Safety scalpel with replaceable blade cartridge

In an embodiment, there is a safety scalpel having a handle, and a replaceable blade cartridge assembly that is releasably attached to the handle. The handle comprises a first end and a second end. The blade cartridge assembly comprises a housing that can be slideably mounted onto the second end of the handle, a blade holder that can be disposed within the housing, and a blade that can be attached to the blade holder. The safety scalpel has a resilient lock member that prevents the cartridge assembly from being detached from the handle during use.

TECHNICAL FIELD

Embodiments of the invention relate to surgical cutting instruments and more particularly, to a safety scalpel comprising a blade cartridge releasably attached to a handle.

BACKGROUND

A conventional scalpel used in the healthcare industry includes a metal handle and a disposable blade that is mounted on the handle prior to use, and removed after use. The process of mounting and dismounting of the blade is a difficult and dangerous procedure as it exposes the medical practitioner to potential injury from the exposed blade and contamination due to blood that may be present on the blade. Further, sharps injuries may also occur during an operation as the surgeon passes the exposed scalpel to a colleague.

An example of a safety scalpel with a releasable blade cartridge is described in U.S. Pat. No. 5,938,676 (Cohn). Although Cohn describes a slidable shield which is slidable to cover the blade when the scalpel is to be disposed, a user is required to push the shield in a forward direction to cover the blade. This action is counter intuitive because it differs from a conventional direction of use in conventional box cutter devices. U.S. Pat. No. 8,567,072 (Yi) describes another example of a safety scalpel with a detachable blade cartridge. The safety scalpel in Yi is adapted to extend and retract by pushing downward on the button and then sliding along the shield to change its position.

The blade cartridge with an extended blade may be inadvertently detached and this may cause potential injury from the exposed blade. To avoid the danger of an exposed blade when the blade cartridge is detached for replacement, some prior art safety scalpels include arrangements in which the blade is self-retractable into the handle or the blade cartridge. Such self-retracting safety scalpels are continually biased towards the retracted position and into the handle using a retractable blade holder by having spring mechanisms arranged to bias the blade holder rearward. However, such self-retracting safety scalpels still require the user to initiate an action to retract the blade. If the user forgets to retract the blade and proceed to remove the blade cartridge with the extended blade, potential injury will still be caused during removal of the blade cartridge.

SUMMARY

In an embodiment, there is a safety scalpel comprising:a handle;a blade cartridge releasably attached to the handle, the blade cartridge comprising:a blade;a housing; anda blade holder in communication with the blade, wherein the blade holder is configured to allow the blade to extend between a stowed position in a pre-cutting state of the blade holder and a cutting position upon activation of the blade holder; anda resilient lock member disposed within the housing, wherein the resilient lock member is in an unbiased condition when the blade holder is in the pre-cutting state, and wherein the resilient lock member is configured to engage the blade holder to lock the blade cartridge to the handle when the blade is in the cutting position upon activation of the blade holder.

The resilient lock member may be arranged to be moved by the blade holder into a locking aperture of the handle to lock the blade cartridge to the handle when the blade is in the cutting position upon activation of the blade holder.

The resilient lock member may be integral with the housing.

The resilient lock member may comprise a resilient arm portion and a catch extending from the resilient arm portion.

The blade holder may include an inclined surface adapted to engage the resilient arm portion of the resilient lock member and allow the catch of the resilient lock member to be moved into the locking aperture to lock the blade cartridge to the handle when the blade is in the cutting position upon activation of the blade holder.

The blade cartridge may comprise a blade lock mechanism having a ramp adapted to abut the blade holder to prevent movement of the blade in the stowed position before the handle is inserted.

The blade cartridge may comprise a blade lock mechanism having a housing ramp provided on the housing, wherein a handle ramp is provided on the handle, wherein the handle ramp is adapted to push on a housing ramp upon insertion of the handle, to move the housing ramp out of an aperture in the blade holder.

The blade holder may include an activation member configured to be pressed down to enable the blade to slide between the stowed position when the blade holder is in a pre-cutting state and the cutting position upon activation of the blade holder.

The activation member may be configured to engage the housing to prevent movement of the blade when the blade holder is in the pre-cutting state.

The safety scalpel may further comprise a flip guard provided above the activation member.

The activation member may include an embedded button.

The safety scalpel may further comprise a slide guard provided below the activation member.

The safety scalpel may further comprise a button guard provided on the housing and around the activation member to prevent inadvertent activation of the blade holder.

The safety scalpel may further comprise a cartridge release mechanism arranged for allowing release of the blade cartridge upon exerting a force perpendicular to a direction of movement of the blade holder along a longitudinal axis of the handle.

The cartridge release mechanism may comprise a resilient lift tab provided on the blade cartridge wherein the lift tab is arranged adjacent a recess on the handle for allowing release of the blade cartridge when the blade is in the stowed position.

The housing may comprise a first housing part and a second housing part ultrasonically welded together to form the housing.

The housing may comprise a cantilever member adapted for releasably mounting the blade cartridge to the handle.

The blade cartridge may comprise snap features located on opposing sides of the housing, wherein the snap features are adapted to releasably attach the blade cartridge to the handle.

