WO1997037915A1

WO1997037915A1 - A prehensile head for moving containers

Info

Publication number: WO1997037915A1
Application number: PCT/IT1997/000068
Authority: WO
Inventors: Claudio Ghelfi
Original assignee: Az Gomma Ricambi S.R.L.
Priority date: 1996-04-05
Filing date: 1997-03-26
Publication date: 1997-10-16
Also published as: ITRM960222A0; ITRM960222A1; IT1284621B1

Abstract

A prehensile head for moving containers for liquids or powders, characterized in that it comprises one pair of lever jaws (1a, 1b) provided with a horizontally pivoted movement around a pin (5) fixed to a support hull (2), having at a first end (6) shaped surfaces (7) according to a suitable profile, and at the opposite end (8), grasping elements (9), and in that it comprises a movable steel (3) provided with an alternate movement ending up in a bulb (4) that cooperates with said shaped surfaces (7) in a dragging relationship so as to determine the opening and/or closing of the ends (8) of the jaws (1a, 1b) provided with seizing elements (9).

Description

"A PREHENSILE HEAD FOR MOVING CONTAINERS"

The present invention concerns a prehensile head for moving containers, in particular for liquids or powders.

It is well known that in the realization, transport, filling and packing lines of containers for liquids or granular products or powders, the problem exists of moving said containers which usually may be of any shape, structure, weight etc., may have any kind of opening and may be realized out of any material.

At present, the problem is partially solved by means of the use of mechanic hooks that exploit the particular shape of the container or the presence of particular structures in the opening of the containers or again the presence of supports like handles, eyelets etc.

As an alternative, the use of pneumatic prehensile heads, provided with a cavity containing an inflatable membrane, preferably out of rubber, is widespread.

First the opening of the container is introduced into said cavity; now the membrane is blown up, wh i c h tightens totally or partially, with the help of plastic or metal inserts, around the opening fitting in it and thus allowing to grasp and move the container. The first kind of moving device is evidently limited to the use of containers having a hooking possibility due to their particular shape or due to projections, supports or handles that can be engaged by said mechanic hooks.

The second device with a pneumatic prehensile head - even if being more universal - does not always succeed to fit in the shape of the container's opening or in the diameter of the neck of the bottle or of the small jar.

Furthermore, it sometimes does not guarantee a safe grasping of the container, mainly when the contained product is greasy or makes the opening of said container viscid.

Some kinds of containers may, furthermore, damage the inflatable membrane, which however may breake during use; said containers may also be too heavy for grasping and therefore slip out.

At last, said heads seem to be rather encumbersome because, as they are of cylindric shape, they radially project from the shape of the container's opening, and consequently don't allow to bring the container very near nor to save space in the moving lines, where they may be stoccked in packets. It is the aim of the present invention to overcome above mentioned inconveniences.

The aim set forth is reached by means of the present invention, which solves the problem of realizing a prehensile head for moving containers for liquids o r powders, characterized in that it comprises one pair of lever jaws provided with a horizontally pivoted movement around a pin fixed to a support hull, having at a first end shaped surfaces according to a suitable profile, and at the opposite end grasping elements, and in that it comprises a movable steel provided with a n alternate movement ending up in a bulb that cooperates with said shaped surfaces in a dragging relationship so as to determine the opening and/or closing of the ends of the jaws provided with seizing elements.

The advantages obtained by means of the present invention mainly consist in that the action of grasping the opening of the containers is realized by means of tongs comprising only mechanic members able to develop great forces by simply varying the relationship between the lever arms; in that the heads may be adaptable to different kinds of containers, replacing the seizing elements that are interchangeable by insertion and that are provided at the ends of the jaws; in that the encumbrance of the head in the normal working direction of the jaws is reduced and that therefore the heads may be arranged in packings one near the other taking away less space than those heads working radially onto the opening of the container.

Further features and advantages of the head according to the present invention will be described more i n detail hereinbelow relating to the encloseddrawings in which two embodiments are shown.

Figure 1 shows a front view of a prehensile head for moving containers for liquids or powders according to the present invention, in seizing position, according to a first variant of the present invention.

Figure 2 shows a front view of the prehensile head of figure 1 , in released position.

Figure 3 shows a front view of a prehensile head in seizing position according to a further variant of the present invention.

Figure 4 shows a front view of the prehensile head of figure 3, in released position. Relating to the details shown in the enclosed figures, the head according to the present invention mainly comprises:

- a pair of jaws 1 a and 1 b;

- a supporting hull 2;

- a movable shaft 3;

- a bulb 4 linked to said shaft 3.

The pair of jaws comprises a left jaw l a and a right jaw l b, identical but symmetric to the axis of the movable shaft 3. Each jaw has its fulcrum in the supporting hull 2 by means of a pin 5 and has at its first end 6 shaped surfaces 7 and at its second end 8 an insert 9 interchangeable seizing element.

The supporting hull 2 is linked at the top to the pneumatic cylinder 1 0 of known kind, and comprises two holes in which pins 5 are housed. Through said hull 2, the movable shaft 3 freely slides, being operated, in its extension and return movement, by said cylinder 1 0.

The movable shaft 3 ends up in a bulb 4 shaped so as to cooperate with surfaces 7.

As it is shown in figures 1 and 2, that show a first embodiment of the head according to the present invention, the shaped surfaces 7 comprise a first surface 1 1 arranged above the plane connecting rotation pins 5 of said jaws l a and l b, linked with a second surface 1 2 below said plane. Said first surface 1 1 of said first jaw 1 a forms a guide converging to the top, when it is coupled with the corresponding first surface 1 1 of said second jaw 1 b.

