referring now to the drawings , the needle protection holder is designated by the numeral 10 and is designed to be interposed between a hypodermic syringe 12 and a needle 14 ( fig8 - 11 inclusive ). the holder 10 comprises an elongated cylinder , tube or main housing unit 16 having an elongated extending axis 18 . the holder is made from a clear plastic material . the syringe 12 is a conventional disposable or nondisposable hypodermic syringe having a luer lock coupling 20 and a needle hub 22 at the needle end of the syringe housing , cylinder or barrel 24 . the barrel 24 of the syringe 12 at the other end is open and receives a conventional plunger 26 having a thumb rest 28 at one end and a piston - like element 30 attached thereto at the other end . the plunger 26 moves up and down within the syringe barrel 24 when pressure is applied to the thumb rest 28 of the plunger and to thereby dispense fluid from the syringe 12 through the needle 14 . the open end of the barrel 24 is provided with a finger flange 32 . the outer surface 34 of the barrel 24 is provided with suitable graduations 36 which can be viewed through the clear plastic holder 10 in fig1 and 4 . such graduations are used on the syringe 12 to indicate the capacity of the medication to be administered . the needle protection holder 10 , excluding the hypodermic syringe 12 and needle 14 , includes the main housing , tube or cylinder 16 , and a compression spring 38 shown in an expanded or extended position in fig1 and 11 and in a compressed position in fig8 and 9 . the needle protection holder 10 further includes an improved unitary washer or washer assembly 40 and a unique thumb latch 42 . the upper end of the elongated cylinder 16 is open and is enlarged to provide an oval - like entrance 44 to the cylinder or tube 16 . the enlarged oval entrance 44 has various curves and / or flat surfaces 46 terminating at the entrance by the ring - like rim 48 . the other end of the cylinder 16 has an inwardly turned flange providing a bottom wall 50 . the bottom wall 50 has an opening 52 through which the needle 14 and the needle cap 54 may extend as illustrated in fig8 and 9 . the bottom wall 50 and the interior thereof provides a spring seat 56 for the compression spring 38 as illustrated in fig8 and 9 . the oval surface or wall 46 provided at the enlarged mouth of the cylinder 16 has a pair of stop pedestals 60 ( fig3 and 10 ) which are formed out or struck out of the walls of the oval wall 46 . the purpose of the stop pedestals 60 as will subsequently appear is to prevent the thumb latch 42 from traveling too far outwardly away from the longitudinal axis 18 of the cylinder 16 . the exterior of the oval wall 46 is provided with a pair of axles 62 . the axles 62 are located generally directly below the stop pedestals 60 . the stop pedestals 60 are formed out of the walls 46 of the cylinder 16 to which the axles 62 are connected . the thumb latch 42 has an integral body 64 made from a plastic material . the top surface of the thumb latch 42 is provided with a curved area 66 upon which the thumb of the user rests when operating the syringe 12 . the thumb latch 42 further includes a pair of integral laterally spaced apart arms 68 , the outer or free ends of the arms 68 each being provided with an opening 70 for receiving an axle 62 . the one - piece plastic molding or thumb latch 42 further includes a downwardly extending rim or lip 72 that causes the latch 42 to catch and stop when the latch 42 stops . the lip is molded into the underside of the thumb latch 42 . the unitary thumb latch 42 includes a resistance spring 74 that is built into the thumb latch 42 . the spring 74 is elongated and of generally rectangular cross - section . the plastic material used to make the thumb latch 42 is taken from the group of plastic including polypropylene and nylon . the underside of the oval - like entrance 44 to the cylinder 16 is provided with a finger hold or surface 76 which a person grips with the fingers when applying thumb pressure to the thumb rest 28 of the plunger 26 . with respect to the use and functioning of the novel thumb latch 42 , the stop pedestals 60 which are struck out from the walls of the cylinder 16 ( fig3 ) are provided to provide pivot points , elements or axles 62 . one axle or pivot point 62 is located below each of the stop pedestals 60 . this feature ensures that the built - in spring 74 of the thumb latch 42 does not extend past the points where the finger rest or surface 76 begins as shown in fig8 . specifically , the resistance spring 74 which guides smoothly on the surface 46 adjacent the entrance to the cylinder 16 applies pressure thereto ( fig1 ) as the thumb latch 42 travels away from the longitudinal axis 18 of the cylinder 16 . at such time the thumb latch 42 , specifically the lip 72 , engages the stop pedestals 60 as shown in fig1 thereby preventing the thumb latch from rotating further away from the center axis 18 . the spring 74 assists in stabilizing the lateral movement of the thumb latch 42 about the hinge or pivot points or axles 62 . as mentioned previously , the resistance spring 74 when