Printing machine equipped with a device for the selective supply of sheets from two feed trays

The printing machine comprises a device for the supply of sheets. This dee is constituted in the form of a removable unitary module comprising means for taking-up motion. Selection means are provided and comprise motion distributing means associated with said take-up means to direct the motion to means for extraction of sheets.

BACKGROUND OF THE INVENTION 
The present invention relates to improvements in or to the portion of a 
printing machine for supplying sheets to be printed, and more particularly 
the invention relates to a printing machine comprising a device for the 
supply of sheets to be printed with at least two removable feed trays 
containing the sheets to be printed, extraction means, driven by a single 
principal motor, to extract the sheets from one of the trays and to propel 
them in the machine to the printing means, as well as selection means to 
cause the extraction means to cooperate selectively with one of these 
trays. 
It is customary at present, to equip printing machines or the like with two 
trays for sheets to be printed, either to facilitate the supply of the 
machine with a sheet of the same type, or to use selectively sheets of 
different characteristics (formats and/or colors particularly). 
Systems for the extraction of sheets from feed trays and for the selection 
of the appropriate tray are, in these known machines, driven by an 
electric motor this special purpose, that is to say, which is different 
from motors for advancing and printing sheets particularly; a motor with 
two directions of rotation is associated with a transmission train 
including two free wheels so as to drive selectively rollers for selecting 
sheets or starting rolls respectively in the two trays. The motor used has 
a very high rotary speed, so that the motion-transmitting gears also 
rotate fast, whence the generation of considerable noise: in addition, the 
pinions, to be sufficiently strong, must be metallic, which increases 
their cost and, taking into account the high speeds of rotation, they must 
be mounted on ball bearings or the like, whence an additional increase in 
costs. 
SUMMARY OF THE INVENTION 
It is a particular object of the invention to overcome the drawbacks 
presented by these known printing machines, and to construct the device 
for the selective supply of sheets so as to reduce its cost and to render 
it more silent in operation. It is also an object of the invention to 
improve thereby access to the different parts of the device for the 
selective supply of sheets, and even to the parts of the rest of the 
printing machine, so that the maintenance and possible replacement of 
parts are thereby facilitated, simplified and hence less laborious. 
Accordingly, a printing machine arranged according to the invention is 
characterized in that the device for the supply of sheets for printing is 
constituted in the form of a removable unitary module and comprises in 
addition means for taking up motion which are adapted to cooperate by 
simple contact with a rotary member driven by the abovesaid principal 
motor situated outside the supply device, in the remaining part of the 
printing machine, and which are arranged in addition to transmit this 
motion to the inside of the device, and wherein the abovesaid selection 
means comprise distributing means for movements associated with said means 
for taking up and transmitting motion to direct the motion to the means 
for sheet extraction from the selected tray and drive means to actuate 
said distributing means so that the latter can occupy at least three 
positions, namely at least two operational positions in which they 
cooperate selectively respectively with the means for extraction from the 
two trays and a neutral position in which they cooperate with none of the 
means for extraction from the trays. 
The arrangement according to the invention enables the need for a specific 
motor for the taking up of sheets from the feed trays to be dispensed 
with, whence a further source of considerable economies. 
In addition, the arrangement of the device in the form of a removable 
module procures, after extraction of the latter from the printing machine, 
a greater facility of access to the mechanisms and simplifies the work of 
maintenance. A damaged device can immediately be replaced and the machine 
thus only undergoes stoppage for a short period. In addition, the 
maintenance of the rest of the printing machine can be facilitated 
thereby, since the extraction of the module provides easy access to the 
other internal components. Finally, this arrangement multiplies the 
operational possibilities of the machine, since it is possible to provide 
modules of different types, equipped, for example, for sheets of 
particular format and/or composition. 
It is particularly advantageous for the taking up of the necessary motion 
to be done on a rotary member forming part of the mechanism for moving the 
sheets line by line in the course of the printing and for the aforesaid 
principal drive motor be the inter-line motor actuating this mechanism: in 
fact, such a motor rotates very slowly (for example one revolution per 
second) and the drive mechanism can then be constructed by means of gears 
and parts of plastics material, obtained by molding, and hence 
inexpensive: in addition, the whole operates with an extremely low noise 
level; finally, this unity of the drive means for the extraction of the 
sheets from the trays and movement of the sheets in the course of printing 
before the printing means results in a synchronism for the advance of the 
sheets throughout their passage from the storage tray to the outlet from 
the printing machine after printing. 