The blade cartridge may comprise a snap feature adapted to engage with an aperture in the handle.

The blade cartridge may comprise a portion configured to move in tandem with the snap feature, and the portion is moveable by the blade holder.

In an embodiment, there is a replaceable blade cartridge for releasably attaching to a handle to form a safety scalpel, the replaceable blade cartridge comprisinga blade;a housing;a blade holder in communication with the blade, wherein the blade holder is configured to allow the blade to extend between a stowed position in a pre-cutting state of the blade holder and a cutting position upon activation of the blade holder; anda resilient lock member disposed within the housing, wherein the resilient lock member is in an unbiased condition when the blade holder is in the pre-cutting state, and wherein the resilient lock member is configured to engage the blade holder to lock the blade cartridge to the handle when the blade is in the cutting position upon activation of the blade holder.

The resilient lock member may be arranged to be moved by the blade holder into a locking aperture of the handle to lock the blade cartridge to the handle when the blade is in the cutting position upon activation of the blade holder.

The resilient lock member may be integral with the housing.

The resilient lock member may comprise a resilient arm portion and a catch extending from the resilient arm portion.

The blade holder may comprise an inclined surface adapted to engage the resilient arm portion of the resilient lock member and allow the catch of the resilient lock member to be moved into the locking aperture to lock the blade cartridge to the handle when the blade is in the cutting position upon activation of the blade holder.

The blade holder may include an integral activation member configured to be pressed down to enable sliding of the blade holder and the blade.

The activation member may be configured to engage the housing to prevent movement of the blade when the blade holder is in the pre-cutting state.

The activation member may include an embedded button.

In an embodiment, there is a method of operating a safety scalpel, the method comprising the steps of:sliding a blade of a blade cartridge on a handle in a longitudinal direction, the blade cartridge comprising:the blade;a housing;a blade holder in communication with the blade, wherein the blade holder is configured to allow the blade to extend between a stowed position in a pre-cutting state of the blade holder and a cutting position upon activation of the blade holder; anda resilient lock member disposed within the housing, wherein the resilient lock member is in an unbiased condition when the blade holder is in the pre-cutting state, and wherein the resilient lock member is configured to engage the blade holder to lock the blade cartridge to the handle when the blade is in the cutting position upon activation of the blade holder; andsliding the blade forward to the cutting position, and to move the resilient lock member into the locking aperture to lock the blade cartridge onto the handle when the blade is in the cutting position.

The step of sliding the blade holder may include pressing an activation member of the blade holder in a direction perpendicular to a handle motion to disengage the activation member from the housing.

In an embodiment, there is a blade housing adapted to support a blade holder in communication with a surgical blade for linear sliding in a safety scalpel, the blade housing comprising:a first housing; anda second housing adapted for attaching to the first housing to form a cavity for supporting the blade holder and the surgical blade, wherein the blade housing is adapted to be mounted to a handle of the safety scalpel;a resilient lock member disposed within the blade housing, wherein the resilient lock member is in an unbiased condition when the blade is in a stowed position and the blade holder is in a pre-cutting state, and wherein the resilient lock member is configured to engage the blade holder to lock the blade housing to the handle when the blade is in a cutting position upon activation of the blade holder; anda blade lock mechanism comprising a resilient ramp, and a lock mechanism adapted for locking the blade to the handle in a stowed position, wherein the ramp is adapted to bias the lock mechanism upon engagement with the handle.

DESCRIPTION

While exemplary embodiments pertaining to the invention have been described and illustrated, it will be understood by those skilled in the technical field that many variations or modifications involving particular design, implementation or construction are possible and may be made without deviating from the inventive concepts described herein.

FIG. 1Ais a top perspective view of a safety scalpel1in a stowed configuration and in a pre-cutting condition in accordance with an embodiment. The safety scalpel1comprises a handle2, and a blade cartridge3releasably attached to the handle3. The handle2includes a first end4and a second end5. Referring toFIG. 1B, the blade cartridge3includes a blade6, a housing7, and a blade holder8in communication with the blade6. The blade holder8may be configured to allow the blade6to extend between a stowed position in a pre-cutting state of the blade holder8and a cutting position upon activation of the blade holder8. For example as shown inFIGS. 1B and 1C, the blade holder8may include an activation member9arranged to be slidable along a longitudinal axis of the handle2.

The safety scalpel1also comprises a resilient lock member10which will be described in further detail with reference toFIGS. 2A to 2C. Referring toFIG. 2A, the resilient lock member10may be disposed within the housing7wherein the resilient lock member10is in an unbiased condition when the blade holder8is in the pre-cutting state, and wherein the resilient lock member10does not engage a locking aperture11of the handle2. The resilient lock member10may be configured to engage the blade holder8to lock the blade cartridge3to the handle2when the blade6is in the cutting position upon activation of the blade holder8. In an example, the resilient lock member10may be arranged to be moved by the blade holder8into a locking aperture11of the handle2to lock the blade cartridge3to the handle2.

