U.S. patent number 3,604,113 [Application Number 04/830,309] was granted by the patent office on 1971-09-14 for knife.
Invention is credited to John F. Cuscovitch.
United States Patent |
3,604,113 |
Cuscovitch |
September 14, 1971 |
KNIFE
Abstract
A knife is presented having a removable blade housed in a body
which is composed of two pivotally mounted segments. A pivot arm
with a locking cam element is mounted on one of the body segments,
and a removable blade is mounted on a loop on the other of the body
segments. In the operating condition of the knife, the cam of the
pivot arm engages the loop to simultaneously lock the body segments
together and to also secure the blade in a desired position.
Inventors: |
Cuscovitch; John F. (East
Hartford, CT) |
Family
ID: |
25256723 |
Appl.
No.: |
04/830,309 |
Filed: |
June 4, 1969 |
Current U.S.
Class: |
30/331;
30/337 |
Current CPC
Class: |
B26B
5/00 (20130101) |
Current International
Class: |
B26B
5/00 (20060101); B26b 001/02 () |
Field of
Search: |
;30/329,330,331,337,338,339 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Custer, Jr.; Granville Y.
Claims
What is claimed is:
1. A knife comprising:
a first elongated body section, said first body section being
provided with a recess in one surface thereof, said recess being
adjacent a first end of said first section;
a second elongated body section;
means pivotally connecting said body sections to each other
adjacent the second ends thereof whereby said sections may be moved
relative to one another between an open and a working position,
said body sections being installed on said connecting means such
that said one surface of said first section faces a first surface
of said second section when said body sections are in the working
position;
a projection extending from said first surface of said second body
section, said projection being provided with a cam-receiving
opening and being positioned so as to be received in said recess in
said one surface of said first body section;
a blade removably mounted on said projection, said blade being
supported against said second body section;
locking arm means pivotally connected to said first body section
adjacent said first end thereof, said locking arm means pivoting
between an open and a blade locking position; and
locking cam means extending from said locking arm means, said cam
means passing through said opening in said projection when said
locking arm means is in the locking position and said body sections
are in the working position whereby said blade will be locked
internally of the body defined by said sections, said blade being
held on said projection between said cam means and said first
surface of said second body section.
2. A knife as in claim 1 wherein:
said recess in said first body section has two parts, one of said
parts being deeper than the other, said deeper part receiving said
projection in said assembled position of said body sections.
3. A knife as in claim 1 further including:
an actuating element on said locking arm means.
4. A knife as in claim 1 further including:
a recess in one of said body sections for storing spare blades;
and
leaf spring means for retaining spare blades in said recess.
5. A knife as in claim 1 further including:
a locking nipple on one of said body sections and a mating locking
recess on the other of said body sections.
6. The knife as in claim 2 further including:
an actuating element on said locking arm means.
7. The knife as in claim 6 further including:
a storage recess in the surface of one of said body sections which
faces the other body section, said storage recess having a shape
complementary to said blade; and
spring means for retaining spare blades in said storage recess.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of cutting tools. More
particularly, this invention relates to the field of knives having
removable and replaceable blades. The knife of the present
invention was designed especially as a cutting tool for use in
carpet installation, and it has particular utility in that
application. However, although the invention will be described with
respect to such application, it is to be understood that the knife
of the present invention has general utility in the field of knives
with replaceable blades.
2. Description of the Prior Art
Knives with replaceable blades have long been known in the art, but
these prior art devices have all been characterized by one or more
deficient features. A typical prior art knife is one in which the
body is formed in two halves which are held together by one or more
fastening screws or one or more screw-and-nut sets. Particular
disadvantages of this arrangement are that changing of a blade is
time consuming because it is necessary to unscrew the handle
segments; the screw threads may become deformed; and parts are
easily lost. Other prior art approaches have included arrangements
wherein blade elements are mounted on pins and the body sections
are clamped or pinned together. However, these arrangements have
all been defective in one or more ways, such as in that the body
sections have not been firmly secured or in that the blade has
tended to move. Such deficiencies, of course, have made these
knives unacceptable for practical use since the knives could not be
relied upon to render long term dependable field service.
