with reference to fig1 a - 1 b and fig2 a - 2 b , a first embodiment of a needle device that has the one - handed sheath removal apparatus is shown . in particular , a needle mechanism in the form of a needle assembly 2 coupled to a syringe 4 is shown to have a needle base 6 to which a needle or cannula 8 extends from a needle hub 6 a that is at a distal or patient end of base 6 . base 6 further includes a proximal end 6 b that has a luer that allows needle assembly 2 to be matingly coupled to a counterpart luer end of a syringe , such as 4 shown in fig1 a and 1 b . needle assembly 2 for the instant invention is further shown to include a needle protective housing 10 that has a main portion 10 a that , as best shown in fig3 b , has a slot 12 that allows needle 8 to pass into housing 10 , when housing 10 is pivoted in the direction as indicated by directional arrow 14 . housing 10 also has a lower portion 10 b that is pivotally connected to base 6 , by way of a living hinge 16 . as best shown in the enlarged illustration of the circled portion 18 of fig2 b , there is a finger means in the shape of a cam 20 having a finger portion 22 a that extends from the lower edge of the lower portion 10 b of housing 10 . in fig2 b , finger 20 a is shown to be pointed upwards toward the tip of needle 8 . for the needle assembly 2 shown in fig2 a - 2 d , a needle sheath that is mated to base 6 for covering needle 8 prior to needle 8 being used is not shown . such sheath is shown in fig1 a and 1 b with designation 22 . with reference to fig2 c , housing 10 is shown to have a back wall 10 c and two sidewalls 10 d and 10 d ′ that together form an enclosed portion 10 c , with a slot 12 formed thereat to allow needle 8 to pass into housing 10 , when housing 10 is pivoted in the direction as indicated by directional arrow 14 . as further shown , cam 10 extends from the lower edge of the lower portion 10 b of housing 10 so as to be substantially in the middle of housing 10 . the lower edge of housing 10 is designated 10 e in the enlarged circled illustration 24 , per shown in fig2 d . the illustration in fig2 d further shows two hooks 26 a and 26 b that extend from a rib 28 that extends from the patient end 6 a of base 6 . as best shown in fig2 c , there are four ribs 28 extending from the patient end 6 a of the needle hub . as shown in fig2 d , one of the ribs 28 ′ faces housing 10 . in practice and for the discussion of this invention , ribs 28 may be referred to as a part of the needle hub , or the patient end or the needle end of base 6 . two loops 30 a and 30 b that extend from back wall 10 c of housing 10 are shown in fig2 c . housing 30 a and 30 b come into contact with and lockingly mate to hooks 26 a and 26 b , respectively , when housing 10 is pivotally moved along the direction indicated by directional arrow 14 , after needle 8 has passed into the interior of housing 10 and housing 10 substantially is in alignment along the longitudinal axis 32 that runs through needle 8 and base 6 . fig1 a and 1 b show the attachment of needle assembly 2 to a syringe 4 . the needle assembly 2 shown in fig1 a and 1 b is an alternative embodiment of the needle assembly 2 shown in fig2 a - 2 d . for the further discussion of the instant invention , elements that are the same or have the same functionality for the different disclosed embodiments are labeled the same . the needle assembly 2 shown in fig1 a and 1 b , and illustrated in fig3 a - 3 c , is different from the needle assembly 2 shown in fig2 a - 2 d in that the cam mechanism for the fig1 a - 1 b embodiment comprises two finger means each extending from a corresponding one of the sidewalls of needle protective housing 10 . as particularly shown in fig1 a and 1 b , at sidewall 10 d ′ of housing 10 there is extended a cam 34 that has a tip or finger 34 a that is positioned below the lip 22 a at the opening or open end of sheath 22 . as shown , lip 22 a has a surface 22 b that is above or adjacent to finger 34 a of cam 34 . in other words , finger 34 a of cam 34 is below lip 22 a of sheath 22 . in practice , finger 34 a may be adjacent to or be in contact with surface 22 b of lip 22 a of the sheath 22 . in the position shown in fig1 a and 1 b , housing 10 is at an angle in relative proximity to the sheath 