Record sheet cutter control device

A record sheet cutter control device which can cut a record sheet after a normal record sheet feeding operation has completely been stopped. The device comprises means for involving a difference in time between a signal for stopping the operation of a record sheet feed roller and a signal for starting the operation of a cutter.

BACKGROUND OF THE INVENTION 
This invention relates to a record sheet cutter control device for 
electrographic apparatus and the like, which comprises a roll-shaped 
record sheet, a record sheet feed roller and a cutter, and which can 
control the operational timing of the cutter for cutting the record sheet 
into a required given length. 
In such electrographic apparatus and the like which makes use of the 
roll-shaped record sheet, the record sheet is delivered therefrom by means 
of the record sheet feed roller and cut into a given length by means of 
the cutter, thereby using such given length of record sheet. In the above 
described kind of electrographic apparatus, the given length of record 
sheet delivered from the roll-shaped record sheet is detected by means of, 
for example, a microswitch, etc. so as to deliver a signal which functions 
to stop the feeding operation of the record sheet feed rollers and at the 
same time to operate the cutter. That is, use is made of an instruction 
device such as a microswitch which delivers an instruction for not only 
stopping the feeding operation of the record sheet feed rollers but also 
operating the cutter. 
In the above described conventional device, if the travel speed of the 
record sheet is not high, even when a cutter blade becomes in touch with 
the width of the record sheet with a time lag, it is possible to cut the 
record sheet in a line perpendicular to the side edge thereof, and as a 
result, that amount of the front end of the record sheet which is bitten 
onto the cutter blade is not sufficient to cause trouble. But, if the 
travel speed of the record sheet is high, when the feeding operation of 
the record sheet feed rollers is stopped at the same time as the operation 
of the cutter, the cutter becomes operated prior to the complete stop of 
the record sheet. As a result, the cutter blade becomes in touch with the 
width of the record sheet with a time lag. This causes the record sheet to 
be cut along lines other than the line perpendicular to the side edge 
thereof or causes the front end of the record sheet to bend downwardly 
along the cutter blade, thereby preventing the next successive record 
sheet from being normally fed. 
SUMMARY OF THE INVENTION 
An object of the invention, therefore, is to provide a record sheet cutter 
control device, which can eliminate the above mentioned drawbacks which 
have been encountered with the prior art techniques and which can cut a 
record sheet after a normal record sheet feeding operation has completely 
been stopped. 
A feature of the invention is the provision, in a record sheet cutter 
control device comprising a roll-shaped record sheet, a record sheet feed 
roller and a cutter, of the improvement comprising means for involving a 
difference in time between a signal for stopping the operation of the 
record sheet feed roller and a signal for starting the operation of the 
cutter. 
The invention will now be described in greater detail with reference to the 
accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In FIG. 1 is shown a prior art record sheet cutter control device which 
makes use of a roll-shaped record sheet. 
A record sheet is delivered from a roll-shaped record sheet 1 by means of a 
record sheet feed rollers 2 and supplies through a cutter 3 and delivery 
rollers 4 to an image transfer portion of the record sheet where an image 
on a photosensitive body is transferred onto the record sheet. The 
delivery rollers 4 are always rotated by a suitable driving means (not 
shown). One of the record sheet feed rollers 2 is driven by a driving 
means through an electrographic clutch (not shown) adapted to be operated 
by a feed roller solenoid 5. The cutter 3 is composed of an upper movable 
blade and a lower stationary blade. The upper movable blade is made 
movable with respect to the lower stationary blade when a cutter solenoid 
6 is energized. The cutter solenoid 6 is provided at its movable core with 
an operating plate 7 for operating a microswitch 8 which is normally made 
ON and becomes OFF when the cutter 3 is operated. 
In FIG. 2 is shown a prior art electric circuit of the record sheet cutter 
control device shown in FIG. 1. 
