Improvements in Printing Presses.
Year: 1897

page_text: Date of Application, 9th Aug., 1897- Accepted, 11th Sept., 1897
Improvements in Printing Presses.
A communication from abroad by C. B. COTTRELL & SONS COMPANY, a corporation
duly organized under the Laws of the State of New Jersey, and having its
principal place of business at Grand and Green Streets, Jersey City, New
Jersey, United States of America.
I, JOHN CORRY FELL, of the Firm of Fell & James, of No. 1 Queen Victoria
Street, in the City of London, Chartered Patent Agent, 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 more particularly to that class of bed motions for printing
presses in which tlie reciprocating rectilinear movements of the bed are effected
in the main by a toothed driving wheel and two straight racks with which said
wheel is brought alternately into and out of gear.
The improvements consist in the various features of construction and combina-
tions of devices hereinafter more fully described and particularly pointed out in the
appended claims, and by which the bed of the press is started very slowly and has
its movement gradually accelerated at the commencement of its stroke, in either
direction, and gradually retarded towards the end of its stroke.
In the accompanying drawings:-
Figure 1 represents in side elevation the bed motion of a printing press involving
my invention.
Figure 2 is a plan view of the same showing the frame which carries the two
racks partly in section.
Figure 3 represents a transverse section taken at the line 3, 3, of Figure 2.
Figure 4 is a side elevation of the main driving gear and its associated parts,
viewed on the side opposite to that shown in Figure 1.
Figures 5, 6, 7 and 8 are side views representing the parts in different positions.
Figure 9 is a side elevation showing a modification of the invention in which
the main driving gear is raised and lowered into and out of engagement with
the straight racks instead of sliding laterally into and out of such engagement
therewith, as in the previous views.
Figure 10 is a top plan view of Figure 9, partly in section.
Figure 11 is a vertical cross section taken at the line y, y, of Figure 10.
Figure 12 is a side view of the cam and its lever or arm shown in dotted lines
at Figure 9.
Similar letters of reference designate corresponding parts in the various views.
Referring more particularly to Figures 1 to 8 inclusive, A is the rack frame upon
which is mounted the bed of the press, as usual, and said frame has rigidly
attached to it two straight racks B B₁ and two curved semi-circular internally
toothed racks or sectors S S. This rack frame may be bolted or otherwise secured
in the usual or any suitable manner to the printing-machine bed.
C is the driving wheel and C¹ the shaft to which it is fastened arranged in fixed

page_text: bearings aain a suitable frame F and furnished with a gear C through which it
receives constant rotatory motion.
The straight racks B B have their teeth facing each other and their pitch
lines at a distance apart equal to the pitch diameter of the wheel C, the axis of which
is central between the pitch lines of the racks. The said racks are not exactly
opposite each other, but are as shown in Figures 2 and 3, set off laterally the one
from the other, so that the driving wheel C, by being moved laterally as hereinafter
described, may be brought into gear with either one of them while it is out of
gear with the other. The length of the said racks must at least be equal to the
pitch circumference of the driving wheel or an exact multiple of that circum-
ference, according to the number of revolutions that the driving wheel may be
required to make during each movement of the racks back and forth. In the
example represented the lengths of the racks and circumference of the pitch lines
are equal. The semi-circular internally toothed sectors S S₁ have their centers
approximately opposite the ends of the straight racks and have the radii of their
pitch lines equal to half the distance between the pitch lines of the racks. The
said sectors or gears are both in the same plane, but not in the same plane with
either of the racks, being set off laterally at some distance from the latter, as shown
in Figures 2 and 3.
Across the rack frame A, there are formed thereon or affixed thereto, a little
beyond the ends of the straight racks and the centers of the sectors, two straight
guides D D (Figs. 1, 2, 3), the edges of said guides being perpendicular to the
racks and set off laterally therefrom beyond the sectors as shown in Figs. 2 and. 3.
The driving wheel Chas affixed to it eccentrically by screw bolts, a continuous
circular gear E for engaging with the toothed sectors during portions of the
movements of the driving wheel, which take place as hereinafter described, while
the straight racks have run in either direction out of gear with the said wheel, and
while they so remain out of gear. This gear E is represented as having a pitch
line radius equal to half the radius of the sector and having its center midway
between the center and the pitch line of the driving wheel. The teeth of the
said gear are of such width and the said gear is offset by its hub, e, so far from
the driving wheel that it may be in gear with the toothed sector at either end of
the rack frame while the driving wheel is in line with either of the straight racks.
To the said gear E and consequently to the driving wheel or gear, there is affixed
an arm to which there is pivoted a roller which runs against the straight
guide or D¹ at either end of the rack frame while the gear E engages with the
sector at the same end of the frame. The driving wheel has also affixed to it,
opposite to the gear E and crank roller b', a cam c, which runs against a roller d
on the toothed sector S, or a roller on the sector S¹ during the last part of the
movement of the rack frame in either direction and the first part of its movement
in the opposite direction.
In order to shift the driving wheel laterally from a position in line with one
straight rack to a position in line with the other, its shaft C₁ is capable of being
moved longitudinally in its bearings a, in the framing F, by a horizontal lever G
which works on a fulcrum g, in a stand G³, one end of the said lever engaging
with a collar C2, fast on the driving wheel shaft C₁, and the other end being
engaged with and actuated by a cam H on a shaft H', which works in bearings
in the frame F, to which rotatory motion may be imparted in any suitable manner
at such speed relatively to that of the driving wheel C that the cam may operate
to shift the driving wheel laterally in one direction or the other near the end of the
stroke of the rack frame in either direction, and while the said wheel is out of gear
with both of said racks. In the example represented in which three revolu-
tions of the driving wheel are required for the complete movement of the rack
back and forth, the cam requires to move the lever once in each direction during
every three revolutions: therefore, the cam shaft is geared with the gear C* on the
driving shaft to make one revolution for every three revolutions of the latter. The
pitch lines of this gearing are indicated by dotted circles in Fig. 1.

