Improvements in Clasp Knives and other like Instruments.
Year: 1899

page_text: Date of Application, 8th Apr., 1899
Complete Specification Left, 8th Jan., 1900-Accepted, 10th Feb., 1900
Improvements in Clasp Knives and other like Instruments.
I, CHARLES RALPH AUGUSTUS EDMONDS, of No. 9, Gray's Inn Square, in the
Administrative County of London, Solicitor, do hereby declare the nature of this
invention to be as follows:-
This invention relates to improvements in clasp knives and other like instru-
ments, such for instance, as fleams, lancets, and indeed any instrument hitherto
fitted or attached to its haft or handle in like manner to the blade of a clasp or a
spring knife.
ог
spring knife
or
Hitherto it has been customary to attach the blade or blades or other tools of a
clasp
other
a hole
like instrument by drilling
through the blade or other tool and a corresponding hole through each
of the sides composing the haft or handle so that when the blade or tool is in
place in its haft the said holes all coincide; a rivet is then passed through from
side to side and riveted over. It will be readily understood that a knife blade or
tool thus secured to its haft cannot be again removed without destroying the rivet.
The general experience is that it would be a great advantage if the blades
of knives or other tools similarly fitted were made removeable at will from the
haft. One would then be able to readily replace an old blade or tool by a new
one when desired, instead of having to pay for skilled repairs or an entire knife
or other instrument as the case may be. Again, particularly in such cases, for
instance, as pruning, budding, and surgeons' knives, fleams or other similarly
hafted instruments, pocket or otherwise, the blades and other tools are required
to vary in regard to shape, angle of edge, etc., and, apart from the expense, it is
inconvenient to have a number of complete instruments which may, collectively,
be cumbersome to carry about as compared with carrying several blades or tools;
in a case and only one handle into which they all fit interchangeably.
My present invention is designed to obviate the above-mentioned disadvantage,
and it consists in cutting or providing a slot in the tang of the blade or other
tool, said slot being inclined and extending from the edge of the front of the
tang into the rivet hole, thus constituting a clear passage leading from the edge
of the tang into the rivet hole; thus enabling the tang to be passed around or
removed from the rivet which is previously fixed in position to receive it, without
necessitating the removal or destruction of the rivet.
In the case of a spring-backed knife or other tool the spring may remain as
usual and by suitably forming the nose or extremity of the tang it may be
placed or forced around the rivet against the pressure of the said spring by
obtaining a leverage by utilizing the rivet as the fulcrum; but preferably I
prefer to replace the ordinary back spring by a similarly shaped piece but not a
spring, simply a lever pivoted near its centre by a rivet. At the rear extremity
of the haft is pivoted an eccentric cam in such manner that the said cam on being
turned in one direction presses against the rear end of the aforesaid lever which,
being pivoted, is thereby caused to approach and enter a recess formed in the back
edge of the tang and thus hold the blade or other tool in position, as desired.

page_text: A projection or thumb-piece is provided at the extremity of the cam piece to
facilitate the operation of the latter. The release of the blade or other tool is
effected by first turning the pivoted. cam by means of the said projection at its
extremity, into the position for freeing the pivoted lever from the notch in the
tang and this being done the blade or other tool can readily be unhooked from its
fixed rivet.
Dated the 8th dox of Annil 1900
COMPLETE SPECIFICATION.
Improvements in Clasp Knives and other like Instruments.
I, CHARLES RALPH AUGUSTUS EDMONDS, of No. 9, Gray's Inn Square, in the
Administrative County of London, Solicitor, 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:-
This invention relates to improvements in clasp knives and other like instru-
ments, such for instance, as fleams, lancets, and indeed any instrument hitherto
fitted or attached to its haft or handle in like manner to the blade of a clasp or a
spring knife.
Hitherto it has been customary to attach the blade or blades or other tools of a
clasp or spring knife or other like instrument by drilling a hole
through the blade or other tool and a corresponding hole through each
of the sides composing the haft or handle so that when the blade or tool is in
place in its haft the said holes all coincide; a rivet is then passed through from
side to side and riveted over. It will be readily understood that a knife blade or
tool thus secured to its haft, cannot be again removed without first destroying the
rivet.
The general experience is that it would be a great advantage if the blades
of knives or other tools similarly fitted were made removable at will from the
haft. One would then be able to readily replace an old blade or tool by a new
one when desired, instead of having to pay for skilled repairs or an entire knife
or other instrument as the case may be. Again, particularly in such cases, for
instance, as pruning, budding and surgeons' knives, fleams or other similarly
hafted instruments, pocket or otherwise, the blades and other tools are required
to vary in regard to shape, angle of edge, etc., and, apart from the expense, it is
inconvenient to have a number of complete instruments which may collectively
be cumbersome to carry about as compared with carrying several blades or tools
in a case and only one handle into which they all fit interchangeably.
My present invention is designed to obviate the above-mentioned disadvantage,
and I will now proceed to describe it with reference to the accompanying drawings
illustrating an ordinary pruning set provided with my improved means for the
attachment of the blade or other tool to the handle or haft, and in which :-
Figure 1 is a side elevation of a pruning knife complete provided with my
invention; the blade being shown in the fully open and (by dotted lines) half
closed positions.
Figures 2, 3, 4 and 5 are plan views of other blades or tools constructed according
to this invention and therefore interchangeable at will with the blade in Figure 1.
The invention consists in cutting or providing a slot a in the tang of the blade
or other tool, said slot being inclined and extending from the front edge of the
tang into the locus of the rivet hole, thus constituting a clear passage leading

page_text: from the edge of the tang into the rivet hole; thus enabling the tang to be
passed around or removed from the rivet c which is previously fixed in position
to receive it, without necessitating the removal or distruction of the rivet.
In the case of a spring-backed knife or other tool, as shown in Figure 1, the
spring may remain as usual, and by suitably forming the nose or extremity of
the tang at d as shown it may be placed or forced around the rivet c against the
pressure of the spring e by obtaining a leverage by utilising the rivet c as the
fulcrum; but, preferably I replace the ordinary back-spring e by a similarly
shaped piece but not a spring, simply a lever pivoted near its centre on a rivet. At
the rear extremity of the haft is pivoted at x an eccentric cam g in such manner
that the said cam on being turned in one direction presses against the rear end of
the aforesaid lever, which being pivoted at y is thereby caused to approach and
enter a recess h formed in the back edge of the tang and thus hold the blade or
other tool in position as desired. A projection or thumb piece gl is provided at
the extremity of the cam piece to facilitate the operation of the latter. The
release of the blade or other tool is effected by first turning the pivoted cam by
means of the said projection at its extremity, into the position shown by dotted
lines in Figure 1, for freeing the pivoted lever from the notch in the tang and
this being done the blade or other tool can readily be unhooked from its fixed
rivet.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
The means for rendering the blades or other instruments of clasp knives, lancets,
fleams and the like interchangeable in the haft, consisting in the combination
with the back-spring or lever of the haft, of a slot or gating in the tang of the
blade or other tool said slot leading from the front edge to the ordinary rivet hole
and a cam pivoted near the rear end of the haft and adapted to press against when
closed the back-spring or lever, substantially as and for the purpose described and
set forth.
Data h 0th day of Tonname 1000
PHILLIPS & LEIGH,
No. 22, Southampton Buildings, Chancery Lane, W.C.,
Agents for the Applicant.