In FIG. 2, SOL1 designates the feed roller solenoid 5 shown in FIG. 1 and 
SOL2 designates the cutter solenoid 6 shown in FIG. 1. Microswitches MS1, 
MS2 and a relay RY1 are connected in series across terminals of an 
electric source V. A relay contact RY1/1 of the relay RY1 is connected in 
parallel with the microswitch MS1. Across the terminals of the electric 
source V are connected to solenoids SOL1 and SOL2 through a relay contact 
RY2/1 of the relay RY1 and a microswitch MS3. Under the normal condition, 
the microswitch MS1 is made OFF, and the microswitch MS2 is made ON and 
both the relay contacts RY1/1 and RY2/1 are made OFF. The microswitch MS3 
is a two-way switch which is provided with a common arm having one end 
connected to the relay contact RY2/1 and the other end selectively 
connected to either one of the solenoids SOL1 and SOL2. The microswitch 
MS3 is normally connected to the solenoid SOL1. 
If the microswitch MS1 is made ON so as to give an instruction of feeding 
the record sheet, the relay RY1 is energized so close both the relay 
contacts RY1/1 and RY2/1, thereby closing a self-holding circuit of the 
relay RY1 through the closed relay contact RY1/1. The closed relay contact 
RY2/1 causes the feed roller solenoid SOL1 to operate so as to permit the 
electromagnetic clutch to connect the record sheet feed rollers 2 to the 
driving means, thereby driving the record sheet feed rollers 2. If the 
record sheet feed rollers 2 are rotated, the delivery rollers 4 are 
rotated to deliver the record sheet. When that portion of the record sheet 
which is delivered from the feed rollers 2 arrives at a given length, the 
microswitch MS3 becomes operated to change over its common arm from the 
contact connected to the feed roller solenoid SOL1 to the contact 
connected to the cutter solenoid SOL2. As a result, the feed roller 
solenoid SOL1 becomes OFF to disengage the electrographic clutch from the 
driving means, thereby stopping the record sheet feed rollers 2. On the 
one hand, the cutter solenoid SOL2 is energized to permit the cutter 3 to 
cut the record sheet. That portion of the record sheet which is cut is 
delivered from the normally rotating delivery rollers 4. If the cutter 
solenoid SOL2 is energized, the record sheet is cut by the cutter 3 and at 
the same time the operating plate 7 secured to the movable core of the 
cutter solenoid 6 causes a microswitch 8 which represents the microswitch 
MS2 to be made OFF. As a result, the relay RY1 is deenergized to make the 
relay contacts RY1/1 and RY2/1 open, thereby opening the self-holding 
circuit of the relay RY1 and making both the solenoid SOL1 and SOL2 OFF. 
In addition, the microswitch MS3 is changed over and connected to the feed 
roller solenoid SOL1. This condition is maintained until the microswitch 
MS1 is made ON again. 
In such prior art device, when the microswitch MS3 is changed over from the 
feed roller solenoid SOL1 to the cutter solenoid SOL2, the cutter 3 
becomes operated prior to the complete stop of the record sheet feed 
rollers 2. As a result, there is a risk of the record sheet being cut 
along lines other than a line perpendicular to the side edge of the record 
sheet and, in addition, there is a risk of the front end of the record 
sheet being bitten onto the cutter blade. 
In FIG. 3 is shown one embodiment a control device according to the 
invention, which is constructed and arranged such that the above mentioned 
drawbacks which have been encountered with the prior art device shown in 
FIG. 2 can be eliminated. In FIG. 3, those circuit elements which function 
in the same manner as those shown in FIG. 2 are designated by the same 
reference numerals. 
In the present embodiment, between the microswitch MS3 and the cutter 
solenoid SOL2 is connected in series a timer circuit T. 
Similar to the prior art device shown in FIG. 2, if the microswitch MS1 is 
made ON, the relay RY1 is energized to close both the relay contacts RY1/1 
and RY2/1 whereby a self-holding circuit of the relay RY1 is maintained. 
