IMPROVEMENTS IN THE MANUFACTURE OF METALLIC WINDOW FRAMES, SKYLIGHTS, AND FLOOR GRATINGS.
Year: 1877

page_text: LETTERS PATENT to Joseph Thomas Harris, of the City and County of Bristol,
Engineer, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
METALLIC WINDOW FRAMES, SKYLIGHTS, AND FLOOR GRATINGS.".
000
1 7010
.. 10th Nezambon 197
PROVISIONAL SPECIFICATION left by the said Joseph Thomas Harris at the
Office of the Commissioners of Patents on the 19th November 1877.
JOSEPH THOMAS HARRIS, of the City and County of Bristol, Engineer. "IMPROVE-
MENTS IN THE MANUFACTURE OF METALLIC WINDOW FRAMES, SKYLIGHTS, AND
FLOOR GRATINGS."
My Invention has reference to the manufacture of metallic frames of windows,
skylights, and floor gratings from a number of detached pieces of bar. In the manu-
facture of these metallic frames the pieces of bar have hitherto been laid together in
the required form, and have then been united by casting a boss around the bars at
each of the junctions, but these bosses have generally been large and unsightly, and
they have had other objections.
In the Specification of Letters Patent granted to me on 5th April 1877, No. 1328,
I described certain improvements, by means of which, as therein explained, the
bosses could be made much smaller, and the other objections thereto were altogether
or in great measure overcome. Now my present Invention consists in manufacturing
the metallic frames in such manner that the bosses are entirely done away with.
For this purpose I cut a semi-dovetail recess in the upper edge of the end of each of
the bars to be united, and a similar semi-dovetail recess in the lower edge of the.
same end, these two recesses together forming one dovetail. I also form one or
more other dovetail recesses in the middle of the end of each bar, and I cut away a
portion of the ordinary rebate or moulding of the bar. I then bring together the
ends of the four bars to be united in a mould of the proper shape, and I run in
molten metal so as to fill up the dovetail recesses and the space of the cutaway
portions of the rebates; this molten metal will when cold hold all the parts firmly.

page_text: together without the production of any boss, and give the appearance of ordinary
mitred bars.
Similar dovetail arrangements are adopted for all the various forms of junction,
whether for two, three, or more bars.
In order to give an ornamental appearance to the junction when desired the mould
is made of such form as to cause a rosette or enrichment to be cast at the junction
simultaneously with the dovetail fillings, such enrichment however not projecting
beyond the line of the rebates or mouldings, therefore offering no obstruction to the
light.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Joseph Thomas Harris in the Great Seal Patent Office on the 18th
May 1878.
JOSEPH THOMAS HARRIS, of the City of Bristol, Engineer.
"IMPROVEMENTS IN
THE MANUFACTURE OF METALLIC WINDOW FRAMES, SKYLIGHTS, AND FLOOR
GRATINGS."
My Invention has reference to the manufacture of metallic frames of windows,
skylights, and floor gratings from a number of detached pieces of bar. In the
manufacture of these metallic frames the pieces of bar have hitherto been laid
together in the required form, and have been united by casting a boss around the
bars at each of the junctions, but these bosses have generally been large and unsightly,
and they have had other objections.
In the Specification of Letters Patent granted to me on 5th April 1877, No. 1328,
I described certain improvements, by means of which, as therein explained, the bosses
could be made much smaller, and the other objections thereto were altogether or in
great measure overcome. Now my present Invention consists in manufacturing the
metallic frames in such manner that the bosses are entirely done away with. For
this purpose
I cut a semi-dovetail recess in the upper edge of the end of each of the
bars to be united, and a similar semi-dovetail recess in the lower edge of the same
end, these two recesses together forming one dovetail. I also form one or more
other dovetail recesses in the middle of the end of each bar, and I cut away a
portion of the ordinary rebate or moulding of the bar. I then bring together the
ends of the four bars to be united in a mould of the proper shape, and I run in
molten metal so as to fill up the dovetail recesses and the space of the cutaway
portions of the rebates; this molten metal will when cool hold all the part firmly
together without the production of any boss, and give the appearance of ordinary
mitred bars.
Similar dovetail arrangements are adopted for all the various forms of junction,
whether for two, three, or more bars.
The manner in which I carry my Invention into effect is represented in the annexed
Drawings.
Figure 1 is a side view of two bars a, a, of the form I employ for a junction of
four bars.
Figure 2 is a plan of four bars in the position they occupy relatively to each
other when in the mould.

page_text: On reference to these Figures it will be seen that the end of each of these bars is
formed with a semi-dovetail recess b in its upper edge, and a semi-dovetail recess 6'
in its lower edge, these two recesses together forming one dovetail. There is also
another dovetail recess c in the middle of the end of each bar, and the ordinary
rebate or moulding d is cut away towards the end, so as not to extend beyond the
line of the bottom of the dovetails. When the four bars are brought together in a
mould of the proper shape, and the molten metal is run in in the ordinary manner,
the latter fills up the dovetail recesses, and when cool will hold the parts firmly
together without the production of any boss.
Figure 3 is a plan, and Figure 4 is a side view partly in section, shewing a
finished junction of four bars; the portion formed by the molten metal or casting is
marked e, e.
In some cases I dispense with the half dovetail 6 at the upper edge of each bar,
as in practice I find that the parts are generally held sufficiently firm by means of
the dovetail b¹ and c.
In order to give an ornamental appearance to the junction when desired the
mould is made of such form as to cause a rosette or enrichment to be cast at the
junction simultaneously with the dovetail fillings, such enrichment however not
projecting beyond the line of the rebates or mouldings, therefore offering no obstruc-
tion to the light.
Figure 5 is a plan, and Figure 6 a side view, partly in section, of a junction
of four bars made with a rosette or enrichment, as just mentioned; e¹, e¹, is the
enrichment.
Figures 7, 8, and 9 represent the manner in which I apply my Invention to
junctions, such as those at the side or top of the window frame. a¹ is the side or top
bar, and a the bar which meets it; this bar a is of the same form as those shewn in
Figures 1 and 2, except that the half dovetail bis dispensed with. The side or top
bar a¹ has a portion of its rebate or moulding & cut away, so as to form a dovetail f;
it has also a dovetail hole g, and a portion cut away dovetail fashion at h. When
the parts are put in the mould, and the molten metal is run in, the metal fills up
the dovetails in the two bars, including the hole g and part h, and when cool holds
the bars firmly together.
Figures 10 and 11 represent the manner in which I apply my Invention to a
junction at the corner of a frame. Each of the bars a has a dovetail c in its end,
and a half dovetail 61 at its lower edge; it may likewise have a similar dovetail at
its upper edge, as in the bars shewn in Figure 1. The ends of the bars are bevilled,
as seen at i, i, in order to give the metal cast upon them more hold, and for the
same purpose the dovetails b¹ and c are cut with bevilled edges, as shewn.
The way in which the moulds for my improved junctions may be made, and the
junctions cast therein, will be fully understood on reference to the Specification of
my Letters Patent of 5th April 1877, herein-before referred to.
And having now described the nature of my said Invention, and in what manner
the same is to be performed, I declare that I claim, forming the sash or other bars
for metallic window frames, skylights, and floor gratings in such manner that the
metal run in at the junctions of the said bars will hold them firmly together without
the production of any boss, substantially as herein-before described and represented
in the annexed Drawings.
In witness whereof, I, the said Joseph Thomas Harris, have hereunto set my '
hand and seal, this Sixteenth day of May, One thousand eight hundred
and seventy-eight
JOS. T. HARRIS. (LS.)