WO2010118994A2

WO2010118994A2 - Device for cap screwing and unscrewing

Info

Publication number: WO2010118994A2
Application number: PCT/EP2010/054724
Authority: WO
Inventors: Massimo Serrani; Fabio Gianfelici
Original assignee: Pol.Mec. Srl
Priority date: 2009-04-16
Filing date: 2010-04-09
Publication date: 2010-10-21
Also published as: IT1394040B1; ITMC20090081A1; WO2010118994A3

Abstract

The present invention relates to a device for cap screwing-unscrewing that is composed of a collar (1, 10) provided on the internal surface (1a) with a series of seats (2, 20) and comprises corresponding catches (3, 30) contained with possibility of sliding inside the seats (2, 20) together with a spring (M) that pushes them towards the centre of the collar (1, 10).

Description

Device for cap screwing and unscrewing

The present patent application for industrial invention relates to a device for cap screwing and unscrewing that on the one hand allows for screwing any type of cap without tightening it excessively and on the other hand allows for unscrewing any type of cap easily although it is tightened energetically. The device for cap screwing and unscrewing of the present patent application has been devised with special reference to plastic bottles provided with plastic cap, although it can be advantageously used in any other field by simply adjusting its dimensions to the cap to be screwed and unscrewed. As it is known, the caps of plastic bottles are sealed with means that guarantee closure and usually consist in a fixed lower collar made of plastic material that is connected by means of tear strips to the lower border of the cap.

A force must be applied on such a cap to unscrew it for the first time in order to tear off said strips. Such a operation provides for the operator to hold the cap firmly, normally with two fingers, precisely between forefinger and thumb, and simultaneously apply a turning torque to rotate the cap.

Individuals who are not too strong in their hands, such as women or the elderly, may face problems in rotating the cap while holding it firmly between their fingers. If the tightening pressure is not sufficient, the cap remains still and the fingers tend to rub the lateral surface of the cap.

In order to make this operation easier, the aforementioned plastic caps are laterally provided with anti-slip surface with grooved section obtained by means of a dense series of thin vertical notches for improved grip. Once the strips have been torn off, the cap can be easily unscrewed and screwed back. The same drawbacks that are encountered during the tearing off of the strips are also encountered also after opening the bottle, precisely when the cap is tightened excessively.

If the cap is screwed by an especially strong person, a weaker operator will find it difficult to unscrew it. In such a case, in order to unscrew a cap that was energetically screwed, the operator must apply a force that is identical and opposite to the force that was used to screw the cap to the end of the rotation travel.

The European patent application EP 1 798 192 discloses a device for unscrewing caps provided with catches that protrude inwards to come into contact with the cap to be unscrewed.

The purpose of the present invention is to disclose a device for cap screwing and unscrewing that, because of its configuration, allows for unscrewing any type of cap although it requires a minimum tightening force.

Another purpose of the present invention is to disclose a device for cap screwing and unscrewing that, in addition to achieving the aforementioned purpose, allows for predefining and adequately limiting the tightening torque of the cap during screwing, in such a way that said torque does not reach excessive values that would make it difficult to open the bottle.

In other words, it could be stated that the device of the invention allows for always having the same value of the tightening torque of the cap, regardless of the force applied from time to time by the user who has closed the bottle.

These and other purposes have been achieved by the device for cap screwing and unscrewing of the invention, the main characteristics of which are illustrated in the first claim. The device of the invention is composed of a frame having the shape of a collar, which is provided with a series of shaped grooves with longitudinal axis on the internal surface.

Each groove houses a catch that protrudes towards the centre of the collar and is constantly subjected to the expulsive force of a return spring. Obviously, the catch and relevant groove are given such a configuration that, once the catch has been inserted into a corresponding seat, the catch can only make alternating radial travels without coming out of said seat. More precisely, each of said catches is normally ejected from the groove, and can be brought back into the groove by applying a force on its tip that is sufficient to win the expulsive force exerted by the spring. In order to use the device, the internal diameter of the collar must have a higher value than the diameter of the cap to be unscrewed, whereas the tip of the catches, in ejected position, lies on an imaginary circumference with lower diameter than the cap.

In view of the above, when the collar is lowered on the cap to be unscrewed, because of the interference of their tip with the upper border of the cap, the catches are partially retracted inside their seat.

Now the cap is surrounded by the collar with the catches that press and bite against the lateral surface of the cap under the thrust of the springs, thus relieving the operator from the obligation to hold the cap with his fingers with sufficient energy to prevent his hand from slipping around the cap when the turning torque is applied.

In view of the above, the user must simply exert the opening torque with his hand, being favoured by the fact that the external diameter of the collar is larger than the diameter of the cap, so that the arm of the forces increases with the same intensity of the couple of forces exerted. Moreover, it must be noted that the grip of the collar is favoured by the presence of a series of gripping protuberances.

For purposes of clarity, the description of the device for cap screwing and unscrewing of the invention continues with reference to the enclosed drawings, which are intended for purposes of illustration only and not in a limiting sense, wherein:

- figure 1 is a plan view of a device for cap screwing and unscrewing;

- figure 2 is a plan view of the device for cap screwing and unscrewing of the invention according to a preferred embodiment;

- figure 3 is an exploded view of the device of the invention according to the preferred embodiment of figure 2, perfectly aligned with the cap of the bottle;

- figure 4 is a cross-sectional view of the device of the invention according to another embodiment, wherein the front section of the inserts is of inclined type in order to be used on caps with different diameter;

- figure 5 is an enlarged view of figure 2 that shows one of the catches with relevant force system.

