U.S. patent number 3,872,591 [Application Number 05/417,103] was granted by the patent office on 1975-03-25 for knife handle.
Invention is credited to Michel Quenot.
United States Patent |
3,872,591 |
Quenot |
March 25, 1975 |
Knife handle
Abstract
The hollow handle of a knife with a retractable blade is made of
two shells secured together side-by-side, one shell having an
integral female portion defining an oblique nose with a slot-like
aperture in which a flat male tongue at the end of the other shell
is inserted to define a blade outlet slot. A press button enables a
blade held in a slidably mounted plate-like blade supporting
carriage to be held against a face of the outlet slot during
cutting, simultaneously locking the carriage and blade against
unwanted longitudinal movement.
Inventors: |
Quenot; Michel (Besancon,
FR) |
Family
ID: |
9107762 |
Appl.
No.: |
05/417,103 |
Filed: |
November 19, 1973 |
Foreign Application Priority Data
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|
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|
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Nov 27, 1972 [FR] |
|
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72.42087 |
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Current U.S.
Class: |
30/162;
30/125 |
Current CPC
Class: |
B26B
5/001 (20130101) |
Current International
Class: |
B26B
5/00 (20060101); B26b 001/08 (); B26b 005/00 () |
Field of
Search: |
;30/162,293,320,335,163,125 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Smith; Al Lawrence
Assistant Examiner: Peters; J. C.
Attorney, Agent or Firm: Prutzman, Hayes, Kalb &
Chilton
Claims
What is claimed is:
1. A hollow knife handle comprising first and second elongate shell
members secured together generally edge-to-edge to define
therebetween a blade-receiving cavity, in which the first member
has at one end a slot-like aperture and an integral oval shaped
female portion extending continuously around said aperture and
defining a nose end of the handle, said slot-like aperture
communicating with and being in alignment with said blade receiving
cavity, and the second member has a male end part inserted in said
aperture to cooperate with the oval portion to define therein a
blade outlet slot.
2. A knife handle according to claim 1, in which said male end part
consists of a flat tongue having an outer face applied against one
face of said aperture and an inner face defining, with the other
face of said aperture, said blade outlet slot.
3. A knife handle according to claim 1, further comprising a
blade-supporting carriage in the form of a plate having a planar
main part with parallel edges protruding perpendicular to one face
of the main part, means for releasably securing a blade in said
carriage against said main part, means for mounting the carriage
within said cavity with said main part disposed parallel to the
blade outlet slot and said edges of the carriage parallel to the
longitudinal direction of the handle for a sliding movement of the
carriage along the longitudinal direction of the handle towards and
away from said blade outlet slot, and means for releasably holding
the carriage in selected positions relative to the handle.
4. A knife handle according to claim 3, in which said blade
securing means include a resilient tongue integral with said plate,
a projection on said tongue normally adopting a blade-securing
position protruding from said one face of the main part but being
resiliently deformable to a blade-disengaging position in which it
does not protrude from said one face of the main part, and means
for moving the projection to the blade-disengaging position when
the carriage is disposed in a given position relative to the
handle.
5. A knife handle according to claim 4, in which said means for
moving the projection include a push button disposed on a part of
the handle tapering towards said nose end thereof.
6. A knife handle according to claim 5, in combination with a blade
held in said carriage, in which when the carriage is disposed in
positions other than said given position said button is adapted to
move the carriage and blade together to apply the blade
transversely against one face of the blade outlet slot.
7. A knife handle according to claim 3, in combination with a
blade, in which the blade is in the shape of a trapezium and
includes on a shorter parallel edge thereof two symmetrical notches
adapted to cooperate with said projection to hold the blade in
either of two orientations relative to the carriage.
8. A knife handle according to claim 7, in which the blade outlet
slot is inclined obliquely in relation to the longitudinal
direction of the handle in the direction opposite to the
non-parallel edge of a held blade protruding from the blade outlet
slot, the longer parallel edge of the blade being a cutting
edge.
9. A knife handle according to claim 1, comprising a spare-blade
magazine pivotally connected to the handle for movement between a
first position flush with the handle and a second protruding
position by means of an eyelet in the magazine engaging on inwardly
facing studs in the first and second shell members.
10. A knife handle according to claim 9, comprising a press-stud
cooperating with a clip for releasably locking the magazine in the
first position, said press-stud being disposed on a rear end of the
handle opposite to said nose end.
Description
The invention relates to knives, particularly knives with
retractable blades such as those that are commonly used to cut
moquette carpets, linoleum and other floor coverings and similar
sheet materials.
A known type of knife with a retractable blade includes two shell
members fitted together side-by-side and enclosing a slidably
mounted blade-carrying carriage the longitudinal position of which
is set by means of several notches in the blade to adjust the
length of a blade protruding from an oblique blade outlet slot.
