IMPROVEMENTS IN ENDLESS OR BAND SAWS
Year: 1881

page_text: LETTERS PATENT to John Henry Johnson of 47, Lincoln's Inn Fields in the
County of Middlesex Gentleman, for an Invention of "IMPROVEMENTS IN
ENDLESS OR BAND SAWS." A communication from abroad by Henriette
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 21st December 1881.
JOHN HENRY JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex
Gentleman. 'IMPROVEMENTS IN ENDLESS OR BAND SAWS." A communication
from abroad by Henriette Tuyssuzian formerly Delong of Paris in the Republic of
France.
This Invention relates to certain improvements hereinafter described in the
construction of endless or band saws whereby they are rendered more adapted for
cutting fret or open work in metal and other materials.
The band saws or endless saws employed for cutting fretwork as heretofore
constructed present no solution of continuity so that their application is confined
to cutting external lines or curves as it is not possible to pass these saws through
holes drilled at any point on a metal plate for example as is done when reciprocating
saws are employed.
According to this Invention this disadvantage is obviated by cutting a band or
endless saw and hooking or joining together the two ends in such a manner as to
restore it to the form of an endless saw.
Important advantages are hereby secured for example the saw is enabled to
enter holes drilled in the material at any desired point of the curve or line along
which it is desired to cut and it is also rendered possible to cut fretwork in plates
of considerable thickness an operation which could not be performed with recipro-
cating saws having necessarily a limited stroke whereby the parts holding the saw
are rendered liable to strike the work.
The junction of the two extremities of the saw is effected by means of a hook or
interlocking joint.

page_text: A portion of the saw near each extremity is reduced in thickness in such a
manner that when the two extremities are superposed or laid together as herein-
after described the two combined do not exceed the thickness of the remaining part
of the saw.
Portions of the back and front of the extreme ends are also cut away
so as to leave narrow tongues at each extremity of the saw and these tongues are
provided on opposite sides relatively to each other with snugs or hooks hereinafter
referred to.
In the thin portions herein before described at the extremities of the saw there
are formed at equal distances from the tongues two longitudinal slits or openings
presenting bevelled or inclined surfaces at the edges nearest the ends of the saw
corresponding exactly to the snugs on the tongues herein before described.
The opposite edge of each opening is also bevelled or inclined but at a much
more acute angle so as to form a recess in the side of the saw for the reception of
the extreme end of the corresponding tongue which is suitably reduced in
thickness towards the extremity in order to enable it to be well within the said
recess.
In order to set up the band saw that is to say to join the two ends together the
two tongues are introduced simultaneously into the two corresponding openings
and the ends of the saw are pressed together laterally in such a manner as to cause
the snugs on the tongues to engage with or look on to the bevelled edges herein-
before described in the said openings and the thin ends of the tongues then lie in
the inclined recesses in the sides of the saw. When the parts are in this position
the two extremities of the saw cannot be separated either by a considerable strain
in the direction of its length or by a diminution of the tension.
In order to disconnect the ends of the screw it is simply necessary to separate the
hooked and bevelled edges by applying lateral pressure and at the same time
drawing the extremities apart in opposite directions.

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
20th June 1882.
JOHN HENRY JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex
Gentleman. "IMPROVEMENTS IN ENDLESS OR BAND SAWS." A communication
from abroad by Henriette Tuyssuzian formerly Delong of Paris in the Republic of
France.
This Invention relates to certain improvements hereinafter described in the
construction of "endless" or band saws whereby they are rendered more adapted
for cutting fret or open work in metal and other materials.
The band saws or endless saws employed for cutting fretwork as heretofore
constructed cannot be separated and rejoined so that their application is confined
to cutting external lines or curves as it is not possible to pass these saws through
holes drilled at any point on a metal plate for example as is done when recipro-
cating saws are employed.
According to this Invention this disadvantage is obviated by forming a band or
endless saw with ends hooked or so formed that they can be joined so as to form
an endless or band saw.
Important advantages are thereby secured for example the saw is enabled to
enter holes drilled in the material at any desired point of the curve or line along
which it is desired to cut and it is also rendered possible to cut fretwork in plates
of considerable thickness an operation which could not be conveniently performed
with reciprocating saws having necessarily a limited stroke as the parts holding
the saw would be liable to strike the work.
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 represents in side view the two ends of a band saw constructed
according to this Invention the said ends being detached or disconnected from each
other and Figure 2 is a view at right angles to Figure 1 one end being shown in
section.
Figure 3 is a side view and Figure 4 is a longitudinal section showing the two
ends joined or connected together.
A portion of the saw at A and B is reduced in thickness in such a manner that
when the two extremities of the saw are superposed or laid together as hereinafter
described the two combined do not exceed the thickness of the remaining part of
the saw.
Portions of the back and front at the extreme ends are also cut away
so as to leave narrow tongues C and D diminishing in thickness towards their
extremities at each end of the saw and these tongues are provided on opposite
sides relatively to each other with projecting snugs or hooks a
In the thin portions A and B at the extremities of the saw there are formed
at equal distances from the tongues two longitudinal slits or openings E and F
presenting bevelled or inclined surfaces b at the edges nearest the ends of the saw
corresponding exactly to the snugs a on the tongues C and D. The opposite
edge g of each opening is also bevelled or inclined but at a much more acute angle
so as to form a recess in the side of the saw for the reception of the extreme end
of the corresponding tongue (C or D) which is suitably reduced in thickness
towards the extremity in order to enable it to lie well within the said recess.
In order to join the two ends of the saw together the two tongues C and D are
introduced simultaneously into the two corresponding openings E and F and the

page_text: ends of the saw are pressed together laterally in such a manner as to cause the
snugs a on the tongues C and D to engage with or hook on to the bevelled edges b
in the said openings and the thin ends of the tongues then lie in the inclined
recesses in the sides of the saw as shown in Figures 3 and 4. When the parts are
in this position the two extremities of the saw cannot be separated either by a
considerable strain in the direction of its length or by a diminution of the tension.
In order to disconnect the ends of the saw it is simply necessary to separate the
hooked and bevelled edges by applying lateral pressure and at the same time
drawing the extremities apart in opposite directions.
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 :-
The bereinbefore described improvements in band saws consisting in forming
them with ends capable of being connected and separated substantially as and
for the purpose hereinbefore described and illustrated in the accompanying
Drawings.
In witness whereof I the said John Henry Johnson have to this my Specifi-
cation set my hand and seal this Twentieth day of June One thousand eight
hundred and eighty two.