IMPROVEMENTS IN THE MANU- FACTURE OF SECTION KNIVES AND RAZORS USED FOR MICROSCOPIC PURPOSES, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO OTHER ARTICLES HAVING A CUTTING EDGE
Year: 1881

page_text: LETTERS PATENT to Thomas Heiffor, of 3, Paradise Square, Sheffield, in the
County of Yorkshire, for an Invention of "IMPROVEMENTS IN THE MANU-
FACTURE OF SECTION KNIVES AND RAZORS USED FOR MICROSCOPIC PURPOSES,
WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO OTHER ARTICLES HAVING
A CUTTING EDGE"
PROVISIONAL SPECIFICATION left by the said Thomas Heiffor at the
Office of the Commissioners of Patents on the 10th June 1881.
THOMAS HEIFFOR, of 3, Paradise Square, Sheffield, in the County of Yorkshire.
"IMPROVEMENTS IN THE MANUFACTURE OF SECTION KNIVES AND RAZORS USED
FOR MICROSCOPIC PURPOSES, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO
OTHER ARTICLES HAVING A CUTTING EDGE"
The object of this Invention is the manufacture of knife, razor, and other cutting
blades of a special section, whereby a finer, smoother, and keener edge can be
produced and preserved than by the present mode of manufacture.
In connection with the manufacture I employ a grinding stone, specially
prepared and fitted on a disc and mounted upon a vertical shaft with a rigger under
the table, in order that the stone may be rotated from below, and to enable the
attendant or workman to use both hands freely and thereby obtain a better
command over his work.
For the purposes of my Invention I prepare the blade by hammering it slightly
hollow on one side and leaving tho other side comparatively flat.
In the grinding operation I use a vertical stone of a given diameter to produce
the necessary concavity between the shoulder and the outer end, the depth of the
concave being regulated to the desired or intended use of the blade when finished
and "handled" up.
The grinding of the other side is done on a horizontally revolving stone provided
and kept with a true flat upper surface. The stone has the centre portion of it

page_text: removed, the aperture being large enough to admit one hand of the workman to
enable a fair flat pressure to be imparted from the inside and from the outside.
The stone is secured to a disc by pitch, and is mounted upon a vertical spindle
which can be adjusted by screw appliances to ensure its
"free run " without
vibration and without any " wobbling." The lower end of the spindle is "stepped'
into a socket and carries a rigger or pulley, the band of which is wholly or partially
enclosed to prevent injury to the workman.
"
The particular section of blade above referred to is specially useful for knives
used in surgical operations and for dissecting purposes, also for the removal and the
display of minute atoms and virus for microscopical examination.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Heiffor in the Great Seal Patent Office on the 9th
December 1881.
THOMAS HEIFFOR, of 3, Paradise Square, Sheffield, in the County of Yorkshire.
"IMPROVEMENTS IN THE MANUFACTURE OF SECTION KNIVES AND RAZORS USED
FOR MICROSCOPIC PURPOSES, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO
OTHER ARTICLES HAVING A CUTTING EDGE."
The object of this Invention is the manufacture of knife, razor, and other
cutting blades whereby a finer, smoother, truer, uniform, and perfect edge can be
produced and preserved than by the present mode of manufacture. In connection
with the manufacture I employ a grinding stone, a "glazier," or a "lap," with a
hollow central part and fitted on a disc by pitch as the cement, said disc being
mounted upon a vertical shaft with a rigger under the table in order that the
stone, "glazier," or "lap," may be rotated from below, and to enable the attendant
or workman to use both hands freely and thereby obtain a better command over
his work.
My Invention is represented in the annexed Drawings, in which at Figure 1
I show the section of a razor blade having one hollow side A and one perfectly flat
side B, this latter being produced by a horizontally arranged and revolving
grindstone, "glazier," or "lap," Figures 2, 3, and 4, this having a central opening Ď
in which one hand of the workman can be inserted to enable the blade to be pressed
and held perfectly flat from both ends. The grindstone, "glazier," or "lap" C is
mounted on a disc F and secured in place by pitch as the cement, the disc F being
fixed on the upper end of a vertical spindle or shaft G, capable of adjustment as to
height by the set screw H, and held in bearings I, J, of the frame J' to steady it
in its rotative action which is effected by a strap upon the rigger or pulley K. The
stone, "glazier," or "lap" C may be within a tank L, as in Figures 2 and 4, so
that water from a tap M may trickle on to the stone to expedito the grinding.
The grindstone, "glazier," or "lap" C may be in a solid piece, as in Figuros
3 and 4, or be formed from a series of pieces shaped to fit, as in Figures 5 and 6.
For dry grinding or where oil is used in small quantities, such as for setting the
edge of the razor or other blade, the open stone and frame shown at Figure 7
would be found of value.
The particular section of blade above referred to is specially useful for knives
and razors and like blades used in surgical operations and for dissecting purposes,
also for the removal and the display of minute atoms and virus for microscopical
examination.
Having now described the nature of my said Invention and in what manner the
same is to be performed, I declare that I claim,―
Forming a perfect and true edge on razor and other cutlery blades used for
scientific and microscopical purposes by a hollow central grindstone, "glazier," or
lap" C fitted and revolving horizontally on a vertical shaft G in the manner
described, and as shown in the Drawings, said stone, "glazier," or "lap" being
affixed to the disc F by pitch as a cement, as set forth.
In witness whereof, I, the said Thomas Heiffor, have hereunto set my hand
and seal, this Sixth day of December, in the year of our Lord One thousand
eight hundred and eighty one.
THOMAS HEIFFOR. (L.S.)