U.S. patent application number 14/398219 was filed with the patent office on 2015-03-26 for feeding and cutting unit for a dispenser of paper sheets obtained from a continuous band.
The applicant listed for this patent is Q T S S.r.l.. Invention is credited to Gianandrea Niada.
Application Number | 20150082960 14/398219 |
Document ID | / |
Family ID | 46124638 |
Filed Date | 2015-03-26 |
United States Patent
Application |
20150082960 |
Kind Code |
A1 |
Niada; Gianandrea |
March 26, 2015 |
Feeding And Cutting Unit For A Dispenser Of Paper Sheets Obtained
From A Continuous Band
Abstract
A feeding and cutting unit for a dispenser of paper sheets
obtained from a continuous band comprises a supporting structure
(1, 2, 3) that rotatably supports a feeding roller (4) which in
turn internally rotatably supports a shaft (5) parallel thereto
which carries a blade (6) that during the rotation of the
blade-carrying shaft (5) projects through a corresponding
longitudinal slot formed in the feeding roller (4), the unit
including a pair of constantly engaged end gearings formed by a
first toothed wheel (7) integral with and coaxial to the
blade-carrying shaft (5) and a second toothed wheel (8) formed on
the supporting structure (1, 2, 3) at a position coaxial to the
axis of rotation of the feeding roller (4). In this way, a
simplification of the unit is achieved as well as a greater
reliability and smoothness of operation guaranteed by the constant
engagement whereby there are no problems of synchronized rotation
of the blade-carrying shaft (5) and of the feeding roller (4)
regardless of plays or wear that may rise over time.
Inventors: |
Niada; Gianandrea; (Milano
MI, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Q T S S.r.l. |
Caponago MI |
|
IT |
|
|
Family ID: |
46124638 |
Appl. No.: |
14/398219 |
Filed: |
April 18, 2013 |
PCT Filed: |
April 18, 2013 |
PCT NO: |
PCT/IB2013/053072 |
371 Date: |
October 31, 2014 |
Current U.S.
Class: |
83/203 |
Current CPC
Class: |
A47K 10/3643 20130101;
B65H 16/021 20130101; A47K 10/3637 20130101; A47K 2010/365
20130101; Y10T 83/4443 20150401 |
Class at
Publication: |
83/203 |
International
Class: |
B65H 16/02 20060101
B65H016/02 |
Foreign Application Data
Date |
Code |
Application Number |
May 2, 2012 |
IT |
MI2012A000724 |
Claims
1. Feeding and cutting unit for a dispenser of paper sheets
obtained from a continuous band wound up in a roll (R), comprising
a supporting structure (1, 2, 3) that rotatably supports a feeding
roller (4) which in turn internally rotatably supports a shaft (5)
parallel thereto which carries at least one blade (6) that during
the rotation of said blade-carrying shaft (5) projects through a
corresponding longitudinal slot formed in said feeding roller (4),
further comprising at least one constantly engaged end gearing
formed by at least a first toothed wheel (7) integral with and
coaxial to the blade-carrying shaft (5) and a second toothed wheel
(8) formed on said supporting structure (1, 2, 3) at a position
coaxial to an axis of rotation of the feeding roller (4).
2. Feeding and cutting unit according to claim 1, further
comprising a second constantly engaged end gearing identical with
said first gearing (7, 8) and located at the opposite end.
3. Feeding and cutting unit according to claim 1, wherein a
transmission ratio of the first and second end gearing is 1:1.
4. Feeding and cutting unit according to claim 2, wherein the end
gearing includes a third toothed wheel interposed between the first
two toothed wheels (7, 8) and also carried by the feeding roller
(4).
5. Feeding and cutting unit according to claim 1, further
comprising a counter-pressure shaft (9) rotatably supported by the
supporting structure (1, 2, 3) and with an axis of rotation
parallel to the axis of rotation of the feeding roller (4) and at a
position such to be in contact with a top portion of the feeding
roller (4).