22 , which is covering needle 8 and is frictionally coupled to base 6 of the needle assembly 2 . fig3 a - 3 c illustrate the removal of sheath 22 from needle assembly 2 . such removal is done in a one - handed fashion by a user , with the user holding the body of syringe 4 with the palm of her hand and a number of her fingers , and moving needle protective housing 10 with one of her digits , for example her thumb per the direction indicated by directional arrow 36 . as housing 10 is moved from where it is in close proximity to sheath 22 towards another position substantially at right angle from longitudinal axis 32 , cam fingers 34 a that extend from each of the sidewalls 10 d and 10 d ′ at the lower portion of housing 10 would first come into contact with surface 22 d of lip 22 a ( if they are not already in contact with surface 22 d ), and then push against lip 22 a and therefore sheath 22 with an upwards force . as long as the movement of housing 10 in the direction of directional arrow 36 produces a force via the cams against sheath 22 that exceeds the predetermined force that holds sheath 22 in frictional contact connection to base 6 of the needle assembly , sheath 22 is disengaged from base 6 . with housing 10 at the position shown in fig3 b , the open end of sheath 22 is no longer in frictional engagement with base 6 . sheath 22 can then readily be removed , as for example by the user turning syringe 4 upside down or sideways so that the sheath can slide off or fall off from the needle assembly . the ejection removal of sheath 22 from needle assembly 2 is shown in fig3 c , whereby the removal force by the cams is such that housing 10 may actually be popped off from base 6 . as illustrated in fig3 b and 3 c , sheath 22 is disengaged from base 6 , and housing 10 has been moved to a second position that is substantially orthogonal to the longitudinal axis 32 . but it should be appreciated that the location of the position of housing 10 when sheath 22 is disengaged from base 6 is dependent to a large extent on the design of cam 34 , as finger 34 a of cam 34 may well be designed to angle in such a way relative to the lip of sheath 22 that housing 10 may only need to be moved to a second position that is 45 °, or some other degree less than 90 °, from the longitudinal axis 32 in order to force sheath 22 to be disengaged from base 6 . fig4 a - 4 c are illustrations of the removal of sheath 22 from base 6 of the needle assembly 2 by the use of the cam mechanism shown in fig2 a - 2 d . in particular , the single cam 20 that extends from the bottom edge of housing 10 is positioned below lip 22 a of sheath 22 , when housing 10 is in a close proximity position relative to sheath 22 , per shown in fig4 a . with the user holding syringe 4 and probably plunger 4 a with possibly her index , middle and ring fingers , the user can use her thumb to move housing 10 to the second position shown in fig3 b and 3 c to forcedly disengage sheath 22 from base 6 of the needle assembly . although the needle assembly 2 and syringe 4 shown in fig1 a - 1 b , 3 a - 3 c and 4 a - 4 d are separate components , it should be appreciated that the cam mechanism provided at housing 10 may be incorporated into a fixed needle syringe where needle 8 extends from the needle hub that is part of a syringe . in other words , the fixed needle syringe is a one - piece syringe that includes the needle hub and the syringe body into which the plunger is inserted , with the needle of the syringe mounted to the needle hub to be in fluid communication with the interior of the barrel of the syringe . for the fixed needle syringe embodiment , there is no luer end 4 b that is present in a conventional syringe , per shown by the illustrated syringe 4 in fig3 a - 3 c . however , the needle of a fixed needle syringe continues to be covered by a sheath , and the needle protective housing with the cam mechanism of the instant invention may be either mounted about the needle hub or the distal end of the syringe , or be molded together with the syringe to effect a one piece unitary fixed needle syringe with the cam fingered needle protective housing of the instant invention . the cam mechanism is an integral extension of housing 10 in that housing 10 and base 6 are molded as a one