As a result, the feed roller solenoid SOL1 becomes operated to permit the 
electromagnetic clutch to connect the record sheet feed rollers 2 to the 
driving means whereby the record sheet feed rollers 2 are driven by the 
driving means to deliver the record sheet. If a given length of the record 
sheet is delivered from the roll-shaped record sheet 1, the microswitch 
MS3 is changed over from the contact connected to the feed roller solenoid 
SOL1 to the contact connected through the timer circuit T to the cutter 
solenoid SOL2. This changed over condition of the microswitch MS3 is kept 
until the microswitch MS2 becomes OFF. As a result, the feed roller 
solenoid SOL1 is deenergized to permit the electromagnetic clutch to be 
disconnected from the driving means whereby the record sheet feed rollers 
2 become stopped. On the one hand, the timer circuit T functions to 
prevent the cutter solenoid SOL2 from being energized immediately after 
the change-over of the microswitch MS3 and permit the cutter solenoid SOL2 
to be energized after a lapse of time within which the record sheet is 
completely stopped. If the cutter solenoid SOL2 is energized, the record 
sheet is cut by the cutter 3 and at the same time the operating plate 7 
secured to the movable core of the cutter solenoid SOL2 causes the 
microswitch 8 which represents the microswitch MS2 to be made OFF. As a 
result, the relay RY1 is deenergized to make both the relay contacts RY1/1 
and RY2/1 open, thereby opening the self-holding circuit of the relay RY1 
and making both the solenoids SOL1 and SOL2 OFF. In addition, the 
microswitch MS3 is changed over and connected to the feed roller solenoid 
SOL1. This condition is maintained until the microswitch MS1 is made ON 
again. 
As seen from the above, the invention is capable of operating the cutter 3 
after the record sheet feeding operation has completely been stopped and 
hence is capable of eliminating the drawbacks that the record sheet is cut 
along lines not perpendicular to the side edge thereof and that the front 
end of the record sheet is bitten onto the cutter blade, those drawbacks 
being inherent to the prior art record sheet cutter control device. 
If that travel length of the record sheet which is located between the 
cutter 3 and the image transfer portion of the record sheet is longer than 
a given length of the record sheet to be cut, there occurs no problem. 
But, if the above mentioned travel length is shorter than the given length 
of the record sheet to be cut, the image transferred onto the record sheet 
which is cut by the cutter after it has completely been stopped is 
subjected to strain. As a result, in the latter case, it is necessary to 
adjust the timer circuit T such that the cutter 3 can be operated after 
such a time delay that the record sheet can be cut along a line 
perpendicular to the side edge thereof, that the front end of the record 
sheet is prevented from being bitten onto the cutter blade, and that the 
image transfer portion of the record sheet is not subjected to the strain. 
Thus, it is possible to feed the record sheet under a normal condition. 
In FIGS. 4 and 5 is shown another embodiment of a record sheet cutter 
control device according to the present invention. In the present 
embodiment, use is made of a spring clutch mechanism instead of the 
electrographic clutch for the feed roller solenoid 5 (SOL1) shown in FIG. 
1. 
In the present embodiment, a feed roller solenoid 9 is connected through an 
arm 11 to a lever 14 pivoted at a pivot 13, the arm 11 having one end 
pivoted by a pin 10 to the feed roller solenoid 9 and the other end 
pivoted by a pin 12 to one end of the lever 14. The lever 14 is provided 
at its intermediate portion between the pivot 13 and the other end of the 
lever 14 with a pawl 15 and between the pawl 15 and the pivot 13 with a 
spring 29 for urging the lever 14 in a counterclockwise direction about 
the pivot 13. To the other end of the lever 14 is opposed an operating 
plate 16 of a microswitch 17 which is adapted to be operated by the lever 
14. The record sheet feed roller 2 (FIG. 1) is provided at its shaft 18 
with a spring clutch mechanism adapted to be driven through a chain 19 by 
a driving means (not shown). 
