AU3622293A - An apparatus for feeding plastic caps in a capping machine - Google Patents

Description

- AN APPARATUS FOR FEEDING PLASTIC CAPS IN A CAPPING MACHINE

The present invention relates to an apparatus for feeding plastic caps in a capping machine and to a capping machine that incorporates the plastic cap feeding apparatus.

The procedure for capping metal caps onto bottles containing carbonated beverages or other liquids in a conventional capping machine for metal caps includes the steps of locating unthreaded metal cap shells on the bottles, rolling threads in the shells to form the metal caps in situ on the bottles, and then tightening the metal caps to the required torque by means of capping heads comprising capping chucks and spindles arranged in a capping turret. The diameter of the unthreaded metal cap shells is larger than that of the bottle necks and the shells easily fit over the bottle necks and, as a consequence, usually there is little difficulty locating the shells properly on the bottle necks. This is an important consideration since locating the metal caps properly on bottles is crucial to obtaining acceptable seals between the metal caps and the bottles.

There have been attempts by plastic cap manufacturers to modify the conventional metal cap capping machines to accept and cap plastic caps so that bottlers can change over from metal caps to plastic caps with minimal capital expenditure. However, the attempts have not been altogether successful.

A major reason for the lack of success is that it is difficult to locate consistently the plastic caps in the proper position on bottle necks because the diameter of the plastic caps, which are pre-threaded, is close to that of the bottle necks.

As a consequence, bottlers that wish to change over from metal caps to plastic caps have to commission dedicated plastic cap capping lines. The procedure for capping plastic caps onto bottles in a conventional dedicated capping machine for plastic caps involves locating the plastic caps initially in the chucks of the capping heads, rather than on the bottle necks, and then locating the capping heads on the bottles and operating the capping heads to position and tighten the plastic caps on the bottle necks in a single operation. In order to locate the plastic caps in the chucks, the plastic caps are received on a star wheel which rotates the plastic caps successively to a position directly below the path of rotation of the capping heads, and the arrangement is synchronised so that when a plastic cap is at the position a capping head moves downwardly and picks up the plastic cap .

The general approach of locating plastic caps in the capping heads prior to capping the bottles avoids the difficulties of locating the plastic caps properly on the bottles prior to capping by means of the capping heads. However, it is impractical to fit retrospectively the star wheel delivery system of the conventional dedicated plastic cap capping machines onto the conventional metal cap capping machine.

An object of the present invention is to provide an apparatus for feeding plastic caps in a capping machine which can be fitted retrospectively to metal cap capping machines and can be used in dedicated plastic cap capping machines.

According to the present invention there is provided an apparatus for feeding plastic caps in a capping machine, the apparatus comprising, a means for supporting the plastic caps one at a time at a position below a circular path of movement of a plurality of capping heads fitted to a capping turret, a means for lifting the plastic cap at the' position at a point in time so that the plastic cap is received in a chuck of one of the capping heads as the capping heads move along the circular path of movement, and a means for synchronising the operation of the lifting means with the movement of the capping heads past the position.

It is preferred that the apparatus further comprises a means for feeding plastic caps to the position below the circular path of movement of the capping heads. According to the present invention there is also provided an apparatus for feeding plastic caps in a capping machine, the apparatus comprising, a means for feeding the plastic caps successively to a position below a circular path of movement of a plurality of capping heads fitted to a capping turret, a means for lifting the plastic cap at the position at a point in time so that the plastic cap is received in a chuck of one of the capping heads as the capping heads move along the circular path, and a means for synchronising the operation of the lifting means with the movement of the capping heads past the position.

It is preferred that the apparatus further comprises a means for supporting the plastic caps at the position.

It is preferred that the lifting means comprises a ram assembly having a piston head movable between a retracted position and an extended position.

It is preferred particularly that the piston head underlie the plastic cap at the position when the piston head is in the retracted position.

It is preferred particularly that the piston head comprises an elongated upper surface which extends in the direction of the path of movement of the capping heads and defines a surface over which the plastic cap slides during the time that the plastic is being received in the chuck of one of the capping heads as the capping heads move along the path of movement.

It is preferred that the synchronising means comprise a cam assembly coupled to the capping turret or to a bottle infeed for the capping turret and operable to selectively actuate the ram assembly.

According to the present invention there is also provided an apparatus for capping plastic caps comprising, a capping turret having a plurality of capping heads for locating and tightening plastic caps on bottles, the apparatus described in the preceding paragraphs arranged for feeding plastic caps to the capping turret, and a means for feeding bottles to the capping turret for capping with the plastic caps.

The present invention is described further with reference to the accompanying drawings in which:

Figure 1 is a top plan view of a preferred embodiment of an apparatus for feeding plastic caps to a capping machine in accordance with the present invention with a guide for plastic caps removed;

Figure 2 is a section along the line 2-2 in Figure 1 with the guide shown in section and a ram assembly in a retracted position; and

Figure 3 is the section shown in Figure 2 with the ram assembly in an extended position.

The apparatus for feeding plastic caps shown in the figures is adapted to form part of an otherwise conventional capping machine. In this regard, the capping machine comprises a capping turret supporting a plurality of capping heads for movement along a circular path that is centred on a vertical axis of the capping turret with each capping head having a rotatable chuck for receiving a plastic cap and capping the plastic cap to a bottle neck. The capping machine also comprises a conveyor system for feeding bottles to the capping turret.