the thumb latch 42 is moved in the opposite direction towards the longitudinal axis 18 of the cylinder 16 provides pressure on the thumb latch 42 so that the locking of the syringe 12 in the downward position can take place as viewed in fig1 and 8 . specifically , the pivot points or axles 62 protrude outwardly from the main cylinder or housing 16 at a 90 ° angle from the position of the thumb latch 42 . such pivot points or axles 62 are located near the center axis 18 of the cylinder 16 and are aligned or located directly under the holding lip 72 of the thumb latch 42 as illustrated in fig1 . the purpose of the relationship between the axles or pivot 62 and the lip 72 of the thumb latch 42 is to maximize the holding ability of the thumb latch 42 when upward pressure is applied to it by the compression spring 38 of the hypodermic syringe 12 when located in the locked or down position shown in fig1 and 9 . to attach the thumb latch 42 to the main cylinder housing 16 , pressure is merely applied to the arms 68 of the thumb latch 42 with the result that the arms 68 snap onto the axles 62 by means of the corresponding holes or openings 70 provided in the arms . the pair of spaced apart arms 68 of the thumb latch 42 have the ends adjacent the openings 70 beveled at the inner edges to facilitate the mounting of the arms and latch 42 on the axles 62 . the openings or holes 70 provided in the arms 68 create points at which the thumb latch 42 can pivot back and forth or up and down , with the downwardly direction limited by the engagement of the lip 72 with the stop pedestals 60 ( fig1 ) as previously described . the improved and novel washer assembly 40 as best illustrated in fig1 and 16 is of generally cylindrical configuration and is telescopically moveable within the cylinder 16 along the longitudinal axis 18 . the washer 40 has a unitary body 78 , first side 80 and a second side 82 . a centrally located passage 84 of varying diameter extends through the washer body 78 between the first and second sides 80 and 82 . the washer assembly 40 includes a first coupling means 86 through which the centrally located passage 84 extends . the coupling 86 is in the form of a luer lock type coupling which is standardized by the international standards organization and by the american standards national institute to fit all type luer - lock and luer - slip tip syringes . the passage 84 may be non - threaded in accordance with the aforementioned standards or threaded to fit certain other types of syringes . the washer 40 further includes a second coupling means 88 in the form of a luer lock type coupling with the internal passage 84 also extending therethrough . this passage 84 as mentioned previously is aligned with the passage in the first coupling 86 . the passage 84 in the second coupling 88 of the luer lock construction is non - threaded although in certain cases it may be threaded to fit other types of needles . both couplings 86 and 88 are luer lock couplings in accordance with the aforementioned standards . the second coupling 88 is designed to carry the needle 14 as best illustrated in fig8 - 11 inclusive . the cylinder 16 is provided with two pairs of channels 85 , which are approximately 90 ° apart on the interior surface 87 thereof . each channel 85 is formed or grooved into the interior surface 87 of the cylinder 16 as best illustrated in fig8 - 11 . the channels 85 extend from one end of the cylinder 16 to near the other end . the purpose of the channels 85 is to provide a guide or guide means between the cylinder 16 and the washer 40 for maintaining the orientation of the washer 40 and the cylinder 16 as best illustrated in fig9 - 11 inclusive as will be subsequently described . the washer assembly 40 further includes a first pair of arms 90 and a second pair of arms 92 . the arms of each pair of arms are located 180 ° apart as best illustrated in fig1 . an arm of one pair of arms is located 90 ° from the arms of the other pair of arms as best shown in fig1 . the arms 90 of the first pair are integrally attached to the washer body 78 at the lower ends thereof 96 . the upper ends 98 of the first pair of arm 90 are provided with outwardly extending protrusions or buttons 100 . each button or protrusion 100 of the first pair of arms 90 has a top surface 102 , a pair of side surfaces 104 which are flat and parallel , an outer surface 106 and a bottom surface 108 . the upper half of the cylinder 16 is provided with a first pair of elongated openings 112 which extend completely through the cylindrical wall 16 . the openings 112 are elongated and of generally rectangular cross section . such openings 112 are located approximately 180 ° apart for receiving the outwardly extending protrusions or buttons 100 of the first pair of arms 90 thereby preventing movement of the washer 40 towards the lower end of the cylinder 16 when viewed in fig1 thus preventing the washer 40 , syringe 12 and needle 14 from exiting the cylinder 16 when the spring means or compression spring 38 is activated and thereby applies an upward thrust to the washer 40 . the top surfaces 102 of the protrusions or