IMPROVEMENTS IN POCKET-KNIVES
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I, HERBERT JOHN HADDAN, of the firm of Herbert & Company, Patent Agents,
of 67, Strand, in the City of Westminster, Civil Engineer, do hereby declare the
nature of said Invention for "IMPROVEMENTS IN POCKET-KNIVES," a communication
to me from abroad by Carl Helsner, of 6, Reichstrasse, Leipzig, in the Kingdom of
Saxony, to be as follows:-
This invention relates to mechanism for automatically folding and unfolding the
blades and other tools of a pocket knife and for securing such blades or tools in
either position.
In describing the invention reference will be made to the annexed drawing
Figs. 1 to 7 representing various modifications of the mechanism embodying this
invention.
In the arrangement illustrated by Figs 1 and 2 the blade a folded into the haft.
or handle b, is secured in this position by means of the projection o of the spring c
mounted at the rear end of the handle.
The spring c is provided with a knob d. On pressing on the knob d, the spring
is pushed downward, whereby the projection o of the spring c releases the blade a;
at this instant the blade a is forced to turn on its pivot i as far as the stop g owing
to the pressure of the spring ħ against the shank a¹ which has a peculiar shape
adapted to facilitate the action of the spring h.
The blade is thus unfolded and secured in this position by the spring hand the
stop g.
For folding the knife, the blade is turned into the haft until the projection o of
the spring c is placed in front of the blade whereby the latter is secured. At the
same time the shaft al forces the spring hinto its previous position and stretches
the same.
The plate k serves to cover the whole of the mechanism.
The arrangement.represented by Fig. 3. chiefly comprises an adjustable tongue m
enclosed by the haft band attached to the main spring h.
The tongue m receives the pressure from the spring and transmits the same,
according to the position of the blade, in front or behind the fulcrum i of the
shank a The tongue m is provided with two pins passing through the
-

page_text: slots o of the haft b and adapted to be shifted in the same so that the end of
the tongue m may be placed in front or behind the fulcrum i of the blade. The
blade a is secured or disengaged by adjusting the tongue m.
Another arrange-
ment for operating the blades or other tools of a pocket knife is illustrated by
Figs 4 and 5.
It comprises a spring pressing with the loose end against the tongue o arranged
one sided on the shank a' of the blade a. The spring furthermore presses against
the plate b carrying the pin n.
The tongue o and the pin n bave the same height on the plate b¹ and are so
arranged that when the blade is turned out of the haft until its rear end comes in
contact with the stop pin g, the spring his placed between the pin n and the
tongue o thus securing the blade; on the other hand when the blade is folded into
the haft, the end of the spring engages with the opposite end of the tongue o,
whereby the blade is secured in its folded position. For releasing the blade or tool
previously to unfolding the saine, the spring / must be lifted from the plate b¹ so
far as to pass over the pin n and the tongue o so as to be free to press against the
shank a of the blade.
h
This may be obtained in two manners, represented in figs 5, 6 and 7.
The mechanism represented by fig. 5 comprises a knob c at the extremity of a
spring mounted on the plate 6' and connected with a lug d passing through a slot
in the haft. The lug & has a projectionz (Fig. 5) passing over the edge of the slot
and serving to prevent the accidental unfolding of the blade. Opposite this pro-
jection the lug is allowed as much play in the slot as the said projection = protrūdos
over the edge of the same.
By shifting the knob in the direction of the arrow and by simultaneously
pressing on the same, the lug with its projection is pressed through the slot against
the spring h, thereby lifting the same over the pin n and tongue o.
The appliance for lifting the spring h, represented in figs. 6 and 7, comprises a
lever m pivoted on the plato b', and pressing with the shorter end, which passes
through a slot in the plato b', against the spring h. By turning the longer end of
the lever upward by means of the knob m², the spring his lifted from the plate 6¹.
In this arrangement the pin n is attached to the spring h. When the blade is
unfolded, the -pin n engages in the recess 7, and when tho blado is folded the pin n
engages in the recess, thereby securing the blade or tool in either position. The
blades and other tools of pocket knives provided with this device may consequently
be opened and closed automatically by pressing the knob c into the haft and by
simultaneously shifting the same in the direction of the arrow. The projection
. merely serves to prevent the accidental oponing of the blades by the pressure of a
solid body on the knob, whilst the knife is carried in the pocket.

