U.S. patent application number 10/569553 was filed with the patent office on 2006-11-23 for dosing device for feeding an infusion product.
Invention is credited to Pierluigi Castellari, Dario Rea.
Application Number | 20060260274 10/569553 |
Document ID | / |
Family ID | 34971968 |
Filed Date | 2006-11-23 |
United States Patent
Application |
20060260274 |
Kind Code |
A1 |
Rea; Dario ; et al. |
November 23, 2006 |
Dosing device for feeding an infusion product
Abstract
A dosing device (1) for feeding an infusion product comprises a
rotary drum (2) positioned between a web (3) of filter material and
a hopper (4) for containing the infusion product; the drum (2)
having a plurality of radial cells (5) made in it for containing
the infusion product and in which there slide piston type dosing
means (6); each dosing piston (6) being driven axially by
respective eccentric cam actuating means (7) between two end
positions, one of which corresponds to a top dead centre (PMS)
where each dosing cell (5) faces the hopper (4) in order to receive
a quantity of the infusion product, and the other corresponds to a
bottom dead centre (PMI) where the dosing cell (5) faces the web
(3) of filter material in order to discharge the quantity of
infusion product onto the web (3) of filter material. Between the
actuating means (7) and each piston (6) there are crank mechanisms
(8) designed to act coaxially on the piston (6) in such a way as to
enable the piston (6) to move in a direction that is perfectly
aligned with a longitudinal axis (Z) of the respective dosing cell
(5).
Inventors: |
Rea; Dario; (Monterenzio,
IT) ; Castellari; Pierluigi; (Castel San Pietro
Terme, IT) |
Correspondence
Address: |
ARENT FOX PLLC
1050 CONNECTICUT AVENUE, N.W.
SUITE 400
WASHINGTON
DC
20036
US
|
Family ID: |
34971968 |
Appl. No.: |
10/569553 |
Filed: |
June 30, 2005 |
PCT Filed: |
June 30, 2005 |
PCT NO: |
PCT/IB05/02004 |
371 Date: |
February 27, 2006 |
Current U.S.
Class: |
53/122 ;
53/550 |
Current CPC
Class: |
G01F 11/024 20130101;
B65B 1/385 20130101 |
Class at
Publication: |
053/122 ;
053/550 |
International
Class: |
B65B 9/06 20060101
B65B009/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 21, 2004 |
IT |
BO2004A00450 |
Claims
1. A dosing device (1) for feeding an infusion product comprising a
rotary drum type conveyor means (2) positioned between a web (3) of
filter material and a hopper (4) for containing the infusion
product; the drum type conveyor means (2) having a plurality of
radial cells (5) made in them for containing the infusion product
and in which there slide piston type dosing means (6); each dosing
piston (6) being driven axially by respective eccentric cam
actuating means (7) between two end positions, one of which
corresponds to a top dead centre (PMS) where each dosing cell (5)
faces the hopper (4) in order to receive a quantity of the infusion
product, and the other corresponds to a bottom dead centre (PMI)
where the dosing cell (5) faces the web (3) of filter material in
order to discharge the quantity of infusion product onto the web
(3) of filter material; the device being characterised in that
between the actuating means (7) and each piston (6) there are crank
mechanisms (8) designed to act coaxially on the piston (6) in such
a way as to enable the piston (6) to move in a direction that is
perfectly aligned with a longitudinal axis (z) of the respective
dosing cell (5).
2. The device according to claim 1, characterised in that the
eccentric cam actuating means (7) comprise at least one cam track
(7a) in which there runs a cam follower (7b) for each piston (6)
the crank mechanisms (8) comprising a first crank (10) connected at
one end to the cam follower (7b) and, at the other end, to a
transmission shaft (11); the transmission shaft (11) being rigidly
attached to a first end of a second crank (13) that is in turn
connected at its other end to a first end (14a) of a connecting
control rod (14); the connecting rod (14) being linked to the
piston (6).
