IMPROVEMENTS IN SAWING METALS AND IN THE MACHINERY OR APPARATUS EMPLOYED THEREIN.
Year: 1882

page_text: LETTERS PATENT to John Henry Johnson of 47 Lincolns Inn Fields in the
County of Middlesex, Gentleman, for an Invention of "IMPROVEMENTS IN
SAWING METALS AND IN THE MACHINERY OR APPARATUS EMPLOYED THEREIN.”.
Communicated to him from abroad by Henrietto Tuyssuzian formerly
Delong of Paris in the Republic of France
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 15th July 1882.
JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman "IMPROVEMENTS IN SAWING METALS AND IN THE MACHINERY OR
APPARATUS EMPLOYED THEREIN a communication to me from abroad by Henriette
Tuyssuzian formerly Delong of Paris in the Republic of France
"
This Invention relating to Sawing metals and to the machinery or apparatus
employed therein consists in certain improvements hereinafter described in the
construction and arrangement of the saws and apparatus for operating the same
whereby it is rendered possible to cut fretwork or openwork in sheets or plates of
metal of considerable dimensions with great accuracy and facility.
In cutting fret or open work in metal by means of reciprocating saws arranged
to this Invention the saw is operated by oscillating levers to which motion
is imparted by means of cranks or their equivalents as described in the Specifi-
cation to former Letters Patent granted to John Henry Johnson and dated the
fourteenth September One thousand eight hundred and sixty six N° 2365 but
in place of oscillating upon centres arranged at the sides of the supports as described
in the said Specification the oscillating levers according to the present Invention
work in hollows or recesses formed in the body of the supports important
advantages are realized by this Improvement the studs or centres on which the
levers oscillate and which are necessarily exposed to great strain when operating on
thick plates are more firmly supported and the machine is thus enabled to work
more steadily and accurately.

page_text: In cutting fret or open work in metal by means of a reciprocating saw connected
to a bow spring at one end and at the other end to a pulley or other equivalent
means for actuating the saw.
An apparatus similar in general construction to that ordinarily used for cutting
wood fret work is employed but in order to ensure the power and precision of
action requisite in sawing metal the saw is maintained in the proper state of
tension by means of a powerful steel spring operating in a somewhat similar
'manner to the wooden bow spring employed in apparatus for cutting fret or open
work in wood.
"
An improved feature of this Invention consists in the peculiar formation of the
saw teeth which are "set or inclined laterally to the right and left alternatley so as
to cut with a certain amount of "weigh" or "clearance" and thus enable the saw
to follow all the curves or angles of the design or pattern to be cut with facility
and precision
This result is obtained by forming and setting the teeth before tempering the
saw to the degree of hardness necessary for cutting metal.
The teeth are made of various sizes according to the nature of the metal to be
operated upon and are formed without "fleam" or bevel on the cutting face which
perpendicular or nearly so that is to say has little or no rake-This method of
forming the teeth is applicable to reciprocating saws as well as to endless riband or
bandsaws employed in cutting metals.
By means of the improvements herein before described it is rendered possible to
cut open or fretwork in metal plates or sheets of considerable thickness according
to any desired design or pattern with great precision and facility and thus obtain
products which are susceptible of a variety of useful and ornamental applications in
architecture and otherwise such for example as frames for windows of colored or
other glass ventilators glazed and other fanlights shop fittings screens partitions
and the like.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Henry Johnson in the Great Seal Patent Office on the
13th January 1883.
JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman "IMPROVEMENTS IN SAWING METALS AND IN THE MACHINERY OR
APPARATUS EMPLOYED THEREIN a communication to me from abroad by Henriette
Tuyssuzian formerly Delong of Paris in the Republic of France
"
This Invention relating to sawing Metals and to the machinery or apparatus
employed therein consists in certain Improvements hereinafter described in the
construction and arrangement of the saws and apparatus for operating the same
whereby it is rendered possible to cut fret work or open work in sheets or plates
of metal of considerable dimensions with great accuracy and facility.
In cutting fret or open work in metal by means of reciprocating saws arranged
according to this Invention the saw is operated by oscillating levers to which motion
is or may be imparted by means of cranks or their equivalents as described in the
Specification to former Letters Patent granted to John Henry Johnson as a
communication from the said Madame Delong and dated the Fourteenth day of
September in the year of our Lord One thousand eight hundred and sixty six
N° 2365 but in place of oscillating upon centres arranged at the sides of the
supports as described in the said Specification according to the present Invention
the oscillating levers work in hollows or recesses formed in the body of the
supports Important advantages are realised by this improvement; the studs or
centres on which the levers oscillate and which are necessarily exposed to great
strain when operating on thick plates, are more firmly supported and the machine
is thus enabled to work more steadily and accurately.
The Invention also relates to improvements in the saws themselves as hereinafter
described.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same and for that purpose shall refer
to the several figures on the annexed sheet of drawings the same letters of
reference indicating corresponding parts in all the figures.
Figure 1 is a side elevation, figure 2 is a plan; and figure 3 is an elevation of the
back end of a machine constructed according to this invention.
Figure 4 is a side elevation and figure 5 is a front elevation drawn to an
enlarged scale of a saw provided with an improved form of teeth as hereinafter
described.
A is the table of the machine supported upon legs or pillars B and to one
extremity of this table are bolted a pair of rigid arms or supports D carrying
levers E E¹ connected respectively by sliding bars G. G¹ to the two ends of a
reciprocating saw K. The lever E¹ receives its motion from the lever E by means
of a connecting rod J and the lever E is worked by a connecting rod I and a
crank F on a shaft H driven by a cone pulley R. This shaft is connected to the
pulley R by a clutch arrangement H worked by a handle or preferably by a
pedal Q which enables the motion of the saw to be instantaneously arrested when
required.
As shown more clearly in figures 2 and 3 the levers E. E' turn upon fulcra
or axes L. L' and work in hollows or recesses M M' in the arms or supports D
which are consequently enabled to present a firm bearing for the said axes L. L' on
both sides of the levers
An important feature of this Invention consists in the peculiar formation of the
saw teeth which are "set" or inclined laterally to the right and left alternately as

