IMPROVEMENTS IN APPARATUS FOR GRINDING AND POLISHING METAL, AND FOR CUTTING WOOD AND SIMILAR MATERIALS
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by John Donnelly at the Office of the
Commissioners of Patents on the 6th April 1878.
JOHN DONNELLY, of Campbell Road, Bow, in the County of Middlesex,
Engincer. "IMPROVEMENTS IN APPARATUS FOR GRINDING AND POLISHING METAL,
AND FOR CUTTING WOOD AND SIMILAR MATERIALS."
My Invention relates to novel apparatus for facilitating the grinding and
polishing of metal, and for cutting wood and similar comparatively soft materials.
The said apparatus is designed to form an attachment or addition to an ordinary
turning lathe, and is provided with an emery wheel or other suitable grinding and
polishing wheel or roller. This wheel or roller is mounted upon a shaft or spindle,
which is fitted to turn freely in a bearing or bearings provided for it in an arm or
piece, which is so constructed as to be capable of being readily attached in any
ordinary manner to the slide rest of the lathe, in connection with which the apparatus
is to be used.
I prefer to form the said arm or piece with a solid enlarged part at one end, and
through this enlarged part or head a hole is drilled to receive the shaft or spindle
of the said wheel or roller, thus forming the bearing for this shaft or spindle. The
wheel or roller is fitted to one end of the said shaft, and will therefore be at one
side of the said bearing piece or head.
If desired the said arm may have a forked end instead of the solid enlargement,
and the wheel or roller may be placed within the arms of the fork.
The required rotary motion is communicated to the said grinding or polishing
wheel or roller from the cone pulleys of the lathe through the medium of a double
or endless cord passed around the said cone pulleys, the other end of which cord is
passed around a pulley, which is rigidly attached to one end of the shaft or spindle
carrying the said grinding or polishing wheel or roller.
The apparatus for supporting the said cord in a suitable position to enable
motion to be communicated from the cone pulley of the lathe to the grinding or
polishing wheel or roller is constructed as follows, that is to say:-I provide a tube,
into which a rod or another tube of smaller diameter, herein-after called the

page_text: vertical rod, fits loosely, so that the two may slide together telescopically. This
rod is attached to the middle of another rod, herein-after called the horizontal rod,
the latter extending right and left, the two rods being at right angles to cach
other, and thus forming together a T shaped piece. The said vortical rod has
upon it a sliding collar, provided with a thumbscrew, to enable it to be adjusted at
any part of the said rod as desired, and a spiral spring is placed around the lower
part of this rod, and which bears at one end against the said collar, and at the
other end against the top of the tube, into which the rod fits.
I also provide two carriages or blocks arranged to slide or run upon the said
horizontal rod. To each one of these blocks I attach two rollers or pulleys
designed to receive the aforesaid cord, and the said rollers are fitted to forked or
other suitable pieces, which are fastened to the said blocks or carriages by means
of pins or rivets in such a manner that they will move upon the said pins or rivets,
and thus yield laterally to the motions of the aforesaid cord as it travels over the
rollers. One of these sliding blocks or carriages is placed upon one arm of the said
horizontal rod, and the other upon the other arm, a division being formed by the
said vertical rod, which is attached to and extends vertically from the centre of the
horizontal rod upon which the blocks slide.
The said vertical rod is arranged to slide within the said tubo in order that the
apparatus may be raised and lowered, so as to adjust the cord to the necessary
tension, according to the work which has to be ground, polished, or cut, and the
said spiral spring provides for the automatic adjustment of slight variations in the
tension of the cord, which will occur during the operation of the apparatus, owing
to the variation of position of the grinding or polishing wheel or roller as the work
proceeds.
To provide for attaching the said apparatus to the lathe the said tube is provided
at its lower end with a piece which fits into the oil hole on the headstock of the
lathe. The said apparatus is by this means readily attached to or detached from a
lathe as desired.
I prefer to construct the tube and the rods all of ordinary gas pipe, which is
inexpensive, and very suitable for the purposes of my said Invention.
For cutting wood and other comparatively soft materials I substitute for the said
grinding or polishing wheel or roller a rotary cutter, and operate the same as above
described.