[0001] The present invention relates to mechanisms for delivering pieces of paper or the
like material, which are severed from a continuous source of continuous paper band,
such as those used, for example, for supplying paper towels for hand drying or cleaning
purposes.
BACKGROUND OF THE INVENTION
[0002] Mechanisms for delivering pieces of continuous or band paper, comprising a pair of
mutually tangent pressure rollers are well known, wherein a first one of the said
rollers is mounted rotating about a fixed axis while the other, second roller, is
mounted on an oscillating frame which is spring biased against the first roller, the
end of a paper band issuing from a bobbin being caught between both rollers, the
mechanism further comprising a locking device associated to the shaft of one of the
rollers and restricting the length of paper which is delivered each time that a pull
is applied to the paper band end, a timing device holding the mechanism locked during
a restricted period, and a device operating one of the rollers once a paper band length
has been withdrawn, to eject a short band length to make its grasping easier, the
ensemble being located within a box provided with a paper outlet opening.
[0003] A mechanism of the above features makes the subject of the Spanish Utility Model
N
º 290 203 of which the applicant is the owner.
[0004] The practice has shown that some aspects of this kind of delivery mechanisms are
subject to improvement.
[0005] For example, the device automatically supplying a short paper length once a user
has taken out the band and detached a length of it corresponding to a towel or the
like dose, acts directly upon the shaft of one of the band drawing rollers by means
of a cam biased by a spring which is released under the control of a timing system
and which is loaded through a reducing transmission connected to the shaft of the
said roller. The fact that the device for delivering the short band length acts directly
upon the shaft of the roller, and the timer winding mechanism acts through a reducing
transmission creates a lack of timing of the number of turns which is necessary to
place the winding mechanism in working position. Consequently, the triggering of the
mechanism supplying the short paper length operates in two steps with a short time
period between these latter, which may induce the user to apply a pull on the paper
band in order to obtain a new dose, in the wrong timing thus causing the mechanism
to become blocked.
[0006] In other aspects, it would be advisable that the device for restricting the length
of the delivered paper had provision for delivering paper pieces of different lengths
according to the needs of the user.
[0007] The device for cutting the pulled paper band can also be subject of improvement with
a view of simplifying its conformation though with no loss in efficiency.
DESCRIPTION OF THE INVENTION
[0008] According to the above feasibilities, the present invention have been devised to
provide higher performances of the mechanism.
[0009] According to the present invention, the spring loading cam of the ejector device
for delivering the short paper length when the mechanism has been unlocked, is mounted
fixed on the shaft of a set of sprockets having different diameters and adapted to
be selectively engaged by a set of different diameter sprockets secured to the shaft
of one of the paper band drawing rollers.
[0010] To advantage, the ejector device and the timer winding device, which are of a common
construction, are mounted on the same shaft of the set of sprockets selectively meshing
with the sprockets mounted in a position which is displaceable at will on the shaft
of one of the paper band drawing rollers.
[0011] In a preferred embodiment, the oscillating support carrying mounted thereon the
movable roller is formed with an arcuate gutter or ramp located immediately under
the opening through which the paper band coming from the supply bobbin issues, the
said gutter or ramp receiving the engagement of one end of springs having their opposite
ends anchored in fixed points of the support structure of the mechanism, thus forcing
the supported roller to rest onto the other roller.
[0012] Optionally, the border of the paper exit opening formed in the enclosure containing
the mechanism, has a cutting edge, which can be toothed, for cutting the withdrawn
paper band.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] For a better understanding of the description in the present specification, a set
of drawings is enclosed showing, only by way of example, a practical case of embodiment
of the mechanism. In the said drawings:
Figure 1 is a plan view from above the mechanism;
Figure 2 is a detail, as seen from above, of the sprocket transmission associated
with the device which automatically delivers a short paper run, though in a different
position as regards the position shown in the previous Figure;
Figure 3 is a detail in longitudinal section showing the opening through which the
paper band coming from the bobbin issues, the two rollers trapping the band, the ramp
or gutter of the oscillating support, and the toothed cutting edge located at the
paper band issuing mouth, and
Figure 4 is a detail in side elevation showing the device for delivering the short
paper run.
DESCRIPTION OF A PREFERRED EMBODIMENT
[0014] The continuous paper delivery mechanism according to the invention consists, in
the drawings, of two rollers 1,2 trapping a paper band 3 coming from a bobbin 4 located
within a container 5, the bottom of which is shaped as a funnel 6, according to a
known embodiment.
