new method for configuring paint rollers, in accordance with the application of heat in a completely different manner.  
         SUMMARY OF THE INVENTION  
         [0019]    The invention is a procedure for the manufacture of paint rollers comprised of a polyolefin core covered with a pile fabric in which the invention has a mechanism which pushes the tube across the heating point and, at the same time, the fabric-applying station, propelling a spiral movement along the entire center line of the tube, which facilitates the movement of the hollow tubular body without the need of a supporting mandrel whatsoever on the inside thereof.  
           [0020]    Both the mechanisms for the lengthwise thrusting and rotational movement of the cylindrical body made of plastic material and hollow inside, which is covered in fabric material by way of the action of the heating point, as well as the guiding of the fabric and the cutting element, are located on the frame of the machine.  
           [0021]    The aforementioned movements can be achieved by way of several different embodiments.  
           [0022]    In one embodiment, the present invention is directed to a mechanism which thrusts the tube, which will subsequently be used as a nexus for covering the fabric, through the heat source in which the tube is heated. Then, the mechanism thrusts the tube through a fabric-applying area where a fabric covering is applied thereto. During the heating and covering process, the tubular body to which the fabric is applied moves spirally on its center line.  
           [0023]    The invention likewise has a mechanism which removes the tube duly covered in the fabric from the area in which the heat-generating element is located and from the area where the fabric is applied to the tube surface duly heated by the effect of the heat. This mechanism, like the aforementioned ones, ensures a traveling and rotating movement of the tube, always in the same direction, along its entire center line.  
           [0024]    It must be said that both the heat-generating mechanism and the fabric guide are affixed to the frame of the machine.  
           [0025]    The invention is equipped with a cutting mechanism which automatically makes the cut of the fabric covering when the hollow tubular body reaches a point in its traveling movement which requires being separated from the tube moving along behind it which is undergoing the same application.  
           [0026]    Afterward, the tubular bodies covered in fabric material will be put through the pertinent cutting operations in accordance with the paint roller bodies which are required. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0027]    In order to complete the description which is being provided and for the purpose of aiding toward a better comprehension of the characteristics of the invention, a set of drawings is attached to the present descriptive account as an integral part thereof, showing, on an illustrative and non-limiting basis, the following:  
         [0028]    [0028]FIG. 1 provides a simplified view of the machine of the invention;  
         [0029]    [0029]FIG. 2 shows one possible embodiment of the mechanisms responsible for the movement of the tubular bodies along their entire center lines;  
         [0030]    [0030]FIG. 3 shows a second embodiment of the devices shown in FIG. 2;  
         [0031]    [0031]FIG. 4 is a front and side view of a third embodiment of the devices shown in FIGS. 2 and 3;  
         [0032]    [0032]FIG. 5 is, once again, a fourth embodiment of the devices shown in FIGS. 2, 3 and  4 ; and  
         [0033]    [0033]FIG. 6 shows two possible embodiments of the guides affixed to the machine frame. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0034]    Following FIG. 1, it can be seen how the mechanisms  1  and  3  are those responsible for the spiral movement of the tubular bodies along their entire center lines, it necessarily being said that mechanism  1  must be affixed to the frame of the machine and placed following the cutting device  2  in relation to the moving direction in which the tubes travel.  
         [0035]    Device  3  must be placed prior to the fabric-covering station  5  and affixed to the machine frame, it being taken into account that mechanisms  1  and  3  must not be spaced further than one tube length apart, it being necessary for all of the tubes put through the process to be of one same length.  
         [0036]    The spiral movement is ensured by devices  1  and  3 , determining a perfect winding of the strip of fabric, so that the edges of the successive spirals are touching those of the following spiral without overlapping with one another.  
         [0037]    According to FIG. 2, mechanisms  1  and  3  include claws  10  which can hold the tube  11  by its starting or final end. A circular component revolving on its axis, together with the traveling of the claws, determines the spiral movement of the tube. The claws hold the tube  11  in place along the outside so that the tube can be used continuously up to its separation with the similar element which is incorporated into the manufacturing line.  
         [0038]    These claws  10 , equipped with fingers actuated by mechanisms, are capable of holding both the tube which reaches the mechanism  1  as well as that which is thrust by the mechanism  3 , and are affixed to the base  33  such that they turn on their own axis.  
         [0039]    The traveling component is set into motion by the moving of the assembly which turns on a guide  20  affixed to the machine frame.  
         [0040]    The length of the guides  20  must make it possible for the process to be performed continuously without halting, and this mechanism will obviously drag the tube  11  in the case of using some claws  10  as a mechanism  1 , or will thrust it in the case of being used as mechanism  3 .  