buttons 100 are angled upwardly to facilitate the movement of the protrusions 100 into the corresponding elongated openings 112 in the cylinder wall 16 to thereby assist in catching and holding the washer 40 in position in the elongated openings 112 . the bottom surfaces 108 of the protrusions 100 of the first pair of arms 90 are inclined upwardly as viewed in fig1 to permit the washer 40 to move towards the bottom wall 50 of the cylinder 16 without catching in the elongated openings 112 . each arm 90 and 92 has inner and outer cylindrical surfaces 114 and 116 . it should be understood that the elongated openings 112 provided in cylinder 16 are offset from the center , with the protrusions 100 of the first pair of arms 90 being offset from the centerline of each arm 90 as best illustrated in fig1 . the arms 92 of the second pair of arms are symmetrical about the centerline of each arm . the upper end of each arm has a centrally located protrusion or button 120 and inner cylindrical surface 122 and an outer cylindrical surface 124 . the top surface , side surfaces , outer surface , and bottom surface of each protrusion 120 are flat . with such a construction , the top and bottom surfaces are parallel , the side surfaces are parallel and the outer surface is cylindrical . the cylinder 16 further includes a second pair of openings in the form of inverted t - shaped slots 126 . the slots 126 are located in the upper portion of the cylinder 16 and are located 180 ° apart . the inverted t - shaped slots 126 are constructed and arranged to receive the protrusions or buttons 120 provided on the second pair of arms 92 when the washer 40 is in the upper portion of the cylinder 16 as viewed in fig1 . at such time the protrusions 120 fill the t - shaped slot 126 . the purpose of the protrusions 120 is to stop downward movement and the unlocking of the washer 40 when required . in addition , means are provided for urging the protrusions 120 inwardly to disengage same from the slots 126 so that downward movement of the washer 40 can occur . the cylinder 16 adjacent the upper end of the cylinder immediately below the oval entrance 44 is provided with a pair of elongated flexible release arms 130 . the arms 130 overlie the t - slots 126 . the free end 132 of each arm 126 is provided with a rounded bulge or formation opposite the protrusions 120 when in the locked position as viewed in fig1 . when it is required to release the washer 40 , pressure is applied to the flexible release arms 130 so as to move the formations 132 inwardly against the protrusions 120 of the second pair of arms 92 to thereby disengage the protrusions 120 from the t - shaped slots 126 . thereafter , pressure may be manually applied to the syringe 12 by moving the plunger 26 downwardly from the position illustrated in fig1 and 11 to the positions illustrated in fig8 and 9 . this results in the washer 40 , syringe 12 and needle 14 moving downwardly into the bottom of the cylinder 16 where the syringe 12 is locked in the down position by the thumb latch 42 as illustrated in fig8 . at such time , the compression spring 38 is compressed as viewed in fig8 and 9 between the bottom portion of the washer assembly and the spring seat 56 . the release arms 130 and cylinder 16 are molded an integral unit from plastic material taken from the group of plastics including polypropylene and nylon . as mentioned previously , the cylinder 16 is made from a clear plastic material which permits viewing of the syringe 12 including the graduations 36 and the amount of medications remaining in the syringe . with the washer construction just described , it should be noted that all four arms 90 and 92 assist or aid in the stopping of the upward movement of the syringe 12 while still maintaining the orientation of the washer 40 . this is accomplished by the outer tips or ends of the protrusions or buttons 100 , 120 being seated in the channels 85 and moving upwardly or downwardly in the channels 85 . the arms 90 of the first pair of arms and the corresponding protrusions or buttons 100 which cooperate with the elongated openings 112 provided in the cylinder 116 are designed primarily to stop upward movement . as mentioned previously , the buttons 100 are angled upwardly to allow a better attachment , catch and to hold the washer 40 in the openings 112 . this keeps the washer 40 , syringe 12 and needle 14 from exiting the main housing unit or cylinder 16 when the spring 38 is activated and upward thrust is applied to the washer 40 . as also mentioned previously , the underside or bottom surface 108 of protrusions or buttons 100 are also angled upwardly to allow easy downward movement of the washer 40 without hanging in the elongated holes 112 . such holes 112 are offset from the center position of the inner channels 85 . this has been done to eliminate an extra step in the manufacturing of the dies for this product . the protrusions or buttons 100 on the ends of the arms 90 are the only elements that are offset on the washer 40 . it will be appreciated that the channels 85 for the arms 90 have also been modified to match the position of the buttons 