Improvements in Offset Mechanism for Printing Machines.
Year: 1894

page_text: Date of Application, 23rd Oct., 1894-Accepted, 24th Nov., 1894
COMPLETE SPECIFICATION.
[Communicated from abroad by C. B. COTTRELL & SONS COMPANY, a
corporation organised under the laws of the State of New Jersey, and
engaged in business at Stonington, in the State of Connecticut, and at
No. 8, Spruce Street, in the City of New York, in the State of New
York, United States of America.]
Improvements in Offset Mechanism for Printing Machines.
1, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, 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 mechanism applied to the impression cylinder of a
printing machine for automatically shifting the tympan on said cylinder while the
machine is in operation, such mechanism including a supply roller from which a
web constituting the tympan is supplied, feed and take up rollers for drawing clean
portions of the web from said supply roller over the periphery of the cylinder and
taking up the soiled portions, and means for producing the necessary movements
of the feed and take-up rollers and for permitting, controlling and stopping the
movements of the supply roller.
The invention will be first described in detail with reference to the accompanying
drawings in which
Figure 1 represents an end view of an impression cylinder and parts attached
and contiguous thereto necessary to illustrate the improvements.
Figure 2 is a rear view partly in section of one end of the cylinder and the parts
of the printing machine contiguous thereto.
Figure 2 is an inner side view of one of the gears shown in Figure 2.
Figure 2 is a sectional view of parts of the cylinder and tympan and of a
tympan clamp.
Figure 3 represents a central vertical section of the same end of the cylinder
as is shown in Figure 2 and of the parts contiguous thereto.
Figure 4 is a side view of certain parts of the tympan shifting mechanism in a
different position from that shown in Figure 1.
Figure 5 is a front view of what is hereinafter termed the movable switch.
Figure 6 is a plan view of one end of the cylinder and parts thereunto attached
and adjacent.
Figures 7 and 8 are plan views to be hereinafter explained, of some of the parts
detached.
Figure 9 is a side view of part of the cylinder and attached parts illustrating a
modification of the tympan controlling mechanism represented in the preceding
figures.
Figure 10 represents a section, taken parallel with the axis of the cylinder, of
some of the parts shown in Figure 9.
Figure 11 a side view including part of the framing of the machine and one end
of the cylinder and of the mechanism which controls the stopping and starting of
the operation of the tympan shifting mechanism.
Figure 12 a horizontal section of certain parts detached.
Similar letters and numbers of reference designate corresponding parts in the
several figures.

page_text: A is one of the side frames of the machine and C the impression cylinder to
which our invention is applied, the said cylinder rotating in the direction of the
arrow shown upon it in Figures 1 and 11. The shaft C¹ of the said cylinder is
fitted to bearings in boxes a which are capable of an upward and downward
movement in housings on the framing in the usual manner.
The cylinder is represented as having only one tympan b, which consists of a
roll or web of paper nearly as wide as the cylinder and of a length many tinies
what is required to cover that portion of the surface of the cylinder by which the
impression is given. One end of this web is fastened to a roller c,
which may
be
termed the "supply-roller" and the other end is fastened to the roller d which
may be termed the "take-up roller," the said rollers being within the cylinder and
having their journals fitted to bushings c and d in the cylinder-heads. The
tympan bruns from the roller c to the exterior of the cylinder, as shown at in
Figure 1, thence over the impression-surface of said cylinder to the other end of
said surface, thence successively around and between the two feed rollers e f
arranged within the cylinder, and from the roller to the take-up roller d, as shown
in Figure 1. The feed rollers are fitted to bushings elf in the cylinder-heads
and are geared together by small spur gears e* and *, so that both rotate together
at the same speed, but in opposite directions..