6. Feeding and cutting unit according to claim 1, further
comprising a front guard (12) mounted on the supporting structure
(1, 2, 3) and provided, preferably at a central position, with a
rib (12a) that enters a corresponding groove formed in the feeding
roller (4) such that the continuous band is surely deviated outside
the dispenser by said rib (12a) whenever the continuous band
remains stuck on the feeding roller (4) even beyond an angular
rotatory position corresponding to an outlet slot of the
dispenser.
7. Feeding and cutting unit according to claim 1, further
comprising a ratchet (10) and a manual loading knob (11) that are
integral with respective opposite supporting pins of the feeding
roller (4).
8. Feeding and cutting unit according to claim 7, further
comprising a spring (13) arranged between a peg formed on the
ratchet (10) and a peg formed on the supporting structure (1, 2, 3)
and suitable to complete a rotation of the feeding roller (4) so as
to guarantee that an end tip (L) of the continuous band projects
from the dispenser for a next user.
Description
[0001] The present invention relates to devices for the controlled
dispensing of portions of paper from a continuous band to be used
as towels, and in particular to a dispenser of the
manually-operated type in which it is the pull exerted by the user
on the tip of paper projecting from the dispenser that controls the
feeding of a pre-established length of band and the cutting
thereof. Specific reference will be made in the following to a
dispenser of paper for towels, yet it is clear that what is being
said is also applicable with obvious modifications to toilet paper,
kitchen paper and the like.
[0002] There are well-known dispensers of paper towels obtained
from a continuous band in which the cutting blade is fixed and the
user must only carry thereon the portion of paper pulled out from
the dispenser, so as to severe it from the band and thus be able to
use it. This type of device, described for example in JP
2006034596, is very simple and reliable but it leaves up to the
user both the feeding function, i.e. the choice of the length of
the portion of paper to be cut with consequential unavoidable
wastes, and the cutting function, which implies the presence of a
blade in a region always accessible to the user and therefore
potentially dangerous.
[0003] A natural evolution of said device is the automatic paper
cutting, still through a manually-operated device and without
resorting to motor-driven solutions which are much more expensive,
bulkier and less reliable.
[0004] An example of such a kind of device is a device in which a
blade-driving cam is provided that is connected to the
paper-feeding roller, so that the blade springs out radially from a
rest position within a longitudinal slot formed in the roller
itself to a cutting position wherein it intersects the paper
outside the roller. This involves a clear danger of a possible
springing out of the blade while the user is manually performing
the paper inserting operation on the feeding roller, moreover the
spring-driven mechanism is noisy both in the cutting phase and when
the blade is returned to its rest position. An example of this type
of cutting mechanism is disclosed in GB 837194.
[0005] Another kind of device similar to the preceding one is a
device in which the blade acts on the strip of paper in a radial
direction from outside towards the inside of the feeding roller by
entering a longitudinal slot thereof. In this case, the blade is
mounted on a cutting group by means of a fork pivoted and laterally
guided so as to be operated in synchronism with the rotation of the
roller, and an example of such a device is described in the
applicant's previous application WO 97/36531. Though being safer,
however also this solution implies a quite noisy and fairly
complicated mechanism which is therefore expensive and not
completely reliable. Furthermore, the presence of the cutting
mechanism outside the feeding roller makes the device bulkier.
[0006] A different type of cutting mechanism is that in which a
first blade is mounted on the feeding roller and a second blade is
fixedly mounted on the supporting structure of the feeding roller
at such a position as to interfere with said first blade. Even in
this case, although a simpler and more compact device is obtained,
there is always the problem of the presence of a blade in an
accessible and therefore potentially dangerous region when the user
is manually performing the paper inserting operation on the feeding
roller. Moreover, the contact between the two blades causes them to
wear out and the effectiveness of the mechanism is strictly related
to the prevention of the rising of plays that could reduce or
cancel the interference between the blades. Examples of this type
of mechanism are described in EP 693268 and EP 930039.
