[0001] This invention relates to knives of the kind having a blade which is movable between
an extended or operative position and a retracted or inorperative position. It is
usual for the blade to be contained within a handle of the knife when retracted, and
the invention will be hereinafter described with particular reference to that form
of knife.
[0002] Retractable blade knives of the foregoing kind are generally constructed so that
a worn or damaged blade can be removed and replaced by a new blade. Example constructions
of that kind are disclosed by U.S. patents 3,577,637, 3,593,417 and 4,242,795. It
is not convenient to sharpen the blade in knives of the foregoing kind and as a result
blade replacement may occur or be required at relatively short intervals of time.
[0003] It has been proposed in the past to provide a retractable blade knife with a self-sharpening
facility, and U.S. patent 1,890,506 (Frank) discloses that particular construction.
The Frank knife is not known to have been manufactured in commercial quantities, and
is distinguished from the other retractable blade knives referred to above in that
the blade is not readily replaced. It has the further disadvantage in that retraction
of the blade extends rather than reduces the overall size of the knife. The Frank
knife is also not satisfactory because the self-sharpening facility does not sharpen
the entire length of the blade cutting edge, and in particular does not and cannot
sharpen the very tip of the blade which is often the most used portion of the blade.
[0004] Another common problem with knives of the foregoing kind is that the blade is not
firmly restrained in the extended position so that pressure on the blade during use
can cause unintentional retraction of the blade.
[0005] It is an object of the present invention to provide a knife of the foregoing kind
which has an effective self-sharpening facility. It is another object to provide such
a knife having means to prevent inadvertent extension of the blade. It is a further
object to provide such a knife with means whereby the blade is positively retained
in the extended position.
[0006] According to one aspect of the present invention, there is provided a retractable
blade knife including, a hollow handle, a blade opening at a front end of said handle,
a blade carrier mounted within said handle for movement between a rest position at
which a blade connected to said carrier is contained within said handle and a forward
position at which the said blade is projected through said opening beyond said handle
front end, actuator means connected to said carrier and being operable to cause said
movement thereof, a blade sharpener located within said handle adjacent said opening
and being mounted for movement relative to said handle, biasing means urging said
sharpener towards a stop position at which the sharpener prevents movement of a said
blade forwardly through said opening, release means operable to move said sharpener
away from said stop position and into a release position at which a said blade is
able to be moved forwardly through said opening, and said sharpener is engageable
with the cutting edge of a said blade so as to sharpen that edge as said blade is
moved through said opening.
[0007] According to another aspect of the invention, there is provided a retractable blade
knife including, a hollow handle, a blade opening at a front end of said handle, a
blade carrier mounted within said handle, a blade removably connected to said carrier,
said carrier being movable relative to said handle between a rest position at which
said blade is contained within said handle and a forward position at which said blade
is projected through said opening beyond said handle front end, actuator means operable
to cause said carrier movement, a blade sharpener located within said handle adjacent
said opening and being operable to engage the cutting edge of said blade so as to
sharpen that edge during movement of said blade with said carrier, said sharpener
including sharpening means which is engageable with said cutting edge and which is
located forwardly of the front end of said blade when said carrier is in said rest
position, and release means connected to said sharpener and being selectively operable
to render said sharpener inoperable.
[0008] According to still another aspect of the invention, there is provided a retractable
blade knife including, a hollow handle, a blade opening at a front end of said handle,
a blade carrier mounted within said handle for movement relative thereto, connecting
means whereby a blade can be connected to and removed from said carrier, said carrier
being movable between a rest position at which a blade connected to said carrier is
contained within said handle and a forward position at which the said blade is projected
through said opening beyond said handle front end, actuator means operable to cause
said carrier movement, a blade sharpener located within said handle adjacent said
opening and being operable to engage the cutting edge of the said blade so as to sharpen
that edge during movement of said blade through said opening, and sharpener release
means which is selectively operable to render said sharpener inoperable.
[0009] According to yet another aspect of the invention, there is provided a retractable
blade knife including, a hollow handle, a blade opening at a front end of said handle,
a blade carrier mounted within said handle for movement between a rest position at
which a blade connected to said carrier is contained within said handle and a forward
position at which the said blade is projected through said opening beyond said handle
front end, actuator means operable to cause said carrier movement, a blade sharpener
located within said handle adjacent said opening and being engageable with the cutting
edge of a said blade so as to sharpen that edge as said blade is moved with said carrier,
and stop means mounted on said handle for movement between a stop position at which
it is operative to prevent movement of a said blade forwardly through said opening
and a release position at which it is not so operative, and release means which is
operable to move said stop means from said stop position to said release position.
