IMPROVEMENTS IN TAKING OFF APPARATUS FOR PRINTING MACHINES."
Year: 1881

page_text: LETTERS PATENT to Henry Thomas Leigh Wilkinson, of Clerkenwell, in the
County of Middlesex, for an Invention of "IMPROVEMENTS IN TAKING OFF
APPARATUS FOR PRINTING MACHINES."
PROVISIONAL SPECIFICATION left by the said Henry Thomas Leigh
Wilkinson at the Office of the Commissioners of Patents on the 18th August
* 1881.
HENRY THOMAS LEIGH WILKINSON, of Clerkenwell, in the County of Middlesex.
"IMPROVEMENTS IN TAKING OFF APPARATUS FOR PRINTING MACHINES,"
My Invention relates to taking off apparatus for single cylinder typographic or
lithographic printing machines, whereby I am enabled, without the aid of a fly, to
remove the printed sheets from the blanket or impression cylinder, and deposit the
same upon the receiving board in an even and regular manner without creasing or
otherwise damaging the sheets. To this end my Invention consists in mounting
the taking off devices in a reciprocating frame which is operated directly from the
axis of the blanket or impression cylinder, and connected therewith in such manner
that the grippers may be accurately adjusted to seize the sheets and release them at
the proper moments.
The reciprocating frame is composed of pairs of parallel rods or levers arranged
at each side of the machine, and carrying the taking off gripper shaft and gripper
edge, and a horizontal rock shaft which is mounted in the brackets of the receiving
board, and extends from end to end at rear of same. The ends of the gripper shaft
are supported in the oscillating gun metal cheeks as usual, said cheeks being
however extended upwards and jointed to one limb of each pair of the parallel rods,
whose opposite extremities are pivoted to the brackets of the receiving board. The
cheeks are mounted on pivots in the two other limbs of each pair of rods, and these
rods are secured to the rock shaft which is operated by the shaft of the cylinder by
means of a connecting rod. The connecting rod is attached to an arm on the rock
shaft, and to a wrist pin projecting from a disc set adjustably on the cylinder shaft,
which to this end is prolonged beyond the machine framing.

page_text: As the cylinder revolves the frame is reciprocated, thereby alternately raising the
gripping devices away from, and lowering them into proximity with the cylinder.
The apparatus is so adjusted that the taking off grippers shall meet the opening in
the cylinder as it comes round, and seize the sheets as they are released by the feed
grippers, the continued revolution of the cylinder causing the apparatus to rise and 5
withdraw the sheets. The grippers are opened to take the sheets by means of a
lever as usual, and they are separated from the gripping edge to deposit the sheets
on the receiving board by contact with a cam or other suitable device on the
receiving board.
By the employment of the pairs of parallel rods the grippers are caused to nip 1
the edges of the sheets against the gripping edge, until finally released without
bend or crease, this being of importance in the case of high class work.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Thomas Leigh Wilkinson in the Great Seal Patent Office
on the 18th February 1882.
HENRY THOMAS LEIGH WILKINSON, of Clerkenwell, in the County of Middlesex.
"IMPROVEMENTS IN TAKING OFF APPARATUS FOR PRINTING MACHINES."
My Invention relates to a simple, compact, and effective combination of
automatic take-off apparatus for removing the printed sheets from the blanket or
impression cylinder of single cylinder typographic or lithographic printing machines,
and depositing them evenly upon the receiving board. The apparatus is intended
to replace the flyers or tapes commonly used, and it consists of a reciprocating or
Oscillating frame composed of pairs of parallel rods or levers at opposite sides of the
machine, turning at their lower ends upon axes supported by the brackets which
carry the receiving board, and carrying at their free ends oscillating cheeks or
brackets in which the taking-off gripper shaft and gripper edge are mounted, tho
cheeks being so pivotted to the combination of rods as to form a kind of parallel
motion, whereby the grippers are caused to retain the same or nearly the same
relative direction or inclination at all points of the arc in which they swing above.
the receiving board, so as to nip the sheet without bending or creasing it, which is
of importance in high class work.
In order that the Invention may be more readily understood, I will proceed to
describe it with reference to the accompanying Drawings, in which Figure 1
illustrates in side elevation so much of a printing machine as is necessary to explain
the Invention, the take-off apparatus being represented in its extreme highest and
lowest positions. Figure 2 is a section of the impression cylinder and the gripping
appliances of the take off apparatus, and Figure 3 is a part plan of the same.
A is a rock shaft mounted in bearings formed in the brackets which carry
the receiving board B, and extending across from side to side. C is a lever keyed
on the rock shaft at one side of the receiving board, there being a similar lever
keyed on the rock shaft at the opposite side. These levers C are at a sufficient
distance from the receiving board to work outside the radius rods hereafter men-
tioned, and to the free end of each lever C is pivotted a cheek or bracket D
which is free to oscillate on a stud or pivot d at or about the middle of its length.
The lower arms of the pair of cheeks D are rigidly connected by studs e and a
cross bar E which forms the gripping edge, and the upper arms are pivotted by
studs f to the free ends of radius rods F pivotted one at each side of the receiving
board or studs F¹ above the rock shaft A, and at a distance therefrom about equal
to the distance between the centres of the pivots d and f. G is a cross shaft
mounted to turn in extensions of the lower arms of the cheeks D, and g are the
gripper fingers fixed by set screws on the shaft G at suitable intervals, according
to the size of the sheet. H is a short arm keyed on the gripper shaft G, having a
stud at its extremity carrying a friction roller h which rolls on the plain part of
the impression cylinder at one end thereof. I is the blanket cylinder provided
with the ordinary grippers actuated in the usual way to grip and release the sheet
at the proper times, and i is a depression in the plain part at the end of the
cylinder whereon the roller runs, into which the said roller falls at the proper
moment to permit the grippers g to close against the gripper edge E to seize the
sheet; K is an india rubber or other spring by which the arm H is drawn or pressed
towards the cheek D so as to turn the shaft G in its bearings, and close the gripper
fingers g against the gripper edge E. At the other end of the gripper shaft G
there is fixed a short arm L having at its end a stud / which projects from the side
of the arm so as to come in contact with the radius rod F just as the apparatus
arrives at its highest position, as shown, and thereby turn the gripper shaft in the
opposite direction to open the grippers and release the sheet, and deposit it upon
the receiving board. M is an arm keyed on the end of the rock shaft A (or forming
an extension of one of the levers C) to which is jointed a connecting rod N worked

