A mechanism for advancing package blanks

Abstract: The invention relates to a mechanism for advancing flat-laid package blanks (10) disposed in a magazine (14). A shaft (1) extending through the mechanism at right angles to the magazine (14) is journalled by means of a free-wheel hub (5) so that it may rotate in only one direction. The shaft (1) is urged against at least one endless elastic belt (9) which interconnects two or more wheels (11). In its turn, the belt (9) presses against the flat-laid package, blanks (10). The free-wheel hub (5) is surrounded by a lever (6), reciprocally pivotal and connected to a drive unit (8). When the lever (6) is pivoted in the one direction, the movement is transferred via the shaft (1) to the belt (9) and the package blanks (10) are fed forwardly in the magazine (14). When the lever (6) is pivoted in the other direction, the free-wheel hub (5) locks and no movement is transmitted to the belt (9) which might counteract the forward advancement of the package blanks (10) in the magazine (14).

Description: The invention relates to an apparatus for advancing flat-laid package blanks in a magazine according to the first part of claim 1. An apparatus of this type is described in EP-A-0 339 178. The endless belt is a support on which the quantity of package blanks is packed so that this quantity is advanced when said endless belt is advancing, too. Single-use disposable packages for liquid contents are often manufactured today from a laminate with a core of paper or board and different layers of plastic. Some of these disposable packages start from package blanks, i.e. the packaging material piece which is required for making a package, sealed on one longitudinal side so that the package blank constitutes a square tube. The package blanks are supplied to the packaging (or filling) machines flat-laid and stacked in bundles. The flat-laid package blanks are thereafter loaded into a magazine connected to a packaging machine. From the magazine, the package blanks, still flat-laid, are fed into the packaging machine, are righted to square tubes, an end wall is sealed on, the packages are filled and the final package is sealed at its other end wall. The infeed of the flat-laid package blanks can constitute a problem, since the package blanks can become bent in the event of unsuitable storage. Careless loading on the part of the machine operator can also cause problems on infeed of the package blanks. Other prior art infeed devices have consisted of fingers which advance the package blanks. However, the problems involved were that the movements of the fingers were relatively short in stroke and, when package blanks have been bent, this movement has not proved sufficient to advance a new package blank. These fingers also described a reciprocating return movement after each advancement, and then there is the risk that the package blanks are retracted a slight distance. An object of the present invention is to avoid the draw backs mentioned above that means to realize an even and reliable infeed of the package blanks independent of the quality of the blank and how they are loaded. The invention is characterized in claim 1. Preferred embodiments are claimed in sub-claims. According to the present invention the belt is an elastic one and it urges against the upper edges of the quantity of the blanks thereby providing friction against them from above. The elasticity of the belts is depending on the material thereof. Rubber material is a preferred one. The invention allows to compensate variations heights of the package blanks thereby solving the problem mentioned above. The shaft driving said endless elastic belt is journalled so as to rotate in one direction only. Said shaft cooperates with a lever being reciprocally pivotal and connected to the drive unit and is urged against said endless belt. DESCRIPTION OF ONE EMBODIMENT One preferred embodiment of the present invention will now be described in greater detail hereinbelow, with particular reference to the accompanying Drawings, in which: Fig. 1 is a perspective view of the mechanism according to the present invention; and Fig. 2 is a side elevation of the mechanism of Fig. 1, partly in section. The Drawings show only those details essential to an understanding of the present invention. The infeed mechanism includes a shaft 1 extending through the greater part of the mechanism. The shaft 1 is oriented at right angles to a magazine 14 holding flat-laid package blanks 10. At both ends 2 and 4, the shaft 1 is journalled with a conventional bearing such as a ball bearing or sliding bearing 3. At one end 4, the shaft 1 is moreover journalled so that it may rotate in only one direction, with a so-called free-wheel hub 5 or reverse stop. The free-wheel hub 5 is surrounded by a lever 6. This lever 6 is, in its turn, interconnected with a piston rod 7. The piston rod 7 is displaceable with a reciprocating movement and is connected to a drive unit, preferably a pneumatic piston and cylinder assembly 8. The drive unit may also consist of a hydraulic piston and cylinder assembly. In the preferred embodiment, the lever 6 receives its movement via a piston rod 7, but other solutions are also conceivable here, such as a cam. The shaft 1 extending through the mechanism is urged against at least one elastic belt 9 oriented in the longitudinal direction of the magazine 14. In Fig. 1, four such belts 9 are shown, but this number may of course be varied, depending upon the length of the package blanks 10 which are to be fed through the mechanism. The belt or belts 9 each interconnect at least two wheels 11 anchored in a bracket 12 for each belt 9. By employing two wheels 11, a suitable pressure point 13 for the shaft 1 will be created between the wheels 11. In turn, the belts 9 are urged against the upper edge of the package blanks 10. Naturally, a larger number of wheels 11 may be employed, but practical trials have demonstrated that, by employing two wheels 11, a reliable and even infeed of the package blanks 10 will be obtained. The elasticity of the belts 9 compensates for variations in height of the package blanks 10. At the same time, the material (for example an elastic rubber material) provides friction against the package blanks 10, which contributes to a reliable infeed or advancement of the package blanks 10. The operation of the mechanism according to the present invention is described substantially with reference to Fig. 2 in which directional arrows have been drawn. When the pneumatic piston and cylinder assembly 8 causes the piston rod 7 to execute its positive movement (+), this movement is transferred via the lever 6 to the shaft 1. In such instance, the free-wheel hub 5 locks and the linear movement of the piston rod 7 is converted into a circular shaft movement. The shaft 1 presses on a point 13 on the endless elastic belt 9 and the circular shaft movement is then transferred to the belt 9 with its wheel 11, which thereupon feeds the package blank 10 forwardly. The belts 9 which are oriented in the longitudinal direction of the magazine 14 are urged against the upper edge of the package blanks 10. The movement from the shaft 1 is transferred via the belts 9 and the wheels 11 to the package blanks 10 and they move forwardly in the longitudinal direction of the magazine 14. In such instance, a package blank 10 reaches the gap 15. At this point, the package blank 10 is entrapped, moved up through the gap 15 for further processing in the filling machine by righting of the package blank, bottom sealing, filling and final sealing to form a finished package. When the piston rod 7 executes its negative movement (-), the free-wheel hub 5 will act as a standard ball bearing in respect of the lever 6. Thus, no movement will be transferred from the negative movement of the piston rod 7 to the shaft 1. Hence, the negative movement of the piston rod 7 does not give rise to any reciprocal or return movement which affects the package blanks 10. By making those holes in which the wheels 11 are secured in their brackets 12 slightly oval, it is possible to impart to the wheels 11 a slight springing action, which may be of advantage if the package blanks 10 are loaded into the magazine so that their upper edge is not even. As will have been apparent from the above description, the present invention will realize an infeed mechanism for flat-laid package blanks which functions irrespective of the quality and method of loading of the package blanks. The infeed mechanism gives an even and reliable forward movement without any disruptive return strokes. The present invention should not be considered as restricted to that described above and shown on the Drawings, many modifications being conceivable without departing from the scope of the appended Claims.

