Abstract:
An apparatus for extruding a jacket and/or insulative material onto an extruded product with one or more longitudinal stripes incorporated onto the surface of said extruded product comprising a body, a primary feed conduit for conveying a primary extrusion material, a striping die, a secondary feed conduit for conveying a secondary extrusion material, a striping die adapter, a striping feed conduit extending through the striping die adapter for conveying striping extrusion material. The striping die adapter may also include a thermocouple for maintaining the viscosity of the striping extrusion material and a thermocouple for monitoring the temperature of said striping die adapter. The striping die includes one or more striping extrusion outlets for conveying striping extrusion material onto the extruded product. The striping die may also include a wishbone-shaped trough for delivering equal amounts of striping extrusion material to said extrusion outlets for extrusion onto the product.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     REFERENCE TO A COMPACT DISK APPENDIX 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an apparatus and method for producing extruded products, and particularly to incorporating longitudinal stripes onto extruded products useful in color coding the extruded products for identification, decorative, and other useful purposes. 
     2. Description of the Related Art 
     While this invention relates generally to extruded products, for purposes of illustration, references will be made to electrically insulating coatings for cable or wire. However, the invention is applicable to other products such as extruded pipe and other extruded products. 
     The outer jacket or insulative material of an electric wire or cable is formed by means of extrusion coating. It is well-known that many electrical conducting wires are jacketed and/or insulated with thermoplastic materials such as polyethylene, polyvinyl chloride, or nylon. Such materials may be applied to the surface of a wire by well-known extruding apparatus and methods using an extrusion apparatus designed for this purpose. 
     Methods and apparatus for producing striped cable are also known in the art. Stripes are often incorporated onto extruded products in order to identify such extruded products. For example, a wire or a cable may be run from one end of a building to another end and different color stripes help to identify the wires at the opposite end and prevent erroneous connections from being made. 
     Various methods of striping extruded products have been used in the past. For example, an ink striping method applies a stripe of colored ink to wire by means of a wheel running in an ink bath and transferring the ink to the surface of the wire coating, or alternatively, uses a needle running along the surface of the wire through which ink is forced through the needle and onto the coating. Another method of striping involves utilizing multiple extruders containing different colored materials to form a multi-colored or striped coating on the wire. In this method, the separate stripe extruder is often provided for the purpose of extruding one or more stripes on the surface of the jacket or insulating material of the conductor. 
     The current invention provides many advantages over the prior art. The current invention involves combining the step of extruding stripes onto an extruded product with the step of extruding a jacket and/or insulative materials onto the extruded product. The combination of these two steps eliminates time loss and costly logistics involved in extruding the stripes and the jacket and/or insulative material onto the extruded product in two separate steps. Additionally, the striping extrusion assembly of the current invention is adaptable to an existing extrusion apparatus and can be easily removed and placed onto another existing extrusion apparatus. The portable and exchangeable nature of the striping extrusion assembly provides for versatility and adaptability of the extrusion apparatus. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides a method and apparatus for the extrusion of stripes onto extruded products useful in color coding said extruded products for identification, decorative, or other useful purposes. 
     According to one embodiment of the present invention, an extrusion apparatus provides for the extrusion of a primary extrusion material onto an extruded product, the extrusion of a secondary extrusion material onto an extruded product, and the extrusion of one or more stripes onto the extruded product using a striping die with one or more extrusion chambers therein. The extrusion device may also include a striping die adapter to connect the striping die to the striping extruder for transfer of extrusion material onto the striping die for extrusion onto the extruded product. The striping die adapter may also include a heating element for maintaining the viscosity of the striping extrusion material. The striping die adapter may also include a thermocouple port adapted to a thermostat for monitoring and controlling the temperature of said striping die adapter. 
     In another embodiment, an apparatus is used for extruding one or more stripes onto the extruded product. The apparatus comprises a striping die with an upstream and downstream side wherein the upstream side of striping die is removably connectable to an apparatus for extruding an outer jacket and/or insulative material onto the extruded product. The apparatus further comprises a striping die adapter with an upstream and downstream side, the upstream side being removably connectable to said downstream side of the striping die. The apparatus may further include a heating element removably connectable to the striping die adapter and a thermocouple port connected to the striping die adapter. 
     In another embodiment, the extrusion of the extruded product with one or more longitudinal stripes thereon is accomplished by providing a striping die with an upstream and downstream side wherein the upstream side of the striping die is removably connectable to an apparatus for extruding an outer jacket and/or insulative material onto the extruded product. The method further comprises providing a striping die adapter with an upstream and downstream side, the upstream side being removably connectable to the downstream side of the striping die. The method may further include providing a heating element removably connectable to the striping die adapter and a thermocouple port connected to the striping die adapter. 
