Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
_a~ round Of The Invention
The present invention relates to an apparatus for
dispensing paper towels of a predetermined length from a
supply roll of a continuous paper web.
There are known dispensers of the above type wherein,
upon pressing a push button or a lever, a predetermined
length of paper web is advanced outside the dispenser so
that the user can detach a paper towel by hand, usually by
tearing the pro-truding web length through a pull action
against a saw-toothed blade.
~he known dispensers have a number oF drawbacks, the
most relevant of which are the following. The length of the
paper web dispensed each time is rigorously predetermined
when designing the apparatus and cannot be altered, or only
through replacement of a considerable portion of the
dispensing mechanism. This is a disadvantage for the
manufacturer forced to market more than one model of the
same apparatus or to appreciably modify an existing model to
meet the requirements of his customers. Moreover, where the
dispensed paper length is either too long or too short,
there will be a waste of paper since in the latter case the
user will draw more than one towel from the apparatus.
A second drawback of prior art dispensers is that the
user must positively detach the dispensed web, often causing
the apparatus to jam. It is to be noted that the user's
hands are wet when tearing the web preventing use of papers
with lower tear s-trength. On the other hand papers formed
of two thin sheets are highly desirable for their
absorbency, softness and cost, but cannot withstand a
pulling action with wet hands.
A prior art dispenser is described in U.S. Patent No.
3,408,125 which provides for the manual extraction and
cutting of a paper strip by the user, while the apparatus
stores a fraction of the power received so that after a
predetermined number of cycles, a length of paper to start a
new cycle is caused to be fed outward.
U.S. Patent No. 3,730,409 describes a dispenser
apparatus in which cutting the paper web available at the
~ 2 ~ ~ "~_
outside is carried out manually by the user and causes the
actuation of an electric rnotor that feeds a further paper
length.
U.S. Pa-tent No. 4,131,044 describes a dispenser of the
above-mentioned type, in which a predetermined paper length
is drawn manually while some power is stored at the same
time for -the suhsequent operation of a movable blade for
cutting the paper web.
U.S. Patent No. 4,697,146 describes a manualIy operated
dispensing apparatus in which only a prefixed length of
paper web can be drawn outside and torn by means of a timer
preventing the paper web from unrolling. A fraction of the
applied power is stored to cause a length of paper to be
fed, after tearing, and to remain accessible from outside in
order to start the subsequent cycle. The length of the
dispensed strip can be previously selected among two or
three values by acting onto the dispensing mechanism.
All these devices provide for a completely manual
operation, except for the one described in U.S. Patent No.
3,730,409 wherein only the feeding operation is motorized
and the cut still must be carried out manually by the user.
Therefore the above-mentioned drawbacks remain unsolved and
even according to the last mentioned patent a certain length
of paper is left exposed outside of the apparatus with
further inconveniences of hygienic nature.
Summary Of The Invention
It is therefore an object of the present invention to
provide a dispensing apparatus for paper webs usable as
towels, wherein the length of the dispensed web available
outside can be fully adjusted, even by untrained persons
without requiring any mechanical adjustment of the
dispenser.
Another object of the invention is to provide an
apparatus which automatically supplies and partially cuts
the dispensed web length so that the towel hangs from the
apparatus without falling and can be completely detached
with a minimum pulling effort.
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A further object of the invention is to provide an
autornatic towel dispenser which does not require a positive
action or a physical contact to be s-tarted but can supply
the paper towel without being touched by the user.
Still another object of the invention is to provide a
dispenser wherein the adjustable dispensing and -the cutting
of the paper are obtained through the same power means, thus
avoiding a secor-d power source, such as an additional mo-tor
or temporarily storing means, for actuating a cut-ting device
at the end of the dispensing step.
Another object of the invention is to provide a
dispensing mechanism of the above-men-tioned type which is
battery powered.
These and additional objects are achieved by the
invention which provides an apparatus for dispensing a
predetermined length of a paper web comprising a housing
provided with a slot through which the paper web is supplied
outside from a supply roll contained in said housing;
bidifectional electric motor; ;means for advancing the paper
web through the slot; means for partially transversely
cutting the paper web protruding outside said slot; coupling
means for selectively coupling the motor either to one of
the advancing means or to the cutting means, the motor when
coupled to the cutting means advancing the paper web through
the slots and when coupled to the cutting means actuating
the cutting means partially to cut the paper web; a control
circuit for driving the motor when coupled to the advancing
means for a duration proportional to the predeterrnined
length, and then driving the motor, after coupling to the
cutting means, whereby the dispensed paper web is at least
partially cut.
