|Title of Invention||
A VOLUMETRIC WEIGHER FOR A PACKING/PACKING MACHINE
|Abstract||(57) Abstract: A volumetric weigher for a packing/packaging machine comprises a bottom plate and a top plate.The bottom plate is fixed and the top plate is pivotally mounted on the said fixed bottom plate.A pneumatic actuator causes a to and fro horizontal swinging or curving motion to the top plate.The moving top plate has an aperture at a predetermined location. Mean are provided for adjusting the volume of the said aperture. The bottom plate is provided with a hole at a predetermined locationon the to and fro path of the said aperture.|
This invention relates to a volumetric weigher for a packing/ packaging machine, in particular, but not exclusively, a ver¬tical Form-Fill-Seal type packaging machine used for packing tea, coffee, etc.
The existing volumetric weigher operates on the principle of volume of cttp to detennine the cpaantity to be packed. Different sizes of cups are required for packing various sizes of packs, viz, Rs 2/«, Rs 1^50/=, Rs 1/"* etc. Very fine adjustments for maintaining the correct pack weight is not possible especially when there are changes in blend formulation. The movable bottom portion of the cup is susceptible to wear and tear and therefore cups have to be replaced frequently. Further, due to the conti¬nuous motion of the feeding drum the tea tends to become brow¬nish which is not an acceptable characteristic. Furthermore, the bearing supporting the feeding drum fails frequently due to continuous rotation* Moreover, the large number of the movable parts in the system catases frequent brakedown due to wear and tear.
An object of the present invention is to avoid, if not, minimise, the abovementioned drawbacks.
Accordingly, the present invention provides a volumetric weigher for a packing/packaging machine, comprising a bottom plate and a top plate, the bottom plate being fixed and the top plate being
pivotally mounted on said fixed bottom plate, a pneiamatic actu¬ator to cause to and fro horizontal swinging or curving motion to said top plate, said moving top plate having an aperture at a predetermined location, means for adjusting the volume of said aperture, and the bottom plate being provided with a hole at a predetermined location on the to and fro path of said aperture.
The volume of the aperture can be adjusted by means of a block sliding within said aperture and a screw means to cause to and fro sliding movement to said block.
The invention will now be apparent from the following nonlimi-tative description with reference to the accompanying drawings, in which :-
Pig. 1 shows a perspective view of the volumetric weigher according to an embodiment of the present invention;
Fig. 2 shows the volume trie weigher with its top plate swung to one direction;
Figs. 3a, 3b & 3c show, respectively, the top« front, and
side views of the volumetric weigher;
Figs. 4a & 4b show the top plate of the volumetric weigher in detail;
Figs. 5a & 5b show the bottom plate of the volumetric weigher in detail;
Fig. 6 shows means for adjusting the volume of the top plate aperture; and
Fig. 7 shows the volumetric weigher fitted on a Form-Fill-Seal type packing machine.
The volumetric weigher, as can be seen from the drawings, has two plates one mounted over the other. The bottom plate 1 is fixed to a stand 2. The upper plate 3 is rotatably mounted on a pivot 4 attached to the bottom plate. A pneumatic cylinder 5 is fixed to the bottom plate 1, and its moving rod is fixed to the top plate 3. The pneumatic cylinder when actuated cavtses the top plate to move to and fro almost in a semi-circular path. As the top plate is mounted on the pivot through a bearing 6, a free movement of the plate is achieved.
The top plate 3 has an aperture 7 which acts as a cup for measu¬ring the material, for example tea, to be packed, rhe volume of the aperture 7 can be adjusted by means of a screw 8. As the screw is turned clockwise ia, silding block 9 provided within the aperture moves forward and reduces the aperture volume and vice versa. Thus the volume of the aperture can be adjusted or pre¬set to any desired value. The volume of the aperture can be
directly read from the gauge 10 (see Fig. 6) .
The bottom plate 1 has a hole 11. The location of the hole is such that at a particular position of the top plate its opening (aperture) coincides or comes face to face with the hole 11.