[0010] According to a further aspect of the invention, there is provided a retractable blade
knife including, a hollow handle, a blade opening at a front end of said handle, a
blade carrier mounted within said handle for movement between a rest position at which
a blade connected to said carrier is contained within said handle and a forward position
at which the said blade is projected through said opening beyond said handle front
end, actuator means operable to cause said carrier movement, a blade sharpener located
within said handle adjacent said opening and being operable to engage the cutting
edge of the said blade so as to sharpen that edge during movement of said blade through
said opening, and releasable locking means which is operable to prevent movement of
said carrier out of said forward position.
[0011] The blade sharpener is arranged so that when it engages the cutting edge of a blade
it automatically sharpens that blade as a consequence of movement of the blade into
or out of the knife handle. In a preferred embodiment hereinafter described, the sharpening
operation is most effective during withdrawal of the blade into the handle, and means
is provided to enable that sharpener to be held inoperative during at least part of
the movement of the blade into its extended operative position.
[0012] An embodiment of the invention is described in detail in the following passages of
the specificaton which refer to the accompanying drawings. The drawings, however,
are merely illustrative of how the invention might be put into effect, so that the
specific form and arrangement of the various features as shown is not to be understood
as limiting on the invention.
[0013] In the drawings:
Figure 1 is a side elevational view of one form of retractable blade knife incorporating
an embodiment of the invention,
Figure 2 is a top plan view of the knife shown in Figure 1,
Figure 3 is a partially sectioned and exploded view of the rear end portion of the
knife shown in Figure 1,
Figure 4 is an end view of the removable end portion shown in Figure 3,
Figure 5 is a cross-sectional view taken along line V-V of Figure 1,
Figure 6 is a longitudinal sectional view of the knife shown in Figures 1 and 2, but
with parts omitted for convenience of illustration,
Figure 7 is a sectional view taken along line VII-VII of Figure 5,
Figure 8 is a view similar to Figure 7 but showing the blade fully retracted,
Figure 9 is a view similar to Figure 8 but with parts omitted for convenience of illustration,
Figure 10 is a view similar to Figure 9 but showing the stop means rendered inoperative,
Figure 11 is a view similar to Figure 10 and showing the blade carrier in a forward
position,
Figure 12 is a part sectional view showing the manner of actuation of the blade carrier
of the knife of Figure 1,
Figure 13 is a view similar to Figure 12 but showing the blade carrier moved to its
forwardmost position,
Figure 14 is a view similar to Figure 13 and showing the blade actuator in its stored
position,
Figure 15 is a cross-sectional view taken along line XV-XV of Figure 6.
Figure 16 is a view taken along line XVI-XVI of Figure 14.
[0014] According to the example form shown in the drawings, the knife includes an elongate
handle 1 having a passage 2 (Figures 5 and 6) extending lengthwise therein. That passage
2 is defined between an upper wall 3, a lower wall 4, and two side walls 5 and 6,
and extends from a rear end portion 7 of the handle 1 to a front end wall 8. An opening
9 (Figure 6) is provided through the front end wall 8 to permit movement of a blade
10 into and out of the handle passage 2. Preferably, that opening 9 is in the form
of a narrow slot extending between upper and lower sides of the handle 1 and which
is dimensioned to allow passage of the knife blade 10 with little clearance. That
is, it is preferred that the opening 9 is dimensioned so as to at least minimise lateral
movement of the blade 10 relative to the handle 1, and preferably also provide a support
which is engageable by the upper edge 11 of the blade 10 when the knife is in use.
[0015] The rear end portion 7 of the handle 1 is removable in the construction shown to
enable access to the interior of the handle 1. Removal of that end portion 7 may be
employed to enable exchange of the knife blade 10 if it becomes worn or damaged. Also,
the handle 1 may include a spare blade storage compartment 12 (Figure 5) which is
accessible as a consequence of removing the end portion 7. The compartment 12 may
be adapted to contain a single spare blade (not shown), or a plurality of such blades.
