Improvements in Knives for Trimming Type, Printing Bars, and Linotypes.
Year: 1894

page_text: Date of Application, 26th Nov., 1894
Complete Specification Left, 26th Aug, 1895-Accepted, 28th Sept., 1895
Improvements in Knives for Trimming Type, Printing Bars, and
Linotypes.
We, THE LINOTYPE COMPANY LIMITED, of No. 6
Serjeants' Inn, Fleet
Street, in the City of London, Licensors and Vendors under the "Linotype"
Patents, and CHARLES HOLLIWELL of No. 166 Ashton New Road, Manchester,
in the County of Lancaster, Engineer, do hereby declare the nature of this
invention to be as follows:-
Our invention relates to improvements in knives for trimming type, printing
bars and linotypes; and the object of it is to prevent the piece operated on from
being delivered cut to a taper.
Taking the present construction of the "Linotype" trimming knives as indicative
of the state of the art which the present invention is intended to improve, the
linotype is travelled in a horizontal direction edge on and end up between two
parallel vertical knives. When it has passed the latter, the bottom of the bar is
thinner than the top. According to the present invention, some portions of the
edge of each knife are set back so that the knife gets into cut gradually. In other
words, there is not strain or stress enough to make either the knives, or either of
them, or the piece to be trimmed, spring.
Which portions of the edges above mentioned are to be set back, forms no part
of the present invention. This minor point is left to be decided according to the
circumstances of each particular case in respect of the order in which the strains or
stresses make themselves felt. In the case of knives for trimming ordinary news-
paper linotypes, as the latter are made at the present time, we propose to set two
portions back, viz. :-a portion between each end and the middle of the edge.
This arrangement will produce three leading portions aligned with each other and
a portion set back between each end portion and the middle one.
በለ
1.
L. 1004
PHILLIPS & LEIGH,
Agents for the Applicants.
Improvements in Knives for Trimming Type, Printing Bars, and
Linotypes.
We, THE LINOTYPE COMPANY LIMITED, of No. 6 Serjeants' Inn, Fleet
Street, in the City of London, Sole Proprietors, Licensors, and Vendors of and
under the " Linotype" Patents, and CHARLES HOLLIWELL of No. 166 Ashtou
New Road, Manchester, in the County of Lancaster, Engineer, 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 :-
Our invention relates to improvements in knives for trimming type, printing
bars, and linotypes; and the object of it is to prevent the piece operated on being
delivered cut (.e., trimmed) on the taper. It is applicable to all machines for