In particular, referring toFIG. 2Bin which the safety scalpel1is being moved from the stowed configuration towards a cutting configuration upon activation of the blade holder8in a direction of travel20, the resilient lock member10may be configured to be moved in a direction21by the blade holder8into a locking aperture11of the handle2to lock the blade cartridge3to the handle2upon activation of the blade holder8. The direction21of movement of the resilient lock member10may be substantially perpendicular to a direction22of movement of the blade holder8and the direction of travel20of the blade6.

Still further, in an example, the resilient lock member10may comprise an arm12and a catch13. The arm12may be adapted to deflect upon engagement with a ramp76of the handle2of the safety scalpel1. The ramp76may include a surface adapted to engage a surface of the resilient lock member10to bias the resilient lock member10in a direction21to engage with the locking aperture11.

In another example, the arm12may be a resilient arm portion and the catch13extends from the resilient arm portion. The blade holder8may also include an inclined surface adapted to engage the resilient arm portion of the resilient lock member10and allow the catch of the resilient lock member10to be moved into the locking aperture to lock the blade cartridge3to the handle2when the blade6is in the cutting position upon activation of the blade holder8.

The resilient lock member10may be integral with the housing7and may extend from an opening14of the housing7. The housing7may also comprise a catch15and a release tab16for attaching to a corresponding slot in the handle2to releasably attach the blade cartridge3to the handle2.

FIG. 2Cis a rear view of the safety scalpel1when the blade6is in the cutting position upon activation of the blade holder8. Referring toFIG. 2C, the blade6is extended in the cutting position and the blade cartridge3is locked to the handle2through the resilient lock member10in engagement with the locking aperture11of the handle2.

FIG. 3andFIG. 4illustrate components of the blade cartridge3. The blade cartridge3may include a first housing part30and a second housing part31which, upon assembly, form the housing7for housing the blade6, and the blade holder8. For example, the second housing part31may include a plurality of joining portions32for attaching the first housing part30to the second housing part31through manufacturing methods for joining plastics such as ultrasonic welding. The housing7may be adapted to be mounted to a handle of the safety scalpel1.

The first housing part30has a slot33extending longitudinally on a top side of the housing7and is adapted for allowing the blade holder8to slide between a pre-cutting state when the blade6is in a stowed position and a cutting state when the blade6is in a cutting position upon activation of the blade holder8. The slot33may include cut-outs34shaped to receive the activation member9of the blade holder8. The activation member9may include extended portions35to be received in the cut-outs34. In a stowed position of the blade6, the extended portions35of the activation member9abut surfaces (not shown inFIG. 3) in the housing7. The blade housing7may also be adapted to support a surgical blade for linear sliding of the blade in the safety scalpel1.

The blade holder8may be configured to be slidably mounted within a cavity of the housing7. Referring toFIG. 4, the blade holder8may be configured to slidably engage the handle2and the housing7. Specifically, the blade holder8includes side walls37for sliding within the cavity of the housing7. The activation member9may be integral with the blade holder8.

FIG. 5Ais a top perspective view of the handle2for the safety scalpel1, andFIG. 5Bis a side view of the handle2. The handle2may include a holding portion50and a blade cartridge receiving portion51. The holding portion50may extend from the first end4to an approximate midpoint. The blade cartridge receiving portion51may extend from the approximate midpoint to the second end5.

The blade cartridge receiving portion51of the handle2may be adapted to be received in a hollow cavity of the cartridge assembly3. Further, the blade cartridge receiving portion51of the handle2may be configured to slidably engage the blade cartridge assembly3. For example, a longitudinal groove feature22may be provided in the blade cartridge receiving portion51to enable sliding of a blade holder of the blade cartridge. Still further, the blade cartridge receiving portion51may include a side wall17extending from a top surface18of the blade cartridge receiving portion51. The side wall17may include a side wall surface19adapted to slidably engage the housing of the blade cartridge assembly3.

The blade cartridge receiving portion51includes a locking aperture23configured to receive a portion of the resilient locking member8for locking the blade cartridge assembly3to the handle2when the safety scalpel1is in use, i.e. when the blade6is in a cutting position. In the stowed position of the blade6, the resilient locking member8does not engage the locking aperture23.

The handle2may have a blade cartridge lock mechanism for locking the cartridge assembly3to the handle2in the stowed position of the blade6. The blade cartridge lock mechanism may comprise a tab receiving aperture21configured to receive a tab of the blade cartridge assembly3. The tab may be a release tab integral with the housing7wherein the tab has a protrusion for engaging the tab receiving aperture21. Further, the blade cartridge lock mechanism may comprise a sloped recess20in the blade cartridge receiving portion51of the handle2. The blade cartridge lock mechanism may also be adapted to have a locating surface21afor guiding the release tab in the cartridge into the tab receiving aperture21on the handle2.

FIG. 6Ais a perspective view of a blade cartridge60according to an embodiment, before assembly to a scalpel handle. The blade cartridge60includes a blade housing61that is partially removed for a clearer view of components in the blade cartridge60. A blade holder62is slidably mounted within a cavity of the housing61, and is adapted to support a surgical blade64. For example, the blade holder62may include surfaces for linear sliding along corresponding guide surfaces of the blade housing61.