[0015] The roller 1 is mounted on an oscillating support 7 provided with wings 8 which
are articulated about a shaft 9 mounted on fixed lugs 10. This oscillating support
8 is biased by springs 11 having one end anchored to the fixed lugs 10 and the opposite
end resting upon the back of an arcuate gutter or ramp 12 extending upwards of the
support, thus forming a guide for the paper band 3 at the outlet of this latter from
the funnel 6 (Fig. 3).
[0016] A conventional escapement device, formed of a sprocket 13 against which a tooth 14
impinges under the biasing of a spring 15 to prevent the back motion of the roller
2, is mounted at one end of the shaft 2a of the said roller 2.
[0017] The opposite end of the shaft 2a has mounted thereon two sprockets 16,17 having different
diameters and adapted to mesh selectively and alternatively with two sprockets 18,19
which are fast with a shaft 20 mounted for rotation on a support 21. The same shaft
20 has secured thereon a cam 22 with a spring 23 constituting the automatic feed device
of the shaft 2a for the delivery of a short run or length of the band 3. This delivery
device is associated, according to a known embodiment, to a timer device formed of
two mutually faced suction cups 24,25 of which the cup 24 can be displaced by a movable
arm 26 in turn operated by a cam 27 joined to the shaft 20 of the sprockets 18,19.
[0018] The described mechanism is housed in a pan 28 having an opening 29 for the outlet
of the band 3a and formed with a toothed wing 30 for severing the delivered band.
[0019] From the above description and looking to the drawings, it follows that it is possible
to vary the length of the run obtained by pulling out the band 3a, by changing the
position of the sprockets 16,17 as regards the sprockets 18,19 (Fig. 1 and 2).
[0020] It is also to underline that, thanks to the relation between the sprockets 16,17
and 18,19 and to the location of the cam or eccentric 22 on the same shaft 20 of the
set of sprockets 18,19, it is obtained that the cam 27 drives the arm 26 with a single
turn of the shaft 20, to place the timer movable suction cup 24 in the locking position.
[0021] Another advantage as regards the known embodiments consists in the arrangement of
the springs 11 to act directly upon the arcuate ramp 12, thus forcing the support
7 to move in order that the roller 1 comes to rest onto the roller 2 for trapping
the band 3.
[0022] It is to be emphasized the embodying of the toothed cutting edge 30 instead of a
cutter blade joined by conventional means to the structure which the mechanism is
secured upon, for severing the delivered band run 3a. This cutting edge 30 may be
obtained directly integral with the pan 28, or by inserting on this latter a stiffer
part, either of plastics or metallic material.
1. A continuous paper and the like delivering mechanism, of the type comprising a
pair of mutually tangent rollers (1,2), one of which (1) is mounted on an oscillating
frame which is spring biased against the other roller (2), the end (3a) of a paper
band (3) issuing from a bobbin (4) being caught between both rollers; a locking device
associated to the shaft of one of the rollers and restricting the length of paper
which is delivered each time that a pull is applied to the paper end; a timer (24,25)
holding the mechanism locked during a restricted period, and a device (22,23) operating
one of the rollers (2) once a paper length (3) has been withdrawn, to draw off a short
paper length to make its grasping easier, the ensemble being located within a box
(4) provided with a paper outlet opening (6), the mechanism being characterized in
that the cam (22) of the ejector device for the short paper run when the meachanism
has been unlocked, is mounted on the shaft (20) of a set of sprockets (18,19) having
different diameters and adapted to be selectively engaged by a set of different diameter
sprockets (16,17) secured to the shaft (2a) of one of the paper band drawing rollers
(2).
2. A delivering mechanism, according to claim 1, characterized in that the ejector
device (22) and the timer winding device (26,27) are mounted on the same shaft (20)
of the set of sprockets (18,19) selectively meshing with the sprockets (16,17) mounted
in a position which is displaceable at will on the shaft (2a) of one of the paper
band drawing rollers.
3. A delivering mechanism, according to claim 1, characterized in that the oscillating
support (7) carrying mounted thereon the movable roller (1) is formed with an arcuate
gutter or ramp (12) located immediately under the opening (6) through which the paper
band (3) coming from the supply bobbin issues, the said gutter or ramp (12) being
engaged by one end of springs (11) having their opposite ends anchored in fixed points
(10) of the support structure of the mechanism, thus forcing the supported roller
(1) to rest onto the other roller (2).
4. A delivering mechanism, according to claim 1, characterized in that the border
of the paper exit opening (6) formed in the enclosure (28) containing the mechanism,
has a cutting edge (30), which can be toothed, for cutting the withdrawn paper band
(3).