KNOTTER AND METHOD FOR FORMING A KNOT

MACHINE A NOUER ET METHODE DE FORMATION DE NOEUDS

Description

CA 02357135 2001-09-07
KNOTTER AND METHOD FOR FORMING A KNOT
Field of the invention
The present invention relates to a knotter and to the method for operating the
same.
Background of the invention
It is well known in the art that many times, products are conventionally
wrapped with stretch film and nothing else is required other than a brush to
wipe the
last tail. In fact, when stretch film is used, the static generated as it is
stretched and
the tacky material added to one side of the film makes the tail stick to the
layer
previously applied. This method is perfect when the product is shipped in a
close
trailer or container but is inadequate when the product is shipped on an open
trailer
or stored outside, because the tails are subject to getting loose as they are
exposed
to wind or bad weather.
In other applications, the products are wrapped with netting material. This
allows product like fruit or vegetable to breathe during shipping. This kind
of wrapping
material does not have a tacky side nor creates static when it is stretched.
To keep
the product wrapped, it is mandatory to hold the tail otherwise it will
automatically
unwind and expose the product as it will be unwrapped. Blood knots are well
known
in the art.
Therefore, there is a need for a knotter and method for forming a knot.
Summary of the invention
The object of the present invention is to provide a device which satisfies
some
of the above-mentioned needs .and which is thus an improvement over the above-
discussed prior art.

CA 02357135 2001-09-07
Brief description of the drawings
Fig. 1 is an isometric view of the knotter.
Fig. 2 is a schematic representation of a first step of the method for forming
a knot
according to a preferred embodiment of the invention.
Fig. 3 is a schematic representation of a second step of the method for
forming a
knot according to a preferred embodiment of the invention.
Fig. 4 is a schematic representation of a third step of the method for forming
a knot
according to a preferred embodiment of the invention.
Fig. 5 is a schematic representation of a fourth step of the method for
forming a knot
according to a preferred embodiment of the invention.
Description of a preferred embodiment
In the following description, the same numerical references refer to similar
elements. The embodiment shown in the figures is preferred.
Moreover, although the present invention was primarily designed for use with
a film wrapping machine for wrapping purposes, it could be used with other
types of
objects of different fields for other purposes, such as braiding purposes for
example,
as apparent to a person skilled in the art. For this reason, expressions such
as
"wrapping" andlor "knotting" and any other references and/or other expressions
equivalent thereto should not be taken as to limit the scope of the present
invention
and include all other objects with which the present invention could be used
and may
be useful.
In addition, although the preferred embodiment of the knotter as shown
comprises various components as listed hereinbelow, not all of these
components
are necessarily essential to the invention and thus should not be taken in
their
restrictive sense, i.e. should not be taken as to limit the scope of the
present
invention. It is to be understood, as also apparent to a person skilled in the
art, that

CA 02357135 2001-09-07
other suitable components and cooperations thereinbetween may be used for the
film
wrapping machine and knotter used therewith according to the present
invention, as
will be explained hereinafter, without departing from the scope of the
invention.
Moreover, expressions such as "~Im" and "knot", as well as any equivalent
expressions and/or compound words thereof, may be used interchangeably in the
context of the present description. The same applies for any other mutually
equivalent expressions, such as "web" and "knot" for example, as also apparent
to a
person skilled in the art.
Furthermore, it is to be understood that the expressions "film", "web",
"rope",
etc., as used in the context of the present description refers to various
different
objects which may be used with the present invention, as also apparent to a
person
skilled in the art. '
Referring now to figure 1, there is shown a roped portion of the film that is
placed in the initial clamp (11). The wrapping cycle is started with the film
delivering
carriage (not shown) in roping configuration as to form the first tail. After
the first %Z
revolution of the wrapping arm (not shown), the film delivering carriage is
brought
back to full web configuration. The product is fully wrapped with full web and
during
the last %2 revolutions, the film delivering carriage is once more brought
into rope
configuration in order to make the last tail.
A gathering mechanism (5-6-13) gathers the two tails and clamps them at a
pre determined position between the knotter head and the wrapped product
The knotter head is brought up (12) in order to position the two tails between
the knotting sleeve (7) and the cam clamp (8) and into the guides (4). The
knotting
sleeve (7) is then rotated with the motor and gears (2) until the two tails
are locked
against the knotting sleeve (7) and the cam clamp (8) and then stopped.
The first tail, which is still in the initial clamp (11 ), is release from it.
The last
tail, which is going from the knotting sleeve (7) too the film delivering
carriage is then
clamped into the initial clamp (11). The last tail is then cut between the
initial clamp
(11) and the knotting sleeve (7). The initial clamp (11) now holds the first
tail of the
next cycle.
The knotting sleeve (7) is reactivated with the motor and gears (2) as to
complete a full revolution in order to wrap a portion of the tails around the
knotting
sleeve (7). As the revolution is completed, the two ends of the tails are
gripped into
the tail gripper (9). Once gripped, a rotary actuator (1 } brings the tail
ends portion

CA 02357135 2001-09-07
over the wrapped knotting sleeve (7) into the jaws (3) of the tail pullet
(10). Once the
tail ends are into the tail pullet jaws, the tail pullet (10) is retracted
pulling the two tail
ends into the core of the knotting sleeve (7). The knotting sleeve (7) is then
pulled
downward in order to release the wrapped portion around it. The gathering
clamp (5-
6-13) releases the two rope portions. The knot is now formed between the load
and
the tail pullet. The tail pullet releases the two tail ends and the knot is
free on the
wrapped product.
All the mechanisms are return to their initial position and the next cycle is
ready to start.
Referring now to figures 2 to 5, there are shown the steps of the method for
forming a knot by means of the knotter shown in figure 1.
Of course, numerous modifications could be made to be above-described
embodiments without departing from the scope of the invention as apparent to a
person skilled in the art.

Representative Drawing