HK1118792B - Screwing and rolling head for the application of pre-threaded caps - Google Patents

Description

Screwing and rolling head for mounting pre-threaded caps

Technical Field

The present invention relates to a screw-in rolling head for mounting a pre-threaded cap on a container having a threaded neck.

Background

The pre-screw cap of the bottle has a cylindrical wall made of deformable metal material (for example aluminium or similar material) which, after screwing the cap onto the neck of the bottle, is subjected to a low-temperature plastic deformation operation by rolling. This rolling action causes the annular portion of the side wall of the cap to deform at the bottom of the threaded portion relative to the annular groove provided on the container neck.

The invention relates to a machining head designed to enable screwing and rolling operations to be carried out jointly. In document No. ep- ｃA-1519891 ｃA combined screw-in rolling head is disclosed, which has the features contained in the preamble of claim 1. In the solution disclosed in this document, the means for screwing the cap onto the top surface of the neck of the container operate by friction on the top surface of the cap. Applying a clamping torque to the neck of the container by friction may result in a risk of damaging the top surface of the cap. In particular, the screwing-in and stitching heads of the known type involve the risk of damaging the text and images printed on the top face of the cap.

Disclosure of Invention

The object of the present invention is to provide a combined screwing and rolling head for fitting pre-threaded caps which overcomes the drawbacks of the prior art.

According to the invention, this object is achieved by a screwing and rolling head having the features forming the subject of claim 1.

Drawings

The characteristics and advantages of the head of the invention will be more clearly understood in the course of the detailed description, given purely by way of non-limiting example, with reference to the accompanying drawings, in which:

fig. 1 is an axial sectional view of a screw-in rolling head according to the invention;

FIG. 2 is an axial cross-sectional view of the head of FIG. 1, shown on an enlarged scale;

FIG. 2a is a detail of a portion of the head as may be seen in the plan view of FIG. 2;

figures 3, 4, 5 and 6 show the sequence of operation of the head of the invention.

Detailed Description

Referring to fig. 1 and 2, reference numeral 10 designates a screw-in rolling head according to the present invention. The head 10 is designed to enable a pre-threaded cap 12 to be fitted on a container 14 having a threaded neck (in the illustrated example, the container is a bottle). The pre-threaded cap 12 is known per se. The cover includes a planar top surface 16 and a generally cylindrical side surface 18. The cap 12 comprises an outer skirt formed by a thin layer of plastically deformable metal material and a threaded inner insert which engages a threaded portion provided on the neck of the container 14. Such a pre-threaded cap is also provided with a disc-shaped flexible gasket located within the metal skirt below top surface 16. The gasket is designed to press against the front edge of the neck of the container 14.

The screwing and rolling head 10 comprises a first support 20 having a helical movement indicated by the arrow 22 in fig. 1. The screwing motion of the first support 20 is formed by a linear motion in the direction of the longitudinal axis 26 of the head 10 (indicated by the double-headed arrow 24) and a rotary motion about the longitudinal axis 26. The first support 20 comprises a tubular spindle 28 connected to an actuating device (not shown) able to impart a helical motion to the first support 20. The actuation means are not described, since they do not fall within the scope of protection of the present invention. Said actuating means can be obtained in any way known in the art of capping machines, designed to act on the thread crests. The bottom end of the spindle 28 is secured to a first flange 30 that extends radially outwardly relative to the spindle 28.

The head 10 comprises a second support 32 movable along the longitudinal axis 26 with respect to the first support 20 and rotatably fixed with respect to the first support 20. Which means that: the second support 32 is both rotatable about the axis 26 and fixed relative to the first support 20, while it is free to undergo displacement relative to the first support 20 in the direction of the axis 26. The connection between the first support 20 and the second support 32 is obtained by means of guide rods 34, which extend parallel to the longitudinal axis 26. Each guide bar 34 has a bottom end fixed to the second support 32 and a top end engaged so that it can slide in the hole provided in the first flange 30 of the first support 20. The head 10 comprises a plurality of guide rods 34 arranged at a distance from each other in the circumferential direction. Only one of these guide rods 34 can be seen in the drawing. For example, they may be at 90 to each other. Four guide rods 34 are provided.