In order to render less critical the tolerances of positioning the module 
in the printing machine, it is advantageous for the means for taking up 
the movement to be able to cooperate by simple contact and without precise 
adjustment with the rotary member fast to the motor. To this end, it is 
possible to provide for the means for taking up and transmitting movement 
to comprise an arm, projecting at least partly outside the device for 
supplying sheets and articulated in rotation on said device; a motion 
take-up wheel, borne by the free end of the arm, adapted to cooperate with 
the rotary member of the mechanism for driving sheets into the printer; 
endless belt supported by two pullies or the like, one of which is coaxial 
with the movement take-up wheel and fast to the latter in rotation and the 
other of which is coaxial with the axis of articulation of the arm on the 
device; and elastic return means associated with the arm arranged so that 
the movement take-up wheel is applied elastically between the rotary 
member. 
In a preferred embodiment, the distributing means comprise a balance wheel 
supported for rotation coaxially with the articulation axle of the arm and 
bearing at least one satellite wheel which coacts with a driven wheel, 
fast to the support pulley of the coaxial endless belt, coaxial with the 
articulation axle of the arm and which is adapted to come into contact 
selectively with one or other of the means for extraction of sheets from 
the trays. 
Advantageously, the drive means for the actuation of the balance arm 
comprise a drive member coupled to the pivoting balance wheel and an 
electric motor of which the output shaft cooperates in rotation with the 
circular actuate edge of the drive member of the balance wheel. 
In the case of a printing machine equipped with two trays, the balance 
wheel advantageously supports two satellite wheels adapted to cooperate 
selectively with the sheet extraction means associated respectively with 
the two trays and the electric motor can be actuated in both directions of 
rotation to result in the cooperation of the balance wheel respectively 
with one or other tray.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now first more specifically to FIGS. 1 and 2, is shown a portion 
(in general the rear portion or a side portion) of a printing machine 1 
denoted by its casing 2, the part concerned of the machine being that 
where the reserve of sheets to be printed (for example, sheets of paper) 
is to be found. Of the rest of the machine there are shown 
diagrammatically only the motor 3 or the interlinear motor designed to 
move a sheet (not visible) before the printing means line by line (not 
shown), as well as a gear wheel 4 fixed to the axle of this motor. 
The rear or lateral surface 5 of the casing 2 is dismountable to yield 
passage (positioning or extraction) to a module device 6 for the supply of 
sheets constituted in the form of a removable module. The device 6 is 
arranged to support, in any manner known in itself for this purpose, two 
trays 7 superimposed and charged with sheets 8, the trays being removable 
through corresponding openings of the face 5. Above each tray is situated 
a detachment roller or wheel 9, fixed to an axle 10, driven in rotation, 
which extracts the sheet 8 situated on the top of the corresponding pile. 
To drive the appropriate roller 9, recourse is had to the following means. 
Device 6 is provided with an arm 11, projecting partially outside, which 
at its inner end (right-hand end in FIG. 2), is mounted to pivot on an 
axle 12. At its other end, (left hand end in FIG. 2), the arm 11 bears a 
gear wheel 13 adapted to cooperate with the gear wheel 4 driven by the 
motor 3. In addition, an endless link, such as a notched belt 14, is 
supported on one side by a pulley 15 coaxial with the wheel 13 and fast in 
rotation with the latter and by a pulley 16 rotating loose on the axle 12 
of the opposite end of the arm. A gear wheel 17 is mounted on the axle 12 
and is fast in rotation with the pulley 16. In addition, a balance wheel 
18 is also supported to rotate freely on the axle 12, this balance wheel 
having the shape of a circular sector centered on the axle 12 and 
supporting at its two ends two loose gear wheels or satellite wheels 19 
enmeshing with the gear wheel 17. The circular periphery, or a portion of 
the latter, of the balance wheel 18 is toothed (at 20) to cooperate with a 
gear wheel 21 driven by a motor 22 with two directions of rotation 
controlled by a suitable selection means (commutator-reversor) (not 
shown). 
In the operating position of the printing machine shown in the figures, the 
gear wheel 13 borne by the outer end of the arm 11 is held supported 
against the leading gear wheel 4 under the action of an elastic return 
force due to a spring 23 inserted between the arm 4 and a fixed part of 
the device. The motion is thus transmitted to the gear wheels 19 which are 
driven permanently. 
