Improvements in Mechanism for Starting and Intercepting the Printing Cylinder of Rotary Printing Presses and like Machines.
Year: 1898

page_text: Date of Application, 8th Dec., 1898-Accepted, 24th June, 1899
COMPLETE
SPECIFICATION.
Improvements in Mechanism for Starting and Intercepting the
Printing Cylinder of Rotary Printing Presses and like Machines.
I, FRITZ FRISCH, of V., Academy Street 7, Budapest, in the Empire of Austria,
Mechanical Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:
-
This invention relates to certain novel mechanism intended to be attached to or
form part of rotary printing machines and the like, wherein the printing (or
pressure) cylinder is set in rotary motion-say by means of racks, rigidly secured
to a reciprocating carriage and of a toothed wheel in gear therewith, after having
taken up the sheet of paper to be printed on; while, as the rack (or racks) recede
i.e. move in the direction opposite to that of the revolving cylinder, they come out
of gear with the said toothed wheel, with the result that the printing cylinder
remains stationary upon its shaft or spindle and thereby enables the other opera-
tions, such as the moving into position of the next sheet and so on, to be performed.
The means which have hitherto been employed in securing this temporary
stoppage of the printing cylinder consisted in removing the tooth of the toothed
wheel at the part (and for a distance) corresponding to the period during which
it was to remain out of gear with the rack; while the cylinder was at the identical
moment intercepted and detained by a fork-shaped arrangement. By this con-
trivance the printing cylinder, set in rapid rotary motion, is, by its own momentum,
while in full swing, thrust into the said intercepting fork, the moment it gets
out of gear with the rack. Now in consequence of this sudden movement the
machine invariably sustains a shock, which interferes with its smooth operation
and has a damping influence upon the quality of the printing.
This invention, therefore, consists of an improved cylinder intercepting device,
the main feature of which is that the printing cylinder, or its toothed wheel,-
which is never disengaged from the rack-is not caught, or held, until after it has
already ceased moving the moment, when this occurs, coinciding with the "dead
point reached by the rack when it is about to reverse the direction of its motion.
In the accompanying drawings;
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Figure 1 is a side elevation of the parts of a rotary printing press to which this
invention relates:
Figure 2 is a rear elevation of the same:
Figure 3 is a section on line y-y Figure 1, illustrating the arresting device,
but omitting the intercepting lever and the mechanism controlling it;
Figure 4 is a section on line ra, Figure 1.
Upon the spindle or shaft 1, Figures 1 and 4 of the stationary printing
cylinder 2, there is loosely mounted a toothed wheel 3 which is in gear with the
rack 4 of the reciprocating carriage.
This wheel 3 is provided with guides 5 in which there moves a slide 6, the guide

page_text: groove of which moreover slides upon the knob or nave of the toothed wheel;
this last mentioned guiding arrangement serving to limit the extent of its motion.
The slide 6 is constantly pressed in the direction of the axis of the cylinder by
springs 8 mounted upon the toothed wheel. Upon the cylinder-shaft there is
keyed a cam 9 provided with a recess or notch 10, in which a tappet 11, belonging
to the slide 6, is adapted to engage.
The slide 6 is so operated, that as the rack 4 moves in the direction of the
arrow a (i.c. at the time of a sheet of paper being printed), its tappet 11 is in
engagement with the cam-notch 10; and consequently the cam 9 itself and,
through the medium of the shaft 1, the printing cylinder 2 also, are thus thrown
into gear with the tootlied wheel 3, and now perform exactly one revolution
therewith. (See the position indicated in dotted lines in Figure 1). Now when
the direction of motion of the rack comes to be reversed, and changed to that
indicated by the arrow 6 (See the full-line position in Figure 1), the tappet 11
of the slide becomes released from the notch 10, that is to say the cam 9 and
printing cylinder 2 are thrown out of gear, while the toothed wheel 3 runs back
idle upon the cylinder shaft ; and at the same time the printing cylinder is
retained by an arrangement specially provided for the purpose. The toothed
wheel 3 thus constantly remains in gear with the rack 4.
The arrangement which serves to operate the coupling device mentioned above
and to intercept or arrest the printing cylinder at the moment at which the
rack attains its dead point, so that the printing cylinder must stand still,-
consists of an intercepting lever 12 pivoted to the frame of the machine (as shewn
in Figures 1 and 2) which is connected by a rod or link 13 with a bell-crank
lever 14 also pivoted to the frame of the machine, the roller 15 of which, owing
to the action of the spring 16 engaging with the intercepting lever 12, constantly
rests against the cam 17 rigidly secured upon the crank shaft 18.
The cam 17 is so constructed that while its larger radius is in operation,―
which corresponds to one half of a revolution of the crank 19 moving from the
dotted position 191 into the position indicated in full lines; or to the movement of
the rack in the direction of the arrow b; a head or stock 20 of the intercepting
lever 12 strikes the slide 12 and keeps the tappet 11 out of engagement with the
notch 10, with the result that the toothed wheel 3 must run idle. When however
the smaller radius y is in operation,-which corresponds to that half of the
revolution of the crank during which it moves from the position 19 to the posi-
tion 191; or to the movement of the rack in the direction of the arrow
indicated in dotted lines in Figure 1); then the intercepting lever 12 releases the
slide which, being controlled by the spring 8, springs into gear with the above
mentioned notch by means of its tappet 11, thereby effecting the coupling of the
printing cylinder in its operative position.
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These two movements of the intercepting lever takes place alternately, cach
commencing the moment the rack attains the dead point, that is to say when the
crank 18 reverses the direction of motion of the rack 4 and also that of its carriage;
the printing cylinder being stationary at the time.
In order to retain the printing cylinder in position whilst it is inoperative, the 4
head 20 of the intercepting lever is furthermore provided with a projection 21
extending over the printing cylinder (Figure 2); such projection carrying a
projection 22 which, when the head 20 strikes the slide 6, simultaneously engages
in a perforation 23 provided for the purpose in the printing cylinder; which
cylinder it retains in position during the return movement of the carriage, after 5
the printed sheet has been given up."
The invention described above is applicable both to machines operated by means
of a crank handle and to those arranged for circular motion; and it possesses this
advantage in addition to those already named, that the machine fitted with the
normal mechanism, whilst operating more smoothly and producing a better quality 5
of work than the old machines of the same class have done, may move at a con-
siderably higher speed than those machines.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. Mechanism for starting and intercepting the cylinders of rotary printing
machines, the main feature of which is the driving wheel 3 loose upon the
cylinder shaft 1, which is provided with a resilient or spring-controlled slide 6
moving in suitable guides 5, a tappet 11 of which, being adapted to engage with a
notch 10 in a cam 9 mounted upon the said shaft 1 thereby throws the printing
cylinder into or out of gear with the toothed wheel.
2. In connection with the device claimed in the first claim, an intercepting
lever 12 serving for the operation of the same, the head of which, by striking the
slide 6 at the proper time, or by releasing it, as the case may be, throws the
printing cylinder into or out of gear with the toothed wheel; while, as the said
parts are thrown out of gear, a pin 22 provided on the intercepting lever 12, by
engaging with a perforation 23 of the printing cylinder, secures such cylinder in
position.
Dated this 8th day of December 18OS
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.