The blade cartridge60may comprise a resilient blade lock mechanism65formed in the housing61. The resilient blade lock mechanism65may have a ramp adapted to abut the blade holder62to prevent movement of the blade64in a stowed position before the handle is inserted. The blade holder62is in a pre-cutting state when the blade64is in the stowed position.

FIG. 6Bis a detailed view (Detail A) of an example of a design of the resilient blade lock mechanism65.

FIG. 7Ais a perspective view of the blade cartridge60in a process of assembly to a scalpel handle72having a handle portion73and a blade receiving portion74. The blade receiving portion74may include a groove75adapted for slidable movement of the blade holder62relative to the handle72.FIG. 7Bis a partial perspective view of the blade cartridge60before assembly.FIG. 7DandFIG. 7Eare section views of the blade cartridge60before and during assembly of the handle.

Referring to the abovementioned figures, the blade lock mechanism65comprising a resilient ramp66, and a lock mechanism68for locking the blade64so as to prevent movement of the blade holder62prior to assembly to a handle. The ramp66may be integral with the blade housing61and may be adapted to bias the lock mechanism away from the blade holder62upon engagement with the scalpel handle72. For example, the ramp66may comprise a sloped surface69shaped to lead in the scalpel handle72. Due to the resilience properties of the ramp66, the lock mechanism68is disengaged from the blade holder62.

In another example, the blade cartridge60may comprise a resilient blade lock mechanism in which the ramp66may be configured to engage comprise a handle ramp (not shown) provided on the handle72. Upon insertion of the handle72, the handle ramp is adapted to push on the ramp66to move the ramp66out of an aperture in the blade holder62.

FIG. 8Ais a section view of a safety scalpel80in a cutting condition when a blade82of the safety scalpel80is in a cutting position upon activation of a blade holder81from a pre-cutting state.FIG. 8Bis a section view of the safety scalpel80being retracted from the cutting condition to a pre-cutting condition. The safety scalpel80comprises a handle800and a blade cartridge802releasably attached to the handle800. The blade cartridge802comprises a blade holder81in communication with a blade82. The blade82is extended in a cutting position upon activation of the blade holder81. The blade holder81may comprise an activation member899having a resilient portion84and a button86provided on the resilient portion84. The resilient portion84may include a latch portion85adapted to be received in an opening88of the blade cartridge802.

Referring toFIG. 8B, the resilient portion84may be configured to, or be made of a material with elastic properties which enable the activation member899to deflect in a direction87so as to enable the blade82to be retracted in a direction of travel89. The direction87in which the activation member899may be deflected may be substantially perpendicular to the direction of travel89. When the activation member899is deflected in a direction87, the latch portion85may be movable between a first position (FIG. 8A) in which it is engaged with and on a top surface of the blade cartridge802and a second position (FIG. 8B) in which it is below the top surface to enable sliding of the blade holder81and the blade82.

FIG. 8Cis a section view of the safety scalpel80in a stowed configuration and in a pre-cutting condition wherein the blade82is retracted to a stowed position and the activation member899is at a third position along the top surface of the blade cartridge802.

FIG. 9Ais a rear perspective view of a safety scalpel90when a blade (Not shown inFIG. 9A) of the safety scalpel90is in a stowed position. The safety scalpel90has a scalpel handle91and a blade cartridge92releasably attached to the handle91. In the present example, the blade cartridge92comprises the blade (Not shown inFIG. 9A), a housing96, and a blade holder98. The blade cartridge92has a resilient lock member95disposed within the housing96wherein the resilient lock member95is in an unbiased condition when the blade (Not shown inFIG. 9A) is in the stowed position. The blade cartridge92may also include a blade lock mechanism configured to lock the blade (not shown inFIG. 9A) residing in the safety scalpel90before the handle91is assembled to the blade cartridge92to form the safety scalpel90. The blade cartridge92may comprise a resilient release tab93for engaging the handle91to lock the blade cartridge92to the handle91. The handle91may include a cut-out feature97formed in a rear surface of a blade receiving portion of the handle91. The cut-out feature97may be a sloped recess97configured to be inclined at an angle relative to a rear surface of the handle91to enable ease of disassembly of the blade cartridge92in a stowed position in a pre-cutting state of the blade holder98. A graphic91asuch as a trade mark or a logo may be provided on a handle portion of the handle91.

FIG. 9Bis a section AA view of the safety scalpel90ofFIG. 9Awith the handle91and the blade cartridge92.

FIG. 9Cis an illustrative view of a method of releasing the blade cartridge92from the handle91.FIG. 9Dis a side section view of the safety scalpel90showing a force application in directions99aand99bto release or detach the blade cartridge92from the handle91resulting in disassembly of the safety scalpel90.

As seen in the direction99b, a motion to apply a force in the direction99bat the release tab93is perpendicular to a direction of movement99cof a blade holder (Not shown inFIG. 9C). This may be regarded as a safety mechanism of the safety scalpel90to prevent inadvertent release of the blade cartridge92employed during normal use of the scalpel90.