    
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
       A more complete appreciation of the present invention is provided by reference to the following detailed description of the appended drawings and figures. The following description in conjunction with the appended figures enables a person having skill in the art to recognize the numerous advantages and features of the present invention by understanding the various disclosed embodiments. It should be understood, however, the invention is not limited to the precise arrangements in the instrumentality shown. The following figures are utilized to best illustrate these features: 
         FIG. 1  illustrates an overview of an improved extrusion device; 
         FIG. 2  provides a cross section view of an apparatus for extruding an outer jacket and/or insulative material and one or more longitudinal stripes onto an extruded product according to one aspect of the invention; 
         FIG. 3  illustrates a side elevation view of a striping extrusion assembly according to one aspect of the invention; 
         FIG. 4  illustrates a front elevation view of a striping die adapter according to one aspect of the invention; 
         FIG. 5  illustrates a back elevation view of a striping die adapter according to one aspect of the invention; 
         FIG. 6  illustrates a front elevation view of a single striping die according to one aspect of the invention; 
         FIG. 7  illustrates a back elevation view of a single striping die according to one aspect of the invention; 
         FIG. 8  illustrates a front elevation view of a dual striping die according to one aspect of the invention; and 
         FIG. 9  illustrates a back elevation view of a dual striping die according to one aspect of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following discussion is presented to enable a person skilled in the art to make and use the present invention. The general principles described herein may be applied to embodiments and applications other than those specifically detailed below without departing from the spirit and scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments expressly shown, but is to be accorded the widest possible scope of invention consistent with the principles and features disclosed herein. 
     Referring to  FIG. 1 , an extrusion device  12  of the present invention is shown. Extrusion device  12  comprises, from upstream to downstream, a payout station  5  (which may comprise multiple payout reels  38 ), an extrusion station  1 , a primary extruder  3 , a secondary extruder  4 , a striping extruder  2 , and a takeup station  6 . The payout station  5  may comprise a plurality of payout reels  38  about which is wound a bare conductor or wire  9 , e.g., copper wire. From the payout station  5 , the bare wire  9  travels to the extrusion station  1 , where individual extruders  2 ,  3 , and  4  supply a material such as, but not limited to, a jacket and/or insulating material for coating the extruded product. The material is extruded onto the bare wire  9  passing through the extrusion station  1 . The material may be of any suitable jacket or insulating material such as PVC, nylon, or polyethylene. After the bare wire  9  or extruded product  10  is coated with one or more coats of jacket or insulating material, it enters a cooling trough  43  containing water varying in temperature from its upstream end to its downstream end. The temperature of the water in the cooling trough  43  may decrease from upstream to downstream in order to sufficiently cool the extruded product  10 . 
     Referring to  FIG. 2 , the extrusion station  1  of the extrusion device  12  is shown. Bare wire  9  is fed into the extrusion station  1  from the payout station  5  (see  FIG. 1 ). A primary feed conduit  32  allows for feeding of a primary extrusion material into a primary extrusion chamber  34  for extrusion onto the bare wire  9  or extruded product  10 . A secondary feed conduit  33  is provided for feeding a secondary extrusion material into a secondary extrusion chamber  40  for extrusion onto the bare wire  9  or extruded product  10 . The primary extrusion material travels through the primary feed conduit  32  from a primary extruder  3  and into the primary extrusion chamber  34  defined by a primary extrusion head  35 , a body  37  and a secondary extrusion head  36 . The primary extrusion head  35  may be spiral as shown or any configuration known in the art. As the primary extrusion material emerges from the primary extrusion chamber  34  just downstream of the secondary extrusion chamber  40 , it coats the bare wire  9  or extruded product  10  in a uniform manner resulting in an extruded product  10  with a protective jacket or insulative coating around it. 
     The secondary extrusion material may be either the same material as the primary extrusion material with the exception that it may be pigmented differently to exhibit a different color or it can be selected from materials that are at least compatible with the primary extrusion material. The secondary extrusion material enters the secondary extrusion chamber  40  via the secondary feed conduit  33 . The secondary extrusion material contacts and penetrates the stream of the primary extrusion material where the primary extrusion chamber  34  meets the mandrel  39 , resulting in the formation of a dual coated extruded product  10  which then passes through a striping die  7  where striping extrusion material contacts and penetrates the secondary extrusion material resulting in the formation of one or more longitudinal stripes of extrusion material on and within the exterior surface of the secondary extrusion material. As the wire  9  passes through the die adapter  8 , the end product is formed comprising an extruded product  10  with a jacket and/or insulative coat which includes one or more longitudinal identifying stripes on its outer surface. 
     Primary extrusion head  35  and secondary extrusion head  36  together with the mandrel  39  and striping die  7  function to direct the flow of fluent extrusion material onto the bare wire  9  to form an extruded wire or product  10  with one or more stripes thereon. 
     The striping die  7  is removably connectable to an existing extrusion station  1  within a die retainer  41  as more fully disclosed below. The die cap  42  functions to secure the die  7  into the die retainer  41 . The striping die adapter  8  is removably connectable to the striping die  7  as shown in  FIG. 3  and more fully described below. 