[0016] In the arrangement shown, the end portion 7 is slidably engaged with the main body
13 of the handle 1 so as to be relatively movable in a direction transverse to the
longitudinal axis of the handle 1. Keying ribs 14 (Figures 1 and 3) provided on the
end portion 7 slidably engage within complementary slots formed in the handle main
body 13 so as to hold the end portion 7 against endwise removal from the main body
13. Snap engaging means comprising a detent 15 (Figures 3 and 4) may be provided on
the end portion 7 for cooperation with the main body 13 so as to resist inadvertent
dislodgement of the end portion 7 from the main body 13. As best seen in Figure 4,
the detent 15 is at the end of a flexible arm 16 formed integral with the end portion
7.
[0017] The blade 10 may be of any suitable form, but is generally of plate-like form having
a substantially straight cutting edge 17. It is preferred that a front edge 18 and
the upper edge 11 of the blade 10 are also substantially straight and that the front
edge slopes upwardly and rearwardly from a tip 19 at its junction with the cutting
edge 17. In such a case, it is also preferred that the front wall 8 of the knife handle
1 slopes downwardly and rearwardly as shown so as to expose a substantial part of
the blade cutting edge 17 when the blade 10 is extended (Figure 1). It is also preferred
that the blade 10 is double ended so as to be reversible.
[0018] A blade carrier 20 (Figure 16) is mounted within the knife handle passage 2 for sliding
movement towards and away from the front wall 8. That carrier 20 can be of any suitable
form such as to provide support for a blade 10, and any appropriate releasable connection
can be provided between the blade 10 and the carrier 20 to ensure that the blade 10
moves with the carrier 20. In the construction shown, that connection includes a plurality
of laterally projecting pins 21 on a side surface 22 of the carrier 20, each of which
neatly engages within a respective hole 23 formed through a portion 24 of the blade
10 which overlies the carrier surface 22. Confinement of the blade 10 within the handle
1 may be such as to prevent the carrier pins 21 disengaging from the blade holes 23.
[0019] Exchange of a blade 10 may be effected by sliding the carrier 20 and connected blade
10 out of the handle 1 through the rear end thereof. Such removal is of course prevented
while the rear end portion 7 of the handle 1 remains in place.
[0020] The carrier 20 is movable between two extreme positions. One is a rest position as
shown in Figure 8, and in that position the blade 10 is fully contained within the
handle 1. The other is a forward position as shown in Figure 7, and in that position
the blade 10 has been projected through the opening 9 so as to extend beyond the handle
front wall 8. That is, the blade 10 is positioned so as to be operative.
[0021] Movement of the carrier 20 may be effected through any suitable actuator means, but
in the construction shown that actuator means comprises a lever 27 which is pivotally
connected at an inner end 28 to the carrier 20 for relative movement between an operative
position (Figures 12 and 13) and a stored position (Figure 14). Also, the lever 27
is preferably arranged to be accessible at the side wall 5 of the handle 1.
[0022] According to the arrangement shown, the lever 27 is pivotally connected to the carrier
20 so that it can be swung about a pivot 29 (Figure 12) having its axis extending
between the upper and lower walls 3 and 4 of the handle 1. An elongate opening 30
is provided in the side wall 5 to accommodate the lever 27 when it is in the stored
position. The length of the opening 30 is such as to accommodate the full length of
the lever 27 without substantial clearance at either end. One end 31 of the opening
30 is formed by a surface 32 (Figure 3) of the handle end portion 7.
[0023] The pivoted inner end 28 of the lever 27 is adjacent the rear end portion 7 of the
handle 1 when the lever 27 is in its stored position and the knife blade 10 is retracted
(Figure 8). The outer or free end 33 of the lever 27 is located towards the front
end of the handle 1 under those circumstances, and the lever 27 is substantially contained
within the opening 30. A raised finger engageable portion 48 of the lever 27 is accessible
to permit the lever 27 to be pulled outwards about the pivot 29 to adopt the operative
position as shown in Figure 13.
[0024] When it is desired to extend the blade 10, the lever 27 is pivoted laterally outwards
from the handle 1 and is pushed forward so that the carrier 20 and connected blade
10 also move forward. The blade 10 is thereby projected through the front wall opening
9 of the handle 1 to adopt the extended position as shown in Figure 1. At that time
the pivoted inner end 28 of the lever 27 is at the forwardmost end of the opening
30 in the handle side wall 5 and the lever 27 can be swung inwards to be again accommodated
in that opening 30. The relative disposition of the lever ends 28 and 33, however,
is now the reverse of that existing when the blade 10 is retracted.
