Note: Descriptions are shown in the official language in which they were submitted.
790
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The invention relates to filters, especially to a novel
coffee filter to be attached to the edge of a cup or sim-
ilar preparation vessel and ~o a blank and a process for
producing a filter of this type.
It is known to put tea and a:Lso ground coffee into pour-on
bags, the filling quantity being intended for one or more
cups~ However, after brewing, pour-on coffee bags either
provide an unsatisfactory drink because the e~tract con-
tent is too low, or have to be stirred vigorously in thecup for a sufficient time to obtain the necessary extract
content. Furthermore, the ground coffee absorbs a con-
siderable quantity of water, with a result that the cup is
no longer full after the bag has been ta~en out.
Starting from this state of the art, the object on which
the present invention is based is to provide a means of
preparing coffee in an amount appropriate for a cup, by
means of which the necessary extract content is obtained
directly after brewing and which is simple in terms of
2Q production and handling. The object of the invention is
also to provide processes for producing such an auxiliary
means, and an associated semi-finished product for this.
This object is achieved in a surprisingly simple way by
means of the characterizing features of Claims 1, 11 and
12 respectively, Claims 2 to 10 and 13 to 16 relating to
advantageous details of the construction according to the
invention or of the process according to the invention.
Thus, the significance of the invention is to be found in
the provision of a cup filter and the production of the
latter by the simplest possible means. At the same time,
the cup filter designed according to the invention is
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characterized by maximum functional capacity and ease of
handling.
According to the invention, the filter bag extends into
the corners of the triangular frame, that is to say com-
pletely fills ~he free cross-section of the triangular
frame, thus ensuring that, when hot water is poured on,
this does not flow past the filter bag into the cup. In
production terms, this can be achieved very simply by
using the blank described in Claim 11, this blank being
characterized in that the filter-paper blank e~tends over
the entire length of the associated cardboard blankO
Accordingly, the filter-paper blank is joined to the top
edge of the triangular frame formed from a cardboard
blank, over the entire original length of the cardboard
blank.
Thus, the design of the cup filter according to Claim 2
and the following claims is especially advantageous as
regards both production and handling. Ease of handling
also arises from, among other things, the measures accord-
ing to Claim 3, according to which the paperboard or card-
board frame which can be unfolded into a triangle is fold-
ed inwards on at least one side to form an M-shape fold.
This makes it possible to fold the filter together flat,
with a result that a minimum transport and stowage space
is required. On the other hand, this folding makes it
possible to match the filter to different edge diameters
of cups or suchlike vessels, whilst at the same time en-
suring high stability. In particular, the M-shaped fold
guarantees that the filter frame cannot slip off directly
sideways over the cup edge. Stability can be further in-
creased as a result of the measures according to Claim 10
according to which the filter frame, on its supporting
edge assigned to the cup or the like, has recesses for
receiving the edge of the cup or the like.
~29~7go
Preferably, the filter bag is closed on all sides at the
factory, at the same time containing a predetermined
quantity of coffee or the like, the filter bag being
opened, before use, along its upper limiting edge.
According to Claim 8, the filter bag can be closed by
means of an adhesive strip or a tab connected to the
frame element.
When a predetermined quantity of coffee has been intro-
duced, the cup filter according to the invention, folded
together ~lat, is enclosed in an air-tight and aroma-
tight manner, preferably vacuum-packaged, in an outer
pouch-like wrapping.
The blank for producing a filter with a paperboard or
cardboard frame is the simplest possible. It is designed
as a rectangular blank of cardboard or the like, along
one longitudinal edge of which a preferably approximately
identical blank of filter paper is fastened, especially
sealed or sewn. It is important that the filter-paper
blank should be of the same length as the cardboard blank.
The width of the filier-paper blank can also be less than
the width of the cardboard blank.
With such a double-ply blank being used, the production
of the filter designed according to the invention is the
simplest possible. Accordingly, the cup filter according
to the invention is suitable for factory production as a
mass-produced article. Attention is-drawn to Claim 12 for
the individual process steps, and advantageous process
details are described in Claim 13 and the following claims.
An exemplary embodiment of a cup filter designed according
to the invention and its production is explained in detail
below with reference to the accompanying drawing. In the
drawing:
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Figures 1 to 6 show a diagrammatic representation of
the individual process steps for producing a
cup filter designed according to the invention;
Figures 7a and 7b show plan views of the cup filter pro-
duced or designed according to the invention,
specifically partially un~olded (Figure 7a) and
completely unfolded (Figure 7b); and
Figure 8 shows a perspective view of the cup filter
according to Figures 7a and 7b attached to a cup.