Referring toFIGS. 9A and 9D, the sloped recess97in the handle91may be adapted to have a locating surface for guiding the release tab93in the cartridge into a tab receiving aperture on the handle91. The tab receiving aperture may be similar to the tab receiving aperture21of the handle2inFIG. 5A. For example, the handle91may have a notch-shaped feature and a longitudinal groove feature provided on the blade receiving portion to guide a protrusion93bof the release tab93into the tab receiving aperture to releasably lock the blade cartridge92to the handle91. Further, the sloped recess77may be configured to facilitate single-handed release of the blade cartridge92such that the user may not require a tool to detach the blade cartridge92from the handle91.

Further embodiments of a safety scalpel with a replaceable blade cartridge will be described below with reference toFIGS. 10A to 24B. It is to be understood by those skilled in the art that the further embodiments may be configured to have components similar to the components described inFIGS. 1 to 9D, and such components will not be described. Similarly, it is to be understood that the mention of one or more components in a device (component, part) or an assembly (system) does not preclude the presence of additional components or intervening component s between those components expressly identified.

FIG. 10Ais a rear view of a safety scalpel100when a blade (107inFIG. 10B) of the safety scalpel100is in a stowed position. The safety scalpel100has a handle102releasably attached to a blade cartridge assembly101. The blade cartridge assembly101includes the blade (107inFIG. 10B), a housing109, and a blade holder (108inFIG. 10B) in communication with the blade (107inFIG. 10B). A resilient lock mechanism or member103may be provided within the housing when the blade holder (108inFIG. 10B) is in a pre-cutting state as shown inFIG. 10A. The resilient lock mechanism or member103may include a resilient arm104and a latch member105adapted to engage a locking aperture106of the handle102.

FIG. 10Bis a rear view of the safety scalpel100in the process of moving from a stowed configuration to a cutting configuration wherein the blade107is in a cutting position upon activation of the blade holder108from a pre-cutting state of the blade holder108. Referring toFIG. 10B, a blade holder108may be adapted to engage with the resilient arm104to move the latch member105into the locking aperture106to lock the blade cartridge assembly101to the handle102when the blade107reaches the cutting position. For example, the blade holder108may include a wall portion108aadapted to slidably engage the resilient arm104of the resilient lock mechanism103.

FIG. 11Ais a top perspective view of a safety scalpel110when a blade114of the safety scalpel110is in a cutting position upon activation of a blade holder113from a pre-cutting state of the blade holder113.FIG. 11Bis a side section view of the safety scalpel110. The safety scalpel110comprises a handle111, and a blade cartridge112releasably attached to the handle111. The blade cartridge112may include a blade holder113in communication with a blade114. The blade holder113further comprises an activation member113aadapted to allow the blade holder113to slide relative to a housing of the blade cartridge112, and the handle111.

FIG. 12Ais a top perspective view of a safety scalpel120when a blade (124inFIG. 12B) of the safety scalpel120is in a stowed position.FIG. 12Bis another top perspective view of the safety scalpel120when the blade124is in a cutting position upon activation of a blade holder123andFIG. 12Cis a side section view ofFIG. 12B. The safety scalpel120comprises a handle121, and a blade cartridge122releasably attached to the handle121. The blade cartridge122may include the blade holder123in communication with the blade124. The blade holder123further comprises an activation member123aadapted to allow the blade holder123to slide relative to a housing of the blade cartridge122, and the handle121.

FIG. 13Ais a top perspective view of a blade holder130having the activation member123a. A blade131is attached to the blade holder130.FIG. 13Bis a side section view ofFIG. 13A. The activation member123amay include a first button125embedded (or embedded button) in a second button126which is larger in size relative to the first button. The first button125may be configured to actuate the blade holder130. The second button126may be formed to flush or in the same plane with the cartridge122. The first button125may be directly connected to the blade holder130. The activation member123amay include a resilient section132for allowing the activation member123ato be deflected to allow sliding of the blade holder130along the handle (Not shown inFIG. 13Abut similar to121inFIGS. 12A, 12B and 12C).

FIG. 14Ais a top perspective view of a safety scalpel140according to another embodiment. The safety scalpel140comprises a handle141, and a blade cartridge142releasably attached to the handle141. The blade cartridge142may include a blade holder149in communication with a blade143, and an activation mechanism144adapted to allow the blade holder149to slide relative to a housing of the blade cartridge142, and the handle141.

FIG. 14Bis a side section view ofFIG. 14A. The activation mechanism144may include a button guard145configured to slide under a button146such that the activation mechanism144locks the blade holder149during use. A sliding action may also actuate the activation mechanism144. For example, the activation mechanism144may be configured to slide linearly in a groove147adapted to receive the activation mechanism144.FIG. 14Cis a side view ofFIG. 14A.

FIG. 15Ais a top perspective view of a safety scalpel150having an activation mechanism151.FIG. 15Bis a side section view ofFIG. 15A. The safety scalpel150is similar in configuration to the safety scalpel140ofFIG. 14A. For the safety scalpel150, an activation mechanism151of it may include a flip guard152adapted to cover a button153during use.

