Improvements in Letterpress Printing Machines.
Year: 1889

page_text: Date of Application, 7th Sept., 1889
Complete Specification Left, 23rd Apr., 1890-Accepted, 24th May, 1890:
PROVISIONAL SPECIFICATION.
Improvements in Letterpress Printing Machines.
WILLIAM RANKIN 146 Renfield Street, Glasgow Letterpress Printer do hereby
déclare the nature of this invention to be as follows:-
My invention has for its object the construction of letterpress printing machines
which will have great speed in action combined with perfect safety to the attendant
or feeder.
The improvements consist in a feeding blanket, which revolves or travels, whereby
sheets or cards are carried under the printing cylinder. I propose to suspend by
weights or levers, the table on which the impression is taken, whereby any foreign
matter introduced would not injure the machine. In front of the feeding gauge is a
dropping roller holding the sheets or cards and arranged to come into play before the
forward motion for carrying in the sheets or cards takes place. For the purpose of
counterbalancing the dead weight of the cylinder I propose by means of weighted
levers or other mechanical appliance always to have it in equipoise.
Dated thin Ch
1000
COMPLETE SPECIFICATION.
Improvements in Letterpress Printing Machines.
I, WILLIAM RANKIN of 146 Renfield Street, Glasgow Letterpress Printer 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 printing presses or machines for printing sheets or cards,
and the machines may also be arranged to print from the web, and by lengthening the
frame paging and perforating machinery may be attached, so as to perform these
operations simultaneously.
The principal characteristics of the machines are, speed in action, safety to the
feeder or attendant, smoothness of working owing to the printing cylinder being in
equipoise; and little risk of damage or jar to the machines owing to impression
table being set on springs. A dropping roller takes the sheet or card away from the
feeder.
In order that the said Invention may be fully understood I proceed more particularly
to describe the same, and for that purpose I shall refer to the Figures on the two
sheets of drawings hereunto annexed, the same letters of reference indicating corre-
sponding parts throughout all the Figures.
Fig. 1. shews a side elevation of the improved machine.
Fig. 2 shews an end elevation of same.
Fig. 3. shews an end elevation of same with parts of the machine removed.
The sheets or cards are put in from the feed board A, under the dropping roller B.
They are then carried on to the blanket C, the blanket being driven from the drum D
by means of a feed ratchet wheel E, which is worked from a disc crank F and rod G.
When the blanket has carried the sheet or card under the printing cylinder H, the
cylinder which has the chase containing the type underneath then descends and the
impression is taken on the table or platten J. The cylinder has a vertical reciprocating
motion and is driven by an eccentric K.
After receiving the impression the sheet or card is carried on by the blanket and is
thrown on the delivery board L.
For the purpose of relieving the sheet or card from the type, tapes are carried by
D

page_text: means of rollers over the top of the machine, and thence on top of blanket, the
small rollers M being used for the purpose of binding the tapes on blanket, and also
to receive motion from it. The platten or table J is suspended on springs N which
are guided by lugs O cast on machine frame. Any injury from the introduction of
any foreign matter is thus rendered unlikely; as the thrust or shock would be taken
up by the springs.
7P shews the balance weight for keeping the cylinder in equipoise, it is connected
by means of the levers Q, and the connecting links R to the side arms S of the
cylinder. These arms also receive motion from the eccentric K and have a vertical
reciprocating motion similar to the cylinder. The wheels T are covered with loather
for binding blanket on drum and also to prevent it slipping.
1
The other parts of the machine are common to many printing presses.
I do not confine myself to any particular method of keeping the cylinder in
equipoise, although the balance weight is shewn below the cylinder, it may be arranged
to be above it.
Instead of tapes for removing the sheet or card from the type, a frisket made of
thin steel or other suitable material may be employed as a substitute.
The frisket should be set on springs sufficient to raise it one eighth of an inch above
the blanket.
Having now particularly described and ascertained the nature of my said Inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is.
1st. The equipoise of the printing cylinder whether it be done by means of balance
weight and levers as shewn, or by springs or other mechanical means.
2nd. The carrying of the impression table on springs, or weighted levers or by
other mechanical appliance which will allow the table to yield a little when undue
strain is thrown on it.
3rd. The arrangement of dropping roller for taking the sheet or card from the
hands of the feeder; thus giving him absolute safety.
4th. The general arrangement of the machine with the foregoing novelties embodied
in it, substantially as shewn and described.
Dated this 92nd day of April 1890
WM. RANKIN.