D is a spur-gear concentric with the cylinder C. This gear is carried by
brackets g (see Figures 2 and 3) secured to one of the cylinder-boxes a, and as it
has no rotary motion, but simply rises and falls with the box a and always remains
in the same relation to the cylinder, it will be hereinafter spoken of as a
"stationary gear." On the stud f', (see Figures 1 and 2) which constitutes one
of the journals of the feed-roller f, is loosely fitted a small spur gear f³, which
gears with the said stationary gear D, and to which is firmly secured one member f
of a clutch, the other member 5 of which is affixed to the said stud *. To the
last mentioned clutch member there is secured a spur gear fe, larger than ƒ³,
which gears with a smaller gear on the take-up roller d. The small spur-
gear as it is carried around the stationary gear D by the rotation of the cylinder
is caused to derive a constant rotary motion upon its own axis; but it is only when
the clutch member attached to it, engages with the clutch member f, which is
fast upon the feed roller stud f, that any motion is given to the said feed-rollers
on their own axes and to the tympan, and this engagement does not take place
until it is desired to shift the tympan.
So far as the means for carrying out the present invention have hereinabove been
described, they do not differ from what is described in English Patent No. 5352,
dated April 8, 1890 and are now only described for the purpose of explaining the
means of throwing the clutch member into and out of engagement with its
mate. These means consist of what are hereinafter termed a "stationary
switch" E E' and a "movable switch" F F F F 12 and mechanism for effecting
and controlling the movements of the said movable switch. The said switches are
shown in Figures 1, 2 and 3, the movable switch being also shown separately in
Figures 4 and 5.
The stationary switch E E¹ consists of an arc-formed piece of metal concentric
with and rigidly attached to the outside of the stationary gear D. This switch_is
represented in Figure 1 as extended around a considerable portion of the gear D;
but it is not necessary for it to extend so far, its operating part being only at or
near the point E. The movable switch F F F F 12 is also of arc form, and is
attached to the gear D at the inner side thereof by means of a pivot F. This
movable switch may be said to be double, the part F 12 behind the pivot F³
constituting one member and the part F F above the said pivot being the other
member. The disengagement of the gear f³ and its attached clutch member f
from the other clutch member f, which is affixed to the feed roller stud f³,
effected by a cheek or flange on the outer side of the said gear being
brought by the revolution of the said gear with the cylinder against the bevelled
or rounded lower or rear end E¹ of the stationary switch. The engagement of the

page_text: said gear and the clutch member f¹ is produced by a cheek or flange ƒ³
on the inner side of the said gear f' being brought by the said revolution into
contact with the oblique face F (see Figure 5) of the upper member of the
movable switch. The movable switch is, however, only brought into the position
(shown in dotted outline in Figure 1) to act upon the cheek or flange of the
gear f³ at such times as it is necessary to shift the tympan, the said part of
the said switch at all other times occupying a position nearer to the centre of the
cylinder. The movement of the movable switch into and out of its operative
position is effected through a toggle connection with a lever G G. This lever
works on a fulcrum g', which is secured in the cylinder journal-box a. The said
lever has a long arm G, which extends more than half way round the cylinder-
shaft, and a shorter arm G¹, which constitutes one member of a toggle and is
connected by a link G2 which constitutes the other member of the toggle, and
pins with the movable switch. The toggle-arm G' has connected with it a
rod g, which runs through a guide 9 (see Figures 1 and 3) secured in one of
the brackets g by which the stationary gear D is attached to the cylinder-box.
Between said guide g³ and a nut or collar 9 on the said rod is a coiled spring g',
which exerts a tendency to straighten the toggle G' G, as shown in Figure 1
and bring the movable switch to its operative position when the lever G G
is free from a locking lever H, by which the said lever G G is engaged, as
shown in Figure 4, at all times except when the shifting of the tympan is to
be produced. The toggle when straight locks the switch positively in its
operative position. The locking lever H swings upon a pivot h, which is secured in
one of the aforesaid brackets g, and its lower end is notched to engage with the
free end of the lever G G¹, as shown in Figure 4, the said end being pointed to
engage with a notch in the locking lever. The said pointed end is furnished
with an antifriction roller 8, to be operated upon by a cam I, Figures 1 and 3,
bolted, as shown at i in Figure 3, to the hub of the cylinder C for the purpose of
throwing out the said end and producing the flexure of the toggle G G2, by which
the movable switch is brought to its inoperative position, in which it is locked
by the engagement of the levers G G and H, as shown in Figure 4.