Elastic compression means are provided between the first support 20 and the second support 32, so as to be able to push the second support 32 away from the first support 20. Referring to fig. 2 and 2a, the resilient means takes the form of helical compression springs 36, 38 arranged coaxially with respect to the respective guide rods 34. The first series of springs 36 (fig. 2a) exert a lower strength force. The second series of springs 38 (fig. 2) exert a higher force. The second series of springs 38 acts and generates a higher intensity of force only after the second support 32 has moved with respect to the first support 20 (which is greater than a preset threshold). When the relative movement of the second support 32 in the axial direction with respect to the first support 20 is less than the threshold value, the second support 32 is just affected by the force generated by the spring 36 (force of lesser intensity). When the axial movement of the second support 32 with respect to the first support 20 exceeds said threshold, the second support 32 is affected by the sum of the elastic forces generated by the springs 36 and 38. For example, the lower strength force generated by spring 36 may be in the range of 15kg, while the higher strength force generated by springs 36 and 38 may be in the range of 50 kg. The second support 32 is subjected to a lower intensity force during the first 3-4 mm of movement, and then the second support 32 is subjected to a higher intensity force during about 12mm of movement. As described below, the first movement enables screwing in of the cap and the second movement enables rolling of the cap.

The second support member 32 includes a tubular sleeve 40 and a second flange 42 secured to the tubular sleeve 40 and extending radially outwardly from the tubular sleeve 40. The guide bar 34 is fixed to the second flange 42 of the second support 32. The tubular sleeve 40 extends coaxially with respect to the longitudinal axis 26 of the head 10, in the direction of the first support 20. The first support 20 carries a cam 44 fixed with respect to the first flange 30. The cam 44 extends towards the second support 32 and has a bottom end in sliding contact with the top end of the tubular sleeve 40.

The shoulders present in both the sleeve 40 and the cam 44 limit the maximum displacement between the first support 20 and the second support 32 in the direction of the axis 26.

The second flange 42 of the second support 32 carries at least one vibrating arm 46 articulated about a transverse axis 46. The vibrating arm 46 is movable between an inoperative position and an operative position and carries, at its bottom end, an idle rolling disc 50 designed to enable rolling of the side wall 18 of the cover 12. The vibrating arm 46 comprises an extension 52 hinged about a second axis 54 and cooperating with a compression spring 54. The extension 52 of the oscillating arm 46 carries an idle wheel 58 cooperating with the cam 44 of the first support 20. The compression spring 59 is able to push the vibrating arm 46 towards its rest position. The wheel 58 of the oscillating arm 46 is always kept in contact with the cam 44 by the action of the springs 56 and 59. The head 10 is preferably provided with two or more oscillating arms 46 arranged at equal intervals from each other in the circumferential direction and provided with respective rolling wheels 60. The different vibrating arms 46 all cooperate with the same cam 46.

The head 10 comprises means 60 for screwing the cap, which means comprise a tubular shaft 62 coaxial with the longitudinal axis 26 of the head 10. The tubular shaft 62 is axially fixed relative to the second support 32 and is rotatably supported about the axis 26 by the tubular sleeve 40 of the second support 32. In the embodiment shown in the drawings, the tubular shaft 62 is carried by the tubular sleeve 40 by a pair of radial bearings 64 and a pair of axial bearings 66. The tubular shaft 62 is rotatably connected to the second support 32 by a torque limiting device 68. In the example shown in the figures, the torque-limiting device 68 is constituted by a magnetic clutch comprising two rings 70, 72 magnetically coupled to each other. The first ring 70 is fixed with respect to the tubular sleeve 40 of the second support 32 and the second ring 72 is fixed with respect to the tubular shaft 62. A ring nut 74 screwed on the threaded portion of the tubular shaft 62 enables the axial clearance between the two rings 70, 72 to be adjusted in order to vary the threshold of interference of the torque-limiting device 68. Below a preset threshold value of torque (value adjustable by means of the ring nut 74), the shaft 62 rotates with respect to the second support 32. When the torque transmitted between the second support 32 and the tubular shaft 62 exceeds the threshold of interference of the torque limiting device 68, the tubular shaft 62 is free to rotate relative to the second support 32.

The means 60 for screwing the cap comprise a clamp 76 provided at the bottom end of the tubular shaft 62. The clamp 76 includes a plurality of swing arms 78 at the bottom end of the tubular shaft 62, which are hinged about a transverse axis 80. The rocker arms 78 (for example three) carry, at their bottom ends, blocks 82 made of elastic material having cylindrical zones of perimeter equal to the outer perimeter of the cover 12. A rocker arm 78, generally forming the clamp 76, is movable between an open position and a closed position. The top end of the rocker arm 78 has corresponding radial appendages 84 which cooperate with a cam portion 86 provided at the bottom end with a control lever 88. The control rod 88 is coaxially mounted within the tubular shaft 62 and is slidable relative to the tubular shaft 62 in the direction of the longitudinal axis 14.

The annular spring 83 keeps the radial appendage 86 of the arm in contact with the cam portion 86.

