IMPROVEMENTS IN APPLYING MOTIVE POWER TO DAW FRAMES.
Year: 1867

page_text: LETTERS PATENT to John Robinson, of Rochdale, in the County of Lan-
caster, Engineer, and John Smith, of the same Place, Engineer, for the
Invention of "IMPROVEMENTS IN APPLYING MOTIVE POWER TO DAW FRAMES.
Sealed the 18th February 1868, and dated the 21st August 1867.
PROVISIONAL SPECIFICATION left by the said John Robinson and John
Smith, the Office of the Commissioners of Patents, with their Petition,
on the 21st August 1867.
We, JOHN ROBINSON, of Rochdale, in the County of Lancaster, Engineer,
and JOHN SMITH, of the same Place, Engineer, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN APPLYING MOTIVE POWER TO SAW
FRAMES," to be as follows:-
Our Invention consists in arrangements whereby we are enabled to drive
saw franes by the direct action of steam, air, or gas cylinders.
Firstly, we use the said steam, air, or gas as an elastic abutment for the
piston, and this we effect by admitting steam, air, or gas to the cylinder before
the piston has completed its stroke. Also we place throttle valves in the
ports, by which means the flow of steam, air, or gas may be regulated.
Another part of our Invention consists in methods of giving motion to the
valves of the cylinders. For this purpose we connect the saw frame by
suitable links or levers to a rocking shaft, upon which we mount a plate
carrying projecting pins. These pins as the aforesaid, shaft rocks to and fro
arrive in contact with a lever connected to the valve rod and push it forward
or cause it to fall over, whereby motion is communicated to the valve; or we

page_text: reverse the action by making the lever act upon the projecting pins, and com-
municate motion to the valve therefrom. The aforesaid pins we mount in
slots, in order to render them adjustable for variations of motion of the valve.
We also render the junctions of the connecting levers or links adjustable.
According to another method of giving motion to the valve we connect the
saw frame to a lever turning upon a centre, which is mounted in a slot carried
by a fixed part of the framework, and which centre is capable of being moved
by a screw or similar means. This lever imparts motion to other levers or
links which communicate motion to the valve rod.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the 'said John Robinson and John Smith in the Great Seal Patent
Office on the 21st February 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, 'JOHN
.ROBINSON, of 'Rochdale, in the County of Lancaster, Engineer, and JOHN
SMITH, of the same Place, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of August, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
us, the said John Robinson and John Smith, Her special license that we,
the said John 'Robinson and John Smith, our executors, administrators, and
assigns, or 'such others 'as we, the said John Robinson and John Smith,
our "executors, administrators, and assigns, "should at any time lagree with,
and no others, from time to time and at all times thereafter during the
term 'therein expressed, should 'and 'lawfully might make, use, fexercise, and
vend, within the United Kingdom of Great Britain' and Ireland, the Channel.
Islands, and Isle of Man, an 'Invention for " IMPROVEMENTS IN APPLYING MOTIVE
POWER TO SAW FRAMES," upon the condition (amongst others) that 'we, the said
John Robinson and John Smith,' by an instrument' in writing under our-hands
and seals, or under the 'hand and seal of one of us, 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
Office within six calendar months next and immediately after the date of the
said Letters 'Patent.
NOW KNOW YE, 'that we, the said John Robinson and John Smith, do:
hereby déclare "the nature of our said-Invention, and in what manner the

page_text: same is to be performed, to be particularly described and ascertained in and
by the following statement and accompanying, Drawings, that is, to say:
Our Invention consists in, arrangements whereby we are enabled, to drive
saw frames by the direct action of steam, air, or gas cylinders.
Firstly, we use the said steam, air, or gas as an elastic abutment for the
piston, and this, we effect by admitting steam, air, or gas to the cylinder before
the piston has completed its stroke. The said elastic fluid therefore exerts a
resistance to the impetus of the piston and saw frame, but at the same time
yields thereto, so as to constitute the said elastic abutment.
In the accompanying Drawing Figs. 1 and 2 represent a saw frame with
motive-power engine attached' according to our Invention.
The framework is at 1 mounted on a foundation plate 2, and carrying the
reciprocating frame 3 for the saws as usual. Upon the upper part of the
frame 1 is the cylinder 4, to be used with steam, air, or gas, as may be
desired. At 5, 5*, are the valve boxes, at 7 the, induction pipe, and 6 the
exhaust. The piston rod is shewn at 8, which passes downward through an
ordinary stuffing box 9, and is then attached to the, saw frame 8. For the
present we will suppose that the induction and eduction passages are opened
and closed by any suitable means, but according to our Invention we admit
the motive-power fluid above and below the piston before, it has completed its
strokes, and so obtain the aforesaid elastic abutment. Within the parts 10, 10*,
which lead to the upper and lower parts of the cylinder we place throttle valves,
the axes of which are shewn at 11, 11*, carrying levers 12,, 12°. To, these
levers are connected rods 13, 13*, provided with screws at their lower ends
taking into nuts formed upon pulley handles 14, 14, which bear against pro-
jections 15, 15, through which the, rods, 13, 13*, pass. By turning the
pulley handles 14, 14*, the throttle valves in the ports 10, 10, may be turned
upon their centres, so as to admit more or less fluid to, the cylinder. The
object of this part of our Invention is this. It is well known that the frame 3
is sometimes furnished with, more saws than at others, and that the power
required to effect the cutting stroke (in this instance the down stroke), varies
to a great extent, but as the weight of the saws to be lifted, does not constitute
any considerable portion of the whole weight the power recquired for the
up-stroke is nearly constant. We will suppose the full compliment of saws to
be. in the frame 3, and that the power to drive them requires as much steam.
or other fluid as the ports will pass, then the throttle valve at 10 will be
opened to the full extent, but that at 10 may be contracted, as the piston.
will merely have to lift the dead weight of the frame 3, but suppose now
that a certain number of saws are removed, then the power required for the

