Improvements 11 Clasp
Year: 1896

page_text: Date of Application, 7th Apr., 1896-Accepted, 4th July, 1896
Improvements 11 Clasp
A communication by ADOLPH KARL BRAUER, of Nos. 315 and 317, South Main
Street, Los Angeles City, in the County of Los Angeles and State of
California, United States of America, Travelling Salesman.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street,
Manchester, both in the County of Lancaster, 118, New Street, Birmingham in
the County of Warwick, and 322, High Holborn in the County of Middlesex,
Civil Engineer, 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 invention relates to that class of knives in which provision is made for the
automatic opening of the blade when released, and for locking the blade in its
closed position and firmly holding the same in its open position.
There are several difficulties to be overcome in providing pocket knives with a
spring whereby the blade becomes self opening. The principal difficulty is that
there is considerable friction between the heel of the blade and the bolsters of the
knife, and to overcome this friction a spring of considerable strength must be used.
It is desirable that this spring be entirely concealed from view in order to
prevent the knife from appearing unsightly or clumsy. The spring chamber
should also be guarded against the entrance of dirt and dust. It has been
proposed to arrange a coil spring in a chamber formed partially in the heel of the
knife and partially in the bolster of the handle, and to pivot the blade to the
handle by means of a pivot passing through a portion of the blade. This con-
struction is faulty in that it brings the bearing of the blade upon the pivot wholly
at one side of the axis of the blade, and in that it also reduces the width of the
bearing which the blade has upon the pivot to such a degree as to cause the pivot
to very quickly become worn through from the strain and friction thus brought to
bear upon the limited extent thereof. Also dirt and dust or water can gain free
entrance into the spring chamber through the joint between the rib or bolster and
the blade, to clog or rust the spring. Furthermore, by this construction the spring
chamber cannot be made of sufficient size to contain a spring which is strong
enough to insure the opening of the blade without making the knife so thick as to
present an unsightly appearance.
An object of the invention is to provide a coiled spring actuated self opening
knife which will have a better pivot bearing, will have its blade of the usual
thickness and yet be provided with a large spring chamber within which to arrange
the spring which operates the blade, and thereby to apply the invention to knives
having more than one blade, without increasing to any appreciable degree their
bulk or rendering them in any manner unsightly and without bringing the sides
of the spring into frictional contact with the walls of the spring chamber.
The only coiled spring actuated self opening knife which has come to my
correspondent's notice, is the one above referred to in which a cavity is made for
the spring on one side of the blade and in one of the ribs of the handle. In that
knife one end of the spring is fastened to the heel of the blade and the other end
of the spring is fastened to the pivot post upon which the blade is pivoted. Only

page_text: a small proportion of the width of the spring, (about one-half) can be seated in the
blade and the spring cannot be fastened to the blade across the entire width of the
spring and the pivot bearing of the blade is at one side of the mid thickness of
the blade and the attachment of the spring is upon the other side of such mid line,
so that the blade is not balanced either at its pivot bearings or in its spring
attachment.
One object of the present invention is to balance the blade in both of these
respects, so that the pivot bearings on opposite sides of the blade will correspond
with each other, and the spring will be attached to the blade across the entire
width of the spring, thus making the tension of the spring equal clear across the
spring.
The invention in this respect includes as a new part of a knife, a knife blade,
the heel of which is provided with oppositely arranged projecting collars extending
outward from the opposite parallel flat sides of such line, and with a hole extending
through said heel so as to form in connection with the collars a chamber; and the
manner in which my correspondent applies such new part in the manufacture of
knives will be hereinafter fully described.
An object of his invention is to provide an improvement in the connection
between the coiled spring and the handle; this being done in such a way as to give
great strength and rigidity and also to prevent any binding upon the blade and
consequent friction which might prevent the blade from being thrown open by the
coiled spring when the catch is released. Also to provide improvement in the
fastening between the spring and the blade.
Another object of the invention is to provide an improvement in the means for
holding the knife blade in its closed position and releasing it to allow it to be
opened by the coiled spring.
A difficulty to be overcome with automatically opening knives is that the
mechanism by which the blade is operated interferes with the application of more
than one self opening blade at the same end of the handle.