[0007] In order to overcome the problems of noisiness, safety,
bulkiness and reliability of the above-described devices the most
recently developed cutting mechanisms include a blade that is
rotationally received within the feeding roller and acts with an
oscillatory movement controlled by the rotation of said roller.
Examples of this type of cutting mechanism are described in WO
2006/30138 and WO 2007/17603, both showing a blade-carrying shaft
provided at one end thereof with a toothed sector that acts as a
rack and during the rotation of the feeding roller periodically
engages with a corresponding fixed toothed sector, formed on the
roller supporting structure, that acts as a pinion.
[0008] In this way, the blade performs a partial rotation to come
out of the roller during the cutting phase defined by the arc of
engagement of the two toothed sectors and then rotates back inside
the feeding roller under the action of a return spring when said
toothed sectors disengage. Although this arrangement is effective
from the points of view of safety and bulkiness, it still has
drawbacks as to noisiness, reliability and smoothness of
operation.
[0009] A first drawback stems from the fact that the engagement and
disengagement of the toothed sectors at each operating cycle
require a perfect synchronization of the rotation of the
blade-carrying shaft and of the feeding roller to prevent jamming
of the mechanism and an early wear of the first teeth that start
the engagement. In fact, to this purpose, WO 2006/30138 provides
for the rack and pinion to be provided with a pulley and for a belt
to be always taut between said two pulleys to synchronize the
movement thereof. This obviously implies a structure that is quite
complicated, expensive and scarcely reliable since a slackening,
slipping or wear of the belt is sufficient to negatively affect the
smoothness of operation.
[0010] A second drawback resides in the noise caused by the blade
returning to its rest position under the action of the return
spring, and in this respect WO 2007/17603 provides for the rack and
pinion to be provided with corresponding cam surfaces sliding on
each other during the return run of the blade in order to slow it
down and reduce the noise. Also this arrangement, however, implies
a greater complexity of the mechanism which being also subjected to
a sliding wear will end up over time in being noisy.
[0011] Still another drawback intrinsic to the periodical
engagement of the toothed sectors, even in the condition of perfect
efficiency of the mechanism, is given by the variation of the
resistance of the mechanism in the different phases of the
operating cycle which results in less smoothness of operation and
in an inconvenience for the user. In fact when the user begins to
pull on the projecting tip of paper he/she encounters a minimum
resistance since the rack and pinion are not engaged, then the
resistance increases upon engagement and then decreases again upon
disengagement.
[0012] A similar cutting mechanism comprising a blade rotationally
received within the feeding roller and acting with an oscillatory
movement controlled by the rotation of said roller is disclosed
also in EP 1153565A1 in the name of the same applicant. Also in
this case, the blade performs a partial rotation to come out of the
roller during the cutting phase and then rotates back inside the
feeding roller under the action of a return spring, but the arc of
operation of the blade rather than being defined by the arc of
engagement of two toothed sectors like in the above-described
mechanisms is defined by the angular extension of two curved
reliefs internally formed on the sides of the feeding roller
supporting structure.
[0013] More specifically, these reliefs act on a rod mounted on the
feeding roller so as to be able to rotate and longitudinally slide
with respect thereto, said rod being provided at a first end with a
skid and at a second end with a toothed wheel that engages a fixed
toothed wheel formed on the supporting structure at a position
coaxial with the feeding roller. Due to this gearing and to said
reliefs that extend along consecutive non-overlapping angular
positions, the rotation of the feeding roller results in a constant
rotation and a longitudinal reciprocating motion of the rod that
slides to the left when its toothed wheel meets the relief adjacent
to and coaxial with the fixed toothed wheel and then slides to the
right when its skid meets the other relief on the opposite
side.