[0025] Positive locking means is provided to prevent the blade 10 being inadvertently pushed
back into the handle 1 from the extended position when the blade 10 is subjected to
endwise pressure in use. In the construction shown, that locking means includes the
lever 27 and a cooperative abutment surface formed by the end 31 of the handle opening
30. That is, when the lever 27 is accommodated within the opening 30 as shown in Figure
14, the outer end 33 of the lever 27 is arranged in opposed relationship to that abutment
surface so as to positively resist rearward movement of the carrier 20. Pivotal movement
of the lever 27 out of the opening 30 releases that locking arrangement by removing
the lever end 33 from a position at which it can engage the abutment surface.
[0026] Stop means is provided to prevent inadvertent movement of the blade 10 into the extended
position. That may include a movable stop member located within the handle 1 which
is engageable with the blade 10 or a cooperable part of the carrier 20. That is, when
the carrier 20 is at the rest position, that stop member is arranged to be engaged
by the blade 10 or the carrier 20 such as to prevent forward movement of the carrier
20 beyond a particular position.
[0027] In the preferred construction shown, the stop means is formed by cooperable parts
of a blade sharpener 34 and the carrier 20, but other arrangements are possible. The
sharpener 34 is located within the handle 1 adjacent the front wall 8, and its function
and construction will be further described below. The sharpener 34 includes a body
member 35 and the stop means part of the sharpener 34 is formed by a lateral projection
36 provided on a rear end portion of an arm 37 which is connected to and extends rearwardly
from the body member 35. The cooperable part of the carrier 20 is formed by the front
end portion 25 of a laterally projecting lip 26 formed along the upper side of the
carrier 20.
[0028] When the carrier 20 is at the rest position as shown in Figure 8, the carrier stop
part 25 is located rearwardly of the sharpener stop part 36. Forward movement of the
carrier 20 results in the stop part 25 engaging the stop part 36, and further forward
movement is thereby prevented. At that time, the blade 10 has not been projected through
the opening 9.
[0029] Release means is provided whereby the stop means can be selectively rendered inoperable.
In the construction shown, that release means is connected to the sharpener 34 so
as to be operable to move the stop part 36 out of the path of the carrier stop part
25 and thereby permit extension of the blade 10. That release means includes a button
38 which is accessible at the upper side of the handle 1 and which is spring biased
into an upper stop operative position as shown in Figure 9. Depression of the button
38 against the influence of the biasing spring 39 is effective to move the stop part
36 into its inoperative position as shown by Figure 10.
[0030] The button biasing spring 39 is preferably formed by a resilient arm as shown in
Figure 6 which extends lengthwise of the handle 1, and has one end 40 fixed to the
handle 1 and its opposite end 41 attached to the sharpener 34. The spring end 40 is
preferably secured to the handle adjacent the rear end thereof as shown. The arrangement
is such that the spring 39 normally urges the sharpener 34 and connected button 38
in an upward direction and any appropriate means may be provided to limit such upward
movement. Furthermore, the sharpener 34 and/or button 38 may cooperate with appropriate
guide means provided on or within the handle 1 so as to be confined to a particular
path of movement.
[0031] Sharpening means 42 is provided on the sharpener 34 and is arranged so as to be operative
to automatically sharpen the cutting edge 17 of the blade 10. In the arrangement shown,
the sharpening means 42 is not engageable with the blade cutting edge 17 when the
button 38 is depressed, but is so engageable when the button 38 is allowed to move
upwards under the influence of its biasing spring 39. It is an important feature of
the construction shown that the tip 19 of the blade 10 is located rearwards of the
sharpening means 42 when the blade 10 is fully retracted.
[0032] With the foregoing arrangement, it is necessary to depress the release button 38
to permit extension of the blade 10 and as a consequence the blade 10 does not contact
the sharpening means 42, at least during the initial part of that extension movement.
If the button 38 is released during the course of that movement, there may be sharpening
engagement, but that is not essential nor is it preferred. When the blade 10 is fully
extended, the button 38 is released so that the sharpening means 42 is moved into
engagement with part of the blade cutting edge 17 which is located within the handle
1 and is therefore not normally operative.
[0033] Retraction of the blade 10 does not require depression of the release button 38.
