IMPROVEMENTS IN PAPER-CUTTING MACHINES
Year: 1878

page_text: LETTERS PATENT to James Robertson, of Springfield Mills, Lasswade, in the
County of Mid Lothian, North Britain, for the Invention of "IMPROVEMENTS
IN PAPER-CUTTING MACHINES."
PROVISIONAL SPECIFICATION left by the said James Robertson at the
Office of the Commissioners of Patents on the 24th May 1878.
JAMES ROBERTSON, of Springfield Mills, Lasswade, in the County of Mid Lothian,
North Britain. "IMPROVEMENTS IN PAPER-CUTTING MACHINES."
This Invention relates to improvements in those paper-cutting machines in which
a revolving knife is employed to divide into sheets the web of paper travelling from
a roll or from the paper-making machine.
According to this said Invention the driving of the wheel or drum carrying the
revolving knife is effected from the driving shaft by a pair of elliptical wheels, so
centered and mounted on the axis of the knife drum and the driving shaft respec-
tively that that portion of the elliptical wheel upon the driving shaft, which is at
the greatest distance from the said shaft, is in gear with that portion of the
elliptical wheel on the axis of the knife drum which is at the least distance from
the said axis at the time when the knife on- the drum is making its cut. By this
arrangement the knife drum is rotated rapidly during the action of the knife, which
thus makes its cut very quickly, whereby large sheets or widths of paper may be
cut square, or more nearly so than can be effected in the machines driven in the
ordinary manner.
Where very large sheets have to be cut from a wide web the following arrange-
ment may be employed, by which arrangement a very rapid motion is given to the
knife whilst it is making its cut:-According to the said arrangement an inter-
mediate shaft is mounted between the driving shaft and the knife-drum axis, the
[Price Bd1

page_text: said shaft being provided with an elliptical wheel gearing with the elliptical wheel
on the knife-drum axis. The wheel on the intermediate shaft is bushed to run
loosely on the said shaft when the knife is not making its cut. This intermediate
shaft is driven from the driving shaft by a pinion on the said driving shaft gearing
into a toothed wheel upon the intermediate shaft, at the back of which wheel is a
cam groove, in which engages and by which is operated a clutch shifter, which at
a certain period of the rotation of the intermediate shafts shifts a clutch on the
said shaft into a clutch box on the elliptical wheel of the said shaft. Thus at each
rotation of the said intermediate shaft the clutch shifter, being operated upon by
the cam groove, causes the clutch to be disengaged from and engaged with the
clutch box of the elliptical wheel on the intermediate shaft, consequently the knife
drum is either allowed to remain at rest or is rapidly and suddenly rotated. The
elliptical wheel on the intermediate shaft, and that on the knife drum axis, will be
arranged so that when the knife is making its cut the knife drum is receiving a
quickened movement through the elliptical wheels. By proportioning the pinion on
the driving shaft to the toothed wheel on the intermediate shaft, and by the figure
that is given to the cam groove, it will be evident that the knife may be caused to
make its cut very rapidly at any desired period and when any required amount of
web has passed through the cutting machine..
The machine may thus be arranged to cut sheets of any desired length, and
owing to the rapidity of the knife's action very broad sheets may be cut squaro,
or nearly square.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Robertson in the Great Seal Patent Office on the 16th
November 1878.
JAMES ROBERTSON, of Springfield Mills, Lasswade, in the County of Mid.
Lothian, North Britain. "IMPROVEMENTS IN PAPER-CUTTING MACHINES."
My said Invention relates to improvements in those paper-cutting machines in
which a revolving knife is employed to divide into sheets the web of paper
travelling from a roll or from the paper-making machine.
According to my said Invention the driving of the wheel or drum carrying the
revolving knife is effected from the driving shaft by a pair of elliptical or eccentric
wheels, so centred and mounted on the axis of the knife drum and the driving shaft
respectively that that portion of the elliptical or eccentric wheel upon the driving
shaft which is at the greatest distance from the said shaft is in gear with that
porton of the elliptical or, eccentric wheel on the axis of the knife drum which is
at the least distance from the said axis at the time when the knife on the drum is
making its cut. By this arrangement the knife drum is rotated rapidly during
the action of the knife, which thus makes its cut very quickly, whereby large sheets
or widths of paper may be cut square, or more nearly so than can be effected in
the machines driven in the ordinary manner.
Figure 1 of the accompanying Drawings represents in side elevation a part of a
paper-cutting machine with my improvements applied thereto.
The motion of the driving shaft A being transmitted to the knife-drum axis B
through the elliptical or eccentric wheels a and b, keyed upon the said shafts, the
knife k is represented in the position in which it is making its cut, the wheel a at
this point being in such relative position with the wheel b that an accelerated
motion is given to the knife drum.
Where very large sheets have to be cut from a wide web, the following arrange-
mont may be employed, by which arrangement a very rapid motion is given to the
knife whilst it is making its cut:-According to the said arrangement an inter-
mediate shaft C, Figure 2, is mounted between the driving shaft A and the knife-
drum axis B, the said shaft being provided with an elliptical or eccentric wheel c
gearing with the elliptical or eccentric wheel b on the knife-drum axis. The
wheel c is bushed to run loosely on the said shaft C. This intermediate shaft C is
driven from a driving shaft A by a pinion a¹ on the said driving shaft gearing into
a toothed wheel c' upon the intermediate shaft C, at the back of which wheel is a
cam groove d, in which engages and by which is operated a clutch shifter D, which
at a certain period of the rotation of the intermediate shaft shifts a clutch e
revolving with the said shaft into a clutch box c on the wheel c. Thus at each
rotation of the intermediate shaft C the clutch shifter D being operated upon by
the cam grooved causes the clutch e to be disengaged from and engaged with the
clutch box c of the wheel c. The elliptical or eccentric wheel on the intermediate
shaft and that on the knife-drum axis will be arranged so that when the knife is
making its cut the knife drum is receiving a quickened movement through the said
wheels. By proportioning the pinion a' on the driving shaft to the toothed wheel c¹
on the intermediate shaft, and by the figure that is given to the cam groove d, it
will be evident that the knife may be caused to make its cut very rapidly at
any desired period, and when any required amount of web has passed through the
cutting machine. The machine may thus be arranged to cut sheets of any desired
length, and owing to the rapidity of the knife's action very large sheets may be cut
square, or nearly square.
When the last-described arrangement is employed, the wheels b and c may be
concentric wheels in place of being elliptical or eccentric, their relative proportions
being such that a rapid movement is given to the knife when it is making its cut.
Having now described and particularly ascertained the nature of my said Inven-

page_text: tion, and the system, mode, or manner in or under which the same is or may be
used or practically carried into effect, 'I would observe in conclusion that what I
consider to be novel and original, and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is,―
First. The improvements in paper-cutting machines consisting in transmitting
the motion from the driving shaft to the knife drum by means of elliptical or
eccentric wheels so arranged as to give an accelerated motion to the knife drum
when the cut is being made.
Second. The improvements in paper-cutting machines consisting of the arrange-
ment for transmitting the motion of the driving shaft to the knife drum, so that
the said drum remains inoperative until the desired amount of web has passed, and
then received a rapid or accelerated movement for making the cut, essentially as
herein before described with reference to Figure 2 of the accompanying Drawings,
In witness whereof, I, the said James Robertson, have hereunto set my hand
and seal, this Fourteenth day of November, in the year of our Lord One
thousand eight hundred and seventy-eight.