The invention relates to a device for applying a self-adhesive
material strip to a substrate, which self-adhesive material strip has
on one side an adhesive layer protected by means of a peel-off
protective tape, comprising a guide track along which the material
strip is movable from a feed point, for feeding the material strip
with protective tape to a discharge point for the material strip with
exposed adhesive layer, and peel-off means for peeling off the
protective tape, which peel-off means are carried out for gripping and
driving the protective tape in the direction away from the material
strip.
Such device is known from DE-A-3336926. This known device has a
pressure roller at its discharge point, by means of which pressure
roller the material strip can be pressed firmly onto the substrate and
by means of which said strip can be applied progressively.
A driving belt has been provided around the pressure roller,
which driving belt engages a set of feed rollers which are near the
feed point of the device. As soon as the pressure rollers are set in
motion, the feed rollers feed the material strip, with protected tape
sticking thereto while the material strip is virtually free of pulling
stresses; in this process, the protective tape is removed.
This known device has several disadvantages. First of all, the
discharge point is rather sizeable due to the pressure roller at this
point, which means that e.g. the corner regions of a window frame
cannot be reached fully. Moreover, the mechanism is vulnerable and
less reliable, having regard to the rather large number of rollers and
the belt drive.
The object of the invention is therefore to provide a device by
means of which a material strip such as a self-adhesive draught
excluder strip can be applied more effectively and more efficiently.
To that end, the invention relates to a device the peel-off means of
which are situated remotely from the discharge point, and are drivable
by means of the pulling force generated in the material strip upon
progressively applying of said material strip on the substrate.
In the device according to the invention, the discharge point can
be made narrow and tapered, which means that almost any location,
including corners, can be reached. The peeling-off mechanism, which is
driven by the pulling stress in the moving material strip with
protective tape, can be situated at sufficiently large distance from
said end, e.g. at the region of the gripping part.
It is preferable in this case to hold the device in the hand and
keep it pressed down lightly at the position of the discharge point on
the object to be treated. During the movement of the device along the
desired track over said object, the material strip moves into its
intended position, and the protective tape is peeled off
automatically.
According to a variant of the method of application, the device
according to the invention can, however, also be set up in a
stationary position, in which case the object then has to be moved
along the device set up in this way.
According to an advantageous embodiment, the device comprises at
least two rotating elements, one of which is in contact with the
material strip, between which elements the protective tape can be
accommodated in such a way that when the rotating elements are driven
the protective tape is moved off the material strip as a result of the
movement of the material strip.
Said rotating elements can be designed in various ways. One
possibility is two rotating endless belts such as toothed belts, the
teeth of which mesh with each other, which are kept lightly pressed
against each other, and between which the protective tape can be
accommodated. However, it is preferable to use a device in which the
rotating elements are rollers with a toothed periphery, and the teeth
of the rollers mesh with each other in such a way that the protective
tape can be gripped in the meshing region of the two rollers.
The protective tape can be gripped reliably by the meshing teeth,
so that slipping is virtually ruled out. The teeth also produce a
zigzag track for the protective tape, as a result of which the latter
is stretched. The protective tape is consequently pulled off the
material strip at slightly greater speed and under constant initial
tension, with the result that the protective tape is prevented from
lagging and ultimately hanging slack.
According to a preferred embodiment, three toothed rollers are
provided, two of which rollers can be driven in the same direction of
rotation by the material strip, and the third toothed roller of which
is in mesh with the other two toothed rollers, in such a way that the
protective tape can be gripped in the two meshing regions.
In the case of this embodiment, the protective tape is gripped in
two places, namely at the position of the two meshings between the
toothed rollers. The protective tape in this case is also conveyed
along two zigzag routes, and is stretched twice, with the result that
a very reliable peel-off effect is achieved.
In order to obtain a good grip between the material strip and the
protective tape, a supporting roller is situated on the side of the
other two rollers which faces away from the third toothed roller, in
such a way that the material strip with protective tape can be held
gripped between a toothed roller and a supporting roller in each case.
A fixed guide is also possible.
In addition, a diversion roller can be situated past the toothed
rollers in the direction of movement of the material strip, along
which diversion roller the material strip can be guided and around
which the protective tape can be peeled off and guided in the
direction of the toothed rollers.
