in one embodiment of a unitary needle safety clip , as illustrated in fig1 a thin piece of metal , molded plastic or other suitable material is formed in a manner such that when it is installed on a needle , forces are directed in minimally two opposing directions , at the same time , toward a common axis defined by the needle . in the embodiments of fig1 and 2 the unitary clip 20 has a hole 22 which is sized to accommodate a hypodermic needle 24 . an alignment portion 26 of clip 20 has a slightly angled engagement surface which is substantially parallel to the hypodermic needle 24 . the alignment portion engagement surface has a guide means 28 which maintains the safety clip 20 in alignment with the needle 24 . guide means 28 may be furcated as in fig2 or it may be any other geometric configuration having two sides and a bottom 27 , wherein the two sides are fitted to contact the periphery of the needle in order to maintain alignment . the bottom 27 of guide means 28 also contacts the periphery of the needle and exerts a force thereon . a compression portion 30 of the clip 20 has a sliding surface 32 which contacts the periphery of the hypodermic needle 24 . sliding surface 32 exerts a force on needle 24 in a direction opposing the force exerted by the bottom 27 of guide means 28 . compression portion 30 is bent in a manner which creates opposing or transverse forces between compression portion 30 and alignment portion 26 . including bends , the compression portion is slightly longer than the alignment portion 26 such that the sliding surface 32 is closer to the injecting end of the needle 24 than the contacting portion of guide means 28 . the compression portion 30 also has an abutting engagement surface 34 . when safety clip 20 is in a first position , in which the injecting end is exposed , the clip 20 is proximate to a syringe / needle interface or hub 35 which typically comprises male / female threaded members . in this position virtually the entire length of the needle is exposed for injecting purposes . sliding surface 32 of the compression portion 30 is in contact with the periphery of needle 24 exerting a force opposing the bottom 27 of guide means 28 which also contacts a portion of the periphery of needle 24 . to activate the clip , a force is exerted at the back of clip 20 , along the axis of the needle 24 and toward the injecting end . the activation force may be applied manually or by a biasing spring . the bottom 27 of guide means 28 and the sliding surface 32 of compression portion 30 each slideably engage opposed portions of the needle periphery with sliding surface 32 exerting force closer to the injecting end than the guide means 28 . hole 22 and guide means 28 keep the clip 20 in alignment with needle 24 so that sliding surface 32 is maintained in sliding engagement with needle 24 . when sliding surface 32 goes beyond the injecting end or point of the needle 24 as illustrated in fig3 the needle no longer counters the force exerted by the compression portion 30 and contact surface 32 is actuated downward through the axis of the needle 24 . abutting engagement surface 34 engages the injecting end in abutting relation and a friction engagement surface 36 snaps against a portion of needle 24 so as to engage the safety clip . the frictional engagement of friction engagement surface 36 and possibly hole 22 with the needle resists further slideable movement of the clip along the needle . friction engagement surface 36 may be provided with knurling or other surface roughness so as to further increase the force required to slide the clip along the needle following engagement of the needle by the friction engagement surface 36 . fig4 illustrates an alternative embodiment of a unitary needle safety clip according to the invention . in this embodiment the needle clip 20 &# 39 ; comprises alignment portion 26 &# 39 ; having guide means 28 &# 39 ; with bottom 27 &# 39 ; and compression portion 30 &# 39 ; having sliding surface 32 &# 39 ; and abutting engagement surface 34 &# 39 ;, all of which function substantially as discussed hereinbefore with respect to fig1 and 3 . in this embodiment a second guide means 37 is provided . alignment portion 26 &# 39 ; and compression portion 30 &# 39 ; are separated by a bent or arcuate end 38 having a hole 22 &# 39 ; approximately centered therein . hole 22 &# 39 ; is of a diameter sized to be slightly larger than the outer diameter of needle 24 when sliding surface 32 &# 39 ; and the bottom 27 &# 39 ; of guide means 28 &# 39 ; are separated a distance equal to the outer diameter of the needle 24 . the diameter of hole 22 &# 39 ; is sized to fit slideably on the needle 24 and is also sized such that when sliding surface 32 &# 39 ; goes beyond the injecting end of needle 24 a deformation of hole 22 &# 39 ; results from the actuation of contact surface 32 through the axis of needle 24 . an inner surface of hole 22 &# 39 ; effects frictional engagement of the periphery of needle 24 such that deformation of hole 22 &# 39 ; results in grasping of needle 24 providing a high degree of frictional engagement between the clip 20 &# 39 ; and the needle 24 . it should be appreciated by one of skill in the art , that depending on the diameter and relative strength of the needle on which a clip according to the invention is used , it may be possible to provide the compression portion 30 , 30 &# 39 ; discussed hereinbefore , or other surfaces of embodiments discussed hereinafter , with sufficient force such that actuation of the contact surface 32 , 32 &# 39 ; and engagement of the abutting surface 34 , 34 &# 39 ;, or equivalents thereof , bends or otherwise deforms the injecting end of needle 24 , rendering the needle 24 permanently non - reusable . the embodiment of fig5 illustrates a unitary safety clip according to the invention having a split bushing configuration . in this embodiment the clip 20 &# 34 ; is disposed on needle 24 by separating resilient prongs 40 , 42 . an end of the clip 20 &# 34 ; opposing the end having prongs 40 , 42 comprises a collar 44 fitting slideably about needle 24 while the prongs 40 , 42 exert opposing forces against the needle 24 . a portion of the clip 20 &# 34 ; defining prong 40 has an arcuate surface 46 which serves as a slideable contact surface and an inner surface 48 providing an abutment surface . a portion of clip 20 &# 34 ; defining prong 42 also has an arcuate surface 50 which serves as a guide means in slideable contact with the periphery of the needle 24 and an inner surface 48 &# 39 ; providing an