Improvements in or applicable to Pocket or Folding Knives, or other Folding Instruments.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in or applicable to Pocket or Folding Knives, or
other Folding Instruments.
I JOSEPH CLARKSON, of 34. Dawson Street, Manchester, in the County of
Lancaster, Phonograph Expert, do hereby declare the nature of this invention to
be as follows:-
The object of this invention is to provide simple and efficient means for
preventing the accidental closing of a clasp knife or other folding instrument (say
a folding fork or a surgical instrument for example).
The invention consists in forming or fixing upon the spring of the instrument a
catch into or against which a similar catch upon the pivotted end of the knife blade
or folding part of the instrument engages when the instrument is opened, the spring
being pivotted at about the centre and its other or rear end being kept in place by
a removable block at the end of the handle or haft, and thus the instrument cannot
be closed until the block is removed, when the rear end of the spring can be
pushed inwards and release the catch so that the knife can be closed.
The block may be pivotted to one of the rivets of the handle or may be slotted
and slide thereon, and is preferably so formed as to be held in place when the knife
is closed or locked open by the end of the spring.
Dated this 2nd day of March 1807
GEO. DAVIES & SON,
4, St. Aun's Square, Manchester, Agents for the Applicant.
Improvements in or applicable to Pocket or Folding Knives, or
other Folding Instruments.
I JOSEPH CLARKSON, of 34 Dawson Street, Manchester, in the County of
Lancaster, Phonograph Expert, 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 invention is to provide simple and efficient means for
preventing the accidental closing of a clasp knife or other folding instrument (say
a folding fork or a surgical instrument for example).
The invention consists in forming or fixing upon the spring of the instrument
a catch into or against which a similar catch upon the pivotted end of the knife
blade or folding part of the instrument engages when the instrument is opened, the
spring being pivotted at about the centre and its other or rear end being kept in
place by a removable block or equivalent device at the end of the handle or haft,
and thus the instrument cannot be closed until the block or its equivalent is
removed when the rear end of the spring can be pushed inwards and release the
catch so that the knife can be closed.

page_text: The block or its equivalent may be pivotted to one of the rivets of the handle or
may be slotted and slide thereon, and is preferably so formed as to be held in
place when the knife is closed, or locked open by the end of the spring, or it may
be held in place by a spring.
My invention can be carried into practical effect in many ways, for example as
shewn by the accompanying drawings which illustrate several ways of applying the
invention to an ordinary pocket knife.
Fig. 1 is a longitudinal section through a pocket knife with my invention applied
thereto, the blade being closed.
Fig. 2 is a similar view with the blade opened and locked in this position.
Fig. 3 shews the same with the blade in the act of being closed again.
Figs. 4, 5 and 6 illustrate various modifications of the block hereafter described.
The blade a is fitted to the handle by the usual pivot bx and at the butt end
the said blade a is made with the notch or catch a 1. The spring c is provided
with a catch c 1 engaging with this catch a 1 when the knife is opened (see Fig. 2)
and preventing its return until the block dis turned on its pivot or rivet d see Fig. 3,
when the spring c can be pushed inwards on its pivot or rivet ex and the catch el
disengaged from the notch a 1, and the blade a of the knife can then be closed into
the handle. It will be seen that the block d is so formed at d 1 (Figs. 1 and 2) as
to be held in place by the spring c. Figs. 1, 2 and 3 shew the block or stop so
formed that the part d 2 can be used as a screw driver.
Fig. 4 shows a block not so formed. Fig. 5 shews a block d which can slide on
its rivet d to release the end of the spring c. Fig. 6 shews that the stop d may be
made in the form of or provided with a spring as seen at 3.
Although I have illustrated my invention as applied to a pocket knife it will be
evident that it is equally applicable to other folding instruments such as a pocket
fork, or a surgical instrument for example.
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. The combination with the handle of a folding instrument of a pivotted spring
provided or made with a catch at one end engaging, when the instrument is open,
with a catch or notch on the butt end of the blade or instrument, and supported at
the other end by a removable block stop or equivalent device, so that the
instrument when opened is automatically locked in that position but can be
released for closing the same by the removal of the stop or block substantially as
herein before described.
2. The means for locking a folding instrument when open and for releasing the
same substantially as described with reference to the accompanying drawings.
GEO. DAVIES & SON.