Improvement in Planes.
Year: 1892

page_text: Date of Application, 28th Apr., 1892-Accepted, 28th May, 1892
COMPLETE SPECIFICATION.
Improvement in Planes.
I JOHN MITCHELL of Auckland in the Provincial District of Auckland in the
Colony of New Zealand Architect do hereby declare the nature of my invention
for an IMPROVEMENT IN PLANES and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:-
My invention relates to an improvement in planes especially to that class of
planes adapted for the use of carpenters and joiners, and has for its object to
provide a cutting blade capable of being quickly and easily sharpened and also
capable of being reversed when required and constructed so that it may be
used in combination with any of the old blades usually employed in planes if
desired.
The invention consists in the novel construction and combination of the several
parts as will be hereinafter fully set forth and pointed out in the claims.
The cutting blade consists of a single thin plate of metal properly tempered and
having a cutting edge at both ends. This plate is adapted to be adjusted and
reversed, and to that end is provided with a slot located longitudinally at the
central portion thereof, which slot is of a suitable length; and in order that the
cutting blade may be easily reversed or adjusted between its tie-plates or blocks,
the central (portion of the) side edges are preferably provided with serrations.
The cutting blade is held between a back plate or block and a forward clamping
plate or block. The back plate or block may consist of a new or old blade of the
old type, and the three parts are bound together by means of a set screw which
passes through the clamping block or plate through the slot in the cutting blade
and through the slot or opening usually formed in the old style of cutting blade or
through a slot or opening in whatever form of back plate or block that may be
employed.
It is evident that the thin metal of the cutting blade will be sufficiently braced
and stiffened by the plates or blocks between which it is located; and as it is very
thin the edges may be quickly sharpened and in the event that one edge of the
blade should become blunt or dented by being brought in contact with a nail or other
solid obstruction, the set screw may be quickly loosened and the cutting blade
reversed thereby bringing a perfect edge into position and at once ready for going
on with the work, thus greatly economizing in time.
This invention is applicable to any style of plane, and as heretofore stated, the
old-style cutting blades (whether new or worn out) may be utilized as back plates
for the new blade.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. As an improved article of manufacture, an adjustable and reversible cutting
blade for carpenters' planes and similar planes used by joiners and cabinet makers."
2. As an improved article of manufacture, a cutting blade for carpenters and
joiners planes the same consisting of a thin piece of metal provided with a cutting
edge at each end and a longitudinal opening between its ends as and for the purpose
specified and substantially as described.
3. In a carpenters and joiners plane, the combination with a cutting blade having
a cutting surface at each end and a longitudinal slot between its ends, of a plate
held in engagement with the back of the blade, a clamping block engaging with
the front of the blade, and a set screw passing through the clamping block the back

page_text: plate and the slot in the blade, whereby the cutting blade is reinforced and
supported, and is rendered adjustable and reversible as and for the purpose
specified.
Dated tAIS ZOLL
7401 OIRTA TO
Witness:
Jos. J. MACKY,
Auckland, New Zealand.
JOHN MITCHELL.