IMPROVEMENTS IN PREPARING AND FINISHING CASTINGS "
Year: 1883

page_text: LETTERS PATENT to David Perfitt Griffiths Matthews of Newport in the
County of Monmouth for an Invention of "IMPROVEMENTS IN PREPARING
AND FINISHING CASTINGS
"
PROVISIONAL SPECIFICATION left by the said David Perfitt Griffiths
Matthews at the Office of the Commissioners of Patents on the 7th February
1883.
DAVID PERFITT GRIFFITHS MATTHEWS, of Newport in the County of Monmouth,
"IMPROVEMENTS IN PREPARING AND FINISHING CASTINGS.
"
The principal objects in this Invention relate to improvements in finishing
machinery bearings by cleansing and freeing the whole surfaces and the pores or
inundations of such bearings and bronze or brass castings subject to friction, wear
and tear, of that siliceous scale or skin taken up from the sand forming the moulds
of such castings by the molten metal, and the same is at present bored and faced
off in the lathe, and in some instances, as for tin rolling and steel rail rolling mills,
the same bearings at present are partially and uniformly filed or scraped on their
bearing surface only and the fact of this work taking more off one place than
another, gives to the bearings an unequal surface, and in the absence of files and
the labour necessary to use them, the bearings are put into their respective places
and used just as they leave the foundry trimmer, and the different journals, roll
necks etc, have to contend with the many evils (too well known to engineers, and
millwrights) and injuries in the shape of extraordinary friction in all parts, wear
and tear, and scoring both the journals, and their bearings to such an extent as to
sometimes necessitate their being again faced or turned up.-The grit in fact thus
given out more or less is ground into the roll necks or journals thereby causing
the bronze bearings to rapidly wear out together with the journals, the grit having
much the effect of emery, and remaining as it does about the axle for a very
considerable time, notwithstanding the extra greasing and extra attention demanded
in all these cases.-To overcome these difficulties at a cheap and expeditious rate,
I have recourse mainly to the following plan of treating such castings viz:-
I subject them to the action of sulphuric acid, or any other suitable acid may be

page_text: used, and of suitable strength, placing each casting separately, or several castings
together in a cistern containing the necessary acid, subjected to dry heat, or that
of steam, may be used, or the acid applied in any other form, or applied to the
wearing or motion surface only, or the whole surfaces, for the purposes herein
described.
In performing upon several castings at one operation, I place them upon a
suitable platform, which may be suspended or otherwise, and made to lower with
its load into the said bath or cistern, and the whole immersed then to be moved in
any direction, for the purpose of agitating the acid, and when sufficiently oxidized,
I withdraw the work so operated upon, and pass the whole to the No. 2 bath,
containing a continual supply of cold water, same to be thoroughly swilled therein,
afterwards dried and then rubbed all over by hand or by any suitable machine,
using any suitable substance or powder for rubbing or polishing purposes, say card
wire, and after making a few strokes or rubs, I get a clean bright surface of the
pure metal or bronze
I would here remark that I am aware of acids and spirits being used in cleansing
brass castings for lacquering and bronzing the same. But my Invention relates to
the application to the cleansing, polishing and superior finish of machinery bearings
and castings subjected to friction, wear and tear, and of any one surface or the
whole surfaces or any part thereof as herein described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said David Perfitt Griffiths Matthews in the Great Seal Patent
Office on the 7th August 1883.
DAVID PERFITT GRIFFITHS MATTHEWS, of Newport in the County of Monmouth,
"IMPROVEMENTS IN PREPARING AND FINISHING CASTINGS,"
The principal objects of this Invention relate to improvements in finishing
machinery and railway rolling stock bearings by cleansing and freeing the whole
surfaces and the pores or inundations of such bearings and bronze or brass castings
subject to friction, wear and tear, of that siliceous scale or skin taken up from the
same, forming the moulds of such castings by the molten metal, and the same is
at present bored and faced off in the lathe, and in some instances as for tin rolling
and steel rail rolling mills, the same bearings at present are partially and uniformly
filed or scraped on their bearing surfaces only and the fact of this work taking
more off one place than another, gives to the bearings an unequal surface, and in
the absence of files and the labour necessary to use them, the bearings are put into
their respective places, and used just as they leave the foundry trimmer, and the
different journals, roll necks, etc have to contend with the many evils (too well
known to engineers and millwrights) and injuries in the shape of extraordinary
friction in all parts, wear and tear, and scoring both the journals and their bearings
to such an extent as to sometimes necessitate their being again faced or turned up.-
The grit in fact thus given out more or less, is ground into the roll necks or
journals, thereby causing the bronze bearings to rapidly wear out, together with
the journals, the grit having much the effect of emery, and remaining, as it
does about the axle for a very considerable time, notwithstanding the extra
greasing and extra attention demanded in all these cases. To overcome
these difficulties at a cheap and expeditious rate, I have recourse mainly to
the following plan of treating such castings, viz:-I subject them to the
action of sulphuric acid, or any other suitable acid may be used, and of suitable
strength, placing each casting separately, or several castings together, in a
cistern containing the necessary acid, subjected to dry heat, or that of steam
may be used, or the acid applied in any other form, or applied to the wearing or
motion surface only, or the whole surfaces, for the purposes herein described.―In
performing upon several castings at one operation, I place them upon a suitable
platform which may be suspended or otherwise, and made to lower with its load
into the said bath or cistern, and the whole immersed then to be moved in any
direction for the purpose of agitating the acid, and when sufficiently oxidized, I
withdraw the work so operated upon, and pass the whole to the No. 2 bath,
containing a continual supply of cold water, same to be thoroughly swilled therein
afterwards dried, and then rubbed all over by hand or by any suitable machine,
using any suitable substance or powder for rubbing or polishing purposes, say card
wire, and after making a few strokes or rubs, I get a clean bright surface of the
pure metal or bronze
I would here remark that I am aware of acids and spirits being used in cleansing
brass castings for lacquering and bronzing the same; But my Invention relates to
the application to the cleansing, polishing and superior finish of machinery bearings
and castings subjected to friction wear and tear, and of any one surface or the
whole surfaces or any part thereof as herein described.
In carrying my Invention into effect, the first preparation is to make the superior
accurate finish of bronze, gun metal or brass castings, to produce the saving and
economy both in metal and labour I use machine made patterns either in wood or
metal, and the same to be as truthfully made as possible with the metal's contraction
only, in some cases accurately allowed in the patterns but in patterns for castings
required for tight and accurate fitting, I make only one half the present practical
allowance in addition to the metal's contraction for such filling and boring, and