The top end of the lever 88 engages an actuation cam (not shown). The coil compression spring 90 always urges the control lever 86 upward; thus, the clamp is normally closed. A cam associated with lever 88 pushes the lever downwards against the action of spring 90, so as to be able to open the clamp in a preset step of the working cycle of the capping machine.

The clamp 76 incorporates a safety device 92 which prevents the clamp from closing in the absence of the lid 12 on the container 14. The safety device 92 includes a ring 94 that encircles the outside of the rocker arm 78. The ring 94 is movable between a lowered position and a raised position in the direction of the longitudinal axis 26 of the head 10. The ring 94 has an annular groove 96 that is capable of receiving a projection 98 formed on the outside of the rocker arm 78 in the raised position of the ring 94. The safety device 92 comprises a central contact pin 100 fixed to the ring 94 by a transverse pin 102. The contact pin 100 is pushed down by a spring 104 having a lower strength.

Head 10 includes a central member 106 which is secured to second support 32 by a series of axial posts 108. A stationary member 110 that idles with respect to the tubular shaft 62 is fixed to the bottom end of the tubular shaft 62 and is set inside the vibration arm 78 forming the jig 76.

Next, the operation of the head 10 of the present invention will be explained.

The container 12 itself is located beneath the head 10 and the cap 12 is inserted onto the neck of the container, but not yet screwed in. Initially, the head 10 assumes the configuration shown in fig. 2. In this configuration, the gripper 10 is in the open position, the second support 32 is at the maximum distance from the first support 20, and the arms 46 carrying the rolling wheels 50 are in their inactive position (outwardly diverging position).

Starting from the above structure, the first support 20 moves downward in a spiral motion. In this first step, the second support 32 moves in a fixed manner with respect to the first support 20. The tubular shaft 62 is fixed relative to the second support 32 by a torque limiting device 68.

Fig. 3 shows the step of the head 10 approaching the cover 12. The stationary member 110 rests on the top end of the cover 102. Top surface 16 of cover 12 pushes contact pin 100 upward against the action of spring 104. The upward movement of the contact pin 100 pushes the ring 94 upward. In the raised position, the annular groove 96 of the ring 94 is at a position corresponding to the outer protrusion 98 of the arm 78 in the clamp 96. In this position, the clamp can be closed. The purpose of the safety device 76 is to: if the lid 12 is not present on the container 14, the clamp is prevented from closing. In practice, without cover 12, contact pin 100 is not pushed upwards and projection 98 of arm 78 hits against the inner surface of the ring, thus preventing the movement of the inner surface of the clamp.

At this time, as shown in fig. 4, the cam that pushes the control lever 88 downward is raised, so that the control lever 88 is moved upward by the spring 90. Upward movement of the control rod 88 controls the closing of the clamp 76. The block 82 of the clamp 76 grips a portion of the outer surface of the cover 12.

Subsequently, head 10 screws cap 12 onto container 14. During the screwing step, the clamp 76 is pushed downwards by the spring force of lower intensity provided only by the spring 36 acting between the first support 20 and the second support 32. At the end of the screwing, a cam associated with the control rod 88 controls the opening of the clamp (fig. 6).

The downward movement amount of the first support 20 is greater than the twisting amount. Subsequently, once the screwing step is completed, the downward movement of the tubular shaft 62 and of the second support 32 is interrupted, while the downward movement of the first support 20 continues. In this way, the second spring 38 is compressed, thereby exerting a greater strength of force on the second support 32. Once the screwing-in movement is completed, the magnetic clutch 68 starts to slip so that the tubular shaft 62 and the clamp 76 remain stationary, while the second support 32 rotates about the tubular shaft 62. In this step (shown in fig. 5), the jig 76 is stationary with respect to the cover 12, and the jig 76 is pushed down by a large intensity of force. This force presses the deformable gasket located within the lid 12 against the top rim of the container.

In the next step, the rolling process is started. While the cap 12 is fully screwed in and pushed downward by a strong force, the further downward movement of the first support 20 controls the vibration of the arm 46 by the cam 44, thereby bringing the stitching wheel into contact with the outer wall of the cap 12. Further downward spiral movement of the first support 20 results in pure rotational movement of the second support 32, while the stitching wheel 50 is pressed in an elastic manner against the outer edge of the lid 12. Rotation of stitching wheel 50 about lid 12 produces plastic deformation of the lid within a corresponding annular collar (which is disposed at the bottom of the threaded portion of the container).

At the end of the rolling step, the first support 20 is moved upwards and the head 10 is automatically returned to the initial position of fig. 2.