FIG. 16Ais a top perspective view of a safety scalpel160having an activation mechanism161adapted to slide within a plurality of side projections162provided on a blade cartridge163of the safety scalpel160.FIG. 16Bis a side section view ofFIG. 16A. The side projections162function as a guard against inadvertent activation of the activation mechanism161because a user would be required to execute purposeful motion to actuate the activation mechanism161.

FIG. 17Ais a top perspective view of a safety scalpel170having a handle171and a blade cartridge172releasably attached to the handle171and having a cartridge release mechanism173.FIG. 17Bis a side section view ofFIG. 17A. For example, the cartridge release mechanism173may comprise a resilient portion174and a catch175extending from the resilient portion174. When the blade cartridge172is attached to the handle171, the catch175engages with the handle171through a corresponding recess of the handle171. When the resilient portion174is moved in a direction perpendicular to a direction of sliding of the blade (not shown) of the safety scalpel, the resilient portion174deflects and the catch175disengages from the corresponding recess of the handle171to release the cartridge172from the handle171.

FIG. 18Ais a top perspective view of a safety scalpel180having a handle181and a blade cartridge182releasably attached to the handle181and having a cartridge release mechanism183.FIG. 18Bis a side section view ofFIG. 18A.

The cartridge release mechanism183may comprises a resilient member184having an activation member185located at one end and a catch member186located at another end. The catch member186may be arranged to engage with the handle181through a corresponding recess of the handle181. When the activation member185is pressed in a direction towards a surface of the handle181, the resilient portion185may be adapted to deflect and allow the catch186to be disengaged from the corresponding recess of the handle181to release the cartridge182from the handle181.

FIG. 19Ais a top perspective view of a safety scalpel190having a handle191and a blade cartridge192releasably attached to the handle191and having a cartridge release mechanism.FIG. 19Bis a side section view ofFIG. 19A. The cartridge release mechanism may comprises snap features193located on opposing sides of the housing, wherein the snap features193are adapted to releasably attach the blade cartridge192to the handle.

For example, each of the snap features193may comprise a resilient portion193and a catch194extending from the resilient portion193. When the blade cartridge192is attached to the handle191, the catch194engages with the handle191through a corresponding recess of the handle191. When each of the snap features193is pressed at the resilient portion193in a direction toward a recess195of the handle191, the resilient portion193deflects and the catch194disengages from the corresponding recess of the handle191to release the cartridge192from the handle191.

FIG. 20Ais a top perspective view of a safety scalpel200having a handle201and a blade cartridge202releasably attached to the handle201by having a cartridge release mechanism203.FIG. 20Bis a rear view of the safety scalpel200andFIG. 20Cis a side section view of the safety scalpel200. For example, the cartridge release mechanism203may comprise a resilient portion204and a catch205extending from the resilient portion204. When the blade cartridge202is attached to the handle201, the catch205engages with the handle201through a corresponding recess206of the handle206.

FIG. 21Ais a rear perspective view of a safety scalpel210having a cartridge release mechanism211.FIG. 21Ais a detailed view of the safety scalpel210.

FIG. 22Ais a rear view of a safety scalpel220when a blade of the safety scalpel223is in a cutting position upon activation of a blade holder (Not shown inFIG. 22A), wherein the safety scalpel220has a handle221and a blade cartridge222releasably attached to the handle221.FIG. 22Bis a left side view of the safety scalpel220andFIG. 22Cis a right side view of the safety scalpel220.

FIG. 23Ais a side section view of a safety scalpel230having a handle231and a blade cartridge232releasably attached to the handle231.FIG. 23Bis a rear view of the safety scalpel230showing a blade holder233of the blade cartridge232.FIG. 23Cis a rear view of the safety scalpel230with the blade holder233removed. In an example, the safety scalpel230may comprise a handle ramp (not shown) provided on the handle231, wherein the handle ramp is adapted to push on a housing ramp (not shown) upon insertion of the handle, to move the housing ramp out of an aperture in the blade holder233. The housing ramp may be provided on the blade cartridge232and similar in configuration as the ramp66as shown inFIG. 6Aexcept that instead of abutting the blade holder233, the housing ramp engages with an aperture in the blade holder233.

FIG. 24AandFIG. 24Bare rear section views of an example safety scalpel240having a handle248. A blade cartridge247on an outermost surface is releasably attached to the handle248. A blade holder246holding a blade (not shown inFIG. 24A) is disposed between the the blade cartridge247and the handle248. The blade holder246is configured to allow the blade (not shown inFIG. 24A) to extend between a stowed position in a pre-cutting state of the blade holder246and a cutting position upon activation of the blade holder246. The blade holder246is in the pre-cutting state when the blade (not shown inFIG. 24A) is in the stowed position. A releasable scalpel snap241(or resilient lock member) is disposed within a housing of the blade cartridge247. It is appreciated that the snap241can be separately mounted to the housing of the blade cartridge247instead of being integral in another example.

