C478 § 
[Dec 
THE NEW PATENTS, 
Enrolled in Ofober. and November. 
This Article will in future be confiderably enlarged and improved, under the Condu& 
of a Gentleman of diflinguifbed Eminence in the Chemical and Philofophical World.. 
MACHINE FOR cuTTiING Comps. 
ON the roth of July, 1796, was enrolled 
the {pecificationof a patent granted 
to. Mr. ‘WiLitiam Bunpy, of Pratt- 
place, Camden-town, for cutting eombs 
by machinery. It appears, at firft fight, 
to be a fingular circumftance, that in a 
country famous for its attention to me- 
chanical proceffes, the teeth of ivory 
combs fhould be cut, one firoke after the 
other, by the human hand, affifted’ by no 
ether tool than a pair of faws rudely faft- 
ened in a wooden back, and kept afunder 
by means of a {mall flip of wood. With 
thefe rough implements, however, it is 
that the very delicate fuperfine ivory 
combs, containing from fifty to fixty 
teeth in an inch, are manufactured. It 
may readily be conceived, that the ima- 
ginations of mechanical men muft have 
been employed in an attempt to folve the 
practical problem of conftruCting a ma- 
chine which, without {kill in the agent 
or firt mover, might perform all that 
mien, conyerted by practice into a kind of 
living machine, are capable of doing, but 
with lefs coft.or greater produ, in pro. 
Portion as it Is eafier to maintain the one 
than the other. Accordingly, it is not 
difficulc to find traces of attempts of this 
kind during the laf forty years, in the 
traditions of our manufacturing towns and 
counties. From what caufes their failure 
may have arifen, fiace none of them have 
been eftabltfhed to fuperfede the old prac- 
tice, is not eafy to difcover ; but it is cer- 
tain, that Mr. BuNDy’s machine is the 
firft and only one which has yet appeared 
at the patent office. 
as follows : 
An iron fly-wheel of three feet in dia- 
meter, is moved by a crank and treadle, or 
by any other power or means of applica- 
tion. On the fame axis is a wheel or pul- 
ley of 15 inches diameter,which, by a gut, 
drives another pulley of nine inches at- 
tached to a puppet-head above, sheers re- 
fembling thofe of a common foot-lathe. 
An arbor is driven by this upper wheel 
in the fame manner as work is thrown 
round between centres before the man- 
drell,in the common lathe. On the ar- 
bor are fixed a number of circular cutters, 
about two inches diameter, correfpond- 
ing to the notches intended to be cut in 
the combs. Thefe cutters are all of a 
5 
Its conftruction is. 
thicknefs, and have brafs wafhers between 
them ; and alfo from another arbor in a 
frame, there are fteel pieces called guiders, 
which ftand between the cutters and keep 
them regularly afunder, juft above the 
place where the combenters. The comb 
is held by a plate and two {crews upon 
the top of a biock or carriage, which runs 
off and on by means of a platform and 
dove-tail upon the lathe-bed. The 
comb moves in its own plane, right on- 
ward to the centre on axis of the cutters, 
and the carriage is driven by a ferew of 
10 threads in the inch, into which a knife- 
edge from the carriage falls, inftead of a 
nut. On the extremity or tail of the 
{crew, is fixed a {pur-wheel of 30 teeth, 
driven by an endlefs ferew, the arbor of 
which laft is, of courfe, parallel to the ar= 
hor of the cutters. It is driven by a pul- 
ley of fix inches concentric with the cut- 
ting-arbor, and itfelf has a pulley of 
three. . ie 
Hence, if the great wheel be moved 
once per fecond, the arbor will‘revolve 
4” times, and the endlefs fcrew-arbor % 
times. But, from the dimenfions of the 
f{crew, 30 revolutions of the endlefs ferew 
make | inch of the tooth, or 150 revo- 
lutions, make 3 inch. With this length 
of tooth, the great wheel will revolve 45 
times, and the cutting arbor 75 times. 
One fide of the comb will therefore be cut 
in three Guarters of a miaute. . 
The combs are pointed by applying 
them to an arbor clothed with cutters 
with chamford edges and teeth, 3, inch 
deep. They are applied by hand. This 
arbor is driven by a wheel on the crank 
axis. 
The cutters are made of tempered fteel, 
as are alfo the guides. The teeth of the 
cutters are fet fo as to clear the back, or 
fcllowing part, from fri€tion im the cut. 
The cutters, the cutter-wafhers, the 
guides, and the guide-wafhers, are all 
ground fiat and thin upon a brafs plate, 
in the fame manner as. optical work is 
ground; during which operation the piece 
is retained again on an upper moveable 
plate of its own fize, by means of a circu- 
lar rim or edge, which is adjuftable by 
{crews, fo as to form a deeper or fhallower 
cell, as may be required. 
The guides are one-twentieth part thin- 
ner than the wathers of the cutters, and 
the guide-wathers are ' part thicker 
than 