3. The device according to claim 2, characterised in that a first
end of the second crank (13) is rigidly attached to the shaft (11)
in such a way as to enable transmission of motion between the cam
follower (7b) and the piston (6).
4. The device according to claim 2 or 3, characterised in that the
end of the second crank (13) that is linked to the connecting rod
(14) is fork-shaped so as to hold the end of the connecting rod
(14) on both sides; the connecting rod (14) being coupled with the
second crank (13) through a first pin (16) that passes through a
respective hole (17) made in said forked end.
5. The device according to claim 4, characterised in that the
connecting rod (14) is linked to the piston (6) by a second,
transversal pin (18) which is housed in a respective hole (19) made
in the piston (6) and which engages the respective end of the
connecting rod (14).
Description
TECHNICAL FIELD
[0001] This invention relates to a dosing device for feeding an
infusion product.
[0002] In particular, this invention can be advantageously used for
measured feeding of an infusion product such as tea, coffee,
camomile or the like to an automatic machine for making infusion
packets, which the present specification expressly refers to but
without restricting the scope of the invention.
BACKGROUND ART
[0003] Usually, an automatic machine for making infusion packets
such as filter bags, sachets, filter-paper pods, etc. comprises a
plurality of stations located one after the other along a
production line forming part of the automatic machine itself, and
including, in particular, a feed station for placing measured
quantities or doses of infusion product on a web of filter material
used to make the packets.
[0004] A station for feeding the infusion product is known from
U.S. Pat. No. 4,870,808, which describes a volumetric dosing unit
of the type comprising a drum which rotates about a horizontal axis
and which is positioned above the web of filter material advancing
in a given direction of feed transversal to said axis of
rotation.
[0005] Above the drum, there is a hopper that feeds the infusion
product into uniformly spaced, open cylindrical cells extending
radially into the drum. Inside each cell, there is a piston that
slides axially in the cylindrical cell itself.
[0006] In the device described in the United States patent, each
drum piston is driven by an eccentric cam mechanism including a cam
inside the drum associated with a cam follower. The cam follower is
positioned on one side of the piston, that is to say, it is offset
with respect to the piston so as to enable the piston to move up
and down in the cylindrical cell.
[0007] In other words, the cam, which is preferably divided into
two separate, arc-shaped parts, drives the piston from a bottom
dead centre (first cam part) approximately corresponding to the
point where the product dose is discharged onto the web of filter
material, to a top dead centre (second cam part) corresponding to
the position where the product is received and dosed.
[0008] The second cam part is adjustable from the outside of the
drum through suitable adjusters enabling the top dead centre of the
piston to be located at a different position so as to vary the
volume of product inside the dosing cells.
[0009] The unit described above has proved effective and accurate
and has made it possible to significantly increase the working
speeds of modern automatic machinery for the packaging of infusion
products.
[0010] Recent tests have shown, however, that if the infusion
product is mixed with additives or herbs, such as powdered sugar or
flavouring substances, the dosing unit has considerable problems
and the pistons frequently get jammed inside the cylindrical dosing
cells. Jamming is mainly the result of the offset arrangement of
the components acting on each piston.
[0011] If the product being dosed has inherent lubricating
properties, any product that escapes past the edges of the piston
does not cause problems for the sliding motion of the piston. On
the other hand, products with additives, sugar or flavourings may,
in time, adhere to the sides of the cell in which the piston
slides, forming a layer that (however thin) increases the friction
between the piston and the cell and leads to jamming.
[0012] Indeed, the constantly increasing friction eventually blocks
the axial movement of the piston, bringing the packaging machine to
a stop and making it necessary to dismantle the drum in order to
clean it or to change it entirely. This means prolonged down times
and the need to have a spare drum in stock at all times, with all
the additional costs that this involves.
[0013] The aim of this invention is to provide a dosing device that
overcomes the disadvantages described above.
[0014] In particular, it is an aim of this invention to provide a
high-performance, high-output infusion product dosing device
offering maximum dosing precision and operating reliability
independently of the type of product to be dosed.