According to a preferred embodiment of the invention,
the selective coupling means comprises first unidirectional
coupling means connecting the motor with the advancing means
so that the latter is driven only when the motor is rotated
in a first direction and second unidirectional coupling
means connecting the motor with the cutting means so that
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the latter is driverl when the motor is rotated in a second
direction opposite to the first.
The invention consists of certain novel features and a
combination of parts hereinafter fully described,
illustrated in the accornpanying drawings, and particularly
pointed out in the appended claims, it being understood that
various changes in -the de-tails may be made without departing
from the spirit, or sacrificing any of the advantages of the
present invention.
~rief Description of the Drawings
For the purpose of facilitating an understanding of the
invention, there is illustrated in the accompanying drawin~s
a preferred embodirnent thereof, from an inspection of which,
when considered in connection with the following
description, the invention, its construction and operation,
and many of its advantages should be readily understood and
appreciated.
FIGURE 1 is a perspective view showing the dispensing
apparatus opened;
FIG. 2 is a top view of the apparatus of Figure l with
its cover removed;
FIG. 3 is a cross-section along line lll-lll of Fig. 2
showing the apparatus driving gears;
FIG. 4 is a partial front view showing the driving
gears;
FIG. 5 illustrates the cutting blade for the paper;
FIG. 6 is a cross-section along line Vl-VI of Fig. 2
illustrating the working of the cutting rneans;
FIG. 7 is a perspective view of the plate supporting
the paper web before leaving the apparatus;
FIG. 8 is a block diagram of the control circuit of the
apparatus;
FIG. 9 is a perspective view of a second embodiment of
the dispensing apparatus of the present invention, showing
the dispensing apparatus in the open position;
FIG. lO is a top view of -the apparatus shown in FIG. 99
with is cover removed;
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FIG. 11 is a fragmentary view showing details of a
safety switch of the apparatus, relative to the closing and
opening of its cover;
FIG. 12 is a fragmentary view illustrating the push
button control device for battery operation of the
apparatus;
FIG. 13 is a fragmentary view illustrating
self-centering paper roll brackets of the apparatus;
FIG. 14 illustrates the unidirection coupling
assemblies of the paper advance and cutter bar drive
mechanism for the apparatus;
FIG. 15 is a fragmentary view illustrating details of
the cutting device mechanism for the apparatus; and
FIG. 16 is a block diagram of the control circuit of
the apparatus shown in FIG. 9.
Detailed Description of the Preferred Embodiment
As shown in Fig. 1, the apparatus 1 according to the
invention comprises a case la housing the main components
vhich is closed by a cover 2 connected to the case through
hinges 9. Both the case and the cover are preferably made
of plastic material by molding. The cover 2 is provided
with a central portion 3 that is transparent and partially
curved to allow for the supply roll 8 of paper carried by
the case. Through the transparent portion 3 the quantity of
paper still available can be checked. The cover is further
provided with a key lock 48 or the like engaging the case to
prevent unauthorized opening, and with an elongated notch 47
cooperating with a similar notch 46 on the front (or lower)
portion of the case to define an outlet slot for the paper
web.
Since the apparatus is preferably mounted vertically,
e.g. against a wall or the like, the case and the cover are
further connected by a pair of articulated bars 4 adapted to
keep the cover lifted when replacing the paper roll or
adjusting the length of the paper web to be cut as will be
explained later. When the cover is closed a peg 44
protruding from the inner surface of the cover actuates a
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safe~y swi~ch 50 in the case so that upon lifting the cover
the appara-tus is deenergi~ed.
The case la comprises a bottom wall I0, two side walls
11, 12, a front wall 13 and a rear wall 14. The bottom wall
10 is provided with rneans (not shown) for fastening the
apparatus to a wall. A pair of brackets 15 rise from the
bottom wall to hold the roll 8 of a continuous paper web 5.
The remaining part of case la is divided into three
compartments, a central one 71 and two lateral ones 72, 73
10 ~see Fig. 2). The central compartment 71 is defined by the
bot-tom wall 10, by two uprising lateral metal plates 51, 52
and by an upper par-tially curved plate 60 upon which is
supported the paper web 5 unwinding from roll 8 towards the
outlet. As it will be ilIustrated later, the frame 55
15 formed by plates 51, 52 and 60 carrying the paper driving
mechanism, the control circuit board 39 (Fig. 7) and all the
other components is detachable from the bottom wall 10 and
fastened to it by elas-tic pawls 24, 57 formed in the bottom
wall.