The snap241is adapted to lock to the handle248in a default configuration (or unbiased condition) where the blade holder246is extended to set the blade (not shown inFIG. 24A) in the cutting position. The snap241is adapted to disengage from the handle248when the blade holder246is retracted to set the blade (not shown inFIG. 24A) in the stowed position. As the blade holder246retracts, it will slide to abut against or engage the snap241and cause the snap241to disengage from the handle. It is appreciated that the portion of the blade holder246abutting against the snap241can also be said to be an activation member as discussed in the present disclosure. After blade retraction, removal of the blade cartridge247from the handle248is allowed as the snap241disengages (or unlocks) from the handle248. During blade extension to the cutting position, the blade holder246slides away from the snap241and no longer abuts the snap241. This causes the snap241to revert back to lock the handle248.

In the present example, an end portion of the snap241is in a form of a protrusion244protruding in a direction towards the handle248. The protrusion244is configured to engage a locking aperture of the handle248when the snap241is locked to the handle248. The snap has a recess243located adjacent to the protrusion244for receiving a locking protrusion of the handle248. Furthermore, the snap241has a sloped protrusion242located adjacent to the recess243and away from the location of the protrusion244. The sloped protrusion242has a sloped surface tapering away from the protrusion244.

With reference toFIG. 24B, during blade retraction, the blade holder246slides toward the sloped protrusion242and gradually exerts force on the sloped protrusion242beginning from the tapered end of sloped surface of the sloped protrusion242. As the retracting blade holder246slides further along the sloped surface, the sloped protrusion242, the recess243and the protrusion244of the snap241will be pushed away to disengage (or unlock) and lose contact with the handle248. When the snap241no longer contacts the handle248, the blade cartridge247can be removed from the handle248by detaching (in this case, through sliding) it away from the handle in the direction of the extension of the blade (not shown inFIG. 24B).

With reference toFIG. 24A, during blade extension, the blade holder246slides away from the sloped protrusion242of the snap241and progressively releases the force exerted on the sloped surface of the slope protrusion242. In this manner, the recess243and the protrusion244of the snap241will revert back to engage (or lock) the locking protrusion and the locking aperture of the handle248respectively such that the blade cartridge247cannot be removed from the handle248by forces pulling it in the direction of the extension of the blade (not shown inFIG. 24A).

FIG. 25AandFIG. 25Bare rear section views of an example safety scalpel251having a handle258. A blade cartridge257on an outermost surface is releasably attached to the handle258. A blade holder256holding a blade (not shown inFIGS. 25A and 25B) is disposed between the blade cartridge257and the handle258. The blade holder256is configured to allow the blade (not shown inFIG. 25AandFIG. 25B) to extend between a stowed position in a pre-cutting state of the blade holder256and a cutting position upon activation of the blade holder256. The blade holder256is in the pre-cutting state when the blade (not shown inFIG. 25AandFIG. 25B) is in the stowed position. A releasable scalpel snap251(or resilient lock member) is disposed within a housing of the blade cartridge257. It is appreciated that the snap251can be separately mounted to the housing of the blade cartridge257instead of being integral in another example.

The snap251is adapted to lock to the handle258in a default configuration (or unbiased condition) where the blade holder256is extended to set the blade in the cutting position. The snap251is adapted to disengage from the handle258when the blade holder256is retracted to set the blade (not shown inFIG. 25AandFIG. 25B) in the stowed position. As the blade holder256retracts, it will slide to abut against or engage the snap251and cause the snap251to disengage from the handle. It is appreciated that the portion of the blade holder256abutting against the snap251can also be said to be an activation member as discussed in the present disclosure. After blade retraction, removal of the blade cartridge257from the handle258is allowed as the snap251disengages (or unlocks) from the handle258. During blade extension to the cutting position upon activation of the blade holder256, the blade holder256slides away from the snap251and no longer abuts the snap251. This causes the snap251to revert back to lock the handle258.

In the present example, an end portion of the snap251is in a form of a protrusion254protruding in a direction towards the handle258. The protrusion254acts like a hook that is configured to engage a locking aperture of the handle258when the snap251is locked to the handle258. The locking aperture of the handle258is located further into a main body of the handle258compared to the handle248of the example described with reference toFIGS. 24A and 24B. In the default position, the snap251is angled away from the blade cartridge257and towards the handle. As the snap251is angled, a slope tapering towards the blade cartridge257is formed.

With reference toFIG. 25B, during blade retraction, the blade holder256slides toward the angled snap251and gradually exerts force on the angled snap251beginning from the tapered end of angled snap251. As the retracting blade holder256slides further along a sloped surface of the angled snap251, the protrusion254will be pushed away to disengage (or unlock) and lose contact with the handle258. When the snap251no longer contacts the handle258, the blade cartridge257can be removed from the handle258by detaching (in this case, through sliding) it away from the handle258in the direction of the extension of the blade (not shown inFIG. 25AandFIG. 25B).

With reference toFIG. 25A, during blade extension, the blade holder256slides away from the angled snap251and progressively releases the force exerted on the angled snap251. In this manner, the protrusion254of the snap251will return to engage (or lock) the locking aperture of the handle258such that the blade cartridge257cannot be removed from the handle258by forces pulling it in the direction of the extension of the blade (not shown inFIG. 25AandFIG. 25B).