[0014] The blade-carrying shaft is mounted on the feeding roller
coaxial with said sliding rod and, at the end towards the fixed
toothed wheel, rather than being provided with a toothed sector is
provided with a first longitudinal pin that during the rotation of
the feeding roller periodically engages with a corresponding second
longitudinal pin formed on the toothed wheel of the sliding rod.
This second pin draws into rotation the blade-carrying shaft
causing the projection of the blade against the resistance of a
return spring as long as said rod is positioned on the left, and
then disengages from the first pin when the rod slides to the
right. In this way, the sliding rod makes a complete rotation at
each operating cycle whereas the blade-carrying shaft only performs
the conventional oscillatory movement.
[0015] It is therefore clear that also this mechanism suffers the
above-mentioned drawbacks of noisiness, possible pin wear,
necessity for synchronization, variation of the resistance of the
mechanism in the different phases of the operating cycle and a
certain structural complexity that increases its cost and decreases
its reliability.
[0016] FR 2828084 discloses another similar yet much more
complicated mechanism in which the blade-carrying shaft is not
mounted on the feeding roller but on a second roller adjacent
thereto that is drawn into rotation by the feeding roller through
an end gearing. A second toothed wheel of the feeding roller is
further engaged with a toothed wheel rotationally mounted on the
side of the supporting structure and provided with a cam which in
turn engages another cam also rotationally mounted on the side of
the supporting structure. Said second cam is provided with a third
toothed wheel that engages in turn a fourth toothed wheel arranged
at the end of the blade-carrying shaft, the oscillatory run of said
shaft being limited by a projection formed at the opposite end of
the shaft which abuts against a stop formed on the second
roller.
[0017] Such a complicated mechanism is clearly quite expensive,
scarcely reliable, noisy and particularly prone to problems of
synchronization among all the several components that interact for
its operation.
[0018] Finally, it should also be considered that a common drawback
of the above-described four mechanisms where motion is transmitted
through teeth is the presence of the toothed members only at one of
the two ends of the mechanism, which inevitably implies an
unbalance in the forces acting on the mechanism. Such an unbalance
negatively affects the smoothness of operation especially when the
user's pull is not centered.
[0019] Therefore the object of the present invention is to provide
a feeding and cutting unit for a dispenser of paper towels which
overcomes the above-mentioned drawbacks.
[0020] This object is achieved by means of a feeding and cutting
unit in which the blade-carrying shaft received in the feeding
roller is provided at least at one end, preferably at both ends,
with a toothed wheel that acts as a rack and is constantly engaged
with a corresponding fixed toothed wheel, formed on the supporting
structure, that acts as a pinion. Other advantageous features are
recited in the dependent claims.
[0021] A first important advantage of the present unit resides in
the greater reliability and smoothness of operation guaranteed by
the constant engagement of the rack and pinion, whereby there are
no problems of synchronized rotation of the blade-carrying shaft
and of the feeding roller regardless of plays or wear that might
rise over time. In this way, moreover, the resistance of the
mechanism in the different phases of the operating cycle is
substantially constant, since the gearing is constantly engaged,
and it requires a lower effort on the part of the user thanks to
the greater smoothness of operation.
[0022] A second significant advantage of this unit consists in the
elimination of the blade return spring, which results in a
reduction of noise and a simplification of the unit that is
cheaper. It should be noted that the simplification results also
from being able to dispense with the belt transmission and the cam
profiles described in the above-mentioned prior art. The saving is
even more evident with respect to the prior art that provides for a
still more complicated structure with a second roller for the
blade-carrying shaft in addition to the feeding roller.
[0023] Another advantage of the present unit is given by its
capacity to operate effectively also with paper having a weight
higher than foreseen in that the cutting is carried out along the
maximum possible arc of rotation of the feeding roller, and
therefore for the maximum time, whereas in mechanisms with an
oscillating blade a portion of the arc of rotation is taken up by
the return run of the blade that may not have sufficient time to
complete the cutting of a paper heavier than the paper for which
the unit was designed.
