Improvements in Guides for Band Saws and Circular Saws.
Year: 1895

page_text: Date of Application, 14th Dec., 1895
Complete Specification Left, 14th Sept., 1896-Accepted, 14th Dec., 1896
Improvements in Guides for Band Saws and Circular Saws.
We, ANDREW LINCOLN THOMPSON, of Newgate House, Bishop Auckland, in
the County of Durham, Cabinet Maker, and JOHN OSBORN MORGAN of
H, Exchange Buildings, King Street, Newcastle-on-Tyne, Marine Inspecting
and Consulting Engineer, do hereby declare the nature of this invention to be
as follows:-
:-
This invention relates to improvements in guides of saw blades, which improve-
ments are especially suitable for band saws and are also applicable for circular
saws.
In saws of this description which are driven at a high speed by machinery ;
guides are necessary to guide the edge of the saw to its cut, and the principal
defect in such saws as hitherto constructed, is the resistance to the saw blade by
friction against the guides, often resulting in the fracture of band saws which
would be much more used but for this defect. This friction also necessitates a
released grip of the saw which in consequence is ever liable to deviate from the
intended line of division through the material being cut especially by slipping
round knots and hard places, that is in taking the direction of the least resistance,
and this because a tighter grip of the saw would set up friction enough to stop the
aw or break it.
We will first describe the nature of our invention as applied to a band saw.
In carrying our invention into effect we substitute roller guides for fixed blocks
as side guides to the saw blade. Roller guides when accurately fitted to their
spindles and especially when ball bearings are used cau be set to grip the saw
blade with any degree of pressure required in practice without setting up as much
friction as can be appreciably felt on the saw blade, the friction being obviously
reduced to the vanishing point from the fact that the circumferential velocity of
the roller guides is always the same as the linear velocity of the saw blade. The
roller guides may be provided with a shoulder on one or other of them, adapted to
receive in contact the back-edge of the saw, and although the circumferential
velocity of the surface in contact with the saw back-edge is necessarily greater
than the circumferential velocity of the roller guide surface in contact with the
side of the saw, owing to the slight increase of radius, that is, when one roller is
used to serve as a combination side and back-èdge guide, we do not apprehend
that this will be appreciably felt in practice. But this can if desired be obviated
by constructing the side roller guide to abut against the back edge roller
guide, each part of the roller guide being mounted on the same spindle but kept
separate.
Our improved guide rollers can be used in combination with back edge guide
rollers of the kind hitherto in use. The guide rollers are mounted on spindles
which are adjustable in their face plate to adapt their position to varying thicknesses
of saw blades and this is done by any suitable means.
The saw guides are also adjustable to any width of saw blade being mounted on
an adjustable spindle, which is held in the desired position by a set screw.
Having explained the nature of our invention as applied to band saws, it will be
readily understood that similar rotary side guides can be applied with the like