FIGS. 26A and 26Bshows rear views of another example safety scalpel261having a blade holder266and a handle267that is similar to the example described with reference toFIGS. 2A and 2Bwith similar elements having the same name. A blade cartridge263is releasably attached to the handle267. The resilient lock member10inFIGS. 2A and 2Bis similar to the resilient lock member264inFIGS. 26A and 26B. The locking aperture11inFIGS. 2A and 2Bis similar to the locking aperture265residing on a handle inFIGS. 26A and 26B. The only difference however is that the resilient lock member264comprises a sloped surface268(or inclined surface), which assists the blade holder266to push the resilient lock member264into the locking aperture265when the blade holder266is sliding into a cutting state wherein a blade268held by the blade holder266is in a cutting position.

FIG. 27A,FIG. 27BandFIG. 27Cillustrate partial cross section views (FIG. 27AandFIG. 27B) and cross section view (FIG. 27C) of a mid-section of another example safety scalpel271having a handle278. A blade cartridge277(partially shown inFIGS. 27A, 27B and 27C) located on an outermost surface of the safety scalpel271is releasably attached to an extension2701of the handle278. Parts277aand277binFIG. 27Cdenote top and bottom sides of the blade cartridge277. A blade holder276holding a blade (not shown inFIG. 27A) is disposed between the blade cartridge277and the handle278. InFIG. 27B, the handle278is removed in the drawing to provide better visibility of the features of the blade cartridge277and the blade holder276.

The blade holder276has a push assistant279(or an activation member) having a corrugated surface to assist a user to push and slide the blade holder276against the extension2701of the handle278. The corrugated surface provides friction to aid the pushing. Most of the blade holder276except for the push assistant279resides in the blade cartridge277. The blade holder276is configured to allow the blade (not shown inFIGS. 27A, 27B and 27C) to extend between a stowed position in a pre-cutting state of the blade holder276and a cutting position upon activation of the blade holder276. The blade holder276is in the pre-cutting state when the blade (not shown inFIGS. 27A, 27B and 27C) is in the stowed position. The blade holder276is configured to slide along the extension2701of the handle278. The extension2701of the handle278acts as a support for holding the blade holder276. The blade cartridge277to inserted into the extension2701.

A releasable scalpel snap272(or resilient lock member) is disposed within a housing of the blade cartridge277. The releasable scalpel snap272(or resilient lock member) is coupled to an adjacent inclined portion27. The releasable scalpel snap272is configured to move in tandem and in a same direction as the inclined portion27when the inclined portion27is moved. Both the snap272and the inclined portion27are shaped to protrude in a direction towards the extension2701of the handle278. The extension2701of the handle278has a recessed portion2702for housing the protrusion of the snap272. However, the shape of the snap272protrudes more in the direction towards the extension2701of the handle278compared to the protrusion of the inclined portion27. It is appreciated that the snap272can be separately mounted to the housing of the blade cartridge277instead of being integral in another example.

The snap272is adapted to lock to the handle278in a default configuration (or unbiased condition) where the blade holder276is extended to set the blade (not shown inFIGS. 27A, 27B and 27C) in the cutting position. The snap272is adapted to disengage from the handle278when the blade holder276is retracted to set the blade (not shown inFIGS. 27A, 27B and 27C) in the stowed position. The adjacent inclined portion27comprises a slope273inclined in a manner such that when the blade holder276is moved to retract fully, the blade holder276will slide to abut against or engage the slope273of the inclined portion27. The portion of the blade holder276abutting against the slope273can be deemed as an activation member. As the inclined portion27is abut against or pushed by the blade holder276to move, the snap272moves in tandem with the pushed inclined portion27until the protrusion of the snap272disengages from the recessed portion2702of the extension2701of the handle278. After blade retraction that is when the blade holder276is retracted fully, removal of the blade cartridge277together with the blade holder276residing in the blade cartridge277from the handle278is allowed as the snap272would have disengaged (or unlocked) from the recessed portion2702of the extension2701. During blade extension to the cutting position, the blade holder276slides away from the snap272and no longer abuts the inclined portion27. This causes the snap272to revert back to lock to the extension2701of the handle278by having the protrusion of the snap272sit in the recessed portion2702of the extension2701. When the protrusion of the snap272is in the recessed portion2702, the blade cartridge277along with the blade holder276are fitted to the handle278and not allowed to be removed from the handle278.

In addition, in all the above embodiments, the handle, and in particular, the surfaces for gripping such as the holding portion of the handle, may be made of or coated with a anti-slip material such as rubber material that can improve the friction between the hand and the grip surfaces. For example, the holding portion may be coated with a synthetic rubber material. The handle can be made of a metal material suitable for surgical applications. The blade housing, the blade holder, and the activation member can be made of materials not limited to plastics, such as a thermoplastic material such as for example, polycarbonate materials, plastics with resilient material properties. Still further, the blade housing, the blade holder, and the activation member may be injection molded or manufactured by 3D printing. Whilst there has been described in the foregoing description embodiments of the invention, it will be understood by those skilled in the technology concerned that many variations or modifications in details of design or construction may be made without departing from the scope of the invention.