page_text: with patterns thus made, I purpose effecting some of the advantages as described in
making bearing patterns.-First of wood.-I tool them by hand to something near
the size required; then bore the motion surface upon a lathe mandril of the
required size, made of wood or any other material or materials.-If of wood, I
cover the said mandril with sand paper or its equivalent, and the said mandril to
have at its one end or both ends a face plate or collar in the solid or otherwise of
the mandril, and the facing side or collar covered with the same material as the
mandril, for facing the pattern ends, which I do in the same operation of boring or
facing the motion surface, and to perform this work effectually, I use an adjustable
double rest secured to the lathe bed, the mandril to be as near as possible a fac
similé plus the metal's contraction, and allowance if necessary for very accurate
fitting or boring the ends and motion side of new patterns being thus finished, I
work and finish all other sides thereto to the given dimensions.-The fact of the
grit etc, taken up by the molten metal from the sand forming the moulds, being
thoroughly separated from the castings in the manner described, gives to all the
surfaces a homogeneous finish, so that the journals or axles will have nothing but
the pure metal to contend with.-In taking the castings from the swilling bath,
they may be dried or not prior to being operated upon in producing a rubbing or
frictional contact, consisting of any material or materials applied or used by hand
or by any mechanical means-a circular block may be used, made of any suitable
material or materials and of any suitable diameter and thickness with its periphery
or any width or length on face curved to a radius suiting the motion surface of the
castings and the same covered with say file card, (or steel wire may be used) fitted
into the rim or periphery, or a mandril with or without a collar covered with file
card, or wired after the fashion of a brush, and made to rotate in a foot lathe, or by
any other means, or may be arranged to operate on the castings (after the fashion
or principle of the well known hair brushing machine) mounted or fitted with
steel wires or file card.
Another modification consists of a box or boxes, barrel or barrels of any suitable
section, and made to revolve, (or any other motion may be given to them), each box
to contain water and sand or iron scale or other frictional material for rubbing or
polishing purposes. Thus, a finely polished or finished surface, after being
subjected to the action of the acid or any other liquid, for removing or cleansing
the metal's pores and all inundations of grit is produced-The friction process may
be dispensed with and the castings used direct from cleaning process, by the acid
and washing as described.
Having now particularly described the nature of my Invention, and in what
manner same is to be performed, I hereby declare that I claim :-
(1.) The application of cleansing and freeing castings of grit etc, substantially as
herein before described.
(2.) The finishing of brass or bronze castings in the shape of bearings or all such
castings subjected to friction, wear and tear, by first operating on the patterns
instead of the castings, substantially as and for the purposes hercinbefore described.
In Witness whereof I the said David Perfitt Griffiths Matthews have hereunto
set my hand and seal this fourth day of August one thousand eight hundred and
Witness:-
W. HILLIER
21 Cockspur Street
S.W
D. P. G. MATTHEWS (L.S.)