A fundamental drawback of these known knives in which the blade
outlet slot is defined between facing parts of the two shell
members is that the blade outlet slot risks becoming pried open in
the event of abrupt lateral efforts, or as a result of repeated
shaking of the blade upon prolonged use, since the edges of the
slot are inherently insufficiently rigid to resist large separating
forces.
A primary aim of the invention is to overcome this drawback by
providing a hollow knife handle comprising first and second
elongate shell members secured together generally edge-to-edge to
define therebetween a blade-receiving cavity, in which the first
member has at one end an integral female portion defining a nose
end of the handle including a slot-like aperture communicating and
in alignment with said blade receiving cavity, and the second
member has a male end part inserted in said aperture to define
therein a blade outlet slot.
The male end part preferably consists of a flat tongue having an
outer face applied against one face of said aperture and an inner
face defining, with the other face of said aperture, said blade
outlet slot.
Another drawback of known knives of the specified type is that to
ensure a smooth forward and rearward sliding of the blade and
carriage, and to facilitate replacement of the blade, the blade
must have a certain lateral play in the outlet slot but during use
this play adversely affects the precision of cutting.
The invention aims to overcome this drawback by providing means
which enable the blade to be firmly applied against a face of the
outlet slot. The same means can be used provide a braking effect to
avoid unwanted slipping of the blade in case its position-setting
means is unwantedly actuated, and also to enable changing of the
blade, when a blade-supporting carriage is in a given position. For
example, the blade handle may further comprise a blade-supporting
carriage in the form of a plate having a planar main part with
parallel edges protruding perpendicular to one face of the main
part, means for releasably securing a blade in said carriage
against said main part, means for mounting the carriage within said
cavity with said main part disposed parallel to the blade outlet
slot and said edges of the carriage parallel to the longitudinal
direction of the handle for a sliding movement of the carriage
along the longitudinal direction of the handle towards and away
from said blade outlet slot, and means for releasably holding the
carriage in selected positions relative to the handle. The blade
securing means advantageously include a resilient tongue integral
with said plate, a projection on said tongue normally adopting a
blade-securing position protruding from said one face of the main
part but being resiliently deformable to a blade-disengaging
position in which it does not protrude from said one face of the
main part, and means for moving the projection to the
blade-disengaging position when the carriage is disposed in a given
position relative to the handle. The means for moving the
projection can include a push button disposed on a part of the
handle tapering towards said nose end thereof. When a blade is held
in the carriage, and the carriage is disposed in positions other
than said given positions, said button is adapted to move the
carriage and blade together to apply the blade transversely against
one face of the blade outlet slot.
An embodiment of the invention will now be particularly described,
by way of example, with reference to the accompanying drawings, in
which:
FIG. 1 is a side elevational view thereof;
FIG. 2 is a top plan view;
FIG. 3 is a cross-section taken along line III--III of FIG. 2;
FIG. 4 is a cross-section taken along line IV--IV of FIG. 3;
FIG. 5 is a cross-section taken along line V--V of FIG. 3; and
FIG. 6 is a cut-away perspective view of the blade-supporting
carriage.
The hollow knife handle shown comprises two elongate shells 1 and 2
fitted together generally edge-to-edge to define a cavity
therebetween. Shell 2 has at the left hand end (looking at FIGS. 1
and 2) an integral female portion defining a nose 4, oblique in
relation to the longitudinal axis of the handle looking in side
elevation, this nose 4 having a slot-like aperture communicating
and in alignment with the central cavity. The corresponding end of
shell 1 has a flat male tongue 3 inserted in said aperture with its
outer (i.e., lower looking at FIG. 2) face applied against the
corresponding face of the aperture. The inner face of tongue 4
defines, with the other face of the aperture, a slot through which
a blade 19 and, as shown, a forward part of a plate-like
blade-supporting carriage 14 pass.
A central screw 6 tightly holds the two shells 1 and 2 edge-to-edge
against one another, these shells already being held together in
nose 4 by the above-mentioned arrangment.
A button 5 slidably mounted in an upper slot of the handle controls
a blade-moving device.
On a tapered front part of the handle, a button 7 serves as brake
for blade-supporting carriage 14 enabling, by a thumb pressure,
lateral shaking of the blade 19, when it protrudes from slot 4, to
be avoided.
The rear end of the handle has a bore 8 passing right through the
two shells 1 and 2 and adapted to permit the passage of a ring,
cord or any other device for suspending the knife.
A press stud or boss 9 protruding from a part of the said rear end
enables, when pressed, opening of a clip 10 engaging with a notch
11 to lock a spare-blade magazine 12 in a closed position. The
magazine 12 can then pivot about an eyelet 13 receiving two facing
studs each integral with and protruding inwardly from a shell 1, 2
and holding magazine 12 onto the handle. In its closed position,
magazine 12 does not protrude from the handle apart from the boss 9
which, being located outside the points of gripping in a hand, does
not risk being unwantedly operated.
