Improvements in Circular Sawing Machines for Cutting Metal.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Circular Sawing Machines for Cutting Metal.
I, CHARLES HENRY CLIFTON, of Gleniffer View, Johnstone, Renfrewshire,
Engineer, do hereby declare the nature of this invention to be as follows:-
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My invention relates to improvements in circular sawing machines for cutting
metal, whereby the saw is traversed forward by a friction feed motion consisting
of the worm wheel on a feed screw driven in the usual way but running loose
and driving by friction a disc or blank wheel fastened to feed screw; the said
worm wheel and disc being kept in frictional contact by a spring or springs
made adjustable and arranged to compensate for the wear of frictional driving
surfaces. This friction feed motion may be on the feed screw or feed shaft
direct, or placed intermediate between the feed screw and the usual driving
motion.
Dated this Second day of September 1899.
I, CHARLES HENRY CLIFTON, of Gleniffer View, Johnstone, Renfrewshire,
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:-
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This invention relates to improvements in circular sawing machines for cutting
metals in which the saw is traversed forward by a friction feed motion consisting
of a worm wheel arranged to drive the feed screw which acts in the usual way
to traverse the saw carriage, this worm wheel being according to the present
invention loose, but adapted to drive by friction a disc or blank wheel keye:
to the feed screw, and kept in frictional contact with the worm wheel by means
of a spring or springs made adjustable and arranged to compensate for the wear
of the frictional driving surfaces. The frictional feed motion may be fitted direct
upon the feed screw shaft, or intermediate between the feed screw shaft and the
usual driving gear.
The invention is illustrated under one modification by the accompanying
drawings, Fig. 1 being an elevation and Fig. 2 a plan of a circular sawing
machine of the type in which the saw is traversed into the work, said machine
having my improved driving device applied thereto. Fig. 3 is a vertical section
of one example of the frictional driving device.
As shewn by Figs. 1 and 2, circular sawing machines of this type consist

page_text: ordinarily of a bed A carrying on a transverse shaft A¹ driving pulleys B and
bevel gear C, C, the latter being fixed on the end of the worm D driving the
worm wheel E keyed on the shaft F on which is also keyed the saw G. "This
shaft F has its bearings in a carriage H traversed towards the work by the action
upon it of the usual feed screw I carried in the machine bed A. The ordinary
driving pulleys K, worm L and worm wheel M are provided in connection with the
driving of the feed screw I, but instead of keying the worm wheel M upon said
feed screw, I interpose a friction device such as illustrated and in the manner
hereinafter described, in order to enable the saw, which runs at a uniform speed,
to deal with articles of varying thickness of metal at the proper rate of feed.
In order that the forward feed of the saw G may be automatically regulated
to suit the cut, i.e. the amount of saw periphery involved at any instant, I key
on the end of the feed screw shaft I, a friction disc or blank wheel J preferably
made in two portions J, J', as shewn at Fig. 3, these portions being drawn
towards each other by springs J³ interposed between the portion J and the heads
of bolts J screwed into the part J. Around a shoulder J formed on the
portion J¹ of the friction disc the usual worm wheel M for driving the feed screw
is loosely fitted in such wise that the pressure of the springs J clamps the friction
dise J to the worm wheel M and the former thus rotates the feed screw I, the
friction disc J slipping more or less within the worm wheel according as the
cut is heavy or light. By means of the bolts J already referred to, the degree
of compression of the springs Ja and consequently the degree of friction between
the disc J and the worm wheel M may be regulated as also compensation made for
wear upon the frictional surfaces.
Instead of a number of springs J³ a single spring may be employed bearing on
the outer end of the friction disc J, to press said disc into engagement with the
worm wheel M and it is obvious that the form of frictional device employed may
be varied provided sufficient slip is automatically obtained to reduce the speed
of the forward feed of the saw to suit the cut being made.
It is also obvious that the friction device, instead of being keyed direct on the
feed screw, may be keyed on any intermediate shaft from which power may be
transmitted to the feed screw.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. A circular sawing machine for cutting metal in which the feed of the saw
is automatically regulated by the interposition of friction gear arranged and
operating substantially as described.
2. In a circular sawing machine for cutting metal, a feed device, consisting, in
combination with the usual feed screw, of a friction disc keyed upon the feed
screw shaft or upon an intermediate shaft and driven by a loosely centred worm
wheel or like gear substantially as described.