DISCLOSURE OF THE INVENTION
[0015] Accordingly, the present invention provides a dosing device
for feeding an infusion product, comprising conveying means of the
rotary drum type, positioned between a web of filter material and a
hopper for containing the infusion product; the drum type conveyor
means having a plurality of radial cells made in it for containing
the infusion product and in which there slide piston type dosing
means; each dosing piston being driven axially by respective
eccentric cam actuating means between two end positions, one of
which corresponds to a top dead centre where each dosing cell faces
the hopper in order to receive a quantity of the infusion product,
and the other corresponds to a bottom dead centre where the dosing
cell faces the web of filter material in order to discharge the
quantity of infusion product onto the web of filter material; the
dosing device being characterised in that between the actuating
means and each piston there are crank mechanisms designed to act
coaxially on the piston in such a way as to enable the piston to
move in a direction that is perfectly aligned with a longitudinal
axis of the respective dosing cell.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The technical characteristics of the invention, with
reference to the above aims, are clearly described in the claims
below and its advantages are apparent from the detailed description
which follows, with reference to the accompanying drawings which
illustrate a preferred embodiment of the invention provided merely
by way of example without restricting the scope of the inventive
concept, and in which:
[0017] FIG. 1 is a schematic front view, partly in cross section
and with some parts cut away for clarity, of a preferred embodiment
of the dosing device according to the invention;
[0018] FIG. 2 illustrates the dosing device of FIG. 1 in a
schematic front view showing the actuating means of the dosing
device;
[0019] FIG. 3 is a lateral cross section through line III-III of
the dosing device of FIG. 1; and
[0020] FIG. 4 is a top plan view, with some parts in cross-section
and others cut away, of a detail from FIG. 3, showing the crank
mechanism of the dosing device according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE
INVENTIONS
[0021] With reference to FIGS. 1 and 2, the dosing device according
to the invention, labelled 1 in its entirety, is used for feeding
an infusion product (tea, coffee, camomile, etc.) to an automatic
machine (of known type and therefore not illustrated) which is
designed to make packets containing the infusion product and of
which the dosing device forms an integral part.
[0022] The device 1 comprises a first drum 2 that rotates about a
horizontal axis Y in an anticlockwise direction V in FIGS. 1 and 2,
the first drum 2 being positioned between a web 3 of filter paper
advancing tangentially at the bottom of it and an infusion product
feed hopper 4 at the top of it.
[0023] In FIGS. 1 and 2, the web 3 of filter paper is drawn with a
dashed line and is advanced continuously in a horizontal feed
direction A.
[0024] As illustrated in FIGS. 1, 2 and 3, the first drum 2 has, on
its lateral cylindrical surface, a plurality of radial cells 5 for
containing the infusion product and within which respective dosing
pistons 6 slide axially (arrow F), driven by respective actuating
cam means 7 acting on each piston 6.
[0025] More specifically, the cam means 7 move the pistons 6
between two end positions (shown in FIGS. 1 and 2), one of which
corresponds to a top dead centre PMS where the dosing cell 5 faces
the hopper 4, and in particular, a levelling blade 27, in order to
receive a quantity of the infusion product, and the other
corresponds to a bottom dead centre PMI where the dosing cell 5
faces the web 3 of filter material in order to discharge the
quantity of infusion product onto the web 3 of filter material.
[0026] Again with reference to FIGS. 1 and 2, the cam means 7
comprise, for each piston 6, at least one circular cam track 7a in
which a cam follower 7b runs.
[0027] More specifically, the cam track 7a consists of two
separate, substantially semicircular segments 7a, 25 which enable
the pistons 6 to move in the manner described above: the segment 25
(FIGS. 2 and 3) is fixed and enables each piston 6 to discharge the
dose onto the web 3; the segment 7a, on the other hand, is
adjustable by suitable means 26 that protrude from the first drum 2
in order to adjust the distance, within a predetermined range,
between the piston 6 and the outside surface of the first drum 2 so
as to vary the quantity of infusion product that is placed in the
respective dosing cell 5.
