The present invention relates to the technical sector of automatic machinery for filling containers with liquid products.
A variety of automatic machines are known which fill liquids into containers such as bottles or vials. These machines usually have carousels or starwheels which rotate about a vertical axis and which are designed to receive the bottles to be filled in orderly fashion from a feed line. The carousel mounts means for dispensing the liquid product which work synchronously with means which match each bottle with the nozzle of the corresponding dispensing unit. The filled bottles are then transferred to an outfeed line. Such a machine is known from US-A-4 108 221, which discloses a device in accordance with the preamble of claim 1.
The liquid dispensing units usually consist of a plurality of cylinder and plunger assemblies connected through valves to a feed tube and to a dispensing nozzle alternately.
In the aforesaid machines the liquid dispensing units and the means which move the bottles relative to the filling nozzles must operate in perfect synchrony.
In traditional machines drive is achieved through complicated mechanisms which hinder machine efficiency, In particular, the known machines require separate means to effect each individual movement, thus encumbering the carousel and making it difficult to carry out the necessary maintenance operations.
The aim of the present invention is to provide a device capable of simultaneously driving the cylinder and plunger assemblies and the mechanisms which move the bottles relative to the liquid dispensing units in automatic machines for filling liquid products into said bottles.
Another aim of the invention is to provide a drive device made according to a simple, reliable and efficient technique that can be applied to a wide range of bottle sizes.
The said aims are achieved in accordance with the invention by the characterizing features of claim 1.
The characteristics of the invention are highlighted in the following detailed description, with reference to the accompanying drawings, where:
With reference to the drawings just listed, the machine for filling bottles 1 with a liquid product has means 2 for feeding the said bottles to a carousel 3 which rotates about a vertical axis in the direction indicated by arrow A.
Feed means 2 consist of a bottle 1 conveying line 4 along which there is an auger 5 which rotates axially in such a manner as to space the conveyed bottles 1 apart. Auger 5 is designed to operate in conjunction with a distributor 6, shaped like a star, for example, which rotates in the direction of arrow B. The bottles to be fed are held and guided by recesses 6a in distributor 6 and by ring guide 7 which partially surrounds the distributor itself.
Carousel 3 receives bottles 1 fed by distributor 6 one by one at the point where the equally spaced grippers 8, mounted on the circumference of the carousel itself, are activated. Carousel 3 also mounts dispensing units, labelled 9 in the drawings, which fill the liquid product into bottles 1.
Downstream of carousel 3 there is a full bottle outfeed system 10 consisting of a conveyor line 11 and another distributor 12, shaped like a star, for example, which rotates in the direction of arrow C. The outgoing bottles are received by distributor 12 at the point where they are released by grippers 8 and are held and guided by recesses 12a in the distributor and by a ring guide 13 which partially surrounds the distributor.
Dispensing units 9 consist of a plurality of cylinder and plunger assemblies mounted by carousel 3 which lines them up with grippers 8. Each of the said cylinder and plunger assemblies 14 is connected through a valve 15 to a liquid feed chamber 16 and to a filling nozzle 17 alternately. Chamber 16 is mounted on a platform 18 attached to the rotating part of carousel 3.
Platform 18 is secured to the top of a vertical shaft 19, rotated continuously by the drive motor of the machine through transmission means 20 located at the bottom of the said shaft where the lower face 21 of the carousel frame is situated. Shaft 19 is set inside a tubular casing 22 which rotates with it. At the top, casing 22 is covered by a cylindrical sleeve 18a formed under platform 18.
Between shaft 19 and casing 22 and coaxial to them there is a tubular element 24, with appropriate rotational means, about which shaft 19 and casing 22 rotate. The bottom end of tubular element 24 is attached to a plate 25 supported by columns 26 which pass through plate 21 and are fixed to plate 27.
Grippers 8 and cylinder and plunger assemblies 14 are driven synchronously by drive means 28 which form a set of vertical columns arranged around the circumference of carousel 3. Each of the said drive means consists of a first sleeve 29 the top of which mounts casing 30 of grippers 8 and which is axially crossed by a stem 31.
The first sleeve 29 is in turn located inside a second sleeve 32 at the top of which there is a crosswise fitting 32a attached to stem 33a of plunger 33 of cylinder and plunger assembly 14. Second sleeve 32 is guided by a bushing 34 mounted on the circumference of a plate 35 attached to tubular casing 22.