page_text: Having described the construction and separate operations of the several
parts of my invention, I will now describe their combined operations.
The driving wheel C makes one revolution in gear with each of the straight
racks, moving the rack frame in one direction while in gear with one rack and in
the opposite direction while in gear with the other rack, and it makes half a
revolution free from the straight racks with its gear E in engagement with each
of the toothed sectors. While the wheel is in gear with either of the racks the
movement in either direction is like that produced by an ordinary rack-and-pinion,
the gear the sectors S S¹, and their attached parts being then inoperative, but
as the end of the rack which has been in operation passes the center of the driving
wheel, the gear E comes into engagement with the toothed sector S or S¹ at the
Corresponding end of the rack frame and at the same time the roller bor b¹ runs
into contact with the guide bar Dor D The continuance of this engagement
and contact during half a revolution of the driving wheel first produces the com-
pletion, at a gradually diminishing speed, of the movement of the rack frame in
the direction in which it has just been moved by the driving gear and straight
rack, and afterwards starts, at a gradually increasing speed, the movement in the
opposite direction and continues to produce such movement until the other rack
arrives in gear with the driving wheel, the lateral shifting of the driving wheel
taking place while the gear E is in engagement with the sector and being
permitted by the width of the teeth of the said gear.
In the above operation the roller running against the guide D or D¹ has first
the effect of slowing down the movement of the rack frame; next the effect of
positively stopping the rack frame against over-running its movement by its own
momentum and afterwards the effect of starting its return movement of the rack
frame, and the cam c on the driving wheel passing beyond the roller d or d¹ on
the sector S or S¹, just before the termination of the movement of the rack frame,
serves to confine the guide D or D¹ to the roller bor b¹ and to keep the sector in
engagement with the gear E. This operation is illustrated by Figs. 5, 6, 7 and S.
Referring first to Fig. 5, the rack frame is therein represented as moving, to
the right, the lower rack is just leaving the driving wheel C, and the gear E is just
coming into engagement with the lower part of the sector S to continue the
movement of the frame which is gradually slowed by the action of the gear in the
sector, but the slowing down is more positively effected by the action of the roller b
against the lower part of the guide .D. which latter action prevents backlash
between the gear E and the sector. Referring next to Fig. 6, the rack frame is
represented as having its movement further continued in the same direction by the
gear and the sector, and the roller b¹ as running up the guide still continuing
its slowing down action, while the cam c is coming Into operation on the roller
on the sector S, to confine the sector to the gear E. The rack frame continues
moving in the same direction until the parts arrive in the relative positions shown
in Fig. 9, the rack frame being then positively stopped by the guide D being in
contact with the roller b. The continued rotation of the driving wheel as illustrated
by Fig. 7 keeps the cam c for some time against the roller d and keeps confining
the sector S to the gear E, while the frame is slowly started on its return movement
to the left by the movement of the gear E into the upper part of the sector and
by the running of the roller b' against the upper part of the guide D. This action
of the gear E and the sector and of the roller b' against the guide D) are continued
until, as shown in Fig. 8, the driving wheel C strikes into the upper rack,
the said wheel having now been moved laterally into line with
said rack. Precisely the same operation of the gear E the roller b and the
cam c take place in connection with the sector S¹, the guide D', and the roller
at the other end of the rack bar to retard the movement of the rack frame to the
left and start its movement to the right.
the
I have before stated that the lengths of the straight racks correspond exactly
with or are an exact multiple of the pitch circumference of the driving wheel.
Thus, for example, if the length of the racks should be double the length of the