A tiltable plate 30 is pivotally connected to the
lateral plates 51, 52 and defines a passage for the web 5.
An idle shaft 33 is pivotally mounted on this plate 30 and
is provided with a plurality of rollers 35. Plate 30 is
further provided with an opening 41 in correspondence of a
25 similar aperture 59 formed in the plate 60, through which
protrudes a -tongue 40 connected to a switch 49 (Fig. 8) for
detecting the exhaustion of the paper web, as will be better
explained in the following. In use plate 30 lays in
proximity of plate 60 (both preferably of metal) so that the
30 paper web 5 keeps the tongue (40 in Fig. 7) depressed and
the associated switch 49 closed. Upon exhaustion of the
paper web 5, such to tongue 40 is free to move upward thus
opening the associated switch 49 and putting the apparatus
out of service. Either condition is displayed outside the
35 dispenser through light indicators 36 or 37, typically LED
devices, on the top of the lateral compartment 73 visible on
the right portion of Figs. L and 2. Both indicators are
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visible outside through a pair of small holes (not shown) in
the cover.
The right-hand compartment is defined by bottom wall
10, side wall 12 and lateral plate 52 and houses a block 45
having a side recess 58, the two above mentioned light
indicators 36, 37 and an aperture 43 into which fits the peg
44 upon closure of the cover 2 to close switch 50 connected
to the apparatus power supply by depressing tab 42. A
photoelectric arrangement 53, 54 is provided in recess 58
for starting the paper dispensing and -the cover 2 is
correspondingly shaped so that the user can start the
apparatus by p~as~ing even only one f in~er in recess 58 even
without touching the recess wall. As seen in Fig. 2 the
recess 58 houses an aligned pair of cooperating elements
such as a LED 53 and a phototransistor 54 connected in a
circuit arrangement such as to start a dispensing cycle when
the light beam from the LED does not reach the
phototransistor. Of course other optical or proximity
devices can be used instead of the represented one.
2Q The left compartment 72 is defined by bottom wall 10,
side wall 11 and lateral plate 51 and houses the drive gear
(82 to 122 in Fig. 3) for advancing and cutting the paper
web 5 as will be illustrated later. As can be seen in Fig.
2, an inner housing 16 is formed adjacent the rear wall 14
and covers an electrical transformer (not shown), but the
housing 16 is unnecessary when the transformer is placed
outside the apparatus, e.g. to meet safety provisions
requiring that only a low voltage be present in the
dispenser.
Brackets 15 of which only one is shown (see also Fig.
1), holding the paper roll 8 are symmetrically and slidably
mounted on rails 28 and elastically pushed -toward each other
against stop members not shown, by means of compression
springs 78 in a housing 29 on the bottom. The upper ends of
the brackets 15 carry suitable plugs 17 for engaging a paper
roll 8 which can be either provided with a core or not.
Since the distance between the brackets if adjustable, rolls
of different width can be fitted to the apparatus, while
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maintaining in any case a self-centering arrangement thanks
to the above-mentioned symmetrically slidable and
elastically pressed moun-ting.
A paper roll 8 is easily loaded in the dispensing
apparatus by further spacing apart the brackets 15 (i.e.
pushing laterally on protruding tabs 19), and then releasing
them after positioning the roll between the plugs 17.
The advancing, cutting and control devices are all
mounted on the metal frarne 55 formed by plates 60~ 51 and
52, these latter being provided with engaging means with the
bottom wall lO such as metal blades movable in slots (both
not shown) in the bottom wall. Two tab strips 57 are formed
in the bo+tom wall 10 by means of cuts 59 extending along
the three sides of a C-shaped and the ends of these tabs
abut against the higher portion of wedge-shaped projections
24 sloping down to the bottorn. When the frame 55 is
positioned in the case, these tabs 57 are elastically biased
toward the outside and abutting against the frame 55 to hold
it firmly in position. By depressing these tabs and pushing
the frame 55 toward the brackets 15, the frame 55 can be
disengaged and remoYed, e.g. for maintenance purposes.
A tiItable door 25 (better shown in Fig. 7) is provided
in plate 60 for access to the control circuit board 39 and
more particularly to a set of microswitches ~ for adjusting
the length of the dispensed paper web.