One object of the invention is to provide a structure and combination of parts
for a self opening knife by which two blades can be mounted side by side at
either end of the knife, so that by this invention my correspondent is enabled to
provide a four bladed knife, each of the blades of which will fully open automatically
and in which all of the blades can be fully opened at the same time.
An objection to be overcome is the sudden stop and consequent snapping noise
made by the blade when it has been thrown open.
Another difficulty to be overcome in self-opening knives is that of making the
blade rigid in the handle when open. It has been proposed to do this by means of
a catch to hold the blade when open.
An object of this invention is to cushion the blade at the close of its movement
when it is thrown open, and to so construct the knife that when it is open the blade
will be held rigid and firm by the back spring as is the case with ordinary pocket
knives which open with the finger nail.
In order to do this, it is necessary to so arrange the parts that the force exerted
by the coiled spring will be effective to throw the blade open against the action of
the back spring and leave the back spring and blade in such position when the
blade is open that the back spring must be sprung back again before the blade will
close.
In order to do this and also to cushion the blade when it is thrown open, a blade
is provided having a back spring seat and shoulder extending from in front of the
line drawn through the pivotal point of the blade at right angles to the axis of the
blade and the back spring seat is extended to the rear of such line and the heel is
rounded from that point toward the front edge of the blade, to form a cam increasing
in radius from the front edge of the heel of the blade backward to its junction
with the back spring seat; and the back spring and blade are set in the handle
with such relation to each other that the initial movement of the blade in opening
is not obstructed by the action of the back spring, and at the end of the

page_text: opening movement of the blade the back spring cushions the blade and prevents
the snapping sound.
The invention comprises the parts and combinations herein described and claimed
and the improved article of manufacture consisting of the knife as hereinafter
described and claimed.
Fig. 1 is a side view of a four-bladed knife embodying the invention. A portion
of one end of the handle is broken away to expose the interior parts.
Fig. 2 is an enlarged fragmental side elevation of one end of the same, a portion
being broken away.
Fig. 3 is a longitudinal mid-section of one end of the same cutting through
the axis of the post; both blades being shown open. Line 3-3 indicates the line
of section.
Fig. 4 is a like view showing the connecting post riveted in place, and shorter
collars on the blades.
Fig. 5 is a fragmental view of the inner side of one side of the handle and a
fragment of one blade detached from the knife and from each other and looking in
the direction indicated by the arrow in Fig. 3.
Fig. 6 is a fragmental longitudinal mid-section of one of the blades.
A is a knife blade, the heel of which is provided with oppositely arranged
projecting annular flanges or collars a, a', and with a hole a extending through
said heel so as to form in connection with the collars a chamber within the heel
and collars. B indicates one of the side ribs of the knife and B indicates the
other side rib of the knife, and B" indicates the middle rib. Each of these ribs is
provided with a circular collar seat. The several collar seats fit their respective
collars, so that when the collars are seated in the collar seats the blade is pivoted
thereby. The ribs are respectively fitted against the flat sides of the heel of the
blade in a manner similar to the ribs in ordinary clasp knives. The collar seats of
the several ribs are indicated in the drawings by the letters , b, ", respectively.
C, C' indicate caps for the two side ribs B, B¹; and these caps cover the circular
collar seats of such ribs. These caps, together with the ends of the ribs to which
they are brazed or otherwise fastened form the bolsters of the knife. Each cap is
provided with an angular post socket (c) and preferably with a screw holed, (d')
through the cap into the post socket. In the form shown in Fig. 3, D indicates a
post arranged with its ends seated in the sockets of the caps respectively, and
d", d indicate screws respectively passed through the screw holes in the caps and
screwed into the ends of the post which has threaded sockets in its ends to receive
the screws. The ends of the post are angular to correspond with the sockets.
Fig. 4 the ends of the post D' are riveted. In the drawings my correspondent has
shown the post square in cross-section throughout. In Fig. 3, he has also shown
each of the caps, provided with a circular recess 2, (21) to accommodate the outer
ends of the outer collars of two blades, A and A'. The length of the post and the
proportions of the several parts are such that when the blades are in place and the
post passed through the chamber and seated in the sockets in the caps and the caps
are secured in place by the screws or by riveting the post, the binding pressure of
the fastening will all be upon the post and caps and the blades will be relieved of
any binding. The post passes through the middle of the chamber and does not
touch the blade at any point and the blades are pivoted solely by the bearings
formed upon each side of each blade by the collars and the collar seats just
described, and this construction balances the blade and spring and provides a
strong pivotal bearing and at the same time provides an ample chamber to receive
a strong coiled spring E, (E) for each blade to throw the same open. The coiled
spring of each blade is arranged in the chamber all in the blade and has one end
fastened to the heel of the blade and the other end fastened to the post.