As shown in FIG. 5, the spring clutch mechanism is composed of a sprocket 
wheel 20 engaged with the chain 19 and rotatably journaled in bearings 21, 
21 secured to the shaft 18 of the record sheet feed roller 2. The sprocket 
wheel 20 is provided at its hub with two stepped portions so as to form 
large and reduced diameter portions formed concentrically with the shaft 
18. On the large diameter portion of the sprocket wheel 20 is mounted an 
annular ratchet wheel 23 which is provided at its inside with a spring 24 
concentrically arranged with the shaft 18. The spring 24 is wound around 
the reduced diameter portion of the sprocket wheel 20. One end of the 
spring 24 is extended through a hole formed in the ratchet wheel 23 so as 
to function as a stopper whereby the position of the spring 24 relative to 
the ratchet wheel 23 in its rotational direction is made constant. 
The spring 24 is wound around the reduced diameter portion of the sprocket 
wheel 20 in a direction which is opposite to the rotational direction of 
the sprocket wheel 20 viewed from the side of the record sheet feed roller 
2. A front end portion of the spring 24 is wound around one portion of a 
boss 25 secured to the roller shaft 18. The ratchet wheel 23 is rotatably 
journaled on a portion of the boss 25 and on the large diameter portion of 
the hub of the sprocket wheel 20. The boss 25 is secured to the roller 
shaft 18 by means of a pin 26 so as to be rotated together with the roller 
shaft 18. Reference numeral 27 designates a thrust collar adapted to 
prevent the bearings 21, 21 and boss 25 from being axially displaced and 
28 is a bearing for rotatably supporting the roller shaft 18. 
As shown in FIG. 4, the lever 4 is normally pulled downwardly by means of 
the spring 29 so as to bring the pawl 15 into engagement with the ratchet 
wheel 23. 
If the feed roller solenoid 9 is made OFF, the pawl 15 engages with the 
ratchet wheel 23 to prevent rotation of the ratchet wheel 23. At the same 
time, rotation of the spring 24 is also stopped. As a result, the driving 
force transmitted from the chain 19 to the sprocket wheel 20 is not 
transmitted to the roller shaft 18 and hence the roller shaft 18 is 
stopped. In this case, the microswitch 17 is made ON, the operation of 
which will be described later. 
If the feed roller solenoid 9 is made ON, the arm 11 is pulled downwardly 
against the action of the spring 29 and hence the lever 14 is rotated in a 
clockwise direction about the pivot 13 to a position shown by dotted 
lines, thereby disengaging the pawl 15 from the ratchet wheel 23. As a 
result, the driving force transmitted from the chain 19 to the sprocket 
wheel 20 is transmitted through the spring 24, boss 25 and shaft 18 to the 
record sheet feed roller 2, thereby rotating the record sheet feed roller 
2. In this case, the microswitch 17 is made OFF. 
If the solenoid 9 is made OFF again, the spring 29 functions to pull the 
lever 14 downwardly so as to bring the pawl 15 into engagement with the 
ratchet wheel 23. As a result, the rotation of the ratchet wheel 23 is 
gradually retarded. If the pawl 15 becomes completely engaged with the 
ratchet wheel 23, the ratchet wheel 23 becomes stopped. As a result, the 
spring clutch mechanism functions to stop the record sheet feed roller 2 
and at the same time the microswitch 17 becomes ON. Thus, it is possible 
to control the rotation of the record sheet feed roller 2 by making the 
feed roller solenoid 9 ON and OFF. 
In FIG. 6 is shown an embodiment of an electric circuit of a record sheet 
cutter control device according to the invention for controlling the 
cutter with the aid of the above described spring clutch mechanism. 
In the present embodiment, microswitches MS1, MS2, relay RY1, and relay 
contacts RY1/1, RY2/1 are connected in the same manner as in the electric 
circuit shown in FIG. 3. The feed roller solenoid 9 shown in FIG. 4 is 
connected as the feed roller solenoid SOL1 and between the cutter solenoid 
SOL2 and the microswitch MS3 is connected the microswitch 17 shown in FIG. 
4 as a microswitch MS4 instead of the timer circuit T shown in FIG. 3. 
In the present embodiment, when the circuit is not operated, the 
microswitches MS1, MS4 and the relay contacts RY1/1, RY2/1 are made OFF 
and the microswitch MS2 is made ON. The microswitch MS3 is selectively 
connected to the feed roller solenoid SOL1. 
