IMPROVEMENTS IN MACHINERY FOR SAWING WOOD
Year: 1861

page_text: LETTERS PATENT to Thomas Greenwood, of Leeds, in the County of
York, Machine Maker, for the Invention of "IMPROVEMENTS IN MACHINERY
FOR SAWING WOOD."
Sealed the 11th February 1862, and dated the 5th September 1861.
PROVISIONAL SPECIFICATION left by the said Thomas Greenwood at, the
Office of the Commissioners of Patents, with his Petition, on the 5th
September 1861.
I, THOMAS GREENWOOD, of Leeds, in the County of York, Machine Maker,
do hereby declare the, nature of the said Invention for "IMPROVEMENTS IN
MACHINERY FOR SAWING WOOD," to be as follows:-
The object of this Invention is to facilitate the cutting of curvilinear, bevil,
and twisted forms by means of band saws.. This I propose to effect by giving
any required inclination to the cutting edge either preparatory to or during the
action of, sawing. The pulleys which carry the saw, band I mount on a
vertical segmental frame capable of moving axially on or in its supports, and
on a portion of the periphery of this frame I form a segment rack, into which
a worm gears for the purpose of giving an axial motion thereto. By this
axial motion the direction of the cut of the saw band is determined; thus the
saw may be adjusted to make a vertical cut or a diagonal cut at pleasure.
The axial motion of the vertical frame may be regulated by hand or
mechanism; and it may be either regular or variable. It may also take place

page_text: while the saw is quiescent or simultaneously with the action of the saw, or in
conjunction with the table or bogies by which the timber to be sawn is
'brought up to and carried past the saw. Band saws thus constructed are
peculiarly applicable to cutting out the ribs or timbers for ships and for
other purposes where irregularly-curved or bevilled forms or shapes are 5
required.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Greonwood in tho Great Seal Patent Office on the
5th March 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
GREENWOOD, of Leeds, in the County of York, Machine Maker, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patont, bearing date the Fifth day of September, in the year of our Lord
One thousand cight, hundred and sixty-one, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Greenwood, Her special license that I, the said Thomas Greenwood,
my executors, administrators, and assigns, or such others as I, the said Thomas
Greenwood, my executors, administrators, and assigns, should at any time agree
with; and no others,, from time to time and at all times thereafter during the s
term therein, expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN MACHINERY
FOR SAWING WOOD," upon the condition (amongst others) that I, the said
Thomas Greenwood, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Invention, and
in what manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Offico within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Thomas Greenwood, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described, and ascertained-in and by the following
statement, reference being hind to the Drawing' hereunto annexed, and to the
letters and figures marked thereon (that is to say):
The object of this Invention is to facilitate the cutting of straight, cur-s
vilinear, and other bevilled forms by means of band saws. This I propose to

page_text: effect by making the inclination of the saw band adjustable to the work while
the action of sawing is proceeding.
In the accompanying Drawing, Fig. 1 is a side elevation of a band saw
machine constructed according to my Invention; Fig. 2, an end view of the
same; and Fig. 3 is a plan view. In these views it will be seen that the
main element of novelty consists in mounting the tension pulleys which carry
the band saw upon an adjustable or rocking frame, which by moving around
a point cut by the operating edge of the saw will allow of the adjustment of
the saw while the machine is in action.
>
I may bere remark, that the adjustable frame admits of many obvious
modifications, but I prefer the arrangement shewn in the Drawing, because
by it the operating side of the saw will always cut in the line of the centre
round which the frame moves.
1
Secured to the bed plate of the machine are two standards A, A,,carrying
the table A¹ of the machine; these standards are furnished with bearings for
receiving the cranked trunnion supports of a rocking frame B. This frame is
made of cast iron of a segmental form, and furnished with rack teeth C on its
outer edge, into which gears a worm wheel D for imparting when desired an
axial motion thereto. Upon this frame B is mounted a pair of tension
pulleys E, E', which carry the saw band. The upper pulley E is mounted in
adjustable bearings for the purpose of ensuring the maintenance of the saw F
at a proper tension, and the shaft of the lower pulley E¹ is carried by pendent
brackets of the frame B, shewn best at Fig. 2.. G is a guide supporting a
pendent arm G' attached to the frame B for keeping the saw up to its work.
The worm D is mounted on a vertical shaft supported in a hollow standard D'
attached to the bed plate of the machine. Keyed to the lower end of the
worm shaft is a bevil pinion a, into which a bevil pinion (see Fig. 3) on a
short horizontal, shaft 6 gears. The opposite end of the shaft 6 is fitted with a
bevil wheel b, which gears into and is driven by a pinion on a cross,shaft,
carrying at its opposite end a bevil wheel c in gear with a pair of pinions c', c²;
these pinions c, c, are supported by a horizontal driving shaft c, which has
its bearings in short standards bolted to the bed plate. To this shaft the
pinion c¹ is keyed, and also the pulley d of a set of band pullies d, d², d.
The pinion ² is keyed to a hollow shaft on the shafts, and to it is also keyed
the pulley d¹. The pulley d² is loose on the shaft c. This arrangement, it
will be understood, is for the purpose of driving the worm wheel in either
direction, at pleasure. It is also important that the speed of the worm (which
causes the rocking of the band saw frame) should be capable of easy adjust-
ment relatively to the speed of the sawing operation; I propose, therefore, to