[0024] Still a further advantage of said unit, in its preferred
embodiment with a gearing at each end, derives from the symmetry of
the stresses on the cutting mechanism even in case of off-center
pull by the user, which results in a greater reliability and
smoothness of operation.
[0025] These and other advantages and characteristics of the
feeding and cutting unit according to the present invention will be
clear to those skilled in the art from the following detailed
description of an embodiment thereof, with reference to the annexed
drawings wherein:
[0026] FIG. 1 is a perspective exploded view of the main components
of the feeding and cutting unit;
[0027] FIG. 2 is a perspective view of the unit of FIG. 1 in the
assembled condition, yet without the components on the left and the
front guard for the sake of clarity of the drawing;
[0028] FIG. 3 is a front view of the unit of FIG. 1 in the
assembled condition, yet without the front guard;
[0029] FIG. 4 is a right side elevational view of the unit of FIG.
1 with a paper roll whose end tip passes through the unit and comes
out below;
[0030] FIG. 5 is a front view similar to the preceding one;
[0031] FIG. 6 is a left side elevational view similar to the
preceding one with the addition of the spring for completing the
rotation;
[0032] FIG. 7 is a sectional view taken along line A-A of FIG. 5
showing better the path of the paper band through the feeding and
cutting unit; and
[0033] FIGS. 8-15 are diagrammatic views similar to the preceding
one that illustrate an operating cycle.
[0034] Referring first to FIGS. 1 to 5, there is seen that the
feeding and cutting unit for a dispenser of paper sheets according
to the present invention substantially comprises a rear support
element 1 with vertical end seats for the insertion of lateral
shoulders left 2 and right 3 between which there is rotatably
supported a feeding roller 4, formed by two half-cylinders 4a and
4b, which in turn internally rotatably supports a shaft 5 parallel
thereto which carries a serrated blade 6 which, during a part of
the rotation of shaft 5, protrudes through a corresponding
longitudinal slot formed in roller 4 as better illustrated in the
following.
[0035] The rotation of the blade-carrying shaft 5 is obtained as a
result of the rotation of roller 4 by means of at least one end
gearing, preferably two as shown in the figures, formed at least by
a toothed wheel 7, integral with and coaxial to shaft 5, which
engages a corresponding toothed wheel 8 formed on the inner side of
the relevant left 2 and right 3 shoulder at a position coaxial with
the axis of rotation of roller 4.
[0036] A counter-pressure shaft 9 is also rotatably supported
between shoulders 2, 3 with an axis of rotation parallel to the
axis of rotation of the feeding roller 4 and in such a position as
to be in contact with pre-load with the upper portion of the
latter. Shoulders 2, 3 respectively carry on their outer sides a
ratchet 10 and a manual loading knob 11 which are integral with
respective opposite support pins of roller 4. A front guard 12 is
finally mounted on shoulders 2, 3 and is provided, preferably at a
central position, with a rib 12a that fits into a corresponding
groove formed on roller 4 so that the paper band is surely deviated
outside the dispenser by said rib 12a whenever the band remains
stuck on the feeding roller 4 even beyond the angular rotatory
position corresponding to the outlet slot.
[0037] With reference also to FIGS. 6 and 7, there is seen that
roller 4 can rotate only in the counter-clockwise direction (seen
from the left) because the ratchet mechanism 10 located on the
outer side of the left shoulder 2 is mounted so that the pawl 10a
pivoted on said shoulder 2 prevents the clockwise rotation of the
serrated wheel 10b integral with the left pin of roller 4.
Obviously, in another embodiment different from that illustrated
the rotation might be only clockwise if this were necessary, it
would suffice to reverse the arrangement of ratchet 10.
[0038] FIG. 6 also shows a spring 13, arranged between a peg of the
serrated wheel 10b and a peg formed on shoulder 2, which provides
to complete the rotation of roller 4 so that the cutting results
smooth and light being performed more by the strength of spring 13
than by the user's pull on the end tip L of roll R which protrudes
downward from the dispenser. Furthermore, spring 13 ensures that an
end tip L of the band protrudes from the dispenser for the next
user.