In order to produce a cup filter of the type yet to be
described in detail, two webs of ~ilter paper 20 and card-
board 21, of essentially the same size, in particular the
same width, are conveyed onto one another, to form a
double-ply web of material 28. A continuous sealing seam
22 is made progressively on one longitudinal edge, for
example, by means of wheel-shaped sealing tools 23.
Accordingly, both the filter paper and the cardboard must
be made of sealable material or be surface-coated with a
sealable material.
~0 The continuous double-web or double-ply structure 28 is
then divided into blanks 24 according to Figure 2, which
correspond to the necessary length for a cup filter. The
two plys of each blank are now unfolded from one another
(the arrow 29 in Figure 2), so that a cardboard blank 25
and filter-paper blank 26 are next to one another, but,
as before, remain joined to one another via the seaIing
seam 22 (Figure 3). In this position, the two blanks are
first folded centrally, and then an M-shaped fold 16
according to Figure ~ is made by means of a continuously
operating folding tool, especially a folding blade (not
shown). Sealing is then carried out on the free end edges
of the cardboard blank 25, which are on the right in Fig-
ure 4, and the corresponding edge sealing seam 13 is made
(Figure 5). Subsequently, but preferably simultaneously,
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the filter-paper blank 24, which projects from the card-
board blank 25 and which is likewise identified on one
side by the above mentioned ~-shaped fold 16, is provided
with a V-shaped, preferably trapezoidal sealing seam 19,
so as to form a filter bag 10. The triangular filter-
paper gussets 17 and 18 (Figure 5) projecting laterally
or at the corners are detached or cut off. The filter bag
thus acquires a generally trapezoidal shape.
Subsequently, the filter bag 10 is brought between the
walls of the cardboard blank 25. For this purpose, com-
pressed air is directed at the filter bag 10 via a blowing
nozzle 27 from below in Figure 5 and from above in Figure
6, so that this compressed air flows inwards between the
walls of the cardboard blank 25. The cardboard blank 25,
in the embodiment described, forms an unfoldable triang-
ular frame for the filter bag which is joined, in parti-
cular sealed, to the cardboard blank along the entire top
edge 12.
As a result of the M-shaped fold 16, the cup filter pro-
duced in the way described can be folded together flat
and, when unfolded, can be matched to different edge di-
ameters of coffee or suchlike cups, so that, after it has
been attached to the cup edge, it cannot slip off directly
from this, that is to say it rests securely on the cup
edge. In Figure 8, the cup filter designed according to
the invention is attached to the edge 11 of a cup 14.
To make it easier to unfold the cup filter described, in
Figure 5 the sealing seam 19 is made, in the region of the
M-shaped fold 16, in such a way that it is present only
between two blank parts resting directly on one another.
Attention is drawn, in this respect, to Figures 7a to 8.
Preferably, the filter bag 10 is filled with a predeter-
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mined quantity of coffee at the factory. After filling,
the cup filter is folded together flat, closed along the
top edge 12, for example by means of an adhesive strip or
a closing tab, and subsequently accommodated in an air-
tight and aroma-tight manner, preferably vacuum-packaged,
in an outer wrapping. For use, this outer wrapping is
torn open and removed, the above-mentioned adhesive tape
pulled off, and the cup filter unfolded and attached to a
cup or to the cup edge 11 of a cup 14. The quantity of
coffee appropriate for a cup can subsequently be brewed
by means of hot water.
In order to increase the stability of the cup filter des-
cribed or of the cardboard blank 25 which can be unfolded
into a triangle on the cup edge 11 of a cup 14, the card-
board frame produced from the blank 25, on its supportingedge 15 assigned to the cup 14, can have recesses 30 for
receiving the cup edge 11 (see Figure 8).
These recesses are made continuously in the web of card-
board material 20, before the individual blanks 24 are
produced, by means of appropriately associated roller or
cylinder stamping tools. In Figure 1, the recesses are
made on the longitudinal edge of the web of cardboard
material 22 located opposite the sealing seam 22, spec-
ifically during the continuous transport of the latter.
All the features disclosed in the documents are claimed
as essential to the invention, in so far as they are new
in relation to the state of the art either individually
or in combination.
