[0001] 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.
[0002] 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.
[0003] 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.
[0004] 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.
This object is achieved with a package according to claim 1.
[0005] 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.
[0006] The drawing shows practical non limiting embodiments of the invention, and more in
particular:
figure 1 shows a side view of a package according to one embodiment;
figure 2 shows a side view similar to that of figure 1 of a plurality of stacked packages;
figure 3 shows a plan view according to III-III in figure 1;
figure 4 shows a modified embodiment of the package not falling within the scope of
the claims;
figure 5 shows a further embodiment in an axonometric view; and
figure 6 shows a section along VI-VI in figure 5.
[0007] With initial reference to figures 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 1A 1 B made
of thermoformed, for example vacuum molded, plastic material. Once coupled, the semi-shells
1A, 1 B define a housing space, inside which the cutting line F is wound, as shown
in figure 3. More in particular, the semi-shells 1A, 1 B are welded along the edge
1C of the package and can have respective projections, which form a slot or eyelet
1D for hanging the package on a displayer.
[0008] Characteristically, one of the two semi-shells (in the example the semi-shell 1A)
has an approximately round aperture in a substantially central position.
[0009] Around the central aperture of the upper semi-shell or semi-shell 1A, 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 semi-shell 1A. 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.
[0010] 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 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 figure 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.
[0011] In a modified embodiment (figure 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 semi-shells 1A, 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 figures 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.
[0012] Figures 5 and 6 show an embodiment of the package according to the invention. In
this case, the package 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
semi-shells. 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.
[0013] 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.
[0014] As in the case of the embodiment of figures 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.
[0015] 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.
1. A package (51) of cutting line (F) made of polymeric material for brush cutters, lawn
mowers, cutting devices for removing side shoots and the like, including: a laminar
plastic material defining a housing shell for housing said cutting line (F), said
housing shell having a substantially flat form; an aperture arranged in a nearly central
position on a first face of said shell and provided with a removable cap (57), which
can be applied in a reversible manner to said package (51) and which projects from
said shell; a cutting line (F) in said housing; characterized in that said shell is made by blowmolding; and that a cavity is provided on a second face
of said shell, to allow more packages to be stacked.
2. Package according to claim 1, wherein said cavity is arranged nearly in correspondence
of said aperture, in such a way that a plurality of packages can be stacked by arranging
the cap (57) of one package in correspondence of and inside the cavity of an adjacent
package.
3. Package as claimed in claim 1 or 2, wherein said aperture is surrounded by a ring
or collar, molded together with the shell, provided with means for reversible application
of the removable cap.
4. Package as claimed in claim 1 or 2 or 3, containing water in order to maintain said
cutting line under optimum humidity conditions.
5. Package as claimed in one or more of the previous claims, wherein said cutting line
is made of a plastic material containing amide groups (CO-NH).
6. Package as claimed in one or more of the previous claims, wherein said cap is a screw
or bayonet cap.
7. Package as claimed in one or more of the previous claims, wherein said aperture is
surrounded by a ring of plastic material comprising coupling means for reversible
coupling of said cap.