page_text: COMPLETE SPECIFICATION.
I, HERBERT JOHN HADDAN, of the firm of Herbert and Company, Patent
Agents, of 67, Strand, in the City of Westminster, Civil Engineer, do hereby
declare the nature of my invention for IMPROVEMENTS IN POCKET KNIVES, a
communication to me from abroad by Carl Helsner, of 6, Reichsstrasse, Leipzig,
Saxony, 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 a pocket-knife which opens without the assistance of
the finger-nails. It is only necessary to press on a certain spot, when any blade at
pleasure opens automatically and is ready for use, or, according to the construction,
the blade can be secured, so that it cannot be closed until, by pressing on a certain
spot, it is again released.
Many attempts have been made for this purpose, but only with lever-springs
which raise the blade a little and then cease to act. To secure the blade in position
ready for use, other and generally complicated contrivances had to be used.
In the present invention, the blade a, (Figs 1-2) has such a form that the
rounded portion a¹ represents part of an eccentric disc, and at the spot where the
curve approaches nearest to the fulcrum i, it runs into a plane surface a²
Owing to the peculiar construction of the blade a at the shoulder a' a², thọ
spring hacts in such a way, that, if steadily pressed against the shoulder a', it
turns the blade out of the groove in the handle, without ceasing to act, and, on
reaching the plane surface a³ (the knife being now open, Fig. 2) it secures the blade
ready for use.
A blade constructed in this manner and pressed by the spring / always endeavours
to regain its open position, so that a locking contrivance is necessary to keep the
blade in its groove when it is shut.
Such a contrivance for locking the blades is shown in three different forms
Figs 1-18. In Figs. 1-3 the blade is represented as shut and secured by the
spring o which is provided with a catch. When the knife is closed, the spring
with its catch snaps over the blade which can be again released by pressing the
pin d.
For the same purpose, and as shown in Figs. 4-6, a tongue m is introduced
between the spring h and the somewhat elongated shoulder of the blade a'. This
tonguo is moveable in the groove 9 and communicates the pressure of the spring /
to the blade before or behind the fulcrum i. To set this contrivance in action, the
tongue mis pushed upwards behind the fulcrum i, after the knife is closed, by
pressing the pin n whereby the blade has a tendency to enter the groove (Fig. 4).
If it is wished to open the knife, the tongue m is pushed downwards before the
fulcrum i, by pressing the pin n, and the blade opens again automatically Fig 6.
In Figs. 7-18 there is represented a third contrivance for securing the blade
whether, open or shut. This is accomplished by the same spring h, which opens

page_text: the blade, the shoulder of the Dindo paving not only the form already descrived
but being also provided with a truncated tongue r, which affords a stay to the
spring.
Fig. 17 is a perspective view of such a blade and shank.
Morcover, the spring his so constructed that it is only half as high or thick as
the blade at the shoulder, and always exerts an clastic pressure on the tongue r
when in a closed position, as shown in Fig. 9.
If the spring his pushed by the tongue r on to the rounded half of the blade-
shoulder the blade is released from the catch and opens at once, as seen in Fig. 13
or Fig. 7.
The spring falls again in this position behind the tongue and stiffens the
blade when open.
Such a knife can be closed in the ordinary way; the spring / describes its path
over the tongue until it falls before the latter and again assumes the closed
position.
The spring is raised, either by means of the lever ƒ Figs. 15-16, or by the
snap c Fig. 8 or Fig. 12.
As regards the first kind of construction, Figs 15-16, the lever fis moveable
on the plate, and so fastened that, by pressing its longer end f₁ in the direction of
the arrow, its shorter end enters the interior of the knife and raises the spring h
over the tongue r.
The second contrivance (Fig. 8 or Fig. 12) is a snap c, passing through the
frame b and the plate band communicating the pressure of the finger to the
spring h, so that the latter is lifted over the tongue r.
In order to prevent the accidental opening of the knife, which might happen
with this contrivanco by striking against some hard object, the snap c can be so
arranged that it lies partly over the plate b¹, as seen in Fig. 18, and, therefore,
would not yield to direct pressure. In this case the snap c must first be pushed off
the plate b in the direction of the arrow, and then tho knife can be opened by
pressing the snap c.
If a blade is to be secured when open, it is only necessary to fix a pin v to
the plato b', (Fig. 13).so that, after the knife is opened, the spring h, falling behind
the tongue, rests firmly against the pin-v. Or, as in Figs. 15-16, a pin p can be
attached to the spring h, so that, when the spring falls behind the tongue, the said
pin falls into the hole p' made for the purpose and secures the spring h.
-
In both cases the blade can only be closed, when the spring his raised by the
tongue in the same manner and with the same pressure as when it is to bo
opened.
The spring h, therefore, describes the same path when the knife is being opened
or shut, and Fig. 14 represents a knife being opened.
All these contrivances and arrangements can be applied to several blades, also to
corkscrews and any other instruments applicable to pocket knives. In the case of
corkscrews, however, the shape of the shoulder at a² and the tongue r is somewhat
different, as, on being opened, it has only to describe a quarter of a circle; in other
respects there is no difference.
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
1. In pocket-knife blades, corkscrews, and other such instruments the
excentrically rounded shape a a³ of the shank or shoulder for the purpose of
opening tho, blade & automatically, and a tongue 7, which affords a stay to the
spring for the purpose of securing the knife when open or closed.
2. Tho spring which, besides its upward action, can also work sideways and
therefore ensures the antomatic opening, checking and securing of the blades.

page_text: 3. The employment of a pin v (Fig. 13) in the plate b¹, or of a hole p³ (Fig 15—
16) in the plate and a pin p in the spring h, both adapted to secure the blade when
open.
4. The lever f (Figs. 15-16) or the snap o (Figs. 8-12) adapted to act on
the spring h
5. The employment of the spring o (Figs. 1–3) or the tongue m (Figs. 4—6)
for checking the blade &º.
Dated thi. 09-1 of mah 100k
H. J. HADDAN.
By Herbert & Co., Agents,
67, Strand.