Improvements in Doctors for Calico Printing and other Machines.
Year: 1890

page_text: Date of Application, 24th Mar., 1890
Complete Specification Left, 25th Nov., 1890-Accepted, 24th Jan.; 1891
PROVISIONAL SPECIFICATION.
Improvements in Doctors for Calico Printing and other Machines.
I, JOHN THOMSON, of William Pinder & Sons, Fenwick Street, Hulme, Manchester,
in the County of Lancaster. Doctor and File Maker, do hereby declare the nature of
this invention to be as follows:-
The object of the invention is to provide a doctor for calico printing machines, of
any gauge or thickness, with more flexibility than has hitherto been the case.
It consists in weakening a part of the doctor, by grinding, cutting, or milling
away a portion of the material, to thin it; by perforating or slotting out a portion of
the metal behind the working edge; or by rolling the metal to the required section.
In each case the working edge is retained at the most suitable thickness while the
remaining part is rendered more flexible. The doctor may be reduced to the required
state of Hexibility, behind the working edge, by combining two or
methods above enumerated.
more of the
I am well aware that doctors have been formed of two pieces of steel of unequal
breadth, soldered together to render the working edge stiffer or more rigid than the
part behind it, and such forms no part of my invention.
Dated this 20th day of March 1900
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester, Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Doctors for Calico Printing and other Machines.
I, JOHN THOMSON, of William Pinder & Sons, of Fenwick Street, Hulme,
Manchester, in the County of Lancaster, Doctor and File Maker, 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:
The object of this invention is to provide a doctor-used for removing the
superfluous colour from the printing rollers or surfaces in the machines in which
calico, paper and other textile materials are printed-of any gauge or thickness,
with more flexibility than has usually been the case in a plate of the same gauge or
thickness.
It consists essentially of a doctor formed with perforations, slots, slits or holes of
any desired shape or size, cut or punched out of a portion of the metal behind its
working edge.
The invention will be fully described with reference to the accompanying drawings,
in which three examples of the invention are shown.
Fig. 1. is a front elevation of doctor with square holes cut in the blade behind the
working surface.
Fig. 2. sectional elevation on line -.
Fig. 3. sectional elevation on line y―y.
Fig. 4. front elevation of doctor with oblong holes cut therein.
Fig. 5. front elevation of doctor with circular holes cut therein.
The blade A, of the doctor, is first formed in the usual way from sheet steel or
other metal of the required gauge or thickness. From the blade so formed, and
preferably before being hardened, or tempered, I cut or punch holes B, and thereby
reduce the strength and weight of metal behind the working edge. This cutting
out of holes and reducing the strength of the metal in the blade, renders it more

page_text: flexible along the line of holes than was the case before the holes were made. and I
thus secure greater flexibility without reducing the stiffness of the working edge.
The holes B. although herein only shown square, oblong, and circular, may be of
any desired shape and size, and they may be disposed in two or more rows instead of
a single row, as shown. I may say, however, that I at present prefer a single row
of square holes as shown in Fig. 1.
To prevent any colour that may collect on the doctor running through the holes,
I paste a piece of calico, paper or other similar flexible material over the holes.
I am aware that it has been proposed to make doctors of unequal thickness,
thicker at the working edge than at the back, either by forming them of two pieces
of steel of unequal breadth soldered together, or by cutting down the back part of
the blade until it is of thinner gange than the working edge, so as to leave the
working edge thicker and stiffer than the part behind it, and such forms no part of
my invention.
Having now particularly described and ascertained the nature of the said inver-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
:-
A doctor for removing superfluous colour from printing rollers or surfaces,
formed with a series of holes, slots, or perforations in the back part, behind the
working edge, to render the blade more flexible without reducing the stiffness of
the working edge substantially as described.
Dated this 24th day of November 1800.
WM. P. THOMPSON & Co.,
Manchester, Liverpool, and London, Patent Agents.