Consequently, the sharpening means 42 remains in engagement with and sharpens the
cutting edge 17 during movement of the blade 10 back into the handle 1. Furthermore,
that sharpening is effected up to the very tip 19 of the blade 10 because the blade
10 is moved rearwardly beyond the sharpening means 42 when adopting the fully retracted
position. Such full retraction has the affect of automatically conditioning the stop
means to be operative, because the spring 39 urges the sharpener 34 into its uppermost
position when the blade 10 moves clear of the sharpening means 42.
[0034] As will be apparent from Figures 9 to 11, the stop part 36 is provided with a ramp
surface 45 and the stop part 25 is provided with a ramp surface 46. The ramp surfaces
45 and 46 may be flat or curved as required. When the stop part 25 is located forwardly
of the stop part 36, the ramp surfaces 45 and 46 are arranged in opposed relationship
as shown by Figure 11. Rearward movement of the carrier 20 results in those two surfaces
45 and 46 engaging with the consequence that the sharpener 34 is ramped upwards against
the action of the spring 39, and the carrier 20 can continue to move rearward. The
stop means is thereby automatically rendered inoperative during rearward movement
of the carrier. Other arrangements could be adopted to achieve the same result.
[0035] The sharpening means 42 can be of any suitable form. In the construction shown, it
comprises a device having a pair of cutting plates 43 of tungsten carbide or other
suitable material and which are relatively arranged to define a V-shaped sharpening
recess 44 between them. Preferably, the plates 43 overlap to define that recess 44
and are in face to face relationship. It is further preferred that the plates 43 slope
upwardly and rearwardly to facilitate a relatively smooth sharpening action during
retraction of the blade 10.
[0036] Since the two plates 43 are out of lateral alignment, only one will be engaged by
the blade 10 during the final part of the retracting movement of the blade 10 over
the sharpening device 42. That may cause lateral deflection of the blade 10 and consequently
an absence of sharpening at one side of the blade tip. If such deflection does occur,
a third blade or a rubbing member may be located opposite to the rearmost plate 43
of the pair referred to. That third blade or rubbing member can be arranged to prevent
or minimise the aforementioned deflection and thereby ensure that effective sharpening
of the blade 10 is carried up to the tip 19 of the blade 10.
[0037] A channel-shaped metal insert 47 (Figures 6 and 15) is preferably provided at the
top of the handle opening 9. That insert 47 receives an upper edge portion of the
knife blade 10 and provides a rigid and wear resistant support against which the upper
edge 11 of the blade 10 can bear during use and movement into and out of the handle
1.
[0038] It will be apparent from the foregoing description that the present invention provides
an effective knife of the retractable blade type, particularly in the ability to prevent
inadvertent extension of the blade and to also provide for self-sharpening of the
blade.
[0039] Various alterations, modifications and/or additions may be introduced into the constructions
and arrangements of parts previously described without departing from the spirit or
ambit of the invention as defined by the appended claims.
1. A retractable blade knife including, a hollow handle (1), a blade opening (9) at
a front end of said handle (1), a blade carrier (20) mounted within said handle (1)
for movement relative thereto, connecting means (21,23) whereby a blade (10) can be
connected to and removed from said carrier (20), said carrier (20) being movable between
a rest position at which a blade (10) connected to said carrier (20) is contained
within said handle (1) and a forward position at which the said blade (10) is projected
through said opening (9) beyond said handle front end, and actuator means (27) operable
to cause said carrier movement; characterised in that a blade sharpener (34) is located
within said handle (1) adjacent said opening ( 9) and being operable to engage the
cutting edge (17) of the said blade (10) so as to sharpen that edge (17) during movement
of said blade (10) through said opening (9), and that a sharpener release means (38)
is selectively operable to render said sharpener (34) inoperable.
2. A knife according to claim 1, wherein a said blade (10) is releasably connected
to said carrier (20), and said carrier (20) is removable from said handle (1) through
a rear end thereof to permit removal and connection of a said blade (10) respectively
from and to said carrier (20)
3. A knife according to claim 2, wherein a rear end portion (7) of said handle (1)
is removable from the main body (13) of the handle (1) to permit movement of said
carrier (20) through said rear end.
4. A knife according to claim 2 or 3, wherein said rear end portion (7) is slidably
connected to said main body (13) for relative movement in a direction transverse to
the longitudinal axis of said handle (1).