The paper web 5 unwinding from roll 8 initially lays
over plate 60 and then is guided between plate 60 and plate
30 which is provided with side arms 34 (only one of which is
shown), pivotally connected to plates 51, 52 by means of
pins 27. Thus the plate 30 can be swung upward when
inserting paper web 5. Moreover plate 30 is provided with a
longitudinally extending raised portion 38 which abuts
against the cover to keep the plate 30 in position when the
apparatus is in operation. Plate 30 further carries a
plurality of rolls 35 mounted on a common idle shaft 33
connected to pla-te 30. These rolls 35 partially lean out
from plate 30 through openings 32 to contact a plurality o-f
rollers 63 mounted on frame 55. These rollers are the
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driving or feed rollers of ~he paper web and are carried by
a shaft 120 in the central compartment 71. As also seen in
Fig. 7~ shaft 120 is journalled between plates 51, 52 at
such a position -that rollers 63 partially protrude from
plate 60 through an elongated opening 61 in this plate. The
surface of rollers 63 is such as to frictionally engage the
paper web and for example the rollers are covered with
rubber.
Wi-thout -the paper web 5 interposed, rollers 63 and
10 rolls 35 would be in contac-t with a certain degree of
pressure, so that when p~per web 5 is present between plates
60 and 30, it is pressed between them when plate 30 is in
its working position.
Referring to FIGS. 2 and 6, a cut~ing device 85 is
15 provided at the output of paper web 5 from the space between
plates 60 and 30. It comprises a fixed blade 31, mounted
between plates 51, 52, and a movable blade 56. Blade 31 and
blade 56 have sharp edge and both are preferably of steel.
The paper web length 6, accessible from outside is still
20 supported by plate 60 and is advanced to the required length
between the fixed blade 31 and the blade 56 and it is cut by
the movement of the latter in a scissor-like manner as will
be described later in detail.
With reference to Figs. 3 and 4 it will now be
25 disclosed the arrangement for advancing and cutting the
paper web 5. Fig 3 is a cross-section taken along line
III-III of Fig. 2, showing plate 51 on which a plurality of
gears is mounted, whereas Fig. 4 is a plan view of the
arrangement.
The shaft 80 of an electric d.c. motor 64 housed in the
central compartment 71 passes through plate 51 and carries a
pinion 82 engaging the outer teeth of a first toothed wheel
88. 1he inner teeth 86 of this wheel 88 engage in turn the
outer teeth of a second toothed wheel 94 having inner teeth
35 92 driving a third toothed wheel 102 mounted on pin 100.
The first 88 to third 102 toothed wheels form a reduction
gear between the motor 64 and two pinions 112 and 122. For
clarity sake, in Fig. 4 pinions 112 and 122 are shown as if
L
they were longitudinally spaced apart more than they really
are, as can be seen in Fig. 3 wherein it is clearly shown
that wheel 102 meshes with both pinions. Apart from pinion
82, all the gears are preferably of nylon or other ~lastic
materialO
Pinions 112 and 122 are connected to shaft 110 and 120
respectively, through one-way clutches 115 and 116. Both
pinions are freely rotatable in both directions with respect
to plate 51 on which they are supported. Clutch 115 couples
to pinion 112 to shaf~ 110 only when pinion 112 is rotated
in a counterclockwise direction, when observing Fig. 3,
whereas a clockwise rotation of the same pinion does not
drive shaft 110. Moreover a shaped cam 130 having a pin 132
is fastened to shaft I10 and is therefore rotated only when
]-5 tllis shaft is rotated.
On the contrary clutch 116 couples pinion 122 to shaft
120 only when this pinion is rotated clockwise when
observing Fig. 3 while disengaging such a shaft during
rotation in the opposite direction. The two one-way
clutches 115 and 116 may be for example constructed, as
represented in Fig. 4, so as to be extremely simple and of
low cost, by using a so-called "pinching" or "throttling"
spring 109 with some coils wound around a hub 113 co-axial
and integral with shaft 110, and other coils wound in an
opposite direction on a hub 114 co-axial and integral with
shaft 120. One end of the spring 109 is fixed to the case
la and the other end is free whereby, when the rotation of
the two pinions (which has always the same direction~ is
such as to cause a tightening of coils on one of the two
hubs, this is driven in ro-tation together with the
associated sllaft, whereas the coils wound in the opposite
direction will loosen around the associated hub which is not
driven into engagement, thus causing the corresponding shaft
to remain stationary. Of course also different types, all
know, of one-way clutch could be provided.