alternative abutment surface . prong 42 further includes a frictional engagement surface 52 which , when the prongs 40 , 42 are slid beyond the injecting end of needle 24 , engages the periphery of needle 24 providing frictional resistance against further slideable movement of the clip 20 &# 34 ;. at that point , inner surface 48 or 48 &# 39 ; is in abutting relation with the injecting end of needle 24 . alternatively the frictional engagement surface may be provided on prong 40 or on both prongs 40 and 42 . referring now to fig6 and 7a , a needle safety clip is produced having multiple pieces to effect the same function and result as discussed hereinbefore with respect to fig1 - 5 . the embodiment of fig6 comprises a clip which has a cammed piece 60 biased against needle 24 by a compressed spring portion 62 . cammed piece 60 has a slideable contact surface 64 and an internal abutting surface 66 . a lower piece 68 comprises a cam opposing surface 70 and a pair of support contact surfaces 72 dimensioned to receive slideable contact surface 64 therebetween . cammed piece 60 is mounted to a housing comprising lower piece 68 , at a point which is slightly offset from the center of the arc of the cammed piece 60 . the cammed clip of fig6 slideably engages the needle 24 until the contact surface 64 goes beyond the injecting end of the needle 24 . at that point , compressed spring portion 62 forces contact surface 64 downward and the injecting end of the needle 24 engages internal abutting surface 66 . further actuation of the contact surface 64 beyond the injecting end of needle 24 results in contact surface 64 fitting in between support contact surfaces 72 and cammed piece 60 rotating such that the cammed piece exerts greater friction engagement against needle 24 until the needle is fully frictionally engaged . at this point the injecting end is covered protecting the user from inadvertent penetration by the needle . the embodiment of fig7 and 7a illustrates a multiple piece needle safety clip which accommodates various sized needles . this multiple piece embodiment has a first portion 74 with a first slideable contact surface 76 , an inner abutting engagement surface 78 , and a first friction engagement surface 80 . the first portion 74 engages a second portion 82 having a second slideable contact surface 84 and a second friction engagement surface 86 . first portion 74 is mounted to second portion 82 at an interface region 83 by ultrasonic welding or other mechanical fastening means . prior to fastening , first portion 74 is vertically adjustable so as to accommodate a needle of a predetermined size . subsequent to fastening , first portion 74 is flexibly disposed so that the first slideable contact surface 76 normally extends below first friction engagement surface 80 when not engaging a needle . thus , fastening of first portion 74 to second portion 82 in the above manner results in the exertion of a force by contact surface 76 on the needle 24 when the clip is disposed thereon in the first position . this embodiment illustrates an optional locking means or latch 88 which has a hook 90 that extends over the syringe / needle interface or hub 35 , as known in the art , to latch the needle safety clip in the first position . manually depressing a lever arm 92 disengages hook 90 from the hub 35 enabling activation of the clip to the second position wherein slideable contact surface 76 extends beyond the injecting end of needle 24 , and is actuated through the axis of needle 24 , causing the force to be exerted against the needle by the first and second friction engagement surfaces 80 , 86 , as illustrated in fig7 a . alternatively , for syringe / needle interfaces wherein the needle hub is a male threaded member for screw insertion into a female threaded syringe ( not shown ) a nib 94 is provided for engagement with the female threads of such a syringe 50 that the safety clip can be rotated into locking engagement in the first position and counter - rotated to release the clip in a second position . further , a biasing means such as a spring 96 may be provided to assist in activating the needle safety device according to the invention from the first position to the second position . fig8 and 9 indicate that a unitary safety clip according to the invention can be provided with an antiseptic medium 100 . for example , cotton , gauze or any other suitable absorbent material may be provided with antiseptic and incorporated in the clip 20 and about the needle 24 in a manner that results in wiping of the needle by the antiseptic during slideable movement of the safety clip along the needle to the protective position . provision of the antiseptic medium and wiping of the needle in the above described manner further enhances the safety afforded a user . an antiseptic medium can likewise be used in conjunction with other embodiments of the safety clip discussed hereinabove . additionally , the clips in accordance with the present invention may be color coded to indicate the size of the needle the respective clip is intended to accommodate . additionally , safety clips according to the invention may be variously sized and the transverse forces according to the invention may be provided by other geometric configurations . for example , the clip may be large to facilitate manual manipulation or sufficiently small so as to fit beneath commercially available needle / syringe covers . although the needle safety clips according to the invention have been discussed as plastic injection molded or stamped metal parts and although ultrasonic welding is discussed as a method of joining multiple piece embodiments , other materials and methods of fabrication may be used to fabricate such devices . although the invention has been shown and described with respect to exemplary embodiments thereof , it should be understood by those skilled in the art that the foregoing and various other changes , omissions and additions in the form and detail thereof may be made without departing from the spirit and scope of the invention .
a needle safety device , which is usable on long , short , straight or curved needles , is actuated to enclose the injecting end of a needle when an engagement surface of the device is slid beyond the injecting end . a unitary or multiple piece clip is provided which is slideable from a first position wherein a hypodermic needle is usable for injection purposes to a second position wherein the injecting end of the hypodermic needle is covered rendering the needle unusable and protected .