The rollers can be accommodated in a housing with a U-shaped
cross-section, which rollers are rotatable about shafts suspended in
at least one of the parallel walls of the housing.
The two walls of the housing are interconnected by a back part,
in such a way that the material strip can be guided through the
housing with its side opposite the adhesive layer facing the back
part. Near the discharge point of the material strip, the back part of
the housing in this case forms a pressure face for the material strip,
for pressing the latter onto a substrate.
The invention will be explained in greater detail below with
reference to an exemplary embodiment shown in the figures.
Figure 1 shows the view in perspective according to the
invention, during use.
Figure 2 shows a longitudinal section through the device
according to the invention.
Figure 3 shows an enlarged detail according to Figure 2.
The device shown in the figures comprises a housing 1, consisting
of two parallel walls 2, with a back part 3 between them. The housing
also has a stop 4, by means of which the device can be guided, as
shown in Figure 1, for example along a frame 5.
The device is used to apply a self-adhesive material strip 6 to
the rebate of the frame. Said material strip 6 is fed together with a
protective tape 7 to the device, during use the protective tape 7
being peeled off and emerging from the housing at the rear side. The
remaining material strip 6 emerges at the front side of the housing,
which forms a pressure face 8 by means of which the material strip 6
can be pressed into the rebate.
The mode of operation of this device will be explained further
with reference to the sections shown in Figures 2 and 3.
As shown in Figure 2, the front part of the back 3 of the housing
1, also called the pressure face 8, presses the self-adhesive material
strip 6 onto the substrate 5. At the same time the device is shifted
backwards, indicated by arrow 9. As a result of this movement, the
material strip 6 is pulled through the device, a new piece of material
strip 6 with the protective tape 7 still adhering to it always being
fed in through the rear side 10 of the device.
Material strip 6 and protective tape 7 run over two toothed
rollers 11, 12 here, in particular through the double nip formed by
said toothed rollers 11, 12 and the supporting rollers 13, 14. The nip
determined between the tips of the teeth 15 of the toothed rollers 11,
12 and the supporting rollers 13, 14 is slightly smaller than the
thickness of the material strip 6 and the protective tape 7, in such a
way that the material strip 6 is compressed a little and the toothed
rollers 11, 12 are driven by the moving material strip 6 and the
protective tape 7.
The assembly, consisting of material strip 6 and protective tape
7, then continues up to the diversion roller 16, over which the
protective tape 7 is diverted and continuously peeled off the material
strip 6.
The peeling-off means that the protective tape 7 is continuously
discharged, back in the direction of the feed point 10. As shown in
Figure 3, for this purpose the protective tape 7 is guided between the
toothed rollers 11, 12, and a further toothed roller 17, the teeth 19
of which mesh with the teeth 15 of the toothed rollers 11, 12.
The protective tape 7 thereby acquires a zigzag course between
the teeth 15, 19, which has the following advantages. First of all,
the protective tape 7 is gripped well, owing to its zigzag course, so
that slipping cannot occur. A further advantage is that the protective
tape 7 is tightened additionally, as a result of the additional length
needed to allow it to follow the zigzag course. This means that the
protective tape 7 is kept continually under initial tension while it
is being peeled off the material strip 6, in such a way that
protective tape 7 is constantly kept around the diversion roller 16.
The advantage of this is that no surplus part of the protective
tape 7 is left at the position of the diversion roller 16. For the
problem about that could be that the surplus part goes between the
material strip 6 and the substrate 5, causing the application to stop.
A guide 18 is fitted at the rear side of the toothed roller 12,
the purpose of which guide is to divert the protective tape 7 reliably
without it being able to creep up along the toothed roller 12.
The guide bar 4 is accommodated in a slit 24 extending through
the back 3 and part of the walls 2 of the device. The guide bar 4 is
held in place by the hook-shaped end 25. A U-shaped spring 20, passed
around the support points 21, 22, is also provided. Said spring rests
against the lug 23 of the guide rod 4, in such a way that the latter
is held in position. The guide rod can also be rotated into any
desired position.
The front edge of the pressure face 8 is in the form of a cutting
edge 26, in such a way that the material strip can be severed at the
desired point.
The material strip can also be driven by a motor, for example by
means of an electric motor.