1 "CUTTER ASSEMBLY"
FIELD OF THE INVENTION
This invention relates to a cutter assembly.
This invention has particular but not exclusive application to a stitch cutter. However, the invention is equally applicable to other surgical cutter assemblies such as scalpels, for example, or other non-surgical cutter assemblies such as craft knives.
DISCLOSURE OF THE INVENTION
This invention resides broadly in a cutter assembly including:- a housing; a cutter displacable relative to the housing between an inoperative position and an operative position; wherein a portion of the cutter protrudes from the housing when the cutter is in the inoperative position and wherein the protruding portion can be urged towards the housing to displace the cutter to the operative position.
Preferably, the cutter assembly also includes frangible packaging means for sealing the cutter, wherein displacement of the cutter to the operative position breaks the frangible packaging means.
Preferably, the frangible packaging means seals the cutter and housing when the cutter is in the inoperative position, however it may seal only the cutter.
The frangible packaging means may be a plastics material which may be vacuum sealed or heat shrunk. However, it may be any other appropriate material.
Whilst the cutter may be rotatable relative to the housing between the operative and inoperative positions, in the prefered embodiment the cutter is displacable relative to the housing along an axis, and the axial dimension of the cutter is greater than the axial
dimension of the housing.
In this embodiment, the housing has a forward end and a rearward end and the cutter has a forward end and a rearward end, and, when in the inoperative position, the rearward end of the cutter protrudes from the rearward end of the housing, and, when in the operative position, the forward end of the cutter protrudes from the forward end of the housing.
In the preferred embodiment, when in the inoperative position, a forwardly directed force can be applied to the protruding rearward end of the cutter to displace the cutter to the operative position. Whilst this force can be applied in any manner including a direct manual force on the rearward end of the cutter, it is preferred that the forwardly directed force be applied to the cutter by manually applying a rearwardly directed force to the housing and abutting the protruding rearward end of the cutter against a support surface.
It is preferred that the cutter assembly includes detent means for releasably maintaining the cutter in the operative position. The detent may take any form.
In one preferred embodiment, the detent means includes a recess or aperture in the cutter and complementary recess or aperture engaging means on the housing. The complementary recess or aperture engaging means is resiliently biased to a disengaged position and manual pressure on the exterior of the housing causes the recess or aperture engaging means to engage the recess or aperture in the cutter. The cutter can also be maintained in the operative position by manually preventing the rearward end of the cutter from protruding from the rearward end of the housing.
In one preferred embodiment, the protruding forward end of the cutter can be urged rearwardly relative to the housing to displace the cutter to the inoperative position. This can be done by abutting the forward end of the cutter against a support surface. Alternatively
or additionally, the cutter can be displaced to the inoperative position by manually pulling the protruding rear end of the cutter or alternatively again by some biasing means such as a spring. The cutter may be re-usable after the cutter has been displaced to the inoperative position. However, preferably, the cutter assembly includes locking means for locking the cutter in the inoperative position after use. The locking means may take any form. In another aspect the invention resides in a cutter assembly including:- a housing; a cutter displacable relative to the housing between an inoperative position and an operative position; and frangible packaging means for sealing the cutter, wherein displacement of the cutter to the operative position breaks the frangible packaging means.
In another aspect the invention resides in a cutter assembly including:- a housing; a cutter mounted relative to the housing for displacement between an inoperative position and an operative position; and detent means for releasably maintaining the cutter in the operative position, the detent means including a recess or aperture in the cutter and complementary recess or aperture engaging means disposed on the housing, wherein the complementary recess or aperture engaging means is resiliently biased to a disengaged position and wherein manual pressure on the exterior of the housing causes the recess or aperture engaging means to engage the recess or aperture in the cutter.
BRIEF DESCRIPTION OF THE FIGURES
In order that this invention may be more easily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate
a preferred embodiment of the invention, wherein:-
FIG 1 is a side elevation of a cutter and housing with the cutter in the inoperative position;
FIG 2 is a side elevation of the cutter and housing of FIG 1 with the cutter in the operative position;
FIG 3 is a perspective view of a packaged cutter and housing with the cutter in the inoperative position;
FIGS 4 & 5 are perspective views of the cutter being displaced to the operative position; FIGS 6 & 7 are perspective views of the cutter being displaced to the inoperative position;
FIG 8 is a perspective view of packaged cutter and housing in which the frangible packaging means is heat shrunk or vacuum sealed; FIG 9 is an exploded perspective view of a cutter and housing with one half of the housing removed;
FIG 10 is a side elevation of another cutter and housing with the cutter in the operative position; and
FIG 11 is a side elevation of the cutter and housing of FIG 10 with the cutter in the inoperative position.
BEST MODE
Referring to FIG 3, cutter assembly 2 includes cutter 4, housing 6, and frangible packaging means 8.
In the embodiment illustrated in FIGS 1 to 9, cutter 4 is a conventional stitch cutting metal blade, housing 6 is an ergonomically shaped injection moulded plastics handle having internal guide means for guiding the cutter, and frangible packaging means 8 is a frangible transparent plastic which, until broken, maintains the sterility of the stitch cutting blade. The plastic may be vacuum sealed or heat shrunk or sealed in any other known manner. With reference to FIGS 1 & 2, cutter 4 is mounted for sliding movement along an axis within housing 6 between an inoperative position (FIG 1) and an operative position (FIG 2) .
As will be apparent, the axial dimension of cutter 4 is greater than the axial dimension of housing 6.