The supply roller c is furnished outside of the cylinder C with a ratchet wheel c³,
to be engaged by teeth jij on the arm J of a pawl lever J J¹ (Figures 1, 2, 6 and 7),
which is fulcrumed on a stud jsecured in the cylinder head. The other arm J of
the said pawl lever has connected with it a rod 2, which passes through a guide
secured in the cylinder head, and between said guide and a nut or collar on the
said rod there is coiled upon the said rod a spring, which serves to throw the
teeth of the said lever into engagement with the ratchet wheel e².
To the arm J of the pawl lever there is firmly bolted or secured a sliding piece,
which conforms to an interrupted circular track D', which projects from the inner
face of the stationary gear D, concentric therewith. This track is not a complete
circle, but only extends about two hundred and sixty degrees, being interrupted,
as shown at 10, 11, in Figure 1. so that the said sliding piece je may pass from its
exterior to its interior and vice versa. At all times except when the tympan is to
be shifted, the said sliding piece remains held outward by the action of the
spring to run on the outside of the track D', and it passes by the interruption
or opening 10, 11 therein and clear of the end F and adjacent part 12 of the
movable switch, which is kept by the flexure of the toggle G G2 in such position
(shown in Figure 4) that there is room for the said sliding piece je to pass between
the said end and adjacent part of the switch and the said end 11 of the track;
but when the toggle lever G G has been unlocked by the disengagement of
the locking lever H, as shown in Figure 1, and its toggle G G has been
straightened by the action of the spring g', and the movable switch has been thereby
brought to the operative position shown in Figure 1, the lower member F2 12
of the said switch constitutes a prolongation of the inner face of the track DI
beyond the end 11 thereof, and the sliding piece is then carried by its
revolution with the cylinder into contact with the said member F' 12 of the switch,

page_text: which causes it and the end of the pawl lever to which it is attached to move
inward toward the centre of the cylinder and so to produce the disengagement of
the said teethjj of said lever from the ratchet wheel and leave the supply roller
free to permit the drawing off of the roll of paper therefrom by the feed
rollers ef. The said sliding piece runs from the part 12 of the lower
member of the movable switch into the interior of the track D', along which it
then runs and by which it is caused to hold the pawl lever disengaged from
the ratchet wheel until it passes the end 10 of the opening in the track and
permits the spring to produce the re-engagement of the pawl lever with the
ratchet wheel and the locking of the supply roller.
It will be understood from the foregoing description that the unlocking of
the supply roller c from the pawl lever J and the engagement of the feed
roller e with the gear f³, through which the latter roller receives its rotary
motion for shifting the tympan, are both produced and are produced separately
and independently of each other, through the movable switch F F F F 12 after
the said switch has been moved from its inoperative position shown in Figure 4,
to its operative position shown in Figure 1, and that this movement of the said
switch is produced by the action of the spring g' upon the toggle lever G G
on the liberation of the latter from the locking lever H. This liberation is
produced by the movement of the said lever H when, after the determined number
of revolutions of the cylinder, the proper time arrives for shifting the tympan.
The means by which the movement of the locking-lever H for the purpose of
liberating the toggle lever G G is effected will now be described. The said lever H
is connected by a rod with the arm K of a trip lever K K₁ (see Figures 1, 2
and 11) the fulcrum of which consists of a short rock-shaft k which works in a
bearing on the framing A. The other arm K' of the trip-lever has connected
with it a rod ², which runs through a fixed guide k, secured on the framing.
