The present invention relates to a method and to a machine for inserting a plurality of components which are to be assembled to form a toy in a generally egg-shaped case formed by two half-shells.
In the confectionery industry small, hollow chocolate eggs containing gifts enclosed in generally egg-shaped cases which take up almost the entire space in the cavity of the egg are very widespread. The gifts are often constituted by toys which can be assembled from a certain number of components (normally up to eight different components).
In order to produce better quality gifts, it is desirable to make the components as large as possible to make maximum use of the space in the case. However, this considerably complicates the packaging of the gifts, that is, the operation of inserting the various components in the generally egg-shaped case. Whereas with smaller gifts composed of a smaller number of components it was possible to produce automatic machines which inserted the unitary gifts or the various components inside the case, with larger toy gifts constituted by larger numbers of components, a machine which can automatically package the gifts is not yet available and the packaging has to be done manually with considerable labour costs.
The object of the present invention is to provide a method and a machine which can insert the components in their cases automatically even when the components together take up a considerable portion of the space available in the case.
According to the invention, this object is achieved by a method and a machine having the characteristics which form the subjects of Claims 1 and 2.
The present invention is based on the concept of transforming the gift constituted by several distinct components into a single unit by binding the various components with a sheet of heat-shrinkable material which is first welded so as to wrap the various components and is then heated, packing the components close together (as an example see GB-A-934 389). The group of bound components can thus be treated as an independent body the insertion of which in one of the half-shells of the case is greatly simplified in comparison with the insertion of several loose components.
Further characteristics and advantages of the present invention will become clear in the course of the following detailed description given purely by way of non-limiting example, with reference to the appended drawings, in which:
With reference initially to Figures 7-11, the method of binding several components which are intended to form a generic toy and packing them close together will now be described.
A sheet 1 of heat-shrinkable plastics material (for example PVC) is cut to the desired length and constitutes a substrate on which the components 2a, 2b, 2c, etc., are placed in a predetermined sequence. The sequence in which the components are deposited on the sheet 1 and their relative positions are determined in dependence on the shapes and sizes of the components and remain the same for all toys of the same type.
When the components 2 have been deposited on the sheet 1, the opposite ends of the sheet 1 are raised (as shown in Figure 9). After this, the ends of the sheet 1 are placed close together and welded together (as shown in Figure 10) so as to wrap the components. Upon completion of the welding, the various components are held quite firmly but the group of components is not yet compact enough to be treated as a unitary body. Upon completion of the welding, a step for heating the group is consequently carried out (Figure 11) to shrink the sheet of heat-shrinkable material 1 to a predetermined extent. The various components are thus packed close together and reach and maintain a stable overall shape which approximates as closely as possible to the shape of a generally egg-shaped case which is intended to house them.
The group of components bound by the sheet 1 of heat-shrinkable material is then inserted between the two half-shells 4, 6 constituting the case.
An automatic machine for putting the method just described into practice will now be described with reference to Figures 1-6.
With reference initially to Figures 1 and 2, the machine, generally indicated 10, comprises a plurality of parallel belt conveyors 12a, 12b, ... 12f, each of which supplies components of a particular type 2a, 2b, ... 2f in the direction indicated by the arrows 14 in Figure 2.
Along a line for packaging the components 2a-2f, indicated 15 in Figure 2, can be distinguished a station 16 for the supply of a sheet of heat-shrinkable material, a plurality of stations 18a, 18b, ... 18f which load the components 2a-2f onto the sheet 1 of heat-shrinkable material, a welding station 20 and a heating station 22. At the end of the line 15 is a device 24 which picks up the group of components bound together by the sheet 1 of heat-shrinkable material and inserts it in the half-shells of the case which are supplied by a conveyor 25.
A plurality of transfer members 26 is movable in steps along the line 15 in the direction indicated by the arrows 28 in Figure 2. The transfer members 26 are spaced uniformly along the line 15 and, if the distance between two adjacent stations is not equal to the distance between two adjacent transfer members (as is the case for the distances between the loading stations 18a-18f), it is equal to an integer multiple of the spacing of the transfer members 26.