The device for cap screwing and unscrewing is composed of a frame having the shape of a collar (1 ) provided on the internal lateral surface (1 a) with a series of grooves (2) parallel to the longitudinal axis (Y-Y) of said collar (1 ).

Each groove (2) acts as seat to house and guide a catch (3) that is constantly subjected to the expulsive force of a spring (M), the tip (3a) of which protrudes towards the centre of the collar (1 ). Referring to figure 1 , said groove has a T-shaped cross-section that comprises a first wing (2b) that lies along a radial direction and ends inside the collar (1 ) and a second wing (2a) perpendicular to the first one (2b).

Each catch (3) has a T-shaped configuration that comprises a head (3a) housed inside a second wing (2a) and a stem (3b) ending with a tip (3c) and slidingly housed inside said first wing (2b) of the seat (2).

According to the first embodiment the tip (3c) of said catches (3) is tapered.

Referring to figure 1 , the tips (3c) of said catches (3) lie along an imaginary circumference (A) and the device (D) of the invention can be only used for caps (4) with diameter comprised between the diameter of the imaginary circumference (A) and the diameter of the internal surface (1 a) of the collar

(1 )-

With reference to the operation of the device, it must be noted that each catch

(3) can make alternating forward or backward travels between two positions, a first position in which the tip (3c) protrudes from the seat (2) completely and a second position in which said tip (3c) is housed in retracted position completely inside the seat (2).

In the latter position the spring (M) is in maximum compression configuration and the tip (3c) of the catch (3) is flush with the internal wall (1 a) of the collar

(1 )- According to the preferred embodiment of the invention shown in figure 2, the device of the invention has been realised in such a way that, if the cap (4) is tightened excessively by the operator, the collar (1 ) automatically slides around the cap (4).

As shown in Figure 2, according to said preferred embodiment of the device (D2) the grooves (20) have a T-shaped cross-section with the difference that the first wing (20b) ending inside the collar (10) is tilted by an angle (α) with respect to radial direction.

Still referring to Figure 2, each catch (30) ends with a flat tip (30c) that comprises two right corners (3Od and 3Oe) having a different distance from the centre of the collar due to the inclination given to the first wing (20b) of each groove (20). More precisely, the right corner (3Od) is closer to the centre of the right corner (3Oe), for which only the right corner (3Od) will interfere with the cap (4) and bite on the external surface (4a) of the cap (4).

While closing the cap, the operation of the second embodiment (D2) of the invention is the same as the first embodiment (D), except for that, when the cap (4) has reached the end of the screwing travel, a different behaviour between the two embodiments is recorded, according to which the second embodiment (D2) does not allow for exceeding a predefined tightening value that depends on the value of the expulsive force exerted by the springs (M) on the catches (30). As shown in Figure 5, the resistant force (F1 ) that acts on the corner (3Od), once screwing has been completed, can be divided into two forces (F2 and F3), one (F2) with radial direction and one (F3) with direction tilted by an angle (α) with respect to radial direction. The force (F2) has opposite direction with respect to the expulsive force (F3) exerted by the spring (M) on the catch (30). Therefore, as soon as the force (F2) reaches a value higher than the force (F3), the catch (30) moves back inside the seat (20) with consequent sliding of the collar (10) around the cap (4). So, the lower the expulsive force (F3) exerted by the spring, the lower the tightening of the cap will be. Finally, figure 4 shows a different longitudinal section of the catches, which could be given both to the catches (3) with tapered tip (3c) of the first embodiment (D) and to the catches (30) with flat tip (30c) of the second embodiment (D2).

The different section refers to the section of the catches (3, 30) in longitudinal direction, that is to say along a direction parallel to the longitudinal axis (Y-Y) of the collar (1 ). As shown in fig. 4, the longitudinal section (300) of the catches (3, 30) is tilted by an angle (β) with respect to the longitudinal axis Y of the collar (1 ). Still referring to Fig. 4, two caps (4) with different diameter housed inside the same collar (1 ) are diagramatically represented. It can be easily understood that said tilted section (300) increases the diameter range of the caps (4) that can be screwed-unscrewed with the same device of the invention.

More precisely, because of said tilted section (300), the device of the invention (D, D2) according to the latter version can be used for all caps (4) with diameter included between a minimum diameter equal to the diameter of the circumference where the tips of the catches (300) lie and a maximum diameter equal to the internal diameter of the collar (1 , 10).

According to a further embodiment of the invention, in a top view, the tip (30c) of the catches (30) is provided with concave section in such a way that the two corners (3Od and 3Oe) have an angle lower than the right angle.

Claims

1 ) Device for cap screwing-unscrewing that is composed of a collar (10) provided on the internal surface (1 a) with a series of seats (20) and comprises corresponding catches (30) contained with possibility of sliding inside the seats (20) together with a spring (M) that pushes them towards the centre of the collar (10), characterised in that

- said seats (20) consist in grooves (20) with T-shaped cross-section that comprises a vertical wing (20b) ending in the collar (10) and tilted by an angle

(α) with respect to the radial direction;

- each catch (30) has a T-shaped cross-section that comprises a vertical wing (30b) with flat tip (30c) provided with two right corners (3Od and 3Oe), with a different distance from the centre of the collar (10) due to the inclination given to the first wing (20b) of each groove (20).

2) Device according to claim 1 , characterised in that the tip (30c) of the catches (3) has a longitudinal profile (300) tilted by an angle (β) with respect to the axis (Y-Y) of the collar (10).

3) Device according to claim 1 or 2, characterised in that the collar (10) is provided with a series of protuberances on the external surface.