CA2357135A1

CA2357135A1 - Knotter and method for forming a knot

Info

Publication number: CA2357135A1
Application number: CA 2357135
Authority: CA
Inventors: Alec Van Zuiden; Glen Ditchburn; Guy Lopes; Francois Couture; Wolfgang Geisinger; Sylvain Samson; Yanick Marois
Original assignee: Wulftec International Inc
Current assignee: Wulftec International Inc
Priority date: 2001-09-07
Filing date: 2001-09-07
Publication date: 2003-03-07

Description

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.

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 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 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.