Claims: Apparatus for advancing flat-laid package blanks (10) in a magazine (14) holding a quantity of said blanks (10) substantially upright wherein at least one endless belt running over at least two wheels (11) and being driven by a rotatable shaft (1) advances said blanks (10) in the longitudinal direction of said magazine (14) and wherein a drive unit (8) drives said shaft (1) in one direction of rotation, characterized in that an elastic belt (9) is used as said endless belt and that a belt section extending between at least two of said wheels (11) urges against the upper edges of said quantity of blanks (10), providing friction against them, that said shaft (1) driving said endless elastic belt (9) is journalled so as to rotate in one direction only and co-operates with a lever (6) being reciprocally pivotal and connected to said drive unit (8) and that said shaft (1) is urged against said endless belt (9). Apparatus as claimed in claim 1, characterized in that said lever (6) receives its movement via a piston rod (7). Apparatus as claimed in claim 1 or claim 2, characterized in that said drive unit (8) consists of a pneumatic piston and cylinder assembly. Apparatus as claimed in claim 1, characterized in that said lever (6) receives its movement via a cam. Apparatus as claimed in one of the preceding claims, characterized in that said shaft (1) is urged against the belt (9) at a point (13) between said two wheels (11). Apparatus as claimed in one of the preceding claims, characterized in that a plurality of belts (9) is disposed in spaced apart relationship from one another in the direction of said shaft (1). Apparatus as claimed in one of the preceding claims, characterized in that anchorage holes of said wheels (1) are oval. Apparatus as claimed in one of the preceding claims, characterized in that said shaft (1) is locked in its one direction of rotation by means of a free-wheel hub (5).

Inventors: JANSON MAGNUS, OLANDER JONNY, JANSON, MAGNUS, OLANDER, JONNY
Applicants: TETRA LAVAL HOLDINGS & FINANCE, TETRA LAVAL HOLDINGS & FINANCE SA
Application year: 1992
Main classification: B65B43
IPC codes: B65B43, B65B41, B65H1, B65H3