page_text: casting type, printing bars, and linotypes; but it has been worked out with more
particular reference to the machine known as the "Linotype" machine, for the
following reasons:-(a) the product of this machine being a printing bar as
distinguished from a printing type, the risks of strain or stress transverse to the
length of the bar, are greater than in the case of a printing type, because of
the considerable difference between the lengths of the two, and (b) because the
"Linotype" machine is the only machine for making printing bars, which is
practically known to the printing trade of this country.
For the purpose of this Specification, we take the present construction of the
"Linotype" trimming knives as indicative of the state of the art which the present
invention is intended to improve. After the linotype is cast, it is pushed in a
horizontal direction, edge on and end up, up to and between two parallel vertical
knives When the linotype has been pu.hed passed these knives it is found to be
cut or trimmed on the taper-its back or base being thinner than its front or top.
It is not pretended that the amount of taper is linearly considerable in a single
notype, but it is obvious that, as all the linotypes trimmed are equally affected,
the total taper amounts to enough to prevent a column of linotypes presenting that
parallelism between their opposite planes, which is an assumed condition precedent
to the locking up of the form.
The production of the taper above described is due primarily, to the fact that
the two knife edges in question being rectilinear, each knife edge gets into cut
along its entire length at the same moment, and simultaneously with its fellow.
According to the present invention, some portions of the edge of each knife,
are set back so that the entire edge gets into cut gradually. The direct results
of this getting into cut gradually are that the linotype is put under stress
gradually, that the knives are put under strain gradually, that those portions of
the linotype and of the knives which are the first to get under and into cut serve,
by their mutual and combined engagement, to prevent other portions springing;
and finally, the linotype is delivered from the knives having its two sides cut
parallel with each other.
Referring to the accompanying drawings;
Figure 1 is a side elevation of the shorter of the two trimming knives of a
Linoty pe machine looking at it from the left hand of the machine.
Figure 2 is a side elevation of the longer of the two trimming knives of a
Linotype machine, looking at it from the left hand of the machine.
Figure 3 is a rear elevation of the same two trimming "knives including the set
screws, looking at them from behind the machine.
Figure 4 is a plan of the same knives excluding the ends of the set screws.
Figure 5 is a horizontal section on the line 5-5 of Figure 3, and includes, in
plan, a linotype under cut and the nose of the ejector blade which is pushing it
through between the knives.
a is the shorter; and b, the longer, of the two knives. c, c are the screw threaded
holes for the set screws by which they are held to the machine. The difference
in the lengths of them is caused by the presence of the two set screws d, d which are
used to set the cutting edge of the knife b exactly parallel with that of the shorter
one a.
e, e are those portions of the cutting edges of each knife which are set back
behind the remaining portions f, f.
When the linotype g is pushed up to the knives by the ejector blade h it is the
front portions f, f that get into cut first; and after they have got fairly in cut,
then the set back portions e, e get into cut, but not before. The amount of set
back may be varied as may be desired, but that illustrated is a satisfactory one
under average circumstances.
It will be evident from what has been said about the way in which the present
invention achieves the prevention of springing, that the relative positions of the
leading and the set back portions f and e respectively, may, under favourable
cucumstances, exert a marked influence upon the amount of prevention achieved,

page_text: As a rule, much depends upon this relative position. We consider that the one
illustrated in the figures is the best that can be adopted. The two ends and the
middle portions of the cutting edges get into cut first because they are the leading
portions. This means that both knives are in cut along their extremities and over
their middle portions before the intermediate portions are called upon. but it means
something of more importance still, viz. that there are intermediate portions of
both cutting edge and linotype which have time to adjust themselves under the
general strain, before they are under actual and maximum strain. Further, it
ineans that the strains along the two lines where the portions f, f are in cut, are not
continuous but separated by the interposition of the set back portions e, e. So,
likewise the lines where the last mentioned portions are in cut.
It is obvious that it is better that there should be a respectively odd and even
number of leading and set back portions, for then there will be a leading portion
at each end. In fact to have both in even numbers would go far to defeat the
object of the invention.
Another relation in respect of dunension is that between the length of a set
back and that of a leading portion. A set back portion e is shewn as longer than
an end leading portion f, and of the same length as the central leading portion.
The relation in question is of secondary importance only and may be decided
according to the circumstances of each particular case. At the same time, we
have to point out that the relation illustrated is a very satisfactory one.
The figures shew the cutting edge of one knife as the counterpart of that of
the other one (excepting as to the trivial shortening caused by the presence of the
set screws d, d). We prefer this correspondence and recommend that it be always
provided for.
Having now particularly described and ascertained the nature of this invention,
and in what manner the same is to be performed, we declare that what we
claim is :-
1. The combination in a knife for trimming type, printing bars, or linotypes; of
a set back and a leading portion; as set forth.
2. The combination in a kuife for trimming type, printing bars, or linotypes;
of one or more set back portions with one or more leading portions; as set forth.
3. The combination in mechanism for trimining type, linotypes, and printing
bars; of one or more set back portions of cutting edge with one or more leading
portions of cutting edge; as set forth.
Dated this 26th day of August 1895.
PHILLIPS & LEIGH,
No. 22 Southampton Buildings, Chancery Lane, W.C.,
Agents for the Applicants.