If the microswitch MS1 is made ON, the relay RY1 is energized to make the 
relay contacts RY1/1, RY2/1 ON, respectively. The relay contact RY1/1 
functions to maintain a self-holding circuit of the relay RY1. If the 
relay contact RY2/1 is made ON, the feed roller solenoid SOL1 (the feed 
roller solenoid 9 shown in FIG. 4) is energized to disengage the pawl 15 
from the ratchet wheel 23 thus rotating the record sheet feed roller 2. 
When a given length of the record sheet is delivered from the record sheet 
feed roller 2, the microswitch MS3 is operated to change over its contact 
arm from the feed roller solenoid SOL1 to the cutter solenoid SOL2 to make 
the feed roller solenoid SOL1 OFF. At this instant, the record sheet feed 
roller 2 is still rotated, but if the pawl 15 of the lever 14 becomes 
completely engaged with the ratchet wheel 23, the rotation of the ratchet 
wheel 23 is stopped, thereby stopping the rotation of the record sheet 
feed roller 2. At the same time, the lever 14 causes the microswitch 17 
(MS4 shown in FIG. 6) to be made ON. As a result, the cutter solenoid SOL2 
is energized from the electric source V through the relay contact RY2/1 
and microswitches MS3, MS4. As soon as the cutter solenoid SOL2, that is, 
the cutter solenoid 6 is energized, the cutter 3 becomes operated to cut 
the record sheet. 
As seen from the above, when the record sheet becomes substantially 
stopped, the microswitch MS4 (microswitch 17 shown in FIG. 4) becomes ON 
and the cutter solenoid SOL2 causes the cutter 3 to operate. As a result, 
it is possible to cut the record sheet along a line perpendicular to the 
side edge thereof and there is no risk of the front end of the record 
sheet being bitten onto the cutter blade. 
In addition, when the cutter solenoid SOL2 is operated, the microswitch MS2 
(the microswitch 8 shown in FIG. 1) becomes OFF to deenergize the relay 
RY1. As a result, both the solenoids SOL1 and SOL2 become OFF and both the 
microswitches MS3 and MS4 are returned to their original conditions. If 
the microswitch MS1 is made ON again, the above described record sheet 
feeding operation will be repeated. 
The use of the spring clutch mechanism described above provides the 
advantage that the spring clutch mechanism is cheaper than the timer T 
shown in FIG. 3, and that the cutter 3 becomes operated on the instant 
when the record sheet has substantially stopped irrespective of the 
distance from the cutter position to the image transfer position of the 
record sheet and of the length of the record sheet, so that the 
retardation time can easily be adjusted without involving any troublesome 
adjustment contrary to the timer circuit. 
In addition, if the rotating speed of the record sheet feed roller 2 and 
hence the travel speed of that portion of the record sheet which is 
located in the rear of the cutter 3 is made slightly higher than the 
rotating speed of the delivery roller 4 and hence the travel speed of that 
portion of the record sheet which is located in front of the cutter 3, 
that portion of the record sheet which is located between the cutter 3 and 
the delivery roller 4 is folded into a loop. As a result, the record sheet 
feeding operation becomes stopped, so oscillation, etc. induced in the 
record sheet when it is cut by the cutter 3 is not transmitted to the 
image transfer portion of the record sheet, whereby it is possible to 
eliminate the bad influence of such oscillations upon the image transfer 
portion of the record sheet. In addition, since the record sheet feeding 
operation can forcedly be stopped, it is possible to eliminate out of 
synchronism between the image transfer portion of the photosensitive body 
and the picture image forming portion of the record sheet. 
The invention is not limited to the above embodiments and various 
modifications and alternations may be made. The invention may be applied 
not only to the roll-shaped record sheet of the electrographic apparatus, 
but also to the roll-shaped record sheet of any other apparatus, for 
example, a facsimile receiver. 
The invention is capable of speeding up the travel speed of the record 
sheet and hence of speeding up the operation of the electrographic 
apparatus and the like.