The selection of the upper tray 7 or lower tray is effected by controlling 
the appropriate direction of rotation of the selection motor 22 which 
drives the balance wheel 18; for example in the direction of the arrow 24, 
as shown in the Figures, to bring the upper gear wheel 19 into contact 
with a gear wheel 25 fixed to the upper shaft 10 (the lower gear wheel 19 
then being disengaged from the gear wheel 25 fixed to the lower shaft 10): 
it is then the sheets 8 from the upper tray which are delivered to the 
printing machine during the printing. 
The selection of the lower tray is done by reversing the direction of 
rotation of the motor 22 so as to disengage the upper wheels 25 and 19 and 
to cause the lower wheels 25 and 19 to cooperate. 
In addition, a return spring 26 is associated with the balance wheel 18 to 
bring back the latter into neutral position in the absence of a command 
from the selection motor 22: the wheels 25 and 19 both lower and upper no 
longer cooperate. 
In the assembly which has just been described with reference to FIGS. 1 and 
2, it is observed that, for a given direction of rotation of the wheel 17, 
the cooperation of one or other of the satellite wheels 19 with the 
corresponding wheels 25 is not performed identically: for one of the pairs 
of wheels 19-25, this cooperation is "engaging" (that is to say the forces 
which are exerted on the satellite wheel 19 tend to force the latter into 
its contact with the wheel 25), whilst for the other pair of wheels 19-25 
this cooperation is "disengaging" (that is to say the forces which are 
exerted on the satellite wheel 19 tend to separate the latter from contact 
with the wheel 25). Consequently, it is necessary for the motor 22 to 
generate sufficiently high torque to maintain the required engagement of 
the wheel 19 with the wheel 25, including here the case of "disengaging" 
cooperation, which risks resulting in excessive fatigue of the motor and 
its rapid wear or the overdimensioning of the motor which is then more 
laborious. 
To overcome this drawback, it is proposed to provide the modification of 
the embodiment shown in FIG. 3 (in which the same reference numerals 
denote parts identical with those of the device of FIGS. 1 and 2). In this 
embodiment, the gear wheel 21 of the motor 22 acts on the balance wheel 
18, not directly, but through a pivoting drive member 27. The member 27 is 
shaped as a circular sector mounted freely on its central axle 28 and 
enmeshing, through its toothed edge of circular arcuate form 20, with the 
leading wheel 21. Opposite the toothed edge 20, the drive member 27 bears 
a finger 29 projecting laterally and engaged in an elongated aperture 30 
of one portion facing the balance wheel 18'. In addition, the member 27 is 
provided with stop studs 31 projecting laterally adapted to come against 
corresponding fixed stops 32 (for example borne by the frame). Finally a 
stop 33, rectractable on encountering a return force due to a spring 34, 
can be engaged in a notch 35 of the drive member 27 to materialize the 
neutral position (position shown in FIG. 3). Generally, the arrangement is 
such that the pivoting axle 12 of the arm 11, the pivoting axle 28 of the 
drive member 27 and the axle of the gear wheel 21 are aligned, the axle of 
the finger 29 being also situated in this alignment in the neutral 
position of the device. 
In the embodiment which has just been described, the rotation of the wheel 
21 causes the pivoting of the member 27 which, in its turn, through the 
finger 29 engaged in the aperture 30, causes the tilting of the balance 
wheel 18' in the appropriate direction. The reaction forces to which the 
balance wheel 18' is subjected are taken up and compensated by the drive 
member 27, and the motor 22 then has only to provide a relatively weak 
maintenance torque, permitting the use of a motor of low power. 
Taking into account the rotary speed (of the order of 1 rotation per 
second) of the interlining motor 3, the whole of the kinematic chain of 
the device 6 itself also operates at low speed and hence remains silent. 
Another consequence of this low speed is the possibility of resorting to 
gear wheels of plastics material less expensive and less noisy than 
metallic gear wheels. In addition, resorting to an elastic return arm 11 
ensures efficient cooperation of the gear wheels 4 and 13, whatever the 
longitudinal position (within a certain range) of the device 6 with 
respect to the motor 3, which renders the tolerances of said positioning 
less critical. 
In addition, this arrangement enables an economy to be effected in the 
motor traditionally allocated to the extraction of the sheets from the 
trays. 
Finally, this arrangement procures a synchronization of the advance of the 
sheets both on their extraction from the tray and on their passage before 
the printing means of the printing machine. 
While preferred embodiments of the present invention have been illustrated 
and described, it will be apparent to those skilled in the art that 
modifications can be made within the scope of the invention which is 
defined in the appended claims. Accordingly, the foregoing embodiments are 
to be considered as illustrative only, rather than restricting the 
invention and those modifications which come within the meaning and range 
of equivalency of the claims are to be included herein.