SUMMARY OF THE INVENTION
In the present invention the body sections of the knife are
pivotally connected at the end removed from the blade. The blade is
mounted on a projecting element extending from the inner wall of
one of the body sections. A pivot arm is mounted on the inner arm
of the other body section, and this pivot arm has a projecting cam
which is adapted to engage the passageway in the mounting
projection. The interaction between the projecting cam and the
passageway pulls and locks the body sections tightly together while
at the same time the cam locks the blade in place. A mating nipple
and recess are also provided to align and assist in retaining the
body sections in place during use of the knife. As an additional
feature, one of the body sections may be provided with a storage
recess in which spare blades are stored, and a leaf spring element
retains these blades in place.
The construction of the present invention results in a replaceable
blade knife wherein the body sections can be quickly and easily
separated for blade replacement merely by disengaging the locking
cam and pivoting the body sections with respect to each other.
Thus, a major deficiency of the prior art, i.e., ease of blade
replacement, is overcome, and other major deficiencies such as
blade slippage and inadvertent separation of body segments during
use are also overcome.
Accordingly, one object of the present invention is to provide a
novel and improved replaceable blade knife.
Another object of the present invention is to provide a novel and
improved replaceable blade knife wherein blade changing can be
accomplished quickly and conveniently.
Another object of the present invention is to provide a novel and
improved replaceable blade knife wherein blade positioning is
maintained during use.
Other objects and advantages of the present invention will be
apparent and understood to those skilled in the art from the
following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing the knife of the present invention with
the body sections pivoted with respect to each other.
FIG. 2 is a view taken along line 2--2 of FIG. 1 showing a partial
sectional view of one of the body sections.
FIG. 3 is a view taken along line 3--3 of FIG. 1 showing the blade
mounting and locking projection.
FIG. 4 is a sectional view of the knife of the present invention in
the closed position with a blade mounted between the body halves,
the view being that which would be seen if taken at the same
position of line 3--3 of FIG. 1 with the body sections brought
together.
FIG. 5 is a sectional view showing the body sections as they would
appear if taken along line 5--5 of FIG. 1 with the body sections
brought together.
FIG. 6 is a detailed view of the interior surface of one of the
body sections at the end removed from the pivot end.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, the knife 10 is shown in the open position
with body sections 12 and 14 pivoted with respect to each other.
Body sections 12 and 14 are joined together at one end for pivotal
motion with respect to each other by a rivet or other type pivot
pin 16 (which can best be seen in FIG. 2). The ends of the body
sections which are pinned together will be referred to as the rear
ends, and the other end of each section will be referred to as the
front end.
The front end of body section 12 has a shallow recess 18 of a depth
approximately equal to the thickness of a cutting blade 20. A blade
mounting projection 22 extends from recess 18 toward the inner
surface of body section 14. Blade 20 has an elongated opening 24
sized to allow the blade to be mounted on projection 22, and the
projection of blade 20 beyond the front end of the knife can be
adjusted by moving blade 20 forward or back in recess 18.
As has been previously stated, the knife is shown in the open
position in FIG. 1. To close the knife after a new blade has been
mounted on projection 22, the body sections 12 and 14 are pivoted
and brought into matching alignment. A pivot arm 26 is pivotally
connected to the inner surface of body section 14 by a pivot pin
28. Pivot arm 26 has a locking cam 30 projecting therefrom at a
position between the ends of the arm, and the end of the arm
removed from the pivot pin has an actuating thumb plate 32 which is
offset from the body of the arm. After the two body sections have
been brought into alignment, pivot arm 26 is rotated
counterclockwise to bring locking cam 30 into alignment with
projection 22. Projection 22 has a through central passage 34 which
is sized so that locking cam 30 can pass therethrough when a blade
is mounted on a projection, the sizing of passage 34 being such
that locking cam 30 tightly grips both the blade and the inner wall
of the passage when it is positioned in passage 34. When pivot arm
26 is thus rotated so that locking cam 30 is engaged in passage 34,
the pivot arm is aligned along the upper surfaces 36 and 38 of the
body sections, and thumb plate 32 fits into a recess 40 on the
outer side of body section 14.