Said second surface 1 2 of said first jaw 1 a, forms a guide converging to the bottom when it is coupled with the corresponding second surface 1 2 of said opposite jaw 1 b. The bulb 4 has a mainly spherical shape and is linked to the movable shaft 3.

According to this first embodiment of the head according to the present invention, said bulb 4 is always comprised between the guide converging to the top, consisting of the surfaces 1 1 , and the guide converging to the bottom, consisting of the surfaces 1 2, moving between an upper and a lower dead point, exploitig the alternate movement given by said pneumatic cylinder 10 to said shaft 3.

In the rising movement of said movable shaft 3, the bulb 4 drags onto surfaces 1 1 of jaws 1 a and 1 b distancing them and consequently determining the approaching of the lower ends 8 of jaws l a and l b provided with the insert seizing element 9, which grasp the container. In the descent movement of the movable shaft 3, said bulb 4 drags onto the surfaces 1 2 of jaws 1 a and l b, distancing them and consequently determining t h e distancing of the lower ends 8 of jaws l a and l b provided with insert prehensile element 9, which release the container.

As shown in figures 3 and 4, that show a second embodiment of the head according to the present invention, the shaped surfaces 7 of each jaw l a and l b comprise a surface 1 3 arranged above the plane linking the rotation pins 5 of jaws l a and l b. Said surface 1 3 of said first jaw 1 a forms a guide converging to the bottom when it is coupled wuth the corresponding surface 1 3 arranged on said second opposite jaw 1 b. The bulb 4 has a mainly conical shape or concave hemispheric shape to the bottom, and is linked to the movable shaft 3.

Between the upper ends 6 of jaws l a and 1 b, at least one elastic element is linked.

According to above described second embodimet of the head according to the present invention, the bulb 4 moves between an upper and a lower dead point, exploiting the alternate movement given by the pneumatic cylinder 1 0 to said shaft 3. In the descent movement towards the lower dead point, the bulb 4 drags onto the surfaces 1 3 of jaws 1 a and 1 b that form the guide converging to the bottom, overcoming the force of the elastic element 1 4, distancing them and consequently determining t h e approach of the lower ends 8 of said jaws l a and 1 b provided with a prehensile element 9, which grasp the container.

In the rising movement towards the upper dead point, the bulb 4 - getting back - allows the elastic element to determine the approach of said surfaces 1 3 of jaws l a and l b forming the guide converging to the bottom and consequently the distancing of the lower ends 8 of said jaws l a and l b provided with a prehensile element 9, which release the container.

Claims

1 . A prehensile head for moving containers, in particular for liquids or powders, characterized in that it comprises:

- one pair of lever jaws ( l a, l b) provided with a horizontally pivoted movement around a pin (5) fixed to a support hull (2), having at a first end (6) shaped surfaces (7) according to a suitable profile, and at the opposite end (8) grasping elements (9);

- a movable steel (3 ) provided with an alternate movement ending up in a bulb (4) that cooperates with said shaped surfaces (7) (identical and specular to the axis of said movable shaft) in a dragging relationship, so as to determine the opening and/or closing of said ends (8) of jaws ( l a, l b) provided with seizing elements (9).

2. A prehensile head according to claim 1 , characterized in tha t said shaped surfaces (7) are identical and symmetric to the axis of said movable shaft (3).

3. A prehensile head according to claims 1 and 2, characterized in that said shaped surfaces comprise a first surface ( 1 1 ) arranged above the plane connecting rotation pins (5) of said jaws ( l a, l b), linked with a second surface ( 1 2) arranged below said plane so that, when said bulb (4), in its rising movement, drags between the first surfaces (11) of said two jaws (la, 1b), it determines a progressive distancing of the same and, due to the fulcrum position of said jaws (la, lb), determines a consequent approaching of the opposite ends (8) of said jaws provided with grasping elements (9); while when said bulb (4), in its descent movement, drags between the second susrfaces (12) of said two jaws (la, 1b), it determines again a progressive distancing of the same but, always due to the fulcrum position of the jaws, determines the distancing of the ends (8) of said jaws provided with grasping elements (9).

4. A prehensile head according to claim 1 , characterized in that between the first ends (6) of said jaws (1a, lb) at least one elastic element (14) is linked.

5. A prehensile head according to claims 1, 2 and 4, characterized in that said shaped surfaces (7) comprise a surface (13) arranged above the plane connecting rotation pins (5) of said jaws, so that when said bulb (4), in its descent movement, drags, wedging itself in between said surfaces (13), determines a progressive distancing of the same overcoming the force performed by said elastic element (14) and, due to the fulcrum position of the jaws, determines a consequent approaching of the opposite ends (8) of the jaws provided with grasping elements (9); while when said bulb (4), in its rising movement, progressively gets back from said surfaces ( 1 3), the force performed by said elastic element ( 14) determines the approaching of said surfaces (1 3) and, due to the fulcrum position of said jaws, determines the consequent distancing of said ends (8) of said jaws provided with grasping elements (9).

6. A prehensile head according to any of the preceding claims, characterized in that said grasping elements (9) are interchangeable insert elements according to the dimensions of the container to be moved.

7. A prehensile head according to any of the preceding claims, characterized in that said movable shaft (3) is operated by a pneumatic piston ( 10).