In Fig. 3 the arrows show the rotations of the gears
for which pinion 122 rotates clockwise, so tha~ it drives
shaft 120 with the rollers 63 and the paper web is advanced,
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whereas pinion 112 although rotating as shown by the arrow,
does not drive either shaft 112 or cam 130. On the
con-trary, when the rotations are reversed, paper advancement
is stopped and shaft il0 is rotatecl. This shaft drives cam
130, as well as an eccentric 13g with pin 136 on the
opposite side (see Fig. 4) for actuating the cutting means
%5 as will be better described later.
In Figs. 37 4, 5 and 6 the construc-tion of the cutting
means 85 is clearly shown. Blade 31 is fastened at an end
to plate 51 and at -the other end to plate 52 (Fig. 6)
whereas blade 56 is carried by sha~t 14~ through fastenin~
blocks 142 (e.g. of nylon) allowing for a limited rotation
with respect to the fixed blade. The edge of blade 56 is
not parallel to blade 31, as between seen in Fig. 4, for a
progressive cutting action and is is interrupted by a recess
145 in the middle so that a central strip of paper web is
left uncut after the cutting step.
The reciprocating movement of blade 56 is obtained
through levers 131 and 135, in the left and right
compartments respectively. The lever 131, 135 have the same
shape and are mounted parallel in the frame. One end (127
in Fig. 4, 128 in Fig. 6) of each lever 131, 135,
respectively, is pivotally coupled to the corresponding
plate (51, 52) whereas the other ends (125 in Fig. 4, 126 in
Fig. 6) are connected together by shaft 140 transversely
extending through the frame and supporting the blade 56.
The upper ends 133, 134 of blade 56 are further connected to
plates 51, 52 by elastic means such as springs 96, shown in
Figs. ? and 3, for a smoother movement.
The middle portion of each lever 131, 135 has a slot
137, 138 (Figs. 4 and 6) housing a pin 132, 136 mounted on a
corresponding cam 130, 139. As already mentioned these cams
130, 139 are rigidly connected each other at the ends of
shaft 110 which in turn is coupled to pinion 112 by
unidirectional clutch 115. A comple'e rotation of pinion
112 in a counterclockwise direction causes a reciprocating
movement of blade 56 as clearly visible in Fig. 6 wherein
the upper position of lever 135 and blade 56 is shown in
D~ "L
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dashed lines. The same figure illustrates in dashed lines
the partialIy lifted cover 2 and plate 30 fully swung
outward.
A device for measuring the length of the dispensed
paper web is provided in the right-hand compartment 73 and
will be summarily described since it is of convention type
(see Fig. 7). It comprises a disc 65 mounted on shaft 120
and provided with a number (e.g. four) of peripheral cuts
66. A detector 68, 69 of the optical type detects the
passage of each cut ~6 during the advancing rotation of
shaft 120 and delivers to the control circuit a number of
pulses that is propor-tional to the length of dispensed web
6.
A block diagram of the electric control circuit 20 of
the apparatus is shown in Fig. 8. The terminals of d.c.
motor 64 are connected to the outputs 21, 22 of a drive
circuit 23 which is controlled by a logical unit 26. The
motor 64 is kept at rest by supplying an equal d.c. voltage
on both outputs 21, 22 (e.g. 12 V). When one of the
outputs, e.g. 21, is brought to a near zero voltage, a
voltage difference will be applied to the motor terminals,
thus driving the motor in one direction. In reversing the
above situation the motor 64 is driven in the opposite
direction. Typically the outputs 21, 22 are connected to
the collectors of two power transistors (not shown). By
driving one of them, into a saturation state, its collector
will assume a predetermined voltage level, such as a few
tenths of volt thus allowing for the motor rotation.
Logical unit 26 receives a start pulse from the
photoelectric detector 53, 54 which starts the rotation of
the motor 64 in the dispensing direction. This rolation is
sensed by tt-e above-described monitoring device comprising a
disc 65 with peripheral cuts 66 rotated by shaft 120 and a
photoelectric detector 68, 69. In this way a number of
pulses proportional to the rotation of rollers 63 (that is
to the dispensed paper length) is supplied to the logical
unit 26. These pulses are stored and their is compared with
the preselected configuration set on the described switches
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M. When a nurnber of pulses has been received -that is equal
to the selected one, the motor 64 is stopped and its
rotation reversed for a predetermined tirne to accomplish the
complete rotation of pinion 112, i.e. the cut of the web 5.