         [0041]    In FIG. 3, another embodiment is shown of mechanisms  1  and  3  responsible for the spiral movement of the tubular bodies, showing a similar functioning identical to that which is shown in FIG. 2, the only difference being that the claws  12  hold the tube on its inside.  
         [0042]    The mechanism shown in FIGS. 2 and 3 will solely work if they are located facing the tube end  11 .  
         [0043]    In FIG. 4, another embodiment of the invention in question is shown corresponding to mechanisms  1  and  3  responsible for the spiral movement of the tubular bodies, in which the tube  11  is shown moved by working wheels  13  and  14 , it necessarily being said that the wheels  13  are located on the inside of the circular body  14  at a 90°-angle to the inside area of the wheel  14 , consequently being configured as four internal wheels  13  which make contact with the outside of the tube, turning such that they propel the tube in a traveling movement, while the wheel  14 , which incorporates the four wheels  13  supported on the guide-supports  32  which are located in the area on the inside of the circular body constituting the wheels positioning the elements, turns on its own axis and is in charge of the rotating movement of the tubular body configured as a tube  11  supported by guide-supports  15 .  
         [0044]    [0044]FIG. 5 shows another embodiment of the mechanisms  1  and  3  responsible for the movement of the tubular bodies, in which the two wheels  13 ′ and  14 ′, affixed to the frame of the machine by means of guide-supports  15 ′, are slanted appropriately to the tube center line, turning in a direction such as to generate the moving of the tube  11 .  
         [0045]    Again, in following with FIG. 1, a heat source  4  is seen to exist, which can be substituted by an extruder of the same polyolefin of which the tube  11  is comprised.  
         [0046]    Number  2  shows the cutting device, located following the station  5 , where the covered tubes are appropriately cut to their original length, in the area where the end and beginning of the tubes which have been put in one after the other to be covered coincide.  
         [0047]    This cutting device  2 , affixed to the machine frame, is placed after winding station  5  and prior to mechanism  1 .  
         [0048]    This placement can be achieved solely if the cutting device  2  is located prior to the movement mechanism  1  according to the direction in which the tube moves.  
         [0049]    As has previously been stated, the invention in question is equipped with a mechanism  5  for winding the fabric around the outside of the tube  11 , allowing for the winding in accordance with the existing spiral movement on the tube  11  along its entire center line, which must logically be located after the heat-generating element  4  or similar mechanism in relation to the direction in which the tube moves.  
         [0050]    The guides affixed to the machine frame are indicated by number  6  and are structured so as to allow the other elements to operate.  
         [0051]    [0051]FIG. 6 shows a front view of the support mechanisms  6  comprising the guides which may be configured into two slanted parts over which the tubular body  11  moves, or in the form of hollow cylinder through which the tubular body  11  also moves.  
         [0052]    [0052]FIG. 1 again shows the tube  11  entering into the machine  30  through the side where the movement mechanism  3  is located, and the tube may be put into the machine manually or automatically using mechanisms readily apparent to those of skill in the art.  
         [0053]    On the mechanism  3  which generates the movement of the tube  11  being set into motion, the tube travels lengthwise in a spiral movement. The tube  11  moves past the device used for generating heat  4  or for similar purposes and is subsequently subjected to the action of the mechanism  5  for the winding of the fabric covering, this being an action which is performed along the entire length of the tube  11  up to the point of losing contact with the movement device  3 , it necessarily being said that prior to its losing contact with the device  3 , the device  1  is already touching the starting end of the tube  11  and therefore the covering of the tubular body can continue, given that the device  1  becomes responsible for the spiral movement which continues ensuring a proper winding.  
         [0054]    In following, a second tube is threaded into the process following the first tube  11 , so that the space between the first and the second tube  11  is very small, affording the possibility of the winding operation not being interrupted in accordance with the actuation of the mechanisms  4  and  5 , achieving a continuous process.  
         [0055]    Device  2 , that is to say, the cutting device, functions when the first tube  11  is already fully covered or wound with the fabric material, and the space between the ends of the two tubular bodies  11  are located exactly in front of the cutting mechanism  2 .  
         [0056]    Following the cutting operation, when the movement mechanism  1  stops functioning, the tube exits the process.  
         [0057]    Said movement device  1 , before the second tube loses contact with the device  3 , ensures that there will be no interruption in the spiral movement of the tube, providing the process with continuity.  
         [0058]    It will be recognized by one of ordinary skill in the art that changes may be made in the above-described embodiment of the invention without departing from the inventive concepts thereof. It is understood, therefore, that the invention is not limited to the particular embodiments disclosed, but is intended to encompass any modification which are within the scope and spirit of the invention.