TITLE: PREFORM POSITIONING DEVICE

DESCRIPTION

The present invention relates to a preform positioning device, particularly for use in systems for orderly packaging of plastic preforms in boxes or containers, generally of cardboard or plastic, in which they are stored; the preform positioning device holds a row of preforms and enters the box to position such row therein as desired. The introduction of the positioning device in the box is affected by certain drawbacks , particularly caused by the small clearances between the ends of the device and the box, which sometimes bring about undesired dragging effects, with consequent damages to the box and the partition introduced therein.

The present invention has the object of obviating the above drawbacks , by providing a positioning device as defined in the annexed claims .

The present device is composed of two arms which may be moved against each other or define a smaller angle to increase the distance between the ends and the walls of the box and/or the partitions contained therein, to avoid the above drawbacks .

These objects and advantages are achieved by the preform positioning device of this invention, which is characterized by the annexed claims .

These and other features will be more apparent from the following description of a few embodiments , which are shown by way of example and without limitation in the accompanying drawings, in which:

Figure 1 is a perspective view of the positioning device of this invention, and particularly of the positioning head,

- Figure 2 shows a front view of the head of Figure 1 ,

- Figure 3 is a detail view of a movable arm with bellows , - Figure 4 is an exploded view of the device.

Referring to Figures 1 and 2 , numeral 1 generally designates a device for positioning preforms 10, and particularly its end part, i.e. the positioning head.

A handling unit, not shown, is provided upstream from said head, which comprises a vertically extending arm with the movable gripping head 1 mounted at its bottom end, namely in corresponding flanges, which are designated by numeral 2 , and are connected to a side 3 that supports additional components, as described below.

The handling unit and the head are used for orderly introduction of the rows of preforms 10 in a special box, in view of space optimization.

Means 4 , 5 , 8 are provided for moving two independent arms 7 and 9 that form the gripping head 1.

More in detail, said means 4, 5 and 8 include a cylinder 4 at whose ends two racks 5 mesh with corresponding wheels 8 , which are axially mounted to two shafts 15 and connected to the supports 6 for connection with the arms 7 and 9 for gripping and holding the preforms 10.

Due to the cylinder 4 and the shafts 15 being attached to the flange 3, the actuation of the cylinder 4 causes a linear displacement of the rack to set the wheels 8, and hence the supports 6 and the arms 7 and 9 into rotation; this favorable conformation of the positioning device 1 of the invention allows the latter to enter the underlying box with the arms 7 and 9 one

against the other, i.e. pivoted upwards (see Figure 2) , whereas the arms 7 and 9 can be restored to their linear position in the box, to rearrange and properly deposit the row of picked up preforms 10. Particularly referring to Figure 4 , a detail of the preform 10 gripping arm 7 is shown, including a plurality of cavities 20, each with a bellows 21 projecting therefrom: the bellows 21 creates a certain degree of negative pressure (by vacuum) , thanks to means contained in the arms, which are known per se and will not be described herein, whereas the cavity 20 is adapted to stabilize and lock the preform 10 once it has been sucked in by the bellows 21.