page_text: 'transmit motion to the driving shaft c through a friction gear arrangement; the
speed given off by which may be determined by the adjustment of a hand
'lever;
it consists of a feathered horizontal shaft e, to which band pulleys are
keyed. Mounted loosely on this shaft is a friction roller f, which is embraced
'by a forked guide g; this guide is free to slide on a fixed guide rod carried
by standards, which also afford bearings for the feathered shaft e. Jointed to
'a lug on the under side of this forked guidé is a rod which connects the guide g
with a crank arm on the outer end of a rock shaft g; this shaft at its inner
end carries a hand lever g³, which works in front of a fixed quadrant, and a
'pin on the hand lever dropping into the notches formed on this quadrant
"retains it in any desired position. The friction roller f works upon the face
of a vertical disc f keyed to a horizontal shaft, to which a belt pulley is
keyed, and a strap proceeding from this pulley to the pulleys d'transmits
the requisite motion for rocking the saw frame.
It will now be understood that when it is desired to decrease the speed of
'the worm D, it is only necessary to move the friction roller fnenrer to the
centre of the friction disc f', which movement is effected by simply rocking
the shaft g¹ through the hand lever. As the shaft g rocks the forked guide g
is moved to or fro over the feathered shaft e, and with it the friction roller f,
which drives the disc. f slower in proportion as it is advanced to the centre of
the disc, the disc being kept up in close contact with the roller f by means of
aspring, which bears upon the rear end of the disc shaft. Tho saw band
is driven by a belt from any first mover passing over the pullies on the shaft
of the lower tension pulley E. h is a belt shifter for throwing the band from
the friction gear into either of the pullies d, d', d, according to the work
under operation. When a square cut is required the belt will be on the loose
pulley, and no axial motion of the worm D will take place, the gearing in
connection therewith being thrown out of action; but when a bevil either to
the right or left is required in the work, the belt will be thrown on one or
other of the pullies d,'d'.
It will now be understood that, according to the direction of the axial
motion of the frame B, so will the direction of the cut of the saw band be
determined; thus the saw being adjusted to make a vertical cut, may be
re-adjusted while running to produce a diagonal cut with a gradually increasing
inclination (if desired) at pleasure.
'I'may remark, that I have not thought it necessary to shew the means for
presenting the timber to the action of the saw band, as my Invention in no
way affects that well known movement, which may be carried out in any
ordinary or approved manner. It will be obvious that band saws constructed

page_text: as above described are peculiarly applicable to cutting out the ribs or timbers
for ships and for other purposes where irregularly curved or bevilled forms or
shapes are required. For ensuring great exactness in the angle of the bevil,
it may be desirable to graduate the segment frame B, as shewn at Fig. 1, and
provide a fixed pointer which will facilitate the reading off of the angles at
which the machine is from time to time set.
Having now set forth the nature of my Invention of "Improvements in
Machinery for Sawing Wood," and explained the manner of carrying the same
into effect, I wish it to be understood that under the above in part recited
Letters Patent, I claim mounting the tension pulleys of band saws on an
adjustable rocking frame, whereby the angle of the saw blade to its work may
be varied, as above described.
In witness whereof, I, the said Thomas Greenwood, have hereunto set
my hand and seal, the Third day of March, in the year of our Lord
One thousand eight hundred and sixty-two.
THOMAS GREENWOOD. (L.S.)