In
By this new construction of blade the width of the spring is allowed to be greater
than the thickness of the heel of the blade, the projecting collars on each side of.
the heel giving increased accommodation for the spring so that with this.
construction my correspondent is enabled to use in a blade of given thickness a

page_text: much stronger coiled spring than it has heretofore been possible to put into such
blades. Furthermore, the projecting collars close the joint between the blade and
the ribs which in the former construction referred to is open.
6 indicates a spring seating slot in the wall of the spring chamber all to
seat the end of the coiled spring. This slot extends from end to end of the
chamber parallel with its axis and can be formed by sawing or in any other
suitable way.
The angular ends of the post, being seated in the angular sockets in the caps,
give a perfect fastening for the post to resist the resiliency of the coiled spring.
The coiled spring is adjusted and fastened in such a way that its resiliency will
throw the blade open. It could by a reverse arrangement be made to close the
blade.
In order to allow the coiled spring to freely operate to open the blade, that
portion of the heel of the blade which is presented toward the back spring F
when the blade is shut, is rounded so that the back spring will not interfere
with the opening of the blade at the initial movement, but the curvature of the
rim of the heel is slightly spiral constantly and regularly increasing in radius
toward the back of the blade to form a snail cam 3 which continues to a point
on the back edge of the heel which is at the rear of a line drawn at right angles to
the axis of the blade through the axis of the pivot formed by the collars; and
from that point onward toward the point of the blade, the back of the heel of
the blade is straight substantially parallel with the axis of the blade for about
one-fourth of an inch more or less depending upon the size of the blade to form
the back spring seat 4 and there the blade is provided with a shoulder 5 in the
manner of ordinary knives and the back spring is of such length and is so
arranged in the knife that when the knife is open the back spring presses against
the straight part or back spring seat 4 of the heel and receives the shoulder 5
in. the manner of ordinary knives. The purpose of the cam form of the heel of
the blade is to allow the coiled spring to operate at the initial movement of the
blade and then, after the blade has received a momentum and the spring is in
full action, forcing the blade open, the cam presses against the back spring and
gradually forces it out until the blade is opened and when the blade is open,
that part of the straight face or back spring seat 4 which is to the rear of the
line drawn at right angles as aforesaid, will engage the back spring and must
press it outward before the blade can be closed, so that the resiliency of the back
spring and also of the coiled spring are operative in conjunction with each other
to hold the blade in its open position.
This construction also cushions the blade at the latter part of its movement in
opening and prevents any snapping noise.
The invention in this respect embraces the combination of a knife blade having
a spring arranged to force the blade open and having a rounded heel and the back
spring shoulder and having such rounded heel arranged eccentric to the pivot of the
blade; the distance from the pivot to the outer edge of the heel gradually
increasing toward the back spring shoulder, so that the pressure of the back spring
upon the heel will be gradually increased as the knife blade is opened, thereby to
form a cushion to prevent the blade from being thrown against the back spring
with too great force; and the back spring arranged to bear against such rounded
heel. That is to say, the rounded portion of the beel of the blade is eccentric at
the back part of the blade, so that the back part of the rounded portion of the
heel where it joins the back spring seat 4 of the heel is further from the pivot
flange a, than the rest of the rounded portion of the beel, so that before the knife.
is fully open the heel engages the back spring F of the knife with a cam movement,
thus wedging against the back spring and is thereby prevented from battering the
end of such spring, by easing the blow which would otherwise have been given by
the shoulder of the blade against the end of the spring. The spring end if battered
would let the blade throw back too far. The heel of the blade is provided with
the catch socket a with which the catch G engages to hold the blade in its closed

page_text: position. Improved concealed means are provided for operating and releasing the
catch to allow the blade to open when desired. The catch G is mounted upon the
free end of the catch spring G' which is fixed at its opposite end to the handle
between the side ribs B and the facing H. A catch spring operating lever g is
fixed to the free end of the catch spring and extends backward therefrom along
the handle of the knife and is provided at its end with the push plate g' which in
practice may be one end of the escutcheon plate h of the knife handle. The .