With reference to Figure 3, the machine 10 comprises a straight guide 30 along which a motor-driven chain 32, to which the transfer members 26 are fixed, is movable. Each transfer member 26 has an upper horizontal surface 34 in which a seat 36 opens for receiving the components 2a-2f. The profile of the seat 36 is of a shape corresponding to that produced by a section taken in a plane extending through the larger axis of symmetry of the case in which the components 2a-2f are to be inserted. The base of the seat 36 is formed by a piston 38 which is movable relative to the transfer member 26 in the directions indicated by the double arrow 40. The movement of the piston 38 relative to the transfer member 26 is brought about by the reaction of a projecting element 42 thereof on a fixed profile 44 extending parallel to the direction of movement of the transfer members 26.
The piston 38 of each transfer member 26 has a suction hole which puts the seat 36 into communication with a pipe 46 connected to a vacuum source by means of a rotary distributor (not shown). Each transfer member 26 also has a series of grooves 48 disposed transverse the direction of movement of the member 26 and communicating with the seat 36.
As already stated above, the transfer members 26 which are moved by means of the motor-driven chain 32, advance in steps and remain stationary at each station for the time necessary for the execution of the operative steps described in detail below.
If a transfer member 26 is followed in its movement along the line 15, it first comes to the station 16 for the supply of a sheet of heat-shrinkable material (Figure 2). In the station 16 there is a reel 50 on which a strip of heat-shrinkable material is wound. When the transfer member 26 stops in the station 16, the end of the strip is placed on the surface 34 of the transfer member 26 by a conventional linear actuator (not shown).
The strip is then cut along the line indicated 52 in Figure 2. The sheet 1 which remains on the transfer member 26 is restrained by the vacuum inside the cavity 36. In fact, as explained with reference to Figure 3, the transfer members 26 are constantly connected to a vacuum source by means of respective flexible pipes 46 and by means of a rotary distributor which prevents the pipes 46 from becoming twisted during the movement of the transfer members 26 along the closed loop of the chain 32.
Still with reference to Figure 2, after receiving the sheet 1 of heat-shrinkable material, the transfer member 26 is brought to the loading stations 18a-18f. In each of these stations there is a pneumatic actuator 54a-54f carrying, at its end, suction cup means 56a-56f which are movable between a position for picking up a component 2a-2f and a position for depositing the component on the sheet 1 in the seat 36 of the transfer member 26. The positions and the sequence in which the components are deposited are established in a manner such as to reduce the size of the group of components to a minimum. It is important to note that the loading stations 18a-18f can achieve a high degree of repeatability in the composition of the pack of components, ensuring that the final dimensions of the finished pack of components fall within quite tight tolerance margins.
With reference now to Figure 4, upon completion of the loading of the components, the transfer member 26 is brought to the welding station 20. In this station there are two positioning members 58 for clamping together the ends of the sheet 1 which project from the seat 36 perpendicular to the upper surface 34 of the transfer member. The positioning members 58 are movable towards one another transverse the direction of movement of the transfer member 26 and have prongs 60 which are inserted in the grooves 48 of the transfer member 26. After the ends of the sheet 1 of heat-shrinkable material have been placed close together, a pair of heating elements 62 comes into action clamping together and welding the close-together edges of the sheet 1.
With reference now to Figure 5, upon completion of the welding, the transfer member 26 is brought to the heating station 22 and is placed adjacent a supply spout 64 which sends a jet of hot air at about 300°C onto the group of components wrapped in the sheet 1 of heat-shrinkable material. The supply spout 64 is shaped so as partially to surround the group of components to improve heat-exchange efficiency. The temperature of the hot-air jet is quite high since the time for which the transfer member 26 remains in the heating station is very short (no more than a few seconds) and it is necessary for sufficient heat to be transferred to the sheet 1 of heat-shrinkable material to shrink the sheet so as to pack the components close together within this limited time.
Finally, with reference to Figure 6, after the heating station, the transfer member 26 reaches the end of the line where the group of components enclosed by the sheet of heat-shrinkable material is urged out of the seat 36 by the piston 38. The group of components can thus be picked up by the gripping device 24 which has a movable pincer 70 for gripping the group of components and inserting it in a half-shell which is supplied by a conveyor 25 (Figure 2) synchronized with the line for preparing the pack of components.
It will be appreciated that the machine according to the invention prevents all the problems of hygiene connected with manual handling of the components, which is of particular value in view of the fact that the components are then inserted in a food product intended for children.