100 within the main housing unit or cylinder 16 . in further summary of the invention , the second set of arms 92 and the corresponding protrusions or buttons 120 are utilized for stopping downward movement and also unlocking the washer 40 so downward movement can thereafter occur . when the protrusions 120 are set into the t - shaped slots 126 , which are located on both sides of the main housing unit 16 , the protrusions 120 keep the washer 40 from being pushed down into the bottom of the main housing unit or cylinder 16 . however , when the pressure is applied inwardly by the thumb and index finger on the release arms 126 , the buttons 120 are flexibly forced inwardly , disengaging themselves from their seated position within the slots 126 . this allows or permits manual pressure to be applied by the operator to move the washer 40 , syringe 12 and needle 14 downward into the bottom of the main housing unit 16 , where the combination of the washer , syringe and needle are locked in the down position by the novel thumb latch 42 . at this point , injections can be performed . it should be noted that the needle 14 does not need to be attached to the washer for this process to take place . it will generally be attached to the washer 40 after the abovementioned steps have been completed . it will be observed that the flexible release arms 130 overlie the t - shaped slots 126 so that when they are pushed inwardly against the protrusions 120 , release of the washer 40 from its seated position is achieved . the release arms 130 are the means by which the entire device is unlocked and prepared for injection use . the release arms 130 have a slightly rounded bulge or formation 132 on their inner ends created for comfort and for added torque when pressure is applied by the fingers of the operator . the release arms 130 are molded into the main housing unit or cylinder 16 and are able to flex inwardly and outwardly to a point needed to cause release or locking depending on the desired setting . the washer 40 is equipped with the luer lock , luer - slip male and female attachments that are standardized by the international standards organization and the american standards national institute to fit all luer lock and luer - slip tipped syringes . the use of such standards assist in providing a fully automated retractable safety syringe . the oval end 44 of the cylinder 16 is provided with a pair of reinforcing ribs 140 ( fig3 ) which are located on opposite sides of the enlarged opening on the interior surface thereof . the reinforcing ribs 140 as illustrated in fig8 also serve as stops to prevent the syringe 12 from moving downwardly . such ribs 140 also assist in preventing the syringe 12 from crushing the compression spring 38 . it will now be apparent that the medical technicians or operators can use a needle protection holder 10 with one hand allowing the technicians the freedom to perform other tasks with their other hands . the holder 10 is designed to protect medical technicians and personnel from exposures to infectious diseases . the holder 10 is designed to accept more than one type of syringe and to meet national standards . in operation or use , once the needle is placed in the body of a patient or animal using the needle protection holder 10 , the needle 14 will never contact the open air , another patient or the technician unless the technician takes a direct action to unlock the assembly in the manner described previously . it would be appreciated that the holder 10 could be reused . earlier devices which have claimed to isolate the needle after use have certain drawbacks or restrictions . some devices require you to use all the contents of the syringe before it retracts the needle into the provided enclosure . still others are made to be used only with the manufacturer &# 39 ; s syringes which limits the ability of hospitals or clinics to choose to purchase the type of syringe which best suits their purpose and budget . thus , with the present invention the holder 10 provides choices for the medical technicians and for the hospitals . medical personnel can choose what syringe to use with the present invention , where and when to retract the needle and whether or not the needle protection holder is to be used again . the holder permits it to be used in the same manner as a luer lock syringe would normally be used , with the additional ability to protect all medical personnel from deadly needle sticks or punctures . it will be further understood that the embodiment of the invention described herein is to be taken as a preferred example of the same and that various changes in size , shape and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the claims which follow . further , while the principles of the invention have now been made clear , there will be immediately obvious to those skilled in the art certain modifications of structure , arrangement , proportions , elements , materials and other components used in the practice of the invention which are particularly adapted for specific environments and operating requirements without departing from those principles .