page_text: T.....
from a crank pin of an eccentric or cam on the main shaft, or any other convenient
shaft of the machine; or from a crank on an extension of the shaft of the impression
cylinder itself. This crank pin may be adjustable for the purpose of properly
timing the oscillation of the take-off apparatus with regard to the rotation of the
impression cylinder. A counterweight is fixed on the rock shaft A to counter-
balance the take-off apparatus; or instead of a counterweight a spring may be
coiled on the shaft and connected thereto by one end and to the bearing by the
other, so as by its torsion to answer the same purpose. The gripper edge E is a
wooden bar with a curved surface, being a segment of a cylinder as shown. O is
a roller on the stud e which rolls on the plain part of the impression cylinder to
steady the take off apparatus and hold it at the proper distance from the cylinder.
Instead of separate gripper fingers g a bar or gripping edge may be attached to
the ends of arms like the fingers g, so that the paper will be nipped along its
entire edge instead of at intervals only, as when separate fingers g are used.
The take-off apparatus oscillates above the receiving board between the two
positions shown, the arms C turning on the axis of the rock shaft A as a centre,
whilst the radius rods F turn on their pivots F¹, the result being that the lower
ends of the brackets in which the grippers are carried receive a compound motion
and describe a curve E*, whereby the positions of the brackets at all points of the
stroke are rendered parallel to one another, so that the position of the grippers
relatively to the sheet remains unchanged, and the sheet is taken off by a straight
draft or pull, whereby the creasing or marking the edge of the sheet is avoided,
which is important in the case of enamelled or glazed papers. X represents the
position of the sheet just. before it is released.
The take-off apparatus being timed to approach the impression cylinder at the
proper moment, the grippers are opened (as shown in dotted lines in Figure 2) by
the friction roller meeting the plain part of the cylinder, and are held open
(whilst the crank which operates the take-off apparatus is passing its dead point),
by the roller rolling on the cylinder until the grippers of the cylinder itself have
been opened in the usual way, and the edge of the sheet by the continued rotation
of the cylinder has been carried between the grippers g and the gripping edge E.
At this moment the roller / falls into the recess i, and the nippers close on the
sheet, as shown, and at the same instant the take-off apparatus is (by its operating
crank having passed its dead point), caused to recede from the cylinder and draw
off the sheet with a gradual and steady pull. Upon the take-off apparatus reaching
the raised position shown the stud 7 strikes the adjacent rod F, and the grippers
are opened and release the sheet, which falls on the receiving board B, the sheets
being superposed in a regular and even pile.
Having described the nature of the said Invention, and the manner of performing
the same, I declare that what I claim as my Invention to be protected by the
herein before in part recited Letters Patent is,―
1st. The combination of parts constituting the take-off apparatus applied to a
printing machine and arranged to operate, substantially as herein shown and
described.
2nd. The combination of the rock shatt A, oscillating arms C, radius links F, and
cheeks or brackets D, carrying suitable gripping devices, the combination operating
substantially in the manner and for the purpose specified.
In witness whereof, I, the said Henry Thomas Leigh Wilkinson, have
hereunto set my hand and seal, this Eighteenth day of February, in the
year of our Lord One thousand eight hundred and eighty two.
HENRY THOMAS LEIGH WILKINSON. (LS.)