IMPROVEMENTS IN SAWING MACHINES
Year: 1881

page_text: LETTERS PATENT to Thomas Nield Robinson, of the Firm of Messieurs
Thomas Robinson and Son, Limited, of Rochdale, in the County of Lancaster,
for an Invention of "IMPROVEMENTS IN SAWING MACHINES." A commu-
nication from abroad by William Henry Smyth, of San Francisco,
California, U.S.
PROVISIONAL SPECIFICATION left by the said Thomas Nield Robinson.at
the Office of the Commissioners of Patents on the 23rd July 1881.
THOMAS NIELD ROBINSON, of the Firm of Messieurs Thomas Robinson and Son,
Limited, of Rochdale, in the County of Lancaster. "IMPROVEMENTS IN SAWING
MACHINES." A communication from abroad by William Henry Smyth, of San
Francisco, California, U.S.
This Invention is particularly applicable to sawing machines for cross cutting
and tree felling, similar to the machinery described in the Specification of the
above named William Henry Smyth, dated A.D. 1878, 11th November, No. 4567;
but it is applicable to other reciprocating sawing machines.
The object of this Invention is to impart a rocking motion to the saw while it
is at work in order to give it an increasing action during the cut, and to ease it
during the return stroke. In applying this Invention to a machine in which is a
reciprocating saw fixed to a sliding block moving upon or between suitable guides,
the sliding block being connected to the crank shaft or other driving shaft by a
connecting rod, curved slots of sufficient length are made in the inner ends of the
said guides through which the crank shaft passes; there are two eccentrics fixed
on the crank shaft which work in recesses formed in the ends of the guides, the
outer ends of the guides being pivoted on a cross piece or rod fixed to the frame of
the machine; the action of the eccentrics when the machine is at work raises and
lowers the inner ends of the guides, and thus lowers the saw gradually during the
cut and lifts it during the return stroke, causing the saw to do its work more
quickly and efficiently. The saw may be raised and lowered at any portion of the
stroke by adjusting the eccentrics. In applying this Invention to other sawing
machines having one or more reciprocating saws the guides must be mounted so
as to allow them to receive a rocking motion from the eccentrics. The eccentrics
may be fitted and mounted in any convenient manner or position to impart the
rocking motion to the saws.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Nield Robinson in the Great Seal Patent Office on the
19th January 1882.
"
THOMAS NIELD ROBINSON, of the Firm of Messieurs Thomas Robinson and Son,
Limited, of Rochdale, in the County of Lancaster. IMPROVEMENTS IN SAWING
MACHINES." A communication from abroad by William Henry Smyth, of San
Francisco, California, U.S.
This Invention is particularly applicable to sawing machinery for cross cutting
and tree felling, similar to the machinery described in the Specification of the above
named William Henry Smyth, dated A.D. 1878, 11th November, No. 4567; but
it is applicable to other reciprocating sawing machines.
The object of this Invention is to impart a rocking motion to the saw while it
is at work in order to give it an increasing action during the cut, and to ease it
during the return stroke.
In applying this Invention to a machine in which is a reciprocating saw fixed to
a sliding block moving upon or between suitable guides, the sliding block being
connected to the crank shaft or other driving shaft by a connecting rod, slots of
sufficient length are made in the inner ends of the said guides through which the
crank shaft passes; there are two eccentrics fixed on the crank shaft which work
in recesses formed in the ends of the guides, the outer ends of the guides being
pivoted on a cross piece or rod fixed to the frame of the machine; the action of the
eccentrics when the machine is at work raises and lowers the inner ends of the
guides, and thus lowers the saw gradually during the cut and lifts it during the
return stroke, causing the saw to do its work quickly and efficiently. The saw
may be raised and lowered at any portion of the stroke by adjusting the
eccentrics.
In applying this Invention to other sawing machines having one or more recip-
rocating saws the guides must be mounted so as to allow them to receive a rocking
--motion from the-cccentrics.-
The eccentrics may be fitted and mounted in any convenient manner or position
to impart the rocking motion to the saws.
And in order that this Invention may be fully understood and readily carried
into effect I will describe the accompanying Sheet of Drawings, reference being
had to the figures and letters marked thereon.
Fig. 1 is a partially sectional elevation, and Fig. 2 is a plan of a sawing machine
constructed according to this Invention; Fig. 3 is a view of a guide, and the dotted
lines indicate its position when raised.
a is the saw fixed to the sliding block b, to which motion is imparted by the
crank shaft c, through the connecting rod d; e, e, are the guides on which the
block b slides; these guides are at one end pivoted on the cross piece f connected
to the frame g, g; the other or inner ends of the guides are slotted to allow the
crank shaft to pass through them; near the slot on each guide are two projecting
lips or flanges, and in the space between the flanges on each guide works an
eccentric h; these eccentrics are fixed on the crank shaft c, and are or may be
adjustable, and they are set so as to raise the inner ends of the guides as the saw
moves forward, thus depressing the saw gradually during the cut; the eccentrics
lower the inner ends of the guides and raise the saw so as to ease it during its
return stroke. By the use of this Invention the saw is caused to do its work with
economy and efficiency, and the saw seldom requires to be taken from the machine
for sharpening and setting.

page_text: Having stated the nature of this Invention, and described the manner of per-
formning the same.
I declare that I claim,-
The eccentrics h, h, for imparting a rocking motion to the guides e, e, substantially
as and for the purpose shown and described.
In witness whereof, I, the said Thomas Nield Robinson, have hereunto set
my hand and seal, this Fourteenth day of January, One thousand eight
hundred and eighty two.
THOS. N. ROBINSON. (L.S.)