referring now the drawing and in particular to fig1 through 5 , there is shown a razor head 10 adapted for assembly onto a razor handle 11 having a body portion 12 . the razor head 10 further comprises a button member 14 , a pair of finger plates 16 and 18 , a cam follower 20 , a spring 22 and a cover plate 24 for retaining the assembly of the razor head 10 in position when attached to the razor handle 11 . as best shown in fig1 and 6 , the body member 12 has a centrally disposed stepped groove 25 formed therein for receiving the button 14 and an upwardly facing laterally extending surface 26 for receiving the finger plates 16 and 18 in registry therewith . a pair of upwardly extending guide blocks 27 and 2 are disposed adjacent opposite sides of the surface 26 and a pair of slots 29 and 30 are formed in the surface 26 , one adjacent each of the guide blocks 27 and 28 , the slots extending rearwardly from adjacent the rear of the surface to adjacent the front of the surface . each of the fingers plates 16 and 18 comprises a downwardly facing surface 32 and 33 respectively for registry with the laterally extending surface 26 of the body portion 12 . each finger plate 16 and 18 further comprises a first slotted opening 34 and 35 respectively extending laterally and disposed in registration with a mating guide block 27 , 28 with the razor head 10 in the assembled condition . a second slotted opening 36 and 37 is formed in each of the respective guide plates 16 and 18 , the second slotted opening 36 and 37 having a rearward portion thereof in registration with a body member surface slot 29 and 30 and a forward portion thereof extending inwardly of the respective body member surface slot . it will further be observed that each of the finger plates 16 and 18 comprises a pair of arms 38 and 39 respectively extending forwardly of the finger plate and having a finger 40 and 41 respectively facing inwardly for engaging a blade supporting cartridge ( not shown ). the button member 14 comprises a rearwardly facing pressure surface 42 and a pair of laterally extending arms 44 and 45 , each having a downwardly projecting pin 46 and 47 respectively for extending through a rearward portion of a slotted opening 36 or 37 respectively in a finger plate and into a respective slot 29 or 30 in the body portion 12 . as best shown in fig1 and 3 through 5 , the button member 14 has a cylindrical opening 48 formed therein for receiving the spring 22 and the forward end of the spring is dimensioned to receive the cylindrical shaped rod 49 extending rearwardly from the cam follower 20 . the cam follower 20 further comprises a pair of opposed outwardly facing surfaces 50 and 51 , each disposed for registration with an inwardly facing surface 52 and 53 disposed on a respective finger plate 16 and 18 . the cam follower 20 further comprises a cam surface 54 extending forwardly of said body portion 12 for contacting a blade supporting cartridge when the surfaces 50 and 51 are in contact with the surfaces 52 and 53 of the finger plates 16 and 18 . in assembly of the razor head 10 , the finger plates 16 and 18 are disposed on the body member 10 with the surface 32 in registration with the surface 26 and the finger plate 18 is disposed at the opposite side of the body portion 12 with the surface 33 in registration with the surface 26 , the guide block 26 extending through the slotted opening 34 and the guide block 28 extending upwardly through the slotted opening 35 . the finger plates 16 and 18 are moved until the rear portions of the slotted opening 36 and 37 are in alignment with the slots 29 and 30 and the button member is placed into the assembly with the button extending into the stepped groove 25 and the pins 46 and 47 projecting downwardly through the slotted opening 36 and 37 into the slots 29 and 30 . the spring 22 is placed through the assembly by inserting one end into the cylindrical opening 48 of the button member 14 and the rod 49 is inserted into the forward end of the spring and placed into the assembly with the surfaces 50 and 51 lying adjacent the surfaces 56 and 57 of the finger plates 16 and 18 . the cover plate 24 is now placed over the assembly having a top plate 60 for retaining the above described elements in position and a pair of tabs 61 and 62 are bent rearwardly to the underside of the body member 12 . when so positioned , a rectangular opening 64 is disposed such that the pressure surface 42 of the button member 14 extends rearwardly through the cover plate 24 and a rectangular detent 65 disposed on the body portion 12 extends through a second rectangular opening 66 formed in the cover plate . with the structure thus assembled , as best shown in fig1 , the latter most portion of the razor head 10 with the cover plate 24 in position is pressed into the opening of the handle 11 to complete the simplified construction . it will be appreciated that the minimum number of steps required , and the lack of need for soldering or other fastening techniques provides an extremely simple construction which is easily assembled in a minimum period of time . referring now to fig7 and 8 , the razor head 10 is shown therein in its operative positions wherein a blade supporting cartridge is held between the arms 38 and 39 with the fingers 40 and 41 engaging a blade supporting cartridge ( fig7 ) and in a position wherein the blade supporting cartridge is released from , or is about to be received onto the razor head 10 ( fig8 ). with the razor head 10 in the assembled position , as shown in fig7 the cam surface 54 of the cam follower 20 is disposed in its retracted position with the spring 22 in compression and the fingers 40 and 41 in the inward most position . the pressure surface 42 of the button member 14 extends to its rear most position through the opening 64 in the cover plate 24 . to eject a blade supporting cartridge from the razor head 10 and engage a new cartridge , the button member 14 is moved forwardly to the position shown in fig8 . during movement of the button member 14 to its forward - most position , the pins 46 and 47 move into the portion of the slotted openings 36 and 37 which are directed inwardly , and the retaining of the pins 46 and 47 in the slots 29 and 30 cause the arms 38 and 39 to move outwardly from the cartridge maintaining their alignment perpendicular to movement of the button 14 , and parallel to an edge at a blade contained in the cartridge . simultaneously , the cam follower 20 is moved forwardly until the surfaces 50 and 51 are disposed between the finger plates 16 and 18 and in contact with the surfaces 52 and 53 , thus locking the arms 38 and 39 in their outward - most position while the cam follower surface 54 is effective to push the cartridge away from the body portion 12 . in this position , the face of the spring 22 disposed between the cam follower 20 and the bottom 14 is attempting to move the button to its original rearmost position . however , retention of the pins 46 and 47 within the slotted openings 36 and 37 would require the finger plates 16 and 18 to move inwardly for this to occur , which movement is prevented by the surfaces 50 and 51 . with the razor head 10 in the position as shown in fig8 a new blade supporting cartridge is assembled to the unit by placing the cam surface 54 in contact with the rear surface of the cartridge forcing the cam follower 20 rearwardly against the bias of the spring 22 and releasing the finger plates 16 and 18 from their locked position by disengaging the finger plate surfaces 52 and 53 from engagement with the surfaces 50 and 51 of the cam follower . this motion causes the fingers 40 and 41 to move linearly towards one another to contact and engage with suitably placed openings in the blade supporting cartridge , and the button member 14 is returned to the position shown in fig7 . thus , the combination of the locking arrangement , taken with the linear movement of the fingers 40 and 41 is effective to prevent misloading and unintentional cartridge removal in the employment of the razor head 10 .