A protection circuit 76 disables the drive circuit 23 in
case switch 49 (paper exhaustion) is open and further
provides for the control of light indicators 36, 37. A d.c.
power supply 77 feeds all the circuits and cuts the feeding
upon the opening of -the cover 2. The following is a brief
description of the operation of the dispensing apparatus
according to the invention, as desoribed above.
The apparatus is vertically mounted on a wall or the
like and properly connected to the mains for the power
supply, so that the light indicators 36, 37 show its state
of service. in case the paper roll 8 is exhausted (or the
paper web not currently introduced between plates 60 and
30), light 36 signals an out-of-service condition.
To introduce a fresh paper roll 8, the cover 2 is
opened by the service personnel with the proper key and
lifted until the articulated bars 4 are aligned and keep it
open. Upon lifting the cover 2, peg 44 disengages the tab
42, thus opening switch 50 so that the electric power supply
is cut off during servicing. A paper roll 8 is mounted and
automatically centered between brackets 15 and thereafter
plate 30 is tiIted forward to correctly position the paper
web 5 on rollers 63. Then plate 30 is returned to the
original position and the cover 2 is closed again. Paper
web 5 is pressed between rollers 63 and rolls 35 by the
closed cover 2 pressing on raised portion 38 of plate 30,
rollers 35 being slightly displaced against the action of
spring means (not shown) on which the shaft 33 of idle
rollers is mounted. Paper web 5 fur-ther presses tongue 40
of switch 49 so that the out of service indicator 37 is off
when the cover 2 is closed and paper web 5 in place.
In case the length of the paper towel is to be changed,
before introducing the web 5 between plates 60 and 30~ the
operator opens door 25 and sets a different configuration on
the microswitches M o-f the control circuit board 39. These
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switches (for example four) represent how many elementary
lengths of paper web 5 will be dispensed before the web is
cut. As an exarnple, in case all the switches are set on,
the rnaximum length of paper will be dispensed. If only the
first switch is sent on and all the remaining are off, the
length of the dispensed paper web will be haIf of the
maximurn, ancl so on, according to the rules of binary
arithmetics. As an example, the elernentary length chosen
for the apparatus can be in the order of 2 cm and the
maximum length dispensed at each cycle would be 15 times
this length, corresponding to binary configuration 1111 of
the switches. A table showing the correspondence between
the towel length and the configuration of the switches can
be attached to plate 60 for easy reference.
When the user moves a finger in recess 58 he interrupts
the light beam between the LED 53 and the phototransistor 54
thus starting the dispensing cycle. Known circuit
arrangements can be provided to disable further actuation of
the apparatus for a predetermined time. The control circuit
23 wilI drive the motor 64 in a direction such as to rotate
rollers 63 and advance the paper web 5 out of the dispenser
apparatus. The rotation of shaft 120 carrying the driving
rollers 63 will be monitored by the control circuit which
compares the number of pulses received from the
above-rnentioned photoelectric device 68~ 69 with the
predetermined number deriving from the set switches M. Upon
detecting the identify of the two numbers, motor 64 is
s-topped and driven in the opposite direction for a complete
rotation of pinion 112. This way blade 56 performs a
reciprocating movement cutting alrnost completely the
protruding web 6 and returning to the original position.
Since a narrow middle strip of paper web is left uncut by
the presence of recess 145 in blade 56, the towel 6 will
remain hanging below the dispenser and can be easily
detached by the userO After the cutting, the apparatus is
ready for another dispensing cycle.
Referring to FIGS 9 and 10, there is illustrated a
further embodiment of the paper towel dispensing apparatus
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provided by the invention and indicated generally by
reference numeral 1'. The apparatus 1' is generally similar
to the apparatus 1 illustrated in FIGS. 1 and 2, and
accordingly, like elements have been given the same
reference numeral and similar elements have been given the
same reference numeral with a prime notation.
The apparatus 1' in battery-powered and the internal
housing 16 formed near the rear wall ~4 contains the battery
holder (not shown). The battery may be, for example, nine
elements of 1.5 volts each. The battery holder includes
suitable connectors for extending power to the elements of
the apparatus 1'. Preferably, the housin~ 16 may be adapted
to be opened to allow substituting the individual battery
elements only from the inside of the apparatus 1' in or~er
that access is possible exclusively to authorized personnel.