piece unit from a single mold . color pigments may be added to the plastics molding material so that the one piece needle assembly may be molded to have a color that corresponds to the gauge of the needle extending from the needle end of the needle assembly . thus , be the cam mechanism the unitary finger that extends from the back wall of the housing per shown in fig2 a - 2 d or the opposing cams that extend from each sidewall of the housing per shown in fig1 a - 1 b and 3 a - 3 c , the cam mechanism disclosed thus far is an integral extension of the needle protective housing 10 . instead of being an integral extension of housing 10 , the cam mechanism may be a separate component that is retrofitted to housing 10 of a needle device to allow one handed removal of the sheath that covers the needle at the needle device prior to its use . for ease of illustration , housing 10 is shown by itself in fig5 a - 5 d . as shown , needle protective housing 10 has an upper closed end portion 10 a and a lower portion 10 b that has sidewalls 10 d and 10 d ′. as best shown in fig5 a , a slot 12 allows the needle to pass through is provided at upper portion 10 a and two loops 30 a and 30 b that engage the anchors 26 a and 26 b ( fig2 d ) to fixedly hold housing 10 to base 6 are provided at lower portion 10 d . for a more securement of needle 8 , a hook 36 may also be formed inside housing 10 for grasping needle 8 , when the housing is pivotally moved to cover needle 8 . there is an aperture 38 ( fig5 a ) at the lower portion of back wall 10 c of housing 10 . fig6 a - 6 e show an add - on cam , in the form of a clip attachable to housing 10 , for effecting the cam mechanism of the instant invention . in particular , clip 40 has a back wall 40 a and two sidewalls 40 b and 40 b ′. the sidewalls 40 b and 40 b ′, as well as back wall 40 a , are configured to enable clip to conform to the back and sidewalls at the lower portion 10 b of housing 10 . at each of sidewalls 40 b and 40 b ′ there is a cam portion 42 and 42 a , respectively . cams 42 and 42 a have respective fingers 42 ′ and 42 a ′. there is moreover extending from back wall 40 a an anchor 44 that may be made of two pieces 44 a and 44 b ( fig6 b ) that have an enlarged upper portion with a reduced portion 44 c ( fig6 d and 6 e ) configured to fit into aperture 38 ( fig5 a ) of housing 10 so as to securely couple clip 40 to the lower portion of housing 10 when clip 40 is press - fitted to housing 10 . fig7 and 8 each illustrate housing 10 having fixedly coupled thereto clip 40 . as shown in fig7 , sheath 22 has been substantially disengaged from base 6 by finger 42 ′ of cam 42 ( and the not shown opposed finger 42 a ′ of cam 42 a ) so that sheath 22 is freely resting on base 6 and also cams 42 and 42 a . fig8 shows a perspective view of the needle assembly of fig7 with the sheath having been removed . even though different embodiments of the inventive needle assembly have been shown in fig2 a and 2 d and fig7 and 8 , it should be appreciated that the one handed automatic sheath removal mechanism of the instant invention may also be adapted to be used in other needle devices such as a vacuum tube holder that is disclosed in the above - mentioned u . s . pat . nos . 5 , 139 , 489 and 5 , 277 , 311 . the disclosures of the &# 39 ; 489 and &# 39 ; 311 patents are incorporated by reference herein .
a needle protective housing used to cover a contaminated needle after use is configured to have at least one cam positioned below the lip of the sheath attached to the base of the needle device for covering the needle prior to use . when the sheath is attached to the base of the needle device , the needle protective housing is positioned in proximity to the sheath . to remove the sheath , a user would pivotally move the needle protective housing in a direction away from the sheath so that the cam coacts against the lip of the sheath in an upward direction as the needle protective housing is pivoted downwards relative to the needle device . consequently , the sheath that covers the needle prior to use is forced upwards until it is disengaged from the needle base . the cam may be an integral extension of the needle protective housing , or it may be a clip retrofittable to the needle protective housing .