Between this guide and a nut or collar * on the said rod there is coiled upon
the said rod a spring * which by its pressure against said nut or collar tends to
press the locking lever H toward the toggle-lever so that when it is engaged with
the latter lever it will keep, the movable switch locked in its inoperative position
(shown in Fig. 4). The trip-lever K K' at the proper time for throwing out the
locking-lever H and allowing the movable switch to come to its operative position
is operated upon for that purpose through the agency of two intermeshing tappet-
gears L M which are both shown in Figure 12 and of which the one L is also
shown in Figure 2. The said gear L is fast on the cylinder shaft C' and drives
the gear M, which turns freely on a fixed stud m³, secured in the framing. The
gear M, which may be termed the "trip-gear," has a larger number of teeth
than L; the number on L being equal to the number of revolutions which the
cylinder C is to make before the shifting of the tympan, which is effected during
the next revolution. Suppose, for example, that L has two hundred and fifty-one
and M two hundred and fifty-two teeth, it being desired to shift the tympan during
every two hundred and fifty-second revolution of the cylinder. Every time the
gear L makes a revolution, the gear M lacks one tooth of the full revolutions, so
that during two hundred and fifty-two revolutions of the gear L the gear M will
make only two hundred and fifty-one revolutions. On the gear L is affixed a
tappet-tooth 1, and on the trip-gear M is a trip tappet m which is fitted to slide
radially on a guide m¹ on the said gear M, and to which is applied a spring m³,
which tends to press it outward. The tappet-tooth, the trip-tappet, and the
spring m are shown in Figure 12 which represents a section of parts of the
gears L M in a plane in which both of their axes are situated. In every two
hundred and fifty-second revolution of the said gear L the said tappet-tooth and
trip-tappet come together just as they are opposite a tappet-lug 13 on the arm K
of the trip-lever K K³, and the tappet-tooth will push in the trip-tappet far
enough to strike the said tappet-lug 13 and push the trip-lever A K¹ outward
from the centre of the cylinder and by that means, through the rod ², trip the
locking lever H from the toggle-lever G G¹. During two hundred and fifty-one

page_text: of every two hundred and fifty-two revolutions of the gear L, the tappet-tooth /
does not meet the trip-tappet m, and the spring m³ keeps the said tappet pushed
out so far that its inner end will not reach the tappet-lug 13 on the trip-lever
arm K, and therefore it is only in every two hundred and fifty-second revolution of
the gear L that the tripping of the locking lever H, as before described, takes
place. The tripping of the lever H is only instantaneous. As soon as the trip-
tappet m passes by the lug 13 on the trip-lever K K', the spring by its action
on the said lever returns the locking lever H to the position to again re-engage
and lock the toggle-lever the next time the point of the latter lever arrives at the
notch h¹ of the locking-lever.
The operations of the several parts of the tympan-shifting mechanism take
place in the following order. When in every two hundred and fifty-second
revolution of the cylinder C the locking-lever H is tripped, the spring g' at
once operates on the toggle-lever G G and produces the straightening of the
toggle G G³, and by that means the movable switch is brought to the operative
position shown in Figure 1, and immediately after this the sliding piece j on the
pawl-lever J is brought by the revolution of the cylinder within the cam-like
portion F 12 of the said switch, and as the said piece moves along the said portion
of the switch it throws the pawl-lever out of engagement with the ratchet-wheel c³,
and so unlocks the supply-roller c. Just as this takes place the inner flange or
cheek of the loose gear f³ comes in contact with the part F' of the switch, and
the continued revolution of the cylinder causes the said loose gear and with it
the clutch member to be moved inward into engagement with the member f³
of the clutch, which is fast in the journal-stud f' of the feed roller f, so that in the
further continued revolution of the said gears with the cylinder and in gear with
the stationary gear D, the said gear fs and with it the feed roller f will be caused
to rotate on their own axes. The two feed rollers e and f, being geared together
by the gears ef*, both operate to produce the drawing off from the roller c and
over the cylinder a clean portion of the tympan b, while the soiled portion which
they drew from the exterior of the cylinder is taken up by the take-up roller d.
This shifting of the tympan continues until a clean portion is brought to the
exterior of the cylinder, after which the continued revolution of the cylinder
brings the cam into operation on the roller 9% of the toggle-lever and thereby
throws the switch to its inoperative position, (shown in Figure 5) where it is locked
by the locking-lever H until after two hundred and fifty-one more revolutions of
the cylinder C have been made. After the shifting of the tympan, as before
described, has been completed, the cheek or flange of the gear is brought
against the bevelled end E' of the stationary switch, and the said gear and its
clutch member f' are thereby moved outward from the clutch member and feed
roller and disengaged therefrom. At the same time that the disengagement of
the gear from the feed roller f takes place the sliding piece of the pawl
lever J which has been running inside of the circular track D', passes the end 10
of the said track and is permitted to move outward, so that the spring is
permitted to throw the pawl lever into engagement with the ratchet wheel c² and
lock the supply roller c. The sliding piece ja will now continue to run outside of
the track D, the movable switch will remain in its inoperative position, the spur
gear remains disengaged from the feed roller, and the tympan will remain
stationary during two hundred and fifty-one more revolutions of the cylinder C,
when the operations of shifting the movable switch, throwing the gear f³ into
engagement and the pawl lever J out of engagement and the consequent operation
of shifting the tympan, as herein before described, will be repeated through the
next following revolution.