[0039] As shown in the sectional view of FIG. 7, the paper band
coming from roll R is first wound on the front of the
counter-pressure shaft 9 then sandwiched between the latter and the
feeding roller 4, so as to pass on the back of roller 4 and to exit
at the bottom through the slot between the latter and the rear
support 1. The blade-carrying shaft 5 rotates inside roller 4
around its own axis of rotation, which in turn rotates together
with roller 4 around the axis of rotation of the latter so that
blade 6 protrudes therefrom for about half a turn from the angular
position shown in FIG. 7.
[0040] The simple and effective operation of the present device can
be easily understood from the description above, as now illustrated
with the aid of FIGS. 8 to 15 in which the blade-carrying shaft 5
has been omitted to show more clearly how the rotation of blade 6
is due to the constant engagement of the toothed wheel 7 and of the
toothed wheel 8 which form the end gearing.
[0041] For the loading of the device, the continuous paper band
unwound from roll R is inserted from the front between the
counter-pressure shaft 9 and roller 4 which is rotated by means of
knob 11 until the end tip L comes out. When the user pulls tip L,
this causes the rotation of roller 4 that carries shaft 5 whose
toothed wheel 7 engaged with the toothed wheel 8 in turn causes the
rotation of shaft 5 and therefore of blade 6.
[0042] From the rest position of FIG. 8 in which blade 6 is located
on the front of roller 4 (three o'clock position) and is directed
inside the latter, in the first phase of the operating cycle the
simultaneous rotation of roller 4 and shaft 5 carried thereon leads
to the position of FIG. 11, substantially coinciding with FIG. 7,
in which blade 6 is located just beyond the top of roller 4 (eleven
o'clock position) and begins to protrude through the longitudinal
slot of the latter.
[0043] The cutting of the paper band takes place along about a
quarter of a turn in the second phase of the operating cycle
between the position of FIG. 11 and the position of FIG. 13, in
which blade 6 is located just below the back of roller 4 (eight
o'clock position) and projects substantially perpendicular from it.
At this point, usually, the end tip L has already been cut from the
rest of the band so as to form a towel T available to the user.
However, in the case of paper more resistant to cutting, the
detachment of towel T can also occur further downstream of the
position of FIG. 13 since blade 6 continues to exert its cutting
action until the band arrives out of the reach of blade 6 moving
away from roller 4.
[0044] In the third phase of the operating cycle of the unit, with
the aid of spring 13 as illustrated above, roller 4 and blade 6
complete their rotation to return to the rest position of FIG. 8
passing through the positions illustrated in FIGS. 14 and 15. The
presence of ratchet 10 prevents any reverse rotation of roller 4 at
the end of the rotation under the thrust of spring 13, thus
ensuring the projection of the end tip L for the fraction by the
next user.
[0045] It is clear that the embodiment of the feeding and cutting
unit according to the invention described and illustrated above is
just an example susceptible of various modifications. In
particular, to obtain a greater "aggressiveness" of the cut by
having blade 6 come out from roller 4 in the direction opposite to
the direction of advancement of the paper band (i.e. clockwise in
the example shown), the end gearing could also include a third
toothed wheel interposed between the toothed wheels 7, 8 and also
carried by roller 4 so as to reverse the rotation of the
blade-carrying shaft 5.
[0046] Similarly, if the overall gear ratio between the toothed
wheel 7 and the toothed wheel 8 is different from the 1:1 ratio of
the illustrated embodiment, other variations are possible. For
example, if shaft 5 performs only half a turn at every rotation of
roller 4 (1:2 ratio) there might be two opposing blades 6 along the
circumference of shaft 5, or you could dispense a towel T of double
length if blade 6 is always single.
* * * * *