Patent Publication Number: US-2011048987-A1

Title: Package for a cutting line for lawn mowers, brush cutters and the like

Description:
DESCRIPTION 
     In the field of gardening equipment for use at both amateur and professional level, the use is well known of grass cutting heads for lawn mowers, brush cutters and the like, which use, as cutting elements, cutting lines in polymeric material. These lines project from a housing, which is carried in fast rotation around the drive shaft of the machine, and, due to centrifugal effect, they cut the vegetation. The cutting lines are subject to wear and breakage, and therefore they must be often replaced. For this purpose, packages of cutting lines in polymeric material are marketed, containing a several meters of line for its replacement in the cutting heads. 
     Usually, these lines are produced in polyamides with different chemical structures, all usually containing amide group CO—NH. Among the most important starting products for the production of these cutting lines there are the caprolactam, the adipic acid, and the hexamethylene diamine. Polyamides 6 and 6.6. are often associated with the mark “nylon”. The features of the single polyamides do not differ much from each other; Immediately after the thermoplastic working, under dry condition, they are hard and less or more fragile materials. Following the absorption of water from the atmosphere or following water conditioning, they become more tough and abrasion resistant. 
     The packages used for marketing these materials are usually open and can last for a very long time before they finish, above all if the user does not use great quantities of line. This can entail, also based upon the environmental conditions of use, an excessive drying of the product and thus the loss of the characteristics of abrasion resistance and of toughness linked with the water absorption inside the polymeric structure. 
     The object of the invention is to provide a package, which allows a better conservation of the polymeric material forming the cutting line also after the first use thereof. 
     Substantially, according to one embodiment, the package of cutting line made of polymeric material for brush cutters, lawn mowers, cutting devices for removing side shoots and the similar, comprises an aperture provided with a removable cap which can be applied in a reversible manner to the package, so that the package—once opened—can be effectively closed again in order to maintain the humidity conditions inside it. It is also possible, both during the packaging phase and during use, to add water inside the package, so as to maintain a high humidity condition inside the package and therefore to maintain the polymer, forming the cutting line, water-logged. 
     Further characteristics and embodiments of the package according to the invention are described in the appended dependant claims, and will be described in greater detail with reference to embodiments disclosed hereunder. 
    
    
     
       The drawing shows practical non limiting embodiments of the invention, and more in particular: 
         FIG. 1  shows a side view of a package according to one embodiment; 
         FIG. 2  shows a side view similar to that of  FIG. 1  of a plurality of stacked packages; 
         FIG. 3  shows a plan view according to in  FIG. 1 ; 
         FIG. 4  shows a modified embodiment of the package according to the invention; 
         FIG. 5  shows a further embodiment in an axonometric view; and 
         FIG. 6  shows a section along VI-VI in  FIG. 5 . 
     
    
    
     With initial reference to  FIGS. 1 to 3 , the package, indicated as a whole by reference number  1 , can include a shell structure formed by a pair of semi-shells or valves  1 A  1 B made of thermoformed, for example vacuum molded, plastic material. Once coupled, the valves or semi-shells  1 A,  1 B define a housing space, inside which the cutting line F is wound, as shown in  FIG. 3 . More in particular, the semi-shells or valves  1 A,  1 B are welded along the edge  1 C of the package and can have respective projections, which form a slot or eyelet  1 D for hanging the package on a displayer. 
     Characteristically, one of the two valves (in the example the valve  1 A) has an approximately round aperture in a substantially central position. 
     Around the central aperture of the upper valve or semi-shell  1 A, a ring or collar  3  is applied, for example a ring in plastic material welded, for example by means of ultrasounds, or glued, or in any way blocked to the laminar material forming the upper valve  1 A. The ring or collar  3  can be coupled in a reversible manner to a cover or cap  5 . The coupling can be made through a thread, a bayonet grafting, a shape coupling joint or in any other manner. The coupling can be provided with a security seal which, once removed, allows to remove and to place the cap  5  again, so as to open and close the container or package  1 . In this way, the user can open the package and extract the desired quantity of cutting line, cut it and close the package again by means of the cap  5 . This safeguards the humidity conditions inside the package  1 , conditions which can be made optimal in terms of saturation of the polyamide or other analogous polymer which forms the line F by adding of a small quantity of water inside the package. 
     Advantageously, in order to allow a simpler storage of the packages  1  in a small space, both for display and for transportation or storage, on the face of the package  1  opposite to that on which the cap  5  is applied to the ring  3 , the semi-shell or valve  1 B has a cavity  7  having a shape substantially corresponding to, and preferably slightly wider, than the cap  5 . In this way it is possible to stack (see  FIG. 2 ) more packages  1  one on top of the other, in such a way that the cap of each package inserts in the cavity  7  of the overlying package. 
     In a modified embodiment ( FIG. 4 ) the aperture for the extraction of the cutting line F is obtained in a tangential position or on the edge of the package, instead of on the front face of one of the valves  1 A,  1 B forming the package, so that the line exits laterally and not centrally. In this case, according to an advantageous embodiment, the aperture can be surrounded by a bush  11  which forms the seat for a cap  13  which can be inserted in a reversible manner inside the bush  11  in order to close the package  1  with a sufficient sealing degree, analogously to what occurs with the cap  5  in the embodiment of  FIGS. 1 to 3 . In this case again, the user can close the package  1  with the cap  13  every time he/she has extracted the desired quantity of line F, to safeguard the desired high humidity conditions inside the package and therefore to maintain the characteristics of toughness and abrasion resistance of the line F. In order to facilitate unwinding of the line, this can be wound on a spool rotatingly housed inside the package. 
       FIGS. 5 and 6  show a modified embodiment of the package which, in this case, is produced by blow molding, in a manner similar, for example to the technique used for producing bottles of mineral water. The package indicated with the reference number  51  is formed by a single body  53  instead of by two welded valves. The body  53  is produced by blow-molding in a mold, in which a tube made of polymeric material and coming from the extruder is inserted. The mold is closed so as to cut the tube of polymeric material along a substantially circular edge, and air is blown inside the tube of polymeric material still at the plastic status. The air is injected through a needle which perforates the polymeric material in correspondence of the portion which will be subsequently removed to form the aperture for the extraction of the line. With the molding operation the body  53  of the package is obtained, provided with a collar or ring  55  formed by molding along with the body  53 . The ring or collar  55  is provided with a thread or other constraining mechanism, formed by molding, on which the cover  57  screws or engages. The membrane of plastic material which remains for closing the collar  55  is removed by means of an adequate cutting tool after cooling of the molded package. With the same molding it is possible to form—if required—a projection  59  forming a slot, an eyelet or a hook for hanging the package on a displayer. 
     The cover  57  can be engaged in a reversible manner with the collar or ring  55 , instead of through a thread, by means of a bayonet grafting, through friction or in other suitable manner. 
     As in the case of the embodiment of  FIGS. 1 to 3 , also in the case of blow-molded package a cavity can be provided on the face opposite to the cap or cover, to allow more packages to be stacked. 
     With the package object of the present invention it is possible for the user to maintain the line F always in the optimal conditions for its use, guaranteeing that it is always water-logged or in any way sufficiently impregnated with water. It is also possible that a certain quantity of water is loaded inside the package during the phase of production of the package itself, so that, even in case of particularly long periods of storage in dry environmental conditions and with an imperfect seal of the package  1 , the line  1  remains always water-logged and therefore it remains always ready for use as the package is open.