[0028] The infusion product dose is then levelled off by the
levelling blade 27 which consists of an arc-shaped plate positioned
on the path of the first drum 2.
[0029] As shown in FIG. 3, between the cam means 7 and each piston
6 there is a crank mechanism 8 designed to act coaxially on the
piston 6 in such a way as to permit the reciprocating motion of the
piston 6 itself along the axis Z of the cell 6, in a direction
always perfectly aligned with the axis z.
[0030] As illustrated in FIGS. 3 and 4, the crank mechanism 8 is
rotatably mounted on a second drum 9, which is associated with the
first drum 2, being mounted inside the first drum 2, and sealed off
from the first drum 2 by interposed sealing means 28, and which
rotates as one with the drum 2 about the aforementioned horizontal
axis Y.
[0031] Looking in more detail, each crank mechanism 8 comprises a
first crank 10 connected at one end to the cam follower 7b and, at
the other end, to a transmission shaft 11 that is rotatably
supported in a respective hole 12 passing through the second drum
9.
[0032] The shaft 11 is rigidly attached at the opposite, free end
which protrudes from the second drum 9, to a first end of a second
crank 13.
[0033] The second crank 13 is in turn connected at its other end to
a first end 14a of a connecting control rod 14 connected along the
axis Z of the cell 5, and, at its other end, to the piston 6: this
creates a mechanism much like a crankshaft and, as shown in FIG. 3,
makes it possible to apply a pushing and pulling action centrally
on the piston 6.
[0034] Looking more closely at the technical details, the first end
of the second crank 13 is rigidly attached to the shaft 11 by a key
15 in such a way that motion between the cam follower 7b and the
piston can be transmitted directly and correctly.
[0035] As clearly illustrated in FIG. 4, the end of the crank 13
that is linked to the connecting rod 14 is fork-shaped so as to
hold the end of the connecting rod 14 on both sides, thus obtaining
a correct axial movement along the respective cell 5.
[0036] The connecting rod 14 is coupled with the second crank 13
through a first pin 16 that passes through a respective hole 17
made in the forked end of the second crank 13 itself.
[0037] At the other end, the connecting rod 14 is linked to the
piston 6 by a second, transversal pin 18 which is housed in a
respective hole 19 made in the piston 6 and which engages the
respective end of the connecting rod 14.
[0038] To enable the motion of the cam follower 7b to be
transmitted correctly to the piston 6, each transmission shaft 11
has two bearings 20 and 21 positioned between the shaft 11 itself
and the hole 12 in the second drum 9 in such a way as to rotate the
entire crank drive mechanism for the piston 6.
[0039] The operation of the dosing device 1 may be easily inferred
from the above description with reference to the accompanying
drawings and will not therefore be described in further detail.
[0040] The dosing device structured as described above therefore
achieves the aforementioned aims thanks to the application of a
crank mechanism which enables each piston to be driven in a precise
axial direction in such a way as to obtain a correct and reliable
movement at all times, irrespective of the type of product being
dosed.
[0041] The application of this crank mechanism does not affect the
overall dimensions of the device since the working parts for
transmitting drive to the pistons remain unchanged.
[0042] The compactness of the crank and connecting rod assembly
also permits an extremely precise and fast up and down driving
action on the pistons, keeping each piston parallel to the
respective dosing cell in which it slides in a direction that is at
all times exactly aligned with the longitudinal axis of the cell
itself, thus preventing the pistons from seizing up during normal
operation.
[0043] The provision of a second drum mounted inside the first drum
and sealed off from the latter isolates the drive mechanisms and
makes it possible to keep them clean. It also slightly increases
the total thickness of the dosing unit and allows the above
mentioned actuating cam means to be positioned in a more convenient
area, with a more compact cam control which, in practice, reduces
the overall dimensions compared to the prior art device, where the
control mechanism protrudes from the first drum and is further away
from the cam.
[0044] The invention described can be modified and adapted in
several ways without thereby departing from the scope of the
inventive concept. Moreover, all the details of the invention may
be substituted by technically equivalent elements.
* * * * *