page_text: pitch line circumference of the wheel; the rack frame would make one movement
for every five revolutions of the wheel; that is to say,-two revolutions in gear
with each rack and a half revolution with the gear E in each sector.
I may here mention that a few of the teeth of the gear E may be omitted at
that part of its circumference nearest the shaft C', the starting of the rack frame
being effectively provided for by the action of the roller b¹ against the guide D
or
This is
The rollers d d have been herein described as attached to the sectors.
virtually an attachment to the rack frame. It is obvious that they might be
attached directly to part of the rack frame.
.
Referring now to Figs. 9, 10, 11 and 12, the straight racks B and B are
arranged one directly over the other, or in the same plane and the shaft of the
main driving gear C is mounted in a vibratory bearing consisting of a hollow
sleeve Z, at one end of an arm Y, whose opposite tubular end X is pivotally
mounted on a pin or fulcrum W, and the portion X is provided with a downwardly
extending arm V, which at its lower end is pivotally connected at U to one end
of an arm T, whose opposite end is forked or bifurcated at R to embrace a shaft Q,
mounted in suitable fixed bearings P. On. the said arm. T is mounted an anti-
friction roller O which is acted upon by a grooved or box cam N affixed to the
said shaft Q and in a manner such as to periodically move, said arm T in the
direction of its length and cause the vibratory frame composed of the parts ZYX
and V to vibrate about the pivot or fulcrum W and thereby effect at the proper
times a raising and lowering of the main driving gear C and its appurtenances.
M may represent the driving shaft of the machine, to which the power is applied.
On this shaft is mounted a pinion L which drives a spur gear K on the shaft Q,
and on said shaft M is also mounted a pinion J which drives a spur gear I on the
fixed shaft or fulcrum. W, and which spur gear meshes with a similar gear I¹ on
the shaft carrying the main driving gear C, which gear, as in the previous views,
carries the continuous circular gear E to engage with the continuous sectors or
racks SS; the crank roller b₁ to engage with the straight racks D.D'; and
the cam to engage with the bed frame rolls d d'; the said main driving gear C
meshing alternately with the upper and lower straight racks B and B', but moving
into and out of engagement with said racks by a vibratory or swinging movement,
produced by the cam and intermediate devices described, instead of by a rectilinear
laterally sliding movement as shown and described with reference to Figures 1 to 8
inclusive. At Figures 9 to 12 inclusive; the main driving gear C is represented
as out of engagement with the straight racks and as being vibrated downwardly
to engage the lowermost rack at the proper time. While in such engagement the
concentric portion 1 of the cam travels in contact with or over the roller O, and
hence there is no swinging movement of the vibratory frame; and when the
main driving gear is in mesh with the uppermost rack the concentric portion 2 of
the cam passes over the said roller 0, thus again leaving the said vibratory frame
unaffected.
If desired, in connection with the cam c¹ on the main driving gear, and its
associated rollers or pins, the toothed sectors S S on the bed frame may be divided
or made in two parts and offset laterally one from the other, and the eccentrically-
arranged pinion or gear E, in that case, may also be divided or made in two parts
and each arranged in the vertical plane of its associated divided sector or curved
rack section.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what I
claim is:-
1. The combination of a reciprocating bed frame having two straight toothed
racks and curved end racks beyond the ends of the straight racks, a main driving
gear adapted to mesh alternately with the straight racks, a toothed gear attached
to or travelling with said main driving gear for engaging said curved end racks,

page_text: and a cam attached to or travelling with said main driving gear to engage with
means at the ends of the rack frame for holding the toothed gear in mesh with the
end rack during the reversing action of the bed frame.
2. The combination of the bed frame having two straight racks and curved end
racks and vertical guides, a main driving gear adapted to mesh alternately with
said straight racks and carrying an eccentrically-arranged toothed gear, a crank
pin or roller and a cam, and a pin or roller at each end of the bed frame to act
with said cam.
3. The combination of a reciprocating rack frame, two straight toothed racks
on said frame, two toothed sectors on said frame one at each end thereof, beyond
the ends of the racks, a toothed driving wheel for gearing with the racks, a single
toothed gear attached eccentrically to one side of the driving wheel for engaging
with each of the two sectors in turn, two guides on said frame located near the
ends of the racks and approximately perpendicular thereto, and a roller carried by
the driving wheel for running against said guides; substantially as herein
described.
4. The combination of a reciprocating rack frame, two straight toothed racks
on said frame, two toothed sectors on said frame beyond the ends of the racks, a
toothed driving wheel for gearing with the racks, a toothed gear attached eccentri-
cally to the driving wheel for engaging with the sectors, a cam on the driving
wheel, and rollers on the rack frame against which said cam acts to confine the
sector to the said gear; substantially as herein described.
5. The combination of a reciprocating rack frame, two straight toothed racks
on said frame, two toothed sectors on said frame beyond the ends of the racks, a
toothed driving wheel for gearing with the racks, a toothed gear attached eccentri-
cally to the driving wheel for engaging with the sectors, two guides on said frame
located near the ends of the racks and approximately perpendicular thereto, a
roller carried by the driving wheel for running against said guides, a cam on the
driving wheel, and rollers on the frame against which said cam acts; substantially
as herein described.
.
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