page_text: advantage to circular saws, the guide rollers being suitably and adjustably mounted
in a line with or below the table of saw bench.
G. J. CLARKSON,
Chartered Patent Agent,
Stockton-on-Tees, Agent for the Applicants.
the
Improvements in Guides for Band Saws and Circular Saws.
We, ANDREW LINCOLN THOMPSON, of Newgate House, Bishop Auckland, in
County of Durham, Cabinet Maker, and JOHN OSBORN MORGAN of
H, Exchange Buildings, King Street, Newcastle-on-Tyne, Marine Inspecting
and Consulting Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This invention relates to improvements in guides for saw blades which improve-
ments are especially suitable for band saws and are also applicable for circular
Baws.
In saws of this description which are driven at a high speed by machinery ;
guides are necessary to guide the edge of the saw to its cut, and the principal
defect in such saws as hitherto constructed; is the resistance to the saw blade by
friction against the guides, often resulting in the fracture of band saws which would
be much more used but for this'defect. This friction also necessitates a released
grip of the saw which in consequence is ever liable to deviate from the intended
line of division through the material being cut especially by slipping round. knots
and hard places, that is in taking the direction of the least resistance, and this
because a tighter grip of the saw would set up friction enough to stop the saw or
break it.
And in order that our invention may be clearly understood and readily carried
into effect we will now proceed to describe the same with reference to the
accompanying drawings.
Fig. 1 is a side elevation of a band saw guide constructed in accordance with this
invention.
'
Fig. 2 is a corresponding front view of same..
Fig. 3 is a sectional plan view taken on line of Fig. 1.
In the arrangement represented in Figs. 1, 2 and 3, roller guides are employed
which serve as a combination side and back edge guide to the saw blade.
Fig. 4 is a front view and Fig. 5 a corresponding horizontal sectional view of a
band saw guide constructed in accordance with this invention in which roller
guides are employed as side guides to the saw blade in combination with back edge
guide rollers of the kind hitherto in use.
Referring to Figs. 1, 2 and 3, a and b are the roller guides which we substitute
for fixed blocks as side' guides to the saw blades c. Roller guides when accurately
fitted to their spindles and especially when ball bearings are used can be set to grip
the saw blade with any degree of pressure required in practice without setting up
as much friction as can be appreciably felt on the saw blade, the friction being
obviously reduced to the vanishing point from the fact that the circumferential
velocity of the roller guides is always the same as the linear velocity of the saw
blade. The roller guides may be provided with a shoulder a¹ on one or other of
them, adapted to receive in contact the back edge of the saw, and although the
circumferential velocity of the surface in contact with the saw back edge is

page_text: necessarily greater than the circumferential velocity of the roller guide surface in
contact with the side of the saw, owing to the slight increase of radius, that is,
when one roller is used to serve as a combination side and back edge guide, we
do not apprehend that this will be appreciably felt in practice. But this can if
desired be obviated by constructing the side roller guide a to abut against the
back edge roller guide a¹, each part of the roller guide being mounted on the
same spindle but kept separate. The roller a with the shoulder a¹ revolve in.
the guide arm d fitted with ball bearings and a loose sleeve e, which roller a is.
furnished with a left handed thread with which the lock nut f engages so as to
adjust the shoulder to the back edge of the saw blade. The neck of the guide
roller is also screwed to receive washers g to suit different widths of saws as
shown by dotted lines in Fig. 1; and the said guide roller b is also adjustable to.
any thickness of saw blade by being mounted on an adjustable spindle h, which is
held in the desired position by the set screw h¹.
In the arrangement represented in Figs. 4 and 5, in which our improved guide
rollers are used in combination with back edge guide rollers of the kind hitherto
in use, a and b are the roller guides which are employed as side guides to the saw
blade G and are mounted on spindles d fitted with ball bearings and adjustable
in the face plate e to adapt their position to varying thicknesses of saw blades by
means of a nut f. 9 is the back edge saw guide of the kind hitherto in use.
Having explained the nature of our invention as applied to band saws, it will be
readily understood that similar rotary side guides can be applied with the like
advantage to circular saws, the guide rollers being suitably and adjustably mounted
in a line or below the table of saw bench.
Having now particularly described and ascertained the nature of our said inven--
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. In a band saw guide, the substitution of roller guides for fixed blocks by
which friction is reduced owing to rollers on ball bearings being used for both
back and side thrusts, substantially as and for the purpose as hereinbefore
described with reference to the accompanying drawings.
2. In a band saw guide, the substitution of roller guides for fixed blocks by
which vibration is reduced owing to back of saw being adjustable close to guide-
arm, substantially as and for the purpose as herein before described with reference
to the accompanying drawings.
Dated this 12th day of September 1896.
G. J. CLARKSON,
Chartered Patent Agent,
Stockton-on-Tees, Agent for the Applicauts..
G. J. CLARKSON,
Chartered Patent Agent,
Stockton-on-Tees, Agent for the Applicauts..