5. A knife according to claim 2, 3 or 4, wherein snap engaging means (15) acts between
said rear end portion (7) and said main body (13) so as to resist removal of said
rear end portion (7) from the main body (1).
6. A knife according to any preceding claim, wherein biasing means (39) urges said
sharpener (34) towards a stop position at which the sharpener (34) prevents movement
of a said blade (10) forwardly through said opening (9), and said release means (38)
is operable to move said sharpener (34) away from said stop position and into a release
position at which a said blade (10) is able to be moved forwardly through said opening
(9).
7. A knife according to claim 6, wherein cooperable parts (36,25) of said sharpener
(34) and said carrier (20) are engageable to prevent forward movement of said carrier
(20) to a position at which said blade (10) extends over said sharpening means (42).
8. A knife according to claim 7, wherein said cooperable parts (36,25) do not prevent
rearward movement of said carrier (20) from said forward position to said rest position.
9. A knife according to any preceding claim, wherein said sharpener (34) includes
sharpening means (42) which is engageable with said blade edge (17), and said sharpening
means (42) is located forwardly of a front end of a said blade (10) when said carrier
(20) is in said rest position.
10. A knife according to claim 9, wherein said sharpener (34) includes a body member
(35), and said sharpening means (42) is secured to that body member (35) and defines
a V-shaped sharpening recess (44) for receiving the cutting edge (17) of a said blade
(10).
11. A knife according to claim 10 when appended to claim 6, wherein said biasing means
(39) includes a spring arm (39) which extends longitudinally of a passage (2) and
has its opposite ends connected to said handle (1) and said body member (35) respectively.
12. A knife according to claim 10 or 11, wherein said sharpening means (42) includes
two overlapping cutter plates (43), and said cutter plates (43) slope upwardly and
rearwardly.
13. A knife according to claim 10 when appended to claim 7, wherein one of said cooperable
parts (36,25) comprises an arm (37) secured to and extending rearwardly from said
body member (35) and a lateral projection (36) provided on a rear end portion of said
arm (37), and the other said cooperable part (25) is provided on a front end portion
of said carrier (20).
14. A knife according to claim 13, wherein a ramp surface (45,46) is provided on each
said cooperable part (36,25), and said ramp surfaces (45,46) engage during rearward
movement of said carrier (20) so as to render said cooperable parts (36,25) inoperable
to prevent said rearward movement.
15. A knife according to any one of claims 6 to 8, wherein said handle (1) has an
upper wall (3), a lower wall (4) and two side walls (5,6), each of said walls extends
between front and rear ends of said handle (1), a passage (2) is defined between said
walls, said carrier (20) is located within said passage (2), and said biasing means
(39) urges said sharpener (34) in a direction towards said upper wall (3).
16. A knife according to claim 15, wherein said release means (38) includes a button
(38) connected to said sharpener (34) and which projects upwardly through and beyond
said upper wall (3) at least when said sharpener (34) is in said stop position.
17. A knife according to any one of claims 6 to 8, wherein said sharpener (34) is
positioned between said stop and release positions when engaging a cutting edge (17)
of a said blade (10).
18. A knife according to any one of claims 6, 7, 8 and 17, wherein guide means is
provided on said handle (1) and cooperates with said sharpener (34) to guide said
sharpener (34) in its movement between said stop and release positions.
19. A knife according to any preceding claim, wherein stop means (36,25) is operative
to prevent movement of said carrier (20) forwardly from said rest position to a position
at which said sharpening means (42) is operatively engageable with said blade edge
(17), and said release means (38) is operable to render said stop means (36,25) inoperative.
20. A knife according to any preceding claim, wherein said actuator means (27) includes
a lever (27) which is pivotally connected at an inner end (28) to said carrier (20)
so as to be movable relative thereto between operative and stored positions, said
lever (27) projects laterally outwards of said handle (1) when in said operative position
and is substantially contained within said handle (1) when in said stored position.
21. A knife according to claim 20, wherein said lever (27) projects outwardly through
an elongate opening (30) in said handle (1) when in said operative position, and the
outer end (33) of the lever (27) is engageable with respective opposite ends of said
opening (30) when in the stored position according to whether said carrier (20) is
in the rest or forward position respectively.
22. A knife according to claim 20 or 21, wherein releasable locking means (27,31)
is operable to prevent movement of said carrier (20) out of said forward position.
23. A knife according to claim 22, wherein said actuator means (27) forms at least
part of said locking means (27,31).