In our co-pending Indian Patent Application No. 441/Mas/94, we have described and claimed an improved PJ?.S type packing ma¬chine, and Pig, 7 of the instant application shows such a
packing machine fitted with the volumetric weigher according
for to the present invention. Therefore,/a proper and clear under¬standing of the present invention, a reference to said copending application is recommended.
As can be seen from Fig, 7, the volumetric weigher 12 according to the Invention is mounted below hopper 13 containing the blended tea to be packed. The discharge end of the hopper is in sliding contact with the top plate of the weigher. Below hole 11 of the bottom plate of the weigher there is mounted chute 14 which leads:the tea to fall into the packet being formed in the F,F,S. machine.
In operation, when .the_4me^ tpp.
plate 3 of the weigher moves from its initial position, i,e,, the position at which the openings 7 & 11 of the top and bottom plates are in face to face, to the position when the opening 7 ±3 Just below the discharge end of the hopper 13, At this posi-
tion the tea from hopper 13 falls down and fills the aperture 7
which has been pre-set to the required volume using screw 8.
The bottom mouth of the aperture 7 is in sliding contact with
the bottom plate so that tea collected in aperture 7 remains
intact and does not fall down. Simultaneously, an empty packet
with its vertical portion and the bottom horizontal portion
Only sealed is forroed in the F.F.S. machine./the top horizontal
portion of the packet is open. At this time, pneumatic cylinder
5 gets reactuated thereby causing top plate 3 to move back to
its initial position. Now that the apertuire 7 is in ccmuminication
with hole 11 of the bottom plate, the measured quantity of tea
collected in aperture 7 falls down into the packet throgh hole
11 and chute 14, Now the top horizontal portion of the filled
packet gets sealed to form a fully sealed filled packet. The
operation is repeated in a cyclic manner.
A few advantages of the present volumetric weigher are:-
1. It can be used for weighing any quantity (say, from 25 grams to 1 kg) without using any add-ons like cups.
2. There are no motors and gear boxes unlike the existing volume-trie weigher.
3. Fine adjustments aire possible easily by using the screw provided.
4. Less moving parts and, therefore, less maintenance.
1, A volumetric weigher for a packing/packaging machine, com¬
prising a bottom plate and a top plate, the bottom plate
being fixed and the top plate being pivotally mounted on
said fixed-bottom plate, a pneumatic actuator to cause to-
and-fro horizontal swinging or curving motion to said top
plate, said moving top plate having an aperture at a pre-
aetertnined location, means for adjusting the volume of
said aperture, and the bottom plate being provided with
a hole at a predetermined location on the to and fro path of said aperture.
2. A volumetric weigher as claimed in claim 1, wheirein the
bottom opening of said aperture is in sliding contact with
the bottom plate.
3* A volumetric weigher as claimed in claim 1 or 2, wherein said actuator is a pneumatic cylinder.
4. A volumetric weigher as claimed in any o£ the preceding claims 1 to 3, wherein in one position oil the to-and-fro moving path of said top plat3 its aperture is open to the hole of the bottom ptlate and as it moves to the other direction said aperture gets cut-off from said hole and opens to the feeding end of the material to be packed.
5. A volumetric weigher as claimed in any of the preceding
clalroa 1 to 4, wherein said volume adjusting means comprises a block sliding within said aperture and a screw means to cause to and £ro sliding movement to said block.
6. A volumetric weigher for a packing/packaglng machine, sub¬stantially as herein described and Illustrated with refe-rence to the accompanying drawings •
|Indian Patent Application Number||1509/MAS/1995|
|PG Journal Number||35/2005|
|Date of Filing||22-Nov-1995|
|Name of Patentee||M/S. TATA TEA LIMITED|
|Applicant Address||SOUTH INDIAN PLANTATION DIVISION, POST BOX NO.9, MUNNAR 685612,|
|PCT International Classification Number||G0115/02|
|PCT International Application Number||N/A|
|PCT International Filing date|