First sleeve 29, on the other hand, mounts on its bottom end a roller 36 which rotates about a radial axis in relation to the carousel, the said roller engaging a cam 37 made on a cylindrical wall 38 mounted on lower plate 21 and concentric with the axis of the carousel.
The bottom end of stem 31 mounts a lever with a roller 40 that rotates about a vertical axis. Roller 40 engages a ring cam 41 formed on lower plate 21, as shown in Fig.3.
As shown by enlarged details P and R in the said Fig. 3, grippers 8 consist of a pair of jaws 8a and 8b which rotate on casing 30 by means of pins 42a and 42b respectively. Jaws 8a and 8b are attached to toothed gears 43a and 43b which mesh with each other. Pin 42a has inserted in it a fork 44 which engages a pin 45 vertically attached to stem 31. The rotation of stem 31 through a defined angle, by action of cam 41, thus determines the rotation of the gear pair formed by toothed gears 43a and 43b in such a way as to cause jaws 8a and 8b to move symmetrically from the gripping position P to the release position R and vice versa.
The bottom end of the aforesaid second sleeve 32 mounts a roller 46 which rotates diametrically in relation to the carousel. Roller 46 runs in a groove 47 defined by a ring 48 around tubular casing 22. One side of ring 48 is hinged at the bottom to a pivot 49 whose axis is horizontally tangent to a circle concentric with the axis of the carousel. Pivot 49 is mounted on a support 50 fixed to a ring shaped disc supported horizontally by columns 52 standing on lower plate 21. On the side diametrically opposite pivot 49, ring 48 is pivotally attached to stem 53a of an actuator 53. The said actuator is supported in vertical position by disc 51.
The operation of the device claimed will now be described starting from the moment when grippers 8 and related cylinder and plunger assemblies 14, rotated by carousel 3, move to the area where the aforesaid bottles, fed by distributor 6, are picked up.
The closing of jaws 8a and 8b to gripping position P is effected by cam 41, which at the said pickup area, causes stem 31 to rotate axially (refer to Fig. 3). Stem 31 is carried in direction A by carousel 3, so that roller 40 slides in cam 41. The rotation of stem 31 through a defined angle is transmitted to gear pair 43a and 43b and hence to jaws 8a and 8b.
After being gripped by jaws 8a and 8b, bottle 1 is lifted vertically, as shown by arrow D in Fig.6a, in such a way that nozzle 17 of dispensing unit 9 is inserted into the mouth of bottle 1. The raising of the bottle is achieved by the axial sliding of the first sleeve 29, attached to casing 30 of grippers 8. The said sliding motion is controlled by cam 37 in which roller 36 carried by sleeve 29 runs.
When nozzle 17 has been inserted into bottle 1, cylinder and plunger assembly 14 starts discharging its fill of liquid. While nozzle 17 was being inserted into bottle 1, plunger 33 of cylinder and plunger assembly 14 was driven downwards, as shown by arrow E, Fig. 2a, in such a manner as to suck liquid product out of chamber 16; then, once nozzle 17 has been inserted into the bottle, the plunger is driven upwards again so as to allow the liquid product to flow into nozzle 17. At the same time, valve 15 closes the liquid suction duct and opens the liquid delivery duct.
The reciprocating motion of plunger 33 of cylinder and plunger assembly 14 is achieved by the axial sliding of second sleeve 32, attached to stem 33a of the plunger. This sliding motion is effected by roller 46, mounted by sleeve 32, which runs in the circumferential groove of ring 48.
The stroke of plunger 33 may be adjusted by varying the angle of ring 48, usually set in an oblique plane in relation to carousel 3. To adjust the stroke, the ring may be shifted using actuator 53, to the side opposite its pivot 49, as shown schematically by dashed line 54 in Fig.2b. Adjusting the stroke of the plunger makes it possible to vary the amount of liquid to be filled into the bottles.
When the bottle is full, bottle 1 is lowered again in such a way that nozzle 17 is disengaged. At this stage, cam 41 is synchronized to open jaws 8a and 8b at release position R in such a way that distributor 12 of outfeed system 10 can engage the bottle and move it away.
In short, the device described constitutes a means for synchronously driving cylinder and plunger assembly 14, opening and closing bottle gripper 8, and moving said gripper 8 upwards in such a manner as to insert nozzle 17 of dispensing unit 9 into the bottle.
It should be stressed in particular that the above movements are obtained with a device that forms a sort of upright column arranged around carousel 3. The device therefore occupies very little space and allows easy access to the internal parts of the carousel. Furthermore, since the structure of the device is very simple, the machine to which it is applied has added efficiency and reliability.