In order to prevent the stoppage of the roller c by the pawl lever J before the
stoppage of the feed rollers fand the consequent tearing of the tympan, the ratchet
wheel is not rigidly affixed to the said roller c, but is fitted loosely to the shaft
or journal c✶ thereof and is connected therewith by a coiled spring c³, one end of
which is secured to a collar c* (see Figure 10) fast on the journal e* and the other

page_text: end secured to the said ratchet wheel by a pin c. The said spring is so coiled
that when the said ratchet wheel is locked by the teeth jj of the pawl J J', the
said spring will tend to turn the journal and the supply roller in a direction to
wind back the tympan on the supply roller and so take up any slack that may
have been left in the portion of the tympan between the supply roller and the feed
rollers and draw the said portion of the tympan to a proper tension. It may be
understood that the said ratchet wheel, pawl lever and spring constitute a stop to
the supply roller which yields sufficiently to prevent the tearing of the tympan by
too early or abrupt stoppage of said roller. The spring e continues to produce a
tension on the tympan after the completion of the shifting operation and might be
made just sufficiently strong to lock the supply roller and hold the tympan securely
against the outside of the cylinder were it not that its effect on the tympan varies
according as there is greater or less length or quantity of tympan on that roller, its
tendency being to pull back the tympan when there is very little on the supply
roller and to yield to the drag of the impression and let the tympan move forward
when there is a larger quantity on the supply roller, in either case producing a
slight offset.
To overcome the tendency of the tympan to yield to the drag of the impression
there is represented in Figures 1, 2, 2B and 6, a clamp P P which constitutes
a positive stop, coming into operation after the yielding stop before described and
after the spring has brought the necessary tension on the tympan and clamping
the tympan to the cylinder at a point between the supply roller and the periphery
of the cylinder and so holding the tympan independently of the ratchet wheel c
and pawl lever J J. One of the members of this clamp consists of an eccentric
roller P. The other member P' may consist of any suitable bearing provided
within the cylinder but is represented as consisting of the hub or stock of the
clamp P such as is commonly employed for securing the blanket to the cylinder
under the tympan. The eccentric journals p of the said roller or clamp member P
are fitted to turn in bearings in the ends of the cylinder. On one of these
journals p is firmly secured an arm p' which is connected by a short rod or link p³
with one arm N of a clamping lever N N₁ (see Figures 1, 6 and 8) which is
pivoted to the same end of the cylinder with the lever J J' by a pivot n'. That
arm N of the said lever N N¹ which is connected by the link p² and arm pl with
the clamp member P has pivoted to it a sliding piece n which is capable of running
either on the inside or on the outside of the stationary interrupted track D'. To
the other arm N' of the said lever N N¹ is secured a rod n which works through
a guide fast on the end of the cylinder. This rod n² is furnished with a nut or
adjustable collar between which, and the same guide a spiral spring n³ is
coiled around said rod. The spring n' exerts a tendency to throw the arm N of
the lever N N outward from the centre of the cylinder towards a position in
which the sliding piece n may run on the outside of the track D' as shown in
Figure 1, in which position the lever acting through the link p and arm pl of the
clamping member P, holds said member in a position to clamp the tympan, as
shown in Figure 28. The lever arm N is furnished with a stud or projection n'
which projects under the lower edge of the arm J of the pawl lever J J¹ for two
purposes, first of keeping the teeth j of the pawl lever in engagement with the
ratchet wheel c³ for some time after the sliding piece of the latter passes the
end 10 of the track D', and second, of afterwards causing the clamping lever to be
operated by the pawl lever to open the clamp.