     With reference to  FIG. 3 , a striping extrusion assembly  15  is shown. The assembly includes the striping die  7 , removably attached to the striping die adapter  8 , which is threadedly attached to an extruder nipple  14 , which is removably attached to the striping extruder  2 . The striping die  7 , die adapter  8 , and nipple  14  may be manufactured using any suitable material such as stainless tool steel. Extrusion material used for extruding one or more stripes on the surface of the extruded product  10  flows through the striping extruder  2  in the direction of the arrow shown  16 . The extrusion material travels through the striping extruder  2 , to the extrusion nipple  14 , into the striping die adapter  8 , which is heated by a heating element  13  to maintain the viscosity of the striping material. The striping extrusion material then travels through the striping die  7  (discussed in detail below) onto the extruded product  10  or wire  9 . The heating element  13  may be any suitable heating element known to one of skill in the art, but will preferably be made from a flexible material so as to be easily adaptable to the striping die adapter  8 . The temperature of the striping die adapter  8  may be monitored and regulated via a thermocouple and thermostat (not shown). The striping die adapter  8  may be equipped with a thermocouple port  17  in which a thermocouple may be removably inserted in order to measure and regulate the temperature of the striping die adapter  8 . 
       FIG. 4  shows the front side of the striping die adapter  8 , the front side being removably connectable to the striping die  7 . The threaded connection  18  of the striping die adapter  8  is used to threadably connect the extruder nipple  14  to the striping die adapter  8 . The extruder nipple  14  is then removably connected to the striping extruder  2 . The mounting holes  19  may be used to removably connect the striping die adapter  8  and the striping die  7  and to removably connect the striping die  7  to the remainder of the extrusion station  1  as shown in  FIG. 2 . The demounting holes  20  may be used to separate the striping die adapter  8  from the striping die  7  in the event the two cannot be separated without the use of tools. 
       FIG. 5  is a depiction of the backside of the striping die adapter  8 . Dowel pins  21  are used to removably connect the striping die adapter  8  to the front of the striping die  7  (see  FIG. 6 ). The mounting holes  19  again are used to removably connect the striping die adapter  8  to the striping die  7  and to removably connect the striping die  7  to the remainder of the extrusion station  1  as shown in  FIG. 2 . The demounting holes  20  are used to separate the striping die adapter  8  from the striping die  7  in the event the two cannot be disconnected without the use of tools. The flow of the striping extrusion material flows from the striping extruder  2 , to the extruder nipple  14 , through the threaded connection  18  in the striping die adapter  8 , through an internal chamber (not shown) of the striping die adapter  8  and out the backside of the striping die adapter  8  through the extrusion outlet hole  22  and onto the striping die  7 , as more fully discussed below. 
     One embodiment of the invention may include a single striping die  7 ′ that extrudes one stripe onto the extruded product  10  or wire  9 , and another embodiment of the invention may include extruding two or more stripes onto the extruded product  10  or wire  9 .  FIGS. 6 and 7  depict the single striping die  7 ′ for extruding a single stripe onto wire  9  or an extruded product  10 .  FIGS. 8 and 9  depict a double striping die  7 ″ for extruding two or more stripes onto an extruded product  10 . 
     The front side of the single striping die  7 ′ in  FIG. 6  is removably attachable to the backside of the striping die adapter  8  shown in  FIG. 5 . Specifically, the dowel pins  21  of the striping die adapter  8  of  FIG. 5  are removably insertable into the dowel pin holes  23  on the front of the single striping die  7 ′ shown in  FIG. 6 . The mounting holes  24  on the front of the single striping die  7 ′ are used to removably attach the single striping die  7 ′ to the striping die adapter  8  and to the remainder of the extrusion station  1  as shown in  FIG. 2 . The extrusion outlet hole  22  on the back of the striping die adapter  8  is in flow communication with the extrusion chamber  25  on the front of the single striping die  7 ′. The striping extrusion material then flows through the extrusion chamber  25  of the single striping die  7 ′ to the outlet  26  on the back of the single striping die  7 ′ shown in  FIG. 7  and onto the extruded product  10  or wire  9 . 
     In another embodiment shown in  FIGS. 8 and 9 , the double striping die  7 ″ provides for the extrusion of two or more stripes onto the extruded product  10  or wire  9 . The front side of the double striping die  7 ″ provides two holes  27  for inserting the dowel pins  21  on the back side of the striping die adapter  8 . The mounting holes  28  are used to removably attach the double striping die  7 ″ to the striping die adapter  8  and to the remainder of the extrusion station  1  as shown in  FIG. 2 . The wishbone-shaped flow channel  29  on the front of the dual striping die  7 ″ is in flow communication with the outlet  22  of the striping die adapter  8 . The extrusion product flows from the striping die adapter  8  through the outlet  22  onto the wishbone-shaped flow channel  29  on the front of the double striping die  7 ″ and down through the wishbone-shaped flow channel  29  to the extrusion chambers  30  and out of the extrusion outlets  31  on the back side of the double striping die  7 ″ shown in  FIG. 9  and onto the extruded product  10  or wire  9 . The flow channel  29  functions to evenly distribute the striping extrusion material to two or more extrusion chambers  30  for the extrusion of two or more evenly-distributed stripes onto the extruded product  10  or wire  9 . 
     The striping die adapter  8  may be universally adaptable to various striping dies (i.e., single striping die  7 ′ and double striping die  7 ″). 
     It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that the invention disclosed herein is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.