FIGS. 3 and 6 show the blade-supporting carriage 14 movement of
which is controlled by button 5 to which it is connected by a
spring blade 15 terminating with a T-shaped catch 16 whose two
unequal arms pass all the way through button 5. These two arms come
to engage in corresponding notches of a rack 17 provided in each
shell 1, 2 thereby setting the position of carriage 14 and
consequently the length of blade 19 protruding from slot 4. The
notches of rack 17 enable a choice, from the various positions of
blade 19, of that which is best suited for the thickness of
material to be cut.
To avoid that the lateral play required to facilitate the manoeuvre
of pressing button 5 to make catch 16 move from one notch of rack
17 to another is not too great, an elongate protecting plate 18
slidably fitted about button 5 slides with it along grooves 18
provided for this purpose in the shells 1, 2 of the handle.
An interchangeable trapezium-shaped blade 19 whose longer parallel
edge is a cutting edge is held in place in carriage 14 by two
notches 20, 21 disposed symmetrically in the shorter parallel edge
in a manner to enable the blade 19 to be held in either of two
orientations relative to carriage 14, whereby the blade can be
turned around to use both cutting points. A corresponding catch 22
of carriage 14 engages in either of notches 20 or 21 according to
whichever face of blade 19 is used.
FIGS. 5 and 6 show the metal plate forming the blade-supporting
carriage 14 including parallel edge flanges 23, 24 bent
perpendicularly to the plane of blade 19 to hold the latter in the
working position, and ensure guiding of the assembly by means of
grooves 25, 26 provided for this purpose in the female shell 2 of
the handle, and a narrow channel defined between facing ribs 27a,
27b and 28a and 28b of the shells 1 and 2 respectively.
Catch 22 is provided on a resiliently deformable tongue 30 integral
with the main face of carriage 14 and including a separate portion
24' of the lower edge flange 24. When button 5 and carriage 14 are
in the forwardmost position (shown in FIG. 3) the enlarged inner
end of button 7, when depressed, presses against only portion 24'
of flange 24 whereby tongue 30 is deformed (to the right looking at
FIG. 5) into a corresponding opening 29 in rib 28b to disengage
catch 22 from the notch 20 or 21, since the blade 19 remains held
against the undeformed main part of carriage 14. In this position
therefore, the blade 19 can be removed and turned around or
replaced by another blade.
When a blade is fitted and the button 5 is moved rearwards into
another notch of rack 17, the carriage and blade 19 are retracted
by a corresponding amount. If the button 7 is now pressed in, it
acts against flange 24 and the entire carriage 14, and with it
blade 19, tend to tilt very slightly and the blade 19 is pressed
against tongue 14. This prevents any rattling or shaking of blade
19 during use, and consequently reduces wear to the blade outlet
slot. Moreover, longitudinal movement of carriage 14 and blade 19
is braked, and the positioning of arms 16 of button 5 in the chosen
groove of the rack 17 is improved to such an extent that if the
button 5 should be unwantedly pressed during cutting, the braking
effect produced by button 7 practically eliminates any possibility
of the blade 19 unwantedly retracting by a notch. The button 7 is
so positioned that such a pressure can easily be exerted during use
of the knife. Consequently, the knife can be safely used to cut a
material to a particular depth (for example to avoid cutting a
backing material) by adjusting the blade position and applying the
inclined nose 4 against the material during cutting.
The principal advantages of the described embodiment are as
follows.
Since the nose end of the knife with the blade outlet slot is in a
single piece integral with one of the shells of the handle, the
slot can no longer open out under the effect of lateral efforts
made necessary by the cutting operation.
The blade positioning device is controlled by means of a press
button with a particularly accessible lateral disposition. Its
location outside the points of bearing of the hand on the handle
enables false manoeuvres to be avoided, even during difficult
cutting involving large efforts.
The device for braking and removing the blade is provided in a
manner to avoid a false manoeuvre from causing unwanted removal or
withdrawal of the blade. For this purpose, the braking button is
arranged on the front sloping face of the handle at the blade end.
In the working position with the blade withdrawn, the thumb rests
naturally on the said button which thus serves as a brake,
reinforcing the positioning of the blade-carrying carriage in the
chosen notch of the rack and eliminating lateral shaking of the
blade.
The moving forwards and backwards of the blade-carrying carriage is
facilitated by the provision of the handle-forming shells in
plastics material, which material enables reduction of the
coefficient of friction of said carriage in its guide grooves,
while ensuring a self-lubrification.
The provision on the rear end of the handle of the press-stud for
locking the spare blade magazine also avoids the risks of unwanted
opening thereof during cutting.
* * * * *