The operation of the clamp P P1 takes place in the following manner. The
cylinder rotating in the direction of the arrow shown upon it in Figure 1, we will
first suppose the pawl lever J J' and the clamping lever N N to be held by their
respective springs and in such positions that their sliding pieces ; and n may
run on the outside of the circular track D', as shown in Figure 1, the teeth ; of the
pawl lever JJ stopping the ratchet wheel c and the clamping lever N N holding
the clamp member P in action on the tympan until the time arrives for shifting the
tympan when the pawl lever is to be automatically disengaged from the ratchet

page_text: wheel and the clamp P P¹ automatically loosened, the said disengagement and.
loosening being permitted by their sliding pieces and n passing by the end 10 of.
the track D. The disengagement of the pawl lever J J¹ à es not occur until the
sliding piece n of the clamping lever N N₁ has passed the end 10 of the track
because up to that time the pawl lever has been held in engagement by the
projection n' on the clamping lever; but as soon as the sliding piece has passed.
the point 10, the clamping lever is left free to be moved to open the clamp by the
action of the pawl lever on its projection or stud n. The sliding pieces both.
having arrived opposite the opening 10, 11 in the track D', may both pass into the:
interior thereof. As long as they run inside the track, the ratchet wheel c² remains.
free and the pawl lever holds the eccentric roller P or clamping member in a
position to leave the tympan free so that the turning of the supply roller is
permitted while the feed and take-up rollers operate to shift the tympan, but just.
before the shifting of the tympan is completed, the sliding piece *, running on the
inside of the track D¹, passes the point 10 of the opening and permits the spring
to produce automatically the re-engagement of the pawl lever J J' with the loose
ratchet wheel c². A short interval of time then elapses before the sliding piece na.
passes the point 10 and permits the clamping lever to be actuated by the spring nº.
to produce the turning of the eccentric roller or clamp member P to a position to
clamp the tympan. The stoppage of the feed and take-up occurs during this.
interval but during the first part of the interval and before the stoppage occurs..
the draft produced on the tympan causes the supply roller to wind up the spring c³
between the ratchet wheel c and the supply roller. This winding up of the spring
gives it a tension which, while it permits a slight further movement of the supply
roller, so holds back the said roller as to produce and maintain a tension on the
tympan until the latter is positively clamped by the action of the clamp P PL
produced automatically by the lever N N₁ under the influence of the spring n° and
maintained by the sliding piece n having again arrived on the outside of the
track D. The clamp P P operating positively on the tympan independently of
the supply roller prevents any such slight shifting of the tympan as might be.
produced by the drag produced by the impression in printing not meeting with
sufficient resistance from the spring applied between the ratchet wheel c³ and the:
supply roller journal.
(Figures 1, 2 and 6) is a ratchet wheel fast on the supply roller journal c* inside
of the cylinder. This ratchet wheel has its teeth set in the opposite direction to.
the teeth of c³, and it has applied to it a pawls which is held in engagement with
it by a spring. This pawl s' is always in engagement with the ratchet wheel s.
when the printing machine is in operation and they constitute a stop to prevent the
spring from turning the supply roller backwards sufficiently to pull back the:
tympan from the feed rollers.
?"
In the modification of the invention shown in Figures 9 and 10, instead of the
clamp P P for holding the tympan positively to the cylinder, there is an additional
ratchet wheel provided on the supply roller journal c* outside of the cylinder..
This ratchet wheel has its teeth set in the same direction as those of the ratchet.
wheel c² of the yielding stop but instead of being loose on the journal it is keyed.
fast thereon so that when properly engaged by a pawl, the said pawl and the said
ratchet wheel will constitute a positive stop to any tendency of the supply roller
to turn in a direction to unwind the tympan therefrom. The lever N N¹
(see Figure 9) is made to serve as this pawl by being provided with one or more
teeth n on its upper side to engage with the said ratchet wheel. This lever N N
is exactly like the first described lever N N¹ shown in Figure 1 and herein before.
described for operating the clamp member P except for the addition of the teeth n
and the suppression of that part of the said first described lever N N¹ which is
extended upward beyond the sliding piece to make connection with said clamp, and
the said lever N N₁ so provided with teeth n to act as a pawl, is combined in the
same way with the pawl lever J of the yielding stop and otherwise operated in the:
same way by precisely similar mechanism as the first described lever N N'.