The engagement of locking cam 30 with passage 34 results
simultaneously in the locking together of body sections 12 and 14
and also in the stabilizing of the position of blade 20. The tight
fit between locking cam 30 and passage 34 shows that the locking
cam is simultaneously bearing against the blade and firmly holding
the body sections together.
Referring now to FIGS 3, 4 and 6, details of the locking structure
are shown. FIG. 3 shows a sectional view of the front end of body
section 12 with blade 20 shown mounted on projection 22. Passage 34
can also clearly be seen.
FIG. 6 shows the interior wall of the front end of body portion 14.
It can be seen that this interior wall has an upper recessed
portion 41 to accommodate both the locking cam 30 on arm 26 when in
the locked position thereof, and projection 22. This inner wall
contains a shallower recess 42 which also accommodates locking cam
30 when the body sections are in the locked position.
Referring now to FIG. 4, a sectional view is shown of the knife in
the operative position with the body sections aligned and the blade
and locking cam in place. As can be seen, the body sections 12 and
14 are in mating alignment, and projection 22 nests in recess 41.
Arm 26 can be seen positioned against the two body sections, and
cam 30 can be seen extending through passage 34 and into the recess
42. One side of the cam tightly engages the inner wall of passage
34, and the other side of the cam tightly engages blade 20. The
body sections are thus held together and the position of the blade
is stabilized against any undesired tilting or movement forward or
back.
Referring now to FIG. 5, a nipple 46 extends from the inner surface
of body section 14 and engages a corresponding recess 48 in the
inner surface of body section 12 when the body sections are in the
closed position. This mating nipple and recess structure assists in
locking the body halves together and preventing any relative
sliding portion when the knife is being used. This nipple and
recess structure can also be seen in FIG. 1.
A feature is also included whereby replacement blades can be stored
in the handle of the knife. A recess or hollow section 50 having a
width approximately equal to the width of blade 20 is formed in
body section 12, and several blades 20 (as indicated by the dotted
lines) may be stored in recess 50. A leaf spring 52 which is
connected to body section 12 by pin 16 extends over recess 50 and
exerts a retaining force to hold the replacement blades in place.
The forward end of recess 50 is contoured to form a ramp 54 so that
replacement blades can easily be slid out of recess 50.
In the use of the knife of the present invention the body sections
would, as indicated above, be aligned and locked together by pivot
arm 26 and cam 30. The rearward position of the body sections form
a gripping handle with which the user may grip the knife, and blade
20 would project beyond the forward end to be used for any desired
cutting purpose. Sections of the handle may, as desired, be
hollowed out to lighten the weight of the knife. Whenever it is
desired to change a blade, the change can be accomplished quickly
and conveniently merely by exerting a force on thumb plate 32 to
rotate pivot arm 26 clockwise to disengage cam 30 from passage 34.
Upon disengagement of the cam, the body sections are then pivoted
with respect to each other about pivot 16; the blade is removed
from mounting projection 22; a new blade is inserted on mounting
projection 22; the body sections are realigned; and pivot arm 26 is
rotated counterclockwise to reengage cam 30 in passage 34.
Similarly, the knife can be opened and the blade can be retracted
into the body of the knife for safe storage merely by sliding it
rearwardly along projection 34 to change the relative position of
engagement between projection 34 and elongated blade opening 24. Of
course, it will be understood that the ability to withdraw the
knife completely into the handle will depend on the relative size
of the blade and the forward end of the handle.
From the foregoing description it can be seen that the knife of the
present invention overcomes the several deficiencies of the prior
art and results in a knife in which the blade is firmly secured in
position when in use and in which changing of the blade can be
accomplished swiftly and conveniently.
While a preferred embodiment has been shown and described, various
modifications and substitutions may be made without departing from
the spirit and scope of this invention. Accordingly, it is to be
understood that this invention has been described by way of
illustration and not limitation.
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