Improvements in Wood Mortise Chisels.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in Wood Mortise Chisels.
I WILLIAM OSMENT of Sanford House Clapton in the County of Middlesex
Builder do hereby declare the nature of this invention to be as follows:-
The object of my invention is to create in and provide with wood mortise chisels or
that is to say chisels that can make mortises and the like in wood such devices that the
core that has been cut out by the chisel shall certainly and surely be withdrawn by
the same on its return movement.
To carry out this object the chisel can be made in any ordinary manner with an
inclined or tapered groove or recess along its back and the walls at the sides of this
longitudinal groove or recess are parallel with each other and with the plane and with
the line of such chisel. In these walls near the cutting edge or end of the chisel are
made corresponding notches of any desired sizes and shapes preferably angular and
those sides of these notches that are nearer to the cutting end or edge of the chisel
are most conveniently at about right angles with the line of such chisel. These notches
are preferably arranged in pairs in the walls of the groove or recess and such a number
of these pairs of notches are created in the length of the chisel as may be appropriate
in each case.
Therefore when this chisel has been forced as is usual into the wood to make the
mortise or the like the core that is so cut out will be engaged in and by the notches
and thus be withdrawn from the mortise or partly withdrawn on the return movement
of the chisel.
Again when one notch or one pair of notches has been obliterated by the gradual
grinding away or abrasion of the chisel for purposes of sharpening or otherwise the
next notch or the next pair of notches will perform the same function.
HART & Co.,
168, Fleet Street, London, E.C., Agents.
I WILLIAM OSMENT of Sanford House Clapton in the County of Middlesex Builder
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:-
The object of this my invention is to create in and provide with wood mortise chisels
or that is to say chisels for making mortises and the like in wood such devices and
arrangements that the core that has been cut out by the chisel shall certainly and surely
be withdrawn from the mortise or the like by such chisel on its return movement.
In order the more clearly to explain this my invention and in what manner the same
is to be performed I refer to the accompanying drawing wherein I have shewn a very

page_text: convenient and efficient form and style of construction and arrangement of my wood
mortise chisel and Figure 1 is an elevation of the back of such chise!
Figure 2 is a longitudinal section of the chisel Figure 3 is a transverse section of
the same taken at a bin Figure 1 and Figure 4 is a transverse section of the sume
taken at ed in Figure 1.
The chisel A can be formed and made in any ordinary and suitable manner as may
be desirable or expedient in each particular case but to carry out my object rein-
before mentioned in and along the back of the blalo of this chisel A is created a groove
or recess B which is preferably inclined or tapered as is shown in Figure 2 and the
narrow walls C at the sides of this longitudinal groove or recess B are exactly parallel
with each other and in themselves and with the line of such chisel A while the edges
of these walls C may be and preferably are parallel with the plane of the blade of such
chisel A or thereabouts. In these walls Care created corresponding notches D of any
desired sizes and shapes preferably angular and those sides of these notches D that are
the nearer to the cutting end or edge of the chisel A are most conveniently and
effectively at right angles with the plane of the blade of such chisel A or thereabouts.
These notches D are preferably arranged in pairs in the walls C and such a number of
these pairs of notches D are created in the length of the chisel A as may be appropriate
or convenient in each particular case.
Therefore when this chisel A so made and created and provided with such devices
and arrangements as is hereinbefore described has been forced as is usual into the
wood to make the mortise or the like therein the core that is so cut out will he engaged
in and by the notches D and on the return movement of such chisel A will thus
be withdrawn or partly withdrawn from the mortise or the like in accordance with the
length of such return movement.
Again when as is generally preferable the notches Dare created in manner as is herein-
before described in and along the whole length or very nearly the whole length of
the blade of the chisel A and of the walls theroof as is shewn in Figures 1 and 2
and when one notch D or one pair of notches D has been obliterated by the gradual
grinding away or abrasion of the blade of the chisel A for purposes of sharpening
or otherwise the next notch D or the next pair of notches D will obviously perform
the same function. This chisel will thus be ensured a long life as it will practically be
capable of use and proper for use until all or very nearly all of its blade has been so
ground away or abraded.
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. In a wood mortise chisel the combination of a longitudinal recess B in the back
of the blade thereof walls C for such recess B exactly parallel with each other and in
themselves and with the line of the chisel and notches D in such walls C substantially
as and for the purpose herein before described and declared.
2. The wood mortise chisel substantially as hereinbefore described and shown in the
accompanying drawing.