The apparatus shown in the figures is adapted to guide plastic caps successively from a storage hopper to a position below the circular path of movement of the capping heads and to raise the plastic cap that is at the position at any point in time to be received in the capping head that is moving past the position at that time.

With reference to the figures, the position is generally identified by the numeral 5 in each figure and is illustrated further by the plastic cap which is shown in outline and referenced with the numeral 7 in Figure 2 and is shown located at the position 5. In addition, the circular path of movement of the capping heads is identified by the numeral 3 in Figure 1.

The apparatus comprises a platform 9 for supporting plastic caps at the position 5 and a guide 11 for feeding plastic caps in a line from a remote storage hopper (not shown) . It is noted that the platform 9 is formed with an indented section having side walls 13 that accurately locate plastic caps on the platform 9.

The apparatus further comprises a pneumatically operated ram assembly for lifting the plastic cap 7 from the position 5 into the path of movement 3 of the capping heads and driving the plastic cap 7 into the chuck of one of the capping heads.

The ram assembly comprises a piston/cylinder assembly generally identified by the numeral 15. The piston head 17 of the piston/cylinder assembly is formed to extend through an opening in the platform 9 and has an elongated upper surface 19 which extends in the direction of the path of movement of the capping heads. The piston head 17 is positioned so that the upper surface 19 at least partially underlies plastic caps at the position 5. It can readily be appreciated that on actuation of the ram assembly the piston head 17 lifts the plastic cap 7 from the position 5 into the path of movement 3 of the capping heads, as is shown in Figure 3, and drives the plastic cap 7 into the chuck of one of the capping heads, and then retracts to the position shown in Figure 2.

The apparatus further comprises a means for synchronising the operation of the ram assembly with the movement of the capping heads. The synchronising means comprises a programmable cam switch (not shown) coupled to the capping turret or to the bottle infeed to the capping turret and operable to activate the ram assembly selectively to raise the plastic cap 7 as one of the capping heads moves along the path of movement 3 above the position 5 so that the plastic cap 7 is driven into and retained in the chuck of the capping head. In this regard, it is noted that the elongated upper surface 19 of the piston head 17 defines a surface over which the plastic cap 7 slides during the time that the plastic cap 7 is being fully driven into the chuck as the capping head continues to move along the path of movement.

It can readily be appreciated that when the ram assembly retracts to the position shown in Figure 3 another plastic cap slides into the position 5 for insertion into the chuck of the next capping head. The apparatus is relatively compact and can be fitted without difficulty in the limited space available in conventional metal cap capping machines. Furthermore, the apparatus is such that minimal modification of the operation of the components of the metal cap capping machine, such as the capping turret, is necessary to install and operate the apparatus.

In addition, the apparatus can be included as part of a dedicated plastic cap capping machine.

Many modifications may be made to the preferred embodiment described above without departing from the spirit and scope of the present invention.

In this regard, it is noted that whilst the preferred embodiment includes a programmable cam switch as part of the synchronisation means, the present invention is not limited to such an arrangement and any suitable means to synchronise the operation of the ram assembly with the capping heads could be used.

Claims (9)

CLAIMS ;

1. An apparatus for feeding plastic caps in a capping machine, the apparatus comprising, a means for supporting the plastic caps one at a time at a position below a circular path of movement of a plurality of capping heads fitted to a capping turret, a means for lifting the plastic cap at the position at a point in time so that the plastic cap is received in a chuck of one of the capping heads as the capping heads move along the circular path of movement, and a means for synchronising the operation of the lifting means with the movement of the capping heads past the position.

2. The apparatus defined in claim 1, further comprising a means for feeding plastic caps to the position below the circular path of movement of the capping heads.

3. An apparatus for feeding plastic caps in a capping machine, the apparatus comprising, a means for feeding the plastic caps successively to a position below a circular path of movement of a plurality of capping heads fitted to a capping turret, a means for lifting the plastic cap at the position at a point in time so that the plastic cap is received in a chuck of one of the capping heads as the capping heads move along the circular path, and a means for synchronising the operation of the lifting means with the movement of the capping heads past the position.

4. The apparatus defined in claim 3, further comprising a means for supporting the plastic caps at the position.

5. The apparatus defined in any one of the preceding claims, wherein the lifting means comprises a ram assembly having a piston head movable between a retracted position and an extended position.

6. The apparatus defined in claim 5, wherein the piston head underlies the plastic cap at the position when the piston head is in the retracted position.

7. The apparatus defined in claim 6, wherein the piston head comprises an elongated upper surface which extends in the direction of the path of movement of the capping heads and defines a surface over which the plastic cap slides during the time that the plastic is being received in the chuck of one of the capping heads as the capping heads move along the path of movement.

8. The apparatus defined in any one of the preceding claims, wherein the synchronising means comprises a cam assembly coupled to the capping turret or to a bottle infeed for the capping turret and operable to selectively actuate the ram assembly.

9. An apparatus for capping plastic caps comprising, a capping turret having a plurality of capping heads for locating and tightening plastic caps on bottles, the apparatus defined in any one of the preceding claims arranged for feeding plastic caps to the capping turret, and a means for feeding bottles to the capping turret for capping with the plastic caps.