In the event that the lid 12 is not on the container 14, the safety device 92 in combination with the clamp 76 prevents the rolling motion in addition to preventing the clamp 76 from closing. Referring to fig. 2, when the ring 94 of the safety device 92 is in the lowered position, the projections 112 of the arms 46 abut against the outer surface of the ring 94 without the feeler pins 100 having lifted the ring. Referring to FIGS. 3-6, when the ring 94 is in the raised position, the projections 112 do not interfere with the ring 94 and the arms 46 can move to the rolled position. In this way, it is possible to avoid damage or breakage of the container 14 caused by rolling directly on the container without the lid 12.

At the end of the rolling step, such a head enables a subsequent final step of screwing the cap. In addition, since the opening and closing of the head are controlled, the rolling step can be performed with the jig opened, and thus, the damage of the stamp on the cap can be further reduced.

Naturally, the details of construction and the arrangement may be varied widely with respect to what is disclosed and described herein, without thereby departing from the principle of the invention, and such variations are therefore not to be considered as being outside the scope of the invention as defined in the claims.

Claims (11)

1. A screw-in rolling head for mounting a pre-threaded cap (12) on a container (14), comprising:

-a first support (20) designed to be able to perform a helical movement consisting of a linear movement along a longitudinal axis (26) and a rotation around said axis;

-a second support (32) movable with respect to the first support (20) in the direction of said longitudinal axis (26) and rotationally fixed with respect to the first support (20);

-means (60) for screwing the cap, which are axially fixed with respect to the second support (32) and are rotatable with respect to the second support (32);

-torque limiting means (68) connected between the means (60) for screwing in the cap and the second support (32), wherein the torque limiting means (68) are able to rotationally fix the means (60) for screwing in the cap with respect to the second support (32) below a preset torque threshold and are able to act with a torque above said preset threshold to rotate the means (60) for screwing in the cap with respect to the second support (32);

-at least one vibrating arm (46) with a rolling element (50) and hinged about a transverse axis (48) to the second support (32), said vibrating arm (46) being movable between an active position and an inactive position and cooperating with a cam actuator (44) carried by the first support (20); and

-first elastic means (36) for exerting a lower axial force between the first support (20) and the second support (32) during the screwing-in step of the cap, and second elastic means (38) for exerting a higher axial force between the first support (20) and the second support (32) during the rolling-in step,

the head is characterized in that: the device (60) for screwing in the cap comprises a clamp (76) movable between an open position and a closed position and designed to be able to clamp the cap (12) along its side walls, the opening and closing movements of the clamp (76) being controlled by a control rod (88) movable in an axial direction.

2. Screwing and rolling head according to claim 1, characterized in that: the clamp (76) incorporates a safety device (92) which prevents closure of the clamp (76) in the absence of a lid (12) on the container (14).

3. Screwing and rolling head according to claim 2, characterized in that: the safety device (92) prevents the vibrating arm (46) from moving towards the operating position in the absence of the lid (12) on the container (14).

4. Screwing and rolling head according to claim 2 or 3, characterized in that: the safety device (92) comprises a ring (94) axially movable between a lowered position and a raised position and connected to a feeler pin (100) which abuts against the top surface (16) of the lid (12) and moves it towards the raised position when it comes into contact with the lid (12).

5. Screwing and rolling head according to claim 4, characterized in that: the ring (94) has an annular groove (96) designed to receive an outer protrusion (98) of the clamp (76) in the raised position of the ring (94).

6. Screwing and rolling head according to claim 4, characterized in that: the vibrating arm (46) has a projection (112) designed to abut against the outer surface of the ring (94) when the ring (94) is in its lowered position.

7. Screwing and rolling head according to claim 1, characterized in that: the device (60) for screwing the cap comprises a tubular shaft (62) hinged at one end thereof with a plurality of rocker arms (78) forming said clamp (76).

8. Screw-in rolling head according to claim 7, characterized in that: a control rod (88) coupled to the clamp (76) is coaxially disposed within the tubular shaft (62).

9. Screw-in rolling head according to claim 8, characterized in that: the second support (32) comprises a tubular sleeve (40) and a second flange (42) extending radially outwards with respect to said tubular sleeve (40), the aforementioned tubular shaft (62) of the means (60) for screwing the cap being coaxially arranged inside said tubular sleeve (40).

10. Screw-in rolling head according to claim 9, characterized in that: the first support (20) comprises a first radially extending flange (30) connected to said second flange (42) of the second support (32) by a plurality of guide rods (34).

11. Screw-in rolling head according to claim 10, characterized in that: the first and second elastic means comprise helical compression springs (36, 38) arranged coaxially with respect to the guide rod (34).