Improvements in Machines to be employed for Cutting Hollow Faced Worms.
Year: 1899

page_text: Date of Application, 12th May, 1899
Complete Specification Left, 10th Feb., 1900-Accepted, 7th Apr, 1900
PROVISIONAL SPECIFICATION.
Improvements in Machines to be employed for Cutting Hollow
Faced Worms.
We, JAMES BUTLER, of the Victoria Iron Works, Halifax, in the County of York,
Machine Tool Maker, and RICHARD HENRY HAYHURST, of the same place, Mechanical
Draughtsman, do hereby declare the nature of this invention to be as follows:-
Our invention has reference to machines to be employed for cutting hollow faced
worms with a differential pitch, and this we propose to do by the employment of a
cutting tool, so mounted that the centre of the said cutting tool will always remain
at right angles to the axis of the worm, notwithstanding that the cutting tool and its
holder are going around a revolution or part of a revolution. By this means a hollow
faced worm with a differential pitch is formed or cut to suit the varying radial pitch
of the worm wheel.
In carrying out our invention, we use a gear wheel and fix it upon a vertical or
other shaft. Gearing with this fixed wheel is another corresponding wheel attached
to a shaft, the opposite end of which has also a wheel gearing with a second wheel.
These various wheels are mounted upon and connected to suitable plates, and a tool
holder; therefore when the tool holder is caused to form an arc or turn around,
one of the wheels in gear with the fixed gear wheel is caused to rotate in a relative
proportion to the sweep given to the cutting tool, but as the tool holder is suitably
connected to a gear wheel underneath it, the cutting tool always maintains a vertical
position, or is always at right angles to the axis of the worm, consequently a hollow
faced worm is produced which will freely inesh or gear with the teeth of a worm
wheel. By these means the power of the worm is considerably increased as it is
The
made to mesh deeply into the teeth of a worm wheel with which it is in gear;
apparatus herein described can be applied to existing machines for cutting the teeth
of worm wheels or it may he applied to a new machine fitted up and adapted for the
purpose of cutting hollow faced worms.
Ordinary or mitre wheels may be used to obtain the necessary motion.
1000
COMPLETE SPECIFICATION.
Improvements in Machines to be employed for Cutting Hollow
Faced Worms.
We, JAMES BUTLER, of the Victoria Iron Works, Halifax, in the County of York,
Machine Tool Maker, and RICHARD HENRY HAYHURST, of the same place, Mechanical
Draughtsman, do hereby declare the nature of this invention and in what manner

page_text: the same is to be performed, to be particularly described and ascertained in and by
the following statement:---
Our invention has reference to machines to be employed for cutting hollow faced
worms with a differential pitch, and this we propose to do by the employment of a
cutting tool, so mounted that the centre or axis of the said cutting tool will always
remain at right angles to the axis of the worm, notwithstanding that the cutting
tool and its holder are going round a revolution or part of a revolution. By this
means a hollow faced worm with a differential pitch is formed or cut to suit the
varying radial pitch of the worm wheel. In order that our invention or improvement
may be better understood reference is made to the annexed 'drawings, wherein
Fig. 1 is plan view, and
Fig. 2 is cross section of same.
In carrying out our invention we use a gear wheel or segment a provided on its
underside with a boss, or hub a¹ which enters and is free to turn in an opening made
therefor in the main casting m. The boss a¹ is bored centrally to admit of a
spindle passing freely therethrough, such spindle being fixed or prevented from
rotating by the fixing plate or bar secured to the main casting m and having fast
on its upper or projecting end a bevel wheel c with which gears a corresponding
bevel wheel c¹ on a shaft supported in bearings in and secured to an adjustable
slide or plate g, carrying the tool holder h. The bevel wheel c¹ is held in gear with
the wheel c by a suitable support or bracket attached to or integral with the
segment a and it is secured rotatively on said shaft by a sliding key or feather taking
into a groove in the shaft which admits of the shaft d moving endwise with the
slide to adjust the tool holder to or from the worm to be cut without placing the
bevels c. and c¹ out of gear. On the opposite ends of shaft d is mounted a bevel
wheel e gearing with a second bevel wheel fast on a spindle h¹ which secures the tool
holder h to the slide or plate g and at the same time forms a centre or pivot on which
the tool holder is capable of turning in either direction.
The position of the slide y on the segment a can be adjusted endwise to any extent
within the limits of the slots in said segment and, when set to bring the tool holder h
and tool i into the required position to suit the diameter of worm whose teeth are to be
cut, motion is imparted by worm to the segment a to turn it about the centre a² to
move the tool holder through the are of a circle extending from end to end of the
toothed surface to be cut, whatever its length. As the segment a and slide g and
parts connected therewith, turn about the centre the bevel wheel c' is traversed;
over and in engagement with the teeth of the bevel wheel which, being fixed,
causes the wheel c¹ to be turned partially around and then turn the shaft d
progressively in relative proportion to the sweep or are of movement being described
by the tool holder, the motion of shaft & being imparted through bevel wheel e, to the
bevel wheel which turns the tool holder / about its centre h¹ synchronously with the
are of motion of the tool holder, the movements of the parts about the centre and
of the tool holder about the centre h¹ being so proportioned relatively to each other
that the said tool holder hand tool are thereby maintained throughout the whole
of the movement in a position at right angles to the axis of the worm being cut.
By the means aforesaid, a hollow faced worm can be produced which will freely 4
mesh or gear concentrically, with the teeth of a worm wheel, the power of the worm
thus being considerably increased, as it is made to mesh deeply froin end to end, into
the teeth of the worm wheel with which it is in gear.
The apparatus herein described can be applied to existing machines for cutting the
teeth of worm wheels or it may be applied to a new machine fitted up and adapted
for the purpose of cutting hollow faced worms..
Ordinary or mitre wheels may be used instead of the bevel wheels shewn to obtain
the necessary motion.

page_text: invention and in what manner the same is to be performed, I declare that what
I claim is :-
The apparatus substantially as herein shewn and described for cutting or forming
hollow faced worms.
Dated this 0th day of February 1900.
TASKER & CROSSLEY,
Patent. Agents, Halifax, Agents for Applicant.