page_text: cut or down stroke not being so great the throttle valve at 11 is turned so as
partly to close the port 10, while the other valve 11* may remain unaltered.
Again, should the pressure of the steam or other fluid vary, then the quantity
admitted to the cylinder may be regulated by shifting both the throttle valves.
We will now proceed to describe how the slide valves are worked according
to our Invention. To the upper end of the saw frame 3 is jointed a link 16
connected to a lever 17 turning upon a shaft 18, but extending beyond it, so
as to give a vibratory movement to a shaft 19 through the medium of a
link 20 and lever 21. Having thus shewn how the shaft 19 is caused to
vibrate we refer to the detached views, Fig. 3, 4, drawn upon an enlarged
scale. Upon the said shaft 19 is fixed a disc 20 provided with slots 21, 21*,
within which are pins 22, 22*, capable of being adjusted in any desired
position by means of nuts 23. Upon the shaft 19 is. mounted loosely a
lever 24 extending between the pins 22, 22*, and connected at its other end
'to the valve spindle 25, Figs. 1 and 2. As the saw frame 3 moves.upward
and downward its link 16, through the medium of the levers 17, 21, causes
the shaft 19 to vibrate úpon its centre, carrying with it the disc 20 and pins
22, 22*, and these pins by acting alternately upon the lever 24 effect the
shifting of the slide valve. By altering the positions of the pins 22, 22*, in
these slots the amount of fluid admitted to, the cylinder for each-stroke may
be regulated, and the object of the first part of our Invention may be attained
by causing the pins 22, 22*, to act so as to admit the fluid before the piston
has completed its stroke.
A modification of 'the above described method of shifting the slide valve is
shewn in the above referred to, Figs. 1 and 2, and also in the detached views,
Figs. 5 and 6, drawn upon an enlarged scale. Upon the shaft 19 (to which
a vibratory motion is-communicated as abové described) is a lever 26 carrying
a pin 27 mounted in a slot, and capable of being adjusted in any required
position by a screw 28 which passes through it. This pin extends beyond the
Tever: 26, and is then formed as a wedge projecting into a wedge-formed
groove 28 formed in a lever 29, 29* loose upon the shaft 19; the end 29*
being coupled to the valve spindle 25.
the screw 28, so that the wedge-formed end of the said pin occupies and fits
'the sinaller end of the slot 28, then the vibratory movement of the shaft 19
would impart a constant and uniform motion to the lever 29*, and con-
sequently valve spindle 25, but if the pin 27 be drawn back towards the
larger end-of-the slot 28 then a space will be left between the two surfaces,
and the vibration of the shaft 19 will cause the said pin to act alternately at
intervals against the lever 29, and thus the cut-off. may be regulated as before
Suppose the pin 27 to be moved by

page_text: described in reference to Figs. 3 and 4, the adjustment of the pin 27 in its
slot answering to the adjustment of the pins 22, 22*, in their slots 21, 21*.
The detached views, Figs. 7 and 8, shew another method by which we
effect the shifting of the slide valve. A lever connected by a link to the saw
frame is shewn at 17, mounted in this instance upon a centre 30 situate
within a slot formed in a fixed bracket 31, and capable of being adjusted in
position by a screw 32. To the lever 17 is connected by means of a slot a
link 33, the other end of which is jointed to a lever 34 attached to the
shaft 19 of the formerly described Figures, and upon which is a lever 35 con-
nected to the valve spindle. The lever 17 being caused to vibrate upon its
centre 30 communicates motion by the means above described to the slide
valve, but the centre of motion 30 is adjustable by the screw 32, and by
altering its position the point of connexion with the link 33 may be caused to
move through a greater or less space, and a proportionate amount of motion
In the above
will be imparted to the valve so as to regulate the cut-off.
description we have alluded to the motive-power cylinder as
the top of the saw frame, but it is evident that it may be adapted to the
bottom thereof if desired. We have shewn the feed motion for the timber to
be cut taken from our improved apparatus by means of a rod 36, but any
ordinary method may be adopted.
being placed on
Having thus described and ascertained the nature of our said Invention,
and the manner in which the same is to be performed, I desire it to be
understood that we claim as secured to us under the above in part recited
Letters Patent,-
Firstly. Using the motive-power fluid as an elastic abutment for the piston
by admitting the said fluid thereto before it has completed its stroke.
Secondly. The use of throttle valves in the ports.
Thirdly. The arrangement substantially as described for shifting the slide
valves, and shewn in two modifications at Figs. 1, 2, 3, 4, 5, 6. Also the
arrangement depending upon the moveable centre of motion 30, Figs. 7 and 8.
In witness whereof, I, the said John Smith, have hereunto set my hand
and seal, this Twentieth day of February, One thousand eight hundred
aud sixty-eight..
JOHN SMITH. (L.S.).