facing H of the handle is provided with a push plate hole ' near the middle
thereof. A pivot pin p is set into the handle and extends across a slot b in the
side rib of the handle and rests upon the outer face of said side rib and extends
between the spring G¹ and the lever intermediate of the ends of the lever to
fulcrum the lever so that when the plate g' is pushed, the lever will operate to
withdraw the catch from the socket alii in the knife blade.
The catch spring G is arranged in and plays in the longitudinal slot b
provided in the side rib of the handle, and the upper wall of this slot serves as a
retaining shoulder and prevents the catch from being displaced by the action of
the spring E.
Where the invention is applied to a knife having two blades at one end, as.
shown in the drawings, the partition or middle-rib B should be thick, as shown in
Fig. 3, in order to allow the flanges of each blade to set into the partition.
Where the invention is applied to a knife having but one blade at one end,
the pivot flanges of the blade are seated in the pivot holes in the ribs on each
side of the handle.
By providing the heel of the blade with the large hole a passing through the
blade, and surrounding the margin of said large hole with the pivot collars or
flanges a, a', and thus forming the chamber for containing the blade operating
spring, my correspondent is enabled to assemble the parts more compactly for
forming a knife than has been possible in former modes of constructing knives of
this class and is enabled to apply two blades to the end of the knife, placing the
catch for each blade upon that side of the handle upon which is the blade.
In the former construction above referred to the spring post formed the pivot
for the blade and the spring was therefore necessarily exterior to the blade in
order to give a bearing in the blade for the pivot, and the spring therefore had to
extend into the handle of the knife to such an extent as to weaken the same or
require the same to be made large and clumsy, while with the present invention
the spring post does not serve as a pivot and does not engage the blade at all, and
the spring is chambered within the heel of the blade, and the pivot is not required.
to extend beyond the rib or lining of the handle. The ribs are arranged to seat
the pivot collars or flanges and form the bearings for said pivot flanges, and owing
to the large size of the pivots formed by the flanges, the bearings of short length
which are given by the knife ribs afford such strength as to secure the blade in a.
more perfect manner than was the case in said former construction.
The push plate is arranged flush with the face of the handle, and the catch
operating lever is thin, and only a small pivot is required to fulcrum the same, and
the lever is wholly concealed underneath the facing of the handle so that to
exterior view the knife presents the appearance of an ordinary knife and the catch
operating device does not form a protuberance and is not liable to be accidentally
operated to release the blade while the knife is in the pocket.
When it is desired to open the knife, the push plate is pressed in and this.
withdraws the catch from its socket and allows the coiled spring to throw the
blade open. The heel of the blade forms a hearing for the catch when the catch
is not in the socket, so that the blade can easily be closed and when it is closed the
catch spring will force the catch into the catch socket, thus holding the blade in its
closed position until released by pressure upon the push plate. The operation can
be performed with one hand; both in opening and in closing. The blade when
open is always ready to be closed just the same as the blade of an ordinary pocket.
knife.

page_text: In practice, each blade of the knife is provided with a spring catch and any
blade may be opened by pressing upon its respective push plate.
If the post is fastened in the handle by the screws, as shown in Fig. 3, the knife
may be easily taken to pieces by removing such screws, to allow repair if the
spring should become broken.
The invention may be applied to knives having a single blade, or to knives
having any number of blades desired and where knives have more than one blade,
one or more of the blades may be applied in accordance with the invention and the
other blades may be applied in the usual manner, if desired.
It is to be understood that a helical spring may be used instead of the form of
coiled spring shown, and applied in the same manner, that is to say, one end of the
spring will be attached to the post D, and the other end to the blade A.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
1. A knife blade, the heel of which is provided with oppositely arranged
projecting collars extending outward from the opposite parallel flat sides of such
heel, and with a hole extending through said heel so as to form in connection
with the collars a chamber.