page_text: In order to prevent the tearing of the tympan by the too sudden starting of
the feed rollers ef before the liberation of the supply roller c, the clutch member f*
is not affixed rigidly to the stud or journal of the roller f, but is fitted to be
capable of turning thereon, and is represented in Figures 2 and 2A as connected
therewith by means of a coiled spring f, one end of which is secured to the
said clutch member and the other end to a collar f10, which is fast on said stud or
journal.
To compensate for the increasing diameter of the roll of soiled tympan-paper on
the take-up roller d, the gears f and d are so proportioned that they will drive the
roller at a surface speed corresponding with or not less than that of ef; but
the gear is represented in Figure 2 as fitted to the shaft of d with a friction-box
in its hub, as shown at d³ d in Figure 2, so that as the diameter of the roll increases,
the said gear d may have a backward slip.
66
The track D¹ and the switch E E' have sometimes been herein before mentioned
as stationary," but the term "stationary" has only been used with reference to
them as it has with reference to the gear D to indicate that they are fixed relatively
to the axis and the mass of the cylinder, though, being attached to the cylinder
journal-box a, by the said gear they have a rising and falling motion with the
cylinder.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondents, I declare that what 1 claim is :-
1. The combination with the impression cylinder and a tympan supply roller
therein, of a yielding stop and a positive stop, substantially as herein set forth.
2. The combination with the impression cylinder and a tympan supply-roller
therein, of a tympan clamp independent of said roller arranged between said roller
and the periphery of the cylinder, substantially as herein set forth.
3. The combination with the impression cylinder and a tympan supply
roller therein, of a tympan clamp independent of said roller arranged between said
roller and the periphery of the cylinder and automatic means of closing and
loosening said clamp, substantially as herein set forth.
4. The combination with the impression cylinder and a tympan supply roller
therein, a yielding stop, a positive stop, levers connected with or forming portions
of said stops, and a stationary interrupted circular track which is arranged outside
of the cylinder and upon the inside and outside of which the said levers run to hold
the said stops in or out of operation, substantially as herein set forth.
5. The combination with the impression cylinder and a tympan supply roller
therein furnished with a spring-controlled ratchet wheel, of a positive stop arranged
within said cylinder, a pawl lever on said cylinder for engaging with said ratchet
wheel, a lever on said cylinder for operating said positive stop, one of said levers
having a projection through which each is capable of acting on the other for the
engagement and disengagement of the ratchet wheel and the operation of the positive
stop, substantially as herein set forth.
6. The combination with the impression cylinder and a tympan supply roller
therein, of a yielding stop applied to said supply roller to control the letting off and
tension of the tympan, and a positive stop independent of said roller and yielding
stop arranged between said roller and the periphery of the cylinder, substantially
as and for the purpose herein set forth.
7. The combination with the impression cylinder and a tympan supply roller
therein, of two ratchet wheels one fast and the other loose on said roller and both
having their teeth set in one direction, a spring applied between said loose ratchet
wheel and said roller, pawls one for each ratchet wheel attached to said cylinder,
and means of automatically engaging said pawls with and disengaging them from
said ratchet wheels by the revolution of the cylinder, substantially as herein set
forth.
8. The combination with the impression cylinder and a tympan supply roller

page_text: therein, of two ratchet wheels c' s, one fast and the other loose upon said roller and
having their teeth set in opposite directions, a pawl J J' attached to said cylinder
for engaging with the loose ratchet wheel c, a pawls attached to said cylinder in
permanent engagement with the fast ratchet wheels, a spring between said loose
ratchet wheel and the said roller, and means of automatically engaging the
pawl J J with and disengaging it from the loose ratchet wheel by the revolution
of the cylinder, substantially as herein set forth.
Dated this 23rd day of October 1894.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.