page_text: "
shown in figure 5 so as to cut with a certain amount of “ Iway" or "clearance
and thus enable the saw to follow all the curves or angles of the design or pattern
to be cut with facility and precision. This result is obtained by forming and setting
the teeth before tempering the saw to the degree of hardness necessary for cutting
metal.
"
The teeth are made of various sizes according to the nature of the metal to be
operated upon and are formed without "fleam or bevel on the cutting face which
is perpendicular or nearly so that is to say has little or no rake as shown in
figure 4 This method of forming the teeth is applicable to endless riband or
bandsaws (as well as to reciprocating saws) employed in cutting metals.
By means of the improvements herein before described it is rendered possible to
cut fretwork in metal plates or sheets of considerable thickness according to any
desired design or pattern with great precision and facility and thus obtain products
which are susceptible of a variety of useful and ornamental applications in
architecture and otherwise such for example as frames for windows of colored or
other glass, ventilators, glazed and other fanlights, shop fittings screens partitions
and the like.
Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or 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 hereinbefore in part
recited Letters Patent is :-
First In machines for sawing metal and of the class described in the
Specification of the former Letters Patent N° 2365 in the year of our Lord One
thousand eight hundred and sixty six hereinbefore referred to, arranging the levers
which impart motion to the saw in the interior of hollow arms or supports
substantially as hereinbefore described and illustrated in the accompanying drawing.
Secondly-In the manufacture of saws for sawing metal and having teeth with
square cutting edges and no rake "setting" the teeth so formed before tempering
the saw as herein before described.
Thirdly The use, in combination with machines for sawing metal fretwork and
provided with the improvements herein before set forth, of saws the teeth of which
are "set or bent alternately to the right and to the left, such setting being effected
before the saws are tempered as herein before described.
"
In witness whereof I the said John Henry Johnson have to this my
Specification set my hand and seal this tenth day of January Que thousand
eight hundred and eighty three.