2. A. knife having a blade the heel of which is provided with oppositely
arranged projecting collars extending outward from the opposite parallel flat
sides of such heel and with a bole which extends through the heel so as to form
in connection with the collars a chamber; and having its ribs fitted against the
flat sides of the heel and provided with circular seats for such collars arranged
to seat the collars, respectively; and held by a suitable connection which extends
through the chamber and is fastened to the opposite sides of the knife.
3. In a knife the combination of a blade, the heel of which is provided with
oppositely arranged projecting collars and with a hole extending through the heel
to form in connection with the collars a chamber; the ribs provided with circular
seats arranged to seat the collars, respectively; a post extending through the
chamber and fastened to the sides of the knife and a spring arranged within
the chamber and having one end fastened to the heel and the other to the post.
4. In a knife, the combination of a blade the heel of which is provided with
oppositely arranged projecting collars and with a hole which extends through the
heel so as to form in connection with the collars a chamber; the ribs provided
with circular seats arranged to seat the collars, respectively; caps arranged
outside such seats and each provided with a hole; a post extending from cap to
cap through the chamber; and screws inserted through the holes in the caps and
screwed into the ends of the post.
5. In a knife the combination of a blade, the heel of which is provided with
oppositely arranged projecting collars and with a hole which extends through the
blade so as to form in connection with the collars a chamber; the ribs provided
with circular seats arranged to seat the collars, respectively; caps arranged
outside such seats and provided with the angular post sockets and with holes
extending from the outside of such caps into such sockets, respectively; a post
extending through the chamber and arranged with its ends fastened in the sockets;
and a spring arranged within the chamber and having one end fastened to the heel
and the other end fastened to the post.
6. The knife set forth comprising two blades, the heel of each of which is
provided with oppositely arranged projecting collars and with a hole which extends
through the blade and forms in connection with the collars, a chamber; the
middle-rib, provided with a circular collar seat and arranged with one collar of
each blade in such seat; the side-rib provided with a circular collar seat aud
arranged with the outer collar of one of the blades in such seat; the other
side-rib provided with a circular collar seat and arranged with the outer collar
of the other blade in such collar seat; two caps, one for each collar seat of the

page_text: outer ribs; a post extending through the chambers of both blades and fixed at
its ends to the caps; two springs, one in each of the chambers and each fastened
at one end to the post and at the other end to its respective blade; and the
two blade catches respectively mounted in the opposite outside ribs to catch and
release the opposite blades, respectively.
7. In the knife the combination of the three ribs each provided with a circular
collar seat, the two blades, each provided with the oppositely arranged projecting
collars and with the hole to form the chambers, and arranged on opposite sides of
the middle rib with one collar of each blade seated in the collar seat of such rib,
and with the outer collars of the blades seated in the collar seats of the outer ribs,
respectively; the two caps, each provided with an angular post seat and a screw
hole and respectively fastened to the outer ribs and arranged to cover the collar
seats of the outer ribs; the post extending through the chambers and arranged
with angular ends seated in the post seats in the caps, and the screws respectively
inserted through the caps and screwed into the ends of the posts.
8. In a knife such as set forth the combination of the side rib provided with a
longitudinal slot; a spring provided at its free end with a catch and fixed at the
other end to the handle of the knife and arranged in said slot; the facing of the
handle provided with a push plate hole near the middle thereof; the spring catch
operating lever fixed to the free end of the catch spring and arranged in the slot
in the rib and provided at its other end with the push plate arranged in the push
plate hole; and the pivot fixed to the handle and arranged between the spring and
lever intermediate the ends of the lever to fulcrum the lever and extending across
the slot and resting upon the outer face of the side rib.
9. In a knife, the combination of a blade having a heel which is rounded and is
slightly spiral, constantly and regularly increasing in radius toward the back of
the blade to form a snail cam which continues to a point in the back edge of the
heel, which point is just at the rear of a line drawn at right angles to the axis of
the blade, through the axis of the pivot, and which heel from that point onward
toward the point of the blade is straight a short distance to form the back spring
seat and is there provided with the back spring shoulder; the blade opening
spring arranged, independent of the back spring, to force the blade open; and the
back spring arranged to bear against such rounded heel and engage such shoulder
substantially as and for the purpose set forth.
Dated this 2nd day of April 1896.
WM. P. THOMPSON & Co.,
Agents.