Housing 6 has a forward end 10 and a rearward end 12 and cutter 4 has a forward end 14 and a rearward end 16. In the inoperative position (FIG 1), rearward end 16 of cutter 4 protrudes from rearward end 12 of housing 6.
In the operative position (FIG 2), forward end 14 of cutter 4 protrudes from forward end 10 of housing 6 and hence is available to cut stitches. When in the inoperative position, a forwardly directed force can be applied to the protruding rearward end 16 of the cutter to displace the cutter to the operative position.
Referring to FIGS 4 & 5, the forwardly directed force can be applied to the cutter by manually applying a rearwardly directed force to the housing and abutting the protruding rearward end 16 of the cutter against a support surface 18.
As will be clear from FIG 5, the frangible packaging means 8 is perforated by cutter 4 as cutter 4 is displaced to the operative position. Thus, breaking the sterile seal and deploying the cutter is a single operation.
Referring to FIG 9, the cutter assembly includes detent means for releasably maintaining the cutter in the operative position.
The detent means includes a recess or aperture 20 in cutter 4 and complementary recess or aperture engaging means 22 on housing 6. It should be noted that conventional stitch cutting blades (and scalpel blades) have a longitudinally extending aperture or slot 20. The recess or aperture engaging means 22 of the detent means is adapted to selectively engage the forward end of the slot 20 in the blade to thereby selectively prevent rearward movement of blade 4 relative to housing 6.
Housing 6 also includes limiting means 26 which protrudes through slot 20 and engages the rearward end of
slot 20 to thereby limit forward sliding movement of the cutter relative to the housing. Limiting means 26 also assists in guiding the sliding of the cutter and ensuring that the slot aligns with the recess or aperture engaging means of the detent means and locking means, respectively.
The complementary recess or aperture engaging means 22 is integrally formed with housing 6 and is resiliently biased to a disengaged position. The complementary recess or aperture engaging means 22 includes a convex protrusion disposed on the inner side of the distal end of a resilient arm. Manual pressure from the exterior of housing 6 on the resilient arm causes the convex protrusion to engage the recess or aperture 20 (the forward end of the slot).
Whilst engaged by the convex protrusion, the cutter cannot move from the operative position. An alternative means by which the cutter can be maintained in the operative position is to manually prevent the rearward end of the cutter from protruding from the rearward end of the housing. This can be done by covering the rearward end of housing 6 with the palm or a finger of the hand holding the cutter assembly.
Referring to FIGS 6 & 7, the protruding forward end 14 of the cutter can be urged rearwardly relative to the housing to displace the cutter to the inoperative position. As illustrated, this can be done by abutting the forward end 14 of cutter 4 against support surface 18 and applying a downward (or forward) force to housing 6. Alternatively or additionally, the cutter can be displaced to the inoperative position by manually pulling the protruding rear end 16 of the cutter once it protrudes to a sufficient degree to grasp it.
The cutter assembly includes locking means for locking the cutter in the inoperative position after use. Hence the preferred embodiment of the cutter assembly is a single-use disposable article.
The locking means can take any form. However, with
reference to FIG 4, the locking means of the illustrated embodiment takes a similar form to the detent means insofar as it includes recess or aperture engaging means 24 for engaging the recess or aperture in the cutter. However, unlike the detent means, the recess or aperture engaging means of the locking means is not biased to a disengaged position. Rather, it is biased inwardly to non-releasably engage the recess or aperture in the cutter. As previously noted, conventional blades have a longitudinally extending slot. The recess or aperture engaging means in this case is adapted to engage the rear end of the slot when the blade is returned to the inoperative position after use.
In use, the cutter assembly is supplied packaged as shown, for example, in FIG 3 or FIG 8. Thus the cutter is provided packaged and sterile.
A user abuts the rearward end of the cutter against a support surface as shown in FIGS 4 & 5 to simultaneously break the seal of the packaging and deploy the cutter.
The cutter is then used in the conventional manner, without removing the packaging if desired.
During use, the cutter is maintained in the operative position by the detent means. Specifically, pressure is applied to the exterior of the housing to cause the convex protrusion to engage the forward end of the slot which is provided in conventional blades.
After use, the pressure is released from the exterior of the housing to disengage the detent means and the forward end of the cutter is abutted against a support surface as shown in FIGS 6 & 7 to displace the cutter to the inoperative position whereat it is non- releasably locked.
It will be understood that the locking means is not operative when the cutter is initially in the inoperative position prior to use.
Referring to FIGS 10 and 11, there is illustrated another embodiment of a cutter assembly in the form of a
scalpel. The scalpel may be re-usable or single-use. In this case cutter 4 consists of the scalpel blade plus the mandrel to which it is mounted. The rearward end of the cutter extends from the housing when the cutter is in the inoperative position as shown in FIG 11. It will be understood that, as used herein, the term "cutter" is used to refer to the blade and mandrel.
The cutter is spring biased to the inoperative position and is manually urged to the operative position as previously described.
As previously, the scalpel is preferably supplied packaged in frangible packaging means.
The preferred embodiments of the present invention provides a cutter assembly which is supplied under sterile conditions with the cutter safely stored and protected from damage.
The cutter need never be touched by the user thereby avoiding the possibility of injury and disease transmission. The breaking of the sterile seal and deployment of the cutter is a single simple operation.
The preferred embodiment of the present invention utilises a conventional cutter and hence is compatible with currently manufactured blades. After use, the cutter is safely locked in an inoperative protected position for disposal.
It will of course be realised that whilst the above has been given by way of an illustrative example of this invention, all such and other modifications and variations hereto, as would be apparent to persons skilled in the art, are deemed to fall within the broad scope and ambit of this invention as is herein set forth.