Additional modifications of the apparatus 1' relative
to the apparatus 1 reside in the elimination of the optical
devices, which require continuous emission of light, in
order to minimize drain on the battery.
To this end, the indicators 36 and 37 (FIG. 1) are
eliminated, and the photoelectric arrangement 53,54 is
replaced with a microswitch assembly 53' mounted on the
underside of cover 2 and contacts 36a and 37a which are
mounted in a lateral block 45'. Block 45' corresponds to
block 45 in the apparatus 1, but is formed with a pair of
recesses 58' within which the contacts 36a and 37a are
mounted. Referring to FIG. J2, the microswitch assembly 53'
includes a microswitch 53a, a mounting plate 170 on which
the microswitch 53a is mounted and screws 54 which secure
the plate 170 to the posts 172 in the underside of the cover
2. The microswitch 54a provides an input to the logic unit
26 (FIG. 16) in place of the optical detectors 53, 54 (FIG.
~) of the apparatus 1 (FIG. 1).
As it is better seen in Fig. 12, block 45' mounts the
two contacts 36a and 37a which, upon closing of the cover 2
of apparatus 1, are connected with the terminals of
microswitch 53a provided for the starting of the operative
cycle of the rnachine. The microswitch 53a, when operated,
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interconnects contacts 36a and 37a via its contacts and
plate 170 to a connect power to the logic circuit 26 (Fl~.
14) which energizes the motor 64.
The start microswitch 53a is advantageously fixed on
the under side of the cover 2 by means of screws 54 which,
besides fixing tne plate 170 onto which -the microswitch is
mounted, engage the contacts 36a and 37a of the block 45a
upon closing of the cover 2. Plate 170, for example, may
include conductive portions dispersed in electrically
conducting relation with screws 54, and adapted to be
interconnected by the microswitch contacts when the
microswitch 53a is operated. Access to the microswitch 53a
preferably takes places without direct contact, by means of
an elas-tic membrane 171 provided on cover 2, onto which it
is sufficient to exert a slight pressure in order to s-tart
the operation cycle. Naturally other control devices may be
used in lieu of the mentioned microswitch, but preferably
avoiding optical devices which require a continuous emission
of light, in order to reduce as far as possible the
consumption of the battery.
In accordance with another aspect of the invention, the
apparatus 1' includes an improved safety device for cutting
off the power from the apparatus 1' when the cover 2 is
lifted. With reference to FIG. 11, the cover 2 is provided
with a peg 44 as in the apparatus 1 shown in FIG. 1, but
which, in contrast thereto, does not actuate switch 50' by
simply lowering a tab projecting therefrom as for apparatus
1' shown in Fig. 6. In the apparatus 1, the opening 43
provided in the right-hand compartment of the apparatus
enables peg 44, passing through it upon closing the cover 2,
to depress a lever 150 which pivots about arm 152a about
pivot 154, rotating arm 152b therewith, against the force of
restoring spring 153 which is connected between the free end
of arm 152b and the paddle 151 of a transmission element
152. Depressing of element 152 closes switch 50' connected
with the power supply of the apparatus.
In the apparatus 1' the brackets 15', which carry the
paper roll 8 are represented sche,natically in FIC.S. 9 and 10
lt~~ t~"~,
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as well as, in greater detail, in FIG. 13 wherein they are
represented symmetrically slidable in a self-centering
fashion, under the push of a tension spring 78. The
self-centering characteristic of brackets 15' is realized by
means of an idle gear transmission 155 which mutually
connects the bracke-ts 1~' to each other by rneans of
rack-type toothed profiles 156 solidly fixed or integral to
the brackets themselves. In such a way, displacing one of
the two brackets from i-ts equilibrium position determined by
10 the spring 78, the gear 155 rotates by a certain number of
teeth, thus displacin~ by the same number of teeth in an
opposite direction the rack relative to the other bracket
15' so that the two brackets always moves symmetrically with
respect to a center axis passing through -the rotating shaft
of gear 155. ~he self-centering brackets may be used in
dispensing apparatus for paper towels powered by electric
distribution network, such as the apparatus 1 shown in FIG.
1 .
The apparatus 1' also includes a modified
unidirectional spring type control for the operation of the
shafts 110 and 120, which control the paper cutting
mechanism and the paper advancement mechanism, as will be
described. The modified control rnay be used in the
apparatus 1' shown in FIG. 1. With reference to Flg. 14,
the pinions 112' and 122', both moved by a power shaft 80
(Fl&. 3) through a kinematic chain, such as that for the
apparatus 12 in (FIG. 3), are connected respectively with
said shafts 110 and 120 through unidirectional couplings
160' and 161' of opposite direction. Both pinions may
rotate freely in both directions with respect to the plate
51 onto which they are mounted. The coupling 160' couples
pinion 112' with shaft 110 only when such a pinion is
rotated in a determined first direction, while a rotation in
the opposite direction of the same pinion does not drive
shaft 110.
The coupling 161' connects pinion 122' with shaft 120
only when this pinion is rotated in an opposite direction
with respect of said first direction, while it disengages
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shaft 120 during rotation of the pinion in the other
direction. The two unidirectional couplings 160' and 161'
are made, according to the present invention, as shown in
FIG. 14, thus been extremely reliable though been simple and
unexpensive. To this end, only two springs 162' and 163' of
the so-called "pinching" or "throttling" type are used being
would, respectively, in opposite directions, over the hub
113' co-axial and integral with the shaft 110 and over the
hub 114 which is in turn co-axial and integral with the
shaft 120. One end of each spring 162', 163' is fixed to
the corresponding pinion 112' and 122' respectively, while
the other is free so that, when rotation of the two pinions
(which takes place always in the same direction) is such to
cause a tight clamping of the coils over one of the two
hubs, the latter is driven in rotation -together with the
corresponding shaft, while the coils of the other coupling,
wound in the opposite direction, will loosen around the
associated hub which shall not be driven into engagement
thus causing the corresponding shaft to remain stationary.
To the aim of ensuring that such a shaft which is not
to be rotated remains effectively still, a reversal device
is provided which is formed by a double spring of the
"pinching" type 109' would with a portion of its coils 115'
around a second hub 113a' co-axial and integral with said
first hub 113' on shaft 110 and having a second portion of
coils 116' wound around another hub 114a' co-axial and
integral with hub 114' on shaft 120. With one or the other
of said portions 115' and 116', said spring 109' blocks one
or the other hub, and the associated shaft, whichever is
left free by the associated spring 162' or 163', preventing
any accidental reaction.
Referring to FIG. 15, the cutting device 85' for
apparatus 1' is operated as described and shown for the
cutting device 85 tFlG. 5) for the apparatus 1 illustrated
in FIG. 1, by a cam 130 rigidly connected to one end of the
shaft 110 and provided with a pin 132 running in a slot of a
lever 131. At the other end, a similar device (such as cam
139 with the pin 136 illustrated in FIG. 6) ensures the
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correct opera-tion of the cutting device 85' formed by a
stationary blade and a mobile blade. \~i-th reference to
FIGS. 15 and 16, a paddle 165 is rigidly connected with the
lever 131 by a screw 166 (similarly another paddle rigidly
fixed with lever 135 is mounted on the opposite side of the
appara~us), while -the small shaft 127 onto which lever 131
is pivo-tedly mounted, may move with respect to paddle 165
sliding in a slot 164 formed therein. At the end of the
cutting step of the paper web, rotation of pinion 112' still
continues until said paddle, in its movement represented
with dash lines in FIG. 15, blinds a photoelectric sensor
167 which, as shown in FiG. 16 is connected with the logic
unit 26 in parallel with the photoelectric detector 68-69,
causes the motor -to stop. It shouId be noted that the
energization of the logic unit 26 is determined by closing
of the microswitch 53a. It should be noted further that
whenever the paper roll ~ is exhausted (or if the paper web
is not properly inserted between plates 60 and 30 of FIG. 9
the cycle would not be activated. The paper web 5, when
correctly inserted, presses down the tab (indicated with 40
in FIG. 7) associated with the switch 49 of FIG. 16 which
thus enables the performance of the working cycle through
microswitch 53a with the cover 2 closed and therefore
contacts 36a and 37a preset and switch 50 closed.
As in the apparatus 1 (FIG. 1), before introducing the
paper web 5 between plates 30 and 60, the operator may
preset a different combination of the microswitches M of the
electronic circuit board 39 (FIG. 7) to program the number
of elementary lengths of paper web tha-t will be dispersed
before the web is cut, each time the microswitch 53a is
operated to initiate a dispensing cycle.
Possible additions and/or variations can be performed
by those skilled in the art to the above-described and
illustra-ted embodiment of the dispensing apparatus according
to the invention, without exceeding the scope of the
invention itself, with particular reference to the following
claims.
